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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/0308156
|
Mu-Chun Chen
|
Mu-Chun Chen and K.T. Mahanthappa
|
Symmetric Textures in SO(10) and LMA Solution for Solar Neutrinos
|
4 pages; talk presented at the Conference on the Intersections of
Particle and Nuclear Physics (CIPANP2003), New York City, May 19-24, 2003,
and at the Tenth Marcel Grossmann Meeting on General Relativity, Rio de
Janeiro (Brazil), July 20-26, 2003. v2: typo corrected
|
AIP Conf. Proc. 698 (2004) 222.
|
10.1063/1.1664230
|
BNL-HET-03/18, COLO-HEP-491
|
hep-ph
| null |
A model based on SUSY SO(10) combined with SU(2) family symmetry is
constructed. In contrast with the commonly used effective operator approach,
126-dimensional Higgs fields are utilized to construct the Yukawa sector.
R-parity symmetry is thus preserved at low energies. The symmetric mass
textures arising from the left-right symmetry breaking chain of SO(10) give
rise to very good predictions for quark and lepton masses and mixings. The
prediction for sin(2beta) agrees with the average of current bounds from BaBar
and Belle. In the neutrino sector, our predictions are in good agreement with
results from atmospheric neutrino experiments. Our model accommodates the LMA
solution to the solar neutrino anomaly. The prediction of our model for the
|U(e nu_3)| element in the MNS matrix is close to the sensitivity of current
experiments; thus the validity of our model can be tested in the near future.
We also investigate the correlation between the |U(e nu_3)| element and
tan^{2}(theta_odot) in a general two-zero neutrino mass texture.
|
[
{
"created": "Thu, 14 Aug 2003 18:44:06 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Aug 2003 15:11:39 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Chen",
"Mu-Chun",
""
],
[
"Mahanthappa",
"K. T.",
""
]
] |
A model based on SUSY SO(10) combined with SU(2) family symmetry is constructed. In contrast with the commonly used effective operator approach, 126-dimensional Higgs fields are utilized to construct the Yukawa sector. R-parity symmetry is thus preserved at low energies. The symmetric mass textures arising from the left-right symmetry breaking chain of SO(10) give rise to very good predictions for quark and lepton masses and mixings. The prediction for sin(2beta) agrees with the average of current bounds from BaBar and Belle. In the neutrino sector, our predictions are in good agreement with results from atmospheric neutrino experiments. Our model accommodates the LMA solution to the solar neutrino anomaly. The prediction of our model for the |U(e nu_3)| element in the MNS matrix is close to the sensitivity of current experiments; thus the validity of our model can be tested in the near future. We also investigate the correlation between the |U(e nu_3)| element and tan^{2}(theta_odot) in a general two-zero neutrino mass texture.
|
1909.02176
|
Masamichi Ishihara
|
Masamichi Ishihara
|
Chiral phase transition in the linear sigma model within Hartree
factorization in the Tsallis nonextensive statistics
|
9 pages, 6 figures
|
The European Physical Journal A 56, 145 (2020)
|
10.1140/epja/s10050-020-00156-2
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We studied chiral phase transition in the linear sigma model within the
Tsallis nonextensive statistics in the case of small deviation from the
Boltzmann-Gibbs (BG) statistics. The statistics has two parameters: the
temperature $T$ and the entropic parameter $q$. The normalized $q$-expectation
value and the physical temperature $\Tph$ were employed in this study. The
normalized $q$-expectation value was expanded as a series of the value $(1-q)$,
where the absolute value $|1-q|$ is the measure of the deviation from the BG
statistics. We applied the Hartree factorization and the free particle
approximation, and obtained the equations for the condensate, the sigma mass,
and the pion mass. The physical temperature dependences of these quantities
were obtained numerically. We found following facts. The condensate at $q$ is
smaller than that at $q'$ for $q>q'$. The sigma mass at $q$ is lighter than
that at $q'$ for $q>q'$ at low physical temperature, and the sigma mass at $q$
is heavier than that at $q'$ for $q>q'$ at high physical temperature. The pion
mass at $q$ is heavier than that at $q'$ for $q>q'$. The difference between the
pion masses at different values of $q$ is small for $\Tph \le 200$ MeV. That is
to say, the condensate and the sigma mass are affected by the Tsallis
nonextensive statistics of small $|1-q|$, and the pion mass is also affected by
the statistics of small $|1-q|$ except for $\Tph \le 200$ MeV.
|
[
{
"created": "Thu, 5 Sep 2019 01:48:51 GMT",
"version": "v1"
}
] |
2020-05-26
|
[
[
"Ishihara",
"Masamichi",
""
]
] |
We studied chiral phase transition in the linear sigma model within the Tsallis nonextensive statistics in the case of small deviation from the Boltzmann-Gibbs (BG) statistics. The statistics has two parameters: the temperature $T$ and the entropic parameter $q$. The normalized $q$-expectation value and the physical temperature $\Tph$ were employed in this study. The normalized $q$-expectation value was expanded as a series of the value $(1-q)$, where the absolute value $|1-q|$ is the measure of the deviation from the BG statistics. We applied the Hartree factorization and the free particle approximation, and obtained the equations for the condensate, the sigma mass, and the pion mass. The physical temperature dependences of these quantities were obtained numerically. We found following facts. The condensate at $q$ is smaller than that at $q'$ for $q>q'$. The sigma mass at $q$ is lighter than that at $q'$ for $q>q'$ at low physical temperature, and the sigma mass at $q$ is heavier than that at $q'$ for $q>q'$ at high physical temperature. The pion mass at $q$ is heavier than that at $q'$ for $q>q'$. The difference between the pion masses at different values of $q$ is small for $\Tph \le 200$ MeV. That is to say, the condensate and the sigma mass are affected by the Tsallis nonextensive statistics of small $|1-q|$, and the pion mass is also affected by the statistics of small $|1-q|$ except for $\Tph \le 200$ MeV.
|
hep-ph/0201227
|
Ulrich Baur
|
U. Baur (Buffalo), R. Brock (MSU), J. Parsons (Columbia) M. Albrow
(FNAL), D. Denisov (FNAL), T. Han (Wisconsin), A. Kotwal (Duke), F. Olness
(SMU), J. Qian (Michigan), S. Belyaev, et al
|
Physics at Future Hadron Colliders
|
summary report of the Snowmass 2001 E4 working group "Physics at
Future Hadron Colliders", RevTex4, 26 pages, 22 figures, 5 tables, full
Author list included in paper
|
eConf C010630:E4001,2001
| null |
UB-HET-02-01
|
hep-ph
| null |
We discuss the physics opportunities and detector challenges at future hadron
colliders. As guidelines for energies and luminosities we use the proposed
luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of
a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of
future hadron colliders for a variety of new physics scenarios (supersymmetry,
strong electroweak symmetry breaking, new gauge bosons, compositeness and extra
dimensions). We also investigate the prospects of doing precision Higgs physics
studies at such a machine, and list selected Standard Model physics rates.
|
[
{
"created": "Wed, 23 Jan 2002 21:32:09 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Baur",
"U.",
"",
"Buffalo"
],
[
"Brock",
"R.",
"",
"MSU"
],
[
"Parsons",
"J.",
"",
"Columbia"
],
[
"Albrow",
"M.",
"",
"FNAL"
],
[
"Denisov",
"D.",
"",
"FNAL"
],
[
"Han",
"T.",
"",
"Wisconsin"
],
[
"Kotwal",
"A.",
"",
"Duke"
],
[
"Olness",
"F.",
"",
"SMU"
],
[
"Qian",
"J.",
"",
"Michigan"
],
[
"Belyaev",
"S.",
""
]
] |
We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders for a variety of new physics scenarios (supersymmetry, strong electroweak symmetry breaking, new gauge bosons, compositeness and extra dimensions). We also investigate the prospects of doing precision Higgs physics studies at such a machine, and list selected Standard Model physics rates.
|
hep-ph/0204346
|
Z. Xiao
|
Zhenjun Xiao, Kuang-Ta Chao and Chong Sheng Li
|
$B \to \pi^+ \pi^-, K \pi, K \etap$ decays and new physics effects in
the general two-Higgs-doublet model: an update
|
9 pages, Latex file, to be published in Phys. Rev. D
|
Phys.Rev. D65 (2002) 114021
|
10.1103/PhysRevD.65.114021
| null |
hep-ph
| null |
In this paper, we reexamine the new physics contributions to seven well
measured $B \to PP$ decays in the standard model (SM) and the general
two-Higgs-doublet model (model III) and compare the theoretical predictions
with the new data. Within the considered parameter space we found that: (a) the
measurements of the branching ratios for $B\to \pi^+ \pi^-, K^- \pi^+$ and $K^0
\pi^+$ lead to a strong constraint on the form factor $F_0^{B\pi}(0)$:
$F_0^{B\pi}(0)=0.24 \pm 0.03$; (b) the new physics enhancements to the
penguin-dominated $B \to K \pi$ and $K \etap$ decays are significant in size,
$\sim (40-65)%$ $w.r.t$ the SM predictions, and play an important role in
restoring the consistency between the data and the theory.
|
[
{
"created": "Tue, 30 Apr 2002 04:27:28 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Xiao",
"Zhenjun",
""
],
[
"Chao",
"Kuang-Ta",
""
],
[
"Li",
"Chong Sheng",
""
]
] |
In this paper, we reexamine the new physics contributions to seven well measured $B \to PP$ decays in the standard model (SM) and the general two-Higgs-doublet model (model III) and compare the theoretical predictions with the new data. Within the considered parameter space we found that: (a) the measurements of the branching ratios for $B\to \pi^+ \pi^-, K^- \pi^+$ and $K^0 \pi^+$ lead to a strong constraint on the form factor $F_0^{B\pi}(0)$: $F_0^{B\pi}(0)=0.24 \pm 0.03$; (b) the new physics enhancements to the penguin-dominated $B \to K \pi$ and $K \etap$ decays are significant in size, $\sim (40-65)%$ $w.r.t$ the SM predictions, and play an important role in restoring the consistency between the data and the theory.
|
1811.04084
|
Cristina Mondino
|
Marco Farina, Cristina Mondino, Duccio Pappadopulo, and Joshua T.
Ruderman
|
New Physics from High Energy Tops
|
13 pages, 2 appendices, 5 figures, references added
| null |
10.1007/JHEP01(2019)231
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Precision measurements of high energy top quarks at the LHC constitute a
powerful probe of new physics. We study the effect of four fermion operators
involving two tops and two light quarks on the high energy tail of the $t\bar
t$ invariant mass distribution. We use existing measurements at a center of
mass energy of 13 TeV, and state of the art calculations of the Standard Model
contribution, to derive bounds on the coefficients of these operators. We
estimate the projected reach of the LHC at higher luminosities and discuss the
validity of these limits within the Effective Field Theory description. We find
that current measurements constrain the mass scale of these operators to be
larger than about 1-2 TeV, while we project that future LHC data will be
sensitive to mass scales of about 3-4 TeV. We apply our bounds to constrain
composite Higgs models with partial compositeness and models with approximate
flavor symmetries. We find our limits to be most relevant to flavor
non-universal models with a moderately large coupling of the heavy new physics
states to third generation quarks.
|
[
{
"created": "Fri, 9 Nov 2018 19:00:00 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Nov 2018 21:28:44 GMT",
"version": "v2"
}
] |
2019-02-20
|
[
[
"Farina",
"Marco",
""
],
[
"Mondino",
"Cristina",
""
],
[
"Pappadopulo",
"Duccio",
""
],
[
"Ruderman",
"Joshua T.",
""
]
] |
Precision measurements of high energy top quarks at the LHC constitute a powerful probe of new physics. We study the effect of four fermion operators involving two tops and two light quarks on the high energy tail of the $t\bar t$ invariant mass distribution. We use existing measurements at a center of mass energy of 13 TeV, and state of the art calculations of the Standard Model contribution, to derive bounds on the coefficients of these operators. We estimate the projected reach of the LHC at higher luminosities and discuss the validity of these limits within the Effective Field Theory description. We find that current measurements constrain the mass scale of these operators to be larger than about 1-2 TeV, while we project that future LHC data will be sensitive to mass scales of about 3-4 TeV. We apply our bounds to constrain composite Higgs models with partial compositeness and models with approximate flavor symmetries. We find our limits to be most relevant to flavor non-universal models with a moderately large coupling of the heavy new physics states to third generation quarks.
|
1405.3864
|
Jorge Casalderrey-Solana
|
Jorge Casalderrey-Solana, Doga Can Gulhan, Jos\'e Guilherme Milhano,
Daniel Pablos, Krishna Rajagopal
|
A Hybrid Strong/Weak Coupling Approach to Jet Quenching
|
47 pages, 10 figures, typos corrected. Small mistake in the
implementation of the Gluaber Monte-Carlo for the collision geometry
corrected. Correction results in small changes to values of fitted parameters
and to plots. No changes to any discussion or conclusions
| null |
10.1007/JHEP10(2014)019
|
MIT-CTP-4550, CERN-PH-TH-2014-089, ICCUB-14-051
|
hep-ph hep-th nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose and explore a new hybrid approach to jet quenching in a strongly
coupled medium. The basis of this phenomenological approach is to treat physics
processes at different energy scales differently. The high-$Q^2$ processes
associated with the QCD evolution of the jet from production as a single hard
parton through its fragmentation, up to but not including hadronization, are
treated perturbatively. The interactions between the partons in the shower and
the deconfined matter within which they find themselves lead to energy loss.
The momentum scales associated with the medium (of the order of the
temperature) and with typical interactions between partons in the shower and
the medium are sufficiently soft that strongly coupled physics plays an
important role in energy loss. We model these interactions using qualitative
insights from holographic calculations of the energy loss of energetic light
quarks and gluons in a strongly coupled plasma, obtained via gauge/gravity
duality. We embed this hybrid model into a hydrodynamic description of the
spacetime evolution of the hot QCD matter produced in heavy ion collisions and
confront its predictions with jet data from the LHC. The holographic expression
for the energy loss of a light quark or gluon that we incorporate in our hybrid
model is parametrized by a stopping distance. We find very good agreement with
all the data as long as we choose a stopping distance that is comparable to but
somewhat longer than that in ${\cal N}=4$ supersymmetric Yang-Mills theory. For
comparison, we also construct alternative models in which energy loss occurs as
it would if the plasma were weakly coupled. We close with suggestions of
observables that could provide more incisive evidence for, or against, the
importance of strongly coupled physics in jet quenching.
|
[
{
"created": "Thu, 15 May 2014 14:28:24 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Jun 2014 19:41:54 GMT",
"version": "v2"
},
{
"created": "Tue, 4 Aug 2015 13:44:22 GMT",
"version": "v3"
}
] |
2015-08-05
|
[
[
"Casalderrey-Solana",
"Jorge",
""
],
[
"Gulhan",
"Doga Can",
""
],
[
"Milhano",
"José Guilherme",
""
],
[
"Pablos",
"Daniel",
""
],
[
"Rajagopal",
"Krishna",
""
]
] |
We propose and explore a new hybrid approach to jet quenching in a strongly coupled medium. The basis of this phenomenological approach is to treat physics processes at different energy scales differently. The high-$Q^2$ processes associated with the QCD evolution of the jet from production as a single hard parton through its fragmentation, up to but not including hadronization, are treated perturbatively. The interactions between the partons in the shower and the deconfined matter within which they find themselves lead to energy loss. The momentum scales associated with the medium (of the order of the temperature) and with typical interactions between partons in the shower and the medium are sufficiently soft that strongly coupled physics plays an important role in energy loss. We model these interactions using qualitative insights from holographic calculations of the energy loss of energetic light quarks and gluons in a strongly coupled plasma, obtained via gauge/gravity duality. We embed this hybrid model into a hydrodynamic description of the spacetime evolution of the hot QCD matter produced in heavy ion collisions and confront its predictions with jet data from the LHC. The holographic expression for the energy loss of a light quark or gluon that we incorporate in our hybrid model is parametrized by a stopping distance. We find very good agreement with all the data as long as we choose a stopping distance that is comparable to but somewhat longer than that in ${\cal N}=4$ supersymmetric Yang-Mills theory. For comparison, we also construct alternative models in which energy loss occurs as it would if the plasma were weakly coupled. We close with suggestions of observables that could provide more incisive evidence for, or against, the importance of strongly coupled physics in jet quenching.
|
hep-ph/0205030
|
Antonio Pich Zardoya
|
A. Pich (IFIC, Valencia)
|
Colourless Mesons in a Polychromatic World
|
20 pages, Latex
| null |
10.1142/9789812776914_0023
|
IFIC/02-15, FTUV/02-0502
|
hep-ph
| null |
The limit of a large number of QCD colours gives a useful approximation
scheme to the physical hadronic world. A brief overview of the mesonic sector
is presented. The large-Nc constraints on the low-energy chiral couplings are
summarized and the role of unitarity corrections is discussed. As an important
illustration of the 1/Nc expansion techniques, the Standard Model prediction of
epsilon'/epsilon is reviewed.
|
[
{
"created": "Thu, 2 May 2002 19:12:32 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Pich",
"A.",
"",
"IFIC, Valencia"
]
] |
The limit of a large number of QCD colours gives a useful approximation scheme to the physical hadronic world. A brief overview of the mesonic sector is presented. The large-Nc constraints on the low-energy chiral couplings are summarized and the role of unitarity corrections is discussed. As an important illustration of the 1/Nc expansion techniques, the Standard Model prediction of epsilon'/epsilon is reviewed.
|
hep-ph/0505211
|
Guy D. Moore
|
Joshua W. Elliott, Guy D. Moore, Horace Stoica
|
Constraining the New Aether: Gravitational Cherenkov Radiation
|
19 pages, one figure. Minor revisions, published version
|
JHEP 0508:066,2005
|
10.1088/1126-6708/2005/08/066
| null |
hep-ph gr-qc hep-th
| null |
We study the simplest concrete theory for spontaneous Lorentz violation, the
``New Aether Theory'' of Jacobson and Mattingly, which is a vector-tensor
gravitational theory with a fixed-modulus condition on the vector field. We
show that the observation of ultra-high energy cosmic rays (which implies the
absence of energy loss via various Cherenkov type processes) places constraints
on the parameters of this theory, which are much stronger than those previously
found in the literature and are also stronger than the constraints generically
arising when gravity displays sub-luminal propagation.
|
[
{
"created": "Tue, 24 May 2005 21:16:17 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Jul 2005 21:22:07 GMT",
"version": "v2"
}
] |
2014-11-18
|
[
[
"Elliott",
"Joshua W.",
""
],
[
"Moore",
"Guy D.",
""
],
[
"Stoica",
"Horace",
""
]
] |
We study the simplest concrete theory for spontaneous Lorentz violation, the ``New Aether Theory'' of Jacobson and Mattingly, which is a vector-tensor gravitational theory with a fixed-modulus condition on the vector field. We show that the observation of ultra-high energy cosmic rays (which implies the absence of energy loss via various Cherenkov type processes) places constraints on the parameters of this theory, which are much stronger than those previously found in the literature and are also stronger than the constraints generically arising when gravity displays sub-luminal propagation.
|
hep-ph/9307327
| null |
N.I. Ussyukina and A.I. Davydychev
|
Some Exact Results for Two-Loop Diagrams with Three and Four External
Lines
|
To appear in Proc. VII Intern. Workshop "High Energy Physics and
Quantum Field Theory" (Sochi, Russia, October 1992), Yad.Fiz., v.56, No.11,
p.172-179 (November 1993)
|
Phys.Atom.Nucl. 56 (1993) 1553-1557; Yad.Fiz. 56N11 (1993) 172-179
| null | null |
hep-ph
| null |
Evaluation of three- and four-point diagrams with massless internal particles
and arbitrary external momenta is considered. Exact results for some two-loop
diagrams (planar and non-planar three-point contributions and the "double box"
diagram) are obtained in terms of polylogarithms.
|
[
{
"created": "Fri, 23 Jul 1993 15:29:18 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Ussyukina",
"N. I.",
""
],
[
"Davydychev",
"A. I.",
""
]
] |
Evaluation of three- and four-point diagrams with massless internal particles and arbitrary external momenta is considered. Exact results for some two-loop diagrams (planar and non-planar three-point contributions and the "double box" diagram) are obtained in terms of polylogarithms.
|
2203.06323
|
Daniela Hern\'andez-Otero
|
D. Hern\'andez-Otero, J. Hern\'andez-S\'anchez, S. Moretti and T.
Shindou
|
The $Z_3$ soft breaking in the I(2+1)HDM and its probes at present and
future colliders
|
17 pages, 18 figures
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
A $ Z_3 $ symmetric 3-Higgs Doublet Model (3HDM) with two inert doublets and
one active doublet (that plays the role of the Higgs doublet), the so-called
I(2+1)HDM, is studied. We discuss the behaviour of this 3HDM realisation when
one allows for a $ Z_3 $ soft breaking term. Such a symmetry enables the
presence of a two-component Dark Matter (DM) scenario in the form of
"Hermaphrodite DM", where the two inert candidates have opposite CP parity and
are protected by this discrete symmetry from decaying into Standard Model (SM)
particles. Furthermore, the two DM states are potentially distinguishable from
each other as they cannot be subsumed into a complex field, having different
masses and gauge couplings. With this in mind, we study differential spectra
with a distinctive shape from which the existence of two different DM component
distributions could be easily inferred. We prove this to be possible at the
Large Hadron Collider (LHC) via the $q\bar{q} \to 2l+H_1H_1$ and $q\bar{q} \to
2l+A_1A_1$ processes as well as at a future electron-positron machine via the
$e^{+}e^{-} \to 2l+H_1H_1$ and $e^{+}e^{-} \to 2l+A_1A_1$ channels, where
$l=e,\mu$.
|
[
{
"created": "Sat, 12 Mar 2022 02:50:33 GMT",
"version": "v1"
}
] |
2022-03-15
|
[
[
"Hernández-Otero",
"D.",
""
],
[
"Hernández-Sánchez",
"J.",
""
],
[
"Moretti",
"S.",
""
],
[
"Shindou",
"T.",
""
]
] |
A $ Z_3 $ symmetric 3-Higgs Doublet Model (3HDM) with two inert doublets and one active doublet (that plays the role of the Higgs doublet), the so-called I(2+1)HDM, is studied. We discuss the behaviour of this 3HDM realisation when one allows for a $ Z_3 $ soft breaking term. Such a symmetry enables the presence of a two-component Dark Matter (DM) scenario in the form of "Hermaphrodite DM", where the two inert candidates have opposite CP parity and are protected by this discrete symmetry from decaying into Standard Model (SM) particles. Furthermore, the two DM states are potentially distinguishable from each other as they cannot be subsumed into a complex field, having different masses and gauge couplings. With this in mind, we study differential spectra with a distinctive shape from which the existence of two different DM component distributions could be easily inferred. We prove this to be possible at the Large Hadron Collider (LHC) via the $q\bar{q} \to 2l+H_1H_1$ and $q\bar{q} \to 2l+A_1A_1$ processes as well as at a future electron-positron machine via the $e^{+}e^{-} \to 2l+H_1H_1$ and $e^{+}e^{-} \to 2l+A_1A_1$ channels, where $l=e,\mu$.
|
hep-ph/9911488
|
Supratim Sengupta
|
Raghavan Rangarajan (1), Supratim Sengupta and Ajit M. Srivastava (2);
((1) Physical Research Laboratory, Ahmedabad,India. (2) Institute of Physics,
Bhubaneswar,India.)
|
Electroweak Baryogenesis in a Cold Universe
|
Revtex, 26 pages including 2 postscript figures. Contains improved
calculations taking into account effect of relativistic plasma. Some
important results modified and some references added
|
Astropart.Phys.17:167-182,2002
|
10.1016/S0927-6505(01)00146-3
| null |
hep-ph astro-ph
| null |
We discuss the possibility of generating the baryon asymmetry of the Universe
when the temperature of the Universe is much below the electroweak scale. In
our model the evaporation of primordial black holes or the decay of massive
particles re-heats the surrounding plasma to temperatures above the electroweak
transition temperature leading to the restoration of electroweak symmetry
locally. The symmetry is broken again spontaneously as the plasma cools and a
baryon asymmetry is generated during the phase transition. This mechanism
generates sufficient asymmetry for a second order electroweak phase transition.
For a first order phase transition, sufficient asymmetry is generated if
viscous effects slow down the heated plasma as it moves away from the black
hole. In our scenario there is no wash-out of the asymmetry after the phase
transition as the plasma rapidly cools to lower temperatures thereby shutting
off the sphaleron processes.
|
[
{
"created": "Thu, 25 Nov 1999 14:15:29 GMT",
"version": "v1"
},
{
"created": "Wed, 16 Feb 2000 16:01:35 GMT",
"version": "v2"
}
] |
2011-05-23
|
[
[
"Rangarajan",
"Raghavan",
""
],
[
"Sengupta",
"Supratim",
""
],
[
"Srivastava",
"Ajit M.",
""
],
[
";",
"",
""
]
] |
We discuss the possibility of generating the baryon asymmetry of the Universe when the temperature of the Universe is much below the electroweak scale. In our model the evaporation of primordial black holes or the decay of massive particles re-heats the surrounding plasma to temperatures above the electroweak transition temperature leading to the restoration of electroweak symmetry locally. The symmetry is broken again spontaneously as the plasma cools and a baryon asymmetry is generated during the phase transition. This mechanism generates sufficient asymmetry for a second order electroweak phase transition. For a first order phase transition, sufficient asymmetry is generated if viscous effects slow down the heated plasma as it moves away from the black hole. In our scenario there is no wash-out of the asymmetry after the phase transition as the plasma rapidly cools to lower temperatures thereby shutting off the sphaleron processes.
|
hep-ph/0610429
|
Egle Tomasi-Gustafsson
|
C. Adamuscin, E. A. Kuraev, E. Tomasi-Gustafsson, F. E. Maas
|
Testing axial and electromagnetic nucleon form factors in time-like
regions in the processes $\bar p + n\to \pi^- +\ell^-+\ell^+$ and $\bar p+
p\to \pi^0 +\ell^- + \ell^+$, $\ell=e$, $\mu$
|
23 pages, 9 figures
|
Phys.Rev.C75:045205,2007
|
10.1103/PhysRevC.75.045205
| null |
hep-ph
| null |
In frame of a phenomenological approach based on Compton-like Feynman
amplitudes, we study the annihilation channel in antiproton nucleon collisions
with production of a single charged or neutral pion and a lepton-antilepton
pair. These reactions allow to access nucleon and axial electromagnetic form
factors in time-like region and offer a unique possibility to study the
kinematical region below two nucleon threshold. The differential cross section
in an experimental set-up where the pion is fully detected is given with
explicit dependence on the relevant nucleon form factors. The possibility to
measure heavy charged pion in the annihilation channel is also discussed.
|
[
{
"created": "Tue, 31 Oct 2006 13:58:33 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Adamuscin",
"C.",
""
],
[
"Kuraev",
"E. A.",
""
],
[
"Tomasi-Gustafsson",
"E.",
""
],
[
"Maas",
"F. E.",
""
]
] |
In frame of a phenomenological approach based on Compton-like Feynman amplitudes, we study the annihilation channel in antiproton nucleon collisions with production of a single charged or neutral pion and a lepton-antilepton pair. These reactions allow to access nucleon and axial electromagnetic form factors in time-like region and offer a unique possibility to study the kinematical region below two nucleon threshold. The differential cross section in an experimental set-up where the pion is fully detected is given with explicit dependence on the relevant nucleon form factors. The possibility to measure heavy charged pion in the annihilation channel is also discussed.
|
2102.05914
|
Peter Matak
|
Tom\'a\v{s} Bla\v{z}ek, Peter Mat\'ak
|
CP Asymmetries and Higher-Order Unitarity Relations
|
7 pages, 3 figures
|
Phys. Rev. D 103, L091302 (2021)
|
10.1103/PhysRevD.103.L091302
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The main focus of this paper is to introduce a new method to control
perturbative calculations of CP asymmetric reaction rates in the Boltzmann
equation. CP asymmetries in particle reactions are traditionally calculated in
terms of complex couplings, Feynman integrals, and Cutkosky rules. We use an
expansion of the $S$-matrix unitarity condition instead, obtaining a general
expression for the asymmetries without reference to the imaginary part of the
loops. Asymmetry cancelations implied by CPT and unitarity are manifested in a
diagrammatic way and easy to track at any order of perturbation theory. We
demonstrate the power of this general framework within the right-handed
neutrino and top-quark scattering asymmetries in seesaw type-I leptogenesis.
|
[
{
"created": "Thu, 11 Feb 2021 09:59:28 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Apr 2021 07:48:45 GMT",
"version": "v2"
}
] |
2022-02-22
|
[
[
"Blažek",
"Tomáš",
""
],
[
"Maták",
"Peter",
""
]
] |
The main focus of this paper is to introduce a new method to control perturbative calculations of CP asymmetric reaction rates in the Boltzmann equation. CP asymmetries in particle reactions are traditionally calculated in terms of complex couplings, Feynman integrals, and Cutkosky rules. We use an expansion of the $S$-matrix unitarity condition instead, obtaining a general expression for the asymmetries without reference to the imaginary part of the loops. Asymmetry cancelations implied by CPT and unitarity are manifested in a diagrammatic way and easy to track at any order of perturbation theory. We demonstrate the power of this general framework within the right-handed neutrino and top-quark scattering asymmetries in seesaw type-I leptogenesis.
|
1104.5239
|
Jennifer Kile
|
Jennifer Kile, Amarjit Soni
|
Flavored Dark Matter in Direct Detection Experiments and at LHC
|
19 pages, 5 figures
|
Phys.Rev.D84:035016,2011
|
10.1103/PhysRevD.84.035016
|
NUHEP-TH/11-01
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the possibility that dark matter can communicate with the
Standard Model fields via flavor interactions. We take the dark matter to
belong to a "dark sector" which contains at least two types, or "flavors", of
particles and then hypothesize that the Standard Model fields and dark matter
share a common interaction which depends on flavor. As, generically,
interaction eigenstates and mass eigenstates need not coincide, we consider
both flavor-changing and flavor-conserving interactions. These interactions are
then constrained by meson decays, kaon mixing, and current collider bounds, and
we examine their relevance for direct detection and LHC.
|
[
{
"created": "Wed, 27 Apr 2011 20:06:22 GMT",
"version": "v1"
}
] |
2011-09-15
|
[
[
"Kile",
"Jennifer",
""
],
[
"Soni",
"Amarjit",
""
]
] |
We consider the possibility that dark matter can communicate with the Standard Model fields via flavor interactions. We take the dark matter to belong to a "dark sector" which contains at least two types, or "flavors", of particles and then hypothesize that the Standard Model fields and dark matter share a common interaction which depends on flavor. As, generically, interaction eigenstates and mass eigenstates need not coincide, we consider both flavor-changing and flavor-conserving interactions. These interactions are then constrained by meson decays, kaon mixing, and current collider bounds, and we examine their relevance for direct detection and LHC.
|
hep-ph/9911411
|
Norbert E. Ligterink
|
N.E. Ligterink
|
Solving multi-loop Feynman diagrams using light-front coordinates
|
7 pages, 3 figures
|
Phys.Rev. D61 (2000) 105010
|
10.1103/PhysRevD.61.105010
|
ECT*-99-016
|
hep-ph
| null |
We determine the numerical values of scalar multi-loop two-vertex Feynman
diagrams, the generalized sunset diagrams, by integrating all but the
longitudinal momenta analytically. For the longitudinal momenta we introduce
one collective coordinate, which allows us to determine the numerical value of
the diagram efficiently and to an arbitrary accuracy. The imaginary part and
the threshold behavior of the diagram are also handled within this framework.
|
[
{
"created": "Fri, 19 Nov 1999 15:11:06 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Ligterink",
"N. E.",
""
]
] |
We determine the numerical values of scalar multi-loop two-vertex Feynman diagrams, the generalized sunset diagrams, by integrating all but the longitudinal momenta analytically. For the longitudinal momenta we introduce one collective coordinate, which allows us to determine the numerical value of the diagram efficiently and to an arbitrary accuracy. The imaginary part and the threshold behavior of the diagram are also handled within this framework.
|
2206.06123
|
Jun Jiang
|
Qi-Li Liao, Jun Jiang, and Yu-Han Zhao
|
Production of double heavy quarkonium at super $Z$ factory
|
15 pages, 6 tables, and 4 figures. Version published at EPJC
|
The European Physical Journal C volume 83, Article number: 22
(2023)
|
10.1140/epjc/s10052-023-11174-x
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Within the color singlet model, we calculate the exclusive production of
double charmonia, double bottomonia, and double $B_c$ mesons at future super
$Z$ factory. The two heavy quarkonia or $B_c$'s are either two S-wave Fock
states ($^1S_0, ~^3S_1$), or one S-wave and one P-wave states
($^1P_1,~^3P_J~(J=0,1,2)$). The top three $Z^0$ propagated channels in cross
sections for double charmonia are $J/\psi+h_c,\eta_c+\chi_{c2}$, and
$\eta_c+\chi_{c0}$. For double bottomonia, they are $\eta_b+\Upsilon,
\Upsilon+\chi_{b2}$, and $\Upsilon+\Upsilon$. For double $B_c$ mesons, they are
$B_c^{*+}+B_c^{*-}$,$B_c^{*+}+\chi_{bc2}^-$, and $\eta_{bc}^++B_c^{*-}$. The
cross sections of double $B_c$ mesons are roughly one order of magnitude larger
than those of the double bottomonia, and two orders of magnitude larger than
those of the double charmonia. To make it helpful for experimental study, we
present the total cross sections $\sigma$ as functions of CM energy $\sqrt{s}$,
$\sigma$ as functions of the renormalization scale $\mu$, the angle
distributions $d\sigma/dcos\theta$, and the $p_T$ distributions
$d\sigma/dp_{t}$. The uncertainties come from the varying masses of constituent
heavy quarks bring up to 20% corrections. We also find that the initial state
radiation can bring about 30%$\sim$40% suppresions when 1\%$m_Z$ energy is
losing, and cross sections can increase by about $2\sim3$ times or decrease by
an order of magnitude when adopting different potential models which becomes
the major source of uncertainty. The numerical results show that it might be
not optimistic for the experimental observation, but it is still far from
excluded at the FCC-ee and also the CEPC running in the $Z$ factory mode.
|
[
{
"created": "Mon, 13 Jun 2022 13:01:47 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Aug 2022 03:55:05 GMT",
"version": "v2"
},
{
"created": "Mon, 16 Jan 2023 23:43:25 GMT",
"version": "v3"
}
] |
2023-01-18
|
[
[
"Liao",
"Qi-Li",
""
],
[
"Jiang",
"Jun",
""
],
[
"Zhao",
"Yu-Han",
""
]
] |
Within the color singlet model, we calculate the exclusive production of double charmonia, double bottomonia, and double $B_c$ mesons at future super $Z$ factory. The two heavy quarkonia or $B_c$'s are either two S-wave Fock states ($^1S_0, ~^3S_1$), or one S-wave and one P-wave states ($^1P_1,~^3P_J~(J=0,1,2)$). The top three $Z^0$ propagated channels in cross sections for double charmonia are $J/\psi+h_c,\eta_c+\chi_{c2}$, and $\eta_c+\chi_{c0}$. For double bottomonia, they are $\eta_b+\Upsilon, \Upsilon+\chi_{b2}$, and $\Upsilon+\Upsilon$. For double $B_c$ mesons, they are $B_c^{*+}+B_c^{*-}$,$B_c^{*+}+\chi_{bc2}^-$, and $\eta_{bc}^++B_c^{*-}$. The cross sections of double $B_c$ mesons are roughly one order of magnitude larger than those of the double bottomonia, and two orders of magnitude larger than those of the double charmonia. To make it helpful for experimental study, we present the total cross sections $\sigma$ as functions of CM energy $\sqrt{s}$, $\sigma$ as functions of the renormalization scale $\mu$, the angle distributions $d\sigma/dcos\theta$, and the $p_T$ distributions $d\sigma/dp_{t}$. The uncertainties come from the varying masses of constituent heavy quarks bring up to 20% corrections. We also find that the initial state radiation can bring about 30%$\sim$40% suppresions when 1\%$m_Z$ energy is losing, and cross sections can increase by about $2\sim3$ times or decrease by an order of magnitude when adopting different potential models which becomes the major source of uncertainty. The numerical results show that it might be not optimistic for the experimental observation, but it is still far from excluded at the FCC-ee and also the CEPC running in the $Z$ factory mode.
|
hep-ph/9706313
|
Choudhury S. Rai
|
S.Rai Choudhury
|
Forward-Backward Asymmetry in $B\to X_d e^+e^-$
|
5 pages, latex formatted
|
Phys.Rev. D56 (1997) 6028-6030
|
10.1103/PhysRevD.56.6028
| null |
hep-ph
| null |
The Forward-backward asymmetry in the angular distribution of $e^+e^-$ is
studied in the process $B\to e^+e^- and \bar{B}\to \bar{X}_d e^+e^-$ . The
possibility of observing CP violation through the asymmetries in these two
processes is examined.
|
[
{
"created": "Tue, 10 Jun 1997 12:57:52 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Choudhury",
"S. Rai",
""
]
] |
The Forward-backward asymmetry in the angular distribution of $e^+e^-$ is studied in the process $B\to e^+e^- and \bar{B}\to \bar{X}_d e^+e^-$ . The possibility of observing CP violation through the asymmetries in these two processes is examined.
|
2107.10913
|
Ian Chaffey
|
Ian Chaffey
|
Vector Portal Pseudo-Goldstone Dark Matter
|
16 pages + references; Typos corrected
| null | null | null |
hep-ph astro-ph.CO
|
http://creativecommons.org/licenses/by/4.0/
|
We present a model of pseudo-Goldstone dark matter that interacts through a
light vector mediator based on a spontaneously broken $SU(2)$ dark sector. The
dark matter mass is induced by the explicit breaking of the dark $SU(2)$
symmetry. A residual global $U(1)$ symmetry prevents dark matter decay. The
behavior of this model is studied under the assumption that the observed dark
matter relic abundance is due to thermal freeze-out. We consider
self-interaction targets for small scale structure anomalies and the
possibility of interacting with the Standard model through the vector mediator.
|
[
{
"created": "Thu, 22 Jul 2021 20:18:37 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Oct 2022 19:22:38 GMT",
"version": "v2"
}
] |
2022-10-06
|
[
[
"Chaffey",
"Ian",
""
]
] |
We present a model of pseudo-Goldstone dark matter that interacts through a light vector mediator based on a spontaneously broken $SU(2)$ dark sector. The dark matter mass is induced by the explicit breaking of the dark $SU(2)$ symmetry. A residual global $U(1)$ symmetry prevents dark matter decay. The behavior of this model is studied under the assumption that the observed dark matter relic abundance is due to thermal freeze-out. We consider self-interaction targets for small scale structure anomalies and the possibility of interacting with the Standard model through the vector mediator.
|
hep-ph/0602107
|
Tatsumi Aoyama
|
T. Aoyama, M. Hayakawa, T. Kinoshita, M. Nio
|
Automated Calculation Scheme for alpha^n Contributions of QED to Lepton
g-2
|
5 pages, Talk presented at the 7th International Symposium on
Radiative Corrections (RADCOR 2005), Shonan Village, Japan, October 2-7, 2005
| null |
10.1016/j.nuclphysbps.2006.03.040
| null |
hep-ph
| null |
This article reports an automated approach to the evaluation of higher-order
terms of QED perturbation to anomalous magnetic moments of charged leptons by
numerical means. We apply this approach to tenth-order correction due to a
particular subcollection of Feynman diagrams, which have no virtual lepton
loops. This set of diagrams is distinctive in that it grows factorially in
number as the order increases, and also each of the diagrams holds quite a
large number of subtraction terms to be treated along renormalization
procedure. Thus some automated scheme has long been required to evaluate
correctly this class of diagrams. We developed a fast algorithm and an
implementation which automates necessary steps to generate from the
representation of each Feynman diagram the FORTRAN codes for numerical
integration. Currently those diagrams of tenth order are being evaluated.
|
[
{
"created": "Mon, 13 Feb 2006 07:59:32 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Aoyama",
"T.",
""
],
[
"Hayakawa",
"M.",
""
],
[
"Kinoshita",
"T.",
""
],
[
"Nio",
"M.",
""
]
] |
This article reports an automated approach to the evaluation of higher-order terms of QED perturbation to anomalous magnetic moments of charged leptons by numerical means. We apply this approach to tenth-order correction due to a particular subcollection of Feynman diagrams, which have no virtual lepton loops. This set of diagrams is distinctive in that it grows factorially in number as the order increases, and also each of the diagrams holds quite a large number of subtraction terms to be treated along renormalization procedure. Thus some automated scheme has long been required to evaluate correctly this class of diagrams. We developed a fast algorithm and an implementation which automates necessary steps to generate from the representation of each Feynman diagram the FORTRAN codes for numerical integration. Currently those diagrams of tenth order are being evaluated.
|
1403.4960
|
Kristjan Kannike
|
Genevi\`eve B\'elanger, Kristjan Kannike, Alexander Pukhov and Martti
Raidal
|
Minimal semi-annihilating $\mathbb{Z}_N$ scalar dark matter
|
41 pages, 12 figures
| null |
10.1088/1475-7516/2014/06/021
|
LAPTH-017/14
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the dark matter from an inert doublet and a complex scalar singlet
stabilized by $\mathbb{Z}_N$ symmetries. This field content is the minimal one
that allows dimensionless semi-annihilation couplings for $N > 2$. We consider
explicitly the $\mathbb{Z}_3$ and $\mathbb{Z}_4$ cases and take into account
constraints from perturbativity, unitarity, vacuum stability, necessity for the
electroweak $\mathbb{Z}_N$ preserving vacuum to be the global minimum,
electroweak precision tests, upper limits from direct detection and properties
of the Higgs boson. Co-annihilation and semi-annihilation of dark sector
particles as well as dark matter conversion significantly modify the cosmic
abundance and direct detection phenomenology.
|
[
{
"created": "Wed, 19 Mar 2014 20:19:54 GMT",
"version": "v1"
}
] |
2015-06-19
|
[
[
"Bélanger",
"Geneviève",
""
],
[
"Kannike",
"Kristjan",
""
],
[
"Pukhov",
"Alexander",
""
],
[
"Raidal",
"Martti",
""
]
] |
We study the dark matter from an inert doublet and a complex scalar singlet stabilized by $\mathbb{Z}_N$ symmetries. This field content is the minimal one that allows dimensionless semi-annihilation couplings for $N > 2$. We consider explicitly the $\mathbb{Z}_3$ and $\mathbb{Z}_4$ cases and take into account constraints from perturbativity, unitarity, vacuum stability, necessity for the electroweak $\mathbb{Z}_N$ preserving vacuum to be the global minimum, electroweak precision tests, upper limits from direct detection and properties of the Higgs boson. Co-annihilation and semi-annihilation of dark sector particles as well as dark matter conversion significantly modify the cosmic abundance and direct detection phenomenology.
|
1001.1509
|
Masato Arai
|
Masato Arai, Shinsuke Kawai, Nobuchika Okada
|
A gauge mediation scenario with hidden sector renormalization in MSSM
|
8 pages, 5 figures, comments added, to appear in PRD
|
Phys.Rev.D81:035022,2010
|
10.1103/PhysRevD.81.035022
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the hidden sector effects to the mass renormalization of a simplest
gauge-mediated supersymmetry breaking scenario. We point out that possible
hidden sector contributions render the soft scalar masses smaller, resulting in
drastically different sparticle mass spectrum at low energy. In particular, in
the ${\bf 5}+\bar{\bf 5}$ minimal gauge mediated supersymmetry breaking with
high messenger scale (that is favored by the gravitino cold dark matter
scenario), we show that stau can be the next lightest superparticle for
moderate values of hidden sector self coupling. This provides a very simple
theoretical model of long-lived charged next lightest superparticles, that
imply distinctive signals in ongoing and upcoming collider experiments.
|
[
{
"created": "Sun, 10 Jan 2010 12:39:26 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Jan 2010 15:04:07 GMT",
"version": "v2"
},
{
"created": "Sat, 6 Feb 2010 02:17:20 GMT",
"version": "v3"
}
] |
2010-05-12
|
[
[
"Arai",
"Masato",
""
],
[
"Kawai",
"Shinsuke",
""
],
[
"Okada",
"Nobuchika",
""
]
] |
We study the hidden sector effects to the mass renormalization of a simplest gauge-mediated supersymmetry breaking scenario. We point out that possible hidden sector contributions render the soft scalar masses smaller, resulting in drastically different sparticle mass spectrum at low energy. In particular, in the ${\bf 5}+\bar{\bf 5}$ minimal gauge mediated supersymmetry breaking with high messenger scale (that is favored by the gravitino cold dark matter scenario), we show that stau can be the next lightest superparticle for moderate values of hidden sector self coupling. This provides a very simple theoretical model of long-lived charged next lightest superparticles, that imply distinctive signals in ongoing and upcoming collider experiments.
|
2111.08025
|
Digvijay Wadekar
|
Digvijay Wadekar, Zihui Wang
|
Strong constraints on decay and annihilation of dark matter from heating
of gas-rich dwarf galaxies
|
11+4 pages, 7 figures. Version appearing in PRD. Added more
conservative estimates of DM limits and a discussion of senstivity of the
limits to DM halo model. The code associated with this paper is available at
https://github.com/JayWadekar/Gas_rich_dwarfs
|
Phys. Rev. D 106, 075007 (2022)
|
10.1103/PhysRevD.106.075007
| null |
hep-ph astro-ph.CO astro-ph.GA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Gas-rich dwarf galaxies located outside the virial radius of their host are
relatively pristine systems and have ultra-low gas cooling rates. This makes
them very sensitive to heat injection by annihilation or decay of dark matter
(DM). Such dwarfs are particularly sensitive to DM producing e$^\pm$ with
energies 1$-$100 MeV or photons with energies 13.6 eV$-1$ keV, because these
products can be efficiently thermalized in the neutral hydrogen gas of the
dwarfs. Following the methodology of Wadekar and Farrar (2021), we require the
rate of heat injection by DM to not exceed the ultra-low radiative cooling rate
of gas in the Leo T dwarf galaxy. This gives model-independent bounds on $(i)$
the decay lifetime of DM to $e^\pm$ (photons) which are stronger than all the
previous literature for $m_\mathrm{DM}\sim$ 1$-$10 MeV
($m_\mathrm{DM}\sim0.02-1$ keV), $(ii)$ annihilation of DM to $e^{\pm}$
comparable to constraints from CMB and X/$\gamma$-ray surveys. We also
translate our bounds for the case of the following DM models: axion-like
particles (ALPs), sterile neutrinos, excited DM states, higgs portal scalars
and dark baryons. Observations of gas-rich low-mass dwarfs from upcoming 21cm
and optical surveys can therefore be powerful probes of a multitude of models
of DM.
|
[
{
"created": "Mon, 15 Nov 2021 19:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Oct 2022 14:52:33 GMT",
"version": "v2"
}
] |
2022-10-12
|
[
[
"Wadekar",
"Digvijay",
""
],
[
"Wang",
"Zihui",
""
]
] |
Gas-rich dwarf galaxies located outside the virial radius of their host are relatively pristine systems and have ultra-low gas cooling rates. This makes them very sensitive to heat injection by annihilation or decay of dark matter (DM). Such dwarfs are particularly sensitive to DM producing e$^\pm$ with energies 1$-$100 MeV or photons with energies 13.6 eV$-1$ keV, because these products can be efficiently thermalized in the neutral hydrogen gas of the dwarfs. Following the methodology of Wadekar and Farrar (2021), we require the rate of heat injection by DM to not exceed the ultra-low radiative cooling rate of gas in the Leo T dwarf galaxy. This gives model-independent bounds on $(i)$ the decay lifetime of DM to $e^\pm$ (photons) which are stronger than all the previous literature for $m_\mathrm{DM}\sim$ 1$-$10 MeV ($m_\mathrm{DM}\sim0.02-1$ keV), $(ii)$ annihilation of DM to $e^{\pm}$ comparable to constraints from CMB and X/$\gamma$-ray surveys. We also translate our bounds for the case of the following DM models: axion-like particles (ALPs), sterile neutrinos, excited DM states, higgs portal scalars and dark baryons. Observations of gas-rich low-mass dwarfs from upcoming 21cm and optical surveys can therefore be powerful probes of a multitude of models of DM.
|
1310.8073
|
Torbjorn Sjostrand
|
Torbj\"orn Sj\"ostrand
|
Colour reconnection and its effects on precise measurements at the LHC
|
8 pages, 1 figure, to appear in the proceedings of the XLIII
International Symposium on Multiparticle Dynamics (ISMD13), Chicago, USA, 15
-- 20 September 2013
| null | null |
LU TP 13-37, MCnet-13-16
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
There are experimental evidence for the occurrence of colour reconnection,
but the mechanisms involved are far from understood. Previous reconnection
studies are briefly summarized, and some potential implications for LHC physics
are outlined.
|
[
{
"created": "Wed, 30 Oct 2013 09:04:23 GMT",
"version": "v1"
}
] |
2013-10-31
|
[
[
"Sjöstrand",
"Torbjörn",
""
]
] |
There are experimental evidence for the occurrence of colour reconnection, but the mechanisms involved are far from understood. Previous reconnection studies are briefly summarized, and some potential implications for LHC physics are outlined.
|
2201.05652
|
Mario Neves Junior
|
Y. M. P. Gomes and M. J. Neves
|
Reconciling LSND and super-Kamiokande data through the dynamical Lorentz
symmetry breaking in a four-Majorana fermion model
|
13 pages, 6 figures, published version in the Physical Review D
|
Phys. Rev. D 106, 015013 (2022)
|
10.1103/PhysRevD.106.015013
| null |
hep-ph hep-th
|
http://creativecommons.org/licenses/by/4.0/
|
We propose a model of Majorana fermions with quartic self-couplings. These
Majorana fermions acquire masses via a type II seesaw mechanism in which the
physical eigenstates are identified as a light Majorana fermion and another
heavy Majorana fermion. On a physical basis, the quartic self-couplings involve
axial currents of these Majorana fermions, and also the interaction of the
axial current for the light particle with the heavy particle one. We introduce
two auxiliaries gauge fields in this model, and we study the stability
conditions of the correspondent effective potential of the model. The ground
state of the effective potential introduces two 4-vectors as scales of vacuum
expected values, and consequently, the dynamical Lorentz symmetry breaking
(DLSB) emerges in the model. We use the expansion of the effective action to
calculate the effective Lagrangian up to second order in the auxiliary fields
as fluctuations around the ground state. This mechanism generates dynamics for
the auxiliary gauge fields, mixed mass terms, longitudinal propagation, and
Chern-Simons term through radiative corrections. After the diagonalization, the
two gauge fields gain masses through an analogous type II seesaw mechanism in
which a gauge boson has a light mass, and the other one acquires a heavy mass.
In this scenario of Lorentz symmetry breaking, we obtain the correspondent
dispersion relations for the Majorana fermions and the gauge boson fields.
Posteriorly, we analyze the neutrino's oscillations in the presence of a DLSB
parameter, in the transition $\nu_{e} \rightarrow \nu_{\mu}$. We discuss the
parameter space of this transition and show that the DLSB can conciliate the
LSND and super-Kamiokande results.
|
[
{
"created": "Fri, 14 Jan 2022 19:59:05 GMT",
"version": "v1"
},
{
"created": "Fri, 15 Jul 2022 15:24:51 GMT",
"version": "v2"
}
] |
2022-07-18
|
[
[
"Gomes",
"Y. M. P.",
""
],
[
"Neves",
"M. J.",
""
]
] |
We propose a model of Majorana fermions with quartic self-couplings. These Majorana fermions acquire masses via a type II seesaw mechanism in which the physical eigenstates are identified as a light Majorana fermion and another heavy Majorana fermion. On a physical basis, the quartic self-couplings involve axial currents of these Majorana fermions, and also the interaction of the axial current for the light particle with the heavy particle one. We introduce two auxiliaries gauge fields in this model, and we study the stability conditions of the correspondent effective potential of the model. The ground state of the effective potential introduces two 4-vectors as scales of vacuum expected values, and consequently, the dynamical Lorentz symmetry breaking (DLSB) emerges in the model. We use the expansion of the effective action to calculate the effective Lagrangian up to second order in the auxiliary fields as fluctuations around the ground state. This mechanism generates dynamics for the auxiliary gauge fields, mixed mass terms, longitudinal propagation, and Chern-Simons term through radiative corrections. After the diagonalization, the two gauge fields gain masses through an analogous type II seesaw mechanism in which a gauge boson has a light mass, and the other one acquires a heavy mass. In this scenario of Lorentz symmetry breaking, we obtain the correspondent dispersion relations for the Majorana fermions and the gauge boson fields. Posteriorly, we analyze the neutrino's oscillations in the presence of a DLSB parameter, in the transition $\nu_{e} \rightarrow \nu_{\mu}$. We discuss the parameter space of this transition and show that the DLSB can conciliate the LSND and super-Kamiokande results.
|
hep-ph/0411101
|
Maxim Dvornikov
|
Maxim Dvornikov
|
Evolution of coupled classical fields
|
7 pages, RevTeX4, some typos corrected, 2 references added; final
version published in Phys.Lett. B
|
Phys.Lett. B610 (2005) 262-269
|
10.1016/j.physletb.2005.02.013
| null |
hep-ph hep-th
| null |
We study the evolution of the coupled scalar and fermion fields within the
classical field theory. We examine the case of N coupled fields in 1+3
dimensional space. The general expressions for the fields distributions are
obtained. The particular case of two fields in 1+1 dimensional space is
carefully studied. We obtain the expressions for the averaged fields
intensities and show that in the relativistic limit they are similar to the
usual transition probabilities formulae of neutrino oscillations.
|
[
{
"created": "Sun, 7 Nov 2004 18:25:32 GMT",
"version": "v1"
},
{
"created": "Sun, 20 Mar 2005 11:12:05 GMT",
"version": "v2"
}
] |
2008-07-31
|
[
[
"Dvornikov",
"Maxim",
""
]
] |
We study the evolution of the coupled scalar and fermion fields within the classical field theory. We examine the case of N coupled fields in 1+3 dimensional space. The general expressions for the fields distributions are obtained. The particular case of two fields in 1+1 dimensional space is carefully studied. We obtain the expressions for the averaged fields intensities and show that in the relativistic limit they are similar to the usual transition probabilities formulae of neutrino oscillations.
|
2111.03960
|
Tamer Elkafrawy Dr.
|
Tamer Elkafrawy, Marcus Hohlmann, Teruki Kamon, Paul Padley, Hyunyong
Kim, Mehdi Rahmani, and Sven Dildick
|
Illuminating long-lived dark vector bosons via exotic Higgs decays at
$\sqrt{s} = 13\,{\text {TeV}}$
|
6 pages, 4 figures
| null |
10.22323/1.397.0224
|
PoS(LHCP2021)224
|
hep-ph hep-ex
|
http://creativecommons.org/licenses/by-nc-nd/4.0/
|
The possibility of producing a measurable long-lived dark $Z$ boson, that is
assumed to be produced either via its kinetic mixing with the hypercharge gauge
boson or via mixing of the observed 125-GeV Higgs boson with the dark Higgs
boson, called Higgs mixing, in Run 2 of the Large Hadron Collider (LHC) is
investigated. Displaced dimuons in the final state are considered where each of
the $Z$ and the dark $Z$ bosons decays directly to a dimuon. The Higgs
production cross sections via gluon-gluon fusion at 13 TeV calculated to a
combination of next-to-next-to-next-to-leading order with QCD corrections
(N$^{3}$LO QCD) and next-to-leading order with electroweak corrections (NLO EW)
from the literature are used, while the branching fractions are calculated to
NLO by using Monte Carlo simulation in the framework of
{\textsc{MadGraph5}}\_aMC@NLO and compared to the available analytical
calculations to leading order (LO). Sensitivities of the LHC in Run 2 to such
searches are discussed.
|
[
{
"created": "Sat, 6 Nov 2021 20:31:57 GMT",
"version": "v1"
},
{
"created": "Sun, 27 Feb 2022 08:01:00 GMT",
"version": "v2"
}
] |
2022-09-21
|
[
[
"Elkafrawy",
"Tamer",
""
],
[
"Hohlmann",
"Marcus",
""
],
[
"Kamon",
"Teruki",
""
],
[
"Padley",
"Paul",
""
],
[
"Kim",
"Hyunyong",
""
],
[
"Rahmani",
"Mehdi",
""
],
[
"Dildick",
"Sven",
""
]
] |
The possibility of producing a measurable long-lived dark $Z$ boson, that is assumed to be produced either via its kinetic mixing with the hypercharge gauge boson or via mixing of the observed 125-GeV Higgs boson with the dark Higgs boson, called Higgs mixing, in Run 2 of the Large Hadron Collider (LHC) is investigated. Displaced dimuons in the final state are considered where each of the $Z$ and the dark $Z$ bosons decays directly to a dimuon. The Higgs production cross sections via gluon-gluon fusion at 13 TeV calculated to a combination of next-to-next-to-next-to-leading order with QCD corrections (N$^{3}$LO QCD) and next-to-leading order with electroweak corrections (NLO EW) from the literature are used, while the branching fractions are calculated to NLO by using Monte Carlo simulation in the framework of {\textsc{MadGraph5}}\_aMC@NLO and compared to the available analytical calculations to leading order (LO). Sensitivities of the LHC in Run 2 to such searches are discussed.
|
2202.12673
|
Jingjing Feng
|
Wei Chao and Jing-Jing Feng and Ming-Jie Jin
|
$\mathbf{{N}_{eff}}$ from Excited DM state
| null | null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
For a cold dark matter (DM) originating from the co-annihilation processes,
there will be excited state(s) in the dark sector, that may decay or annihilate
away shortly after their freeze-out. In this paper we investigate the impact of
the decay of these excited states on the effective number of neutrino species,
$N_{\rm eff}^{}$, which is an important cosmological parameter and will be
tested by the future CMB-S4 project. We work in the framework of pseudo-Dirac
DM mode via the Higgs portal. The relic density and the direct detection signal
of the DM are calculated, which gives the available parameter space. Impacts of
the excited state (the heavy component of the pseudo-Dirac fermion) on the
decoupling of active neutrinos are investigated by solving Boltzmann equations
of photon and neutrinos with collision term induced by the decay of the excited
state. The numerical result shows that $|N_{\rm eff}^{}|$ can be of the order
$10^{-4}$, which depends on the mass and lifetime of excited DM state.
|
[
{
"created": "Fri, 25 Feb 2022 13:12:13 GMT",
"version": "v1"
}
] |
2022-02-28
|
[
[
"Chao",
"Wei",
""
],
[
"Feng",
"Jing-Jing",
""
],
[
"Jin",
"Ming-Jie",
""
]
] |
For a cold dark matter (DM) originating from the co-annihilation processes, there will be excited state(s) in the dark sector, that may decay or annihilate away shortly after their freeze-out. In this paper we investigate the impact of the decay of these excited states on the effective number of neutrino species, $N_{\rm eff}^{}$, which is an important cosmological parameter and will be tested by the future CMB-S4 project. We work in the framework of pseudo-Dirac DM mode via the Higgs portal. The relic density and the direct detection signal of the DM are calculated, which gives the available parameter space. Impacts of the excited state (the heavy component of the pseudo-Dirac fermion) on the decoupling of active neutrinos are investigated by solving Boltzmann equations of photon and neutrinos with collision term induced by the decay of the excited state. The numerical result shows that $|N_{\rm eff}^{}|$ can be of the order $10^{-4}$, which depends on the mass and lifetime of excited DM state.
|
hep-ph/9501376
|
Jeff Forshaw
|
J.R.Forshaw and M.G.Ryskin
|
Diffractive Vector Meson Production at Large Momentum Transfer
|
25 pages LaTex plus 6 figures appended as a uuencoded file
|
Z.Phys.C68:137-148,1995
|
10.1007/BF01579812
|
DESY 94-162; RAL-94-058 (revised version)
|
hep-ph
| null |
The diffractive process $\gamma p\to V + X$ (where $V$ is a vector meson and
$X$ results from the dissociation of the proton) is studied. In particular, we
consider the region of large momentum transfer (i.e. $|t|\gg\Lambda_{QCD}^2$)
and large centre-of-mass (CM) energy, $s$. The asymptotic $(s \to \infty,
s/|t|\gg 1$) behaviour is derived from the BFKL equation and compared to that
which is obtained in the Born approximation (two-gluon exchange). We also
calculate the corrections to the Born graphs by iterating the BFKL kernel
numerically. Improved convergence of the BFKL series is found by summing the
logarithms which occur when an exchanged gluon goes nearly on shell.
Importantly, we find evidence that the asymptotic solution to the BFKL equation
is inappropriate over most of the HERA range and we provide more realistic
predictions for the cross section. The predicted cross section is not too small
and can be measured at HERA, up to momentum transfers $|t| \sim 10$GeV$^2$.
|
[
{
"created": "Wed, 25 Jan 1995 21:31:46 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Jan 1995 10:19:40 GMT",
"version": "v2"
}
] |
2016-09-01
|
[
[
"Forshaw",
"J. R.",
""
],
[
"Ryskin",
"M. G.",
""
]
] |
The diffractive process $\gamma p\to V + X$ (where $V$ is a vector meson and $X$ results from the dissociation of the proton) is studied. In particular, we consider the region of large momentum transfer (i.e. $|t|\gg\Lambda_{QCD}^2$) and large centre-of-mass (CM) energy, $s$. The asymptotic $(s \to \infty, s/|t|\gg 1$) behaviour is derived from the BFKL equation and compared to that which is obtained in the Born approximation (two-gluon exchange). We also calculate the corrections to the Born graphs by iterating the BFKL kernel numerically. Improved convergence of the BFKL series is found by summing the logarithms which occur when an exchanged gluon goes nearly on shell. Importantly, we find evidence that the asymptotic solution to the BFKL equation is inappropriate over most of the HERA range and we provide more realistic predictions for the cross section. The predicted cross section is not too small and can be measured at HERA, up to momentum transfers $|t| \sim 10$GeV$^2$.
|
1211.1331
|
Juan M. Torres-Rincon
|
Luciano M. Abreu, Daniel Cabrera, and Juan M. Torres-Rincon
|
Transport properties of bottomed mesons in a hot mesonic gas
|
14 pages, 16 figures, 3 tables. Version published in Phys.Rev.D87,
034019 (2013). Only minor improvements with respect to v1: corrected typos,
further clarifications and updated references
|
Physical Review D 87, Issue 3, 034019 (2013)
|
10.1103/PhysRevD.87.034019
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work we evaluate the B-meson drag and diffusion coefficients in a hot
medium constituted of light mesons (pions, kaons and eta mesons). We treat the
B-meson and B*-meson interaction with pseudo-Goldstone bosons in chiral
perturbation theory at next-to-leading order within the constraints from heavy
quark symmetry, and employ standard unitarization techniques of NLO amplitudes
in order to account for dynamically generated resonances (leading to a more
efficient heavy-flavor diffusion) and thus reach higher temperatures. We
estimate individual meson contributions from the gas to the transport
coefficients and perform a comparison with other findings in literature. We
report a bottom relaxation length of about 80 fm at a temperature of 150 MeV
and for typical momenta of 1 GeV, at which our approach is reliable. Compared
to a charm relaxation length of 40 fm in the same conditions, we conclude that
the B mesons provide a cleaner probe of the early stages of a heavy-ion
collision.
|
[
{
"created": "Tue, 6 Nov 2012 18:04:08 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Feb 2013 16:17:56 GMT",
"version": "v2"
}
] |
2013-02-14
|
[
[
"Abreu",
"Luciano M.",
""
],
[
"Cabrera",
"Daniel",
""
],
[
"Torres-Rincon",
"Juan M.",
""
]
] |
In this work we evaluate the B-meson drag and diffusion coefficients in a hot medium constituted of light mesons (pions, kaons and eta mesons). We treat the B-meson and B*-meson interaction with pseudo-Goldstone bosons in chiral perturbation theory at next-to-leading order within the constraints from heavy quark symmetry, and employ standard unitarization techniques of NLO amplitudes in order to account for dynamically generated resonances (leading to a more efficient heavy-flavor diffusion) and thus reach higher temperatures. We estimate individual meson contributions from the gas to the transport coefficients and perform a comparison with other findings in literature. We report a bottom relaxation length of about 80 fm at a temperature of 150 MeV and for typical momenta of 1 GeV, at which our approach is reliable. Compared to a charm relaxation length of 40 fm in the same conditions, we conclude that the B mesons provide a cleaner probe of the early stages of a heavy-ion collision.
|
hep-ph/0512250
|
Stefano Frixione
|
S. Frixione, E. Laenen, P. Motylinski, B.R. Webber
|
Single-top production in MC@NLO
|
31 pages Latex; 13 figures included.Minor modifications to the text
|
JHEP0603:092,2006
|
10.1088/1126-6708/2006/03/092
|
Cavendish-HEP-05/24, GEF-TH-12/2005, ITP-UU-05/57, NIKHEF/2005-026
|
hep-ph
| null |
We match next-to-leading order QCD results for single-top hadroproduction
with parton shower Monte Carlo simulations, according to the prescription of
the MC@NLO formalism. In this way, we achieve the first practical
implementation in MC@NLO of a process that has both initial- and final-state
collinear singularities. We show that no difficulties of principle arise from
this complication, and present selected results relevant to the Tevatron.
|
[
{
"created": "Tue, 20 Dec 2005 09:53:57 GMT",
"version": "v1"
},
{
"created": "Fri, 31 Mar 2006 09:03:21 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Frixione",
"S.",
""
],
[
"Laenen",
"E.",
""
],
[
"Motylinski",
"P.",
""
],
[
"Webber",
"B. R.",
""
]
] |
We match next-to-leading order QCD results for single-top hadroproduction with parton shower Monte Carlo simulations, according to the prescription of the MC@NLO formalism. In this way, we achieve the first practical implementation in MC@NLO of a process that has both initial- and final-state collinear singularities. We show that no difficulties of principle arise from this complication, and present selected results relevant to the Tevatron.
|
0810.3598
|
Chien-Yi Ma
|
George Wei-Shu Hou, Fei-Fan Lee and Chien-Yi Ma
|
Fourth Generation Leptons and Muon $g-2$
|
Poster write-up at ICHEP08, Philadelphia, USA, July 2008. 3 pages,
LaTeX, 1 eps figure
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the contributions to $g_\mu-2$ from fourth generation neutral and
charged leptons, $N$ and $E$, at the one-loop level. Diagramatically, there are
two types of contributions: boson-boson-$N$, and $E$-$E$-boson in the loop
diagram. In general, the effect from $N$ is suppressed by off-diagonal PMNS
matrix element $V_{N\mu}$, from the Standard Model to the Two-Higgs Doublet
Models. With contribution from $E$, we consider flavor changing neutral
couplings.
|
[
{
"created": "Mon, 20 Oct 2008 16:17:15 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Nov 2008 11:57:13 GMT",
"version": "v2"
}
] |
2008-11-04
|
[
[
"Hou",
"George Wei-Shu",
""
],
[
"Lee",
"Fei-Fan",
""
],
[
"Ma",
"Chien-Yi",
""
]
] |
We consider the contributions to $g_\mu-2$ from fourth generation neutral and charged leptons, $N$ and $E$, at the one-loop level. Diagramatically, there are two types of contributions: boson-boson-$N$, and $E$-$E$-boson in the loop diagram. In general, the effect from $N$ is suppressed by off-diagonal PMNS matrix element $V_{N\mu}$, from the Standard Model to the Two-Higgs Doublet Models. With contribution from $E$, we consider flavor changing neutral couplings.
|
1310.1436
|
Nikolay Achasov
|
N.N. Achasov and E.V.Rogozina
|
How learn the branching ratio X(3872)\to D^{*0}\bar D^0 + c.c
|
8 pages, 4 figures,the published variant
|
Pis'ma v ZhETF, 2014, vol. 100, iss. 4, pp. 252-255; JETP Letters,
2014, Vol. 100, No. 4, pp.227-231
| null | null |
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Enfant terrible of charmonium spectroscopy, the resonance $X(3872)$,
generated a stream of interpretations and ushered in a new exotic $XYZ$
spectroscopy. In th meantime, many (if not all) characteristics of $X(3872)$
are rather ambiguous. We construct spectra of decays of the resonance $X(3872)$
with good analytical and unitary properties which allows to define the
branching ratio of the $X(3872) \to D^{*0}\bar D^0 + c.c.$ decay studying only
one more decay, for example, the $X(3872)\to\pi^+\pi^- J/\psi(1S)$ decay. We
next define the range of values of the coupling constant of the $X(3872)$
resonance with the $D^{*0}\bar D^0$ system. Finally, we show that our spectra
are effective means of selection of models for the resonance $X(3872)$.
|
[
{
"created": "Sat, 5 Oct 2013 03:04:26 GMT",
"version": "v1"
},
{
"created": "Sat, 23 Nov 2013 11:22:35 GMT",
"version": "v2"
},
{
"created": "Thu, 30 Oct 2014 05:42:55 GMT",
"version": "v3"
}
] |
2014-10-31
|
[
[
"Achasov",
"N. N.",
""
],
[
"Rogozina",
"E. V.",
""
]
] |
Enfant terrible of charmonium spectroscopy, the resonance $X(3872)$, generated a stream of interpretations and ushered in a new exotic $XYZ$ spectroscopy. In th meantime, many (if not all) characteristics of $X(3872)$ are rather ambiguous. We construct spectra of decays of the resonance $X(3872)$ with good analytical and unitary properties which allows to define the branching ratio of the $X(3872) \to D^{*0}\bar D^0 + c.c.$ decay studying only one more decay, for example, the $X(3872)\to\pi^+\pi^- J/\psi(1S)$ decay. We next define the range of values of the coupling constant of the $X(3872)$ resonance with the $D^{*0}\bar D^0$ system. Finally, we show that our spectra are effective means of selection of models for the resonance $X(3872)$.
|
1606.08848
|
Georgios K. Karananas Mr.
|
Georgios K. Karananas, Javier Rubio
|
On the geometrical interpretation of scale-invariant models of inflation
|
14 pages, no figures
|
Phys. Lett. B, 761 (2016), pp. 223-228
|
10.1016/j.physletb.2016.08.037
| null |
hep-ph astro-ph.CO gr-qc hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the geometrical properties of scale-invariant two-field models of
inflation. In particular, we show that when the field-derivative space in the
Einstein frame is maximally symmetric during inflation, the inflationary
predictions can be universal and independent of the details of the theory.
|
[
{
"created": "Tue, 28 Jun 2016 20:00:01 GMT",
"version": "v1"
}
] |
2016-08-31
|
[
[
"Karananas",
"Georgios K.",
""
],
[
"Rubio",
"Javier",
""
]
] |
We study the geometrical properties of scale-invariant two-field models of inflation. In particular, we show that when the field-derivative space in the Einstein frame is maximally symmetric during inflation, the inflationary predictions can be universal and independent of the details of the theory.
|
hep-ph/0605035
|
Rouzbeh Allahverdi
|
Rouzbeh Allahverdi, Juan Garcia-Bellido, Kari Enqvist, Anupam Mazumdar
|
Gauge invariant MSSM inflaton
|
4 revtex pages, some references added, stabilization of moduli and
supergravity effects are discussed
|
Phys.Rev.Lett.97:191304,2006
|
10.1103/PhysRevLett.97.191304
|
NORDITA-2006-13, IFT-UAM/CSIC-06-18, HIP-2006-22/TH
|
hep-ph astro-ph gr-qc hep-th
| null |
We argue that all the necessary ingredients for successful inflation are
present in the flat directions of the Minimally Supersymmetric Standard Model.
We show that out of many gauge invariant combinations of squarks, sleptons and
Higgses, there are two directions, ${\bf LLe}$, and ${\bf udd}$, which are
promising candidates for the inflaton. The model predicts more than $10^3$
e-foldings with an inflationary scale of $H_{\rm inf}\sim {\cal O}(1-10)$ GeV,
provides a tilted spectrum with an amplitude of $\delta_H\sim 10^{-5}$ and a
negligible tensor perturbation. The temperature of the thermalized plasma could
be as low as $T_{rh}\sim {\cal O}(1-10)$~TeV. Parts of the inflaton potential
can be determined independently of cosmology by future particle physics
experiments.
|
[
{
"created": "Wed, 3 May 2006 16:17:43 GMT",
"version": "v1"
},
{
"created": "Mon, 15 May 2006 10:22:11 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Allahverdi",
"Rouzbeh",
""
],
[
"Garcia-Bellido",
"Juan",
""
],
[
"Enqvist",
"Kari",
""
],
[
"Mazumdar",
"Anupam",
""
]
] |
We argue that all the necessary ingredients for successful inflation are present in the flat directions of the Minimally Supersymmetric Standard Model. We show that out of many gauge invariant combinations of squarks, sleptons and Higgses, there are two directions, ${\bf LLe}$, and ${\bf udd}$, which are promising candidates for the inflaton. The model predicts more than $10^3$ e-foldings with an inflationary scale of $H_{\rm inf}\sim {\cal O}(1-10)$ GeV, provides a tilted spectrum with an amplitude of $\delta_H\sim 10^{-5}$ and a negligible tensor perturbation. The temperature of the thermalized plasma could be as low as $T_{rh}\sim {\cal O}(1-10)$~TeV. Parts of the inflaton potential can be determined independently of cosmology by future particle physics experiments.
|
1604.07838
|
Tathagata Ghosh
|
Bhaskar Dutta, Yu Gao, Tathagata Ghosh, Ilia Gogoladze, Tianjun Li,
Joel W. Walker
|
An SU(6) GUT Origin of the TeV-Scale Vector-like Particles Associated
with the 750 GeV Diphoton Resonance
|
19 pages, 4 tables, 2 figures; v2: effective theory calculation has
been replaced by full loop calculation, typos corrected, references added,
dijet bounds from recent ATLAS analysis (ATLAS-CONF-2016-030) has been
discussed
|
Phys. Rev. D 94, 036006 (2016)
|
10.1103/PhysRevD.94.036006
|
MI-TH-1614
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the $SU(6)$ GUT model as an explanation for the diphoton final
state excess, where the masses of all associated particles are linked with a
new symmetry breaking scale. In this model, the diphoton final states arise due
to loops involving three pairs of new vector-like particles having the same
quantum numbers as down-type quarks and lepton doublets. These new vector-like
fermions are embedded alongside the SM fermions into minimal anomaly-free
representations of the $SU(6)$ gauge symmetry. The $SU(6)$ symmetry is broken
to the Standard Model times $U(1)_X$ at the GUT scale, and masses for the
vector-like fermions arise at the TeV scale only after the residual $U(1)_X$
symmetry is broken. The vector-like fermions do not acquire masses via breaking
of the SM symmetry at the EW scale. The field which is responsible for the
newly observed resonance belongs to the $\bar{6}_H$ representation. The dark
matter arises from the SM singlet fermion residing in $\bar{6}$ and is of
Majorana type. We explicitly demonstrate gauge coupling unification in this
model, and also discuss the origin of neutrino masses. In addition to the
diphoton final states, we make distinctive predictions for other final states
which are likewise accessible to the ongoing LHC experimental effort.
|
[
{
"created": "Tue, 26 Apr 2016 20:05:40 GMT",
"version": "v1"
},
{
"created": "Sun, 10 Jul 2016 05:36:57 GMT",
"version": "v2"
}
] |
2016-08-31
|
[
[
"Dutta",
"Bhaskar",
""
],
[
"Gao",
"Yu",
""
],
[
"Ghosh",
"Tathagata",
""
],
[
"Gogoladze",
"Ilia",
""
],
[
"Li",
"Tianjun",
""
],
[
"Walker",
"Joel W.",
""
]
] |
We consider the $SU(6)$ GUT model as an explanation for the diphoton final state excess, where the masses of all associated particles are linked with a new symmetry breaking scale. In this model, the diphoton final states arise due to loops involving three pairs of new vector-like particles having the same quantum numbers as down-type quarks and lepton doublets. These new vector-like fermions are embedded alongside the SM fermions into minimal anomaly-free representations of the $SU(6)$ gauge symmetry. The $SU(6)$ symmetry is broken to the Standard Model times $U(1)_X$ at the GUT scale, and masses for the vector-like fermions arise at the TeV scale only after the residual $U(1)_X$ symmetry is broken. The vector-like fermions do not acquire masses via breaking of the SM symmetry at the EW scale. The field which is responsible for the newly observed resonance belongs to the $\bar{6}_H$ representation. The dark matter arises from the SM singlet fermion residing in $\bar{6}$ and is of Majorana type. We explicitly demonstrate gauge coupling unification in this model, and also discuss the origin of neutrino masses. In addition to the diphoton final states, we make distinctive predictions for other final states which are likewise accessible to the ongoing LHC experimental effort.
|
1107.5386
|
Massimo Blasone
|
Massimo Blasone
|
Physical flavor neutrino states
|
Presented at 5th International Workshop DICE2010: Space-Time-Matter -
Current Issues in Quantum Mechanics and Beyond
|
J. Phys.: Conf. Ser. 306 (2011) 012037
|
10.1088/1742-6596/306/1/012037
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The problem of representation for flavor states of mixed neutrinos is
discussed. By resorting to recent results, it is shown that a specific
representation exists in which a number of conceptual problems are resolved.
Phenomenological consequences of our analysis are explored.
|
[
{
"created": "Wed, 27 Jul 2011 05:28:31 GMT",
"version": "v1"
}
] |
2011-07-28
|
[
[
"Blasone",
"Massimo",
""
]
] |
The problem of representation for flavor states of mixed neutrinos is discussed. By resorting to recent results, it is shown that a specific representation exists in which a number of conceptual problems are resolved. Phenomenological consequences of our analysis are explored.
|
1611.09845
|
David Blaschke
|
D. Blaschke, A. Dubinin, L. Turko
|
Mott-hadron resonance gas and lattice QCD thermodynamics
|
4 pages, 4 figures, abstract and text updated, figure 4 replaced
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A unified equation of state for quark-hadron matter is presented in the
generalized Beth-Uhlenbeck form. It follows from a $\Phi-$derivable approach to
the thermodynamic potential where the ansatz for the $\Phi$ functional contains
all 2PI diagrams at two-loop order formed with quark cluster Green's functions
for quark, diquark, meson and baryon propagators. We present numerical results
using an effective model for the generic behaviour of hadron masses and phase
shifts at finite temperature which shares basic features with recent
developments within the PNJL model for correlations in quark matter. We obtain
the transition between a hadron resonance gas phase and the quark gluon plasma
where the Mott dissociation of hadrons is encoded in the hadronic phase shifts.
The resulting thermodynamics is in very good agreement with recent lattice QCD
simulations.
|
[
{
"created": "Tue, 29 Nov 2016 20:57:20 GMT",
"version": "v1"
},
{
"created": "Thu, 18 May 2017 16:22:37 GMT",
"version": "v2"
}
] |
2017-05-19
|
[
[
"Blaschke",
"D.",
""
],
[
"Dubinin",
"A.",
""
],
[
"Turko",
"L.",
""
]
] |
A unified equation of state for quark-hadron matter is presented in the generalized Beth-Uhlenbeck form. It follows from a $\Phi-$derivable approach to the thermodynamic potential where the ansatz for the $\Phi$ functional contains all 2PI diagrams at two-loop order formed with quark cluster Green's functions for quark, diquark, meson and baryon propagators. We present numerical results using an effective model for the generic behaviour of hadron masses and phase shifts at finite temperature which shares basic features with recent developments within the PNJL model for correlations in quark matter. We obtain the transition between a hadron resonance gas phase and the quark gluon plasma where the Mott dissociation of hadrons is encoded in the hadronic phase shifts. The resulting thermodynamics is in very good agreement with recent lattice QCD simulations.
|
2112.00223
|
Zhan Sun
|
Zhan Sun, Xuan Luo, and Ying-Zhao Jiang
|
Impact of $Z \to \eta_{c,b}+g+g$ on the inclusive $\eta_{c,b}$ meson
yield in $Z$-boson decay
|
17 pages, 5 figures, and 2 tables; accepted for publication in
Physical Review D
|
Phys. Rev. D 106, 034001 (2022)
|
10.1103/PhysRevD.106.034001
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In this paper, we carry out the next-to-leading-order QCD corrections to $Z
\to \eta_Q+g+g~(Q=c,b)$ (labeled as $gg$) through the color-singlet (CS) state
of $Q\bar{Q}[^1S_0^{[1]}]$, with the aim of assessing the impact of this
process on $Z$ bosons decaying into inclusive $\eta_Q$. We find that the QCD
corrections to the $gg$ process can notably enhance its leading-order results,
especially for the $\eta_c$ case, which would then greatly increase the
existing predictions of $\Gamma_{Z \to \eta_Q+X}$ given by the CS-dominant
process $Z \to \eta_{Q}[^1S_0^{[1]}]+Q+\bar{Q}$. Moreover, with these
significant QCD corrections, the $gg$ process would exert crucial influence on
the CS-predicted $\eta_Q$ energy distributions. In conclusion, in the CS
studies of $Z \to \eta_Q+X$, besides $Z \to \eta_{Q}[^1S_0^{[1]}]+Q+\bar{Q}$,
$Z \to \eta_Q[^1S_0^{[1]}]+g+g$ can provide phenomenologically indispensable
contributions as well.
|
[
{
"created": "Wed, 1 Dec 2021 01:54:24 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Aug 2022 01:27:28 GMT",
"version": "v2"
}
] |
2022-08-03
|
[
[
"Sun",
"Zhan",
""
],
[
"Luo",
"Xuan",
""
],
[
"Jiang",
"Ying-Zhao",
""
]
] |
In this paper, we carry out the next-to-leading-order QCD corrections to $Z \to \eta_Q+g+g~(Q=c,b)$ (labeled as $gg$) through the color-singlet (CS) state of $Q\bar{Q}[^1S_0^{[1]}]$, with the aim of assessing the impact of this process on $Z$ bosons decaying into inclusive $\eta_Q$. We find that the QCD corrections to the $gg$ process can notably enhance its leading-order results, especially for the $\eta_c$ case, which would then greatly increase the existing predictions of $\Gamma_{Z \to \eta_Q+X}$ given by the CS-dominant process $Z \to \eta_{Q}[^1S_0^{[1]}]+Q+\bar{Q}$. Moreover, with these significant QCD corrections, the $gg$ process would exert crucial influence on the CS-predicted $\eta_Q$ energy distributions. In conclusion, in the CS studies of $Z \to \eta_Q+X$, besides $Z \to \eta_{Q}[^1S_0^{[1]}]+Q+\bar{Q}$, $Z \to \eta_Q[^1S_0^{[1]}]+g+g$ can provide phenomenologically indispensable contributions as well.
|
1809.04602
|
Gregory Soyez
|
Davide Napoletano and Gregory Soyez
|
Computing $N$-subjettiness for boosted jets
|
30 pages, 12 figures
| null |
10.1007/JHEP12(2018)031
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Jet substructure tools have proven useful in a number of high-energy
particle-physics studies. A particular case is the discrimination, or tagging,
between a boosted jet originated from an electroweak boson (signal), and a
standard QCD parton (background). A common way to achieve this is to cut on a
measure of the radiation inside the jet, i.e. a jet shape. Over the last few
years, analytic calculations of jet substructure have allowed for a deeper
understanding of these tools and for the development of more efficient ones.
However, analytic calculations are often limited to the region where the jet
shape is small. In this paper we introduce a new approach in perturbative QCD
to compute jet shapes for a generic boosted jets, waiving the above limitation.
We focus on an example common in the substructure literature: the jet mass
distribution after a cut on the $N$-subjettiness $\tau_{21}$ ratio, extending
previous works to the region relevant for phenomenology. We compare our
analytic predictions to Monte Carlo simulations for both plain and
SoftDrop-groomed jets. We use our results to construct analytically a
decorrelated tagger.
|
[
{
"created": "Wed, 12 Sep 2018 18:00:01 GMT",
"version": "v1"
}
] |
2018-12-26
|
[
[
"Napoletano",
"Davide",
""
],
[
"Soyez",
"Gregory",
""
]
] |
Jet substructure tools have proven useful in a number of high-energy particle-physics studies. A particular case is the discrimination, or tagging, between a boosted jet originated from an electroweak boson (signal), and a standard QCD parton (background). A common way to achieve this is to cut on a measure of the radiation inside the jet, i.e. a jet shape. Over the last few years, analytic calculations of jet substructure have allowed for a deeper understanding of these tools and for the development of more efficient ones. However, analytic calculations are often limited to the region where the jet shape is small. In this paper we introduce a new approach in perturbative QCD to compute jet shapes for a generic boosted jets, waiving the above limitation. We focus on an example common in the substructure literature: the jet mass distribution after a cut on the $N$-subjettiness $\tau_{21}$ ratio, extending previous works to the region relevant for phenomenology. We compare our analytic predictions to Monte Carlo simulations for both plain and SoftDrop-groomed jets. We use our results to construct analytically a decorrelated tagger.
|
1207.4042
|
York Schroder
|
M. Nishimura (Tohoku U.), Y. Schroder (Bielefeld U.)
|
IBP methods at finite temperature
|
16 pages, 4 Axodraw figures
| null |
10.1007/JHEP09(2012)051
|
BI-TP 2012/28
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We demonstrate the applicability of integration-by-parts (IBP) identities in
finite-temperature field theory. As a concrete example, we perform 3-loop
computations for the thermodynamic pressure of QCD in general covariant gauges,
and confirm earlier Feynman-gauge results.
|
[
{
"created": "Tue, 17 Jul 2012 16:08:45 GMT",
"version": "v1"
}
] |
2015-06-05
|
[
[
"Nishimura",
"M.",
"",
"Tohoku U."
],
[
"Schroder",
"Y.",
"",
"Bielefeld U."
]
] |
We demonstrate the applicability of integration-by-parts (IBP) identities in finite-temperature field theory. As a concrete example, we perform 3-loop computations for the thermodynamic pressure of QCD in general covariant gauges, and confirm earlier Feynman-gauge results.
|
1604.06699
|
German F. R. Sborlini
|
German F. R. Sborlini, Felix Driencourt-Mangin, Roger Hernandez-Pinto,
German Rodrigo
|
Four-dimensional unsubtraction from the loop-tree duality
|
39 pages, 7 figures. Final version published in JHEP
|
JHEP 08 (2016) 160
|
10.1007/JHEP08(2016)160
|
IFIC/15-73
|
hep-ph hep-th math-ph math.MP
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a new algorithm to construct a purely four dimensional
representation of higher-order perturbative corrections to physical
cross-sections at next-to-leading order (NLO). The algorithm is based on the
loop-tree duality (LTD), and it is implemented by introducing a suitable
mapping between the external and loop momenta of the virtual scattering
amplitudes, and the external momenta of the real emission corrections. In this
way, the sum over degenerate infrared states is performed at integrand level
and the cancellation of infrared divergences occurs locally without introducing
subtraction counter-terms to deal with soft and final-state collinear
singularities. The dual representation of ultraviolet counter-terms is also
discussed in detail, in particular for self-energy contributions. The method is
first illustrated with the scalar three-point function, before proceeding with
the calculation of the physical cross-section for $\gamma^* \to q \bar{q}(g)$,
and its generalisation to multi-leg processes. The extension to
next-to-next-to-leading order (NNLO) is briefly commented.
|
[
{
"created": "Fri, 22 Apr 2016 15:07:34 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Sep 2016 15:18:24 GMT",
"version": "v2"
}
] |
2016-09-12
|
[
[
"Sborlini",
"German F. R.",
""
],
[
"Driencourt-Mangin",
"Felix",
""
],
[
"Hernandez-Pinto",
"Roger",
""
],
[
"Rodrigo",
"German",
""
]
] |
We present a new algorithm to construct a purely four dimensional representation of higher-order perturbative corrections to physical cross-sections at next-to-leading order (NLO). The algorithm is based on the loop-tree duality (LTD), and it is implemented by introducing a suitable mapping between the external and loop momenta of the virtual scattering amplitudes, and the external momenta of the real emission corrections. In this way, the sum over degenerate infrared states is performed at integrand level and the cancellation of infrared divergences occurs locally without introducing subtraction counter-terms to deal with soft and final-state collinear singularities. The dual representation of ultraviolet counter-terms is also discussed in detail, in particular for self-energy contributions. The method is first illustrated with the scalar three-point function, before proceeding with the calculation of the physical cross-section for $\gamma^* \to q \bar{q}(g)$, and its generalisation to multi-leg processes. The extension to next-to-next-to-leading order (NNLO) is briefly commented.
|
1610.08810
|
Thomas Flacke
|
Mihailo Backovi\'c, Thomas Flacke, Bithika Jain, Seung J. Lee
|
LHC vector resonance searches in the $t\bar{t} Z$ final state
|
37 pages, 6 figures, 9 tables. v2: typos corrected, Version published
in JHEP
|
JHEP 1703 (2017) 127
|
10.1007/JHEP03(2017)127
|
CTPU-16-30, KIAS - P16078
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
LHC searches for BSM resonances in $l^+ l^-, \, jj, \, t\bar{t}, \gamma
\gamma$ and $VV$ final states have so far not resulted in discovery of new
physics. Current results set lower limits on mass scales of new physics
resonances well into the $\mathcal{O}(1)$ TeV range, assuming that the new
resonance decays dominantly to a pair of Standard Model particles. While the SM
pair searches are a vital probe of possible new physics, it is important to
re-examine the scope of new physics scenarios probed with such final states.
Scenarios where new resonances decay dominantly to final states other than SM
pairs, even though well theoretically motivated, lie beyond the scope of SM
pair searches. In this paper we argue that LHC searches for (vector) resonances
beyond two particle final states would be useful complementary probes of new
physics scenarios. As an example, we consider a class of composite Higgs
models, and identify specific model parameter points where the color singlet,
electrically neutral vector resonance $\rho_0$ decays dominantly not to a pair
of SM particles, but to a fermionic top partner $T_{f1}$ and a top quark, with
$T_{f1} \rightarrow tZ$. We show that dominant decays of $\rho_0 \rightarrow
T_{f1} t$ in the context of Composite Higgs models are possible even when the
decay channel to a pair of $T_{f1}$ is kinematically open. Our analysis deals
with scenarios where both $m_\rho$ and $m_{T_{f1}}$ are of $\mathcal{O}(1)$
TeV, leading to highly boosted $t\bar{t}Z$ final state topologies. We show that
the particular composite Higgs scenario we consider is discoverable at the
LHC13 with as little as 30 fb$^{-1}$, while being allowed by other existing
experimental constraints.
|
[
{
"created": "Thu, 27 Oct 2016 14:44:00 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Apr 2017 09:33:16 GMT",
"version": "v2"
}
] |
2017-04-11
|
[
[
"Backović",
"Mihailo",
""
],
[
"Flacke",
"Thomas",
""
],
[
"Jain",
"Bithika",
""
],
[
"Lee",
"Seung J.",
""
]
] |
LHC searches for BSM resonances in $l^+ l^-, \, jj, \, t\bar{t}, \gamma \gamma$ and $VV$ final states have so far not resulted in discovery of new physics. Current results set lower limits on mass scales of new physics resonances well into the $\mathcal{O}(1)$ TeV range, assuming that the new resonance decays dominantly to a pair of Standard Model particles. While the SM pair searches are a vital probe of possible new physics, it is important to re-examine the scope of new physics scenarios probed with such final states. Scenarios where new resonances decay dominantly to final states other than SM pairs, even though well theoretically motivated, lie beyond the scope of SM pair searches. In this paper we argue that LHC searches for (vector) resonances beyond two particle final states would be useful complementary probes of new physics scenarios. As an example, we consider a class of composite Higgs models, and identify specific model parameter points where the color singlet, electrically neutral vector resonance $\rho_0$ decays dominantly not to a pair of SM particles, but to a fermionic top partner $T_{f1}$ and a top quark, with $T_{f1} \rightarrow tZ$. We show that dominant decays of $\rho_0 \rightarrow T_{f1} t$ in the context of Composite Higgs models are possible even when the decay channel to a pair of $T_{f1}$ is kinematically open. Our analysis deals with scenarios where both $m_\rho$ and $m_{T_{f1}}$ are of $\mathcal{O}(1)$ TeV, leading to highly boosted $t\bar{t}Z$ final state topologies. We show that the particular composite Higgs scenario we consider is discoverable at the LHC13 with as little as 30 fb$^{-1}$, while being allowed by other existing experimental constraints.
|
hep-ph/9711386
|
Chris Sachrajda
|
C.T.Sachrajda
|
Theoretical Aspects of Heavy Flavour Physics
|
Plenary lecture presented at the XVIII International Symposium on
Lepton-Photon Interactions, Hamburg, July 28th - August 1st 1997. To be
published in the Proceedings. 23 Pages - Latex file plus six *.eps figures
and 2 style files
| null | null |
SHEP 97/26
|
hep-ph
| null |
I review the status of theoretical aspects of B-decays. The principal
difficulty in interpreting the wealth of experimental data is the control of
non-perturbative QCD effects, and the talk is focused on attempts to control
these effects. Lattice results for the decay constants, B-$\bar B$ mixing and
semileptonic form-factors are summarized. The discrepancy of the theoretical
predictions and experimental measurements for the ratio of lifetimes
$\tau(\Lambda_b)/\tau(B_0)$ is discussed, as well as the status of the
semileptonic branching ratio of the B-meson. The difficulties in making
quantitative predictions for exclusive nonleptonic decays are stressed, and
some recent approaches to this problem are outlined.
|
[
{
"created": "Wed, 19 Nov 1997 14:41:02 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Sachrajda",
"C. T.",
""
]
] |
I review the status of theoretical aspects of B-decays. The principal difficulty in interpreting the wealth of experimental data is the control of non-perturbative QCD effects, and the talk is focused on attempts to control these effects. Lattice results for the decay constants, B-$\bar B$ mixing and semileptonic form-factors are summarized. The discrepancy of the theoretical predictions and experimental measurements for the ratio of lifetimes $\tau(\Lambda_b)/\tau(B_0)$ is discussed, as well as the status of the semileptonic branching ratio of the B-meson. The difficulties in making quantitative predictions for exclusive nonleptonic decays are stressed, and some recent approaches to this problem are outlined.
|
2307.15160
|
Monica Verducci
|
Monica Verducci, Natascia Vignaroli, Chiara Roda, Vincenzo Cavasinni
|
A study of the measurement of the $\tau$ lepton anomalous magnetic
moment in high energy lead-lead collisions at LHC
|
35 pages, 17 Figures Added minor changes on text and some references
| null | null | null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
The $\tau$ lepton anomalous magnetic moment: $a_\tau = \frac{g_{\tau}-2}{2}$
was measured, so far, with a precision of only several percents despite its
highly sensitivity to physics beyond the Standard Model such as compositeness
or Supersymmetry. A new study is presented to improve the sensitivity of the
$a_\tau $ measurement with photon-photon interactions from ultra-peripheral
lead-lead collisions at LHC. The theoretical approach used in this work is
based on an effective Lagrangian and on a photon flux implemented in the
MadGraph5 Monte Carlo simulation. Using a multivariate analysis to discriminate
the signal from the background processes, a sensitivity to the anomalous
magnetic moment $\rm{a_{\tau}}$ = 0 $_{+0.011} ^{-0.019}$ is obtained at 95\%
CL with a dataset corresponding to an integrated luminosity of 2 nb$^{-1}$ of
lead-lead collisions and assuming a conservative 10\% systematic uncertainty.
The present results are compared with previous calculations and available
measurements.
|
[
{
"created": "Thu, 27 Jul 2023 19:21:57 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Jan 2024 12:54:38 GMT",
"version": "v2"
}
] |
2024-01-23
|
[
[
"Verducci",
"Monica",
""
],
[
"Vignaroli",
"Natascia",
""
],
[
"Roda",
"Chiara",
""
],
[
"Cavasinni",
"Vincenzo",
""
]
] |
The $\tau$ lepton anomalous magnetic moment: $a_\tau = \frac{g_{\tau}-2}{2}$ was measured, so far, with a precision of only several percents despite its highly sensitivity to physics beyond the Standard Model such as compositeness or Supersymmetry. A new study is presented to improve the sensitivity of the $a_\tau $ measurement with photon-photon interactions from ultra-peripheral lead-lead collisions at LHC. The theoretical approach used in this work is based on an effective Lagrangian and on a photon flux implemented in the MadGraph5 Monte Carlo simulation. Using a multivariate analysis to discriminate the signal from the background processes, a sensitivity to the anomalous magnetic moment $\rm{a_{\tau}}$ = 0 $_{+0.011} ^{-0.019}$ is obtained at 95\% CL with a dataset corresponding to an integrated luminosity of 2 nb$^{-1}$ of lead-lead collisions and assuming a conservative 10\% systematic uncertainty. The present results are compared with previous calculations and available measurements.
|
1712.08122
|
Abhishek Iyer M
|
Giancarlo D'Ambrosio and Abhishek M. Iyer
|
Flavour issues in warped custodial models: $B$ anomalies and rare $K$
decays
|
V2: 30 pages, 11 Figures. Discussion on custodial RS model,
constraints from $\Delta F=2$ processes, collider bounds included.
Typographical errors corrected. Matches published version
| null |
10.1140/epjc/s10052-018-5915-9
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explore the flavour structure of custodial Randall-Sundrum (RS) models in
the context of the recently observed deviations in the decay of the $B$ mesons.
The anomalies in the $b\rightarrow s ll$ processes can be easily fit with
partially composite second generation leptons and third generation quarks. We
establish correlation with the parameter space consistent with the flavour
anomalies in the neutral current sector and obtain predictions for rare $K$-
decay which are likely to be another candle for NP with increased precision.
Two scenarios are considered: A) Right handed muon coupled more to NP that the
corresponding muon doublets (unorthodox case). Non-universality exists in the
right handed sector. B) Standard scenario with anomalies explained primarily by
non-universal couplings to the lepton doublets. The prediction for rare
$K$-decays are different according to the scenario, thereby serving as a useful
discriminatory tool. We note that, in this setup $R(D^*)$ is at best consistent
with the SM and increasing the compositeness of the $\tau_L$ generates a net
contribution becoming below the SM expectation. This makes this framework
fairly predictive and easily verifiable. Finally, we also comment on the
implications of flavour violation in the lepton sector and present an explicit
example with the implementation of bulk leptonic MFV which helps in alleviating
the constraints.
|
[
{
"created": "Thu, 21 Dec 2017 17:59:52 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Oct 2018 12:17:57 GMT",
"version": "v2"
}
] |
2018-10-22
|
[
[
"D'Ambrosio",
"Giancarlo",
""
],
[
"Iyer",
"Abhishek M.",
""
]
] |
We explore the flavour structure of custodial Randall-Sundrum (RS) models in the context of the recently observed deviations in the decay of the $B$ mesons. The anomalies in the $b\rightarrow s ll$ processes can be easily fit with partially composite second generation leptons and third generation quarks. We establish correlation with the parameter space consistent with the flavour anomalies in the neutral current sector and obtain predictions for rare $K$- decay which are likely to be another candle for NP with increased precision. Two scenarios are considered: A) Right handed muon coupled more to NP that the corresponding muon doublets (unorthodox case). Non-universality exists in the right handed sector. B) Standard scenario with anomalies explained primarily by non-universal couplings to the lepton doublets. The prediction for rare $K$-decays are different according to the scenario, thereby serving as a useful discriminatory tool. We note that, in this setup $R(D^*)$ is at best consistent with the SM and increasing the compositeness of the $\tau_L$ generates a net contribution becoming below the SM expectation. This makes this framework fairly predictive and easily verifiable. Finally, we also comment on the implications of flavour violation in the lepton sector and present an explicit example with the implementation of bulk leptonic MFV which helps in alleviating the constraints.
|
hep-ph/9601245
|
Peter Sieber
|
Joerg Schaldach, Peter Sieber, Dmitri Diakonov, and Klaus Goeke
|
Decay of high-density matter in the electroweak theory
|
13 pages, 4 Postscript figures
|
Phys.Lett. B378 (1996) 194-200
|
10.1016/0370-2693(96)00334-6
|
RUB-TPII-28/95
|
hep-ph
| null |
High-density fermion matter is meta-stable due to the anomalous
non-conservation of baryon and lepton numbers in the electroweak theory. The
meta-stable state decays by penetrating the sphaleron barrier separating
topologically different vacua. The decay happens locally, and results in an
annihilation of twelve fermions, accompanied by a production of gauge and Higgs
bosons. We find numerically local bounce solutions determining the decay rate,
which are classical paths in imaginary time, connecting two adjacent
topological sectors. We also follow the real-time evolution of the bosonic
fields after the tunneling and analyze the spectrum of the created bosons.
|
[
{
"created": "Thu, 11 Jan 1996 13:40:03 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Schaldach",
"Joerg",
""
],
[
"Sieber",
"Peter",
""
],
[
"Diakonov",
"Dmitri",
""
],
[
"Goeke",
"Klaus",
""
]
] |
High-density fermion matter is meta-stable due to the anomalous non-conservation of baryon and lepton numbers in the electroweak theory. The meta-stable state decays by penetrating the sphaleron barrier separating topologically different vacua. The decay happens locally, and results in an annihilation of twelve fermions, accompanied by a production of gauge and Higgs bosons. We find numerically local bounce solutions determining the decay rate, which are classical paths in imaginary time, connecting two adjacent topological sectors. We also follow the real-time evolution of the bosonic fields after the tunneling and analyze the spectrum of the created bosons.
|
hep-ph/9609338
|
Eric Braaten
|
Eric Braaten (Ohio State University)
|
Quarkonium Polarization in the NRQCD Factorization Framework
|
11 pages, LaTeX, invited talk presented at the Quarkonium Physics
Workshop, University of Illinois at Chicago, June 1996
|
Int.J.Mod.Phys.A12:3941-3950,1997
|
10.1142/S0217751X97002097
|
OHSTPY-HEP-T-96-025
|
hep-ph
| null |
The NRQCD factorization approach for calculating inclusive production of
heavy quarkonium gives unambiguous predictions for the polarization of
quarkonium states. The factorization formula for polarized states can be
obtained by using the threshold expansion method to calculate the
short-distance coefficients and then using symmetries of NRQD to reduce the
NRQCD matrix elements. A particularly dramatic prediction of the NRQCD
factorization framework is that prompt psi's and psi-primes's produced at the
Tevatron should be predominantly transversely polarized at large transverse
momentum.
|
[
{
"created": "Thu, 12 Sep 1996 20:45:55 GMT",
"version": "v1"
}
] |
2011-04-15
|
[
[
"Braaten",
"Eric",
"",
"Ohio State University"
]
] |
The NRQCD factorization approach for calculating inclusive production of heavy quarkonium gives unambiguous predictions for the polarization of quarkonium states. The factorization formula for polarized states can be obtained by using the threshold expansion method to calculate the short-distance coefficients and then using symmetries of NRQD to reduce the NRQCD matrix elements. A particularly dramatic prediction of the NRQCD factorization framework is that prompt psi's and psi-primes's produced at the Tevatron should be predominantly transversely polarized at large transverse momentum.
|
hep-ph/9903205
|
Cohen Iuliana
|
Gideon Alexander and Harry J. Lipkin
|
Isospin Invariance and Generalized Bose Statistics applied to Low Energy
$K^{+-}K^0$ and $\pi^{+-}\pi^0$ Space Symmetries
|
10 pages
|
Phys.Lett. B456 (1999) 270-276
|
10.1016/S0370-2693(99)00496-7
|
TAUP-2563-99, WIS-99/04/Feb.DPP
|
hep-ph
| null |
The use of isospin invariance and Generalized Bose statistics shows that the
Bose-Einstein correlation (BEC) of identical bosons seen in the $K^+K^+$ and
$\pi^+ \pi^+$ systems can be extended to apply to $K^+ K^o$ and $\pi^+ \pi^o$
pairs when they are produced from an initial state with isospin zero; e.g. by
the fragmentation of gluons or of a strange quark pair accompanied by gluons.
This might be useful in constructing more realistic model dependent Monte Carlo
programs for the investigation of the isospin structure of the particles
produced in a given kinematic region like the central region in high energy
hadronic collisions or quark-gluon plasma. Some of the consequences of this
extension are here applied to the hadronic $Z^o$ decays. In particular the
study addresses the question how much of the observed low $K^o_S K^o_S$ mass
enhancement is to be attributed to a BEC effect and how much to the
$f_0(980)\to K^o_S K^o_S$ decay. Finally we point out the restrictions imposed
by the extension on the choice of reference samples for the BEC studies.
|
[
{
"created": "Mon, 1 Mar 1999 09:11:25 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Alexander",
"Gideon",
""
],
[
"Lipkin",
"Harry J.",
""
]
] |
The use of isospin invariance and Generalized Bose statistics shows that the Bose-Einstein correlation (BEC) of identical bosons seen in the $K^+K^+$ and $\pi^+ \pi^+$ systems can be extended to apply to $K^+ K^o$ and $\pi^+ \pi^o$ pairs when they are produced from an initial state with isospin zero; e.g. by the fragmentation of gluons or of a strange quark pair accompanied by gluons. This might be useful in constructing more realistic model dependent Monte Carlo programs for the investigation of the isospin structure of the particles produced in a given kinematic region like the central region in high energy hadronic collisions or quark-gluon plasma. Some of the consequences of this extension are here applied to the hadronic $Z^o$ decays. In particular the study addresses the question how much of the observed low $K^o_S K^o_S$ mass enhancement is to be attributed to a BEC effect and how much to the $f_0(980)\to K^o_S K^o_S$ decay. Finally we point out the restrictions imposed by the extension on the choice of reference samples for the BEC studies.
|
1502.03827
|
Jorge Segovia
|
Jorge Segovia and David R. Entem and Francisco Fernandez
|
Charmed-strange Meson Spectrum: Old and New Problems
|
10 pages, 1 figure. arXiv admin note: text overlap with
arXiv:1205.2215
|
Phys. Rev. D 91, 094020 (2015)
|
10.1103/PhysRevD.91.094020
| null |
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The LHCb Collaboration has recently reported the observation for the first
time of a spin-$3$ resonance in the heavy quark sector. They have shown that
the $\bar{D}^{0}K^{-}$ structure seen in the $B_{s}^{0}\to
\bar{D}^{0}K^{-}\pi^{+}$ reaction and with invariant mass $2.86\,{\rm GeV}$ is
an admixture of a spin-$1$ and a spin-$3$ resonances. Motivated by the good
agreement between our theoretical predictions some time ago and the properties
extracted from the experiment of the $D_{s1}^{\ast}(2860)$ and
$D_{s3}^{\ast}(2860)$ states, we perform an extension of the study of the
strong decay properties of the $D_{sJ}^{\ast}(2860)$ and present the same
analysis for the $D_{s1}^{\ast}(2700)$ and $D_{sJ}(3040)$ mesons. This provides
a unified and simultaneous description of the three higher excited
charmed-strange resonances observed until now. For completeness, we present
theoretical results for masses and strong decays of the low-lying
charmed-strange mesons and those experimental missing states which belong to
the spin-multiplets of the discovered $D_{s1}^{\ast}(2700)$,
$D_{sJ}^{\ast}(2860)$ and $D_{sJ}(3040)$ resonances. The theoretical framework
used is a constituent quark model which successfully describes hadron
phenomenology from light to heavy quark sectors.
|
[
{
"created": "Thu, 12 Feb 2015 21:00:20 GMT",
"version": "v1"
}
] |
2015-05-20
|
[
[
"Segovia",
"Jorge",
""
],
[
"Entem",
"David R.",
""
],
[
"Fernandez",
"Francisco",
""
]
] |
The LHCb Collaboration has recently reported the observation for the first time of a spin-$3$ resonance in the heavy quark sector. They have shown that the $\bar{D}^{0}K^{-}$ structure seen in the $B_{s}^{0}\to \bar{D}^{0}K^{-}\pi^{+}$ reaction and with invariant mass $2.86\,{\rm GeV}$ is an admixture of a spin-$1$ and a spin-$3$ resonances. Motivated by the good agreement between our theoretical predictions some time ago and the properties extracted from the experiment of the $D_{s1}^{\ast}(2860)$ and $D_{s3}^{\ast}(2860)$ states, we perform an extension of the study of the strong decay properties of the $D_{sJ}^{\ast}(2860)$ and present the same analysis for the $D_{s1}^{\ast}(2700)$ and $D_{sJ}(3040)$ mesons. This provides a unified and simultaneous description of the three higher excited charmed-strange resonances observed until now. For completeness, we present theoretical results for masses and strong decays of the low-lying charmed-strange mesons and those experimental missing states which belong to the spin-multiplets of the discovered $D_{s1}^{\ast}(2700)$, $D_{sJ}^{\ast}(2860)$ and $D_{sJ}(3040)$ resonances. The theoretical framework used is a constituent quark model which successfully describes hadron phenomenology from light to heavy quark sectors.
|
hep-ph/0405184
|
Nestor Armesto
|
N. Armesto, C. A. Salgado and U. A. Wiedemann
|
Gluon Radiation off Massive Quarks in a QCD Medium
|
4 pages, uses enclosed moriond.sty, 3 eps figures included using
epsfig; presented by N. Armesto at the XXXIXth Rencontres de Moriond: QCD and
High Energy Hadronic Interactions, La Thuile, March 28th-April 4th 2004, to
appear in the proceedings
| null | null |
CERN-PH-TH/2004-093
|
hep-ph
| null |
Medium-induced gluon radiation from massless and massive quarks is treated in
the same formalism. The dead cone which regulates gluon radiation from massive
quarks in the vacuum at small angles, is filled in the medium but constitutes a
small fraction of the available phase space. Our study indicates that the
energy loss for charmed hadrons at RHIC should be smaller than for light
hadrons, but still sizable.
|
[
{
"created": "Wed, 19 May 2004 12:07:05 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Armesto",
"N.",
""
],
[
"Salgado",
"C. A.",
""
],
[
"Wiedemann",
"U. A.",
""
]
] |
Medium-induced gluon radiation from massless and massive quarks is treated in the same formalism. The dead cone which regulates gluon radiation from massive quarks in the vacuum at small angles, is filled in the medium but constitutes a small fraction of the available phase space. Our study indicates that the energy loss for charmed hadrons at RHIC should be smaller than for light hadrons, but still sizable.
|
hep-ph/0208250
|
Gregory W. Carter
|
G.W. Carter
|
Axial Vector Current and Coupling of the Quark in the Instanton Model
|
8 pages Revtex4, 3 PostScript figures, sign error corrected (results
unchanged)
|
Phys.Rev. D67 (2003) 014008
|
10.1103/PhysRevD.67.014008
|
NT@UW-02-027
|
hep-ph nucl-th
| null |
We compute the axial vector current, form factor, and coupling for quarks in
the instanton liquid model with two light flavors. Non-local current
corrections are derived, as required by the effective 't Hooft interaction. We
obtain a pion-mediated axial form factor and an axial coupling which, when
simply applied in the non-relativistic limit for constituent quarks, matches
the experimental value to within a few percent, both in and out of the chiral
limit.
|
[
{
"created": "Tue, 27 Aug 2002 16:54:28 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Aug 2002 17:56:01 GMT",
"version": "v2"
},
{
"created": "Wed, 4 Sep 2002 19:09:28 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Carter",
"G. W.",
""
]
] |
We compute the axial vector current, form factor, and coupling for quarks in the instanton liquid model with two light flavors. Non-local current corrections are derived, as required by the effective 't Hooft interaction. We obtain a pion-mediated axial form factor and an axial coupling which, when simply applied in the non-relativistic limit for constituent quarks, matches the experimental value to within a few percent, both in and out of the chiral limit.
|
1709.05080
|
Yueling Yang
|
Junfeng Sun, Yueling Yang, Jie Gao, Qin Chang, Jinshu Huang, Gongru Lu
|
$J/{\psi}$ ${\to}$ $D_{s,d}{\pi}$, $D_{s,d}K$ decays with perturbative
QCD approach
|
17 pages, 2 figures, revtex
|
Phys Rev D 94, 034029 (2016)
|
10.1103/PhysRevD.94.034029
| null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
Besides the conventional strong and electromagnetic decay modes, the
$J/{\psi}$ particle can also decay via the weak interaction in the standard
model. In this paper, nonleptonic $J/{\psi}$ ${\to}$ $D_{s,d}{\pi}$, $D_{s,d}K$
weak decays, corresponding to the externally emitted virtual $W$ boson process,
are investigated with the perturbative QCD approach. It is found that branching
ratio for the Cabibbo-favored $J/{\psi}$ ${\to}$ $D_{s}{\pi}$ decay can reach
up to ${\cal O}(10^{-10})$, which might be potentially measurable at the future
high-luminosity experiments.
|
[
{
"created": "Fri, 15 Sep 2017 07:21:44 GMT",
"version": "v1"
}
] |
2017-09-19
|
[
[
"Sun",
"Junfeng",
""
],
[
"Yang",
"Yueling",
""
],
[
"Gao",
"Jie",
""
],
[
"Chang",
"Qin",
""
],
[
"Huang",
"Jinshu",
""
],
[
"Lu",
"Gongru",
""
]
] |
Besides the conventional strong and electromagnetic decay modes, the $J/{\psi}$ particle can also decay via the weak interaction in the standard model. In this paper, nonleptonic $J/{\psi}$ ${\to}$ $D_{s,d}{\pi}$, $D_{s,d}K$ weak decays, corresponding to the externally emitted virtual $W$ boson process, are investigated with the perturbative QCD approach. It is found that branching ratio for the Cabibbo-favored $J/{\psi}$ ${\to}$ $D_{s}{\pi}$ decay can reach up to ${\cal O}(10^{-10})$, which might be potentially measurable at the future high-luminosity experiments.
|
hep-ph/0504211
|
Nidal Chamoun
|
N. Chamoun (1) and S. Khalil (2,3)((1)HIAST, Damascus, Syria,(2)Ain
Shams Univ., Cairo, Egypt,(3)GUC, Cairo, Egypt)
|
Fermion Masses and Mixing in Four and More Dimensions
|
a review based on seminars presented by S.K. in different places, 34
pages, latex
|
Int.J.Mod.Phys. A21 (2006) 6267-6302
|
10.1142/S0217751X06033131
| null |
hep-ph
| null |
We give an overview of recent progress in the study of fermion mass and
flavor mixing phenomena. Mass matrix ansatze are considered within the SM and
SUSY GUTs where some predictive frameworks based on SU(5) and SO(10) are
reviewed. We describe a variety of schemes to construct quark mass matrices in
extra dimensions focusing on four major classes: models with the SM residing on
3-brane, models with universal extra dimensions, models with split fermions and
models with warped extra dimensions. We outline how realistic patterns of quark
mass matrices could be derived from orbifold models in heterotic superstring
theory. Finally, we address the fermion mass problem in intersecting D-branes
scenarios, and present models with D6-branes able to give a good quantitatively
description of quark masses and mixing. The role of flavor/CP violation problem
as a probe of new physics is emphasized.
|
[
{
"created": "Sat, 23 Apr 2005 07:58:12 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Chamoun",
"N.",
""
],
[
"Khalil",
"S.",
""
]
] |
We give an overview of recent progress in the study of fermion mass and flavor mixing phenomena. Mass matrix ansatze are considered within the SM and SUSY GUTs where some predictive frameworks based on SU(5) and SO(10) are reviewed. We describe a variety of schemes to construct quark mass matrices in extra dimensions focusing on four major classes: models with the SM residing on 3-brane, models with universal extra dimensions, models with split fermions and models with warped extra dimensions. We outline how realistic patterns of quark mass matrices could be derived from orbifold models in heterotic superstring theory. Finally, we address the fermion mass problem in intersecting D-branes scenarios, and present models with D6-branes able to give a good quantitatively description of quark masses and mixing. The role of flavor/CP violation problem as a probe of new physics is emphasized.
|
2104.01861
|
Valentin V. Khoze
|
V.A. Khoze, V.V. Khoze, D.L. Milne and M.G. Ryskin
|
Hunting for QCD Instantons at the LHC in Events with Large Rapidity Gaps
|
26 pages, 5 figures. v2: updated cuts, improved signal to background
ratio
|
Phys. Rev. D 104, 054013 (2021)
|
10.1103/PhysRevD.104.054013
|
IPPP/20/93
|
hep-ph hep-ex hep-th
|
http://creativecommons.org/licenses/by/4.0/
|
We outline a strategy of how to search for QCD instantons of invariant mass
20 -- 60 GeV in diffractive events in low luminosity runs at the LHC. We show
that by imposing appropriate selection criteria on the final states, one can
select the kinematic regime where the instanton signal exceeds the background
by a factor of at least 8. In spite of the relatively strong cuts that we
impose on the total transverse energy and the number of charged tracks, $\sum_i
E_{T,i}>15$ GeV, $N_{\rm ch}>20$ measured within the $0<\eta<2$ interval and
excluding events with high $p_{T}$ particles, the expected cross-section is
sufficiently large to study the instanton production in the events with Large
Rapidity Gaps at low luminosities, thus avoiding problems with pile-up. The
paper also includes an updated computation of instanton cross-sections and
other parameters relevant for the ongoing studies.
|
[
{
"created": "Mon, 5 Apr 2021 11:47:40 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Apr 2021 17:29:03 GMT",
"version": "v2"
}
] |
2021-09-22
|
[
[
"Khoze",
"V. A.",
""
],
[
"Khoze",
"V. V.",
""
],
[
"Milne",
"D. L.",
""
],
[
"Ryskin",
"M. G.",
""
]
] |
We outline a strategy of how to search for QCD instantons of invariant mass 20 -- 60 GeV in diffractive events in low luminosity runs at the LHC. We show that by imposing appropriate selection criteria on the final states, one can select the kinematic regime where the instanton signal exceeds the background by a factor of at least 8. In spite of the relatively strong cuts that we impose on the total transverse energy and the number of charged tracks, $\sum_i E_{T,i}>15$ GeV, $N_{\rm ch}>20$ measured within the $0<\eta<2$ interval and excluding events with high $p_{T}$ particles, the expected cross-section is sufficiently large to study the instanton production in the events with Large Rapidity Gaps at low luminosities, thus avoiding problems with pile-up. The paper also includes an updated computation of instanton cross-sections and other parameters relevant for the ongoing studies.
|
0909.3410
|
Alexander Manashov
|
V.M. Braun, A.N. Manashov, B. Pirnay
|
Scale dependence of twist-three contributions to single spin asymmetries
|
14pages, 4 figures; Eq.(58) is corrected
|
Phys.Rev.D80:114002,2009
|
10.1103/PhysRevD.80.114002
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We reexamine the scale dependence of twist-three correlation functions
relevant for the single transverse spin asymmetry in the framework of collinear
factorization. Evolution equations are derived for both the flavor-nonsinglet
and flavor--singlet distributions and arbitrary parton momenta. Our results do
not agree with the recent calculations of the evolution in the limit of
vanishing gluon momentum. Possible sources for this discrepancy are identified.
|
[
{
"created": "Fri, 18 Sep 2009 11:14:35 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Dec 2009 14:20:04 GMT",
"version": "v2"
},
{
"created": "Tue, 4 Dec 2012 15:29:17 GMT",
"version": "v3"
}
] |
2012-12-05
|
[
[
"Braun",
"V. M.",
""
],
[
"Manashov",
"A. N.",
""
],
[
"Pirnay",
"B.",
""
]
] |
We reexamine the scale dependence of twist-three correlation functions relevant for the single transverse spin asymmetry in the framework of collinear factorization. Evolution equations are derived for both the flavor-nonsinglet and flavor--singlet distributions and arbitrary parton momenta. Our results do not agree with the recent calculations of the evolution in the limit of vanishing gluon momentum. Possible sources for this discrepancy are identified.
|
hep-ph/9607308
| null |
H. Garc\'ia-Compe\'an, A. P\'erez-Lorenzana and A. Zepeda
|
Topological Defects in $[SU(6)]^3 \times Z_3$
|
Replaced version includes minor corrections along the paper, abstract
updated. 24 pages, Latex file, uses epsf style, two PostScript figures
included
|
Int.J.Mod.Phys.A14:1859-1876,1999
|
10.1142/S0217751X99000944
|
CINVESTAV-FIS 05/96
|
hep-ph astro-ph hep-th
| null |
We study topological defects arising in the Grand Unification Model
$SU(6)_L\otimes SU(6)_c \otimes SU(6)_R \times Z_3$. We show that the model
does not contain domain walls, while it produces massive magnetic monopoles and
it may, depending on the symmetry breaking chain, give rise to the formation of
strings. We also discuss their possible relation$ the origin of the highest
energy cosmic rays detected.
|
[
{
"created": "Mon, 15 Jul 1996 05:45:01 GMT",
"version": "v1"
},
{
"created": "Thu, 3 Oct 1996 15:32:06 GMT",
"version": "v2"
},
{
"created": "Fri, 22 Aug 1997 15:56:44 GMT",
"version": "v3"
},
{
"created": "Tue, 14 Jul 1998 18:38:00 GMT",
"version": "v4"
}
] |
2016-08-15
|
[
[
"García-Compeán",
"H.",
""
],
[
"Pérez-Lorenzana",
"A.",
""
],
[
"Zepeda",
"A.",
""
]
] |
We study topological defects arising in the Grand Unification Model $SU(6)_L\otimes SU(6)_c \otimes SU(6)_R \times Z_3$. We show that the model does not contain domain walls, while it produces massive magnetic monopoles and it may, depending on the symmetry breaking chain, give rise to the formation of strings. We also discuss their possible relation$ the origin of the highest energy cosmic rays detected.
|
hep-ph/0401001
|
Ramond
|
P. Ramond
|
Neutrinos: Windows to Planck Physics
|
COntribution to Quantum Theory and Symmetries COnference, Univ of
Cincinatti, October 2003; Latex, 11 pages
| null |
10.1142/9789812702340_0004
| null |
hep-ph
| null |
After recalling some elegant contributions of the late Freydoon Mansouri, we
turn to neutrino physics and use a {\it modicum} of grand unification to relate
quark and lepton mixing matrices. We advocate an expansion for the MNS matrix,
{\it \`a la} Wolfenstein, and argue that in a wide class of models,
$\theta_{13}$ is a Cabibbo mixing effect. Also the large neutrino mixing angles
reflect the mass patterns of the right-handed neutrinos near the Planck scale,
and provide evidence for family structure at that scale.
|
[
{
"created": "Wed, 31 Dec 2003 21:33:22 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Ramond",
"P.",
""
]
] |
After recalling some elegant contributions of the late Freydoon Mansouri, we turn to neutrino physics and use a {\it modicum} of grand unification to relate quark and lepton mixing matrices. We advocate an expansion for the MNS matrix, {\it \`a la} Wolfenstein, and argue that in a wide class of models, $\theta_{13}$ is a Cabibbo mixing effect. Also the large neutrino mixing angles reflect the mass patterns of the right-handed neutrinos near the Planck scale, and provide evidence for family structure at that scale.
|
hep-ph/9803481
|
Hitoshi Murayama
|
Andre de Gouvea, Alexander Friedland, and Hitoshi Murayama (UC
Berkeley, LBNL)
|
Less Minimal Supersymmetric Standard Model
|
11 pages, 1 figure, uses psfig
|
Phys.Rev.D59:095008,1999
|
10.1103/PhysRevD.59.095008
|
LBNL-41631, UCB-PTH-98/17
|
hep-ph
| null |
Most of the phenomenological studies of supersymmetry have been carried out
using the so-called minimal supergravity scenario, where one assumes a
universal scalar mass, gaugino mass, and trilinear coupling at M_{GUT}. Even
though this is a useful simplifying assumption for phenomenological analyses,
it is rather too restrictive to accommodate a large variety of phenomenological
possibilities. It predicts, among other things, that the lightest
supersymmetric particle (LSP) is an almost pure B-ino, and that the
mu-parameter is larger than the masses of the SU(2)_{L} and U(1)_{Y} gauginos.
We extend the minimal supergravity framework by introducing one extra
parameter: the Fayet--Iliopoulos D-term for the hypercharge U(1), D_Y. Allowing
for this extra parameter, we find a much more diverse phenomenology, where the
LSP is \tilde{\nu}_{\tau}, \tilde{\tau} or a neutralino with a large higgsino
content. We discuss the relevance of the different possibilities to collider
signatures. The same type of extension can be done to models with the gauge
mediation of supersymmetry breaking. We argue that it is not wise to impose
cosmological constraints on the parameter space.
|
[
{
"created": "Sat, 28 Mar 1998 00:29:04 GMT",
"version": "v1"
}
] |
2009-09-29
|
[
[
"de Gouvea",
"Andre",
"",
"UC\n Berkeley, LBNL"
],
[
"Friedland",
"Alexander",
"",
"UC\n Berkeley, LBNL"
],
[
"Murayama",
"Hitoshi",
"",
"UC\n Berkeley, LBNL"
]
] |
Most of the phenomenological studies of supersymmetry have been carried out using the so-called minimal supergravity scenario, where one assumes a universal scalar mass, gaugino mass, and trilinear coupling at M_{GUT}. Even though this is a useful simplifying assumption for phenomenological analyses, it is rather too restrictive to accommodate a large variety of phenomenological possibilities. It predicts, among other things, that the lightest supersymmetric particle (LSP) is an almost pure B-ino, and that the mu-parameter is larger than the masses of the SU(2)_{L} and U(1)_{Y} gauginos. We extend the minimal supergravity framework by introducing one extra parameter: the Fayet--Iliopoulos D-term for the hypercharge U(1), D_Y. Allowing for this extra parameter, we find a much more diverse phenomenology, where the LSP is \tilde{\nu}_{\tau}, \tilde{\tau} or a neutralino with a large higgsino content. We discuss the relevance of the different possibilities to collider signatures. The same type of extension can be done to models with the gauge mediation of supersymmetry breaking. We argue that it is not wise to impose cosmological constraints on the parameter space.
|
hep-ph/9307310
| null |
Benjamin Grinstein, Yosef Nir and Joao M. Soares
|
Constraints on Extended Technicolor Models from B -> mu+ mu- X
|
7 pages and 1 figure (.ps file included), SSCL-Preprint-482,
WIS-93/67/July-PH, CMU-HEP93-10
|
Phys.Rev. D48 (1993) 3960-3962
|
10.1103/PhysRevD.48.R3960
| null |
hep-ph
| null |
A recent study by Randall and Sundrum shows that models of Extended
Technicolor (ETC) have interesting implications on rare B decays. We extend
their study to the decay B -> mu+ mu- X. ETC models with a GIM mechanism
predict a decay rate that is a factor of order 30 above the Standard Model,
violating the experimental upper bound by a factor of 2-4. ``Traditional" ETC
models predict a decay rate that is a factor of order 4 above the Standard
Model, and will be probed when an improvement in the sensitivity of experiments
by a factor of order 2-4 is achieved.
|
[
{
"created": "Tue, 20 Jul 1993 20:54:00 GMT",
"version": "v1"
}
] |
2009-10-22
|
[
[
"Grinstein",
"Benjamin",
""
],
[
"Nir",
"Yosef",
""
],
[
"Soares",
"Joao M.",
""
]
] |
A recent study by Randall and Sundrum shows that models of Extended Technicolor (ETC) have interesting implications on rare B decays. We extend their study to the decay B -> mu+ mu- X. ETC models with a GIM mechanism predict a decay rate that is a factor of order 30 above the Standard Model, violating the experimental upper bound by a factor of 2-4. ``Traditional" ETC models predict a decay rate that is a factor of order 4 above the Standard Model, and will be probed when an improvement in the sensitivity of experiments by a factor of order 2-4 is achieved.
|
0710.4287
|
Victor Goncalves
|
V. P. Goncalves, M. V. T. Machado
|
Diffractive photoproduction of Z^0 bosons in coherent interactions at
CERN-LHC
|
6 pages, 2 figures, 1 table; The erroneus additional factor of $2\pi$
in the normalization of the cross sections is removed. Figures and table are
updated
|
Eur.Phys.J.C56:33-38,2008; Erratum-ibid.C61:351,2009
|
10.1140/epjc/s10052-009-1009-z 10.1140/epjc/s10052-008-0633-3
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The exclusive $Z^0$ photoproduction at high energies in $\gamma p (A)$, $p p$
and $AA$ collisions is investigate within the color dipole formalism. We
generalize the description of the deeply virtual compton scattering (DVCS)
process, which describe quite well the HERA data, for the production of $Z^0$
bosons and estimate the total cross section for the exclusive process $\gamma^*
h\to Z^0 h$ ($h=p,A$) for different energies, photon virtualities and atomic
numbers. As hadrons at collider energies are a source of Weizs\"{a}cker -
Williams photons, we consider electromagnetic interactions in hadron-hadron
collisions at Tevatron and LHC energies and estimate the rapidity distribution
and total cross section for $Z^0$ production in the $h h\to h Z^0 h$ process.
This is the first estimation for such a process in literature. It can allow us
to study, for instance, the physics of hadronic $Z^0$ decays in a clean
environment characterized by two rapidity gaps. Our results indicate that the
experimental analyzes of this process could be feasible in $pp$ but the physics
scenario for $AA$ collisions is not promising.
|
[
{
"created": "Tue, 23 Oct 2007 16:01:52 GMT",
"version": "v1"
},
{
"created": "Thu, 25 Oct 2007 20:07:48 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Nov 2007 13:49:21 GMT",
"version": "v3"
},
{
"created": "Tue, 6 May 2008 19:57:23 GMT",
"version": "v4"
},
{
"created": "Thu, 26 Feb 2009 23:24:01 GMT",
"version": "v5"
}
] |
2014-11-18
|
[
[
"Goncalves",
"V. P.",
""
],
[
"Machado",
"M. V. T.",
""
]
] |
The exclusive $Z^0$ photoproduction at high energies in $\gamma p (A)$, $p p$ and $AA$ collisions is investigate within the color dipole formalism. We generalize the description of the deeply virtual compton scattering (DVCS) process, which describe quite well the HERA data, for the production of $Z^0$ bosons and estimate the total cross section for the exclusive process $\gamma^* h\to Z^0 h$ ($h=p,A$) for different energies, photon virtualities and atomic numbers. As hadrons at collider energies are a source of Weizs\"{a}cker - Williams photons, we consider electromagnetic interactions in hadron-hadron collisions at Tevatron and LHC energies and estimate the rapidity distribution and total cross section for $Z^0$ production in the $h h\to h Z^0 h$ process. This is the first estimation for such a process in literature. It can allow us to study, for instance, the physics of hadronic $Z^0$ decays in a clean environment characterized by two rapidity gaps. Our results indicate that the experimental analyzes of this process could be feasible in $pp$ but the physics scenario for $AA$ collisions is not promising.
|
1404.2438
|
Stefan Kofler
|
Alexander Goritschnig, Stefan Kofler, Wolfgang Schweiger
|
Hard exclusive photoproduction of charmed mesons
|
proceedings of Photon 2013, May 20-24 2013, Paris, France
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
{We investigate the photoproduction process $ p \gamma \rightarrow
\Lambda_{c}^{+} \overline{D^{0}}$ within the handbag approach, which we assume
to be the dominant mechanism at energies well above the production threshold
and in the forward scattering hemisphere.
|
[
{
"created": "Wed, 9 Apr 2014 11:16:00 GMT",
"version": "v1"
}
] |
2014-04-10
|
[
[
"Goritschnig",
"Alexander",
""
],
[
"Kofler",
"Stefan",
""
],
[
"Schweiger",
"Wolfgang",
""
]
] |
{We investigate the photoproduction process $ p \gamma \rightarrow \Lambda_{c}^{+} \overline{D^{0}}$ within the handbag approach, which we assume to be the dominant mechanism at energies well above the production threshold and in the forward scattering hemisphere.
|
2402.16697
|
Yue Tan
|
Yue Tan, Xuejie Liu, Xiaoyun Chen, Yuheng Wu, Hongxia Huang, and
Jialun Ping
|
Equivalence among color singlet, color octet and diquark structure in a
chiral quark model
| null | null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Since the quark model was put forward, theoretical researchers have always
attached great importance to the study of hidden color channels (including
color octets and diquark structure). Because of the influence of color Van der
waals forces, the hidden color channel itself has strong attraction, which
provides a dynamic mechanism for the formation of resonance state or bound
state. In this paper, taking the $T_{cc}$ system as an example, under the
framework of multi-Gaussian expansion method, a set of relatively complete
color singlets (that is, the ground state of the color singlet plus its
corresponding higher-order component) is used to replace the contribution of
the color octet. Similarly, we endeavor to replace the diquark structure with a
relatively complete set of molecular states, encompassing both the ground state
and excited states. Our results demonstrate that the color octet structure can
be effectively replaced by a set of relatively complete color singlet bases,
while the diquark structure cannot be entirely substituted by an equivalently
comprehensive set of molecular state bases.
|
[
{
"created": "Mon, 26 Feb 2024 16:11:05 GMT",
"version": "v1"
}
] |
2024-02-27
|
[
[
"Tan",
"Yue",
""
],
[
"Liu",
"Xuejie",
""
],
[
"Chen",
"Xiaoyun",
""
],
[
"Wu",
"Yuheng",
""
],
[
"Huang",
"Hongxia",
""
],
[
"Ping",
"Jialun",
""
]
] |
Since the quark model was put forward, theoretical researchers have always attached great importance to the study of hidden color channels (including color octets and diquark structure). Because of the influence of color Van der waals forces, the hidden color channel itself has strong attraction, which provides a dynamic mechanism for the formation of resonance state or bound state. In this paper, taking the $T_{cc}$ system as an example, under the framework of multi-Gaussian expansion method, a set of relatively complete color singlets (that is, the ground state of the color singlet plus its corresponding higher-order component) is used to replace the contribution of the color octet. Similarly, we endeavor to replace the diquark structure with a relatively complete set of molecular states, encompassing both the ground state and excited states. Our results demonstrate that the color octet structure can be effectively replaced by a set of relatively complete color singlet bases, while the diquark structure cannot be entirely substituted by an equivalently comprehensive set of molecular state bases.
|
hep-ph/9609417
|
Jorge Portoles
|
M.R. Pennington (Centre for Particle Theory, University of Durham, UK)
and J. Portoles (INFN, Sezione di Napoli, I)
|
Standard vs. Generalized Chiral Perturbation Theory : the Chell-Olsson
test
|
23 pages, plain LaTeX file, 1 figure included as several PS files,
uses epsf.sty, submitted to Phys. Rev. D
|
Phys.Rev. D55 (1997) 3082-3091
|
10.1103/PhysRevD.55.3082
|
DTP-95/84,INFNNA-IV-96/39,DSFNA-IV-96/39
|
hep-ph
| null |
A way of testing the $\pi \pi$ predictions of Chiral Perturbation Theory
against experimental data is to use dispersion relations to continue
experimental information into the subthreshold region where the theory should
unambiguously apply. Chell and Olsson have proposed a test of the subthreshold
behaviour of chiral expansions which highlights potential differences between
the Standard and the Generalized forms of the theory. We illustrate how, with
current experimental uncertainties, data cannot distinguish between these
particular {\em discriminatory} coefficients despite their sensitivity.
Nevertheless, the Chell--Olsson test does provide a consistency check of the
chiral expansion, requiring that the ${\cal O}(p^6)$ corrections to the {\em
discriminatory} coefficients in the Standard theory must be $\sim 100%$.
Indeed, some of these have been deduced from the new ${\cal O}(p^6)$
computations and found to give such large corrections. One can then check that
the ${\cal O}(p^8)$ corrections must be much smaller. We conclude that this
test, like others, cannot distinguish between the different forms of Chiral
Symmetry Breaking embodied in the alternative versions of Chiral Perturbation
Theory without much more precise experimental information near threshold.
|
[
{
"created": "Fri, 20 Sep 1996 08:57:08 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Pennington",
"M. R.",
"",
"Centre for Particle Theory, University of Durham, UK"
],
[
"Portoles",
"J.",
"",
"INFN, Sezione di Napoli, I"
]
] |
A way of testing the $\pi \pi$ predictions of Chiral Perturbation Theory against experimental data is to use dispersion relations to continue experimental information into the subthreshold region where the theory should unambiguously apply. Chell and Olsson have proposed a test of the subthreshold behaviour of chiral expansions which highlights potential differences between the Standard and the Generalized forms of the theory. We illustrate how, with current experimental uncertainties, data cannot distinguish between these particular {\em discriminatory} coefficients despite their sensitivity. Nevertheless, the Chell--Olsson test does provide a consistency check of the chiral expansion, requiring that the ${\cal O}(p^6)$ corrections to the {\em discriminatory} coefficients in the Standard theory must be $\sim 100%$. Indeed, some of these have been deduced from the new ${\cal O}(p^6)$ computations and found to give such large corrections. One can then check that the ${\cal O}(p^8)$ corrections must be much smaller. We conclude that this test, like others, cannot distinguish between the different forms of Chiral Symmetry Breaking embodied in the alternative versions of Chiral Perturbation Theory without much more precise experimental information near threshold.
|
2012.05380
|
Mary Hall Reno
|
Mary Hall Reno, Yu Seon Jeong, Sergio Palomares-Ruiz and Ina Sarcevic
|
Probing secret interactions of eV-scale sterile neutrinos with the
diffuse supernova neutrino background
|
Submitted to Proceedings of ICHEP 2020, July 28-August 6, Prague,
Czech Republic (virtual meeting), 6 pages
| null | null | null |
hep-ph astro-ph.HE
|
http://creativecommons.org/licenses/by-nc-nd/4.0/
|
While three flavors of "active" neutrinos are consistent with mixing angle
results within error bars, there are anomalies may be hints of physics beyond
the standard model that can accommodate a fourth mostly "sterile" neutrino
species with an eV-scale mass and a mixing angle with active neutrinos of order
$\theta_0\simeq 0.1$. We describe a scenario with eV-scale sterile neutrinos
that have self-interactions via a new gauge vector boson, a "secret" mediator
$\phi$. We show that their production in the early Universe via mixing with
active neutrinos is consistent with Big Bang Nucleosynthesis and free-streaming
constraints in the Cosmic Microwave Background epoch. For $M_\phi=4-8$ keV and
sterile neutrino coupling $g_s=10^{-4}$, we find that resonant interactions of
diffuse supernova neutrinos with relic sterile neutrinos in transit to the
Earth would cause spectral dips in the neutrino flux. We illustrate the
corresponding (anti-)neutrino event distributions as a function of energy in
the DUNE (Hyper-Kamiokande) detector.
|
[
{
"created": "Thu, 10 Dec 2020 00:23:53 GMT",
"version": "v1"
}
] |
2020-12-11
|
[
[
"Reno",
"Mary Hall",
""
],
[
"Jeong",
"Yu Seon",
""
],
[
"Palomares-Ruiz",
"Sergio",
""
],
[
"Sarcevic",
"Ina",
""
]
] |
While three flavors of "active" neutrinos are consistent with mixing angle results within error bars, there are anomalies may be hints of physics beyond the standard model that can accommodate a fourth mostly "sterile" neutrino species with an eV-scale mass and a mixing angle with active neutrinos of order $\theta_0\simeq 0.1$. We describe a scenario with eV-scale sterile neutrinos that have self-interactions via a new gauge vector boson, a "secret" mediator $\phi$. We show that their production in the early Universe via mixing with active neutrinos is consistent with Big Bang Nucleosynthesis and free-streaming constraints in the Cosmic Microwave Background epoch. For $M_\phi=4-8$ keV and sterile neutrino coupling $g_s=10^{-4}$, we find that resonant interactions of diffuse supernova neutrinos with relic sterile neutrinos in transit to the Earth would cause spectral dips in the neutrino flux. We illustrate the corresponding (anti-)neutrino event distributions as a function of energy in the DUNE (Hyper-Kamiokande) detector.
|
1004.5347
|
Amandeep Josan Mr
|
Amandeep S. Josan, Anne M. Green
|
Constraints from primordial black hole formation at the end of inflation
|
5 pages, 5 figures v3: version to appear in Phys. Rev. D with minor
changes
|
Phys.Rev.D82:047303,2010
|
10.1103/PhysRevD.82.047303
| null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Primordial black hole (PBH) abundance limits constrain the primordial power
spectrum, and hence models of inflation, on scales far smaller than those
probed by cosmological observations. Single field inflation models which are
compatible with all cosmological data can have large enough perturbations on
small scales to overproduce PBHs, and hence be excluded. The standard formulae
for the amplitude of perturbations do not hold for modes that exit the horizon
close to the end of inflation however. We use a modified flow analysis to
identify models of inflation where the amplitude of perturbations on small
scales is large. For these models we then carry out a numerical evolution of
the perturbations and use the PBH constraints on the power spectrum to
eliminate models which overproduce PBHs. Significant PBH formation can occur in
models in which inflation can continue indefinitely and is ended via a
secondary mechanism. We demonstrate that PBHs constrain these types of
inflation models and show that a numerical evaluation of the power spectrum
decreases the number of otherwise viable models of inflation.
|
[
{
"created": "Thu, 29 Apr 2010 17:45:47 GMT",
"version": "v1"
},
{
"created": "Wed, 5 May 2010 10:54:15 GMT",
"version": "v2"
},
{
"created": "Mon, 2 Aug 2010 11:47:15 GMT",
"version": "v3"
}
] |
2014-11-20
|
[
[
"Josan",
"Amandeep S.",
""
],
[
"Green",
"Anne M.",
""
]
] |
Primordial black hole (PBH) abundance limits constrain the primordial power spectrum, and hence models of inflation, on scales far smaller than those probed by cosmological observations. Single field inflation models which are compatible with all cosmological data can have large enough perturbations on small scales to overproduce PBHs, and hence be excluded. The standard formulae for the amplitude of perturbations do not hold for modes that exit the horizon close to the end of inflation however. We use a modified flow analysis to identify models of inflation where the amplitude of perturbations on small scales is large. For these models we then carry out a numerical evolution of the perturbations and use the PBH constraints on the power spectrum to eliminate models which overproduce PBHs. Significant PBH formation can occur in models in which inflation can continue indefinitely and is ended via a secondary mechanism. We demonstrate that PBHs constrain these types of inflation models and show that a numerical evaluation of the power spectrum decreases the number of otherwise viable models of inflation.
|
2111.15401
|
Jos\'e Filipe Bastos
|
Francisco J. Botella, G. C. Branco, M. N. Rebelo, J. I. Silva-Marcos
and Jos\'e Filipe Bastos
|
Decays of the Heavy Top and New Insights on $\epsilon_K$ in a one-VLQ
Minimal Solution to the CKM Unitarity Problem
|
33 pages, 8 figures, 1 table
| null |
10.1140/epjc/s10052-022-10299-9
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a minimal extension of the Standard Model where an up-type
vector-like quark, denoted $T$, is introduced and provides a simple solution to
the CKM unitarity problem. We adopt the Botella-Chau parametrization in order
to extract the $4\times 3$ quark mixing matrix which contains the three angles
of the $3\times 3$ CKM matrix plus three new angles denoted $\theta_{14}$,
$\theta_{24}$, $\theta_{34}$. It is assumed that the mixing of $T$ with
standard quarks is dominated by $\theta_{14}$. Imposing a recently derived, and
much more restrictive, upper-bound on the New Physics contributions to
$\epsilon_{K}$, we find, in the limit of exact $\theta_{14}$ dominance where
the other extra angles vanish, that $\epsilon_{K}^{\text{NP}}$ is too large.
However, if one relaxes the exact $\theta_{14}$ dominance limit, there exists a
parameter region, where one may obtain $\epsilon_{K}^{\text{NP}}$ in agreement
with experiment while maintaining the novel pattern of $T$ decays with the
heavy quark decaying predominantly to the light quarks $d$ and $u$. We also
find a reduction in the decay rate of $K_L\rightarrow \pi^o \nu\bar{\nu}$.
|
[
{
"created": "Tue, 30 Nov 2021 13:48:00 GMT",
"version": "v1"
},
{
"created": "Sun, 22 May 2022 19:17:37 GMT",
"version": "v2"
}
] |
2022-05-24
|
[
[
"Botella",
"Francisco J.",
""
],
[
"Branco",
"G. C.",
""
],
[
"Rebelo",
"M. N.",
""
],
[
"Silva-Marcos",
"J. I.",
""
],
[
"Bastos",
"José Filipe",
""
]
] |
We propose a minimal extension of the Standard Model where an up-type vector-like quark, denoted $T$, is introduced and provides a simple solution to the CKM unitarity problem. We adopt the Botella-Chau parametrization in order to extract the $4\times 3$ quark mixing matrix which contains the three angles of the $3\times 3$ CKM matrix plus three new angles denoted $\theta_{14}$, $\theta_{24}$, $\theta_{34}$. It is assumed that the mixing of $T$ with standard quarks is dominated by $\theta_{14}$. Imposing a recently derived, and much more restrictive, upper-bound on the New Physics contributions to $\epsilon_{K}$, we find, in the limit of exact $\theta_{14}$ dominance where the other extra angles vanish, that $\epsilon_{K}^{\text{NP}}$ is too large. However, if one relaxes the exact $\theta_{14}$ dominance limit, there exists a parameter region, where one may obtain $\epsilon_{K}^{\text{NP}}$ in agreement with experiment while maintaining the novel pattern of $T$ decays with the heavy quark decaying predominantly to the light quarks $d$ and $u$. We also find a reduction in the decay rate of $K_L\rightarrow \pi^o \nu\bar{\nu}$.
|
1608.07824
|
Guang-Juan Wang
|
Guang-Juan Wang, Zhan-Wei Liu, Shi-Lin Zhu
|
The axial charges of the hidden-charm pentaquark states
|
13 pages
|
Phys. Rev. C 94, 065202 (2016)
|
10.1103/PhysRevC.94.065202
|
ADP-16-28/T983
|
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
With the chiral quark model, we have calculated the axial charges of the
pentaquark states with $(I,I_3)=(\frac{1}{2},\frac{1}{2})$ and
$J^{P}=\frac{1}{2}^{\pm},\frac{3}{2}^{\pm},\frac{5}{2}^{\pm}$. The $P_c$ states
with the same $J^P$ quantum numbers but different color-spin-flavor
configurations have very different axial charges, which encode important
information on their underlying structures. For some of the
$J^{P}=\frac{3}{2}^{\pm}$ or $\frac{5}{2}^{\pm}$ pentaquark states, their axial
charges are much smaller than that of the proton.
|
[
{
"created": "Sun, 28 Aug 2016 15:40:05 GMT",
"version": "v1"
},
{
"created": "Mon, 2 Jan 2017 23:53:39 GMT",
"version": "v2"
}
] |
2017-01-04
|
[
[
"Wang",
"Guang-Juan",
""
],
[
"Liu",
"Zhan-Wei",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] |
With the chiral quark model, we have calculated the axial charges of the pentaquark states with $(I,I_3)=(\frac{1}{2},\frac{1}{2})$ and $J^{P}=\frac{1}{2}^{\pm},\frac{3}{2}^{\pm},\frac{5}{2}^{\pm}$. The $P_c$ states with the same $J^P$ quantum numbers but different color-spin-flavor configurations have very different axial charges, which encode important information on their underlying structures. For some of the $J^{P}=\frac{3}{2}^{\pm}$ or $\frac{5}{2}^{\pm}$ pentaquark states, their axial charges are much smaller than that of the proton.
|
1208.6263
|
Sven Bjarke Gudnason
|
Roberto Auzzi, Amit Giveon, Sven Bjarke Gudnason, Tomer Shacham
|
A Light Stop with Flavor in Natural SUSY
|
LaTeX, 22 pages, 4 figures; V2: references added
|
JHEP 1301:169,2013
|
10.1007/JHEP01(2013)169
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The discovery of a SM-like Higgs boson near 125 GeV and the flavor texture of
the Standard Model motivate the investigation of supersymmetric quiver-like BSM
extensions. We study the properties of such a minimal class of models which
deals naturally with the SM parameters. Considering experimental bounds as well
as constraints from flavor physics and Electro-Weak Precision Data, we find the
following. In a self-contained minimal model - including the full dynamics of
the Higgs sector - top squarks below a TeV are in tension with b->s{\gamma}
constraints. Relaxing the assumption concerning the mass generation of the
heavy Higgses, we find that a stop not far from half a TeV is allowed. The
models have some unique properties, e.g. an enhancement of the h->
b\bar{b},\tau\bar{{\tau}} decays relative to the h->\gamma{\gamma} one, a
gluino about 3 times heavier than the stop, an inverted hierarchy of about 3-20
between the squarks of the first two generations and the stop, relatively light
Higgsino neutralino or stau NLSP, as well as heavy Higgses and a W' which may
be within reach of the LHC.
|
[
{
"created": "Thu, 30 Aug 2012 18:53:39 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Sep 2012 15:12:55 GMT",
"version": "v2"
}
] |
2013-01-31
|
[
[
"Auzzi",
"Roberto",
""
],
[
"Giveon",
"Amit",
""
],
[
"Gudnason",
"Sven Bjarke",
""
],
[
"Shacham",
"Tomer",
""
]
] |
The discovery of a SM-like Higgs boson near 125 GeV and the flavor texture of the Standard Model motivate the investigation of supersymmetric quiver-like BSM extensions. We study the properties of such a minimal class of models which deals naturally with the SM parameters. Considering experimental bounds as well as constraints from flavor physics and Electro-Weak Precision Data, we find the following. In a self-contained minimal model - including the full dynamics of the Higgs sector - top squarks below a TeV are in tension with b->s{\gamma} constraints. Relaxing the assumption concerning the mass generation of the heavy Higgses, we find that a stop not far from half a TeV is allowed. The models have some unique properties, e.g. an enhancement of the h-> b\bar{b},\tau\bar{{\tau}} decays relative to the h->\gamma{\gamma} one, a gluino about 3 times heavier than the stop, an inverted hierarchy of about 3-20 between the squarks of the first two generations and the stop, relatively light Higgsino neutralino or stau NLSP, as well as heavy Higgses and a W' which may be within reach of the LHC.
|
0707.4586
|
Hua-Xing Chen
|
Hua-Xing Chen, Atsushi Hosaka, and Shi-Lin Zhu
|
Light Scalar Tetraquark Mesons in the QCD Sum Rule
|
18 pages, 5 figures; reference added, minor corrections; version to
appear in Phys.Rev.D
|
Phys.Rev.D76:094025,2007
|
10.1103/PhysRevD.76.094025
| null |
hep-ph
| null |
We study the lowest-lying scalar mesons in the QCD sum rule by considering
them as tetraquark states. We find that there are five independent currents for
each state with a certain flavor structure. By forming linear combinations, we
find that some mixed currents give reliable QCD sum rules. Among various
tetraquark currents, we consider those which are constructed by the diquarks
having anti-symmetric and symmetric flavor structures. That the results of the
QCD sum rule derived from the two types of currents are similar suggests that
the tetraquark states can have a large mixing between different flavor
structures.
|
[
{
"created": "Tue, 31 Jul 2007 11:21:32 GMT",
"version": "v1"
},
{
"created": "Fri, 9 Nov 2007 07:59:05 GMT",
"version": "v2"
}
] |
2011-11-10
|
[
[
"Chen",
"Hua-Xing",
""
],
[
"Hosaka",
"Atsushi",
""
],
[
"Zhu",
"Shi-Lin",
""
]
] |
We study the lowest-lying scalar mesons in the QCD sum rule by considering them as tetraquark states. We find that there are five independent currents for each state with a certain flavor structure. By forming linear combinations, we find that some mixed currents give reliable QCD sum rules. Among various tetraquark currents, we consider those which are constructed by the diquarks having anti-symmetric and symmetric flavor structures. That the results of the QCD sum rule derived from the two types of currents are similar suggests that the tetraquark states can have a large mixing between different flavor structures.
|
2311.06406
|
Michael Sanhueza Roa
|
Michael Sanhueza, Jos\'e Garrido M. and Miguel Guevara
|
CGC/saturation approach: Impact-parameter dependent model in
next-to-leading order of perturbative QCD and combined HERA data
|
22 pages, 15 figures, 3 tables
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In this paper we confront the next-to-leading order (NLO) CGC/saturation
approach of Ref. [1] with the experimental combined HERA data and obtain its
parameters. The model includes two features that are in accordance with our
theoretical knowledge of deep inelastic scattering. These consist of: $i$) the
use of analytical solution for the non-linear Balitsky-Kovchegov (BK) evolution
equation and $ii$) the exponential behavior of the saturation momentum on the
impact parameter $b$-dependence, characterized by $Q_s$ $\propto\exp( -m b )$
which reproduce the correct behaviour of the scattering amplitude at large $b$
in accord with Froissart theorem. The model results are then compared to data
at small-x for the structure function of the proton $F_{2}$, the longitudinal
structure function $F_{L}$, the charm structure function $F_2^{c\bar{c}}$, the
exclusive vector meson ($J/\psi,\phi,\rho$) production and Deeply Virtual
Compton Scattering (DVCS). We obtain a good agreement for the processes in a
wide kinematic range of $Q^2$ at small $x$. Our results provide a strong guide
for finding an approach, based on Color Glass Condensate/saturation effective
theory for high energy QCD, to make reliable predictions from first principles
as well as for forthcoming experiments like the Electron-Ion Collider and the
LHeC.
|
[
{
"created": "Wed, 8 Nov 2023 21:55:39 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Apr 2024 18:56:44 GMT",
"version": "v2"
}
] |
2024-04-09
|
[
[
"Sanhueza",
"Michael",
""
],
[
"M.",
"José Garrido",
""
],
[
"Guevara",
"Miguel",
""
]
] |
In this paper we confront the next-to-leading order (NLO) CGC/saturation approach of Ref. [1] with the experimental combined HERA data and obtain its parameters. The model includes two features that are in accordance with our theoretical knowledge of deep inelastic scattering. These consist of: $i$) the use of analytical solution for the non-linear Balitsky-Kovchegov (BK) evolution equation and $ii$) the exponential behavior of the saturation momentum on the impact parameter $b$-dependence, characterized by $Q_s$ $\propto\exp( -m b )$ which reproduce the correct behaviour of the scattering amplitude at large $b$ in accord with Froissart theorem. The model results are then compared to data at small-x for the structure function of the proton $F_{2}$, the longitudinal structure function $F_{L}$, the charm structure function $F_2^{c\bar{c}}$, the exclusive vector meson ($J/\psi,\phi,\rho$) production and Deeply Virtual Compton Scattering (DVCS). We obtain a good agreement for the processes in a wide kinematic range of $Q^2$ at small $x$. Our results provide a strong guide for finding an approach, based on Color Glass Condensate/saturation effective theory for high energy QCD, to make reliable predictions from first principles as well as for forthcoming experiments like the Electron-Ion Collider and the LHeC.
|
2008.06207
|
Alisa Katanaeva
|
Domenec Espriu and Alisa Katanaeva
|
Soft Wall holographic model for the minimal Composite Higgs
|
35 pages, 5 figures and a table
|
Phys. Rev. D 103, 055006 (2021)
|
10.1103/PhysRevD.103.055006
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We reassess employing the holographic technique to the description of 4D
minimal composite Higgs model with $SO(5)\to SO(4)$ global symmetry breaking
pattern. The particular 5D bottom-up holographic treatment is inspired by
previous work in the context of QCD and it allows to study spin one and spin
zero resonances. The resulting spectrum consists of the states transforming
under the unbroken $SO(4)$ subgroup and those with quantum numbers in the
$SO(5)/SO(4)$ coset. The spin one states are arranged in linear radial
trajectories, and the states from the broken subgroup are generally heavier.
The spin zero states from the coset space correspond to the four massless
Goldstone bosons in 4D. One of them takes the role of the Higgs boson.
Restrictions derived from the experimental constraints (Higgs couplings, $S$
parameter, etc.) are then implemented and we conclude that the model is able to
accommodate new vector resonances with masses in the range $2$ TeV to $3$ TeV
without encountering phenomenological difficulties. The couplings governing the
production of these new states in the processes of the SM gauge boson
scattering are also estimated. The method can be extended to other breaking
patterns.
|
[
{
"created": "Fri, 14 Aug 2020 06:32:08 GMT",
"version": "v1"
}
] |
2021-03-17
|
[
[
"Espriu",
"Domenec",
""
],
[
"Katanaeva",
"Alisa",
""
]
] |
We reassess employing the holographic technique to the description of 4D minimal composite Higgs model with $SO(5)\to SO(4)$ global symmetry breaking pattern. The particular 5D bottom-up holographic treatment is inspired by previous work in the context of QCD and it allows to study spin one and spin zero resonances. The resulting spectrum consists of the states transforming under the unbroken $SO(4)$ subgroup and those with quantum numbers in the $SO(5)/SO(4)$ coset. The spin one states are arranged in linear radial trajectories, and the states from the broken subgroup are generally heavier. The spin zero states from the coset space correspond to the four massless Goldstone bosons in 4D. One of them takes the role of the Higgs boson. Restrictions derived from the experimental constraints (Higgs couplings, $S$ parameter, etc.) are then implemented and we conclude that the model is able to accommodate new vector resonances with masses in the range $2$ TeV to $3$ TeV without encountering phenomenological difficulties. The couplings governing the production of these new states in the processes of the SM gauge boson scattering are also estimated. The method can be extended to other breaking patterns.
|
hep-ph/9307325
| null |
Daren Austin, E.J. Copeland and T.W.B. Kibble
|
Evolution of cosmic string configurations
|
61 pages, requires RevTex v3.0, SUSSEX-TH-93/3-4,
IMPERIAL/TP/92-93/42
|
Phys.Rev. D48 (1993) 5594-5627
|
10.1103/PhysRevD.48.5594
| null |
hep-ph astro-ph
| null |
We extend and develop our previous work on the evolution of a network of
cosmic strings. The new treatment is based on an analysis of the probability
distribution of the end-to-end distance of a randomly chosen segment of
left-moving string of given length. The description involves three distinct
length scales: $\xi$, related to the overall string density, $\bar\xi$, the
persistence length along the string, and $\zeta$, describing the small-scale
structure, which is an important feature of the numerical simulations that have
been done of this problem. An evolution equation is derived describing how the
distribution develops in time due to the combined effects of the universal
expansion, of intercommuting and loop formation, and of gravitational
radiation. With plausible assumptions about the unknown parameters in the
model, we confirm the conclusions of our previous study, that if gravitational
radiation and small-scale structure effects are neglected, the two dominant
length scales both scale in proportion to the horizon size. When the extra
effects are included, we find that while $\xi$ and $\bar\xi$ grow, $\zeta$
initially does not. Eventually, however, it does appear to scale, at a much
lower level, due to the effects of gravitational back-reaction.
|
[
{
"created": "Thu, 22 Jul 1993 14:59:57 GMT",
"version": "v1"
}
] |
2016-09-01
|
[
[
"Austin",
"Daren",
""
],
[
"Copeland",
"E. J.",
""
],
[
"Kibble",
"T. W. B.",
""
]
] |
We extend and develop our previous work on the evolution of a network of cosmic strings. The new treatment is based on an analysis of the probability distribution of the end-to-end distance of a randomly chosen segment of left-moving string of given length. The description involves three distinct length scales: $\xi$, related to the overall string density, $\bar\xi$, the persistence length along the string, and $\zeta$, describing the small-scale structure, which is an important feature of the numerical simulations that have been done of this problem. An evolution equation is derived describing how the distribution develops in time due to the combined effects of the universal expansion, of intercommuting and loop formation, and of gravitational radiation. With plausible assumptions about the unknown parameters in the model, we confirm the conclusions of our previous study, that if gravitational radiation and small-scale structure effects are neglected, the two dominant length scales both scale in proportion to the horizon size. When the extra effects are included, we find that while $\xi$ and $\bar\xi$ grow, $\zeta$ initially does not. Eventually, however, it does appear to scale, at a much lower level, due to the effects of gravitational back-reaction.
|
2312.14911
|
Wan-Li Ju
|
Giancarlo Ferrera, Wan-Li Ju, Marek Schoenherr
|
Zero-bin subtraction and the $q_{\mathrm{T}}$ spectrum beyond leading
power
| null | null | null |
IPPP/23/83;MCnet/23/21
|
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In this paper, we present an algorithm to construct the qT distribution at
NLO accuracy to arbitrary power precision, including the assembly of suitable
zero-bin subtrahends, in a mathematically well-defined way for a generic choice
of rapidity-divergence regularisation prescription. In its derivation, we
divide the phase space into two sectors, the interior of the integration domain
as well as the integration boundary, which we include here for the first time.
To demonstrate the applicability and usefulness of our algorithm, we calculate
the NNLP corrections for Higgs hadroproduction for the first time. We observe
that our approximate NNLP-accurate qT spectra replicate the asymptotic
behaviour of the full QCD calculation to a much better degree than the
previously available results, both within the $q_{\mathrm{T}}\to 0$ limit and
in the large-qT domain for all the involved partonic processes. While playing a
minor role at larger transverse momenta, we show that the newly incorporated
boundary contribution plays a vital role in the $q_{\mathrm{T}}\to 0$ limit,
where any subleading power accuracy would be lost without them. In particular,
our NNLP-accurate qT expansion can approximate the exact qT distribution up to
$q_{\mathrm{T}}\sim30\,\text{GeV}$ at the percent level for rapidities
$|Y_H|\lesssim 3$.
|
[
{
"created": "Fri, 22 Dec 2023 18:46:33 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Apr 2024 09:26:18 GMT",
"version": "v2"
}
] |
2024-04-08
|
[
[
"Ferrera",
"Giancarlo",
""
],
[
"Ju",
"Wan-Li",
""
],
[
"Schoenherr",
"Marek",
""
]
] |
In this paper, we present an algorithm to construct the qT distribution at NLO accuracy to arbitrary power precision, including the assembly of suitable zero-bin subtrahends, in a mathematically well-defined way for a generic choice of rapidity-divergence regularisation prescription. In its derivation, we divide the phase space into two sectors, the interior of the integration domain as well as the integration boundary, which we include here for the first time. To demonstrate the applicability and usefulness of our algorithm, we calculate the NNLP corrections for Higgs hadroproduction for the first time. We observe that our approximate NNLP-accurate qT spectra replicate the asymptotic behaviour of the full QCD calculation to a much better degree than the previously available results, both within the $q_{\mathrm{T}}\to 0$ limit and in the large-qT domain for all the involved partonic processes. While playing a minor role at larger transverse momenta, we show that the newly incorporated boundary contribution plays a vital role in the $q_{\mathrm{T}}\to 0$ limit, where any subleading power accuracy would be lost without them. In particular, our NNLP-accurate qT expansion can approximate the exact qT distribution up to $q_{\mathrm{T}}\sim30\,\text{GeV}$ at the percent level for rapidities $|Y_H|\lesssim 3$.
|
1210.4148
|
Bronislav Zakharov
|
B. G. Zakharov
|
Nuclear modification factor for light and heavy flavors within pQCD and
recent data from the LHC
|
10 pages, 3 figures
| null |
10.1134/S002136401222016X
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We examine the flavor dependence of the nuclear modification factor $R_{AA}$
in the pQCD calculations at LHC energies. The computations are performed
accounting for radiative and collisional parton energy loss with running
coupling constant. Our results show that the recent LHC data on the $R_{AA}$
for charged hadrons, D-mesons and non-photonic electrons agree reasonably with
the pQCD picture of the parton energy loss with the dominating contribution
from the radiative mechanism.
|
[
{
"created": "Mon, 15 Oct 2012 19:51:42 GMT",
"version": "v1"
}
] |
2015-06-11
|
[
[
"Zakharov",
"B. G.",
""
]
] |
We examine the flavor dependence of the nuclear modification factor $R_{AA}$ in the pQCD calculations at LHC energies. The computations are performed accounting for radiative and collisional parton energy loss with running coupling constant. Our results show that the recent LHC data on the $R_{AA}$ for charged hadrons, D-mesons and non-photonic electrons agree reasonably with the pQCD picture of the parton energy loss with the dominating contribution from the radiative mechanism.
|
hep-ph/0010151
|
Vergados Ioannis
|
J.D. Vergados (Theoretical Physics Division, University of Ioannina)
|
The Directional Rate and the Modulation Effect for Direct Supersymmetric
Dark Matter Detection
|
35 LATEX pages, 14 tables included
|
Part.Nucl.Lett.106:74-108,2001
| null | null |
hep-ph astro-ph
| null |
The detection of the theoretically expected dark matter is central to
particle physics and cosmology. Current fashionable supersymmetric models
provide a natural dark matter candidate which is the lightest supersymmetric
particle (LSP). Such models combined with fairly well understood physics like
the quark substructure of the nucleon and the nuclear structure (form factor
and/or spin response function), permit the evaluation of the event rate for
LSP-nucleus elastic scattering. The thus obtained event rates are, however,
very low. So it is imperative to exploit the modulation effect, i.e. the
dependence of the event rate on the earth's annual motion. Also it is useful to
consider the directional rate, i.e its dependence on the direction of the
recoiling nucleus. In this paper we study the modulation effect both in non
directional and directional experiments. We calculate both the differential and
the total rates usingi both isothermal, symmetric as well as only axially
asymmetric, and non isothermal, due to caustic rings, velocity distributions.
We consider We find that in the symmetric case the modulation amplitude is
small. The same is true for the case of caustic rings. The inclusion of
asymmetry, with a enhanced velocity dispersion in the galactocentric direction,
yields an enhanced modulation effect, especially in directional experiments.
|
[
{
"created": "Sun, 15 Oct 2000 16:42:53 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Vergados",
"J. D.",
"",
"Theoretical Physics Division, University of Ioannina"
]
] |
The detection of the theoretically expected dark matter is central to particle physics and cosmology. Current fashionable supersymmetric models provide a natural dark matter candidate which is the lightest supersymmetric particle (LSP). Such models combined with fairly well understood physics like the quark substructure of the nucleon and the nuclear structure (form factor and/or spin response function), permit the evaluation of the event rate for LSP-nucleus elastic scattering. The thus obtained event rates are, however, very low. So it is imperative to exploit the modulation effect, i.e. the dependence of the event rate on the earth's annual motion. Also it is useful to consider the directional rate, i.e its dependence on the direction of the recoiling nucleus. In this paper we study the modulation effect both in non directional and directional experiments. We calculate both the differential and the total rates usingi both isothermal, symmetric as well as only axially asymmetric, and non isothermal, due to caustic rings, velocity distributions. We consider We find that in the symmetric case the modulation amplitude is small. The same is true for the case of caustic rings. The inclusion of asymmetry, with a enhanced velocity dispersion in the galactocentric direction, yields an enhanced modulation effect, especially in directional experiments.
|
2309.15920
|
Yanou Cui
|
Chia-Feng Chang and Yanou Cui
|
Dynamics of Long-lived Axion Domain Walls and Its Cosmological
Implications
|
19 pages, 25 figures
| null | null | null |
hep-ph astro-ph.CO hep-lat
|
http://creativecommons.org/licenses/by/4.0/
|
We perform an updated analysis on a long-lived axion domain wall (DW)
network. By simulating the axion field on a 3D lattice and fitting an
analytical model for the DW evolution, we identify the leading energy loss
mechanisms of the DWs and compute the spectrum of axions emitted from the
network. The contribution from the DWs to axion dark matter (DM) density is
derived, with viable parameter space given. The application to both QCD axions
and general axion-like particles (ALPs) are considered. Due to the new
approaches taken, while our results bear consistency with earlier literature,
notable discrepancies are also revealed, such as the prediction for DM
abundance, which may have a profound impact on axion phenomenology at large.
|
[
{
"created": "Wed, 27 Sep 2023 18:00:37 GMT",
"version": "v1"
}
] |
2023-09-29
|
[
[
"Chang",
"Chia-Feng",
""
],
[
"Cui",
"Yanou",
""
]
] |
We perform an updated analysis on a long-lived axion domain wall (DW) network. By simulating the axion field on a 3D lattice and fitting an analytical model for the DW evolution, we identify the leading energy loss mechanisms of the DWs and compute the spectrum of axions emitted from the network. The contribution from the DWs to axion dark matter (DM) density is derived, with viable parameter space given. The application to both QCD axions and general axion-like particles (ALPs) are considered. Due to the new approaches taken, while our results bear consistency with earlier literature, notable discrepancies are also revealed, such as the prediction for DM abundance, which may have a profound impact on axion phenomenology at large.
|
hep-ph/9905320
|
Walter Grimus
|
W. Grimus, R. Pfeiffer, T. Schwetz
|
A 4-neutrino model with a Higgs triplet
|
Latex, 14 pages, no figures
|
Eur.Phys.J.C13:125-132,2000
|
10.1007/s100520000255
|
UWThPh-1999-36
|
hep-ph
| null |
We take as a starting point the Gelmini -- Roncadelli model enlarged by a
term with explicit lepton number violation in the Higgs potential and add a
neutrino singlet field coupled via a scalar doublet to the usual leptons. This
scenario allows us to take into account all three present indications in favour
of neutrino oscillations provided by the solar, atmospheric and LSND neutrino
oscillation experiments. Furthermore, it suggests a model which reproduces
naturally one of the two 4-neutrino mass spectra favoured by the data. In this
model the solar neutrino problem is solved by large mixing MSW \nu_e\to\nu_\tau
transitions and the atmospheric neutrino problem by transitions of \nu_\mu into
a sterile neutrino.
|
[
{
"created": "Wed, 12 May 1999 14:50:36 GMT",
"version": "v1"
}
] |
2011-09-13
|
[
[
"Grimus",
"W.",
""
],
[
"Pfeiffer",
"R.",
""
],
[
"Schwetz",
"T.",
""
]
] |
We take as a starting point the Gelmini -- Roncadelli model enlarged by a term with explicit lepton number violation in the Higgs potential and add a neutrino singlet field coupled via a scalar doublet to the usual leptons. This scenario allows us to take into account all three present indications in favour of neutrino oscillations provided by the solar, atmospheric and LSND neutrino oscillation experiments. Furthermore, it suggests a model which reproduces naturally one of the two 4-neutrino mass spectra favoured by the data. In this model the solar neutrino problem is solved by large mixing MSW \nu_e\to\nu_\tau transitions and the atmospheric neutrino problem by transitions of \nu_\mu into a sterile neutrino.
|
2306.17086
|
Sudhakantha Girmohanta
|
Kohei Fujikura, Sudhakantha Girmohanta, Yuichiro Nakai and Motoo
Suzuki
|
NANOGrav Signal from a Dark Conformal Phase Transition
|
9 pages, 1 figure. v2: additional references added
| null | null |
UT-Komaba/23-6
|
hep-ph astro-ph.CO hep-th
|
http://creativecommons.org/licenses/by/4.0/
|
We explore the possibility that a confining first-order phase transition of a
nearly-conformal dark sector generates the reported NANOGrav signal of a
stochastic gravitational wave background. The visible Standard Model (SM)
sector and the dark sector are initially thermally decoupled so that their
temperatures are different. The nearly conformal phase transition is described
by the shallow potential of a dilaton (or a radion in the 5D holographic
perspective) generated by a new dark Yang-Mills field coupled to the conformal
sector. For a dark sector only gravitationally connected with the visible
sector, the NANOGrav signal is explained by the phase transition without
contradicting the $\Delta N_{\rm eff}$ constraint, together with a contribution
from supermassive black hole binaries. While the dilaton and dark glueballs can
be produced after the phase transition, they immediately decay into dark
radiation, which can help ameliorate the Hubble tension and be tested by the
future CMB-S4 experiment. Alternatively, for a dark conformal sector decaying
into the visible sector after the phase transition, the $\Delta N_{\rm eff}$
constraint is not applied and the phase transition can solely explain the
NANOGrav signal.
|
[
{
"created": "Thu, 29 Jun 2023 16:40:39 GMT",
"version": "v1"
},
{
"created": "Sat, 8 Jul 2023 03:12:45 GMT",
"version": "v2"
}
] |
2023-07-11
|
[
[
"Fujikura",
"Kohei",
""
],
[
"Girmohanta",
"Sudhakantha",
""
],
[
"Nakai",
"Yuichiro",
""
],
[
"Suzuki",
"Motoo",
""
]
] |
We explore the possibility that a confining first-order phase transition of a nearly-conformal dark sector generates the reported NANOGrav signal of a stochastic gravitational wave background. The visible Standard Model (SM) sector and the dark sector are initially thermally decoupled so that their temperatures are different. The nearly conformal phase transition is described by the shallow potential of a dilaton (or a radion in the 5D holographic perspective) generated by a new dark Yang-Mills field coupled to the conformal sector. For a dark sector only gravitationally connected with the visible sector, the NANOGrav signal is explained by the phase transition without contradicting the $\Delta N_{\rm eff}$ constraint, together with a contribution from supermassive black hole binaries. While the dilaton and dark glueballs can be produced after the phase transition, they immediately decay into dark radiation, which can help ameliorate the Hubble tension and be tested by the future CMB-S4 experiment. Alternatively, for a dark conformal sector decaying into the visible sector after the phase transition, the $\Delta N_{\rm eff}$ constraint is not applied and the phase transition can solely explain the NANOGrav signal.
|
hep-ph/0204166
|
Chuan Hung Chen
|
Chuan-Hung Chen, Yong-Yeon Keum, Hsiang-nan Li
|
Perturbative QCD analysis of $B \to \phi K^* $ decays
|
14 pages, 2 tables, brief disscussion on hard sacle added, version to
appear in PRD
|
Phys.Rev. D66 (2002) 054013
|
10.1103/PhysRevD.66.054013
| null |
hep-ph
| null |
We study the first observed charmless $B\to VV$ modes, the $B\to\phi K^*$
decays, in perturbative QCD formalism. The obtained branching ratios
$B(B\to\phi K^*)\sim 15 \times 10^{-6}$ are larger than $\sim 9\times 10^{-6}$
from QCD factorization. The comparison of the predicted magnitudes and phases
of the different helicity amplitudes, and branching ratios with experimental
data can test the power counting rules, the evaluation of annihilation
contributions, and the mechanism of dynamical penguin enhancement in
perturbative QCD, respectively.
|
[
{
"created": "Mon, 15 Apr 2002 09:56:52 GMT",
"version": "v1"
},
{
"created": "Wed, 10 Jul 2002 06:20:18 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Chen",
"Chuan-Hung",
""
],
[
"Keum",
"Yong-Yeon",
""
],
[
"Li",
"Hsiang-nan",
""
]
] |
We study the first observed charmless $B\to VV$ modes, the $B\to\phi K^*$ decays, in perturbative QCD formalism. The obtained branching ratios $B(B\to\phi K^*)\sim 15 \times 10^{-6}$ are larger than $\sim 9\times 10^{-6}$ from QCD factorization. The comparison of the predicted magnitudes and phases of the different helicity amplitudes, and branching ratios with experimental data can test the power counting rules, the evaluation of annihilation contributions, and the mechanism of dynamical penguin enhancement in perturbative QCD, respectively.
|
hep-ph/0308043
|
Andrea Soddu
|
A. Soddu, N-K. Tran
|
Democratic Mass Matrices From Five Dimensions
|
25 pages Revtex4, 25 ps figures, new references added
|
Phys.Rev.D69:015010,2004
|
10.1103/PhysRevD.69.015010
| null |
hep-ph
| null |
We reconstruct the Standard Model (SM) quark masses and the
Cabibbo-Kobayashi-Maskawa (CKM) matrix from a five-dimensional model, with the
fifth dimension compactified on an S^1/Z_2 orbifold. Fermions are localized
only at the orbifold fixed points and the induced quark mass matrices are
almost democratic. Two specific versions of our model with 15 and 24 parameters
are presented, and for both versions we can reproduce the quark mass spectrum
and CKM matrix correctly to the level they are observed in current experiments.
|
[
{
"created": "Tue, 5 Aug 2003 04:01:10 GMT",
"version": "v1"
},
{
"created": "Wed, 20 Aug 2003 22:56:15 GMT",
"version": "v2"
},
{
"created": "Mon, 25 Aug 2003 08:05:44 GMT",
"version": "v3"
}
] |
2014-11-17
|
[
[
"Soddu",
"A.",
""
],
[
"Tran",
"N-K.",
""
]
] |
We reconstruct the Standard Model (SM) quark masses and the Cabibbo-Kobayashi-Maskawa (CKM) matrix from a five-dimensional model, with the fifth dimension compactified on an S^1/Z_2 orbifold. Fermions are localized only at the orbifold fixed points and the induced quark mass matrices are almost democratic. Two specific versions of our model with 15 and 24 parameters are presented, and for both versions we can reproduce the quark mass spectrum and CKM matrix correctly to the level they are observed in current experiments.
|
2001.04078
|
Bo Peng
|
Chengcheng Han, M.L. L\'opez-Ib\'a\~nez, Bo Peng and Jin Min Yang
|
Dirac dark matter in $U(1)_{B-L}$ with Stueckelberg mechanism
|
12 pages, 3 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate a $U(1)_{B-L}$ gauge extension of the Standard Model (SM)
where the gauge boson mass is generated by the Stueckelberg mechanism. Three
right-handed neutrinos are added to cancel the gauge anomaly and hence the
neutrino masses can be explained. A new Dirac fermion could be a WIMP dark
matter whose interaction with the SM sector is mediated by the new gauge boson.
Assuming the perturbativity of the gauge coupling up to the Planck scale, we
find that only the resonance region is feasible for the dark matter abundance.
After applying the $\Delta N_{eff}$ constraints from the current Planck
experiment, the collider search constraints as well as the dark matter direct
detection limits, we observe that the $B-L$ charge of dark matter satisfies
$|Q_{\chi}|>0.11$. Such a scenario might be probed conclusively by the
projected CMB-S4 experiment, assuming the right-handed neutrinos are
thermalized with the SM sector in the early universe.
|
[
{
"created": "Mon, 13 Jan 2020 06:22:02 GMT",
"version": "v1"
}
] |
2020-01-14
|
[
[
"Han",
"Chengcheng",
""
],
[
"López-Ibáñez",
"M. L.",
""
],
[
"Peng",
"Bo",
""
],
[
"Yang",
"Jin Min",
""
]
] |
We investigate a $U(1)_{B-L}$ gauge extension of the Standard Model (SM) where the gauge boson mass is generated by the Stueckelberg mechanism. Three right-handed neutrinos are added to cancel the gauge anomaly and hence the neutrino masses can be explained. A new Dirac fermion could be a WIMP dark matter whose interaction with the SM sector is mediated by the new gauge boson. Assuming the perturbativity of the gauge coupling up to the Planck scale, we find that only the resonance region is feasible for the dark matter abundance. After applying the $\Delta N_{eff}$ constraints from the current Planck experiment, the collider search constraints as well as the dark matter direct detection limits, we observe that the $B-L$ charge of dark matter satisfies $|Q_{\chi}|>0.11$. Such a scenario might be probed conclusively by the projected CMB-S4 experiment, assuming the right-handed neutrinos are thermalized with the SM sector in the early universe.
|
2310.20282
|
Luis Anchordoqui
|
Luis A. Anchordoqui and Ignatios Antoniadis
|
Large extra dimensions from higher-dimensional inflation
|
Matching version published in PRD
|
Phys. Rev. D 109 (2024) 103508
|
10.1103/PhysRevD.109.103508
| null |
hep-ph astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose the possibility that compact extra dimensions can obtain large
size by higher dimensional inflation, relating the weakness of the actual
gravitational force to the size of the observable universe. Solution to the
horizon problem implies that the fundamental scale of gravity is smaller than
$10^{13}$ GeV which can be realised in a braneworld framework for any number of
extra dimensions. However, requirement of (approximate) flat power spectrum of
primordial density fluctuations consistent with present observations makes this
simple proposal possible only for one extra dimension at around the micron
scale. After the end of five-dimensional inflation, the radion modulus can be
stabilised at a vacuum with positive energy of the order of the present dark
energy scale. An attractive possibility is based on the contribution to the
Casimir energy of right-handed neutrinos with a mass at a similar scale.
|
[
{
"created": "Tue, 31 Oct 2023 08:54:03 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Jun 2024 12:07:53 GMT",
"version": "v2"
}
] |
2024-06-26
|
[
[
"Anchordoqui",
"Luis A.",
""
],
[
"Antoniadis",
"Ignatios",
""
]
] |
We propose the possibility that compact extra dimensions can obtain large size by higher dimensional inflation, relating the weakness of the actual gravitational force to the size of the observable universe. Solution to the horizon problem implies that the fundamental scale of gravity is smaller than $10^{13}$ GeV which can be realised in a braneworld framework for any number of extra dimensions. However, requirement of (approximate) flat power spectrum of primordial density fluctuations consistent with present observations makes this simple proposal possible only for one extra dimension at around the micron scale. After the end of five-dimensional inflation, the radion modulus can be stabilised at a vacuum with positive energy of the order of the present dark energy scale. An attractive possibility is based on the contribution to the Casimir energy of right-handed neutrinos with a mass at a similar scale.
|
1910.06795
|
Christian Fischer
|
Gernot Eichmann, Christian S. Fischer and Richard Williams
|
Kaon-box contribution to the anomalous magnetic moment of the muon
|
6 pages, 4 figures; v3: improved numerics, updated number for
kaon-box, conclusions unchanged. arXiv admin note: text overlap with
arXiv:1903.10844
|
Phys. Rev. D 101, 054015 (2020)
|
10.1103/PhysRevD.101.054015
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present results for the charged kaon-box contributions to the hadronic
light-by-light (HLBL) correction of the muon's anomalous magnetic moment. To
this end we determine the kaon electromagnetic form factor within the
functional approach to QCD using Dyson-Schwinger and Bethe-Salpeter equations
and evaluate the kaon-box contribution as defined in the dispersive approach to
HLBL. As an update to previous work we also re-evaluate the charged pion-box
contribution taking effects due to isospin breaking into account. Our results
are $a_\mu^{\pi^\pm-\text{box}} = -15.7 \,(2)(3) \times 10^{-11}$ and
$a_\mu^{K^\pm-\text{box}} = -0.48 \,(2)(4) \times 10^{-11}$ thus confirming the
large suppression of box contributions beyond the leading pion box.
|
[
{
"created": "Mon, 14 Oct 2019 14:26:02 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Oct 2019 14:22:58 GMT",
"version": "v2"
},
{
"created": "Tue, 18 Feb 2020 13:51:38 GMT",
"version": "v3"
}
] |
2020-03-18
|
[
[
"Eichmann",
"Gernot",
""
],
[
"Fischer",
"Christian S.",
""
],
[
"Williams",
"Richard",
""
]
] |
We present results for the charged kaon-box contributions to the hadronic light-by-light (HLBL) correction of the muon's anomalous magnetic moment. To this end we determine the kaon electromagnetic form factor within the functional approach to QCD using Dyson-Schwinger and Bethe-Salpeter equations and evaluate the kaon-box contribution as defined in the dispersive approach to HLBL. As an update to previous work we also re-evaluate the charged pion-box contribution taking effects due to isospin breaking into account. Our results are $a_\mu^{\pi^\pm-\text{box}} = -15.7 \,(2)(3) \times 10^{-11}$ and $a_\mu^{K^\pm-\text{box}} = -0.48 \,(2)(4) \times 10^{-11}$ thus confirming the large suppression of box contributions beyond the leading pion box.
|
hep-ph/9207259
| null |
R. L. Jaffe (Center for Theoretical Physics, MIT)
|
Spin Structure Functions
|
23 single-spaced pages
| null | null |
MIT-CTP-2114
|
hep-ph
| null |
I review the spin dependent structure functions which control dominant
(twist-2) and sub-dominant (twist-3) phenomena in hard processes. Novel effects
associated with chirally odd parton distributions and with transverse
polarization are emphasized.
|
[
{
"created": "Fri, 24 Jul 1992 23:10:53 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Jaffe",
"R. L.",
"",
"Center for Theoretical Physics, MIT"
]
] |
I review the spin dependent structure functions which control dominant (twist-2) and sub-dominant (twist-3) phenomena in hard processes. Novel effects associated with chirally odd parton distributions and with transverse polarization are emphasized.
|
hep-ph/0412397
|
Brandon Carter
|
Brandon Carter
|
Frozen rigging model of the energy dominated universe
|
14 pages, LaTex. Contrib. to Micro and Macro Structures of Spacetime,
Peyresq, June, 2004, extended to include illustrations of "8 color" and "5
color" examples of "even" (as opposed to "odd") lattices
|
Int.J.Theor.Phys. 44 (2005) 1729-1741
| null | null |
hep-ph
| null |
Composite rigging systems, involving membranes that meet on strings that meet
on monopoles, arise naturally by the Kibble mechanism as topological defects in
field theories involving spontaneous symmetry breaking. Such systems will tend
to freeze out into static lattice type configurations with energy contribution
ultimately be provided by the membranes. It has been suggested by Bucher and
Spergel that on scales large compared with the relevant (interstellar
separation) distance characterising the relevant mesh length, such a system may
behave as a rigidity - stabilised solid, having an approximately isotropic
stress energy tensor with negative pressure, as given by a polytropic index
$\gamma=w+1=1/3$. It has recently been shown that such a system can be rigid
enough to be stable if the number of membranes meeting at a junction is even
(though not if it is odd). Using as examples an approximately O(3) symmetric
scalar field model that can provide an ``8 color'' (body centered) cubic
lattice, and an approximate U(1)$\times$ U(1) model offering a disordered ``5
color'' lattice, it is argued that such a mechanism can account naturally for
the observed dark energy dominance of the universe, without ad hoc assumptions,
other than that the relevant symmetry breaking phase transition should have
occurred somewhere about the Kev energy range.
|
[
{
"created": "Tue, 28 Dec 2004 11:44:50 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Feb 2005 16:10:34 GMT",
"version": "v2"
},
{
"created": "Wed, 23 Feb 2005 16:06:01 GMT",
"version": "v3"
}
] |
2007-05-23
|
[
[
"Carter",
"Brandon",
""
]
] |
Composite rigging systems, involving membranes that meet on strings that meet on monopoles, arise naturally by the Kibble mechanism as topological defects in field theories involving spontaneous symmetry breaking. Such systems will tend to freeze out into static lattice type configurations with energy contribution ultimately be provided by the membranes. It has been suggested by Bucher and Spergel that on scales large compared with the relevant (interstellar separation) distance characterising the relevant mesh length, such a system may behave as a rigidity - stabilised solid, having an approximately isotropic stress energy tensor with negative pressure, as given by a polytropic index $\gamma=w+1=1/3$. It has recently been shown that such a system can be rigid enough to be stable if the number of membranes meeting at a junction is even (though not if it is odd). Using as examples an approximately O(3) symmetric scalar field model that can provide an ``8 color'' (body centered) cubic lattice, and an approximate U(1)$\times$ U(1) model offering a disordered ``5 color'' lattice, it is argued that such a mechanism can account naturally for the observed dark energy dominance of the universe, without ad hoc assumptions, other than that the relevant symmetry breaking phase transition should have occurred somewhere about the Kev energy range.
|
2012.09016
|
Jan Heisig
|
Chiara Arina, Jan Heisig, Fabio Maltoni, Luca Mantani, Daniele
Massaro, Olivier Mattelaer, Gopolang Mohlabeng
|
Studying dark matter with MadDM 3.1: a short user guide
|
17 pages + references; contribution to "Tools for High Energy Physics
and Cosmology" (TOOLS2020), 2-6 Nov. 2020, IP2I Lyon, France
| null | null |
CP3-20-62, MCNET-20-26
|
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
MadDM is an automated numerical tool for the computation of dark-matter
observables for generic new physics models. We announce version 3.1 and
summarize its features. Notably, the code goes beyond the mere cross-section
computation for direct and indirect detection. For instance, it allows the user
to compute the fully differential nuclear recoil rates as well as the energy
spectra of photons, neutrinos and charged cosmic rays for arbitrary $2\to n$
annihilation processes. This short user guide equips researchers with all the
relevant information required to readily perform comprehensive phenomenological
studies of particle dark-matter models.
|
[
{
"created": "Wed, 16 Dec 2020 15:22:12 GMT",
"version": "v1"
}
] |
2020-12-17
|
[
[
"Arina",
"Chiara",
""
],
[
"Heisig",
"Jan",
""
],
[
"Maltoni",
"Fabio",
""
],
[
"Mantani",
"Luca",
""
],
[
"Massaro",
"Daniele",
""
],
[
"Mattelaer",
"Olivier",
""
],
[
"Mohlabeng",
"Gopolang",
""
]
] |
MadDM is an automated numerical tool for the computation of dark-matter observables for generic new physics models. We announce version 3.1 and summarize its features. Notably, the code goes beyond the mere cross-section computation for direct and indirect detection. For instance, it allows the user to compute the fully differential nuclear recoil rates as well as the energy spectra of photons, neutrinos and charged cosmic rays for arbitrary $2\to n$ annihilation processes. This short user guide equips researchers with all the relevant information required to readily perform comprehensive phenomenological studies of particle dark-matter models.
|
1911.01136
|
Miguel Angel Escobedo Espinosa
|
Miguel \'Angel Escobedo and Tuomas Lappi
|
The dipole picture and the non-relativistic expansion
|
33 pages. 9 figures. Updated to incorporate the changes made to the
published version
|
Phys. Rev. D 101, 034030 (2020)
|
10.1103/PhysRevD.101.034030
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study exclusive quarkonium production in the dipole picture at
next-to-leading order (NLO) accuracy, using the non-relativistic expansion for
the quarkonium wavefunction. This process offers one of the best ways to obtain
information about gluon distributions at small $x$, in ultraperipheral heavy
ion collisions and in deep inelastic scattering. The quarkonium light cone wave
functions needed in the dipole picture have typically been available only at
tree level, either in phenomenological models or in the nonrelativistic limit.
In this paper, we discuss the compatibility of the dipole approach and the
non-relativistic expansion and compute NLO relativistic corrections to the
quarkonium light-cone wave function in light-cone gauge. Using these
corrections we recover results for the NLO decay width of quarkonium to
$e^{+}e^{-}$ and we check that the non-relativistic expansion is consistent
with ERBL evolution and with B-JIMWLK evolution of the target. The results
presented here will allow computing the exclusive quarkonium production rate at
NLO once the one loop photon wave function with massive quarks, currently under
investigation, is known.
|
[
{
"created": "Mon, 4 Nov 2019 11:26:30 GMT",
"version": "v1"
},
{
"created": "Fri, 6 Mar 2020 11:57:31 GMT",
"version": "v2"
}
] |
2020-03-09
|
[
[
"Escobedo",
"Miguel Ángel",
""
],
[
"Lappi",
"Tuomas",
""
]
] |
We study exclusive quarkonium production in the dipole picture at next-to-leading order (NLO) accuracy, using the non-relativistic expansion for the quarkonium wavefunction. This process offers one of the best ways to obtain information about gluon distributions at small $x$, in ultraperipheral heavy ion collisions and in deep inelastic scattering. The quarkonium light cone wave functions needed in the dipole picture have typically been available only at tree level, either in phenomenological models or in the nonrelativistic limit. In this paper, we discuss the compatibility of the dipole approach and the non-relativistic expansion and compute NLO relativistic corrections to the quarkonium light-cone wave function in light-cone gauge. Using these corrections we recover results for the NLO decay width of quarkonium to $e^{+}e^{-}$ and we check that the non-relativistic expansion is consistent with ERBL evolution and with B-JIMWLK evolution of the target. The results presented here will allow computing the exclusive quarkonium production rate at NLO once the one loop photon wave function with massive quarks, currently under investigation, is known.
|
1903.00408
|
Sabrina Cotogno
|
Wim Cosyn, Sabrina Cotogno, Adam Freese, and C\'edric Lorc\'e
|
The energy-momentum tensor of spin-1 hadrons: formalism
|
16 pages
| null |
10.1140/epjc/s10052-019-6981-3
| null |
hep-ph nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We provide the complete decomposition of the local gauge-invariant
energy-momentum tensor for spin-1 hadrons, including non-conserved terms for
the individual parton flavors and antisymmetric contributions originating from
intrinsic spin. We state sum rules for the gravitational form factors appearing
in this decomposition and provide relations for the mass decomposition, work
balance, total and orbital angular momentum, mass radius, and inertia tensor.
Generalizing earlier work, we derive relations between the total and orbital
angular momentum and the Mellin moments of twist-2 and 3 generalized parton
distributions, accessible in hard exclusive processes with spin-1 targets.
Throughout the work, we comment on the unique features in these relations
originating from the spin-1 nature of the hadron, being absent in the lower
spin cases.
|
[
{
"created": "Fri, 1 Mar 2019 17:01:44 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Jun 2019 14:39:33 GMT",
"version": "v2"
}
] |
2019-06-26
|
[
[
"Cosyn",
"Wim",
""
],
[
"Cotogno",
"Sabrina",
""
],
[
"Freese",
"Adam",
""
],
[
"Lorcé",
"Cédric",
""
]
] |
We provide the complete decomposition of the local gauge-invariant energy-momentum tensor for spin-1 hadrons, including non-conserved terms for the individual parton flavors and antisymmetric contributions originating from intrinsic spin. We state sum rules for the gravitational form factors appearing in this decomposition and provide relations for the mass decomposition, work balance, total and orbital angular momentum, mass radius, and inertia tensor. Generalizing earlier work, we derive relations between the total and orbital angular momentum and the Mellin moments of twist-2 and 3 generalized parton distributions, accessible in hard exclusive processes with spin-1 targets. Throughout the work, we comment on the unique features in these relations originating from the spin-1 nature of the hadron, being absent in the lower spin cases.
|
1602.04192
|
Igor Anikin
|
I.V. Anikin, O.V. Teryaev
|
Factorization theorem, gluon poles and new contributions in
semi-inclusive processes
|
6 pages, 2 figures. Talk given at 6th International Conference on
Physics Opportunities at Electron-Ion Collider, POETIC VI, Palaiseau, France,
7-11 September 2015. arXiv admin note: substantial text overlap with
arXiv:1512.02501
| null |
10.1051/epjconf/201611201002
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the role of gluon poles and the gauge invariance for the hadron
tensors of Drell-Yan and direct photon production processes with the
transversely polarized hadron.
|
[
{
"created": "Fri, 12 Feb 2016 20:04:22 GMT",
"version": "v1"
}
] |
2016-04-20
|
[
[
"Anikin",
"I. V.",
""
],
[
"Teryaev",
"O. V.",
""
]
] |
We discuss the role of gluon poles and the gauge invariance for the hadron tensors of Drell-Yan and direct photon production processes with the transversely polarized hadron.
|
1103.3053
|
Brian Batell
|
Adisorn Adulpravitchai, Brian Batell, Josef Pradler
|
Non-Abelian Discrete Dark Matter
|
12 pages, 6 figures
|
Phys.Lett.B700:207-216,2011
|
10.1016/j.physletb.2011.04.015
| null |
hep-ph astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the minimal model in which dark matter is stabilized by a
non-Abelian discrete symmetry. The symmetry group is taken to be D_3, which is
the smallest non-Abelian finite group. The minimal model contains (nontrivial)
singlet and doublet scalar representations of D_3 which couple to the Standard
Model fields via the Higgs portal. This construction predicts two species of
dark matter over much of the parameter space. Nontrivial interactions under D_3
lead to a novel thermal history of dark matter, while the multi-component
nature of dark matter can be tested by future direct detection experiments.
|
[
{
"created": "Tue, 15 Mar 2011 21:59:24 GMT",
"version": "v1"
}
] |
2015-03-19
|
[
[
"Adulpravitchai",
"Adisorn",
""
],
[
"Batell",
"Brian",
""
],
[
"Pradler",
"Josef",
""
]
] |
We consider the minimal model in which dark matter is stabilized by a non-Abelian discrete symmetry. The symmetry group is taken to be D_3, which is the smallest non-Abelian finite group. The minimal model contains (nontrivial) singlet and doublet scalar representations of D_3 which couple to the Standard Model fields via the Higgs portal. This construction predicts two species of dark matter over much of the parameter space. Nontrivial interactions under D_3 lead to a novel thermal history of dark matter, while the multi-component nature of dark matter can be tested by future direct detection experiments.
|
1606.04957
|
Christopher T. Hill
|
Christopher T. Hill
|
Theorem: A Static Magnetic N-pole Becomes an Oscillating Electric N-pole
in a Cosmic Axion Field
|
2 pages
| null | null |
FERMILAB-PUB-16-222-T
|
hep-ph astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We show for the classical Maxwell equations, including the axion
electromagnetic anomaly source term, that a cosmic axion field induces an
oscillating electric N-moment for any static magnetic N-moment. This is a
straightforward result, accessible to anyone who has taken a first year
graduate course in electrodynamics.
|
[
{
"created": "Wed, 15 Jun 2016 20:01:14 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Jul 2016 16:22:58 GMT",
"version": "v2"
}
] |
2016-07-15
|
[
[
"Hill",
"Christopher T.",
""
]
] |
We show for the classical Maxwell equations, including the axion electromagnetic anomaly source term, that a cosmic axion field induces an oscillating electric N-moment for any static magnetic N-moment. This is a straightforward result, accessible to anyone who has taken a first year graduate course in electrodynamics.
|
0801.1374
|
Byung-Yoon Park
|
Byung-Yoon Park, Mannque Rho, Vicente Vento
|
The Role of the Dilaton in Dense Skyrmion Matter
| null |
Nucl.Phys.A807:28-37,2008
|
10.1016/j.nuclphysa.2008.03.015
| null |
hep-ph nucl-th
| null |
In this note, we report on a remarkable and surprising interplay between the
omega meson and the dilaton chi in the structure of a single skyrmion as well
as in the phase structure of dense skyrmion matter which may have a potentially
important consequence on the properties of compact stars. In our continuing
effort to understand hadronic matter at high density, we have developed a
unified field theoretic formalism for dense skyrmion matter using a single
Lagrangian to describe simultaneously both matter and meson fluctuations and
studied in-medium properties of hadrons. The effective theory used is the
Skyrme model Lagrangian gauged with the vector mesons rho and omega,
implemented with the dilaton field that describes the spontaneously broken
scale symmetry of QCD, in a form consistent with the symmetries of QCD and our
expectations regarding the high density limit. We analyze the restoration of
scale invariance and chiral symmetry as the density of the system increases. In
order to preserve the restoration of scale symmetry and chiral symmetry,
signalled in our case by the vanishing of the expectation value of the dilaton,
and to be consistent with the vector manifestation of hidden local symmetry, a
density dependent omega coupling is introduced. We uncover the crucial role
played by both the dilaton and the omega meson in the phase structure of dense
medium and discover how two different phase transition regimes arise as we dial
the dilaton mass.
|
[
{
"created": "Wed, 9 Jan 2008 15:06:30 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Park",
"Byung-Yoon",
""
],
[
"Rho",
"Mannque",
""
],
[
"Vento",
"Vicente",
""
]
] |
In this note, we report on a remarkable and surprising interplay between the omega meson and the dilaton chi in the structure of a single skyrmion as well as in the phase structure of dense skyrmion matter which may have a potentially important consequence on the properties of compact stars. In our continuing effort to understand hadronic matter at high density, we have developed a unified field theoretic formalism for dense skyrmion matter using a single Lagrangian to describe simultaneously both matter and meson fluctuations and studied in-medium properties of hadrons. The effective theory used is the Skyrme model Lagrangian gauged with the vector mesons rho and omega, implemented with the dilaton field that describes the spontaneously broken scale symmetry of QCD, in a form consistent with the symmetries of QCD and our expectations regarding the high density limit. We analyze the restoration of scale invariance and chiral symmetry as the density of the system increases. In order to preserve the restoration of scale symmetry and chiral symmetry, signalled in our case by the vanishing of the expectation value of the dilaton, and to be consistent with the vector manifestation of hidden local symmetry, a density dependent omega coupling is introduced. We uncover the crucial role played by both the dilaton and the omega meson in the phase structure of dense medium and discover how two different phase transition regimes arise as we dial the dilaton mass.
|
hep-ph/0305282
|
Laura Reina
|
S. Dawson (BNL), L.H. Orr (Rochester U.), L.Reina (FSU), D.Wackeroth
(SUNY, Buffalo)
|
Associated Higgs boson production with heavy quarks
|
6 pages, 4 figures, Talk given at the XXXVIII Rencontres de Moriond
on Electroweak Interactions and Unified Theories, Les Arcs, France, March
15-22, 2003
| null | null |
BNL-HET-03/10, FSU-HEP-2003-0513, UB-HET-03/04
|
hep-ph
| null |
The production of a Higgs boson in association with a pair of t-tbar quarks
will play a very important role at both hadron and lepton colliders. We review
the status of theoretical predictions and their relevance to Higgs boson
studies, with particular emphasis on the recently calculated NLO QCD
corrections to the inclusive cross section for p-pbar,pp -> t-tbar-h. We
conclude by briefly discussing the case of exclusive b-bbar-h production and
the potential of this process in revealing signals of new physics beyond the
Standard Model.
|
[
{
"created": "Sun, 25 May 2003 01:59:30 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Dawson",
"S.",
"",
"BNL"
],
[
"Orr",
"L. H.",
"",
"Rochester U."
],
[
"Reina",
"L.",
"",
"FSU"
],
[
"Wackeroth",
"D.",
"",
"SUNY, Buffalo"
]
] |
The production of a Higgs boson in association with a pair of t-tbar quarks will play a very important role at both hadron and lepton colliders. We review the status of theoretical predictions and their relevance to Higgs boson studies, with particular emphasis on the recently calculated NLO QCD corrections to the inclusive cross section for p-pbar,pp -> t-tbar-h. We conclude by briefly discussing the case of exclusive b-bbar-h production and the potential of this process in revealing signals of new physics beyond the Standard Model.
|
hep-ph/0601136
|
Jonathan Rosner
|
Michael Gronau, Yuval Grossman, and Jonathan L. Rosner
|
Isospin in $B$ Decays and the $(B^0 \bar B^0)/(B^+ B^-)$ Production
Ratio
|
6 pages, no figures, to be published in Phys. Rev. D (Brief Reports).
One reference and acknowledgment added; slight text change
|
Phys.Rev.D73:057501,2006
|
10.1103/PhysRevD.73.057501
|
TECHNION-PH-2006-02, EFI 06-02
|
hep-ph
| null |
Methods are proposed for measuring the ratio $R^{+/0} = \Gamma(\Upsilon(4S)
\to B^+ B^-)/$ $\Gamma(\Upsilon(4S) \to \bo \ob)$ without assuming isospin
invariance in exclusive hadronic decays such as $B \to J/\psi K$. The validity
of isospin invariance in various B decays is discussed. Isospin violations are
expected to be especially small in inclusive semileptonic decays, so that
$\Gamma(B^+ \to X_c^0 \ell^+ \nu_\ell) = \Gamma(B^0 \to X_c^- \ell^+ \nu_\ell)$
is expected to hold at the sub-percent level. Suggestions are made for
utilizing this relation. The accuracy of a ``double-tag'' method for obtaining
$R^{+/0}$, such as that used for measuring the $D^+ D^-/D^0 \od$ ratio at the
$\psi'' \equiv \psi(3770)$, is also estimated.
|
[
{
"created": "Tue, 17 Jan 2006 18:48:47 GMT",
"version": "v1"
},
{
"created": "Mon, 27 Feb 2006 15:29:32 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Gronau",
"Michael",
""
],
[
"Grossman",
"Yuval",
""
],
[
"Rosner",
"Jonathan L.",
""
]
] |
Methods are proposed for measuring the ratio $R^{+/0} = \Gamma(\Upsilon(4S) \to B^+ B^-)/$ $\Gamma(\Upsilon(4S) \to \bo \ob)$ without assuming isospin invariance in exclusive hadronic decays such as $B \to J/\psi K$. The validity of isospin invariance in various B decays is discussed. Isospin violations are expected to be especially small in inclusive semileptonic decays, so that $\Gamma(B^+ \to X_c^0 \ell^+ \nu_\ell) = \Gamma(B^0 \to X_c^- \ell^+ \nu_\ell)$ is expected to hold at the sub-percent level. Suggestions are made for utilizing this relation. The accuracy of a ``double-tag'' method for obtaining $R^{+/0}$, such as that used for measuring the $D^+ D^-/D^0 \od$ ratio at the $\psi'' \equiv \psi(3770)$, is also estimated.
|
1710.06859
|
Ian Moult
|
Ian Moult, Benjamin Nachman and Duff Neill
|
Convolved Substructure: Analytically Decorrelating Jet Substructure
Observables
|
20 pages, 11 figures. v2. Corrected typo in legend in Figure 5.
Updated Figure 11, minor modification to conclusions on discrimination power.
v3. Updated to published version. Minor typos corrected
| null |
10.1007/JHEP05(2018)002
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A number of recent applications of jet substructure, in particular searches
for light new particles, require substructure observables that are decorrelated
with the jet mass. In this paper we introduce the Convolved SubStructure (CSS)
approach, which uses a theoretical understanding of the observable to
decorrelate the complete shape of its distribution. This decorrelation is
performed by convolution with a shape function whose parameters and mass
dependence are derived analytically. We consider in detail the case of the
$D_2$ observable and perform an illustrative case study using a search for a
light hadronically decaying $Z'$. We find that the CSS approach completely
decorrelates the $D_2$ observable over a wide range of masses. Our approach
highlights the importance of improving the theoretical understanding of jet
substructure observables to exploit increasingly subtle features for
performance.
|
[
{
"created": "Wed, 18 Oct 2017 18:00:01 GMT",
"version": "v1"
},
{
"created": "Sun, 29 Oct 2017 22:45:28 GMT",
"version": "v2"
},
{
"created": "Mon, 14 Jan 2019 21:28:55 GMT",
"version": "v3"
}
] |
2019-01-16
|
[
[
"Moult",
"Ian",
""
],
[
"Nachman",
"Benjamin",
""
],
[
"Neill",
"Duff",
""
]
] |
A number of recent applications of jet substructure, in particular searches for light new particles, require substructure observables that are decorrelated with the jet mass. In this paper we introduce the Convolved SubStructure (CSS) approach, which uses a theoretical understanding of the observable to decorrelate the complete shape of its distribution. This decorrelation is performed by convolution with a shape function whose parameters and mass dependence are derived analytically. We consider in detail the case of the $D_2$ observable and perform an illustrative case study using a search for a light hadronically decaying $Z'$. We find that the CSS approach completely decorrelates the $D_2$ observable over a wide range of masses. Our approach highlights the importance of improving the theoretical understanding of jet substructure observables to exploit increasingly subtle features for performance.
|
1910.12917
|
Ariane Dekker
|
Ariane Dekker, Marco Chianese, Shin'ichiro Ando
|
Probing dark matter signals in neutrino telescopes through angular power
spectrum
|
14 pages, 9 figures. v2: KM3NeT results updated after correcting the
effective area normalization. v3: Accepted for publication in JCAP
|
JCAP 09 (2020) 007
|
10.1088/1475-7516/2020/09/007
| null |
hep-ph astro-ph.CO astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The hypothesis of two different components in the high-energy neutrino flux
observed with IceCube has been proposed to solve the tension among different
data-sets and to account for an excess of neutrino events at 100 TeV. In
addition to a standard astrophysical power-law component, the second component
might be explained by a different class of astrophysical sources, or more
intriguingly, might originate from decaying or annihilating dark matter. These
two scenarios can be distinguished thanks to the different expected angular
distributions of neutrino events. Neutrino signals from dark matter are indeed
expected to have some correlation with the extended galactic dark matter halo.
In this paper, we perform angular power spectrum analyses of simulated neutrino
sky maps to investigate the two-component hypothesis with a contribution from
dark matter. We provide current constraints and expected sensitivity to dark
matter parameters for future neutrino telescopes such as IceCube-Gen2 and
KM3NeT. The latter is found to be more sensitive than IceCube-Gen2 to look for
a dark matter signal at low energies towards the galactic center. Finally, we
show that after 10 years of data-taking, they will firmly probe the current
best-fit scenario for decaying dark matter by exploiting the angular
information only.
|
[
{
"created": "Mon, 28 Oct 2019 19:00:01 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Apr 2020 16:18:20 GMT",
"version": "v2"
},
{
"created": "Wed, 2 Sep 2020 12:43:20 GMT",
"version": "v3"
}
] |
2020-09-03
|
[
[
"Dekker",
"Ariane",
""
],
[
"Chianese",
"Marco",
""
],
[
"Ando",
"Shin'ichiro",
""
]
] |
The hypothesis of two different components in the high-energy neutrino flux observed with IceCube has been proposed to solve the tension among different data-sets and to account for an excess of neutrino events at 100 TeV. In addition to a standard astrophysical power-law component, the second component might be explained by a different class of astrophysical sources, or more intriguingly, might originate from decaying or annihilating dark matter. These two scenarios can be distinguished thanks to the different expected angular distributions of neutrino events. Neutrino signals from dark matter are indeed expected to have some correlation with the extended galactic dark matter halo. In this paper, we perform angular power spectrum analyses of simulated neutrino sky maps to investigate the two-component hypothesis with a contribution from dark matter. We provide current constraints and expected sensitivity to dark matter parameters for future neutrino telescopes such as IceCube-Gen2 and KM3NeT. The latter is found to be more sensitive than IceCube-Gen2 to look for a dark matter signal at low energies towards the galactic center. Finally, we show that after 10 years of data-taking, they will firmly probe the current best-fit scenario for decaying dark matter by exploiting the angular information only.
|
2306.15109
|
Fady Bishara
|
Fady Bishara and Zhuoni Qian
|
Complementary constraints on $Zb\bar{b}$ couplings at the LHC
|
18 + 8 pages, 9 figures
| null | null |
DESY 23-086
|
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
We propose a new strategy to probe the $Z$ boson couplings to bottom and
charm quarks at the LHC. In this work we mainly focus on the case of bottom
quarks. Here, the $Z$ boson is produced in association with two $b$-jets and
decays to electrons or muons. In this final state, tagging the charge of the
$b$-jets allows us to measure the charge asymmetry and thus to directly probe
the $Zb\bar{b}$ couplings. The leptonic final state not only allows us to
cleanly reconstruct the $Z$ boson but also to mitigate the otherwise
overwhelming backgrounds. Furthermore, while LEP could only scan a limited
range of dilepton invariant masses, there is no such limitation at the LHC.
Consequently, this allows us to make full use of the interference between the
amplitudes mediated by a $Z$ boson and a photon. Using the full high-luminosity
LHC dataset of $3~\text{ab}^{-1}$ and with the current flavor and
charge-tagging capabilities would allow us to reject the wrong-sign
right-handed coupling solution by 4$\sigma$. Further improving the
charge-tagging efficiency would disfavor it by 6$\sigma$.
|
[
{
"created": "Mon, 26 Jun 2023 23:17:11 GMT",
"version": "v1"
}
] |
2023-06-28
|
[
[
"Bishara",
"Fady",
""
],
[
"Qian",
"Zhuoni",
""
]
] |
We propose a new strategy to probe the $Z$ boson couplings to bottom and charm quarks at the LHC. In this work we mainly focus on the case of bottom quarks. Here, the $Z$ boson is produced in association with two $b$-jets and decays to electrons or muons. In this final state, tagging the charge of the $b$-jets allows us to measure the charge asymmetry and thus to directly probe the $Zb\bar{b}$ couplings. The leptonic final state not only allows us to cleanly reconstruct the $Z$ boson but also to mitigate the otherwise overwhelming backgrounds. Furthermore, while LEP could only scan a limited range of dilepton invariant masses, there is no such limitation at the LHC. Consequently, this allows us to make full use of the interference between the amplitudes mediated by a $Z$ boson and a photon. Using the full high-luminosity LHC dataset of $3~\text{ab}^{-1}$ and with the current flavor and charge-tagging capabilities would allow us to reject the wrong-sign right-handed coupling solution by 4$\sigma$. Further improving the charge-tagging efficiency would disfavor it by 6$\sigma$.
|
1109.1832
|
Atri Bhattacharya
|
Atri Bhattacharya, Raj Gandhi and Satyanarayan Mukhopadhyay
|
Revisiting the implications of CPT and unitarity for baryogenesis and
leptogenesis
|
v2: Text improved and clarified; discussion on Leptogenesis model
improved, new Baryogenesis example added; version to appear in Phys.Rev.D; 10
pages, 4 figs
|
Phys. Rev. D 89, 116014 (2014)
|
10.1103/PhysRevD.89.116014
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In the context of GUT baryogenesis models, a well-known theorem asserts that
CPT conservation and the unitarity of S-matrix require that the lowest order
contribution that leads to the generation of a non-zero net CP-violation via
the decay of a heavy particle must be to $\mathcal{O}({\alpha_\slashed{B}}^3)$,
where $\alpha_\slashed{B}$ is a baryon number (B) violating coupling. We
revisit this theorem (which holds for lepton number (L) violation, and hence
for leptogenesis as well) and examine its implications for models where the
particle content allows the heavy particle to also decay via modes which
conserve B (or L) in addition to modes which do not. We systematically expand
the S-matrix order by order in B\slash L-violating couplings, and show, in such
cases, that the net CP-violation is non-zero even to
$\mathcal{O}({\alpha_\slashed{B}}^2)$, without actually contradicting the
theorem. By replacing a B/L violating coupling (usually constrained to be
small) by a relatively unconstrained B/L conserving one, our result may allow
for sufficient CP violation in models where it may otherwise have been
difficult to generate the observed baryon asymmetry. As an explicit application
of this result, we construct a model in low-scale leptogenesis.
|
[
{
"created": "Thu, 8 Sep 2011 20:02:14 GMT",
"version": "v1"
},
{
"created": "Wed, 4 Jun 2014 20:20:05 GMT",
"version": "v2"
}
] |
2014-06-24
|
[
[
"Bhattacharya",
"Atri",
""
],
[
"Gandhi",
"Raj",
""
],
[
"Mukhopadhyay",
"Satyanarayan",
""
]
] |
In the context of GUT baryogenesis models, a well-known theorem asserts that CPT conservation and the unitarity of S-matrix require that the lowest order contribution that leads to the generation of a non-zero net CP-violation via the decay of a heavy particle must be to $\mathcal{O}({\alpha_\slashed{B}}^3)$, where $\alpha_\slashed{B}$ is a baryon number (B) violating coupling. We revisit this theorem (which holds for lepton number (L) violation, and hence for leptogenesis as well) and examine its implications for models where the particle content allows the heavy particle to also decay via modes which conserve B (or L) in addition to modes which do not. We systematically expand the S-matrix order by order in B\slash L-violating couplings, and show, in such cases, that the net CP-violation is non-zero even to $\mathcal{O}({\alpha_\slashed{B}}^2)$, without actually contradicting the theorem. By replacing a B/L violating coupling (usually constrained to be small) by a relatively unconstrained B/L conserving one, our result may allow for sufficient CP violation in models where it may otherwise have been difficult to generate the observed baryon asymmetry. As an explicit application of this result, we construct a model in low-scale leptogenesis.
|
2301.04057
|
Sangeeta Dey
|
Sangeeta Dey and Mahadev Patgiri
|
Study of neutrino mass matrices with vanishing trace and one vanishing
minor
| null | null |
10.1103/PhysRevD.107.035012
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
In this work we carry out a systematic texture study of the neutrino mass
matrix with the ansatzes - (i) one vanishing minor and (ii) the zero sum of the
mass eigenvalues with the CP phases (henceforth vanishing trace). There are six
possible textures of a neutrino mass matrix with one vanishing minor. The
viability of each texture is checked with $3\sigma$ values of current neutrino
data by drawing scatter plots. In our analysis we are motivated to use the
ratio of solar to atmospheric mass-squared differences $R_{\nu}$ for its
precise measurement (and also the atmospheric mixing angle $\theta_{23}$) to
constrain phenomenologically first the Dirac CP phase $\delta$ in the range of
$0^{\degree}-360^{\degree}$ for a given texture with the solutions of the
constraint equations. Subsequently we employ this constrained $\delta$ to
determine the range of completely unknown Majorana CP Phases ($\alpha$ and
$\beta$) for all the viable textures. We also check the neutrinoless double
beta decay rate, $|m_{ee}|$ and the Jarlskog invariant, $J_{cp}$ for the
textures. Finally the symmetry realization of all the viable textures under the
flavor symmetry group $Z_5$ via seesaw mechanism is implemented along with the
FN mechanism to determine mass hierarchy structure.
|
[
{
"created": "Tue, 10 Jan 2023 16:17:28 GMT",
"version": "v1"
}
] |
2023-02-22
|
[
[
"Dey",
"Sangeeta",
""
],
[
"Patgiri",
"Mahadev",
""
]
] |
In this work we carry out a systematic texture study of the neutrino mass matrix with the ansatzes - (i) one vanishing minor and (ii) the zero sum of the mass eigenvalues with the CP phases (henceforth vanishing trace). There are six possible textures of a neutrino mass matrix with one vanishing minor. The viability of each texture is checked with $3\sigma$ values of current neutrino data by drawing scatter plots. In our analysis we are motivated to use the ratio of solar to atmospheric mass-squared differences $R_{\nu}$ for its precise measurement (and also the atmospheric mixing angle $\theta_{23}$) to constrain phenomenologically first the Dirac CP phase $\delta$ in the range of $0^{\degree}-360^{\degree}$ for a given texture with the solutions of the constraint equations. Subsequently we employ this constrained $\delta$ to determine the range of completely unknown Majorana CP Phases ($\alpha$ and $\beta$) for all the viable textures. We also check the neutrinoless double beta decay rate, $|m_{ee}|$ and the Jarlskog invariant, $J_{cp}$ for the textures. Finally the symmetry realization of all the viable textures under the flavor symmetry group $Z_5$ via seesaw mechanism is implemented along with the FN mechanism to determine mass hierarchy structure.
|
hep-ph/9601240
|
Mohamed Tarek Hussein
|
M.T. Hussein and N.M. Hassan (Cairo University)
|
High Energy Electron Proton Scattering in View of Born Approximation
|
13 pages Revtex + 5 figures as postscript
| null | null |
Cairo-Phys-95-121
|
hep-ph
| null |
The hadronic quark structure is investigated in the frame of high energy
electron proton scattering. A phenomenological model based on the Born
approximation is used to calculate the transition matrix element for the quark
system forming the proton target. A potential of electromagnetic nature is
assumed for the calculation of the multiple scattering of electron with the
constituent valance quarks of the proton. It is found that the first two terms
of the Born approximation are sufficient to describe the experimental data of
differential cross section for the electron proton system only at low momentum
transfer square. On the other hand, a two body scattering amplitude with a
relevant form factor may give proper agreement extended to high momentum
transfer square region. A harmonic oscillator wave function is used to
reproduce the data of the experiment at low momentum transfer. This satisfies
quietly the confinement condition of the quarks in the hadron system. However
the data of the experiment at relatively high momentum transfer, show that
hadronic quarks behave more freely and may be described by just a Coulomb wave
function.
PACS: 13.40.Fn , 25.40.Cm
|
[
{
"created": "Thu, 11 Jan 1996 11:54:36 GMT",
"version": "v1"
},
{
"created": "Sat, 13 Jan 1996 16:29:56 GMT",
"version": "v2"
},
{
"created": "Sun, 30 Jun 1996 14:01:29 GMT",
"version": "v3"
}
] |
2008-02-03
|
[
[
"Hussein",
"M. T.",
"",
"Cairo University"
],
[
"Hassan",
"N. M.",
"",
"Cairo University"
]
] |
The hadronic quark structure is investigated in the frame of high energy electron proton scattering. A phenomenological model based on the Born approximation is used to calculate the transition matrix element for the quark system forming the proton target. A potential of electromagnetic nature is assumed for the calculation of the multiple scattering of electron with the constituent valance quarks of the proton. It is found that the first two terms of the Born approximation are sufficient to describe the experimental data of differential cross section for the electron proton system only at low momentum transfer square. On the other hand, a two body scattering amplitude with a relevant form factor may give proper agreement extended to high momentum transfer square region. A harmonic oscillator wave function is used to reproduce the data of the experiment at low momentum transfer. This satisfies quietly the confinement condition of the quarks in the hadron system. However the data of the experiment at relatively high momentum transfer, show that hadronic quarks behave more freely and may be described by just a Coulomb wave function. PACS: 13.40.Fn , 25.40.Cm
|
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