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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1012.2733
|
Karim Ghorbani
|
Karim Ghorbani, Mohammad.M. Yazdanpanah, Abolfazl Mirjalili
|
Pion mass dependence of the $K_{l3}$ semileptonic scalar form factor
within finite volume
|
19 pages, 5 figures, accepted for publication in EPJC
| null |
10.1140/epjc/s10052-011-1671-9
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We calculate the scalar semileptonic kaon decay in finite volume at the
momentum transfer $t_{m} = (m_{K} - m_{\pi})^2$, using chiral perturbation
theory. At first we obtain the hadronic matrix element to be calculated in
finite volume. We then evaluate the finite size effects for two volumes with $L
= 1.83 fm$ and $L= 2.73 fm$ and find that the difference between the finite
volume corrections of the two volumes are larger than the difference as quoted
in \cite{Boyle2007a}. It appears then that the pion masses used for the scalar
form factor in ChPT are large which result in large finite volume corrections.
If appropriate values for pion mass are used, we believe that the finite size
effects estimated in this paper can be useful for Lattice data to extrapolate
at large lattice size.
|
[
{
"created": "Mon, 13 Dec 2010 14:21:40 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Jun 2011 19:07:24 GMT",
"version": "v2"
}
] |
2015-05-20
|
[
[
"Ghorbani",
"Karim",
""
],
[
"Yazdanpanah",
"Mohammad. M.",
""
],
[
"Mirjalili",
"Abolfazl",
""
]
] |
We calculate the scalar semileptonic kaon decay in finite volume at the momentum transfer $t_{m} = (m_{K} - m_{\pi})^2$, using chiral perturbation theory. At first we obtain the hadronic matrix element to be calculated in finite volume. We then evaluate the finite size effects for two volumes with $L = 1.83 fm$ and $L= 2.73 fm$ and find that the difference between the finite volume corrections of the two volumes are larger than the difference as quoted in \cite{Boyle2007a}. It appears then that the pion masses used for the scalar form factor in ChPT are large which result in large finite volume corrections. If appropriate values for pion mass are used, we believe that the finite size effects estimated in this paper can be useful for Lattice data to extrapolate at large lattice size.
|
0902.4287
|
A. H. Rezaeian
|
B. Z. Kopeliovich, E. Levin, A. H. Rezaeian, Ivan Schmidt
|
Direct photons at forward rapidities in high-energy pp collisions
|
7 pages, 8 figures, minor clarifications added. The version to appear
in PLB
|
Phys.Lett.B675:190-195,2009
|
10.1016/j.physletb.2009.04.023
|
USM-TH-245
|
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate direct photon production in pp collisions at the energies of
RHIC, CDF and LHC, at different rapidities employing various color-dipole
models. The cross section peaks at forward rapidities due to the abelian
dynamics of photon radiation. This opens new opportunities for measurement of
direct photons at forward rapidities, where the background from radiative
hadronic decays is strongly suppressed. Our model calculations show that photon
production is sensitive to the gluon saturation effects, and strongly depends
on the value of the anomalous dimension.
|
[
{
"created": "Wed, 25 Feb 2009 17:32:50 GMT",
"version": "v1"
},
{
"created": "Sat, 28 Feb 2009 15:56:49 GMT",
"version": "v2"
},
{
"created": "Wed, 8 Apr 2009 21:13:26 GMT",
"version": "v3"
}
] |
2009-04-22
|
[
[
"Kopeliovich",
"B. Z.",
""
],
[
"Levin",
"E.",
""
],
[
"Rezaeian",
"A. H.",
""
],
[
"Schmidt",
"Ivan",
""
]
] |
We investigate direct photon production in pp collisions at the energies of RHIC, CDF and LHC, at different rapidities employing various color-dipole models. The cross section peaks at forward rapidities due to the abelian dynamics of photon radiation. This opens new opportunities for measurement of direct photons at forward rapidities, where the background from radiative hadronic decays is strongly suppressed. Our model calculations show that photon production is sensitive to the gluon saturation effects, and strongly depends on the value of the anomalous dimension.
|
1307.3546
|
James Gainer
|
James S. Gainer, Joseph Lykken, Konstantin T. Matchev, Stephen Mrenna,
Myeonghun Park
|
The Matrix Element Method: Past, Present, and Future
|
3 pages, no figures. Snowmass white paper. Minor revisions.
References added
| null | null |
CERN-PH-TH-2013-165, FERMILAB-FN-0963-CD-T
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The increasing use of multivariate methods, and in particular the Matrix
Element Method (MEM), represents a revolution in experimental particle physics.
With continued exponential growth in computing capabilities, the use of
sophisticated multivariate methods-- already common-- will soon become
ubiquitous and ultimately almost compulsory. While the existence of
sophisticated algorithms for disentangling signal and background might naively
suggest a diminished role for theorists, the use of the MEM, with its inherent
connection to the calculation of differential cross sections will benefit from
collaboration between theorists and experimentalists. In this white paper, we
will briefly describe the MEM and some of its recent uses, note some current
issues and potential resolutions, and speculate about exciting future
opportunities.
|
[
{
"created": "Fri, 12 Jul 2013 19:40:29 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Jul 2013 18:29:11 GMT",
"version": "v2"
}
] |
2013-07-29
|
[
[
"Gainer",
"James S.",
""
],
[
"Lykken",
"Joseph",
""
],
[
"Matchev",
"Konstantin T.",
""
],
[
"Mrenna",
"Stephen",
""
],
[
"Park",
"Myeonghun",
""
]
] |
The increasing use of multivariate methods, and in particular the Matrix Element Method (MEM), represents a revolution in experimental particle physics. With continued exponential growth in computing capabilities, the use of sophisticated multivariate methods-- already common-- will soon become ubiquitous and ultimately almost compulsory. While the existence of sophisticated algorithms for disentangling signal and background might naively suggest a diminished role for theorists, the use of the MEM, with its inherent connection to the calculation of differential cross sections will benefit from collaboration between theorists and experimentalists. In this white paper, we will briefly describe the MEM and some of its recent uses, note some current issues and potential resolutions, and speculate about exciting future opportunities.
|
hep-ph/9804411
|
Masashi Hashimoto
|
M. Hashimoto, K.-I. Izawa, M. Yamaguchi and T. Yanagida
|
Gravitino Overproduction through Moduli Decay
|
6 pages, latex
|
Prog.Theor.Phys. 100 (1998) 395-398
|
10.1143/PTP.100.395
|
UT-812, TU-544, RCNS-98-06
|
hep-ph
| null |
We derive cosmological constraints on the masses of generic scalar fields
which decay only through gravitationally suppressed interactions into unstable
gravitinos and ordinary particles in the supersymmetric standard model. For the
gravitino mass 100GeV-1TeV, the scalar masses should be larger than 100TeV to
keep the success of big-bang nucleosynthesis if no late-time entropy production
dilutes the gravitino density.
|
[
{
"created": "Mon, 27 Apr 1998 05:06:03 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Hashimoto",
"M.",
""
],
[
"Izawa",
"K. -I.",
""
],
[
"Yamaguchi",
"M.",
""
],
[
"Yanagida",
"T.",
""
]
] |
We derive cosmological constraints on the masses of generic scalar fields which decay only through gravitationally suppressed interactions into unstable gravitinos and ordinary particles in the supersymmetric standard model. For the gravitino mass 100GeV-1TeV, the scalar masses should be larger than 100TeV to keep the success of big-bang nucleosynthesis if no late-time entropy production dilutes the gravitino density.
|
1709.04486
|
Peter Stoffer
|
Elizabeth E. Jenkins, Aneesh V. Manohar, Peter Stoffer
|
Low-Energy Effective Field Theory below the Electroweak Scale: Operators
and Matching
|
46 pages, 22 tables; version published in JHEP; includes erratum JHEP
12 (2023) 043
|
JHEP 03 (2018) 016
|
10.1007/JHEP03(2018)016
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The gauge-invariant operators up to dimension six in the low-energy effective
field theory below the electroweak scale are classified. There are 70 Hermitian
dimension-five and 3631 Hermitian dimension-six operators that conserve baryon
and lepton number, as well as $\Delta B= \pm \Delta L = \pm 1$, $\Delta L=\pm
2$, and $\Delta L=\pm 4$ operators. The matching onto these operators from the
Standard Model Effective Field Theory (SMEFT) up to order $1/\Lambda^2$ is
computed at tree level. SMEFT imposes constraints on the coefficients of the
low-energy effective theory, which can be checked experimentally to determine
whether the electroweak gauge symmetry is broken by a single fundamental scalar
doublet as in SMEFT. Our results, when combined with the one-loop anomalous
dimensions of the low-energy theory and the one-loop anomalous dimensions of
SMEFT, allow one to compute the low-energy implications of new physics to
leading-log accuracy, and combine them consistently with high-energy LHC
constraints.
|
[
{
"created": "Wed, 13 Sep 2017 18:07:21 GMT",
"version": "v1"
},
{
"created": "Thu, 8 Mar 2018 18:45:52 GMT",
"version": "v2"
},
{
"created": "Wed, 20 Mar 2024 08:48:07 GMT",
"version": "v3"
}
] |
2024-03-21
|
[
[
"Jenkins",
"Elizabeth E.",
""
],
[
"Manohar",
"Aneesh V.",
""
],
[
"Stoffer",
"Peter",
""
]
] |
The gauge-invariant operators up to dimension six in the low-energy effective field theory below the electroweak scale are classified. There are 70 Hermitian dimension-five and 3631 Hermitian dimension-six operators that conserve baryon and lepton number, as well as $\Delta B= \pm \Delta L = \pm 1$, $\Delta L=\pm 2$, and $\Delta L=\pm 4$ operators. The matching onto these operators from the Standard Model Effective Field Theory (SMEFT) up to order $1/\Lambda^2$ is computed at tree level. SMEFT imposes constraints on the coefficients of the low-energy effective theory, which can be checked experimentally to determine whether the electroweak gauge symmetry is broken by a single fundamental scalar doublet as in SMEFT. Our results, when combined with the one-loop anomalous dimensions of the low-energy theory and the one-loop anomalous dimensions of SMEFT, allow one to compute the low-energy implications of new physics to leading-log accuracy, and combine them consistently with high-energy LHC constraints.
|
1001.1054
|
Lusaka Bhattacharya
|
Lusaka Bhattacharya and Pradip Roy
|
Jet-photons from an anisotropic {\em Quark-Gluon-Plasma}
|
15 pages, 11 eps figures, Accepted for publication in Journal of
Physics G
|
J.Phys.G37:105010,2010
|
10.1088/0954-3899/37/10/105010
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We calculate the $p_T$ distributions of jet conversion photons from {\em
Quark Gluon Plasma} with pre-equilibrium momentum-space anisotropy. A
phenomenological model has been used for the time evolution of hard momentum
scale $p_{\rm hard}(\tau)$ and anisotropy parameter $\xi(\tau)$. As a result of
pre-equilibrium momentum-space anisotropy, we find significant modification of
the jet conversion photon $p_T$ distribution. For example, with {\em fixed
initial condition} (FIC) pre-equilibrium anisotropy, we predict significant
enhancement of the jet-photon $p_T$ distribution in the entire region, whereas
for pre-equilibrium anisotropy with {\em fixed final multiplicity} (FFM),
suppression of the jet conversion photons $p_T$ distribution is observed. The
results with FFM (as it is the most realistic situation) have been compared
with high $p_T$ PHENIX photon data. It is found that the data is reproduced
well if the isotropization time lies within $1.5$ fm/c.
|
[
{
"created": "Thu, 7 Jan 2010 11:26:21 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Jul 2010 09:30:45 GMT",
"version": "v2"
}
] |
2011-03-28
|
[
[
"Bhattacharya",
"Lusaka",
""
],
[
"Roy",
"Pradip",
""
]
] |
We calculate the $p_T$ distributions of jet conversion photons from {\em Quark Gluon Plasma} with pre-equilibrium momentum-space anisotropy. A phenomenological model has been used for the time evolution of hard momentum scale $p_{\rm hard}(\tau)$ and anisotropy parameter $\xi(\tau)$. As a result of pre-equilibrium momentum-space anisotropy, we find significant modification of the jet conversion photon $p_T$ distribution. For example, with {\em fixed initial condition} (FIC) pre-equilibrium anisotropy, we predict significant enhancement of the jet-photon $p_T$ distribution in the entire region, whereas for pre-equilibrium anisotropy with {\em fixed final multiplicity} (FFM), suppression of the jet conversion photons $p_T$ distribution is observed. The results with FFM (as it is the most realistic situation) have been compared with high $p_T$ PHENIX photon data. It is found that the data is reproduced well if the isotropization time lies within $1.5$ fm/c.
|
hep-ph/9910257
|
Ulrich Nierste
|
U. Nierste
|
Theoretical status of epsilon'/epsilon
|
10 pages, 5 figures, Talk at QCD 99, Montpellier, uses
fleqn,espcrc2,epsf,rotate,times
|
Nucl.Phys.Proc.Suppl.86:329-338,2000
|
10.1016/S0920-5632(00)00583-1
|
FERMILAB-Conf-99/288-T
|
hep-ph
| null |
I give a detailed introduction into the theoretical formalism for
epsilon'/epsilon, which measures direct CP-violation in K -> pi pi decays. The
current status of hadronic matrix elements and the strange quark mass is
discussed. Several possible explanations of the unexpectedly high experimental
results for epsilon'/epsilon are pointed out: A small strange quark mass, an
enhancement of the hadronic parameter B_6^(1/2) from the sigma resonance, an
underestimate of isospin breaking and possible new physics contributions in the
sdZ-vertex and the sd-gluon-vertex.
|
[
{
"created": "Wed, 6 Oct 1999 20:31:06 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Nierste",
"U.",
""
]
] |
I give a detailed introduction into the theoretical formalism for epsilon'/epsilon, which measures direct CP-violation in K -> pi pi decays. The current status of hadronic matrix elements and the strange quark mass is discussed. Several possible explanations of the unexpectedly high experimental results for epsilon'/epsilon are pointed out: A small strange quark mass, an enhancement of the hadronic parameter B_6^(1/2) from the sigma resonance, an underestimate of isospin breaking and possible new physics contributions in the sdZ-vertex and the sd-gluon-vertex.
|
2405.17564
|
Debasish Borah
|
Amit Adhikary, Debasish Borah, Satyabrata Mahapatra, Indrajit Saha,
Narendra Sahu, Vicky Thounaojam
|
Rescuing thermally under-abundant dark matter with a first-order phase
transition
|
11 pages, 6 captioned figures
| null | null | null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a novel scenario where thermally under-abundant dark matter (DM)
can be revived with a first-order phase transition (FOPT). In the absence of
FOPT, thermal DM abundance remains suppressed due to efficient annihilation via
mediators. A FOPT brings sharp change to the mass of the mediator at the
nucleation temperature such that the final DM relic agrees with observations.
We implement this idea in a scenario where DM interacts via a mediator whose
initial mass is of same order as DM mass keeping DM annihilation either in
allowed or forbidden ballpark. As the mediator mass decreases sharply at the
nucleation temperature of the FOPT, the frozen out DM suffers further depletion
while keeping final relic within observed limits. DM with sizeable interactions
with a light mediator can also give rise to the required self-interactions
necessary to solve the small scale structure issues of cold dark matter. While
the mechanism is generic to any thermal DM mass, choosing it in the GeV
ballpark forces the FOPT to MeV scale which predicts stochastic gravitational
waves with nano-Hz frequencies within reach of pulsar timing array (PTA) based
experiments like NANOGrav. The existence of light scalar mediator and its
mixing with the Higgs keep the scenario verifiable at different particle
physics experiments.
|
[
{
"created": "Mon, 27 May 2024 18:00:12 GMT",
"version": "v1"
}
] |
2024-05-29
|
[
[
"Adhikary",
"Amit",
""
],
[
"Borah",
"Debasish",
""
],
[
"Mahapatra",
"Satyabrata",
""
],
[
"Saha",
"Indrajit",
""
],
[
"Sahu",
"Narendra",
""
],
[
"Thounaojam",
"Vicky",
""
]
] |
We propose a novel scenario where thermally under-abundant dark matter (DM) can be revived with a first-order phase transition (FOPT). In the absence of FOPT, thermal DM abundance remains suppressed due to efficient annihilation via mediators. A FOPT brings sharp change to the mass of the mediator at the nucleation temperature such that the final DM relic agrees with observations. We implement this idea in a scenario where DM interacts via a mediator whose initial mass is of same order as DM mass keeping DM annihilation either in allowed or forbidden ballpark. As the mediator mass decreases sharply at the nucleation temperature of the FOPT, the frozen out DM suffers further depletion while keeping final relic within observed limits. DM with sizeable interactions with a light mediator can also give rise to the required self-interactions necessary to solve the small scale structure issues of cold dark matter. While the mechanism is generic to any thermal DM mass, choosing it in the GeV ballpark forces the FOPT to MeV scale which predicts stochastic gravitational waves with nano-Hz frequencies within reach of pulsar timing array (PTA) based experiments like NANOGrav. The existence of light scalar mediator and its mixing with the Higgs keep the scenario verifiable at different particle physics experiments.
|
hep-ph/9701265
|
Evgenii Feinberg
|
O.D.Chernavskaya (Lebedev Physics Institute, Moscow)
|
Double Phase Transition Model and the problem of entropy and baryon
number conservation
|
20 pages, 10 PostScript Figures; use sprocl.sty
| null | null | null |
hep-ph
| null |
The problem of entropy S and baryon number N_B conservation in phase
transitions from deconfined phases (QGP and Q) to hadronic matter H is
considered. It is shown that standard construction of both first order phase
transitions, H-Q as well as Q-QGP implies a discontinuous structure of entropy
per baryon S/N_B when crossing phase boundary; this results in impossibility of
equilibrium transition from QGP to hadron gas.
We follow the way suggested recently by H. Satz et al. for the same problem
concerning direct transition H-QGP. They proposed a modification of bag
pressure parameter B_{QGP} by making it dependent on system temperature T and
baryon chemical potential mu; this modification has been demonstrated to be
sufficient to provide S/N_B conservation.
Here we show that within DPTM such a modification turns out to be necessary
and sufficient for bag pressure B_Q in the Q phase only. The DPTM modified in
such a way is shown to satisfy equilibrium Gibbs criteria for phase
transitions. Location of phase boundaries in $\mu -T$ plane has been
demonstrated to be changed but slightly; the modification tells mainly on
baryon number density within Q phase. Two alternative descriptions of
nucleon-nucleon interaction - the Hard Core Model and the Mean Field
Approximation - have been tested; the results for both cases appeared to be
similar. All the results are shown to be stable against rather broad variations
of model parameters.
|
[
{
"created": "Fri, 10 Jan 1997 15:51:54 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Chernavskaya",
"O. D.",
"",
"Lebedev Physics Institute, Moscow"
]
] |
The problem of entropy S and baryon number N_B conservation in phase transitions from deconfined phases (QGP and Q) to hadronic matter H is considered. It is shown that standard construction of both first order phase transitions, H-Q as well as Q-QGP implies a discontinuous structure of entropy per baryon S/N_B when crossing phase boundary; this results in impossibility of equilibrium transition from QGP to hadron gas. We follow the way suggested recently by H. Satz et al. for the same problem concerning direct transition H-QGP. They proposed a modification of bag pressure parameter B_{QGP} by making it dependent on system temperature T and baryon chemical potential mu; this modification has been demonstrated to be sufficient to provide S/N_B conservation. Here we show that within DPTM such a modification turns out to be necessary and sufficient for bag pressure B_Q in the Q phase only. The DPTM modified in such a way is shown to satisfy equilibrium Gibbs criteria for phase transitions. Location of phase boundaries in $\mu -T$ plane has been demonstrated to be changed but slightly; the modification tells mainly on baryon number density within Q phase. Two alternative descriptions of nucleon-nucleon interaction - the Hard Core Model and the Mean Field Approximation - have been tested; the results for both cases appeared to be similar. All the results are shown to be stable against rather broad variations of model parameters.
|
hep-ph/0412047
|
Alejandro Lorca
|
Alejandro Lorca and Tord Riemann
|
An Integrated Tool for Loop Calculations: aITALC
|
24 pages, 5 figures, 8 tables
|
Comput.Phys.Commun. 174 (2006) 71-82
|
10.1016/j.cpc.2005.09.003
|
DESY 04-226, SFB/CPP-04-63
|
hep-ph
| null |
aITALC, a new tool for automating loop calculations in high energy physics,
is described. The package creates Fortran code for two-fermion scattering
processes automatically, starting from the generation and analysis of the
Feynman graphs. We describe the modules of the tool, the intercommunication
between them and illustrate its use with three examples.
|
[
{
"created": "Fri, 3 Dec 2004 13:52:09 GMT",
"version": "v1"
}
] |
2009-11-10
|
[
[
"Lorca",
"Alejandro",
""
],
[
"Riemann",
"Tord",
""
]
] |
aITALC, a new tool for automating loop calculations in high energy physics, is described. The package creates Fortran code for two-fermion scattering processes automatically, starting from the generation and analysis of the Feynman graphs. We describe the modules of the tool, the intercommunication between them and illustrate its use with three examples.
|
2202.04410
|
Sergei Gninenko
|
S.N. Gninenko, N.V. Krasnikov
|
Leptonic scalar portal: Origin of muon $g-2$ anomaly and dark matter?
|
6 pages, 3 figures. References added, matches published version
|
Phys. Rev. D 106 (2022) 1, 015003
|
10.1103/PhysRevD.106.015003
| null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
We present a model explaining both the 4.2 $\sigma$ muon $g-2$ anomaly and
the relic density of dark matter (DM) in which DM interacts with the Standard
Model (SM) via a scalar portal boson $\varphi$ carrying both dark and SM
leptonic numbers, and mediating a nondiagonal interaction between the electron
and muon that allows $e \leftrightarrow \mu$ transitions. The $\varphi$ could
be produced in high-energy electron scattering off a target nuclei in the
reaction $e Z \to \mu Z\varphi$ followed by the prompt invisible decay
$\varphi~\to$~DM particles and searched for in events with large missing energy
accompanied by a single outgoing muon in the final state. Interestingly,
several events with a similar signature have been observed in a data sample of
$\simeq 3\times 10^{11}$ electrons on target collected during 2016-2018 for the
search for light dark matter in the NA64 experiment at the CERN SPS [PRL {\bf
123}, 121801 (2019)]. Attributing so far these events to background allows us
to set first constraints on the $\varphi$ mass and couplings while leaving at
the same time decisively probing the origin of these events and a large
fraction of the remaining parameter space to a near exiting future with the
upgraded NA64 detector or other planned experiments.
|
[
{
"created": "Wed, 9 Feb 2022 11:45:34 GMT",
"version": "v1"
},
{
"created": "Sun, 6 Mar 2022 10:12:17 GMT",
"version": "v2"
},
{
"created": "Thu, 7 Jul 2022 10:28:04 GMT",
"version": "v3"
}
] |
2022-07-08
|
[
[
"Gninenko",
"S. N.",
""
],
[
"Krasnikov",
"N. V.",
""
]
] |
We present a model explaining both the 4.2 $\sigma$ muon $g-2$ anomaly and the relic density of dark matter (DM) in which DM interacts with the Standard Model (SM) via a scalar portal boson $\varphi$ carrying both dark and SM leptonic numbers, and mediating a nondiagonal interaction between the electron and muon that allows $e \leftrightarrow \mu$ transitions. The $\varphi$ could be produced in high-energy electron scattering off a target nuclei in the reaction $e Z \to \mu Z\varphi$ followed by the prompt invisible decay $\varphi~\to$~DM particles and searched for in events with large missing energy accompanied by a single outgoing muon in the final state. Interestingly, several events with a similar signature have been observed in a data sample of $\simeq 3\times 10^{11}$ electrons on target collected during 2016-2018 for the search for light dark matter in the NA64 experiment at the CERN SPS [PRL {\bf 123}, 121801 (2019)]. Attributing so far these events to background allows us to set first constraints on the $\varphi$ mass and couplings while leaving at the same time decisively probing the origin of these events and a large fraction of the remaining parameter space to a near exiting future with the upgraded NA64 detector or other planned experiments.
|
1204.1791
|
Chien-Wen Hwang
|
Chien-Wen Hwang
|
Meson distribution amplitudes in holographic models
|
30 pages, 11 figures, 2 tables, minor modifications and one short
paragraph added, some references added and removed, accepted for publication
in PRD
|
Phys. Rev. D 86: 014005, 2012
|
10.1103/PhysRevD.86.014005
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the wave functions of light and heavy mesons in both hard-wall (HW)
and soft-wall (SW) holographic models which use AdS/CFT correspondence. In the
case of massless constituents, the asymptotic behaviors of the electromagnetic
form factor, the distribution amplitudes, and the decay constants for the two
models are the same, if the relation between the dilaton scale parameter and
the size of meson is an inverse proportion. On the other hand, by introducing a
quark mass dependence in the wave function, the differences of the distribution
amplitudes between the two models are obvious. In addition, for the SW model,
the dependences of the decay constants of meson on the dilaton scale parameter
$\kappa$ differ; especially f_{Qq}\sim \kappa^3/m_Q^2 is consistent with the
prediction of the heavy quark effective theory if \kappa\sim m_Q^{1/2}. Thus
the parameters of the two models are fit by the decay constants of the distinct
mesons; the distribution amplitudes and the \xi-moments are calculated and
compared.
|
[
{
"created": "Mon, 9 Apr 2012 04:36:06 GMT",
"version": "v1"
},
{
"created": "Thu, 21 Jun 2012 06:49:32 GMT",
"version": "v2"
}
] |
2013-05-30
|
[
[
"Hwang",
"Chien-Wen",
""
]
] |
We study the wave functions of light and heavy mesons in both hard-wall (HW) and soft-wall (SW) holographic models which use AdS/CFT correspondence. In the case of massless constituents, the asymptotic behaviors of the electromagnetic form factor, the distribution amplitudes, and the decay constants for the two models are the same, if the relation between the dilaton scale parameter and the size of meson is an inverse proportion. On the other hand, by introducing a quark mass dependence in the wave function, the differences of the distribution amplitudes between the two models are obvious. In addition, for the SW model, the dependences of the decay constants of meson on the dilaton scale parameter $\kappa$ differ; especially f_{Qq}\sim \kappa^3/m_Q^2 is consistent with the prediction of the heavy quark effective theory if \kappa\sim m_Q^{1/2}. Thus the parameters of the two models are fit by the decay constants of the distinct mesons; the distribution amplitudes and the \xi-moments are calculated and compared.
|
1202.4775
|
Zhi-Guo He
|
Zhi-Guo He
|
Investigating the heavy quarkonium radiative transitions with the
effective Lagrangian method
|
9 pages, no figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work, we study the radiative decay of heavy quarkonium states by
using the effective Lagrangian approach. Firstly, we construct the
spin-breaking terms in the effective Lagrangian for the $nP\leftrightarrow mS$
transitions and determine the some of the coupling constants by fitting the
experimental data. Our results show that in $\chi_{cJ}$, $\psi(2S)$,
$\Upsilon(2S)$, and $\Upsilon(3S)$ radiative decays, the spin-breaking effect
is so small that can be ignored. Secondly, we investigate the radiative decay
widths of the $c\bar{c}(1D)$ states and find the if $\psi(3770)$ is a pure
$^3D_1$ state its radiative decay into $\chi_{cJ}+\gamma$ roughly preserve the
heavy-quark spin symmetry, while if it is a $S-D$ mixing state with mixing
angel $12^{\circ}$ the heavy quark-spin symmetry in its radiative decay and in
the radiative decay of $\psi(3686)$ will be largely violated. In the end, we
show that combining the radiative decay and the light hadron decay of $P$-wave
$\chi_{bJ}(1,2P)$ can provide another way to extract the information of the
color-octet matrix element in the context of non-relativistic QCD (NRQCD)
effective theory, and our result is consistent with potential NRQCD hypothesis.
|
[
{
"created": "Tue, 21 Feb 2012 21:57:18 GMT",
"version": "v1"
}
] |
2012-02-23
|
[
[
"He",
"Zhi-Guo",
""
]
] |
In this work, we study the radiative decay of heavy quarkonium states by using the effective Lagrangian approach. Firstly, we construct the spin-breaking terms in the effective Lagrangian for the $nP\leftrightarrow mS$ transitions and determine the some of the coupling constants by fitting the experimental data. Our results show that in $\chi_{cJ}$, $\psi(2S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ radiative decays, the spin-breaking effect is so small that can be ignored. Secondly, we investigate the radiative decay widths of the $c\bar{c}(1D)$ states and find the if $\psi(3770)$ is a pure $^3D_1$ state its radiative decay into $\chi_{cJ}+\gamma$ roughly preserve the heavy-quark spin symmetry, while if it is a $S-D$ mixing state with mixing angel $12^{\circ}$ the heavy quark-spin symmetry in its radiative decay and in the radiative decay of $\psi(3686)$ will be largely violated. In the end, we show that combining the radiative decay and the light hadron decay of $P$-wave $\chi_{bJ}(1,2P)$ can provide another way to extract the information of the color-octet matrix element in the context of non-relativistic QCD (NRQCD) effective theory, and our result is consistent with potential NRQCD hypothesis.
|
2105.05866
|
Ethan Neil
|
Hooman Davoudiasl, Roman Marcarelli, Nicholas Miesch, and Ethan T.
Neil
|
Searching for Flavor-Violating ALPs in Higgs Decays
|
26 pages, 10 figures. v2: updated to published version
|
Phys. Rev. D 104, 055022 (2021)
|
10.1103/PhysRevD.104.055022
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Pseudo-scalar particles, often referred to as axion-like-particles (ALPs),
arise in a variety of theoretical contexts. The phenomenology of such states is
typically studied assuming flavor-conserving interactions, yet they can in
principle have flavor-violating (FV) couplings to fermions. We consider this
general possibility, focusing on models where the ALP has non-negligible
coupling to the Standard Model Higgs boson $h$. For a lepton FV ALP $a$ of mass
$m_a \gtrsim 2$ GeV, $a\to \tau \ell$, where $\ell\neq \tau$ is a charged
lepton, could have $\mathcal{O}(1)$ branching fraction, leading to potentially
detectable $h \to a a \to \tau \ell \tau \ell$ at the LHC and its future
program. We examine this possibility, in light of existing bounds on FV
processes, in a general effective theory. We obtain constraints on the
effective couplings from both prompt and long-lifetime searches at the LHC;
some projections for envisioned measurements are also provided. The
implications of the recently announced first results of the muon $g-2$
measurement at Fermilab for the ALP interactions considered in our work are
also briefly discussed.
|
[
{
"created": "Wed, 12 May 2021 18:00:04 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Aug 2023 16:08:15 GMT",
"version": "v2"
}
] |
2023-08-08
|
[
[
"Davoudiasl",
"Hooman",
""
],
[
"Marcarelli",
"Roman",
""
],
[
"Miesch",
"Nicholas",
""
],
[
"Neil",
"Ethan T.",
""
]
] |
Pseudo-scalar particles, often referred to as axion-like-particles (ALPs), arise in a variety of theoretical contexts. The phenomenology of such states is typically studied assuming flavor-conserving interactions, yet they can in principle have flavor-violating (FV) couplings to fermions. We consider this general possibility, focusing on models where the ALP has non-negligible coupling to the Standard Model Higgs boson $h$. For a lepton FV ALP $a$ of mass $m_a \gtrsim 2$ GeV, $a\to \tau \ell$, where $\ell\neq \tau$ is a charged lepton, could have $\mathcal{O}(1)$ branching fraction, leading to potentially detectable $h \to a a \to \tau \ell \tau \ell$ at the LHC and its future program. We examine this possibility, in light of existing bounds on FV processes, in a general effective theory. We obtain constraints on the effective couplings from both prompt and long-lifetime searches at the LHC; some projections for envisioned measurements are also provided. The implications of the recently announced first results of the muon $g-2$ measurement at Fermilab for the ALP interactions considered in our work are also briefly discussed.
|
0903.3334
|
Karol Kolodziej
|
Karol Kolodziej
|
'carlomat', A program for automatic computation of lowest order cross
sections
|
18 pages, 2 figures; submitted to Comput. Phys. Commun
|
Comput.Phys.Commun.180:1671-1680,2009
|
10.1016/j.cpc.2009.03.011
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The current version of 'carlomat', a program for automatic computation of the
lowest order cross sections of multiparticle reactions, is described. The
program can be used as the Monte Carlo generator of unweighted events as well.
|
[
{
"created": "Thu, 19 Mar 2009 14:00:33 GMT",
"version": "v1"
}
] |
2014-11-18
|
[
[
"Kolodziej",
"Karol",
""
]
] |
The current version of 'carlomat', a program for automatic computation of the lowest order cross sections of multiparticle reactions, is described. The program can be used as the Monte Carlo generator of unweighted events as well.
|
1410.3484
|
Landon Lehman
|
Joseph Bramante, Antonio Delgado, Landon Lehman, Adam Martin
|
Boosted Higgses from chromomagnetic $b$'s: $b\bar{b}h$ at high
luminosity
|
21 pages, 7 figures, 4 tables
|
Phys. Rev. D 93, 053001 (2016)
|
10.1103/PhysRevD.93.053001
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
This paper examines detection prospects and constraints on the chromomagnetic
dipole operator for the bottom quark. This operator has a flavor, chirality and
Lorentz structure that is distinct from other dimension six operators
considered in Higgs coupling studies. Its non-standard Lorentz structure
bolsters boosted $b \bar{b} h$ events, providing a rate independent signal of
new physics. To date, we find this operator is unconstrained by $p p
\rightarrow h + {\rm jets}$ and $pp \rightarrow \bar b b $ searches: for
order-one couplings the permitted cutoff $\Lambda$ for this operator can be as
low as $\Lambda \sim 1~{\rm TeV}$. We show how to improve this bound with
collider cuts that allow a $b$-tagged Higgs plus dijet search in the Higgs to
diphoton decay channel to exclude cutoffs as high as $\sim 6~{\rm TeV}$ at $2
\sigma$ with 3 $\text{ab}^{-1}$ of luminosity at the 14 TeV LHC. Cuts on the
$p_T$ of the Higgs are key to this search, because the chromomagnetic dipole
yields a non-standard fraction of boosted Higgses.
|
[
{
"created": "Mon, 13 Oct 2014 20:01:07 GMT",
"version": "v1"
}
] |
2016-03-09
|
[
[
"Bramante",
"Joseph",
""
],
[
"Delgado",
"Antonio",
""
],
[
"Lehman",
"Landon",
""
],
[
"Martin",
"Adam",
""
]
] |
This paper examines detection prospects and constraints on the chromomagnetic dipole operator for the bottom quark. This operator has a flavor, chirality and Lorentz structure that is distinct from other dimension six operators considered in Higgs coupling studies. Its non-standard Lorentz structure bolsters boosted $b \bar{b} h$ events, providing a rate independent signal of new physics. To date, we find this operator is unconstrained by $p p \rightarrow h + {\rm jets}$ and $pp \rightarrow \bar b b $ searches: for order-one couplings the permitted cutoff $\Lambda$ for this operator can be as low as $\Lambda \sim 1~{\rm TeV}$. We show how to improve this bound with collider cuts that allow a $b$-tagged Higgs plus dijet search in the Higgs to diphoton decay channel to exclude cutoffs as high as $\sim 6~{\rm TeV}$ at $2 \sigma$ with 3 $\text{ab}^{-1}$ of luminosity at the 14 TeV LHC. Cuts on the $p_T$ of the Higgs are key to this search, because the chromomagnetic dipole yields a non-standard fraction of boosted Higgses.
|
1612.06759
|
Peihong Gu
|
Hang Zhou, Pei-Hong Gu
|
Non-thermal leptogenesis with distinct CP violation and minimal dark
matter
|
9 pages, 1 figure
| null |
10.1088/1475-7516/2017/01/030
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We demonstrate a unified scenario for neutrino mass, baryon asymmetry, dark
matter and inflation. In addition to a fermion triplet for the so-called
minimal dark matter, we extend the standard model by three heavy fields
including a scalar singlet, a fermion triplet and a fermion singlet/Higgs
triplet. The heavy scalar singlet, which is expected to drive an inflation, and
the dark matter fermion triplet are odd under an unbroken $Z_2^{}$ discrete
symmetry, while the other fields are all even. The heavy fermion triplet offers
a tree-level type-III seesaw and then mediates a three-body decay of the
inflaton into the standard model lepton and Higgs doublets with the dark matter
fermion triplet. The heavy fermion singlet/Higgs triplet not only results in a
type-I/II seesaw at tree level but also contributes to the inflaton decay at
one-loop level. In this scenario, the type-I/II seesaw contains all of the
physical CP phases in the lepton sector and hence the CP violation for the
non-thermal leptogenesis by the inflaton decay exactly comes from the imaginary
part of the neutrino mass matrix.
|
[
{
"created": "Tue, 20 Dec 2016 17:05:46 GMT",
"version": "v1"
}
] |
2017-01-25
|
[
[
"Zhou",
"Hang",
""
],
[
"Gu",
"Pei-Hong",
""
]
] |
We demonstrate a unified scenario for neutrino mass, baryon asymmetry, dark matter and inflation. In addition to a fermion triplet for the so-called minimal dark matter, we extend the standard model by three heavy fields including a scalar singlet, a fermion triplet and a fermion singlet/Higgs triplet. The heavy scalar singlet, which is expected to drive an inflation, and the dark matter fermion triplet are odd under an unbroken $Z_2^{}$ discrete symmetry, while the other fields are all even. The heavy fermion triplet offers a tree-level type-III seesaw and then mediates a three-body decay of the inflaton into the standard model lepton and Higgs doublets with the dark matter fermion triplet. The heavy fermion singlet/Higgs triplet not only results in a type-I/II seesaw at tree level but also contributes to the inflaton decay at one-loop level. In this scenario, the type-I/II seesaw contains all of the physical CP phases in the lepton sector and hence the CP violation for the non-thermal leptogenesis by the inflaton decay exactly comes from the imaginary part of the neutrino mass matrix.
|
hep-ph/9902288
| null |
Arjun Berera
|
A Quantum Field Theory Warm Inflation Model
|
5 pages, 0 figure, Latex, presented COSMOS-98
| null |
10.1063/1.59431
|
VAND-TH-99-01
|
hep-ph
| null |
A quantum field theory warm inflation model is presented that solves the
cosmological horizon/flatness problems. An interpretation of the model is given
from supersymmetry and superstring theory.
|
[
{
"created": "Tue, 9 Feb 1999 23:16:56 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Berera",
"Arjun",
""
]
] |
A quantum field theory warm inflation model is presented that solves the cosmological horizon/flatness problems. An interpretation of the model is given from supersymmetry and superstring theory.
|
hep-ph/9909482
|
Bruce Bassett
|
Bruce A. Bassett (1,2), Christopher Gordon (2), Roy Maartens (2) and
David I. Kaiser (3) ((1) Oxford, (2) Portsmouth, (3) Harvard)
|
Restoring the sting to metric preheating
|
6 pages, 3 ps figures, RevTex, revised discussion of backreaction and
new figure. To appear Phys. Rev. D (Rapid Communication)
|
Phys.Rev.D61:061302,2000
|
10.1103/PhysRevD.61.061302
| null |
hep-ph astro-ph gr-qc hep-th
| null |
The relative growth of field and metric perturbations during preheating is
sensitive to initial conditions set in the preceding inflationary phase. Recent
work suggests this may protect super-Hubble metric perturbations from resonant
amplification during preheating. We show that this possibility is fragile and
sensitive to the specific form of the interactions between the inflaton and
other fields. The suppression is naturally absent in two classes of preheating
in which either (1) the vacua of the non-inflaton fields during inflation are
deformed away from the origin, or (2) the effective masses of non-inflaton
fields during inflation are small but during preheating are large. Unlike the
simple toy model of a $g^2 \phi^2 \chi^2$ coupling, most realistic particle
physics models contain these other features. Moreover, they generically lead to
both adiabatic and isocurvature modes and non-Gaussian scars on super-Hubble
scales. Large-scale coherent magnetic fields may also appear naturally.
|
[
{
"created": "Wed, 22 Sep 1999 23:57:13 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Feb 2000 17:12:11 GMT",
"version": "v2"
}
] |
2009-12-30
|
[
[
"Bassett",
"Bruce A.",
"",
"Oxford",
"Portsmouth"
],
[
"Gordon",
"Christopher",
"",
"Portsmouth"
],
[
"Maartens",
"Roy",
"",
"Portsmouth"
],
[
"Kaiser",
"David I.",
"",
"Harvard"
]
] |
The relative growth of field and metric perturbations during preheating is sensitive to initial conditions set in the preceding inflationary phase. Recent work suggests this may protect super-Hubble metric perturbations from resonant amplification during preheating. We show that this possibility is fragile and sensitive to the specific form of the interactions between the inflaton and other fields. The suppression is naturally absent in two classes of preheating in which either (1) the vacua of the non-inflaton fields during inflation are deformed away from the origin, or (2) the effective masses of non-inflaton fields during inflation are small but during preheating are large. Unlike the simple toy model of a $g^2 \phi^2 \chi^2$ coupling, most realistic particle physics models contain these other features. Moreover, they generically lead to both adiabatic and isocurvature modes and non-Gaussian scars on super-Hubble scales. Large-scale coherent magnetic fields may also appear naturally.
|
2008.00743
|
Tong Li
|
Tong Li, Jiajun Liao
|
Loop effect in the coherent neutrino-nucleus scattering
|
18 pages, 4 figures. Version to appear in JHEP
| null |
10.1007/JHEP02(2021)099
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A connection between the neutrino and an exotic fermion is described in the
general neutrino model. In this model the neutrinos can convert into the new
fermion and thus the interaction leads to novel recoil spectrum in the neutrino
scattering experiments. We study the general neutrino interaction by evaluating
both the tree-level and loop-level contributions to the coherent elastic
neutrino-nucleus scattering. We illustrate the scattering by taking the
framework of a simplified neutrino model with a Dirac fermion $\chi$ and a
spin-0 mediator. For the CP phase in the quark sector being 0 and $\pi/2$, the
detection processes are dominated by the tree-level and loop-level
contribution, respectively. We investigate the constraints on the couplings
between the mediator and the new particle $\chi$ or the quarks by fitting to
the COHERENT data. The parameter space with $m_\chi$ larger than the maximal
energy of incoming neutrinos can be also constrained by including the
loop-level contribution.
|
[
{
"created": "Mon, 3 Aug 2020 09:47:20 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Feb 2021 11:28:31 GMT",
"version": "v2"
}
] |
2021-03-17
|
[
[
"Li",
"Tong",
""
],
[
"Liao",
"Jiajun",
""
]
] |
A connection between the neutrino and an exotic fermion is described in the general neutrino model. In this model the neutrinos can convert into the new fermion and thus the interaction leads to novel recoil spectrum in the neutrino scattering experiments. We study the general neutrino interaction by evaluating both the tree-level and loop-level contributions to the coherent elastic neutrino-nucleus scattering. We illustrate the scattering by taking the framework of a simplified neutrino model with a Dirac fermion $\chi$ and a spin-0 mediator. For the CP phase in the quark sector being 0 and $\pi/2$, the detection processes are dominated by the tree-level and loop-level contribution, respectively. We investigate the constraints on the couplings between the mediator and the new particle $\chi$ or the quarks by fitting to the COHERENT data. The parameter space with $m_\chi$ larger than the maximal energy of incoming neutrinos can be also constrained by including the loop-level contribution.
|
1403.5512
|
Yoshio Kitadono
|
Yoshio Kitadono (AS), Hsiang-nan Li (AS)
|
Jet substructures of boosted polarized top quarks
|
18 pages, 8 figures
|
Phys. Rev. D 89, 114002 (2014)
|
10.1103/PhysRevD.89.114002
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study jet substructures of a boosted polarized top quark, which undergoes
the semileptonic decay $t\to b\ell\nu$, in the perturbative QCD framework. The
jet mass distribution (energy profile) is factorized into the convolution of a
hard top-quark decay kernel with the bottom-quark jet function (jet energy
function). Computing the hard kernel to leading order in QCD and inputting the
latter functions from the resummation formalism, we observe that the jet mass
distribution is not sensitive to the helicity of the top quark, but the energy
profile is: energy is accumulated faster within a left-handed top jet than
within a right-handed one, a feature related to the $V-A$ structure of weak
interaction. It is pointed out that the energy profile is a simple and useful
jet observable for helicity discrimination of a boosted top quark, which helps
identification of physics beyond the Standard Model at the Large Hadron
Collider. The extension of our analysis to other jet substructures, including
those associated with a hadronically decaying polarized top quark, is proposed.
|
[
{
"created": "Fri, 21 Mar 2014 16:38:05 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Sep 2014 06:12:57 GMT",
"version": "v2"
}
] |
2015-06-19
|
[
[
"Kitadono",
"Yoshio",
"",
"AS"
],
[
"Li",
"Hsiang-nan",
"",
"AS"
]
] |
We study jet substructures of a boosted polarized top quark, which undergoes the semileptonic decay $t\to b\ell\nu$, in the perturbative QCD framework. The jet mass distribution (energy profile) is factorized into the convolution of a hard top-quark decay kernel with the bottom-quark jet function (jet energy function). Computing the hard kernel to leading order in QCD and inputting the latter functions from the resummation formalism, we observe that the jet mass distribution is not sensitive to the helicity of the top quark, but the energy profile is: energy is accumulated faster within a left-handed top jet than within a right-handed one, a feature related to the $V-A$ structure of weak interaction. It is pointed out that the energy profile is a simple and useful jet observable for helicity discrimination of a boosted top quark, which helps identification of physics beyond the Standard Model at the Large Hadron Collider. The extension of our analysis to other jet substructures, including those associated with a hadronically decaying polarized top quark, is proposed.
|
2007.07866
|
Damiano Francesco Giuseppe Fiorillo
|
Damiano F. G. Fiorillo, Stefano Morisi, Gennaro Miele, Ninetta Saviano
|
Observable features in (ultra)high energy neutrinos due to
active-sterile secret interactions
|
11 pages, 8 figures
|
Phys. Rev. D 102, 083014 (2020)
|
10.1103/PhysRevD.102.083014
| null |
hep-ph astro-ph.HE
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the effects of active-sterile secret neutrino interactions,
mediated by a new pseudoscalar particle, on high- and ultra high-energy
neutrino fluxes. In particular, we focus on the case of 3 active and 1 sterile
neutrino coupled by a flavor dependent interaction, extending the case of 1
active and 1 sterile neutrino we have recently examined. We find that,
depending on the kind of interaction of sterile neutrino with the active
sector, new regions of the parameter space for secret interactions are now
allowed leading to interesting phenomenological implications on two benchmark
fluxes we consider, namely an astrophysical power law flux, in the range below
100 PeV, and a cosmogenic flux, in the Ultrahigh energy range. First of all,
the final active fluxes can present a measurable depletion observable in future
experiments. Especially, in the case of only tau neutrino interacting, we find
that the effects on the astrophysical power law flux can be so large to be
already probed by the IceCube experiment. Moreover, we find intriguing features
in the energy dependence of the flavor ratio.
|
[
{
"created": "Wed, 15 Jul 2020 17:39:20 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Nov 2020 17:42:32 GMT",
"version": "v2"
}
] |
2020-11-26
|
[
[
"Fiorillo",
"Damiano F. G.",
""
],
[
"Morisi",
"Stefano",
""
],
[
"Miele",
"Gennaro",
""
],
[
"Saviano",
"Ninetta",
""
]
] |
We consider the effects of active-sterile secret neutrino interactions, mediated by a new pseudoscalar particle, on high- and ultra high-energy neutrino fluxes. In particular, we focus on the case of 3 active and 1 sterile neutrino coupled by a flavor dependent interaction, extending the case of 1 active and 1 sterile neutrino we have recently examined. We find that, depending on the kind of interaction of sterile neutrino with the active sector, new regions of the parameter space for secret interactions are now allowed leading to interesting phenomenological implications on two benchmark fluxes we consider, namely an astrophysical power law flux, in the range below 100 PeV, and a cosmogenic flux, in the Ultrahigh energy range. First of all, the final active fluxes can present a measurable depletion observable in future experiments. Especially, in the case of only tau neutrino interacting, we find that the effects on the astrophysical power law flux can be so large to be already probed by the IceCube experiment. Moreover, we find intriguing features in the energy dependence of the flavor ratio.
|
hep-ph/9610352
|
Borut Bajc
|
Borut Bajc and Goran Senjanovic
|
Symmetry Restoration in Hot SUSY
|
8 pages, revtex, no figures. Based on the talk given by G. Senjanovic
at SUSY96, University of Maryland, 1996. To appear in the Proceedings
|
Nucl.Phys.Proc.Suppl. 52A (1997) 246-250
|
10.1016/S0920-5632(96)00572-5
|
IJS-TP-96/18
|
hep-ph
| null |
It is by now well known that symmetries may be broken at high temperature.
However,in renormalizable supersymmetric theories any internal symmetry gets
always restored. In nonrenormalizable theories the situation is far less
simple. We review here some recent work which seems to indicate that
renormalizability is not essential for the restoration of internal symmetries
in supersymmetry.
|
[
{
"created": "Mon, 14 Oct 1996 17:00:53 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Bajc",
"Borut",
""
],
[
"Senjanovic",
"Goran",
""
]
] |
It is by now well known that symmetries may be broken at high temperature. However,in renormalizable supersymmetric theories any internal symmetry gets always restored. In nonrenormalizable theories the situation is far less simple. We review here some recent work which seems to indicate that renormalizability is not essential for the restoration of internal symmetries in supersymmetry.
|
2301.13238
|
Drona Vatsyayan
|
Juan Herrero-Garcia, Giacomo Landini and Drona Vatsyayan
|
Asymmetries in Extended Dark Sectors: A Cogenesis Scenario
|
41 pages, 10 figures, 6 tables; v2: Matches published version
|
J. High Energ. Phys. 2023, 49 (2023)
|
10.1007/JHEP05(2023)049
|
IFIC-23/03
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The observed dark matter relic abundance may be explained by different
mechanisms, such as thermal freeze-out/freeze-in, with one or more
symmetric/asymmetric components. In this work we investigate the role played by
asymmetries in determining the yield and nature of dark matter in non-minimal
scenarios with more than one dark matter particle. In particular, we show that
the energy density of a particle may come from an asymmetry, even if the
particle is asymptotically symmetric by nature. To illustrate the different
effects of asymmetries, we adopt a model with two dark matter components. We
embed it in a multi-component cogenesis scenario that is also able to reproduce
neutrino masses and the baryon asymmetry. In some cases, the model predicts an
interesting monochromatic neutrino line that may be searched for at neutrino
telescopes.
|
[
{
"created": "Mon, 30 Jan 2023 19:05:04 GMT",
"version": "v1"
},
{
"created": "Fri, 12 May 2023 09:24:16 GMT",
"version": "v2"
}
] |
2023-05-15
|
[
[
"Herrero-Garcia",
"Juan",
""
],
[
"Landini",
"Giacomo",
""
],
[
"Vatsyayan",
"Drona",
""
]
] |
The observed dark matter relic abundance may be explained by different mechanisms, such as thermal freeze-out/freeze-in, with one or more symmetric/asymmetric components. In this work we investigate the role played by asymmetries in determining the yield and nature of dark matter in non-minimal scenarios with more than one dark matter particle. In particular, we show that the energy density of a particle may come from an asymmetry, even if the particle is asymptotically symmetric by nature. To illustrate the different effects of asymmetries, we adopt a model with two dark matter components. We embed it in a multi-component cogenesis scenario that is also able to reproduce neutrino masses and the baryon asymmetry. In some cases, the model predicts an interesting monochromatic neutrino line that may be searched for at neutrino telescopes.
|
1103.5049
|
Agam Jha
|
R. Ramanathan, Agam K. Jha and S. S. Singh
|
A model density of states for Quarks and Gluons in QGP
|
7 pages, 2 figures LaTeX
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose an algebraic form for the density of states of quarks and gluons
in a Quark-Gluon Plasma (QGP) fireball in quasi-equilibrium with a hadronic
medium as $\rho(k)= \frac {\alpha}{k} + {\beta}k + {\delta}k^{2}$, and
determine the parameters $\alpha$, $\beta$ and $\delta$ using Lattice Gauge
results on the velocity of sound in QGP. The behaviour of the resulting
$\rho(k)$ can be easily compared with the thermodynamic data on QGP that is
expected from LHC and other RHIC experiments. Our numerical result shows a
linear rise of the value of $\rho(k)$ for $k\sim T \approx 160 to 180 MeV$,
which is significant, and throws light on the evolution of the QGP phase.
|
[
{
"created": "Fri, 25 Mar 2011 17:58:32 GMT",
"version": "v1"
}
] |
2011-03-28
|
[
[
"Ramanathan",
"R.",
""
],
[
"Jha",
"Agam K.",
""
],
[
"Singh",
"S. S.",
""
]
] |
We propose an algebraic form for the density of states of quarks and gluons in a Quark-Gluon Plasma (QGP) fireball in quasi-equilibrium with a hadronic medium as $\rho(k)= \frac {\alpha}{k} + {\beta}k + {\delta}k^{2}$, and determine the parameters $\alpha$, $\beta$ and $\delta$ using Lattice Gauge results on the velocity of sound in QGP. The behaviour of the resulting $\rho(k)$ can be easily compared with the thermodynamic data on QGP that is expected from LHC and other RHIC experiments. Our numerical result shows a linear rise of the value of $\rho(k)$ for $k\sim T \approx 160 to 180 MeV$, which is significant, and throws light on the evolution of the QGP phase.
|
1211.6058
|
Rui-Lin Zhu
|
Long-Bin Chen, Cong-Feng Qiao, and Rui-Lin Zhu
|
Reconstructing the 125 GeV SM Higgs Boson Through $\ell\bar{\ell}\gamma$
|
to appear in Phys. Lett. B
| null |
10.1016/j.physletb.2013.08.050
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
To ascertain the new boson with mass near 125 {GeV} observed recently by
ATLAS and CMS Collaborations to be the Standard Model Higgs, and to determine
its intrinsic properties, more measurements on its various decay channels are
still necessary. In this work we reanalyze the processes of the Standard Model
Higgs radiative decays to lepton pairs. We find that when photon and leptons
are hard, that is possessing energies larger than 1 {GeV}, the branching
fractions of $H\rightarrow \ell\bar{\ell}\gamma (\ell=e~or~\mu)$ processes are
about two-thirds of the $H\rightarrow\mu^+\mu^-$ process. Since the lepton-pair
yields of the radiative processes mainly come from the Z-boson conversion,
which will greatly suppress the backgrounds, we believe the signal should be
observable in presently accumulated data or in the next run of the LHC
experiment, provided the Standard Model Higgs is indeed light.
|
[
{
"created": "Mon, 26 Nov 2012 18:34:03 GMT",
"version": "v1"
},
{
"created": "Thu, 30 May 2013 16:42:56 GMT",
"version": "v2"
},
{
"created": "Mon, 19 Aug 2013 04:59:56 GMT",
"version": "v3"
}
] |
2015-06-12
|
[
[
"Chen",
"Long-Bin",
""
],
[
"Qiao",
"Cong-Feng",
""
],
[
"Zhu",
"Rui-Lin",
""
]
] |
To ascertain the new boson with mass near 125 {GeV} observed recently by ATLAS and CMS Collaborations to be the Standard Model Higgs, and to determine its intrinsic properties, more measurements on its various decay channels are still necessary. In this work we reanalyze the processes of the Standard Model Higgs radiative decays to lepton pairs. We find that when photon and leptons are hard, that is possessing energies larger than 1 {GeV}, the branching fractions of $H\rightarrow \ell\bar{\ell}\gamma (\ell=e~or~\mu)$ processes are about two-thirds of the $H\rightarrow\mu^+\mu^-$ process. Since the lepton-pair yields of the radiative processes mainly come from the Z-boson conversion, which will greatly suppress the backgrounds, we believe the signal should be observable in presently accumulated data or in the next run of the LHC experiment, provided the Standard Model Higgs is indeed light.
|
0709.3294
|
Alexander Merle
|
Alexander Blum, Alexander Merle
|
General Conditions for Lepton Flavour Violation at Tree- and 1-Loop
Level
|
31 pages, 2 figures
|
Phys.Rev.D77:076005,2008
|
10.1103/PhysRevD.77.076005
| null |
hep-ph
| null |
In this work, we compile the necessary and sufficient conditions a theory has
to fulfill in order to ensure general lepton flavour conservation, in the
spirit of the Glashow-Weinberg criteria for the absence of flavour-changing
neutral currents. At tree-level, interactions involving electrically neutral
and doubly charged bosons are investigated. We also investigate flavour changes
at 1-loop level. In all cases we find that the essential theoretical
requirements can be reduced to a few basic conditions on the particle content
and the coupling matrices. For 1-loop diagrams, we also investigate how exactly
a GIM-suppression can occur that will strongly reduce the rates of lepton
flavour violating effects even if they are in principle present in a certain
theory. In all chapters, we apply our criteria to several models which can in
general induce lepton flavour violation, e.g. LR-symmetric models or the MSSM.
In the end we give a summarizing table of the obtained results, thereby
demonstrating the applicability of our criteria to a large class of models
beyond the Standard Model.
|
[
{
"created": "Thu, 20 Sep 2007 20:00:05 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Blum",
"Alexander",
""
],
[
"Merle",
"Alexander",
""
]
] |
In this work, we compile the necessary and sufficient conditions a theory has to fulfill in order to ensure general lepton flavour conservation, in the spirit of the Glashow-Weinberg criteria for the absence of flavour-changing neutral currents. At tree-level, interactions involving electrically neutral and doubly charged bosons are investigated. We also investigate flavour changes at 1-loop level. In all cases we find that the essential theoretical requirements can be reduced to a few basic conditions on the particle content and the coupling matrices. For 1-loop diagrams, we also investigate how exactly a GIM-suppression can occur that will strongly reduce the rates of lepton flavour violating effects even if they are in principle present in a certain theory. In all chapters, we apply our criteria to several models which can in general induce lepton flavour violation, e.g. LR-symmetric models or the MSSM. In the end we give a summarizing table of the obtained results, thereby demonstrating the applicability of our criteria to a large class of models beyond the Standard Model.
|
2012.11449
|
Mikhail Bashkanov
|
M. Bashkanov, G. Clash, M. Mocanu, M. Nicol, D.P. Watts
|
Decay properties of the $d^*(2380)$ hexaquark multiplet
| null | null | null | null |
hep-ph nucl-ex
|
http://creativecommons.org/licenses/by/4.0/
|
The recently discovered $d^*(2380)$ hexaquark is expected to be the lightest
member of an extended SU(3) antidecuplet of hexaquark states. The experimental
search for the other heavier and strange partners of the $d^*(2380)$ in the
antidecuplet is a challenging task. Evaluating the most appropriate
methodologies necessitates some understanding of the underlying properties of
the decuplet states such as mass, width and decay branches. In this paper we
provide estimates of these key properties for all decuplet states,
extrapolating from information and insights garnered for the $d^*(2380)$. The
predictions form a basis for the design of future discovery experiments.
|
[
{
"created": "Mon, 21 Dec 2020 16:13:40 GMT",
"version": "v1"
}
] |
2020-12-22
|
[
[
"Bashkanov",
"M.",
""
],
[
"Clash",
"G.",
""
],
[
"Mocanu",
"M.",
""
],
[
"Nicol",
"M.",
""
],
[
"Watts",
"D. P.",
""
]
] |
The recently discovered $d^*(2380)$ hexaquark is expected to be the lightest member of an extended SU(3) antidecuplet of hexaquark states. The experimental search for the other heavier and strange partners of the $d^*(2380)$ in the antidecuplet is a challenging task. Evaluating the most appropriate methodologies necessitates some understanding of the underlying properties of the decuplet states such as mass, width and decay branches. In this paper we provide estimates of these key properties for all decuplet states, extrapolating from information and insights garnered for the $d^*(2380)$. The predictions form a basis for the design of future discovery experiments.
|
2311.09916
|
Joshua Isaacson
|
Joshua Isaacson, Yao Fu, C.-P. Yuan
|
Improving ResBos for the precision needs of the LHC
|
41 pages, 26 figures
| null | null |
FERMILAB-PUB-23-322-T, MSUHEP-23-017
|
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
The resummation calculation (ResBos) is a widely used tool for the simulation
of single vector boson production at colliders. In this work, we develop a
significant improvement over the ResBos code by increasing the accuracy from
NNLL+NLO to N${}^3$LL+NNLO and release the ResBos v2.0 code. Furthermore, we
propose a new non-perturbative function that includes information about the
rapidity of the system (IFY). The IFY functional form was fitted to data from
fixed target experiments, the Tevatron, and the LHC. We find that the
non-perturbative function has mild rapidity dependence based on the results of
the fit. Finally, we investigate the effects that this increased precision has
on the measurement of the $W$ boson by CDF and impacts on future LHC
measurements.
|
[
{
"created": "Thu, 16 Nov 2023 14:14:18 GMT",
"version": "v1"
}
] |
2023-11-17
|
[
[
"Isaacson",
"Joshua",
""
],
[
"Fu",
"Yao",
""
],
[
"Yuan",
"C. -P.",
""
]
] |
The resummation calculation (ResBos) is a widely used tool for the simulation of single vector boson production at colliders. In this work, we develop a significant improvement over the ResBos code by increasing the accuracy from NNLL+NLO to N${}^3$LL+NNLO and release the ResBos v2.0 code. Furthermore, we propose a new non-perturbative function that includes information about the rapidity of the system (IFY). The IFY functional form was fitted to data from fixed target experiments, the Tevatron, and the LHC. We find that the non-perturbative function has mild rapidity dependence based on the results of the fit. Finally, we investigate the effects that this increased precision has on the measurement of the $W$ boson by CDF and impacts on future LHC measurements.
|
0812.1991
|
Viktor Toth
|
J. W. Moffat and V. T. Toth
|
A finite electroweak model without a Higgs particle
|
32 pages, 5 figures
| null | null | null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
An electroweak model in which the masses of the W and Z bosons and the
fermions are generated by quantum loop graphs through a symmetry breaking is
investigated. The model is based on a regularized quantum field theory in which
the quantum loop graphs are finite to all orders of perturbation theory and the
massless theory is gauge invariant, Poincare invariant, and unitary. The
breaking of the electroweak symmetry SU_L(2) X U_Y(1) is achieved without a
Higgs particle. A fundamental energy scale \Lambda_W (not to be confused with a
naive cutoff) enters the theory through the regularization of the Feynman loop
diagrams. The finite regularized theory with \Lambda_W allows for a fitting of
low energy electroweak data. \Lambda_W ~ 542 GeV is determined at the Z pole by
fitting it to the Z mass m_Z, and anchoring the value of \sin^2\theta_w to its
experimental value at the Z pole yields a prediction for the W mass m_W that is
accurate to about 0.5% without radiative corrections. The scattering amplitudes
for W_LW_L -> W_LW_L and e+e- -> W_L^+W_L^- processes do not violate unitarity
at high energies due to the suppression of the amplitudes by the running of the
coupling constants at vertices. There is no Higgs hierarchy fine-tuning problem
in the model. The unitary tree level amplitudes for W_LW_L -> W_LW_L scattering
and e+e- -> W_L^+W_L^- annihilation, predicted by the finite electroweak model
are compared with the amplitudes obtained from the standard model with Higgs
exchange. These predicted amplitudes can be used to distinguish at the LHC
between the standard electroweak model and the Higgsless model.
|
[
{
"created": "Wed, 10 Dec 2008 18:58:16 GMT",
"version": "v1"
},
{
"created": "Thu, 29 Jan 2009 03:07:35 GMT",
"version": "v2"
},
{
"created": "Sat, 5 Sep 2009 02:08:35 GMT",
"version": "v3"
},
{
"created": "Fri, 12 Feb 2010 19:52:21 GMT",
"version": "v4"
}
] |
2010-02-12
|
[
[
"Moffat",
"J. W.",
""
],
[
"Toth",
"V. T.",
""
]
] |
An electroweak model in which the masses of the W and Z bosons and the fermions are generated by quantum loop graphs through a symmetry breaking is investigated. The model is based on a regularized quantum field theory in which the quantum loop graphs are finite to all orders of perturbation theory and the massless theory is gauge invariant, Poincare invariant, and unitary. The breaking of the electroweak symmetry SU_L(2) X U_Y(1) is achieved without a Higgs particle. A fundamental energy scale \Lambda_W (not to be confused with a naive cutoff) enters the theory through the regularization of the Feynman loop diagrams. The finite regularized theory with \Lambda_W allows for a fitting of low energy electroweak data. \Lambda_W ~ 542 GeV is determined at the Z pole by fitting it to the Z mass m_Z, and anchoring the value of \sin^2\theta_w to its experimental value at the Z pole yields a prediction for the W mass m_W that is accurate to about 0.5% without radiative corrections. The scattering amplitudes for W_LW_L -> W_LW_L and e+e- -> W_L^+W_L^- processes do not violate unitarity at high energies due to the suppression of the amplitudes by the running of the coupling constants at vertices. There is no Higgs hierarchy fine-tuning problem in the model. The unitary tree level amplitudes for W_LW_L -> W_LW_L scattering and e+e- -> W_L^+W_L^- annihilation, predicted by the finite electroweak model are compared with the amplitudes obtained from the standard model with Higgs exchange. These predicted amplitudes can be used to distinguish at the LHC between the standard electroweak model and the Higgsless model.
|
1009.0008
|
William Shepherd
|
Jessica Goodman, Masahiro Ibe, Arvind Rajaraman, William Shepherd, Tim
M.P. Tait, Hai-Bo Yu
|
Gamma Ray Line Constraints on Effective Theories of Dark Matter
|
20 pages, 9 figures
|
Nucl.Phys.B844:55-68,2011
|
10.1016/j.nuclphysb.2010.10.022
|
UCI-HEP-TR-2010-18
|
hep-ph astro-ph.CO hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A monochromatic gamma ray line results when dark matter particles in the
galactic halo annihilate to produce a two body final state which includes a
photon. Such a signal is very distinctive from astrophysical backgrounds, and
thus represents an incisive probe of theories of dark matter. We compare the
recent null results of searches for gamma ray lines in the galactic center and
other regions of the sky with the predictions of effective theories describing
the interactions of dark matter particles with the Standard Model. We find that
the null results of these searches provide constraints on the nature of dark
matter interactions with ordinary matter which are complementary to constraints
from other observables, and stronger than collider constraints in some cases.
|
[
{
"created": "Tue, 31 Aug 2010 20:00:07 GMT",
"version": "v1"
},
{
"created": "Sat, 18 Dec 2010 00:07:03 GMT",
"version": "v2"
}
] |
2010-12-21
|
[
[
"Goodman",
"Jessica",
""
],
[
"Ibe",
"Masahiro",
""
],
[
"Rajaraman",
"Arvind",
""
],
[
"Shepherd",
"William",
""
],
[
"Tait",
"Tim M. P.",
""
],
[
"Yu",
"Hai-Bo",
""
]
] |
A monochromatic gamma ray line results when dark matter particles in the galactic halo annihilate to produce a two body final state which includes a photon. Such a signal is very distinctive from astrophysical backgrounds, and thus represents an incisive probe of theories of dark matter. We compare the recent null results of searches for gamma ray lines in the galactic center and other regions of the sky with the predictions of effective theories describing the interactions of dark matter particles with the Standard Model. We find that the null results of these searches provide constraints on the nature of dark matter interactions with ordinary matter which are complementary to constraints from other observables, and stronger than collider constraints in some cases.
|
hep-ph/0406297
|
Radhey Shyam
|
Radhey Shyam
|
Dynamics of strangeness production in the near threshold nucleon-nucleon
collisions
|
15 pages, 5 figures, Talk presented in the second symposium on
threshold meson production in pp and pd interactions, Jagellonian University,
Cracow, Poland,May 31-June 3, 2004
|
Matter and Materials 21 (2004) 15
| null | null |
hep-ph nucl-ex nucl-th
| null |
We investigate the associated strangeness Lambda K+ and Sigma0 K+ productions
in proton-proton collisions within an effective Lagrangian model. The initial
interaction between the two nucleons is modeled by the exchange of pi, rho,
omega, and sigma mesons and the strangeness production proceeds via excitations
of N*(1650), N*(1710), and N*(1720) baryonic resonances. The parameters of the
model at the nucleon-nucleon-meson vertices are determined by fitting the
elastic nucleon-nucleon scattering with an effective interaction based on the
exchange of these four mesons, while those at the resonance vertices are
calculated from the known decay widths of the resonances and from the vector
meson dominance model. Experimental data taken recently by the COSY-11
collaboration are described well by this approach. The one-pion-exchange
diagram dominates the production process at both higher and lower beam
energies. The excitation of the N*(1650) resonance dominates both the
production channels at near threshold energies. Our model with final state
interaction effects among the outgoing particles included within the
Watson-Migdal approximation, is able to explain the observed beam energy
dependence of the ratio of the total cross sections of these two reactions.
|
[
{
"created": "Sun, 27 Jun 2004 16:01:58 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Shyam",
"Radhey",
""
]
] |
We investigate the associated strangeness Lambda K+ and Sigma0 K+ productions in proton-proton collisions within an effective Lagrangian model. The initial interaction between the two nucleons is modeled by the exchange of pi, rho, omega, and sigma mesons and the strangeness production proceeds via excitations of N*(1650), N*(1710), and N*(1720) baryonic resonances. The parameters of the model at the nucleon-nucleon-meson vertices are determined by fitting the elastic nucleon-nucleon scattering with an effective interaction based on the exchange of these four mesons, while those at the resonance vertices are calculated from the known decay widths of the resonances and from the vector meson dominance model. Experimental data taken recently by the COSY-11 collaboration are described well by this approach. The one-pion-exchange diagram dominates the production process at both higher and lower beam energies. The excitation of the N*(1650) resonance dominates both the production channels at near threshold energies. Our model with final state interaction effects among the outgoing particles included within the Watson-Migdal approximation, is able to explain the observed beam energy dependence of the ratio of the total cross sections of these two reactions.
|
1403.4923
|
Federico Dradi Mr
|
L. Covi, F. Dradi
|
Long-Lived stop at the LHC with or without R-parity
|
35 pages
| null |
10.1088/1475-7516/2014/10/039
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider scenarios of gravitino LSP and DM with stop NLSP both within
R-parity conserving and R-parity violating supersymmetry (RPC and RPV SUSY,
respectively). We discuss cosmological bounds from Big Bang Nucleosynthesis
(BBN) and the gravitino abundance and then concentrate on the signals of
long-lived stops at the LHC as displaced vertices or metastable particles.
Finally we discuss how to distinguish R-parity conserving and R-parity breaking
stop decays if they happen within the detector and suppress SM backgrounds.
|
[
{
"created": "Wed, 19 Mar 2014 19:42:20 GMT",
"version": "v1"
}
] |
2015-06-19
|
[
[
"Covi",
"L.",
""
],
[
"Dradi",
"F.",
""
]
] |
We consider scenarios of gravitino LSP and DM with stop NLSP both within R-parity conserving and R-parity violating supersymmetry (RPC and RPV SUSY, respectively). We discuss cosmological bounds from Big Bang Nucleosynthesis (BBN) and the gravitino abundance and then concentrate on the signals of long-lived stops at the LHC as displaced vertices or metastable particles. Finally we discuss how to distinguish R-parity conserving and R-parity breaking stop decays if they happen within the detector and suppress SM backgrounds.
|
0707.3162
|
Joan Sola
|
Giancarlo Ferrera, Jaume Guasch, David Lopez-Val, Joan Sola
|
Triple Higgs boson production in the Linear Collider
|
LaTeX, 17 pages, 4 figures, 5 tables. References and comments added.
Version accepted in Phys. Lett. B
|
Phys.Lett.B659:297-307,2008
|
10.1016/j.physletb.2007.10.072
|
UB-ECM-PF-07/22
|
hep-ph
| null |
Triple Higgs boson production (3H) may provide essential information to
reconstruct the Higgs potential. We consider 3H-production in the International
Linear Collider (ILC) both in the Minimal Supersymmetric Standard Model (MSSM)
and in the general Two-Higgs-doublet Model (2HDM). We compute the total
cross-section for the various 3H final states, such as H^+ H^- h^0, H^0 A^0
h^0, etc. and compare with the more traditional double Higgs (2H) boson
production processes. While the cross-sections for the 2H final states lie
within the same order of magnitude in both the MSSM and 2HDM, we find that for
the 3H states the maximum 2HDM cross-sections, being of order 0.1 pb, are much
larger than the MSSM ones which in most cases are of order 10^{-6} pb or less.
Actually, the 3H processes could be the dominant mechanism for Higgs boson
production in the 2HDM. Ultimately the origin of the remarkable enhancement of
the 3H channels in the 2HDM case (for both type I and type II models)
originates in the structure of the trilinear Higgs boson couplings. The
extremely clean environment of the ILC should allow a relatively comfortable
tagging of the three Higgs boson events. In view of the fact that the MSSM
contribution is negligible, these events should manifest themselves mainly in
the form of 6 heavy-quark jet final states. Some of these signatures could be
spectacular, and in case of being detected would constitute strong evidence of
an extended Higgs sector of non-supersymmetric origin.
|
[
{
"created": "Fri, 20 Jul 2007 23:08:01 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Oct 2007 10:48:10 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Ferrera",
"Giancarlo",
""
],
[
"Guasch",
"Jaume",
""
],
[
"Lopez-Val",
"David",
""
],
[
"Sola",
"Joan",
""
]
] |
Triple Higgs boson production (3H) may provide essential information to reconstruct the Higgs potential. We consider 3H-production in the International Linear Collider (ILC) both in the Minimal Supersymmetric Standard Model (MSSM) and in the general Two-Higgs-doublet Model (2HDM). We compute the total cross-section for the various 3H final states, such as H^+ H^- h^0, H^0 A^0 h^0, etc. and compare with the more traditional double Higgs (2H) boson production processes. While the cross-sections for the 2H final states lie within the same order of magnitude in both the MSSM and 2HDM, we find that for the 3H states the maximum 2HDM cross-sections, being of order 0.1 pb, are much larger than the MSSM ones which in most cases are of order 10^{-6} pb or less. Actually, the 3H processes could be the dominant mechanism for Higgs boson production in the 2HDM. Ultimately the origin of the remarkable enhancement of the 3H channels in the 2HDM case (for both type I and type II models) originates in the structure of the trilinear Higgs boson couplings. The extremely clean environment of the ILC should allow a relatively comfortable tagging of the three Higgs boson events. In view of the fact that the MSSM contribution is negligible, these events should manifest themselves mainly in the form of 6 heavy-quark jet final states. Some of these signatures could be spectacular, and in case of being detected would constitute strong evidence of an extended Higgs sector of non-supersymmetric origin.
|
0804.1753
|
Oleg Lebedev
|
Gian F. Giudice and Oleg Lebedev
|
Higgs-dependent Yukawa couplings
|
18 pages, 4 figures; a comment on CP and a ref. added, to appear in
PLB; a factor of 2 in eq.34 fixed
|
Phys.Lett.B665:79-85,2008
|
10.1016/j.physletb.2008.05.062
|
CERN-PH-TH/2008-069
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the possibility that the Yukawa couplings depend on the Higgs
field, with the motivation of generating the fermion mass hierarchy through
appropriate powers of the Higgs vacuum expectation value. This leads to drastic
modifications of the Higgs branching ratios, new Higgs contributions to various
flavor-violating processes, and observable rates for the top quark decay t->
hc. The underlying flavor dynamics must necessarily appear at the TeV scale and
is within the reach of the LHC.
|
[
{
"created": "Thu, 10 Apr 2008 16:41:03 GMT",
"version": "v1"
},
{
"created": "Mon, 26 May 2008 10:42:28 GMT",
"version": "v2"
},
{
"created": "Tue, 27 Jan 2009 12:08:15 GMT",
"version": "v3"
}
] |
2009-01-27
|
[
[
"Giudice",
"Gian F.",
""
],
[
"Lebedev",
"Oleg",
""
]
] |
We consider the possibility that the Yukawa couplings depend on the Higgs field, with the motivation of generating the fermion mass hierarchy through appropriate powers of the Higgs vacuum expectation value. This leads to drastic modifications of the Higgs branching ratios, new Higgs contributions to various flavor-violating processes, and observable rates for the top quark decay t-> hc. The underlying flavor dynamics must necessarily appear at the TeV scale and is within the reach of the LHC.
|
hep-ph/9509250
|
Lee Lin
|
Lee Lin (Dep. of Physics,Chung Hsing Univ,Taichung,Taiwan,ROC)
|
Mass Bounds in Mirror-Fermion Models
|
6 pages, 1 compressed Postscript figure, talk presented at Joint
Meeting of the Chinese Physical Societies--First International Conference on
Frontiers of Physics, Shantou, China, August 5-9, 1995
| null | null | null |
hep-ph
| null |
Numerical simulations are performed on different lattice sizes of chiral U(1)
and SU(2) scalar-fermion models with explicit mirror pairs of fermions in the
broken symmetry phase. Relevance of these models to the electroweak theory is
discussed. Shift symmetry of the action is exploited to decouple the unwanted
mirror-fermion. Upper and lower bounds on the renormalized scalar mass as a
function of the renormalized fermion mass are obtained in the SU(2) version of
the model. Our numerical data are found to be in qualitative agreement with
one-loop results. No evidence for a nontrivial fixed point has been observed.
The mirror-fermion models are likely to be trivial in the continuum limit. Our
Monte Carlo data show that with a $180\, GeV$ top quark, the Standard Model
Higgs boson should have a mass between $100$ and $800\, GeV$.
|
[
{
"created": "Fri, 8 Sep 1995 13:53:25 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Lin",
"Lee",
"",
"Dep. of Physics,Chung Hsing Univ,Taichung,Taiwan,ROC"
]
] |
Numerical simulations are performed on different lattice sizes of chiral U(1) and SU(2) scalar-fermion models with explicit mirror pairs of fermions in the broken symmetry phase. Relevance of these models to the electroweak theory is discussed. Shift symmetry of the action is exploited to decouple the unwanted mirror-fermion. Upper and lower bounds on the renormalized scalar mass as a function of the renormalized fermion mass are obtained in the SU(2) version of the model. Our numerical data are found to be in qualitative agreement with one-loop results. No evidence for a nontrivial fixed point has been observed. The mirror-fermion models are likely to be trivial in the continuum limit. Our Monte Carlo data show that with a $180\, GeV$ top quark, the Standard Model Higgs boson should have a mass between $100$ and $800\, GeV$.
|
1112.0218
|
Natascia Vignaroli
|
Natascia Vignaroli
|
Phenomenology of heavy fermion and vector resonances in composite Higgs
models
|
Ph.D. Thesis (Advisor: Roberto Contino). Dec 2011. 110 pp. Graduation
date added. References added
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this project we study the phenomenology of models where the Higgs is a
bound state of a strongly interacting dynamics at the TeV scale and we assess
the LHC potential to discover new heavy colored states. In the first part of
the thesis we analyze the bounds on the spectrum of Composite Higgs Models
(CHM) that come from flavor observables. In the second part we propose a novel
strategy to discover a heavy gluon ($G^*$) and heavy fermions at the LHC. We do
so by means of simple two-site effective Lagrangians, which could also be used
in further phenomenological studies on CHM. From the analysis of the bounds on
the CHM spectrum, we derive an important constraint on the masses of the heavy
fermions which does not depend on the flavor structure of the sector beyond the
SM. This bound is obtained from the infrared contribution to $b \to s\gamma$
induced by the flavor-conserving effective vertex $Wt_Rb_R$. We find that the
presence of a custodial symmetry can play a role in protecting this effective
coupling. Studying the heavy colored vectors phenomenology, we find that heavy
composite fermions have a great impact on the phenomenology of heavy composite
gluon at the LHC. If the composite gluon is heavier than the composite
fermions, as flavor observables seem to suggest, the search in the channels
where $G^*$ decays into one heavy fermion plus its Standard Model partner is
very promising, with the possibility for both the $G^*$ and heavy fermions to
be discovered at the early stage of the LHC. These channels offer also the
possibility to extract important information on model's parameters, such as the
top degree of compositeness.
|
[
{
"created": "Thu, 1 Dec 2011 15:54:30 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Dec 2011 22:55:35 GMT",
"version": "v2"
},
{
"created": "Fri, 13 Apr 2012 18:46:50 GMT",
"version": "v3"
}
] |
2012-04-16
|
[
[
"Vignaroli",
"Natascia",
""
]
] |
In this project we study the phenomenology of models where the Higgs is a bound state of a strongly interacting dynamics at the TeV scale and we assess the LHC potential to discover new heavy colored states. In the first part of the thesis we analyze the bounds on the spectrum of Composite Higgs Models (CHM) that come from flavor observables. In the second part we propose a novel strategy to discover a heavy gluon ($G^*$) and heavy fermions at the LHC. We do so by means of simple two-site effective Lagrangians, which could also be used in further phenomenological studies on CHM. From the analysis of the bounds on the CHM spectrum, we derive an important constraint on the masses of the heavy fermions which does not depend on the flavor structure of the sector beyond the SM. This bound is obtained from the infrared contribution to $b \to s\gamma$ induced by the flavor-conserving effective vertex $Wt_Rb_R$. We find that the presence of a custodial symmetry can play a role in protecting this effective coupling. Studying the heavy colored vectors phenomenology, we find that heavy composite fermions have a great impact on the phenomenology of heavy composite gluon at the LHC. If the composite gluon is heavier than the composite fermions, as flavor observables seem to suggest, the search in the channels where $G^*$ decays into one heavy fermion plus its Standard Model partner is very promising, with the possibility for both the $G^*$ and heavy fermions to be discovered at the early stage of the LHC. These channels offer also the possibility to extract important information on model's parameters, such as the top degree of compositeness.
|
1504.06483
|
Kyrill Bugaev
|
V.A. Kizka, V.S.Trubnikov, K.A. Bugaev and D.R. Oliinychenko
|
A possible evidence of the hadron-quark-gluon mixed phase formation in
nuclear collisions
|
33 pages, 6 figures and 11 tables
| null | null | null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The performed systematic meta-analysis of the quality of data description
(QDD) of existing event generators of nucleus-nucleus collisions allows us to
extract a very important physical information. Our meta-analysis is dealing
with the results of 10 event generators which describe data measured in the
range of center of mass collision energies from 3.1 GeV to 17.3 GeV. It
considers the mean deviation squared per number of experimental points obtained
by these event generators, i.e. the QDD, as the results of independent
meta-measurements. These generators and their QDDs are divided in two groups.
The first group includes the generators which account for the quark-gluon
plasma formation during nuclear collisions (QGP models), while the second group
includes the generators which do not assume the QGP formation in such
collisions (hadron gas models). Comparing the QDD of more than a hundred of
different data sets of strange hadrons by two groups of models, we found two
regions of the equal quality description of data which are located at the
center of mass collision energies 4.4-4.87 GeV and 10.8-12 GeV. At the
collision energies below 4.4 GeV the hadron gas models describe data much
better than the QGP one and, hence, we associate this region with hadron phase.
At the collision energies between 5 GeV and 10.8 GeV and above 12 GeV we found
that QGP models describe data essentially better than the hadron gas ones and,
hence, these regions we associate with the quark-gluon phase. As a result, the
collision energy regions 4.4-4.87 GeV and 10.8-12 GeV we interpret as the
energies of the hadron-quark-gluon mixed phase formation. Based on these
findings we argue that the most probable energy range of the QCD phase diagram
(tri)critical endpoint is 12-14 GeV.
|
[
{
"created": "Fri, 24 Apr 2015 12:20:39 GMT",
"version": "v1"
}
] |
2015-04-27
|
[
[
"Kizka",
"V. A.",
""
],
[
"Trubnikov",
"V. S.",
""
],
[
"Bugaev",
"K. A.",
""
],
[
"Oliinychenko",
"D. R.",
""
]
] |
The performed systematic meta-analysis of the quality of data description (QDD) of existing event generators of nucleus-nucleus collisions allows us to extract a very important physical information. Our meta-analysis is dealing with the results of 10 event generators which describe data measured in the range of center of mass collision energies from 3.1 GeV to 17.3 GeV. It considers the mean deviation squared per number of experimental points obtained by these event generators, i.e. the QDD, as the results of independent meta-measurements. These generators and their QDDs are divided in two groups. The first group includes the generators which account for the quark-gluon plasma formation during nuclear collisions (QGP models), while the second group includes the generators which do not assume the QGP formation in such collisions (hadron gas models). Comparing the QDD of more than a hundred of different data sets of strange hadrons by two groups of models, we found two regions of the equal quality description of data which are located at the center of mass collision energies 4.4-4.87 GeV and 10.8-12 GeV. At the collision energies below 4.4 GeV the hadron gas models describe data much better than the QGP one and, hence, we associate this region with hadron phase. At the collision energies between 5 GeV and 10.8 GeV and above 12 GeV we found that QGP models describe data essentially better than the hadron gas ones and, hence, these regions we associate with the quark-gluon phase. As a result, the collision energy regions 4.4-4.87 GeV and 10.8-12 GeV we interpret as the energies of the hadron-quark-gluon mixed phase formation. Based on these findings we argue that the most probable energy range of the QCD phase diagram (tri)critical endpoint is 12-14 GeV.
|
hep-ph/0609055
|
Douglas Gingrich Mr.
|
Douglas M. Gingrich
|
Black Hole Cross Section at the Large Hadron Collider
|
28 pages, 9 figures, LaTeX; added references, corrected typos,
expanded discussion
|
Int.J.Mod.Phys. A21 (2006) 6653-6676
|
10.1142/S0217751X06035087
| null |
hep-ph gr-qc hep-th
| null |
Black hole production at the Large Hadron Collider (LHC) was first discussed
in 1999. Since then, much work has been performed in predicting the black hole
cross section. In light of the start up of the LHC, it is now timely to review
the state of these calculations. We review the uncertainties in estimating the
black hole cross section in higher dimensions. One would like to make this
estimate as precise as possible since the predicted values, or lower limits,
obtain for the fundamental Planck scale and number of extra dimensions from
experiments will depend directly on the accuracy of the cross section. Based on
the current knowledge of the cross section, we give a range of lower limits on
the fundamental Planck scale that could be obtained at LHC energies.
|
[
{
"created": "Wed, 6 Sep 2006 04:19:59 GMT",
"version": "v1"
},
{
"created": "Fri, 22 Dec 2006 17:11:20 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Gingrich",
"Douglas M.",
""
]
] |
Black hole production at the Large Hadron Collider (LHC) was first discussed in 1999. Since then, much work has been performed in predicting the black hole cross section. In light of the start up of the LHC, it is now timely to review the state of these calculations. We review the uncertainties in estimating the black hole cross section in higher dimensions. One would like to make this estimate as precise as possible since the predicted values, or lower limits, obtain for the fundamental Planck scale and number of extra dimensions from experiments will depend directly on the accuracy of the cross section. Based on the current knowledge of the cross section, we give a range of lower limits on the fundamental Planck scale that could be obtained at LHC energies.
|
hep-ph/9808483
|
Evgene Levin
|
E. Levin (DESY & Tel Aviv Univ.)
|
25 years with the Pomeron
|
21 pp in latex file, 3 figures in eps files
| null | null |
DESY 98-118, TAUP 2522/98
|
hep-ph
| null |
This paper is written for "Gribov Memorial Volume", Heavy Ion Physics, Acta
Physica Hungarica. This is a report on my 25 years activity in understanding of
the Pomeron structure. Since I was involved in the Pomeron business moreless
from the beginning, I hope, that this report shows the development of the main
ideas in their historical perspective from the first enthusiastic attempts to
find a simple solution to understanding of the complexity and difficulty of the
problem. In other words, this is a story about a young guy who wanted to
understand everything in high energy interaction, who did his best but who is
still in the beginning, but who has not lost his temper and considers the
Pomeron structure as the beautiful and difficult problem, which deserves his
time and efforts to be solved.
|
[
{
"created": "Mon, 31 Aug 1998 09:54:20 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Levin",
"E.",
"",
"DESY & Tel Aviv Univ."
]
] |
This paper is written for "Gribov Memorial Volume", Heavy Ion Physics, Acta Physica Hungarica. This is a report on my 25 years activity in understanding of the Pomeron structure. Since I was involved in the Pomeron business moreless from the beginning, I hope, that this report shows the development of the main ideas in their historical perspective from the first enthusiastic attempts to find a simple solution to understanding of the complexity and difficulty of the problem. In other words, this is a story about a young guy who wanted to understand everything in high energy interaction, who did his best but who is still in the beginning, but who has not lost his temper and considers the Pomeron structure as the beautiful and difficult problem, which deserves his time and efforts to be solved.
|
0907.4206
|
Roman Kezerashvili
|
R. Ya. Kezerashvili, I. M. Narodetskii, A. I. Veselov
|
Baryons in the Field Correlator Method
|
6 pages, 2 figures. Talk given at APS April Meeting, Denver,
Colorado, May 2-5, 2009 and at the Tenth Conference on the Intersections of
Particle and Nuclear Physics (CIPANP 2009), San Diego, California, May 26-31,
2009
|
AIP Conf.Proc.1182:526-531,2009
|
10.1063/1.3293861
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The ground and $P$-wave excited states of $nnn$, $nns$ and $ssn$ baryons are
studied in the framework of the field correlator method using the running
strong coupling constant in the Coulomb-like part of the three-quark potential.
The string correction for the confinement potential of the orbitally excited
baryons, which is the leading contribution of the proper inertia of the
rotating strings, is estimated.
|
[
{
"created": "Fri, 24 Jul 2009 13:38:16 GMT",
"version": "v1"
}
] |
2010-01-15
|
[
[
"Kezerashvili",
"R. Ya.",
""
],
[
"Narodetskii",
"I. M.",
""
],
[
"Veselov",
"A. I.",
""
]
] |
The ground and $P$-wave excited states of $nnn$, $nns$ and $ssn$ baryons are studied in the framework of the field correlator method using the running strong coupling constant in the Coulomb-like part of the three-quark potential. The string correction for the confinement potential of the orbitally excited baryons, which is the leading contribution of the proper inertia of the rotating strings, is estimated.
|
1103.1591
|
Zhong-Bo Kang
|
Zhong-Bo Kang, Jian-Wei Qiu, Werner Vogelsang, Feng Yuan
|
An Observation Concerning the Process Dependence of the Sivers Functions
|
11 pages, 4 figures
|
Phys.Rev.D83:094001,2011
|
10.1103/PhysRevD.83.094001
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The $k_\perp$-moment of a quark's Sivers function is known to be related to
the corresponding twist-three quark-gluon correlation function $T_{q,F}(x, x)$.
The two functions have been extracted from data for single-spin asymmetries in
semi-inclusive deep inelastic scattering and in single-inclusive hadron
production in $pp$ collisions, respectively. Performing a consistent comparison
of the extracted functions, we find that they show a "sign mismatch": while the
magnitude of the functions is roughly consistent, the $k_\perp$-moment of the
Sivers function has opposite sign from that of $T_{q,F}(x, x)$, both for up and
for down quarks. Barring any inconsistencies in our theoretical understanding
of the Sivers functions and their process dependence, the implication of this
mismatch is that either, the Sivers effect is not dominantly responsible for
the observed single-spin asymmetries in $pp$ collisions or, the current
semi-inclusive lepton scattering data do not sufficiently constrain the
$k_\perp$-moment of the quark Sivers functions. Both possibilities strengthen
the case for further experimental investigations of single-spin asymmetries in
high-energy $pp$ and $ep$ scattering.
|
[
{
"created": "Tue, 8 Mar 2011 18:21:57 GMT",
"version": "v1"
}
] |
2011-05-12
|
[
[
"Kang",
"Zhong-Bo",
""
],
[
"Qiu",
"Jian-Wei",
""
],
[
"Vogelsang",
"Werner",
""
],
[
"Yuan",
"Feng",
""
]
] |
The $k_\perp$-moment of a quark's Sivers function is known to be related to the corresponding twist-three quark-gluon correlation function $T_{q,F}(x, x)$. The two functions have been extracted from data for single-spin asymmetries in semi-inclusive deep inelastic scattering and in single-inclusive hadron production in $pp$ collisions, respectively. Performing a consistent comparison of the extracted functions, we find that they show a "sign mismatch": while the magnitude of the functions is roughly consistent, the $k_\perp$-moment of the Sivers function has opposite sign from that of $T_{q,F}(x, x)$, both for up and for down quarks. Barring any inconsistencies in our theoretical understanding of the Sivers functions and their process dependence, the implication of this mismatch is that either, the Sivers effect is not dominantly responsible for the observed single-spin asymmetries in $pp$ collisions or, the current semi-inclusive lepton scattering data do not sufficiently constrain the $k_\perp$-moment of the quark Sivers functions. Both possibilities strengthen the case for further experimental investigations of single-spin asymmetries in high-energy $pp$ and $ep$ scattering.
|
0902.2797
|
Guido Altarelli
|
Guido Altarelli
|
Particle Physics at the LHC Start
|
25 pages, 7 figures. Talk given at the Conference "The Legacy of
Edoardo Amaldi in Science and Society", Rome, Italy, October 23-25, 2008
| null | null |
RM3-TH/09-3, CERN-PH-TH/2009-011
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
I present a concise review of where we stand in particle physics today.
First, I will discuss the status of the Standard Model, its open problems and
the expected answers from the LHC. Then I will briefly review the avenues for
New Physics that can be revealed by the LHC.
|
[
{
"created": "Mon, 16 Feb 2009 21:42:32 GMT",
"version": "v1"
}
] |
2009-02-18
|
[
[
"Altarelli",
"Guido",
""
]
] |
I present a concise review of where we stand in particle physics today. First, I will discuss the status of the Standard Model, its open problems and the expected answers from the LHC. Then I will briefly review the avenues for New Physics that can be revealed by the LHC.
|
hep-ph/0010108
|
Hiesmayr Beatrix
|
B. C. Hiesmayr
|
A generalized Bell-Inequality and Decoherence for the
K^0\bar{K^0}-System
|
16 pages
|
Found.Phys.Lett. 14 (2001) 231-245
| null | null |
hep-ph quant-ph
| null |
First a generalized Bell-inequality for different times and for different
quasi-spin states is developed. We focus on special quasi-spin eigenstates and
times. The inequality based on a local realistic theory is violated by the
CP-violating parameter, if the quantum theory is used to recalculate the
probabilities. Next the quantum mechanical probabilities are modified by the
decoherence approach which enables the initial state to factorize
spontaneously. In this way we get a lower limit for the decoherence parameter
\zeta, which measures the degree of decoherence. This result is compared with
the experimental value of the decoherence parameter \zeta deduced from the data
of the CPLEAR-experiment.
|
[
{
"created": "Wed, 11 Oct 2000 09:58:43 GMT",
"version": "v1"
},
{
"created": "Thu, 26 Oct 2000 10:29:53 GMT",
"version": "v2"
},
{
"created": "Tue, 13 Feb 2001 12:06:36 GMT",
"version": "v3"
}
] |
2016-09-06
|
[
[
"Hiesmayr",
"B. C.",
""
]
] |
First a generalized Bell-inequality for different times and for different quasi-spin states is developed. We focus on special quasi-spin eigenstates and times. The inequality based on a local realistic theory is violated by the CP-violating parameter, if the quantum theory is used to recalculate the probabilities. Next the quantum mechanical probabilities are modified by the decoherence approach which enables the initial state to factorize spontaneously. In this way we get a lower limit for the decoherence parameter \zeta, which measures the degree of decoherence. This result is compared with the experimental value of the decoherence parameter \zeta deduced from the data of the CPLEAR-experiment.
|
hep-ph/0202209
|
Tomohiro Matsuda
|
Tomohiro Matsuda
|
Affleck-Dine baryogenesis after thermal brane inflation
|
13pages, latex2e, references added, typos corrected, final version to
appear in PRD
|
Phys.Rev. D65 (2002) 103501
|
10.1103/PhysRevD.65.103501
| null |
hep-ph astro-ph hep-th
| null |
We propose a new scenario of Affleck-dine baryogenesis in the context of
theories with large extra dimensions. In this paper we consider baryogenesis
after thermal brane inflation and show how our mechanism works. We specifically
consider models in which supersymmetry is broken at the distant brane.
|
[
{
"created": "Fri, 22 Feb 2002 08:31:38 GMT",
"version": "v1"
},
{
"created": "Fri, 1 Mar 2002 06:10:50 GMT",
"version": "v2"
},
{
"created": "Tue, 5 Mar 2002 07:28:02 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Matsuda",
"Tomohiro",
""
]
] |
We propose a new scenario of Affleck-dine baryogenesis in the context of theories with large extra dimensions. In this paper we consider baryogenesis after thermal brane inflation and show how our mechanism works. We specifically consider models in which supersymmetry is broken at the distant brane.
|
hep-ph/0010350
|
Brian Harris
|
A. Chuvakin, J. Smith, B. W. Harris
|
Variable flavor number schemes versus fixed order perturbation theory
for charm quark electroproduction
|
15 pages, 10 Postscript figures; H1 data added, references updated,
typos corrected
|
Eur.Phys.J.C18:547-553,2001
|
10.1007/s100520000546
|
YITP-SB-00-68, ANL-HEP-PR-00-113
|
hep-ph
| null |
Data for D*(2010) meson electroproduction in the range 10 < Q2 < 1350 GeV^2
has recently been presented by the ZEUS collaboration at HERA. We use these
results together with previously published data for Q2 > 1 GeV^2 to test
whether one can distinguish between different theoretical schemes for charm
quark electroproduction. We find that up to the largest Q2 measured, it is not
possible to make such a differentiation. Then we point out the regions where
differences between the various schemes arise.
|
[
{
"created": "Tue, 31 Oct 2000 18:18:08 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Nov 2000 19:50:46 GMT",
"version": "v2"
}
] |
2009-01-07
|
[
[
"Chuvakin",
"A.",
""
],
[
"Smith",
"J.",
""
],
[
"Harris",
"B. W.",
""
]
] |
Data for D*(2010) meson electroproduction in the range 10 < Q2 < 1350 GeV^2 has recently been presented by the ZEUS collaboration at HERA. We use these results together with previously published data for Q2 > 1 GeV^2 to test whether one can distinguish between different theoretical schemes for charm quark electroproduction. We find that up to the largest Q2 measured, it is not possible to make such a differentiation. Then we point out the regions where differences between the various schemes arise.
|
1503.02448
|
Hannu Paukkunen
|
Hannu Paukkunen
|
Neutron skin and centrality classification in high-energy heavy-ion
collisions at the LHC
|
11 pages, to appear in PLB
| null |
10.1016/j.physletb.2015.04.037
| null |
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The concept of centrality in high-energy nuclear collisions has recently
become a subject of an active debate. In particular, the experimental methods
to determine the centrality that have given reasonable results for many
observables in high-energy lead-lead collisions at the LHC have led to
surprising behaviour in the case of proton-lead collisions. In this letter, we
discuss the possibility to calibrate the experimental determination of
centrality by asymmetries caused by mutually different spatial distributions of
protons and neutrons inside the nuclei --- a well-known phenomenon in nuclear
physics known as the neutron-skin effect.
|
[
{
"created": "Mon, 9 Mar 2015 12:18:37 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Apr 2015 07:08:51 GMT",
"version": "v2"
}
] |
2015-05-20
|
[
[
"Paukkunen",
"Hannu",
""
]
] |
The concept of centrality in high-energy nuclear collisions has recently become a subject of an active debate. In particular, the experimental methods to determine the centrality that have given reasonable results for many observables in high-energy lead-lead collisions at the LHC have led to surprising behaviour in the case of proton-lead collisions. In this letter, we discuss the possibility to calibrate the experimental determination of centrality by asymmetries caused by mutually different spatial distributions of protons and neutrons inside the nuclei --- a well-known phenomenon in nuclear physics known as the neutron-skin effect.
|
0711.3157
|
Paul Sorba
|
H. Hogaasen, Paul Sorba (LAPTH)
|
On Quarks and Flavour Symmetry
| null | null |
10.1142/S0217751X08039438
|
LAPTH-1198/07
|
hep-ph physics.ed-ph
| null |
Hadronic spectroscopy can be introduced to students and developed rather far
without requiring SU(N) flavour symmetry. In such a "minimalist" presentation,
we are naturally led to comment and clarify the concept of the "generalized"
Pauli principle.
|
[
{
"created": "Tue, 20 Nov 2007 15:23:40 GMT",
"version": "v1"
}
] |
2009-11-13
|
[
[
"Hogaasen",
"H.",
"",
"LAPTH"
],
[
"Sorba",
"Paul",
"",
"LAPTH"
]
] |
Hadronic spectroscopy can be introduced to students and developed rather far without requiring SU(N) flavour symmetry. In such a "minimalist" presentation, we are naturally led to comment and clarify the concept of the "generalized" Pauli principle.
|
1308.3226
|
Juan Antonio Aguilar-Saavedra
|
J.A. Aguilar-Saavedra, P.M. Boavida, F.R. Joaquim
|
Flavoured searches for type-III seesaw at the LHC
|
LaTeX 6 pages. New simulations, comments and references added.
Version to appear in PRD
|
Phys. Rev. D 88, 113008 (2013)
|
10.1103/PhysRevD.88.113008
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a reinterpretation of CMS searches for type-III seesaw lepton
triplets at the LHC, both for the normal and the inverse seesaw. We find that,
in contrast with previous expectations, these searches in the trilepton final
state have a good sensitivity to triplets with predominant coupling to the tau
lepton. We also show that the limits resulting from direct searches can be
neatly presented for arbitrary masses and general flavour mixings. Thus, it
turns out that the common (and often unrealistic) simplifying assumptions about
the flavour couplings of the triplets used by experimental collaborations to
present their results are unnecessary and should be dropped.
|
[
{
"created": "Wed, 14 Aug 2013 19:59:20 GMT",
"version": "v1"
},
{
"created": "Sat, 7 Dec 2013 07:26:38 GMT",
"version": "v2"
}
] |
2014-01-01
|
[
[
"Aguilar-Saavedra",
"J. A.",
""
],
[
"Boavida",
"P. M.",
""
],
[
"Joaquim",
"F. R.",
""
]
] |
We present a reinterpretation of CMS searches for type-III seesaw lepton triplets at the LHC, both for the normal and the inverse seesaw. We find that, in contrast with previous expectations, these searches in the trilepton final state have a good sensitivity to triplets with predominant coupling to the tau lepton. We also show that the limits resulting from direct searches can be neatly presented for arbitrary masses and general flavour mixings. Thus, it turns out that the common (and often unrealistic) simplifying assumptions about the flavour couplings of the triplets used by experimental collaborations to present their results are unnecessary and should be dropped.
|
1010.5417
|
Adam Latosinski
|
Adam Latosinski, Krzysztof A. Meissner and Hermann Nicolai
|
Axions without Peccei-Quinn Symmetry
|
10 pages, 1 figure
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We argue that the axion arising in the solution of the strong CP problem can
be identified with the Majoron, the (pseudo-)Goldstone boson of spontaneously
broken lepton number symmetry. At low energies, the associated $U(1)_L$
becomes, via electroweak parity violation and neutrino mediation,
indistinguishable from an axial Peccei-Quinn symmetry in relation to the strong
interactions. The axionic couplings are then fully computable in terms of known
SM parameters and the Majorana mass scale, as we illustrate by computing the
effective couplings to photons and quarks at two loops.
|
[
{
"created": "Tue, 26 Oct 2010 14:55:15 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Feb 2011 08:34:54 GMT",
"version": "v2"
}
] |
2011-02-08
|
[
[
"Latosinski",
"Adam",
""
],
[
"Meissner",
"Krzysztof A.",
""
],
[
"Nicolai",
"Hermann",
""
]
] |
We argue that the axion arising in the solution of the strong CP problem can be identified with the Majoron, the (pseudo-)Goldstone boson of spontaneously broken lepton number symmetry. At low energies, the associated $U(1)_L$ becomes, via electroweak parity violation and neutrino mediation, indistinguishable from an axial Peccei-Quinn symmetry in relation to the strong interactions. The axionic couplings are then fully computable in terms of known SM parameters and the Majorana mass scale, as we illustrate by computing the effective couplings to photons and quarks at two loops.
|
0707.2202
|
Andrey Kormilitzin
|
Andrey Kormilitzin
|
Saturation model in the non-Glauber approach
|
27 pages, 18 figures and one table, typos were corrected
| null | null | null |
hep-ph
| null |
In this paper a new saturation model is presented. This model is based on the
theoretical solution for the generating functional, and it is quite different
and not more complicated than the Glauber-like approach used before. The model
describes the structure function F_{2} of the proton, as well as the
diffractive structure function F_{2}^{D}. We show the difference between our
model, and the eikonal approach by calculating the multiplicity distribution,
using the AGK cutting rules strategy.
|
[
{
"created": "Sun, 15 Jul 2007 13:03:32 GMT",
"version": "v1"
},
{
"created": "Wed, 18 Jul 2007 14:38:44 GMT",
"version": "v2"
},
{
"created": "Sun, 22 Jul 2007 15:04:50 GMT",
"version": "v3"
},
{
"created": "Tue, 31 Jul 2007 09:46:24 GMT",
"version": "v4"
}
] |
2007-07-31
|
[
[
"Kormilitzin",
"Andrey",
""
]
] |
In this paper a new saturation model is presented. This model is based on the theoretical solution for the generating functional, and it is quite different and not more complicated than the Glauber-like approach used before. The model describes the structure function F_{2} of the proton, as well as the diffractive structure function F_{2}^{D}. We show the difference between our model, and the eikonal approach by calculating the multiplicity distribution, using the AGK cutting rules strategy.
|
0801.0189
|
Xiao-Gang He
|
Xiao-Gang He (NTU) and Sandip Pakvasa (Hawaii)
|
Unparticle Induced Baryon Number Violating Nucleon Decays
|
Latex 10 pages with two figures
|
Phys.Lett.B662:259-263,2008
|
10.1016/j.physletb.2008.03.025
| null |
hep-ph astro-ph hep-ex nucl-ex
| null |
We study baryon number violating nucleon decays induced by unparticle
interactions with the standard model particles. We find that the lowest
dimension operators which cause nucleon decays can arise at dimension 6 +
(d_s-3/2) with the unparticles being a spinor of dimension d_s=d_\U +1/2. For
scalar and vector unparticles of dimension d_\U, the lowest order operatoers
arise at 6+d_\U and 7+d_\U dimensions,respectively. Comparing the spinor
unparticle induced n \to O^s_\U and experimental bound on invisible decay of a
neutron from KamLAND, we find that the scale for unparticle physics is required
to be larger than 10^{10} GeV for d_\U < 2 if the couplings are set to be of
order one. For scalar and vector unparticles, the dominant baryon number
violating decay modes are n\to \bar \nu + O_\U (O^\mu_\U) and p \to e^+ + O_\U
(O^\mu_\U). The same experimental bound puts the scales for scalar and vector
unparticle to be larger than 10^{7} and 10^{5} GeV for d_\U <2 with couplings
set to be of order one. Data on, p \to e^+ invisible, puts similar constraints
on unparticle interactions.
|
[
{
"created": "Mon, 31 Dec 2007 06:10:12 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Jan 2008 00:50:15 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"He",
"Xiao-Gang",
"",
"NTU"
],
[
"Pakvasa",
"Sandip",
"",
"Hawaii"
]
] |
We study baryon number violating nucleon decays induced by unparticle interactions with the standard model particles. We find that the lowest dimension operators which cause nucleon decays can arise at dimension 6 + (d_s-3/2) with the unparticles being a spinor of dimension d_s=d_\U +1/2. For scalar and vector unparticles of dimension d_\U, the lowest order operatoers arise at 6+d_\U and 7+d_\U dimensions,respectively. Comparing the spinor unparticle induced n \to O^s_\U and experimental bound on invisible decay of a neutron from KamLAND, we find that the scale for unparticle physics is required to be larger than 10^{10} GeV for d_\U < 2 if the couplings are set to be of order one. For scalar and vector unparticles, the dominant baryon number violating decay modes are n\to \bar \nu + O_\U (O^\mu_\U) and p \to e^+ + O_\U (O^\mu_\U). The same experimental bound puts the scales for scalar and vector unparticle to be larger than 10^{7} and 10^{5} GeV for d_\U <2 with couplings set to be of order one. Data on, p \to e^+ invisible, puts similar constraints on unparticle interactions.
|
0908.3660
|
Chris Quigg
|
Chris Quigg
|
LHC Physics Potential vs. Energy
|
18 pages, 12 figures, pdflatex; reference added, curve added to
Figure 1
| null | null |
FERMILAB-FN-0839-T
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Parton luminosities are convenient for estimating how the physics potential
of Large Hadron Collider experiments depends on the energy of the proton beams.
I present parton luminosities, ratios of parton luminosities, and contours of
fixed parton luminosity for $gg$, $u\bar{d}$, and $qq$ interactions over the
energy range relevant to the Large Hadron Collider, along with example analyses
for specific processes.
|
[
{
"created": "Tue, 25 Aug 2009 18:49:37 GMT",
"version": "v1"
},
{
"created": "Tue, 8 Sep 2009 04:05:09 GMT",
"version": "v2"
}
] |
2009-09-08
|
[
[
"Quigg",
"Chris",
""
]
] |
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for $gg$, $u\bar{d}$, and $qq$ interactions over the energy range relevant to the Large Hadron Collider, along with example analyses for specific processes.
|
hep-ph/0607161
|
Hiroyuki Kawamura
|
Hiroyuki Kawamura, Jiro Kodaira, Kazuhiro Tanaka
|
Transverse double-spin asymmetries for small $Q_T$ Drell-Yan pair
production in $pp$ and $p\bar{p}$ collisions
|
4 pages, 2 figures, Talk given at DIS06, April 20-24, 2006, Tsukuba,
Japan
| null |
10.1142/9789812706706_0168
| null |
hep-ph
| null |
We discuss transverse double-spin asymmetries for dimuon production at small
transverse-momentum $Q_T$ in $pp$ and $p\bar{p}$ collisions. All order
resummation of large logarithms relevant in small $Q_T$ region is performed at
next-to-leading logarithmic (NLL) accuracy, and asymmetries at RHIC, J-PARC and
GSI are calculated.
|
[
{
"created": "Fri, 14 Jul 2006 04:13:07 GMT",
"version": "v1"
}
] |
2017-08-23
|
[
[
"Kawamura",
"Hiroyuki",
""
],
[
"Kodaira",
"Jiro",
""
],
[
"Tanaka",
"Kazuhiro",
""
]
] |
We discuss transverse double-spin asymmetries for dimuon production at small transverse-momentum $Q_T$ in $pp$ and $p\bar{p}$ collisions. All order resummation of large logarithms relevant in small $Q_T$ region is performed at next-to-leading logarithmic (NLL) accuracy, and asymmetries at RHIC, J-PARC and GSI are calculated.
|
hep-ph/9708306
|
Christian Bauer
|
Christian Bauer, Aneesh V. Manohar
|
Renormalization Group Scaling of the 1/m^2 HQET Lagrangian
|
8 pages, revtex
|
Phys.Rev. D57 (1998) 337-343
|
10.1103/PhysRevD.57.337
|
UTPT-97-17
|
hep-ph
| null |
The operator mixing matrix for the dimension six operators in the heavy quark
effective theory Lagrangian is computed at one loop. The results are shown to
be consistent with constraints from the equations of motion, and from
reparametrization invariance.
|
[
{
"created": "Mon, 11 Aug 1997 18:22:16 GMT",
"version": "v1"
}
] |
2009-10-30
|
[
[
"Bauer",
"Christian",
""
],
[
"Manohar",
"Aneesh V.",
""
]
] |
The operator mixing matrix for the dimension six operators in the heavy quark effective theory Lagrangian is computed at one loop. The results are shown to be consistent with constraints from the equations of motion, and from reparametrization invariance.
|
hep-ph/9901244
|
Sharon Jensen
|
Steven Bass, Stanley J. Brodsky, and Ivan Schmidt
|
Gluon Virtuality and Heavy Sea Quark Contributions to the Spin-Dependent
g_1 Structure Function
|
LaTex, 19 pages
|
Phys.Rev.D60:034010,1999
|
10.1103/PhysRevD.60.034010
|
SLAC-PUB-8025
|
hep-ph
| null |
We analyze the quark mass dependence of photon gluon fusion in polarized deep
inelastic scattering for both the intrinsic and extrinsic gluon distributions
of the nucleon. We calculate the effective number of flavors for each of the
heavy and light quark photon gluon fusion contributions to the first moment of
the spin-dependent structure function $g_1(x)$.
|
[
{
"created": "Thu, 7 Jan 1999 22:21:11 GMT",
"version": "v1"
}
] |
2009-09-11
|
[
[
"Bass",
"Steven",
""
],
[
"Brodsky",
"Stanley J.",
""
],
[
"Schmidt",
"Ivan",
""
]
] |
We analyze the quark mass dependence of photon gluon fusion in polarized deep inelastic scattering for both the intrinsic and extrinsic gluon distributions of the nucleon. We calculate the effective number of flavors for each of the heavy and light quark photon gluon fusion contributions to the first moment of the spin-dependent structure function $g_1(x)$.
|
hep-ph/0101127
|
Johan Bijnens
|
G. Amoros (Lund and Valencia), J. Bijnens (Lund) and P. Talavera
(Orsay)
|
QCD Isospin Breaking in Meson Masses, Decay Constants and Quark Mass
Ratios
|
22 pages, uses axodraw.sty
|
Nucl.Phys. B602 (2001) 87-108
|
10.1016/S0550-3213(01)00121-3
|
LU TP 01-01, IPNO-DR/01-003
|
hep-ph
| null |
The procedure to calculate masses and matrix-elements in the presence of
mixing of the basis states is explained in detail. We then apply this procedure
to the two-loop calculation in Chiral Perturbation Theory of pseudoscalar
masses and decay constants including quark mass isospin breaking. These results
are used to update our analysis of $K_{\ell4}$ done previously and obtain a
value of $m_u/m_d$ in addition to values for the low-energy-constants $L_i^r$.
|
[
{
"created": "Fri, 12 Jan 2001 13:40:28 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Amoros",
"G.",
"",
"Lund and Valencia"
],
[
"Bijnens",
"J.",
"",
"Lund"
],
[
"Talavera",
"P.",
"",
"Orsay"
]
] |
The procedure to calculate masses and matrix-elements in the presence of mixing of the basis states is explained in detail. We then apply this procedure to the two-loop calculation in Chiral Perturbation Theory of pseudoscalar masses and decay constants including quark mass isospin breaking. These results are used to update our analysis of $K_{\ell4}$ done previously and obtain a value of $m_u/m_d$ in addition to values for the low-energy-constants $L_i^r$.
|
1107.4616
|
Aldo Deandrea
|
Giacomo Cacciapaglia, Roberto Chierici, Aldo Deandrea, Luca Panizzi,
St\`ephane Perries, Silvano Tosi
|
Four tops on the real projective plane at LHC
|
26 pages, 4 figures, minor modifications and few references added
|
JHEP10(2011)042
|
10.1007/JHEP10(2011)042
|
LYCEN 2011-04; KCL-PH-TH/2011-14
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We explore the four top signal ttbar ttbar at the 7 TeV Large Hadron Collider
as a probe of physics beyond the standard model. Enhancement of the
corresponding cross-section with respect to the Standard Model value can probe
the electroweak symmetry breaking sector or test extra dimensional models with
heavy Kaluza-Klein gluons and quarks. We perform a detailed analysis including
background and detector simulation in the specific case of a universal
extra-dimensional model with two extra dimensions compactified using the
geometry of the real projective plane. For masses around 600 GeV, a discovery
is possible for an effective cross section above 210 fb (36 fb) for 1/fb
(10/fb) of integrated luminosity. This implies a branching ratio in tops of the
(1,1) heavy photon above 13% (5%). Furthermore, the 4-top signal from the (2,0)
and (0,2) tiers can be discovered with an integrated luminosity of 3.5/fb. The
results of our simulation can be easily adapted to other models since the
background processes are identical. Concerning the signal, typical production
mechanisms for the ttbar ttbar signal are similar even if cross-section values
may vary considerably depending on the model and the spectrum of the new
particles.
|
[
{
"created": "Fri, 22 Jul 2011 20:17:35 GMT",
"version": "v1"
},
{
"created": "Wed, 19 Oct 2011 10:05:45 GMT",
"version": "v2"
}
] |
2015-05-28
|
[
[
"Cacciapaglia",
"Giacomo",
""
],
[
"Chierici",
"Roberto",
""
],
[
"Deandrea",
"Aldo",
""
],
[
"Panizzi",
"Luca",
""
],
[
"Perries",
"Stèphane",
""
],
[
"Tosi",
"Silvano",
""
]
] |
We explore the four top signal ttbar ttbar at the 7 TeV Large Hadron Collider as a probe of physics beyond the standard model. Enhancement of the corresponding cross-section with respect to the Standard Model value can probe the electroweak symmetry breaking sector or test extra dimensional models with heavy Kaluza-Klein gluons and quarks. We perform a detailed analysis including background and detector simulation in the specific case of a universal extra-dimensional model with two extra dimensions compactified using the geometry of the real projective plane. For masses around 600 GeV, a discovery is possible for an effective cross section above 210 fb (36 fb) for 1/fb (10/fb) of integrated luminosity. This implies a branching ratio in tops of the (1,1) heavy photon above 13% (5%). Furthermore, the 4-top signal from the (2,0) and (0,2) tiers can be discovered with an integrated luminosity of 3.5/fb. The results of our simulation can be easily adapted to other models since the background processes are identical. Concerning the signal, typical production mechanisms for the ttbar ttbar signal are similar even if cross-section values may vary considerably depending on the model and the spectrum of the new particles.
|
2204.13246
|
Elsayed Elmaghraby
|
Ateia W. Mahmoud, Elsayed K. Elmaghraby, A. H. M. Solieman, E. Salama,
A. Elghazaly, S. A. El-fiki
|
Stimulated perturbation on the neutron flux distribution in the
mutually-dependent source-to-absorber geometry
|
10 pages, 13 figures, 26 references
|
Physica Scripta, 2022
|
10.1088/1402-4896/ac831c
| null |
hep-ph
|
http://creativecommons.org/licenses/by-nc-nd/4.0/
|
The complexity of the neutron transport phenomenon throws its shadows on
every physical system wherever neutron is produced or absorbed. The Monte Carlo
N-Particle Transport Code (MCNP) was used to investigate the flux perturbations
in the neutron field caused by an absorber. The geometry of the present
experiment was designed to reach a simulation of an isotopic neutron field. The
neutron source was a ${}^{241}$AmBe with the production physics of neutrons is
dependent only on alpha-beryllium interaction and is independent of what
happened to the neutron after it was generated. The geometries have been
designed to get a volume of uniform neutron densities within a spherical volume
of radius 15 cm in every neutron energy group up to 10 MeV. Absorbers of
different dimensions were placed within the volume to investigate the field
perturbation. Different neutron absorbers were used to correlate the phenomenon
to the integral cross-section of the absorber. Flux density inside and outside
the absorber samples was determined, while the spatial neutron flux
distribution produced by the AmBe source without an absorber was taken as a
reference. This study displayed that absorbers of various dimensions perturb
the neutron field in a way that is dependent on the absorption and scattering
cross-sections, particularly in the neutron resonance region. Unlike the simple
picture of reducing the number density of neutrons, the perturbation was found
to influence the moderation of neutrons in the medium, significantly above 1
MeV.
|
[
{
"created": "Thu, 28 Apr 2022 01:11:15 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Jul 2022 13:24:21 GMT",
"version": "v2"
}
] |
2022-07-25
|
[
[
"Mahmoud",
"Ateia W.",
""
],
[
"Elmaghraby",
"Elsayed K.",
""
],
[
"Solieman",
"A. H. M.",
""
],
[
"Salama",
"E.",
""
],
[
"Elghazaly",
"A.",
""
],
[
"El-fiki",
"S. A.",
""
]
] |
The complexity of the neutron transport phenomenon throws its shadows on every physical system wherever neutron is produced or absorbed. The Monte Carlo N-Particle Transport Code (MCNP) was used to investigate the flux perturbations in the neutron field caused by an absorber. The geometry of the present experiment was designed to reach a simulation of an isotopic neutron field. The neutron source was a ${}^{241}$AmBe with the production physics of neutrons is dependent only on alpha-beryllium interaction and is independent of what happened to the neutron after it was generated. The geometries have been designed to get a volume of uniform neutron densities within a spherical volume of radius 15 cm in every neutron energy group up to 10 MeV. Absorbers of different dimensions were placed within the volume to investigate the field perturbation. Different neutron absorbers were used to correlate the phenomenon to the integral cross-section of the absorber. Flux density inside and outside the absorber samples was determined, while the spatial neutron flux distribution produced by the AmBe source without an absorber was taken as a reference. This study displayed that absorbers of various dimensions perturb the neutron field in a way that is dependent on the absorption and scattering cross-sections, particularly in the neutron resonance region. Unlike the simple picture of reducing the number density of neutrons, the perturbation was found to influence the moderation of neutrons in the medium, significantly above 1 MeV.
|
hep-ph/9904465
|
Lisi Eligio
|
G.L. Fogli, E. Lisi, A. Marrone, G. Scioscia (Bari U. and INFN, Bari)
|
A phenomenological outlook on three-flavor atmospheric neutrino
oscillations
|
5 pages, 3 figures. Presented at WIN99. Updated analysis including 45
kTy Super-Kamiokande data
| null | null | null |
hep-ph
| null |
The recent observations of atmospheric nu events from the Super-Kamiokande
experiment are compatible with three-flavor neutrino oscillations, occurring
dominantly in the nu_mu<--->nu_tau channel and subdominantly in the
nu_mu<--->nu_e channel. We present an updated analysis of the three-flavor
mass-mixing parameters consistent with the present phenomenology, including the
latest 45 kTy data sample from Super-Kamiokande. A comparison with our previous
results, based on 33 kTy data, shows that the oscillation evidence is
strengthened, and that the neutrino mass-mixing parameters are constrained in
smaller ranges.
|
[
{
"created": "Tue, 27 Apr 1999 13:59:30 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Fogli",
"G. L.",
"",
"Bari U. and INFN, Bari"
],
[
"Lisi",
"E.",
"",
"Bari U. and INFN, Bari"
],
[
"Marrone",
"A.",
"",
"Bari U. and INFN, Bari"
],
[
"Scioscia",
"G.",
"",
"Bari U. and INFN, Bari"
]
] |
The recent observations of atmospheric nu events from the Super-Kamiokande experiment are compatible with three-flavor neutrino oscillations, occurring dominantly in the nu_mu<--->nu_tau channel and subdominantly in the nu_mu<--->nu_e channel. We present an updated analysis of the three-flavor mass-mixing parameters consistent with the present phenomenology, including the latest 45 kTy data sample from Super-Kamiokande. A comparison with our previous results, based on 33 kTy data, shows that the oscillation evidence is strengthened, and that the neutrino mass-mixing parameters are constrained in smaller ranges.
|
2012.09587
|
Shoaib Munir
|
Biswaranjan Das, Stefano Moretti, Shoaib Munir, Poulose Poulose
|
Quantum interference effects in Higgs boson pair-production beyond the
Standard Model
|
22 pages, 7 figures, 2 table. Some improvements in text, figures and
tables. Results unchanged. Version to appear in EPJC
|
Eur. Phys. J. C81 (2021), 347
|
10.1140/epjc/s10052-021-09023-w
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
New physics frameworks like the Next-to-Minimal Supersymmetric Standard Model
and the Next-to-2-Higgs-doublet Model contain three neutral CP-even Higgs
bosons. It is possible for the heavier two of these states to have masses
identical to each other, which can result in a sizeable quantum interference
between their propagators in processes they mediate. For both these models, we
study the impact of such interference on the pair-production of the lightest of
the three scalars, which we identify with the observed 125 GeV Higgs boson, in
the gluon-fusion channel at the Large Hadron Collider (LHC). We find that the
inclusion of these effects can substantially alter the cross section, compared
to its value when they are ignored, for this process. Our results illustrate
the importance of taking possible quantum interference effects into account not
only when investigating the phenomenology of extended Higgs sectors at the
future Run(s) of the LHC, but also when imposing its current exclusion bounds
on the parameter spaces of these models.
|
[
{
"created": "Thu, 17 Dec 2020 14:00:18 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Apr 2021 18:40:26 GMT",
"version": "v2"
}
] |
2021-05-05
|
[
[
"Das",
"Biswaranjan",
""
],
[
"Moretti",
"Stefano",
""
],
[
"Munir",
"Shoaib",
""
],
[
"Poulose",
"Poulose",
""
]
] |
New physics frameworks like the Next-to-Minimal Supersymmetric Standard Model and the Next-to-2-Higgs-doublet Model contain three neutral CP-even Higgs bosons. It is possible for the heavier two of these states to have masses identical to each other, which can result in a sizeable quantum interference between their propagators in processes they mediate. For both these models, we study the impact of such interference on the pair-production of the lightest of the three scalars, which we identify with the observed 125 GeV Higgs boson, in the gluon-fusion channel at the Large Hadron Collider (LHC). We find that the inclusion of these effects can substantially alter the cross section, compared to its value when they are ignored, for this process. Our results illustrate the importance of taking possible quantum interference effects into account not only when investigating the phenomenology of extended Higgs sectors at the future Run(s) of the LHC, but also when imposing its current exclusion bounds on the parameter spaces of these models.
|
2303.10943
|
Vadim Bednyakov Dr.
|
V.A.Bednyakov
|
On massive neutral lepton scattering on nucleus
|
60 pages, 3 figures, to be published in Physics of Elementary
Particles and Atomic Nuclei (in Russian)
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
The paper presents a theoretical approach to the description of the
relativistic scattering of a massive (neutral) lepton on a nucleus, in which
the latter retains its integrity. The measurable cross section of this process
includes the elastic (or coherent) contribution, when the nucleus remains in
its original quantum state and the inelastic (incoherent) contribution, when
the nucleus goes into another (excited) quantum state. Transition from the
elastic scattering regime to the inelastic scattering regime is regulated
automatically by the dependence of the form factors on the momentum transferred
to the nucleus. At small momentum transfers elastic scattering dominates. AS
the transferred momentum increases, the contribution of the inelastic
scattering increases, and the latter becomes dominant at sufficiently large
transferred momenta. The scattering of massive (anti)neutrinos interacting with
nucleons through the $V\mp A$ currents of the Standard Model is considered in
detail. Because of the nonzero masses, an additional channel arises for elastic
and inelastic scattering of these (anti)neutrinos on nuclei due to the
possibility of changing the helicity of these (anti)neutrinos. The expressions
obtained for the cross sections are applicable to any precision data analysis
involving neutrinos and antineutrinos, especially when non-zero neutrino masses
can be taken into account. These expressions can also be used in the analysis
of experiments on direct detection of (neutral) massive weakly interacting
relativistic dark matter particles since, unlike the generally accepted case,
they simultaneously take into account both elastic and inelastic interactions
of the particles. The presence of an "inelastic signal" with its characteristic
signature may be the only registrable evidence of interaction of the dark
matter particle with the nucleus.
|
[
{
"created": "Mon, 20 Mar 2023 08:56:16 GMT",
"version": "v1"
}
] |
2023-03-21
|
[
[
"Bednyakov",
"V. A.",
""
]
] |
The paper presents a theoretical approach to the description of the relativistic scattering of a massive (neutral) lepton on a nucleus, in which the latter retains its integrity. The measurable cross section of this process includes the elastic (or coherent) contribution, when the nucleus remains in its original quantum state and the inelastic (incoherent) contribution, when the nucleus goes into another (excited) quantum state. Transition from the elastic scattering regime to the inelastic scattering regime is regulated automatically by the dependence of the form factors on the momentum transferred to the nucleus. At small momentum transfers elastic scattering dominates. AS the transferred momentum increases, the contribution of the inelastic scattering increases, and the latter becomes dominant at sufficiently large transferred momenta. The scattering of massive (anti)neutrinos interacting with nucleons through the $V\mp A$ currents of the Standard Model is considered in detail. Because of the nonzero masses, an additional channel arises for elastic and inelastic scattering of these (anti)neutrinos on nuclei due to the possibility of changing the helicity of these (anti)neutrinos. The expressions obtained for the cross sections are applicable to any precision data analysis involving neutrinos and antineutrinos, especially when non-zero neutrino masses can be taken into account. These expressions can also be used in the analysis of experiments on direct detection of (neutral) massive weakly interacting relativistic dark matter particles since, unlike the generally accepted case, they simultaneously take into account both elastic and inelastic interactions of the particles. The presence of an "inelastic signal" with its characteristic signature may be the only registrable evidence of interaction of the dark matter particle with the nucleus.
|
1604.08307
|
Keisuke Yanagi
|
Kyu Jung Bae, Koichi Hamaguchi, Takeo Moroi, Keisuke Yanagi
|
Probing the origin of 750 GeV diphoton excess with the precision
measurements at the ILC
|
14 pages, 5 figures
| null |
10.1016/j.physletb.2016.06.026
|
UT-16-19, IPMU-16-0063
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The recently reported diphoton excess at the LHC may imply the existence of a
new resonance with a mass of about 750 GeV which couples to photons via loops
of new charged particles. In this letter, we study the possibility to test such
models at the ILC, paying attention to the new charged particles responsible
for the diphoton decay of the resonance. We show that they affect the
scattering processes $e^+e^- \to f\bar{f}$ (with $f$ denoting Standard Model
fermions) at the ILC, which makes it possible to indirectly probe the new
charged particles even if they are out of the kinematical reach. We also show
that the discriminations of the diphoton models may be possible based on a
study of the angular distributions of $f\bar{f}$.
|
[
{
"created": "Thu, 28 Apr 2016 05:39:27 GMT",
"version": "v1"
}
] |
2016-06-29
|
[
[
"Bae",
"Kyu Jung",
""
],
[
"Hamaguchi",
"Koichi",
""
],
[
"Moroi",
"Takeo",
""
],
[
"Yanagi",
"Keisuke",
""
]
] |
The recently reported diphoton excess at the LHC may imply the existence of a new resonance with a mass of about 750 GeV which couples to photons via loops of new charged particles. In this letter, we study the possibility to test such models at the ILC, paying attention to the new charged particles responsible for the diphoton decay of the resonance. We show that they affect the scattering processes $e^+e^- \to f\bar{f}$ (with $f$ denoting Standard Model fermions) at the ILC, which makes it possible to indirectly probe the new charged particles even if they are out of the kinematical reach. We also show that the discriminations of the diphoton models may be possible based on a study of the angular distributions of $f\bar{f}$.
|
hep-ph/0001051
|
Klaus Rabbertz
|
K. Rabbertz (RWTH Aachen, Germany)
|
Power Corrections to Event Shape Variables measured in ep Deep-Inelastic
Scattering
|
Ph.D. thesis, RWTH Aachen 12/1998, 140 pages, 22 tables, 51 figures
(eps), figures 2.1, 2.2 and 2.4 as low resolution version only
| null | null |
PITHA 98/44
|
hep-ph
| null |
Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are
used to study event shape variables over a large range of "relevant energy" Q
between 7 GeV and 100 GeV. Previously published analysis on thrust, jet
broadening, jet mass and C parameter are substantially refined and updated;
differential two-jet rates treated as event shapes are presented for the first
time.
The Q dependence of the mean values is fit to second order calculations of
perturbative QCD applying power law corrections proportional to 1/Q^p to
account for hadronization effects. The concept of these power corrections is
tested by a systematic investigation in terms of a non-perturbative parameter
\bar{alpha}_{p-1} and the strong coupling constant.
|
[
{
"created": "Thu, 6 Jan 2000 17:33:57 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Rabbertz",
"K.",
"",
"RWTH Aachen, Germany"
]
] |
Deep-inelastic ep scattering data, taken with the H1 detector at HERA, are used to study event shape variables over a large range of "relevant energy" Q between 7 GeV and 100 GeV. Previously published analysis on thrust, jet broadening, jet mass and C parameter are substantially refined and updated; differential two-jet rates treated as event shapes are presented for the first time. The Q dependence of the mean values is fit to second order calculations of perturbative QCD applying power law corrections proportional to 1/Q^p to account for hadronization effects. The concept of these power corrections is tested by a systematic investigation in terms of a non-perturbative parameter \bar{alpha}_{p-1} and the strong coupling constant.
|
1707.08523
|
Ismail Zahed
|
Yizhuang Liu and Ismail Zahed
|
Hydrodynamical corrections to electromagnetic emissivities in QCD
|
20 pages, 5 figures
|
Phys. Rev. D 96, 116021 (2017)
|
10.1103/PhysRevD.96.116021
| null |
hep-ph hep-th nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We provide a general framework for the derivation of the hydrodynamical
corrections to the QCD electromagnetic emissivities in a viscous fluid.
Assuming that the emission times are short in comparison to the fluid evolution
time, we show that the leading corrections in the fluid gradients are
controlled by the bulk and shear tensors times pertinent response functions
involving the energy-momentum tensor. In a hadronic fluid phase, we explicit
these contributions using spectral functions. Using the vector dominance
approximation, we show that the bulk viscosity correction to the photon rate is
sizable, while the shear viscosity is negligible for about all frequencies. In
the partonic phase near the transition temperature we provide an assessment of
the viscous corrections to the photon and dilepton emissions, using a
non-perturbative quark-gluon plasma with soft thermal gluonic corrections in
the form of operators of leading mass dimension. Again, the thermal bulk
viscosity corrections are found to be larger than the thermal shear viscosity
corrections at all energies for both the photon and dilepton in the partonic
phase.
|
[
{
"created": "Wed, 26 Jul 2017 16:17:43 GMT",
"version": "v1"
}
] |
2018-01-03
|
[
[
"Liu",
"Yizhuang",
""
],
[
"Zahed",
"Ismail",
""
]
] |
We provide a general framework for the derivation of the hydrodynamical corrections to the QCD electromagnetic emissivities in a viscous fluid. Assuming that the emission times are short in comparison to the fluid evolution time, we show that the leading corrections in the fluid gradients are controlled by the bulk and shear tensors times pertinent response functions involving the energy-momentum tensor. In a hadronic fluid phase, we explicit these contributions using spectral functions. Using the vector dominance approximation, we show that the bulk viscosity correction to the photon rate is sizable, while the shear viscosity is negligible for about all frequencies. In the partonic phase near the transition temperature we provide an assessment of the viscous corrections to the photon and dilepton emissions, using a non-perturbative quark-gluon plasma with soft thermal gluonic corrections in the form of operators of leading mass dimension. Again, the thermal bulk viscosity corrections are found to be larger than the thermal shear viscosity corrections at all energies for both the photon and dilepton in the partonic phase.
|
1111.3247
|
Bertram Klein
|
Bertram Klein (1), Jens Braun (2), Piotr Piasecki (3) ((1) Technische
Universit\"at M\"unchen, (2) Friedrich-Schiller-Universit\"at Jena, (3)
Technische Universit\"at Darmstadt)
|
Scaling behavior in two-flavor QCD, finite quark masses and finite
volume effects
|
Talk given at The XXIX International Symposium on Lattice Field
Theory - Lattice 2011, July 10-16, 2011, Squaw Valley, Lake Tahoe, California
7 pages, 4 figures
| null | null | null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The question of the exact nature of the phase transition in two-flavor QCD is
still under discussion. Recent results for small quark masses in simulations
with 2+1 flavors show scaling behavior consistent with the O(4) or O(2)
universality class. For a precise determination, an assessment of deviations
from the ideal scaling behavior due to finite quark masses and finite
simulation volumes is necessary.
We study the scaling behavior at the chiral phase transition with an
effective quark-meson model. In our Renormalization Group approach, the quark
masses in the model can be varied from the chiral limit over a wide range of
values, which allows us to estimate scaling deviations due to large quark
masses and the extent of the scaling region. We conclude that scaling
deviations are already large at pion masses of 75 MeV, but that the effect is
difficult to see in the absence of results for even smaller masses. Comparing
results only in a narrow window of pion masses leads to the observation of
apparent scaling behavior. While the scaling deviations are not necessarily
universal, we expect that this may affect current lattice simulation results.
By placing the system in a finite box, we investigate the transition between
infinite-volume scaling behavior and finite-size scaling. We estimate that
finite-size scaling behavior can be tested in regions where pion mass times box
size is approximately 2 - 3, which is smaller than in most current lattice
simulations. We expect that finite-volume effects are small for pion masses of
75 MeV and lattice aspect ratios with TL > 8, but that they will become
significant when pion masses in lattice simulations become smaller.
|
[
{
"created": "Mon, 14 Nov 2011 15:30:28 GMT",
"version": "v1"
}
] |
2011-11-15
|
[
[
"Klein",
"Bertram",
""
],
[
"Braun",
"Jens",
""
],
[
"Piasecki",
"Piotr",
""
]
] |
The question of the exact nature of the phase transition in two-flavor QCD is still under discussion. Recent results for small quark masses in simulations with 2+1 flavors show scaling behavior consistent with the O(4) or O(2) universality class. For a precise determination, an assessment of deviations from the ideal scaling behavior due to finite quark masses and finite simulation volumes is necessary. We study the scaling behavior at the chiral phase transition with an effective quark-meson model. In our Renormalization Group approach, the quark masses in the model can be varied from the chiral limit over a wide range of values, which allows us to estimate scaling deviations due to large quark masses and the extent of the scaling region. We conclude that scaling deviations are already large at pion masses of 75 MeV, but that the effect is difficult to see in the absence of results for even smaller masses. Comparing results only in a narrow window of pion masses leads to the observation of apparent scaling behavior. While the scaling deviations are not necessarily universal, we expect that this may affect current lattice simulation results. By placing the system in a finite box, we investigate the transition between infinite-volume scaling behavior and finite-size scaling. We estimate that finite-size scaling behavior can be tested in regions where pion mass times box size is approximately 2 - 3, which is smaller than in most current lattice simulations. We expect that finite-volume effects are small for pion masses of 75 MeV and lattice aspect ratios with TL > 8, but that they will become significant when pion masses in lattice simulations become smaller.
|
hep-ph/9805295
|
Werner Vogelsang
|
Werner Vogelsang (CERN)
|
Q^2-evolution of spin-dependent parton densities
|
12 Pages, LaTeX, 4 figures as eps files, Invited talk presented at
the `Cracow Epiphany Conference on Spin Effects in Particle Physics and
Tempus Workshop', Jan. 9--11, 1998, Cracow, Poland
|
Acta Phys.Polon. B29 (1998) 1189-1200
| null |
CERN-TH/98-151
|
hep-ph
| null |
We discuss the NLO evolution of quark transversity densities and of the
parton distribution function for linearly polarized gluons in a linearly
polarized hadron. A supersymmetric relation between the NLO evolution kernels
for transversity and for linear polarization is found. We also study the
implications of NLO evolution for Soffer's inequality and the prospects of
measuring transversity densities in polarized Drell-Yan at RHIC.
|
[
{
"created": "Tue, 12 May 1998 13:09:32 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Vogelsang",
"Werner",
"",
"CERN"
]
] |
We discuss the NLO evolution of quark transversity densities and of the parton distribution function for linearly polarized gluons in a linearly polarized hadron. A supersymmetric relation between the NLO evolution kernels for transversity and for linear polarization is found. We also study the implications of NLO evolution for Soffer's inequality and the prospects of measuring transversity densities in polarized Drell-Yan at RHIC.
|
hep-ph/0104096
|
Arnd Brandenburg
|
W. Bernreuther, A. Brandenburg, Z.G. Si, P. Uwer
|
Next-to-leading order QCD corrections to top quark spin correlations at
hadron colliders: the reactions $g g \to t {\bar t} (g)$ and $g q ({\bar q})
\to t {\bar t} q ({\bar q})$
|
10 pages, 8 figures
|
Phys.Lett. B509 (2001) 53-58
|
10.1016/S0370-2693(01)00557-3
|
PITHA 01/02, DESY 01-040, TTP01-11
|
hep-ph
| null |
We have computed the cross section for $t\bar t$ production by gluon-gluon
fusion at next-to-leading order (NLO) in the QCD coupling, keeping the full
dependence on the $t\bar t$ spins. Furthermore we have determined to the same
order the spin dependent cross sections for the processes $g + q ({\bar q})\to
t {\bar t} + q ({\bar q})$. Together with our previous results for $q + {\bar
q} \to t {\bar t} (g)$ these results allow for predictions, at NLO QCD, of the
hadronic production of $t\bar t$ pairs in a general spin configuration. As an
application we have determined the degree of correlation of the $t$ and $\bar
t$ spins at NLO, using various spin quantisation axes.
|
[
{
"created": "Tue, 10 Apr 2001 14:23:40 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Bernreuther",
"W.",
""
],
[
"Brandenburg",
"A.",
""
],
[
"Si",
"Z. G.",
""
],
[
"Uwer",
"P.",
""
]
] |
We have computed the cross section for $t\bar t$ production by gluon-gluon fusion at next-to-leading order (NLO) in the QCD coupling, keeping the full dependence on the $t\bar t$ spins. Furthermore we have determined to the same order the spin dependent cross sections for the processes $g + q ({\bar q})\to t {\bar t} + q ({\bar q})$. Together with our previous results for $q + {\bar q} \to t {\bar t} (g)$ these results allow for predictions, at NLO QCD, of the hadronic production of $t\bar t$ pairs in a general spin configuration. As an application we have determined the degree of correlation of the $t$ and $\bar t$ spins at NLO, using various spin quantisation axes.
|
1110.6102
|
C\'edric Lorc\'e
|
Cedric Lorce and Barbara Pasquini
|
Hadron tomography through Wigner distributions
|
6 pages, 1 figure, 1 table, Prepared for the Third International
Workshop on Transverse Polarization Phenomena in Hard Scattering
(Transversity2011), Veli Lo\v{s}inj, Croatia, 29 Aug - 2 Sep 2011
| null |
10.1393/ncc/i2012-11176-x
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the Wigner functions of the nucleon which provide multidimensional
images of the quark distributions in phase space and combine in a single
picture all the information contained in the generalized parton distributions
(GPDs) and the transverse-momentum dependent parton distributions (TMDs). In
particular, we present results for the distribution of unpolarized quarks in a
longitudinally polarized nucleon obtained in a light-cone constituent quark
model. Treating the Wigner distribution as it was a classical distribution, we
obtain the quark orbital angular momentum and compare it with alternative
definitions given in terms of the GPDs and the TMDs.
|
[
{
"created": "Thu, 27 Oct 2011 15:01:01 GMT",
"version": "v1"
}
] |
2022-03-02
|
[
[
"Lorce",
"Cedric",
""
],
[
"Pasquini",
"Barbara",
""
]
] |
We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space and combine in a single picture all the information contained in the generalized parton distributions (GPDs) and the transverse-momentum dependent parton distributions (TMDs). In particular, we present results for the distribution of unpolarized quarks in a longitudinally polarized nucleon obtained in a light-cone constituent quark model. Treating the Wigner distribution as it was a classical distribution, we obtain the quark orbital angular momentum and compare it with alternative definitions given in terms of the GPDs and the TMDs.
|
1408.6365
|
Taizan Watari
|
Ryoichi Nishio, Taizan Watari
|
Skewness Dependence of GPD / DVCS, Conformal OPE and AdS/CFT
Correspondence II: a holographic model of GPD
|
For better readability, almost the full text of Part I
(arXiv:1212.3322) by the same authors is included in this preprint, after
minimal changes. Sections 2--5.3 and the appendix A.1--A.4 have appeared in
Part I; sections 5.4--7 and the appendix A.5--B are the net material in this
Part II. 88 pages
| null | null |
UT-14-38, IPMU14-291
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Traditional idea of Pomeron/Reggeon description for hadron scattering is now
being given theoretical foundation in gravity dual descriptions, where Pomeron
corresponds to exchange of spin-$j \in 2\mathbb{Z}$ states in the graviton
trajectory. Deeply virtual Compton scattering (DVCS) is essentially a 2 to 2
scattering process of a hadron and a photon, and hence one should be able to
study non-perturbative aspects (GPD) of this process by the Pomeron/Reggeon
process in gravity dual. We find, however, that even one of the most developed
formulations of gravity dual Pomeron (Brower--Polchinski--Strassler--Tan (BPST)
2006) is not able to capture skewness dependence of GPD properly. In Part I
(arXiv:1212.3322), therefore, we computed Reggeon wavefunctions on AdS$_5$ so
that the formalism of BPST can be generalized. In this article, Part II, we use
the wavefunctions to determine the DVCS amplitude, bring it to the form of
conformal OPE/collinear factorization, and extract a holographic model of GPD,
which naturally fits into the framework known as "dual parametrization" or
"(conformal) collinear factorization approach".
|
[
{
"created": "Wed, 27 Aug 2014 09:47:14 GMT",
"version": "v1"
}
] |
2014-08-28
|
[
[
"Nishio",
"Ryoichi",
""
],
[
"Watari",
"Taizan",
""
]
] |
Traditional idea of Pomeron/Reggeon description for hadron scattering is now being given theoretical foundation in gravity dual descriptions, where Pomeron corresponds to exchange of spin-$j \in 2\mathbb{Z}$ states in the graviton trajectory. Deeply virtual Compton scattering (DVCS) is essentially a 2 to 2 scattering process of a hadron and a photon, and hence one should be able to study non-perturbative aspects (GPD) of this process by the Pomeron/Reggeon process in gravity dual. We find, however, that even one of the most developed formulations of gravity dual Pomeron (Brower--Polchinski--Strassler--Tan (BPST) 2006) is not able to capture skewness dependence of GPD properly. In Part I (arXiv:1212.3322), therefore, we computed Reggeon wavefunctions on AdS$_5$ so that the formalism of BPST can be generalized. In this article, Part II, we use the wavefunctions to determine the DVCS amplitude, bring it to the form of conformal OPE/collinear factorization, and extract a holographic model of GPD, which naturally fits into the framework known as "dual parametrization" or "(conformal) collinear factorization approach".
|
1303.0431
|
Krzysztof Marek Kutak
|
Krzysztof Kutak, Wieslaw Placzek, Dawid Toton
|
Numerical solution of the integral form of the resummed
Balitsky-Kovchegov equation
|
9 pages, typos corrected. Accepted for publication in Acta Physica
Polonica B
|
Acta Physica Polonica B Vol. 44 (2013) No 7
| null |
IFJPAN-IV-2013-8
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Balitsky--Kovchegov (BK) evolution equation in its resummed integral form
as obtained in JHEP 1202 (2012) 117 and arXiv:1206.1223 is considered. We solve
it numerically and compare to the unresummed BK equation formulated as an
integral equation and to the solution obtained by the BKsolver package.
Sensitivity of the solution to an introduced resolution parameter and initial
conditions is investigated.
|
[
{
"created": "Sat, 2 Mar 2013 22:15:54 GMT",
"version": "v1"
},
{
"created": "Mon, 18 Mar 2013 15:08:48 GMT",
"version": "v2"
},
{
"created": "Tue, 21 May 2013 20:50:44 GMT",
"version": "v3"
},
{
"created": "Fri, 5 Jul 2013 22:33:31 GMT",
"version": "v4"
}
] |
2013-09-17
|
[
[
"Kutak",
"Krzysztof",
""
],
[
"Placzek",
"Wieslaw",
""
],
[
"Toton",
"Dawid",
""
]
] |
The Balitsky--Kovchegov (BK) evolution equation in its resummed integral form as obtained in JHEP 1202 (2012) 117 and arXiv:1206.1223 is considered. We solve it numerically and compare to the unresummed BK equation formulated as an integral equation and to the solution obtained by the BKsolver package. Sensitivity of the solution to an introduced resolution parameter and initial conditions is investigated.
|
2203.07088
|
Andrew McLeod
|
Jacob L. Bourjaily, Johannes Broedel, Ekta Chaubey, Claude Duhr,
Hjalte Frellesvig, Martijn Hidding, Robin Marzucca, Andrew J. McLeod, Marcus
Spradlin, Lorenzo Tancredi, Cristian Vergu, Matthias Volk, Anastasia
Volovich, Matt von Hippel, Stefan Weinzierl, Matthias Wilhelm, Chi Zhang
|
Functions Beyond Multiple Polylogarithms for Precision Collider Physics
|
32+24 pages, 11 figures, contribution to Snowmass 2021
| null | null |
BONN-TH-2022-05, UUITP-11/22, CERN-TH-2022-029, TUM-HEP-1391/22,
HU-EP-22/08, MITP-22-022
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Feynman diagrams constitute one of the essential ingredients for making
precision predictions for collider experiments. Yet, while the simplest Feynman
diagrams can be evaluated in terms of multiple polylogarithms -- whose
properties as special functions are well understood -- more complex diagrams
often involve integrals over complicated algebraic manifolds. Such diagrams
already contribute at NNLO to the self-energy of the electron, $t \bar{t}$
production, $\gamma \gamma$ production, and Higgs decay, and appear at two
loops in the planar limit of maximally supersymmetric Yang-Mills theory. This
makes the study of these more complicated types of integrals of
phenomenological as well as conceptual importance.
In this white paper contribution to the Snowmass community planning exercise,
we provide an overview of the state of research on Feynman diagrams that
involve special functions beyond multiple polylogarithms, and highlight a
number of research directions that constitute essential avenues for future
investigation.
|
[
{
"created": "Mon, 14 Mar 2022 13:18:26 GMT",
"version": "v1"
}
] |
2022-03-15
|
[
[
"Bourjaily",
"Jacob L.",
""
],
[
"Broedel",
"Johannes",
""
],
[
"Chaubey",
"Ekta",
""
],
[
"Duhr",
"Claude",
""
],
[
"Frellesvig",
"Hjalte",
""
],
[
"Hidding",
"Martijn",
""
],
[
"Marzucca",
"Robin",
""
],
[
"McLeod",
"Andrew J.",
""
],
[
"Spradlin",
"Marcus",
""
],
[
"Tancredi",
"Lorenzo",
""
],
[
"Vergu",
"Cristian",
""
],
[
"Volk",
"Matthias",
""
],
[
"Volovich",
"Anastasia",
""
],
[
"von Hippel",
"Matt",
""
],
[
"Weinzierl",
"Stefan",
""
],
[
"Wilhelm",
"Matthias",
""
],
[
"Zhang",
"Chi",
""
]
] |
Feynman diagrams constitute one of the essential ingredients for making precision predictions for collider experiments. Yet, while the simplest Feynman diagrams can be evaluated in terms of multiple polylogarithms -- whose properties as special functions are well understood -- more complex diagrams often involve integrals over complicated algebraic manifolds. Such diagrams already contribute at NNLO to the self-energy of the electron, $t \bar{t}$ production, $\gamma \gamma$ production, and Higgs decay, and appear at two loops in the planar limit of maximally supersymmetric Yang-Mills theory. This makes the study of these more complicated types of integrals of phenomenological as well as conceptual importance. In this white paper contribution to the Snowmass community planning exercise, we provide an overview of the state of research on Feynman diagrams that involve special functions beyond multiple polylogarithms, and highlight a number of research directions that constitute essential avenues for future investigation.
|
hep-ph/0510274
|
Alexey A. Petrov
|
Ken Kiers, Michael Assis, David Simons, Alexey A. Petrov, Amarjit Soni
|
Neutrinos in a left-right model with a horizontal symmetry
|
26 pages, 4 figures
|
Phys.Rev. D73 (2006) 033009
|
10.1103/PhysRevD.73.033009
|
BNL-HET-05/25, WSU-HEP-0506
|
hep-ph
| null |
We analyze the lepton sector of a Left-Right Model based on the gauge group
SU(2)_L x SU(2)_R x U(1), concentrating mainly on neutrino properties. Using
the seesaw mechanism and a horizontal symmetry, we keep the right-handed
symmetry breaking scale relatively low, while simultaneously satisfying
phenomenological constraints on the light neutrino masses. We take the
right-handed scale to be of order 10's of TeV and perform a full numerical
analysis of the model's parameter space, subject to experimental constraints on
neutrino masses and mixings. The numerical procedure yields results for the
right-handed neutrino masses and mixings and the various CP-violating phases.
We also discuss phenomenological applications of the model to neutrinoless
double beta decay, lepton-flavor-violating decays (including decays such as
\tau \to 3\mu) and leptogenesis.
|
[
{
"created": "Thu, 20 Oct 2005 19:06:45 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Kiers",
"Ken",
""
],
[
"Assis",
"Michael",
""
],
[
"Simons",
"David",
""
],
[
"Petrov",
"Alexey A.",
""
],
[
"Soni",
"Amarjit",
""
]
] |
We analyze the lepton sector of a Left-Right Model based on the gauge group SU(2)_L x SU(2)_R x U(1), concentrating mainly on neutrino properties. Using the seesaw mechanism and a horizontal symmetry, we keep the right-handed symmetry breaking scale relatively low, while simultaneously satisfying phenomenological constraints on the light neutrino masses. We take the right-handed scale to be of order 10's of TeV and perform a full numerical analysis of the model's parameter space, subject to experimental constraints on neutrino masses and mixings. The numerical procedure yields results for the right-handed neutrino masses and mixings and the various CP-violating phases. We also discuss phenomenological applications of the model to neutrinoless double beta decay, lepton-flavor-violating decays (including decays such as \tau \to 3\mu) and leptogenesis.
|
hep-ph/9611426
|
Dima Bardin
|
Dima Bardin, Johannes Bl\"umlein, Penka Christova, Lida Kalinovskaya,
and Tord Riemann
|
QED and Electroweak Corrections to Deep Inelastic Scattering
|
22 pages Latex, including 6 eps-figures; to appear in the Proceedings
of the 3rd International Symposium on Radiative Corrections, Cracow, August
1-5, 1996, Acta Phys. Polonica B
|
Acta Phys.Polon.B28:511-528,1997
| null |
DESY 96-243
|
hep-ph
| null |
We describe the state of the art in the field of radiative corrections for
deep inelastic scattering. Different methods of calculation of radiative
corrections are reviewed. Some new results for QED radiative corrections for
polarized deep inelastic scattering at HERA are presented. A comparison of
results obtained by the codes POLRAD and HECTOR is given for the kinematic
regime of the HERMES experiment. Recent results on radiative corrections to
deep inelastic scattering with tagged photons are briefly discussed.
|
[
{
"created": "Tue, 26 Nov 1996 12:27:41 GMT",
"version": "v1"
}
] |
2011-04-15
|
[
[
"Bardin",
"Dima",
""
],
[
"Blümlein",
"Johannes",
""
],
[
"Christova",
"Penka",
""
],
[
"Kalinovskaya",
"Lida",
""
],
[
"Riemann",
"Tord",
""
]
] |
We describe the state of the art in the field of radiative corrections for deep inelastic scattering. Different methods of calculation of radiative corrections are reviewed. Some new results for QED radiative corrections for polarized deep inelastic scattering at HERA are presented. A comparison of results obtained by the codes POLRAD and HECTOR is given for the kinematic regime of the HERMES experiment. Recent results on radiative corrections to deep inelastic scattering with tagged photons are briefly discussed.
|
hep-ph/9605459
|
Lawrence Horwitz
|
L. Burakovsky, L.P. Horwitz and W.C. Schieve
|
Hadronic Resonance Spectrum May Help in Resolution of Meson Nonet
Enigmas
|
Latex, 13 pages plus 8 figures
|
Nucl.Phys. A609 (1996) 585-599
|
10.1016/S0375-9474(96)00310-7
|
LA-UR-96-1809, IASSNS-96/47
|
hep-ph
| null |
The identification of problematic meson states as the members of the quark
model $q\bar{q}$ nonets by using a hadronic resonance spectrum is discussed.
The results favor the currently adopted $q\bar{q}$ assignments for the
axial-vector, tensor, and 1 $^3F_4$ $J^{PC}=4^{++}$ meson nonets, and suggest a
new $q\bar{q}$ assignment for the scalar meson nonet which favors the
interpretation of the $f_0(980)$ and $f_0(1710)$ mesons as non-$q\bar{q}$
objects. We also suggest that the 2 $^3S_1$ $\frac{1}{2}(1^{-})$ state should
be identified with the $K^\ast (1680)$ rather than $K^\ast (1410)$ meson.
|
[
{
"created": "Fri, 31 May 1996 16:24:04 GMT",
"version": "v1"
}
] |
2016-09-06
|
[
[
"Burakovsky",
"L.",
""
],
[
"Horwitz",
"L. P.",
""
],
[
"Schieve",
"W. C.",
""
]
] |
The identification of problematic meson states as the members of the quark model $q\bar{q}$ nonets by using a hadronic resonance spectrum is discussed. The results favor the currently adopted $q\bar{q}$ assignments for the axial-vector, tensor, and 1 $^3F_4$ $J^{PC}=4^{++}$ meson nonets, and suggest a new $q\bar{q}$ assignment for the scalar meson nonet which favors the interpretation of the $f_0(980)$ and $f_0(1710)$ mesons as non-$q\bar{q}$ objects. We also suggest that the 2 $^3S_1$ $\frac{1}{2}(1^{-})$ state should be identified with the $K^\ast (1680)$ rather than $K^\ast (1410)$ meson.
|
0807.1096
|
Alper Hayreter
|
Alper Hayreter, Asli Sabanci, Levent Solmaz, Saime Solmaz
|
Electric Dipole Moments in U(1)' Models
|
24 pages, 9 figures, 1 table
|
Physical Review D 78, 055011 (2008)(14 pages)
|
10.1103/PhysRevD.78.055011
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study electric dipole moments (EDM) of electron and proton in
E(6)--inspired supersymmetric models with an extra U(1) invariance. Compared to
the Minimal Supersymmetric Standard Model (MSSM), in addition to offering a
natural solution to the mu problem and predicting a larger mass for the
lightest Higgs boson, these models are found to yield suppressed EDMs.
|
[
{
"created": "Mon, 7 Jul 2008 19:58:37 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Aug 2008 22:46:30 GMT",
"version": "v2"
}
] |
2008-10-28
|
[
[
"Hayreter",
"Alper",
""
],
[
"Sabanci",
"Asli",
""
],
[
"Solmaz",
"Levent",
""
],
[
"Solmaz",
"Saime",
""
]
] |
We study electric dipole moments (EDM) of electron and proton in E(6)--inspired supersymmetric models with an extra U(1) invariance. Compared to the Minimal Supersymmetric Standard Model (MSSM), in addition to offering a natural solution to the mu problem and predicting a larger mass for the lightest Higgs boson, these models are found to yield suppressed EDMs.
|
hep-ph/9903221
|
Stephen Wong
|
S.M.H. Wong
|
Colour Octet Contribution in Exclusive P-Wave Charmonium Decay into
Proton-Antiproton
|
25 pages latex file, 6 embedded PS figures, refined arguments,
version to appear in Nucl. Phys. B
|
Nucl.Phys. A674 (2000) 185-204
|
10.1016/S0375-9474(00)00160-3
|
NUC-MINN-98/11-T
|
hep-ph hep-ex
| null |
In inclusive P-wave charmonium decay, to cancel infrared divergence in the
colour singlet contribution requires the inclusion of the colour octet which
becomes degenerate with the former in the infrared limit. In the corresponding
exclusive decay, such an infrared divergence does not exist. On this ground, it
becomes doubtful whether the colour octet is needed in exclusive reactions. A
contradiction in the underlying picture, however, would result once all strong
decay channels are summed. We provide an answer to this question in support of
the colour octet with theoretical arguments as well as an explicit calculation
of Chi_J ---> p \bar p.
|
[
{
"created": "Mon, 1 Mar 1999 22:58:51 GMT",
"version": "v1"
},
{
"created": "Mon, 6 Dec 1999 20:26:52 GMT",
"version": "v2"
},
{
"created": "Wed, 9 Feb 2000 00:52:05 GMT",
"version": "v3"
}
] |
2009-10-31
|
[
[
"Wong",
"S. M. H.",
""
]
] |
In inclusive P-wave charmonium decay, to cancel infrared divergence in the colour singlet contribution requires the inclusion of the colour octet which becomes degenerate with the former in the infrared limit. In the corresponding exclusive decay, such an infrared divergence does not exist. On this ground, it becomes doubtful whether the colour octet is needed in exclusive reactions. A contradiction in the underlying picture, however, would result once all strong decay channels are summed. We provide an answer to this question in support of the colour octet with theoretical arguments as well as an explicit calculation of Chi_J ---> p \bar p.
|
2110.01623
|
Andreas Papaefstathiou
|
Carsten Bittrich, Patrick Kirchgae{\ss}er, Andreas Papaefstathiou,
Simon Pl\"atzer, Stefanie Todt
|
Soft QCD Effects in VBS/VBF Topologies
|
9 pages, 5 figures. Additional figures can be found at:
https://cern.ch/apapaefs/VBSQCD/
| null |
10.1140/epjc/s10052-022-10741-y
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the impact of multi-parton interactions, colour reconnection and
hadronization on the modeling of vector boson fusion and vector boson
scattering (VBS) final states at the Large Hadron Collider (LHC). We
investigate how the variation of the model parameters, compatible with a
reasonable spread of predictions around typical tuning observables,
extrapolates into the VBS phase space. We study the implications of this
variation on the total uncertainty budget attached to realistic simulation of
the final states in current event generator predictions. We find that the
variations have a non-trivial phase space dependence and become comparable in
size to the perturbative uncertainties once next-to-leading order predictions
are combined with parton shower evolution.
|
[
{
"created": "Mon, 4 Oct 2021 18:00:00 GMT",
"version": "v1"
}
] |
2022-09-21
|
[
[
"Bittrich",
"Carsten",
""
],
[
"Kirchgaeßer",
"Patrick",
""
],
[
"Papaefstathiou",
"Andreas",
""
],
[
"Plätzer",
"Simon",
""
],
[
"Todt",
"Stefanie",
""
]
] |
We consider the impact of multi-parton interactions, colour reconnection and hadronization on the modeling of vector boson fusion and vector boson scattering (VBS) final states at the Large Hadron Collider (LHC). We investigate how the variation of the model parameters, compatible with a reasonable spread of predictions around typical tuning observables, extrapolates into the VBS phase space. We study the implications of this variation on the total uncertainty budget attached to realistic simulation of the final states in current event generator predictions. We find that the variations have a non-trivial phase space dependence and become comparable in size to the perturbative uncertainties once next-to-leading order predictions are combined with parton shower evolution.
|
hep-ph/0307267
|
Edward Shuryak
|
Edward V. Shuryak and Ismail Zahed
|
Rethinking the Properties of the Quark-Gluon Plasma at $T\sim T_c$
|
v2 version have one more figure and one more reference, v3 is the
same as v2 except a double-page format (the v2 had corrupted last lines on
the page)
|
Phys.Rev. C70 (2004) 021901
|
10.1103/PhysRevC.70.021901
| null |
hep-ph
| null |
We argue that although at asymptotically high temperatures the QGP in bulk
behaves as a gas of weakly interacting quasiparticles (modulo long-range
magnetism), at temperatures up to few times the critical temperature $T_c$ it
displays different properties. If the running of the QCD coupling constant
continues in the Coulomb phase till the screening length scale, it reaches the
strong coupling treshold $\alpha_s(m_D)\sim 1$. As a result, the Coulomb phase
supports weakly bound Coulombic s-wave $\bar c c$, light quark and even $gg$
states.
The existence of shallow bound states dramatically increases the
quasiparticle rescattering at low energies, reducing the viscosity and thereby
explaining why heavy ion collisions at RHIC exhibit robust collective
phenomena. In conformal gauge theories at finite temperature the Coulomb
binding persists further in the strong coupling regime, as found for ${\cal
N}=4$ SUSY YM in the Maldacena regime.
|
[
{
"created": "Mon, 21 Jul 2003 19:19:23 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Aug 2003 20:01:10 GMT",
"version": "v2"
},
{
"created": "Tue, 12 Aug 2003 22:24:24 GMT",
"version": "v3"
}
] |
2016-09-06
|
[
[
"Shuryak",
"Edward V.",
""
],
[
"Zahed",
"Ismail",
""
]
] |
We argue that although at asymptotically high temperatures the QGP in bulk behaves as a gas of weakly interacting quasiparticles (modulo long-range magnetism), at temperatures up to few times the critical temperature $T_c$ it displays different properties. If the running of the QCD coupling constant continues in the Coulomb phase till the screening length scale, it reaches the strong coupling treshold $\alpha_s(m_D)\sim 1$. As a result, the Coulomb phase supports weakly bound Coulombic s-wave $\bar c c$, light quark and even $gg$ states. The existence of shallow bound states dramatically increases the quasiparticle rescattering at low energies, reducing the viscosity and thereby explaining why heavy ion collisions at RHIC exhibit robust collective phenomena. In conformal gauge theories at finite temperature the Coulomb binding persists further in the strong coupling regime, as found for ${\cal N}=4$ SUSY YM in the Maldacena regime.
|
0806.4529
|
Martin Zdrahal
|
M. Zdrahal, J. Novotny
|
Dispersive Approach to Chiral Perturbation Theory
|
25 pages, 1 figure; added one appendix and correction of typos
|
Phys.Rev.D78:116016,2008
|
10.1103/PhysRevD.78.116016
|
UWThPh-2008-10
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We generalise the reconstruction theorem of Stern, Sazdjian, and Fuchs based
on the dispersion relations to the case of the (2 -> 2) scattering of all the
pseudoscalar octet mesons (pi, K, eta). We formulate it in a general way and
include also a discussion of the assumptions of the theorem. It is used to
obtain the amplitudes of all such processes in the isospin limit to the
one-loop order (and can be straightforwardly extended to two loops)
independently on the particular power-counting scheme of the chiral
perturbation theory in question. The results in this general form are
presented.
|
[
{
"created": "Fri, 27 Jun 2008 14:09:44 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Dec 2008 11:49:24 GMT",
"version": "v2"
}
] |
2008-12-30
|
[
[
"Zdrahal",
"M.",
""
],
[
"Novotny",
"J.",
""
]
] |
We generalise the reconstruction theorem of Stern, Sazdjian, and Fuchs based on the dispersion relations to the case of the (2 -> 2) scattering of all the pseudoscalar octet mesons (pi, K, eta). We formulate it in a general way and include also a discussion of the assumptions of the theorem. It is used to obtain the amplitudes of all such processes in the isospin limit to the one-loop order (and can be straightforwardly extended to two loops) independently on the particular power-counting scheme of the chiral perturbation theory in question. The results in this general form are presented.
|
hep-ph/0106020
|
Adrian Ghinculov
|
A. Ghinculov, Y.-P. Yao
|
Electroweak radiative corrections:Towards a full two-loop analysis
|
Presented at the Fifth International Symposium on Radiative
Corrections (RADCOR 2000), Carmel, CA, September 11-15, 2000
| null | null | null |
hep-ph
| null |
In calculating electroweak radiative corrections at two-loop level, one
encounters Feynman graphs with several different masses on the internal
propagators and on the external legs, which lead to complicated scalar
functions. We describe a general analytic-numerical reduction scheme for
evaluating any two-loop diagrams with general kinematics and general
renormalizable interactions, whereby ten basic functions form a complete set
after tensor reduction. We illustrate this scheme by applying it to two- and
three-point functions. We discuss the treatment of infrared singularities
within this numerical approach.
|
[
{
"created": "Fri, 1 Jun 2001 21:06:13 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Ghinculov",
"A.",
""
],
[
"Yao",
"Y. -P.",
""
]
] |
In calculating electroweak radiative corrections at two-loop level, one encounters Feynman graphs with several different masses on the internal propagators and on the external legs, which lead to complicated scalar functions. We describe a general analytic-numerical reduction scheme for evaluating any two-loop diagrams with general kinematics and general renormalizable interactions, whereby ten basic functions form a complete set after tensor reduction. We illustrate this scheme by applying it to two- and three-point functions. We discuss the treatment of infrared singularities within this numerical approach.
|
1209.0269
|
M.G.A. Buffing
|
M. G. A. Buffing and P. J. Mulders
|
Generalized Universality for TMD Distribution Functions
|
9 pages, updated references and minor corrections, to appear in the
proceedings of the QCD Evolution Workshop 2012 (May 14-17, JLAB)
| null |
10.1142/S2010194512009105
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Azimuthal asymmetries in high-energy processes, most pronounced showing up in
combination with single or double (transverse) spin asymmetries, can be
understood with the help of transverse momentum dependent (TMD) parton
distribution and fragmentation functions. These appear in correlators
containing expectation values of quark and gluon operators. TMDs allow access
to new operators as compared to collinear (transverse momentum integrated)
correlators. These operators include nontrivial process dependent Wilson lines
breaking universality for TMDs. Making an angular decomposition in the
azimuthal angle, we define a set of universal TMDs of definite rank, which
appear with process dependent gluonic pole factors in a way similar to the sign
of T-odd parton distribution functions in deep inelastic scattering or the
Drell-Yan process. In particular, we show that for a spin 1/2 quark target
there are three pretzelocity functions.
|
[
{
"created": "Mon, 3 Sep 2012 08:38:55 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Nov 2012 13:41:39 GMT",
"version": "v2"
}
] |
2015-06-11
|
[
[
"Buffing",
"M. G. A.",
""
],
[
"Mulders",
"P. J.",
""
]
] |
Azimuthal asymmetries in high-energy processes, most pronounced showing up in combination with single or double (transverse) spin asymmetries, can be understood with the help of transverse momentum dependent (TMD) parton distribution and fragmentation functions. These appear in correlators containing expectation values of quark and gluon operators. TMDs allow access to new operators as compared to collinear (transverse momentum integrated) correlators. These operators include nontrivial process dependent Wilson lines breaking universality for TMDs. Making an angular decomposition in the azimuthal angle, we define a set of universal TMDs of definite rank, which appear with process dependent gluonic pole factors in a way similar to the sign of T-odd parton distribution functions in deep inelastic scattering or the Drell-Yan process. In particular, we show that for a spin 1/2 quark target there are three pretzelocity functions.
|
1401.0264
|
Maxim Chernodub
|
M. N. Chernodub, Jos Van Doorsselaere and Henri Verschelde
|
Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting
phase
|
12 pages, 3 figures; v2: minor changes, published version
|
Phys. Rev. D 89, 105011 (2014)
|
10.1103/PhysRevD.89.105011
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In the background of a sufficiently strong magnetic field the vacuum was
suggested to become an ideal electric conductor (highly anisotropic
superconductor) due to an interplay between the strong and electromagnetic
forces. The superconducting ground state resembles an Abrikosov lattice state
in an ordinary type--II superconductor: it is an inhomogeneous structure made
of a (charged vector) quark-antiquark condensate pierced by vortices. In this
paper the acoustic (phonon) vibrational modes of the vortex lattice are studied
at zero temperature. Using an effective model based on a vector meson
dominance, we show that in the infrared limit the longitudinal (transverse)
acoustic vibrations of the vortex lattice possess a linear (quadratic)
dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.
|
[
{
"created": "Wed, 1 Jan 2014 08:18:19 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Jun 2014 10:16:47 GMT",
"version": "v2"
}
] |
2014-06-17
|
[
[
"Chernodub",
"M. N.",
""
],
[
"Van Doorsselaere",
"Jos",
""
],
[
"Verschelde",
"Henri",
""
]
] |
In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type--II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.
|
hep-ph/9210264
| null |
H. C. Eggers, H-Th. Elze and I. Sarcevic
|
Three Dimensional Statistical Field Theory for Density Fluctuations in
Heavy-Ion Collsiions
|
16 pages, 3 figs (not included, available as .ps files on request)
|
Int. J. Mod. Phys. A9 (1994) 3821-3840
|
10.1142/S0217751X94001540
|
TPR-92-41; AZPH-TH/92-25
|
hep-ph
| null |
A statistical field theory of particle production is presented using a
gaussian functional in three dimensions. Identifying the field with the
particle density fluctuation results in zero correlations of order three and
higher, while the second order correlation function is of a Yukawa form. A
detailed scheme for projecting the theoretical three-dimensional correlation
onto data of three and fewer dimensions illustrates how theoretical predictions
are tested against experimental moments in the different dimensions. An example
given in terms of NA35 parameters should be testable against future NA35 data.
|
[
{
"created": "Mon, 26 Oct 1992 23:35:42 GMT",
"version": "v1"
}
] |
2015-06-25
|
[
[
"Eggers",
"H. C.",
""
],
[
"Elze",
"H-Th.",
""
],
[
"Sarcevic",
"I.",
""
]
] |
A statistical field theory of particle production is presented using a gaussian functional in three dimensions. Identifying the field with the particle density fluctuation results in zero correlations of order three and higher, while the second order correlation function is of a Yukawa form. A detailed scheme for projecting the theoretical three-dimensional correlation onto data of three and fewer dimensions illustrates how theoretical predictions are tested against experimental moments in the different dimensions. An example given in terms of NA35 parameters should be testable against future NA35 data.
|
1304.5047
|
Guido Altarelli
|
Guido Altarelli
|
Neutrino Mixing: Theoretical Overview
|
8 pages, no figures. Talk presented at Les Rencontres de Physique de
la Vallee d'Aoste, La Thuile, Italy, February 2013
| null |
10.1393/ncc/i2014-11618-5
|
RM3-TH/13-4, CERN-PH-TH/2013-077
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a concise review of the recent important experimental developments
on neutrino mixing (hints for sterile neutrinos, large $\theta_{13}$, possible
non maximal $\theta_{23}$, approaching sensitivity on $\delta_{CP}$) and their
implications on models of neutrino mixing. The new data disfavour many models
but the surviving ones still span a wide range going from Anarchy (no
structure, no symmetry in the lepton sector) to a maximum of symmetry, as for
the models based on discrete non-abelian flavour groups that can be improved
following the indications from the data.
|
[
{
"created": "Thu, 18 Apr 2013 08:19:33 GMT",
"version": "v1"
}
] |
2022-03-02
|
[
[
"Altarelli",
"Guido",
""
]
] |
We present a concise review of the recent important experimental developments on neutrino mixing (hints for sterile neutrinos, large $\theta_{13}$, possible non maximal $\theta_{23}$, approaching sensitivity on $\delta_{CP}$) and their implications on models of neutrino mixing. The new data disfavour many models but the surviving ones still span a wide range going from Anarchy (no structure, no symmetry in the lepton sector) to a maximum of symmetry, as for the models based on discrete non-abelian flavour groups that can be improved following the indications from the data.
|
2402.16940
|
Eetu Loisa
|
Eetu Loisa and Jim Talbert
|
Froggatt-Nielsen Meets the SMEFT
|
49 pages, 5 figures
| null | null | null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We study the matching of Froggatt-Nielsen theories of flavour onto the
Standard Model Effective Field Theory (SMEFT), upon integrating out a heavy
Beyond-the-Standard-Model (BSM) scalar `flavon' whose vacuum expectation value
breaks an Abelian flavour symmetry at energies $\Lambda_\text{FN}$ well above
the electroweak scale, $\Lambda_\text{FN} > \Lambda_\text{SM}$. We include
matching contributions to the infrared $d_\text{SM}=6$ (Warsaw basis) SMEFT
sourced from ultraviolet contact terms suppressed up to order $1 /
\Lambda_\text{UV}^2$ in the Froggatt-Nielsen Lagrangian, where
$\Lambda_\text{UV} > \Lambda_\text{FN}$ is an arbitrary deep-ultraviolet scale
where further unspecified BSM particles are dynamical. This includes tree-level
(one-loop) ultraviolet diagrams with $d_{\text{FN}}=6$ $(5)$ effective
vertices. We first do so with a toy model, but then generalize our findings to
arbitrary Frogatt-Nielsen charges. Our results indicate a rich and non-trivial
signature of Froggatt-Nielsen theories on the (otherwise) model-independent
operators of the SMEFT, and we briefly speculate on extending our analysis to
broader classes of BSM flavour models, e.g. non-Abelian and/or gauged theories.
We thus take an important step towards determining how to use rapidly
developing theoretical and experimental SMEFT technologies to gain unambiguous
insight into the SM's longstanding fermion flavour puzzle.
|
[
{
"created": "Mon, 26 Feb 2024 19:00:00 GMT",
"version": "v1"
}
] |
2024-02-28
|
[
[
"Loisa",
"Eetu",
""
],
[
"Talbert",
"Jim",
""
]
] |
We study the matching of Froggatt-Nielsen theories of flavour onto the Standard Model Effective Field Theory (SMEFT), upon integrating out a heavy Beyond-the-Standard-Model (BSM) scalar `flavon' whose vacuum expectation value breaks an Abelian flavour symmetry at energies $\Lambda_\text{FN}$ well above the electroweak scale, $\Lambda_\text{FN} > \Lambda_\text{SM}$. We include matching contributions to the infrared $d_\text{SM}=6$ (Warsaw basis) SMEFT sourced from ultraviolet contact terms suppressed up to order $1 / \Lambda_\text{UV}^2$ in the Froggatt-Nielsen Lagrangian, where $\Lambda_\text{UV} > \Lambda_\text{FN}$ is an arbitrary deep-ultraviolet scale where further unspecified BSM particles are dynamical. This includes tree-level (one-loop) ultraviolet diagrams with $d_{\text{FN}}=6$ $(5)$ effective vertices. We first do so with a toy model, but then generalize our findings to arbitrary Frogatt-Nielsen charges. Our results indicate a rich and non-trivial signature of Froggatt-Nielsen theories on the (otherwise) model-independent operators of the SMEFT, and we briefly speculate on extending our analysis to broader classes of BSM flavour models, e.g. non-Abelian and/or gauged theories. We thus take an important step towards determining how to use rapidly developing theoretical and experimental SMEFT technologies to gain unambiguous insight into the SM's longstanding fermion flavour puzzle.
|
hep-ph/9803368
|
Matthias Neubert
|
A.L. Kagan (Univ. Cincinnati) and M. Neubert (CERN)
|
Direct CP Violation in B -> X_s gamma Decays as a Signature of New
Physics
|
several references added and some numerical results updated to
include QED corrections (version to appear in Physical Review D)
|
Phys. Rev. D 58, 094012 (1998)
|
10.1103/PhysRevD.58.094012
|
CERN-TH/98-1, UCHEP-98/7
|
hep-ph
| null |
We argue that the observation of a sizable direct CP asymmetry A_{CP} in the
inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the
Standard Model, A_{CP} can be calculated reliably and is found to be below 1%
in magnitude. In extensions of the Standard Model with new CP-violating
couplings, large CP asymmetries are possible without conflicting with the
experimental value of the branching ratio for the decays B -> X_s gamma. In
particular, large asymmetries arise naturally in models with enhanced
chromo-magnetic dipole operators. Some generic examples of such models are
explored and their implications for the semileptonic branching ratio and charm
yield in B decays discussed.
|
[
{
"created": "Tue, 17 Mar 1998 20:28:46 GMT",
"version": "v1"
},
{
"created": "Fri, 15 May 1998 20:37:10 GMT",
"version": "v2"
}
] |
2016-08-25
|
[
[
"Kagan",
"A. L.",
"",
"Univ. Cincinnati"
],
[
"Neubert",
"M.",
"",
"CERN"
]
] |
We argue that the observation of a sizable direct CP asymmetry A_{CP} in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, A_{CP} can be calculated reliably and is found to be below 1% in magnitude. In extensions of the Standard Model with new CP-violating couplings, large CP asymmetries are possible without conflicting with the experimental value of the branching ratio for the decays B -> X_s gamma. In particular, large asymmetries arise naturally in models with enhanced chromo-magnetic dipole operators. Some generic examples of such models are explored and their implications for the semileptonic branching ratio and charm yield in B decays discussed.
|
1510.05432
|
Kazem Azizi
|
K. Azizi, Y. Sarac, H. Sundu
|
On the strong coupling $N^{(*)}N^{(*)}\pi$
|
15 Pages, 4 Figures and 3 Tables
| null |
10.1140/epja/i2016-16114-2
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the strong vertices $N^*N\pi$, $N^*N^*\pi$ and $NN\pi$ in QCD, where
$N^*$ denotes the negative parity $N (1535)$ state. We use the most general
form of the interpolating currents to calculate the corresponding strong
coupling constants. It is obtained that the coupling associated to $N^*N\pi$
vertex is strongly suppressed compared to those related to two other vertices.
The strong coupling corresponding to $N^*N^*\pi$ is obtained to be roughly half
of that of $NN\pi$ vertex. We compare the obtained results on $N^*N\pi$ and
$NN\pi$ vertices with the existing predictions of other theoretical studies as
well as those extracted from the experimental data.
|
[
{
"created": "Mon, 19 Oct 2015 11:39:16 GMT",
"version": "v1"
},
{
"created": "Mon, 22 Feb 2016 12:12:40 GMT",
"version": "v2"
}
] |
2016-05-25
|
[
[
"Azizi",
"K.",
""
],
[
"Sarac",
"Y.",
""
],
[
"Sundu",
"H.",
""
]
] |
We study the strong vertices $N^*N\pi$, $N^*N^*\pi$ and $NN\pi$ in QCD, where $N^*$ denotes the negative parity $N (1535)$ state. We use the most general form of the interpolating currents to calculate the corresponding strong coupling constants. It is obtained that the coupling associated to $N^*N\pi$ vertex is strongly suppressed compared to those related to two other vertices. The strong coupling corresponding to $N^*N^*\pi$ is obtained to be roughly half of that of $NN\pi$ vertex. We compare the obtained results on $N^*N\pi$ and $NN\pi$ vertices with the existing predictions of other theoretical studies as well as those extracted from the experimental data.
|
1604.07921
|
Yu Zhang
|
Yu Zhang, Wei-Hua Li, Peng-Fei Duan, Mao Song and Gang Li
|
Electroweak radiative corrections to triple photon production at the ILC
|
6 pages, 8 figures, accepted for publication in Physics Letters B
| null |
10.1016/j.physletb.2016.04.054
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper, we present the precision predictions for three photon
production in the standard model (SM) at the ILC including the full
next-to-leading (NLO) electroweak (EW) corrections, high order initial state
radiation (h.o.ISR) contributions and beamstrahlung effects. We present the LO
and the NLO EW+h.o.ISR+beamstrahlung corrected total cross sections for various
colliding energy when $\sqrt s \ge 200 {\rm GeV}$ and the kinematic
distributions of final photons with $\sqrt s = 500 {\rm GeV}$ at ILC, and find
that the NLO EW corrections, the h.o.ISR contributions and the beamstrahlung
effects are important in exploring the process $e^+e^- \to \gamma\gamma\gamma$.
|
[
{
"created": "Wed, 27 Apr 2016 03:47:26 GMT",
"version": "v1"
}
] |
2016-05-04
|
[
[
"Zhang",
"Yu",
""
],
[
"Li",
"Wei-Hua",
""
],
[
"Duan",
"Peng-Fei",
""
],
[
"Song",
"Mao",
""
],
[
"Li",
"Gang",
""
]
] |
In this paper, we present the precision predictions for three photon production in the standard model (SM) at the ILC including the full next-to-leading (NLO) electroweak (EW) corrections, high order initial state radiation (h.o.ISR) contributions and beamstrahlung effects. We present the LO and the NLO EW+h.o.ISR+beamstrahlung corrected total cross sections for various colliding energy when $\sqrt s \ge 200 {\rm GeV}$ and the kinematic distributions of final photons with $\sqrt s = 500 {\rm GeV}$ at ILC, and find that the NLO EW corrections, the h.o.ISR contributions and the beamstrahlung effects are important in exploring the process $e^+e^- \to \gamma\gamma\gamma$.
|
1107.1988
|
Vladimir Galkin
|
D. Ebert, R. N. Faustov, V. O. Galkin
|
Exclusive semileptonic and nonleptonic decays of B mesons to orbitally
excited light mesons
|
21 pages, 5 figures, version to be published in Physical Review D
|
Phys. Rev. D 85 (2012) 054006
|
10.1103/PhysRevD.85.054006
|
HU-EP-11/32
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The form factors of weak decays of the B meson to orbitally excited scalar,
axial vector and tensor light mesons are calculated in the framework of the
QCD-motivated relativistic quark model based on the quasipotential approach.
Relativistic effects are systematically taken into account. The form factors
are expressed trough the overlap integrals of the meson wave functions and
their dependence on the momentum transfer is selfconsistently determined in the
whole kinematical range. On this basis semileptonic and two-body nonleptonic B
decay rates to orbitally excited light mesons are calculated. Good agreement of
the obtained predictions with available experimental data is found.
|
[
{
"created": "Mon, 11 Jul 2011 10:30:21 GMT",
"version": "v1"
},
{
"created": "Thu, 16 Feb 2012 08:02:28 GMT",
"version": "v2"
}
] |
2013-04-12
|
[
[
"Ebert",
"D.",
""
],
[
"Faustov",
"R. N.",
""
],
[
"Galkin",
"V. O.",
""
]
] |
The form factors of weak decays of the B meson to orbitally excited scalar, axial vector and tensor light mesons are calculated in the framework of the QCD-motivated relativistic quark model based on the quasipotential approach. Relativistic effects are systematically taken into account. The form factors are expressed trough the overlap integrals of the meson wave functions and their dependence on the momentum transfer is selfconsistently determined in the whole kinematical range. On this basis semileptonic and two-body nonleptonic B decay rates to orbitally excited light mesons are calculated. Good agreement of the obtained predictions with available experimental data is found.
|
2309.13023
|
Aniruddha Venkata
|
George Sterman and Aniruddha Venkata
|
Local infrared safety in time-ordered perturbation theory
|
61 pages, 9 figures
|
J. High Energ. Phys. 2024, 101 (2024)
|
10.1007/JHEP02(2024)101
|
YITP-SB-2023-28
|
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We develop a general expression for weighted cross sections in leptonic
annihilation to hadrons based on time-ordered perturbation theory (TOPT). The
analytic behavior of the resulting integrals over spatial momenta can be
analyzed in the language of Landau equations and infrared (IR) power counting.
For any infrared-safe weight, the cancellation of infrared divergences is
implemented locally at the integrand level, and in principle can be evaluated
numerically in four dimensions. We go on to show that it is possible to
eliminate unphysical singularities that appear in time-ordered perturbation
theory for arbitrary amplitudes. This is done by reorganizing TOPT into an
equivalent form that combines classes of time orderings into a ``partially
time-ordered perturbation theory". Applying the formalism to leptonic
annihilation, we show how to derive diagrammatic expressions with only physical
unitarity cuts.
|
[
{
"created": "Fri, 22 Sep 2023 17:34:37 GMT",
"version": "v1"
},
{
"created": "Mon, 11 Dec 2023 18:05:59 GMT",
"version": "v2"
}
] |
2024-02-19
|
[
[
"Sterman",
"George",
""
],
[
"Venkata",
"Aniruddha",
""
]
] |
We develop a general expression for weighted cross sections in leptonic annihilation to hadrons based on time-ordered perturbation theory (TOPT). The analytic behavior of the resulting integrals over spatial momenta can be analyzed in the language of Landau equations and infrared (IR) power counting. For any infrared-safe weight, the cancellation of infrared divergences is implemented locally at the integrand level, and in principle can be evaluated numerically in four dimensions. We go on to show that it is possible to eliminate unphysical singularities that appear in time-ordered perturbation theory for arbitrary amplitudes. This is done by reorganizing TOPT into an equivalent form that combines classes of time orderings into a ``partially time-ordered perturbation theory". Applying the formalism to leptonic annihilation, we show how to derive diagrammatic expressions with only physical unitarity cuts.
|
hep-ph/0002167
|
David London
|
Ahmed Ali (DESY), David London (Montreal U.)
|
CP Violation and Quark Mixing
|
20 pages, 5 figures (requires dafne99pro.sty), To appear in the
Proceedings of the Workshop: Physics and Detectors for DAPHNE, Frascati, Nov.
16-19, 1999
| null | null |
DESY 00-026, UdeM-GPP-TH-00-68 (February 2000)
|
hep-ph
| null |
Measurements of CP asymmetries in B decays will soon be made at $B$ factories
and hadron machines. In light of this, we review and update the profile of the
CKM unitarity triangle and the resulting CP asymmetries in B decays. This is
done both in the standard model and in several variants of the minimal
supersymmetric standard model (MSSM), which are characterized by a single phase
in the quark flavour mixing matrix. After imposing present constraints on the
parameters of these models, the predicted ranges of $\sin 2 \beta$ in the
standard model and in the MSSM are found to be similar. However, these theories
may be distinguished by future precise measurements of the other two
CP-violating phases $\alpha$ and $\gamma$.
|
[
{
"created": "Tue, 15 Feb 2000 16:35:31 GMT",
"version": "v1"
},
{
"created": "Tue, 22 Feb 2000 15:42:34 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Ali",
"Ahmed",
"",
"DESY"
],
[
"London",
"David",
"",
"Montreal U."
]
] |
Measurements of CP asymmetries in B decays will soon be made at $B$ factories and hadron machines. In light of this, we review and update the profile of the CKM unitarity triangle and the resulting CP asymmetries in B decays. This is done both in the standard model and in several variants of the minimal supersymmetric standard model (MSSM), which are characterized by a single phase in the quark flavour mixing matrix. After imposing present constraints on the parameters of these models, the predicted ranges of $\sin 2 \beta$ in the standard model and in the MSSM are found to be similar. However, these theories may be distinguished by future precise measurements of the other two CP-violating phases $\alpha$ and $\gamma$.
|
hep-ph/9710538
|
Mikko Laine
|
K. Kajantie, M. Laine, K. Rummukainen and M. Shaposhnikov
|
High Temperature Dimensional Reduction and Parity Violation
|
12 pages, 1 figure. Small clarifications added. To appear in
Phys.Lett.B
|
Phys.Lett. B423 (1998) 137-144
|
10.1016/S0370-2693(97)01584-0
|
CERN-TH/97-298, NORDITA-97/78P
|
hep-ph hep-th
| null |
The effective super-renormalizable 3-dimensional Lagrangian, describing the
high temperature limit of chiral gauge theories, has more symmetry than the
original 4d Lagrangian: parity violation is absent. Parity violation appears in
the 3d theory only through higher-dimensional operators. We compute the
coefficients of dominant P-odd operators in the Standard Electroweak theory and
discuss their implications. We also clarify the parametric accuracy obtained
with dimensional reduction.
|
[
{
"created": "Thu, 30 Oct 1997 09:47:27 GMT",
"version": "v1"
},
{
"created": "Fri, 19 Dec 1997 15:27:43 GMT",
"version": "v2"
}
] |
2009-10-30
|
[
[
"Kajantie",
"K.",
""
],
[
"Laine",
"M.",
""
],
[
"Rummukainen",
"K.",
""
],
[
"Shaposhnikov",
"M.",
""
]
] |
The effective super-renormalizable 3-dimensional Lagrangian, describing the high temperature limit of chiral gauge theories, has more symmetry than the original 4d Lagrangian: parity violation is absent. Parity violation appears in the 3d theory only through higher-dimensional operators. We compute the coefficients of dominant P-odd operators in the Standard Electroweak theory and discuss their implications. We also clarify the parametric accuracy obtained with dimensional reduction.
|
2406.18434
|
Alessio Zaccone
|
Alessio Zaccone
|
Relativistic theory of the viscosity of fluids across the entire energy
spectrum
| null | null | null | null |
hep-ph cond-mat.stat-mech hep-th physics.class-ph physics.plasm-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The shear viscosity is a fundamental transport property of matter. Here we
derive a general theory of the viscosity of gases based on the relativistic
Langevin equation (deduced from a relativistic Lagrangian) and nonaffine linear
response theory. The proposed relativistic theory is able to recover the
viscosity of non-relativistic classical gases, with all its key dependencies on
mass, temperature, particle diameter and Boltzmann constant, in the limit of
Lorentz factor $\gamma=1$. It also unveils the relativistic enhancement
mechanism of viscosity. In the limit of ultrarelativistic fluids, the theory
provides a new analytical formula which reproduces the cubic increase of
viscosity with temperature in agreement with various estimates for hot dense
matter and the QGP-type fluid.
|
[
{
"created": "Wed, 26 Jun 2024 15:31:44 GMT",
"version": "v1"
},
{
"created": "Sun, 4 Aug 2024 13:23:26 GMT",
"version": "v2"
}
] |
2024-08-06
|
[
[
"Zaccone",
"Alessio",
""
]
] |
The shear viscosity is a fundamental transport property of matter. Here we derive a general theory of the viscosity of gases based on the relativistic Langevin equation (deduced from a relativistic Lagrangian) and nonaffine linear response theory. The proposed relativistic theory is able to recover the viscosity of non-relativistic classical gases, with all its key dependencies on mass, temperature, particle diameter and Boltzmann constant, in the limit of Lorentz factor $\gamma=1$. It also unveils the relativistic enhancement mechanism of viscosity. In the limit of ultrarelativistic fluids, the theory provides a new analytical formula which reproduces the cubic increase of viscosity with temperature in agreement with various estimates for hot dense matter and the QGP-type fluid.
|
1005.4868
|
Savely G. Karshenboim
|
S. G. Karshenboim
|
Constraints on a long-range spin-dependent interaction from precision
atomic physics
|
Cross references to Arxiv are updated (arXiv:1005.4859,
arXiv:1005.4872)
|
Phys.Rev.D82:113013,2010
|
10.1103/PhysRevD.82.113013
| null |
hep-ph physics.atom-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a phenomenological constraint on a pseudovector light boson beyond
the Standard Model, which can induce a long-range spin-dependent interaction
$\alpha^{\prime\prime}({\bf s}_1\cdot{\bf s}_2)\,{\rm e}^{-\lambda r}/r$. In
the range of masses from $4\;{\rm keV}/c^2$ to those related to macroscopic
distances (of $\lambda^{-1}\sim1\;$cm) the spin-dependent coupling constant
$\alpha^{\prime\prime}$ of the electron-muon interaction is constrained at the
level below a part in $10^{15}$. The constraint is weakened while extending to
higher masses. The strongest constraint is related to the lepton-lepton
interaction. Constraints on spin-dependent interactions of some other particles
are also discussed. The results are obtained from data on the HFS interval of
the ground state in muonium and a few other light hydrogen-like atoms.
|
[
{
"created": "Wed, 26 May 2010 16:25:09 GMT",
"version": "v1"
},
{
"created": "Thu, 27 May 2010 08:04:49 GMT",
"version": "v2"
}
] |
2014-11-04
|
[
[
"Karshenboim",
"S. G.",
""
]
] |
We present a phenomenological constraint on a pseudovector light boson beyond the Standard Model, which can induce a long-range spin-dependent interaction $\alpha^{\prime\prime}({\bf s}_1\cdot{\bf s}_2)\,{\rm e}^{-\lambda r}/r$. In the range of masses from $4\;{\rm keV}/c^2$ to those related to macroscopic distances (of $\lambda^{-1}\sim1\;$cm) the spin-dependent coupling constant $\alpha^{\prime\prime}$ of the electron-muon interaction is constrained at the level below a part in $10^{15}$. The constraint is weakened while extending to higher masses. The strongest constraint is related to the lepton-lepton interaction. Constraints on spin-dependent interactions of some other particles are also discussed. The results are obtained from data on the HFS interval of the ground state in muonium and a few other light hydrogen-like atoms.
|
hep-ph/9902476
|
Colin Froggatt
|
A.T. Davies, C.D. Froggatt and A. Usai
|
CP Violation in the Next to Minimal Supersymmetric Standard Model
|
6 page LaTeX file, 2 postscript figures, sprocl.sty style file
included
| null | null |
GUTPA/99/02/01
|
hep-ph
| null |
We consider spontaneous CP violation in the Next to Minimal Supersymmetric
Standard Model (NMSSM), without the usual $Z_3$ discrete symmetry. CP violation
can occur at tree level, raising a potential conflict with the experimental
bounds on the electric dipole moments of the electron and neutron. One escape
from this is to demand that the CP violating angles are small, but we find that
this entails an unacceptably light neutral Higgs.
|
[
{
"created": "Fri, 26 Feb 1999 09:27:43 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Davies",
"A. T.",
""
],
[
"Froggatt",
"C. D.",
""
],
[
"Usai",
"A.",
""
]
] |
We consider spontaneous CP violation in the Next to Minimal Supersymmetric Standard Model (NMSSM), without the usual $Z_3$ discrete symmetry. CP violation can occur at tree level, raising a potential conflict with the experimental bounds on the electric dipole moments of the electron and neutron. One escape from this is to demand that the CP violating angles are small, but we find that this entails an unacceptably light neutral Higgs.
|
hep-ph/0005065
|
Shin Muroya
|
N. Sasaki, O. Miyamura, S. Muroya and C. Nonaka
|
A calculation of the transport coefficients of hot and dense hadronic
matter based on the event generator URASiMA
|
To appear in the Proceeding of the International Conference on Quark
Nuclear Physics(QNP2000), 21-25 February 2000, Adelaide, Australia
|
Nucl.Phys.A680:84-89,2000
|
10.1016/S0375-9474(00)00394-8
|
TWC-00-4
|
hep-ph
| null |
We evaluate thermodynamical quantities and the transport coefficients of a
dense and hot hadronic matter based on the event generator URASiMA
(Ultra-Relativistic AA collision Simulator based on Multiple Scattering
Algorithm) with periodic boundary conditions. As the simplest example of the
transport coefficients we investigate the temperature dependence and the
chemical potential dependence of the baryon diffusion constant of a dense and
hot hadronic matter.
|
[
{
"created": "Mon, 8 May 2000 07:32:05 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Sasaki",
"N.",
""
],
[
"Miyamura",
"O.",
""
],
[
"Muroya",
"S.",
""
],
[
"Nonaka",
"C.",
""
]
] |
We evaluate thermodynamical quantities and the transport coefficients of a dense and hot hadronic matter based on the event generator URASiMA (Ultra-Relativistic AA collision Simulator based on Multiple Scattering Algorithm) with periodic boundary conditions. As the simplest example of the transport coefficients we investigate the temperature dependence and the chemical potential dependence of the baryon diffusion constant of a dense and hot hadronic matter.
|
1505.04594
|
Ahmed Rashed Dr
|
Hongkai Liu, Ahmed Rashed, and Alakabha Datta
|
Probing lepton non-universality in tau neutrino Scattering
|
29 pages, 29 figures. Typos corrected
|
Phys. Rev. D 92, 073016 (2015)
|
10.1103/PhysRevD.92.073016, 10.1103/PhysRevD.93.039902
| null |
hep-ph hep-ex nucl-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Recently hints of lepton flavor non-universality emerged in the BaBar and
LHCb experiments. In this paper we propose tests of lepton universality in
$\nu_{\tau}$ scattering. To parametrize the new physics we adopt an effective
Lagrangian approach and consider the neutrino deep inelastic scattering
processes $\nu_{\tau}+ N \to \tau + X$ and $\nu_{\mu}+ N \to \mu + X$ where we
assume the largest new physics effects are in the $\tau$ sector. We also
consider an explicit leptoquark model in our calculations. In order to make
comparison with the standard model and also in order to cancel out the
uncertainties of the parton distribution functions, we consider the ratio of
total and differential cross sections of tau-neutrino to muon-neutrino
scattering. We find new physics effects that can possibly be observed at the
proposed Search for Hidden Particles (SHiP) experiment at CERN.
|
[
{
"created": "Mon, 18 May 2015 11:09:31 GMT",
"version": "v1"
},
{
"created": "Tue, 13 Oct 2015 15:54:10 GMT",
"version": "v2"
},
{
"created": "Mon, 16 Nov 2015 22:04:41 GMT",
"version": "v3"
},
{
"created": "Thu, 21 Jan 2016 05:25:11 GMT",
"version": "v4"
}
] |
2016-02-09
|
[
[
"Liu",
"Hongkai",
""
],
[
"Rashed",
"Ahmed",
""
],
[
"Datta",
"Alakabha",
""
]
] |
Recently hints of lepton flavor non-universality emerged in the BaBar and LHCb experiments. In this paper we propose tests of lepton universality in $\nu_{\tau}$ scattering. To parametrize the new physics we adopt an effective Lagrangian approach and consider the neutrino deep inelastic scattering processes $\nu_{\tau}+ N \to \tau + X$ and $\nu_{\mu}+ N \to \mu + X$ where we assume the largest new physics effects are in the $\tau$ sector. We also consider an explicit leptoquark model in our calculations. In order to make comparison with the standard model and also in order to cancel out the uncertainties of the parton distribution functions, we consider the ratio of total and differential cross sections of tau-neutrino to muon-neutrino scattering. We find new physics effects that can possibly be observed at the proposed Search for Hidden Particles (SHiP) experiment at CERN.
|
hep-ph/9910336
|
Carlo Giunti
|
Carlo Giunti
|
Four-Neutrino Oscillations
|
10 pages. Talk presented at the ICFA/ECFA Workshop "Neutrino
Factories based on Muon Storage Rings", nu-Fact'99, Lyon, France, 5-9 July
1999
|
Nucl.Instrum.Meth.A451:51-57,2000
|
10.1016/S0168-9002(00)00372-7
|
DFTT 54/99
|
hep-ph
| null |
It is shown that at least four massive neutrinos are needed in order to
accommodate the evidences in favor of neutrino oscillations found in solar and
atmospheric neutrino experiments and in the LSND experiment. Among all
four-neutrino schemes, only two, with a mass spectrum composed of two pairs of
neutrinos with close masses separated by the "LSND gap" of the order of 1 eV,
are compatible with the results of all neutrino oscillation experiments. In
these two schemes the probability of nu_e transitions into other states, the
probability of nu_mu->nu_e transitions and the size of CP violation effects in
nu_mu->nu_e transitions are suppressed in long-baseline experiments.
|
[
{
"created": "Thu, 14 Oct 1999 10:16:07 GMT",
"version": "v1"
}
] |
2011-04-15
|
[
[
"Giunti",
"Carlo",
""
]
] |
It is shown that at least four massive neutrinos are needed in order to accommodate the evidences in favor of neutrino oscillations found in solar and atmospheric neutrino experiments and in the LSND experiment. Among all four-neutrino schemes, only two, with a mass spectrum composed of two pairs of neutrinos with close masses separated by the "LSND gap" of the order of 1 eV, are compatible with the results of all neutrino oscillation experiments. In these two schemes the probability of nu_e transitions into other states, the probability of nu_mu->nu_e transitions and the size of CP violation effects in nu_mu->nu_e transitions are suppressed in long-baseline experiments.
|
1209.2115
|
Roberto Franceschini
|
Kaustubh Agashe, Yanou Cui, Roberto Franceschini
|
Natural Islands for a 125 GeV Higgs in the scale-invariant NMSSM
|
34 pages, 4 figures, references added, minor corrections to text and
figures, version to be published in JHEP
| null |
10.1007/JHEP02(2013)031
|
UMD-PP-012-021
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study whether a 125 GeV standard model-like Higgs boson can be
accommodated within the scale-invariant NMSSM in a way that is natural in all
respects, i.e., not only is the stop mass and hence its loop contribution to
Higgs mass of natural size, but we do not allow significant tuning of NMSSM
parameters as well. We pursue as much as possible an analytic approach which
gives clear insights on various ways to accommodate such a Higgs mass, while
conducting complementary numerical analyses. We consider both scenarios with
singlet-like state being heavier and lighter than SM-like Higgs. With A-terms
being small, we find for the NMSSM to be perturbative up to GUT scale, it is
not possible to get 125 GeV Higgs mass, which is true even if we tune
parameters of NMSSM. If we allow some of the couplings to become
non-perturbative below the GUT scale, then the non-tuned option implies that
the singlet self-coupling, kappa, is larger than the singlet-Higgs coupling,
lambda, which itself is order 1. This leads to a Landau pole for these
couplings close to the weak scale, in particular below ~10^4 TeV. In both the
perturbative and non-perturbative NMSSM, allowing large A_lambda, A_kappa gives
"more room" to accommodate a 125 GeV Higgs, but a tuning of these A-terms may
be needed. In our analysis we also conduct a careful study of the constraints
on the parameter space from requiring global stability of the desired vacuum
fitting a 125 GeV Higgs, which is complementary to existing literature. In
particular, as the singlet-Higgs coupling lambda increases, vacuum stability
becomes more serious of an issue.
|
[
{
"created": "Mon, 10 Sep 2012 20:00:01 GMT",
"version": "v1"
},
{
"created": "Thu, 17 Jan 2013 17:27:59 GMT",
"version": "v2"
}
] |
2015-06-11
|
[
[
"Agashe",
"Kaustubh",
""
],
[
"Cui",
"Yanou",
""
],
[
"Franceschini",
"Roberto",
""
]
] |
We study whether a 125 GeV standard model-like Higgs boson can be accommodated within the scale-invariant NMSSM in a way that is natural in all respects, i.e., not only is the stop mass and hence its loop contribution to Higgs mass of natural size, but we do not allow significant tuning of NMSSM parameters as well. We pursue as much as possible an analytic approach which gives clear insights on various ways to accommodate such a Higgs mass, while conducting complementary numerical analyses. We consider both scenarios with singlet-like state being heavier and lighter than SM-like Higgs. With A-terms being small, we find for the NMSSM to be perturbative up to GUT scale, it is not possible to get 125 GeV Higgs mass, which is true even if we tune parameters of NMSSM. If we allow some of the couplings to become non-perturbative below the GUT scale, then the non-tuned option implies that the singlet self-coupling, kappa, is larger than the singlet-Higgs coupling, lambda, which itself is order 1. This leads to a Landau pole for these couplings close to the weak scale, in particular below ~10^4 TeV. In both the perturbative and non-perturbative NMSSM, allowing large A_lambda, A_kappa gives "more room" to accommodate a 125 GeV Higgs, but a tuning of these A-terms may be needed. In our analysis we also conduct a careful study of the constraints on the parameter space from requiring global stability of the desired vacuum fitting a 125 GeV Higgs, which is complementary to existing literature. In particular, as the singlet-Higgs coupling lambda increases, vacuum stability becomes more serious of an issue.
|
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