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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1805.11480
|
Ya-ping Xie
|
Ya-Ping Xie and Xurong Chen
|
Photoproduction of vector mesons in proton-proton ultraperipheral
collisions at the CERN Large Hadron Collider
|
arXiv admin note: text overlap with arXiv:1805.06210
|
Int.J.Mod.Phys.,A33(2018)1850086
|
10.1142/S0217751X18500860
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Photoproduction of vector mesons are computed in dipole model in
proton-proton ultraperipheral collisions(UPCs) at the CERN Large Hadron
Collider (LHC). The dipole model framework is employed in the calculations of
vector mesons production in diffractive processes. Parameters of the bCGC model
are refitted with the latest inclusive deep inelastic scattering experimental
data. Employing the bCGC model and Boosted Gaussian light-cone wave function
for vector mesons, we obtain prediction of rapidity distributions of $J/\psi$
and $\psi(2s)$ mesons in proton-proton ultraperipheral collisions at the LHC.
The predictions give a good description to the experimental data of LHCb.
Predictions of $\phi$ and $\omega$ mesons are also evaluated in this paper.
|
[
{
"created": "Mon, 28 May 2018 15:00:10 GMT",
"version": "v1"
}
] |
2018-05-30
|
[
[
"Xie",
"Ya-Ping",
""
],
[
"Chen",
"Xurong",
""
]
] |
Photoproduction of vector mesons are computed in dipole model in proton-proton ultraperipheral collisions(UPCs) at the CERN Large Hadron Collider (LHC). The dipole model framework is employed in the calculations of vector mesons production in diffractive processes. Parameters of the bCGC model are refitted with the latest inclusive deep inelastic scattering experimental data. Employing the bCGC model and Boosted Gaussian light-cone wave function for vector mesons, we obtain prediction of rapidity distributions of $J/\psi$ and $\psi(2s)$ mesons in proton-proton ultraperipheral collisions at the LHC. The predictions give a good description to the experimental data of LHCb. Predictions of $\phi$ and $\omega$ mesons are also evaluated in this paper.
|
1604.02037
|
Piotr Lebiedowicz
|
Piotr Lebiedowicz, Marta Luszczak, Roman Pasechnik and Antoni Szczurek
|
Can the diphoton enhancement at 750 GeV be due to a neutral technipion?
|
26 pages, 16 figures, 1 table
|
Phys. Rev. D 94, 015023 (2016)
|
10.1103/PhysRevD.94.015023
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss a scenario in which the diphoton enhancement at $M_{\gamma
\gamma}$ = 750 GeV, observed by the ATLAS and CMS Collaborations, is a neutral
technipion $\tilde{\pi}^0$. We consider two distinct minimal models for the
dynamical electroweak symmetry breaking. In a first one, two-flavor vector-like
technicolor (VTC) model, we assume that the two-photon fusion is a dominant
production mechanism. We include $\gamma \gamma \to {\tilde \pi}^0$ and
production of technipion associated with one or two jets. All the considered
mechanisms give similar contributions. With the strong Yukawa
(technipion-techniquark) coupling $g_{TC}$ = 10 - 20 we obtain the measured
cross section of the "signal". With such values of $g_{TC}$ we get a relatively
small $\Gamma_{\rm tot}$. In a second approach, one-family walking technicolor
(WTC) model, the isoscalar technipion is produced dominantly via the
gluon-gluon fusion. We also discuss the size of the signal at lower energies
(LHC, Tevatron) for $\gamma \gamma$ (VTC) and jet-jet (WTC) final states and
check consistency with the existing experimental data. We predict a measurable
cross section for ${\tilde \pi}^0$ production associated with one or two soft
jets. The technipion signal in both models is compared with the SM background
diphoton contributions. We observe the dominance of inelastic-inelastic
processes for $\gamma \gamma$ induced processes. In the VTC scenario, we
predict the signal cross section for purely exclusive $p p \to p p \gamma
\gamma$ processes at $\sqrt{s}$ = 13 TeV to be about 0.2 fb. Such a cross
section would be, however, difficult to measure with the planned integrated
luminosity. In all considered cases the signal is below the background or/and
below the threshold set by statistics.
|
[
{
"created": "Thu, 7 Apr 2016 15:26:50 GMT",
"version": "v1"
}
] |
2016-07-27
|
[
[
"Lebiedowicz",
"Piotr",
""
],
[
"Luszczak",
"Marta",
""
],
[
"Pasechnik",
"Roman",
""
],
[
"Szczurek",
"Antoni",
""
]
] |
We discuss a scenario in which the diphoton enhancement at $M_{\gamma \gamma}$ = 750 GeV, observed by the ATLAS and CMS Collaborations, is a neutral technipion $\tilde{\pi}^0$. We consider two distinct minimal models for the dynamical electroweak symmetry breaking. In a first one, two-flavor vector-like technicolor (VTC) model, we assume that the two-photon fusion is a dominant production mechanism. We include $\gamma \gamma \to {\tilde \pi}^0$ and production of technipion associated with one or two jets. All the considered mechanisms give similar contributions. With the strong Yukawa (technipion-techniquark) coupling $g_{TC}$ = 10 - 20 we obtain the measured cross section of the "signal". With such values of $g_{TC}$ we get a relatively small $\Gamma_{\rm tot}$. In a second approach, one-family walking technicolor (WTC) model, the isoscalar technipion is produced dominantly via the gluon-gluon fusion. We also discuss the size of the signal at lower energies (LHC, Tevatron) for $\gamma \gamma$ (VTC) and jet-jet (WTC) final states and check consistency with the existing experimental data. We predict a measurable cross section for ${\tilde \pi}^0$ production associated with one or two soft jets. The technipion signal in both models is compared with the SM background diphoton contributions. We observe the dominance of inelastic-inelastic processes for $\gamma \gamma$ induced processes. In the VTC scenario, we predict the signal cross section for purely exclusive $p p \to p p \gamma \gamma$ processes at $\sqrt{s}$ = 13 TeV to be about 0.2 fb. Such a cross section would be, however, difficult to measure with the planned integrated luminosity. In all considered cases the signal is below the background or/and below the threshold set by statistics.
|
hep-ph/0504185
|
Pedro Cunha de Holanda
|
M. M. Guzzo, P. C. de Holanda, O. L. G. Peres
|
Random magnetic fields inducing solar neutrino spin-flavor precession in
a three generation context
|
10 pages, 3 figures
|
Phys.Rev. D72 (2005) 073004
|
10.1103/PhysRevD.72.073004
| null |
hep-ph
| null |
We study the effect of random magnetic fields in the spin-flavor precession
of solar neutrinos in a three generation context, when a non-vanishing
transition magnetic moment is assumed. While this kind of precession is
strongly constrained when the magnetic moment involves the first family, such
constraints do not apply if we suppose a transition magnetic moment between the
second and third families. In this scenario we can have a large non-electron
anti-neutrino flux arriving on Earth, which can lead to some interesting
phenomenological consequences, as, for instance, the suppression of day-night
asymmetry. We have analyzed the high energy solar neutrino data and the KamLAND
experiment to constrain the solar mixing angle, and solar mass difference, and
we have found a larger shift of allowed values.
|
[
{
"created": "Wed, 20 Apr 2005 23:27:41 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Guzzo",
"M. M.",
""
],
[
"de Holanda",
"P. C.",
""
],
[
"Peres",
"O. L. G.",
""
]
] |
We study the effect of random magnetic fields in the spin-flavor precession of solar neutrinos in a three generation context, when a non-vanishing transition magnetic moment is assumed. While this kind of precession is strongly constrained when the magnetic moment involves the first family, such constraints do not apply if we suppose a transition magnetic moment between the second and third families. In this scenario we can have a large non-electron anti-neutrino flux arriving on Earth, which can lead to some interesting phenomenological consequences, as, for instance, the suppression of day-night asymmetry. We have analyzed the high energy solar neutrino data and the KamLAND experiment to constrain the solar mixing angle, and solar mass difference, and we have found a larger shift of allowed values.
|
1603.00290
|
Kazem Azizi
|
S. S. Agaev, K. Azizi, H. Sundu
|
Width of the exotic $X_b(5568)$ state through its strong decay to
$B_s^{0} \pi^{+}$
|
6 Pages, 2 Figures and 1 Table
|
Phys. Rev. D 93, 114007 (2016)
|
10.1103/PhysRevD.93.114007
| null |
hep-ph hep-ex hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The width of the newly observed exotic state $X_b(5568)$ is calculated via
its dominant strong decay to $% B_s^{0} \pi^{+}$ using the QCD sum rule method
on the light-cone in conjunction with the soft-meson approximation. To this
end, the vertex $X_{b}B_{s}\pi$ is studied and the strong coupling
$g_{X_{b}B_{s}\pi}$ is computed employing for $X_b(5568)$ state the
interpolating diquark-antidiquark current of the
$[su][\overline{b}\overline{d}]$ type. The obtained prediction for the decay
width of $X_b(5568)$ is confronted and a nice agreement found with the
experimental data of the D0 Collaboration.
|
[
{
"created": "Tue, 1 Mar 2016 14:40:40 GMT",
"version": "v1"
},
{
"created": "Tue, 19 Apr 2016 11:41:13 GMT",
"version": "v2"
},
{
"created": "Wed, 1 Jun 2016 08:17:05 GMT",
"version": "v3"
}
] |
2016-06-15
|
[
[
"Agaev",
"S. S.",
""
],
[
"Azizi",
"K.",
""
],
[
"Sundu",
"H.",
""
]
] |
The width of the newly observed exotic state $X_b(5568)$ is calculated via its dominant strong decay to $% B_s^{0} \pi^{+}$ using the QCD sum rule method on the light-cone in conjunction with the soft-meson approximation. To this end, the vertex $X_{b}B_{s}\pi$ is studied and the strong coupling $g_{X_{b}B_{s}\pi}$ is computed employing for $X_b(5568)$ state the interpolating diquark-antidiquark current of the $[su][\overline{b}\overline{d}]$ type. The obtained prediction for the decay width of $X_b(5568)$ is confronted and a nice agreement found with the experimental data of the D0 Collaboration.
|
hep-ph/9602348
| null |
G.H.Arakelyan, C.Pajares and Yu.M.Shabelski
|
$D$,$D^*(2010)$ and $D^{*}_{2}(2460)$ charmed mesons production in
hadron--hadron collisions
|
LaTeX, 8 pages plus 3 postscript figures
|
Z.Phys.C73:697-700,1997
|
10.1007/s002880050361
|
US-FT/8-96
|
hep-ph
| null |
A resently developed generalization of the Quark--Gluon String Model to the
case of bosonic resonances production in hadron--hadron collisions is used for
the calculation of inclusive production of charmed mesons $D$, $D^*(2010)$ and
$D^{*}_{2}(2460)$. A simple relation which determines the dependence of the
charmed meson production cross sections on their spin J is obtained. It is
shown that the theoretical predictions for the inclusive spectra and production
cross sections of these charmed mesons are confirmed experimentally with a
reasonable accuracy.
|
[
{
"created": "Tue, 20 Feb 1996 03:01:44 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Arakelyan",
"G. H.",
""
],
[
"Pajares",
"C.",
""
],
[
"Shabelski",
"Yu. M.",
""
]
] |
A resently developed generalization of the Quark--Gluon String Model to the case of bosonic resonances production in hadron--hadron collisions is used for the calculation of inclusive production of charmed mesons $D$, $D^*(2010)$ and $D^{*}_{2}(2460)$. A simple relation which determines the dependence of the charmed meson production cross sections on their spin J is obtained. It is shown that the theoretical predictions for the inclusive spectra and production cross sections of these charmed mesons are confirmed experimentally with a reasonable accuracy.
|
hep-ph/0111164
|
Massimiliano Grazzini
|
S. Catani, D. de Florian, M. Grazzini
|
Direct Higgs production and jet veto at the Tevatron and the LHC in NNLO
QCD
|
22 pages, 12 postscript figures
|
JHEP 0201 (2002) 015
|
10.1088/1126-6708/2002/01/015
|
CERN-TH/2001-222
|
hep-ph
| null |
We consider Higgs boson production through gluon--gluon fusion in hadron
collisions, when a veto is applied on the transverse momenta of the
accompanying hard jets. We compute the QCD radiative corrections to this
process at NLO and NNLO. The NLO calculation is complete. The NNLO calculation
uses the recently evaluated NNLO soft and virtual QCD contributions to the
inclusive cross section. We find that the jet veto reduces the impact of the
NLO and NNLO contributions, the reduction being more sizeable at the LHC than
at the Tevatron.
|
[
{
"created": "Tue, 13 Nov 2001 16:52:59 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Catani",
"S.",
""
],
[
"de Florian",
"D.",
""
],
[
"Grazzini",
"M.",
""
]
] |
We consider Higgs boson production through gluon--gluon fusion in hadron collisions, when a veto is applied on the transverse momenta of the accompanying hard jets. We compute the QCD radiative corrections to this process at NLO and NNLO. The NLO calculation is complete. The NNLO calculation uses the recently evaluated NNLO soft and virtual QCD contributions to the inclusive cross section. We find that the jet veto reduces the impact of the NLO and NNLO contributions, the reduction being more sizeable at the LHC than at the Tevatron.
|
hep-ph/9507232
|
Vadim Konyshev
|
V.Konyshev and I.Polyubin
|
A note on radiative corrections to $\mu$ and $\tau$ decays
|
5 pages, REVTeX, reference added
|
JETP Lett. 62 (1995) 469-471; Pisma Zh.Eksp.Teor.Fiz. 62 (1995)
453-455
| null | null |
hep-ph
| null |
Radiative corrections in the order ${\alpha\over{2\pi}}{{m^2_e}\over
m^2_\mu}$ to $\mu $- and ${\alpha\over{2\pi}}{{m^2_\mu}\over m^2_\tau}$ to
$\tau $- decays are calculated. The decay width is enhanced by $4.48\cdot
10^{-3} ({\alpha\over{2\pi}})$ in the muon case and by $0.283
({\alpha\over{2\pi}})$ for the $\tau \rightarrow \mu \nu_\tau \bar\nu_\mu
(\gamma)$ decay. Influence of these corrections on the electroweak data is
discussed.
|
[
{
"created": "Wed, 5 Jul 1995 16:35:02 GMT",
"version": "v1"
},
{
"created": "Mon, 28 Aug 1995 17:51:14 GMT",
"version": "v2"
}
] |
2008-02-03
|
[
[
"Konyshev",
"V.",
""
],
[
"Polyubin",
"I.",
""
]
] |
Radiative corrections in the order ${\alpha\over{2\pi}}{{m^2_e}\over m^2_\mu}$ to $\mu $- and ${\alpha\over{2\pi}}{{m^2_\mu}\over m^2_\tau}$ to $\tau $- decays are calculated. The decay width is enhanced by $4.48\cdot 10^{-3} ({\alpha\over{2\pi}})$ in the muon case and by $0.283 ({\alpha\over{2\pi}})$ for the $\tau \rightarrow \mu \nu_\tau \bar\nu_\mu (\gamma)$ decay. Influence of these corrections on the electroweak data is discussed.
|
2204.13425
|
Lisa Biermann
|
Lisa Biermann, Margarete M\"uhlleitner, Jonas M\"uller
|
Electroweak Phase Transition in a Dark Sector with CP Violation
|
21 pages, 8 figures, 3 tables
| null |
10.1140/epjc/s10052-023-11612-w
|
KA-TP-13-2022
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper, we investigate the possibility of a strong first-order
electroweak phase transition (SFOEWPT) in the model `CP in the Dark'. The Higgs
sector of the model consists of two scalar doublets and one scalar singlet with
a specific discrete symmetry. After spontaneous symmetry breaking the model has
a Standard-Model-like phenomenology and a hidden scalar sector with a viable
Dark Matter candidate supplemented by explicit CP violation that solely occurs
in the hidden sector. The model `CP in the Dark' has been implemented in the
C++ code BSMPT v2.3 which performs a global minimisation of the
finite-temperature one-loop corrected effective potential and searches for
SFOEWPTs. An SFOEWPT is found to be allowed in a broad range of the parameter
space. Furthermore, there are parameter scenarios where spontaneous CP
violation is generated at finite temperature. The in addition spontaneously
broken $\mathbb{Z}_2$ symmetry then leads to mixing between the dark and the
visible sector so that CP violation in the dark is promoted at finite
temperature to the visible sector and thereby provides additional sources of CP
violation that are not restricted by the electric dipole moment measurements at
zero temperature. Thus, `CP in the Dark' provides a promising candidate for the
generation of the baryon asymmetry of the universe through electroweak
baryogenesis.
|
[
{
"created": "Thu, 28 Apr 2022 11:49:39 GMT",
"version": "v1"
}
] |
2023-06-14
|
[
[
"Biermann",
"Lisa",
""
],
[
"Mühlleitner",
"Margarete",
""
],
[
"Müller",
"Jonas",
""
]
] |
In this paper, we investigate the possibility of a strong first-order electroweak phase transition (SFOEWPT) in the model `CP in the Dark'. The Higgs sector of the model consists of two scalar doublets and one scalar singlet with a specific discrete symmetry. After spontaneous symmetry breaking the model has a Standard-Model-like phenomenology and a hidden scalar sector with a viable Dark Matter candidate supplemented by explicit CP violation that solely occurs in the hidden sector. The model `CP in the Dark' has been implemented in the C++ code BSMPT v2.3 which performs a global minimisation of the finite-temperature one-loop corrected effective potential and searches for SFOEWPTs. An SFOEWPT is found to be allowed in a broad range of the parameter space. Furthermore, there are parameter scenarios where spontaneous CP violation is generated at finite temperature. The in addition spontaneously broken $\mathbb{Z}_2$ symmetry then leads to mixing between the dark and the visible sector so that CP violation in the dark is promoted at finite temperature to the visible sector and thereby provides additional sources of CP violation that are not restricted by the electric dipole moment measurements at zero temperature. Thus, `CP in the Dark' provides a promising candidate for the generation of the baryon asymmetry of the universe through electroweak baryogenesis.
|
1308.3085
|
Tho Hue Le
|
D.T. Binh, L.T. Hue, D.T. Huong and H.N. Long
|
Higgs revised in Supersymmetric Economical 3-3-1 model with B/\mu-type
terms
|
Matches version accepted for publication in EPJC. Typos are
corrected. We add a new section, a new appendix, a new figure and new
references to explain more clearly the properties of the lightest neutral
Higgs. Results unchanged
|
Eur. Phys. J. C74 (2014) 2851
|
10.1140/epjc/s10052-014-2851-1
| null |
hep-ph
|
http://creativecommons.org/licenses/by-nc-sa/3.0/
|
We re-investigate the scalar potential and the Higgs sector of the
supersymmetric economical 3-3-1 model (SUSYE331) in the presence of the B/\mu
type terms which has many important consequences. First, the model contains no
massless Higgs fields. Second, we prove that the soft mass parameters of
Higgses must be at the SU(3)_L scale. As a result, the masses of the Higgses
drift toward this scale except one light real neutral Higgs with the mass of
m_Z|cos(2\gamma)| at the tree level. We also show that there are some Higgses
containing many properties of the Higgses in the minimal supersymmetric
standard model (MSSM), especially in the neutral Higgs sector. One exact
relation in the MSSM, m^2_H^{+/-}=m^2_A+m^2_W, is still true in the SUSYE331.
Based on this result we make some comments on the lepton flavor violating
decays of these Higgses as one of signatures of new physics in the SUSYE331
model which may be detected by present colliders.
|
[
{
"created": "Wed, 14 Aug 2013 11:01:48 GMT",
"version": "v1"
},
{
"created": "Sun, 27 Apr 2014 11:06:51 GMT",
"version": "v2"
},
{
"created": "Fri, 2 May 2014 05:38:14 GMT",
"version": "v3"
}
] |
2014-05-05
|
[
[
"Binh",
"D. T.",
""
],
[
"Hue",
"L. T.",
""
],
[
"Huong",
"D. T.",
""
],
[
"Long",
"H. N.",
""
]
] |
We re-investigate the scalar potential and the Higgs sector of the supersymmetric economical 3-3-1 model (SUSYE331) in the presence of the B/\mu type terms which has many important consequences. First, the model contains no massless Higgs fields. Second, we prove that the soft mass parameters of Higgses must be at the SU(3)_L scale. As a result, the masses of the Higgses drift toward this scale except one light real neutral Higgs with the mass of m_Z|cos(2\gamma)| at the tree level. We also show that there are some Higgses containing many properties of the Higgses in the minimal supersymmetric standard model (MSSM), especially in the neutral Higgs sector. One exact relation in the MSSM, m^2_H^{+/-}=m^2_A+m^2_W, is still true in the SUSYE331. Based on this result we make some comments on the lepton flavor violating decays of these Higgses as one of signatures of new physics in the SUSYE331 model which may be detected by present colliders.
|
0901.3927
|
Sushil Singh Chauhan
|
Satyaki Bhattacharya, Sushil Singh Chauhan, Brajesh Chandra Choudhary
and Debajyoti Choudhury
|
Quark Excitations Through the Prism of Direct Photon Plus Jet at the LHC
|
21 pages, 19 figures
|
Phys.Rev.D80:015014,2009
|
10.1103/PhysRevD.80.015014
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The quest to know the structure of matter has resulted in various theoretical
speculations wherein additional colored fermions are postulated. Arising either
as Kaluza-Klein excitations of ordinary quarks, or as excited states in
scenarios wherein the quarks themselves are composites, or even in theories
with extended gauge symmetry, the presence of such fermions ($q^*$) can
potentially be manifested in $\gamma + jet$ final states at the LHC. Using
unitarized amplitudes and the CMS setup, we demonstrate that in the initial
phase of LHC operation (with an integrated luminosity of $200 \pb^{-1}$) one
can discover such states for a mass upto 2.0 TeV. The discovery of a $q^*$ with
a mass as large as $\sim$5 TeV can be acheived for an integrated luminosity of
$\sim 140 \fb^{-1}$. We also comment on the feasibility of mass determination.
|
[
{
"created": "Sun, 25 Jan 2009 22:44:09 GMT",
"version": "v1"
}
] |
2009-09-02
|
[
[
"Bhattacharya",
"Satyaki",
""
],
[
"Chauhan",
"Sushil Singh",
""
],
[
"Choudhary",
"Brajesh Chandra",
""
],
[
"Choudhury",
"Debajyoti",
""
]
] |
The quest to know the structure of matter has resulted in various theoretical speculations wherein additional colored fermions are postulated. Arising either as Kaluza-Klein excitations of ordinary quarks, or as excited states in scenarios wherein the quarks themselves are composites, or even in theories with extended gauge symmetry, the presence of such fermions ($q^*$) can potentially be manifested in $\gamma + jet$ final states at the LHC. Using unitarized amplitudes and the CMS setup, we demonstrate that in the initial phase of LHC operation (with an integrated luminosity of $200 \pb^{-1}$) one can discover such states for a mass upto 2.0 TeV. The discovery of a $q^*$ with a mass as large as $\sim$5 TeV can be acheived for an integrated luminosity of $\sim 140 \fb^{-1}$. We also comment on the feasibility of mass determination.
|
hep-ph/9505275
|
Smirnov Alexei
|
E. J. Chun, Anjan S. Joshipura and A. Yu. Smirnov
|
Models of Light Singlet Fermion and Neutrino Phenomenology
|
14 pages, latex, no figures
|
Phys.Lett. B357 (1995) 608-615
|
10.1016/0370-2693(95)00967-P
|
IC/95/76, PRL-TH/95-7
|
hep-ph
| null |
We suggest that a singlet fermion $S$ exists beyond the standard see-saw
structure. It mixes with light neutrinos via interactions with the right-handed
neutrino components, so that $\n_e \to S$ conversion solves the solar neutrino
problem. Supersymmetry endowed with R-symmetry is shown to give a natural
framework for existence, mass scale and mixing ($\sin^22\th_{es} \sim
(0.1-1.5)\cdot 10^{-2}$) of such a fermion. Models with an approximate
horizontal symmetry are constructed, which embed the fermion $S$ and explain
simultaneously solar, atmospheric, hot dark matter problems as well as may
predict the oscillation $\bar{\n}_\m \to \bar{\n}_e$ in the region of
sensitivity of KARMEN and LSND experiments.
|
[
{
"created": "Wed, 10 May 1995 18:10:22 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Chun",
"E. J.",
""
],
[
"Joshipura",
"Anjan S.",
""
],
[
"Smirnov",
"A. Yu.",
""
]
] |
We suggest that a singlet fermion $S$ exists beyond the standard see-saw structure. It mixes with light neutrinos via interactions with the right-handed neutrino components, so that $\n_e \to S$ conversion solves the solar neutrino problem. Supersymmetry endowed with R-symmetry is shown to give a natural framework for existence, mass scale and mixing ($\sin^22\th_{es} \sim (0.1-1.5)\cdot 10^{-2}$) of such a fermion. Models with an approximate horizontal symmetry are constructed, which embed the fermion $S$ and explain simultaneously solar, atmospheric, hot dark matter problems as well as may predict the oscillation $\bar{\n}_\m \to \bar{\n}_e$ in the region of sensitivity of KARMEN and LSND experiments.
|
hep-ph/9609262
| null |
A. E. Bergan and J. O. Eeg
|
The self-penguin contribution to $K \to 2 \pi$
|
Latex, 12 pages, 2 figures
|
Phys.Lett.B390:420-426,1997
|
10.1016/S0370-2693(96)01402-5
| null |
hep-ph
| null |
We consider the contribution to $K \rightarrow 2 \pi$ decays from the
non-diagonal $s \ra d$ quark transition amplitude. First, we calculate the most
important part of the $s \rightarrow d$ transition, the so-called self-penguin
amplitude $\sim G_F \alpha_s$, including the heavy top-quark case. Second, we
calculate the matrix element of the $s \rightarrow d$ transition for the
physical $K \rightarrow 2 \pi$ process. This part of the analysis is performed
within the Chiral Quark Model where quarks are coupled to the pseudoscalar
mesons. The CP-conserving self-penguin contribution to $K \rightarrow 2\pi$ is
found to be negligible. The obtained contribution to $\epsilon'/\epsilon$ is
sensitive to the values of the quark condensate $<\bar{q} q>$ and the
constituent quark mass $M$. For reasonable values of these quantities we find
that the self-penguin contribution to $\epsilon'/\epsilon$ is 10-15% of the
gluonic penguin contribution and has the same sign. Given the large
cancellation between gluonic and electroweak penguin contributions, this means
that our contribution is of the same order of magnitude as $\epsilon'/\epsilon$
itself.
|
[
{
"created": "Thu, 5 Sep 1996 12:11:19 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Bergan",
"A. E.",
""
],
[
"Eeg",
"J. O.",
""
]
] |
We consider the contribution to $K \rightarrow 2 \pi$ decays from the non-diagonal $s \ra d$ quark transition amplitude. First, we calculate the most important part of the $s \rightarrow d$ transition, the so-called self-penguin amplitude $\sim G_F \alpha_s$, including the heavy top-quark case. Second, we calculate the matrix element of the $s \rightarrow d$ transition for the physical $K \rightarrow 2 \pi$ process. This part of the analysis is performed within the Chiral Quark Model where quarks are coupled to the pseudoscalar mesons. The CP-conserving self-penguin contribution to $K \rightarrow 2\pi$ is found to be negligible. The obtained contribution to $\epsilon'/\epsilon$ is sensitive to the values of the quark condensate $<\bar{q} q>$ and the constituent quark mass $M$. For reasonable values of these quantities we find that the self-penguin contribution to $\epsilon'/\epsilon$ is 10-15% of the gluonic penguin contribution and has the same sign. Given the large cancellation between gluonic and electroweak penguin contributions, this means that our contribution is of the same order of magnitude as $\epsilon'/\epsilon$ itself.
|
hep-ph/9903547
|
Krishna Rajagopal
|
Krishna Rajagopal (MIT)
|
How to Find the QCD Critical Point
|
To appear in proceedings of the Strong and Electroweak Matter
Workshop, Copenhagen, December 1998. Summary of results of work done in
collaboration with M. Stephanov and E. Shuryak, presented in full in
hep-ph/9903292
| null | null |
MIT-CTP-2848
|
hep-ph nucl-ex nucl-th
| null |
The event-by-event fluctuations in heavy ion collisions carry information
about the thermodynamic properties of the hadronic system at the time of
freeze-out. By studying these fluctuations as a function of varying control
parameters, such as the collision energy, it is possible to learn much about
the phase diagram of QCD. As a timely example, we stress the methods by which
present experiments at the CERN SPS can locate the second order critical point
at which a line of first order phase transitions ends. Those event-by-event
signatures which are characteristic of freeze-out in the vicinity of the
critical point will exhibit nonmonotonic dependence on control parameters. We
focus on observables constructed from the multiplicity and transverse momenta
of charged pions. We find good agreement between NA49 data and thermodynamic
predictions for the noncritical fluctuations of such observables. We then
analyze the effects due to the critical fluctuations of the sigma field. We
estimate the size of these nonmonotonic effects which appear near the critical
point, including restrictions imposed by finite size and finite time.
|
[
{
"created": "Wed, 31 Mar 1999 22:29:56 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Rajagopal",
"Krishna",
"",
"MIT"
]
] |
The event-by-event fluctuations in heavy ion collisions carry information about the thermodynamic properties of the hadronic system at the time of freeze-out. By studying these fluctuations as a function of varying control parameters, such as the collision energy, it is possible to learn much about the phase diagram of QCD. As a timely example, we stress the methods by which present experiments at the CERN SPS can locate the second order critical point at which a line of first order phase transitions ends. Those event-by-event signatures which are characteristic of freeze-out in the vicinity of the critical point will exhibit nonmonotonic dependence on control parameters. We focus on observables constructed from the multiplicity and transverse momenta of charged pions. We find good agreement between NA49 data and thermodynamic predictions for the noncritical fluctuations of such observables. We then analyze the effects due to the critical fluctuations of the sigma field. We estimate the size of these nonmonotonic effects which appear near the critical point, including restrictions imposed by finite size and finite time.
|
1909.00773
|
De-Chang Dai
|
De-Chang Dai, Ruth Gregory, and Dejan Stojkovic
|
Connecting the Higgs Potential and Primordial Black Holes
|
19 pages, 6 figures, accepted by PRD
|
Phys. Rev. D 101, 125012 (2020)
|
10.1103/PhysRevD.101.125012
|
DCPT-19/25
|
hep-ph astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
It was recently demonstrated that small small black holes can act as seeds
for nucleating decay of the metastable Higgs vacuum, dramatically increasing
the tunneling probability. Any primordial black hole lighter than $4.5 \times
10^{14}$g at formation would have evaporated by now, and in the absence of new
physics beyond the standard model, would therefore have entered the mass range
in which seeded decay occurs, however, such true vacuum bubbles must percolate
in order to completely destroy the false vacuum; this depends on the bubble
number density and the rate of expansion of the universe. Here, we compute the
fraction of the universe that has decayed to the true vacuum as a function of
the formation temperature (or equivalently, mass) of the primordial black
holes, and the spectral index of the fluctuations responsible for their
formation. This allows us to constrain the mass spectrum of primordial black
holes given a particular Higgs potential and conversely, should we discover
primordial black holes of definite mass, we can constrain the Higgs potential
parameters.
|
[
{
"created": "Mon, 2 Sep 2019 15:52:56 GMT",
"version": "v1"
},
{
"created": "Thu, 11 Jun 2020 14:58:54 GMT",
"version": "v2"
}
] |
2020-07-01
|
[
[
"Dai",
"De-Chang",
""
],
[
"Gregory",
"Ruth",
""
],
[
"Stojkovic",
"Dejan",
""
]
] |
It was recently demonstrated that small small black holes can act as seeds for nucleating decay of the metastable Higgs vacuum, dramatically increasing the tunneling probability. Any primordial black hole lighter than $4.5 \times 10^{14}$g at formation would have evaporated by now, and in the absence of new physics beyond the standard model, would therefore have entered the mass range in which seeded decay occurs, however, such true vacuum bubbles must percolate in order to completely destroy the false vacuum; this depends on the bubble number density and the rate of expansion of the universe. Here, we compute the fraction of the universe that has decayed to the true vacuum as a function of the formation temperature (or equivalently, mass) of the primordial black holes, and the spectral index of the fluctuations responsible for their formation. This allows us to constrain the mass spectrum of primordial black holes given a particular Higgs potential and conversely, should we discover primordial black holes of definite mass, we can constrain the Higgs potential parameters.
|
1810.00048
|
Alexey Vladimirov
|
V.Braun, A.Vladimirov, J.-H.Zhang
|
Power corrections and renormalons in parton quasi-distributions
|
14 pages, 6 figures; corrected typos in sec.3, matched to the journal
version
|
Phys. Rev. D 99, 014013 (2019)
|
10.1103/PhysRevD.99.014013
| null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Perturbative expansions for short-distance quantities in QCD are factorially
divergent and this deficiency can be turned into a useful tool to investigate
nonperturbative corrections. In this work, we use this approach to study the
structure of power corrections to parton quasi-distributions and
pseudo-distributions which appear in lattice calculations of parton
distribution functions. As the main result, we predict the functional
dependence of the leading power corrections to quasi(pseudo)-distributions on
the Bjorken $x$ variable. We also show that these corrections can be strongly
affected by the normalization procedure.
|
[
{
"created": "Fri, 28 Sep 2018 19:19:29 GMT",
"version": "v1"
},
{
"created": "Sun, 11 Oct 2020 08:49:36 GMT",
"version": "v2"
}
] |
2020-10-13
|
[
[
"Braun",
"V.",
""
],
[
"Vladimirov",
"A.",
""
],
[
"Zhang",
"J. -H.",
""
]
] |
Perturbative expansions for short-distance quantities in QCD are factorially divergent and this deficiency can be turned into a useful tool to investigate nonperturbative corrections. In this work, we use this approach to study the structure of power corrections to parton quasi-distributions and pseudo-distributions which appear in lattice calculations of parton distribution functions. As the main result, we predict the functional dependence of the leading power corrections to quasi(pseudo)-distributions on the Bjorken $x$ variable. We also show that these corrections can be strongly affected by the normalization procedure.
|
1305.4989
|
Zhao Shumin
|
Zhao Shu-Min, Feng Tai-Fu, Wang Fang, Gao Tie-Jun, Zhang Yin-Jie
|
The one-loop on-shell renormalization of some vertexes in MSSM
| null |
Chinese Physics C Vol. 37, No. 5 (2013) 053101
| null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The on-shell renormalization scheme for the electroweak theory is well
studied in the standard model(SM), but a consistent on-shell renormalization
scheme for the minimal supersymmetric standard model(MSSM) is still unknown. In
MSSM, we study the on-shell scheme for three vertexes$Z\bar{l^I}l^I,
W^+\bar{\nu^I}l^I $ and $\tilde{L}^*_i\bar{\chi^0_{\alpha}}l^I$ with virtual
SUSY particles (chargino, sneutrino, neutralino and slepton) at one-loop order.
Instead of amplitude of a single triangle diagram, the sum of amplitude of
triangle diagrams belonging to one suit can be renormalized in the on-shell
scheme. One suit points out that the internal virtual particles are consistent.
Zero-momentum scheme is also used for the renormalization. The two schemes can
make the renormalized results decoupled. In MSSM, some special characters of
the on-shell scheme are shown here. This work is propitious to complete the
on-shell renormalization scheme in MSSM.
|
[
{
"created": "Tue, 21 May 2013 23:50:11 GMT",
"version": "v1"
},
{
"created": "Thu, 6 Jun 2013 07:20:39 GMT",
"version": "v2"
}
] |
2013-06-07
|
[
[
"Shu-Min",
"Zhao",
""
],
[
"Tai-Fu",
"Feng",
""
],
[
"Fang",
"Wang",
""
],
[
"Tie-Jun",
"Gao",
""
],
[
"Yin-Jie",
"Zhang",
""
]
] |
The on-shell renormalization scheme for the electroweak theory is well studied in the standard model(SM), but a consistent on-shell renormalization scheme for the minimal supersymmetric standard model(MSSM) is still unknown. In MSSM, we study the on-shell scheme for three vertexes$Z\bar{l^I}l^I, W^+\bar{\nu^I}l^I $ and $\tilde{L}^*_i\bar{\chi^0_{\alpha}}l^I$ with virtual SUSY particles (chargino, sneutrino, neutralino and slepton) at one-loop order. Instead of amplitude of a single triangle diagram, the sum of amplitude of triangle diagrams belonging to one suit can be renormalized in the on-shell scheme. One suit points out that the internal virtual particles are consistent. Zero-momentum scheme is also used for the renormalization. The two schemes can make the renormalized results decoupled. In MSSM, some special characters of the on-shell scheme are shown here. This work is propitious to complete the on-shell renormalization scheme in MSSM.
|
1905.06344
|
Alexis Plascencia
|
Pavel Fileviez Perez, Clara Murgui, Alexis D. Plascencia
|
Neutrino-Dark Matter Connections in Gauge Theories
|
17 pages, 8 figures. v2: published version
|
Phys. Rev. D 100, 035041 (2019)
|
10.1103/PhysRevD.100.035041
| null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
We discuss the connection between the origin of neutrino masses and the
properties of dark matter candidates in the context of gauge extensions of the
Standard Model. We investigate minimal gauge theories for neutrino masses where
the neutrinos are predicted to be Dirac or Majorana fermions. We find that the
upper bound on the effective number of relativistic species provides a strong
constraint in the scenarios with Dirac neutrinos. In the context of theories
where the lepton number is a local gauge symmetry spontaneously broken at the
low scale, the existence of dark matter is predicted from the condition of
anomaly cancellation. Applying the cosmological bound on the dark matter relic
density, we find an upper bound on the symmetry breaking scale in the multi-TeV
region. These results imply we could hope to test simple gauge theories for
neutrino masses at current or future experiments.
|
[
{
"created": "Wed, 15 May 2019 18:00:03 GMT",
"version": "v1"
},
{
"created": "Fri, 23 Aug 2019 18:22:45 GMT",
"version": "v2"
}
] |
2019-09-04
|
[
[
"Perez",
"Pavel Fileviez",
""
],
[
"Murgui",
"Clara",
""
],
[
"Plascencia",
"Alexis D.",
""
]
] |
We discuss the connection between the origin of neutrino masses and the properties of dark matter candidates in the context of gauge extensions of the Standard Model. We investigate minimal gauge theories for neutrino masses where the neutrinos are predicted to be Dirac or Majorana fermions. We find that the upper bound on the effective number of relativistic species provides a strong constraint in the scenarios with Dirac neutrinos. In the context of theories where the lepton number is a local gauge symmetry spontaneously broken at the low scale, the existence of dark matter is predicted from the condition of anomaly cancellation. Applying the cosmological bound on the dark matter relic density, we find an upper bound on the symmetry breaking scale in the multi-TeV region. These results imply we could hope to test simple gauge theories for neutrino masses at current or future experiments.
|
2312.17523
|
Jingya Zhu
|
Weichao Li, Haoxue Qiao, Kun Wang, Jingya Zhu
|
Smuon contribution to muon g-2 in Grand Unified supersymmetric theories
|
12 pages, 5 figures
| null | null | null |
hep-ph astro-ph.HE hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In GUT-scale constrained (GUTc) supersymmetric (SUSY) models, the mass of
smuon $\tilde{\mu}_1$ is typically heavier than that of stau $\tilde{\tau}_1$,
and stau co-annihilation is a typical annihilation mechanism of dark matter.
However, light smuon is more favored by the muon $g-2$ anomaly, thus
smuon-neutralino loop contribution to muon $g-2$ is usually smaller than that
of sneutrino-chargino. Inspired by the latest muon $g-2$ results, we take the
GUTc- Next-to-Minimal Supersymmetric Model (NMSSM) as an example, where the
gaugino (Higgs) masses are not unified to the usual parameter $M_{1/2}$
($M_0$), exploring its possibility of light smuon and its contribution to muon
$g-2$. After complicated calculations and discussions, we conclude that in
GUTc-NMSSM the smuon can be lighter than stau. In this light-smuon scenario,
the contribution of smuon-neutralino loop to the muon $g-2$ can be larger than
that of the sneutrino-chargino loop. The annihilation mechanisms of dark matter
are dominated by multiple slepton or chargino co-annihilation. In our
calculations, we consider also other latest related constraints like Higgs
data, SUSY searches, dark matter relic density and direct detections, etc.
|
[
{
"created": "Fri, 29 Dec 2023 09:07:24 GMT",
"version": "v1"
}
] |
2024-01-01
|
[
[
"Li",
"Weichao",
""
],
[
"Qiao",
"Haoxue",
""
],
[
"Wang",
"Kun",
""
],
[
"Zhu",
"Jingya",
""
]
] |
In GUT-scale constrained (GUTc) supersymmetric (SUSY) models, the mass of smuon $\tilde{\mu}_1$ is typically heavier than that of stau $\tilde{\tau}_1$, and stau co-annihilation is a typical annihilation mechanism of dark matter. However, light smuon is more favored by the muon $g-2$ anomaly, thus smuon-neutralino loop contribution to muon $g-2$ is usually smaller than that of sneutrino-chargino. Inspired by the latest muon $g-2$ results, we take the GUTc- Next-to-Minimal Supersymmetric Model (NMSSM) as an example, where the gaugino (Higgs) masses are not unified to the usual parameter $M_{1/2}$ ($M_0$), exploring its possibility of light smuon and its contribution to muon $g-2$. After complicated calculations and discussions, we conclude that in GUTc-NMSSM the smuon can be lighter than stau. In this light-smuon scenario, the contribution of smuon-neutralino loop to the muon $g-2$ can be larger than that of the sneutrino-chargino loop. The annihilation mechanisms of dark matter are dominated by multiple slepton or chargino co-annihilation. In our calculations, we consider also other latest related constraints like Higgs data, SUSY searches, dark matter relic density and direct detections, etc.
|
hep-ph/9609496
|
Paul Frampton
|
P.H. Frampton and S.L. Glashow
|
Cabibbo Mixing and the Search for CP Violation
|
6 pages, latex, no figures
|
Phys.Rev. D55 (1997) 1691-1692
|
10.1103/PhysRevD.55.1691
|
HUTP-96/A044 and IFP-735-UNC
|
hep-ph
| null |
We examine certain extensions of the standard model in which $CP$ violation
is spontaneous and the strong $CP$ problem is resolved. In these models, the $3
\times 3$ quark mixing matrix is neither real nor unitary. However, to a
precision of 0.1%, it is real and orthogonal. There are no readily observable
$CP$-violating effects besides those in the neutral kaon system.
|
[
{
"created": "Thu, 26 Sep 1996 17:53:53 GMT",
"version": "v1"
}
] |
2016-09-06
|
[
[
"Frampton",
"P. H.",
""
],
[
"Glashow",
"S. L.",
""
]
] |
We examine certain extensions of the standard model in which $CP$ violation is spontaneous and the strong $CP$ problem is resolved. In these models, the $3 \times 3$ quark mixing matrix is neither real nor unitary. However, to a precision of 0.1%, it is real and orthogonal. There are no readily observable $CP$-violating effects besides those in the neutral kaon system.
|
hep-ph/9911376
|
Cvetic Gorazd
|
G. Cvetic and Ji-Young Yu
|
Nonperturbative dispersive sector in strong (quasi-)Abelian fields
|
25 pages, 15 eps-figures, revtex; improved presentation, results
unchanged; to appear in Int.J.Mod.Phys.A
|
Int.J.Mod.Phys.A16:57-82,2001
|
10.1016/S0217-751X(01)00285-0
| null |
hep-ph
| null |
In strong (quasi-)Abelian fields, even at the one-loop level of the coupling
constant, quantum fluctuations of fermions induce an effective Lagrangian
density whose imaginary (absorptive) part is purely nonperturbative and known
to be responsible for the fermion-antifermion pair creation. On the other hand,
the induced real (dispersive) part has perturbative and nonperturbative
contributions. In the one-loop case, we argue how to separate the two
contributions from each other for any strength of the field. We show
numerically that the nonperturbative contributions are in general comparable
with or larger than the induced perturbative ones. We arrive at qualitatively
similar conclusions also for the induced energy density. Further, we
investigate numerically the quasianalytic continuation of the perturbative
results into the nonperturbative sector, by employing (modified) Borel-Pade. It
turns out that in the case at hand, we have to integrate over renormalon
singularities, but there is no renormalon ambiguity involved.
|
[
{
"created": "Tue, 16 Nov 1999 12:13:32 GMT",
"version": "v1"
},
{
"created": "Thu, 23 Mar 2000 03:25:17 GMT",
"version": "v2"
},
{
"created": "Wed, 13 Sep 2000 11:44:26 GMT",
"version": "v3"
}
] |
2014-11-17
|
[
[
"Cvetic",
"G.",
""
],
[
"Yu",
"Ji-Young",
""
]
] |
In strong (quasi-)Abelian fields, even at the one-loop level of the coupling constant, quantum fluctuations of fermions induce an effective Lagrangian density whose imaginary (absorptive) part is purely nonperturbative and known to be responsible for the fermion-antifermion pair creation. On the other hand, the induced real (dispersive) part has perturbative and nonperturbative contributions. In the one-loop case, we argue how to separate the two contributions from each other for any strength of the field. We show numerically that the nonperturbative contributions are in general comparable with or larger than the induced perturbative ones. We arrive at qualitatively similar conclusions also for the induced energy density. Further, we investigate numerically the quasianalytic continuation of the perturbative results into the nonperturbative sector, by employing (modified) Borel-Pade. It turns out that in the case at hand, we have to integrate over renormalon singularities, but there is no renormalon ambiguity involved.
|
2009.03337
|
Basudeb Dasgupta
|
Soumya Bhattacharyya (Tata Inst.) and Basudeb Dasgupta (Tata Inst.)
|
Fast Flavor Depolarization of Supernova Neutrinos
|
4+4+3 pages; 4+4 figures; v2:minor changes, references added,
comments welcome; v3: approx. identical to published version with
supplemental material with analytical and numerical details
|
Phys. Rev. Lett. 126, 061302 (2021)
|
10.1103/PhysRevLett.126.061302
|
TIFR/TH/20-33
|
hep-ph astro-ph.HE astro-ph.SR hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Flavor-dependent neutrino emission is critical to the evolution of a
supernova and its neutrino signal. In the dense anisotropic interior of the
star, neutrino-neutrino forward-scattering can lead to fast collective neutrino
oscillations, which has striking consequences. We present a theory of fast
flavor depolarization, explaining how neutrino flavor differences become
smaller, i.e., depolarize, due to diffusion to smaller angular scales. We show
that transverse relaxation determines the epoch of this irreversible
depolarization. We give a method to compute the depolarized fluxes, presenting
an explicit formula for simple initial conditions, which can be a crucial input
for supernova theory and neutrino phenomenology.
|
[
{
"created": "Mon, 7 Sep 2020 18:00:08 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Sep 2020 06:52:24 GMT",
"version": "v2"
},
{
"created": "Thu, 18 Feb 2021 19:28:51 GMT",
"version": "v3"
}
] |
2021-02-22
|
[
[
"Bhattacharyya",
"Soumya",
"",
"Tata Inst."
],
[
"Dasgupta",
"Basudeb",
"",
"Tata Inst."
]
] |
Flavor-dependent neutrino emission is critical to the evolution of a supernova and its neutrino signal. In the dense anisotropic interior of the star, neutrino-neutrino forward-scattering can lead to fast collective neutrino oscillations, which has striking consequences. We present a theory of fast flavor depolarization, explaining how neutrino flavor differences become smaller, i.e., depolarize, due to diffusion to smaller angular scales. We show that transverse relaxation determines the epoch of this irreversible depolarization. We give a method to compute the depolarized fluxes, presenting an explicit formula for simple initial conditions, which can be a crucial input for supernova theory and neutrino phenomenology.
|
1601.02459
|
Maximilian Stahlhofen
|
J. Reuter, F. Bach, B. Chokoufe, W. Kilian, M. Stahlhofen, C. Weiss
|
QCD NLO with Powheg matching and top threshold matching in WHIZARD
|
9 pages, 3 figures, Talk given at 12th International Symposium on
Radiative Corrections (Radcor 2015) and LoopFest XIV (Radiative Corrections
for the LHC and Future Colliders); v2: reference added
|
PoS(RADCOR2015)088
| null |
DESY 15-176, MITP/16-007, SI-HEP-2016-02
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present the status of the automation of NLO processes within the event
generator WHIZARD. The program provides an automated FKS subtraction and phase
space integration over the FKS regions, while the (QCD) NLO matrix element is
accessed via the Binoth Les Houches Interface from an externally linked
one-loop program. Massless and massive test cases and validation are shown for
several e+e- processes. Furthermore, we discuss work in progress and future
plans. The second part covers the matching of the NRQCD prediction with NLL
threshold resummation to the NLO continuum top pair production at lepton
colliders. Both the S-wave and P-wave production of the top pair are taken into
account in the resummation. The inclusion in WHIZARD allows to study more
exclusive observables than just the total cross section and automatically
accounts for important electroweak and relativistic corrections in the
threshold region.
|
[
{
"created": "Mon, 11 Jan 2016 14:32:23 GMT",
"version": "v1"
},
{
"created": "Thu, 10 Mar 2016 16:48:52 GMT",
"version": "v2"
}
] |
2016-03-11
|
[
[
"Reuter",
"J.",
""
],
[
"Bach",
"F.",
""
],
[
"Chokoufe",
"B.",
""
],
[
"Kilian",
"W.",
""
],
[
"Stahlhofen",
"M.",
""
],
[
"Weiss",
"C.",
""
]
] |
We present the status of the automation of NLO processes within the event generator WHIZARD. The program provides an automated FKS subtraction and phase space integration over the FKS regions, while the (QCD) NLO matrix element is accessed via the Binoth Les Houches Interface from an externally linked one-loop program. Massless and massive test cases and validation are shown for several e+e- processes. Furthermore, we discuss work in progress and future plans. The second part covers the matching of the NRQCD prediction with NLL threshold resummation to the NLO continuum top pair production at lepton colliders. Both the S-wave and P-wave production of the top pair are taken into account in the resummation. The inclusion in WHIZARD allows to study more exclusive observables than just the total cross section and automatically accounts for important electroweak and relativistic corrections in the threshold region.
|
1905.11747
|
Akihiro Yuu
|
Takuya Morozumi, Yusuke Shimizu, Hiroyuki Umeeda and Akihiro Yuu
|
Hidden relations in three generation seesaw model with Dirac mass matrix
of four-zero texture
|
23 pages, 33 figures, order of references is changed
| null |
10.1016/j.physletb.2019.135046
|
HUPD-1910
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present predictions for CP violating phases of the Type-I seesaw model
with four-zero textures on the Dirac mass matrix. For the four-zero textures,
the effective low energy Majorana mass matrix is parametrized with seven
parameters. They are three mass-dimensional parameters, two angles and two CP
violating sources. The number of these parameters is less than that of the
general description of the Majorana mass matrix with three neutrino masses,
three mixing angles and three CP violating phases. In particular, only two
independent CP violating sources give rise to three CP violating phases. The
efficient and comprehensive method is proposed in this paper to investigate
four-zero textures in Type-I seesaw. We numerically show the possible range of
CP violating phases in the plane of a Dirac CP violating phase and one of
Majorana phases. Some cases show the strong correlations among two phases.
These correlations can be explained by hidden relations among the elements of
Majorana matrix with the four-zero textures. The hidden relations are
classified according to the position of one vanishing off-diagonal element of
Majorana mass matrix. The Majorana mass matrix all of whose elements are
non-vanishing also produces other hidden relations particularly in the case of
four-zero textures. By applying the hidden relations, we describe the concrete
correlations among CP violating phases.
|
[
{
"created": "Tue, 28 May 2019 11:25:19 GMT",
"version": "v1"
},
{
"created": "Thu, 30 May 2019 08:14:27 GMT",
"version": "v2"
}
] |
2019-10-30
|
[
[
"Morozumi",
"Takuya",
""
],
[
"Shimizu",
"Yusuke",
""
],
[
"Umeeda",
"Hiroyuki",
""
],
[
"Yuu",
"Akihiro",
""
]
] |
We present predictions for CP violating phases of the Type-I seesaw model with four-zero textures on the Dirac mass matrix. For the four-zero textures, the effective low energy Majorana mass matrix is parametrized with seven parameters. They are three mass-dimensional parameters, two angles and two CP violating sources. The number of these parameters is less than that of the general description of the Majorana mass matrix with three neutrino masses, three mixing angles and three CP violating phases. In particular, only two independent CP violating sources give rise to three CP violating phases. The efficient and comprehensive method is proposed in this paper to investigate four-zero textures in Type-I seesaw. We numerically show the possible range of CP violating phases in the plane of a Dirac CP violating phase and one of Majorana phases. Some cases show the strong correlations among two phases. These correlations can be explained by hidden relations among the elements of Majorana matrix with the four-zero textures. The hidden relations are classified according to the position of one vanishing off-diagonal element of Majorana mass matrix. The Majorana mass matrix all of whose elements are non-vanishing also produces other hidden relations particularly in the case of four-zero textures. By applying the hidden relations, we describe the concrete correlations among CP violating phases.
|
2007.01654
|
Yannick Ulrich
|
P. Banerjee, T. Engel, A. Signer, Y. Ulrich
|
QED at NNLO with McMule
|
35 pages, 12 figures, minor changes, published version
|
SciPost Phys. 9, 027 (2020)
|
10.21468/SciPostPhys.9.2.027
|
PSI-PR-20-09, ZU-TH 23/20
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
McMule is a framework for fully differential higher-order QED calculations of
scattering and decay processes involving leptons. It keeps finite lepton
masses, which regularises collinear singularities. Soft singularities are
treated with dimensional regularisation and using FKS$^\ell$ subtraction. We
describe the implementation of the framework in Fortran 95, list the processes
that are currently implemented, and give instructions on how to run the code.
In addition, we present new phenomenological results for muon-electron
scattering and lepton-proton scattering, including the dominant NNLO
corrections. While the applications presented focus on MUonE, MUSE, and P2, the
code can be used for a large number of planned and running experiments.
|
[
{
"created": "Fri, 3 Jul 2020 12:47:53 GMT",
"version": "v1"
},
{
"created": "Mon, 31 Aug 2020 12:30:37 GMT",
"version": "v2"
}
] |
2020-09-01
|
[
[
"Banerjee",
"P.",
""
],
[
"Engel",
"T.",
""
],
[
"Signer",
"A.",
""
],
[
"Ulrich",
"Y.",
""
]
] |
McMule is a framework for fully differential higher-order QED calculations of scattering and decay processes involving leptons. It keeps finite lepton masses, which regularises collinear singularities. Soft singularities are treated with dimensional regularisation and using FKS$^\ell$ subtraction. We describe the implementation of the framework in Fortran 95, list the processes that are currently implemented, and give instructions on how to run the code. In addition, we present new phenomenological results for muon-electron scattering and lepton-proton scattering, including the dominant NNLO corrections. While the applications presented focus on MUonE, MUSE, and P2, the code can be used for a large number of planned and running experiments.
|
hep-ph/9601369
|
Silvano Simula
|
N.B. Demchuk, I.L. Grach, I.M. Narodetski, S. Simula
|
Heavy-to-heavy and heavy-to-light weak decay form factors in the
light-front approach: the exclusive $ 0^- $ to $ 0^- $ case
|
revised version (corrections to formulae and references) to appear in
Sov. J. Nucl. Phys
|
Phys.Atom.Nucl. 59 (1996) 2152-2163; Yad.Fiz. 59N12 (1996)
2235-2246
| null |
preprint INFN-ISS 95/18
|
hep-ph nucl-th
| null |
Weak transition form factors among heavy pseudoscalar mesons are investigated
within a relativistic quark model formulated on the light-front. It is shown
that the light-front result derived in the time-like region for the matrix
elements of the plus component of the weak vector current coincides with the
spectator pole term of the quark triangle diagram. For the first time, the
dependence of the form factors on the squared four-momentum transfer $q^2$ is
calculated in the whole accessible kinematical region $0 \leq q^2 \leq
q^2_{max}$. For the numerical investigations of the semileptonic $B \to D \ell
\nu_{\ell}$, $B \to \pi \ell \nu_{\ell}$, $D \to K \ell \nu_{\ell}$ and $D \to
\pi \ell \nu_{\ell}$, the equal-time wave functions corresponding to the
updated version of the ISGW model are adopted. Our results for the form factors
and the decay rates are presented and compared with available experimental data
and predictions of different approaches. Moreover, the $K^0_L \to \pi^{\pm} ~
e^{\mp} ~ \nu_e$ decay is briefly discussed. Our approach is consistent with
experimental data.
|
[
{
"created": "Tue, 30 Jan 1996 08:16:48 GMT",
"version": "v1"
},
{
"created": "Mon, 6 May 1996 07:53:25 GMT",
"version": "v2"
}
] |
2008-02-03
|
[
[
"Demchuk",
"N. B.",
""
],
[
"Grach",
"I. L.",
""
],
[
"Narodetski",
"I. M.",
""
],
[
"Simula",
"S.",
""
]
] |
Weak transition form factors among heavy pseudoscalar mesons are investigated within a relativistic quark model formulated on the light-front. It is shown that the light-front result derived in the time-like region for the matrix elements of the plus component of the weak vector current coincides with the spectator pole term of the quark triangle diagram. For the first time, the dependence of the form factors on the squared four-momentum transfer $q^2$ is calculated in the whole accessible kinematical region $0 \leq q^2 \leq q^2_{max}$. For the numerical investigations of the semileptonic $B \to D \ell \nu_{\ell}$, $B \to \pi \ell \nu_{\ell}$, $D \to K \ell \nu_{\ell}$ and $D \to \pi \ell \nu_{\ell}$, the equal-time wave functions corresponding to the updated version of the ISGW model are adopted. Our results for the form factors and the decay rates are presented and compared with available experimental data and predictions of different approaches. Moreover, the $K^0_L \to \pi^{\pm} ~ e^{\mp} ~ \nu_e$ decay is briefly discussed. Our approach is consistent with experimental data.
|
hep-ph/0102127
|
Chung-I. Tan
|
Chung-I Tan
|
Pomeron and AdS/CFT Correspondence for QCD
|
6 pages, Talks given at ISMD2000, Tihany, Hungary, Oct. 2000, and at
Gribov-2000, Orsay, France, Mar. 2000
| null | null | null |
hep-ph
| null |
The Maldacena conjecture that QCD is holographically dual to gravity in extra
dimensions is briefly reviewed. On the basis of this duality conjecture, the
complete glueball spectrum is computed which bares a striking resemblance to
the known $QCD_4$ spectrum as determined by lattice simulations. In particular,
a strong coupling expansion for the Pomeron intercept is obtained.
|
[
{
"created": "Sat, 10 Feb 2001 21:31:15 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Tan",
"Chung-I",
""
]
] |
The Maldacena conjecture that QCD is holographically dual to gravity in extra dimensions is briefly reviewed. On the basis of this duality conjecture, the complete glueball spectrum is computed which bares a striking resemblance to the known $QCD_4$ spectrum as determined by lattice simulations. In particular, a strong coupling expansion for the Pomeron intercept is obtained.
|
1310.2786
|
Benjamin Rislow
|
Carl E. Carlson (1), Benjamin C. Rislow (1,2) ((1) William and Mary
and (2) Johannes Gutenberg University, Mainz)
|
Constraints to new physics models for the proton charge radius puzzle
from the decay $K^+ \rightarrow \mu^+ +\nu + e^- + e^+$
|
5 pages, 5 figures
|
Phys. Rev. D 89, 035003 (2014)
|
10.1103/PhysRevD.89.035003
|
MITP/13-062
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A possible explanation for the discrepancy between electronic and muonic
hydrogen measurements of the proton charge radius are new, lepton-universality
violating interactions. Several new couplings and particles have been suggested
that account for this discrepancy. At present, these explanations are poorly
constrained. Experiments such as the upcoming kaon decay experiment at JPARC
may constrain or eliminate some explanations by sensitivity to the decay
channel $K^+ \rightarrow \mu^+ +\nu + e^- + e^+$. We calculate the predicted
contributions of the various explanations to this channel. The predicted
signals, if present, should be large enough to be resolved in the experiment.
|
[
{
"created": "Thu, 10 Oct 2013 12:23:43 GMT",
"version": "v1"
}
] |
2014-02-12
|
[
[
"Carlson",
"Carl E.",
""
],
[
"Rislow",
"Benjamin C.",
""
]
] |
A possible explanation for the discrepancy between electronic and muonic hydrogen measurements of the proton charge radius are new, lepton-universality violating interactions. Several new couplings and particles have been suggested that account for this discrepancy. At present, these explanations are poorly constrained. Experiments such as the upcoming kaon decay experiment at JPARC may constrain or eliminate some explanations by sensitivity to the decay channel $K^+ \rightarrow \mu^+ +\nu + e^- + e^+$. We calculate the predicted contributions of the various explanations to this channel. The predicted signals, if present, should be large enough to be resolved in the experiment.
|
1606.04623
|
Yin Huang
|
Yin Huang, Ju-jun Xie, Jun He, Xurong Chen, and Hong-fei Zhang
|
$\bar{K}$ -induced formation of the $f_2(1270)$ and $f_2^{'}(1525)$
resonances on proton targets
|
6 pages,8 figures
| null | null | null |
hep-ph nucl-ex nucl-th
|
http://creativecommons.org/licenses/by/4.0/
|
We investigate the productiong of $f_2(1270)$ and $f_2^{'}(1525)$ mesons in
the $K^{-}p\to\Lambda{}f_2(1270)$,$K^{-}p\to\Lambda{}f^{'}_2(1525)$ and
$K^{-}p\to{}K^{+}K^{-}\Lambda$ reactions within an effective Lagrangian
approach. For $K^{-}p\to{}f_2\Lambda$ reaction, by considering the
contributions from the $t$-channel $K^{+}$ exchange and $u$-channel nucleon
pole, we get a fairly good description of the experimental measurements about
the total and differential cross sections. Based on the studies of the
$K^{-}p\to{}f_2\Lambda$ reaction, we investigate $K^{-}p\to{}K^{+}K^{-}\Lambda$
reaction including the contributions from the $f_2(1270)$ and $f'_2(1525)$
mesons decaying into $K^+K^-$ pair. The total cross sections and invariant mass
distribution of the $K p \to K^+K^- \Lambda$ reaction are predicted. The
results can be tested in future experiments and therefore offer new clues on
the nature of these tensor states.
|
[
{
"created": "Wed, 15 Jun 2016 02:42:10 GMT",
"version": "v1"
}
] |
2016-06-16
|
[
[
"Huang",
"Yin",
""
],
[
"Xie",
"Ju-jun",
""
],
[
"He",
"Jun",
""
],
[
"Chen",
"Xurong",
""
],
[
"Zhang",
"Hong-fei",
""
]
] |
We investigate the productiong of $f_2(1270)$ and $f_2^{'}(1525)$ mesons in the $K^{-}p\to\Lambda{}f_2(1270)$,$K^{-}p\to\Lambda{}f^{'}_2(1525)$ and $K^{-}p\to{}K^{+}K^{-}\Lambda$ reactions within an effective Lagrangian approach. For $K^{-}p\to{}f_2\Lambda$ reaction, by considering the contributions from the $t$-channel $K^{+}$ exchange and $u$-channel nucleon pole, we get a fairly good description of the experimental measurements about the total and differential cross sections. Based on the studies of the $K^{-}p\to{}f_2\Lambda$ reaction, we investigate $K^{-}p\to{}K^{+}K^{-}\Lambda$ reaction including the contributions from the $f_2(1270)$ and $f'_2(1525)$ mesons decaying into $K^+K^-$ pair. The total cross sections and invariant mass distribution of the $K p \to K^+K^- \Lambda$ reaction are predicted. The results can be tested in future experiments and therefore offer new clues on the nature of these tensor states.
|
hep-ph/9711385
| null |
Daniele Dominici
|
Tests for a Strong Electroweak Sector at Future e^+e^- High Energy
Colliders
|
74 pages, 19 figures and 4 tables included, Latex, uses epsf, to
appear in La Rivista del Nuovo Cimento, some minor changes
|
Riv.Nuovo Cim. 20 (1997) 1-64
|
10.1007/BF02877375
|
DFF 291/10/97
|
hep-ph
| null |
The study of the scattering at high energy of the gauge bosons W and Z, in
particular longitudinally polarized W and Z, can clarify the mechanism of
spontaneous symmetry breaking in the Standard Model of the electroweak
interactions. Different models of strong electroweak sector, based on the
effective lagrangian approach are briefly reviewed. They include models with no
resonance, with scalar resonance, additional vector and axial-vector
resonances. The effective Lagrangians are derived from the chiral symmetry of
the symmetry breaking sector. Limits on these models from existing
measurements, mainly LEP and Tevatron, are considered. We study also direct and
indirect effects of the new interactions at high energy future e^+e^- linear
colliders, through WW scattering and the direct production of these new vector
gauge bosons.
|
[
{
"created": "Wed, 19 Nov 1997 12:30:34 GMT",
"version": "v1"
},
{
"created": "Mon, 9 Feb 1998 10:11:49 GMT",
"version": "v2"
}
] |
2017-08-23
|
[
[
"Dominici",
"Daniele",
""
]
] |
The study of the scattering at high energy of the gauge bosons W and Z, in particular longitudinally polarized W and Z, can clarify the mechanism of spontaneous symmetry breaking in the Standard Model of the electroweak interactions. Different models of strong electroweak sector, based on the effective lagrangian approach are briefly reviewed. They include models with no resonance, with scalar resonance, additional vector and axial-vector resonances. The effective Lagrangians are derived from the chiral symmetry of the symmetry breaking sector. Limits on these models from existing measurements, mainly LEP and Tevatron, are considered. We study also direct and indirect effects of the new interactions at high energy future e^+e^- linear colliders, through WW scattering and the direct production of these new vector gauge bosons.
|
1103.4799
|
Gergely Fejos
|
G. Fejos, A. Patkos
|
Spontaneously broken ground states of the U(n)_L x U(n)_R linear sigma
model at large n
|
ReVTeX4, 10 pages, 5 figures. Extended introduction and conclusion.
Version published in Phys. Rev. D
|
Phys.Rev.D84:036001,2011
|
10.1103/PhysRevD.84.036001
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Symmetry breaking patterns of the U(n)_L x U(n)_R symmetric meson model are
investigated in a formulation involving three auxiliary composite fields. The
effective potential is constructed at leading order in the 1/n expansion for a
condensate belonging to the center of the U(n) group. A wide region is found in
the coupling space where in addition to the condensate proportional to the unit
matrix, also metastable minima exist, in which a further breakdown of the
diagonal U_V(n) symmetry to U_V(n-1) is realized. Application of a moderate
external field conjugate to this component of the order parameter changes this
state into the true ground state of the system.
|
[
{
"created": "Thu, 24 Mar 2011 16:22:18 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Aug 2011 14:37:26 GMT",
"version": "v2"
}
] |
2011-08-12
|
[
[
"Fejos",
"G.",
""
],
[
"Patkos",
"A.",
""
]
] |
Symmetry breaking patterns of the U(n)_L x U(n)_R symmetric meson model are investigated in a formulation involving three auxiliary composite fields. The effective potential is constructed at leading order in the 1/n expansion for a condensate belonging to the center of the U(n) group. A wide region is found in the coupling space where in addition to the condensate proportional to the unit matrix, also metastable minima exist, in which a further breakdown of the diagonal U_V(n) symmetry to U_V(n-1) is realized. Application of a moderate external field conjugate to this component of the order parameter changes this state into the true ground state of the system.
|
2402.03432
|
Yifan Chen
|
Yifan Chen, Chunlong Li, Yuxiang Liu, Yuxin Liu, Jing Shu, Yanjie Zeng
|
SRF Cavity as Galactic Dark Photon Telescope
|
16 pages, 3 figures
| null | null | null |
hep-ph astro-ph.HE gr-qc hep-ex physics.acc-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Dark photons, aside from constituting non-relativistic dark matter, can also
be generated relativistically through the decay or annihilation of other dark
matter candidates, contributing to a galactic dark photon background. The
production of dark photons tends to favor specific polarization modes,
determined by the microscopic coupling between dark matter and dark photons. We
leverage data obtained from previous searches for dark photon dark matter using
a superconducting radio-frequency cavity to explore galactic dark photon
fluxes. The interplay of anisotropic directions and Earth's rotation introduces
a diurnal modulation of signals within the cavities, manifesting distinct
variation patterns for longitudinal and transverse modes. Our findings
highlight the efficacy of superconducting radio-frequency cavities,
characterized by significantly high-quality factors, as powerful telescopes for
detecting galactic dark photons, unveiling a novel avenue in the indirect
search for dark matter through multi-messenger astronomy.
|
[
{
"created": "Mon, 5 Feb 2024 19:00:01 GMT",
"version": "v1"
}
] |
2024-02-07
|
[
[
"Chen",
"Yifan",
""
],
[
"Li",
"Chunlong",
""
],
[
"Liu",
"Yuxiang",
""
],
[
"Liu",
"Yuxin",
""
],
[
"Shu",
"Jing",
""
],
[
"Zeng",
"Yanjie",
""
]
] |
Dark photons, aside from constituting non-relativistic dark matter, can also be generated relativistically through the decay or annihilation of other dark matter candidates, contributing to a galactic dark photon background. The production of dark photons tends to favor specific polarization modes, determined by the microscopic coupling between dark matter and dark photons. We leverage data obtained from previous searches for dark photon dark matter using a superconducting radio-frequency cavity to explore galactic dark photon fluxes. The interplay of anisotropic directions and Earth's rotation introduces a diurnal modulation of signals within the cavities, manifesting distinct variation patterns for longitudinal and transverse modes. Our findings highlight the efficacy of superconducting radio-frequency cavities, characterized by significantly high-quality factors, as powerful telescopes for detecting galactic dark photons, unveiling a novel avenue in the indirect search for dark matter through multi-messenger astronomy.
|
hep-ph/0105270
|
Maxim Pospelov
|
Cherif Hamzaoui and Maxim Pospelov
|
How natural is a small \bar\theta in left-right SUSY models ?
|
12 pages, latex, 1 figure, references added
|
Phys.Rev.D65:056002,2002
|
10.1103/PhysRevD.65.056002
|
UMN-TH-1827, UQAM-PHE-01-01
|
hep-ph
| null |
In the world without an axion the smallness of $\bar\theta$ may be achieved
due to a spontaneously broken discrete left-right symmetry. We analyze the
radiatively induced \bar\theta in the context of generic left-right symmetric
SUSY models without assuming flavor degeneracy in the squark sector. Left-right
symmetry allows to keep \bar\theta within its present bound only if the
inter-generational mass splitting in the squark sector at the scale of the
left-right symmetry breaking is smaller than 0.5%. We also consider the
naturalness of m_u=0 solution to the strong CP problem in the context of
horizontal flavor symmetries. A strong bound on the combination of the
horizontal charges in the Up quark sector is found in this case.
|
[
{
"created": "Fri, 25 May 2001 19:09:27 GMT",
"version": "v1"
},
{
"created": "Thu, 31 May 2001 16:52:06 GMT",
"version": "v2"
}
] |
2014-11-17
|
[
[
"Hamzaoui",
"Cherif",
""
],
[
"Pospelov",
"Maxim",
""
]
] |
In the world without an axion the smallness of $\bar\theta$ may be achieved due to a spontaneously broken discrete left-right symmetry. We analyze the radiatively induced \bar\theta in the context of generic left-right symmetric SUSY models without assuming flavor degeneracy in the squark sector. Left-right symmetry allows to keep \bar\theta within its present bound only if the inter-generational mass splitting in the squark sector at the scale of the left-right symmetry breaking is smaller than 0.5%. We also consider the naturalness of m_u=0 solution to the strong CP problem in the context of horizontal flavor symmetries. A strong bound on the combination of the horizontal charges in the Up quark sector is found in this case.
|
1609.01289
|
Alexander Merle
|
Johannes K\"onig, Alexander Merle, Maximilian Totzauer
|
keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: The Most
General Case
|
59 pages (main text 34 pages), 15 figures
| null |
10.1088/1475-7516/2016/11/038
|
MPP-2016-263
|
hep-ph astro-ph.CO astro-ph.GA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the early Universe production of sterile neutrino Dark Matter
by the decays of singlet scalars. All previous studies applied simplifying
assumptions and/or studied the process only on the level of number densities,
which makes it impossible to give statements about cosmic structure formation.
We overcome these issues by dropping all simplifying assumptions (except for
one we showed earlier to work perfectly) and by computing the full course of
Dark Matter production on the level of non-thermal momentum distribution
functions. We are thus in the position to study all aspects of the resulting
settings and apply all relevant bounds in a reliable manner. We have a
particular focus on how to incorporate bounds from structure formation on the
level of the linear power spectrum, since the simplistic estimate using the
free-streaming horizon clearly fails for highly non-thermal distributions. Our
work comprises the most detailed and comprehensive study of sterile neutrino
Dark Matter production by scalar decays presented so far.
|
[
{
"created": "Mon, 5 Sep 2016 20:00:02 GMT",
"version": "v1"
}
] |
2016-12-07
|
[
[
"König",
"Johannes",
""
],
[
"Merle",
"Alexander",
""
],
[
"Totzauer",
"Maximilian",
""
]
] |
We investigate the early Universe production of sterile neutrino Dark Matter by the decays of singlet scalars. All previous studies applied simplifying assumptions and/or studied the process only on the level of number densities, which makes it impossible to give statements about cosmic structure formation. We overcome these issues by dropping all simplifying assumptions (except for one we showed earlier to work perfectly) and by computing the full course of Dark Matter production on the level of non-thermal momentum distribution functions. We are thus in the position to study all aspects of the resulting settings and apply all relevant bounds in a reliable manner. We have a particular focus on how to incorporate bounds from structure formation on the level of the linear power spectrum, since the simplistic estimate using the free-streaming horizon clearly fails for highly non-thermal distributions. Our work comprises the most detailed and comprehensive study of sterile neutrino Dark Matter production by scalar decays presented so far.
|
1301.5344
|
Kouji Kashiwa
|
Kouji Kashiwa, Robert D. Pisarski
|
The Roberge-Weiss transition and 't Hooft loops
|
30 pages, 8 figures, 1 table. Expanded version: clarified
relationship of interface tension to 't Hooft loop; phase diagram for heavy
quarks computed; numerous references added
|
Phys.Rev.D87:096009,2013
|
10.1103/PhysRevD.87.096009
|
RBRC-993; BNL-99061-2013-JA
|
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Roberge and Weiss showed that for SU(N) gauge theories, phase transitions
occur in the presence of an imaginary quark chemical potential. We show that at
asymptotically high temperature, where the phase transition is of first order,
that even with dynamical quarks 't Hooft loops of arbitrary Z(N) charge are
well defined at the phase boundary. To leading order in weak coupling, the 't
Hooft loop satisfies Casimir scaling in the pure glue theory, but not with
quarks. Because the chemical potential is imaginary, typically the interaction
measure is negative on one side of the phase transition. Using a matrix model
to model the deconfining phase transition, we compute the phase diagram for
heavy quarks, in the plane of temperature and imaginary chemical potential. In
general we find intersecting lines of first order transitions. Using a modified
Polyakov loop which is Roberge-Weiss symmetric, we suggest that the interface
tension is related to the 't Hooft loop only at high temperature, where the
imaginary part of this Polyakov loop, and not the real part, is discontinuous
across the phase boundary.
|
[
{
"created": "Tue, 22 Jan 2013 21:46:03 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Apr 2013 17:11:45 GMT",
"version": "v2"
}
] |
2013-09-11
|
[
[
"Kashiwa",
"Kouji",
""
],
[
"Pisarski",
"Robert D.",
""
]
] |
Roberge and Weiss showed that for SU(N) gauge theories, phase transitions occur in the presence of an imaginary quark chemical potential. We show that at asymptotically high temperature, where the phase transition is of first order, that even with dynamical quarks 't Hooft loops of arbitrary Z(N) charge are well defined at the phase boundary. To leading order in weak coupling, the 't Hooft loop satisfies Casimir scaling in the pure glue theory, but not with quarks. Because the chemical potential is imaginary, typically the interaction measure is negative on one side of the phase transition. Using a matrix model to model the deconfining phase transition, we compute the phase diagram for heavy quarks, in the plane of temperature and imaginary chemical potential. In general we find intersecting lines of first order transitions. Using a modified Polyakov loop which is Roberge-Weiss symmetric, we suggest that the interface tension is related to the 't Hooft loop only at high temperature, where the imaginary part of this Polyakov loop, and not the real part, is discontinuous across the phase boundary.
|
hep-ph/9907330
|
Wei Zhu
|
Wei Zhu and Jianhong Ruan
|
A new modified Altarelli-Parisi evolution equation with parton
recombination in proton
|
26 pages, 12 figures. The complete derivations of the parton
recombination functions are presented in a new Appendix
|
Nucl.Phys.B559:378-392,1999
|
10.1016/S0550-3213(99)00461-7
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The coefficients of the nonlinear terms in a modified Altarelli-Parisi
evolution equation with parton recombination are determined in the leading
logarithmic ($Q^2$) approximation. The results are valid in the whole $x$
region and contain the translation $GG\to q\bar q$, which is inhibited in the
double leading logarithmic approximation. The comparisons of the new evolution
equation with the Gribov-Levin-Ryskin equation are presented.
|
[
{
"created": "Tue, 13 Jul 1999 09:08:57 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Oct 2013 06:36:05 GMT",
"version": "v2"
}
] |
2013-10-03
|
[
[
"Zhu",
"Wei",
""
],
[
"Ruan",
"Jianhong",
""
]
] |
The coefficients of the nonlinear terms in a modified Altarelli-Parisi evolution equation with parton recombination are determined in the leading logarithmic ($Q^2$) approximation. The results are valid in the whole $x$ region and contain the translation $GG\to q\bar q$, which is inhibited in the double leading logarithmic approximation. The comparisons of the new evolution equation with the Gribov-Levin-Ryskin equation are presented.
|
1705.08896
|
Alexander Wijangco
|
Qianshu Lu, David E. Morrissey, Alexander M. Wijangco
|
Higgs Boson Decays to Dark Photons through the Vectorized Lepton Portal
|
32 pages, 5 figures, updated to match JHEP version
| null |
10.1007/JHEP06(2017)138
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Vector-like fermions charged under both the Standard Model and a new dark
gauge group arise in many theories of new physics. If these fermions include an
electroweak doublet and singlet with equal dark charges, they can potentially
connect to the Higgs field through a Yukawa coupling in analogy to the standard
neutrino portal. With such a coupling, fermion loops generate exotic decays of
the Higgs boson to one or more dark vector bosons. In this work we study a
minimal realization of this scenario with an Abelian dark group. We investigate
the potential new Higgs decays modes, we compute their rates, and we study the
prospects for observing them at the Large Hadron Collider and beyond given the
other experimental constraints on the theory. We also discuss extensions of the
theory to non-Abelian dark groups.
|
[
{
"created": "Wed, 24 May 2017 18:00:02 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Jun 2017 23:39:04 GMT",
"version": "v2"
}
] |
2017-08-02
|
[
[
"Lu",
"Qianshu",
""
],
[
"Morrissey",
"David E.",
""
],
[
"Wijangco",
"Alexander M.",
""
]
] |
Vector-like fermions charged under both the Standard Model and a new dark gauge group arise in many theories of new physics. If these fermions include an electroweak doublet and singlet with equal dark charges, they can potentially connect to the Higgs field through a Yukawa coupling in analogy to the standard neutrino portal. With such a coupling, fermion loops generate exotic decays of the Higgs boson to one or more dark vector bosons. In this work we study a minimal realization of this scenario with an Abelian dark group. We investigate the potential new Higgs decays modes, we compute their rates, and we study the prospects for observing them at the Large Hadron Collider and beyond given the other experimental constraints on the theory. We also discuss extensions of the theory to non-Abelian dark groups.
|
hep-ph/0611014
|
Donal O'Connell
|
Donal O'Connell, Michael J. Ramsey-Musolf and Mark B. Wise
|
Minimal Extension of the Standard Model Scalar Sector
|
4 pages, 2 figures
|
Phys.Rev.D75:037701,2007
|
10.1103/PhysRevD.75.037701
|
CALT-68-2614
|
hep-ph
| null |
The minimal extension of the scalar sector of the standard model contains an
additional real scalar field with no gauge quantum numbers. Such a field does
not couple to the quarks and leptons directly but rather through its mixing
with the standard model Higgs field. We examine the phenomenology of this model
focusing on the region of parameter space where the new scalar particle is
significantly lighter than the usual Higgs scalar and has small mixing with it.
In this region of parameter space most of the properties of the additional
scalar particle are independent of the details of the scalar potential.
Furthermore the properties of the scalar that is mostly the standard model
Higgs can be drastically modified since its dominant branching ratio may be to
a pair of the new lighter scalars.
|
[
{
"created": "Wed, 1 Nov 2006 21:16:57 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"O'Connell",
"Donal",
""
],
[
"Ramsey-Musolf",
"Michael J.",
""
],
[
"Wise",
"Mark B.",
""
]
] |
The minimal extension of the scalar sector of the standard model contains an additional real scalar field with no gauge quantum numbers. Such a field does not couple to the quarks and leptons directly but rather through its mixing with the standard model Higgs field. We examine the phenomenology of this model focusing on the region of parameter space where the new scalar particle is significantly lighter than the usual Higgs scalar and has small mixing with it. In this region of parameter space most of the properties of the additional scalar particle are independent of the details of the scalar potential. Furthermore the properties of the scalar that is mostly the standard model Higgs can be drastically modified since its dominant branching ratio may be to a pair of the new lighter scalars.
|
hep-ph/0703094
|
Fernando Marroquim Leao de Almeida jr
|
F. M. L. de Almeida Jr., Y. A. Coutinho, J. A. Martins Simoes, A. J.
Ramalho, S. Wulck and M. A. B. do Vale
|
Discriminating among the theoretical origins of new heavy Majorana
neutrinos at the CERN LHC
|
7 pages, 5 figures
|
Phys.Rev.D75:075002,2007
|
10.1103/PhysRevD.75.075002
| null |
hep-ph
| null |
A study on the possibility of distinguishing new heavy Majorana neutrino
models at LHC energies is presented. The experimental confirmation of standard
neutrinos with non-zero mass and the theoretical possibility of lepton number
violation find a natural explanation when new heavy Majorana neutrinos exist.
These new neutrinos appear in models with new right-handed singlets, in new
doublets of some grand unified theories and left-right symmetrical models. It
is expected that signals of new particles can be found at the CERN high-energy
hadron collider (LHC). We present signatures and distributions that can
indicate the theoretical origin of these new particles. The single and pair
production of heavy Majorana neutrinos are calculated and the model dependence
is discussed. Same-sign dileptons in the final state provide a clear signal for
the Majorana nature of heavy neutrinos, since there is lepton number violation.
Mass bounds on heavy Majorana neutrinos allowing model discrimination are
estimated for three different LHC luminosities.
|
[
{
"created": "Thu, 8 Mar 2007 18:04:16 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Almeida",
"F. M. L. de",
"Jr."
],
[
"Coutinho",
"Y. A.",
""
],
[
"Simoes",
"J. A. Martins",
""
],
[
"Ramalho",
"A. J.",
""
],
[
"Wulck",
"S.",
""
],
[
"Vale",
"M. A. B. do",
""
]
] |
A study on the possibility of distinguishing new heavy Majorana neutrino models at LHC energies is presented. The experimental confirmation of standard neutrinos with non-zero mass and the theoretical possibility of lepton number violation find a natural explanation when new heavy Majorana neutrinos exist. These new neutrinos appear in models with new right-handed singlets, in new doublets of some grand unified theories and left-right symmetrical models. It is expected that signals of new particles can be found at the CERN high-energy hadron collider (LHC). We present signatures and distributions that can indicate the theoretical origin of these new particles. The single and pair production of heavy Majorana neutrinos are calculated and the model dependence is discussed. Same-sign dileptons in the final state provide a clear signal for the Majorana nature of heavy neutrinos, since there is lepton number violation. Mass bounds on heavy Majorana neutrinos allowing model discrimination are estimated for three different LHC luminosities.
|
hep-ph/0302168
|
Scott Willenbrock
|
S. Willenbrock
|
Triplicated Trinification
|
8 pages, 1 figure. Minor improvements, references added
|
Phys.Lett. B561 (2003) 130-134
|
10.1016/S0370-2693(03)00419-2
| null |
hep-ph
| null |
Gauge-coupling unification is just as successful in the standard model with
six Higgs doublets as it is in the minimal supersymmetric standard model.
However, the gauge couplings unify at 10^14 GeV, which yields rapid proton
decay in the SU(5) model. I propose that the grand-unified gauge group is
instead SU(3)_c x SU(3)_L x SU(3)_R, in which baryon number is conserved by the
gauge interactions.
|
[
{
"created": "Wed, 19 Feb 2003 09:54:45 GMT",
"version": "v1"
},
{
"created": "Wed, 26 Mar 2003 01:09:52 GMT",
"version": "v2"
}
] |
2010-04-05
|
[
[
"Willenbrock",
"S.",
""
]
] |
Gauge-coupling unification is just as successful in the standard model with six Higgs doublets as it is in the minimal supersymmetric standard model. However, the gauge couplings unify at 10^14 GeV, which yields rapid proton decay in the SU(5) model. I propose that the grand-unified gauge group is instead SU(3)_c x SU(3)_L x SU(3)_R, in which baryon number is conserved by the gauge interactions.
|
1607.08133
|
Hiroki Matsui
|
Kazunori Kohri, Hiroki Matsui
|
Electroweak Vacuum Instability and Renormalized Higgs Field Vacuum
Fluctuations in the Inflationary Universe
|
29 pages, references added, version accepted for publication in JCAP
|
JCAP 08 (2017) 011
|
10.1088/1475-7516/2017/08/011
|
KEK-TH-1918, KEK-Cosmo-195
|
hep-ph astro-ph.CO gr-qc hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this work, we investigated the electroweak vacuum instability during or
after inflation. In the inflationary Universe, i.e., de Sitter space, the
vacuum field fluctuations $\left< {\delta \phi }^{ 2 } \right>$ enlarge in
proportion to the Hubble scale $H^{2}$. Therefore, the large inflationary
vacuum fluctuations of the Higgs field $\left< {\delta \phi }^{ 2 } \right>$
are potentially catastrophic to trigger the vacuum transition to the
negative-energy Planck-scale vacuum state and cause an immediate collapse of
the Universe. However, the vacuum field fluctuations $\left< {\delta \phi }^{ 2
} \right>$, i.e., the vacuum expectation values have an ultraviolet divergence,
and therefore a renormalization is necessary to estimate the physical effects
of the vacuum transition. Thus, in this paper, we revisit the electroweak
vacuum instability from the perspective of quantum field theory (QFT) in curved
space-time, and discuss the dynamical behavior of the homogeneous Higgs field
$\phi$ determined by the effective potential ${ V }_{\rm eff}\left( \phi
\right)$ in curved space-time and the renormalized vacuum fluctuations $\left<
{\delta \phi }^{ 2 } \right>_{\rm ren}$ via adiabatic regularization and
point-splitting regularization. We simply suppose that the Higgs field only
couples the gravity via the non-minimal Higgs-gravity coupling $\xi(\mu)$. In
this scenario, the electroweak vacuum stability is inevitably threatened by the
dynamical behavior of the homogeneous Higgs field $\phi$, or the formations of
AdS domains or bubbles unless the Hubble scale is small enough $H< \Lambda_{I}
$.
|
[
{
"created": "Wed, 27 Jul 2016 14:57:09 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Aug 2017 09:26:06 GMT",
"version": "v2"
}
] |
2017-08-09
|
[
[
"Kohri",
"Kazunori",
""
],
[
"Matsui",
"Hiroki",
""
]
] |
In this work, we investigated the electroweak vacuum instability during or after inflation. In the inflationary Universe, i.e., de Sitter space, the vacuum field fluctuations $\left< {\delta \phi }^{ 2 } \right>$ enlarge in proportion to the Hubble scale $H^{2}$. Therefore, the large inflationary vacuum fluctuations of the Higgs field $\left< {\delta \phi }^{ 2 } \right>$ are potentially catastrophic to trigger the vacuum transition to the negative-energy Planck-scale vacuum state and cause an immediate collapse of the Universe. However, the vacuum field fluctuations $\left< {\delta \phi }^{ 2 } \right>$, i.e., the vacuum expectation values have an ultraviolet divergence, and therefore a renormalization is necessary to estimate the physical effects of the vacuum transition. Thus, in this paper, we revisit the electroweak vacuum instability from the perspective of quantum field theory (QFT) in curved space-time, and discuss the dynamical behavior of the homogeneous Higgs field $\phi$ determined by the effective potential ${ V }_{\rm eff}\left( \phi \right)$ in curved space-time and the renormalized vacuum fluctuations $\left< {\delta \phi }^{ 2 } \right>_{\rm ren}$ via adiabatic regularization and point-splitting regularization. We simply suppose that the Higgs field only couples the gravity via the non-minimal Higgs-gravity coupling $\xi(\mu)$. In this scenario, the electroweak vacuum stability is inevitably threatened by the dynamical behavior of the homogeneous Higgs field $\phi$, or the formations of AdS domains or bubbles unless the Hubble scale is small enough $H< \Lambda_{I} $.
|
1912.00102
|
Adrian Thompson
|
Mohammad Abdullah, Mykhailo Dalchenko, Teruki Kamon, Denis Rathjens,
and Adrian Thompson
|
A heavy neutral gauge boson near the Z boson mass pole via third
generation fermions at the LHC
|
Accepted for publication in PLB
|
Physics Letters B, Volume 803, 10 April 2020, 135326
|
10.1016/j.physletb.2020.135326
|
MI-TH-1940
|
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
We explore the physics of a new neutral gauge boson, ($Z^\prime$), coupling
to only third-generation particles with a mass near the electroweak gauge boson
mass poles. A $Z^\prime$ boson produced by top quarks and decaying to tau
leptons is considered. With a simple search strategy inspired by existing
analyses of the standard model gauge boson production in association with top
quarks, we show that the Large Hadron Collider has good exclusionary power over
the model parameter space of the $Z^\prime$ boson even at the advent of the
high-luminosity era. It is shown that the $t\bar{t}Z^\prime$ process allows one
to place limits on right-handed top couplings with a $Z^\prime$ boson that
preferentially couples to third generation fermions, which are at present very
weakly constrained.
|
[
{
"created": "Sat, 30 Nov 2019 00:24:15 GMT",
"version": "v1"
},
{
"created": "Sun, 1 Mar 2020 08:02:28 GMT",
"version": "v2"
}
] |
2020-03-03
|
[
[
"Abdullah",
"Mohammad",
""
],
[
"Dalchenko",
"Mykhailo",
""
],
[
"Kamon",
"Teruki",
""
],
[
"Rathjens",
"Denis",
""
],
[
"Thompson",
"Adrian",
""
]
] |
We explore the physics of a new neutral gauge boson, ($Z^\prime$), coupling to only third-generation particles with a mass near the electroweak gauge boson mass poles. A $Z^\prime$ boson produced by top quarks and decaying to tau leptons is considered. With a simple search strategy inspired by existing analyses of the standard model gauge boson production in association with top quarks, we show that the Large Hadron Collider has good exclusionary power over the model parameter space of the $Z^\prime$ boson even at the advent of the high-luminosity era. It is shown that the $t\bar{t}Z^\prime$ process allows one to place limits on right-handed top couplings with a $Z^\prime$ boson that preferentially couples to third generation fermions, which are at present very weakly constrained.
|
hep-ph/0101202
|
E. Manfredini
|
E. Manfredini (Physics Department "G. Occhialini", University of
Milan-Bicocca)
|
Aspects of Non-Equilibrium Dynamics in Quantum Field Theory
|
Doctoral thesis. 170 pages, 47 figures. Some references and comments
added. Minor errors corrected. 1 figure added
| null | null |
Bicocca-FT-01-03
|
hep-ph
| null |
This work is devoted to the study of relaxation--dissipation processes in
systems described by Quantum Field Theory. In the first part, I focus on the
phi^4 scalar quantum field theory in finite volume in the large N limit. I find
that the zero-mode quantum fluctuations cannot grow macroscopically large
starting from microscopic initial conditions, while the long-wavelength
fluctuations do scale with the linear size of the system, signalling dynamical
infrared properties quite different from the equilibrium ones. I also introduce
a non-gaussian Hartree-Fock approximation (tdHF) and I derive the mean-field
coupled time-dependent Schroedinger equations for the modes of the scalar
field. The dynamical evolution of a uniform condensate is studied in a further
controlled gaussian approximation, for N=1. Results similar to the large N case
show an internal inconsistency of this approximation. I also study the dynamics
of the system in infinite volume in the broken symmetry phase. The data show
that the fixed points of the evolution cover at most the classically metastable
part of the static effective potential. I finally study the dynamical evolution
for the O(N+1) nonlinear sigma model in 1+1 dimensions in the large N limit. I
first of all verify that the large coupling limit of the O(N+1) phi^4 model,
which renders the model non linear, commutes with the large N limit, so that
the O(infty) nonlinear sigma model is uniquely defined. I then study the
evolution of several observables, like the spectrum of produced particles,
finding no evidence for parametric resonance. I conclude with some remarks on
the ``state of art'' in gauge theories and some comments about the open issues
in the subject.
|
[
{
"created": "Thu, 18 Jan 2001 15:07:03 GMT",
"version": "v1"
},
{
"created": "Wed, 21 Mar 2001 17:01:18 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Manfredini",
"E.",
"",
"Physics Department \"G. Occhialini\", University of\n Milan-Bicocca"
]
] |
This work is devoted to the study of relaxation--dissipation processes in systems described by Quantum Field Theory. In the first part, I focus on the phi^4 scalar quantum field theory in finite volume in the large N limit. I find that the zero-mode quantum fluctuations cannot grow macroscopically large starting from microscopic initial conditions, while the long-wavelength fluctuations do scale with the linear size of the system, signalling dynamical infrared properties quite different from the equilibrium ones. I also introduce a non-gaussian Hartree-Fock approximation (tdHF) and I derive the mean-field coupled time-dependent Schroedinger equations for the modes of the scalar field. The dynamical evolution of a uniform condensate is studied in a further controlled gaussian approximation, for N=1. Results similar to the large N case show an internal inconsistency of this approximation. I also study the dynamics of the system in infinite volume in the broken symmetry phase. The data show that the fixed points of the evolution cover at most the classically metastable part of the static effective potential. I finally study the dynamical evolution for the O(N+1) nonlinear sigma model in 1+1 dimensions in the large N limit. I first of all verify that the large coupling limit of the O(N+1) phi^4 model, which renders the model non linear, commutes with the large N limit, so that the O(infty) nonlinear sigma model is uniquely defined. I then study the evolution of several observables, like the spectrum of produced particles, finding no evidence for parametric resonance. I conclude with some remarks on the ``state of art'' in gauge theories and some comments about the open issues in the subject.
|
hep-ph/0610309
|
Egle Tomasi-Gustafsson
|
E. Tomasi-Gustafsson, G. I. Gakh, and A. P. Rekalo
|
From theory to experiment: hadron electromagnetic form factors in
space-like and time-like regions
|
10 pages, 2 figures, prepared for the QEDSP2006 conference, Kharkov,
Ukraine, September 19-23, 2006
| null | null | null |
hep-ph
| null |
Hadron electromagnetic form factors contain dynamical information on the
intrinsic structure of the hadrons. The pioneering work developed at the
Kharkov Physical-Technical Institute in the 60's on the relation between the
polarized cross section and form factors triggered a number of experiments.
Such experiments could be performed only recently, due to the progress in
accelerator and polarimetry techniques. The principle of these measurements is
recalled and the surprising and very precise results obtained on proton are
presented. The actual status of nucleon electromagnetic form factors is
reviewed, with special attention to the basic work done in Kharkov Institute.
|
[
{
"created": "Tue, 24 Oct 2006 10:43:05 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Tomasi-Gustafsson",
"E.",
""
],
[
"Gakh",
"G. I.",
""
],
[
"Rekalo",
"A. P.",
""
]
] |
Hadron electromagnetic form factors contain dynamical information on the intrinsic structure of the hadrons. The pioneering work developed at the Kharkov Physical-Technical Institute in the 60's on the relation between the polarized cross section and form factors triggered a number of experiments. Such experiments could be performed only recently, due to the progress in accelerator and polarimetry techniques. The principle of these measurements is recalled and the surprising and very precise results obtained on proton are presented. The actual status of nucleon electromagnetic form factors is reviewed, with special attention to the basic work done in Kharkov Institute.
|
2208.00882
|
Li-Sheng Geng
|
Tian-Wei Wu, Ya-Wen Pan, Ming-Zhu Liu, and Li-Sheng Geng
|
Multi-hadron molecules: status and prospect
|
5 pages, 2 figures, 1 table; to appear in Science Bulletin as a
Perspective article
| null | null | null |
hep-ph hep-ex hep-lat nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Starting from 2003, the discovery of a large amount of the so-called exotic
hadronic states, i.e., the $XYZ$ states, the pentaquark states as well as the
tetraquark states, have not only revived studies of hadron spectroscopy, but
also hinted at the existence of new multi-hadron states made of hadrons other
than nucleons and hyperons. We briefly comment on some of the latest studies on
multi-hadron molecules in the light and heavy flavor sectors and highlight what
should be done in the future.
|
[
{
"created": "Mon, 1 Aug 2022 14:18:15 GMT",
"version": "v1"
}
] |
2022-08-02
|
[
[
"Wu",
"Tian-Wei",
""
],
[
"Pan",
"Ya-Wen",
""
],
[
"Liu",
"Ming-Zhu",
""
],
[
"Geng",
"Li-Sheng",
""
]
] |
Starting from 2003, the discovery of a large amount of the so-called exotic hadronic states, i.e., the $XYZ$ states, the pentaquark states as well as the tetraquark states, have not only revived studies of hadron spectroscopy, but also hinted at the existence of new multi-hadron states made of hadrons other than nucleons and hyperons. We briefly comment on some of the latest studies on multi-hadron molecules in the light and heavy flavor sectors and highlight what should be done in the future.
|
1005.3260
|
Jimmy Hutasoit
|
Jun Wu, Jimmy A. Hutasoit, Daniel Boyanovsky and Richard Holman
|
Dynamics of disentanglement, density matrix and coherence in neutrino
oscillations
|
19 pages, v.2: discussions added
|
Phys.Rev.D82:013006,2010
|
10.1103/PhysRevD.82.013006
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In charged current weak interaction processes, neutrinos are produced in an
entangled state with the charged lepton. This correlated state is disentangled
by the measurement of the charged lepton in a detector at the production site.
We study the dynamical aspects of disentanglement, propagation and detection,
in particular the conditions under which the disentangled state is a coherent
superposition of mass eigenstates. The appearance and disappearance
far-detection processes are described from the time evolution of this
disentangled "collapsed" state. The familiar quantum mechanical interpretation
and factorization of the detection rate emerges when the quantum state is
disentangled on time scales \emph{much shorter} than the inverse oscillation
frequency, in which case the final detection rate factorizes in terms of the
usual quantum mechanical transition probability provided the final density of
states is insensitive to the neutrino energy difference. We suggest
\emph{possible} corrections for short-baseline experiments. If the charged
lepton is unobserved, neutrino oscillations and coherence are described in
terms of a reduced density matrix obtained by tracing out an un-observed
charged lepton. The diagonal elements in the mass basis describe the production
of mass eigenstates whereas the off diagonal ones provide a measure of
coherence. It is shown that coherences are of the same order of the diagonal
terms on time scales up to the inverse oscillation frequency, beyond which the
coherences oscillate as a result of the interference between mass eigenstates.
|
[
{
"created": "Tue, 18 May 2010 17:27:49 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Jul 2010 17:06:59 GMT",
"version": "v2"
}
] |
2014-11-21
|
[
[
"Wu",
"Jun",
""
],
[
"Hutasoit",
"Jimmy A.",
""
],
[
"Boyanovsky",
"Daniel",
""
],
[
"Holman",
"Richard",
""
]
] |
In charged current weak interaction processes, neutrinos are produced in an entangled state with the charged lepton. This correlated state is disentangled by the measurement of the charged lepton in a detector at the production site. We study the dynamical aspects of disentanglement, propagation and detection, in particular the conditions under which the disentangled state is a coherent superposition of mass eigenstates. The appearance and disappearance far-detection processes are described from the time evolution of this disentangled "collapsed" state. The familiar quantum mechanical interpretation and factorization of the detection rate emerges when the quantum state is disentangled on time scales \emph{much shorter} than the inverse oscillation frequency, in which case the final detection rate factorizes in terms of the usual quantum mechanical transition probability provided the final density of states is insensitive to the neutrino energy difference. We suggest \emph{possible} corrections for short-baseline experiments. If the charged lepton is unobserved, neutrino oscillations and coherence are described in terms of a reduced density matrix obtained by tracing out an un-observed charged lepton. The diagonal elements in the mass basis describe the production of mass eigenstates whereas the off diagonal ones provide a measure of coherence. It is shown that coherences are of the same order of the diagonal terms on time scales up to the inverse oscillation frequency, beyond which the coherences oscillate as a result of the interference between mass eigenstates.
|
hep-ph/0008151
|
Arcadi Santamaria
|
Joannis Papavassiliou and Arcadi Santamaria
|
Extra dimensions at the one loop level: Z -> b,b(bar) and B-B(bar)
mixing
|
14 pages, 3 figures, revtex
|
Phys.Rev. D63 (2001) 016002
|
10.1103/PhysRevD.63.016002
|
FTUV--00--0815, IFIC/00--48
|
hep-ph
| null |
We study, at the one loop level, the dominant new physics contributions from
extra dimensions to Z -> b,b(bar), as well as B-B(bar) and K-K(bar) mixing. We
use a model with one extra dimension containing fermions which live in four
dimensions, and gauge bosons and one scalar doublet propagating in five
dimensions. We find that the effect of the infinite tower of Kaluza-Klein modes
in Z-> b,b(bar) is finite and gives a negative correction to
R_b=Gamma_b/Gamma_h, which is used to set a lower bound of 1 TeV on the
compactification scale M_c. On the other hand, we show that the box diagrams
contributing to B-B(bar) and K-K(bar) mixing are divergent and, after proper
regularization, we find that they increase the value of the function S(x_t)
which governs this mixing. The obtained value is perfectly compatible with
available data.
|
[
{
"created": "Tue, 15 Aug 2000 12:38:13 GMT",
"version": "v1"
}
] |
2016-09-06
|
[
[
"Papavassiliou",
"Joannis",
""
],
[
"Santamaria",
"Arcadi",
""
]
] |
We study, at the one loop level, the dominant new physics contributions from extra dimensions to Z -> b,b(bar), as well as B-B(bar) and K-K(bar) mixing. We use a model with one extra dimension containing fermions which live in four dimensions, and gauge bosons and one scalar doublet propagating in five dimensions. We find that the effect of the infinite tower of Kaluza-Klein modes in Z-> b,b(bar) is finite and gives a negative correction to R_b=Gamma_b/Gamma_h, which is used to set a lower bound of 1 TeV on the compactification scale M_c. On the other hand, we show that the box diagrams contributing to B-B(bar) and K-K(bar) mixing are divergent and, after proper regularization, we find that they increase the value of the function S(x_t) which governs this mixing. The obtained value is perfectly compatible with available data.
|
hep-ph/9308345
| null |
R.H. Dalitz and Gary R. Goldstein
|
Where is Top?
|
LATEX 26pp., 13 figs available on request (GOLDSTEI@PEARL.TUFTS.EDU)
by mail, preprint OUTP-93-16P
|
Int.J.Mod.Phys.A9:635-666,1994
|
10.1142/S0217751X94000315
| null |
hep-ph
| null |
Possibilities are discussed for determining the top quark mass $m_t$ from
observations on the decay processes for top-antitop pairs produced in
antiproton-proton collisions, assuming that the $t \to bW^+$ decay channel is
dominant and much faster than hadronization. The final states $t \bar{t} \to
\bar{b} b \mu^\pm e^\mp$ provide the most striking signal, with little
background, but they are rare ($\approx 2/81$). If all candidate events prove
to be from $t \bar{t}$, an estimate follows for $P(m_t|rate)$, the probability
distribution for $m_t$. The one reported configuration allows an independent
estimate for $P(m_t|\mu^\pm e^\mp \,2jets)$. These two distributions are
compatible,yielding an estimate of about 122 GeV. Decay events ``1 energetic
lepton($l$) + 4jets'' should appear twelve times as often as ``$\mu^\pm e^\mp
\,2jets$'' events and can be analysed to give estimates for $P(m_t|l\, 4jets)$.
There may be background from non-top events but suitable cuts on the data and
our analysis procedure together reduce this to a low level. The rate observed
for these events does not appear to be as large as this factor 12.
Identification of either or both of the $(b \bar{b})$ jets would be a great
step forward. We advocate an energetic approach to the analysis of individual
events on an event by event basis, with the hope of finding a subgroup of
events with a common mass estimate.
|
[
{
"created": "Thu, 26 Aug 1993 20:03:08 GMT",
"version": "v1"
}
] |
2011-03-02
|
[
[
"Dalitz",
"R. H.",
""
],
[
"Goldstein",
"Gary R.",
""
]
] |
Possibilities are discussed for determining the top quark mass $m_t$ from observations on the decay processes for top-antitop pairs produced in antiproton-proton collisions, assuming that the $t \to bW^+$ decay channel is dominant and much faster than hadronization. The final states $t \bar{t} \to \bar{b} b \mu^\pm e^\mp$ provide the most striking signal, with little background, but they are rare ($\approx 2/81$). If all candidate events prove to be from $t \bar{t}$, an estimate follows for $P(m_t|rate)$, the probability distribution for $m_t$. The one reported configuration allows an independent estimate for $P(m_t|\mu^\pm e^\mp \,2jets)$. These two distributions are compatible,yielding an estimate of about 122 GeV. Decay events ``1 energetic lepton($l$) + 4jets'' should appear twelve times as often as ``$\mu^\pm e^\mp \,2jets$'' events and can be analysed to give estimates for $P(m_t|l\, 4jets)$. There may be background from non-top events but suitable cuts on the data and our analysis procedure together reduce this to a low level. The rate observed for these events does not appear to be as large as this factor 12. Identification of either or both of the $(b \bar{b})$ jets would be a great step forward. We advocate an energetic approach to the analysis of individual events on an event by event basis, with the hope of finding a subgroup of events with a common mass estimate.
|
0809.0191
|
Ekaterina Christova
|
Ekaterina Christova and Elliot Leader
|
Towards a model independent approach to fragmentation functions
|
10 pages and no figures, references added and there are some changes
in the text and the abstract
|
Phys.Rev.D79:014019,2009
|
10.1103/PhysRevD.79.014019
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We show that the difference cross sections in unpolarized SIDIS e+N\to e+h+X
and pp hadron production p+p\to h+X determine independently in a model
independent way, in any order in QCD, the two FFs: D_u^{h-\bar h} and
D_d^{h-\bar h}, h=\pi^\pm, K^\pm or a sum over charged hadrons. If both K^\pm
and K_s^0 are measured, then e+e-\toK+X, e+N\to e+K+X and p+p\to K+X present
independent measurements of just one FF: D_{u-d}^{K^++K^-}. The above results
allow to test the existing parametrizations, obtained with various different
assumptions about the FFs, and to test the $Q^2$ evolution and factorization.
|
[
{
"created": "Mon, 1 Sep 2008 09:10:11 GMT",
"version": "v1"
},
{
"created": "Mon, 10 Nov 2008 12:58:01 GMT",
"version": "v2"
}
] |
2009-02-26
|
[
[
"Christova",
"Ekaterina",
""
],
[
"Leader",
"Elliot",
""
]
] |
We show that the difference cross sections in unpolarized SIDIS e+N\to e+h+X and pp hadron production p+p\to h+X determine independently in a model independent way, in any order in QCD, the two FFs: D_u^{h-\bar h} and D_d^{h-\bar h}, h=\pi^\pm, K^\pm or a sum over charged hadrons. If both K^\pm and K_s^0 are measured, then e+e-\toK+X, e+N\to e+K+X and p+p\to K+X present independent measurements of just one FF: D_{u-d}^{K^++K^-}. The above results allow to test the existing parametrizations, obtained with various different assumptions about the FFs, and to test the $Q^2$ evolution and factorization.
|
hep-ph/9703386
| null |
N.S. Amaglobeli, S.M. Esakia, V.R. Garsevanishvili, G.O. Kuratashvili,
N.K. Kutsidi, R.A. Kvatadze, Yu V. Tevzadze, T.P. Topuria
|
Towards the Light Front Variables for High Energy Production Processes
|
Contact author : {V.R. Garsevanishvili} E-mail: garse@clrvax.in2p3.fr
(till May 5, 1997); garse@imath.acnet.ge (after May 5, 1997). LaTex file. 5
figures EPS format
|
Eur.Phys.J.C8:603-607,1999
|
10.1007/s100520050495
| null |
hep-ph
| null |
Scale invariant presentation of inclusive spectra in terms of light front
variables is proposed. The variables introduced go over to the well-known
scaling variables x_F = 2p_z/sqrt(s) and x_T=2p_T/sqrt{s} in the high p_z and
high p_T limits respectively. So Some surface is found in the phase space of
produced pi-mesons in the inclusive reaction anti p p -> pi+- X at 22.4 GeV/c,
which separates two groups of particles with significantly different
characteristics. In one of these regions a naive statistical model seems to be
in a good agreement with data, whereas it fails in the second region. Key
words: Light front, inclusive, hadron-hadron, electron-positron, relativistic
heavy ions, deep inelastic.
|
[
{
"created": "Fri, 21 Mar 1997 15:50:57 GMT",
"version": "v1"
}
] |
2011-09-13
|
[
[
"Amaglobeli",
"N. S.",
""
],
[
"Esakia",
"S. M.",
""
],
[
"Garsevanishvili",
"V. R.",
""
],
[
"Kuratashvili",
"G. O.",
""
],
[
"Kutsidi",
"N. K.",
""
],
[
"Kvatadze",
"R. A.",
""
],
[
"Tevzadze",
"Yu V.",
""
],
[
"Topuria",
"T. P.",
""
]
] |
Scale invariant presentation of inclusive spectra in terms of light front variables is proposed. The variables introduced go over to the well-known scaling variables x_F = 2p_z/sqrt(s) and x_T=2p_T/sqrt{s} in the high p_z and high p_T limits respectively. So Some surface is found in the phase space of produced pi-mesons in the inclusive reaction anti p p -> pi+- X at 22.4 GeV/c, which separates two groups of particles with significantly different characteristics. In one of these regions a naive statistical model seems to be in a good agreement with data, whereas it fails in the second region. Key words: Light front, inclusive, hadron-hadron, electron-positron, relativistic heavy ions, deep inelastic.
|
2212.11606
|
Camellia Bose
|
Biplob Bhattacherjee, Camellia Bose, Amit Chakraborty, Rhitaja
Sengupta
|
Boosted top tagging and its interpretation using Shapley values
|
27 pages, 14 figures, 8 tables
| null | null | null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
Top tagging has emerged to be a fast-evolving subject due to the top quark's
significant role in probing physics beyond the standard model. For the
reconstruction of top jets, machine learning models have shown a significant
improvement in the tagging and classification performance compared to the
previous methods. In this work, we build top taggers using $N$-Subjettiness
ratios and several observables of the Energy Correlation functions as input
features to train the eXtreme Gradient BOOSTed decision tree (XGBOOST). It is
observed that the performance of the taggers depends on how well the top jets
are matched to their truth-level partons. Furthermore, we use SHapley Additive
exPlanation (SHAP) framework to calculate the feature importance of the trained
models. It helps us to estimate how much each feature of the data contributed
to the model's prediction and what regions are of more importance for each
input variable. Finally, we combine all the tagger variables to form a hybrid
tagger and interpret the results using the Shapley values.
|
[
{
"created": "Thu, 22 Dec 2022 11:01:02 GMT",
"version": "v1"
}
] |
2022-12-23
|
[
[
"Bhattacherjee",
"Biplob",
""
],
[
"Bose",
"Camellia",
""
],
[
"Chakraborty",
"Amit",
""
],
[
"Sengupta",
"Rhitaja",
""
]
] |
Top tagging has emerged to be a fast-evolving subject due to the top quark's significant role in probing physics beyond the standard model. For the reconstruction of top jets, machine learning models have shown a significant improvement in the tagging and classification performance compared to the previous methods. In this work, we build top taggers using $N$-Subjettiness ratios and several observables of the Energy Correlation functions as input features to train the eXtreme Gradient BOOSTed decision tree (XGBOOST). It is observed that the performance of the taggers depends on how well the top jets are matched to their truth-level partons. Furthermore, we use SHapley Additive exPlanation (SHAP) framework to calculate the feature importance of the trained models. It helps us to estimate how much each feature of the data contributed to the model's prediction and what regions are of more importance for each input variable. Finally, we combine all the tagger variables to form a hybrid tagger and interpret the results using the Shapley values.
|
0905.2520
|
Maxim Chernodub
|
M.N. Chernodub, H. Verschelde and V.I. Zakharov
|
Magnetic component of gluon plasma and its viscosity
|
6 pages, no figures, RevTeX 4.0
|
Nucl.Phys.Proc.Suppl.207-208:325-328,2010
|
10.1016/j.nuclphysbps.2010.10.079
|
ITEP-LAT/2009-04
|
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the role of the magnetic degrees of freedom of the gluon plasma in
its viscosity. The main assumption is that motions of the magnetic component
and of the rest of the plasma can be considered as independent. The magnetic
component in the deconfined phase is described by a three-dimensional
(Euclidean) field theory. The parameters of the theory can be estimated
phenomenologically, from the lattice data. It is not ruled out that the
magnetic component is superfluid.
|
[
{
"created": "Fri, 15 May 2009 11:47:08 GMT",
"version": "v1"
}
] |
2011-02-11
|
[
[
"Chernodub",
"M. N.",
""
],
[
"Verschelde",
"H.",
""
],
[
"Zakharov",
"V. I.",
""
]
] |
We discuss the role of the magnetic degrees of freedom of the gluon plasma in its viscosity. The main assumption is that motions of the magnetic component and of the rest of the plasma can be considered as independent. The magnetic component in the deconfined phase is described by a three-dimensional (Euclidean) field theory. The parameters of the theory can be estimated phenomenologically, from the lattice data. It is not ruled out that the magnetic component is superfluid.
|
2109.13243
|
Benjamin Nachman
|
Miguel Arratia, Anja Butter, Mario Campanelli, Vincent Croft, Aishik
Ghosh, Dag Gillberg, Kristin Lohwasser, Bogdan Malaescu, Vinicius Mikuni,
Benjamin Nachman, Juan Rojo, Jesse Thaler, and Ramon Winterhalder
|
Presenting Unbinned Differential Cross Section Results
|
23 pages, 4 figures; v2: Added a missing reference; v3: Added
schematic diagram and extended several discussions
| null |
10.1088/1748-0221/17/01/P01024
|
CP3-21-54
|
hep-ph hep-ex physics.data-an
|
http://creativecommons.org/licenses/by/4.0/
|
Machine learning tools have empowered a qualitatively new way to perform
differential cross section measurements whereby the data are unbinned, possibly
in many dimensions. Unbinned measurements can enable, improve, or at least
simplify comparisons between experiments and with theoretical predictions.
Furthermore, many-dimensional measurements can be used to define observables
after the measurement instead of before. There is currently no community
standard for publishing unbinned data. While there are also essentially no
measurements of this type public, unbinned measurements are expected in the
near future given recent methodological advances. The purpose of this paper is
to propose a scheme for presenting and using unbinned results, which can
hopefully form the basis for a community standard to allow for integration into
analysis workflows. This is foreseen to be the start of an evolving community
dialogue, in order to accommodate future developments in this field that is
rapidly evolving.
|
[
{
"created": "Mon, 27 Sep 2021 18:00:00 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Oct 2021 15:00:41 GMT",
"version": "v2"
},
{
"created": "Thu, 18 Nov 2021 04:13:03 GMT",
"version": "v3"
}
] |
2022-02-02
|
[
[
"Arratia",
"Miguel",
""
],
[
"Butter",
"Anja",
""
],
[
"Campanelli",
"Mario",
""
],
[
"Croft",
"Vincent",
""
],
[
"Ghosh",
"Aishik",
""
],
[
"Gillberg",
"Dag",
""
],
[
"Lohwasser",
"Kristin",
""
],
[
"Malaescu",
"Bogdan",
""
],
[
"Mikuni",
"Vinicius",
""
],
[
"Nachman",
"Benjamin",
""
],
[
"Rojo",
"Juan",
""
],
[
"Thaler",
"Jesse",
""
],
[
"Winterhalder",
"Ramon",
""
]
] |
Machine learning tools have empowered a qualitatively new way to perform differential cross section measurements whereby the data are unbinned, possibly in many dimensions. Unbinned measurements can enable, improve, or at least simplify comparisons between experiments and with theoretical predictions. Furthermore, many-dimensional measurements can be used to define observables after the measurement instead of before. There is currently no community standard for publishing unbinned data. While there are also essentially no measurements of this type public, unbinned measurements are expected in the near future given recent methodological advances. The purpose of this paper is to propose a scheme for presenting and using unbinned results, which can hopefully form the basis for a community standard to allow for integration into analysis workflows. This is foreseen to be the start of an evolving community dialogue, in order to accommodate future developments in this field that is rapidly evolving.
|
hep-ph/9611429
|
Don Lichtenberg
|
D.B. Lichtenberg, R. Roncaglia, and E. Predazzi
|
Diquark model of dibaryons
|
4 pages, plaintex, no figures
| null | null |
IUHET--345, IU/NTC--96--11, DFTT 65/96
|
hep-ph
| null |
A diquark model previously formulated to describe exotic mesons is extended
to dibaryons. In the model, dibaryons containing only light quarks are unbound.
The $H$ dibaryon, consisting of $uuddss$ quarks, is unstable by about 90 MeV or
more, and should decay strongly into two $\Lambda$ baryons. A charmed dibaryon
$H_c$, composed of $uuddsc$, is unstable by about 60 MeV or more and should
decay strongly into $\Lambda + \Lambda_c$. On the other hand, we find that a
bottom dibaryon $H_b$, made of $uuddsb$, may be just bound by about 10 MeV with
respect to $\Lambda + \Lambda_b$. If so, it should decay weakly into various
final states with a charmed hadron. A possible two-body decay would be into
$\Lambda + \Lambda_c$.
|
[
{
"created": "Tue, 26 Nov 1996 14:19:08 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Lichtenberg",
"D. B.",
""
],
[
"Roncaglia",
"R.",
""
],
[
"Predazzi",
"E.",
""
]
] |
A diquark model previously formulated to describe exotic mesons is extended to dibaryons. In the model, dibaryons containing only light quarks are unbound. The $H$ dibaryon, consisting of $uuddss$ quarks, is unstable by about 90 MeV or more, and should decay strongly into two $\Lambda$ baryons. A charmed dibaryon $H_c$, composed of $uuddsc$, is unstable by about 60 MeV or more and should decay strongly into $\Lambda + \Lambda_c$. On the other hand, we find that a bottom dibaryon $H_b$, made of $uuddsb$, may be just bound by about 10 MeV with respect to $\Lambda + \Lambda_b$. If so, it should decay weakly into various final states with a charmed hadron. A possible two-body decay would be into $\Lambda + \Lambda_c$.
|
2111.07546
|
Luis Hernandez
|
Cesareo A. Dominguez and Luis A. Hern\'andez
|
Hadronic contribution to the running QED coupling at the Z-boson mass
scale
|
5 pages, 1 figure, discussion extended
| null | null | null |
hep-ph
|
http://creativecommons.org/publicdomain/zero/1.0/
|
An update is described of a model independent method to determine the
hadronic contribution to the QED running coupling at the Z-boson mass scale,
$\Delta\alpha_{\text{HAD}}(M_{Z}^{2})$. The major source of uncertainty is from
the contribution of the light quark vector current correlator at zero momentum.
This uncertainty is substantially reduced using recently improved lattice QCD
results for this correlator. The result is
$\Delta\alpha_{\text{HAD}}(M_{Z}^{2})=274.13 (0.73)\, \times 10^{-4}$.
|
[
{
"created": "Mon, 15 Nov 2021 05:41:04 GMT",
"version": "v1"
},
{
"created": "Wed, 9 Feb 2022 02:57:20 GMT",
"version": "v2"
},
{
"created": "Mon, 28 Mar 2022 16:08:18 GMT",
"version": "v3"
}
] |
2022-03-29
|
[
[
"Dominguez",
"Cesareo A.",
""
],
[
"Hernández",
"Luis A.",
""
]
] |
An update is described of a model independent method to determine the hadronic contribution to the QED running coupling at the Z-boson mass scale, $\Delta\alpha_{\text{HAD}}(M_{Z}^{2})$. The major source of uncertainty is from the contribution of the light quark vector current correlator at zero momentum. This uncertainty is substantially reduced using recently improved lattice QCD results for this correlator. The result is $\Delta\alpha_{\text{HAD}}(M_{Z}^{2})=274.13 (0.73)\, \times 10^{-4}$.
|
hep-ph/0602083
|
Sergio Palomares-Ruiz
|
Sergio Palomares-Ruiz (Vanderbilt U.)
|
Sterile neutrino decay and the LSND experiment
|
3pp. Talk given at 9th International Conference on Astroparticle and
Underground Physics (TAUP 2005), Zaragoza, Spain, 10-14 Sep 2005
|
J.Phys.Conf.Ser. 39 (2006) 307-309
|
10.1088/1742-6596/39/1/077
| null |
hep-ph
| null |
We propose a new explanation of the intriguing LSND evidence for electron
antineutrino appearance in terms of heavy (mostly sterile) neutrino decay via a
coupling with a light scalar and light (mostly active) neutrinos. We perform a
fit to the LSND data, as well as all relevant null-result experiments, taking
into account the distortion of the spectrum due to decay. By requiring a
coupling g ~ 10^{-5}, a heavy neutrino mass m_4 ~ 100 keV and a mixing with
muon neutrinos |U_{mu 4}|^2 ~ 10^{-2}, we show that this model explains all
existing data evading constraints that disfavor standard (3+1) neutrino models.
|
[
{
"created": "Thu, 9 Feb 2006 18:57:36 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Palomares-Ruiz",
"Sergio",
"",
"Vanderbilt U."
]
] |
We propose a new explanation of the intriguing LSND evidence for electron antineutrino appearance in terms of heavy (mostly sterile) neutrino decay via a coupling with a light scalar and light (mostly active) neutrinos. We perform a fit to the LSND data, as well as all relevant null-result experiments, taking into account the distortion of the spectrum due to decay. By requiring a coupling g ~ 10^{-5}, a heavy neutrino mass m_4 ~ 100 keV and a mixing with muon neutrinos |U_{mu 4}|^2 ~ 10^{-2}, we show that this model explains all existing data evading constraints that disfavor standard (3+1) neutrino models.
|
hep-ph/0209314
|
Andrei Ivanov
|
E. A. Choban, V. A. Ivanova
|
Registration of hydrogen-like leptonic bound states (e^- mu^+) and (e^+
mu^-) in reactions of high-energy scattering of polarized electrons and
positrons by nuclei with Z ~ 100 and analysis of CPT invariance
|
18 pages, Latex, 1 figure, Distortion of wave functions of incoming
and outcoming leptons caused by the strong Coulomb field of a nucleus and
contribution of a finite radius of a nucleus are estimated. Practical
realization of the experiment on the test of CPT invariance is discussed. The
paper is accepted for publication in EPJA
| null | null | null |
hep-ph
| null |
The cross sections for the reactions of muonium(anti-muonium) production in
high energy electron(positron) scattering by nuclei e^-(e^+) + Z -> Z +
M^0(anti-M^0) + mu^-(mu^+) are calculated in dependence on an energy and
polarization of an initial electron(positron) and a polarization of a final
mu^-(mu^+)-meson. Due to coherent phenomenon the cross sections are
proportional to Z^2. For Z ~ 100 due to the factor Z^2 the cross sections are
large enough to be measured at energies available at the HERA Collider in DESY.
The results are discussed in connection with a test of CPT invariance.
|
[
{
"created": "Thu, 26 Sep 2002 13:41:37 GMT",
"version": "v1"
},
{
"created": "Mon, 14 Apr 2003 17:02:20 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Choban",
"E. A.",
""
],
[
"Ivanova",
"V. A.",
""
]
] |
The cross sections for the reactions of muonium(anti-muonium) production in high energy electron(positron) scattering by nuclei e^-(e^+) + Z -> Z + M^0(anti-M^0) + mu^-(mu^+) are calculated in dependence on an energy and polarization of an initial electron(positron) and a polarization of a final mu^-(mu^+)-meson. Due to coherent phenomenon the cross sections are proportional to Z^2. For Z ~ 100 due to the factor Z^2 the cross sections are large enough to be measured at energies available at the HERA Collider in DESY. The results are discussed in connection with a test of CPT invariance.
|
2312.11652
|
Himanshu Raj
|
Himanshu Raj, Raju Venugopalan
|
Wee partons in QCD and gravity: double copy and universality
|
4 pages, Talk in "Proceedings of XXXth International Conference on
Ultra-relativistic Nucleus-Nucleus Collisions (Quark Matter 2023)"
| null | null | null |
hep-ph gr-qc hep-th nucl-th
|
http://creativecommons.org/licenses/by/4.0/
|
We discuss a quantitative "double copy" between radiation from shockwave
collisions in Einstein gravity and in QCD. The correspondence extends to
$2\rightarrow N$ amplitudes in Regge asymptotics. The classicalization and
unitarization of these amplitudes at maximal occupancy, corresponding to black
hole and Color Glass Condensate (CGC) states respectively, are described by the
emergent Goldstone dynamics of wee partons. We outline some consequences of the
universal dynamics on both sides of the correspondence.
|
[
{
"created": "Mon, 18 Dec 2023 19:08:17 GMT",
"version": "v1"
}
] |
2023-12-20
|
[
[
"Raj",
"Himanshu",
""
],
[
"Venugopalan",
"Raju",
""
]
] |
We discuss a quantitative "double copy" between radiation from shockwave collisions in Einstein gravity and in QCD. The correspondence extends to $2\rightarrow N$ amplitudes in Regge asymptotics. The classicalization and unitarization of these amplitudes at maximal occupancy, corresponding to black hole and Color Glass Condensate (CGC) states respectively, are described by the emergent Goldstone dynamics of wee partons. We outline some consequences of the universal dynamics on both sides of the correspondence.
|
hep-ph/0611188
|
Vladimir Kolesnikov
|
D. Bardin, L. Kalinovskaya, V. Kolesnikov, E. Uglov
|
Light-by-light scattering in SANC
|
11 pages, 1 figure, Talk presented at the International
School-Seminar CALC2006, Dubna, 15-25 July 2006
| null | null | null |
hep-ph
| null |
In this paper we describe the implementation of the QED process
$\gamma\gamma\to\gamma\gamma$ through a fermion loop into the framework of SANC
system. The computations of this process takes into account non-zero mass of
loop-fermion. We briefly describe additional precomputation modules used for
calculation of massive fermion-box diagrams. We present the covariant and
helicity amplitudes for this process and also some particular cases of $D_0$
and $C_0$ Passarino-Veltman functions. Whenever possible, we compare the
results with those existing in the literature.
|
[
{
"created": "Tue, 14 Nov 2006 14:22:47 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Bardin",
"D.",
""
],
[
"Kalinovskaya",
"L.",
""
],
[
"Kolesnikov",
"V.",
""
],
[
"Uglov",
"E.",
""
]
] |
In this paper we describe the implementation of the QED process $\gamma\gamma\to\gamma\gamma$ through a fermion loop into the framework of SANC system. The computations of this process takes into account non-zero mass of loop-fermion. We briefly describe additional precomputation modules used for calculation of massive fermion-box diagrams. We present the covariant and helicity amplitudes for this process and also some particular cases of $D_0$ and $C_0$ Passarino-Veltman functions. Whenever possible, we compare the results with those existing in the literature.
|
2310.02531
|
Hai-Xiang Chen
|
Hai-Xiang Chen, Sheng-Kai Cui, Ning-Yu Zhu, Zhao-Yang Zhang and
Huai-Cong Hu
|
B meson rare decays in the TNMSSM
| null | null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the two loop electroweak corrections to B meson rare decays
$\bar B\rightarrow X_s\gamma$ and $B_s^0\rightarrow \mu^+\mu^-$ in the minimal
supersymmetry standard model (MSSM) extension with two triplets and one singlet
(TNMSSM). The new particle contents and interactions in the TNMSSM can affect
the theoretical predictions of the branching ratios ${\rm Br}(\bar B\rightarrow
X_s\gamma)$ and ${\rm Br}(B_s^0\rightarrow \mu^+\mu^-)$, and the corrections
from two loop diagrams to the process $\bar B\rightarrow X_s\gamma$ can reach
around $4\%$. Considering the latest experimental measurements, the numerical
results of ${\rm Br}(\bar B\rightarrow X_s\gamma)$ and ${\rm
Br}(B_s^0\rightarrow \mu^+\mu^-)$ in the TNMSSM are presented and analyzed. It
is found that the results in the TNMSSM can fit the updated experimental data
well and the new parameters $T_{\lambda},\;\kappa,\;\lambda$ affect the
theoretical predictions of ${\rm Br}(\bar B\rightarrow X_s\gamma)$ and ${\rm
Br}(B_s^0\rightarrow \mu^+\mu^-)$ obviously.
|
[
{
"created": "Wed, 4 Oct 2023 02:16:53 GMT",
"version": "v1"
},
{
"created": "Sun, 19 Nov 2023 14:42:45 GMT",
"version": "v2"
}
] |
2023-11-21
|
[
[
"Chen",
"Hai-Xiang",
""
],
[
"Cui",
"Sheng-Kai",
""
],
[
"Zhu",
"Ning-Yu",
""
],
[
"Zhang",
"Zhao-Yang",
""
],
[
"Hu",
"Huai-Cong",
""
]
] |
We investigate the two loop electroweak corrections to B meson rare decays $\bar B\rightarrow X_s\gamma$ and $B_s^0\rightarrow \mu^+\mu^-$ in the minimal supersymmetry standard model (MSSM) extension with two triplets and one singlet (TNMSSM). The new particle contents and interactions in the TNMSSM can affect the theoretical predictions of the branching ratios ${\rm Br}(\bar B\rightarrow X_s\gamma)$ and ${\rm Br}(B_s^0\rightarrow \mu^+\mu^-)$, and the corrections from two loop diagrams to the process $\bar B\rightarrow X_s\gamma$ can reach around $4\%$. Considering the latest experimental measurements, the numerical results of ${\rm Br}(\bar B\rightarrow X_s\gamma)$ and ${\rm Br}(B_s^0\rightarrow \mu^+\mu^-)$ in the TNMSSM are presented and analyzed. It is found that the results in the TNMSSM can fit the updated experimental data well and the new parameters $T_{\lambda},\;\kappa,\;\lambda$ affect the theoretical predictions of ${\rm Br}(\bar B\rightarrow X_s\gamma)$ and ${\rm Br}(B_s^0\rightarrow \mu^+\mu^-)$ obviously.
|
hep-ph/9504226
|
Isamu Watanabe
|
Isamu Watanabe
|
"Intermediate Mass Higgs Study at $\gamma \gamma$ Colliders"
|
compressed and uuencoded PostScript file, 15 pages
| null | null |
OCHA-PP-58
|
hep-ph
| null |
We present the efficient technique to extract the signal of the intermediate
mass Higgs boson from the backgrounds at future $\gamma \gamma$ colliders. For
a clear Higgs detection, it is important to fit the original electron
accelerator energy depending on the Higgs mass, to set the polarization of the
photon beams and to apply the efficient $b$ quark tagging method. We
demonstrate the extraction of information of Higgs parameters and the new
physics from the observable physical quantities. It is clearly shown that a
future $\gamma \gamma$ collider will have a rich potential for study on the new
physics, as well as the Higgs physics.
|
[
{
"created": "Wed, 5 Apr 1995 10:35:52 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Watanabe",
"Isamu",
""
]
] |
We present the efficient technique to extract the signal of the intermediate mass Higgs boson from the backgrounds at future $\gamma \gamma$ colliders. For a clear Higgs detection, it is important to fit the original electron accelerator energy depending on the Higgs mass, to set the polarization of the photon beams and to apply the efficient $b$ quark tagging method. We demonstrate the extraction of information of Higgs parameters and the new physics from the observable physical quantities. It is clearly shown that a future $\gamma \gamma$ collider will have a rich potential for study on the new physics, as well as the Higgs physics.
|
hep-ph/9812469
|
Shi-Lin Zhu
|
Shi-Lin Zhu (Institue of Theoretical Physics, Academia Sinica,
Beijing)
|
Hybrid quarkonium masses up to the order of ${\cal O}(1/m_Q)$
|
4 pages + 2 tables + 2 PS figures
|
Phys.Rev.D60:031501,1999
|
10.1103/PhysRevD.60.031501
| null |
hep-ph hep-ex hep-lat
| null |
We have calculated the binding energy of the hybrid quarkonium up to the
order of ${\cal O}(1/m_Q)$ and found their decay constants scale like
$m_Q^{5/4}$ as $m_Q\to \infty$. The $0^{--}$ and $0^{++}$ hybrid quarkonium is
exactly degenerate in the limit of $m_Q\to\infty$ while the ${\cal O}(1/m_Q)$
correction renders the $0^{--}$ mass lower than that for $0^{++}$. The $1^{-+}$
and $1^{+-}$ hybrid is nearly degenerate and lies 0.7 GeV lower than $0^{--}$.
With $m_b=4.8$GeV the mass of $1^{-+}$ $b\bar b g$ state is $(10.75\pm 0.10)$,
which is the lightest exotic hybrid quarkonium.
|
[
{
"created": "Tue, 22 Dec 1998 00:37:49 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Apr 1999 00:31:07 GMT",
"version": "v2"
}
] |
2016-09-06
|
[
[
"Zhu",
"Shi-Lin",
"",
"Institue of Theoretical Physics, Academia Sinica,\n Beijing"
]
] |
We have calculated the binding energy of the hybrid quarkonium up to the order of ${\cal O}(1/m_Q)$ and found their decay constants scale like $m_Q^{5/4}$ as $m_Q\to \infty$. The $0^{--}$ and $0^{++}$ hybrid quarkonium is exactly degenerate in the limit of $m_Q\to\infty$ while the ${\cal O}(1/m_Q)$ correction renders the $0^{--}$ mass lower than that for $0^{++}$. The $1^{-+}$ and $1^{+-}$ hybrid is nearly degenerate and lies 0.7 GeV lower than $0^{--}$. With $m_b=4.8$GeV the mass of $1^{-+}$ $b\bar b g$ state is $(10.75\pm 0.10)$, which is the lightest exotic hybrid quarkonium.
|
hep-ph/0501061
|
Andrey Vinnikov
|
A.V. Vinnikov
|
Regge and factorized GPD models in $\rho^0$ elastic electroproduction
|
5 pages, 4 figures
| null | null | null |
hep-ph
| null |
A possibility to study Regge and factorized parameterizations of generalized
parton distributions in hard electroproduction of $\rho^0$ on the proton is
considered. For that the dependences of the differential cross sections on the
transferred momentum for these parameterizations are compared.
|
[
{
"created": "Sun, 9 Jan 2005 12:26:56 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Vinnikov",
"A. V.",
""
]
] |
A possibility to study Regge and factorized parameterizations of generalized parton distributions in hard electroproduction of $\rho^0$ on the proton is considered. For that the dependences of the differential cross sections on the transferred momentum for these parameterizations are compared.
|
1705.03599
|
Pilar Coloma
|
Pilar Coloma and Orlando L. G. Peres
|
Visible neutrino decay at DUNE
|
17 pages, 7 figures
| null | null | null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
If the heaviest neutrino mass eigenstate is unstable, its decay modes could
include lighter neutrino eigenstates. In this case part of the decay products
could be visible, as they would interact at neutrino detectors via mixing. At
neutrino oscillation experiments, a characteristic signature of such
\emph{visible neutrino decay} would be an apparent excess of events at low
energies. We focus on a simple phenomenological model in which the heaviest
neutrino decays as $\nu_3 \rightarrow \nu_{1,2} + \phi$, where $\phi$ is a new
light scalar. If neutrinos are Majorana particles the helicity-flipping decays
would be observable (i.e., $\nu \to \bar\nu + \phi$), leading to interesting
observable consequences on the event rates. We compute the sensitivities of the
Deep Underground Neutrino Experiment (DUNE) to the couplings of the new scalar
as a function of the lightest neutrino mass. Under the assumption that only the
heaviest neutrino is unstable, and for a normal mass ordering, we find that
DUNE will be sensitive to values of $\tau_3/m_3 > 1.95 - 2.6\times
10^{-10}$~s/eV (90\% C.L.) (depending on the lightest neutrino mass), where
$\tau_3$ and $m_3$ are the lifetime and mass of $\nu_3$, respectively.
|
[
{
"created": "Wed, 10 May 2017 03:39:54 GMT",
"version": "v1"
}
] |
2017-05-11
|
[
[
"Coloma",
"Pilar",
""
],
[
"Peres",
"Orlando L. G.",
""
]
] |
If the heaviest neutrino mass eigenstate is unstable, its decay modes could include lighter neutrino eigenstates. In this case part of the decay products could be visible, as they would interact at neutrino detectors via mixing. At neutrino oscillation experiments, a characteristic signature of such \emph{visible neutrino decay} would be an apparent excess of events at low energies. We focus on a simple phenomenological model in which the heaviest neutrino decays as $\nu_3 \rightarrow \nu_{1,2} + \phi$, where $\phi$ is a new light scalar. If neutrinos are Majorana particles the helicity-flipping decays would be observable (i.e., $\nu \to \bar\nu + \phi$), leading to interesting observable consequences on the event rates. We compute the sensitivities of the Deep Underground Neutrino Experiment (DUNE) to the couplings of the new scalar as a function of the lightest neutrino mass. Under the assumption that only the heaviest neutrino is unstable, and for a normal mass ordering, we find that DUNE will be sensitive to values of $\tau_3/m_3 > 1.95 - 2.6\times 10^{-10}$~s/eV (90\% C.L.) (depending on the lightest neutrino mass), where $\tau_3$ and $m_3$ are the lifetime and mass of $\nu_3$, respectively.
|
1902.03028
|
Lorenzo Bianchini
|
Lorenzo Bianchini and Gigi Rolandi
|
A critical point in the distribution of lepton energies from the decay
of a spin-1 resonance
|
Revised version, 24 pages, 7 figures
| null |
10.1007/JHEP05(2019)044
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider a spin-$1$ resonance produced with an arbitrary spectrum of
velocities and decaying into a pair of massless leptons, and we study the
probability density function of the energy of the leptons in the laboratory
frame. A special case is represented by the production of $W$ bosons in
proton-proton collisions, for which the energy of the charged lepton from the
decaying $W$ can be measured with sufficient accuracy for a high-precision
measurement of $M_W$. We find that half of the resonance mass is a special
value of the lepton energy, since the probability density function at this
point is in general not analytic for a narrow-width resonance. In particular,
the higher-order derivatives of the density function are likely to develop
singularities, such as cusps or poles. A finite width of the resonance restores
the regularity, for example by smearing cusps and poles into local stationary
points. The quest for such points offers a handle to estimate the resonance
mass with much reduced dependence on the underlying production and decay
dynamics of the resonance.
|
[
{
"created": "Fri, 8 Feb 2019 11:42:59 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Mar 2019 15:03:09 GMT",
"version": "v2"
},
{
"created": "Wed, 24 Apr 2019 14:56:37 GMT",
"version": "v3"
}
] |
2019-06-05
|
[
[
"Bianchini",
"Lorenzo",
""
],
[
"Rolandi",
"Gigi",
""
]
] |
We consider a spin-$1$ resonance produced with an arbitrary spectrum of velocities and decaying into a pair of massless leptons, and we study the probability density function of the energy of the leptons in the laboratory frame. A special case is represented by the production of $W$ bosons in proton-proton collisions, for which the energy of the charged lepton from the decaying $W$ can be measured with sufficient accuracy for a high-precision measurement of $M_W$. We find that half of the resonance mass is a special value of the lepton energy, since the probability density function at this point is in general not analytic for a narrow-width resonance. In particular, the higher-order derivatives of the density function are likely to develop singularities, such as cusps or poles. A finite width of the resonance restores the regularity, for example by smearing cusps and poles into local stationary points. The quest for such points offers a handle to estimate the resonance mass with much reduced dependence on the underlying production and decay dynamics of the resonance.
|
1111.4467
|
Tong Li
|
M. Adeel Ajaib, Tong Li, Qaisar Shafi
|
Stop-Neutralino Coannihilation in the Light of LHC
|
12 pages, 4 figures, 1 table
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We employ the ATLAS search results for events containing jets and large
missing transverse momentum, corresponding to an integrated luminosity of 1
fb^{-1}, to investigate the constrained minimal supersymmetric model (CMSSM)
with b-\tau Yukawa coupling unification. In this scenario, one of the stops is
the next-to-lightest supersymmetric particle (NLSP), which co-annihilates with
the lightest (LSP) neutralino to yield the desired dark matter relic abundance.
The NLSP stop, here taken to be lighter than the top quark, is slightly (<~
20%-30%) heavier than the LSP neutralino, and it primarily decays into the LSP
and a charm quark. We find that the multi-jets and monojet ATLAS searches are
sensitive to this scenario if the stop pair production is accompanied by a hard
QCD jet. The excluded limit for the NLSP stop mass from the ATLAS data can
reach 160 GeV in the coannihilation region, with mass below 140 GeV essentially
excluded. A significant region of the parameter space corresponding to large
m_0 values, 8 TeV<~ m_0<~ 16 TeV, is excluded by our analysis. For LSP
neutralino mass ~ 100 GeV, the LHC constraints in some cases on the
spin-dependent (spin-independent) neutralino-nucleon cross section are
significantly more stringent than the current and expected bounds from Xenon,
CDMS and IceCube.
|
[
{
"created": "Fri, 18 Nov 2011 20:16:07 GMT",
"version": "v1"
}
] |
2011-11-21
|
[
[
"Ajaib",
"M. Adeel",
""
],
[
"Li",
"Tong",
""
],
[
"Shafi",
"Qaisar",
""
]
] |
We employ the ATLAS search results for events containing jets and large missing transverse momentum, corresponding to an integrated luminosity of 1 fb^{-1}, to investigate the constrained minimal supersymmetric model (CMSSM) with b-\tau Yukawa coupling unification. In this scenario, one of the stops is the next-to-lightest supersymmetric particle (NLSP), which co-annihilates with the lightest (LSP) neutralino to yield the desired dark matter relic abundance. The NLSP stop, here taken to be lighter than the top quark, is slightly (<~ 20%-30%) heavier than the LSP neutralino, and it primarily decays into the LSP and a charm quark. We find that the multi-jets and monojet ATLAS searches are sensitive to this scenario if the stop pair production is accompanied by a hard QCD jet. The excluded limit for the NLSP stop mass from the ATLAS data can reach 160 GeV in the coannihilation region, with mass below 140 GeV essentially excluded. A significant region of the parameter space corresponding to large m_0 values, 8 TeV<~ m_0<~ 16 TeV, is excluded by our analysis. For LSP neutralino mass ~ 100 GeV, the LHC constraints in some cases on the spin-dependent (spin-independent) neutralino-nucleon cross section are significantly more stringent than the current and expected bounds from Xenon, CDMS and IceCube.
|
hep-ph/9806530
|
Gianluca Oderda
|
Gianluca Oderda (Stony Brook) and George Sterman (Stony Brook)
|
Energy and Color Flow in Dijet Rapidity Gaps
|
9 pages, LaTeX, 2 epsi figures
|
Phys.Rev.Lett.81:3591-3594,1998
|
10.1103/PhysRevLett.81.3591
|
ITP-SB-98-46
|
hep-ph
| null |
When rapidity gaps in high-$p_T$ dijet events are identified by energy flow
in the central region, they may be calculated from factorized cross sections in
perturbative QCD, up to corrections that behave as inverse powers of the
central region energy. Although power-suppressed corrections may be important,
a perturbative calculation of dijet rapidity gaps in ${\rm p}\bar{\rm p}$
scattering successfully reproduces the overall features observed at the
Tevatron. In this formulation, the average color content of the hard scattering
is well-defined. We find that hard dijet rapidity gaps in quark-antiquark
scattering are not due to singlet exchange alone.
|
[
{
"created": "Tue, 30 Jun 1998 15:42:55 GMT",
"version": "v1"
}
] |
2014-11-17
|
[
[
"Oderda",
"Gianluca",
"",
"Stony Brook"
],
[
"Sterman",
"George",
"",
"Stony Brook"
]
] |
When rapidity gaps in high-$p_T$ dijet events are identified by energy flow in the central region, they may be calculated from factorized cross sections in perturbative QCD, up to corrections that behave as inverse powers of the central region energy. Although power-suppressed corrections may be important, a perturbative calculation of dijet rapidity gaps in ${\rm p}\bar{\rm p}$ scattering successfully reproduces the overall features observed at the Tevatron. In this formulation, the average color content of the hard scattering is well-defined. We find that hard dijet rapidity gaps in quark-antiquark scattering are not due to singlet exchange alone.
|
1311.7356
|
Francois Arleo
|
Francois Arleo, Michel Fontannaz, Jean-Philippe Guillet, Chi Linh
Nguyen
|
Probing fragmentation functions from same-side hadron-jet momentum
correlations in p-p collisions
|
12 pages, 6 figures
| null |
10.1007/JHEP04(2014)147
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A next-to-leading order (NLO) analysis of hadron-jet momentum correlations in
p-p collisions at the LHC is carried out. We show that the inclusive charged
hadron momentum distributions inside jets is a very sensitive observable which
allows one to disentangle among various fragmentation function sets presently
available. Correlations with identified hadrons (kaons, protons) are
investigated as well.
|
[
{
"created": "Thu, 28 Nov 2013 16:24:34 GMT",
"version": "v1"
}
] |
2015-06-18
|
[
[
"Arleo",
"Francois",
""
],
[
"Fontannaz",
"Michel",
""
],
[
"Guillet",
"Jean-Philippe",
""
],
[
"Nguyen",
"Chi Linh",
""
]
] |
A next-to-leading order (NLO) analysis of hadron-jet momentum correlations in p-p collisions at the LHC is carried out. We show that the inclusive charged hadron momentum distributions inside jets is a very sensitive observable which allows one to disentangle among various fragmentation function sets presently available. Correlations with identified hadrons (kaons, protons) are investigated as well.
|
1710.10925
|
Patrick Kirchgae{\ss}er
|
Stefan Gieseke, Patrick Kirchgae{\ss}er, Frasher Loshaj
|
Soft and diffractive scattering
|
6 pages
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A model for soft and diffractive scattering is presented which is
incorporated seamlessly into the pre-existing MPI model in the Monte Carlo
Event Generator Herwig. With the improved model we are able to describe general
aspects of Minimum Bias and Underlying Event data.
|
[
{
"created": "Mon, 30 Oct 2017 13:17:58 GMT",
"version": "v1"
}
] |
2017-10-31
|
[
[
"Gieseke",
"Stefan",
""
],
[
"Kirchgaeßer",
"Patrick",
""
],
[
"Loshaj",
"Frasher",
""
]
] |
A model for soft and diffractive scattering is presented which is incorporated seamlessly into the pre-existing MPI model in the Monte Carlo Event Generator Herwig. With the improved model we are able to describe general aspects of Minimum Bias and Underlying Event data.
|
hep-ph/0404041
|
Kingman Cheung
|
Kingman Cheung (NTHU) and Wei-Shu Hou (NTU)
|
Collider Phenomenology of Light Strange-beauty Squarks
|
RevTex 4, 23 pages, 5 figures
|
Phys.Rev.D70:035009,2004
|
10.1103/PhysRevD.70.035009
| null |
hep-ph
| null |
Strong mixing between right-handed strange and beauty squarks is a possible
solution to the CP violation discrepancy in $B\to \phi K_S$ decay as recently
suggested by the Belle data. In this scenario, thanks to the strong mixing one
of the strange-beauty squarks can be as light as 200 GeV, even though the
generic supersymmetry scale is at TeV.
In this work, we study the production of this light right-handed
strange-beauty squark at hadronic colliders and discuss the detection in
various decay scenarios. Detection prospect at the Tevatron Run II is good for
the strange-beauty squark mass up to about 300 GeV.
|
[
{
"created": "Mon, 5 Apr 2004 15:31:29 GMT",
"version": "v1"
}
] |
2011-01-27
|
[
[
"Cheung",
"Kingman",
"",
"NTHU"
],
[
"Hou",
"Wei-Shu",
"",
"NTU"
]
] |
Strong mixing between right-handed strange and beauty squarks is a possible solution to the CP violation discrepancy in $B\to \phi K_S$ decay as recently suggested by the Belle data. In this scenario, thanks to the strong mixing one of the strange-beauty squarks can be as light as 200 GeV, even though the generic supersymmetry scale is at TeV. In this work, we study the production of this light right-handed strange-beauty squark at hadronic colliders and discuss the detection in various decay scenarios. Detection prospect at the Tevatron Run II is good for the strange-beauty squark mass up to about 300 GeV.
|
0905.2715
|
Honghui Wang
|
Bo Feng, Rijun Huang, Yin Jia, Mingxing Luo, Honghui Wang
|
Cross Section Evaluation by Spinor Integration I: The massless case in
4D
|
28 pages, 1 figure; further comments and references added; Appendix B
added
|
Phys.Rev.D81:016003,2010
|
10.1103/PhysRevD.81.016003
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
To get the total cross section of one interaction from its amplitude ${\cal
M}$, one needs to integrate $|{\cal M}|^2$ over phase spaces of all out-going
particles. Starting from this paper, we will propose a new method to perform
such integrations, which is inspired by the reduced phase space integration of
one-loop unitarity cut developed in the last few years. The new method reduces
one constrained three-dimension momentum space integration to an
one-dimensional integration, plus one possible Feynman parameter integration.
There is no need to specify a reference framework in our calculation, since
every step is manifestly Lorentz invariant by the new method. The current paper
is the first paper of a series for the new method. Here we have exclusively
focused on massless particles in 4D. There is no need to carve out a
complicated integration region in the phase space for this particular simple
case because the integration region is always simply $[0,1]$.
|
[
{
"created": "Sun, 17 May 2009 04:39:35 GMT",
"version": "v1"
},
{
"created": "Sun, 5 Jul 2009 13:01:46 GMT",
"version": "v2"
},
{
"created": "Sat, 31 Oct 2009 02:42:21 GMT",
"version": "v3"
}
] |
2010-04-06
|
[
[
"Feng",
"Bo",
""
],
[
"Huang",
"Rijun",
""
],
[
"Jia",
"Yin",
""
],
[
"Luo",
"Mingxing",
""
],
[
"Wang",
"Honghui",
""
]
] |
To get the total cross section of one interaction from its amplitude ${\cal M}$, one needs to integrate $|{\cal M}|^2$ over phase spaces of all out-going particles. Starting from this paper, we will propose a new method to perform such integrations, which is inspired by the reduced phase space integration of one-loop unitarity cut developed in the last few years. The new method reduces one constrained three-dimension momentum space integration to an one-dimensional integration, plus one possible Feynman parameter integration. There is no need to specify a reference framework in our calculation, since every step is manifestly Lorentz invariant by the new method. The current paper is the first paper of a series for the new method. Here we have exclusively focused on massless particles in 4D. There is no need to carve out a complicated integration region in the phase space for this particular simple case because the integration region is always simply $[0,1]$.
|
hep-ph/9803500
|
Michael Kachelriess
|
V. Berezinsky and M. Kachelriess
|
Limiting SUSY-QCD spectrum and its application for decays of superheavy
particles
|
8 pages, revtex, 3 ps figures. v2 minor changes, v3 typo in eq.(15)
corrected; version to appear in Phys. Lett. B
|
Phys.Lett.B434:61-66,1998
|
10.1016/S0370-2693(98)00728-X
| null |
hep-ph astro-ph
| null |
The supersymmetric generalization of the limiting and Gaussian QCD spectra is
obtained. These spectra are valid for $x \ll 1$, when the main contribution to
the parton cascade is given by gluons and gluinos. The derived spectra are
applied to decaying superheavy particles with masses up to the GUT scale. These
particles can be relics from the Big Bang or produced by topological defects
and could give rise to the observed ultrahigh energy cosmic rays. General
formulae for the fluxes of protons, photons and neutrinos due to decays of
superheavy particles are obtained.
|
[
{
"created": "Tue, 31 Mar 1998 18:21:02 GMT",
"version": "v1"
},
{
"created": "Tue, 9 Jun 1998 17:56:26 GMT",
"version": "v2"
},
{
"created": "Mon, 22 Jun 1998 19:41:31 GMT",
"version": "v3"
}
] |
2014-11-17
|
[
[
"Berezinsky",
"V.",
""
],
[
"Kachelriess",
"M.",
""
]
] |
The supersymmetric generalization of the limiting and Gaussian QCD spectra is obtained. These spectra are valid for $x \ll 1$, when the main contribution to the parton cascade is given by gluons and gluinos. The derived spectra are applied to decaying superheavy particles with masses up to the GUT scale. These particles can be relics from the Big Bang or produced by topological defects and could give rise to the observed ultrahigh energy cosmic rays. General formulae for the fluxes of protons, photons and neutrinos due to decays of superheavy particles are obtained.
|
hep-ph/0703003
|
Edmond Berger
|
Edmond L. Berger (Argonne), M. M. Block (Northwestern), and Chung-I
Tan (Brown)
|
Analytic Expression for the Joint x and Q^2 Dependences of the Structure
Functions of Deep Inelastic Scattering
|
4 pages, 3 figures, a few changes in the text. Version to be
published in Physical Review Letters
|
Phys.Rev.Lett.98:242001,2007
|
10.1103/PhysRevLett.98.242001
|
Argonne report ANL-HEP-PR-07-13
|
hep-ph hep-ex
| null |
We obtain a good analytic fit to the joint Bjorken-x and Q^2 dependences of
ZEUS data on the deep inelastic structure function F_2(x, Q^2). At fixed
virtuality Q^2, as we showed previously, our expression is an expansion in
powers of log (1/x) that satisfies the Froissart bound. Here we show that for
each x, the Q^2 dependence of the data is well described by an expansion in
powers of log Q^2. The resulting analytic expression allows us to predict the
logarithmic derivatives {({\partial}^n F_2^p/{{(\partial\ln Q^2}})^n)}_x for n
= 1,2 and to compare the results successfully with other data. We extrapolate
the proton structure function F_2^p(x,Q^2) to the very large Q^2 and the very
small x regions that are inaccessible to present day experiments and contrast
our expectations with those of conventional global fits of parton distribution
functions.
|
[
{
"created": "Wed, 28 Feb 2007 22:19:56 GMT",
"version": "v1"
},
{
"created": "Mon, 14 May 2007 16:38:42 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Berger",
"Edmond L.",
"",
"Argonne"
],
[
"Block",
"M. M.",
"",
"Northwestern"
],
[
"Tan",
"Chung-I",
"",
"Brown"
]
] |
We obtain a good analytic fit to the joint Bjorken-x and Q^2 dependences of ZEUS data on the deep inelastic structure function F_2(x, Q^2). At fixed virtuality Q^2, as we showed previously, our expression is an expansion in powers of log (1/x) that satisfies the Froissart bound. Here we show that for each x, the Q^2 dependence of the data is well described by an expansion in powers of log Q^2. The resulting analytic expression allows us to predict the logarithmic derivatives {({\partial}^n F_2^p/{{(\partial\ln Q^2}})^n)}_x for n = 1,2 and to compare the results successfully with other data. We extrapolate the proton structure function F_2^p(x,Q^2) to the very large Q^2 and the very small x regions that are inaccessible to present day experiments and contrast our expectations with those of conventional global fits of parton distribution functions.
|
1606.03453
|
Adam Kardos
|
Vittorio Del Duca, Claude Duhr, Adam Kardos, G\'abor Somogyi, Zolt\'an
Sz\H{o}r, Zolt\'an Tr\'ocs\'anyi and Zolt\'an Tulip\'ant
|
Jet production in the CoLoRFulNNLO method: event shapes in
electron-positron collisions
|
45 pages and 6 figures, note added
|
Phys. Rev. D 94, 074019 (2016)
|
10.1103/PhysRevD.94.074019
|
CERN-PH-TH-2016-138, CP3-16-29, NSF-KITP-16-084
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present the CoLoRFulNNLO method to compute higher order radiative
corrections to jet cross sections in perturbative QCD. We apply our method to
the computation of event shape observables in electron-positron collisions at
NNLO accuracy and validate our code by comparing our predictions to previous
results in the literature. We also calculate for the first time jet cone energy
fraction at NNLO.
|
[
{
"created": "Fri, 10 Jun 2016 20:00:01 GMT",
"version": "v1"
},
{
"created": "Fri, 17 Jun 2016 23:19:35 GMT",
"version": "v2"
}
] |
2016-10-19
|
[
[
"Del Duca",
"Vittorio",
""
],
[
"Duhr",
"Claude",
""
],
[
"Kardos",
"Adam",
""
],
[
"Somogyi",
"Gábor",
""
],
[
"Szőr",
"Zoltán",
""
],
[
"Trócsányi",
"Zoltán",
""
],
[
"Tulipánt",
"Zoltán",
""
]
] |
We present the CoLoRFulNNLO method to compute higher order radiative corrections to jet cross sections in perturbative QCD. We apply our method to the computation of event shape observables in electron-positron collisions at NNLO accuracy and validate our code by comparing our predictions to previous results in the literature. We also calculate for the first time jet cone energy fraction at NNLO.
|
1911.01445
|
Artem Lipatov
|
A.V. Kotikov, A.V. Lipatov, B.G. Shaikhatdenov, P. Zhang
|
Transverse momentum dependent parton densities in a proton from the
generalized DAS approach
|
24 pages, 9 figures
| null |
10.1007/JHEP02(2020)028
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We use the Bessel-inspired behavior of parton densities at small Bjorken $x$
values, obtained in the case of the flat initial conditions for DGLAP evolution
equations in the double scaling QCD approximation (DAS), to evaluate the
transverse momentum dependent (TMD, or unintegrated) quark and gluon
distribution functions in a proton. The calculations are performed analytically
using the Kimber-Martin-Ryskin (KMR) prescription with different implementation
of kinematical constraint, reflecting the angular and strong ordering
conditions. The relations between the differential and integral formulation of
the KMR approach is discussed. Several phenomenological applications of the
proposed TMD parton densities to the LHC processes are given.
|
[
{
"created": "Mon, 4 Nov 2019 19:00:21 GMT",
"version": "v1"
}
] |
2020-03-18
|
[
[
"Kotikov",
"A. V.",
""
],
[
"Lipatov",
"A. V.",
""
],
[
"Shaikhatdenov",
"B. G.",
""
],
[
"Zhang",
"P.",
""
]
] |
We use the Bessel-inspired behavior of parton densities at small Bjorken $x$ values, obtained in the case of the flat initial conditions for DGLAP evolution equations in the double scaling QCD approximation (DAS), to evaluate the transverse momentum dependent (TMD, or unintegrated) quark and gluon distribution functions in a proton. The calculations are performed analytically using the Kimber-Martin-Ryskin (KMR) prescription with different implementation of kinematical constraint, reflecting the angular and strong ordering conditions. The relations between the differential and integral formulation of the KMR approach is discussed. Several phenomenological applications of the proposed TMD parton densities to the LHC processes are given.
|
2211.06363
|
Michael Strickland
|
Huda Alalawi, Jacob Boyd, Chun Shen, and Michael Strickland
|
The impact of fluctuating initial conditions on bottomonium suppression
in 5.02 TeV heavy-ion collisions
|
7 pages, 3 figures; 2 page supplement with 3 figures
|
Phys. Rev. C 107, L031901 (2023)
|
10.1103/PhysRevC.107.L031901
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We compute bottomonium suppression and elliptic flow within the pNRQCD
effective field theory using an open quantum systems approach. For the
hydrodynamical background, we use 2+1D MUSIC second-order viscous hydrodynamics
with IP-Glasma initial conditions and evolve bottom/antibottom quantum wave
packets in real time in these backgrounds. We find that the impact of
fluctuating initial conditions is small when compared to results obtained using
smooth initial conditions. Including the effect of fluctuating initial
conditions, we find that the Upsilon(1S) integrated elliptic flow is v_2[1S] =
0.005 +/- 0.002 +/- 0.001, with the first and second variations corresponding
to statistical and systematic theoretical uncertainties, respectively.
|
[
{
"created": "Fri, 11 Nov 2022 17:27:22 GMT",
"version": "v1"
}
] |
2023-03-21
|
[
[
"Alalawi",
"Huda",
""
],
[
"Boyd",
"Jacob",
""
],
[
"Shen",
"Chun",
""
],
[
"Strickland",
"Michael",
""
]
] |
We compute bottomonium suppression and elliptic flow within the pNRQCD effective field theory using an open quantum systems approach. For the hydrodynamical background, we use 2+1D MUSIC second-order viscous hydrodynamics with IP-Glasma initial conditions and evolve bottom/antibottom quantum wave packets in real time in these backgrounds. We find that the impact of fluctuating initial conditions is small when compared to results obtained using smooth initial conditions. Including the effect of fluctuating initial conditions, we find that the Upsilon(1S) integrated elliptic flow is v_2[1S] = 0.005 +/- 0.002 +/- 0.001, with the first and second variations corresponding to statistical and systematic theoretical uncertainties, respectively.
|
hep-ph/0304176
|
Michele Maltoni
|
M. Maltoni, T. Schwetz
|
Testing the statistical compatibility of independent data sets
|
17 pages, LaTeX file using RevTEX4, 2 figures and 2 tables included.
Minor improvements to the text, one section added. Accepted for publication
in Phys.Rev.D
|
Phys.Rev. D68 (2003) 033020
|
10.1103/PhysRevD.68.033020
|
IFIC/03-13, TUM-HEP-506/03
|
hep-ph astro-ph hep-ex
| null |
We discuss a goodness-of-fit method which tests the compatibility between
statistically independent data sets. The method gives sensible results even in
cases where the chi^2-minima of the individual data sets are very low or when
several parameters are fitted to a large number of data points. In particular,
it avoids the problem that a possible disagreement between data sets becomes
diluted by data points which are insensitive to the crucial parameters. A
formal derivation of the probability distribution function for the proposed
test statistic is given, based on standard theorems of statistics. The
application of the method is illustrated on data from neutrino oscillation
experiments, and its complementarity to the standard goodness-of-fit is
discussed.
|
[
{
"created": "Thu, 17 Apr 2003 19:43:55 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Jul 2003 13:24:43 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Maltoni",
"M.",
""
],
[
"Schwetz",
"T.",
""
]
] |
We discuss a goodness-of-fit method which tests the compatibility between statistically independent data sets. The method gives sensible results even in cases where the chi^2-minima of the individual data sets are very low or when several parameters are fitted to a large number of data points. In particular, it avoids the problem that a possible disagreement between data sets becomes diluted by data points which are insensitive to the crucial parameters. A formal derivation of the probability distribution function for the proposed test statistic is given, based on standard theorems of statistics. The application of the method is illustrated on data from neutrino oscillation experiments, and its complementarity to the standard goodness-of-fit is discussed.
|
2403.20303
|
Lipika Kolay
|
Lipika Kolay, Soumitra Nandi
|
Exploring Constraints on Simplified Dark Matter Model Through Flavour
and Electroweak Observables
|
55 pages, 23 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
This study focuses on a combined analysis of various available inputs to
constrain the parameter spaces of a simplified dark matter (SDM) model
featuring a spin-0 mediator and fermionic dark matter (DM). The spin-0 mediator
interacts with standard model (SM) fermions, SM gauge bosons, and DM. We
constrain the parameter spaces of different relevant couplings, DM mass, and
the mediator mass, using the data from flavour-changing charged and neutral
current processes, CKM matrices, $W$ and $Z$-pole observables, DM relic
density, direct and indirect detection bounds. We have calculated bounds on the
couplings from both separate and simultaneous analyses of the mentioned
processes. We identify correlated parameter spaces for all the relevant
parameters which include the couplings and the masses. For the DM and mediator
masses, we have scanned the region between 100 GeV and 1000 GeV. Using our
results, we have obtained bounds on the couplings of possible higher
dimensional operators from which we can formulate our SDM.
|
[
{
"created": "Fri, 29 Mar 2024 17:19:25 GMT",
"version": "v1"
}
] |
2024-04-01
|
[
[
"Kolay",
"Lipika",
""
],
[
"Nandi",
"Soumitra",
""
]
] |
This study focuses on a combined analysis of various available inputs to constrain the parameter spaces of a simplified dark matter (SDM) model featuring a spin-0 mediator and fermionic dark matter (DM). The spin-0 mediator interacts with standard model (SM) fermions, SM gauge bosons, and DM. We constrain the parameter spaces of different relevant couplings, DM mass, and the mediator mass, using the data from flavour-changing charged and neutral current processes, CKM matrices, $W$ and $Z$-pole observables, DM relic density, direct and indirect detection bounds. We have calculated bounds on the couplings from both separate and simultaneous analyses of the mentioned processes. We identify correlated parameter spaces for all the relevant parameters which include the couplings and the masses. For the DM and mediator masses, we have scanned the region between 100 GeV and 1000 GeV. Using our results, we have obtained bounds on the couplings of possible higher dimensional operators from which we can formulate our SDM.
|
1809.06385
|
Pedro Machado
|
C. Boehm, D.G. Cerdeno, P.A.N. Machado, A. Olivares-Del Campo, E.
Perdomo, E. Reid
|
How high is the neutrino floor?
|
10 pages, 3 figures. Author added
| null |
10.1088/1475-7516/2019/01/043
|
IPPP/18/72; FERMILAB-PUB-18-486-T
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
In this paper, we compute the contribution to the coherent elastic
neutrino-nucleus scattering cross section from new physics models in the
neutrino sector. We use this information to calculate the maximum value of the
so-called neutrino floor for direct dark matter detection experiments, which
determines when these detectors are sensitive to the neutrino background. After
including all relevant experimental constraints in different simplified
neutrino models, we have found that the neutrino floor can increase by various
orders of magnitude in the region of dark matter masses below 10 GeV in the
case of scalar mediators, however, this spectacular enhancement is subject to
the re-examination of supernovae bounds. The increase is approximately a factor
of two for vector mediators. In the light of these results, future claims by
direct detection experiments exploring the low-mass window must be carefully
examined if a signal is found well above the expected Standard Model neutrino
floor.
|
[
{
"created": "Mon, 17 Sep 2018 18:00:24 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Oct 2018 14:57:39 GMT",
"version": "v2"
},
{
"created": "Fri, 18 Jan 2019 15:37:17 GMT",
"version": "v3"
},
{
"created": "Wed, 21 Aug 2019 20:59:15 GMT",
"version": "v4"
}
] |
2019-08-23
|
[
[
"Boehm",
"C.",
""
],
[
"Cerdeno",
"D. G.",
""
],
[
"Machado",
"P. A. N.",
""
],
[
"Campo",
"A. Olivares-Del",
""
],
[
"Perdomo",
"E.",
""
],
[
"Reid",
"E.",
""
]
] |
In this paper, we compute the contribution to the coherent elastic neutrino-nucleus scattering cross section from new physics models in the neutrino sector. We use this information to calculate the maximum value of the so-called neutrino floor for direct dark matter detection experiments, which determines when these detectors are sensitive to the neutrino background. After including all relevant experimental constraints in different simplified neutrino models, we have found that the neutrino floor can increase by various orders of magnitude in the region of dark matter masses below 10 GeV in the case of scalar mediators, however, this spectacular enhancement is subject to the re-examination of supernovae bounds. The increase is approximately a factor of two for vector mediators. In the light of these results, future claims by direct detection experiments exploring the low-mass window must be carefully examined if a signal is found well above the expected Standard Model neutrino floor.
|
1907.10298
|
Gennady Lykasov I
|
A.P.Jerusalimov, G.I.Lykasov
|
Dielectron production in pion-nucleon reactions and form factor of
baryon transition within the time-like region
|
12 pages, 10 figures
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Dielectron production in reactions $\pi^- p \rightarrow n e^+e^-$ and $\pi^-
p \rightarrow n e^+e^- \gamma$ at energies less than 1 GeV is studied assuming
electron-positron pair production to occur in the virtual time-like photon
splitting process. Theoretical predictions of the effective mass distribution
of dielectrons and their angular dependence are presented. Extraction of the
electromagnetic form factor of baryon transition in the time-like region from
future experiments of the HADES Collaboration is discussed.
|
[
{
"created": "Wed, 24 Jul 2019 08:36:03 GMT",
"version": "v1"
}
] |
2019-07-25
|
[
[
"Jerusalimov",
"A. P.",
""
],
[
"Lykasov",
"G. I.",
""
]
] |
Dielectron production in reactions $\pi^- p \rightarrow n e^+e^-$ and $\pi^- p \rightarrow n e^+e^- \gamma$ at energies less than 1 GeV is studied assuming electron-positron pair production to occur in the virtual time-like photon splitting process. Theoretical predictions of the effective mass distribution of dielectrons and their angular dependence are presented. Extraction of the electromagnetic form factor of baryon transition in the time-like region from future experiments of the HADES Collaboration is discussed.
|
hep-ph/0308201
|
Jonathan Feng
|
Jonathan L. Feng
|
SuperWIMPs in Supergravity
|
12 pages, 3 figures, invited talk presented at the International
Conference on 20 Years of SUGRA and the Search for SUSY and Unification
(SUGRA20), March 2003, Northeastern University, Boston, USA
| null | null |
UCI-TR-2003-40
|
hep-ph astro-ph hep-ex
| null |
In supergravity theories, a natural possibility is that neutralinos or
sleptons freeze out at their thermal relic density, but then decay to
gravitinos after about a year. The resulting gravitinos are then superWIMPs --
superweakly-interacting massive particles that naturally inherit the desired
relic density from late decays of conventional WIMPs. SuperWIMP dark matter
escapes all conventional searches. However, the late decays that produce
superWIMPs provide new and promising early universe signatures for cold dark
matter.
|
[
{
"created": "Tue, 19 Aug 2003 23:38:32 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Feng",
"Jonathan L.",
""
]
] |
In supergravity theories, a natural possibility is that neutralinos or sleptons freeze out at their thermal relic density, but then decay to gravitinos after about a year. The resulting gravitinos are then superWIMPs -- superweakly-interacting massive particles that naturally inherit the desired relic density from late decays of conventional WIMPs. SuperWIMP dark matter escapes all conventional searches. However, the late decays that produce superWIMPs provide new and promising early universe signatures for cold dark matter.
|
hep-ph/9705257
| null |
W. Cassing and E. L. Bratkovskaya (Giessen Univ.)
|
Production and absorption of $c \bar{c}$ pairs in nuclear collisions at
SPS energies
|
27 pages, LaTeX, including 13 postscript figures, to appear in Nucl.
Phys. A
|
Nucl.Phys. A623 (1997) 570-590
|
10.1016/S0375-9474(97)88426-6
|
UGI-97-06
|
hep-ph
| null |
We study the production of $c \bar{c}$ pairs and dimuons from hard collisions
in nuclear reactions within the covariant transport approach HSD, which
describes successfully both hadronic and electromagnetic observables from p+A
and A+A collisions from SIS to SPS energies. The production of $c \bar{c}$ and
Drell-Yan pairs is treated perturbatively employing experimental cross sections
while the interactions of $c\bar{c}$ pairs with hadrons are included by
conventional cascade-type two-body collisions. Adopting 6mb for the $c
\bar{c}$-baryon cross sections the data on $J/\Psi$ suppression in p+A
reactions are reproduced in line with calculations based on the Glauber model.
We study different models for $c \bar{c}$ dissociation on mesons in comparison
with the experimental data of the HELIOS-3, NA38 and NA50 collaborations.
Adopting absorption cross sections with mesons above the $D\bar{D}$ threshold
in the order of 1.5 - 3mb we find that all data on $J/\Psi$ suppression from
both proton-nucleus and nucleus-nucleus collisions can be described without
assuming the formation of a quark-gluon plasma in these collisions.
|
[
{
"created": "Wed, 7 May 1997 13:04:51 GMT",
"version": "v1"
},
{
"created": "Fri, 20 Jun 1997 19:13:09 GMT",
"version": "v2"
}
] |
2016-09-06
|
[
[
"Cassing",
"W.",
"",
"Giessen Univ."
],
[
"Bratkovskaya",
"E. L.",
"",
"Giessen Univ."
]
] |
We study the production of $c \bar{c}$ pairs and dimuons from hard collisions in nuclear reactions within the covariant transport approach HSD, which describes successfully both hadronic and electromagnetic observables from p+A and A+A collisions from SIS to SPS energies. The production of $c \bar{c}$ and Drell-Yan pairs is treated perturbatively employing experimental cross sections while the interactions of $c\bar{c}$ pairs with hadrons are included by conventional cascade-type two-body collisions. Adopting 6mb for the $c \bar{c}$-baryon cross sections the data on $J/\Psi$ suppression in p+A reactions are reproduced in line with calculations based on the Glauber model. We study different models for $c \bar{c}$ dissociation on mesons in comparison with the experimental data of the HELIOS-3, NA38 and NA50 collaborations. Adopting absorption cross sections with mesons above the $D\bar{D}$ threshold in the order of 1.5 - 3mb we find that all data on $J/\Psi$ suppression from both proton-nucleus and nucleus-nucleus collisions can be described without assuming the formation of a quark-gluon plasma in these collisions.
|
1611.10118
|
Gernot Eichmann
|
Gernot Eichmann
|
More about the light baryon spectrum
|
9 pages, 4 figures. Presented at Light Cone 2016, September 5-8 2015,
IST, Universidade de Lisboa, Lisbon, Portugal
| null |
10.1007/s00601-016-1200-3
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the light baryon spectrum obtained from a recent quark-diquark
calculation, implementing non-pointlike diquarks that are self-consistently
calculated from their Bethe-Salpeter equations. We examine the orbital angular
momentum content in the baryons' rest frame and highlight the fact that baryons
carry all possible values of L compatible with their spin, without the
restriction P=(-1)^L which is only valid nonrelativistically. We furthermore
investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter
equations, their possible connection with 'anomalous' states, and we propose a
method to eliminate them from the spectrum.
|
[
{
"created": "Wed, 30 Nov 2016 12:23:31 GMT",
"version": "v1"
}
] |
2017-03-08
|
[
[
"Eichmann",
"Gernot",
""
]
] |
We discuss the light baryon spectrum obtained from a recent quark-diquark calculation, implementing non-pointlike diquarks that are self-consistently calculated from their Bethe-Salpeter equations. We examine the orbital angular momentum content in the baryons' rest frame and highlight the fact that baryons carry all possible values of L compatible with their spin, without the restriction P=(-1)^L which is only valid nonrelativistically. We furthermore investigate the meaning of complex conjugate eigenvalues of Bethe-Salpeter equations, their possible connection with 'anomalous' states, and we propose a method to eliminate them from the spectrum.
|
1801.00585
|
Hiroshi Okada
|
Kingman Cheung, Hiroshi Okada
|
A generalized one-loop neutrino mass model with charged particles
|
24 pages, 8 figures, 1 table; version accepted for publication in
Physical Review D
|
Phys. Rev. D 97, 075027 (2018)
|
10.1103/PhysRevD.97.075027
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose a radiative neutrino-mass model by introducing 3 generations of
fermion pairs $E^{-(N+1)/2} E^{+(N+1)/2}$ and a couple of multi-charged bosonic
doublet fields $\Phi_{N/2}, \Phi_{N/2+1}$, where $N=1,3,5,7,9$. We show that
the models can satisfy the neutrino masses and oscillation data, and are
consistent with lepton-flavor violations, the muon anomalous magnetic moment,
the oblique parameters, and the beta function of the $U(1)_Y$ hypercharge gauge
coupling. We also discuss the collider signals for various $N$, namely,
multi-charged leptons in the final state from the Drell-Yan production of
$E^{-(N+1)/2} E^{+(N+1)/2}$. In general, the larger the $N$ the more charged
leptons will appear in the final state.
|
[
{
"created": "Tue, 2 Jan 2018 09:05:57 GMT",
"version": "v1"
},
{
"created": "Sat, 31 Mar 2018 13:20:55 GMT",
"version": "v2"
}
] |
2018-04-25
|
[
[
"Cheung",
"Kingman",
""
],
[
"Okada",
"Hiroshi",
""
]
] |
We propose a radiative neutrino-mass model by introducing 3 generations of fermion pairs $E^{-(N+1)/2} E^{+(N+1)/2}$ and a couple of multi-charged bosonic doublet fields $\Phi_{N/2}, \Phi_{N/2+1}$, where $N=1,3,5,7,9$. We show that the models can satisfy the neutrino masses and oscillation data, and are consistent with lepton-flavor violations, the muon anomalous magnetic moment, the oblique parameters, and the beta function of the $U(1)_Y$ hypercharge gauge coupling. We also discuss the collider signals for various $N$, namely, multi-charged leptons in the final state from the Drell-Yan production of $E^{-(N+1)/2} E^{+(N+1)/2}$. In general, the larger the $N$ the more charged leptons will appear in the final state.
|
hep-ph/9810304
|
Filkov
|
L.V. Fil'kov, V.L. Kashevarov (Lebedev Physical Institute, Moscow)
|
Compton Scattering on Pion and Pion Polarizabilities
|
4 pages including 4 figures, LaTex. Contributed paper to the 8th
International Conference on the Structure of Baryons, BARYONS'98, Bonn,
Germany, Sept. 22-26 1998, to appear in proceedings
| null | null | null |
hep-ph nucl-ex nucl-th
| null |
The Compton scattering on a charged pion is studied using the dispersion
relations. Unknown mass, full width and decay width into \gamma \gamma of the
sigma meson are found from a fit to the experimental data for the process
\gamma+\gamma \to \pi^0+\pi^0. These parameters are used for the calculation of
the cross section of the Compton scattering on the charged pion. The analysis
of the obtained results shows that the data on the elastic \gamma\pion
scattering in the energy region up to \sqrt{s}=1 GeV (together with the data on
process \gamma\gamma \to \pi^0\pi^0) could be used both for a determination of
the pion polarizability values with high precision and for research of the
sigma meson.
|
[
{
"created": "Fri, 9 Oct 1998 09:13:27 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Fil'kov",
"L. V.",
"",
"Lebedev Physical Institute, Moscow"
],
[
"Kashevarov",
"V. L.",
"",
"Lebedev Physical Institute, Moscow"
]
] |
The Compton scattering on a charged pion is studied using the dispersion relations. Unknown mass, full width and decay width into \gamma \gamma of the sigma meson are found from a fit to the experimental data for the process \gamma+\gamma \to \pi^0+\pi^0. These parameters are used for the calculation of the cross section of the Compton scattering on the charged pion. The analysis of the obtained results shows that the data on the elastic \gamma\pion scattering in the energy region up to \sqrt{s}=1 GeV (together with the data on process \gamma\gamma \to \pi^0\pi^0) could be used both for a determination of the pion polarizability values with high precision and for research of the sigma meson.
|
hep-ph/9912261
|
Stefan Dittmaier
|
A.Denner, S.Dittmaier, M.Roth and D.Wackeroth
|
O(alpha) corrections to e+e- --> WW --> 4fermions(+gamma): first
numerical results from RACOONWW
|
10 pages, latex, 10 postscript files
|
Phys.Lett.B475:127-134,2000
|
10.1016/S0370-2693(00)00059-9
|
BI-TP 99/45, LU-ITP 1999/020, PSI-PR-99-29, UR-1591
|
hep-ph
| null |
First numerical results of the Monte Carlo generator RACOONWW for e+e- --> WW
--> 4fermions(+gamma) in the electroweak Standard Model are presented. This
event generator is the first one that includes O(alpha) electroweak radiative
corrections in the double-pole approximation completely. We briefly describe
the strategy of the calculation and give numerical results for total cross
sections, including CC03, and various distributions.
|
[
{
"created": "Tue, 7 Dec 1999 16:26:15 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Denner",
"A.",
""
],
[
"Dittmaier",
"S.",
""
],
[
"Roth",
"M.",
""
],
[
"Wackeroth",
"D.",
""
]
] |
First numerical results of the Monte Carlo generator RACOONWW for e+e- --> WW --> 4fermions(+gamma) in the electroweak Standard Model are presented. This event generator is the first one that includes O(alpha) electroweak radiative corrections in the double-pole approximation completely. We briefly describe the strategy of the calculation and give numerical results for total cross sections, including CC03, and various distributions.
|
1307.5955
|
Paolo Panci
|
Eugenio Del Nobile, Marco Cirelli, Paolo Panci
|
Tools for model-independent bounds in direct dark matter searches
|
42+2 pages, many figures. v2: some comments and references added;
matches version published on JCAP. v3: Addendum to include LUX 2013 data. v4:
Addendum to include SuperCDMS 2014 data. v5: Fig.7 slightly corrected. All
results are available at http://www.marcocirelli.net/NRopsDD.html
|
JCAP 1310:019,2013
|
10.1088/1475-7516/2013/10/019
|
SACLAY-T13/022; CP3-Origins-2013-014 DNRF90; DIAS-2013-14
|
hep-ph astro-ph.CO hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss a framework (based on non-relativistic operators) and a
self-contained set of numerical tools to derive the bounds from some current
direct detection experiments on virtually any arbitrary model of Dark Matter
elastically scattering on nuclei.
|
[
{
"created": "Tue, 23 Jul 2013 06:15:31 GMT",
"version": "v1"
},
{
"created": "Mon, 7 Oct 2013 09:48:41 GMT",
"version": "v2"
},
{
"created": "Tue, 26 Nov 2013 19:39:35 GMT",
"version": "v3"
},
{
"created": "Thu, 3 Apr 2014 12:49:17 GMT",
"version": "v4"
},
{
"created": "Sun, 15 Nov 2015 19:59:04 GMT",
"version": "v5"
}
] |
2015-11-17
|
[
[
"Del Nobile",
"Eugenio",
""
],
[
"Cirelli",
"Marco",
""
],
[
"Panci",
"Paolo",
""
]
] |
We discuss a framework (based on non-relativistic operators) and a self-contained set of numerical tools to derive the bounds from some current direct detection experiments on virtually any arbitrary model of Dark Matter elastically scattering on nuclei.
|
hep-ph/0412325
|
Sergey Goloskokov
|
S.V. Goloskokov
|
Electroproduction of Vector Mesons at Small $x$
|
6pages, 3 figures, to appear in Proc of XVII International Baldin
Seminar, Dubna, September 27 - October 1, 2004. One reference is added
| null | null | null |
hep-ph
| null |
Vector meson electroproduction is analyzed within the two-gluon (2G) model
and the generalized parton distribution (GPD) approach at small $x$-Bjorken. We
demonstrate that 2G and GPD models are not completely equivalent. At the same
time, both models are in reasonable agreement with available experimental data
on light vector meson electroproduction.
|
[
{
"created": "Wed, 22 Dec 2004 00:50:41 GMT",
"version": "v1"
},
{
"created": "Thu, 27 Jan 2005 13:17:49 GMT",
"version": "v2"
}
] |
2007-05-23
|
[
[
"Goloskokov",
"S. V.",
""
]
] |
Vector meson electroproduction is analyzed within the two-gluon (2G) model and the generalized parton distribution (GPD) approach at small $x$-Bjorken. We demonstrate that 2G and GPD models are not completely equivalent. At the same time, both models are in reasonable agreement with available experimental data on light vector meson electroproduction.
|
hep-ph/0309264
|
Werner Vogelsang
|
Anna Kulesza, George Sterman, Werner Vogelsang
|
Joint Resummation for Higgs Production
|
22 pages, LaTeX, 5 figures as eps files
|
Phys.Rev.D69:014012,2004
|
10.1103/PhysRevD.69.014012
|
BNL-HET-03/20, BNL-NT-03/26, RBRC-335, YITP-SB-03-47
|
hep-ph
| null |
We study the application of the joint resummation formalism to Higgs
production via gluon-gluon fusion at the LHC, defining inverse transforms by
analytic continuation. We work at next-to-leading logarithmic accuracy. We find
that at low Q_T the resummed Higgs Q_T distributions are comparable in the
joint and pure-Q_T formalisms, with relatively small influence from threshold
enhancement in this range. We find a modest (about ten percent) decrease in the
inclusive cross section, relative to pure threshold resummation.
|
[
{
"created": "Tue, 23 Sep 2003 19:58:25 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Kulesza",
"Anna",
""
],
[
"Sterman",
"George",
""
],
[
"Vogelsang",
"Werner",
""
]
] |
We study the application of the joint resummation formalism to Higgs production via gluon-gluon fusion at the LHC, defining inverse transforms by analytic continuation. We work at next-to-leading logarithmic accuracy. We find that at low Q_T the resummed Higgs Q_T distributions are comparable in the joint and pure-Q_T formalisms, with relatively small influence from threshold enhancement in this range. We find a modest (about ten percent) decrease in the inclusive cross section, relative to pure threshold resummation.
|
1903.11753
|
Tetsutaro Higaki
|
Chandrasekhar Chatterjee, Tetsutaro Higaki, Muneto Nitta
|
Note on a solution to domain wall problem with the Lazarides-Shafi
mechanism in axion dark matter models
|
20 pages, 10 figures
|
Phys. Rev. D 101, 075026 (2020)
|
10.1103/PhysRevD.101.075026
| null |
hep-ph astro-ph.CO hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Axion is a promising candidate of dark matter. After the Peccei-Quinn
symmetry breaking, axion strings are formed and attached by domain walls when
the temperature of the universe becomes comparable to the QCD scale. Such
objects can cause cosmological disasters if they are long-lived. As a solution
for it, the Lazarides-Shafi mechanism is often discussed through introduction
of a new non-Abelian (gauge) symmetry. We study this mechanism in detail and
show configuration of strings and walls. Even if Abelian axion strings with a
domain wall number greater than one are formed in the early universe, each of
them is split into multiple Alice axion strings due to a repulsive force
between the Alice strings even without domain wall. When domain walls are
formed as the universe cools down, a single Alice string can be attached by a
single wall because a vacuum is connected by a non-Abelian rotation without
changing energy. Even if an Abelian axion string attached by domain walls are
created due to the Kibble Zurek mechanism at the chiral phase transition, such
strings are also similarly split into multiple Alice strings attached by walls
in the presence of the domain wall tension. Such walls do not form stable
networks since they collapse by the tension of the walls, emitting axions.
|
[
{
"created": "Thu, 28 Mar 2019 01:50:08 GMT",
"version": "v1"
}
] |
2020-04-22
|
[
[
"Chatterjee",
"Chandrasekhar",
""
],
[
"Higaki",
"Tetsutaro",
""
],
[
"Nitta",
"Muneto",
""
]
] |
Axion is a promising candidate of dark matter. After the Peccei-Quinn symmetry breaking, axion strings are formed and attached by domain walls when the temperature of the universe becomes comparable to the QCD scale. Such objects can cause cosmological disasters if they are long-lived. As a solution for it, the Lazarides-Shafi mechanism is often discussed through introduction of a new non-Abelian (gauge) symmetry. We study this mechanism in detail and show configuration of strings and walls. Even if Abelian axion strings with a domain wall number greater than one are formed in the early universe, each of them is split into multiple Alice axion strings due to a repulsive force between the Alice strings even without domain wall. When domain walls are formed as the universe cools down, a single Alice string can be attached by a single wall because a vacuum is connected by a non-Abelian rotation without changing energy. Even if an Abelian axion string attached by domain walls are created due to the Kibble Zurek mechanism at the chiral phase transition, such strings are also similarly split into multiple Alice strings attached by walls in the presence of the domain wall tension. Such walls do not form stable networks since they collapse by the tension of the walls, emitting axions.
|
hep-ph/9910305
|
Tomohiro Inagaki
|
Kenji Fukazawa, Tomohiro Inagaki, Seiji Mukaigawa and Taizo Muta
|
Structure of Chiral Phase Transitions at Finite Temperature in Abelian
Gauge Theories
|
15pages, uses epic.sty and eepic.sty
|
Prog.Theor.Phys. 105 (2001) 979-998
|
10.1143/PTP.105.979
|
HUPD-9916
|
hep-ph
| null |
The mechanism of the chiral symmetry breaking is investigated in the
strong-coupling Abelian gauge theories at finite temperature. The
Schwinger-Dyson equation in Landau gauge is employed in the real time formalism
and is solved numerically within the framework of the instantaneous exchange
approximation including the effect of the hard thermal loop for the photon
propagator. It is found that the chiral symmetry is broken below the critical
temperature T for sufficiently large coupling. The chiral phase transition is
found to be of the 2nd order and the phase diagram on the $T-\alpha$ plane is
obtained. It is investigated how the structure of the chiral phase transition
is affected by the hard thermal loops in the photon propagator.
|
[
{
"created": "Tue, 12 Oct 1999 06:17:45 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Fukazawa",
"Kenji",
""
],
[
"Inagaki",
"Tomohiro",
""
],
[
"Mukaigawa",
"Seiji",
""
],
[
"Muta",
"Taizo",
""
]
] |
The mechanism of the chiral symmetry breaking is investigated in the strong-coupling Abelian gauge theories at finite temperature. The Schwinger-Dyson equation in Landau gauge is employed in the real time formalism and is solved numerically within the framework of the instantaneous exchange approximation including the effect of the hard thermal loop for the photon propagator. It is found that the chiral symmetry is broken below the critical temperature T for sufficiently large coupling. The chiral phase transition is found to be of the 2nd order and the phase diagram on the $T-\alpha$ plane is obtained. It is investigated how the structure of the chiral phase transition is affected by the hard thermal loops in the photon propagator.
|
1112.2927
|
Kazem Azizi
|
K. Azizi, N. K. Pak, B. B. Sirvanli
|
Double-Lepton Polarization Asymmetries and Branching Ratio of the $B\rar
\gamma l^+ l^- $ transition in Universal Extra Dimension
|
20 Pages and 8 Figures
| null |
10.1007/JHEP02(2012)034
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the radiative dileptonic $B \rar \gamma l^+ l^- $ transition in the
presence of a universal extra dimension in the Applequist-Cheng-Dobrescu model.
In particular, using the corresponding form factors calculated via light cone
QCD sum rules, we analyze the branching ratio and double lepton polarization
asymmetries related to this channel and compare the results with the
predictions of the standard model. We show how the results deviate from
predictions of the standard model at lower values of the compactification
factor ($1/R $) of extra dimension.
|
[
{
"created": "Tue, 13 Dec 2011 15:53:56 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Jan 2012 14:22:35 GMT",
"version": "v2"
}
] |
2015-06-03
|
[
[
"Azizi",
"K.",
""
],
[
"Pak",
"N. K.",
""
],
[
"Sirvanli",
"B. B.",
""
]
] |
We study the radiative dileptonic $B \rar \gamma l^+ l^- $ transition in the presence of a universal extra dimension in the Applequist-Cheng-Dobrescu model. In particular, using the corresponding form factors calculated via light cone QCD sum rules, we analyze the branching ratio and double lepton polarization asymmetries related to this channel and compare the results with the predictions of the standard model. We show how the results deviate from predictions of the standard model at lower values of the compactification factor ($1/R $) of extra dimension.
|
hep-ph/9710377
|
Alexander S. Yelkhovsky
|
A. Yelkhovsky
|
Vacuum Polarization Contribution to Hydrogen and Positronium Energies
|
8 pages, revtex, no figures
| null | null |
BudkerINP-97-80
|
hep-ph
| null |
Relative order \alpha(Z\alpha)^3 shift of the energy levels induced by the
vacuum polarization is reexamined for a bound system of two particles with
masses m and M. Recent results for hydrogen and for positronium are shown to
contain an error due to the inadequate procedure of the infrared divergence
handling. Numerically, the correction to the ground state energy constitutes
0.647 kHz for hydrogen and 46.7 kHz for positronium.
|
[
{
"created": "Thu, 16 Oct 1997 09:35:31 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Yelkhovsky",
"A.",
""
]
] |
Relative order \alpha(Z\alpha)^3 shift of the energy levels induced by the vacuum polarization is reexamined for a bound system of two particles with masses m and M. Recent results for hydrogen and for positronium are shown to contain an error due to the inadequate procedure of the infrared divergence handling. Numerically, the correction to the ground state energy constitutes 0.647 kHz for hydrogen and 46.7 kHz for positronium.
|
1805.00020
|
Johann Brehmer Mr
|
Johann Brehmer, Kyle Cranmer, Gilles Louppe, and Juan Pavez
|
A Guide to Constraining Effective Field Theories with Machine Learning
|
See also the companion publication "Constraining Effective Field
Theories with Machine Learning" at arXiv:1805.00013, a brief introduction
presenting the key ideas. The code for these studies is available at
https://github.com/johannbrehmer/higgs_inference . v2: Added references. v3:
Improved description of algorithms, added references. v4: Clarified text,
added references
|
Phys. Rev. D 98, 052004 (2018)
|
10.1103/PhysRevD.98.052004
| null |
hep-ph physics.data-an stat.ML
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We develop, discuss, and compare several inference techniques to constrain
theory parameters in collider experiments. By harnessing the latent-space
structure of particle physics processes, we extract extra information from the
simulator. This augmented data can be used to train neural networks that
precisely estimate the likelihood ratio. The new methods scale well to many
observables and high-dimensional parameter spaces, do not require any
approximations of the parton shower and detector response, and can be evaluated
in microseconds. Using weak-boson-fusion Higgs production as an example
process, we compare the performance of several techniques. The best results are
found for likelihood ratio estimators trained with extra information about the
score, the gradient of the log likelihood function with respect to the theory
parameters. The score also provides sufficient statistics that contain all the
information needed for inference in the neighborhood of the Standard Model.
These methods enable us to put significantly stronger bounds on effective
dimension-six operators than the traditional approach based on histograms. They
also outperform generic machine learning methods that do not make use of the
particle physics structure, demonstrating their potential to substantially
improve the new physics reach of the LHC legacy results.
|
[
{
"created": "Mon, 30 Apr 2018 18:00:01 GMT",
"version": "v1"
},
{
"created": "Sat, 12 May 2018 18:31:44 GMT",
"version": "v2"
},
{
"created": "Fri, 1 Jun 2018 16:57:01 GMT",
"version": "v3"
},
{
"created": "Thu, 26 Jul 2018 19:03:59 GMT",
"version": "v4"
}
] |
2018-09-19
|
[
[
"Brehmer",
"Johann",
""
],
[
"Cranmer",
"Kyle",
""
],
[
"Louppe",
"Gilles",
""
],
[
"Pavez",
"Juan",
""
]
] |
We develop, discuss, and compare several inference techniques to constrain theory parameters in collider experiments. By harnessing the latent-space structure of particle physics processes, we extract extra information from the simulator. This augmented data can be used to train neural networks that precisely estimate the likelihood ratio. The new methods scale well to many observables and high-dimensional parameter spaces, do not require any approximations of the parton shower and detector response, and can be evaluated in microseconds. Using weak-boson-fusion Higgs production as an example process, we compare the performance of several techniques. The best results are found for likelihood ratio estimators trained with extra information about the score, the gradient of the log likelihood function with respect to the theory parameters. The score also provides sufficient statistics that contain all the information needed for inference in the neighborhood of the Standard Model. These methods enable us to put significantly stronger bounds on effective dimension-six operators than the traditional approach based on histograms. They also outperform generic machine learning methods that do not make use of the particle physics structure, demonstrating their potential to substantially improve the new physics reach of the LHC legacy results.
|
hep-ph/0507130
|
Yannis Burnier
|
Y. Burnier, M. Shaposhnikov
|
One-loop fermionic corrections to the instanton transition in two
dimensional chiral Higgs model
|
36 pages, 5 figures
|
Phys.Rev. D72 (2005) 065011
|
10.1103/PhysRevD.72.065011
| null |
hep-ph
| null |
The one-loop fermionic contribution to the probability of an instanton
transition with fermion number violation is calculated in the chiral Abelian
Higgs model in 1+1 dimensions, where the fermions have a Yukawa coupling to the
scalar field. The dependence of the determinant on fermionic, scalar and vector
mass is determined. We show in detail how to renormalize the fermionic
determinant in partial wave analysis, which is convenient for computations.
|
[
{
"created": "Mon, 11 Jul 2005 16:41:48 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Burnier",
"Y.",
""
],
[
"Shaposhnikov",
"M.",
""
]
] |
The one-loop fermionic contribution to the probability of an instanton transition with fermion number violation is calculated in the chiral Abelian Higgs model in 1+1 dimensions, where the fermions have a Yukawa coupling to the scalar field. The dependence of the determinant on fermionic, scalar and vector mass is determined. We show in detail how to renormalize the fermionic determinant in partial wave analysis, which is convenient for computations.
|
hep-ph/0506311
|
Nikolaos Stefanis
|
A. P. Bakulev, S. V. Mikhailov, N. G. Stefanis
|
QCD Analytic Perturbation Theory. From integer powers to any power of
the running coupling
|
23 pages, 6 figures (figure 4a corrected), Eq.(B13) corrected;
incorporates Erratum sent to PRD. See also hep-ph/0504275
|
Phys.Rev.D72:074014,2005; Erratum-ibid.D72:119908,2005
|
10.1103/PhysRevD.72.074014 10.1103/PhysRevD.72.119908
|
RUB-TPII-06/05, JINR-E2-2005-156
|
hep-ph hep-th
| null |
We propose a new generalized version of the QCD Analytic Perturbation Theory
of Shirkov and Solovtsov for the computation of higher-order corrections in
inclusive and exclusive processes. We construct non-power series expansions for
the analytic images of the running coupling and its powers for any fractional
(real) power and complete the linear space of these solutions by constructing
the index derivative. Using the Laplace transformation in conjunction with
dispersion relations, we are able to derive at the one-loop order closed-form
expressions for the analytic images in terms of the Lerch function. At the
two-loop order we provide approximate analytic images of products of powers of
the running coupling and logarithms--typical in higher-order perturbative
calculations and when including evolution effects. Moreover, we supply explicit
expressions for the two-loop analytic coupling and the analytic images of its
powers in terms of one-loop quantities that can strongly simplify two-loop
calculations. We also show how to resum powers of the running coupling while
maintaining analyticity, a procedure that captures the generic features of
Sudakov resummation. The algorithmic rules to obtain analytic coupling
expressions within the proposed Fractional Analytic Perturbation Theory from
the standard QCD power-series expansion are supplied ready for phenomenological
applications and numerical comparisons are given for illustration.
|
[
{
"created": "Wed, 29 Jun 2005 18:59:58 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Oct 2005 17:00:53 GMT",
"version": "v2"
},
{
"created": "Fri, 25 Nov 2005 08:46:42 GMT",
"version": "v3"
}
] |
2014-11-18
|
[
[
"Bakulev",
"A. P.",
""
],
[
"Mikhailov",
"S. V.",
""
],
[
"Stefanis",
"N. G.",
""
]
] |
We propose a new generalized version of the QCD Analytic Perturbation Theory of Shirkov and Solovtsov for the computation of higher-order corrections in inclusive and exclusive processes. We construct non-power series expansions for the analytic images of the running coupling and its powers for any fractional (real) power and complete the linear space of these solutions by constructing the index derivative. Using the Laplace transformation in conjunction with dispersion relations, we are able to derive at the one-loop order closed-form expressions for the analytic images in terms of the Lerch function. At the two-loop order we provide approximate analytic images of products of powers of the running coupling and logarithms--typical in higher-order perturbative calculations and when including evolution effects. Moreover, we supply explicit expressions for the two-loop analytic coupling and the analytic images of its powers in terms of one-loop quantities that can strongly simplify two-loop calculations. We also show how to resum powers of the running coupling while maintaining analyticity, a procedure that captures the generic features of Sudakov resummation. The algorithmic rules to obtain analytic coupling expressions within the proposed Fractional Analytic Perturbation Theory from the standard QCD power-series expansion are supplied ready for phenomenological applications and numerical comparisons are given for illustration.
|
hep-ph/0309246
|
Alessandro Bacchetta
|
Alessandro Bacchetta, Andreas Schaefer, Jian-Jun Yang (U. Regensburg)
|
Sivers function in a spectator model with axial-vector diquarks
|
8 pages, 7 figures, uses RevTex, added calculation of h1^perp, final
version accepted for publication in PLB
|
Phys.Lett. B578 (2004) 109-118
|
10.1016/j.physletb.2003.10.045
| null |
hep-ph
| null |
We perform a calculation of the Sivers function in a spectator model of the
nucleon, with scalar and axial-vector diquarks. We make use of gluon
rescattering to produce the nontrivial phases necessary to generate the Sivers
function. The inclusion of axial-vector diquarks enables us to obtain a nonzero
Sivers function for down quarks. Using the results of our model, we discuss the
phenomenology of transvere single spin asymmetries in pi+, pi-, and pi0
production, which are currently analysed by the HERMES and COMPASS
collaborations. We find that the inclusion of axial-vector diquarks
substantially reduces the asymmetries.
|
[
{
"created": "Mon, 22 Sep 2003 12:52:22 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Sep 2003 14:17:07 GMT",
"version": "v2"
},
{
"created": "Fri, 24 Oct 2003 10:50:22 GMT",
"version": "v3"
}
] |
2015-06-25
|
[
[
"Bacchetta",
"Alessandro",
"",
"U. Regensburg"
],
[
"Schaefer",
"Andreas",
"",
"U. Regensburg"
],
[
"Yang",
"Jian-Jun",
"",
"U. Regensburg"
]
] |
We perform a calculation of the Sivers function in a spectator model of the nucleon, with scalar and axial-vector diquarks. We make use of gluon rescattering to produce the nontrivial phases necessary to generate the Sivers function. The inclusion of axial-vector diquarks enables us to obtain a nonzero Sivers function for down quarks. Using the results of our model, we discuss the phenomenology of transvere single spin asymmetries in pi+, pi-, and pi0 production, which are currently analysed by the HERMES and COMPASS collaborations. We find that the inclusion of axial-vector diquarks substantially reduces the asymmetries.
|
hep-ph/0102203
|
Alexander Nesterenko
|
A. V. Nesterenko
|
Investigation of a new analytic running coupling in QCD
|
LaTeX 2.09, 12 pages with 4 EPS figures, uses mpla1.sty. Mod. Phys.
Lett. A (to be published)
|
Mod. Phys. Lett. A 15 (2000) p. 2401-2411
|
10.1142/S0217732300003030
| null |
hep-ph hep-th
| null |
The mathematical properties of the new analytic running coupling (NARC) in
QCD are investigated. This running coupling naturally arises under
``analytization'' of the renormalization group equation. One of the crucial
points in our consideration is the relation established between the NARC and
its inverse function. The latter is expressed in terms of the so-called Lambert
$W$ function. This relation enables one to present explicitly the NARC in the
renorminvariant form and to derive the corresponding $\beta$ function. The
asymptotic behavior of this $\beta$ function is examined. The consistent
estimation of the parameter $\Lambda_{QCD}$ is given.
|
[
{
"created": "Fri, 16 Feb 2001 08:13:12 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Nesterenko",
"A. V.",
""
]
] |
The mathematical properties of the new analytic running coupling (NARC) in QCD are investigated. This running coupling naturally arises under ``analytization'' of the renormalization group equation. One of the crucial points in our consideration is the relation established between the NARC and its inverse function. The latter is expressed in terms of the so-called Lambert $W$ function. This relation enables one to present explicitly the NARC in the renorminvariant form and to derive the corresponding $\beta$ function. The asymptotic behavior of this $\beta$ function is examined. The consistent estimation of the parameter $\Lambda_{QCD}$ is given.
|
hep-ph/9506217
|
My Account
|
X. Wang, J. Lopez, and D. Nanopoulos
|
$R_b$ in supersymmetric models
|
20 pages (LaTeX), 10 figures (included)
|
Phys.Rev. D52 (1995) 4116-4124
|
10.1103/PhysRevD.52.4116
|
CTP-TAMU-25/95
|
hep-ph
| null |
We compute the supersymmetric contribution to $R_{b}\equiv \Gamma (Z\to
b{\bar b})/\Gamma (Z\to {\rm hadrons})$ in a variety of supersymmetric models.
In the context of supergravity models with universal
soft-supersymmetry-breaking and radiative electroweak breaking we find $R^{\rm
susy}_b\lsim0.0004$, which does not shift significantly the Standard Model
prediction ($R^{\rm SM}_b=0.2157$ for $m_t=175\GeV$; $R^{\rm
exp}_b=0.2204\pm0.0020$). We also compute $R_b$ in the minimal supersymmetric
standard model (MSSM), and delineate the region of parameter space which yields
interestingly large values of $R_b$. This region entails light charginos and
top-squarks, but is {\em strongly} restricted by the {\em combined} constraints
from $B(b\to s\gamma)$ and a not-too-large invisible top-quark branching ratio:
only a few percent of the points with $R^{\rm susy}_b>0.0020\,(1\sigma)$ are
allowed.
|
[
{
"created": "Thu, 1 Jun 1995 21:37:09 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Wang",
"X.",
""
],
[
"Lopez",
"J.",
""
],
[
"Nanopoulos",
"D.",
""
]
] |
We compute the supersymmetric contribution to $R_{b}\equiv \Gamma (Z\to b{\bar b})/\Gamma (Z\to {\rm hadrons})$ in a variety of supersymmetric models. In the context of supergravity models with universal soft-supersymmetry-breaking and radiative electroweak breaking we find $R^{\rm susy}_b\lsim0.0004$, which does not shift significantly the Standard Model prediction ($R^{\rm SM}_b=0.2157$ for $m_t=175\GeV$; $R^{\rm exp}_b=0.2204\pm0.0020$). We also compute $R_b$ in the minimal supersymmetric standard model (MSSM), and delineate the region of parameter space which yields interestingly large values of $R_b$. This region entails light charginos and top-squarks, but is {\em strongly} restricted by the {\em combined} constraints from $B(b\to s\gamma)$ and a not-too-large invisible top-quark branching ratio: only a few percent of the points with $R^{\rm susy}_b>0.0020\,(1\sigma)$ are allowed.
|
1010.5909
|
Liam Keegan
|
Simon Catterall, Luigi Del Debbio, Joel Giedt, Liam Keegan
|
MCRG Minimal Walking Technicolor
|
7 pages, 5 figures. Talk given at the XXVIII International Symposium
on Lattice Field Theory (Lattice 2010), June 14-19,2010, Villasimius,
Sardinia, Italy
|
PoS Lattice2010:057,2010
| null | null |
hep-ph hep-lat
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a Monte Carlo renormalisation group study of the SU(2) gauge
theory with two Dirac fermions in the adjoint representation. Using the two
lattice matching technique recently advocated and exploited in
[arXiv:0907.0919], we measure the running of the coupling and the anomalous
mass dimension.
|
[
{
"created": "Thu, 28 Oct 2010 10:01:23 GMT",
"version": "v1"
}
] |
2011-03-18
|
[
[
"Catterall",
"Simon",
""
],
[
"Del Debbio",
"Luigi",
""
],
[
"Giedt",
"Joel",
""
],
[
"Keegan",
"Liam",
""
]
] |
We present a Monte Carlo renormalisation group study of the SU(2) gauge theory with two Dirac fermions in the adjoint representation. Using the two lattice matching technique recently advocated and exploited in [arXiv:0907.0919], we measure the running of the coupling and the anomalous mass dimension.
|
0801.3355
|
Robert Harlander
|
Robert Harlander, Jens Vollinga, Marcus Weber
|
Gluon-Induced Weak Boson Fusion
|
9 pages, 8 figures (21 included ps- and eps-files)
|
Phys.Rev.D77:053010,2008
|
10.1103/PhysRevD.77.053010
|
NIKHEF/2007-025, WUB/07-12
|
hep-ph
| null |
The gluon-gluon induced terms for Higgs production through weak boson fusion
(WBF) are computed. Formally, these are of NNLO in the strong coupling
constant. This is the lowest order at which non-zero color exchange occurs
between the scattering quarks, leading to a color field and thus additional
hadronic activity between the outgoing jets. Using a minimal set of cuts, the
numerical impact of these terms is at the percent level with respect to the NLO
rate for weak boson fusion. Applying the so-called WBF cuts leads to an even
stronger suppression, so that we do not expect a significant deterioration of
the WFB signal by these color exchange effects.
|
[
{
"created": "Tue, 22 Jan 2008 12:46:39 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Harlander",
"Robert",
""
],
[
"Vollinga",
"Jens",
""
],
[
"Weber",
"Marcus",
""
]
] |
The gluon-gluon induced terms for Higgs production through weak boson fusion (WBF) are computed. Formally, these are of NNLO in the strong coupling constant. This is the lowest order at which non-zero color exchange occurs between the scattering quarks, leading to a color field and thus additional hadronic activity between the outgoing jets. Using a minimal set of cuts, the numerical impact of these terms is at the percent level with respect to the NLO rate for weak boson fusion. Applying the so-called WBF cuts leads to an even stronger suppression, so that we do not expect a significant deterioration of the WFB signal by these color exchange effects.
|
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