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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
hep-ph/9406380
|
Kurt Langfeld
|
K. Langfeld, H. Reinhardt
|
Scale Anomaly Induced Instanton Interaction
|
11 LaTex pages (3 figures available on request), in press by Physics
Letters B, UNITUE-THEP-4-1994
|
Phys.Lett. B333 (1994) 396-402
|
10.1016/0370-2693(94)90159-7
| null |
hep-ph
| null |
The binary interaction of large size instantons in a SU(2) Yang-Mills theory
is obtained from the one-loop effective action for the field strength. The
instanton interaction is calculated as a function of the instanton separation
and in dependence on radius and relative orientation of the instantons. Two
equally oriented instantons with radii large compared with the scale defined by
the gluon condensate have purely attractive interaction, whereas the
interaction of maximal disoriented instantons is repulsive. We argue that the
medium range attractive interaction of the instantons generally holds and is
solely due to the instability of the perturbative vacuum.
|
[
{
"created": "Thu, 23 Jun 1994 15:01:09 GMT",
"version": "v1"
}
] |
2009-10-28
|
[
[
"Langfeld",
"K.",
""
],
[
"Reinhardt",
"H.",
""
]
] |
The binary interaction of large size instantons in a SU(2) Yang-Mills theory is obtained from the one-loop effective action for the field strength. The instanton interaction is calculated as a function of the instanton separation and in dependence on radius and relative orientation of the instantons. Two equally oriented instantons with radii large compared with the scale defined by the gluon condensate have purely attractive interaction, whereas the interaction of maximal disoriented instantons is repulsive. We argue that the medium range attractive interaction of the instantons generally holds and is solely due to the instability of the perturbative vacuum.
|
2112.12051
|
P. S. Bhupal Dev
|
Ingolf Bischer, P. S. Bhupal Dev, Werner Rodejohann, Xun-Jie Xu,
Yongchao Zhang
|
Searching for new physics from SMEFT and leptoquarks at the P2
experiment
|
16 pages, 3 figures, 5 tables; published version
|
Phys. Rev. D 105, 095016 (2022)
|
10.1103/PhysRevD.105.095016
| null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
The P2 experiment aims at high-precision measurements of the parity-violating
asymmetry in elastic electron-proton and electron-$^{12}$C scatterings with
longitudinally polarized electrons. We discuss here the sensitivity of P2 to
leptoquarks, which within the P2 energy range can be described in the language
of Standard Model Effective Field Theory (SMEFT). We give the expected P2
limits on the SMEFT operators and on the leptoquark parameters, which will test
energy scales up to 15 TeV. In many cases those limits exceed current
constraints from LHC and atomic parity violation (APV) experiments. We also
demonstrate that degeneracies of different SMEFT operators can partially be
resolved by use of APV experiments and different targets (protons and $^{12}$C)
at P2. Moreover, we show that P2 could confirm or resolve potential tensions
between the theoretical and experimental determinations of the weak charge of
$^{133}$Cs.
|
[
{
"created": "Wed, 22 Dec 2021 17:21:44 GMT",
"version": "v1"
},
{
"created": "Fri, 20 May 2022 16:14:45 GMT",
"version": "v2"
}
] |
2022-05-23
|
[
[
"Bischer",
"Ingolf",
""
],
[
"Dev",
"P. S. Bhupal",
""
],
[
"Rodejohann",
"Werner",
""
],
[
"Xu",
"Xun-Jie",
""
],
[
"Zhang",
"Yongchao",
""
]
] |
The P2 experiment aims at high-precision measurements of the parity-violating asymmetry in elastic electron-proton and electron-$^{12}$C scatterings with longitudinally polarized electrons. We discuss here the sensitivity of P2 to leptoquarks, which within the P2 energy range can be described in the language of Standard Model Effective Field Theory (SMEFT). We give the expected P2 limits on the SMEFT operators and on the leptoquark parameters, which will test energy scales up to 15 TeV. In many cases those limits exceed current constraints from LHC and atomic parity violation (APV) experiments. We also demonstrate that degeneracies of different SMEFT operators can partially be resolved by use of APV experiments and different targets (protons and $^{12}$C) at P2. Moreover, we show that P2 could confirm or resolve potential tensions between the theoretical and experimental determinations of the weak charge of $^{133}$Cs.
|
1907.04665
|
Ernest Ma
|
Ernest Ma (UC Riverside)
|
Two-Loop $Z_4$ Dirac Neutrino Masses and Mixing, with Self-Interacting
Dark Matter
|
15 pages, 2 figures. arXiv admin note: substantial text overlap with
arXiv:1905.01535
| null |
10.1016/j.nuclphysb.2019.114725
|
UCRHEP-T599 (July 2019)
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Choosing how gauge $U(1)_\chi$ breaks in the context of $SO(10) \to SU(5)
\times U(1)_\chi$, $Z_4$ lepton number may be obtained which maintains
neutrinos as Dirac fermions. Choosing $\Delta(27)$ as the family symmetry of
leptons, tree-level Dirac neutrino masses may be forbidden. Choosing a specific
set of self-interacting dark-matter particles, Dirac neutrino masses and mixing
may then be generated in two loops. This framework allows the realization of
cobimaximal neutrino mixing, i.e. $\theta_{13} \neq 0$, $\theta_{23} = \pi/4$,
$\delta_{CP} = \pm \pi/2$, as well as the desirable feature that the light
scalar mediator of dark-matter interactions decays only to neutrinos, thereby
not disrupting the cosmic microwave background (CMB).
|
[
{
"created": "Mon, 8 Jul 2019 18:02:38 GMT",
"version": "v1"
}
] |
2019-10-02
|
[
[
"Ma",
"Ernest",
"",
"UC Riverside"
]
] |
Choosing how gauge $U(1)_\chi$ breaks in the context of $SO(10) \to SU(5) \times U(1)_\chi$, $Z_4$ lepton number may be obtained which maintains neutrinos as Dirac fermions. Choosing $\Delta(27)$ as the family symmetry of leptons, tree-level Dirac neutrino masses may be forbidden. Choosing a specific set of self-interacting dark-matter particles, Dirac neutrino masses and mixing may then be generated in two loops. This framework allows the realization of cobimaximal neutrino mixing, i.e. $\theta_{13} \neq 0$, $\theta_{23} = \pi/4$, $\delta_{CP} = \pm \pi/2$, as well as the desirable feature that the light scalar mediator of dark-matter interactions decays only to neutrinos, thereby not disrupting the cosmic microwave background (CMB).
|
1809.02097
|
Martin White Dr
|
The GAMBIT Collaboration: Peter Athron, Csaba Bal\'azs, Andy Buckley,
Jonathan M. Cornell, Matthias Danninger, Ben Farmer, Andrew Fowlie, Tom\'as
E. Gonzalo, Julia Harz, Paul Jackson, Rose Kudzman-Blais, Anders Kvellestad,
Gregory D. Martinez, Andreas Petridis, Are Raklev, Christopher Rogan, Pat
Scott, Abhishek Sharma, Martin White, Yang Zhang
|
Combined collider constraints on neutralinos and charginos
|
38 pages, 16 figures, v3 is the version accepted by EPJC
|
Eur.Phys.J. C79 (2019) no.5, 395
|
10.1140/epjc/s10052-019-6837-x
|
CoEPP-MN-18-7, gambit-physics-2018
|
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Searches for supersymmetric electroweakinos have entered a crucial phase, as
the integrated luminosity of the Large Hadron Collider is now high enough to
compensate for their weak production cross-sections. Working in a framework
where the neutralinos and charginos are the only light sparticles in the
Minimal Supersymmetric Standard Model, we use gambit to perform a detailed
likelihood analysis of the electroweakino sector. We focus on the impacts of
recent ATLAS and CMS searches with 36 fb$^{-1}$ of 13 TeV proton-proton
collision data. We also include constraints from LEP and invisible decays of
the $Z$ and Higgs bosons. Under the background-only hypothesis, we show that
current LHC searches do not robustly exclude any range of neutralino or
chargino masses. However, a pattern of excesses in several LHC analyses points
towards a possible signal, with neutralino masses of $(m_{\tilde{\chi}_1^0},
m_{\tilde{\chi}_2^0}, m_{\tilde{\chi}_3^0}, m_{\tilde{\chi}_4^0})$ = (8-155,
103-260, 130-473, 219-502) GeV and chargino masses of
$(m_{\tilde{\chi}_1^{\pm}}, m_{\tilde{\chi}_2^{\pm}})$ = (104-259, 224-507) GeV
at the 95% confidence level. The lightest neutralino is mostly bino, with a
possible modest Higgsino or wino component. We find that this excess has a
combined local significance of $3.3\sigma$, subject to a number of cautions. If
one includes LHC searches for charginos and neutralinos conducted with 8 TeV
proton-proton collision data, the local significance is lowered to 2.9$\sigma$.
We briefly consider the implications for dark matter, finding that the correct
relic density can be obtained through the Higgs-funnel and $Z$-funnel
mechanisms, even assuming that all other sparticles are decoupled. All samples,
gambit input files and best-fit models from this study are available on Zenodo.
|
[
{
"created": "Thu, 6 Sep 2018 17:11:57 GMT",
"version": "v1"
},
{
"created": "Fri, 5 Oct 2018 01:59:52 GMT",
"version": "v2"
},
{
"created": "Thu, 20 Jun 2019 22:59:27 GMT",
"version": "v3"
}
] |
2020-08-06
|
[
[
"The GAMBIT Collaboration",
"",
""
],
[
"Athron",
"Peter",
""
],
[
"Balázs",
"Csaba",
""
],
[
"Buckley",
"Andy",
""
],
[
"Cornell",
"Jonathan M.",
""
],
[
"Danninger",
"Matthias",
""
],
[
"Farmer",
"Ben",
""
],
[
"Fowlie",
"Andrew",
""
],
[
"Gonzalo",
"Tomás E.",
""
],
[
"Harz",
"Julia",
""
],
[
"Jackson",
"Paul",
""
],
[
"Kudzman-Blais",
"Rose",
""
],
[
"Kvellestad",
"Anders",
""
],
[
"Martinez",
"Gregory D.",
""
],
[
"Petridis",
"Andreas",
""
],
[
"Raklev",
"Are",
""
],
[
"Rogan",
"Christopher",
""
],
[
"Scott",
"Pat",
""
],
[
"Sharma",
"Abhishek",
""
],
[
"White",
"Martin",
""
],
[
"Zhang",
"Yang",
""
]
] |
Searches for supersymmetric electroweakinos have entered a crucial phase, as the integrated luminosity of the Large Hadron Collider is now high enough to compensate for their weak production cross-sections. Working in a framework where the neutralinos and charginos are the only light sparticles in the Minimal Supersymmetric Standard Model, we use gambit to perform a detailed likelihood analysis of the electroweakino sector. We focus on the impacts of recent ATLAS and CMS searches with 36 fb$^{-1}$ of 13 TeV proton-proton collision data. We also include constraints from LEP and invisible decays of the $Z$ and Higgs bosons. Under the background-only hypothesis, we show that current LHC searches do not robustly exclude any range of neutralino or chargino masses. However, a pattern of excesses in several LHC analyses points towards a possible signal, with neutralino masses of $(m_{\tilde{\chi}_1^0}, m_{\tilde{\chi}_2^0}, m_{\tilde{\chi}_3^0}, m_{\tilde{\chi}_4^0})$ = (8-155, 103-260, 130-473, 219-502) GeV and chargino masses of $(m_{\tilde{\chi}_1^{\pm}}, m_{\tilde{\chi}_2^{\pm}})$ = (104-259, 224-507) GeV at the 95% confidence level. The lightest neutralino is mostly bino, with a possible modest Higgsino or wino component. We find that this excess has a combined local significance of $3.3\sigma$, subject to a number of cautions. If one includes LHC searches for charginos and neutralinos conducted with 8 TeV proton-proton collision data, the local significance is lowered to 2.9$\sigma$. We briefly consider the implications for dark matter, finding that the correct relic density can be obtained through the Higgs-funnel and $Z$-funnel mechanisms, even assuming that all other sparticles are decoupled. All samples, gambit input files and best-fit models from this study are available on Zenodo.
|
1906.11414
|
CaiChang Li
|
Ping-Tao Chen, Gui-Jun Ding, Stephen F. King, Cai-Chang Li
|
A New Littlest Seesaw Model
|
29 pages, 5 figures
| null |
10.1088/1361-6471/ab7e8d
|
USTC-ICTS-19-15
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We propose and discuss a new Littlest Seesaw model, realised in the
tri-direct CP approach, in which the couplings of the two right-handed
neutrinos to the lepton doublets are proportional to $(0,-1,1)$ and
$(1,5/2,-1/2)$ respectively with the relative phase $\eta=-\pi/2$. This model
can give an excellent description of lepton flavour mixing, including an
atmospheric neutrino mixing angle in the second octant, in terms of only two
input parameters. We show that the observed baryon asymmetry can be generated
for the lightest right-handed neutrino mass $M_{1}=1.176\times 10^{11}$ GeV in
SM and $M_{1}=3.992\times 10^{10}$ GeV in MSSM with $\tan\beta=5$. We construct
an explicit Littlest Seesaw model based on the flavour symmetry $S_4\times
Z_4\times Z_9$ in which the desired alignments and the phase $\eta=-\pi/2$ are
achieved.
|
[
{
"created": "Thu, 27 Jun 2019 02:37:12 GMT",
"version": "v1"
},
{
"created": "Tue, 26 Nov 2019 17:39:37 GMT",
"version": "v2"
},
{
"created": "Mon, 27 Apr 2020 08:25:54 GMT",
"version": "v3"
}
] |
2020-06-24
|
[
[
"Chen",
"Ping-Tao",
""
],
[
"Ding",
"Gui-Jun",
""
],
[
"King",
"Stephen F.",
""
],
[
"Li",
"Cai-Chang",
""
]
] |
We propose and discuss a new Littlest Seesaw model, realised in the tri-direct CP approach, in which the couplings of the two right-handed neutrinos to the lepton doublets are proportional to $(0,-1,1)$ and $(1,5/2,-1/2)$ respectively with the relative phase $\eta=-\pi/2$. This model can give an excellent description of lepton flavour mixing, including an atmospheric neutrino mixing angle in the second octant, in terms of only two input parameters. We show that the observed baryon asymmetry can be generated for the lightest right-handed neutrino mass $M_{1}=1.176\times 10^{11}$ GeV in SM and $M_{1}=3.992\times 10^{10}$ GeV in MSSM with $\tan\beta=5$. We construct an explicit Littlest Seesaw model based on the flavour symmetry $S_4\times Z_4\times Z_9$ in which the desired alignments and the phase $\eta=-\pi/2$ are achieved.
|
1412.7196
|
Alessandro Pilloni
|
R. Faccini, G. Filaci, A.L. Guerrieri, A. Pilloni, A.D. Polosa
|
A note on the newly observed Y(4220) resonance
|
6 pages, 3 figures. Version accepted on Phys.Rev.D
|
Phys. Rev. D 91, 117501 (2015)
|
10.1103/PhysRevD.91.117501
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
BES III Collaboration has recently observed a vector resonance in the
chi_{c0} omega channel, at a mass of about 4220 MeV, named Y(4220). Hints of a
similar structure appear in the h_c pi+ pi- channel. We find that the two
observations are likely due to the same state, which we identify with one of
the expected diquark-antidiquark resonances with orbital quantum number L = 1.
This assignment fulfills heavy quark spin conservation. The measured branching
fractions ratio into chi_{c0} omega and h_c pi+ pi- is compatible with the
prediction for such a tetraquark state.
|
[
{
"created": "Mon, 22 Dec 2014 22:46:26 GMT",
"version": "v1"
},
{
"created": "Fri, 15 May 2015 14:22:37 GMT",
"version": "v2"
}
] |
2015-06-10
|
[
[
"Faccini",
"R.",
""
],
[
"Filaci",
"G.",
""
],
[
"Guerrieri",
"A. L.",
""
],
[
"Pilloni",
"A.",
""
],
[
"Polosa",
"A. D.",
""
]
] |
BES III Collaboration has recently observed a vector resonance in the chi_{c0} omega channel, at a mass of about 4220 MeV, named Y(4220). Hints of a similar structure appear in the h_c pi+ pi- channel. We find that the two observations are likely due to the same state, which we identify with one of the expected diquark-antidiquark resonances with orbital quantum number L = 1. This assignment fulfills heavy quark spin conservation. The measured branching fractions ratio into chi_{c0} omega and h_c pi+ pi- is compatible with the prediction for such a tetraquark state.
|
hep-ph/0002278
|
Gabriela Miu
|
G\"osta Gustafson and Gabriela Miu
|
Minijets and Transverse Energy Flow in High Energy Collisions
|
1+19 pages, 6 eps-figures, submitted to Physical Review D, text
somewhat modified, results unchanged
|
Phys.Rev. D63 (2001) 034004
|
10.1103/PhysRevD.63.034004
|
LU TP 99-43
|
hep-ph
| null |
When studying the production of minijets and transverse energy flow in high
energy hadron-hadron or nucleus-nucleus collisions, two essential points have
to be taken into account. First, one has to account for the virtuality of the
colliding partons and secondly, it is important to avoid double counting, when
many links in a parton chain can be interpreted as the momentum transfer in a
hard subcollision. The Linked Dipole Chain model, introduced for low-x DIS, is
particularly suitable for a study of these problems. It describes (mini)jet
production in a kT-factorizing formalism, which includes all links in a parton
chain on an equal footing, avoiding double counting. In a ``naive'' calculation
based on integrated structure functions, the cross section blows up for small
pT, which makes it necessary to introduce a soft cutoff. In our approach we
find a dynamical suppression at low pT, which makes it possible to extrapolate
to higher energies and make more reliable predictions for RHIC and LHC.
|
[
{
"created": "Fri, 25 Feb 2000 20:34:25 GMT",
"version": "v1"
},
{
"created": "Thu, 14 Sep 2000 16:13:18 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Gustafson",
"Gösta",
""
],
[
"Miu",
"Gabriela",
""
]
] |
When studying the production of minijets and transverse energy flow in high energy hadron-hadron or nucleus-nucleus collisions, two essential points have to be taken into account. First, one has to account for the virtuality of the colliding partons and secondly, it is important to avoid double counting, when many links in a parton chain can be interpreted as the momentum transfer in a hard subcollision. The Linked Dipole Chain model, introduced for low-x DIS, is particularly suitable for a study of these problems. It describes (mini)jet production in a kT-factorizing formalism, which includes all links in a parton chain on an equal footing, avoiding double counting. In a ``naive'' calculation based on integrated structure functions, the cross section blows up for small pT, which makes it necessary to introduce a soft cutoff. In our approach we find a dynamical suppression at low pT, which makes it possible to extrapolate to higher energies and make more reliable predictions for RHIC and LHC.
|
hep-ph/0011324
|
Sancho Moura Oliveira
|
S. M. Oliveira, L. Bruecher, R. Santos, A. Barroso
|
Electroweak Corrections to the Top Quark Decay
|
7 pages, 2 figures
|
Phys.Rev. D64 (2001) 017301
|
10.1103/PhysRevD.64.017301
| null |
hep-ph
| null |
We have calculated the one-loop electroweak corrections to the decay t-> bW+,
including the counterterm for the CKM matrix elements V(tb). Previous
calculations used an incorrect delta V(tb) that led to a gauge dependent
amplitude. However, since the contribution stemming from delta V(tb) is small,
those calculations only underestimate the width by roughly one part in 10^5.
|
[
{
"created": "Mon, 27 Nov 2000 16:52:25 GMT",
"version": "v1"
},
{
"created": "Thu, 18 Jan 2001 15:42:40 GMT",
"version": "v2"
}
] |
2009-10-31
|
[
[
"Oliveira",
"S. M.",
""
],
[
"Bruecher",
"L.",
""
],
[
"Santos",
"R.",
""
],
[
"Barroso",
"A.",
""
]
] |
We have calculated the one-loop electroweak corrections to the decay t-> bW+, including the counterterm for the CKM matrix elements V(tb). Previous calculations used an incorrect delta V(tb) that led to a gauge dependent amplitude. However, since the contribution stemming from delta V(tb) is small, those calculations only underestimate the width by roughly one part in 10^5.
|
0811.0855
|
Boyang Liu
|
Boyang Liu
|
Muonium-Antimuonium Oscillations in an extended Minimal Supersymmetric
Standard Model with right-handed neutrinos
|
29 pages, 7 figures, 3 tables, Latex
|
Phys.Rev.D79:015001,2009
|
10.1103/PhysRevD.79.015001
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The electron and muon number violating muonium-antimuonium oscillation
process in an extended Minimal Supersymmetric Standard Model is investigated.
The Minimal Supersymmetric Standard Model is modified by the inclusion of three
right-handed neutrino superfields. While the model allows the neutrino mass
terms to mix among the different generations, the sneutrino and slepton mass
terms have only intra-generation lepton number violation but not
inter-generation lepton number mixing. So doing, the muonium-antimuonium
conversion can then be used to constrain those model parameters which avoid
further constraint from the $\mu\to e\gamma$ decay bounds. For a wide range of
parameter values, the contributions to the muonium-antimuonium oscillation time
scale are at least two orders of magnitude below the sensivity of current
experiments. However, if the ratio of the two Higgs field VEVs, $\tan\beta$, is
very small, there is a limited possibility that the contributions are large
enough for the present experimental limit to provide an inequality relating
$\tan\beta$ with the light neutrino mass scale $m_\nu$ which is generated by
see-saw mechanism. The resultant lower bound on $\tan\beta$ as a function of
$m_\nu$ is more stringent than the analogous bounds arising from the muon and
electron anomalous magnetic moments as computed using this model.
|
[
{
"created": "Thu, 6 Nov 2008 01:55:51 GMT",
"version": "v1"
},
{
"created": "Tue, 2 Dec 2008 18:37:38 GMT",
"version": "v2"
},
{
"created": "Wed, 10 Dec 2008 00:27:57 GMT",
"version": "v3"
}
] |
2009-01-16
|
[
[
"Liu",
"Boyang",
""
]
] |
The electron and muon number violating muonium-antimuonium oscillation process in an extended Minimal Supersymmetric Standard Model is investigated. The Minimal Supersymmetric Standard Model is modified by the inclusion of three right-handed neutrino superfields. While the model allows the neutrino mass terms to mix among the different generations, the sneutrino and slepton mass terms have only intra-generation lepton number violation but not inter-generation lepton number mixing. So doing, the muonium-antimuonium conversion can then be used to constrain those model parameters which avoid further constraint from the $\mu\to e\gamma$ decay bounds. For a wide range of parameter values, the contributions to the muonium-antimuonium oscillation time scale are at least two orders of magnitude below the sensivity of current experiments. However, if the ratio of the two Higgs field VEVs, $\tan\beta$, is very small, there is a limited possibility that the contributions are large enough for the present experimental limit to provide an inequality relating $\tan\beta$ with the light neutrino mass scale $m_\nu$ which is generated by see-saw mechanism. The resultant lower bound on $\tan\beta$ as a function of $m_\nu$ is more stringent than the analogous bounds arising from the muon and electron anomalous magnetic moments as computed using this model.
|
0907.2160
|
Pietro Colangelo
|
M.V. Carlucci, P. Colangelo and F. De Fazio
|
Rare $B_s$ decays to $\eta$ and $\eta^\prime$ final states
|
RevTeX, 10 pages, 4 figures
|
Phys.Rev.D80:055023,2009
|
10.1103/PhysRevD.80.055023
|
BARI-TH/09-611
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study exclusive $B_s$ decays to final states with $\eta$ and
$\eta^\prime$, induced by the rare $b \to s \ell^+ \ell^-$ and $b \to s \nu
\bar \nu$ transitions. Differential decay rates and total branching fractions
are predicted in the Standard Model, adopting the flavour scheme for the
description of the $\eta$-$\eta^\prime$ mixing. We discuss the theoretical
uncertainty related to the hadronic matrix elements. We also consider these
decay modes in a new Physics scenario with a single universal extra dimension,
studying the dependence of branching ratios and decay distributions on the
compactification scale $R^{-1}$ of the extra dimension.
|
[
{
"created": "Mon, 13 Jul 2009 16:22:11 GMT",
"version": "v1"
}
] |
2009-11-06
|
[
[
"Carlucci",
"M. V.",
""
],
[
"Colangelo",
"P.",
""
],
[
"De Fazio",
"F.",
""
]
] |
We study exclusive $B_s$ decays to final states with $\eta$ and $\eta^\prime$, induced by the rare $b \to s \ell^+ \ell^-$ and $b \to s \nu \bar \nu$ transitions. Differential decay rates and total branching fractions are predicted in the Standard Model, adopting the flavour scheme for the description of the $\eta$-$\eta^\prime$ mixing. We discuss the theoretical uncertainty related to the hadronic matrix elements. We also consider these decay modes in a new Physics scenario with a single universal extra dimension, studying the dependence of branching ratios and decay distributions on the compactification scale $R^{-1}$ of the extra dimension.
|
hep-ph/0211057
|
Magno Machado
|
A. Lengyel (IEP, National Academy of Sciences of Ukraine, Uzhgorod),
M.V.T. Machado (GFPAE, UFRGS)
|
The QCD gluon ladders and HERA structure function
|
10 pages, 3 figures, uses crckapb.sty. To appear in the proceedings
of Diffraction 2002: Second International "Cetraro" Workshop and NATO
Advanced Research Workshop
| null | null | null |
hep-ph
| null |
We report on the extension of the data fitting considering the QCD inspired
model based on the summation of gluon ladders applied to the $ep$ scattering.
In lines of a two Pomeron approach, the structure function $F_2$ has a hard
piece given by the model and the remaining soft contribution: a soft Pomeron
and non-singlet content. In this contribution, we carefully estimate the
relative role of the hard and the soft pieces from a global fit in a large span
of $x$ and $Q^2$.
|
[
{
"created": "Tue, 5 Nov 2002 14:16:58 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Lengyel",
"A.",
"",
"IEP, National Academy of Sciences of Ukraine, Uzhgorod"
],
[
"Machado",
"M. V. T.",
"",
"GFPAE, UFRGS"
]
] |
We report on the extension of the data fitting considering the QCD inspired model based on the summation of gluon ladders applied to the $ep$ scattering. In lines of a two Pomeron approach, the structure function $F_2$ has a hard piece given by the model and the remaining soft contribution: a soft Pomeron and non-singlet content. In this contribution, we carefully estimate the relative role of the hard and the soft pieces from a global fit in a large span of $x$ and $Q^2$.
|
2310.13737
|
Reed Hodges
|
Marston Copeland, Sean Fleming, Rohit Gupta, Reed Hodges, Thomas Mehen
|
Polarized $J/\psi$ production in semi-inclusive DIS at large $Q^2$:
Comparing quark fragmentation and photon-gluon fusion
|
22 pages, 7 figures
|
Phys. Rev. D 109 (2024), 074032
|
10.1103/PhysRevD.109.074032
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We compare the relative importance of different mechanisms for polarized
$J/\psi$ production in semi-inclusive deep inelastic scattering processes at
large $Q^2$. The transverse momentum dependent (TMD) factorization framework
and nonrelativistic quantum chromodynamics are used to study the leading
contributions from light quark fragmentation to polarized $J/\psi$, and
compared to direct production via photon-gluon fusion, which can proceed
through color-singlet as well as color-octet mechanisms. We identify kinematic
regimes where light quark fragmentation dominates, allowing for the extraction
of the $^3S_1^{[8]}$ matrix element, as well as regimes where photon gluon
fusion dominates, suggesting that the gluon TMD parton distribution function
can be probed.
|
[
{
"created": "Fri, 20 Oct 2023 18:00:02 GMT",
"version": "v1"
},
{
"created": "Mon, 29 Apr 2024 14:23:43 GMT",
"version": "v2"
}
] |
2024-04-30
|
[
[
"Copeland",
"Marston",
""
],
[
"Fleming",
"Sean",
""
],
[
"Gupta",
"Rohit",
""
],
[
"Hodges",
"Reed",
""
],
[
"Mehen",
"Thomas",
""
]
] |
We compare the relative importance of different mechanisms for polarized $J/\psi$ production in semi-inclusive deep inelastic scattering processes at large $Q^2$. The transverse momentum dependent (TMD) factorization framework and nonrelativistic quantum chromodynamics are used to study the leading contributions from light quark fragmentation to polarized $J/\psi$, and compared to direct production via photon-gluon fusion, which can proceed through color-singlet as well as color-octet mechanisms. We identify kinematic regimes where light quark fragmentation dominates, allowing for the extraction of the $^3S_1^{[8]}$ matrix element, as well as regimes where photon gluon fusion dominates, suggesting that the gluon TMD parton distribution function can be probed.
|
1305.0299
|
Uri Maor
|
Uri Maor
|
Unitarity Saturation In P-P Scattering
|
6 pages, 3 figures. To be published in the LISHEP13 proceedings
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The properties of soft p-p scattering amplitudes at the TeV-scale are studied
so as to identify the impact of s and t channel unitarity screenings on their
behavior at exceedingly high energies and determine the rate at which they
approach the bounds implied by unitarity saturation. I shall examine the
relevant high energy soft cross section features, as well as, the corresponding
behavior of the coupled phenomenological models aiming to reproduce this
data.\\ My conclusion is that p-p black body saturation is not attained up to
100 TeV. More over, I do not expect that saturation will be attained at
energies that can be investigated experimentally.
|
[
{
"created": "Wed, 1 May 2013 21:35:22 GMT",
"version": "v1"
}
] |
2013-05-03
|
[
[
"Maor",
"Uri",
""
]
] |
The properties of soft p-p scattering amplitudes at the TeV-scale are studied so as to identify the impact of s and t channel unitarity screenings on their behavior at exceedingly high energies and determine the rate at which they approach the bounds implied by unitarity saturation. I shall examine the relevant high energy soft cross section features, as well as, the corresponding behavior of the coupled phenomenological models aiming to reproduce this data.\\ My conclusion is that p-p black body saturation is not attained up to 100 TeV. More over, I do not expect that saturation will be attained at energies that can be investigated experimentally.
|
hep-ph/0607141
|
Michal Czakon
|
R. Boughezal, M. Czakon, T. Schutzmeier
|
Four-Loop Tadpoles: Applications in QCD
|
5 pages, 1 figure, to appear in the proceedings of the 8th DESY
Workshop on Elementary Particle Theory, Loops and Legs in Quantum Field
Theory, April 23-28, 2006, Eisenach, Germany
| null |
10.1016/j.nuclphysbps.2006.09.041
| null |
hep-ph
| null |
Recent applications of single-scale four-loop tadpoles are briefly reviewed.
An algorithm for the evaluation of current correlators based on differential
equations is described and applied to obtain high moments of the vacuum
polarization function at O(alphas^2) as a preparation of O(alphas^3)
calculations.
|
[
{
"created": "Wed, 12 Jul 2006 15:55:06 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Boughezal",
"R.",
""
],
[
"Czakon",
"M.",
""
],
[
"Schutzmeier",
"T.",
""
]
] |
Recent applications of single-scale four-loop tadpoles are briefly reviewed. An algorithm for the evaluation of current correlators based on differential equations is described and applied to obtain high moments of the vacuum polarization function at O(alphas^2) as a preparation of O(alphas^3) calculations.
|
1311.1348
|
Christoph Bobeth
|
Christoph Bobeth and Martin Gorbahn and Emmanuel Stamou
|
Electroweak Corrections to $B_{s,d} \to \ell^+ \ell^-$
|
16 pages, 6 figures, supplementary Mathematica file "c10.m" with
analytical results; v2: references updated
|
Phys. Rev. D 89, 034023 (2014)
|
10.1103/PhysRevD.89.034023
|
FLAVOUR(267104)-ERC-54, LTH 991
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We calculate the full two-loop electroweak matching corrections to the
operator governing the decay B_q --> l^+ l^- in the Standard Model. Their
inclusion removes an electroweak scheme and scale uncertainty of about 7% of
the branching ratio. Using different renormalization schemes of the involved
electroweak parameters, we estimate residual perturbative electroweak and QED
uncertainties to be less than 1% at the level of the branching ratio.
|
[
{
"created": "Wed, 6 Nov 2013 11:00:29 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Nov 2013 08:45:08 GMT",
"version": "v2"
}
] |
2014-02-26
|
[
[
"Bobeth",
"Christoph",
""
],
[
"Gorbahn",
"Martin",
""
],
[
"Stamou",
"Emmanuel",
""
]
] |
We calculate the full two-loop electroweak matching corrections to the operator governing the decay B_q --> l^+ l^- in the Standard Model. Their inclusion removes an electroweak scheme and scale uncertainty of about 7% of the branching ratio. Using different renormalization schemes of the involved electroweak parameters, we estimate residual perturbative electroweak and QED uncertainties to be less than 1% at the level of the branching ratio.
|
0811.4133
|
Zhe Xu
|
I. Bouras (1), L. Cheng (1,2), A. El (1), O. Fochler (1), J. Uphoff
(1), Z. Xu (1), and C. Greiner (1) ((1) Uni. Frankfurt, (2) Huazhong Normal
University, Wuhan)
|
Viscous Effects on Elliptic Flow and Shock Waves
|
7 pages, 8 figures, to appear in the proceedings of the 2008 Erice
School on Nuclear Physics, Sicily
| null |
10.1016/j.ppnp.2008.12.043
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Fast thermalization and a strong buildup of elliptic flow of QCD matter as
found at RHIC are understood as the consequence of perturbative QCD (pQCD)
interactions within the 3+1 dimensional parton cascade BAMPS. The main
contributions stem from pQCD bremsstrahlung $2 \leftrightarrow 3 $ processes.
By comparing to Au+Au data of the flow parameter $v_2$ as a function of
participation number the shear viscosity to entropy ratio is dynamically
extracted, which lies in the range of 0.08 and 0.2, depending on the chosen
coupling constant and freeze out condition. Furthermore, first simulations on
the temporal propagation of dissipative shock waves are given. The cascade can
either simulate true ideal shocks as well as initially diluted, truely viscous
shocks, depending on the employed cross sections or mean free path,
respectively.
|
[
{
"created": "Tue, 25 Nov 2008 17:04:32 GMT",
"version": "v1"
}
] |
2015-05-13
|
[
[
"Bouras",
"I.",
""
],
[
"Cheng",
"L.",
""
],
[
"El",
"A.",
""
],
[
"Fochler",
"O.",
""
],
[
"Uphoff",
"J.",
""
],
[
"Xu",
"Z.",
""
],
[
"Greiner",
"C.",
""
]
] |
Fast thermalization and a strong buildup of elliptic flow of QCD matter as found at RHIC are understood as the consequence of perturbative QCD (pQCD) interactions within the 3+1 dimensional parton cascade BAMPS. The main contributions stem from pQCD bremsstrahlung $2 \leftrightarrow 3 $ processes. By comparing to Au+Au data of the flow parameter $v_2$ as a function of participation number the shear viscosity to entropy ratio is dynamically extracted, which lies in the range of 0.08 and 0.2, depending on the chosen coupling constant and freeze out condition. Furthermore, first simulations on the temporal propagation of dissipative shock waves are given. The cascade can either simulate true ideal shocks as well as initially diluted, truely viscous shocks, depending on the employed cross sections or mean free path, respectively.
|
1601.04537
|
Piotr Lebiedowicz
|
Piotr Lebiedowicz, Otto Nachtmann, Antoni Szczurek
|
Central exclusive diffractive production of $\pi^{+}\pi^{-}$ continuum,
scalar and tensor resonances in $pp$ and $p \bar{p}$ scattering within tensor
pomeron approach
|
30 pages, 15 figures
|
Phys. Rev. D 93, 054015 (2016)
|
10.1103/PhysRevD.93.054015
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider central exclusive diffractive dipion production in the reactions
$pp \to pp \pi^{+} \pi^{-}$ and $p\bar{p} \to p\bar{p} \pi^{+} \pi^{-}$ at high
energies. We include the dipion continuum, the dominant scalar $f_{0}(500)$,
$f_{0}(980)$, and tensor $f_{2}(1270)$ resonances decaying into the $\pi^{+}
\pi^{-}$ pairs. The calculation is based on a tensor pomeron model and the
amplitudes for the processes are formulated in terms of vertices respecting the
standard crossing and charge-conjugation relations of Quantum Field Theory. The
formulae for the dipion continuum and tensor meson production are given here
for the first time. The theoretical results are compared with existing STAR,
CDF, CMS experimental data and predictions for planned or being carried out
experiments (ALICE, ATLAS) are presented. We show the influence of the
experimental cuts on the integrated cross section and on various differential
distributions for outgoing particles. Distributions in rapidities and
transverse momenta of outgoing protons and pions as well as correlations in
azimuthal angle between them are presented. We find that the relative
contribution of resonant $f_2(1270)$ and dipion continuum strongly depends on
the cut on proton transverse momenta or four-momentum transfer squared
$t_{1,2}$ which may explain some controversial observations made by different
ISR experiments in the past. The cuts may play then the role of a $\pi \pi$
resonance filter. We suggest some experimental analyses to fix model parameters
related to the pomeron-pomeron-$f_{2}$ coupling.
|
[
{
"created": "Mon, 18 Jan 2016 14:40:54 GMT",
"version": "v1"
}
] |
2016-03-23
|
[
[
"Lebiedowicz",
"Piotr",
""
],
[
"Nachtmann",
"Otto",
""
],
[
"Szczurek",
"Antoni",
""
]
] |
We consider central exclusive diffractive dipion production in the reactions $pp \to pp \pi^{+} \pi^{-}$ and $p\bar{p} \to p\bar{p} \pi^{+} \pi^{-}$ at high energies. We include the dipion continuum, the dominant scalar $f_{0}(500)$, $f_{0}(980)$, and tensor $f_{2}(1270)$ resonances decaying into the $\pi^{+} \pi^{-}$ pairs. The calculation is based on a tensor pomeron model and the amplitudes for the processes are formulated in terms of vertices respecting the standard crossing and charge-conjugation relations of Quantum Field Theory. The formulae for the dipion continuum and tensor meson production are given here for the first time. The theoretical results are compared with existing STAR, CDF, CMS experimental data and predictions for planned or being carried out experiments (ALICE, ATLAS) are presented. We show the influence of the experimental cuts on the integrated cross section and on various differential distributions for outgoing particles. Distributions in rapidities and transverse momenta of outgoing protons and pions as well as correlations in azimuthal angle between them are presented. We find that the relative contribution of resonant $f_2(1270)$ and dipion continuum strongly depends on the cut on proton transverse momenta or four-momentum transfer squared $t_{1,2}$ which may explain some controversial observations made by different ISR experiments in the past. The cuts may play then the role of a $\pi \pi$ resonance filter. We suggest some experimental analyses to fix model parameters related to the pomeron-pomeron-$f_{2}$ coupling.
|
hep-ph/0101210
|
Mar Bastero
|
Laura Mersini, Mar Bastero-Gil and Panagiota Kanti
|
Relic Dark energy from Trans-Planckian Regime
|
17 pages, 2 eps fig, new references added, final version, to appear
in Phys. Rev. D
|
Phys.Rev. D64 (2001) 043508
|
10.1103/PhysRevD.64.043508
|
SNS-PH/01-01
|
hep-ph astro-ph gr-qc hep-th
| null |
As yet, there is no underlying fundamental theory for the transplanckian
regime. There is a need to address the issue of how the observables in our
present universe are affected by processes that may have occured during the
transplanckian regime. A particular feature of the family of dispersion
functions chosen is the production of ultralow frequencies at very high momenta
$k> M_P$. We name the range of the ultralow energy modes (of very short
distances) that have frequencies equal or less than the current Hubble rate
$H_0$ as the $\it{tail}$ modes. These modes are still frozen today due to the
expansion of the universe. We calculate their energy today and show that the
$tail$ provides a strong candidate for the {\it dark energy} of the universe.
During inflation, their energy is about 122-123 orders of magnitude smaller
than the total energy. We present the exact solutions and show that: the CMBR
spectrum is that of a (nearly) black body, and that the adiabatic vacuum is the
only choice for the initial conditions. Finally, some of these results can also
be applied to black hole physics.
|
[
{
"created": "Thu, 18 Jan 2001 22:36:10 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Jan 2001 14:53:38 GMT",
"version": "v2"
},
{
"created": "Wed, 6 Jun 2001 09:27:07 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Mersini",
"Laura",
""
],
[
"Bastero-Gil",
"Mar",
""
],
[
"Kanti",
"Panagiota",
""
]
] |
As yet, there is no underlying fundamental theory for the transplanckian regime. There is a need to address the issue of how the observables in our present universe are affected by processes that may have occured during the transplanckian regime. A particular feature of the family of dispersion functions chosen is the production of ultralow frequencies at very high momenta $k> M_P$. We name the range of the ultralow energy modes (of very short distances) that have frequencies equal or less than the current Hubble rate $H_0$ as the $\it{tail}$ modes. These modes are still frozen today due to the expansion of the universe. We calculate their energy today and show that the $tail$ provides a strong candidate for the {\it dark energy} of the universe. During inflation, their energy is about 122-123 orders of magnitude smaller than the total energy. We present the exact solutions and show that: the CMBR spectrum is that of a (nearly) black body, and that the adiabatic vacuum is the only choice for the initial conditions. Finally, some of these results can also be applied to black hole physics.
|
hep-ph/0202237
|
Fabio Maltoni
|
V. Del Duca, F. Maltoni, Z. Trocsanyi
|
The contribution of the four-parton final states to gamma* gamma* ->
hadrons
|
32 pages, 10 figures, published version
|
JHEP 0205 (2002) 005
|
10.1088/1126-6708/2002/05/005
| null |
hep-ph
| null |
In the analysis of the total cross section for the gamma* gamma* -> hadrons
process, we include the four parton final states, which are part of the
O(alpha_s^2) corrections. The four-parton final states contain the diagrams
with gluon exchange in the crossed channel, which constitute the leading order
of the BFKL resummation. We show that the diagrams with gluon exchange in the
crossed channel play an important role in the large Y region, however their
contribution to the cross section must be evaluated exactly. In fact, the
high-energy limit, which constitutes the kinematic framework of the BFKL
resummation, is not sufficiently accurate at LEP2 energies. The inclusion of
the diagrams with gluon exchange in the crossed channel reduces the discrepancy
between the theory and the LEP2 data collected by the L3 Collaboration, but the
data still lie above the theory, even allowing for a large scale uncertainty in
the theory. Thus, in order to describe accurately the data for gamma* gamma* ->
hadrons in the large Y region, corrections of an order higher than O(alpha_s^2)
seem to be necessary.
|
[
{
"created": "Mon, 25 Feb 2002 21:12:50 GMT",
"version": "v1"
},
{
"created": "Tue, 21 May 2002 16:45:44 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Del Duca",
"V.",
""
],
[
"Maltoni",
"F.",
""
],
[
"Trocsanyi",
"Z.",
""
]
] |
In the analysis of the total cross section for the gamma* gamma* -> hadrons process, we include the four parton final states, which are part of the O(alpha_s^2) corrections. The four-parton final states contain the diagrams with gluon exchange in the crossed channel, which constitute the leading order of the BFKL resummation. We show that the diagrams with gluon exchange in the crossed channel play an important role in the large Y region, however their contribution to the cross section must be evaluated exactly. In fact, the high-energy limit, which constitutes the kinematic framework of the BFKL resummation, is not sufficiently accurate at LEP2 energies. The inclusion of the diagrams with gluon exchange in the crossed channel reduces the discrepancy between the theory and the LEP2 data collected by the L3 Collaboration, but the data still lie above the theory, even allowing for a large scale uncertainty in the theory. Thus, in order to describe accurately the data for gamma* gamma* -> hadrons in the large Y region, corrections of an order higher than O(alpha_s^2) seem to be necessary.
|
1603.06566
|
Jernej Kamenik
|
Jernej F. Kamenik, Benjamin R. Safdi, Yotam Soreq and Jure Zupan
|
Comments on the diphoton excess: critical reappraisal of effective field
theory interpretations
|
31 pages, 8 figures; version as published
| null |
10.1007/JHEP07(2016)042
|
MIT-CPT/4786
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the diphoton excess observed by ATLAS and CMS using the most
up-to-date data and estimate the preferred enhancement in the production rate
between 8 TeV and 13 TeV. Within the framework of effective field theory (EFT),
we then show that for both spin-0 and spin-2 Standard Model (SM) gauge-singlet
resonances, two of the three processes S to ZZ, S to Z gamma, and S to WW must
occur with a non-zero rate. Moreover, we demonstrate that these branching
ratios are highly correlated in the EFT. Couplings of S to additional SM states
may be constrained and differentiated by comparing the S production rates with
and without the vector-boson fusion (VBF) cuts. We find that for a given VBF to
inclusive production ratio there is maximum rate of S to gauge bosons, b b-bar,
and lighter quark anti-quark pairs. Simultaneous measurements of the width and
the VBF ratio may be able to point towards the existence of hidden decays.
|
[
{
"created": "Mon, 21 Mar 2016 19:58:38 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Jul 2016 07:51:12 GMT",
"version": "v2"
}
] |
2016-08-03
|
[
[
"Kamenik",
"Jernej F.",
""
],
[
"Safdi",
"Benjamin R.",
""
],
[
"Soreq",
"Yotam",
""
],
[
"Zupan",
"Jure",
""
]
] |
We consider the diphoton excess observed by ATLAS and CMS using the most up-to-date data and estimate the preferred enhancement in the production rate between 8 TeV and 13 TeV. Within the framework of effective field theory (EFT), we then show that for both spin-0 and spin-2 Standard Model (SM) gauge-singlet resonances, two of the three processes S to ZZ, S to Z gamma, and S to WW must occur with a non-zero rate. Moreover, we demonstrate that these branching ratios are highly correlated in the EFT. Couplings of S to additional SM states may be constrained and differentiated by comparing the S production rates with and without the vector-boson fusion (VBF) cuts. We find that for a given VBF to inclusive production ratio there is maximum rate of S to gauge bosons, b b-bar, and lighter quark anti-quark pairs. Simultaneous measurements of the width and the VBF ratio may be able to point towards the existence of hidden decays.
|
hep-ph/9808257
|
Evgene Levin
|
E.Gotsman (Tel Aviv Un.), E.Levin (Tel Aviv Un./DESY), U. Maor (Tel
Aviv Un.) and E.Naftali (Tel Aviv Un.)
|
The effect of screening on the $x$ and $Q^2$ bhaviour of $F_2$ slopes
|
26 pages in latex file,9 figure in eps files, Fig. 3 replaced
|
Nucl.Phys.B539:535-554,1999
|
10.1016/S0550-3213(98)00740-8
|
DESY-98-102, TAUP 2515/98
|
hep-ph
| null |
A systematic study of $\frac{\partial F_2(x,Q^2)}{\partial \ln Q^2}$ and
$\frac{\partial \ln F_2(x,Q^2)}{\partial \ln (1/x)}$ is carried out in pQCD
taking screening corrections into account. The result of calculations, which
are different from the non screened DGLAP prediction, are compared and shown to
agree with the available experimental data as well as a pseudo data base
generated from the ALLM'97 parameterization. This pseudo data base allows us to
study in detail our predictions over a wider kinematic region than is available
experimentally, and allows us to make suggestions for future experiments. Our
results are compared with the GRV'94 parameterization (which is used as an
input for our calculations) as well as the recently proposed MRST structure
functions.
|
[
{
"created": "Fri, 7 Aug 1998 10:23:52 GMT",
"version": "v1"
},
{
"created": "Fri, 14 Aug 1998 10:14:37 GMT",
"version": "v2"
},
{
"created": "Sun, 16 Aug 1998 13:33:58 GMT",
"version": "v3"
}
] |
2014-11-17
|
[
[
"Gotsman",
"E.",
"",
"Tel Aviv Un."
],
[
"Levin",
"E.",
"",
"Tel Aviv Un./DESY"
],
[
"Maor",
"U.",
"",
"Tel\n Aviv Un."
],
[
"Naftali",
"E.",
"",
"Tel Aviv Un."
]
] |
A systematic study of $\frac{\partial F_2(x,Q^2)}{\partial \ln Q^2}$ and $\frac{\partial \ln F_2(x,Q^2)}{\partial \ln (1/x)}$ is carried out in pQCD taking screening corrections into account. The result of calculations, which are different from the non screened DGLAP prediction, are compared and shown to agree with the available experimental data as well as a pseudo data base generated from the ALLM'97 parameterization. This pseudo data base allows us to study in detail our predictions over a wider kinematic region than is available experimentally, and allows us to make suggestions for future experiments. Our results are compared with the GRV'94 parameterization (which is used as an input for our calculations) as well as the recently proposed MRST structure functions.
|
hep-ph/9709365
|
Omar Miranda
|
J. W. F. Valle (U. Valencia-Ific/Csic)
|
Neutrinos Properties Beyond the Standard Model
|
14 pages. Latex. 12 figures. Plenary talk, WIN97, Capri, Italy, June
1997. Minor changes, references and acknowledgements added
|
Phys.Atom.Nucl.61:1012-1023,1998;
Nucl.Phys.Proc.Suppl.66:141-154,1998
|
10.1016/S0920-5632(98)00027-9
|
FTUV/97-54, IFIC/97-70
|
hep-ph
| null |
The present observational status of neutrino physics is sketched, with
emphasis on the hints that follow from solar and atmospheric neutrino
observations, as well as dark matter. I also briefly review the ways to account
for the observed anomalies and some of their implications
|
[
{
"created": "Tue, 16 Sep 1997 17:04:57 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Sep 1997 18:10:39 GMT",
"version": "v2"
}
] |
2009-09-17
|
[
[
"Valle",
"J. W. F.",
"",
"U. Valencia-Ific/Csic"
]
] |
The present observational status of neutrino physics is sketched, with emphasis on the hints that follow from solar and atmospheric neutrino observations, as well as dark matter. I also briefly review the ways to account for the observed anomalies and some of their implications
|
hep-ph/9912266
|
Panagiota Kanti
|
P. Kanti, I.I. Kogan, K.A. Olive and M. Pospelov
|
Single-Brane Cosmological Solutions with a Stable Compact Extra
Dimension
|
25 pages, Latex file, no figures, comments added, references updated,
final version to appear in Physical Review D
|
Phys.Rev.D61:106004,2000
|
10.1103/PhysRevD.61.106004
|
UMN-TH-1829/99, TPI-MINN-99/54, OUTP-99-62P
|
hep-ph astro-ph gr-qc hep-th
| null |
We consider 5-dimensional cosmological solutions of a single brane. The
correct cosmology on the brane, i.e., governed by the standard 4-dimensional
Friedmann equation, and stable compactification of the extra dimension is
guaranteed by the existence of a non-vanishing \hat{T}^5_5 which is
proportional to the 4-dimensional trace of the energy-momentum tensor. We show
that this component of the energy-momentum tensor arises from the backreaction
of the dilaton coupling to the brane. The same positive features are exhibited
in solutions found in the presence of non-vanishing cosmological constants both
on the brane (\Lambda_{br}) and in the bulk (\Lambda_B). Moreover, the
restoration of the Friedmann equation, with the correct sign, takes place for
both signs of $\Lambda_B$ so long as the sign of $\Lambda_{br}$ is opposite
$\Lambda_B$ in order to cancel the energy densities of the two cosmological
constants. We further extend our single-brane thin-wall solution to allow a
brane with finite thickness.
|
[
{
"created": "Wed, 8 Dec 1999 00:04:02 GMT",
"version": "v1"
},
{
"created": "Tue, 29 Feb 2000 15:54:02 GMT",
"version": "v2"
}
] |
2009-09-15
|
[
[
"Kanti",
"P.",
""
],
[
"Kogan",
"I. I.",
""
],
[
"Olive",
"K. A.",
""
],
[
"Pospelov",
"M.",
""
]
] |
We consider 5-dimensional cosmological solutions of a single brane. The correct cosmology on the brane, i.e., governed by the standard 4-dimensional Friedmann equation, and stable compactification of the extra dimension is guaranteed by the existence of a non-vanishing \hat{T}^5_5 which is proportional to the 4-dimensional trace of the energy-momentum tensor. We show that this component of the energy-momentum tensor arises from the backreaction of the dilaton coupling to the brane. The same positive features are exhibited in solutions found in the presence of non-vanishing cosmological constants both on the brane (\Lambda_{br}) and in the bulk (\Lambda_B). Moreover, the restoration of the Friedmann equation, with the correct sign, takes place for both signs of $\Lambda_B$ so long as the sign of $\Lambda_{br}$ is opposite $\Lambda_B$ in order to cancel the energy densities of the two cosmological constants. We further extend our single-brane thin-wall solution to allow a brane with finite thickness.
|
hep-ph/9712530
|
Koichi Yoshioka
|
M. Bando, J. Sato and K. Yoshioka
|
Quark and Lepton Mass Matrix in an Asymptotically Non-Free Theory
|
22 pages, 6 eps figures, typos corrected, version to be published
|
Prog.Theor.Phys.100:797-815,1998
|
10.1143/PTP.100.797
|
UT-801, KUNS-1479
|
hep-ph
| null |
We analyze fermion mass-matrix structure in an asymptotically non-free model
with 4 + 1bar generations. The texture at the GUT scale is uniquely determined
by supposing that the masses of heavy up-type quarks (charm as well as top) are
realized as their infrared fixed point values. By assuming SO(10) GUT-like
relations for Yukawa couplings in this model, this texture can explain all
fermion masses and quark mixing with only one small parameter, which is almost
equal to the Cabibbo angle.
|
[
{
"created": "Sun, 28 Dec 1997 16:11:19 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Jan 1998 12:18:00 GMT",
"version": "v2"
},
{
"created": "Sun, 20 Sep 1998 11:48:18 GMT",
"version": "v3"
}
] |
2014-11-17
|
[
[
"Bando",
"M.",
""
],
[
"Sato",
"J.",
""
],
[
"Yoshioka",
"K.",
""
]
] |
We analyze fermion mass-matrix structure in an asymptotically non-free model with 4 + 1bar generations. The texture at the GUT scale is uniquely determined by supposing that the masses of heavy up-type quarks (charm as well as top) are realized as their infrared fixed point values. By assuming SO(10) GUT-like relations for Yukawa couplings in this model, this texture can explain all fermion masses and quark mixing with only one small parameter, which is almost equal to the Cabibbo angle.
|
hep-ph/0006348
|
Steven D. Bass
|
Steven D. Bass
|
Proton spin structure and the low-energy pp -> pp eta' reaction
|
2 pages, LaTeX, talk at DIS 2000, Liverpool, April 2000
| null | null |
TUM/T39-00-08
|
hep-ph
| null |
Gluonic degrees of freedom induce a contact term in the effective chiral
Lagrangian description of the low-energy pp -> pp eta' reaction. The strength
of this contact term is, in part, related to the amount of spin carried by
polarised gluons in a polarised proton.
|
[
{
"created": "Fri, 30 Jun 2000 14:15:42 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Bass",
"Steven D.",
""
]
] |
Gluonic degrees of freedom induce a contact term in the effective chiral Lagrangian description of the low-energy pp -> pp eta' reaction. The strength of this contact term is, in part, related to the amount of spin carried by polarised gluons in a polarised proton.
|
1304.7888
|
Debtosh Chowdhury
|
Debtosh Chowdhury, Ketan M. Patel
|
Revisiting lepton flavor violation in supersymmetric type II seesaw
|
Minor changes in text; accepted for publication in Phys. Rev. D
|
Phys. Rev. D87 (2013) 095018
|
10.1103/PhysRevD.87.095018
|
TIFR/TH/13-12
|
hep-ph
|
http://creativecommons.org/licenses/publicdomain/
|
In view of the recent measurement of reactor mixing angle $\theta_{13}$ and
updated limit on $BR(\mu \to e \gamma)$ by the MEG experiment, we re-examine
the charged lepton flavor violations in a framework of supersymmetric type II
seesaw mechanism. Supersymmetric type II seesaw predicts strong correlation
between $BR(\mu \to e \gamma)$ and $BR(\tau \to \mu \gamma)$ mainly in terms of
the neutrino mixing angles. We show that such a correlation can be determined
accurately after the measurement of $\theta_{13}$. We compute different factors
which can affect this correlation and show that the mSUGRA-like scenarios, in
which slepton masses are taken to be universal at the high scale, predicts $3.5
\lesssim BR(\tau \to \mu \gamma)/BR(\mu \to e \gamma) \lesssim 30$ for normal
hierarchical neutrino masses. Any experimental indication of deviation from
this prediction would rule out the minimal models of supersymmetric type II
seesaw. We show that the current MEG limit puts severe constraints on the light
sparticle spectrum in mSUGRA model if the seesaw scale lies within
$10^{13}$-$10^{15}$ GeV. It is shown that these constraints can be relaxed and
relatively light sparticle spectrum can be obtained in a class of models in
which the soft mass of triplet scalar is taken to be non-universal at the high
scale.
|
[
{
"created": "Tue, 30 Apr 2013 05:57:48 GMT",
"version": "v1"
},
{
"created": "Thu, 23 May 2013 01:26:43 GMT",
"version": "v2"
}
] |
2013-08-05
|
[
[
"Chowdhury",
"Debtosh",
""
],
[
"Patel",
"Ketan M.",
""
]
] |
In view of the recent measurement of reactor mixing angle $\theta_{13}$ and updated limit on $BR(\mu \to e \gamma)$ by the MEG experiment, we re-examine the charged lepton flavor violations in a framework of supersymmetric type II seesaw mechanism. Supersymmetric type II seesaw predicts strong correlation between $BR(\mu \to e \gamma)$ and $BR(\tau \to \mu \gamma)$ mainly in terms of the neutrino mixing angles. We show that such a correlation can be determined accurately after the measurement of $\theta_{13}$. We compute different factors which can affect this correlation and show that the mSUGRA-like scenarios, in which slepton masses are taken to be universal at the high scale, predicts $3.5 \lesssim BR(\tau \to \mu \gamma)/BR(\mu \to e \gamma) \lesssim 30$ for normal hierarchical neutrino masses. Any experimental indication of deviation from this prediction would rule out the minimal models of supersymmetric type II seesaw. We show that the current MEG limit puts severe constraints on the light sparticle spectrum in mSUGRA model if the seesaw scale lies within $10^{13}$-$10^{15}$ GeV. It is shown that these constraints can be relaxed and relatively light sparticle spectrum can be obtained in a class of models in which the soft mass of triplet scalar is taken to be non-universal at the high scale.
|
hep-ph/9802439
| null |
Stefano Catani (CERN)
|
The Singular Behaviour of QCD Amplitudes at Two-loop Order
|
14 pages, latex, no figures
|
Phys.Lett. B427 (1998) 161-171
|
10.1016/S0370-2693(98)00332-3
|
CERN-TH/98-42
|
hep-ph
| null |
We discuss the structure of infrared singularities in on-shell QCD amplitudes
at two-loop order. We present a general factorization formula that controls all
the $\ep$-poles of the dimensionally regularized amplitudes. The dependence on
the regularization scheme is considered and the coefficients of the $1/\ep^4,
1/\ep^3$ and $1/\ep^2$ poles are explicitly given in the most general case. The
remaining single-pole contributions are also explicitly evaluated in the case
of amplitudes with a $q{\bar q}$ pair.
|
[
{
"created": "Thu, 26 Feb 1998 19:15:08 GMT",
"version": "v1"
}
] |
2009-10-31
|
[
[
"Catani",
"Stefano",
"",
"CERN"
]
] |
We discuss the structure of infrared singularities in on-shell QCD amplitudes at two-loop order. We present a general factorization formula that controls all the $\ep$-poles of the dimensionally regularized amplitudes. The dependence on the regularization scheme is considered and the coefficients of the $1/\ep^4, 1/\ep^3$ and $1/\ep^2$ poles are explicitly given in the most general case. The remaining single-pole contributions are also explicitly evaluated in the case of amplitudes with a $q{\bar q}$ pair.
|
1009.4588
|
Francesco Giacosa
|
Francesco Giacosa
|
Analytical study of a gas of gluonic quasiparticles at high temperature:
effective mass, pressure and trace anomaly
|
Revised version accepted for publication in Phys. Rev. D. 10 pages
and 3 figures
|
Phys.Rev.D83:114002,2011
|
10.1103/PhysRevD.83.114002
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The thermodynamical properties of a pure Yang-Mills theory SU(N) is described
by a gas of gluonic quasiparticles with temperature dependent mass $m(T)$ and a
bag function $B(T).$ The analytic behavior of $m(T)$ and the pressure $p$ at
high $T$ are derived and constraints on the parameters defining $B(T)$ are
discussed. The trace anomaly $\theta=\rho-3p$ is evaluated in the high $T$
domain: it is dominated by a quadratic behavior $\theta =nKT^{2},$ where
$n=2(N^{2}-1)$ is the number of degrees of freedom and $K$ is an integration
constant which does not depend on the bag function $B(T)$. This is a general
result which is in very good agreement with recent lattice simulations.
|
[
{
"created": "Thu, 23 Sep 2010 11:54:27 GMT",
"version": "v1"
},
{
"created": "Tue, 17 May 2011 15:51:39 GMT",
"version": "v2"
}
] |
2011-06-13
|
[
[
"Giacosa",
"Francesco",
""
]
] |
The thermodynamical properties of a pure Yang-Mills theory SU(N) is described by a gas of gluonic quasiparticles with temperature dependent mass $m(T)$ and a bag function $B(T).$ The analytic behavior of $m(T)$ and the pressure $p$ at high $T$ are derived and constraints on the parameters defining $B(T)$ are discussed. The trace anomaly $\theta=\rho-3p$ is evaluated in the high $T$ domain: it is dominated by a quadratic behavior $\theta =nKT^{2},$ where $n=2(N^{2}-1)$ is the number of degrees of freedom and $K$ is an integration constant which does not depend on the bag function $B(T)$. This is a general result which is in very good agreement with recent lattice simulations.
|
2003.04828
|
John Terry
|
Daniel Callos, Zhong-Bo Kang, John Terry
|
Extracting the Transverse Momentum Dependent Polarizing Fragmentation
Functions
|
9 pages, 7 figures, updated fit and improved text
|
Phys. Rev. D 102, 096007 (2020)
|
10.1103/PhysRevD.102.096007
| null |
hep-ph hep-ex nucl-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We demonstrate that spontaneous transverse polarization of Lambda baryon
($\Lambda$) production in $e^+e^-$ annihilation can be described using the
transverse momentum dependent polarizing fragmentation functions (TMD PFFs).
Using a simple Gaussian model, we perform an extraction of the TMD PFFs by
fitting the BELLE collaboration's recent measurement of the $\Lambda$
transverse polarization in back-to-back $\Lambda+h$ production in $e^+ e^-$
collisions, $e^{-} + e^{+} \rightarrow \Lambda^{\uparrow}+h+X$. We find that
this simple model accurately describes the experimental data for $\Lambda$
production associated with pions and kaons, and we are able to determine TMD
PFFs for different quark flavors. We use these newly extracted TMD PFFs to make
predictions for the transverse polarization of $\Lambda$ produced in
semi-inclusive deep inelastic scattering at a future electron-ion collider, and
find that such a polarization is around $10\%$ and should be measurable.
|
[
{
"created": "Tue, 10 Mar 2020 16:18:45 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Mar 2020 06:15:20 GMT",
"version": "v2"
}
] |
2020-11-18
|
[
[
"Callos",
"Daniel",
""
],
[
"Kang",
"Zhong-Bo",
""
],
[
"Terry",
"John",
""
]
] |
We demonstrate that spontaneous transverse polarization of Lambda baryon ($\Lambda$) production in $e^+e^-$ annihilation can be described using the transverse momentum dependent polarizing fragmentation functions (TMD PFFs). Using a simple Gaussian model, we perform an extraction of the TMD PFFs by fitting the BELLE collaboration's recent measurement of the $\Lambda$ transverse polarization in back-to-back $\Lambda+h$ production in $e^+ e^-$ collisions, $e^{-} + e^{+} \rightarrow \Lambda^{\uparrow}+h+X$. We find that this simple model accurately describes the experimental data for $\Lambda$ production associated with pions and kaons, and we are able to determine TMD PFFs for different quark flavors. We use these newly extracted TMD PFFs to make predictions for the transverse polarization of $\Lambda$ produced in semi-inclusive deep inelastic scattering at a future electron-ion collider, and find that such a polarization is around $10\%$ and should be measurable.
|
2106.06393
|
Petr Satunin
|
Petr Satunin
|
Two-sided constraints on Lorentz Invariance violation from
Tibet-AS$\gamma$ and LHAASO Very-High-Energy photon observations
|
11 pages, 2 figures, 1 table. v2: the effect of pair production on
CMB has been added
|
Eur. Phys. J. C 81, 750 (2021)
|
10.1140/epjc/s10052-021-09547-1
|
INR-TH-2021-014
|
hep-ph astro-ph.HE
|
http://creativecommons.org/licenses/by/4.0/
|
We present new two-sided constraints on Lorentz Invariance violation energy
scale for photons with quartic dispersion relation from recent gamma ray
observations by Tibet-AS$\gamma$ and LHAASO experiments. The constraints are
based on the consideration of the processes of photon triple splitting
(superluminal scenario) and the suppression of shower formation (subluminal).
The constraints in subluminal scenario are better than the pair production
constraints and are the strongest in the literature.
|
[
{
"created": "Fri, 11 Jun 2021 13:52:33 GMT",
"version": "v1"
},
{
"created": "Thu, 1 Jul 2021 09:12:10 GMT",
"version": "v2"
},
{
"created": "Mon, 2 Aug 2021 07:39:30 GMT",
"version": "v3"
}
] |
2021-08-26
|
[
[
"Satunin",
"Petr",
""
]
] |
We present new two-sided constraints on Lorentz Invariance violation energy scale for photons with quartic dispersion relation from recent gamma ray observations by Tibet-AS$\gamma$ and LHAASO experiments. The constraints are based on the consideration of the processes of photon triple splitting (superluminal scenario) and the suppression of shower formation (subluminal). The constraints in subluminal scenario are better than the pair production constraints and are the strongest in the literature.
|
1104.4225
|
Arkadii Kozhevnikov
|
N.N. Achasov, A.A. Kozhevnikov
|
Electromagnetic form factor of pion in the field theory inspired
approach
|
12 pages, 8 figures. Text rearranged. Clarifying remarks and
references added
|
Phys.Rev.D83:113005,2011
|
10.1103/PhysRevD.83.113005
| null |
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
A new formula for the pion form factor F_pi is proposed which takes into
account the pseudoscalar meson loops and the mixing among rho(770), rho(1450),
and rho(1700). The expression possesses correct analytical properties and can
be used in both timelike and spacelike kinematical regions. The comparison is
made with the existing experimental data on F_pi collected by the detectors
SND, CMD-2, KLOE, and BaBaR restricted to energies below 1 GeV. A good
description of all four data sets is obtained. In the spacelike region, upon
substituting the resonance parameters found in the timelike one, the formula
gives F_pi, in agreement with the measurements of the NA7 Collaboration.
|
[
{
"created": "Thu, 21 Apr 2011 10:38:07 GMT",
"version": "v1"
},
{
"created": "Mon, 20 Jun 2011 05:34:13 GMT",
"version": "v2"
}
] |
2011-06-30
|
[
[
"Achasov",
"N. N.",
""
],
[
"Kozhevnikov",
"A. A.",
""
]
] |
A new formula for the pion form factor F_pi is proposed which takes into account the pseudoscalar meson loops and the mixing among rho(770), rho(1450), and rho(1700). The expression possesses correct analytical properties and can be used in both timelike and spacelike kinematical regions. The comparison is made with the existing experimental data on F_pi collected by the detectors SND, CMD-2, KLOE, and BaBaR restricted to energies below 1 GeV. A good description of all four data sets is obtained. In the spacelike region, upon substituting the resonance parameters found in the timelike one, the formula gives F_pi, in agreement with the measurements of the NA7 Collaboration.
|
2105.09044
|
Kousik Loho
|
Tanushree Basak, Baradhwaj Coleppa, Kousik Loho
|
An update on the two singlet Dark Matter model
|
14 pages, 9 figures
| null |
10.1007/JHEP06(2021)104
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We revisit the two real singlet extension of the Standard Model with a
$Z_2\times Z_2^\prime$ symmetry. One of the singlet scalars $S_2$, by virtue of
an unbroken $Z_2^\prime$ symmetry, plays the role of a stable dark matter
candidate. The other scalar $S_1$, with spontaneously broken $Z_2$-symmetry,
mixes with the SM Higgs boson and acts as the scalar mediator. We analyze the
model by putting in the entire set of theoretical and recent experimental
constraints. The latest bounds from direct detection Xenon1T experiment
severely restricts the allowed region of parameter space of couplings. To
ensure the dark matter satisfies the relic abundance criterion, we rely on the
Breit-Wigner enhanced annihilation cross-section. Further, we study the
viability of explaining the observed gamma-ray excess in the galactic center in
this model with a dark matter of mass in the $\sim 36-51$ GeV window and
present our conclusions.
|
[
{
"created": "Wed, 19 May 2021 10:23:29 GMT",
"version": "v1"
},
{
"created": "Fri, 18 Jun 2021 05:11:37 GMT",
"version": "v2"
}
] |
2021-06-21
|
[
[
"Basak",
"Tanushree",
""
],
[
"Coleppa",
"Baradhwaj",
""
],
[
"Loho",
"Kousik",
""
]
] |
We revisit the two real singlet extension of the Standard Model with a $Z_2\times Z_2^\prime$ symmetry. One of the singlet scalars $S_2$, by virtue of an unbroken $Z_2^\prime$ symmetry, plays the role of a stable dark matter candidate. The other scalar $S_1$, with spontaneously broken $Z_2$-symmetry, mixes with the SM Higgs boson and acts as the scalar mediator. We analyze the model by putting in the entire set of theoretical and recent experimental constraints. The latest bounds from direct detection Xenon1T experiment severely restricts the allowed region of parameter space of couplings. To ensure the dark matter satisfies the relic abundance criterion, we rely on the Breit-Wigner enhanced annihilation cross-section. Further, we study the viability of explaining the observed gamma-ray excess in the galactic center in this model with a dark matter of mass in the $\sim 36-51$ GeV window and present our conclusions.
|
hep-ph/0210031
|
Luca Silvestrini
|
L.Silvestrini
|
B Physics and Supersymmetry
|
5 pages, uses espcrc2.sty. Contributed talk at ICHEP02
| null |
10.1016/S0920-5632(03)90677-3
| null |
hep-ph
| null |
In this talk, I briefly review a selection of SUSY effects in B physics.
First, I consider models with Minimal Flavour Violation. Then I discuss SUSY
models with new sources of flavour violation in squark mass matrices, analyzing
present constraints and possible developments with forthcoming data on b -> s
and b -> d transitions.
|
[
{
"created": "Wed, 2 Oct 2002 10:53:41 GMT",
"version": "v1"
}
] |
2009-11-07
|
[
[
"Silvestrini",
"L.",
""
]
] |
In this talk, I briefly review a selection of SUSY effects in B physics. First, I consider models with Minimal Flavour Violation. Then I discuss SUSY models with new sources of flavour violation in squark mass matrices, analyzing present constraints and possible developments with forthcoming data on b -> s and b -> d transitions.
|
1309.3462
|
Dorota Sokolowska
|
Dorota Sokolowska
|
Dark Matter and 125 GeV Higgs for IDM
|
4 pages, 3 figures, Proceeding of 25th Rencontres de Blois, May
26-31, 2013
| null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss a scalar Dark Matter candidate from the Inert Doublet Model in
light of discovery of a 125 GeV SM-like Higgs boson at the LHC. We explore the
possibility of using the recent and future data from LHC experiments, namely
the Higgs diphoton decay measurements, to constrain the properties of Dark
Matter particles.
|
[
{
"created": "Fri, 13 Sep 2013 14:16:32 GMT",
"version": "v1"
}
] |
2013-09-16
|
[
[
"Sokolowska",
"Dorota",
""
]
] |
We discuss a scalar Dark Matter candidate from the Inert Doublet Model in light of discovery of a 125 GeV SM-like Higgs boson at the LHC. We explore the possibility of using the recent and future data from LHC experiments, namely the Higgs diphoton decay measurements, to constrain the properties of Dark Matter particles.
|
hep-ph/9609309
|
Richard Ball
|
R.D. Ball and A. De Roeck
|
Structure Functions
|
25 pages, LaTeX with sprocl.sty, 14 figures in postscript. Summary
Talk of WG1 at DIS96
| null | null |
DESY 96-185, Edinburgh 96/24.
|
hep-ph hep-ex
| null |
We summarize recent developments in the understanding of nucleon structure.
New data on F2, R and F2c, over a wide range of Q2 and x, are described.
Conventional leading twist NLO perturbative QCD gives an excellent account of
all the new data with Q2 above a GeV, leaving very little room for either
higher twists or higher logarithms. We summarize the current status of NLO
fits, and the determination of the gluon distribution and the strong coupling
constant from structure function data. Finally we consider some of the
theoretical issues raised by the new data.
|
[
{
"created": "Tue, 10 Sep 1996 16:54:54 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Ball",
"R. D.",
""
],
[
"De Roeck",
"A.",
""
]
] |
We summarize recent developments in the understanding of nucleon structure. New data on F2, R and F2c, over a wide range of Q2 and x, are described. Conventional leading twist NLO perturbative QCD gives an excellent account of all the new data with Q2 above a GeV, leaving very little room for either higher twists or higher logarithms. We summarize the current status of NLO fits, and the determination of the gluon distribution and the strong coupling constant from structure function data. Finally we consider some of the theoretical issues raised by the new data.
|
2305.01449
|
Alessandro Pilloni
|
JPAC Collaboration: D. Winney, C. Fernandez-Ramirez, A. Pilloni, A. N.
Hiller Blin, M. Albaladejo, L. Bibrzycki, N. Hammoud, J. Liao, V. Mathieu, G.
Montana, R. J. Perry, V. Shastry, W. A. Smith, A. P. Szczepaniak
|
Dynamics in near-threshold $J/\psi$ photoproduction
|
15 pages, 7 figures, 2 tables. Version to appear on Phys. Rev. D
|
Phys. Rev. D 108 (2023) 5, 054018
| null |
JLAB-THY-23-3802
|
hep-ph hep-ex nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The study of $J/\psi$ photoproduction at low energies has consequences for
the understanding of multiple aspects of nonperturbative QCD, ranging from
mechanical properties of the proton, to the binding inside nuclei, and the
existence of hidden-charm pentaquarks. Factorization of the photon-$c \bar c$
and nucleon dynamics or Vector Meson Dominance are often invoked to justify
these studies. Alternatively, open charm intermediate states have been proposed
as the dominant mechanism underlying $J/\psi$ photoproduction. As the latter
violates this factorization, it is important to estimate the relevance of such
contributions. We analyse the latest differential and integrated
photoproduction cross sections from the GlueX and $J/\psi$-007 experiments. We
show that the data can be adequately described by a small number of partial
waves, which we parameterize with generic models enforcing low-energy
unitarity. The results suggest a nonnegligible contribution from open charm
intermediate states. Furthermore, most of the models present an elastic
scattering length incompatible with previous extractions based on Vector Meson
Dominance, and thus call into question its applicability to heavy mesons. Our
results indicate a wide array of physics possibilities that are compatible with
present data and need to be disentangled.
|
[
{
"created": "Tue, 2 May 2023 14:29:06 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Sep 2023 15:58:57 GMT",
"version": "v2"
}
] |
2023-09-14
|
[
[
"JPAC Collaboration",
"",
""
],
[
"Winney",
"D.",
""
],
[
"Fernandez-Ramirez",
"C.",
""
],
[
"Pilloni",
"A.",
""
],
[
"Blin",
"A. N. Hiller",
""
],
[
"Albaladejo",
"M.",
""
],
[
"Bibrzycki",
"L.",
""
],
[
"Hammoud",
"N.",
""
],
[
"Liao",
"J.",
""
],
[
"Mathieu",
"V.",
""
],
[
"Montana",
"G.",
""
],
[
"Perry",
"R. J.",
""
],
[
"Shastry",
"V.",
""
],
[
"Smith",
"W. A.",
""
],
[
"Szczepaniak",
"A. P.",
""
]
] |
The study of $J/\psi$ photoproduction at low energies has consequences for the understanding of multiple aspects of nonperturbative QCD, ranging from mechanical properties of the proton, to the binding inside nuclei, and the existence of hidden-charm pentaquarks. Factorization of the photon-$c \bar c$ and nucleon dynamics or Vector Meson Dominance are often invoked to justify these studies. Alternatively, open charm intermediate states have been proposed as the dominant mechanism underlying $J/\psi$ photoproduction. As the latter violates this factorization, it is important to estimate the relevance of such contributions. We analyse the latest differential and integrated photoproduction cross sections from the GlueX and $J/\psi$-007 experiments. We show that the data can be adequately described by a small number of partial waves, which we parameterize with generic models enforcing low-energy unitarity. The results suggest a nonnegligible contribution from open charm intermediate states. Furthermore, most of the models present an elastic scattering length incompatible with previous extractions based on Vector Meson Dominance, and thus call into question its applicability to heavy mesons. Our results indicate a wide array of physics possibilities that are compatible with present data and need to be disentangled.
|
1207.4926
|
Grigory Kirilin
|
Martin Beneke, Grisha Kirilin
|
Soft-collinear gravity
|
16 pages, 2 figures
| null |
10.1007/JHEP09(2012)066
|
TUM-HEP-848/12; TTK-12-31
|
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study collinear and soft singularities in perturbative quantum gravity by
constructing an effective field theory similar to soft-collinear effective
theory for QCD (SCET). We find that the soft sector exhibits factorization
properties similar to those of SCET. The collinear sector is, however, quite
different. While the leading-power collinear effective Lagrangian is trivial,
the presence of the metric field $h_{++}$ with negative scaling dimension
allows for collinear divergences in loop diagrams with couplings to
non-collinear sources. We provide a compact proof of the well-known fact that
there are no collinear singularities in perturbative quantum gravity by
demonstrating the decoupling of $h_{++}$ from the sources. We briefly discuss
the connection of our approach to recent work by Akhoury et al. (Phys. Rev. D84
(2011) 104040) as well as to the Weinberg's original paper (Phys. Rev. 140
(1965) B516), where the cancellation of the collinear singularities was
demonstrated for the first time in the eikonal approximation.
|
[
{
"created": "Fri, 20 Jul 2012 11:54:49 GMT",
"version": "v1"
}
] |
2015-06-05
|
[
[
"Beneke",
"Martin",
""
],
[
"Kirilin",
"Grisha",
""
]
] |
We study collinear and soft singularities in perturbative quantum gravity by constructing an effective field theory similar to soft-collinear effective theory for QCD (SCET). We find that the soft sector exhibits factorization properties similar to those of SCET. The collinear sector is, however, quite different. While the leading-power collinear effective Lagrangian is trivial, the presence of the metric field $h_{++}$ with negative scaling dimension allows for collinear divergences in loop diagrams with couplings to non-collinear sources. We provide a compact proof of the well-known fact that there are no collinear singularities in perturbative quantum gravity by demonstrating the decoupling of $h_{++}$ from the sources. We briefly discuss the connection of our approach to recent work by Akhoury et al. (Phys. Rev. D84 (2011) 104040) as well as to the Weinberg's original paper (Phys. Rev. 140 (1965) B516), where the cancellation of the collinear singularities was demonstrated for the first time in the eikonal approximation.
|
0705.1330
|
Pedro David Ruiz-Femenia
|
Pedro D. Ruiz-Femenia
|
The soft-energy region in the radiative decay of bound states
|
28 pages, 5 figures; typos corrected, one reference added, published
version
|
Nucl.Phys.B788:21-46,2008
|
10.1016/j.nuclphysb.2007.07.013
|
MPP-2007-46
|
hep-ph
| null |
The orthopositronium decay to three photons is studied in the phase-space
region where one of the photons has an energy comparable to the relative
three-momentum of the e+e- system (w ~ m alpha). The NRQED computation in this
regime shows that the dominant contribution arises from distances ~
1/(mw)^(1/2), which allows to treat the Coulomb interaction perturbatively. The
small-photon energy expansion of the 1-loop decay spectrum from full QED yields
the same result as the effective theory. By doing the threshold expansion of
the 1-loop QED amplitude we confirm that the leading term arises from a
loop-momentum region where q^0 ~ q^2/m ~ w. This corresponds to a new
non-relativistic loop-momentum region, which has to be taken into account for
the description of a non-relativistic particle-antiparticle system that decays
through soft photon emission.
|
[
{
"created": "Wed, 9 May 2007 19:10:53 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Sep 2007 17:01:24 GMT",
"version": "v2"
}
] |
2008-11-26
|
[
[
"Ruiz-Femenia",
"Pedro D.",
""
]
] |
The orthopositronium decay to three photons is studied in the phase-space region where one of the photons has an energy comparable to the relative three-momentum of the e+e- system (w ~ m alpha). The NRQED computation in this regime shows that the dominant contribution arises from distances ~ 1/(mw)^(1/2), which allows to treat the Coulomb interaction perturbatively. The small-photon energy expansion of the 1-loop decay spectrum from full QED yields the same result as the effective theory. By doing the threshold expansion of the 1-loop QED amplitude we confirm that the leading term arises from a loop-momentum region where q^0 ~ q^2/m ~ w. This corresponds to a new non-relativistic loop-momentum region, which has to be taken into account for the description of a non-relativistic particle-antiparticle system that decays through soft photon emission.
|
hep-ph/9307348
|
Raju
|
Raju Venugopalan and Axel Vischer
|
Dynamical Growth Rate of a Diffuse Interface in First Order Phase
Transitions
|
LaTex, 9 pages, TPI-MINN-93-34/T, NUC-MINN-93-17/T
|
Phys.Rev. E49 (2004) 5849
|
10.1103/PhysRevE.49.5849
| null |
hep-ph cond-mat nucl-th
| null |
We compute the dynamical prefactor in the nucleation rate of bubbles or
droplets in first order phase transitions for the case where both viscous
damping and thermal dissipation are significant. This result, which generalizes
previous work on nucleation, may be applied to study the growth of bubbles or
droplets in condensed matter systems as well as in heavy ion collisions and in
the expansion of the early universe.
|
[
{
"created": "Tue, 27 Jul 1993 19:57:06 GMT",
"version": "v1"
}
] |
2009-10-22
|
[
[
"Venugopalan",
"Raju",
""
],
[
"Vischer",
"Axel",
""
]
] |
We compute the dynamical prefactor in the nucleation rate of bubbles or droplets in first order phase transitions for the case where both viscous damping and thermal dissipation are significant. This result, which generalizes previous work on nucleation, may be applied to study the growth of bubbles or droplets in condensed matter systems as well as in heavy ion collisions and in the expansion of the early universe.
|
hep-ph/0102004
|
James Letts
|
J. Letts and P. Mattig
|
Direct Determination of the CKM Matrix from Decays of W Bosons and Top
Quarks at High Energy e+e- Colliders
|
28 pages, 4 figures; Submitted to Eur. Phys. J. C
|
Eur.Phys.J.C21:211-223,2001
|
10.1007/s100520100722
|
LC-PHSM-2001-008
|
hep-ph
| null |
At proposed high energy linear e+e- colliders a large number of W bosons and
top quarks will be produced. We evaluate the potential precision to which the
decay branching ratios into the various quark species can be measured, implying
also the determination of the respective CKM matrix elements. Crucial is the
identification of the individual quark flavours, which can be achieved
independent of QCD models. For transitions involving up quarks the accuracy is
of the same order of magnitude as has been reached in hadron decays. We
estimate that for charm transitions a precision can be reached that is superior
to current and projected traditional kinds of measurements. The t->b
determination will be significantly improved, and for the first time a direct
measurement of the t->s transition can be made. In all cases such a
determination is complementary to the traditional way of extracting the CKM
matrix elements.
|
[
{
"created": "Thu, 1 Feb 2001 14:15:46 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Letts",
"J.",
""
],
[
"Mattig",
"P.",
""
]
] |
At proposed high energy linear e+e- colliders a large number of W bosons and top quarks will be produced. We evaluate the potential precision to which the decay branching ratios into the various quark species can be measured, implying also the determination of the respective CKM matrix elements. Crucial is the identification of the individual quark flavours, which can be achieved independent of QCD models. For transitions involving up quarks the accuracy is of the same order of magnitude as has been reached in hadron decays. We estimate that for charm transitions a precision can be reached that is superior to current and projected traditional kinds of measurements. The t->b determination will be significantly improved, and for the first time a direct measurement of the t->s transition can be made. In all cases such a determination is complementary to the traditional way of extracting the CKM matrix elements.
|
1401.5586
|
Dong-Won Jung
|
Dong-Won Jung, P. Ko
|
Higgs-dilaton(radion) system confronting the LHC Higgs data
|
Minor corrections, including a few new figures, version appearing in
Physics Letters B
| null |
10.1016/j.physletb.2014.04.005
|
KIAS-P13004
|
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the Higgs-dilaton(radion) system using the trace of
energy-momentum tensor ($T_{~\mu}^\mu$) with the full Standard Model (SM) gauge
symmetry $G_{\rm SM} \equiv SU(3)_c \times SU(2)_L \times U(1)_Y$, and find out
that the resulting phenomenology for the Higgs-dilaton(radion) system is
distinctly different from the earlier studies based on the $T_{~\mu}^\mu$ with
the unbroken subgroup $H_{\rm SM} \equiv SU(3)_c \times U(1)_{\rm em}$ of
$G_{\rm SM}$. After electroweak symmetry breaking (EWSB), the SM Higgs boson
and dilaton(radion) will mix with each other, and there appear two Higgs-like
scalar bosons and the Higgs-dilaton mixing changes the scalar phenomenology in
interesting ways. The signal strengths for the $gg$-initiated channels could be
modified significantly compared with the SM predictions due to the QCD scale
anomaly and the Higgs-dilaton(radion) mixing, whereas anomaly contributions are
almost negligible for other channels. We also discuss the self-couplings and
the signal strengths of the $126$ GeV scalar boson in various channels and
possible constraints from the extra light/heavy scalar boson. The
Higgs-dilaton(radion) system considered in this work has a number of
distinctive features that could be tested by the upcoming LHC running and at
the ILC.
|
[
{
"created": "Wed, 22 Jan 2014 08:42:01 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Feb 2014 14:11:32 GMT",
"version": "v2"
},
{
"created": "Mon, 21 Apr 2014 07:10:34 GMT",
"version": "v3"
}
] |
2015-06-18
|
[
[
"Jung",
"Dong-Won",
""
],
[
"Ko",
"P.",
""
]
] |
We consider the Higgs-dilaton(radion) system using the trace of energy-momentum tensor ($T_{~\mu}^\mu$) with the full Standard Model (SM) gauge symmetry $G_{\rm SM} \equiv SU(3)_c \times SU(2)_L \times U(1)_Y$, and find out that the resulting phenomenology for the Higgs-dilaton(radion) system is distinctly different from the earlier studies based on the $T_{~\mu}^\mu$ with the unbroken subgroup $H_{\rm SM} \equiv SU(3)_c \times U(1)_{\rm em}$ of $G_{\rm SM}$. After electroweak symmetry breaking (EWSB), the SM Higgs boson and dilaton(radion) will mix with each other, and there appear two Higgs-like scalar bosons and the Higgs-dilaton mixing changes the scalar phenomenology in interesting ways. The signal strengths for the $gg$-initiated channels could be modified significantly compared with the SM predictions due to the QCD scale anomaly and the Higgs-dilaton(radion) mixing, whereas anomaly contributions are almost negligible for other channels. We also discuss the self-couplings and the signal strengths of the $126$ GeV scalar boson in various channels and possible constraints from the extra light/heavy scalar boson. The Higgs-dilaton(radion) system considered in this work has a number of distinctive features that could be tested by the upcoming LHC running and at the ILC.
|
1107.3529
|
Kang Zhao-Feng
|
Xin Gao, Zhaofeng Kang, Tianjun Li
|
Origins of the Isospin Violation of Dark Matter Interactions
|
References added and English greatly improved
| null |
10.1088/1475-7516/2013/01/021
| null |
hep-ph astro-ph.CO
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Light dark matter (DM) with a large DM-nucleon spin-independent cross section
and furthermore proper isospin violation (ISV) $f_n/f_p\approx-0.7$ may provide
a way to understand the confusing DM direct detection results. Combing with the
stringent astrophysical and collider constraints, we systematically investigate
the origin of ISV first via general operator analyses and further via
specifying three kinds of (single) mediators: A light $Z'$ from chiral
$U(1)_X$, an approximate spectator Higgs doublet (It can explain the $W+jj$
anomaly simultaneously) and color triplets. In addition, although $Z'$ from an
exotic $U(1)_X$ mixing with $U(1)_Y$ generating $f_n=0$, we can combine it with
the conventional Higgs to achieve proper ISV. As a concrete example, we propose
the $U(1)_X$ model where the $U(1)_X$ charged light sneutrino is the inelastic
DM, which dominantly annihilates to light dark states such as $Z'$ with sub-GeV
mass. This model can address the recent GoGeNT annual modulation consistent
with other DM direct detection results and free of exclusions.
|
[
{
"created": "Mon, 18 Jul 2011 19:13:02 GMT",
"version": "v1"
},
{
"created": "Tue, 6 Nov 2012 19:10:42 GMT",
"version": "v2"
}
] |
2015-05-28
|
[
[
"Gao",
"Xin",
""
],
[
"Kang",
"Zhaofeng",
""
],
[
"Li",
"Tianjun",
""
]
] |
Light dark matter (DM) with a large DM-nucleon spin-independent cross section and furthermore proper isospin violation (ISV) $f_n/f_p\approx-0.7$ may provide a way to understand the confusing DM direct detection results. Combing with the stringent astrophysical and collider constraints, we systematically investigate the origin of ISV first via general operator analyses and further via specifying three kinds of (single) mediators: A light $Z'$ from chiral $U(1)_X$, an approximate spectator Higgs doublet (It can explain the $W+jj$ anomaly simultaneously) and color triplets. In addition, although $Z'$ from an exotic $U(1)_X$ mixing with $U(1)_Y$ generating $f_n=0$, we can combine it with the conventional Higgs to achieve proper ISV. As a concrete example, we propose the $U(1)_X$ model where the $U(1)_X$ charged light sneutrino is the inelastic DM, which dominantly annihilates to light dark states such as $Z'$ with sub-GeV mass. This model can address the recent GoGeNT annual modulation consistent with other DM direct detection results and free of exclusions.
|
1302.6215
|
Christian Bogner
|
Christian Bogner and Martin L\"uders
|
Multiple polylogarithms and linearly reducible Feynman graphs
|
17 pages, to appear in the proceedings of the workshop "Periods and
Motives", Madrid, July 2012
| null | null | null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We review an approach for the computation of Feynman integrals by use of
multiple polylogarithms, with an emphasis on the related criterion of linear
reducibility of the graph. We show that the set of graphs which satisfies the
linear reducibility with respect to both Symanzik polynomials is closed under
taking minors. As a step towards a classification of Feynman integrals, we
discuss the concept of critical minors and exhibit an example at three loops
with four on-shell legs.
|
[
{
"created": "Mon, 25 Feb 2013 20:19:27 GMT",
"version": "v1"
}
] |
2013-02-26
|
[
[
"Bogner",
"Christian",
""
],
[
"Lüders",
"Martin",
""
]
] |
We review an approach for the computation of Feynman integrals by use of multiple polylogarithms, with an emphasis on the related criterion of linear reducibility of the graph. We show that the set of graphs which satisfies the linear reducibility with respect to both Symanzik polynomials is closed under taking minors. As a step towards a classification of Feynman integrals, we discuss the concept of critical minors and exhibit an example at three loops with four on-shell legs.
|
1206.5047
|
Jackson Wu
|
We-Fu Chang, John N. Ng, Jackson M. S. Wu
|
Constraints on New Scalars from the LHC 125 GeV Higgs Signal
|
23 pages, 8 figures; references addded, typos corrected. Published in
PRD
| null |
10.1103/PhysRevD.86.033003
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the implications the recent results from the LHC Higgs searches have
on scalar new physics. We study the impact on both the Higgs production and
decay from scalars with and without colour, and in cases where decoupling do
and do not happen. We investigate possible constraints on scalar parameters
from the production rate in the diphoton channel, and also the two vector boson
channels. Measurements from both channels can help disentangle new physics due
to colour from that due to charge, and thus reveal the nature of the new scalar
states.
|
[
{
"created": "Fri, 22 Jun 2012 03:37:49 GMT",
"version": "v1"
},
{
"created": "Tue, 7 Aug 2012 02:46:27 GMT",
"version": "v2"
}
] |
2013-05-30
|
[
[
"Chang",
"We-Fu",
""
],
[
"Ng",
"John N.",
""
],
[
"Wu",
"Jackson M. S.",
""
]
] |
We study the implications the recent results from the LHC Higgs searches have on scalar new physics. We study the impact on both the Higgs production and decay from scalars with and without colour, and in cases where decoupling do and do not happen. We investigate possible constraints on scalar parameters from the production rate in the diphoton channel, and also the two vector boson channels. Measurements from both channels can help disentangle new physics due to colour from that due to charge, and thus reveal the nature of the new scalar states.
|
1406.6965
|
Cem Salih Un
|
K. S. Babu, Ilia Gogoladze, Qaisar Shafi and Cem Salih Un
|
Muon g-2, 125 GeV Higgs and Neutralino Dark Matter in sMSSM
| null | null | null | null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We discuss the sparticle (and Higgs) spectrum in a class of flavor
symmetry-based minimal supersymmetric standard models, referred to here as
sMSSM. In this framework the SUSY breaking Lagrangian takes the most general
form consistent with a grand unified symmetry such as SO(10) and a non-Abelian
flavor symmetry acting on the three families with either a 2+1 or a 3 family
assignment. Models based on gauged SU(2) and SO(3) flavor symmetry, as well as
non-Abelian discrete symmetries such as S_3 and A_4, have been suggested which
fall into this category. These models describe supersymmetry breaking in terms
of seven phenomenological parameters. The soft supersymmetry breaking masses at
M_GUT of all sfermions of the first two families are equal in sMSSM, which
differ in general from the corresponding third family mass. In such a framework
we show that the muon g-2 anomaly, the observed Higgs boson mass of ~ 125 GeV,
and the observed relic neutralino dark matter abundance can be simultaneously
accommodated. The resolution of the muon g-2 anomaly in particular yields the
result that the first two generation squark masses, as well the gluino mass,
should be <~ 2 TeV, which will be tested at LHC14.
|
[
{
"created": "Thu, 26 Jun 2014 18:10:50 GMT",
"version": "v1"
}
] |
2014-06-27
|
[
[
"Babu",
"K. S.",
""
],
[
"Gogoladze",
"Ilia",
""
],
[
"Shafi",
"Qaisar",
""
],
[
"Un",
"Cem Salih",
""
]
] |
We discuss the sparticle (and Higgs) spectrum in a class of flavor symmetry-based minimal supersymmetric standard models, referred to here as sMSSM. In this framework the SUSY breaking Lagrangian takes the most general form consistent with a grand unified symmetry such as SO(10) and a non-Abelian flavor symmetry acting on the three families with either a 2+1 or a 3 family assignment. Models based on gauged SU(2) and SO(3) flavor symmetry, as well as non-Abelian discrete symmetries such as S_3 and A_4, have been suggested which fall into this category. These models describe supersymmetry breaking in terms of seven phenomenological parameters. The soft supersymmetry breaking masses at M_GUT of all sfermions of the first two families are equal in sMSSM, which differ in general from the corresponding third family mass. In such a framework we show that the muon g-2 anomaly, the observed Higgs boson mass of ~ 125 GeV, and the observed relic neutralino dark matter abundance can be simultaneously accommodated. The resolution of the muon g-2 anomaly in particular yields the result that the first two generation squark masses, as well the gluino mass, should be <~ 2 TeV, which will be tested at LHC14.
|
hep-ph/9404332
|
Boucaud
|
V. N. Gribov
|
Orsay lectures on confinement (II)
|
LPTHE 94-20, 13 pages with 4 figures in PostScript; uses plain TeX
with epsf.tex (included)
| null | null | null |
hep-ph
| null |
The behaviour of the light quark vacuum in the presence of a heavy quark is
investigated.
|
[
{
"created": "Mon, 25 Apr 1994 14:59:49 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Gribov",
"V. N.",
""
]
] |
The behaviour of the light quark vacuum in the presence of a heavy quark is investigated.
|
hep-ph/0411173
|
Pedro Fernando Simoes Costa
|
Pedro Costa, M. C. Ruivo, Yu. L. Kalinovsky
|
Two photon decay of $\pi^0$ and $\eta$ at finite temperature and density
|
5 pages, 1 figure. Talk given at Strange Quark Matter 2004, Cape
Town, South Africa, 15-20 September, 2004
|
J.Phys. G31 (2005) S1171-S1174
|
10.1088/0954-3899/31/6/080
| null |
hep-ph
| null |
A comparative study of the anomalous decays $\pi^0, \eta \to\gamma\gamma$, at
finite temperature and at finite density, is performed in the framework of the
three--flavor Nambu--Jona-Lasinio. The similarities and differences between
both scenarios are discussed. In both cases the lifetimes of these mesons
decrease significantly at the critical point, although this might not be
sufficient to observe enhancement of these decays in heavy-ion collisions.
|
[
{
"created": "Fri, 12 Nov 2004 16:35:04 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Costa",
"Pedro",
""
],
[
"Ruivo",
"M. C.",
""
],
[
"Kalinovsky",
"Yu. L.",
""
]
] |
A comparative study of the anomalous decays $\pi^0, \eta \to\gamma\gamma$, at finite temperature and at finite density, is performed in the framework of the three--flavor Nambu--Jona-Lasinio. The similarities and differences between both scenarios are discussed. In both cases the lifetimes of these mesons decrease significantly at the critical point, although this might not be sufficient to observe enhancement of these decays in heavy-ion collisions.
|
hep-ph/9804412
|
Seiichi Wakaizumi
|
T. Hattori(Univ. Tokushima), T. Hasuike(Anan Col. Technology), S.
Wakaizumi(Univ. Tokushima)
|
K^+\to\pi^+\nu\bar{\nu} with four generations and its effects on
unitarity triangle
|
14 pages written in LaTex, 2 figures available upon request
| null | null |
TOKUSHIMA 98-01
|
hep-ph
| null |
We analyze in the four-generation model the first measurement of the
branching ratio of rare kaon decay K^+\to\pi^+\nu\bar{\nu}, using the
constraints from \Delta m_K, \epsilon_K, B_d-\bar{B_d} mixing, \Gamma (b\to
s\gamma), B_s-\bar{B_s} mixing, D^0-\bar{D^0} mixing,
B(K_L\to\pi^0\nu\bar{\nu}) and B(K_L\to\mu\bar{\mu}), and study its effects on
the unitarity triangle. With the results of searching for the maximum mixing of
the fourth generation, we predict that D^0-\bar{D^0} mixing \Delta m_D and the
branching ratio of "direct" CP-violating decay process K_L\to\pi^0\nu\bar{\nu}
could attain the values 1-2 orders of magnitude larger than the predictions of
the Standard Model.
|
[
{
"created": "Mon, 27 Apr 1998 09:29:56 GMT",
"version": "v1"
}
] |
2009-09-25
|
[
[
"Hattori",
"T.",
"",
"Univ. Tokushima"
],
[
"Hasuike",
"T.",
"",
"Anan Col. Technology"
],
[
"Wakaizumi",
"S.",
"",
"Univ. Tokushima"
]
] |
We analyze in the four-generation model the first measurement of the branching ratio of rare kaon decay K^+\to\pi^+\nu\bar{\nu}, using the constraints from \Delta m_K, \epsilon_K, B_d-\bar{B_d} mixing, \Gamma (b\to s\gamma), B_s-\bar{B_s} mixing, D^0-\bar{D^0} mixing, B(K_L\to\pi^0\nu\bar{\nu}) and B(K_L\to\mu\bar{\mu}), and study its effects on the unitarity triangle. With the results of searching for the maximum mixing of the fourth generation, we predict that D^0-\bar{D^0} mixing \Delta m_D and the branching ratio of "direct" CP-violating decay process K_L\to\pi^0\nu\bar{\nu} could attain the values 1-2 orders of magnitude larger than the predictions of the Standard Model.
|
hep-ph/0504015
|
Sergio Palomares-Ruiz
|
Olga Mena Requejo (Fermilab), Sergio Palomares-Ruiz (Vanderbilt U.)
and Silvia Pascoli (CERN)
|
Super-NOvA: a long-baseline neutrino experiment with two off-axis
detectors
|
17 pp and 7 figs
|
Phys.Rev.D72:053002,2005
|
10.1103/PhysRevD.72.053002
|
CERN-PH-TH/2005-050, FERMILAB-PUB-05-050-T
|
hep-ph
| null |
Establishing the neutrino mass hierarchy is one of the fundamental questions
that will have to be addressed in the next future. Its determination could be
obtained with long-baseline experiments but typically suffers from degeneracies
with other neutrino parameters. We consider here the NOvA experiment
configuration and propose to place a second off-axis detector, with a shorter
baseline, such that, by exploiting matter effects, the type of neutrino mass
hierarchy could be determined with only the neutrino run. We show that the
determination of this parameter is free of degeneracies, provided the ratio
L/E, where L the baseline and E is the neutrino energy, is the same for both
detectors.
|
[
{
"created": "Sun, 3 Apr 2005 22:44:49 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Requejo",
"Olga Mena",
"",
"Fermilab"
],
[
"Palomares-Ruiz",
"Sergio",
"",
"Vanderbilt U."
],
[
"Pascoli",
"Silvia",
"",
"CERN"
]
] |
Establishing the neutrino mass hierarchy is one of the fundamental questions that will have to be addressed in the next future. Its determination could be obtained with long-baseline experiments but typically suffers from degeneracies with other neutrino parameters. We consider here the NOvA experiment configuration and propose to place a second off-axis detector, with a shorter baseline, such that, by exploiting matter effects, the type of neutrino mass hierarchy could be determined with only the neutrino run. We show that the determination of this parameter is free of degeneracies, provided the ratio L/E, where L the baseline and E is the neutrino energy, is the same for both detectors.
|
hep-ph/0303004
|
Narison
|
Stephan Narison (LPMT-CNRS-Montpellier-FR)
|
Scalar mesons and the muon anomaly
|
Latex file, 5 pages, 2 tables, 1 eps figure. Version to appear in
Phys. Lett. B. Separation of the pure theoretical based and experimental PDG
based estimates of a_mu^SM
|
Phys.Lett. B568 (2003) 231-236
|
10.1016/j.physletb.2003.06.058
| null |
hep-ph astro-ph hep-ex hep-th
| null |
We evaluate systematically some new contributions of the QCD scalar mesons,
including radiative decay-productions, not considered with a better attention
until now in the evaluation of the hadronic contributions to the muon anomaly.
The sum of the scalar contributions to be added to the existing Standard Model
predictions a_mu^{SM} are estimated in units 10^{-10} to be a^{S}_mu= 1.0(0.6)
[TH based]} and 13(11) [ PDG based], where the errors are dominated by the ones
from the experimental widths of these scalar mesons. PDG based results suggest
that the value of a_mu^{SM} and its errors might have been underestimated in
previous works. The inclusion of these new effects leads to a perfect agreement
(< 1.1\sigma) of the measured value a^{exp}_mu and a_mu^{SM} from tau-decay and
implies a (1.5 ~ 3.3) sigma discrepancy between a^{exp}_mu and a_mu^{SM} from
e^+e^- into hadrons data. More refined unbiased estimates of a_mu^{SM} require
improved measurements of the scalar meson masses and widths. The impact of our
results to a_mu^{SM} is summarized in the conclusions.
|
[
{
"created": "Sun, 2 Mar 2003 14:57:11 GMT",
"version": "v1"
},
{
"created": "Sun, 29 Jun 2003 07:29:15 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Narison",
"Stephan",
"",
"LPMT-CNRS-Montpellier-FR"
]
] |
We evaluate systematically some new contributions of the QCD scalar mesons, including radiative decay-productions, not considered with a better attention until now in the evaluation of the hadronic contributions to the muon anomaly. The sum of the scalar contributions to be added to the existing Standard Model predictions a_mu^{SM} are estimated in units 10^{-10} to be a^{S}_mu= 1.0(0.6) [TH based]} and 13(11) [ PDG based], where the errors are dominated by the ones from the experimental widths of these scalar mesons. PDG based results suggest that the value of a_mu^{SM} and its errors might have been underestimated in previous works. The inclusion of these new effects leads to a perfect agreement (< 1.1\sigma) of the measured value a^{exp}_mu and a_mu^{SM} from tau-decay and implies a (1.5 ~ 3.3) sigma discrepancy between a^{exp}_mu and a_mu^{SM} from e^+e^- into hadrons data. More refined unbiased estimates of a_mu^{SM} require improved measurements of the scalar meson masses and widths. The impact of our results to a_mu^{SM} is summarized in the conclusions.
|
1612.02511
|
Kyu Jung Bae
|
Kyu Jung Bae, Howard Baer, Koichi Hamaguchi, and Kazunori Nakayama
|
Affleck-Dine Leptogenesis with Varying Peccei-Quinn Scale
|
1+21 pages, 1 figure
| null |
10.1007/JHEP02(2017)017
|
CTPU-16-44, UT-16-37, IPMU-16-0190
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Affleck-Dine leptogenesis scenario along the LHu flat direction is
reconsidered. It is known that successful Affleck-Dine leptogenesis requires
that the lightest neutrino mass is extremely small. This situation can be
significantly relaxed if the neutrino mass in the early universe is different
from the present one. We consider a supersymmetric
Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) type model, which provides a solution
to the strong CP problem and generates a SUSY mu-term and right-handed neutrino
masses. If the PQ scale during lepton number generation is much larger than the
present value, leptogenesis is very efficient so that enough baryon number can
be generated without introducing a hierarchically small neutrino mass. The
final baryon asymmetry is related to the mu-term, and hence linked to the level
of electroweak fine-tuning. We also show the PQ breaking scalar dynamics that
keeps a large PQ breaking scale during inflation and lepton number generation.
The mu-term generating superpotential plays an important role for preserving
the lepton asymmetry during saxion oscillation. In this scenario, the axion
isocurvature perturbation is naturally suppressed.
|
[
{
"created": "Thu, 8 Dec 2016 02:18:47 GMT",
"version": "v1"
}
] |
2017-03-08
|
[
[
"Bae",
"Kyu Jung",
""
],
[
"Baer",
"Howard",
""
],
[
"Hamaguchi",
"Koichi",
""
],
[
"Nakayama",
"Kazunori",
""
]
] |
The Affleck-Dine leptogenesis scenario along the LHu flat direction is reconsidered. It is known that successful Affleck-Dine leptogenesis requires that the lightest neutrino mass is extremely small. This situation can be significantly relaxed if the neutrino mass in the early universe is different from the present one. We consider a supersymmetric Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) type model, which provides a solution to the strong CP problem and generates a SUSY mu-term and right-handed neutrino masses. If the PQ scale during lepton number generation is much larger than the present value, leptogenesis is very efficient so that enough baryon number can be generated without introducing a hierarchically small neutrino mass. The final baryon asymmetry is related to the mu-term, and hence linked to the level of electroweak fine-tuning. We also show the PQ breaking scalar dynamics that keeps a large PQ breaking scale during inflation and lepton number generation. The mu-term generating superpotential plays an important role for preserving the lepton asymmetry during saxion oscillation. In this scenario, the axion isocurvature perturbation is naturally suppressed.
|
1610.08530
|
Greg Jackson B.Sc.
|
G. Jackson and A. Peshier
|
Tracing the pressure of the gluon plasma
|
18 pages, 7 figures, published version
|
Phys. Rev. D 95, 054021 (2017)
|
10.1103/PhysRevD.95.054021
| null |
hep-ph hep-lat nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Being interested in how a strongly coupled system approaches asymptotic
freedom, we re-examine existing precision lattice QCD results for thermodynamic
properties of the gluon plasma in a large temperature range. We discuss and
thoroughly test the applicability of perturbative results, on which grounds we
then infer that the pressure and other bulk properties approach the free limit
somewhat slower than previously thought. We also revise the value of the first
non-perturbative coefficient in the weak-coupling expansion.
|
[
{
"created": "Wed, 26 Oct 2016 20:04:35 GMT",
"version": "v1"
},
{
"created": "Thu, 30 Mar 2017 13:16:55 GMT",
"version": "v2"
}
] |
2017-04-05
|
[
[
"Jackson",
"G.",
""
],
[
"Peshier",
"A.",
""
]
] |
Being interested in how a strongly coupled system approaches asymptotic freedom, we re-examine existing precision lattice QCD results for thermodynamic properties of the gluon plasma in a large temperature range. We discuss and thoroughly test the applicability of perturbative results, on which grounds we then infer that the pressure and other bulk properties approach the free limit somewhat slower than previously thought. We also revise the value of the first non-perturbative coefficient in the weak-coupling expansion.
|
hep-ph/9506317
|
Paolo Nason
|
P. Nason and M.H. Seymour
|
Infrared Renormalons and Power Suppressed Effects in $e^+e^-$ Jet Events
|
20 pages, Latex, epsfig, 3 tar-gzip-uuencoded figures. Also available
from http://surya11.cern.ch/users/nason/misc/
|
Nucl.Phys. B454 (1995) 291-312
|
10.1016/0550-3213(95)00461-Z
|
CERN-TH/95-150, IFUM 507/FT
|
hep-ph
| null |
We study the effect of infrared renormalons upon shape variables that are
commonly used to determine the strong coupling constant in $e^+e^-$
annihilation into hadronic jets. We consider the model of QCD in the limit of
large $n_f$. We find a wide variety of different behaviours of shape variables
with respect to power suppressed effects induced by infrared renormalons. In
particular, we find that oblateness is affected by $1/Q$ non--perturbative
effects even away from the two jet region, and the energy--energy correlation
is affected by $1/Q$ non--perturbative effects for all values of the angle. On
the contrary, variables like thrust, the $c$ parameter, the heavy jet mass, and
others, do not develop any $1/Q$ correction away from the two jet region at the
leading $n_f$ level. We argue that $1/Q$ corrections will eventually arise at
subleading $n_f$ level, but that they could maintain an extra $\as(Q)$
suppression. We conjecture therefore that the leading power correction to shape
variables will have in general the form $\alpha^n_{\rm S}(Q)/Q$, and it may
therefore be possible to classify shape variables according to the value of
$n$.
|
[
{
"created": "Tue, 13 Jun 1995 15:55:14 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Jun 1995 09:12:53 GMT",
"version": "v2"
},
{
"created": "Fri, 16 Jun 1995 14:03:46 GMT",
"version": "v3"
}
] |
2009-10-28
|
[
[
"Nason",
"P.",
""
],
[
"Seymour",
"M. H.",
""
]
] |
We study the effect of infrared renormalons upon shape variables that are commonly used to determine the strong coupling constant in $e^+e^-$ annihilation into hadronic jets. We consider the model of QCD in the limit of large $n_f$. We find a wide variety of different behaviours of shape variables with respect to power suppressed effects induced by infrared renormalons. In particular, we find that oblateness is affected by $1/Q$ non--perturbative effects even away from the two jet region, and the energy--energy correlation is affected by $1/Q$ non--perturbative effects for all values of the angle. On the contrary, variables like thrust, the $c$ parameter, the heavy jet mass, and others, do not develop any $1/Q$ correction away from the two jet region at the leading $n_f$ level. We argue that $1/Q$ corrections will eventually arise at subleading $n_f$ level, but that they could maintain an extra $\as(Q)$ suppression. We conjecture therefore that the leading power correction to shape variables will have in general the form $\alpha^n_{\rm S}(Q)/Q$, and it may therefore be possible to classify shape variables according to the value of $n$.
|
1712.07237
|
Jia Liu
|
Jia Liu, Lian-Tao Wang, Xiao-Ping Wang, Wei Xue
|
Exposing Dark Sector with Future Z-Factories
|
42 pages, 16 figures, 2 tables. v2: references added, particle
separation improved, minor changes in figures, version matched to the journal
|
Phys. Rev. D 97, 095044 (2018)
|
10.1103/PhysRevD.97.095044
|
CERN-TH-2017-278, EFI-17-28, MITP/17-102, MIT-CTP/4972
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the prospects of searching dark sector models via exotic
Z-boson decay at future $e^+ e^-$ colliders with Giga Z and Tera Z options.
Four general categories of dark sector models: Higgs portal dark matter, vector
portal dark matter, inelastic dark matter and axion-like particles, are
considered. Focusing on channels motivated by the dark sector models, we carry
out a model independent study of the sensitivities of Z-factories in probing
exotic decays. The limits on branching ratios of the exotic Z decay are
typically $\mathcal{O} (10^{-6} - 10^{-8.5}) $ for the Giga Z and $\mathcal{O}
(10^{-7.5} - 10^{-11})$ for the Tera Z, and they are compared with the
projection for the high luminosity LHC. We demonstrate that future Z-factories
can provide its unique and leading sensitivity, and highlight the
complementarity with other experiments, including the indirect and direct dark
matter search limits, and the existing collider limits. Future Z factories will
play a leading role to uncover the hidden sector of the universe in the future.
|
[
{
"created": "Tue, 19 Dec 2017 22:04:18 GMT",
"version": "v1"
},
{
"created": "Fri, 11 May 2018 23:52:09 GMT",
"version": "v2"
}
] |
2018-06-06
|
[
[
"Liu",
"Jia",
""
],
[
"Wang",
"Lian-Tao",
""
],
[
"Wang",
"Xiao-Ping",
""
],
[
"Xue",
"Wei",
""
]
] |
We investigate the prospects of searching dark sector models via exotic Z-boson decay at future $e^+ e^-$ colliders with Giga Z and Tera Z options. Four general categories of dark sector models: Higgs portal dark matter, vector portal dark matter, inelastic dark matter and axion-like particles, are considered. Focusing on channels motivated by the dark sector models, we carry out a model independent study of the sensitivities of Z-factories in probing exotic decays. The limits on branching ratios of the exotic Z decay are typically $\mathcal{O} (10^{-6} - 10^{-8.5}) $ for the Giga Z and $\mathcal{O} (10^{-7.5} - 10^{-11})$ for the Tera Z, and they are compared with the projection for the high luminosity LHC. We demonstrate that future Z-factories can provide its unique and leading sensitivity, and highlight the complementarity with other experiments, including the indirect and direct dark matter search limits, and the existing collider limits. Future Z factories will play a leading role to uncover the hidden sector of the universe in the future.
|
hep-ph/9806212
|
Anna Stasto
|
A.D.Martin, M.G.Ryskin and A.M.Stasto
|
The description of $F_2$ at low $Q^2$
|
18 pages, Latex, 10 ps figures; references to the photoproduction
data points have been changed
|
Eur.Phys.J.C7:643-654,1999
|
10.1007/s100529801035
|
DTP/98/20
|
hep-ph
| null |
We analyse the data for the proton structure function $F_2$ over the entire
$Q^2$ domain, including especially low $Q^2$, in terms of perturbative and
non-perturbative QCD contributions. The small distance configurations are given
by perturbative QCD, while the large distance contributions are given by the
vector dominance model and, for the higher mass $q \bar{q}$ states, by the
additive quark approach. The interference between states of different
$q\bar{q}$ mass (in the perturbative contribution) is found to play a crucial
role in obtaining an excellent description of the data throughout the whole
$Q^2$ region, including photoproduction.
|
[
{
"created": "Mon, 1 Jun 1998 08:07:57 GMT",
"version": "v1"
},
{
"created": "Sun, 21 Jun 1998 16:39:48 GMT",
"version": "v2"
}
] |
2011-09-13
|
[
[
"Martin",
"A. D.",
""
],
[
"Ryskin",
"M. G.",
""
],
[
"Stasto",
"A. M.",
""
]
] |
We analyse the data for the proton structure function $F_2$ over the entire $Q^2$ domain, including especially low $Q^2$, in terms of perturbative and non-perturbative QCD contributions. The small distance configurations are given by perturbative QCD, while the large distance contributions are given by the vector dominance model and, for the higher mass $q \bar{q}$ states, by the additive quark approach. The interference between states of different $q\bar{q}$ mass (in the perturbative contribution) is found to play a crucial role in obtaining an excellent description of the data throughout the whole $Q^2$ region, including photoproduction.
|
hep-ph/9305288
|
Mike Berger
|
V. Barger, M. S. Berger, P. Ohmann, and R.J.N. Phillips
|
Phenomenological Implications of the m_t RGE Fixed Point for SUSY Higgs
Boson Searches
|
(Talk given at the Hawaii LCWS VB), 4 pages + 4 EPS figures included
(uuencoded), MAD/PH/760
|
Phys. Lett. B314 (1993) 351
|
10.1016/0370-2693(93)91248-L
| null |
hep-ph
| null |
In minimal SUSY-GUT models with $M_{SUSY}\alt 1$ TeV, the renormalization
group equations have a solution dominated by the infrared fixed point of the
top Yukawa coupling. This fixed point predicts $m_t\simeq (200\; {\rm GeV})\sin
\beta $; combined with the LEP results it excludes $m_t\alt 130$ GeV. For $m_t$
in the range 130--160 GeV, it predicts that the lightest scalar $h$ has mass
60--85 GeV (detectable at LEP\,II). At SSC/LHC, each of the five scalars $h$,
$H$, $A$, $H^{\pm }$ may be detectable, but not all of them together; in one
parameter region none would be detectable.
|
[
{
"created": "Wed, 19 May 1993 17:08:14 GMT",
"version": "v1"
}
] |
2009-10-22
|
[
[
"Barger",
"V.",
""
],
[
"Berger",
"M. S.",
""
],
[
"Ohmann",
"P.",
""
],
[
"Phillips",
"R. J. N.",
""
]
] |
In minimal SUSY-GUT models with $M_{SUSY}\alt 1$ TeV, the renormalization group equations have a solution dominated by the infrared fixed point of the top Yukawa coupling. This fixed point predicts $m_t\simeq (200\; {\rm GeV})\sin \beta $; combined with the LEP results it excludes $m_t\alt 130$ GeV. For $m_t$ in the range 130--160 GeV, it predicts that the lightest scalar $h$ has mass 60--85 GeV (detectable at LEP\,II). At SSC/LHC, each of the five scalars $h$, $H$, $A$, $H^{\pm }$ may be detectable, but not all of them together; in one parameter region none would be detectable.
|
hep-ph/9507214
| null |
L. Dixon
|
Strings and Supersymmetry as Tools for Perturbative QCD
|
LaTex, 11 pages with 2 encapsulated figures in a uuencoded file.
Presented at SUSY95, Paris, May, 1995
| null | null |
SLAC-PUB-95-6946
|
hep-ph hep-th
| null |
We review techniques simplifying the analytic calculation of one-loop QCD
amplitudes with many external legs, for use in next-to-leading-order
corrections to multi-jet processes. We explain how a supersymmetry-inspired
organization works well in conjunction with other tools, namely the color and
helicity decompositions of amplitudes, and the constraints imposed by
perturbative unitarity and collinear singularities. String theory seems most
useful as a heuristic guide. Using these techniques, the complete set of
one-loop five-parton QCD amplitudes, as well as certain sequences of special
helicity amplitudes with an arbitrary number of external gluons, have been
obtained.
|
[
{
"created": "Tue, 4 Jul 1995 00:52:57 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Dixon",
"L.",
""
]
] |
We review techniques simplifying the analytic calculation of one-loop QCD amplitudes with many external legs, for use in next-to-leading-order corrections to multi-jet processes. We explain how a supersymmetry-inspired organization works well in conjunction with other tools, namely the color and helicity decompositions of amplitudes, and the constraints imposed by perturbative unitarity and collinear singularities. String theory seems most useful as a heuristic guide. Using these techniques, the complete set of one-loop five-parton QCD amplitudes, as well as certain sequences of special helicity amplitudes with an arbitrary number of external gluons, have been obtained.
|
1210.7584
|
Prashant Shukla
|
A. Abdulsalam and Prashant Shukla
|
Suppression of bottomonia states in finite size quark gluon plasma in
PbPb collisions at Large Hadron Collider
|
14 pages, 5 figures, To appear in Int. j. of Mod. Phys
| null |
10.1142/S0217751X13501054
| null |
hep-ph nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The bottomonium states due to their varying binding energies dissolve at
different temperatures and thus their nuclear modification factors and relative
yields have potential to map the properties of Quark Gluon Plasma (QGP). We
estimate the suppression of bottomonia states due to color screening in an
expanding QGP of finite lifetime and size with the conditions relevant for PbPb
collisions at LHC. The properties of $\Upsilon$ states and recent results on
their dissociation temperatures have been used as ingredient in the study. The
nuclear modification factors and the ratios of yields of $\Upsilon$ states are
then obtained as a function of transverse momentum and centrality. We compare
our theoretical calculations with the bottomonia yields measured with CMS in
PbPb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. The model calculations
explain the data very well.
|
[
{
"created": "Mon, 29 Oct 2012 08:04:22 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Aug 2013 06:50:08 GMT",
"version": "v2"
}
] |
2015-06-11
|
[
[
"Abdulsalam",
"A.",
""
],
[
"Shukla",
"Prashant",
""
]
] |
The bottomonium states due to their varying binding energies dissolve at different temperatures and thus their nuclear modification factors and relative yields have potential to map the properties of Quark Gluon Plasma (QGP). We estimate the suppression of bottomonia states due to color screening in an expanding QGP of finite lifetime and size with the conditions relevant for PbPb collisions at LHC. The properties of $\Upsilon$ states and recent results on their dissociation temperatures have been used as ingredient in the study. The nuclear modification factors and the ratios of yields of $\Upsilon$ states are then obtained as a function of transverse momentum and centrality. We compare our theoretical calculations with the bottomonia yields measured with CMS in PbPb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV. The model calculations explain the data very well.
|
hep-ph/9605387
|
Mariano Quiros
|
J.M. Moreno, D.H. Oaknin and M. Quiros
|
Sphalerons in the MSSM
|
36 pages, latex+psfig, 15 figures
|
Nucl.Phys.B483:267-290,1997
|
10.1016/S0550-3213(96)00562-7
|
IEM-FT-127/96
|
hep-ph
| null |
We construct the sphaleron solution, at zero and finite temperature, in the
Minimal Supersymmetric Standard Model as a function of the supersymmetric
parameters, including the leading one-loop corrections to the effective
potential in the presence of the sphaleron. At zero temperature we have
included the one-loop radiative corrections, dominated by the top/stop sector.
The sphaleron energy $E_{\rm MSSM}$ mainly depends on an effective Higgs mass
${\displaystyle m_h^{\rm eff}=\lim_{m_A\gg m_W} m_h}$, where $m_h$ is the
lightest CP-even Higgs mass and $m_A$ the pseudoscalar mass. We have compared
it with the Standard Model result, with $m_h^{\rm SM}=m_h^{\rm eff}$, and found
small differences (1-2\%) in all cases. At finite temperature we have included
the one-loop effective potential improved by daisy diagram resummation. The
sphaleron energy at the critical temperature can be encoded in the temperature
dependence of the vacuum expectation value of the Higgs field with an error
$\simlt 10$\%. The light stop scenario has been re-examined and the existence
of a window where baryon asymmetry is not erased after the phase transition,
confirmed. Although large (low) values of $m_h$ ($m_A$) are disfavoured by the
strength of the phase transition, that window (along with LEP results) allows
for $m_h\simlt 80$ GeV, $m_A\simgt 110$ GeV and $A_t\simlt 0.4\; m_Q$.
|
[
{
"created": "Fri, 24 May 1996 01:18:39 GMT",
"version": "v1"
}
] |
2008-12-25
|
[
[
"Moreno",
"J. M.",
""
],
[
"Oaknin",
"D. H.",
""
],
[
"Quiros",
"M.",
""
]
] |
We construct the sphaleron solution, at zero and finite temperature, in the Minimal Supersymmetric Standard Model as a function of the supersymmetric parameters, including the leading one-loop corrections to the effective potential in the presence of the sphaleron. At zero temperature we have included the one-loop radiative corrections, dominated by the top/stop sector. The sphaleron energy $E_{\rm MSSM}$ mainly depends on an effective Higgs mass ${\displaystyle m_h^{\rm eff}=\lim_{m_A\gg m_W} m_h}$, where $m_h$ is the lightest CP-even Higgs mass and $m_A$ the pseudoscalar mass. We have compared it with the Standard Model result, with $m_h^{\rm SM}=m_h^{\rm eff}$, and found small differences (1-2\%) in all cases. At finite temperature we have included the one-loop effective potential improved by daisy diagram resummation. The sphaleron energy at the critical temperature can be encoded in the temperature dependence of the vacuum expectation value of the Higgs field with an error $\simlt 10$\%. The light stop scenario has been re-examined and the existence of a window where baryon asymmetry is not erased after the phase transition, confirmed. Although large (low) values of $m_h$ ($m_A$) are disfavoured by the strength of the phase transition, that window (along with LEP results) allows for $m_h\simlt 80$ GeV, $m_A\simgt 110$ GeV and $A_t\simlt 0.4\; m_Q$.
|
1408.2620
|
Pankaj Jain
|
Pankaj Jain, Gopal Kashyap and Subhadip Mitra
|
The fine tuning of the cosmological constant in a conformal model
|
26 pages 12 figures, substantial revisions
| null |
10.1142/S0217751X15501717
| null |
hep-ph astro-ph.CO gr-qc hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider a conformal model involving two real scalar fields in which the
conformal symmetry is broken by a soft mechanism and is not anomalous. One of
these scalar fields is representative of the standard model Higgs. The model
predicts exactly zero cosmological constant. In the simplest version of the
model, some of the couplings need to be fine tuned to very small values. We
formulate the problem of fine tuning of these couplings. We argue that the
problem arises since we require a soft mechanism to break conformal symmetry.
The symmetry breaking is possible only if the scalar fields do not evolve
significantly over the time scale of the Universe. We present two solutions to
this fine tuning problem. We argue that the problem is solved if the classical
value of one of the scalar fields is super-Planckian, i.e. takes a value much
larger than the Planck mass. The second solution involves introduction of a
strongly coupled hidden sector that we call hypercolor. In this case the
conformal invariance is broken dynamically and triggers the breakdown of the
electroweak symmetry. We argue that our analysis applies also to the case of
the standard model Higgs multiplet.
|
[
{
"created": "Tue, 12 Aug 2014 05:17:13 GMT",
"version": "v1"
},
{
"created": "Tue, 12 May 2015 12:25:39 GMT",
"version": "v2"
}
] |
2015-12-02
|
[
[
"Jain",
"Pankaj",
""
],
[
"Kashyap",
"Gopal",
""
],
[
"Mitra",
"Subhadip",
""
]
] |
We consider a conformal model involving two real scalar fields in which the conformal symmetry is broken by a soft mechanism and is not anomalous. One of these scalar fields is representative of the standard model Higgs. The model predicts exactly zero cosmological constant. In the simplest version of the model, some of the couplings need to be fine tuned to very small values. We formulate the problem of fine tuning of these couplings. We argue that the problem arises since we require a soft mechanism to break conformal symmetry. The symmetry breaking is possible only if the scalar fields do not evolve significantly over the time scale of the Universe. We present two solutions to this fine tuning problem. We argue that the problem is solved if the classical value of one of the scalar fields is super-Planckian, i.e. takes a value much larger than the Planck mass. The second solution involves introduction of a strongly coupled hidden sector that we call hypercolor. In this case the conformal invariance is broken dynamically and triggers the breakdown of the electroweak symmetry. We argue that our analysis applies also to the case of the standard model Higgs multiplet.
|
hep-ph/0512113
|
Vladimir Shevchenko
|
V.I.Shevchenko (ITEP)
|
Chiral symmetry breaking in confining theories and asymptotic limits of
operator product expansion
|
LaTeX, 20 pages; minor revisions
|
JHEP 0603 (2006) 082
|
10.1088/1126-6708/2006/03/082
| null |
hep-ph hep-th
| null |
The pattern of spontaneous chiral symmetry breaking (CSB) in confining
background fields is analyzed. It is explicitly demonstrated how to get the
inverse square root large proper time asymptotic of the operator product
expansion which is needed for CSB.
|
[
{
"created": "Fri, 9 Dec 2005 16:00:48 GMT",
"version": "v1"
},
{
"created": "Tue, 4 Apr 2006 13:21:30 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Shevchenko",
"V. I.",
"",
"ITEP"
]
] |
The pattern of spontaneous chiral symmetry breaking (CSB) in confining background fields is analyzed. It is explicitly demonstrated how to get the inverse square root large proper time asymptotic of the operator product expansion which is needed for CSB.
|
hep-ph/0102280
|
Willy van Neerven
|
V. Ravindran and W.L. van Neerven
|
QCD and power corrections to sum rules in deep-inelastic lepton-nucleon
scattering
|
47 pages, LaTeX
|
Nucl.Phys. B605 (2001) 517-557
|
10.1016/S0550-3213(01)00190-0
| null |
hep-ph
| null |
In this paper we study QCD and power corrections to sum rules which show up
in deep inelastic lepton-hadron scattering. Furthermore we will make a
distinction between fundamental sum rules which can be derived from quantum
field theory and those which are of a phenomenological origin. Using current
algebra techniques the fundamental sum rules can be expressed into expectation
values of (partially) conserved (axial-) vector currents sandwiched between
hadronic states. These expectation values yield the quantum numbers of the
corresponding hadron which are determined by the underlying flavour group
$SU(n)_F$. In this case one can show that there exist an intimate relation
between the appearance of power and QCD corrections. The above features do not
hold for phenomenological sum rules, hereafter called non-fundamental. They
have no foundation in quantum field theory and they mostly depend on certain
assumptions made for the structure functions like superconvergence relations or
the parton model. Therefore only the fundamental sum rules provide us with a
stringent test of QCD.
|
[
{
"created": "Thu, 22 Feb 2001 18:00:55 GMT",
"version": "v1"
},
{
"created": "Tue, 27 Feb 2001 10:39:10 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Ravindran",
"V.",
""
],
[
"van Neerven",
"W. L.",
""
]
] |
In this paper we study QCD and power corrections to sum rules which show up in deep inelastic lepton-hadron scattering. Furthermore we will make a distinction between fundamental sum rules which can be derived from quantum field theory and those which are of a phenomenological origin. Using current algebra techniques the fundamental sum rules can be expressed into expectation values of (partially) conserved (axial-) vector currents sandwiched between hadronic states. These expectation values yield the quantum numbers of the corresponding hadron which are determined by the underlying flavour group $SU(n)_F$. In this case one can show that there exist an intimate relation between the appearance of power and QCD corrections. The above features do not hold for phenomenological sum rules, hereafter called non-fundamental. They have no foundation in quantum field theory and they mostly depend on certain assumptions made for the structure functions like superconvergence relations or the parton model. Therefore only the fundamental sum rules provide us with a stringent test of QCD.
|
hep-ph/9412362
|
Alexander Makhlin
|
A.Makhlin
|
Quantum Field Kinetics
|
13 pages, REVTeX, 2 postscript figures appended
|
Phys.Rev.C51:3454-3464,1995
|
10.1103/PhysRevC.51.3454
|
WSU-NP-94-3
|
hep-ph
| null |
Using the general framework of quantum field theory, we derive basic
equations of quantum field kinetics. The main goal of this approach is to
compute the observables associated with a quark-gluon plasma at different
stages of its evolution. We start by rewriting the integral equations for the
field correlators in different forms, depending on the relevant dynamical
features at each different stage. Next, two versions of perturbation expansion
are considered. The first is best suited for the calculation of electromagnetic
emission from chaotic, but not equilibrated, strongly interacting matter. The
second version allows one to derive evolution equations, which are
generalizations of the familiar QCD evolution equations, and provide a basis
for the calculation of the initial quark and gluon distributions after the
first hard interaction of the heavy ions.
|
[
{
"created": "Thu, 22 Dec 1994 19:14:11 GMT",
"version": "v1"
}
] |
2009-09-25
|
[
[
"Makhlin",
"A.",
""
]
] |
Using the general framework of quantum field theory, we derive basic equations of quantum field kinetics. The main goal of this approach is to compute the observables associated with a quark-gluon plasma at different stages of its evolution. We start by rewriting the integral equations for the field correlators in different forms, depending on the relevant dynamical features at each different stage. Next, two versions of perturbation expansion are considered. The first is best suited for the calculation of electromagnetic emission from chaotic, but not equilibrated, strongly interacting matter. The second version allows one to derive evolution equations, which are generalizations of the familiar QCD evolution equations, and provide a basis for the calculation of the initial quark and gluon distributions after the first hard interaction of the heavy ions.
|
2008.05703
|
Claude Bourrely
|
Claude Bourrely, Franco Buccella, Jen-Chieh Peng
|
A New Extraction of Pion Parton Distributions in the Statistical Model
|
5 pages, 5 figures
| null |
10.1016/j.physletb.2020.136021
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We present a new analysis to extract pion's parton distribution functions
(PDFs) in the framework of the statistical model. Starting from the statistical
model framework first developed for the spin-1/2 nucleon, we apply appropriate
modifications taking into account the spin-0 nature of pion and the isospin and
charge-conjugation symmetry properties. This results in a significant reduction
of the number of parameters compared to a recent work to extract pion's PDFs.
Using $\pi^-$-induced Drell-Yan data to determine the parameters of this
statistical model approach, we show that a good description of these
experimental data with Next-to-Leading order QCD calculations can be obtained.
Good agreement between the calculations and the $\pi^+/\pi^-$ Drell-Yan cross
section ratio data, not included in the global fit, has confirmed the
predictive power of these new pion PDFs.
|
[
{
"created": "Thu, 13 Aug 2020 06:06:07 GMT",
"version": "v1"
}
] |
2021-02-03
|
[
[
"Bourrely",
"Claude",
""
],
[
"Buccella",
"Franco",
""
],
[
"Peng",
"Jen-Chieh",
""
]
] |
We present a new analysis to extract pion's parton distribution functions (PDFs) in the framework of the statistical model. Starting from the statistical model framework first developed for the spin-1/2 nucleon, we apply appropriate modifications taking into account the spin-0 nature of pion and the isospin and charge-conjugation symmetry properties. This results in a significant reduction of the number of parameters compared to a recent work to extract pion's PDFs. Using $\pi^-$-induced Drell-Yan data to determine the parameters of this statistical model approach, we show that a good description of these experimental data with Next-to-Leading order QCD calculations can be obtained. Good agreement between the calculations and the $\pi^+/\pi^-$ Drell-Yan cross section ratio data, not included in the global fit, has confirmed the predictive power of these new pion PDFs.
|
0710.3100
|
Mikhail Smolyakov
|
Edward E. Boos, Viacheslav E. Bunichev, Mikhail N. Smolyakov, Igor P.
Volobuev
|
Testing extra dimensions below the production threshold of Kaluza-Klein
excitations
|
20 pages, 8 figures, LaTeX. Added figures, enlarged phenomenological
part
|
Phys.Rev.D79:104013,2009
|
10.1103/PhysRevD.79.104013
| null |
hep-ph hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider a stabilized RS1 model in the energy range below the direct
production of KK states. In this range we work out the effective Lagrangian due
to exchange of heavy KK tensor graviton and scalar radion states and compute
explicitly the corresponding effective coupling constants. As an example, the
Drell-Yan lepton pair production at the Tevatron and the LHC is analyzed in two
situations, when the first KK resonance is too heavy to be directly detected at
the colliders, and when the first KK resonance is visible but other states are
still too heavy. It is shown that in both cases the contribution from the KK
invisible tower leads to a modification of final particles distributions. In
particular, for the second case a nontrivial interference between the first KK
mode and the rest KK tower takes place. Expected 95% CL limits for model
parameters for the Tevatron and the LHC are given. In the Appendix useful
formulas for the cross sections and distributions of various new $2\to2$
processes via heavy KK tower exchange are presented, the new formulas
containing nonzero particle masses for final state fermions and bosons. The
formulas and numerical results are obtained by means of the CompHEP code, in
which all new effective interactions are implemented providing a tool for
simulation of corresponding events and a more detailed analysis.
|
[
{
"created": "Tue, 16 Oct 2007 15:54:42 GMT",
"version": "v1"
},
{
"created": "Fri, 26 Oct 2007 14:54:19 GMT",
"version": "v2"
},
{
"created": "Tue, 30 Oct 2007 21:46:32 GMT",
"version": "v3"
},
{
"created": "Sun, 19 Oct 2008 11:35:45 GMT",
"version": "v4"
},
{
"created": "Wed, 13 May 2009 22:26:42 GMT",
"version": "v5"
}
] |
2013-05-29
|
[
[
"Boos",
"Edward E.",
""
],
[
"Bunichev",
"Viacheslav E.",
""
],
[
"Smolyakov",
"Mikhail N.",
""
],
[
"Volobuev",
"Igor P.",
""
]
] |
We consider a stabilized RS1 model in the energy range below the direct production of KK states. In this range we work out the effective Lagrangian due to exchange of heavy KK tensor graviton and scalar radion states and compute explicitly the corresponding effective coupling constants. As an example, the Drell-Yan lepton pair production at the Tevatron and the LHC is analyzed in two situations, when the first KK resonance is too heavy to be directly detected at the colliders, and when the first KK resonance is visible but other states are still too heavy. It is shown that in both cases the contribution from the KK invisible tower leads to a modification of final particles distributions. In particular, for the second case a nontrivial interference between the first KK mode and the rest KK tower takes place. Expected 95% CL limits for model parameters for the Tevatron and the LHC are given. In the Appendix useful formulas for the cross sections and distributions of various new $2\to2$ processes via heavy KK tower exchange are presented, the new formulas containing nonzero particle masses for final state fermions and bosons. The formulas and numerical results are obtained by means of the CompHEP code, in which all new effective interactions are implemented providing a tool for simulation of corresponding events and a more detailed analysis.
|
1007.5520
|
JoAnne Hewett
|
R.C. Cotta, J.A. Conley, J.S. Gainer, J.L. Hewett, and T.G. Rizzo
|
Cosmic Ray Anomalies from the MSSM?
|
57 pages, 31 figures, references added
|
JHEP 1101:064,2011
|
10.1007/JHEP01(2011)064
|
SLAC-PUB-14211, Bonn-TH-2010-05, ANL-HEP-PR-10-40, NUHEP-TH/10-10
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The recent positron excess in cosmic rays (CR) observed by the PAMELA
satellite may be a signal for dark matter (DM) annihilation. When these
measurements are combined with those from FERMI on the total ($e^++e^-$) flux
and from PAMELA itself on the $\bar p/p$ ratio, these and other results are
difficult to reconcile with traditional models of DM, including the
conventional mSUGRA version of Supersymmetry even if boosts as large as
$10^{3-4}$ are allowed. In this paper, we combine the results of a previously
obtained scan over a more general 19-parameter subspace of the MSSM with a
corresponding scan over astrophysical parameters that describe the propagation
of CR. We then ascertain whether or not a good fit to this CR data can be
obtained with relatively small boost factors while simultaneously satisfying
the additional constraints arising from gamma ray data. We find that a specific
subclass of MSSM models where the LSP is mostly pure bino and annihilates
almost exclusively into $\tau$ pairs comes very close to satisfying these
requirements. The lightest $\tilde \tau$ in this set of models is found to be
relatively close in mass to the LSP and is in some cases the nLSP. These models
lead to a significant improvement in the overall fit to the data by an amount
$\Delta \chi^2 \sim 1/$dof in comparison to the best fit without Supersymmetry
while employing boosts $\sim 100$. The implications of these models for future
experiments are discussed.
|
[
{
"created": "Fri, 30 Jul 2010 19:47:18 GMT",
"version": "v1"
},
{
"created": "Mon, 16 Aug 2010 20:52:31 GMT",
"version": "v2"
}
] |
2011-03-07
|
[
[
"Cotta",
"R. C.",
""
],
[
"Conley",
"J. A.",
""
],
[
"Gainer",
"J. S.",
""
],
[
"Hewett",
"J. L.",
""
],
[
"Rizzo",
"T. G.",
""
]
] |
The recent positron excess in cosmic rays (CR) observed by the PAMELA satellite may be a signal for dark matter (DM) annihilation. When these measurements are combined with those from FERMI on the total ($e^++e^-$) flux and from PAMELA itself on the $\bar p/p$ ratio, these and other results are difficult to reconcile with traditional models of DM, including the conventional mSUGRA version of Supersymmetry even if boosts as large as $10^{3-4}$ are allowed. In this paper, we combine the results of a previously obtained scan over a more general 19-parameter subspace of the MSSM with a corresponding scan over astrophysical parameters that describe the propagation of CR. We then ascertain whether or not a good fit to this CR data can be obtained with relatively small boost factors while simultaneously satisfying the additional constraints arising from gamma ray data. We find that a specific subclass of MSSM models where the LSP is mostly pure bino and annihilates almost exclusively into $\tau$ pairs comes very close to satisfying these requirements. The lightest $\tilde \tau$ in this set of models is found to be relatively close in mass to the LSP and is in some cases the nLSP. These models lead to a significant improvement in the overall fit to the data by an amount $\Delta \chi^2 \sim 1/$dof in comparison to the best fit without Supersymmetry while employing boosts $\sim 100$. The implications of these models for future experiments are discussed.
|
hep-ph/0212390
|
Yan QiShu
|
Qi-Shu Yan and Dong-Sheng Du
|
The one loop renormalization of the effective Higgs sector and its
implications
|
ReVTeX, 18 pages; in the sequel to hep-ph/0211258, hep-ph/0211301,
and hep-ph/0212367
| null | null | null |
hep-ph
| null |
We study the one-loop renormalization the standard model with anomalous Higgs
couplings ($O(p^2)$) by using the background field method, and provide the
whole divergence structure at one loop level. The one-loop divergence structure
indicates that, under the quantum corrections, only after taking into account
the mass terms of Z bosons ($O(p^2)$) and the whole bosonic sector of the
electroweak chiral Lagrangian ($O(p^4)$), can the effective Lagrangian be
complete up to $O(p^4)$.
|
[
{
"created": "Mon, 30 Dec 2002 11:47:03 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Yan",
"Qi-Shu",
""
],
[
"Du",
"Dong-Sheng",
""
]
] |
We study the one-loop renormalization the standard model with anomalous Higgs couplings ($O(p^2)$) by using the background field method, and provide the whole divergence structure at one loop level. The one-loop divergence structure indicates that, under the quantum corrections, only after taking into account the mass terms of Z bosons ($O(p^2)$) and the whole bosonic sector of the electroweak chiral Lagrangian ($O(p^4)$), can the effective Lagrangian be complete up to $O(p^4)$.
|
0902.1728
|
A. N. Ivanov
|
M. Faber, A. N. Ivanov, V. A. Ivanova, J. Marton, M. Pitschmann, N. I.
Troitskaya, M. Wellenzohn
|
On Bound-State beta^- Decay Rate of the Free Neutron
|
3 pages
| null | null | null |
hep-ph hep-ex nucl-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We calculate the bound-state beta^- decay rate of the free neutron. We show
that hydrogen in the final state of the decay is produced with a probability of
about 99% in the hyperfine state with zero orbital l = 0 and atomic angular
momentum F = 0.
|
[
{
"created": "Tue, 10 Feb 2009 19:32:42 GMT",
"version": "v1"
}
] |
2009-02-11
|
[
[
"Faber",
"M.",
""
],
[
"Ivanov",
"A. N.",
""
],
[
"Ivanova",
"V. A.",
""
],
[
"Marton",
"J.",
""
],
[
"Pitschmann",
"M.",
""
],
[
"Troitskaya",
"N. I.",
""
],
[
"Wellenzohn",
"M.",
""
]
] |
We calculate the bound-state beta^- decay rate of the free neutron. We show that hydrogen in the final state of the decay is produced with a probability of about 99% in the hyperfine state with zero orbital l = 0 and atomic angular momentum F = 0.
|
1603.08187
|
Alexander Snigirev
|
A.M. Snigirev
|
Triple parton scattering in collinear approximation of perturbative QCD
|
10 pages, considerably extended version, accepted for publication in
Phys. Rev. D
|
Phys. Rev. D 94, 034026 (2016)
|
10.1103/PhysRevD.94.034026
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Revised formulas for the inclusive cross section of a triple parton
scattering process in a hadron collision are suggested basing on the modified
collinear three-parton distributions. The possible phenomenological issues are
discussed.
|
[
{
"created": "Sun, 27 Mar 2016 08:46:43 GMT",
"version": "v1"
},
{
"created": "Thu, 4 Aug 2016 17:23:16 GMT",
"version": "v2"
}
] |
2016-08-17
|
[
[
"Snigirev",
"A. M.",
""
]
] |
Revised formulas for the inclusive cross section of a triple parton scattering process in a hadron collision are suggested basing on the modified collinear three-parton distributions. The possible phenomenological issues are discussed.
|
2104.14881
|
Yu-Feng Zhou
|
Yu-Chen Ding, Yu-Lin Ku, Chun-Cheng Wei, Yu-Feng Zhou
|
Consistent explanation for the cosmic-ray positron excess in p-wave
Sommerfeld-enhanced dark matter annihilation
|
33 pages, 9 figures, discussions on bound-state formation added,
version to appear in JCAP
| null |
10.1088/1475-7516/2021/09/005
| null |
hep-ph
|
http://creativecommons.org/licenses/by/4.0/
|
Sommerfeld-enhanced dark matter (DM) annihilation through $s$-wave has been
widely considered as a consistent explanation for both the observed cosmic-ray
(CR) positron excess and the DM thermal relic density. However, as the $s$-wave
Sommerfeld-enhanced annihilation cross section increases monotonically with
decreasing DM velocity, severe constraints appear from the data of gamma rays
from dwarf spheroidal satellite galaxies (dSphs) and the cosmic microwave
background (CMB), as the relevant typical DM velocities are even lower than
that in the Galactic halo. In this work, we consider Sommerfeld-enhanced
$p$-wave DM annihilation where the DM annihilation cross section can be
enhanced at certain velocities but eventually be highly suppressed when the DM
velocities become extremely low. We calculate the velocity-dependent
astrophysics factors ($J$-factors) for the Sommerfeld-enhanced $p$-wave DM
annihilation for fifteen nearby dSphs. Taking the channel of DM annihilating
into $4\mu$ through two light mediators as an example, we show that there are
parameter regions where this mechanism can account for the CR positron excess
and the DM relic density, while being compatible with the constraints from
dSphs gamma rays measured by Fermi-LAT and that from the CMB measured by
PLANCK.
|
[
{
"created": "Fri, 30 Apr 2021 10:09:14 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Aug 2021 10:30:14 GMT",
"version": "v2"
}
] |
2021-09-29
|
[
[
"Ding",
"Yu-Chen",
""
],
[
"Ku",
"Yu-Lin",
""
],
[
"Wei",
"Chun-Cheng",
""
],
[
"Zhou",
"Yu-Feng",
""
]
] |
Sommerfeld-enhanced dark matter (DM) annihilation through $s$-wave has been widely considered as a consistent explanation for both the observed cosmic-ray (CR) positron excess and the DM thermal relic density. However, as the $s$-wave Sommerfeld-enhanced annihilation cross section increases monotonically with decreasing DM velocity, severe constraints appear from the data of gamma rays from dwarf spheroidal satellite galaxies (dSphs) and the cosmic microwave background (CMB), as the relevant typical DM velocities are even lower than that in the Galactic halo. In this work, we consider Sommerfeld-enhanced $p$-wave DM annihilation where the DM annihilation cross section can be enhanced at certain velocities but eventually be highly suppressed when the DM velocities become extremely low. We calculate the velocity-dependent astrophysics factors ($J$-factors) for the Sommerfeld-enhanced $p$-wave DM annihilation for fifteen nearby dSphs. Taking the channel of DM annihilating into $4\mu$ through two light mediators as an example, we show that there are parameter regions where this mechanism can account for the CR positron excess and the DM relic density, while being compatible with the constraints from dSphs gamma rays measured by Fermi-LAT and that from the CMB measured by PLANCK.
|
hep-ph/0107007
|
Toshihiko Ota
|
Toshihiko Ota, Joe Sato, and Yoshitaka Kuno
|
Search for T-violation in Neutrino Oscillation with the Use of Muon
Polarization at a Neutrino Factory
|
13 pages, 4 figures
|
Phys.Lett. B520 (2001) 289-297
|
10.1016/S0370-2693(01)01135-2
|
KYUSHU-HET 57, OUHEP-01-1
|
hep-ph
| null |
A possibility to search for T-violation in neutrino oscillation with the use
of muon polarization is studied. The sensitivity to T-violation is examined
with different muon polarization as a function of muon energy and long-baseline
distances.
|
[
{
"created": "Mon, 2 Jul 2001 08:35:18 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Jul 2001 01:48:14 GMT",
"version": "v2"
},
{
"created": "Tue, 6 Nov 2001 05:53:52 GMT",
"version": "v3"
}
] |
2009-11-07
|
[
[
"Ota",
"Toshihiko",
""
],
[
"Sato",
"Joe",
""
],
[
"Kuno",
"Yoshitaka",
""
]
] |
A possibility to search for T-violation in neutrino oscillation with the use of muon polarization is studied. The sensitivity to T-violation is examined with different muon polarization as a function of muon energy and long-baseline distances.
|
1003.1838
|
Yutaka Tobita
|
K. Ishikawa and Y. Tobita
|
Macroscopic Interferences of Neutrino Waves
|
12 pages, 2 figures
| null | null |
EPHOU-10-001
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Interference phenomena of neutrinos are studied. High energy neutrino in T2K
near detector and low energy neutrino in KamLAND are possible experiments that
could show macroscopic interferences of neutrino waves. In both experiments
interference patterns may give new insights on the absolute value of the
neutrino mass.
|
[
{
"created": "Tue, 9 Mar 2010 10:21:44 GMT",
"version": "v1"
}
] |
2010-03-10
|
[
[
"Ishikawa",
"K.",
""
],
[
"Tobita",
"Y.",
""
]
] |
Interference phenomena of neutrinos are studied. High energy neutrino in T2K near detector and low energy neutrino in KamLAND are possible experiments that could show macroscopic interferences of neutrino waves. In both experiments interference patterns may give new insights on the absolute value of the neutrino mass.
|
1206.0699
|
Jorge de Blas Mateo
|
Jorge de Blas, Antonio Delgado, Bryan Ostdiek, Alejandro de la Puente
|
LHC Signals of Non-Custodial Warped 5D Models
|
pdfLateX, 22 pages, 17 figures
| null |
10.1103/PhysRevD.86.015028
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study the implications at the LHC for a recent class of non-custodial
warped extra-dimensional models where the AdS_5 metric is modified near the
infrared brane. Such models allow for TeV Kaluza-Klein excitations without
conflict with electroweak precision tests. We discuss both the production of
electroweak and strong Kaluza-Klein gauge bosons. As we will show, only signals
involving the third generation of quarks seem to be feasible in order to probe
this scenario.
|
[
{
"created": "Mon, 4 Jun 2012 18:45:26 GMT",
"version": "v1"
}
] |
2013-05-30
|
[
[
"de Blas",
"Jorge",
""
],
[
"Delgado",
"Antonio",
""
],
[
"Ostdiek",
"Bryan",
""
],
[
"de la Puente",
"Alejandro",
""
]
] |
We study the implications at the LHC for a recent class of non-custodial warped extra-dimensional models where the AdS_5 metric is modified near the infrared brane. Such models allow for TeV Kaluza-Klein excitations without conflict with electroweak precision tests. We discuss both the production of electroweak and strong Kaluza-Klein gauge bosons. As we will show, only signals involving the third generation of quarks seem to be feasible in order to probe this scenario.
|
1306.3861
|
Bhavik Kodrani
|
Amol Dighe (Tata Inst.), Diptimoy Ghosh (INFN, Rome), Bhavik P.
Kodrani (Tata Inst.)
|
Nonuniversality of indirect CP asymmetries in $D \to \pi\pi, KK$ decays
|
23 pages, 14 Postscript figures, matches published version
|
Phys. Rev. D. 89, 096008 (2014)
|
10.1103/PhysRevD.89.096008
|
TIFR/TH/13-20
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We point out that, if the direct CP asymmetries in the $D \to \pi^+ \pi^-$
and $D \to K^+ K^-$ decays are unequal, the indirect CP asymmetries as measured
in these modes are necessarily unequal. This nonuniversality of indirect CP
asymmetries can be significant with the right amount of new physics
contributions, a scenario that may be fine-tuned, but is still viable. A
model-independent fit to the current data allows different indirect CP
asymmetries in the above two decays. This could even be contributing to the
apparent tension between the difference CP asymmetries $\Delta A_{\rm CP}$
measured through the pion-tagged and muon-tagged data samples at the LHCb. This
also implies that the measurements of $A_\Gamma$ and $y_{\rm CP}$ in the $\pi^+
\pi^-$ and $K^+ K^-$ decay modes can be different, and averaging over these two
modes should be avoided. In any case, the complete analysis of CP violation
measurements in the $D$ meson sector needs to take into account the possibility
of different indirect CP asymmetries in the $\pi^+\pi^-$ and $K^+ K^-$
channels.
|
[
{
"created": "Mon, 17 Jun 2013 13:57:02 GMT",
"version": "v1"
},
{
"created": "Sat, 17 May 2014 10:32:10 GMT",
"version": "v2"
},
{
"created": "Tue, 3 Jun 2014 11:35:25 GMT",
"version": "v3"
}
] |
2014-06-04
|
[
[
"Dighe",
"Amol",
"",
"Tata Inst."
],
[
"Ghosh",
"Diptimoy",
"",
"INFN, Rome"
],
[
"Kodrani",
"Bhavik P.",
"",
"Tata Inst."
]
] |
We point out that, if the direct CP asymmetries in the $D \to \pi^+ \pi^-$ and $D \to K^+ K^-$ decays are unequal, the indirect CP asymmetries as measured in these modes are necessarily unequal. This nonuniversality of indirect CP asymmetries can be significant with the right amount of new physics contributions, a scenario that may be fine-tuned, but is still viable. A model-independent fit to the current data allows different indirect CP asymmetries in the above two decays. This could even be contributing to the apparent tension between the difference CP asymmetries $\Delta A_{\rm CP}$ measured through the pion-tagged and muon-tagged data samples at the LHCb. This also implies that the measurements of $A_\Gamma$ and $y_{\rm CP}$ in the $\pi^+ \pi^-$ and $K^+ K^-$ decay modes can be different, and averaging over these two modes should be avoided. In any case, the complete analysis of CP violation measurements in the $D$ meson sector needs to take into account the possibility of different indirect CP asymmetries in the $\pi^+\pi^-$ and $K^+ K^-$ channels.
|
1310.6263
|
Walter Grimus
|
Walter Grimus
|
Residual symmetries in the lepton mass matrices
|
7 pages no figures, talk presented at XXXVII International Conference
of Theoretical Physics, "Matter to the Deepest," Ustron, September 1-6, 2013
| null |
10.5506/APhysPolB.44.2331
|
UWThPh-2013-30
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
It has been suggested that residual symmetries in the charged-lepton and
neutrino mass matrices can possibly reveal the flavour symmetry group of the
lepton sector. We review the basic ideas of this purely group-theoretical
approach and discuss some of its results. Finally, we also list its
shortcomings.
|
[
{
"created": "Wed, 23 Oct 2013 15:37:04 GMT",
"version": "v1"
}
] |
2015-06-17
|
[
[
"Grimus",
"Walter",
""
]
] |
It has been suggested that residual symmetries in the charged-lepton and neutrino mass matrices can possibly reveal the flavour symmetry group of the lepton sector. We review the basic ideas of this purely group-theoretical approach and discuss some of its results. Finally, we also list its shortcomings.
|
hep-ph/0701276
|
Edmond Iancu
|
Edmond Iancu, Larry McLerran
|
Liouville field theory for gluon saturation in QCD at high energy
|
33 pages, 9 figures
|
Nucl.Phys.A793:96-127,2007
|
10.1016/j.nuclphysa.2007.06.010
|
SACLAY-T07/013, BNL-NT-07/10
|
hep-ph hep-th
| null |
We argue that quantum Liouville field theory supplemented with a suitable
source term is the effective theory which describes the short-range
correlations of the gluon saturation momentum in the two-dimensional
impact-parameter space, at sufficiently high energy and for a large number of
colors. This is motivated by recent developments concerning the stochastic
aspects of the high-energy evolution in QCD, together with the manifest scale
invariance of the respective evolution equations and general considerations on
the uncertainty principle. The source term explicitly breaks down the conformal
symmetry of the (pure) Liouville action, thus introducing a physical mass scale
in the problem which is identified with the average saturation momentum. We
construct this source term for the case of a homogeneous distribution and show
that this leads to an interesting theory: the relevant correlation functions
are ultraviolet finite (and not just renormalizable) when computed in
perturbation theory, due to mutual cancellations of the tadpole divergences.
Possible generalizations to inhomogeneous source terms are briefly discussed.
|
[
{
"created": "Wed, 31 Jan 2007 19:01:55 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Iancu",
"Edmond",
""
],
[
"McLerran",
"Larry",
""
]
] |
We argue that quantum Liouville field theory supplemented with a suitable source term is the effective theory which describes the short-range correlations of the gluon saturation momentum in the two-dimensional impact-parameter space, at sufficiently high energy and for a large number of colors. This is motivated by recent developments concerning the stochastic aspects of the high-energy evolution in QCD, together with the manifest scale invariance of the respective evolution equations and general considerations on the uncertainty principle. The source term explicitly breaks down the conformal symmetry of the (pure) Liouville action, thus introducing a physical mass scale in the problem which is identified with the average saturation momentum. We construct this source term for the case of a homogeneous distribution and show that this leads to an interesting theory: the relevant correlation functions are ultraviolet finite (and not just renormalizable) when computed in perturbation theory, due to mutual cancellations of the tadpole divergences. Possible generalizations to inhomogeneous source terms are briefly discussed.
|
1305.3392
|
Valerie Fiona Domcke
|
Wilfried Buchmuller, Valerie Domcke, Kohei Kamada, Kai Schmitz
|
The Gravitational Wave Spectrum from Cosmological B-L Breaking
|
minor changes: references and comments added, experimental
sensitivities updated. Matches version published in JCAP
|
JCAP10(2013)003
|
10.1088/1475-7516/2013/10/003
|
DESY 13-050, IPMU 13-0091
|
hep-ph astro-ph.CO gr-qc hep-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Cosmological B-L breaking is a natural and testable mechanism to generate the
initial conditions of the hot early universe. If B-L is broken at the grand
unification scale, the false vacuum phase drives hybrid inflation, ending in
tachyonic preheating. The decays of heavy B-L Higgs bosons and heavy neutrinos
generate entropy, baryon asymmetry and dark matter and also control the
reheating temperature. The different phases in the transition from inflation to
the radiation dominated phase produce a characteristic spectrum of
gravitational waves. We calculate the complete gravitational wave spectrum due
to inflation, preheating and cosmic strings, which turns out to have several
features. The production of gravitational waves from cosmic strings has large
uncertainties, with lower and upper bounds provided by Abelian Higgs strings
and Nambu-Goto strings, implying \Omega_GW h^2 ~ 10^{-13} - 10^{-8}, much
larger than the spectral amplitude predicted by inflation. Forthcoming
gravitational wave detectors such as eLISA, advanced LIGO, ET, and BBO/DECIGO
will reach the sensitivity needed to test the predictions from cosmological B-L
breaking.
|
[
{
"created": "Wed, 15 May 2013 09:02:48 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Oct 2013 12:24:45 GMT",
"version": "v2"
}
] |
2015-06-15
|
[
[
"Buchmuller",
"Wilfried",
""
],
[
"Domcke",
"Valerie",
""
],
[
"Kamada",
"Kohei",
""
],
[
"Schmitz",
"Kai",
""
]
] |
Cosmological B-L breaking is a natural and testable mechanism to generate the initial conditions of the hot early universe. If B-L is broken at the grand unification scale, the false vacuum phase drives hybrid inflation, ending in tachyonic preheating. The decays of heavy B-L Higgs bosons and heavy neutrinos generate entropy, baryon asymmetry and dark matter and also control the reheating temperature. The different phases in the transition from inflation to the radiation dominated phase produce a characteristic spectrum of gravitational waves. We calculate the complete gravitational wave spectrum due to inflation, preheating and cosmic strings, which turns out to have several features. The production of gravitational waves from cosmic strings has large uncertainties, with lower and upper bounds provided by Abelian Higgs strings and Nambu-Goto strings, implying \Omega_GW h^2 ~ 10^{-13} - 10^{-8}, much larger than the spectral amplitude predicted by inflation. Forthcoming gravitational wave detectors such as eLISA, advanced LIGO, ET, and BBO/DECIGO will reach the sensitivity needed to test the predictions from cosmological B-L breaking.
|
1105.0180
|
Daniel Almeida Fagundes
|
D.A. Fagundes and M.J. Menon
|
Applicability of a Representation for the Martin's Real-Part Formula in
Model-Independent Analyses
|
Two comments and one reference added at the end of Subsec. 3.3; 23
pages, 9 figures; to be published in Int. J. Mod. Phys. A
|
Int.J.Mod.Phys.A26:3219-3247,2011
|
10.1142/S0217751X1105378X
| null |
hep-ph hep-ex
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Using a novel representation for the Martin's real-part formula without the
full scaling property, an almost model-independent description of the
proton-proton differential cross section data at high energies (19.4 GeV - 62.5
GeV) is obtained. In the impact parameter and eikonal frameworks, the extracted
inelastic overlap function presents a peripheral effect (tail) above 2 fm and
the extracted opacity function is characterized by a zero (change of sign) in
the momentum transfer space, confirming results from previous model-independent
analyses. Analytical parametrization for these empirical results are introduced
and discussed. The importance of investigations on the inverse problems in
high-energy elastic hadron scattering is stressed and the relevance of the
proposed representation is commented. A short critical review on the use of
Martin's formula is also presented.
|
[
{
"created": "Sun, 1 May 2011 15:55:48 GMT",
"version": "v1"
},
{
"created": "Fri, 29 Jul 2011 14:13:11 GMT",
"version": "v2"
}
] |
2011-08-03
|
[
[
"Fagundes",
"D. A.",
""
],
[
"Menon",
"M. J.",
""
]
] |
Using a novel representation for the Martin's real-part formula without the full scaling property, an almost model-independent description of the proton-proton differential cross section data at high energies (19.4 GeV - 62.5 GeV) is obtained. In the impact parameter and eikonal frameworks, the extracted inelastic overlap function presents a peripheral effect (tail) above 2 fm and the extracted opacity function is characterized by a zero (change of sign) in the momentum transfer space, confirming results from previous model-independent analyses. Analytical parametrization for these empirical results are introduced and discussed. The importance of investigations on the inverse problems in high-energy elastic hadron scattering is stressed and the relevance of the proposed representation is commented. A short critical review on the use of Martin's formula is also presented.
|
hep-ph/0601117
|
Andrey Bogdan V.
|
A.V.Bogdan, V.S. Fadin
|
A proof of the reggeized form of amplitudes with quark exchanges
|
22 pages, 7 figures, use elsart.cls
|
Nucl.Phys. B740 (2006) 36-57
|
10.1016/j.nuclphysb.2006.01.033
| null |
hep-ph
| null |
A complete proof of the quark Reggeization hypothesis in the leading
logarithmic approximation for any quark--gluon inelastic process in the
multi--Regge kinematics in all orders of $\alpha_s$ is given. First, we show
that the multi--Regge form of QCD amplitudes is guarantied if a set of
conditions on the Reggeon vertices and the trajectories is fulfilled. Then, we
examine these conditions and show that they are satisfied.
|
[
{
"created": "Sat, 14 Jan 2006 09:38:00 GMT",
"version": "v1"
}
] |
2009-11-11
|
[
[
"Bogdan",
"A. V.",
""
],
[
"Fadin",
"V. S.",
""
]
] |
A complete proof of the quark Reggeization hypothesis in the leading logarithmic approximation for any quark--gluon inelastic process in the multi--Regge kinematics in all orders of $\alpha_s$ is given. First, we show that the multi--Regge form of QCD amplitudes is guarantied if a set of conditions on the Reggeon vertices and the trajectories is fulfilled. Then, we examine these conditions and show that they are satisfied.
|
0904.0925
|
Hiroaki Kouno
|
Hiroaki Kouno, Yuji Sakai, Kouji Kashiwa, Masanobu Yahiro
|
Roberge-Weiss phase transition and its endpoint
|
24 pages, 19 figures. Journal version. Some sentences have been
revised and added. Fig. 9 has been revised. (New panels have been added.)
|
J.Phys.G36:115010,2009
|
10.1088/0954-3899/36/11/115010
|
SAGA-HE-246
|
hep-ph hep-lat hep-th nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The Roberge-Weiss (RW) phase transition in the imaginary chemical potential
region is analyzed by the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL)
model. In the RW phase transition, the charge-conjugation symmetry is
spontaneously broken, while the extended Z3 symmetry (the RW periodicity) is
preserved. The RW transition is of second order at the endpoint. At the zero
chemical potential, a crossover deconfinement transition appears as a remnant
of the second-order RW phase transition at the endpoint, while the
charge-conjugation symmetry is always preserved.
|
[
{
"created": "Mon, 6 Apr 2009 14:10:14 GMT",
"version": "v1"
},
{
"created": "Wed, 14 Jul 2010 09:43:34 GMT",
"version": "v2"
}
] |
2010-07-15
|
[
[
"Kouno",
"Hiroaki",
""
],
[
"Sakai",
"Yuji",
""
],
[
"Kashiwa",
"Kouji",
""
],
[
"Yahiro",
"Masanobu",
""
]
] |
The Roberge-Weiss (RW) phase transition in the imaginary chemical potential region is analyzed by the Polyakov-loop extended Nambu--Jona-Lasinio (PNJL) model. In the RW phase transition, the charge-conjugation symmetry is spontaneously broken, while the extended Z3 symmetry (the RW periodicity) is preserved. The RW transition is of second order at the endpoint. At the zero chemical potential, a crossover deconfinement transition appears as a remnant of the second-order RW phase transition at the endpoint, while the charge-conjugation symmetry is always preserved.
|
1004.1424
|
Robert Foot
|
R. Foot
|
A CoGeNT confirmation of the DAMA signal
|
About 8 pages, expanded and updated
|
Phys.Lett.B692:65-69,2010
|
10.1016/j.physletb.2010.07.022
| null |
hep-ph astro-ph.GA
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
The CoGeNT collaboration has recently reported a rising low energy spectrum
in their ultra low noise germanium detector. This is particularly interesting
as the energy range probed by CoGeNT overlaps with the energy region in which
DAMA has observed their annual modulation signal. We show that the mirror dark
matter candidate can simultaneously explain both the DAMA annual modulation
signal and the rising low energy spectrum observed by CoGeNT. This constitutes
a model dependent confirmation of the DAMA signal and adds weight to the mirror
dark matter paradigm.
|
[
{
"created": "Thu, 8 Apr 2010 20:45:35 GMT",
"version": "v1"
},
{
"created": "Mon, 12 Jul 2010 12:49:51 GMT",
"version": "v2"
}
] |
2010-11-16
|
[
[
"Foot",
"R.",
""
]
] |
The CoGeNT collaboration has recently reported a rising low energy spectrum in their ultra low noise germanium detector. This is particularly interesting as the energy range probed by CoGeNT overlaps with the energy region in which DAMA has observed their annual modulation signal. We show that the mirror dark matter candidate can simultaneously explain both the DAMA annual modulation signal and the rising low energy spectrum observed by CoGeNT. This constitutes a model dependent confirmation of the DAMA signal and adds weight to the mirror dark matter paradigm.
|
2302.01356
|
Matthias Steinhauser
|
Joshua Davies, Go Mishima, Kay Sch\"onwald, Matthias Steinhauser
|
Analytic approximations of $2\to 2$ processes with massive internal
particles
|
25 pages
| null |
10.1007/JHEP06(2023)063
|
P3H-23-008, TTP23-004, TU-1178, ZU-TH 06/23
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider two-loop corrections to $2\to 2$ scattering processes with
massive particles in the final state and massive particles in the loop. We
discuss the combination of analytic expansions in the high-energy limit and for
small Mandelstam variable~$t$. For the example of double Higgs boson production
we show that the whole phase space can be covered and time-consuming numerical
integrations can be avoided.
|
[
{
"created": "Thu, 2 Feb 2023 19:00:06 GMT",
"version": "v1"
}
] |
2023-06-28
|
[
[
"Davies",
"Joshua",
""
],
[
"Mishima",
"Go",
""
],
[
"Schönwald",
"Kay",
""
],
[
"Steinhauser",
"Matthias",
""
]
] |
We consider two-loop corrections to $2\to 2$ scattering processes with massive particles in the final state and massive particles in the loop. We discuss the combination of analytic expansions in the high-energy limit and for small Mandelstam variable~$t$. For the example of double Higgs boson production we show that the whole phase space can be covered and time-consuming numerical integrations can be avoided.
|
hep-ph/9803311
|
Robert Baur
|
Robert Baur, Joachim Kambor (University of Zurich)
|
Generalized Heavy Baryon Chiral Perturbation Theory
|
36 pages, 3 ps-figures, uses Latex2e; discussion of results in sect.
4 improved, Appendix A and typos corrected
|
Eur.Phys.J.C7:507-524,1999
|
10.1007/s100529801024
| null |
hep-ph
| null |
Standard SU(2) Heavy Baryon Chiral Perturbation Theory is extended in order
to include the case of small or even vanishing quark condensate. The effective
lagrangian is given to ${\cal O}(p^2)$ in its most general form and to ${\cal
O}(p^3)$ in the scalar sector. A method is developed to efficiently construct
the relativistic baryonic effective lagrangian for chiral SU(2) to all orders
in the chiral expansion. As a first application, mass- and wave-function
renormalization as well as the scalar form factor of the nucleon is calculated
to ${\cal O}(p^3)$. The result is compared to a dispersive analysis of the
nucleon scalar form factor adopted to the case of a small quark condensate. In
this latter analysis, the shift of the scalar form factor between the
Cheng-Dashen point and zero momentum transfer is found to be enhanced over the
result assuming strong quark condensation by up to a factor of two, with
substantial deviations starting to be visible for $r=m_s/\hat{m}\lesssim 12$.
|
[
{
"created": "Wed, 11 Mar 1998 17:11:30 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Nov 1998 10:44:53 GMT",
"version": "v2"
}
] |
2011-09-13
|
[
[
"Baur",
"Robert",
"",
"University of Zurich"
],
[
"Kambor",
"Joachim",
"",
"University of Zurich"
]
] |
Standard SU(2) Heavy Baryon Chiral Perturbation Theory is extended in order to include the case of small or even vanishing quark condensate. The effective lagrangian is given to ${\cal O}(p^2)$ in its most general form and to ${\cal O}(p^3)$ in the scalar sector. A method is developed to efficiently construct the relativistic baryonic effective lagrangian for chiral SU(2) to all orders in the chiral expansion. As a first application, mass- and wave-function renormalization as well as the scalar form factor of the nucleon is calculated to ${\cal O}(p^3)$. The result is compared to a dispersive analysis of the nucleon scalar form factor adopted to the case of a small quark condensate. In this latter analysis, the shift of the scalar form factor between the Cheng-Dashen point and zero momentum transfer is found to be enhanced over the result assuming strong quark condensation by up to a factor of two, with substantial deviations starting to be visible for $r=m_s/\hat{m}\lesssim 12$.
|
2407.21496
|
Wenyang Qian
|
Kazuki Ikeda, Zhong-Bo Kang, Dmitri E. Kharzeev, Wenyang Qian, Fanyi
Zhao
|
Real-time chiral dynamics at finite temperature from quantum simulation
|
16 pages, 4 figures
| null | null | null |
hep-ph hep-lat hep-th nucl-th quant-ph
|
http://creativecommons.org/licenses/by-nc-nd/4.0/
|
In this study, we explore the real-time dynamics of the chiral magnetic
effect (CME) at a finite temperature in the (1+1)-dimensional QED, the massive
Schwinger model. By introducing a chiral chemical potential $\mu_5$ through a
quench process, we drive the system out of equilibrium and analyze the induced
vector currents and their evolution over time. The Hamiltonian is modified to
include the time-dependent chiral chemical potential, thus allowing the
investigation of the CME within a quantum computing framework. We employ the
quantum imaginary time evolution (QITE) algorithm to study the thermal states,
and utilize the Suzuki-Trotter decomposition for the real-time evolution. This
study provides insights into the quantum simulation capabilities for modeling
the CME and offers a pathway for studying chiral dynamics in low-dimensional
quantum field theories.
|
[
{
"created": "Wed, 31 Jul 2024 10:10:42 GMT",
"version": "v1"
}
] |
2024-08-01
|
[
[
"Ikeda",
"Kazuki",
""
],
[
"Kang",
"Zhong-Bo",
""
],
[
"Kharzeev",
"Dmitri E.",
""
],
[
"Qian",
"Wenyang",
""
],
[
"Zhao",
"Fanyi",
""
]
] |
In this study, we explore the real-time dynamics of the chiral magnetic effect (CME) at a finite temperature in the (1+1)-dimensional QED, the massive Schwinger model. By introducing a chiral chemical potential $\mu_5$ through a quench process, we drive the system out of equilibrium and analyze the induced vector currents and their evolution over time. The Hamiltonian is modified to include the time-dependent chiral chemical potential, thus allowing the investigation of the CME within a quantum computing framework. We employ the quantum imaginary time evolution (QITE) algorithm to study the thermal states, and utilize the Suzuki-Trotter decomposition for the real-time evolution. This study provides insights into the quantum simulation capabilities for modeling the CME and offers a pathway for studying chiral dynamics in low-dimensional quantum field theories.
|
0804.0056
|
Seung-il Nam
|
Seung-il Nam, Hui-Young Ryu, M.M.Musakhanov, Hyun-Chul Kim
|
Magnetic susceptibility of the QCD vacuum at finite quark-chemical
potential
|
12 pages, 2 figures
|
J.Korean Phys.Soc.55:429-434,2009
|
10.3938/jkps.55.429
|
CYCU-HEP-09-06, YITP-08-13, INHA-NTG-07/2008
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We investigate the QCD magnetic susceptibility chi at the finite
quark-chemical potential (mu>0) and at zero temperature (T=0) to explore the
pattern of the magnetic phase transition of the QCD vacuum. For this purpose,
we employ the nonlocal chiral quark model derived from the instanton vacuum in
the presence of the chemical potential in the chiral limit. Focusing on the
Nambu-Goldstone phase, we find that the magnetic susceptibility remains almost
stable to mu~200 MeV, and falls down drastically until the the quark-chemical
potential reaches the critical point mu_c~320 MeV. Then, the strength of the
chi is reduced to be about a half of that at mu=0, and the first-order magnetic
phase transition takes place, corresponding to the chiral restoration. From
these observations, we conclude that the response of the QCD vacuum becomes
weak and unstable to the external electromagnetic field near the critical
point, in comparison to that for vacuum. It is also shown that the breakdown of
Lorentz invariance for the magnetic susceptibility, caused by the finite
chemical potential, turns out to be small.
|
[
{
"created": "Tue, 1 Apr 2008 05:58:00 GMT",
"version": "v1"
},
{
"created": "Mon, 21 Jul 2008 10:05:33 GMT",
"version": "v2"
},
{
"created": "Mon, 13 Apr 2009 10:10:36 GMT",
"version": "v3"
},
{
"created": "Thu, 7 May 2009 06:37:40 GMT",
"version": "v4"
}
] |
2009-12-15
|
[
[
"Nam",
"Seung-il",
""
],
[
"Ryu",
"Hui-Young",
""
],
[
"Musakhanov",
"M. M.",
""
],
[
"Kim",
"Hyun-Chul",
""
]
] |
We investigate the QCD magnetic susceptibility chi at the finite quark-chemical potential (mu>0) and at zero temperature (T=0) to explore the pattern of the magnetic phase transition of the QCD vacuum. For this purpose, we employ the nonlocal chiral quark model derived from the instanton vacuum in the presence of the chemical potential in the chiral limit. Focusing on the Nambu-Goldstone phase, we find that the magnetic susceptibility remains almost stable to mu~200 MeV, and falls down drastically until the the quark-chemical potential reaches the critical point mu_c~320 MeV. Then, the strength of the chi is reduced to be about a half of that at mu=0, and the first-order magnetic phase transition takes place, corresponding to the chiral restoration. From these observations, we conclude that the response of the QCD vacuum becomes weak and unstable to the external electromagnetic field near the critical point, in comparison to that for vacuum. It is also shown that the breakdown of Lorentz invariance for the magnetic susceptibility, caused by the finite chemical potential, turns out to be small.
|
hep-ph/0207335
|
Alex Kovner
|
Alexander Kovner, Urs Achim Wiedemann
|
No Froissart Bound from Gluon Saturation
|
5 pages LaTex, final version to be published in Phys. Lett. B, Note
added referring to recent controversy
|
Phys.Lett. B551 (2003) 311-316
|
10.1016/S0370-2693(02)02907-6
| null |
hep-ph
| null |
In the previous work hep-ph/0112140, hep-ph/0204277, we showed that while the
nonlinear QCD evolution equation of Balitsky and Kovchegov (BK) leads to
saturation of the scattering amplitude locally in impact parameter space, it
does not unitarize the total cross section. This result was recently challenged
by Ferreiro, Iancu, Itakura and McLerran (FIIM) who claim that the
dipole-hadron cross section computed from the BK equation saturates the
Froissart bound. In this comment, we point to a fundamental error in the
argument of FIIM which invalidates their conclusion. We show that if the total
cross section violates unitarity for a coloured scattering probe, it does so
also for a colourless scattering probe.
|
[
{
"created": "Sun, 28 Jul 2002 16:15:34 GMT",
"version": "v1"
},
{
"created": "Tue, 5 Nov 2002 17:19:34 GMT",
"version": "v2"
}
] |
2009-11-07
|
[
[
"Kovner",
"Alexander",
""
],
[
"Wiedemann",
"Urs Achim",
""
]
] |
In the previous work hep-ph/0112140, hep-ph/0204277, we showed that while the nonlinear QCD evolution equation of Balitsky and Kovchegov (BK) leads to saturation of the scattering amplitude locally in impact parameter space, it does not unitarize the total cross section. This result was recently challenged by Ferreiro, Iancu, Itakura and McLerran (FIIM) who claim that the dipole-hadron cross section computed from the BK equation saturates the Froissart bound. In this comment, we point to a fundamental error in the argument of FIIM which invalidates their conclusion. We show that if the total cross section violates unitarity for a coloured scattering probe, it does so also for a colourless scattering probe.
|
2008.06821
|
Zhao-Huan Yu
|
Dan-Yang Liu, Chengfeng Cai, Zhao-Huan Yu, Yu-Pan Zeng, Hong-Hao Zhang
|
Inert sextuplet scalar dark matter at the LHC and future colliders
|
37 pages, 11 figures
|
JHEP 10 (2020) 212
|
10.1007/JHEP10(2020)212
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We study a dark matter model constructed by extending the standard model with
an inert $\mathrm{SU}(2)_\mathrm{L}$ sextuplet scalar of hypercharge 1/2. The
sextuplet components are split by the quartic couplings between the sextuplet
and the Higgs doublet after electroweak symmetry breaking, resulting in a dark
sector with one triply charged, two doubly charged, two singly charged, and two
neutral scalars. The lighter neutral scalar boson acts as a dark matter
particle. We investigate the constraints on this model from the $\text{monojet}
+ /\!\!\!\!E_\mathrm{T}$ and $\text{soft-dilepton} + \text{jets} +
/\!\!\!\!E_\mathrm{T}$ searches at the 13 TeV Large Hadron Collider, as well as
from the current electroweak precision test. Furthermore, we estimate the
projected sensitivities of a 100 TeV $pp$ collider and of a future $e^+e^-$
collider, and find that such future projects could probe TeV mass scales.
Nonetheless, such mass scales only correspond to a subdominant component of the
observed relic abundance if the dark matter particles solely originate from
thermal production.
|
[
{
"created": "Sun, 16 Aug 2020 02:43:45 GMT",
"version": "v1"
},
{
"created": "Tue, 3 Nov 2020 02:54:30 GMT",
"version": "v2"
}
] |
2020-11-04
|
[
[
"Liu",
"Dan-Yang",
""
],
[
"Cai",
"Chengfeng",
""
],
[
"Yu",
"Zhao-Huan",
""
],
[
"Zeng",
"Yu-Pan",
""
],
[
"Zhang",
"Hong-Hao",
""
]
] |
We study a dark matter model constructed by extending the standard model with an inert $\mathrm{SU}(2)_\mathrm{L}$ sextuplet scalar of hypercharge 1/2. The sextuplet components are split by the quartic couplings between the sextuplet and the Higgs doublet after electroweak symmetry breaking, resulting in a dark sector with one triply charged, two doubly charged, two singly charged, and two neutral scalars. The lighter neutral scalar boson acts as a dark matter particle. We investigate the constraints on this model from the $\text{monojet} + /\!\!\!\!E_\mathrm{T}$ and $\text{soft-dilepton} + \text{jets} + /\!\!\!\!E_\mathrm{T}$ searches at the 13 TeV Large Hadron Collider, as well as from the current electroweak precision test. Furthermore, we estimate the projected sensitivities of a 100 TeV $pp$ collider and of a future $e^+e^-$ collider, and find that such future projects could probe TeV mass scales. Nonetheless, such mass scales only correspond to a subdominant component of the observed relic abundance if the dark matter particles solely originate from thermal production.
|
2308.02004
|
Paolo Salucci
|
Fabrizio Nesti, Paolo Salucci and Nicola Turini
|
The Quest for the Nature of the Dark Matter: The Need of a New Paradigm
|
15 pages. 9 figures
|
Astronomy, 2023, 2, 90-104
|
10.3390/astronomy2020007
| null |
hep-ph astro-ph.CO
|
http://creativecommons.org/licenses/by/4.0/
|
The phenomenon of the Dark matter baffles the researchers: the underlying
dark particle has escaped so far the detection and its astrophysical role
appears complex and entangled with that of the standard luminous particles. We
propose that, in order to act efficiently, alongside with abandoning the
current $\Lambda CDM$ scenario, we need also to shift the Paradigm from which
it emerged.
|
[
{
"created": "Thu, 3 Aug 2023 19:39:03 GMT",
"version": "v1"
}
] |
2023-08-07
|
[
[
"Nesti",
"Fabrizio",
""
],
[
"Salucci",
"Paolo",
""
],
[
"Turini",
"Nicola",
""
]
] |
The phenomenon of the Dark matter baffles the researchers: the underlying dark particle has escaped so far the detection and its astrophysical role appears complex and entangled with that of the standard luminous particles. We propose that, in order to act efficiently, alongside with abandoning the current $\Lambda CDM$ scenario, we need also to shift the Paradigm from which it emerged.
|
hep-ph/0605209
|
Mikko Laine
|
Takehiko Asaka, Mikko Laine, Mikhail Shaposhnikov
|
On the hadronic contribution to sterile neutrino production
|
28 pages. v2: small clarifications added, published version
|
JHEP 0606 (2006) 053
|
10.1088/1126-6708/2006/06/053
| null |
hep-ph astro-ph
| null |
Sterile neutrinos with masses in the keV range are considered to be a viable
candidate for warm dark matter. The rate of their production through
active-sterile neutrino transitions peaks, however, at temperatures of the
order of the QCD scale, which makes it difficult to estimate their relic
abundance quantitatively, even if the mass of the sterile neutrino and its
mixing angle were known. We derive here a relation, valid to all orders in the
strong coupling constant, which expresses the production rate in terms of the
spectral function associated with active neutrinos. The latter can in turn be
expressed as a certain convolution of the spectral functions related to various
mesonic current-current correlation functions, which are being actively studied
in other physics contexts. In the naive weak coupling limit, the appropriate
Boltzmann equations can be derived from our general formulae.
|
[
{
"created": "Fri, 19 May 2006 12:31:32 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Jun 2006 12:30:38 GMT",
"version": "v2"
}
] |
2009-11-11
|
[
[
"Asaka",
"Takehiko",
""
],
[
"Laine",
"Mikko",
""
],
[
"Shaposhnikov",
"Mikhail",
""
]
] |
Sterile neutrinos with masses in the keV range are considered to be a viable candidate for warm dark matter. The rate of their production through active-sterile neutrino transitions peaks, however, at temperatures of the order of the QCD scale, which makes it difficult to estimate their relic abundance quantitatively, even if the mass of the sterile neutrino and its mixing angle were known. We derive here a relation, valid to all orders in the strong coupling constant, which expresses the production rate in terms of the spectral function associated with active neutrinos. The latter can in turn be expressed as a certain convolution of the spectral functions related to various mesonic current-current correlation functions, which are being actively studied in other physics contexts. In the naive weak coupling limit, the appropriate Boltzmann equations can be derived from our general formulae.
|
hep-ph/9411385
| null |
Michael Gronau
|
Testing the Standard Model of CP Violation in the B System
|
21 pages, Figures can be obtained from PHSECRT@TECHNION
| null | null | null |
hep-ph
| null |
We review the subject of CP violation in the $B$ meson system within the
Standard Model of CP violation, which is based on a complex phase in the
Cabibbo-Kobayashi-Maskawa (CKM) matrix. Three kinds of CP nonconservation are
studied: In $B^0-\Bbar$ mixing, in mixed neutral $B$ decays to states which are
common decay products of $B^0$ and $\Bbar$ and in direct decays of charged $B$
mesons. Measurements of certain CP asymmetries are shown to determine the three
angles of the CKM unitarity triangle. $\beta$ is measured cleanly in
$B^0\to\psi K_S$. Uncertainties due to penguin amplitudes in the determination
of $\alpha$ using the asymmetry in $B^0\to \pi^+\pi^-$ (or $B^0 \to
\rho^+\pi^-$) can be eliminated (or in the worst case only estimated) by
relating the rate of this process to decay rates involving other two light
pseudoscalars. The angle $\gamma$ can be measured in charged $B$ decays,
provided that color suppression in $B\to DK$ (or $B\to DK_i(1400)$) is not too
strong and/or that certain rescattering effects in $B$ decays to two light
pseudoscalars are not too large.
|
[
{
"created": "Thu, 24 Nov 1994 14:01:51 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Gronau",
"Michael",
""
]
] |
We review the subject of CP violation in the $B$ meson system within the Standard Model of CP violation, which is based on a complex phase in the Cabibbo-Kobayashi-Maskawa (CKM) matrix. Three kinds of CP nonconservation are studied: In $B^0-\Bbar$ mixing, in mixed neutral $B$ decays to states which are common decay products of $B^0$ and $\Bbar$ and in direct decays of charged $B$ mesons. Measurements of certain CP asymmetries are shown to determine the three angles of the CKM unitarity triangle. $\beta$ is measured cleanly in $B^0\to\psi K_S$. Uncertainties due to penguin amplitudes in the determination of $\alpha$ using the asymmetry in $B^0\to \pi^+\pi^-$ (or $B^0 \to \rho^+\pi^-$) can be eliminated (or in the worst case only estimated) by relating the rate of this process to decay rates involving other two light pseudoscalars. The angle $\gamma$ can be measured in charged $B$ decays, provided that color suppression in $B\to DK$ (or $B\to DK_i(1400)$) is not too strong and/or that certain rescattering effects in $B$ decays to two light pseudoscalars are not too large.
|
hep-ph/9506303
| null |
F. Hautmann
|
Resummed Predictions for the Structure Function F2 at Small x
|
8 pages, uuencoded postscript
| null | null |
Cavendish-HEP-95/04
|
hep-ph
| null |
We report the results of including resummed splitting functions in the QCD
evolution equations at small x, and discuss the predictions that follow for the
deep inelastic structure functions.
*Contribution at XXX Rencontres de Moriond, Les Arcs, March 1995
|
[
{
"created": "Mon, 12 Jun 1995 20:32:45 GMT",
"version": "v1"
}
] |
2016-09-01
|
[
[
"Hautmann",
"F.",
""
]
] |
We report the results of including resummed splitting functions in the QCD evolution equations at small x, and discuss the predictions that follow for the deep inelastic structure functions. *Contribution at XXX Rencontres de Moriond, Les Arcs, March 1995
|
hep-ph/0312277
|
Jens Braun
|
Jens Braun, Kai Schwenzer, Hans-J\"urgen Pirner
|
Linking the Quark Meson Model with QCD at High Temperature
|
11 pages, 4 figures additional discussion of the second order phase
transition
|
Phys.Rev. D70 (2004) 085016
|
10.1103/PhysRevD.70.085016
| null |
hep-ph
| null |
We model the transition of a system of quarks and gluons at high energies to
a system of quarks and mesons at low energies in a consistent renormalization
group approach. Flow equations interpolate between the physics of the
high-temperature degrees of freedom and the low-temperature dynamics at a scale
of 1 GeV. We also discuss the dependence of the equation of state on baryon
density and compare our results with recent lattice gauge simulations.
|
[
{
"created": "Fri, 19 Dec 2003 11:00:15 GMT",
"version": "v1"
},
{
"created": "Mon, 5 Apr 2004 14:39:08 GMT",
"version": "v2"
}
] |
2009-11-10
|
[
[
"Braun",
"Jens",
""
],
[
"Schwenzer",
"Kai",
""
],
[
"Pirner",
"Hans-Jürgen",
""
]
] |
We model the transition of a system of quarks and gluons at high energies to a system of quarks and mesons at low energies in a consistent renormalization group approach. Flow equations interpolate between the physics of the high-temperature degrees of freedom and the low-temperature dynamics at a scale of 1 GeV. We also discuss the dependence of the equation of state on baryon density and compare our results with recent lattice gauge simulations.
|
1304.6732
|
Howard Baer
|
Howard Baer, Vernon Barger and Maren Padeffke-Kirkland
|
Electroweak versus high scale finetuning in the 19-parameter SUGRA model
|
25 pages with 17 figures; some references added and figures clarified
in version 2
|
Phys. Rev. D 88, 055026 (2013)
|
10.1103/PhysRevD.88.055026
| null |
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Recently, two measures of electroweak finetuning (EWFT) have been introduced
for SUSY models: \Delta_{EW} compares the Z mass to each separate weak scale
contribution to m_Z while \Delta_{HS} compares the Z mass to high scale input
parameters and their consequent renormalizaton group evolution (1/\Delta is the
% of fine tuning). While the paradigm mSUGRA/CMSSM model has been shown to be
highly finetuned under both parameters (\Delta_{EW}> 10^2 and \Delta_{HS}>
10^3), the two-parameter non-universal Higgs model (NUHM2) in the context of
radiatively-driven natural SUSY (RNS) enjoys \Delta_{EW} as low as 10, while
\Delta_{HS} remains > 10^3. We investigate finetuning in the 19-free-parameter
SUGRA model (SUGRA19). We find that with 19 free parameters, the lowest
\Delta_{EW} points are comparable to what can be achieved in NUHM2 with just 6
free parameters. However, in SUGRA19, \Delta_{HS} can now also reach as low as
5-10. The conditions which lead to low \Delta_{HS} include m_{H_u} m_Z at the
high scale, with non-universal gaugino masses M_{1,2}>> M_3 also at m_{GUT}.
The low \Delta_{HS} models are severely constrained by b\to s\gamma branching
fraction. In both cases of low \Delta_{EW} and \Delta_{HS}, the superpotential
\mu parameter should be \sim 100-300 GeV. While SUSY models with low EWFT may
or may not be discoverable at LHC, the predicted light higgsinos must show up
at a linear e^+e^- collider with \sqrt{s}> 2|\mu |.
|
[
{
"created": "Wed, 24 Apr 2013 20:04:02 GMT",
"version": "v1"
},
{
"created": "Thu, 2 May 2013 16:38:23 GMT",
"version": "v2"
}
] |
2013-10-30
|
[
[
"Baer",
"Howard",
""
],
[
"Barger",
"Vernon",
""
],
[
"Padeffke-Kirkland",
"Maren",
""
]
] |
Recently, two measures of electroweak finetuning (EWFT) have been introduced for SUSY models: \Delta_{EW} compares the Z mass to each separate weak scale contribution to m_Z while \Delta_{HS} compares the Z mass to high scale input parameters and their consequent renormalizaton group evolution (1/\Delta is the % of fine tuning). While the paradigm mSUGRA/CMSSM model has been shown to be highly finetuned under both parameters (\Delta_{EW}> 10^2 and \Delta_{HS}> 10^3), the two-parameter non-universal Higgs model (NUHM2) in the context of radiatively-driven natural SUSY (RNS) enjoys \Delta_{EW} as low as 10, while \Delta_{HS} remains > 10^3. We investigate finetuning in the 19-free-parameter SUGRA model (SUGRA19). We find that with 19 free parameters, the lowest \Delta_{EW} points are comparable to what can be achieved in NUHM2 with just 6 free parameters. However, in SUGRA19, \Delta_{HS} can now also reach as low as 5-10. The conditions which lead to low \Delta_{HS} include m_{H_u} m_Z at the high scale, with non-universal gaugino masses M_{1,2}>> M_3 also at m_{GUT}. The low \Delta_{HS} models are severely constrained by b\to s\gamma branching fraction. In both cases of low \Delta_{EW} and \Delta_{HS}, the superpotential \mu parameter should be \sim 100-300 GeV. While SUSY models with low EWFT may or may not be discoverable at LHC, the predicted light higgsinos must show up at a linear e^+e^- collider with \sqrt{s}> 2|\mu |.
|
hep-ph/0209366
|
Reinhard Alkofer
|
Reinhard Alkofer, Christian S. Fischer and Lorenz von Smekal
|
Infrared Exponents and the Running Coupling of Landau gauge QCD and
their Relation to Confinement
|
3 pages, 3 figures; talk given by R.A. at the conference Quark
Nuclear Physics 2002
|
Eur.Phys.J. A17 (2003) 773
|
10.1140/epja/i2002-10212-8
|
UNITUE-THEP-23/2002, FAU-TP3-02/26
|
hep-ph
| null |
The infrared behaviour of the gluon and ghost propagators in Landau gauge QCD
is reviewed. The Kugo-Ojima confinement criterion and the Gribov-Zwanziger
horizon condition result from quite general properties of the ghost
Dyson-Schwinger equation. The numerical solutions for the gluon and ghost
propagators obtained from a truncated set of Dyson-Schwinger equations provide
an explicit example for the anticipated infrared behaviour. The results are in
good agreement with corresponding lattice data obtained recently. The resulting
running coupling approaches a fix point in the infrared, $\alpha(0) =
8.92/N_c$. Two different fits for the scale dependence of the running coupling
are given and discussed.
|
[
{
"created": "Mon, 30 Sep 2002 12:12:31 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Alkofer",
"Reinhard",
""
],
[
"Fischer",
"Christian S.",
""
],
[
"von Smekal",
"Lorenz",
""
]
] |
The infrared behaviour of the gluon and ghost propagators in Landau gauge QCD is reviewed. The Kugo-Ojima confinement criterion and the Gribov-Zwanziger horizon condition result from quite general properties of the ghost Dyson-Schwinger equation. The numerical solutions for the gluon and ghost propagators obtained from a truncated set of Dyson-Schwinger equations provide an explicit example for the anticipated infrared behaviour. The results are in good agreement with corresponding lattice data obtained recently. The resulting running coupling approaches a fix point in the infrared, $\alpha(0) = 8.92/N_c$. Two different fits for the scale dependence of the running coupling are given and discussed.
|
1305.3870
|
Massimiliano Grazzini
|
S. Catani, M. Grazzini, A. Torre
|
Soft-gluon resummation for single-particle inclusive hadroproduction at
high transverse momentum
|
References added. Version published on Nucl. Phys. B
|
Nucl. Phys. B 874 (2013) 720
| null |
ZU-TH 09/13
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We consider the cross section for one-particle inclusive production at high
transverse momentum in hadronic collisions. We present the all-order
resummation formula that controls the logarithmically-enhanced perturbative QCD
contributions to the partonic cross section in the threshold region, at fixed
rapidity of the observed parton (hadron). The explicit resummation up to
next-to-leading logarithmic accuracy is supplemented with the computation of
the general structure of the near-threshold contributions to the
next-to-leading order cross section. This next-to-leading order computation
allows us to extract the one-loop hard-virtual amplitude that enters into the
resummation formula. This is a necessary ingredient to explicitly extend the
soft-gluon resummation beyond the next-to-leading logarithmic accuracy. These
results equally apply to both spin-unpolarized and spin-polarized scattering
processes.
|
[
{
"created": "Thu, 16 May 2013 16:57:50 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Jul 2013 10:07:39 GMT",
"version": "v2"
}
] |
2013-07-25
|
[
[
"Catani",
"S.",
""
],
[
"Grazzini",
"M.",
""
],
[
"Torre",
"A.",
""
]
] |
We consider the cross section for one-particle inclusive production at high transverse momentum in hadronic collisions. We present the all-order resummation formula that controls the logarithmically-enhanced perturbative QCD contributions to the partonic cross section in the threshold region, at fixed rapidity of the observed parton (hadron). The explicit resummation up to next-to-leading logarithmic accuracy is supplemented with the computation of the general structure of the near-threshold contributions to the next-to-leading order cross section. This next-to-leading order computation allows us to extract the one-loop hard-virtual amplitude that enters into the resummation formula. This is a necessary ingredient to explicitly extend the soft-gluon resummation beyond the next-to-leading logarithmic accuracy. These results equally apply to both spin-unpolarized and spin-polarized scattering processes.
|
1411.7876
|
Gernot Eichmann
|
Gernot Eichmann, Christian S. Fischer, Walter Heupel, Richard Williams
|
The muon g-2: Dyson-Schwinger status on hadronic light-by-light
scattering
|
11 pages, 7 figures, 2 tables. Proceedings of the 'XIth Quark
Confinement and the Hadron Spectrum', September 8-12, 2014, St. Petersburg,
Russia. Added references & fixed typos
| null | null | null |
hep-ph hep-lat nucl-th
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
We give a status report on the hadronic light-by-light scattering
contribution to the muon's anomalous magnetic moment from the Dyson-Schwinger
approach. We discuss novel, model-independent properties of the light-by-light
amplitude: we give its covariant decomposition in view of electromagnetic gauge
invariance and Bose symmetry, and we identify the relevant kinematic regions
that are probed under the integral. The decomposition of the amplitude at the
quark level and the importance of its various diagrams are discussed and
related to model approaches.
|
[
{
"created": "Fri, 28 Nov 2014 14:27:52 GMT",
"version": "v1"
},
{
"created": "Wed, 17 Dec 2014 13:47:04 GMT",
"version": "v2"
}
] |
2014-12-18
|
[
[
"Eichmann",
"Gernot",
""
],
[
"Fischer",
"Christian S.",
""
],
[
"Heupel",
"Walter",
""
],
[
"Williams",
"Richard",
""
]
] |
We give a status report on the hadronic light-by-light scattering contribution to the muon's anomalous magnetic moment from the Dyson-Schwinger approach. We discuss novel, model-independent properties of the light-by-light amplitude: we give its covariant decomposition in view of electromagnetic gauge invariance and Bose symmetry, and we identify the relevant kinematic regions that are probed under the integral. The decomposition of the amplitude at the quark level and the importance of its various diagrams are discussed and related to model approaches.
|
hep-ph/0102192
|
Burkhard Kaempfer
|
B. Kampfer, K. Gallmeister, O.P. Pavlenko, C. Gale
|
Dileptons and photons from central heavy-ion collisions at CERN-SPS
|
4 pages, talk at QM2001, Jan. 15 -20, 2001, Stony Brook
|
Nucl.Phys.A698:424-427,2002
|
10.1016/S0375-9474(01)01395-1
| null |
hep-ph
| null |
A unique parameterization of secondary (thermal) dilepton and photon yields
in heavy-ion experiments at CERN-SPS is proposed. Adding those thermal yields
to background contributions the spectral shapes of the CERES/NA45, NA38, NA50,
HELIOS/3 and WA98 data from experiments with lead and sulfur beams can be well
described.
|
[
{
"created": "Thu, 15 Feb 2001 15:12:39 GMT",
"version": "v1"
}
] |
2008-11-26
|
[
[
"Kampfer",
"B.",
""
],
[
"Gallmeister",
"K.",
""
],
[
"Pavlenko",
"O. P.",
""
],
[
"Gale",
"C.",
""
]
] |
A unique parameterization of secondary (thermal) dilepton and photon yields in heavy-ion experiments at CERN-SPS is proposed. Adding those thermal yields to background contributions the spectral shapes of the CERES/NA45, NA38, NA50, HELIOS/3 and WA98 data from experiments with lead and sulfur beams can be well described.
|
1512.09276
|
Igor Ivanov
|
I. P. Ivanov, Joao P. Silva
|
A CP-conserving multi-Higgs model without real basis
|
6 pages; v2: abstract, introduction, conclusions reformulated, all
the results stay unchanged
|
Phys. Rev. D 93, 095014 (2016)
|
10.1103/PhysRevD.93.095014
|
CFTP/16-001
|
hep-ph
|
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
|
Models beyond the Standard Model (bSM) often involve elaborate Higgs sectors,
which can be a source of CP-violation. It brings up the question of recognizing
in an efficient way whether a model is CP-violating. There is a diffuse belief
that the issue of explicit CP invariance can be linked to the existence of a
basis in which all coefficients are real; with even a theorem proposed a decade
ago claiming that the scalar sector of any multi-Higgs doublet model is
explicitly CP-conserving if and only if all of its coefficients can be made
real by a basis change. This is compounded by the fact that in all specific
multi Higgs models considered so far, the calculations complied with this
claim. Here, we present the first counterexample to this statement: a
CP-conserving three-Higgs-doublet model for which no real basis exists. We
outline the phenomenological consequences of this model, and notice that the
extra neutral Higgs bosons are neither CP-even nor CP-odd but are "half-odd"
under the generalized CP-symmetry of the model.
|
[
{
"created": "Thu, 31 Dec 2015 13:08:01 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Jan 2016 17:31:48 GMT",
"version": "v2"
}
] |
2016-05-25
|
[
[
"Ivanov",
"I. P.",
""
],
[
"Silva",
"Joao P.",
""
]
] |
Models beyond the Standard Model (bSM) often involve elaborate Higgs sectors, which can be a source of CP-violation. It brings up the question of recognizing in an efficient way whether a model is CP-violating. There is a diffuse belief that the issue of explicit CP invariance can be linked to the existence of a basis in which all coefficients are real; with even a theorem proposed a decade ago claiming that the scalar sector of any multi-Higgs doublet model is explicitly CP-conserving if and only if all of its coefficients can be made real by a basis change. This is compounded by the fact that in all specific multi Higgs models considered so far, the calculations complied with this claim. Here, we present the first counterexample to this statement: a CP-conserving three-Higgs-doublet model for which no real basis exists. We outline the phenomenological consequences of this model, and notice that the extra neutral Higgs bosons are neither CP-even nor CP-odd but are "half-odd" under the generalized CP-symmetry of the model.
|
2212.10043
|
Zhi-Long Han
|
Ang Liu, Feng-Lan Shao, Zhi-Long Han, Yi Jin, Honglei Li
|
Shinning Light on Sterile Neutrino Portal Dark Matter from Cosmology and
Collider
|
18 pages,8 figures
| null | null | null |
hep-ph hep-ex
|
http://creativecommons.org/licenses/by/4.0/
|
Provided the dark sector consisted of a dark scalar $\phi$ and a dark fermion
$\chi$ under an exact $Z_2$ symmetry, the sterile neutrino $N$ can act as the
messenger between the dark sector and standard model via the Yukawa coupling
$\lambda_{ds} \bar{\chi}\phi N$. In this paper, we focus on the specific
scenario $m_N>m_\phi+m_\chi$ with $\chi$ being a FIMP dark matter. The decay
width of dark scalar $\phi$ is doubly suppressed by the smallness of Yukawa
coupling $\lambda_{ds}$ and mixing angle $\theta$. The delayed decay
$\phi\to\chi\nu$ will have a great impact on cosmological observables such as
the Big Bang Nucleosynthesis, the Cosmic Microwave Background anisotropy power
spectra, the effective number of relativistic neutrino species $N_{\rm eff}$
and the energetic neutrino flux. Meanwhile, the sterile neutrino can generate
displaced vertex signature at colliders when $m_N<m_W$. The dark scalar $\phi$
will also induce measurable Higgs invisible decay for relatively large quartic
coupling. A comprehensive analysis of constraints from cosmology and collider
is performed in this paper. We find that almost the whole parameter space with
$m_N<m_W$ is under the reach of future experiments.
|
[
{
"created": "Tue, 20 Dec 2022 07:29:51 GMT",
"version": "v1"
}
] |
2022-12-21
|
[
[
"Liu",
"Ang",
""
],
[
"Shao",
"Feng-Lan",
""
],
[
"Han",
"Zhi-Long",
""
],
[
"Jin",
"Yi",
""
],
[
"Li",
"Honglei",
""
]
] |
Provided the dark sector consisted of a dark scalar $\phi$ and a dark fermion $\chi$ under an exact $Z_2$ symmetry, the sterile neutrino $N$ can act as the messenger between the dark sector and standard model via the Yukawa coupling $\lambda_{ds} \bar{\chi}\phi N$. In this paper, we focus on the specific scenario $m_N>m_\phi+m_\chi$ with $\chi$ being a FIMP dark matter. The decay width of dark scalar $\phi$ is doubly suppressed by the smallness of Yukawa coupling $\lambda_{ds}$ and mixing angle $\theta$. The delayed decay $\phi\to\chi\nu$ will have a great impact on cosmological observables such as the Big Bang Nucleosynthesis, the Cosmic Microwave Background anisotropy power spectra, the effective number of relativistic neutrino species $N_{\rm eff}$ and the energetic neutrino flux. Meanwhile, the sterile neutrino can generate displaced vertex signature at colliders when $m_N<m_W$. The dark scalar $\phi$ will also induce measurable Higgs invisible decay for relatively large quartic coupling. A comprehensive analysis of constraints from cosmology and collider is performed in this paper. We find that almost the whole parameter space with $m_N<m_W$ is under the reach of future experiments.
|
hep-ph/0409132
|
Victor Abramovsky
|
V.A. Abramovsky, A.V. Dmitriev, A.A. Shneider
|
Diffractive processes at high energies
|
To be published in proceedings of Quarks-2004. 14 pages, 8 figures
| null | null | null |
hep-ph
| null |
In this work we calculate pomeron flux in the single diffraction processes.
We consider two models: quasi-eikonal model and low constituent model. Both
models give the pictures different from the traditional three-reggeon model.
Successive developing of modeles gives some indications, that the low
constituent model is more attractive.
|
[
{
"created": "Sat, 11 Sep 2004 06:25:18 GMT",
"version": "v1"
}
] |
2007-05-23
|
[
[
"Abramovsky",
"V. A.",
""
],
[
"Dmitriev",
"A. V.",
""
],
[
"Shneider",
"A. A.",
""
]
] |
In this work we calculate pomeron flux in the single diffraction processes. We consider two models: quasi-eikonal model and low constituent model. Both models give the pictures different from the traditional three-reggeon model. Successive developing of modeles gives some indications, that the low constituent model is more attractive.
|
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