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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1806.02836 | Mikael Chala | Shankha Banerjee, Mikael Chala and Michael Spannowsky | Top quark FCNCs in extended Higgs sectors | 18 pages, 4 figures. V3: one typo corrected | Eur.Phys.J. C78 (2018) no.8, 683 | 10.1140/epjc/s10052-018-6150-0 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by-nc-sa/4.0/ | The large number of top quarks produced at the LHC and possible future hadron
colliders allows to study rare decays of this particle. In many well motivated
models of new physics, for example in non-minimal composite-Higgs models, the
existence of scalar singlets can induce new flavor-violating top decays
surpassing the Higgs contribution by orders of magnitude. We study the
discovery prospects of rare top decays within such models and develop new
search strategies to test these interactions in top pair-produced events at the
LHC. We demonstrate that scales as large as $10$--$50$ TeV can be probed.
Improvements by factors of $\sim 1.5$ and $\sim 3$ can be obtained at $\sqrt{s}
= 27$ TeV and $\sqrt{s} = 100$ TeV colliders.
| [
{
"created": "Thu, 7 Jun 2018 18:00:01 GMT",
"version": "v1"
},
{
"created": "Fri, 10 Aug 2018 15:53:06 GMT",
"version": "v2"
},
{
"created": "Fri, 31 Aug 2018 14:12:02 GMT",
"version": "v3"
}
] | 2018-09-03 | [
[
"Banerjee",
"Shankha",
""
],
[
"Chala",
"Mikael",
""
],
[
"Spannowsky",
"Michael",
""
]
] | The large number of top quarks produced at the LHC and possible future hadron colliders allows to study rare decays of this particle. In many well motivated models of new physics, for example in non-minimal composite-Higgs models, the existence of scalar singlets can induce new flavor-violating top decays surpassing the Higgs contribution by orders of magnitude. We study the discovery prospects of rare top decays within such models and develop new search strategies to test these interactions in top pair-produced events at the LHC. We demonstrate that scales as large as $10$--$50$ TeV can be probed. Improvements by factors of $\sim 1.5$ and $\sim 3$ can be obtained at $\sqrt{s} = 27$ TeV and $\sqrt{s} = 100$ TeV colliders. |
hep-ph/0308058 | H. C. G. Caldas | Heron Caldas | Neutral Pion Decay Width in a Hot and Dense Medium | RevTeX, 11 pages, 11 figures, PRC version | Phys.Rev.C69:035204,2004 | 10.1103/PhysRevC.69.035204 | null | hep-ph | null | We study the behavior of the $\pi^0$ width as a function of temperature and
density. We provide simple expressions for the neutral pion width in a hot and
dense medium based on a renormalized version of the microscopic Nambu Jona
Lasinio model. Then we consider the two cases where the pion mass is finite or
vanishes at the critical temperature and discuss the phenomenological
consequences of both cases.
| [
{
"created": "Wed, 6 Aug 2003 18:16:36 GMT",
"version": "v1"
},
{
"created": "Fri, 12 Dec 2003 04:56:34 GMT",
"version": "v2"
},
{
"created": "Fri, 12 Mar 2004 01:36:12 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Caldas",
"Heron",
""
]
] | We study the behavior of the $\pi^0$ width as a function of temperature and density. We provide simple expressions for the neutral pion width in a hot and dense medium based on a renormalized version of the microscopic Nambu Jona Lasinio model. Then we consider the two cases where the pion mass is finite or vanishes at the critical temperature and discuss the phenomenological consequences of both cases. |
hep-ph/9801401 | Dr P. K. Panigrahi | Prasanta. K. Panigrahi and C. Nagaraja (Kumar School of Physics,
University of Hyderabad, Hyderabad (INDIA)) | Soliton Solutions of the $\sigma$ Model and the Disoriented Chiral
Condensates | 4 pages, LaTex, invited talk presented at workshop SOLITONS:
properties, dynamics, interactions and applications, held at Kingston,
Ontario, Canada, July 20 - Jul 26, 1997 | null | null | null | hep-ph | null | We derive travelling soliton solutions of the $\sigma$ model, relevant for
the description of dynamics of pions, in the high-energy, heavy-ion collisions.
These extended objects are analogs of Ne$\grave{e}$l and Bloch type defects in
ferromagnetic systems and could possibly describe the disoriented chiral
condensates. It is shown that these solutions are metastable and can naturally
produce an asymmetry between $\pi^0 $ and $ \pi^+$, $\pi^- $ mesons in the
soft-pion emissions from heavy-ion collisons.
| [
{
"created": "Fri, 23 Jan 1998 11:26:52 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Panigrahi",
"Prasanta. K.",
"",
"Kumar School of Physics,\n University of Hyderabad, Hyderabad"
],
[
"Nagaraja",
"C.",
"",
"Kumar School of Physics,\n University of Hyderabad, Hyderabad"
]
] | We derive travelling soliton solutions of the $\sigma$ model, relevant for the description of dynamics of pions, in the high-energy, heavy-ion collisions. These extended objects are analogs of Ne$\grave{e}$l and Bloch type defects in ferromagnetic systems and could possibly describe the disoriented chiral condensates. It is shown that these solutions are metastable and can naturally produce an asymmetry between $\pi^0 $ and $ \pi^+$, $\pi^- $ mesons in the soft-pion emissions from heavy-ion collisons. |
1207.0333 | Andrzej Sandacz M | A. Sandacz and P. Sznajder | HEPGEN - generator for hard exclusive leptoproduction | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | HEPGEN is a generator of Monte Carlo events, which is dedicated to studies of
hard exclusive single photon or meson production processes at the COMPASS
experiment kinematic domain. In addition HEPGEN allows to generate also single
photon or meson production accompanied by the diffractive dissociation of the
nucleon, which is one of the main sources of background in analyses of
exclusive processes.
| [
{
"created": "Mon, 2 Jul 2012 10:40:40 GMT",
"version": "v1"
}
] | 2012-07-03 | [
[
"Sandacz",
"A.",
""
],
[
"Sznajder",
"P.",
""
]
] | HEPGEN is a generator of Monte Carlo events, which is dedicated to studies of hard exclusive single photon or meson production processes at the COMPASS experiment kinematic domain. In addition HEPGEN allows to generate also single photon or meson production accompanied by the diffractive dissociation of the nucleon, which is one of the main sources of background in analyses of exclusive processes. |
1204.4444 | Christian Hambrock | Christian Hambrock and Gudrun Hiller | Extracting $B \to K^*$ Form Factors from Data | null | null | 10.1103/PhysRevLett.109.091802 | DO-TH 12/10 | hep-ph hep-ex hep-lat | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We extract ratios of $B \to K^*$ form factors at low hadronic recoil from
recent data on $B \to K^* \mu^+ \mu^-$ decays in a model-independent way. The
presented method will improve in the future with further (angular) studies in
semileptonic rare B-decays and advance our understanding of form factors, which
are important inputs in precision tests of the Standard Model.
| [
{
"created": "Thu, 19 Apr 2012 19:41:50 GMT",
"version": "v1"
}
] | 2013-05-30 | [
[
"Hambrock",
"Christian",
""
],
[
"Hiller",
"Gudrun",
""
]
] | We extract ratios of $B \to K^*$ form factors at low hadronic recoil from recent data on $B \to K^* \mu^+ \mu^-$ decays in a model-independent way. The presented method will improve in the future with further (angular) studies in semileptonic rare B-decays and advance our understanding of form factors, which are important inputs in precision tests of the Standard Model. |
2310.01023 | Karim Ghorbani | Karim Ghorbani | Secluded Scalar Dark Matter and the Muon Anomalous Magnetic Moment | 11 pages | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | We consider a dark matter model with a singlet scalar, $\chi$, as our dark
matter (DM) candidate which is secluded from the Standard Model (SM) and
annihilates to the singlet scalar, $\phi$, via a contact interaction. The
singlet scalar, $\phi$, has a leptophilic interaction with the SM leptons and
may decay leptonically at tree level, and decays into a pair of photons at loop
level. The focus in this work is to consider DM masses below 10 GeV. It is
found a viable secluded region in the parameter space after imposing the
observed relic density. There is a one-loop interaction between scalar dark
matter and the atomic electron in this model. We then apply the available
direct detection bounds from Xenon10, Xenon1T, and DarkSide on the DM-electron
elastic scattering cross section. While the model can explain the muon
anomalous magnetic moment, we put bounds from current and future lepton
collider experiments.
| [
{
"created": "Mon, 2 Oct 2023 09:16:07 GMT",
"version": "v1"
}
] | 2023-10-03 | [
[
"Ghorbani",
"Karim",
""
]
] | We consider a dark matter model with a singlet scalar, $\chi$, as our dark matter (DM) candidate which is secluded from the Standard Model (SM) and annihilates to the singlet scalar, $\phi$, via a contact interaction. The singlet scalar, $\phi$, has a leptophilic interaction with the SM leptons and may decay leptonically at tree level, and decays into a pair of photons at loop level. The focus in this work is to consider DM masses below 10 GeV. It is found a viable secluded region in the parameter space after imposing the observed relic density. There is a one-loop interaction between scalar dark matter and the atomic electron in this model. We then apply the available direct detection bounds from Xenon10, Xenon1T, and DarkSide on the DM-electron elastic scattering cross section. While the model can explain the muon anomalous magnetic moment, we put bounds from current and future lepton collider experiments. |
hep-ph/0310233 | Johan Alwall | Johan Alwall and Gunnar Ingelman | Generalized VDM and F_2 data at low Q^2 | 5 pages, 4 figures, latex. Talk given at DIS2003 in St. Petersburg,
to appear in the proceedings | null | null | null | hep-ph | null | The generalised vector meson dominance model (GVDM) gives a good description
of F_2 data at very low Q^2. At intermediate Q^2 a GVDM component avoids
problems when applying the large-Q^2 DIS formalism, such as a negative gluon
distribution in the proton. The fluctuations of the exchanged photon into
vector mesons is also a natural part of a model with hadronic fluctuations of
the target proton, which gives a good description of the non-perturbative
x-shape of the proton's parton density functions at the starting scale Q^2_0
for DGLAP evolution.
| [
{
"created": "Mon, 20 Oct 2003 08:50:01 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Alwall",
"Johan",
""
],
[
"Ingelman",
"Gunnar",
""
]
] | The generalised vector meson dominance model (GVDM) gives a good description of F_2 data at very low Q^2. At intermediate Q^2 a GVDM component avoids problems when applying the large-Q^2 DIS formalism, such as a negative gluon distribution in the proton. The fluctuations of the exchanged photon into vector mesons is also a natural part of a model with hadronic fluctuations of the target proton, which gives a good description of the non-perturbative x-shape of the proton's parton density functions at the starting scale Q^2_0 for DGLAP evolution. |
1312.3022 | Yukio Nemoto | Masakiyo Kitazawa, Teiji Kunihiro, Yukio Nemoto | Possible generation of anomalously soft quark excitations at nonzero
temperature: Nonhyperbolic dispersion of parapion and van Hove singularity | 10 pages, 7 figures, to appear in Phys. Rev. D. Comments on the
parameter dependence, the Matsubara summation, future prospects added.
References added. Typos corrected | null | 10.1103/PhysRevD.89.056002 | null | hep-ph cond-mat.str-el nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the quark spectrum at finite temperature near and above the
pseudocritical temperature of the chiral phase transition incorporating the
effects of the collective modes with the quantum number of the sigma
(parasigma) and pion (parapion) in a chiral effective model with a nonzero
current quark mass. Below the pion zero-binding temperature where the pionic
modes are bound, the quark self-energy has van Hove singularity induced by the
scattering of quarks with the composite bound pions with a nonhyperbolic
dispersion curve. This singularity is found to cause a drastic change in the
quark spectrum from that in the mean field picture near the pseudocritical
temperature: The quark spectrum has an unexpected sharp peak at an energy
considerably lower than the constituent quark mass, while the spectrum
approaches the mean field one at high temperatures. We clarify that the
emergence of this anomalous structure of the quark spectral function originates
from the composite nature of the pionic modes with a non-Lorentz invariant
dispersion relation in the medium at finite temperature.
| [
{
"created": "Wed, 11 Dec 2013 02:39:46 GMT",
"version": "v1"
},
{
"created": "Sun, 16 Feb 2014 23:10:48 GMT",
"version": "v2"
}
] | 2015-06-18 | [
[
"Kitazawa",
"Masakiyo",
""
],
[
"Kunihiro",
"Teiji",
""
],
[
"Nemoto",
"Yukio",
""
]
] | We study the quark spectrum at finite temperature near and above the pseudocritical temperature of the chiral phase transition incorporating the effects of the collective modes with the quantum number of the sigma (parasigma) and pion (parapion) in a chiral effective model with a nonzero current quark mass. Below the pion zero-binding temperature where the pionic modes are bound, the quark self-energy has van Hove singularity induced by the scattering of quarks with the composite bound pions with a nonhyperbolic dispersion curve. This singularity is found to cause a drastic change in the quark spectrum from that in the mean field picture near the pseudocritical temperature: The quark spectrum has an unexpected sharp peak at an energy considerably lower than the constituent quark mass, while the spectrum approaches the mean field one at high temperatures. We clarify that the emergence of this anomalous structure of the quark spectral function originates from the composite nature of the pionic modes with a non-Lorentz invariant dispersion relation in the medium at finite temperature. |
2205.14379 | Andreas Papaefstathiou | Andreas Papaefstathiou, Tania Robens, and Graham White | Signal strength and W-boson mass measurements as a probe of the
electro-weak phase transition at colliders -- Snowmass White Paper | 8 pages, 1 figure; contribution to Snowmass 2021. Minor correction to
v1 | null | null | RBI-ThPhys-2022-20 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider an extension of the scalar sector of the Standard Model (SM) by
an additional gauge singlet, which mixes with a part of the SM-like Higgs
doublet. Within this model, parameter-space regions exist that can lead to a
strong first-order electro-weak phase transition, a necessary condition for
electro-weak baryogenesis. We discuss how such regions of the parameter space
can be tested using the SM-like Higgs boson's signal strength measurements, as
well as precision observables, such as e.g. the W-boson mass, at current and
future colliders.
| [
{
"created": "Sat, 28 May 2022 09:36:36 GMT",
"version": "v1"
},
{
"created": "Fri, 30 Sep 2022 14:25:41 GMT",
"version": "v2"
}
] | 2022-10-03 | [
[
"Papaefstathiou",
"Andreas",
""
],
[
"Robens",
"Tania",
""
],
[
"White",
"Graham",
""
]
] | We consider an extension of the scalar sector of the Standard Model (SM) by an additional gauge singlet, which mixes with a part of the SM-like Higgs doublet. Within this model, parameter-space regions exist that can lead to a strong first-order electro-weak phase transition, a necessary condition for electro-weak baryogenesis. We discuss how such regions of the parameter space can be tested using the SM-like Higgs boson's signal strength measurements, as well as precision observables, such as e.g. the W-boson mass, at current and future colliders. |
1007.2470 | Yumi Ko | Kyung Kiu Kim, Youngman Kim and Yumi Ko | Self-bound dense objects in holographic QCD | 17 pages, 5 figures, figures replaced, minor revision, to appear in
JHEP | JHEP 1010:039,2010 | 10.1007/JHEP10(2010)039 | null | hep-ph hep-th nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study a self-bound dense object in the hard wall model. We consider a
spherically symmetric dense object which is characterized by its radial density
distribution and non-uniform but spherically symmetric chiral condensate. For
this we analytically solve the partial differential equations in the hard wall
model and read off the radial coordinate dependence of the density and chiral
condensate according to the AdS/CFT correspondence. We then attempt to describe
nucleon density profiles of a few nuclei within our framework and observe that
the confinement scale changes from a free nucleon to a nucleus. We briefly
discuss how to include the effect of higher dimensional operator into our
study. We finally comment on possible extensions of our work.
| [
{
"created": "Thu, 15 Jul 2010 04:12:16 GMT",
"version": "v1"
},
{
"created": "Tue, 12 Oct 2010 07:20:50 GMT",
"version": "v2"
}
] | 2014-11-21 | [
[
"Kim",
"Kyung Kiu",
""
],
[
"Kim",
"Youngman",
""
],
[
"Ko",
"Yumi",
""
]
] | We study a self-bound dense object in the hard wall model. We consider a spherically symmetric dense object which is characterized by its radial density distribution and non-uniform but spherically symmetric chiral condensate. For this we analytically solve the partial differential equations in the hard wall model and read off the radial coordinate dependence of the density and chiral condensate according to the AdS/CFT correspondence. We then attempt to describe nucleon density profiles of a few nuclei within our framework and observe that the confinement scale changes from a free nucleon to a nucleus. We briefly discuss how to include the effect of higher dimensional operator into our study. We finally comment on possible extensions of our work. |
1101.3796 | Fabrizio Nesti | Homero Mart\'inez, Alejandra Melfo, Fabrizio Nesti, Goran Senjanovi\'c | Three Extra Mirror or Sequential Families: a Case for Heavy Higgs and
Inert Doublet | Four pages. Some figures and numerical results corrected. References
updated | Phys.Rev.Lett.106:191802,2011 | 10.1103/PhysRevLett.106.191802 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study the possibility of the existence of extra fermion families and an
extra Higgs doublet. We find that requiring the extra Higgs doublet to be inert
leaves space for three extra families, allowing for mirror fermion families and
a dark matter candidate at the same time. The emerging scenario is very
predictive: it consists of a Standard Model Higgs boson, with mass above
400\,\GeV, heavy new quarks between 340 and 500\,\GeV, light extra neutral
leptons, and an inert scalar with a mass below $M_Z$.
| [
{
"created": "Wed, 19 Jan 2011 23:08:34 GMT",
"version": "v1"
},
{
"created": "Sun, 24 Apr 2011 18:29:02 GMT",
"version": "v2"
}
] | 2011-05-23 | [
[
"Martínez",
"Homero",
""
],
[
"Melfo",
"Alejandra",
""
],
[
"Nesti",
"Fabrizio",
""
],
[
"Senjanović",
"Goran",
""
]
] | We study the possibility of the existence of extra fermion families and an extra Higgs doublet. We find that requiring the extra Higgs doublet to be inert leaves space for three extra families, allowing for mirror fermion families and a dark matter candidate at the same time. The emerging scenario is very predictive: it consists of a Standard Model Higgs boson, with mass above 400\,\GeV, heavy new quarks between 340 and 500\,\GeV, light extra neutral leptons, and an inert scalar with a mass below $M_Z$. |
hep-ph/0107256 | Yuri V. Kovchegov | Yuri V. Kovchegov (University of Washington) | Diffractive Gluon Production in Proton-Nucleus Collisions and in DIS | 14 pages, 6 figures, REVTeX, minor corrections included | Phys.Rev.D64:114016,2001; Erratum-ibid.D68:039901,2003 | 10.1103/PhysRevD.64.114016 10.1103/PhysRevD.68.039901 | NT@UW-01-018 | hep-ph nucl-th | null | We derive expressions for the gluon production cross sections in the single
diffractive proton-nucleus scattering and DIS processes in a quasi-classical
approximation. The resulting cross sections include the effects of all multiple
rescatterings in the classical background field of the target proton or
nucleus, which remains intact after the scattering. We also write down an
expression for the inclusive gluon production cross section in DIS in the
quasi-classical approximation.
| [
{
"created": "Wed, 25 Jul 2001 00:13:41 GMT",
"version": "v1"
},
{
"created": "Wed, 2 Jul 2003 19:36:40 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Kovchegov",
"Yuri V.",
"",
"University of Washington"
]
] | We derive expressions for the gluon production cross sections in the single diffractive proton-nucleus scattering and DIS processes in a quasi-classical approximation. The resulting cross sections include the effects of all multiple rescatterings in the classical background field of the target proton or nucleus, which remains intact after the scattering. We also write down an expression for the inclusive gluon production cross section in DIS in the quasi-classical approximation. |
hep-ph/0406155 | Chong Sheng Li | Jian Jun Liu, Chong Sheng Li, Li Lin Yang and Li Gang Jin | $t\to cV$ via SUSY FCNC couplings in the unconstrained MSSM | 15 pages, 3 figures, minor changs in the Table 1 | Phys.Lett.B599:92-101,2004 | 10.1016/j.physletb.2004.07.062 | null | hep-ph | null | We recalculate the branching ratios for $t\to cV$ ($V=g,\gamma,Z$) induced by
SUSY FCNC couplings within the general unconstrained MSSM framework using mass
eigenstate approach. Our results show that the branching ratios for these
decays are larger than ones reported in previous literatures in the MSSM with
R-parity conservation, and they can reach $\sim 10^{-4}$, $\sim 10^{-6}$, and
$\sim 10^{-6}$, respectively, for favorable parameter values allowed by current
precise experiments. Thus, the branching ratios for $t\to cg$ and $t\to
c\gamma$ may be measurable at the LHC.
| [
{
"created": "Tue, 15 Jun 2004 08:33:43 GMT",
"version": "v1"
},
{
"created": "Tue, 31 Aug 2004 01:04:41 GMT",
"version": "v2"
},
{
"created": "Thu, 14 Oct 2004 08:23:08 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Liu",
"Jian Jun",
""
],
[
"Li",
"Chong Sheng",
""
],
[
"Yang",
"Li Lin",
""
],
[
"Jin",
"Li Gang",
""
]
] | We recalculate the branching ratios for $t\to cV$ ($V=g,\gamma,Z$) induced by SUSY FCNC couplings within the general unconstrained MSSM framework using mass eigenstate approach. Our results show that the branching ratios for these decays are larger than ones reported in previous literatures in the MSSM with R-parity conservation, and they can reach $\sim 10^{-4}$, $\sim 10^{-6}$, and $\sim 10^{-6}$, respectively, for favorable parameter values allowed by current precise experiments. Thus, the branching ratios for $t\to cg$ and $t\to c\gamma$ may be measurable at the LHC. |
1302.7240 | Pietro Biancofiore | Pietro Biancofiore | Bounds on the compactification scale of two universal extra dimensions
from exclusive $b \to s \gamma$ decays | 10 pages, 2 figures | null | 10.1088/0954-3899/40/6/065006 | BARI-TH/652-13 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The exclusive radiative $B \to K^* \gamma$, $B \to K^*_2 \gamma$, $B_s \to
\phi \gamma$ and $\Lambda_b \to \Lambda \gamma$ decays are studied in a new
physics scenario with two universal extra dimensions compactified on a chiral
square. The computed branching fractions depend on the size $R$ of the extra
dimensions, and a comparison with the available measurements allows us to put
bounds on such a fundamental parameter. From the mode $B^0 \to K^{*0} \gamma$
we obtain the most stringent bound: $1 \over R>710$ GeV.
| [
{
"created": "Thu, 28 Feb 2013 16:01:59 GMT",
"version": "v1"
}
] | 2015-06-15 | [
[
"Biancofiore",
"Pietro",
""
]
] | The exclusive radiative $B \to K^* \gamma$, $B \to K^*_2 \gamma$, $B_s \to \phi \gamma$ and $\Lambda_b \to \Lambda \gamma$ decays are studied in a new physics scenario with two universal extra dimensions compactified on a chiral square. The computed branching fractions depend on the size $R$ of the extra dimensions, and a comparison with the available measurements allows us to put bounds on such a fundamental parameter. From the mode $B^0 \to K^{*0} \gamma$ we obtain the most stringent bound: $1 \over R>710$ GeV. |
hep-ph/0509171 | Sujoy Poddar | Siba Prasad Das, Amitava Datta and Sujoy Poddar | Top squark and neutralino decays in a R-parity violating model
constrained by neutrino oscillation data | 20 pages, 4 figures, LaTex,typos corrected and reference added for
section 2, a paragraph has been added in the conclusion part | Phys.Rev. D73 (2006) 075014 | 10.1103/PhysRevD.73.075014 | null | hep-ph | null | In a R-parity violating (RPV) model of neutrino mass with three bilinear
couplings $\mu_i$ and three trilinear couplings $\lambda'_{i33}$, where $i$ is
the lepton index, we find six generic scenarios each with a distinctive pattern
of the trilinear couplings consistent with the oscillation data. These patterns
may be reflected in direct RPV decays of the lighter top squark or in the RPV
decays of the lightest superparticle, assumed to be the lightest neutralino.
Typical signal sizes at the Tevatron RUN II and the LHC have been estimated
and the results turn out to be encouraging.
| [
{
"created": "Fri, 16 Sep 2005 14:15:31 GMT",
"version": "v1"
},
{
"created": "Mon, 26 Sep 2005 14:35:48 GMT",
"version": "v2"
},
{
"created": "Fri, 17 Mar 2006 08:07:22 GMT",
"version": "v3"
}
] | 2016-09-06 | [
[
"Das",
"Siba Prasad",
""
],
[
"Datta",
"Amitava",
""
],
[
"Poddar",
"Sujoy",
""
]
] | In a R-parity violating (RPV) model of neutrino mass with three bilinear couplings $\mu_i$ and three trilinear couplings $\lambda'_{i33}$, where $i$ is the lepton index, we find six generic scenarios each with a distinctive pattern of the trilinear couplings consistent with the oscillation data. These patterns may be reflected in direct RPV decays of the lighter top squark or in the RPV decays of the lightest superparticle, assumed to be the lightest neutralino. Typical signal sizes at the Tevatron RUN II and the LHC have been estimated and the results turn out to be encouraging. |
hep-ph/9204233 | S. Umasankar | D. Bhowmick, A. K. Ray, S. Raychaudhuri and S. Uma Sankar | CP-violating Phenomena in an $ SU(2)_L \times SU(2)_R \times U(1)_{B-L}
\times SU(3)_H^{VL}$ Horizontal Symmetric Model | 19 pages, 2 figures, one included, other will be mailed on request
LaTeX file | null | null | null | hep-ph | null | We consider an $SU(2)_L \times SU(2)_R \times U(1)_{B-L} \times SU(3)_H^{VL}$
gauge model with natural flavour conservation in the Higgs sector, in which
CP-violation occurs due to the horizontal interactions only. We calculate the
CP-violating observables $\epsilon$ and $\epsilon'$ of the neutral kaon sector
and $d_n$, the electric dipole moment of the neutron. The regions of the
parameter space which yield a value of $\epsilon$ that is in agreement with the
experiment, lead to predictions for $\epsilon'$ and $d_n$ which are at least
five orders of magnitude smaller than the current experimental upper bounds.
| [
{
"created": "Thu, 23 Apr 1992 23:15:32 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Bhowmick",
"D.",
""
],
[
"Ray",
"A. K.",
""
],
[
"Raychaudhuri",
"S.",
""
],
[
"Sankar",
"S. Uma",
""
]
] | We consider an $SU(2)_L \times SU(2)_R \times U(1)_{B-L} \times SU(3)_H^{VL}$ gauge model with natural flavour conservation in the Higgs sector, in which CP-violation occurs due to the horizontal interactions only. We calculate the CP-violating observables $\epsilon$ and $\epsilon'$ of the neutral kaon sector and $d_n$, the electric dipole moment of the neutron. The regions of the parameter space which yield a value of $\epsilon$ that is in agreement with the experiment, lead to predictions for $\epsilon'$ and $d_n$ which are at least five orders of magnitude smaller than the current experimental upper bounds. |
2112.01449 | Markus Wobisch | L. Sawyer, C. Waits, M. Wobisch | Perturbative QCD predictions in fixed order for cross section ratios | 12 pages, 4 figures, submitted to JHEP | null | null | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In the standard approach, predictions of perturbative Quantum Chromodynamics
for ratios of cross sections are computed as the ratio of fixed-order
predictions for the numerator and the denominator. Beyond the lowest order in
the perturbative expansion, the result does, however, not correspond to a
fixed-order prediction for the ratio. This article describes how exact
fixed-order results for ratios of arbitrary cross sections can be obtained. The
general method for computations in any order of the perturbative expansion is
derived, and results for next-to-leading order and next-to-next-to-leading
order calculations are given. The approach is applied to theory predictions for
various multi-jet cross section ratios measured at hadron colliders. The two
methods are compared with each other and with the experimental data.
Recommendations are made how to obtain improved theory predictions with more
realistic uncertainty estimates.
| [
{
"created": "Thu, 2 Dec 2021 17:43:58 GMT",
"version": "v1"
}
] | 2021-12-03 | [
[
"Sawyer",
"L.",
""
],
[
"Waits",
"C.",
""
],
[
"Wobisch",
"M.",
""
]
] | In the standard approach, predictions of perturbative Quantum Chromodynamics for ratios of cross sections are computed as the ratio of fixed-order predictions for the numerator and the denominator. Beyond the lowest order in the perturbative expansion, the result does, however, not correspond to a fixed-order prediction for the ratio. This article describes how exact fixed-order results for ratios of arbitrary cross sections can be obtained. The general method for computations in any order of the perturbative expansion is derived, and results for next-to-leading order and next-to-next-to-leading order calculations are given. The approach is applied to theory predictions for various multi-jet cross section ratios measured at hadron colliders. The two methods are compared with each other and with the experimental data. Recommendations are made how to obtain improved theory predictions with more realistic uncertainty estimates. |
2205.05744 | Pasquale Di Bari | Pasquale Di Bari | Gravitational waves from neutrino mass genesis | 19 pages, 5 figures; Proceedings of the Corfu Summer Institute 2021 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The discovery of gravitational waves opens new opportunities to test BSM
physics. In particular, the production of a stochastic background of primordial
gravitational waves could provide a signature of the generation of the
right-right Majorana neutrino mass term necessary, within type-I seesaw
mechanism, to explain lightness of neutrinos and their mixing parameters. I
will discuss the possibility that such a generation occurs during a strong
first order phase transition within Majoron models [1]. As well known, this can
indeed produce a stochastic background of gravitational waves. The scale of the
phase transition can or cannot coincide with the seesaw scale. In the latter
case a low scale phase transition, occurring in the pre-recombination era,
might be tested at very low frequencies ($10^{-9}$--$10^{-6}\,{\rm Hz}$). Even
though the signal can hardly reproduce the NANOGrac putative signal such new
physics at low scale might help ameliorating the tensions in the $\Lambda$CDM
cosmological model (e.g., the Hubble tension). I will also discuss how a phase
transition might be responsible for the generation of dark matter in the form
of dark neutrinos coupling to the seesaw neutrinos via Higgs induced right
handed-right handed neutrino mixing [2].
| [
{
"created": "Wed, 11 May 2022 19:23:51 GMT",
"version": "v1"
}
] | 2022-05-13 | [
[
"Di Bari",
"Pasquale",
""
]
] | The discovery of gravitational waves opens new opportunities to test BSM physics. In particular, the production of a stochastic background of primordial gravitational waves could provide a signature of the generation of the right-right Majorana neutrino mass term necessary, within type-I seesaw mechanism, to explain lightness of neutrinos and their mixing parameters. I will discuss the possibility that such a generation occurs during a strong first order phase transition within Majoron models [1]. As well known, this can indeed produce a stochastic background of gravitational waves. The scale of the phase transition can or cannot coincide with the seesaw scale. In the latter case a low scale phase transition, occurring in the pre-recombination era, might be tested at very low frequencies ($10^{-9}$--$10^{-6}\,{\rm Hz}$). Even though the signal can hardly reproduce the NANOGrac putative signal such new physics at low scale might help ameliorating the tensions in the $\Lambda$CDM cosmological model (e.g., the Hubble tension). I will also discuss how a phase transition might be responsible for the generation of dark matter in the form of dark neutrinos coupling to the seesaw neutrinos via Higgs induced right handed-right handed neutrino mixing [2]. |
1205.5035 | Sebastian Sapeta | Krzysztof Kutak and Sebastian Sapeta | Gluon saturation in dijet production in p-Pb collisions at Large Hadron
Collider | 16 pages, 8 figures; v2: minor textual changes, reference added; v3:
extra paragraph and figure for RHIC, several clarifying sentences and
references added, version accepted by PRD | Phys. Rev. D 86, 094043 (2012) | 10.1103/PhysRevD.86.094043 | IPPP/12/35; DCPT/12/70; IFJPAN-IV-2012-1 | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study saturation effects in the production of dijets in p-p and p-Pb
collisions using the framework of high energy factorization. We focus on
central-forward jet configurations, which allow for probing gluon density at
low longitudinal momentum fraction. We find significant suppression of the
central-forward jet decorrelations in p-Pb compared to p-p, which we attribute
to saturation of gluon density in nuclei.
| [
{
"created": "Tue, 22 May 2012 20:00:17 GMT",
"version": "v1"
},
{
"created": "Fri, 25 May 2012 17:01:02 GMT",
"version": "v2"
},
{
"created": "Mon, 5 Nov 2012 17:24:59 GMT",
"version": "v3"
}
] | 2013-05-30 | [
[
"Kutak",
"Krzysztof",
""
],
[
"Sapeta",
"Sebastian",
""
]
] | We study saturation effects in the production of dijets in p-p and p-Pb collisions using the framework of high energy factorization. We focus on central-forward jet configurations, which allow for probing gluon density at low longitudinal momentum fraction. We find significant suppression of the central-forward jet decorrelations in p-Pb compared to p-p, which we attribute to saturation of gluon density in nuclei. |
1109.2236 | Bruno Os\'orio Rodrigues | A. Cerqueira Jr, B. Os\'orio Rodrigues and M. E. Bracco | $B_s^* B K$ vertex from QCD sum rules | 11 pages, 11 figures | null | 10.1016/j.nuclphysa.2011.11.004 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The form factors and the coupling constant of the $B_s^* B K$ vertex are
calculated using the QCD sum rules method. Three point correlation functions
are computed considering both $K$ and $B$ mesons off-shell and, after an
extrapolation of the QCDSR results, we obtain the coupling constant of the
vertex. We study the uncertainties in our result by calculating a third form
factor obtained when the $B^*_s$ is the off-shell meson, considering other
acceptable structures and computing the variations of the sum rules'
parameters. The form factors obtained have different behaviors but their
simultaneous extrapolations reach to the same value of the coupling constant
$g_{B_s^* B K}=10.6 \pm 1.7$. We compare our result with other theoretical
estimates.
| [
{
"created": "Sat, 10 Sep 2011 16:56:11 GMT",
"version": "v1"
}
] | 2014-12-02 | [
[
"Cerqueira",
"A.",
"Jr"
],
[
"Rodrigues",
"B. Osório",
""
],
[
"Bracco",
"M. E.",
""
]
] | The form factors and the coupling constant of the $B_s^* B K$ vertex are calculated using the QCD sum rules method. Three point correlation functions are computed considering both $K$ and $B$ mesons off-shell and, after an extrapolation of the QCDSR results, we obtain the coupling constant of the vertex. We study the uncertainties in our result by calculating a third form factor obtained when the $B^*_s$ is the off-shell meson, considering other acceptable structures and computing the variations of the sum rules' parameters. The form factors obtained have different behaviors but their simultaneous extrapolations reach to the same value of the coupling constant $g_{B_s^* B K}=10.6 \pm 1.7$. We compare our result with other theoretical estimates. |
hep-ph/9709222 | Hans-Guenter Dosch | H.G. Dosch (Institut f\"ur Theoretische Physik der Universit\"at
Heidelberg) | Few-body aspects of non-perturbative QCD | Plenary Talk at 15th Int. Conf. on Few-Body Problems in Physics 16
pages | Nucl.Phys.A631:316c-330c,1998 | 10.1016/S0375-9474(98)00030-X | null | hep-ph | null | After some general remarks on non-perturbative QCD I present shortly models
which lead to a color-electric flux tube formation. The implications of such a
flux tube formation especially on high energy scattering are discussed.
| [
{
"created": "Tue, 2 Sep 1997 16:04:37 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Dosch",
"H. G.",
"",
"Institut für Theoretische Physik der Universität\n Heidelberg"
]
] | After some general remarks on non-perturbative QCD I present shortly models which lead to a color-electric flux tube formation. The implications of such a flux tube formation especially on high energy scattering are discussed. |
hep-ph/9504380 | Boris Kopeliovich | Boris Kopeliovich and Bogdan Povh (MPI-K, Heidelberg) | Nuclear Shadowing and the Proton Structure Function at Small x | 9 pages, LATEX, 3 uuencoded figures | null | null | MPIH-V12-1995 | hep-ph | null | A new scaling variable is introduced in terms of which nuclear shadowing in
deep-inelastic scattering is universal, i.e. independent of $A$, $Q^2$ and $x$.
This variable can be interpreted as a measure of the number of gluons probed by
the hadronic fluctuations of a virtual photon during their lifetime. According
to recent data from the H1 and ZEUS experiments, the gluon density in a proton
rises steeply as $x$ tends to zero. So nuclei which in the infinite momentum
frame have a large surface density of gluons model at larger $x$ values what we
expect for the proton at much smaller $x$. Using experimental information on
nuclear shadowing we predict the unitarity corrections to the proton structure
function at small $x$ and extract the bare Pomeron intercept.
| [
{
"created": "Mon, 24 Apr 1995 17:49:37 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Kopeliovich",
"Boris",
"",
"MPI-K, Heidelberg"
],
[
"Povh",
"Bogdan",
"",
"MPI-K, Heidelberg"
]
] | A new scaling variable is introduced in terms of which nuclear shadowing in deep-inelastic scattering is universal, i.e. independent of $A$, $Q^2$ and $x$. This variable can be interpreted as a measure of the number of gluons probed by the hadronic fluctuations of a virtual photon during their lifetime. According to recent data from the H1 and ZEUS experiments, the gluon density in a proton rises steeply as $x$ tends to zero. So nuclei which in the infinite momentum frame have a large surface density of gluons model at larger $x$ values what we expect for the proton at much smaller $x$. Using experimental information on nuclear shadowing we predict the unitarity corrections to the proton structure function at small $x$ and extract the bare Pomeron intercept. |
2112.07330 | Zbigniew Was | Sw. Banerjee, D. Biswas, T. Przedzinski, Z. Was | The tau lepton Monte Carlo Event Generation -- imprinting New Physics
models with exotic scalar or vector states into simulation samples | Presented by Z. Was on "STRONG 2020 Virtual Workshop on Spacelike and
Timelike determination of the Hadronic LO contribution to the Muon g-2
November, 2021, Frascati (virtual edition), Italy | null | null | IFJPAN-IV-2021-20 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Monte Carlo for lepton pair production andtau decays consist of KKMC for
lepton pair production, tauola for tau lepton decays and photos for radiative
corrections in decays.
An effort for adaptation of the system for precision data being collected at
the Belle II experiment included simulation of additional light lepton pairs.
Extension to processes where lepton pair is produced through narrow resonances,
like dark photon or dark scalar phi resonances, was straight forward.
Modified programs versions are available in stand-alone format from gitlab
repository or through the basf2 system of Belle II software. It was explained
recently during the International Workshop on Tau Lepton Physics September,
2021, Bloomington IN. Now we concentrate on simulations for phi resonance, a
hypothetical object which could be responsible for anomalous moment g-2 in
Z-\tau-\tau interactions through virtual contributions.
| [
{
"created": "Tue, 14 Dec 2021 12:34:58 GMT",
"version": "v1"
}
] | 2021-12-15 | [
[
"Banerjee",
"Sw.",
""
],
[
"Biswas",
"D.",
""
],
[
"Przedzinski",
"T.",
""
],
[
"Was",
"Z.",
""
]
] | The Monte Carlo for lepton pair production andtau decays consist of KKMC for lepton pair production, tauola for tau lepton decays and photos for radiative corrections in decays. An effort for adaptation of the system for precision data being collected at the Belle II experiment included simulation of additional light lepton pairs. Extension to processes where lepton pair is produced through narrow resonances, like dark photon or dark scalar phi resonances, was straight forward. Modified programs versions are available in stand-alone format from gitlab repository or through the basf2 system of Belle II software. It was explained recently during the International Workshop on Tau Lepton Physics September, 2021, Bloomington IN. Now we concentrate on simulations for phi resonance, a hypothetical object which could be responsible for anomalous moment g-2 in Z-\tau-\tau interactions through virtual contributions. |
2311.00350 | Hao Chen | Hao Chen | QCD Factorization from Light-ray OPE | 13 pages | null | null | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The energy-energy correlator (EEC) in Quantum Chromodynamics (QCD) serves as
an important event shape for probing the substructure of jets in high-energy
collisions. A significant progress has been make in understanding the collinear
limit, where the angle between two detectors approaches zero, from the
factorization formula in QCD and the light-ray Operator Product Expansion (OPE)
in Conformal Field Theory. Building upon prior research on the renormalization
of light-ray operators, we take an innovative step to extend the light-ray OPE
into non-conformal contexts, with a specific emphasis on perturbative QCD. Our
proposed form of the light-ray OPE is constrained by three fundamental
properties: Lorentz symmetry, renormalization group invariance, and constraints
from physical observables. This extension allows us to derive a factorization
formula for the collinear limit of EEC, facilitating the future exploration and
understanding on subleading power corrections in collinear limit.
| [
{
"created": "Wed, 1 Nov 2023 07:51:43 GMT",
"version": "v1"
}
] | 2023-11-02 | [
[
"Chen",
"Hao",
""
]
] | The energy-energy correlator (EEC) in Quantum Chromodynamics (QCD) serves as an important event shape for probing the substructure of jets in high-energy collisions. A significant progress has been make in understanding the collinear limit, where the angle between two detectors approaches zero, from the factorization formula in QCD and the light-ray Operator Product Expansion (OPE) in Conformal Field Theory. Building upon prior research on the renormalization of light-ray operators, we take an innovative step to extend the light-ray OPE into non-conformal contexts, with a specific emphasis on perturbative QCD. Our proposed form of the light-ray OPE is constrained by three fundamental properties: Lorentz symmetry, renormalization group invariance, and constraints from physical observables. This extension allows us to derive a factorization formula for the collinear limit of EEC, facilitating the future exploration and understanding on subleading power corrections in collinear limit. |
hep-ph/0006137 | Jai Sam Kim | Jai Sam Kim and Kyungsoo Lee | The Earth Regeneration Effect of Solar Neutrinos: a Numerical Treatment
with Three Active Neutrino Flavors | 8 pages, 2 postscript figures | Comput.Phys.Commun.135:176-189,2001 | 10.1016/S0010-4655(00)00237-X | null | hep-ph | null | We introduce an integrated algorithm for full scale investigation of the
earth regeneration effect of solar neutrinos with all three active neutrinos.
We illustrate that the earth effect on low energy solar neutrinos ($E_\nu < 20$
MeV) causes large variations in the survival probabilities for large values of
the mixing angle $\theta_{12}$ for a given value of $\theta_{13}$. But it is
maximal for small values of $\theta_{13}$ and diminishes for large values at a
given value of $\theta_{12}$. The nadir angle dependence is sensitive to the
value of $E'\equiv E/\Delta_{12}$. As far as low energy solar neutrinos are
concerned we notice that the earth effect is more pronounced for core
penetration. We confirm that the earth effect leaves the SMA region almost
intact regardless of $\theta_{13}$ and that it is significant for high energy
$^8$B and $hep$ neutrinos in the LMA region. We also show that for large values
of $\theta_{13}$, the earth effect is significant for high energy neutrinos
($E'\gtrsim 10^9$) and it can be large at any nadir angle.
| [
{
"created": "Tue, 13 Jun 2000 14:31:41 GMT",
"version": "v1"
}
] | 2014-11-17 | [
[
"Kim",
"Jai Sam",
""
],
[
"Lee",
"Kyungsoo",
""
]
] | We introduce an integrated algorithm for full scale investigation of the earth regeneration effect of solar neutrinos with all three active neutrinos. We illustrate that the earth effect on low energy solar neutrinos ($E_\nu < 20$ MeV) causes large variations in the survival probabilities for large values of the mixing angle $\theta_{12}$ for a given value of $\theta_{13}$. But it is maximal for small values of $\theta_{13}$ and diminishes for large values at a given value of $\theta_{12}$. The nadir angle dependence is sensitive to the value of $E'\equiv E/\Delta_{12}$. As far as low energy solar neutrinos are concerned we notice that the earth effect is more pronounced for core penetration. We confirm that the earth effect leaves the SMA region almost intact regardless of $\theta_{13}$ and that it is significant for high energy $^8$B and $hep$ neutrinos in the LMA region. We also show that for large values of $\theta_{13}$, the earth effect is significant for high energy neutrinos ($E'\gtrsim 10^9$) and it can be large at any nadir angle. |
hep-ph/0001094 | Ma Bo-Qiang | Bo-Qiang Ma | The Spin Structure of the Proton | 8 latex pages, Invited talk presented at Circum-Pan-Pacific RIKEN
Symposium on High Energy Spin Physics, RIKEN, Wako, Japan, November 3-6,
1999. To be published in the proceedings | RIKEN Rev.28:110-113,2000 | null | null | hep-ph hep-ex nucl-ex nucl-th | null | It is shown that the proton "spin crisis'' or "spin puzzle" can be understood
by the relativistic effect of quark transversal motions due to the
Melosh-Wigner rotation. The quark helicity $\Delta q$ measured in polarized
deep inelastic scattering is actually the quark spin in the infinite momentum
frame or in the light-cone formalism, and it is different from the quark spin
in the nucleon rest frame or in the quark model. The flavor asymmetry of the
Melosh-Wigner effect for the valence $u$ and $d$ quarks and the intrinsic sea
$q \bar{q}$ pairs are also the important ingredients in a SU(6)
quark-spectator-diquark model framework to understand the "spin puzzle". Such a
picture of the spin structure can be tested by use of several simple relations
to measure the quark spin distributions in the quark model.
| [
{
"created": "Wed, 12 Jan 2000 09:20:00 GMT",
"version": "v1"
}
] | 2011-04-15 | [
[
"Ma",
"Bo-Qiang",
""
]
] | It is shown that the proton "spin crisis'' or "spin puzzle" can be understood by the relativistic effect of quark transversal motions due to the Melosh-Wigner rotation. The quark helicity $\Delta q$ measured in polarized deep inelastic scattering is actually the quark spin in the infinite momentum frame or in the light-cone formalism, and it is different from the quark spin in the nucleon rest frame or in the quark model. The flavor asymmetry of the Melosh-Wigner effect for the valence $u$ and $d$ quarks and the intrinsic sea $q \bar{q}$ pairs are also the important ingredients in a SU(6) quark-spectator-diquark model framework to understand the "spin puzzle". Such a picture of the spin structure can be tested by use of several simple relations to measure the quark spin distributions in the quark model. |
hep-ph/0502046 | Yogesh Mathur Kumar | R. Ramanathan, Y. K. Mathur, K. K. Gupta, Agam K. Jha and S. S. Singh
(University of Delhi, India) | A Comparative Study of Two Models of QGP-Fireball Formation | Revtex 5 pages and 5 figures, Added some results and references | null | null | null | hep-ph | null | A Comparative study of the strengths and weakness of the models of fireball
formation namely the statistical model of Ramanathan et.al (Physical Review C
70, 027903, 2004) and the approximation schemes of Kapusta et. al (Physical
Review D 46, 1379, 1992) and its subsequent improved variants is made. The way
to complement the various approximation schemes, in order to enhance their
utility in the phenomenological analysis of QGP data that are expected from
ongoing URHIC experiments, is suggested. The calculations demonstrate a
striking QCD behaviour of the surface tension of the QGP droplet resulting in
its increase with temperature, which is due to the confining nature of QCD
forces at the surface and the interface surface tension varies as the cube of
the transition temperature which is in conformity with the results of Lattice
QCD simulations.
| [
{
"created": "Fri, 4 Feb 2005 16:12:21 GMT",
"version": "v1"
},
{
"created": "Fri, 25 Feb 2005 14:49:49 GMT",
"version": "v2"
},
{
"created": "Sat, 5 Mar 2005 10:49:54 GMT",
"version": "v3"
}
] | 2007-05-23 | [
[
"Ramanathan",
"R.",
"",
"University of Delhi, India"
],
[
"Mathur",
"Y. K.",
"",
"University of Delhi, India"
],
[
"Gupta",
"K. K.",
"",
"University of Delhi, India"
],
[
"Jha",
"Agam K.",
"",
"University of Delhi, India"
],
[
"Singh",
"S. S.",
"",
"University of Delhi, India"
]
] | A Comparative study of the strengths and weakness of the models of fireball formation namely the statistical model of Ramanathan et.al (Physical Review C 70, 027903, 2004) and the approximation schemes of Kapusta et. al (Physical Review D 46, 1379, 1992) and its subsequent improved variants is made. The way to complement the various approximation schemes, in order to enhance their utility in the phenomenological analysis of QGP data that are expected from ongoing URHIC experiments, is suggested. The calculations demonstrate a striking QCD behaviour of the surface tension of the QGP droplet resulting in its increase with temperature, which is due to the confining nature of QCD forces at the surface and the interface surface tension varies as the cube of the transition temperature which is in conformity with the results of Lattice QCD simulations. |
hep-ph/9906275 | Carlo Giunti | C. Giunti | Neutrinoless double-beta decay with three or four neutrino mixing | 18 pages including 2 figures, RevTeX | Phys.Rev. D61 (2000) 036002 | 10.1103/PhysRevD.61.036002 | DFTT 32/99 | hep-ph hep-ex nucl-ex | null | Considering the scheme with mixing of three neutrinos and a mass hierarchy
that can accommodate the results of solar and atmospheric neutrino experiments,
it is shown that the results of solar neutrino experiments imply a lower bound
for the effective Majorana mass in neutrinoless double-beta decay, under the
natural assumptions that massive neutrinos are Majorana particles and there are
no unlikely fine-tuned cancellations among the contributions of the different
neutrino masses. Considering the four-neutrino schemes that can accommodate
also the results of the LSND experiment, it is shown that only one of them is
compatible with the results of neutrinoless double-beta decay experiments and
with the measurement of the abundances of primordial elements produced in
Big-Bang Nucleosynthesis. It is shown that in this scheme, under the
assumptions that massive neutrinos are Majorana particles and there are no
cancellations among the contributions of the different neutrino masses, the
results of the LSND experiment imply a lower bound for the effective Majorana
mass in neutrinoless double-beta decay.
| [
{
"created": "Mon, 7 Jun 1999 13:28:10 GMT",
"version": "v1"
},
{
"created": "Fri, 27 Aug 1999 12:45:05 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Giunti",
"C.",
""
]
] | Considering the scheme with mixing of three neutrinos and a mass hierarchy that can accommodate the results of solar and atmospheric neutrino experiments, it is shown that the results of solar neutrino experiments imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay, under the natural assumptions that massive neutrinos are Majorana particles and there are no unlikely fine-tuned cancellations among the contributions of the different neutrino masses. Considering the four-neutrino schemes that can accommodate also the results of the LSND experiment, it is shown that only one of them is compatible with the results of neutrinoless double-beta decay experiments and with the measurement of the abundances of primordial elements produced in Big-Bang Nucleosynthesis. It is shown that in this scheme, under the assumptions that massive neutrinos are Majorana particles and there are no cancellations among the contributions of the different neutrino masses, the results of the LSND experiment imply a lower bound for the effective Majorana mass in neutrinoless double-beta decay. |
hep-ph/0605128 | Zaven Akopoff N | N. Akopov, L. Grigoryan, Z. Akopov | Nuclear Attenuation of high energy two-hadron system in the string model | 8 pages | Eur.Phys.J.C49:1015-1021,2007 | 10.1140/epjc/s10052-006-0183-5 | null | hep-ph | null | Nuclear attenuation of the two-hadron system is considered in the string
model. The two-scale model and its improved version with two different choices
of constituent formation time and sets of parameters obtained earlier for the
single hadron attenuation, are used to describe available experimental data for
the $z$-dependence of subleading hadron, whereas satisfactory agreement with
the experimental data has been observed. A model prediction for
$\nu$-dependence of the nuclear attenuation of the two-hadron system is also
presented.
| [
{
"created": "Thu, 11 May 2006 12:01:45 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Akopov",
"N.",
""
],
[
"Grigoryan",
"L.",
""
],
[
"Akopov",
"Z.",
""
]
] | Nuclear attenuation of the two-hadron system is considered in the string model. The two-scale model and its improved version with two different choices of constituent formation time and sets of parameters obtained earlier for the single hadron attenuation, are used to describe available experimental data for the $z$-dependence of subleading hadron, whereas satisfactory agreement with the experimental data has been observed. A model prediction for $\nu$-dependence of the nuclear attenuation of the two-hadron system is also presented. |
2307.02888 | Wen-Chen Chang | Wen-Chen Chang, Chia-Yu Hsieh, Yu-Shiang Lian, Jen-Chieh Peng,
Stephane Platchkov and Takahiro Sawada | Pion PDFs confronted by Fixed-Target Charmonium Production | 17 pages, 6 figures; invited review. arXiv admin note: text overlap
with arXiv:2006.06947, arXiv:2209.04072 | AAPPS Bulletin volume 33, Article number: 15 (2023) | 10.1007/s43673-023-00085-4 | null | hep-ph hep-ex nucl-ex | http://creativecommons.org/licenses/by/4.0/ | The pion, as the Goldstone boson of the strong interaction, is the lightest
QCD bound state and responsible for the long-range nucleon-nucleon interaction
inside the nucleus. Our knowledge on the pion partonic structure is limited by
the existing Drell-Yan data which are primarily sensitive to the pion
valence-quark distributions. The recent progress of global analysis of pion's
parton distribution functions (PDFs) utilizing various experimental approaches
are introduced. From comparisons between the pion-induced $J/\psi$ and
$\psi(2S)$ production data with theoretical calculations using the CEM and
NRQCD models, we show how these charmonium production data could provide useful
constraints on the pion PDFs.
| [
{
"created": "Thu, 6 Jul 2023 09:45:06 GMT",
"version": "v1"
}
] | 2023-07-07 | [
[
"Chang",
"Wen-Chen",
""
],
[
"Hsieh",
"Chia-Yu",
""
],
[
"Lian",
"Yu-Shiang",
""
],
[
"Peng",
"Jen-Chieh",
""
],
[
"Platchkov",
"Stephane",
""
],
[
"Sawada",
"Takahiro",
""
]
] | The pion, as the Goldstone boson of the strong interaction, is the lightest QCD bound state and responsible for the long-range nucleon-nucleon interaction inside the nucleus. Our knowledge on the pion partonic structure is limited by the existing Drell-Yan data which are primarily sensitive to the pion valence-quark distributions. The recent progress of global analysis of pion's parton distribution functions (PDFs) utilizing various experimental approaches are introduced. From comparisons between the pion-induced $J/\psi$ and $\psi(2S)$ production data with theoretical calculations using the CEM and NRQCD models, we show how these charmonium production data could provide useful constraints on the pion PDFs. |
2108.03248 | David Morrissey | Andrea Gaspert, Pietro Giampa, and David E. Morrissey | Neutrino Backgrounds in Future Liquid Noble Element Dark Matter Direct
Detection Experiments | 44 pages, 11 figures, added references and discussion and updated
figures for clarity, matches published version | null | 10.1103/PhysRevD.105.035020 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | Experiments that use liquid noble gasses as target materials, such as argon
and xenon, play a significant role in direct detection searches for WIMP(-like)
dark matter. As these experiments grow in size, they will soon encounter a new
background to their dark matter discovery potential from neutrino scattering
off nuclei and electrons in their targets. Therefore, a better understanding of
this new source of background is crucial for future large-scale experiments
such as ARGO and DARWIN. In this work, we study the impact of atmospheric
neutrino flux uncertainties, electron recoil rejection efficiency, recoil
energy sensitivity, and other related factors on the dark matter discovery
reach. We also show that a significant improvement in sensitivity can
potentially be obtained, at large exposures, by combining data from independent
argon and xenon experiments.
| [
{
"created": "Fri, 6 Aug 2021 18:00:03 GMT",
"version": "v1"
},
{
"created": "Wed, 3 May 2023 18:11:37 GMT",
"version": "v2"
}
] | 2023-05-05 | [
[
"Gaspert",
"Andrea",
""
],
[
"Giampa",
"Pietro",
""
],
[
"Morrissey",
"David E.",
""
]
] | Experiments that use liquid noble gasses as target materials, such as argon and xenon, play a significant role in direct detection searches for WIMP(-like) dark matter. As these experiments grow in size, they will soon encounter a new background to their dark matter discovery potential from neutrino scattering off nuclei and electrons in their targets. Therefore, a better understanding of this new source of background is crucial for future large-scale experiments such as ARGO and DARWIN. In this work, we study the impact of atmospheric neutrino flux uncertainties, electron recoil rejection efficiency, recoil energy sensitivity, and other related factors on the dark matter discovery reach. We also show that a significant improvement in sensitivity can potentially be obtained, at large exposures, by combining data from independent argon and xenon experiments. |
1203.1918 | James Maxin | Tianjun Li, James A. Maxin, Dimitri V. Nanopoulos, and Joel W. Walker | A Multi-Axis Best Fit to the Collider Supersymmetry Search: The Aroma of
Stops and Gluinos at the \sqrt{s} = 7 TeV LHC | 13 pages, 2 figures, 3 tables | null | null | ACT-04-12, MIFPA-12-09 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In Profumo di SUSY, we presented evidence that CMS&ATLAS may have already
registered a handful of deftly camouflaged supersymmetry events at the LHC in
the multijet channels. Here, we explore the prospect for corroboration of this
suggestion from 5 additional CMS&ATLAS search strategies targeting the
production of light stops & gluinos at lower jet counts, which variously depend
on heavy flavor tagging and the inclusion or exclusion of associated leptons.
The current operating phase of the 7TeV LHC is highly conducive to the
production of gluinos & light stops, given the supersymmetric particle mass
hierarchy M_t_1<M_g<M_q that naturally evolves from the dynamics of the model
named No-Scale FSU5 that we presently study. Moreover, some tension persists
against the SM data-driven and MC generated background predictions in certain
LHC searches of this variety. We demonstrate that the 1-sigma overlap of the
allowed supersymmetric event production for these seven search methodologies
roundly envelops the most favorable phenomenological subspace of FSU5, while
handily generating a 125GeV Higgs boson mass. In order to test the statistical
significance of any correlations across the simulated FSU5 collider response in
these seven search strategies, we implement a multi-axis chi^2 fitting
procedure, yielding a best overall match in the vicinity of M1/2=610GeV,
corresponding to light stop & gluino masses of approximately 665GeV and 830GeV.
Consequently, we suggest that FSU5 is a better global fit to the studied LHC
data than the SM alone, and moreover that its predictions appear to be
meaningfully correlated with observed low-statistics excesses across a wide
variety of specialized search strategies. We suspect the already collected 5/fb
will be sufficient to either condense or disperse the delicate aroma of stops
and gluinos that suffuses the early search.
| [
{
"created": "Thu, 8 Mar 2012 20:57:38 GMT",
"version": "v1"
}
] | 2012-03-09 | [
[
"Li",
"Tianjun",
""
],
[
"Maxin",
"James A.",
""
],
[
"Nanopoulos",
"Dimitri V.",
""
],
[
"Walker",
"Joel W.",
""
]
] | In Profumo di SUSY, we presented evidence that CMS&ATLAS may have already registered a handful of deftly camouflaged supersymmetry events at the LHC in the multijet channels. Here, we explore the prospect for corroboration of this suggestion from 5 additional CMS&ATLAS search strategies targeting the production of light stops & gluinos at lower jet counts, which variously depend on heavy flavor tagging and the inclusion or exclusion of associated leptons. The current operating phase of the 7TeV LHC is highly conducive to the production of gluinos & light stops, given the supersymmetric particle mass hierarchy M_t_1<M_g<M_q that naturally evolves from the dynamics of the model named No-Scale FSU5 that we presently study. Moreover, some tension persists against the SM data-driven and MC generated background predictions in certain LHC searches of this variety. We demonstrate that the 1-sigma overlap of the allowed supersymmetric event production for these seven search methodologies roundly envelops the most favorable phenomenological subspace of FSU5, while handily generating a 125GeV Higgs boson mass. In order to test the statistical significance of any correlations across the simulated FSU5 collider response in these seven search strategies, we implement a multi-axis chi^2 fitting procedure, yielding a best overall match in the vicinity of M1/2=610GeV, corresponding to light stop & gluino masses of approximately 665GeV and 830GeV. Consequently, we suggest that FSU5 is a better global fit to the studied LHC data than the SM alone, and moreover that its predictions appear to be meaningfully correlated with observed low-statistics excesses across a wide variety of specialized search strategies. We suspect the already collected 5/fb will be sufficient to either condense or disperse the delicate aroma of stops and gluinos that suffuses the early search. |
0706.3672 | Kirill Semenov-Tian-Shansky | Kirill M.Semenov-Tian-Shansky, Alexander V.Vereshagin, Vladimir V.
Vereshagin | Bootstrap and the physical values of $\pi N$ resonance parameters | 41 pages, 7 figures | Phys.Rev.D77:025028,2008 | 10.1103/PhysRevD.77.025028 | null | hep-ph hep-th | null | This is the 6th paper in the series developing the formalism to manage the
effective scattering theory of strong interactions. Relying on the theoretical
scheme suggested in our previous publications we concentrate here on the
practical aspect and apply our technique to the elastic pion-nucleon scattering
amplitude. We test numerically the pion-nucleon spectrum sum rules that follow
from the tree level bootstrap constraints. We show how these constraints can be
used to estimate the tensor and vector $NN\rho$ coupling constants. At last, we
demonstrate that the tree-level low energy expansion coefficients computed in
the framework of our approach show nice agreement with known experimental data.
These results allow us to claim that the extended perturbation scheme is quite
reasonable from the computational point of view.
| [
{
"created": "Mon, 25 Jun 2007 17:13:39 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Semenov-Tian-Shansky",
"Kirill M.",
""
],
[
"Vereshagin",
"Alexander V.",
""
],
[
"Vereshagin",
"Vladimir V.",
""
]
] | This is the 6th paper in the series developing the formalism to manage the effective scattering theory of strong interactions. Relying on the theoretical scheme suggested in our previous publications we concentrate here on the practical aspect and apply our technique to the elastic pion-nucleon scattering amplitude. We test numerically the pion-nucleon spectrum sum rules that follow from the tree level bootstrap constraints. We show how these constraints can be used to estimate the tensor and vector $NN\rho$ coupling constants. At last, we demonstrate that the tree-level low energy expansion coefficients computed in the framework of our approach show nice agreement with known experimental data. These results allow us to claim that the extended perturbation scheme is quite reasonable from the computational point of view. |
2408.03068 | Yanbing Cai | Jingxuan Chen, Xiaopeng Wang, Yanbing Cai, Xurong Chen, Qian Wang | Valence Quark Distributions in Pions: Insights from Tsallis Entropy | 11 pages, 3 figures | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the valence quark distributions of pions at a low initial
scale ($Q^2_0$) through the application of Tsallis entropy, a non-extensive
measure adept at encapsulating long-range correlations among internal
constituents. Utilizing the maximum entropy approach, we derive the valence
quark distributions at elevated resolution scales via a modified DGLAP
equation, which integrates GLR-MQ-ZRS corrections for the $Q^2$ evolution. Our
findings indicate that the resulting $Q^2$-dependent valence quark
distributions yield an optimal fit to experimental data, with an inferred
parameter value of $q$ ($q = 0.91$), diverging from unity. This deviation
highlights the significant role that correlations among valence quarks play in
shaping our understanding of pion internal structure. Additionally, our
computations of the first three moments of pion quark distributions at $ Q^2 =
4 \, \mathrm{GeV}^2$ display consistency with alternative theoretical models,
thereby reinforcing the importance of incorporating valence quark correlations
within this analytical framework.
| [
{
"created": "Tue, 6 Aug 2024 09:49:11 GMT",
"version": "v1"
}
] | 2024-08-07 | [
[
"Chen",
"Jingxuan",
""
],
[
"Wang",
"Xiaopeng",
""
],
[
"Cai",
"Yanbing",
""
],
[
"Chen",
"Xurong",
""
],
[
"Wang",
"Qian",
""
]
] | We investigate the valence quark distributions of pions at a low initial scale ($Q^2_0$) through the application of Tsallis entropy, a non-extensive measure adept at encapsulating long-range correlations among internal constituents. Utilizing the maximum entropy approach, we derive the valence quark distributions at elevated resolution scales via a modified DGLAP equation, which integrates GLR-MQ-ZRS corrections for the $Q^2$ evolution. Our findings indicate that the resulting $Q^2$-dependent valence quark distributions yield an optimal fit to experimental data, with an inferred parameter value of $q$ ($q = 0.91$), diverging from unity. This deviation highlights the significant role that correlations among valence quarks play in shaping our understanding of pion internal structure. Additionally, our computations of the first three moments of pion quark distributions at $ Q^2 = 4 \, \mathrm{GeV}^2$ display consistency with alternative theoretical models, thereby reinforcing the importance of incorporating valence quark correlations within this analytical framework. |
hep-ph/0607033 | Vittorio del Duca | V. Del Duca, G. Somogyi, Z. Trocsanyi | Cross sections at NNLO | 4 pages. To appear in the proceedings of DIS06, Tsukuba, Japan | null | 10.1142/9789812706706_0130 | null | hep-ph | null | In this talk we report on the state of the art on the calculation of cross
section at next-to-next-to-leading (NNLO) accuracy.
| [
{
"created": "Tue, 4 Jul 2006 09:56:19 GMT",
"version": "v1"
}
] | 2017-08-23 | [
[
"Del Duca",
"V.",
""
],
[
"Somogyi",
"G.",
""
],
[
"Trocsanyi",
"Z.",
""
]
] | In this talk we report on the state of the art on the calculation of cross section at next-to-next-to-leading (NNLO) accuracy. |
2110.15840 | Giacomo Magni | Raquel Gomez-Ambrosio and Giacomo Magni | SMEFT analysis of the electroweak sector: challenges beyond dimension 6 | null | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In these proceedings we present the latest developments in our effort to
include vector boson scattering (VBS) measurements into global SMEFT fits of
LHC data. We present some updates to our initial study of arXiv:2101.03180 as
well as comment on a possible road map for the inclusion of higher orders
beyond dimension 6 in the SMEFT and on the interpretation of VBS data in other
EFT frameworks.
| [
{
"created": "Fri, 29 Oct 2021 15:04:32 GMT",
"version": "v1"
}
] | 2021-11-01 | [
[
"Gomez-Ambrosio",
"Raquel",
""
],
[
"Magni",
"Giacomo",
""
]
] | In these proceedings we present the latest developments in our effort to include vector boson scattering (VBS) measurements into global SMEFT fits of LHC data. We present some updates to our initial study of arXiv:2101.03180 as well as comment on a possible road map for the inclusion of higher orders beyond dimension 6 in the SMEFT and on the interpretation of VBS data in other EFT frameworks. |
hep-ph/9907489 | Bernd Kniehl | B.A. Kniehl and A.A. Penin | Ultrasoft Effects in Heavy-Quarkonium Physics | 14 pages (Latex), 5 figures (Axodraw), one reference added, accepted
for publication in Nuclear Physics B | Nucl.Phys. B563 (1999) 200-210 | 10.1016/S0550-3213(99)00564-7 | DESY 99-099, MPI/PhT/99-029 | hep-ph | null | In the framework of nonrelativistic QCD, we consider a new class of radiative
corrections, which are generated at next-to-next-to-next-to-leading order
through the chromoelectric dipole interaction of heavy quarkonium with
ultrasoft virtual gluons. We provide analytical formulae from which the
resulting shifts in the quarkonium energy levels and the wave functions at the
origin may be calculated. We discuss the phenomenological implications for the
top-antitop and Upsilon systems and point out some limitations of describing
charmonium using a Coulomb potential.
| [
{
"created": "Mon, 26 Jul 1999 13:55:08 GMT",
"version": "v1"
},
{
"created": "Tue, 21 Sep 1999 17:38:41 GMT",
"version": "v2"
}
] | 2009-10-31 | [
[
"Kniehl",
"B. A.",
""
],
[
"Penin",
"A. A.",
""
]
] | In the framework of nonrelativistic QCD, we consider a new class of radiative corrections, which are generated at next-to-next-to-next-to-leading order through the chromoelectric dipole interaction of heavy quarkonium with ultrasoft virtual gluons. We provide analytical formulae from which the resulting shifts in the quarkonium energy levels and the wave functions at the origin may be calculated. We discuss the phenomenological implications for the top-antitop and Upsilon systems and point out some limitations of describing charmonium using a Coulomb potential. |
1811.02581 | Simone Biondini | S. Biondini and S. Vogl | Coloured coannihilations: Dark matter phenomenology meets
non-relativistic EFTs | Published version, references and section on indirect detection added | null | 10.1007/JHEP02(2019)016 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the phenomenology of a simplified model with a Majorana
fermion as dark matter candidate which interacts with Standard Model quarks via
a colour-charged coannihilation partner. Recently it has been realized that
non-perturbative dynamics, including the Sommerfeld effect, bound state
formation/dissociation and thermal corrections, play an important role in
coannihilations with coloured mediators. This calls for a careful analysis of
thermal freeze-out and a new look at the experimental signatures expected for a
thermal relic. We employ a state of the art calculation of the relic density
which makes use of a non-relativistic effective theory framework and calculate
the effective annihilation rates by solving a plasma-modified Schrodinger
equation. We determine the cosmologically preferred parameter space and
confront it with current experimental limits and future prospects for dark
matter detection.
| [
{
"created": "Tue, 6 Nov 2018 19:00:07 GMT",
"version": "v1"
},
{
"created": "Sun, 17 Mar 2019 13:31:09 GMT",
"version": "v2"
}
] | 2019-03-19 | [
[
"Biondini",
"S.",
""
],
[
"Vogl",
"S.",
""
]
] | We investigate the phenomenology of a simplified model with a Majorana fermion as dark matter candidate which interacts with Standard Model quarks via a colour-charged coannihilation partner. Recently it has been realized that non-perturbative dynamics, including the Sommerfeld effect, bound state formation/dissociation and thermal corrections, play an important role in coannihilations with coloured mediators. This calls for a careful analysis of thermal freeze-out and a new look at the experimental signatures expected for a thermal relic. We employ a state of the art calculation of the relic density which makes use of a non-relativistic effective theory framework and calculate the effective annihilation rates by solving a plasma-modified Schrodinger equation. We determine the cosmologically preferred parameter space and confront it with current experimental limits and future prospects for dark matter detection. |
hep-ph/0005288 | Ernest Ma | D. A. Demir (ICTP), Ernest Ma (UC Riverside), Utpal Sarkar (UC
Riverside and PRL, Ahmedabad) | Neutrino Masses and the Gluino Axion Model | 8 pages, no figure | J.Phys. G26 (2000) L117 | 10.1088/0954-3899/26/11/101 | IC/00/65, UCRHEP-T277 (May 2000) | hep-ph | null | We extend the recently proposed gluino axion model to include neutrino
masses. We discuss how the canonical seesaw model and the Higgs triplet model
may be realized in this framework. In the former case, the heavy singlet
neutrinos are contained in superfields which do not have any vacuum expectation
value, whereas the gluino axion is contained in one which does. We also
construct a specific renormalizable model which realizes the mass scale
relationship $M_{SUSY} \sim f_a^2/M_U$, where $f_a$ is the axion decay constant
and $M_U$ is a large effective mass parameter.
| [
{
"created": "Mon, 29 May 2000 18:32:14 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Demir",
"D. A.",
"",
"ICTP"
],
[
"Ma",
"Ernest",
"",
"UC Riverside"
],
[
"Sarkar",
"Utpal",
"",
"UC\n Riverside and PRL, Ahmedabad"
]
] | We extend the recently proposed gluino axion model to include neutrino masses. We discuss how the canonical seesaw model and the Higgs triplet model may be realized in this framework. In the former case, the heavy singlet neutrinos are contained in superfields which do not have any vacuum expectation value, whereas the gluino axion is contained in one which does. We also construct a specific renormalizable model which realizes the mass scale relationship $M_{SUSY} \sim f_a^2/M_U$, where $f_a$ is the axion decay constant and $M_U$ is a large effective mass parameter. |
1811.06003 | Toshinori Matsui | Toshinori Matsui | Exploring first order phase transition in $U(1)$ extended models by
complementarity between collider measurements and cosmological observations | 4 pages, 2 figures. Talk presented at the International Workshop on
Future Linear Colliders (LCWS2018), Arlington, Texas, 22-26 October 2018.
C18-10-22 | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We consider models with the $U(1)_X$ gauge symmetry, which is spontaneously
broken by dark Higgs mechanism. We discuss patterns of the electroweak phase
transition and detectability of gravitational waves (GWs) when strongly first
order phase transition (1stOPT) occurs. It is pointed out that the collider
bounds on the properties of the discovered Higgs boson exclude a part of
parameter space that could otherwise generate detectable GWs. We find that GWs
produced from multi-step PT can be detected at future observations such as LISA
and DECIGO if the dark photon mass is $m_X^{} \gtrsim 25$ GeV with the
$U(1)_X^{}$ gauge coupling being $g_X^{} \gtrsim 0.5$. In addition, we show
that most of the parameter regions can be covered by precision measurements of
various Higgs boson couplings and direct searches for the singlet scalar boson
at future collider experiments. Furthermore, we expect the complementarity of
the detection of GW observations from the strongly 1stOPT, collider bounds and
dark photon searches in the models of the dark gauge symmetry.
| [
{
"created": "Wed, 14 Nov 2018 19:04:12 GMT",
"version": "v1"
}
] | 2018-11-16 | [
[
"Matsui",
"Toshinori",
""
]
] | We consider models with the $U(1)_X$ gauge symmetry, which is spontaneously broken by dark Higgs mechanism. We discuss patterns of the electroweak phase transition and detectability of gravitational waves (GWs) when strongly first order phase transition (1stOPT) occurs. It is pointed out that the collider bounds on the properties of the discovered Higgs boson exclude a part of parameter space that could otherwise generate detectable GWs. We find that GWs produced from multi-step PT can be detected at future observations such as LISA and DECIGO if the dark photon mass is $m_X^{} \gtrsim 25$ GeV with the $U(1)_X^{}$ gauge coupling being $g_X^{} \gtrsim 0.5$. In addition, we show that most of the parameter regions can be covered by precision measurements of various Higgs boson couplings and direct searches for the singlet scalar boson at future collider experiments. Furthermore, we expect the complementarity of the detection of GW observations from the strongly 1stOPT, collider bounds and dark photon searches in the models of the dark gauge symmetry. |
1708.09408 | Joao Silva | Miguel P. Bento, Howard E. Haber, J. C. Rom\~ao, Jo\~ao P. Silva | Multi-Higgs doublet models: physical parametrization, sum rules and
unitarity bounds | 66 pages, 3 figures. v2: refs added | null | 10.1007/JHEP11(2017)095 | CFTP-17-005, SCIPP-17/10 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | If the scalar sector of the Standard Model is non-minimal, one might expect
multiple generations of the hypercharge-1/2 scalar doublet analogous to the
generational structure of the fermions. In this work, we examine the structure
of a Higgs sector consisting of N Higgs doublets (where N \geq 2). It is
particularly convenient to work in the so-called charged Higgs basis, in which
the neutral Higgs vacuum expectation value resides entirely in the first Higgs
doublet, and the charged components of remaining N-1 Higgs doublets are
mass-eigenstate fields.
We elucidate the interactions of the gauge bosons with the physical Higgs
scalars and the Goldstone bosons and show that they are determined by an Nx2N
matrix. This matrix depends on (N-1)(2N-1) real parameters that are associated
with the mixing of the neutral Higgs fields in the charged Higgs basis. Among
these parameters, N-1 are unphysical (and can be removed by rephasing the
physical charged Higgs fields), and the remaining 2(N-1)^2 parameters are
physical. We also demonstrate a particularly simple form for the cubic
interaction and some of the quartic interactions of the Goldstone bosons with
the physical Higgs scalars. These results are applied in the derivation of
Higgs coupling sum rules and tree-level unitarity bounds that restrict the size
of the quartic scalar couplings. In particular, new applications to three Higgs
doublet models with an order-4 CP symmetry and with a Z_3 symmetry,
respectively, are presented.
| [
{
"created": "Wed, 30 Aug 2017 18:04:25 GMT",
"version": "v1"
},
{
"created": "Fri, 8 Sep 2017 21:49:40 GMT",
"version": "v2"
}
] | 2017-12-06 | [
[
"Bento",
"Miguel P.",
""
],
[
"Haber",
"Howard E.",
""
],
[
"Romão",
"J. C.",
""
],
[
"Silva",
"João P.",
""
]
] | If the scalar sector of the Standard Model is non-minimal, one might expect multiple generations of the hypercharge-1/2 scalar doublet analogous to the generational structure of the fermions. In this work, we examine the structure of a Higgs sector consisting of N Higgs doublets (where N \geq 2). It is particularly convenient to work in the so-called charged Higgs basis, in which the neutral Higgs vacuum expectation value resides entirely in the first Higgs doublet, and the charged components of remaining N-1 Higgs doublets are mass-eigenstate fields. We elucidate the interactions of the gauge bosons with the physical Higgs scalars and the Goldstone bosons and show that they are determined by an Nx2N matrix. This matrix depends on (N-1)(2N-1) real parameters that are associated with the mixing of the neutral Higgs fields in the charged Higgs basis. Among these parameters, N-1 are unphysical (and can be removed by rephasing the physical charged Higgs fields), and the remaining 2(N-1)^2 parameters are physical. We also demonstrate a particularly simple form for the cubic interaction and some of the quartic interactions of the Goldstone bosons with the physical Higgs scalars. These results are applied in the derivation of Higgs coupling sum rules and tree-level unitarity bounds that restrict the size of the quartic scalar couplings. In particular, new applications to three Higgs doublet models with an order-4 CP symmetry and with a Z_3 symmetry, respectively, are presented. |
1811.11699 | Simon Badger | Simon Badger, Christian Br{\o}nnum-Hansen, Heribertus Bayu Hartanto,
Tiziano Peraro | Analytic helicity amplitudes for two-loop five-gluon scattering: the
single-minus case | 18 pages, 2 figures | null | 10.1007/JHEP01(2019)186 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a compact analytic expression for the leading colour two-loop
five-gluon amplitude in Yang-Mills theory with a single negative helicity and
four positive helicities. The analytic result is reconstructed from numerical
evaluations over finite fields. The numerical method combines integrand
reduction, integration-by-parts identities and Laurent expansion into a basis
of pentagon functions to compute the coefficients directly from six-dimensional
generalised unitarity cuts.
| [
{
"created": "Wed, 28 Nov 2018 17:37:08 GMT",
"version": "v1"
}
] | 2019-02-20 | [
[
"Badger",
"Simon",
""
],
[
"Brønnum-Hansen",
"Christian",
""
],
[
"Hartanto",
"Heribertus Bayu",
""
],
[
"Peraro",
"Tiziano",
""
]
] | We present a compact analytic expression for the leading colour two-loop five-gluon amplitude in Yang-Mills theory with a single negative helicity and four positive helicities. The analytic result is reconstructed from numerical evaluations over finite fields. The numerical method combines integrand reduction, integration-by-parts identities and Laurent expansion into a basis of pentagon functions to compute the coefficients directly from six-dimensional generalised unitarity cuts. |
1212.0301 | Andrea Shindler | N. Carrasco, P. Dimopoulos, R. Frezzotti, V. Gimenez, G. Herdoiza, V.
Lubicz, G. Martinelli, C. Michael, D. Palao, G. C. Rossi, F. Sanfilippo, A.
Shindler, S. Simula, C. Tarantino | B-physics from lattice QCD...with a twist | 6 pages, 3 figures. Proceedings of the 36th International Conference
on High Energy Physics - ICHEP 2012; July 4-11 2012; Melbourne, Australia | PoS(ICHEP2012)428 | null | IFIC/12-80; FTUAM-12-113; IFT-UAM/CSIC-12-111; RM3-TH/12-20; LTH966;
CERN-PH-TH/2012-328 | hep-ph hep-ex hep-lat | http://creativecommons.org/licenses/by-nc-sa/3.0/ | We present a precise lattice QCD determination of the b-quark mass, of the B
and Bs decay constants and first results for the B-meson bag parameters. For
our computation we employ the so-called ratio method and our results benefit
from the use of improved interpolating operators for the B-mesons. QCD
calculations are performed with Nf = 2 dynamical light-quarks at four values of
the lattice spacing and the results are extrapolated to the continuum limit.
The preliminary results are mb(mb) = 4.35(12) GeV for the MSbar b-quark mass,
fBs = 234(6) MeV and fB = 197(10) MeV for the B-meson decay constants, BBs(mb)
= 0.90(5) and BB(mb) = 0.87(5) for the B-meson bag parameters.
| [
{
"created": "Mon, 3 Dec 2012 07:17:16 GMT",
"version": "v1"
}
] | 2012-12-04 | [
[
"Carrasco",
"N.",
""
],
[
"Dimopoulos",
"P.",
""
],
[
"Frezzotti",
"R.",
""
],
[
"Gimenez",
"V.",
""
],
[
"Herdoiza",
"G.",
""
],
[
"Lubicz",
"V.",
""
],
[
"Martinelli",
"G.",
""
],
[
"Michael",
"C.",
""
],
[
"Palao",
"D.",
""
],
[
"Rossi",
"G. C.",
""
],
[
"Sanfilippo",
"F.",
""
],
[
"Shindler",
"A.",
""
],
[
"Simula",
"S.",
""
],
[
"Tarantino",
"C.",
""
]
] | We present a precise lattice QCD determination of the b-quark mass, of the B and Bs decay constants and first results for the B-meson bag parameters. For our computation we employ the so-called ratio method and our results benefit from the use of improved interpolating operators for the B-mesons. QCD calculations are performed with Nf = 2 dynamical light-quarks at four values of the lattice spacing and the results are extrapolated to the continuum limit. The preliminary results are mb(mb) = 4.35(12) GeV for the MSbar b-quark mass, fBs = 234(6) MeV and fB = 197(10) MeV for the B-meson decay constants, BBs(mb) = 0.90(5) and BB(mb) = 0.87(5) for the B-meson bag parameters. |
1306.4445 | Lewis Tunstall | R.J. Crewther and Lewis C. Tunstall | Infrared Fixed Point in the Strong Running Coupling: Unraveling the
\Delta I=1/2 puzzle in K-Decays | 8 pages, 3 figures. Contribution to the proceedings of the workshop
"Determination of the Fundamental Parameters of QCD", Nanyang Technological
University, Singapore, 18-22 March 2013, to be published in Mod. Phys. Lett.
A | Mod.Phys.Lett. A28 (2013) 1360010 | 10.1142/S0217732313600109 | ADP-13-14/T834 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In this talk, we present an explanation for the Delta I = 1/2 rule in
K-decays based on the premise of an infrared fixed point alpha_IR in the
running coupling alpha_s of quantum chromodynamics (QCD) for three light quarks
u,d,s. At the fixed point, the quark condensate spontaneously breaks scale and
chiral SU(3)_L x SU(3)_R symmetry. Consequently, the low-lying spectrum
contains nine Nambu-Goldstone bosons: pi,K,eta and a QCD dilaton sigma. We
identify sigma as the f_0(500) resonance and construct a chiral-scale
perturbation theory CHPT_sigma for low-energy amplitudes expanded in alpha_s
about alpha_IR. The Delta I = 1/2 rule emerges in the leading order of
CHPT_sigma through a sigma-pole term K_S --> sigma --> 2 pi, with a K_S-sigma
coupling fixed by data on 2 gamma --> 2 pi^0 and K_S --> 2 gamma. We also
determine R_IR ~ 5 for the nonperturbative Drell-Yan ratio at alpha_IR.
| [
{
"created": "Wed, 19 Jun 2013 07:44:14 GMT",
"version": "v1"
}
] | 2013-12-13 | [
[
"Crewther",
"R. J.",
""
],
[
"Tunstall",
"Lewis C.",
""
]
] | In this talk, we present an explanation for the Delta I = 1/2 rule in K-decays based on the premise of an infrared fixed point alpha_IR in the running coupling alpha_s of quantum chromodynamics (QCD) for three light quarks u,d,s. At the fixed point, the quark condensate spontaneously breaks scale and chiral SU(3)_L x SU(3)_R symmetry. Consequently, the low-lying spectrum contains nine Nambu-Goldstone bosons: pi,K,eta and a QCD dilaton sigma. We identify sigma as the f_0(500) resonance and construct a chiral-scale perturbation theory CHPT_sigma for low-energy amplitudes expanded in alpha_s about alpha_IR. The Delta I = 1/2 rule emerges in the leading order of CHPT_sigma through a sigma-pole term K_S --> sigma --> 2 pi, with a K_S-sigma coupling fixed by data on 2 gamma --> 2 pi^0 and K_S --> 2 gamma. We also determine R_IR ~ 5 for the nonperturbative Drell-Yan ratio at alpha_IR. |
0707.0005 | Scott Thomas | Michael Dine, Nathan Seiberg and Scott Thomas | Higgs Physics as a Window Beyond the MSSM (BMSSM) | LaTex, 28 pages | Phys.Rev.D76:095004,2007 | 10.1103/PhysRevD.76.095004 | SCIPP 07/13, RU-NHETC-07-10 | hep-ph | null | We interpret the current experimental limit on the lightest Higgs boson mass
to suggest that if nature is supersymmetric, there are additional interactions
beyond those of the MSSM coming from new degrees of freedom around the TeV
scale. Within an effective field theory analysis, the leading order corrections
to the MSSM are described in terms of only two operators. This provides a
highly constrained description of Beyond MSSM (BMSSM) physics. The scalar Higgs
spectrum as well as the chargino and neutralino spectrum and couplings are
modified in a distinctive way. These operators can be generated by a variety of
microscopic mechanisms.
| [
{
"created": "Fri, 29 Jun 2007 20:08:08 GMT",
"version": "v1"
},
{
"created": "Tue, 10 Jul 2007 19:49:25 GMT",
"version": "v2"
},
{
"created": "Tue, 7 Aug 2007 20:09:48 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Dine",
"Michael",
""
],
[
"Seiberg",
"Nathan",
""
],
[
"Thomas",
"Scott",
""
]
] | We interpret the current experimental limit on the lightest Higgs boson mass to suggest that if nature is supersymmetric, there are additional interactions beyond those of the MSSM coming from new degrees of freedom around the TeV scale. Within an effective field theory analysis, the leading order corrections to the MSSM are described in terms of only two operators. This provides a highly constrained description of Beyond MSSM (BMSSM) physics. The scalar Higgs spectrum as well as the chargino and neutralino spectrum and couplings are modified in a distinctive way. These operators can be generated by a variety of microscopic mechanisms. |
hep-ph/0102047 | Mark G. Alford | Mark Alford (Glasgow) | Color superconducting quark matter | 31 pages, LaTeX. To appear in Annu. Rev. Nucl. Part. Sci. (Minor
corrections, references added.) | Ann.Rev.Nucl.Part.Sci.51:131-160,2001 | 10.1146/annurev.nucl.51.101701.132449 | GUTPA/01/02/01 | hep-ph | null | I review recent progress in our understanding of the color superconducting
phase of matter above nuclear density, giving particular emphasis to the effort
to find observable signatures of the presence of this phase in compact stars.
| [
{
"created": "Mon, 5 Feb 2001 17:02:00 GMT",
"version": "v1"
},
{
"created": "Fri, 4 May 2001 16:19:01 GMT",
"version": "v2"
}
] | 2014-11-17 | [
[
"Alford",
"Mark",
"",
"Glasgow"
]
] | I review recent progress in our understanding of the color superconducting phase of matter above nuclear density, giving particular emphasis to the effort to find observable signatures of the presence of this phase in compact stars. |
2012.15039 | Wen-Fei Wang | Wen-Fei Wang | Contributions for the kaon pair from $\rho(770)$, $\omega(782)$ and
their excited states in the $B\to K\bar K h$ decays | 25 pages, 3 figures, typos in Eq.(25) corrected | Phys. Rev. D 103, 056021 (2021) | 10.1103/PhysRevD.103.056021 | null | hep-ph hep-ex | http://creativecommons.org/licenses/by/4.0/ | We study the resonance contributions for the kaon pair originating from the
intermediate states $\rho(770,1450,1700)$ and $\omega(782,1420,1650)$ for the
three-body hadronic decays $B\to K\bar K h$ in the perturbative QCD approach,
where $h=(\pi, K)$. The branching fractions of the virtual contributions for
$K\bar K$ from the Breit-Wigner formula tails of $\rho(770)$ and $\omega(782)$
which have been ignored in experimental and theoretical studies for these
decays are found larger than the corresponding contributions from the
resonances $\rho(1450,1700)$ and $\omega(1420,1650)$. The differential
branching fractions for $B\to \rho(770) h\to K\bar K h$ and $B\to\omega(782) h
\to K\bar K h$ are found nearly unaffected by the quite different values of the
full widths for $\rho(770)$ and $\omega(782)$ in this paper. The predictions in
this work for the branching fractions of the quasi-two-body decays $B^+\to
\pi^+ \rho(1450)^0\to \pi^+K^+K^-$ and $B^+\to \pi^+ \rho(1450)^0\to
\pi^+\pi^+\pi^-$ meet the requirement of $SU(3)$ symmetry relation.
| [
{
"created": "Wed, 30 Dec 2020 04:45:31 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Feb 2021 06:16:12 GMT",
"version": "v2"
},
{
"created": "Fri, 9 Jul 2021 10:19:31 GMT",
"version": "v3"
}
] | 2021-07-12 | [
[
"Wang",
"Wen-Fei",
""
]
] | We study the resonance contributions for the kaon pair originating from the intermediate states $\rho(770,1450,1700)$ and $\omega(782,1420,1650)$ for the three-body hadronic decays $B\to K\bar K h$ in the perturbative QCD approach, where $h=(\pi, K)$. The branching fractions of the virtual contributions for $K\bar K$ from the Breit-Wigner formula tails of $\rho(770)$ and $\omega(782)$ which have been ignored in experimental and theoretical studies for these decays are found larger than the corresponding contributions from the resonances $\rho(1450,1700)$ and $\omega(1420,1650)$. The differential branching fractions for $B\to \rho(770) h\to K\bar K h$ and $B\to\omega(782) h \to K\bar K h$ are found nearly unaffected by the quite different values of the full widths for $\rho(770)$ and $\omega(782)$ in this paper. The predictions in this work for the branching fractions of the quasi-two-body decays $B^+\to \pi^+ \rho(1450)^0\to \pi^+K^+K^-$ and $B^+\to \pi^+ \rho(1450)^0\to \pi^+\pi^+\pi^-$ meet the requirement of $SU(3)$ symmetry relation. |
2012.05502 | Rohit Gupta | Rohit Gupta and Satyajit Jena | A generalized approach to study low as well as high $p_T$ regime of
transverse momentum spectra | null | Proceedings of Science ICHEP2020 579 | null | null | hep-ph | http://creativecommons.org/licenses/by-nc-nd/4.0/ | A good understanding of the transverse momentum $(p_T)$ spectra is pivotal in
the study of QCD matter created during the heavy-ion collision. Considering the
difference in the underlying particle production mechanism, $p_T$ spectra can
be divided into two distinct regions. Low-$p_T$ region corresponds to particle
produced in soft-processes whereas particles produced in hard processes
dominate the high-$p_T$ regime of the spectra. We will discuss a unified
formalism to explain both low as well as high-$p_T$ region of the transverse
momentum spectra in a consistent manner. This unified formalism is based on the
generalisation of non-extensive statistical mechanics using the Pearson
distribution. This generalised formalism also gives a strong insight into the
study of elliptic flow in heavy-ion collision.
| [
{
"created": "Thu, 10 Dec 2020 08:13:13 GMT",
"version": "v1"
}
] | 2021-03-23 | [
[
"Gupta",
"Rohit",
""
],
[
"Jena",
"Satyajit",
""
]
] | A good understanding of the transverse momentum $(p_T)$ spectra is pivotal in the study of QCD matter created during the heavy-ion collision. Considering the difference in the underlying particle production mechanism, $p_T$ spectra can be divided into two distinct regions. Low-$p_T$ region corresponds to particle produced in soft-processes whereas particles produced in hard processes dominate the high-$p_T$ regime of the spectra. We will discuss a unified formalism to explain both low as well as high-$p_T$ region of the transverse momentum spectra in a consistent manner. This unified formalism is based on the generalisation of non-extensive statistical mechanics using the Pearson distribution. This generalised formalism also gives a strong insight into the study of elliptic flow in heavy-ion collision. |
0803.2626 | Robi Peschanski | Robi Peschanski | On the maximal noise for stochastic and QCD traveling waves | 19 pages, 2 figures | Nucl.Phys.B805:377-390,2008 | 10.1016/j.nuclphysb.2008.06.010 | null | hep-ph cond-mat.stat-mech hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Using the relation of a set of nonlinear Langevin equations with
reaction-diffusion processes, we note the existence of a maximal strength of
the noise for the stochastic traveling wave solutions of these equations. Its
determination is obtained using the field-theoretical analysis of
branching-annihilation random walks near the directed percolation transition.
We study its consequence for the stochastic
Fisher-Kolmogorov-Petrovsky-Piscounov equation. For the related Langevin
equation modeling the Quantum Chromodynamic nonlinear evolution of the gluon
density with rapidity, the physical maximal-noise limit may appear before the
directed percolation transition, due to a shift in the traveling-wave speed. In
this regime, an exact solution is known from a coalescence process.
Universality and other open problems and applications are discussed in the
outlook
| [
{
"created": "Tue, 18 Mar 2008 13:26:51 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Peschanski",
"Robi",
""
]
] | Using the relation of a set of nonlinear Langevin equations with reaction-diffusion processes, we note the existence of a maximal strength of the noise for the stochastic traveling wave solutions of these equations. Its determination is obtained using the field-theoretical analysis of branching-annihilation random walks near the directed percolation transition. We study its consequence for the stochastic Fisher-Kolmogorov-Petrovsky-Piscounov equation. For the related Langevin equation modeling the Quantum Chromodynamic nonlinear evolution of the gluon density with rapidity, the physical maximal-noise limit may appear before the directed percolation transition, due to a shift in the traveling-wave speed. In this regime, an exact solution is known from a coalescence process. Universality and other open problems and applications are discussed in the outlook |
0805.1735 | Adam K. Leibovich | Chul Kim, Adam K. Leibovich, and Thomas Mehen | Nonperturbative Charming Penguin Contributions to Isospin Asymmetries in
Radiative B decays | 14 pages, 4 figures. Updated analysis of charming penguin extraction | Phys.Rev.D78:054024,2008 | 10.1103/PhysRevD.78.054024 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Recent experimental data on the radiative decays B -> V gamma, where V is a
light vector meson, find small isospin violation in B -> K^* gamma while
isospin asymmetries in B -> rho gamma are of order 20%, with large
uncertainties. Using Soft-Collinear Effective Theory, we calculate isospin
asymmetries in these radiative B decays up to O(1/m_b), also including O(v
alpha_s) contributions from nonperturbative charming penguins (NPCP). In the
absence of NPCP contributions, the theoretical predictions for the asymmetries
are a few percent or less. Including the NPCP can significantly increase the
isospin asymmetries for both B -> V gamma modes. We also consider the effect of
the NPCP on the branching ratio and CP asymmetries in B^\pm -> V^\pm gamma.
| [
{
"created": "Mon, 12 May 2008 20:15:01 GMT",
"version": "v1"
},
{
"created": "Thu, 12 Jun 2008 16:50:03 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Kim",
"Chul",
""
],
[
"Leibovich",
"Adam K.",
""
],
[
"Mehen",
"Thomas",
""
]
] | Recent experimental data on the radiative decays B -> V gamma, where V is a light vector meson, find small isospin violation in B -> K^* gamma while isospin asymmetries in B -> rho gamma are of order 20%, with large uncertainties. Using Soft-Collinear Effective Theory, we calculate isospin asymmetries in these radiative B decays up to O(1/m_b), also including O(v alpha_s) contributions from nonperturbative charming penguins (NPCP). In the absence of NPCP contributions, the theoretical predictions for the asymmetries are a few percent or less. Including the NPCP can significantly increase the isospin asymmetries for both B -> V gamma modes. We also consider the effect of the NPCP on the branching ratio and CP asymmetries in B^\pm -> V^\pm gamma. |
hep-ph/9803310 | Christopher Kolda | Christopher Kolda, Stefan Pokorski and Nir Polonsky | Stabilized Singlets in Supergravity as a Source of the mu-parameter | 9 pages, LaTeX | Phys.Rev.Lett. 80 (1998) 5263-5266 | 10.1103/PhysRevLett.80.5263 | IASSNS-HEP-97-137, CERN-TH/98-75, RU-97-97 | hep-ph | null | Within the context of supergravity-coupled supersymmetry, fields which are
gauge and global singlets are usually considered anathema. Their vacuum
expectation values are shifted by quadratically divergent tadpole diagrams
which are cutoff at the Planck scale, destabilizing the classical potential and
driving the singlet field to large values. We demonstrate a new and generic
mechanism which stabilizes the singlet in the presence of an extended gauge
symmetry. Such a symmetry will be broken down to the Standard Model by the
supergravity interactions near the scale of spontaneous supersymmetry-breaking
in the hidden-sector (about 10^{10-11} GeV). The resulting singlet expectation
value is stabilized and naturally of order the gravitino mass, providing
therefore a weak-scale mass for the Higgs fields of the supersymmetric Standard
Model (a "mu-parameter"). The resulting low-energy theory is the minimal
supersymmetric Standard Model, with all new fields decoupling at the
intermediate scale.
| [
{
"created": "Wed, 11 Mar 1998 16:47:56 GMT",
"version": "v1"
}
] | 2009-10-31 | [
[
"Kolda",
"Christopher",
""
],
[
"Pokorski",
"Stefan",
""
],
[
"Polonsky",
"Nir",
""
]
] | Within the context of supergravity-coupled supersymmetry, fields which are gauge and global singlets are usually considered anathema. Their vacuum expectation values are shifted by quadratically divergent tadpole diagrams which are cutoff at the Planck scale, destabilizing the classical potential and driving the singlet field to large values. We demonstrate a new and generic mechanism which stabilizes the singlet in the presence of an extended gauge symmetry. Such a symmetry will be broken down to the Standard Model by the supergravity interactions near the scale of spontaneous supersymmetry-breaking in the hidden-sector (about 10^{10-11} GeV). The resulting singlet expectation value is stabilized and naturally of order the gravitino mass, providing therefore a weak-scale mass for the Higgs fields of the supersymmetric Standard Model (a "mu-parameter"). The resulting low-energy theory is the minimal supersymmetric Standard Model, with all new fields decoupling at the intermediate scale. |
hep-ph/0412165 | Massimo Passera | J. Bernabeu, J. Papavassiliou, and M. Passera | Dynamical Zero in Antineutrino_e -- Electron Scattering and the Neutrino
Magnetic Moment | 13 pages, 3 figures. V2: one figure and comments added. Published
version | Phys.Lett.B613:162-169,2005 | 10.1016/j.physletb.2005.03.055 | null | hep-ph | null | The Standard Model differential cross section for $\bar{\nu}_e-e^-$ elastic
scattering vanishes exactly, at lowest order, for forward electrons and
incident $\bar{\nu}_e$ energy close to the rest energy of the electron. This
dynamical zero is not induced by a fundamental symmetry of the Lagrangian but
by a destructive interference between the left- and right-handed chiral
couplings of the electron in the charged and neutral current amplitudes. We
show that lowest order analyses based on this favorable kinematic configuration
are only mildly affected by the inclusion of the $O(\alpha)$ radiative
corrections in the $\bar{\nu}_e-e^-$ differential cross section, thus providing
an excellent opportunity for the search of ``new physics''. In the light of
these results, we discuss possible methods to improve the upper limits on the
neutrino magnetic moment by selecting recoil electrons contained in a forward
narrow cone. We conclude that, in spite of the obvious loss in statistics, one
may have a better signal for small angular cones.
| [
{
"created": "Mon, 13 Dec 2004 22:33:39 GMT",
"version": "v1"
},
{
"created": "Thu, 5 May 2005 20:13:51 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Bernabeu",
"J.",
""
],
[
"Papavassiliou",
"J.",
""
],
[
"Passera",
"M.",
""
]
] | The Standard Model differential cross section for $\bar{\nu}_e-e^-$ elastic scattering vanishes exactly, at lowest order, for forward electrons and incident $\bar{\nu}_e$ energy close to the rest energy of the electron. This dynamical zero is not induced by a fundamental symmetry of the Lagrangian but by a destructive interference between the left- and right-handed chiral couplings of the electron in the charged and neutral current amplitudes. We show that lowest order analyses based on this favorable kinematic configuration are only mildly affected by the inclusion of the $O(\alpha)$ radiative corrections in the $\bar{\nu}_e-e^-$ differential cross section, thus providing an excellent opportunity for the search of ``new physics''. In the light of these results, we discuss possible methods to improve the upper limits on the neutrino magnetic moment by selecting recoil electrons contained in a forward narrow cone. We conclude that, in spite of the obvious loss in statistics, one may have a better signal for small angular cones. |
hep-ph/0302138 | Yuly Shabelski | J.Dias de Deus and Yu. M. Shabelski | An Estimate of the Percolation Parameter in Heavy Ion Collisions | 5 pages | Eur.Phys.J.A20:457-458,2004 | 10.1140/epja/i2003-10162-7 | null | hep-ph | null | From existing hadron and heavy ion collisions data on \bar{p}/p central
production we estimate the value of the percolation parameter at RHIC energies.
| [
{
"created": "Mon, 17 Feb 2003 12:10:48 GMT",
"version": "v1"
}
] | 2011-10-11 | [
[
"de Deus",
"J. Dias",
""
],
[
"Shabelski",
"Yu. M.",
""
]
] | From existing hadron and heavy ion collisions data on \bar{p}/p central production we estimate the value of the percolation parameter at RHIC energies. |
1602.04206 | Claudia Hagedorn | Claudia Hagedorn, Emiliano Molinaro | Flavor and CP symmetries for leptogenesis and 0nubb decay | 1+59 pages, 10 figures, 3 tables; v2 matches journal version | null | 10.1016/j.nuclphysb.2017.03.015 | CP3-Origins-2016-005 DNRF90, DIAS-2016-5 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We perform a comprehensive analysis of the phenomenology of leptonic low and
high energy CP phases in a scenario with three heavy right-handed neutrinos in
which a flavor and a CP symmetry are non-trivially broken. All CP phases as
well as lepton mixing angles are determined by the properties of the flavor and
CP symmetry and one free real parameter. We focus on the generation of the
baryon asymmetry Y_B of the Universe via unflavored leptogenesis and the
predictions of m_ee, the quantity measurable in neutrinoless double beta decay.
We show that the sign of Y_B can be fixed and the allowed parameter range of
m_ee can be strongly constrained. We argue on general grounds that the CP
asymmetries epsilon_i are dominated by the contribution associated with one
Majorana phase and that in cases in which only the Dirac phase is non-trivial
the sign of Y_B depends on further parameters. In addition, we comment on the
case of flavored leptogenesis where in general the knowledge of the CP phases
and light neutrino mass spectrum is also not sufficient in order to fix the
sign of the CP asymmetries. As examples we discuss the series of flavor groups
Delta (3 n^2) and Delta (6 n^2), n >= 2 integer, and several classes of CP
transformations.
| [
{
"created": "Fri, 12 Feb 2016 20:54:18 GMT",
"version": "v1"
},
{
"created": "Sun, 23 Apr 2017 10:50:19 GMT",
"version": "v2"
}
] | 2017-04-26 | [
[
"Hagedorn",
"Claudia",
""
],
[
"Molinaro",
"Emiliano",
""
]
] | We perform a comprehensive analysis of the phenomenology of leptonic low and high energy CP phases in a scenario with three heavy right-handed neutrinos in which a flavor and a CP symmetry are non-trivially broken. All CP phases as well as lepton mixing angles are determined by the properties of the flavor and CP symmetry and one free real parameter. We focus on the generation of the baryon asymmetry Y_B of the Universe via unflavored leptogenesis and the predictions of m_ee, the quantity measurable in neutrinoless double beta decay. We show that the sign of Y_B can be fixed and the allowed parameter range of m_ee can be strongly constrained. We argue on general grounds that the CP asymmetries epsilon_i are dominated by the contribution associated with one Majorana phase and that in cases in which only the Dirac phase is non-trivial the sign of Y_B depends on further parameters. In addition, we comment on the case of flavored leptogenesis where in general the knowledge of the CP phases and light neutrino mass spectrum is also not sufficient in order to fix the sign of the CP asymmetries. As examples we discuss the series of flavor groups Delta (3 n^2) and Delta (6 n^2), n >= 2 integer, and several classes of CP transformations. |
hep-ph/9606295 | Denis Michaud | C.P. Burgess and D. Michaud | Neutrino Propagation in a Fluctuating Sun | 45 pages, including 2 postscript figures. (We had a subsection in
section 2 to detail the approximations leading to our results. We also fixed
some typography and added some references) | Annals Phys.256:1-38,1997 | 10.1006/aphy.1996.5660 | McGill-96/18 | hep-ph astro-ph | null | We adapt to neutrino physics a general formulation for particle propagation
in fluctuating media, initially developed for applications to electromagnetism
and neutron optics. In leading approximation this formalism leads to the usual
MSW effective hamiltonian governing neutrino propagation through a medium.
Next-to-leading contributions describe deviations from this description, which
arise due to neutrino interactions with fluctuations in the medium. We compute
these corrections for two types of fluctuations: ($i$) microscopic thermal
fluctuations, and ($ii$) macroscopic fluctuations in the medium's density.
While the first of these reproduces standard estimates, which are negligible
for applications to solar neutrinos, we find the second can be quite large,
since it grows in size with the correlation length of the fluctuation. We
consider two models in some detail. For fluctuations whose correlations are
extend only over a local region in space of length $l$, appreciable effects for
MSW oscillations arise if $(\delta n/n)^2 l\gsim 100$ m or so. Alternatively, a
crude model of helioseismic $p$-waves gives appreciable effects only when
$(\delta n/n) \gsim 1%$.
In general the dominant effect is to diminish the quality of the resonance,
making the suppression of the ${}^7$Be neutrinos a good experimental probe of
fluctuations deep within the sun. Fluctuations can also provide a new mechanism
for reducing the solar neutrino flux, giving an energy-independent suppression
factor of $1/2$, away from the resonant region, even for small vacuum mixing
angles.
| [
{
"created": "Mon, 10 Jun 1996 20:43:54 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Jul 1996 21:57:19 GMT",
"version": "v2"
},
{
"created": "Sun, 18 Aug 1996 03:00:10 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Burgess",
"C. P.",
""
],
[
"Michaud",
"D.",
""
]
] | We adapt to neutrino physics a general formulation for particle propagation in fluctuating media, initially developed for applications to electromagnetism and neutron optics. In leading approximation this formalism leads to the usual MSW effective hamiltonian governing neutrino propagation through a medium. Next-to-leading contributions describe deviations from this description, which arise due to neutrino interactions with fluctuations in the medium. We compute these corrections for two types of fluctuations: ($i$) microscopic thermal fluctuations, and ($ii$) macroscopic fluctuations in the medium's density. While the first of these reproduces standard estimates, which are negligible for applications to solar neutrinos, we find the second can be quite large, since it grows in size with the correlation length of the fluctuation. We consider two models in some detail. For fluctuations whose correlations are extend only over a local region in space of length $l$, appreciable effects for MSW oscillations arise if $(\delta n/n)^2 l\gsim 100$ m or so. Alternatively, a crude model of helioseismic $p$-waves gives appreciable effects only when $(\delta n/n) \gsim 1%$. In general the dominant effect is to diminish the quality of the resonance, making the suppression of the ${}^7$Be neutrinos a good experimental probe of fluctuations deep within the sun. Fluctuations can also provide a new mechanism for reducing the solar neutrino flux, giving an energy-independent suppression factor of $1/2$, away from the resonant region, even for small vacuum mixing angles. |
2101.00224 | Mohamed Jakha | S. Mouslih, M. Jakha, I. Dahiri, S. Taj, B. Manaut and E. Siher | New phenomena in laser-assisted leptonic decays of the negatively
charged boson $W^{-}$ | 19 pages, 13 figures | null | 10.1088/1402-4896/ac5d6e | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | In this paper and within the standard Glashow-Weinberg-Salam model of
electroweak interactions, we study theoretically the leptonic decay of the
$W^{-}$-boson $(W^{-}\rightarrow \ell^{-}\bar{\nu}_{\ell})$ in the presence of
a circularly polarized electromagnetic field and we examine the laser effect,
in terms of its field strength and frequency, on the leptonic decay rate and
the phenomenon of multiphoton processes. The calculations are carried out using
the exact relativistic wave functions of charged particles in an
electromagnetic field. It was found that the laser significantly contributed to
reducing the probability of $W^{-}$-boson decay. We show that the
laser-assisted decay rate is equal to the laser-free one only when the famous
Kroll-Watson sum rule is fulfilled. The notable effect of the laser on the
leptonic decay rate was reasonably interpreted by the well-known quantum Zeno
effect or by the opening of channels other than leptonic ones to decay. We hope
that this article paved the way for an upcoming paper to study the hadronic
decay of the $W^{-}$-boson and then explore the laser effect on its lifetime
and branching ratios.
| [
{
"created": "Fri, 1 Jan 2021 12:30:34 GMT",
"version": "v1"
},
{
"created": "Tue, 23 Feb 2021 19:36:45 GMT",
"version": "v2"
}
] | 2022-04-06 | [
[
"Mouslih",
"S.",
""
],
[
"Jakha",
"M.",
""
],
[
"Dahiri",
"I.",
""
],
[
"Taj",
"S.",
""
],
[
"Manaut",
"B.",
""
],
[
"Siher",
"E.",
""
]
] | In this paper and within the standard Glashow-Weinberg-Salam model of electroweak interactions, we study theoretically the leptonic decay of the $W^{-}$-boson $(W^{-}\rightarrow \ell^{-}\bar{\nu}_{\ell})$ in the presence of a circularly polarized electromagnetic field and we examine the laser effect, in terms of its field strength and frequency, on the leptonic decay rate and the phenomenon of multiphoton processes. The calculations are carried out using the exact relativistic wave functions of charged particles in an electromagnetic field. It was found that the laser significantly contributed to reducing the probability of $W^{-}$-boson decay. We show that the laser-assisted decay rate is equal to the laser-free one only when the famous Kroll-Watson sum rule is fulfilled. The notable effect of the laser on the leptonic decay rate was reasonably interpreted by the well-known quantum Zeno effect or by the opening of channels other than leptonic ones to decay. We hope that this article paved the way for an upcoming paper to study the hadronic decay of the $W^{-}$-boson and then explore the laser effect on its lifetime and branching ratios. |
1112.4423 | Ted Rogers | S. Mert Aybat, Alexei Prokudin and Ted C. Rogers | Calculation of TMD Evolution for Transverse Single Spin Asymmetry
Measurements | 4 pages, 2 figures. Version published in Physical Review Letters | null | 10.1103/PhysRevLett.108.242003 | JLAB-THY-11-1466; NIKHEF-2011-033; YITP-SB-11-48 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The Sivers transverse single spin asymmetry (TSSA) is calculated and compared
at different scales using the TMD evolution equations applied to previously
existing extractions. We apply the Collins-Soper-Sterman (CSS) formalism, using
the version recently developed by Collins. Our calculations rely on the
universality properties of TMD-functions that follow from the TMD-factorization
theorem. Accordingly, the non-perturbative input is fixed by earlier
experimental measurements, including both polarized semi-inclusive deep
inelastic scattering (SIDIS) and unpolarized Drell-Yan (DY) scattering. It is
shown that recent COMPASS measurements are consistent with the suppression
prescribed by TMD evolution.
| [
{
"created": "Mon, 19 Dec 2011 17:52:54 GMT",
"version": "v1"
},
{
"created": "Tue, 20 Dec 2011 23:37:59 GMT",
"version": "v2"
},
{
"created": "Wed, 27 Jun 2012 15:31:56 GMT",
"version": "v3"
}
] | 2013-05-30 | [
[
"Aybat",
"S. Mert",
""
],
[
"Prokudin",
"Alexei",
""
],
[
"Rogers",
"Ted C.",
""
]
] | The Sivers transverse single spin asymmetry (TSSA) is calculated and compared at different scales using the TMD evolution equations applied to previously existing extractions. We apply the Collins-Soper-Sterman (CSS) formalism, using the version recently developed by Collins. Our calculations rely on the universality properties of TMD-functions that follow from the TMD-factorization theorem. Accordingly, the non-perturbative input is fixed by earlier experimental measurements, including both polarized semi-inclusive deep inelastic scattering (SIDIS) and unpolarized Drell-Yan (DY) scattering. It is shown that recent COMPASS measurements are consistent with the suppression prescribed by TMD evolution. |
hep-ph/9503231 | Omar Miranda Romagnoli | M. Maya and O. G. Miranda | Constraints on Z1-Z2 Mixing from the Decay $Z1 \to e-e+$ in the
left-right Symmetric Model | 14 pages in Latex, 3 figures available on request | Z.Phys. C68 (1995) 481-484 | 10.1007/BF01620725 | CINVESTAV-FIS-02/95 | hep-ph | null | We examine the decay of $Z_1$ in electrons with recent data from LEP. The
partial width $\Gamma(Z_1\to e^-e^+)$ is studied in the framework of a
left-right symmetric model with standard electroweak corrections. Processes
measured near the resonance has served to measure the neutral coupling
constants very precisely, which is useful to set bounds on the parameters of
the model. This partial decay occurs in the resonance zone. As a consecuence
the process is independent of the mass of the additional $Z_2$ heavy gauge
boson which appears in this kind of models and so we have the mixing angle $\f$
between the left and the right bosons as the only additional parameter. In this
paper we take advantage of this fact to set a bound for $\f$: $-9\times
10^{-3}\leq\f\leq 4\times 10^{-3}$, which is in agreement with other
constraints previously reported.
| [
{
"created": "Fri, 3 Mar 1995 22:42:58 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Maya",
"M.",
""
],
[
"Miranda",
"O. G.",
""
]
] | We examine the decay of $Z_1$ in electrons with recent data from LEP. The partial width $\Gamma(Z_1\to e^-e^+)$ is studied in the framework of a left-right symmetric model with standard electroweak corrections. Processes measured near the resonance has served to measure the neutral coupling constants very precisely, which is useful to set bounds on the parameters of the model. This partial decay occurs in the resonance zone. As a consecuence the process is independent of the mass of the additional $Z_2$ heavy gauge boson which appears in this kind of models and so we have the mixing angle $\f$ between the left and the right bosons as the only additional parameter. In this paper we take advantage of this fact to set a bound for $\f$: $-9\times 10^{-3}\leq\f\leq 4\times 10^{-3}$, which is in agreement with other constraints previously reported. |
1902.07196 | Greger Torgrimsson | Greger Torgrimsson | Thermally versus dynamically assisted Schwinger pair production | Version 2: Results unchanged, references added, matches PRD version.
9 pages, 4 figures | Phys. Rev. D 99, 096007 (2019) | 10.1103/PhysRevD.99.096007 | null | hep-ph hep-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We study electron-positron pair production by the combination of a strong,
constant electric field and a thermal background. We show that this process is
similar to dynamically assisted Schwinger pair production, where the strong
field is instead assisted by another coherent field, which is weaker but
faster. We treat the interaction with the photons from the thermal background
perturbatively, while the interaction with the electric field is
nonperturbative (i.e. a Furry picture expansion in $\alpha$). At
$\mathcal{O}(\alpha^2)$ we have ordinary perturbative Breit-Wheeler pair
production assisted nonperturbatively by the electric field. Already at this
order we recover the same exponential part of the probability as previous
studies, which did not expand in $\alpha$. This means that we do not have to
consider higher orders, so our approach allows us to calculate the
pre-exponential part of the probability, which has not been obtained before in
this regime. Although the prefactor is in general subdominant compared to the
exponential part, in this case it can be important because it scales as
$\alpha^2\ll1$ and is therefore much smaller than the prefactor at
$\mathcal{O}(\alpha^0)$ (pure Schwinger pair production). We show that, because
of the exponential enhancement, $\mathcal{O}(\alpha^2)$ still gives the
dominant contribution for temperatures above a certain threshold, but, because
of the small prefactor, the threshold is higher than what the exponential alone
would suggest.
| [
{
"created": "Tue, 19 Feb 2019 18:48:57 GMT",
"version": "v1"
},
{
"created": "Wed, 15 May 2019 16:44:02 GMT",
"version": "v2"
}
] | 2019-05-16 | [
[
"Torgrimsson",
"Greger",
""
]
] | We study electron-positron pair production by the combination of a strong, constant electric field and a thermal background. We show that this process is similar to dynamically assisted Schwinger pair production, where the strong field is instead assisted by another coherent field, which is weaker but faster. We treat the interaction with the photons from the thermal background perturbatively, while the interaction with the electric field is nonperturbative (i.e. a Furry picture expansion in $\alpha$). At $\mathcal{O}(\alpha^2)$ we have ordinary perturbative Breit-Wheeler pair production assisted nonperturbatively by the electric field. Already at this order we recover the same exponential part of the probability as previous studies, which did not expand in $\alpha$. This means that we do not have to consider higher orders, so our approach allows us to calculate the pre-exponential part of the probability, which has not been obtained before in this regime. Although the prefactor is in general subdominant compared to the exponential part, in this case it can be important because it scales as $\alpha^2\ll1$ and is therefore much smaller than the prefactor at $\mathcal{O}(\alpha^0)$ (pure Schwinger pair production). We show that, because of the exponential enhancement, $\mathcal{O}(\alpha^2)$ still gives the dominant contribution for temperatures above a certain threshold, but, because of the small prefactor, the threshold is higher than what the exponential alone would suggest. |
hep-ph/9912463 | Helmut Eberl | H. Eberl, K. Hidaka, S. Kraml, W. Majerotto, and Y. Yamada | Improved SUSY QCD corrections to Higgs boson decays into quarks and
squarks | Version to be published in PRD | Phys.Rev.D62:055006,2000 | 10.1103/PhysRevD.62.055006 | HEPHY-PUB 725/99, TGU-25, TU-583 | hep-ph | null | We improve the calculation of the supersymmetric $O(\alpha_s)$ QCD
corrections to the decays of Higgs bosons into quarks and squarks in the
Minimal Supersymmetric Standard Model. In the on-shell renormalization scheme
these corrections can be very large, which makes the perturbative expansion
unreliable. This is especially serious for decays into bottom quarks and
squarks for large $\tan\beta$. Their corrected widths can even become negative.
We show that this problem can be solved by a careful choice of the tree-level
Higgs boson couplings to quarks and squarks, in terms of the QCD and SUSY QCD
running quark masses, running trilinear couplings $A_q$, and on-shell
left-right mixing angles of squarks. We also present numerical results for the
corrected partial decay widths for the large $\tan\beta$ case.
| [
{
"created": "Wed, 22 Dec 1999 13:47:11 GMT",
"version": "v1"
},
{
"created": "Tue, 11 Jan 2000 11:51:02 GMT",
"version": "v2"
},
{
"created": "Thu, 11 May 2000 09:10:21 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Eberl",
"H.",
""
],
[
"Hidaka",
"K.",
""
],
[
"Kraml",
"S.",
""
],
[
"Majerotto",
"W.",
""
],
[
"Yamada",
"Y.",
""
]
] | We improve the calculation of the supersymmetric $O(\alpha_s)$ QCD corrections to the decays of Higgs bosons into quarks and squarks in the Minimal Supersymmetric Standard Model. In the on-shell renormalization scheme these corrections can be very large, which makes the perturbative expansion unreliable. This is especially serious for decays into bottom quarks and squarks for large $\tan\beta$. Their corrected widths can even become negative. We show that this problem can be solved by a careful choice of the tree-level Higgs boson couplings to quarks and squarks, in terms of the QCD and SUSY QCD running quark masses, running trilinear couplings $A_q$, and on-shell left-right mixing angles of squarks. We also present numerical results for the corrected partial decay widths for the large $\tan\beta$ case. |
2201.06948 | Vladimir A. Petrov | Vladimir Petrov, Nikolay Tkachenko | Odderon: Lost or/and Found? | null | null | null | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | This is a quick survey of theoretical and experimental efforts to understand
and identify the Odderon.
| [
{
"created": "Tue, 18 Jan 2022 13:15:45 GMT",
"version": "v1"
}
] | 2022-01-19 | [
[
"Petrov",
"Vladimir",
""
],
[
"Tkachenko",
"Nikolay",
""
]
] | This is a quick survey of theoretical and experimental efforts to understand and identify the Odderon. |
2112.09635 | Alessandro Podo | Roberto Contino, Alessandro Podo, Filippo Revello | Chiral models of composite axions and accidental Peccei-Quinn symmetry | 48 pages. v2: improved classification of models with more inclusive
selection criteria; added clarifications and other minor changes. v3: matches
published version | null | 10.1007/JHEP04(2022)180 | null | hep-ph hep-th | http://creativecommons.org/licenses/by/4.0/ | We introduce a class of composite axion models that provide a natural
solution to the strong CP problem, and possibly account for the observed dark
matter abundance. The QCD axion arises as a composite Nambu-Goldstone boson
(NGB) from the dynamics of a chiral gauge theory with a strongly-interacting
and confining SU(N) factor and a weakly-interacting U(1), with no fundamental
scalar fields. The Peccei-Quinn (PQ) symmetry is accidental and all the mass
scales are generated dynamically. We analyze specific models where the PQ
symmetry is broken only by operators of dimension 12 or higher. We also
classify several other models where the PQ symmetry can be potentially
protected up to the dimension 15 or 18 level. Our framework can be easily
extended to a scenario where the Standard Model (SM) is unified into a simple
gauge group, and we discuss the case of non-supersymmetric SU(5) unification.
The GUT models predict the existence of additional pseudo NGBs, parametrically
lighter than the GUT and PQ scales, which could have an impact on the
cosmological evolution and leave observable signatures. We also clarify the
selection rules under which higher-dimensional PQ-violating operators can
generate a potential for the axion in the IR, and provide a discussion of the
discrete symmetries in composite axion models associated to the number of
domain walls. These results can be of general interest for composite axion
models based on a QCD-like confining gauge group.
| [
{
"created": "Fri, 17 Dec 2021 17:16:08 GMT",
"version": "v1"
},
{
"created": "Tue, 1 Mar 2022 18:21:28 GMT",
"version": "v2"
},
{
"created": "Wed, 11 May 2022 18:10:02 GMT",
"version": "v3"
}
] | 2022-05-13 | [
[
"Contino",
"Roberto",
""
],
[
"Podo",
"Alessandro",
""
],
[
"Revello",
"Filippo",
""
]
] | We introduce a class of composite axion models that provide a natural solution to the strong CP problem, and possibly account for the observed dark matter abundance. The QCD axion arises as a composite Nambu-Goldstone boson (NGB) from the dynamics of a chiral gauge theory with a strongly-interacting and confining SU(N) factor and a weakly-interacting U(1), with no fundamental scalar fields. The Peccei-Quinn (PQ) symmetry is accidental and all the mass scales are generated dynamically. We analyze specific models where the PQ symmetry is broken only by operators of dimension 12 or higher. We also classify several other models where the PQ symmetry can be potentially protected up to the dimension 15 or 18 level. Our framework can be easily extended to a scenario where the Standard Model (SM) is unified into a simple gauge group, and we discuss the case of non-supersymmetric SU(5) unification. The GUT models predict the existence of additional pseudo NGBs, parametrically lighter than the GUT and PQ scales, which could have an impact on the cosmological evolution and leave observable signatures. We also clarify the selection rules under which higher-dimensional PQ-violating operators can generate a potential for the axion in the IR, and provide a discussion of the discrete symmetries in composite axion models associated to the number of domain walls. These results can be of general interest for composite axion models based on a QCD-like confining gauge group. |
hep-ph/9705367 | Jeremy S. Heyl | Jeremy S. Heyl and Lars Hernquist | Birefringence and Dichroism of the QED Vacuum | 8 pages, 2 figures, to appear in Journal of Physics A | J.Phys.A30:6485-6492,1997 | 10.1088/0305-4470/30/18/022 | null | hep-ph astro-ph | null | We use an analytic form for the Heisenberg-Euler Lagrangian to calculate the
birefringent and dichroic properties of the vacuum for arbitrarily strong
wrenchless fields.
PACS : 12.20.Ds, 42.25.Lc 97.60.Jd, 98.70.Rz
| [
{
"created": "Tue, 20 May 1997 20:11:42 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Heyl",
"Jeremy S.",
""
],
[
"Hernquist",
"Lars",
""
]
] | We use an analytic form for the Heisenberg-Euler Lagrangian to calculate the birefringent and dichroic properties of the vacuum for arbitrarily strong wrenchless fields. PACS : 12.20.Ds, 42.25.Lc 97.60.Jd, 98.70.Rz |
2007.13313 | Claude Duhr | Claude Duhr, Falko Dulat, Bernhard Mistlberger | Charged Current Drell-Yan Production at N3LO | 22 pages, 11 figures. v2: Fixed mistake in figure 8 | null | 10.1007/JHEP11(2020)143 | CERN-TH-2020-121, SLAC-PUB-17539 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present the production cross section for a lepton-neutrino pair at the
Large Hadron Collider computed at next-to-next-to-next-to leading order (N3LO)
in QCD perturbation theory. We compute the partonic coefficient functions of a
virtual $W^{\pm}$ boson at this order. We then use these analytic functions to
study the progression of the perturbative series in different observables. In
particular, we investigate the impact of the newly obtained corrections on the
inclusive production cross section of $W^{\pm}$ bosons, as well as on the
ratios of the production cross sections for $W^+$, $W^-$ and/or a virtual
photon. Finally, we present N3LO predictions for the charge asymmetry at the
LHC.
| [
{
"created": "Mon, 27 Jul 2020 05:38:20 GMT",
"version": "v1"
},
{
"created": "Sat, 19 Sep 2020 18:38:22 GMT",
"version": "v2"
}
] | 2020-12-30 | [
[
"Duhr",
"Claude",
""
],
[
"Dulat",
"Falko",
""
],
[
"Mistlberger",
"Bernhard",
""
]
] | We present the production cross section for a lepton-neutrino pair at the Large Hadron Collider computed at next-to-next-to-next-to leading order (N3LO) in QCD perturbation theory. We compute the partonic coefficient functions of a virtual $W^{\pm}$ boson at this order. We then use these analytic functions to study the progression of the perturbative series in different observables. In particular, we investigate the impact of the newly obtained corrections on the inclusive production cross section of $W^{\pm}$ bosons, as well as on the ratios of the production cross sections for $W^+$, $W^-$ and/or a virtual photon. Finally, we present N3LO predictions for the charge asymmetry at the LHC. |
hep-ph/9501330 | null | L. Motyka and K. Zalewski (Jagellonian University, Poland) | NONRELATIVISTIC MODEL FOR $b\OVERLINE{b}$ QUARKONIA | 6 pages, Latex file | Zs. Phys. C69 (1995) 343 | null | TPJU - 1/95 | hep-ph | null | Experimental data for $b\bar{b}$ quarkonia have been compared with the
predictions of a variety of nonrelativistic quark models. It is found that a
potential $a\sqrt{r} - b/r +$ const gives good agreement, while many others do
not. Some implications of this observation are discussed.
| [
{
"created": "Wed, 18 Jan 1995 11:29:00 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Motyka",
"L.",
"",
"Jagellonian University, Poland"
],
[
"Zalewski",
"K.",
"",
"Jagellonian University, Poland"
]
] | Experimental data for $b\bar{b}$ quarkonia have been compared with the predictions of a variety of nonrelativistic quark models. It is found that a potential $a\sqrt{r} - b/r +$ const gives good agreement, while many others do not. Some implications of this observation are discussed. |
1910.02666 | Jing-Yu Zhu | Shao-Feng Ge and Jing-yu Zhu | Phenomenological Advantages of the Normal Neutrino Mass Ordering | 8 pages, 5 figures, the version to be published in Chinese Physics C | null | 10.1088/1674-1137/44/8/083103 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The preference of the normal neutrino mass ordering from the recent
cosmological constraint and the global fit of neutrino oscillation experiments
does not seem like a wise choice at first glance since it obscures the
neutrinoless double beta decay and hence the Majorana nature of neutrinos.
Contrary to this naive expectation, we point out that the actual situation is
the opposite. The normal neutrino mass ordering opens the possibility of
excluding the higher solar octant and simultaneously measuring the two Majorana
CP phases in future $0\nu2\beta$ experiments. Especially, the funnel region
will completely disappear if the solar mixing angle takes the higher octant.
The combined precision measurement by the JUNO and Daya Bay experiments can
significantly reduce the uncertainty in excluding the higher octant. With a
typical $\mathcal O(\mbox{meV})$ sensitivity on the effective mass
$|m_{ee}^{}|$, the neutrinoless double beta decay experiment can tell if the
funnel region really exists and hence exclude the higher solar octant. With the
sensitivity further improved to sub-meV, the two Majorana CP phases can be
simultaneously determined. Thus, the normal neutrino mass ordering clearly
shows phenomenological advantages over the inverted one.
| [
{
"created": "Mon, 7 Oct 2019 08:28:36 GMT",
"version": "v1"
},
{
"created": "Tue, 24 Dec 2019 12:01:38 GMT",
"version": "v2"
},
{
"created": "Thu, 23 Jul 2020 13:53:06 GMT",
"version": "v3"
}
] | 2020-08-26 | [
[
"Ge",
"Shao-Feng",
""
],
[
"Zhu",
"Jing-yu",
""
]
] | The preference of the normal neutrino mass ordering from the recent cosmological constraint and the global fit of neutrino oscillation experiments does not seem like a wise choice at first glance since it obscures the neutrinoless double beta decay and hence the Majorana nature of neutrinos. Contrary to this naive expectation, we point out that the actual situation is the opposite. The normal neutrino mass ordering opens the possibility of excluding the higher solar octant and simultaneously measuring the two Majorana CP phases in future $0\nu2\beta$ experiments. Especially, the funnel region will completely disappear if the solar mixing angle takes the higher octant. The combined precision measurement by the JUNO and Daya Bay experiments can significantly reduce the uncertainty in excluding the higher octant. With a typical $\mathcal O(\mbox{meV})$ sensitivity on the effective mass $|m_{ee}^{}|$, the neutrinoless double beta decay experiment can tell if the funnel region really exists and hence exclude the higher solar octant. With the sensitivity further improved to sub-meV, the two Majorana CP phases can be simultaneously determined. Thus, the normal neutrino mass ordering clearly shows phenomenological advantages over the inverted one. |
1905.01031 | Volodymyr Vovchenko | Volodymyr Vovchenko, Jan Steinheimer, Owe Philipsen, Horst Stoecker | QCD equation of state at finite baryon density with fugacity expansion | 8 pages, 4 figures. Contribution to the proceedings of the CPOD2018
conference, Corfu Island, Greece, September 24-28, 2018 | null | null | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We explore the QCD equation of state at finite baryon density through an
expansion in baryon number fugacity, making use of the recent lattice data on
the four leading Fourier coefficients of the expansion. A state-of-the-art
description of the lattice data at both imaginary $\mu_B$ and $\mu_B = 0$ is
provided by the cluster expansion model (CEM). The CEM pressure function has
three temperature dependent input parameters, which we fix by parameterizing
the available lattice QCD data. This results in a crossover model of the QCD
equation of state at finite baryon density, which can be used in fluid
dynamical simulations of heavy-ion collisions.
| [
{
"created": "Fri, 3 May 2019 04:25:19 GMT",
"version": "v1"
}
] | 2019-05-06 | [
[
"Vovchenko",
"Volodymyr",
""
],
[
"Steinheimer",
"Jan",
""
],
[
"Philipsen",
"Owe",
""
],
[
"Stoecker",
"Horst",
""
]
] | We explore the QCD equation of state at finite baryon density through an expansion in baryon number fugacity, making use of the recent lattice data on the four leading Fourier coefficients of the expansion. A state-of-the-art description of the lattice data at both imaginary $\mu_B$ and $\mu_B = 0$ is provided by the cluster expansion model (CEM). The CEM pressure function has three temperature dependent input parameters, which we fix by parameterizing the available lattice QCD data. This results in a crossover model of the QCD equation of state at finite baryon density, which can be used in fluid dynamical simulations of heavy-ion collisions. |
0904.0139 | Petr Benes | Petr Benes | Fermion flavor mixing in models with dynamical mass generation | 14 pages, REVTeX4, 2 eps figures; discussion of momentum-dependence
of proper vertex and polarization tensors added, gauge boson mixing
considered, additional references added; version published in Phys. Rev. D | Phys.Rev.D81:065029,2010 | 10.1103/PhysRevD.81.065029 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We present a model-independent method of dealing with fermion flavor mixing
in the case when instead of constant, momentum-independent mass matrices one
has rather momentum-dependent self-energies. This situation is typical for
strongly coupled models of dynamical fermion mass generation. We demonstrate
our approach on the example of quark mixing. We show that quark self-energies
with a generic momentum dependence lead to an effective
Cabibbo-Kobayashi-Maskawa (CKM) matrix, which turns out to be in general
non-unitary, in accordance with previous claims of other authors, and to
non-trivial flavor changing electromagnetic and neutral currents. We also
discuss some conceptual consequences of the momentum-dependent self-energies
and show that in such a case the interaction basis and the mass basis are not
related by a unitary transformation. In fact, we argue that the latter is
merely an effective concept, in a specified sense. While focusing mainly on the
fermionic self-energies, we also study the effects of momentum-dependent
radiative corrections to the gauge bosons and to the proper vertices. Our
approach is based on an application of the Lehmann-Symanzik-Zimmermann (LSZ)
reduction formula and for the special case of constant self-energies it gives
the same results as the standard approach based on the diagonalization of mass
matrices.
| [
{
"created": "Wed, 1 Apr 2009 12:02:57 GMT",
"version": "v1"
},
{
"created": "Tue, 30 Mar 2010 12:57:33 GMT",
"version": "v2"
}
] | 2012-02-03 | [
[
"Benes",
"Petr",
""
]
] | We present a model-independent method of dealing with fermion flavor mixing in the case when instead of constant, momentum-independent mass matrices one has rather momentum-dependent self-energies. This situation is typical for strongly coupled models of dynamical fermion mass generation. We demonstrate our approach on the example of quark mixing. We show that quark self-energies with a generic momentum dependence lead to an effective Cabibbo-Kobayashi-Maskawa (CKM) matrix, which turns out to be in general non-unitary, in accordance with previous claims of other authors, and to non-trivial flavor changing electromagnetic and neutral currents. We also discuss some conceptual consequences of the momentum-dependent self-energies and show that in such a case the interaction basis and the mass basis are not related by a unitary transformation. In fact, we argue that the latter is merely an effective concept, in a specified sense. While focusing mainly on the fermionic self-energies, we also study the effects of momentum-dependent radiative corrections to the gauge bosons and to the proper vertices. Our approach is based on an application of the Lehmann-Symanzik-Zimmermann (LSZ) reduction formula and for the special case of constant self-energies it gives the same results as the standard approach based on the diagonalization of mass matrices. |
hep-ph/9511276 | Yasuko Sato | K. Kobayakawa, Y. Sato and S. Tanaka | Moduli Effects on Neutrino Oscillations | 17pages, Latex, 3 figures (available from the author upon request by
FAX or mail) | Phys.Rev.D54:1204-1211,1996 | 10.1103/PhysRevD.54.1204 | KOBE-FHD-95-07 | hep-ph | null | We point out the possibility to detect the low-energy signals of moduli in
the superstring theory through the neutrino oscillation. The idea is based on
the characteristics that the couplings of moduli are different from matter to
matter. We estimate the oscillation probability both in the baseline and solar
neutrino oscillations. In both cases, when there is at least one modulus of
which mass is less than or equal to $10^{-19}$ GeV, the interaction of the
modulus significantly changes the conversion probability from one neutrino
flavor to another.
| [
{
"created": "Thu, 9 Nov 1995 11:42:40 GMT",
"version": "v1"
},
{
"created": "Sun, 3 Dec 1995 09:50:18 GMT",
"version": "v2"
},
{
"created": "Tue, 1 Oct 1996 07:12:57 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Kobayakawa",
"K.",
""
],
[
"Sato",
"Y.",
""
],
[
"Tanaka",
"S.",
""
]
] | We point out the possibility to detect the low-energy signals of moduli in the superstring theory through the neutrino oscillation. The idea is based on the characteristics that the couplings of moduli are different from matter to matter. We estimate the oscillation probability both in the baseline and solar neutrino oscillations. In both cases, when there is at least one modulus of which mass is less than or equal to $10^{-19}$ GeV, the interaction of the modulus significantly changes the conversion probability from one neutrino flavor to another. |
hep-ph/0303252 | Kouhei Hasegawa | K.Hasegawa, C. S. Lim, and K. Ogure | Escape from washing out of baryon number in a two-zero-texture general
Zee model compatible with the large mixing angle MSW solution | 22 pages, 2 eps figures, Type set revtex4 | Phys.Rev. D68 (2003) 053006 | 10.1103/PhysRevD.68.053006 | KOBE-TH-03-04 | hep-ph astro-ph | null | We propose a two-zero-texture general Zee model, compatible with the large
mixing angle Mikheyev-Smirnov-Wolfenstein solution. The washing out of the
baryon number does not occur in this model for an adequate parameter range. We
check the consistency of a model with the constraints coming from flavor
changing neutral current processes, the recent cosmic microwave background
observation, and the Z-burst scenario.
| [
{
"created": "Sat, 29 Mar 2003 19:16:23 GMT",
"version": "v1"
},
{
"created": "Fri, 4 Apr 2003 07:17:51 GMT",
"version": "v2"
},
{
"created": "Sun, 27 Apr 2003 07:00:54 GMT",
"version": "v3"
},
{
"created": "Thu, 9 Oct 2003 16:02:51 GMT",
"version": "v4"
}
] | 2009-11-10 | [
[
"Hasegawa",
"K.",
""
],
[
"Lim",
"C. S.",
""
],
[
"Ogure",
"K.",
""
]
] | We propose a two-zero-texture general Zee model, compatible with the large mixing angle Mikheyev-Smirnov-Wolfenstein solution. The washing out of the baryon number does not occur in this model for an adequate parameter range. We check the consistency of a model with the constraints coming from flavor changing neutral current processes, the recent cosmic microwave background observation, and the Z-burst scenario. |
hep-ph/9406216 | Mikhailov Serge | A.P. Bakulev and S.V. Mikhailov | The Photon Structure Function $F_2$ in QCD with Nonlocal Vacuum Quark
Condensates | 7, LATEX, E2-94-208 | JETP Lett. 60 (1994) 150-155 | null | null | hep-ph | null | We calculate the contribution from nonlocal vacuum condensates of quark
fields to the hadronic part of the photon structure function $F_2(x)$ in the
operator product expansion approach to QCD. The result is a smooth function of
$x$ and its magnitude is comparable with one of gluon condensate. Extrapolation
to the case of real photon is realized with the help of the model, suggested by
Gorsky et al. As a result we obtain a substantial improvement of the agreement
with experimental data for the standard value of the parameter $\lambda_q^2
\equiv \langle\bar qD^2 q\rangle /\langle\bar qq\rangle \approx 0.5 \ \ GeV^2
$.}
| [
{
"created": "Thu, 2 Jun 1994 22:56:22 GMT",
"version": "v1"
},
{
"created": "Fri, 3 Jun 1994 20:44:26 GMT",
"version": "v2"
}
] | 2008-02-03 | [
[
"Bakulev",
"A. P.",
""
],
[
"Mikhailov",
"S. V.",
""
]
] | We calculate the contribution from nonlocal vacuum condensates of quark fields to the hadronic part of the photon structure function $F_2(x)$ in the operator product expansion approach to QCD. The result is a smooth function of $x$ and its magnitude is comparable with one of gluon condensate. Extrapolation to the case of real photon is realized with the help of the model, suggested by Gorsky et al. As a result we obtain a substantial improvement of the agreement with experimental data for the standard value of the parameter $\lambda_q^2 \equiv \langle\bar qD^2 q\rangle /\langle\bar qq\rangle \approx 0.5 \ \ GeV^2 $.} |
0708.0352 | Alice Dechambre | A. Dechambre | Gribov Poles in Diffractive Physics | 4 pages, 7 figures, Proceedings Jjc, La Rochelle, December 2006 | null | null | null | hep-ph | null | High-energy diffractive physics has several interests for theoreticians and
experimentalists. We first remind the reader of the main characteristics of
diffraction in particles physics and present the calculation of a two-gluon
exchange in which non-perturbative effects are introduced via new singularities
from confinement.
| [
{
"created": "Thu, 2 Aug 2007 14:11:15 GMT",
"version": "v1"
}
] | 2007-08-03 | [
[
"Dechambre",
"A.",
""
]
] | High-energy diffractive physics has several interests for theoreticians and experimentalists. We first remind the reader of the main characteristics of diffraction in particles physics and present the calculation of a two-gluon exchange in which non-perturbative effects are introduced via new singularities from confinement. |
1412.8272 | Chun-Khiang Chua | Hai-Yang Cheng, Chun-Khiang Chua | On the smallness of Tree-dominated Charmless Two-body Baryonic $B$ Decay
Rates | 15 pages, 3 figures | Phys. Rev. D 91, 036003 (2015) | 10.1103/PhysRevD.91.036003 | null | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The long awaited baryonic $B$ decay $\bar B{}^0\to p\bar p$ was recently
observed by LHCb with a branching fraction of order $10^{-8}$. All the earlier
model predictions are too large compared with experiment. In this work, we
point out that for a given tree operator $O_i$, the contribution from its
Fiertz transformed operator, an effect often missed in the literature, tends to
cancel the internal $W$-emission amplitude induced from $O_i$. The wave
function of low-lying baryons are symmetric in momenta and the quark flavor
with the same chirality, but antisymmetric in color indices. Using these
symmetry properties and the chiral structure of weak interactions, we find that
half of the Feynman diagrams responsible for internal $W$-emission cancel.
Since this feature holds in the charmless modes but not in the charmful ones,
we advocate that the partial cancellation accounts for the smallness of the
tree-dominated charmless two-body baryonic $B$ decays. This also explains why
most previous model calculations predicted too large rates as the above
consideration was not taken into account. Finally, we emphasize that, contrary
to the claim in the literature, the internal $W$-emission tree amplitude should
be proportional to the Wilson coefficient $c_1+c_2$ rather than $c_1-c_2$.
| [
{
"created": "Mon, 29 Dec 2014 07:32:42 GMT",
"version": "v1"
}
] | 2015-03-05 | [
[
"Cheng",
"Hai-Yang",
""
],
[
"Chua",
"Chun-Khiang",
""
]
] | The long awaited baryonic $B$ decay $\bar B{}^0\to p\bar p$ was recently observed by LHCb with a branching fraction of order $10^{-8}$. All the earlier model predictions are too large compared with experiment. In this work, we point out that for a given tree operator $O_i$, the contribution from its Fiertz transformed operator, an effect often missed in the literature, tends to cancel the internal $W$-emission amplitude induced from $O_i$. The wave function of low-lying baryons are symmetric in momenta and the quark flavor with the same chirality, but antisymmetric in color indices. Using these symmetry properties and the chiral structure of weak interactions, we find that half of the Feynman diagrams responsible for internal $W$-emission cancel. Since this feature holds in the charmless modes but not in the charmful ones, we advocate that the partial cancellation accounts for the smallness of the tree-dominated charmless two-body baryonic $B$ decays. This also explains why most previous model calculations predicted too large rates as the above consideration was not taken into account. Finally, we emphasize that, contrary to the claim in the literature, the internal $W$-emission tree amplitude should be proportional to the Wilson coefficient $c_1+c_2$ rather than $c_1-c_2$. |
1006.1765 | Marek Gazdzicki | Marek Gazdzicki, Mark Gorenstein, Peter Seyboth | Onset of deconfinement in nucleus-nucleus collisions: Review for
pedestrians and experts | 50 pages, 18 figures, the final version published in APP | Acta Phys.Polon.B42:307-351,2011 | 10.5506/APhysPolB.42.307 | null | hep-ph hep-ex nucl-ex nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | Evidence for the energy threshold of creating the quark-gluon plasma in
nucleus-nucleus collisions, the so-called onset of deconfinement, has been
found by the energy scan program of the NA49 experiment at the CERN SPS. In
this paper we review the experimental and theoretical status of this
phenomenon. First, the basic, qualitative ideas are presented for non-experts.
Next, the latest experimental results are compared to a statistical model
within which the onset of deconfinement and its signals had been predicted.
Finally, alternative interpretations and open questions are discussed.
| [
{
"created": "Wed, 9 Jun 2010 11:12:11 GMT",
"version": "v1"
},
{
"created": "Tue, 25 Jan 2011 17:05:32 GMT",
"version": "v2"
},
{
"created": "Wed, 2 Feb 2011 12:35:11 GMT",
"version": "v3"
},
{
"created": "Mon, 21 Feb 2011 16:49:59 GMT",
"version": "v4"
}
] | 2011-06-28 | [
[
"Gazdzicki",
"Marek",
""
],
[
"Gorenstein",
"Mark",
""
],
[
"Seyboth",
"Peter",
""
]
] | Evidence for the energy threshold of creating the quark-gluon plasma in nucleus-nucleus collisions, the so-called onset of deconfinement, has been found by the energy scan program of the NA49 experiment at the CERN SPS. In this paper we review the experimental and theoretical status of this phenomenon. First, the basic, qualitative ideas are presented for non-experts. Next, the latest experimental results are compared to a statistical model within which the onset of deconfinement and its signals had been predicted. Finally, alternative interpretations and open questions are discussed. |
1812.08521 | Toshifumi Yamada | Naoyuki Haba, Yukihiro Mimura and Toshifumi Yamada | Proton Lifetime Upper Bound in Non-SUSY SU(5) GUT | 18 pages, 5 figures. Version accepted for publication in Physical
Review D | Phys. Rev. D 99, 075018 (2019) | 10.1103/PhysRevD.99.075018 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | In preparation for upcoming nucleon decay searches at Hyper-Kamiokande, it is
important to derive a theoretical upper bound on the proton lifetime in a
general class of grand unified theory (GUT) models. In this paper, we make an
attempt along this direction for non-SUSY SU(5) models, under the mild
restrictions that only one or two SM-decomposed multiplets are singularly
light, and that the SU(5) gauge theory is asymptotically free and thus there
are no too large representations in the model. We derive criteria for
SM-decomposed multiplets that potentially enhance the proton lifetime when they
are singularly light. We perform a numerical analysis on the proton lifetime
and show that some choices of singularly light multiplets can provide a
testable upper bound on the proton lifetime.
| [
{
"created": "Thu, 20 Dec 2018 12:32:42 GMT",
"version": "v1"
},
{
"created": "Wed, 3 Apr 2019 12:50:56 GMT",
"version": "v2"
}
] | 2019-04-24 | [
[
"Haba",
"Naoyuki",
""
],
[
"Mimura",
"Yukihiro",
""
],
[
"Yamada",
"Toshifumi",
""
]
] | In preparation for upcoming nucleon decay searches at Hyper-Kamiokande, it is important to derive a theoretical upper bound on the proton lifetime in a general class of grand unified theory (GUT) models. In this paper, we make an attempt along this direction for non-SUSY SU(5) models, under the mild restrictions that only one or two SM-decomposed multiplets are singularly light, and that the SU(5) gauge theory is asymptotically free and thus there are no too large representations in the model. We derive criteria for SM-decomposed multiplets that potentially enhance the proton lifetime when they are singularly light. We perform a numerical analysis on the proton lifetime and show that some choices of singularly light multiplets can provide a testable upper bound on the proton lifetime. |
hep-ph/0305136 | Vladimir Vechernin | V. V. Vechernin and R. S. Kolevatov (St.Petersburg State University) | Cellular Approach to Long-Range $p_t$ and Multiplicity Correlations in
the String Fusion Model | 21 pages, LaTeX, 7 figures in PostScript, Russian version will appear
in the journal "Vestnik SPbU" | null | null | SPbU-IP-03-03 | hep-ph | null | The long-range $p_t$ and multiplicity($n$) correlations in high-energy
nuclear collisions are studied in the framework of a simple cellular analog of
the string fusion model.
Two cases with local and global string fusion is considered. The $p_t$--$n$
and $n$--$n$ correlation functions and correlation coefficients are calculated
analytically in some asymptotic cases using suggested Gauss approximation.
It's shown that at large string density the $p_t$--$n$ and $n$--$n$
correlation coefficients are connected and the scaling takes place. The
behavior of the correlations at small string density is also studied.
The asymptotic results are compared with results of the numerical
calculations in the framework of proposed cellular approach.
| [
{
"created": "Tue, 13 May 2003 12:33:34 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Vechernin",
"V. V.",
"",
"St.Petersburg State University"
],
[
"Kolevatov",
"R. S.",
"",
"St.Petersburg State University"
]
] | The long-range $p_t$ and multiplicity($n$) correlations in high-energy nuclear collisions are studied in the framework of a simple cellular analog of the string fusion model. Two cases with local and global string fusion is considered. The $p_t$--$n$ and $n$--$n$ correlation functions and correlation coefficients are calculated analytically in some asymptotic cases using suggested Gauss approximation. It's shown that at large string density the $p_t$--$n$ and $n$--$n$ correlation coefficients are connected and the scaling takes place. The behavior of the correlations at small string density is also studied. The asymptotic results are compared with results of the numerical calculations in the framework of proposed cellular approach. |
2402.07848 | Mohammad Yousuf Jamal | Indrani Nilima, Mujeeb Hasan, B. K. Singh and Mohammad Yousuf Jamal | Quarkonia dissociation at finite magnetic field in the presence of
momentum anisotropy | 14 pages, 10 figures, 2 tables | null | 10.1140/epjc/s10052-024-12525-y | null | hep-ph nucl-th | http://creativecommons.org/licenses/by/4.0/ | In this study, we investigate the potential of heavy quarkonia within a
magnetized hot QGP medium having finite momentum anisotropy. The phenomenon of
inverse magnetic catalysis is introduced into the system, influencing the
magnetic field-modified Debye mass and thereby altering the effective quark
masses. Concurrently, the impact of momentum anisotropy in the medium is
considered that influence the particle distribution in the medium. The thermal
decay width and dissociation temperature of quarkonium states, specifically the
1S and 2S states of charmonium and bottomonium, are computed. Our results
reveal that both momentum anisotropy and the inverse magnetic catalysis effects
play a significant role in modifying the thermal decay width and dissociation
temperature of these heavy quarkonia states.
| [
{
"created": "Mon, 12 Feb 2024 17:57:13 GMT",
"version": "v1"
}
] | 2024-02-13 | [
[
"Nilima",
"Indrani",
""
],
[
"Hasan",
"Mujeeb",
""
],
[
"Singh",
"B. K.",
""
],
[
"Jamal",
"Mohammad Yousuf",
""
]
] | In this study, we investigate the potential of heavy quarkonia within a magnetized hot QGP medium having finite momentum anisotropy. The phenomenon of inverse magnetic catalysis is introduced into the system, influencing the magnetic field-modified Debye mass and thereby altering the effective quark masses. Concurrently, the impact of momentum anisotropy in the medium is considered that influence the particle distribution in the medium. The thermal decay width and dissociation temperature of quarkonium states, specifically the 1S and 2S states of charmonium and bottomonium, are computed. Our results reveal that both momentum anisotropy and the inverse magnetic catalysis effects play a significant role in modifying the thermal decay width and dissociation temperature of these heavy quarkonia states. |
hep-ph/0607204 | David Kaplan | Linda M. Carpenter, David E. Kaplan, Eun-Jung Rhee | Reduced Fine-Tuning in Supersymmetry with R-parity violation | 5 pages, 2 figures. Significant detail added to the arguments
regarding LEP limits - made more quantitative. Better figures used, plotting
more physical quantities. Typos corrected and references updated. Conclusions
unchanged | Phys.Rev.Lett.99:211801,2007 | 10.1103/PhysRevLett.99.211801 | null | hep-ph | null | Both electroweak precision measurements and simple supersymmetric extensions
of the standard model prefer a mass of the Higgs boson less than the
experimental lower limit of 114 GeV. We show that supersymmetric models with R
parity violation and baryon number violation have a significant range of
parameter space in which the Higgs dominantly decays to six jets. These decays
are much more weakly constrained by current LEP analyses and would allow for a
Higgs mass near that of the $Z$. In general, lighter scalar quark and other
superpartner masses are allowed and the fine-tuning typically required to
generate the measured scale of electroweak symmetry breaking is ameliorated.
The Higgs would potentially be discovered at hadron colliders via the
appearance of new displaced vertices. The lightest neutralino could be
discovered by a scan of vertex-less events LEP I data.
| [
{
"created": "Wed, 19 Jul 2006 18:50:52 GMT",
"version": "v1"
},
{
"created": "Thu, 20 Jul 2006 07:16:15 GMT",
"version": "v2"
},
{
"created": "Thu, 25 Jan 2007 17:46:18 GMT",
"version": "v3"
}
] | 2008-11-26 | [
[
"Carpenter",
"Linda M.",
""
],
[
"Kaplan",
"David E.",
""
],
[
"Rhee",
"Eun-Jung",
""
]
] | Both electroweak precision measurements and simple supersymmetric extensions of the standard model prefer a mass of the Higgs boson less than the experimental lower limit of 114 GeV. We show that supersymmetric models with R parity violation and baryon number violation have a significant range of parameter space in which the Higgs dominantly decays to six jets. These decays are much more weakly constrained by current LEP analyses and would allow for a Higgs mass near that of the $Z$. In general, lighter scalar quark and other superpartner masses are allowed and the fine-tuning typically required to generate the measured scale of electroweak symmetry breaking is ameliorated. The Higgs would potentially be discovered at hadron colliders via the appearance of new displaced vertices. The lightest neutralino could be discovered by a scan of vertex-less events LEP I data. |
hep-ph/9709488 | Santi Peris | S. Peris (UAB) | UV renormalons in QCD and their phenomenological implications | 6 pages, LateX, espcrc2; contribution to QCD97, Montpellier, France,
July 1997, to appear in the proceedings | Nucl.Phys.Proc.Suppl.64:344-349,1998 | 10.1016/S0920-5632(97)01086-4 | UAB-FT-424/97 | hep-ph | null | I report on some recent work done in collaboration with E. de Rafael on the
connection between ultraviolet renormalons in QCD and Nambu-Jona-Lasinio-like
Lagrangians as its effective description at low energies.
| [
{
"created": "Mon, 29 Sep 1997 11:16:39 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Peris",
"S.",
"",
"UAB"
]
] | I report on some recent work done in collaboration with E. de Rafael on the connection between ultraviolet renormalons in QCD and Nambu-Jona-Lasinio-like Lagrangians as its effective description at low energies. |
hep-ph/9307278 | null | J. Segura, J. Bernab\'eu, F.J. Botella and J. Pe\~narrocha | Dynamical zeros in neutrino-electron elastic scattering at leading order | 9 pg.+ 2 figures (not included available upon request) | Phys.Rev. D49 (1994) 1633-1636 | 10.1103/PhysRevD.49.1633 | null | hep-ph | null | We show the existence of dynamical zeros in the helicity amplitudes for
neutrino-electron elastic scattering at lowest order in the standard theory. In
particular, the $\lambda=1/2$ non-flip electron helicity amplitude in the
electron antineutrino process vanishes for an incident neutrino energy
$E_{\nu}=m_{e}/(4sin^{2}\theta_{W})$ and forward electrons (maximum recoil
energy). The rest of helicity amplitudes show kinematical zeros in this
configuration and therefore the cross section vanishes. Prospects to search for
neutrino magnetic moment are discussed.
| [
{
"created": "Fri, 16 Jul 1993 01:19:42 GMT",
"version": "v1"
}
] | 2016-08-14 | [
[
"Segura",
"J.",
""
],
[
"Bernabéu",
"J.",
""
],
[
"Botella",
"F. J.",
""
],
[
"Peñarrocha",
"J.",
""
]
] | We show the existence of dynamical zeros in the helicity amplitudes for neutrino-electron elastic scattering at lowest order in the standard theory. In particular, the $\lambda=1/2$ non-flip electron helicity amplitude in the electron antineutrino process vanishes for an incident neutrino energy $E_{\nu}=m_{e}/(4sin^{2}\theta_{W})$ and forward electrons (maximum recoil energy). The rest of helicity amplitudes show kinematical zeros in this configuration and therefore the cross section vanishes. Prospects to search for neutrino magnetic moment are discussed. |
hep-ph/0601187 | Kochelev Nikolai Innokentevich | N.I.Kochelev | Charge Symmetry Breaking in Pion-Nucleon Coupling Constants Induced by
Axial Anomaly | 4 pages. Contribution to "Sense of Beauty in Physics - a volume in
honour of Adriano Di Giacomo" (Pisa University Press, Pisa, 2006), on the
occasion of his 70th birthday | null | null | null | hep-ph nucl-ex nucl-th | null | The contribution of axial anomaly to charge symmetry breaking in pion-nucleon
coupling constants is calculated within instanton model for QCD vacuum. It has
been demonstrated that the contribution is large and allows to explain
Nolen-Schiffer anomaly.
| [
{
"created": "Mon, 23 Jan 2006 06:28:26 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Jan 2006 00:11:15 GMT",
"version": "v2"
}
] | 2007-05-23 | [
[
"Kochelev",
"N. I.",
""
]
] | The contribution of axial anomaly to charge symmetry breaking in pion-nucleon coupling constants is calculated within instanton model for QCD vacuum. It has been demonstrated that the contribution is large and allows to explain Nolen-Schiffer anomaly. |
2306.15872 | Sabyasachi Chakraborty | Sabyasachi Chakraborty, Aritra Gupta, Miguel Vanvlasselaer | Anomaly induced cooling of Neutron Stars: A Standard Model contribution | 19 pages, Updated section 4.4, matches with the published version of
JCAP, updated Fig. 5 with different values of the nucleon-omega coupling | null | null | null | hep-ph | http://creativecommons.org/licenses/by/4.0/ | Young neutron stars cool via the emission of neutrinos from their core. A
precise understanding of all the different processes producing neutrinos in the
hot and degenerate matter is essential for assessing the cooling rate of such
stars. The main Standard Model processes contributing to this effect are $\nu$
bremsstrahlung, mURCA among others. In this paper, we investigate another
Standard Model process initiated by the Wess-Zumino-Witten term, leading to the
emission of neutrino pairs via $N\gamma\to N\nu\bar\nu$. We find that for
proto-neutron stars, such processes, with degenerate neutrons, can be
comparable and even dominate over the prototypical and well-known cooling
mechanisms.
| [
{
"created": "Wed, 28 Jun 2023 02:17:58 GMT",
"version": "v1"
},
{
"created": "Wed, 25 Oct 2023 03:40:36 GMT",
"version": "v2"
},
{
"created": "Thu, 21 Mar 2024 07:36:24 GMT",
"version": "v3"
},
{
"created": "Wed, 1 May 2024 12:15:21 GMT",
"version": "v4"
}
] | 2024-05-02 | [
[
"Chakraborty",
"Sabyasachi",
""
],
[
"Gupta",
"Aritra",
""
],
[
"Vanvlasselaer",
"Miguel",
""
]
] | Young neutron stars cool via the emission of neutrinos from their core. A precise understanding of all the different processes producing neutrinos in the hot and degenerate matter is essential for assessing the cooling rate of such stars. The main Standard Model processes contributing to this effect are $\nu$ bremsstrahlung, mURCA among others. In this paper, we investigate another Standard Model process initiated by the Wess-Zumino-Witten term, leading to the emission of neutrino pairs via $N\gamma\to N\nu\bar\nu$. We find that for proto-neutron stars, such processes, with degenerate neutrons, can be comparable and even dominate over the prototypical and well-known cooling mechanisms. |
hep-ph/0303051 | George Sterman | Carola F. Berger, Tibor Kucs, George Sterman (Stony Brook) | Event Shape/Energy Flow Correlations | 43 pages, eight eps figures; minor changes, references added | Phys.Rev.D68:014012,2003 | 10.1103/PhysRevD.68.014012 | YITP-SB-03-06 | hep-ph | null | We introduce a set of correlations between energy flow and event shapes that
are sensitive to the flow of color at short distances in jet events. These
correlations are formulated for a general set of event shapes, which includes
jet broadening and thrust as special cases. We illustrate the method for
electron-positron annihilation dijet events, and calculate the correlation at
leading logarithm in the energy flow and at next-to-leading-logarithm in the
event shape.
| [
{
"created": "Thu, 6 Mar 2003 16:06:08 GMT",
"version": "v1"
},
{
"created": "Fri, 7 Mar 2003 13:12:13 GMT",
"version": "v2"
},
{
"created": "Wed, 4 Jun 2003 19:43:04 GMT",
"version": "v3"
}
] | 2014-11-17 | [
[
"Berger",
"Carola F.",
"",
"Stony Brook"
],
[
"Kucs",
"Tibor",
"",
"Stony Brook"
],
[
"Sterman",
"George",
"",
"Stony Brook"
]
] | We introduce a set of correlations between energy flow and event shapes that are sensitive to the flow of color at short distances in jet events. These correlations are formulated for a general set of event shapes, which includes jet broadening and thrust as special cases. We illustrate the method for electron-positron annihilation dijet events, and calculate the correlation at leading logarithm in the energy flow and at next-to-leading-logarithm in the event shape. |
hep-ph/0410151 | Johan Alwall | Johan Alwall | An improved description of charged Higgs boson production | 10 pages, 6 figures. Talk given at the 42nd International School of
Subnuclear Physics at Erice, Sicily, 1 September 2004 | null | null | null | hep-ph | null | Many extensions of the Standard Model predict the existence of charged Higgs
bosons. In order to be able to find those particles, an accurate description of
their production is needed. In Monte Carlo simulations of charged Higgs boson
production at hadron colliders, the two tree-level processes gb->H+/-t and
gg->H+/-tb are used. Since those processes overlap in the collinear region of
the phase-space of the outgoing b-quark, care must be taken not to introduce
double-counting if both processes are to be used together. In this talk I
present a method for matching these processes, developed by Johan Rathsman and
myself. The method also allows for investigations of the factorization scale
dependence of the processes and a better understanding of which factorization
scale to choose to get a reliable description of charged Higgs production.
| [
{
"created": "Mon, 11 Oct 2004 13:09:24 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Alwall",
"Johan",
""
]
] | Many extensions of the Standard Model predict the existence of charged Higgs bosons. In order to be able to find those particles, an accurate description of their production is needed. In Monte Carlo simulations of charged Higgs boson production at hadron colliders, the two tree-level processes gb->H+/-t and gg->H+/-tb are used. Since those processes overlap in the collinear region of the phase-space of the outgoing b-quark, care must be taken not to introduce double-counting if both processes are to be used together. In this talk I present a method for matching these processes, developed by Johan Rathsman and myself. The method also allows for investigations of the factorization scale dependence of the processes and a better understanding of which factorization scale to choose to get a reliable description of charged Higgs production. |
0910.3108 | Nikolaos Stefanis | N. G. Stefanis, I. O. Cherednikov | Renormalization-group anatomy of transverse-momentum dependent parton
distribution functions in QCD | 10 pages, 3 figures; needs ws-mpla-hep.cls (supplied). Talk presented
by the first author at Workshop on "Recent Advances in Perturbative QCD and
Hadronic Physics", 20--25 July 2009, ECT*, Trento, Italy, in Honor of Prof.
Anatoly Efremov's 75th birthday | Mod.Phys.Lett.A24:2913-2923,2009 | 10.1142/S0217732309001121 | RUB-TPII-11/09 | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | The ultraviolet and rapidity divergences of transverse-momentum dependent
parton distribution functions with lightlike and transverse gauge links is
studied, also incorporating a soft eikonal factor. We find that in the
light-cone gauge with $q^-$-independent pole prescriptions extra divergences
appear which amount, at one-loop, to a cusp-like anomalous dimension. We show
that such contributions are absent when the Mandelstam-Leibbrandt prescription
is used. In the first case, the soft factor cancels the anomalous-dimension
defect, while in the second case its ultraviolet-divergent part reduces to
unity.
| [
{
"created": "Fri, 16 Oct 2009 13:15:57 GMT",
"version": "v1"
}
] | 2010-02-05 | [
[
"Stefanis",
"N. G.",
""
],
[
"Cherednikov",
"I. O.",
""
]
] | The ultraviolet and rapidity divergences of transverse-momentum dependent parton distribution functions with lightlike and transverse gauge links is studied, also incorporating a soft eikonal factor. We find that in the light-cone gauge with $q^-$-independent pole prescriptions extra divergences appear which amount, at one-loop, to a cusp-like anomalous dimension. We show that such contributions are absent when the Mandelstam-Leibbrandt prescription is used. In the first case, the soft factor cancels the anomalous-dimension defect, while in the second case its ultraviolet-divergent part reduces to unity. |
0804.3777 | Pena Francisco | Norman Cruz, Samuel Lepe and Francisco Pena | Dark energy interacting with two fluids | null | Phys.Lett.B663:338-341,2008 | 10.1016/j.physletb.2008.04.035 | null | hep-ph astro-ph gr-qc | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | A cosmological model of dark energy interacting with dark matter and another
general component of the universe is investigated. We found general constraints
on these models imposing an accelerated expansion. The same is also studied in
the case for holographic dark energy.
| [
{
"created": "Wed, 23 Apr 2008 18:46:12 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Cruz",
"Norman",
""
],
[
"Lepe",
"Samuel",
""
],
[
"Pena",
"Francisco",
""
]
] | A cosmological model of dark energy interacting with dark matter and another general component of the universe is investigated. We found general constraints on these models imposing an accelerated expansion. The same is also studied in the case for holographic dark energy. |
hep-ph/9803214 | Jos\i Antonio Oller | J.A. Oller | The phi --> gamma K0 bar(K0) Decay | 6 pages, 2 figures, LaTeX | Phys.Lett.B426:7-11,1998 | 10.1016/S0370-2693(98)00298-6 | null | hep-ph | null | The study of the process phi-->gamma K0 bar(K0) is calculated to be 5.10^(-8)
in a scheme which takes into account the different isospin channels involved,
I=0,1 with the resonant, f_0(980), a_0(980), and non resonant contributions.
| [
{
"created": "Mon, 2 Mar 1998 12:34:43 GMT",
"version": "v1"
}
] | 2008-11-26 | [
[
"Oller",
"J. A.",
""
]
] | The study of the process phi-->gamma K0 bar(K0) is calculated to be 5.10^(-8) in a scheme which takes into account the different isospin channels involved, I=0,1 with the resonant, f_0(980), a_0(980), and non resonant contributions. |
hep-ph/9402279 | Mariusz Sadzikowski | H. Hogaasen and M. Sadzikowski | Isgur - Wise Functions for Confined Light Quarks in a Colour Electric
Potential | 9 pages, 1 figure (available upon request), Latex, TPJU - 4/94 | Z.Phys. C64 (1994) 427-430 | 10.1007/BF01560103 | null | hep-ph | null | We explore the influence on the Isgur-Wise function of the colour electric
potential between heavy and light quarks in mesons. It is shown that in bag
models, its inclusion tends to restore light quark flavour symmetry relative to
the MIT bag predictions, and that relative to this model it flattens the
Isgur-Wise function. Results compare very well with observations.
| [
{
"created": "Mon, 14 Feb 1994 17:02:42 GMT",
"version": "v1"
}
] | 2009-10-28 | [
[
"Hogaasen",
"H.",
""
],
[
"Sadzikowski",
"M.",
""
]
] | We explore the influence on the Isgur-Wise function of the colour electric potential between heavy and light quarks in mesons. It is shown that in bag models, its inclusion tends to restore light quark flavour symmetry relative to the MIT bag predictions, and that relative to this model it flattens the Isgur-Wise function. Results compare very well with observations. |
hep-ph/9606233 | John Terning | R.S. Chivukula and J. Terning | Precision Electroweak Constraints on Top-Color Assisted Technicolor | 14 pages, LaTeX, 3 embedded figures, figures are also available at
http://smyrd.bu.edu/htfigs/htfigs.html | Phys.Lett.B385:209-217,1996 | 10.1016/0370-2693(96)00833-7 | BUHEP-96-12 | hep-ph | null | Using precision electroweak data, we put limits on ``natural'' top-color
assisted technicolor models. Generically the new $U(1)$ gauge bosons in these
models must have masses larger than roughly 2 TeV, although in certain
(seemingly unrealistic) models the bound can be much lower.
| [
{
"created": "Tue, 4 Jun 1996 22:12:36 GMT",
"version": "v1"
}
] | 2011-01-13 | [
[
"Chivukula",
"R. S.",
""
],
[
"Terning",
"J.",
""
]
] | Using precision electroweak data, we put limits on ``natural'' top-color assisted technicolor models. Generically the new $U(1)$ gauge bosons in these models must have masses larger than roughly 2 TeV, although in certain (seemingly unrealistic) models the bound can be much lower. |
hep-ph/9712418 | Roberto Pittau | Roberto Pittau (CERN) | A simple method for multi-leg loop calculations 2: a general algorithm | 7 pages, latex, no figures | Comput.Phys.Commun. 111 (1998) 48-52 | 10.1016/S0010-4655(98)00040-X | CERN-TH/97-372 | hep-ph | null | The method introduced in a previous paper to simplify the tensorial reduction
in multi-leg loop calculations is extended to generic one-loop integrals, with
arbitrary internal masses and external momenta.
| [
{
"created": "Wed, 17 Dec 1997 13:50:44 GMT",
"version": "v1"
}
] | 2009-10-30 | [
[
"Pittau",
"Roberto",
"",
"CERN"
]
] | The method introduced in a previous paper to simplify the tensorial reduction in multi-leg loop calculations is extended to generic one-loop integrals, with arbitrary internal masses and external momenta. |
0912.0190 | Antoni Szczurek | Piotr Lebiedowicz and Antoni Szczurek | Exclusive $pp \to pp \pi^{+}\pi^{-}$ reaction: from the threshold to LHC | 19 pages, 18 figures | Phys.Rev.D81:036003,2010 | 10.1103/PhysRevD.81.036003 | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We evaluate differential distributions for the four-body $p p \to p p \pi^+
\pi^-$ reaction which constitutes a irreducible background to three-body
processes $p p \to p p M$, where $M$ are a broad resonances in the $\pi^+
\pi^-$ channel, e.g. $M=\sigma, \rho^{0}, f_{0}(980), f_{2}(1275),
f_{0}(1500)$. We include both double-diffractive contribution (both pomeron and
reggeon exchanges) as well as the pion-pion rescattering contribution. The
first process dominates at higher energies and small pion-pion invariant masses
while the second becomes important at lower energies and higher pion-pion
invariant masses. The amplitude(s) is(are) calculated in the Regge approach. We
compare our results with measured cross sections for the ISR experiments at
CERN. We make predictions for future experiments at PANDA, RHIC, Tevatron and
LHC energies. Differential distributions in effective two-pion mass, pion
rapidities and transverse momenta of pions are presented. The two-dimensional
distribution in $(y_{\pi^+}, y_{\pi^-})$ is particularly interesting. The
higher the incident energy, the higher preference for the same-hemisphere
emission of pions. The processes considered constitute a sizeable contribution
to the total nucleon-nucleon cross section as well as to pion inclusive cross
section.
| [
{
"created": "Tue, 1 Dec 2009 15:56:48 GMT",
"version": "v1"
}
] | 2010-05-07 | [
[
"Lebiedowicz",
"Piotr",
""
],
[
"Szczurek",
"Antoni",
""
]
] | We evaluate differential distributions for the four-body $p p \to p p \pi^+ \pi^-$ reaction which constitutes a irreducible background to three-body processes $p p \to p p M$, where $M$ are a broad resonances in the $\pi^+ \pi^-$ channel, e.g. $M=\sigma, \rho^{0}, f_{0}(980), f_{2}(1275), f_{0}(1500)$. We include both double-diffractive contribution (both pomeron and reggeon exchanges) as well as the pion-pion rescattering contribution. The first process dominates at higher energies and small pion-pion invariant masses while the second becomes important at lower energies and higher pion-pion invariant masses. The amplitude(s) is(are) calculated in the Regge approach. We compare our results with measured cross sections for the ISR experiments at CERN. We make predictions for future experiments at PANDA, RHIC, Tevatron and LHC energies. Differential distributions in effective two-pion mass, pion rapidities and transverse momenta of pions are presented. The two-dimensional distribution in $(y_{\pi^+}, y_{\pi^-})$ is particularly interesting. The higher the incident energy, the higher preference for the same-hemisphere emission of pions. The processes considered constitute a sizeable contribution to the total nucleon-nucleon cross section as well as to pion inclusive cross section. |
2103.12003 | Andreas Crivellin | Andreas Crivellin, Claudio Andrea Manzari, Marc Montull | Correlating Non-Resonant Di-Electron Searches at the LHC to the
Cabibbo-Angle Anomaly and Lepton Flavour Universality Violation | 6 pages, 2 figures | null | 10.1103/PhysRevD.104.115016 | CERN-TH-2021-036, PSI-PR-21-03, ZU-TH 11/21 | hep-ph hep-ex hep-th nucl-ex nucl-th | http://creativecommons.org/licenses/by/4.0/ | In addition to the existing strong indications for lepton flavour university
violation (LFUV) in low energy precision experiments, CMS recently released an
analysis of non-resonant di-lepton pairs which could constitute the first sign
of LFUV in high-energy LHC searches. In this article we show that the Cabibbo
angle anomaly, an (apparent) violation of first row and column CKM unitarity
with $\approx3\,\sigma$ significance, and the CMS result can be correlated and
commonly explained in a model independent way by the operator $[Q_{\ell
q}^{(3)}]_{1111} =
(\bar{\ell}_1\gamma^{\mu}\sigma^I\ell_1)(\bar{q}_1\gamma_{\mu}\sigma^Iq_1)$.
This is possible without violating the bounds from the non-resonant di-lepton
search of ATLAS (which interestingly also observed slightly more events than
expected in the electron channel) nor from $R(\pi)=\pi \to\mu\nu/\pi \to e
\nu$. We find a combined preference for the new physics hypothesis of
$4.5\,\sigma$ and predict $1.0004<R(\pi)<1.0009$ (95\%~CL) which can be tested
in the near future with the forthcoming results of the PEN experiment.
| [
{
"created": "Mon, 22 Mar 2021 16:54:02 GMT",
"version": "v1"
}
] | 2022-01-05 | [
[
"Crivellin",
"Andreas",
""
],
[
"Manzari",
"Claudio Andrea",
""
],
[
"Montull",
"Marc",
""
]
] | In addition to the existing strong indications for lepton flavour university violation (LFUV) in low energy precision experiments, CMS recently released an analysis of non-resonant di-lepton pairs which could constitute the first sign of LFUV in high-energy LHC searches. In this article we show that the Cabibbo angle anomaly, an (apparent) violation of first row and column CKM unitarity with $\approx3\,\sigma$ significance, and the CMS result can be correlated and commonly explained in a model independent way by the operator $[Q_{\ell q}^{(3)}]_{1111} = (\bar{\ell}_1\gamma^{\mu}\sigma^I\ell_1)(\bar{q}_1\gamma_{\mu}\sigma^Iq_1)$. This is possible without violating the bounds from the non-resonant di-lepton search of ATLAS (which interestingly also observed slightly more events than expected in the electron channel) nor from $R(\pi)=\pi \to\mu\nu/\pi \to e \nu$. We find a combined preference for the new physics hypothesis of $4.5\,\sigma$ and predict $1.0004<R(\pi)<1.0009$ (95\%~CL) which can be tested in the near future with the forthcoming results of the PEN experiment. |
2306.14885 | Thomas Cridge | Thomas Cridge and Matthew A. Lim | Constraining the top-quark mass within the global MSHT PDF fit | 35 pages, 13 figures, 3 tables | Eur.Phys.J.C 83 (2023) 9, 805 | 10.1140/epjc/s10052-023-11961-6 | DESY-23-087 | hep-ph hep-ex | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We examine the ability of experimental measurements of top-quark pair
production to constrain both the top-quark mass and the strong coupling within
the global MSHT parton distribution function (PDF) fit. Specifically, we
consider ATLAS and CMS measurements of differential distributions taken at a
centre-of-mass energy of 8 TeV, as well as $t\bar{t}$ total cross section data
taken at a variety of experiments, and compare to theoretical predictions
including next-to-next-to-leading order corrections. We find that supplementing
the global fit with this additional information results in relatively strong
constraints on the top-quark mass, and is also able to bound the strong
coupling in a limited fashion. Our final result is
$m_t=173.0\pm0.6~\mathrm{GeV}$ and is compatible with the world average pole
mass extracted from cross section measurements of $172.5\pm0.7~\mathrm{GeV}$ by
the Particle Data Group. We also study the effect of different top-quark masses
on the gluon parton distribution function, finding changes at high $x$ which
nonetheless lie within the large PDF uncertainties in this region.
| [
{
"created": "Mon, 26 Jun 2023 17:53:11 GMT",
"version": "v1"
},
{
"created": "Wed, 13 Sep 2023 10:07:22 GMT",
"version": "v2"
}
] | 2023-09-14 | [
[
"Cridge",
"Thomas",
""
],
[
"Lim",
"Matthew A.",
""
]
] | We examine the ability of experimental measurements of top-quark pair production to constrain both the top-quark mass and the strong coupling within the global MSHT parton distribution function (PDF) fit. Specifically, we consider ATLAS and CMS measurements of differential distributions taken at a centre-of-mass energy of 8 TeV, as well as $t\bar{t}$ total cross section data taken at a variety of experiments, and compare to theoretical predictions including next-to-next-to-leading order corrections. We find that supplementing the global fit with this additional information results in relatively strong constraints on the top-quark mass, and is also able to bound the strong coupling in a limited fashion. Our final result is $m_t=173.0\pm0.6~\mathrm{GeV}$ and is compatible with the world average pole mass extracted from cross section measurements of $172.5\pm0.7~\mathrm{GeV}$ by the Particle Data Group. We also study the effect of different top-quark masses on the gluon parton distribution function, finding changes at high $x$ which nonetheless lie within the large PDF uncertainties in this region. |
hep-ph/0403237 | Alejandro Gutierrez | A. Guti\'errez-Rodr\'iguez, M. A. Hern\'andez-Ru\'iz and L.N.
Luis-Noriega (Zacatecas University, Mexico) | Limits on the Dipole Moments of the $\tau$-Lepton via the Process
$e^{+}e^{-}\to \tau^+ \tau^- \gamma in a Left-Right Symmetric Model | 15 pages, 3 figures | Mod.Phys.Lett. A19 (2004) 2227 | 10.1142/S0217732304014689 | null | hep-ph | null | Limits on the anomalous magnetic moment and the electric dipole moment of the
$\tau$ lepton are calculated through the reaction $e^{+}e^{-}\to \tau^+ \tau^-
\gamma$ at the $Z_1$-pole and in the framework of a left-right symmetric model.
The results are based on the recent data reported by the L3 Collaboration at
CERN LEP. Due to the stringent limit of the model mixing angle $\phi$, the
effect of this angle on the dipole moments is quite small.
| [
{
"created": "Mon, 22 Mar 2004 14:47:00 GMT",
"version": "v1"
},
{
"created": "Wed, 24 Mar 2004 18:03:18 GMT",
"version": "v2"
}
] | 2009-11-10 | [
[
"Gutiérrez-Rodríguez",
"A.",
"",
"Zacatecas University, Mexico"
],
[
"Hernández-Ruíz",
"M. A.",
"",
"Zacatecas University, Mexico"
],
[
"Luis-Noriega",
"L. N.",
"",
"Zacatecas University, Mexico"
]
] | Limits on the anomalous magnetic moment and the electric dipole moment of the $\tau$ lepton are calculated through the reaction $e^{+}e^{-}\to \tau^+ \tau^- \gamma$ at the $Z_1$-pole and in the framework of a left-right symmetric model. The results are based on the recent data reported by the L3 Collaboration at CERN LEP. Due to the stringent limit of the model mixing angle $\phi$, the effect of this angle on the dipole moments is quite small. |
hep-ph/0111149 | Michael A. Doncheski | M. A. Doncheski | ADD extra dimensional gravity and di-jet production at hadron colliders | 3 pages, 2 figures, RevTeX 4.0, contributed to APS/DPF/DPB Summer
Study on the Future of Particle Physics (Snowmass 2001), Snowmass, Colorado,
June 30 to July 21, 2001 | eConf C010630 (2001) P314 | null | null | hep-ph | null | We re-analyze dijet production at hadron colliders (the Tevatron at Fermilab
and the Large Hadron Collider, LHC, at CERN), to determine the potential limits
on Planck mass in ADD type extra dimensional gravity scenarios. We try a
variety of experimental observables in order to maximize the exclusion limits;
we find that the $p_{_T}$, $p_{_T}^2$ and $\tau$ distributions give the highest
search limits, and these observables provide comparable reaches.
| [
{
"created": "Mon, 12 Nov 2001 19:45:18 GMT",
"version": "v1"
}
] | 2007-05-23 | [
[
"Doncheski",
"M. A.",
""
]
] | We re-analyze dijet production at hadron colliders (the Tevatron at Fermilab and the Large Hadron Collider, LHC, at CERN), to determine the potential limits on Planck mass in ADD type extra dimensional gravity scenarios. We try a variety of experimental observables in order to maximize the exclusion limits; we find that the $p_{_T}$, $p_{_T}^2$ and $\tau$ distributions give the highest search limits, and these observables provide comparable reaches. |
1709.07440 | Wayne W. Repko | Wayne W. Repko and Duane A. Dicus | Muonic hydrogen and the proton size | 18 pages, 2 Tables, content added | Phys. Rev. D 98, 013002 (2018) | 10.1103/PhysRevD.98.013002 | null | hep-ph nucl-th | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We reexamine the structure of the $n=2$ levels of muonic hydrogen using a
two-body potential that includes all relativistic, recoil and one loop
corrections. The potential was originally derived from QED to describe the
muonium atom and accounts for all contributions to order $\alpha^5$. Since one
loop corrections are included, the anomalous magnetic moment contributions of
the muon can be identified and replaced by the proton anomalous magnetic moment
to describe muonic hydrogen with a point-like proton. This serves as a
convenient starting point to include the dominant electron vacuum polarization
corrections to the spectrum and extract the proton's mean squared radius
$r_p=\sqrt{\langle r^2\rangle}$. Our results are consistent with other
theoretical calculations that find that the muonic hydrogen value for $r_p$ is
smaller than the result obtained from electron scattering.
| [
{
"created": "Thu, 21 Sep 2017 17:59:03 GMT",
"version": "v1"
},
{
"created": "Thu, 2 Nov 2017 15:11:38 GMT",
"version": "v2"
},
{
"created": "Thu, 21 Jun 2018 18:55:00 GMT",
"version": "v3"
}
] | 2018-07-11 | [
[
"Repko",
"Wayne W.",
""
],
[
"Dicus",
"Duane A.",
""
]
] | We reexamine the structure of the $n=2$ levels of muonic hydrogen using a two-body potential that includes all relativistic, recoil and one loop corrections. The potential was originally derived from QED to describe the muonium atom and accounts for all contributions to order $\alpha^5$. Since one loop corrections are included, the anomalous magnetic moment contributions of the muon can be identified and replaced by the proton anomalous magnetic moment to describe muonic hydrogen with a point-like proton. This serves as a convenient starting point to include the dominant electron vacuum polarization corrections to the spectrum and extract the proton's mean squared radius $r_p=\sqrt{\langle r^2\rangle}$. Our results are consistent with other theoretical calculations that find that the muonic hydrogen value for $r_p$ is smaller than the result obtained from electron scattering. |
hep-ph/9512294 | Herbert Weigel | L. Gamberg, H. Weigel, U. Z\"uckert and H. Reinhardt | Heavy Quark Solitons in the Nambu--Jona-Lasinio Model | 16 pages REVTEX, one postscript figure, to appear in Phys. Rev. D | Phys.Rev. D54 (1996) 5812-5819 | 10.1103/PhysRevD.54.5812 | UNITU-THEP-18/1995 | hep-ph | null | The Nambu--Jona-Lasinio model (NJL) is extended to incorporate heavy quark
spin-symmetry. In this model baryons containing one heavy quark are analyzed as
bound-states of light baryons, represented as chiral solitons, and mesons
containing one heavy quark. From related studies in Skyrme type models, the
ground-state heavy baryon is known to arise for the heavy meson in a P--wave
configuration. In the limit of an infinitely large quark mass the heavy meson
wave-function is sharply peaked at the center of the chiral soliton. Therefore
the bound state equation reduces to an eigenvalue problem for the coefficients
of the operators contained in the most general P-wave {\it ansatz} for the
heavy meson. Within the NJL model a novel feature arises from the coupling of
the heavy meson to the various light quark states. In this respect conceptual
differences to Skyrme model calculations are discovered: The strongest bound
state is given by a heavy meson configuration which is completely decoupled
from the grand spin zero channel of the light quarks.
| [
{
"created": "Wed, 13 Dec 1995 09:56:25 GMT",
"version": "v1"
},
{
"created": "Fri, 16 Aug 1996 16:08:58 GMT",
"version": "v2"
}
] | 2016-08-15 | [
[
"Gamberg",
"L.",
""
],
[
"Weigel",
"H.",
""
],
[
"Zückert",
"U.",
""
],
[
"Reinhardt",
"H.",
""
]
] | The Nambu--Jona-Lasinio model (NJL) is extended to incorporate heavy quark spin-symmetry. In this model baryons containing one heavy quark are analyzed as bound-states of light baryons, represented as chiral solitons, and mesons containing one heavy quark. From related studies in Skyrme type models, the ground-state heavy baryon is known to arise for the heavy meson in a P--wave configuration. In the limit of an infinitely large quark mass the heavy meson wave-function is sharply peaked at the center of the chiral soliton. Therefore the bound state equation reduces to an eigenvalue problem for the coefficients of the operators contained in the most general P-wave {\it ansatz} for the heavy meson. Within the NJL model a novel feature arises from the coupling of the heavy meson to the various light quark states. In this respect conceptual differences to Skyrme model calculations are discovered: The strongest bound state is given by a heavy meson configuration which is completely decoupled from the grand spin zero channel of the light quarks. |
hep-ph/0405166 | Alexandre Kisselev | A.V. Kisselev and V.A. Petrov (IHEP, Protvino) | Eikonal Amplitude in the Gravireggeon Model at Superplanckian Energies | 21 pages, LaTeX2e, no figures | Eur.Phys.J. C37 (2004) 241-249 | 10.1140/epjc/s2004-01985-y | null | hep-ph | null | The gravity effects in high-energy scattering, described by a
four-dimensional eikonal amplitude related to gravireggeons induced by compact
extra dimensions are studied. It is demonstrated that the real part of the
eikonal (with a massless mode subtracted) dominates its imaginary part at both
small and large impact parameters, in contrast to the usual case of hadronic
high-energy behavior. The real part of the scattering amplitude exhibits an
exponential falloff at large momentum transfer, similar to that of the
imaginary part of the amplitude.
| [
{
"created": "Tue, 18 May 2004 12:05:18 GMT",
"version": "v1"
}
] | 2009-11-10 | [
[
"Kisselev",
"A. V.",
"",
"IHEP, Protvino"
],
[
"Petrov",
"V. A.",
"",
"IHEP, Protvino"
]
] | The gravity effects in high-energy scattering, described by a four-dimensional eikonal amplitude related to gravireggeons induced by compact extra dimensions are studied. It is demonstrated that the real part of the eikonal (with a massless mode subtracted) dominates its imaginary part at both small and large impact parameters, in contrast to the usual case of hadronic high-energy behavior. The real part of the scattering amplitude exhibits an exponential falloff at large momentum transfer, similar to that of the imaginary part of the amplitude. |
hep-ph/9307336 | Chengqian Gong | C. Greiner, C. Gong and B. M\"uller | Some remarks on pion condensation in relativistic heavy ion collisions | 9pp, DUKE-TH-93-53 | Phys.Lett.B316:226-230,1993 | 10.1016/0370-2693(93)90317-B | null | hep-ph | null | Recently it was pointed out that coherent or condensated states of pions may
account for the explanation of the Centauro events observed in cosmic ray
showers. We argue that an occurrence of condensed pions requires that the
system evolves far out of thermal equilibrium. Besides an unusual charge ratio
distribution we show that such a produced state also would lead to strong
isospin correlations.
| [
{
"created": "Mon, 26 Jul 1993 17:21:30 GMT",
"version": "v1"
},
{
"created": "Wed, 28 Jul 1993 16:49:31 GMT",
"version": "v2"
}
] | 2008-11-26 | [
[
"Greiner",
"C.",
""
],
[
"Gong",
"C.",
""
],
[
"Müller",
"B.",
""
]
] | Recently it was pointed out that coherent or condensated states of pions may account for the explanation of the Centauro events observed in cosmic ray showers. We argue that an occurrence of condensed pions requires that the system evolves far out of thermal equilibrium. Besides an unusual charge ratio distribution we show that such a produced state also would lead to strong isospin correlations. |
1309.5785 | George Leontaris | G.K. Leontaris, N.D. Vlachos | A discrete anatomy of the neutrino mass matrix | 12 pages, 2 figures, minor misprints corrected, references added | null | 10.1142/S021773231450179X | null | hep-ph | http://arxiv.org/licenses/nonexclusive-distrib/1.0/ | We investigate the possibility of expressing the charged leptons and neutrino
mass matrices as linear combinations of generators of a single finite group.
Constraints imposed on the resulting mixing matrix by current data restrict the
group types, but allow a non zero value for the theta_13 mixing angle
| [
{
"created": "Mon, 23 Sep 2013 12:37:50 GMT",
"version": "v1"
},
{
"created": "Thu, 15 May 2014 14:56:03 GMT",
"version": "v2"
}
] | 2015-06-17 | [
[
"Leontaris",
"G. K.",
""
],
[
"Vlachos",
"N. D.",
""
]
] | We investigate the possibility of expressing the charged leptons and neutrino mass matrices as linear combinations of generators of a single finite group. Constraints imposed on the resulting mixing matrix by current data restrict the group types, but allow a non zero value for the theta_13 mixing angle |
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