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1412.0432
Asier Lopez
A. Lopez-Eiguren
Calibrating Analytical Models for Semilocal Strings
6 pages and 4 figures. Prepared for the Spanish Relativity Meetings ERE2014
null
10.1088/1742-6596/600/1/012018
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we calibrate two different analytic models of semilocal strings by constraining the values of their free parameters. In order to do so, we use data obtained from the largest and most accurate field theory simulations of semilocal strings to date, and compare several key properties with the predictions of the models. As this is still work in progress, we present some preliminary results together with descriptions of the methodology we are using in the characterisation of semilocal string networks.
[ { "created": "Mon, 1 Dec 2014 11:23:23 GMT", "version": "v1" } ]
2015-05-20
[ [ "Lopez-Eiguren", "A.", "" ] ]
In this work we calibrate two different analytic models of semilocal strings by constraining the values of their free parameters. In order to do so, we use data obtained from the largest and most accurate field theory simulations of semilocal strings to date, and compare several key properties with the predictions of the models. As this is still work in progress, we present some preliminary results together with descriptions of the methodology we are using in the characterisation of semilocal string networks.
1902.05962
Xiao Xue
Huai-Ke Guo, Yingqi Ma, Jing Shu, Xiao Xue, Qiang Yuan, Yue Zhao
Detecting dark photon dark matter with Gaia-like astrometry observations
8 pages, 3 figures
null
10.1088/1475-7516/2019/05/015
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A class of dark photon dark matter models with ultralight masses would lead to oscillation of a test body through a coupling with baryons or $B-L$ charge. This periodical oscillation of an observer results in swing of a star's apparent position due to the effect of aberration of light, which could be probed with high-precision astrometry observations of stars in the Milky Way. We propose to use the observations of stellar positions of a number of stars by Gaia to search for this kind of dark photon dark matter. We show that this astrometry method is able to give promising sensitivities to search for the dark photon dark matter in the mass range of $10^{-23}\sim10^{-21}$ eV.
[ { "created": "Fri, 15 Feb 2019 19:00:09 GMT", "version": "v1" }, { "created": "Mon, 8 Apr 2019 14:15:01 GMT", "version": "v2" }, { "created": "Sat, 4 May 2019 11:21:09 GMT", "version": "v3" } ]
2019-05-14
[ [ "Guo", "Huai-Ke", "" ], [ "Ma", "Yingqi", "" ], [ "Shu", "Jing", "" ], [ "Xue", "Xiao", "" ], [ "Yuan", "Qiang", "" ], [ "Zhao", "Yue", "" ] ]
A class of dark photon dark matter models with ultralight masses would lead to oscillation of a test body through a coupling with baryons or $B-L$ charge. This periodical oscillation of an observer results in swing of a star's apparent position due to the effect of aberration of light, which could be probed with high-precision astrometry observations of stars in the Milky Way. We propose to use the observations of stellar positions of a number of stars by Gaia to search for this kind of dark photon dark matter. We show that this astrometry method is able to give promising sensitivities to search for the dark photon dark matter in the mass range of $10^{-23}\sim10^{-21}$ eV.
hep-ph/0310083
Bryan Webber
Stefan Gieseke, Philip Stephens and Bryan Webber
New formalism for QCD parton showers
31 pages, 12 figures. Replacement has typos corrected, citations added
JHEP 0312:045,2003
10.1088/1126-6708/2003/12/045
Cavendish-HEP-03/18, CERN-TH/2003-239
hep-ph
null
We present a new formalism for parton shower simulation of QCD jets, which incorporates the following features: invariance under boosts along jet axes, improved treatment of heavy quark fragmentation, angular-ordered evolution with soft gluon coherence, more accurate soft gluon angular distributions, and better coverage of phase space. It is implemented in the new HERWIG++ event generator.
[ { "created": "Tue, 7 Oct 2003 12:54:24 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 2003 17:12:45 GMT", "version": "v2" } ]
2014-11-17
[ [ "Gieseke", "Stefan", "" ], [ "Stephens", "Philip", "" ], [ "Webber", "Bryan", "" ] ]
We present a new formalism for parton shower simulation of QCD jets, which incorporates the following features: invariance under boosts along jet axes, improved treatment of heavy quark fragmentation, angular-ordered evolution with soft gluon coherence, more accurate soft gluon angular distributions, and better coverage of phase space. It is implemented in the new HERWIG++ event generator.
hep-ph/0304013
Tsou Sheung Tsun
ST Tsou (Oxford) and JS Palmer (Oxford)
Mass and mixing of fermions from a rotating mass matrix
13 pages latex, with 7 figures. to appear in Mod. Phys. Lett. A
Mod.Phys.Lett. A18 (2003) 807-816
10.1142/S0217732303009927
null
hep-ph
null
We summarize the results showing that all existing data on mixing between up and down fermion states (i.e. CKM matrix and neutrino oscillations) and on the hierarchical quark and lepton mass ratios between generations are consistent with the two phenomena being both consequences of a mass matrix rotating in generation space with changing energy scale. Thus the rotation of the mass matrix can be traced over some 14 orders of magnitude in energy from the mass scale of the $t$-quark at 175 GeV to below that of the atmospheric neutrino at 0.05 eV.
[ { "created": "Tue, 1 Apr 2003 16:31:45 GMT", "version": "v1" } ]
2009-11-10
[ [ "Tsou", "ST", "", "Oxford" ], [ "Palmer", "JS", "", "Oxford" ] ]
We summarize the results showing that all existing data on mixing between up and down fermion states (i.e. CKM matrix and neutrino oscillations) and on the hierarchical quark and lepton mass ratios between generations are consistent with the two phenomena being both consequences of a mass matrix rotating in generation space with changing energy scale. Thus the rotation of the mass matrix can be traced over some 14 orders of magnitude in energy from the mass scale of the $t$-quark at 175 GeV to below that of the atmospheric neutrino at 0.05 eV.
0907.3151
Leonard Gamberg
Leonard Gamberg and Marc Schlegel
Final State Interactions, T-odd PDFs & the Lensing Function
5 pages, 5 figures, misprints corrected: To appear in the Proceedings of the 10th Conference on the Intersection of Particle and Nuclear Physics (CIPANP 2009) San Diego, CA, 25-31 May 2009
AIP Conf.Proc.1182:614-618,2009
10.1063/1.3293884
JLAB-THY-09-1035
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been suggested that under certain approximations the Sivers effect can be described in terms of factorization of final state interactions and a spatial distortion of impact parameter space parton distribution; that is a convolution of the so-called lensing function and the impact parameter GPD $E$. In this approach the lensing function is calculated in a non-perturbative eikonal model. This enables a comparison between the a priori distinct Sivers function and the GPD $E$ which goes beyond the discussion of overall signs.
[ { "created": "Fri, 17 Jul 2009 20:08:04 GMT", "version": "v1" }, { "created": "Mon, 10 Aug 2009 20:04:04 GMT", "version": "v2" } ]
2010-01-15
[ [ "Gamberg", "Leonard", "" ], [ "Schlegel", "Marc", "" ] ]
It has been suggested that under certain approximations the Sivers effect can be described in terms of factorization of final state interactions and a spatial distortion of impact parameter space parton distribution; that is a convolution of the so-called lensing function and the impact parameter GPD $E$. In this approach the lensing function is calculated in a non-perturbative eikonal model. This enables a comparison between the a priori distinct Sivers function and the GPD $E$ which goes beyond the discussion of overall signs.
1807.07742
Alexander A. Osipov
A.A. Osipov and M.M. Khalifa
Electromagnetic interactions of mesons induced by the axial-vector -- pseudoscalar mixings
9 pages, 4 figures
Phys. Rev. D 98, 036023 (2018)
10.1103/PhysRevD.98.036023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that the diagonalization of the axial-vector -- pseudoscalar transitions in the effective meson Lagrangian in presence of electromagnetic interactions leads to a deviation from the vector meson dominance picture which usually arises in the Nambu - Jona-Lasinio model. The essential features of such modification of the theory are studied. Some important examples are considered in detail.
[ { "created": "Fri, 20 Jul 2018 08:41:54 GMT", "version": "v1" } ]
2018-09-12
[ [ "Osipov", "A. A.", "" ], [ "Khalifa", "M. M.", "" ] ]
It is shown that the diagonalization of the axial-vector -- pseudoscalar transitions in the effective meson Lagrangian in presence of electromagnetic interactions leads to a deviation from the vector meson dominance picture which usually arises in the Nambu - Jona-Lasinio model. The essential features of such modification of the theory are studied. Some important examples are considered in detail.
2005.06053
Alexei P. Martynenko
A.E. Dorokhov, R.N. Faustov, A.P. Martynenko, F.A. Martynenko
Photonic production of the pair of $B_c$ mesons
18 pages, 4 figures
Phys. Rev. D 102, 016027 (2020)
10.1103/PhysRevD.102.016027
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the pair production of $B_c$ mesons in the photon-photon interaction in the framework of perturbative quantum chromodynamics and the relativistic quark model. The production amplitudes of a pair of pseudoscalar and vector $B_c$ mesons are constructed in the nonrelativistic approximation and taking into account relativistic effects. Relativistic corrections related to the relative motion of heavy quarks in the production amplitude, as well as in the wave function of the bound state of heavy quarks, are taken into account. Analytical expressions are constructed for the relativistic differential and total cross sections for the pair $B_c$ meson production. Based on them, numerical values of the production cross sections are obtained for various energies and scattering angles.
[ { "created": "Tue, 12 May 2020 21:07:18 GMT", "version": "v1" }, { "created": "Wed, 20 May 2020 10:14:07 GMT", "version": "v2" } ]
2020-08-05
[ [ "Dorokhov", "A. E.", "" ], [ "Faustov", "R. N.", "" ], [ "Martynenko", "A. P.", "" ], [ "Martynenko", "F. A.", "" ] ]
We study the pair production of $B_c$ mesons in the photon-photon interaction in the framework of perturbative quantum chromodynamics and the relativistic quark model. The production amplitudes of a pair of pseudoscalar and vector $B_c$ mesons are constructed in the nonrelativistic approximation and taking into account relativistic effects. Relativistic corrections related to the relative motion of heavy quarks in the production amplitude, as well as in the wave function of the bound state of heavy quarks, are taken into account. Analytical expressions are constructed for the relativistic differential and total cross sections for the pair $B_c$ meson production. Based on them, numerical values of the production cross sections are obtained for various energies and scattering angles.
hep-ph/0505114
Schoeffel Laurent
L. Schoeffel
Phenomenology of next-leading BFKL
4 pages, 2 figures ; contribution to the XXXXth Rencontres de Moriond QCD and High Energy Hadronic Interactions, La Thuile, March 2005
null
null
null
hep-ph
null
We propose a phenomenological study of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach applied to the data on the proton structure function $F_2$ measured at HERA in the small-$x_{Bj}$ region ($x_{Bj}<0.01$) and $Q^2$ in the range 5 to 120 GeV$^2$. With a simplified ``effective kernel'' approximation, we present a comparison between leading-logs (LO) and next-to-leading logs (NLO) BFKL approaches in the saddle-point approximation, using known resummed NLO-BFKL kernels. The LO result gives a very good description of the data with a three parameters fit of $F_2$ but an unphysical value of the strong coupling constant, whereas the NLO two parameters fit leads to a qualitatively satisfactory account of the running coupling constant effect but quantitatively, for $Q^2 < 10$ GeV$^2$, it fails to reproduce properly the data.
[ { "created": "Fri, 13 May 2005 07:38:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Schoeffel", "L.", "" ] ]
We propose a phenomenological study of the Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach applied to the data on the proton structure function $F_2$ measured at HERA in the small-$x_{Bj}$ region ($x_{Bj}<0.01$) and $Q^2$ in the range 5 to 120 GeV$^2$. With a simplified ``effective kernel'' approximation, we present a comparison between leading-logs (LO) and next-to-leading logs (NLO) BFKL approaches in the saddle-point approximation, using known resummed NLO-BFKL kernels. The LO result gives a very good description of the data with a three parameters fit of $F_2$ but an unphysical value of the strong coupling constant, whereas the NLO two parameters fit leads to a qualitatively satisfactory account of the running coupling constant effect but quantitatively, for $Q^2 < 10$ GeV$^2$, it fails to reproduce properly the data.
1703.01255
Conny Beskidt
C. Beskidt (1), W. de Boer (1), D. I. Kazakov (1,2), S. Wayand (1) ((1) Karlsruhe Institute of Technology, Germany, (2) Bogoliubov Laboratory of Theoretical Physics, JINR, Dubna, Russia)
Perspectives of direct Detection of supersymmetric Dark Matter in the NMSSM
22 pages, 3 figures, this version is accepted by PLB after minor modifications
null
10.1016/j.physletb.2017.06.016
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM) the lightest supersymmetric particle (LSP) is a candidate for the dark matter (DM) in the universe. It is a mixture from the various gauginos and Higgsinos and can be bino-, Higgsino- or singlino-dominated. Singlino-dominated LSPs can have very low cross sections below the neutrino background from coherent neutrino scattering which is limiting the sensitivity of future direct DM search experiments. However, previous studies suggested that the combination of both, the spin-dependent (SD) and spin-independent (SI) searches are sensitive in complementary regions of parameter space, so considering both searches will allow to explore practically the whole parameter space of the NMSSM. In this letter, the different scenarios are investigated with a new scanning technique, which reveals that significant regions of the NMSSM parameter space cannot be explored, even if one considers both, SI and SD, searches.
[ { "created": "Fri, 3 Mar 2017 17:28:37 GMT", "version": "v1" }, { "created": "Fri, 22 Sep 2017 07:43:27 GMT", "version": "v2" } ]
2017-09-25
[ [ "Beskidt", "C.", "" ], [ "de Boer", "W.", "" ], [ "Kazakov", "D. I.", "" ], [ "Wayand", "S.", "" ] ]
In the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM) the lightest supersymmetric particle (LSP) is a candidate for the dark matter (DM) in the universe. It is a mixture from the various gauginos and Higgsinos and can be bino-, Higgsino- or singlino-dominated. Singlino-dominated LSPs can have very low cross sections below the neutrino background from coherent neutrino scattering which is limiting the sensitivity of future direct DM search experiments. However, previous studies suggested that the combination of both, the spin-dependent (SD) and spin-independent (SI) searches are sensitive in complementary regions of parameter space, so considering both searches will allow to explore practically the whole parameter space of the NMSSM. In this letter, the different scenarios are investigated with a new scanning technique, which reveals that significant regions of the NMSSM parameter space cannot be explored, even if one considers both, SI and SD, searches.
0907.1473
Leonid Glozman
L. Ya. Glozman
Confined but chirally symmetric hadrons at large density and the Casher's argument
4 pp., PRD, in print; some minor modifications in the text
Phys.Rev.D80:037701,2009
10.1103/PhysRevD.80.037701
null
hep-ph hep-lat hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Casher's argument, which is believed to be quite general, states that in the confining regime chiral symmetry is necessarily broken. In the large-N_c limit and at moderate and low temperatures QCD is confining up to arbitrary large densities, and there should appear a quarkyonic matter. It has been demonstrated, within a manifestly confining and chirally symmetric model, which is a 3+1 dimensional generalization of the 't Hooft model, that, at zero temperature and at a density exceeding a critical one, the chiral symmetry is restored while quarks remain confined in color-singlet hadrons. This is in conflict with the Casher's argument. Here we explain the reason why the Casher's argument fails and clarify the physical mechanism lying behind such confined but chirally symmetric hadrons.
[ { "created": "Thu, 9 Jul 2009 09:38:04 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 2009 15:51:58 GMT", "version": "v2" } ]
2010-01-08
[ [ "Glozman", "L. Ya.", "" ] ]
Casher's argument, which is believed to be quite general, states that in the confining regime chiral symmetry is necessarily broken. In the large-N_c limit and at moderate and low temperatures QCD is confining up to arbitrary large densities, and there should appear a quarkyonic matter. It has been demonstrated, within a manifestly confining and chirally symmetric model, which is a 3+1 dimensional generalization of the 't Hooft model, that, at zero temperature and at a density exceeding a critical one, the chiral symmetry is restored while quarks remain confined in color-singlet hadrons. This is in conflict with the Casher's argument. Here we explain the reason why the Casher's argument fails and clarify the physical mechanism lying behind such confined but chirally symmetric hadrons.
0707.0262
Bastian Kubis
Christoph Hanhart, Bastian Kubis, Jose R. Pelaez
Investigation of a0-f0 mixing
15 pages, 9 figures; discussion extended, title changed, version published in Phys. Rev. D
Phys.Rev.D76:074028,2007
10.1103/PhysRevD.76.074028
FZJ-IKP-TH-2007-21, HISKP-TH-07/18
hep-ph hep-ex nucl-th
null
We investigate the isospin-violating mixing of the light scalar mesons a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating effects are considered to leading order in the quark mass differences and electromagnetism. In this approach both mesons are generated through meson-meson dynamics. Our results provide a description of the mixing phenomenon within a framework consistent with chiral symmetry and unitarity, where these resonances are not predominantly q q-bar states. Amongst the possible experimental signals, we discuss observable consequences for the reaction J/Psi -> phi pi0 eta in detail. In particular we demonstrate that the effect of a0-f0 mixing is by far the most important isospin-breaking effect in the resonance region and can indeed be extracted from experiment.
[ { "created": "Mon, 2 Jul 2007 16:11:11 GMT", "version": "v1" }, { "created": "Wed, 24 Oct 2007 11:15:35 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hanhart", "Christoph", "" ], [ "Kubis", "Bastian", "" ], [ "Pelaez", "Jose R.", "" ] ]
We investigate the isospin-violating mixing of the light scalar mesons a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating effects are considered to leading order in the quark mass differences and electromagnetism. In this approach both mesons are generated through meson-meson dynamics. Our results provide a description of the mixing phenomenon within a framework consistent with chiral symmetry and unitarity, where these resonances are not predominantly q q-bar states. Amongst the possible experimental signals, we discuss observable consequences for the reaction J/Psi -> phi pi0 eta in detail. In particular we demonstrate that the effect of a0-f0 mixing is by far the most important isospin-breaking effect in the resonance region and can indeed be extracted from experiment.
1904.10447
Maksym Ovchynnikov
Iryna Boiarska, Kyrylo Bondarenko, Alexey Boyarsky, Volodymyr Gorkavenko, Maksym Ovchynnikov, Anastasia Sokolenko
Phenomenology of GeV-scale scalar portal
Minor changes/typos fixing
null
10.1007/JHEP11(2019)162
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review and revise the phenomenology of the scalar portal -- a new scalar particle with the mass in GeV range that mixes with the Higgs boson. In particular, we consider production channels $B\to S K_1(1270)$ and $B\to S K_0^*(700)$ and show that their contribution is significant. We extend the previous analysis by comparing the production of scalars from decays of mesons, of the Higgs bosons and direct production via proton bremsstrahlung, deep inelastic scattering and coherent scattering on nuclei. Relative efficiency of the production channels depends on the energy of the beam and we consider the energies of DUNE, SHiP and LHC-based experiments. We present our results in the form directly suitable for calculations of experimental sensitivities.
[ { "created": "Tue, 23 Apr 2019 17:57:05 GMT", "version": "v1" }, { "created": "Wed, 24 Apr 2019 12:16:50 GMT", "version": "v2" }, { "created": "Thu, 5 Dec 2019 20:42:15 GMT", "version": "v3" }, { "created": "Fri, 20 Aug 2021 08:52:40 GMT", "version": "v4" } ]
2021-08-23
[ [ "Boiarska", "Iryna", "" ], [ "Bondarenko", "Kyrylo", "" ], [ "Boyarsky", "Alexey", "" ], [ "Gorkavenko", "Volodymyr", "" ], [ "Ovchynnikov", "Maksym", "" ], [ "Sokolenko", "Anastasia", "" ] ]
We review and revise the phenomenology of the scalar portal -- a new scalar particle with the mass in GeV range that mixes with the Higgs boson. In particular, we consider production channels $B\to S K_1(1270)$ and $B\to S K_0^*(700)$ and show that their contribution is significant. We extend the previous analysis by comparing the production of scalars from decays of mesons, of the Higgs bosons and direct production via proton bremsstrahlung, deep inelastic scattering and coherent scattering on nuclei. Relative efficiency of the production channels depends on the energy of the beam and we consider the energies of DUNE, SHiP and LHC-based experiments. We present our results in the form directly suitable for calculations of experimental sensitivities.
1210.5328
Ambar Ghosal
Biswajit Adhikary, Ambar Ghosal and Probir Roy
$\theta_{13}$, $\mu\tau$ symmetry breaking and neutrino Yukawa textures
20 pages, 8 figures, published version with considerable elaboration
Int.J.Mod.Phys.A28, 1350118, 2013
10.1142/S0217751X13501182
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the type-I seesaw and in the basis where charged lepton and heavy neutrino mass matrices are real and diagonal, $\mu\tau$ symmetric four and three zero neutrino Yukawa textures are perturbed by lowest order $\mu\tau$ symmetry breaking terms. These perturbations are taken to be the {\it most general ones for those textures}. For quite small values of those symmetry breaking parameters, permitting a lowest order analysis, current best-fit ranges of neutrino mass squared differences and mixing angles are shown to be accommodable, including a value of $\theta_{13}$ in the observed range, provided all the light neutrinos have an inverted mass ordering.
[ { "created": "Fri, 19 Oct 2012 07:09:00 GMT", "version": "v1" }, { "created": "Fri, 2 Nov 2012 04:56:56 GMT", "version": "v2" }, { "created": "Mon, 1 Apr 2013 06:48:42 GMT", "version": "v3" }, { "created": "Mon, 16 Sep 2013 09:44:01 GMT", "version": "v4" } ]
2013-09-17
[ [ "Adhikary", "Biswajit", "" ], [ "Ghosal", "Ambar", "" ], [ "Roy", "Probir", "" ] ]
Within the type-I seesaw and in the basis where charged lepton and heavy neutrino mass matrices are real and diagonal, $\mu\tau$ symmetric four and three zero neutrino Yukawa textures are perturbed by lowest order $\mu\tau$ symmetry breaking terms. These perturbations are taken to be the {\it most general ones for those textures}. For quite small values of those symmetry breaking parameters, permitting a lowest order analysis, current best-fit ranges of neutrino mass squared differences and mixing angles are shown to be accommodable, including a value of $\theta_{13}$ in the observed range, provided all the light neutrinos have an inverted mass ordering.
1610.05766
Adrian Carmona
Adrian Carmona and Florian Goertz
A flavor-safe composite explanation of $R_K$
6 pages, 4 figures. Contribution to the proceedings of the 6th Workshop on Theory, Phenomenology and Experiments in Flavour Physics (Capri 2016). Anacapri, Capri, June 2016
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings we discuss a flavor-safe explanation of the anomaly found in $R_K= {\cal B}(B \to K \mu^+ \mu^-)/{\cal B}(B \to K e^+ e^-)$ by LHCb, within the framework of composite Higgs models. We present a model featuring a non-negligible degree of compositeness for all three generations of right-handed leptons, which leads to a violation of lepton-flavor universality in neutral current interactions while other constraints from quark- and lepton-flavor physics are met. Moreoever, the particular embedding of the lepton sector considered in this setup provides a parametrically enhanded contribution to the Higgs mass that can weak considerably the need for ultra-light top partners.
[ { "created": "Tue, 18 Oct 2016 20:00:00 GMT", "version": "v1" } ]
2016-10-20
[ [ "Carmona", "Adrian", "" ], [ "Goertz", "Florian", "" ] ]
In these proceedings we discuss a flavor-safe explanation of the anomaly found in $R_K= {\cal B}(B \to K \mu^+ \mu^-)/{\cal B}(B \to K e^+ e^-)$ by LHCb, within the framework of composite Higgs models. We present a model featuring a non-negligible degree of compositeness for all three generations of right-handed leptons, which leads to a violation of lepton-flavor universality in neutral current interactions while other constraints from quark- and lepton-flavor physics are met. Moreoever, the particular embedding of the lepton sector considered in this setup provides a parametrically enhanded contribution to the Higgs mass that can weak considerably the need for ultra-light top partners.
hep-ph/0406013
Nils Gollub
K. A. Assamagan, N. Gollub
The ATLAS discovery potential for a heavy charged Higgs boson in gg->tbH^{+-} with H^{+-}->tb
null
Eur.Phys.J.C39S2:25-40,2005
10.1140/epjcd/s2004-01-009-7
null
hep-ph
null
The feasibility of detecting a heavy charged Higgs boson, m(H^{+-})>m(t)+m(b), decaying in the H^{+-}->tb channel is studied with the fast simulation of the ATLAS detector. We study the gg->H^{+-}tb production process at the LHC which together with the aforementioned decay channel leads to four b-quarks in the final state. The whole production and decay chain reads gg->H^{+-}tb->t\bar{t}b\bar{b}->b\bar{b}b\bar{b}l\nu\bar{q}q'. Combinatorial background is a major difficulty in this multi-jet environment but can be overcome by employing multivariate techniques in the event reconstruction. Requiring four b-tagged jets in the event helps to effectively suppress the Standard Model backgrounds but leads to no significant improvement in the discovery potential compared to analyses requiring only three b-tagged jets. This study indicates that charged Higgs bosons can be discovered at the LHC up to high masses (m(H^{+-})>400 GeV) in the case of large tan(beta).
[ { "created": "Tue, 1 Jun 2004 15:20:53 GMT", "version": "v1" } ]
2011-03-23
[ [ "Assamagan", "K. A.", "" ], [ "Gollub", "N.", "" ] ]
The feasibility of detecting a heavy charged Higgs boson, m(H^{+-})>m(t)+m(b), decaying in the H^{+-}->tb channel is studied with the fast simulation of the ATLAS detector. We study the gg->H^{+-}tb production process at the LHC which together with the aforementioned decay channel leads to four b-quarks in the final state. The whole production and decay chain reads gg->H^{+-}tb->t\bar{t}b\bar{b}->b\bar{b}b\bar{b}l\nu\bar{q}q'. Combinatorial background is a major difficulty in this multi-jet environment but can be overcome by employing multivariate techniques in the event reconstruction. Requiring four b-tagged jets in the event helps to effectively suppress the Standard Model backgrounds but leads to no significant improvement in the discovery potential compared to analyses requiring only three b-tagged jets. This study indicates that charged Higgs bosons can be discovered at the LHC up to high masses (m(H^{+-})>400 GeV) in the case of large tan(beta).
hep-ph/0102215
Mu-Chun Chen
Mu-Chun Chen and K.T. Mahanthappa
Implications of the Renormalization Group Equations in Three-Neutrino Models with Two-fold Degeneracy
10 pages; RevTeX; 3 eps figures; minor typos corrected; one reference added
Int.J.Mod.Phys. A16 (2001) 3923-3930
10.1142/S0217751X01004979
COLO-HEP-457
hep-ph
null
We obtain a {\it complete set} of one-loop RGE's for a set of combinations of neutrino parameters for the case of two-fold degenerate hierarchical three-neutrino models. The requirement of consistency of exact solutions to these RGE's with the two-fold degeneracy yields conditions which have previously been obtained perturbatively/numerically. These conditions, in the limit $|U_{e\nu_{3}}|=0$, are shown to lead to a strong cancellation in the matrix element of neutrinoless double beta decay.
[ { "created": "Fri, 16 Feb 2001 23:45:08 GMT", "version": "v1" }, { "created": "Wed, 9 May 2001 21:45:57 GMT", "version": "v2" } ]
2009-11-07
[ [ "Chen", "Mu-Chun", "" ], [ "Mahanthappa", "K. T.", "" ] ]
We obtain a {\it complete set} of one-loop RGE's for a set of combinations of neutrino parameters for the case of two-fold degenerate hierarchical three-neutrino models. The requirement of consistency of exact solutions to these RGE's with the two-fold degeneracy yields conditions which have previously been obtained perturbatively/numerically. These conditions, in the limit $|U_{e\nu_{3}}|=0$, are shown to lead to a strong cancellation in the matrix element of neutrinoless double beta decay.
2209.14680
Carlos Merino
G. H. Arakelyan, C. Merino and Yu. M. Shabelski
Centrality dependence of multistrange baryon production in high-energy heavy-ion collisions
4 pages, 2 figures, 1 table Contribution to the 51th International Symposium on Multiparticle Dynamics (ISMD2022), Pitlochry, Scotland, UK, July 31st-August 5th (2022)
null
10.1051/epjconf/202227108007
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the experimental data on the production of strange Lambdas, and multistrange baryons (Xi, Omega), and antibaryons, on nuclear targets, at the energy region from SPS up to LHC, in the framework of the Quark-Gluon String Model. One remarkable result of this analysis is the significant dependence on the centrality of the collision of the experimental ratios bar(Xi)+/bar(Lambda) and bar(Omega)+/bar(Lambda) ratios in heavy-ion collisions, at SPS energies.
[ { "created": "Thu, 29 Sep 2022 10:48:19 GMT", "version": "v1" }, { "created": "Thu, 19 Jan 2023 12:32:28 GMT", "version": "v2" } ]
2023-01-20
[ [ "Arakelyan", "G. H.", "" ], [ "Merino", "C.", "" ], [ "Shabelski", "Yu. M.", "" ] ]
We consider the experimental data on the production of strange Lambdas, and multistrange baryons (Xi, Omega), and antibaryons, on nuclear targets, at the energy region from SPS up to LHC, in the framework of the Quark-Gluon String Model. One remarkable result of this analysis is the significant dependence on the centrality of the collision of the experimental ratios bar(Xi)+/bar(Lambda) and bar(Omega)+/bar(Lambda) ratios in heavy-ion collisions, at SPS energies.
hep-ph/9510246
Jorge L. Lopez
J. Ellis, J. Lopez, and D. Nanopoulos
Lowering alpha_s by flipping SU(5)
11 pages, LaTeX, 2 figures (uuencoded)
Phys.Lett.B371:65-70,1996
10.1016/0370-2693(95)01589-2
CERN-TH-95/260, DOE/ER/40717-17, CTP-TAMU-39/95
hep-ph hep-th
null
We show that the prediction for $\alpha_s(M_Z)$ in flipped SU(5) is naturally lower than in minimal SU(5), and that the former can accommodate the full range of $\alpha_s(M_Z)$ presently allowed by experiment. Our computations include two-loop ($\delta_{\rm 2loop}$) and light ($\delta_{\rm light}$) and heavy ($\delta_{\rm heavy}$) threshold effects. Unlike minimal SU(5), in flipped SU(5) the heavy threshold effects can naturally decrease the predicted value of $\alpha_s(M_Z)$. We also show that the value of the proton lifetime into the dominant channel $p\to e^+\pi^0$ is within the observable range at SuperKamiokande, and should discriminate against minimal supersymmetric SU(5), where the dominant mode is $p\to\bar\nu K^+$.
[ { "created": "Fri, 6 Oct 1995 16:37:17 GMT", "version": "v1" } ]
2009-09-11
[ [ "Ellis", "J.", "" ], [ "Lopez", "J.", "" ], [ "Nanopoulos", "D.", "" ] ]
We show that the prediction for $\alpha_s(M_Z)$ in flipped SU(5) is naturally lower than in minimal SU(5), and that the former can accommodate the full range of $\alpha_s(M_Z)$ presently allowed by experiment. Our computations include two-loop ($\delta_{\rm 2loop}$) and light ($\delta_{\rm light}$) and heavy ($\delta_{\rm heavy}$) threshold effects. Unlike minimal SU(5), in flipped SU(5) the heavy threshold effects can naturally decrease the predicted value of $\alpha_s(M_Z)$. We also show that the value of the proton lifetime into the dominant channel $p\to e^+\pi^0$ is within the observable range at SuperKamiokande, and should discriminate against minimal supersymmetric SU(5), where the dominant mode is $p\to\bar\nu K^+$.
hep-ph/0309127
Kazunori Itakura
Kazunori Itakura
Deep Inelastic Scattering in the Color Glass Formalism
5 pages, no figure. Proceedings for XIth International Workshop on Deep Inelastic Scattering (DIS03), St. Petersburg, April 2003
null
null
SACLAY-T03/135
hep-ph nucl-th
null
I discuss dome phenomenological consequences of the Color Glass formalism for deep inelastic scattering.
[ { "created": "Thu, 11 Sep 2003 15:11:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "Itakura", "Kazunori", "" ] ]
I discuss dome phenomenological consequences of the Color Glass formalism for deep inelastic scattering.
hep-ph/9801315
Dan-Di Wu
Dan-Di Wu (Prairie View A&M University)
Comments on the review of CP Violation in the Particle Data Book
Latex file, 4 pages
Mod.Phys.Lett.A13:1413-1417,1998
10.1142/S0217732398001480
Prairie View A&M, HEP-9-97
hep-ph
null
Rephasing invariant formalism for the $K^0-\bar K^0$ system is recommended for the Particle Data Group. This formalism is accurate and prevents possible errors in generalizing the formalism to other systems, as well as in using CKM matrices not included in the Particle Data Book.
[ { "created": "Thu, 15 Jan 1998 19:35:08 GMT", "version": "v1" } ]
2014-11-17
[ [ "Wu", "Dan-Di", "", "Prairie View A&M University" ] ]
Rephasing invariant formalism for the $K^0-\bar K^0$ system is recommended for the Particle Data Group. This formalism is accurate and prevents possible errors in generalizing the formalism to other systems, as well as in using CKM matrices not included in the Particle Data Book.
1509.06651
Raquel Molina Ms.
E. J. Garzon, R. Molina, A. Hosaka and E. Oset
Strategies for an accurate determination of the X(3872) energy from QCD lattice simulations
To be published in the proceedings of CHARM-2015, Detroit, MI, 18-22 May 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a method to determine accurately the binding energy of the X(3872) from lattice data for the DD* interaction. We show that, because of the small difference between the neutral and charged components of the X(3872), it is necessary to distinguish them in the energy levels of the lattice spectrum if one wishes to have a precise determination of the the binding energy of the X(3872). The analysis of the data requires the use of coupled channels. Depending on the number of levels available and the size of the box we determine the precision needed in the lattice energies to finally obtain a desired accuracy in the binding energy.
[ { "created": "Tue, 22 Sep 2015 15:40:18 GMT", "version": "v1" } ]
2015-09-23
[ [ "Garzon", "E. J.", "" ], [ "Molina", "R.", "" ], [ "Hosaka", "A.", "" ], [ "Oset", "E.", "" ] ]
We develop a method to determine accurately the binding energy of the X(3872) from lattice data for the DD* interaction. We show that, because of the small difference between the neutral and charged components of the X(3872), it is necessary to distinguish them in the energy levels of the lattice spectrum if one wishes to have a precise determination of the the binding energy of the X(3872). The analysis of the data requires the use of coupled channels. Depending on the number of levels available and the size of the box we determine the precision needed in the lattice energies to finally obtain a desired accuracy in the binding energy.
hep-ph/0603245
Martin Block
Martin M. Block and Kyungsik Kang
New limits on "odderon" amplitudes from analyticity constraints
13 pages LaTex, 6 figures
Phys.Rev.D73:094003,2006
10.1103/PhysRevD.73.094003
HUPEP 1261, Brown-HET-1465
hep-ph
null
In studies of high energy $pp$ and $\bar pp$ scattering, the odd (under crossing) forward scattering amplitude accounts for the difference between the $pp$ and $\bar pp$ cross sections. Typically, it is taken as $f_-=-\frac{p}{4\pi}Ds^{\alpha-1}e^{i\pi(1-\alpha)/2}$ ($\alpha\sim 0.5$), which has $\Delta\sigma, \Delta\rho\to0$ as $s\to\infty$, where $\rho$ is the ratio of the real to the imaginary portion of the forward scattering amplitude. However, the odd-signatured amplitude can have in principle a strikingly different behavior, ranging from having $\Delta\sigma\to$non-zero constant to having $\Delta\sigma \to \ln s/s_0$ as $s\to\infty$, the maximal behavior allowed by analyticity and the Froissart bound. We reanalyze high energy $pp$ and $\bar pp$ scattering data, using new analyticity constraints, in order to put new and precise limits on the magnitude of ``odderon'' amplitudes.
[ { "created": "Wed, 29 Mar 2006 19:03:53 GMT", "version": "v1" } ]
2008-11-26
[ [ "Block", "Martin M.", "" ], [ "Kang", "Kyungsik", "" ] ]
In studies of high energy $pp$ and $\bar pp$ scattering, the odd (under crossing) forward scattering amplitude accounts for the difference between the $pp$ and $\bar pp$ cross sections. Typically, it is taken as $f_-=-\frac{p}{4\pi}Ds^{\alpha-1}e^{i\pi(1-\alpha)/2}$ ($\alpha\sim 0.5$), which has $\Delta\sigma, \Delta\rho\to0$ as $s\to\infty$, where $\rho$ is the ratio of the real to the imaginary portion of the forward scattering amplitude. However, the odd-signatured amplitude can have in principle a strikingly different behavior, ranging from having $\Delta\sigma\to$non-zero constant to having $\Delta\sigma \to \ln s/s_0$ as $s\to\infty$, the maximal behavior allowed by analyticity and the Froissart bound. We reanalyze high energy $pp$ and $\bar pp$ scattering data, using new analyticity constraints, in order to put new and precise limits on the magnitude of ``odderon'' amplitudes.
hep-ph/0209296
Andrea Gregori
Andrea Gregori
On the Time Dependence of Fundamental Constants
5 pages, latex, misprint corrected and reference added
null
null
null
hep-ph astro-ph hep-th
null
We discuss how the results of recent measurements on the spectra of quasars are predicted by the non-perturbative solution of String Theory proposed in hep-th/0207195.
[ { "created": "Wed, 25 Sep 2002 12:36:12 GMT", "version": "v1" }, { "created": "Wed, 13 Nov 2002 16:44:02 GMT", "version": "v2" } ]
2007-05-23
[ [ "Gregori", "Andrea", "" ] ]
We discuss how the results of recent measurements on the spectra of quasars are predicted by the non-perturbative solution of String Theory proposed in hep-th/0207195.
2011.12637
Inar Timiryasov
Shintaro Eijima, Mikhail Shaposhnikov, Inar Timiryasov
Freeze-in and freeze-out generation of lepton asymmetries after baryogenesis in the $\nu$MSM
41 page, 19 figures; v2: added the freeze-out generation and the solution of the full momentum dependent equations. Matches the published version
JCAP04(2022)049
10.1088/1475-7516/2022/04/049
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $\nu$MSM -- an extension of the Standard Model by three relatively light singlet Majorana fermions $N_{1,2,3}$ -- allows for the generation of lepton asymmetry which is several orders of magnitude larger than the observed baryon asymmetry of the Universe. The lepton asymmetry is produced in interactions of $N_{2,3}$ (with masses in the GeV region) at temperatures below the sphaleron freeze out $ T \lesssim 130$ GeV and can enhance the cosmological production of dark matter (DM) sterile neutrinos $N_1$ (with the mass of the keV scale) happening at $T \sim 200$ MeV due to active-sterile neutrino mixing. This asymmetry can be generated in freeze-in, freeze-out, or later in decays of heavy neutral leptons. In this work, we address the question of the magnitude of the late-time asymmetry (LTA) generated by the heavy neutral leptons $N_{2,3}$ during their freeze-in and freeze-out, leaving the decays for later work. We study how much of this asymmetry can survive down to the lower temperatures relevant for the sterile neutrino DM creation. We find that this LTA could result in the production of a sizeable fraction of dark matter. We also examine a role played by magnetic fields and the Abelian chiral anomaly in the generation of LTA, not accounted for in the previous studies. We argue that the production of LTA can be increased significantly and make an estimate of the influence of this effect.
[ { "created": "Wed, 25 Nov 2020 10:55:34 GMT", "version": "v1" }, { "created": "Fri, 29 Apr 2022 10:31:28 GMT", "version": "v2" } ]
2022-05-02
[ [ "Eijima", "Shintaro", "" ], [ "Shaposhnikov", "Mikhail", "" ], [ "Timiryasov", "Inar", "" ] ]
The $\nu$MSM -- an extension of the Standard Model by three relatively light singlet Majorana fermions $N_{1,2,3}$ -- allows for the generation of lepton asymmetry which is several orders of magnitude larger than the observed baryon asymmetry of the Universe. The lepton asymmetry is produced in interactions of $N_{2,3}$ (with masses in the GeV region) at temperatures below the sphaleron freeze out $ T \lesssim 130$ GeV and can enhance the cosmological production of dark matter (DM) sterile neutrinos $N_1$ (with the mass of the keV scale) happening at $T \sim 200$ MeV due to active-sterile neutrino mixing. This asymmetry can be generated in freeze-in, freeze-out, or later in decays of heavy neutral leptons. In this work, we address the question of the magnitude of the late-time asymmetry (LTA) generated by the heavy neutral leptons $N_{2,3}$ during their freeze-in and freeze-out, leaving the decays for later work. We study how much of this asymmetry can survive down to the lower temperatures relevant for the sterile neutrino DM creation. We find that this LTA could result in the production of a sizeable fraction of dark matter. We also examine a role played by magnetic fields and the Abelian chiral anomaly in the generation of LTA, not accounted for in the previous studies. We argue that the production of LTA can be increased significantly and make an estimate of the influence of this effect.
hep-ph/9812276
Subir Sarkar
Ernest Ma, Subir Sarkar and Utpal Sarkar
Scale of SU(2)_R symmetry breaking and leptogenesis
4 pages (Revtex); accepted for publication with small modifications; conclusions unchanged
Phys.Lett.B458:73-78,1999
10.1016/S0370-2693(99)00568-7
OUTP-98-69P, UCRHEP-T241
hep-ph astro-ph
null
Models of leptogenesis often invoke the out-of-equilibrium decays of heavy right-handed neutrinos in order to create a baryon asymmetry of the universe through the electroweak phase transition. Their presumed existence argues strongly for the presence of an $SU(2)_R$ gauge symmetry. We study the equilibrating effects of the resulting additional right-handed interactions and find that successful leptogenesis requires that $m_N \gtrsim 10^{16}$ GeV if $m_N > m_{W_R}$, and $m_{W_R} \gtrsim 3 \times 10^6 GeV (m_N /10^2 GeV)^{2/3}$ if $m_{N}<m_{W_R}$, where $m_{N}$ is the mass of the lightest right-handed neutrino. However, the $m_N > m_{W_R}$ option is excluded in a supersymmetric theory with gravitinos.
[ { "created": "Mon, 7 Dec 1998 23:16:14 GMT", "version": "v1" }, { "created": "Sun, 20 Dec 1998 12:27:35 GMT", "version": "v2" }, { "created": "Fri, 7 May 1999 18:29:34 GMT", "version": "v3" }, { "created": "Sun, 9 May 1999 17:14:45 GMT", "version": "v4" } ]
2011-02-16
[ [ "Ma", "Ernest", "" ], [ "Sarkar", "Subir", "" ], [ "Sarkar", "Utpal", "" ] ]
Models of leptogenesis often invoke the out-of-equilibrium decays of heavy right-handed neutrinos in order to create a baryon asymmetry of the universe through the electroweak phase transition. Their presumed existence argues strongly for the presence of an $SU(2)_R$ gauge symmetry. We study the equilibrating effects of the resulting additional right-handed interactions and find that successful leptogenesis requires that $m_N \gtrsim 10^{16}$ GeV if $m_N > m_{W_R}$, and $m_{W_R} \gtrsim 3 \times 10^6 GeV (m_N /10^2 GeV)^{2/3}$ if $m_{N}<m_{W_R}$, where $m_{N}$ is the mass of the lightest right-handed neutrino. However, the $m_N > m_{W_R}$ option is excluded in a supersymmetric theory with gravitinos.
1712.06337
Giuliano Panico
Giuliano Panico, Marc Riembau, Thibaud Vantalon
Probing light top partners with CP violation
31 pages, 10 figures; v2: typos corrected, matches published version
null
10.1007/JHEP06(2018)056
DESY 17-197
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate CP-violating effects induced by light top partners in composite Higgs theories. We find that sizable contributions to the dipole moments of the light SM quarks and leptons are generically generated at the two-loop level through Barr-Zee-type diagrams. The present constraints on the electron and neutron electric dipole moments translate into bounds on top partner masses of order few TeV and are competitive with the reach of LHC direct searches. Interestingly, we find that CP-violation effects are sensitive to the same operators that control top partner single production. Near-future improvements in the determination of the electron dipole moment will extend the reach on top partner masses beyond the 5 - 10 TeV range.
[ { "created": "Mon, 18 Dec 2017 11:08:14 GMT", "version": "v1" }, { "created": "Fri, 12 Apr 2019 08:40:36 GMT", "version": "v2" } ]
2019-04-15
[ [ "Panico", "Giuliano", "" ], [ "Riembau", "Marc", "" ], [ "Vantalon", "Thibaud", "" ] ]
We investigate CP-violating effects induced by light top partners in composite Higgs theories. We find that sizable contributions to the dipole moments of the light SM quarks and leptons are generically generated at the two-loop level through Barr-Zee-type diagrams. The present constraints on the electron and neutron electric dipole moments translate into bounds on top partner masses of order few TeV and are competitive with the reach of LHC direct searches. Interestingly, we find that CP-violation effects are sensitive to the same operators that control top partner single production. Near-future improvements in the determination of the electron dipole moment will extend the reach on top partner masses beyond the 5 - 10 TeV range.
hep-ph/0211416
C. A. de S. Pires
T. Mariz, C. A. de S. Pires, and R. F. Ribeiro
Ward identity in noncommutative QED
some misprint and reference corrected
Int.J.Mod.Phys. A18 (2003) 5433-5444
10.1142/S0217751X03015945
null
hep-ph hep-th
null
Although noncommutative QED presents a nonabelian structure, it does not present structure constants. In view of this we investigate how Ward identity is satisfied in pair annihilation process and $\gamma \gamma \to \gamma \gamma$ scattering in noncommutative QED.
[ { "created": "Tue, 26 Nov 2002 17:45:08 GMT", "version": "v1" }, { "created": "Thu, 28 Nov 2002 19:58:31 GMT", "version": "v2" } ]
2009-11-07
[ [ "Mariz", "T.", "" ], [ "Pires", "C. A. de S.", "" ], [ "Ribeiro", "R. F.", "" ] ]
Although noncommutative QED presents a nonabelian structure, it does not present structure constants. In view of this we investigate how Ward identity is satisfied in pair annihilation process and $\gamma \gamma \to \gamma \gamma$ scattering in noncommutative QED.
1507.05310
Wei Chao
Wei Chao
ATLAS Diboson Excesses from the Stealth Doublet Model
10 pages, 3 figures
null
10.1016/j.physletb.2015.12.007
ACFI-T15-07
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ATLAS collaboration has reported excesses in diboson invariant mass searches of new resonances around 2 TeV, which might be a prediction of new physics around that mass range. We interpret these results in the context of a modified stealth doublet model where the extra Higgs doublet has a Yukawa interaction with the first generation quarks, and show that the heavy CP-even Higgs boson can naturally explain the excesses in the WW and ZZ channels with a small Yukawa coupling, \xi\sim 0.15, and a tiny mixing angle with the SM Higgs boson, \alpha \sim 0.06. Furthermore, the model satisfy constraints from colliders and electroweak precision measurements.
[ { "created": "Sun, 19 Jul 2015 17:29:27 GMT", "version": "v1" } ]
2015-12-09
[ [ "Chao", "Wei", "" ] ]
The ATLAS collaboration has reported excesses in diboson invariant mass searches of new resonances around 2 TeV, which might be a prediction of new physics around that mass range. We interpret these results in the context of a modified stealth doublet model where the extra Higgs doublet has a Yukawa interaction with the first generation quarks, and show that the heavy CP-even Higgs boson can naturally explain the excesses in the WW and ZZ channels with a small Yukawa coupling, \xi\sim 0.15, and a tiny mixing angle with the SM Higgs boson, \alpha \sim 0.06. Furthermore, the model satisfy constraints from colliders and electroweak precision measurements.
hep-ph/0303110
Gudrid Moortgat
E. Boos, H.-U. Martyn, G. Moortgat-Pick, M. Sachwitz, A. Sherstnev, P.M. Zerwas
Polarisation in Sfermion Decays: Determining \tan\beta and Trilinear Couplings
20 pages, 11 eps figures
Eur.Phys.J.C30:395-407,2003
10.1140/epjc/s2003-01288-y
DCPT-03-04, DESY 03-030, IPPP-03-02
hep-ph
null
The basic parameters of supersymmetric theories can be determined at future e^+e^- linear colliders with high precision. We investigate in this report how polarisation measurements in \tilde{\tau} and \tilde{t} or \tilde{b} decays to \tau leptons and t quarks plus neutralinos or charginos can be used to measure \tan\beta (in particular for large values) and to determine the trilinear couplings A_{\tau}, A_t and A_b in sfermion pair production.
[ { "created": "Thu, 13 Mar 2003 17:25:08 GMT", "version": "v1" } ]
2011-01-27
[ [ "Boos", "E.", "" ], [ "Martyn", "H. -U.", "" ], [ "Moortgat-Pick", "G.", "" ], [ "Sachwitz", "M.", "" ], [ "Sherstnev", "A.", "" ], [ "Zerwas", "P. M.", "" ] ]
The basic parameters of supersymmetric theories can be determined at future e^+e^- linear colliders with high precision. We investigate in this report how polarisation measurements in \tilde{\tau} and \tilde{t} or \tilde{b} decays to \tau leptons and t quarks plus neutralinos or charginos can be used to measure \tan\beta (in particular for large values) and to determine the trilinear couplings A_{\tau}, A_t and A_b in sfermion pair production.
hep-ph/0201001
Pran Nath
Utpal Chattopadhyay, Achille Corsetti and Pran Nath
Supersymmetric Dark Matter and Yukawa Unification
28 pages,nLatex including 5 figs
Phys.Rev.D66:035003,2002
10.1103/PhysRevD.66.035003
TIFR/TH/01-49, NUB-TH/3225
hep-ph
null
An analysis of supersymmetric dark matter under the Yukawa unification constraint is given. The analysis utilizes the recently discovered region of the parameter space of models with gaugino mass nonuniversalities where large negative supersymmetric corrections to the b quark mass appear to allow $b-\tau$ unification for a positive $\mu$ sign consistent with the $b\to s+\gamma$ and $g_{\mu}-2$ constraints. In the present analysis we use the revised theoretical determination of $a_{\mu}^{SM}$ ($a_{\mu}= (g_{\mu}-2)/2$) in computing the difference $a_{\mu}^{exp}-a_{\mu}^{SM}$ which takes account of a reevaluation of the light by light contribution which has a positive sign. The analysis shows that the region of the parameter space with nonuniversalities of the gaugino masses which allows for unification of Yukawa couplings also contains regions which allow satisfaction of the relic density constraint. Specifically we find that the lightest neutralino mass consistent with the relic density constraint, $b\tau$ unification for SU(5) and $b-t-\tau$ unification for SO(10) in addition to other constraints lies in the region below 80 GeV. An analysis of the maximum and the minimum neutralino-proton scalar cross section for the allowed parameter space including the effect of a new determination of the pion-nucleon sigma term is also given. It is found that the full parameter space for this class of models can be explored in the next generation of proposed dark matter detectors.
[ { "created": "Mon, 31 Dec 2001 22:13:06 GMT", "version": "v1" } ]
2011-05-05
[ [ "Chattopadhyay", "Utpal", "" ], [ "Corsetti", "Achille", "" ], [ "Nath", "Pran", "" ] ]
An analysis of supersymmetric dark matter under the Yukawa unification constraint is given. The analysis utilizes the recently discovered region of the parameter space of models with gaugino mass nonuniversalities where large negative supersymmetric corrections to the b quark mass appear to allow $b-\tau$ unification for a positive $\mu$ sign consistent with the $b\to s+\gamma$ and $g_{\mu}-2$ constraints. In the present analysis we use the revised theoretical determination of $a_{\mu}^{SM}$ ($a_{\mu}= (g_{\mu}-2)/2$) in computing the difference $a_{\mu}^{exp}-a_{\mu}^{SM}$ which takes account of a reevaluation of the light by light contribution which has a positive sign. The analysis shows that the region of the parameter space with nonuniversalities of the gaugino masses which allows for unification of Yukawa couplings also contains regions which allow satisfaction of the relic density constraint. Specifically we find that the lightest neutralino mass consistent with the relic density constraint, $b\tau$ unification for SU(5) and $b-t-\tau$ unification for SO(10) in addition to other constraints lies in the region below 80 GeV. An analysis of the maximum and the minimum neutralino-proton scalar cross section for the allowed parameter space including the effect of a new determination of the pion-nucleon sigma term is also given. It is found that the full parameter space for this class of models can be explored in the next generation of proposed dark matter detectors.
1003.0061
Xavier Garcia i Tormo
Geoffrey T. Bodwin (Argonne), Xavier Garcia i Tormo (Argonne & Alberta U.), Jungil Lee (Korea U.)
Factorization in exclusive quarkonium production
69 pages, 12 figures, 2 tables. v2: Version published in Physical Review D
Phys.Rev.D81:114014,2010
10.1103/PhysRevD.81.114014
ANL-HEP-PR-09-97, Alberta Thy 15-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present factorization theorems for two exclusive heavy-quarkonium production processes: production of two quarkonia in e^+e^- annihilation and production of a quarkonium and a light meson in B-meson decays. We describe the general proofs of factorization and supplement them with explicit one-loop analyses, which illustrate some of the features of the soft-gluon cancellations. We find that violations of factorization are generally suppressed relative to the factorized contributions by a factor v^2m_c/Q for each S-wave charmonium and a factor m_c/Q for each L-wave charmonium with L>0. Here, v is the velocity of the heavy quark or antiquark in the quarkonium rest frame, Q=sqrt{s} for e^+e^- annihilation, Q=m_B for B-meson decays, sqrt{s} is the e^+e^- center-of-momentum energy, m_c is the charm-quark mass, and m_B is the B-meson mass. There are modifications to the suppression factors if quantum-number restrictions apply for the specific process.
[ { "created": "Sat, 27 Feb 2010 05:00:31 GMT", "version": "v1" }, { "created": "Fri, 25 Jun 2010 17:32:09 GMT", "version": "v2" } ]
2010-06-28
[ [ "Bodwin", "Geoffrey T.", "", "Argonne" ], [ "Tormo", "Xavier Garcia i", "", "Argonne & Alberta\n U." ], [ "Lee", "Jungil", "", "Korea U." ] ]
We present factorization theorems for two exclusive heavy-quarkonium production processes: production of two quarkonia in e^+e^- annihilation and production of a quarkonium and a light meson in B-meson decays. We describe the general proofs of factorization and supplement them with explicit one-loop analyses, which illustrate some of the features of the soft-gluon cancellations. We find that violations of factorization are generally suppressed relative to the factorized contributions by a factor v^2m_c/Q for each S-wave charmonium and a factor m_c/Q for each L-wave charmonium with L>0. Here, v is the velocity of the heavy quark or antiquark in the quarkonium rest frame, Q=sqrt{s} for e^+e^- annihilation, Q=m_B for B-meson decays, sqrt{s} is the e^+e^- center-of-momentum energy, m_c is the charm-quark mass, and m_B is the B-meson mass. There are modifications to the suppression factors if quantum-number restrictions apply for the specific process.
1608.05475
Sachiko Takeuchi
Sachiko Takeuchi and Makoto Takizawa
The hidden charm pentaquarks are the hidden color-octet $uud$ baryons?
6 pages 4 figures, to be published in Physics Letters B
Physics Letters B Volume 764, 10 January 2017, Pages 254-259
10.1016/j.physletb.2016.11.034
RIKEN-QHP-249, J-PARC-TH-0063
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The $I(J^P)={1\over 2}({1\over 2}^-)$, ${1\over 2}({3\over 2}^-)$, and ${1\over 2}({5\over 2}^-)$ $uudc\overline{c}$ pentaquarks are investigated by the quark cluster model. This model, which reproduces the mass spectra of the color-singlet $S$-wave $q^3$ baryons and $q\overline{q}$ mesons, also enables us to evaluate the quark interaction in the color-octet $uud$ configurations. It is shown that the color-octet isospin-${1\over 2}$ spin-${3\over 2}$ $uud$ configuration gains attraction. The $uudc\overline{c}$ states with this configuration have structures around the $\Sigma_c{}^{(*)}\overline{D}{}^{(*)}$ thresholds: one bound state, two resonances, and one large cusp are found. We argue that the negative parity pentaquark found by the LHCb experiments may be given by these structures.
[ { "created": "Fri, 19 Aug 2016 02:22:16 GMT", "version": "v1" }, { "created": "Sun, 27 Nov 2016 14:22:12 GMT", "version": "v2" } ]
2016-12-09
[ [ "Takeuchi", "Sachiko", "" ], [ "Takizawa", "Makoto", "" ] ]
The $I(J^P)={1\over 2}({1\over 2}^-)$, ${1\over 2}({3\over 2}^-)$, and ${1\over 2}({5\over 2}^-)$ $uudc\overline{c}$ pentaquarks are investigated by the quark cluster model. This model, which reproduces the mass spectra of the color-singlet $S$-wave $q^3$ baryons and $q\overline{q}$ mesons, also enables us to evaluate the quark interaction in the color-octet $uud$ configurations. It is shown that the color-octet isospin-${1\over 2}$ spin-${3\over 2}$ $uud$ configuration gains attraction. The $uudc\overline{c}$ states with this configuration have structures around the $\Sigma_c{}^{(*)}\overline{D}{}^{(*)}$ thresholds: one bound state, two resonances, and one large cusp are found. We argue that the negative parity pentaquark found by the LHCb experiments may be given by these structures.
1209.5488
W-Y. P. Hwang
W-Y. Pauchy Hwang
An Anatomy of Neutrino Oscillations
4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We ponder about neutrino oscillations; a particle without a clear identity, a neutrino of a given flavor in fact does not satisfy the Dirac equation (which is used to define the mass eigen-states and mass eigen-values). This alters the basic treatment of neutrino oscillations, in that the Dirac spinors are defined as the mass eigen-states while the flavor states can only be given as linear combinations of the mass eigen-states (of Dirac equations). Even though neutrino masses are tiny, the impacts of several neutrino masses in a single reaction or a single decay, such as possible violation of the energy-momentum conservation, should not be overlooked. Among those sources of oscillating neutrinos, we point out that the ultra high energy cosmic rays (UHECR's) such as the proton of energy $10^{18}\, eV$ or higher, used to think of being rather stable, can capture, in the matter media, an electron to convert into an electron-like neutrino and a spectator neutron. This would be the most important neutrino source of the UHECR origin.
[ { "created": "Tue, 25 Sep 2012 03:44:46 GMT", "version": "v1" }, { "created": "Mon, 12 Aug 2013 08:29:09 GMT", "version": "v2" }, { "created": "Mon, 3 Nov 2014 04:43:37 GMT", "version": "v3" }, { "created": "Tue, 3 Nov 2015 05:14:30 GMT", "version": "v4" } ]
2015-11-04
[ [ "Hwang", "W-Y. Pauchy", "" ] ]
We ponder about neutrino oscillations; a particle without a clear identity, a neutrino of a given flavor in fact does not satisfy the Dirac equation (which is used to define the mass eigen-states and mass eigen-values). This alters the basic treatment of neutrino oscillations, in that the Dirac spinors are defined as the mass eigen-states while the flavor states can only be given as linear combinations of the mass eigen-states (of Dirac equations). Even though neutrino masses are tiny, the impacts of several neutrino masses in a single reaction or a single decay, such as possible violation of the energy-momentum conservation, should not be overlooked. Among those sources of oscillating neutrinos, we point out that the ultra high energy cosmic rays (UHECR's) such as the proton of energy $10^{18}\, eV$ or higher, used to think of being rather stable, can capture, in the matter media, an electron to convert into an electron-like neutrino and a spectator neutron. This would be the most important neutrino source of the UHECR origin.
hep-ph/9911489
Alessandro Ballestrero
Elena Accomando, Alessandro Ballestrero and Ezio Maina
Non-conserved currents and gauge-restoring schemes in single W production
12 pages, 3 figs
Phys.Lett. B479 (2000) 209-217
10.1016/S0370-2693(00)00330-0
DFTT-52/99 CTP-TAMU-46/99
hep-ph
null
We generalize the inclusion of the imaginary parts of the fermionic one-loop corrections for processes with unstable vector bosons to the case of massive external fermions and non conservation of weak currents. We study the effect of initial and final state fermion masses in single W production in connection with the gauge-invariant treatment of the finite-width effects of W and Z bosons, giving numerical comparisons of different gauge-invariance-preserving schemes in the energy range of LEP2 and LC for e+e- -> e- v u d. We do not find significant differences between the results obtained in the imaginary part fermion loop scheme and in other exactly gauge preserving methods.
[ { "created": "Thu, 25 Nov 1999 14:19:07 GMT", "version": "v1" } ]
2016-09-06
[ [ "Accomando", "Elena", "" ], [ "Ballestrero", "Alessandro", "" ], [ "Maina", "Ezio", "" ] ]
We generalize the inclusion of the imaginary parts of the fermionic one-loop corrections for processes with unstable vector bosons to the case of massive external fermions and non conservation of weak currents. We study the effect of initial and final state fermion masses in single W production in connection with the gauge-invariant treatment of the finite-width effects of W and Z bosons, giving numerical comparisons of different gauge-invariance-preserving schemes in the energy range of LEP2 and LC for e+e- -> e- v u d. We do not find significant differences between the results obtained in the imaginary part fermion loop scheme and in other exactly gauge preserving methods.
hep-ph/0008042
Uma Mahanta
Uma Mahanta
Implications of radion-higgs couplings for high energy scattering in the Randall-Sundrum model
Plain Tex, no figures, 7 pages; the reasons for considering the particular process discussed in the paper has been added
Phys.Rev. D63 (2001) 076006
10.1103/PhysRevD.63.076006
null
hep-ph
null
In this report we derive the couplings of the Randall-Sundrum radion to the standard model higgs boson. We then use these couplings to determine the J=0 partial wave amplitude for the process $hh\to h\phi $. We find that at very high energies (i.e. $s\gg m_h^2, \mp^2$) the s wave partial wave unitarity is violated if $m_h>m_c\approx \sqrt{16\pi\vphi v}$ where $\vphi$ is the radion vev. Interestingly this bound is independent of the radion mass to the leading order. We also consider the high energy behaviour of the transition amplitudes for some other processes in the RS scenario and compare them with their SM behaviour.
[ { "created": "Fri, 4 Aug 2000 11:28:09 GMT", "version": "v1" }, { "created": "Mon, 16 Oct 2000 10:17:45 GMT", "version": "v2" } ]
2009-10-31
[ [ "Mahanta", "Uma", "" ] ]
In this report we derive the couplings of the Randall-Sundrum radion to the standard model higgs boson. We then use these couplings to determine the J=0 partial wave amplitude for the process $hh\to h\phi $. We find that at very high energies (i.e. $s\gg m_h^2, \mp^2$) the s wave partial wave unitarity is violated if $m_h>m_c\approx \sqrt{16\pi\vphi v}$ where $\vphi$ is the radion vev. Interestingly this bound is independent of the radion mass to the leading order. We also consider the high energy behaviour of the transition amplitudes for some other processes in the RS scenario and compare them with their SM behaviour.
0810.3210
Massimiliano Chiorboli
Massimiliano Chiorboli
Prospects for non-standard SUSY searches at LHC
Paraller talk presented at ICHEP08 on behalf of the ATLAS and CMS Collaborations
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New studies of the ATLAS and CMS collaborations are presented on the sensitivity to searches for non-standard signatures of particular SUSY scenarios. These signatures include non-pointing photons, as well as pairs of prompt photons, as expected in GMSB SUSY models, as well as heavy stable charged particles produced in split supersymmetry models, long lived staus from GMSB SUSY and long lived stops in other SUSY scenarios. A detailed detector simulation is used for the study, and all relevant Standard Model backgrounds and detector effects that can mimic these special signatures are included. It is shown that already with less than 100 pb$^{-1}$ the ATLAS and CMS sensitivity will probe an interesting as yet by data unexplored parameter range of these models.
[ { "created": "Fri, 17 Oct 2008 18:01:31 GMT", "version": "v1" } ]
2008-10-20
[ [ "Chiorboli", "Massimiliano", "" ] ]
New studies of the ATLAS and CMS collaborations are presented on the sensitivity to searches for non-standard signatures of particular SUSY scenarios. These signatures include non-pointing photons, as well as pairs of prompt photons, as expected in GMSB SUSY models, as well as heavy stable charged particles produced in split supersymmetry models, long lived staus from GMSB SUSY and long lived stops in other SUSY scenarios. A detailed detector simulation is used for the study, and all relevant Standard Model backgrounds and detector effects that can mimic these special signatures are included. It is shown that already with less than 100 pb$^{-1}$ the ATLAS and CMS sensitivity will probe an interesting as yet by data unexplored parameter range of these models.
2002.12519
Jihn E. Kim
Jihn E. Kim
Flavor physics and Jarlskog determinant
5 pages with 2 figures. Talk presented at the "Neutrinos and Dark Matter" Conference, Hurghada, Egypt, 10-15 Jan, 2020, and The 3rd Korea-Japan Bi-lateral Workshop on "String, Axion, Cosmology", Ibuzuki, Kagoshima, Kyushu, Japan, Jan. 17-20, 2020
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The flavor problem is reviewed starting with the chiral symmetry, and the $A_4$ symmetry derivation and its realization in GUTs are presented.
[ { "created": "Fri, 28 Feb 2020 03:06:21 GMT", "version": "v1" } ]
2020-03-02
[ [ "Kim", "Jihn E.", "" ] ]
The flavor problem is reviewed starting with the chiral symmetry, and the $A_4$ symmetry derivation and its realization in GUTs are presented.
1909.01457
Jacek Ksawery Osi\'nski
Rouzbeh Allahverdi and Jacek K. Osi\'nski
Freeze-in Production of Dark Matter Prior to Early Matter Domination
15 pages, 7 figures, updated to match version accepted for publication in Phys. Rev. D
Phys. Rev. D 101, 063503 (2020)
10.1103/PhysRevD.101.063503
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Freeze-out or freeze-in during a period of early matter domination can yield the correct dark matter abundance for small values of the velocity-averaged annihilation cross section, $\langle \sigma_{\rm ann} v \rangle_{\rm f} < 3 \times 10^{-26}$ cm$^3$ s$^{-1}$. However, in a generic non-standard thermal history, such a period is typically preceded by other phases. Here, we study production of dark matter in a simple post-inflationary history where a radiation-dominated phase after reheating is followed by an epoch of early matter domination. Focusing on the freeze-in regime, we show that dark matter production prior to early matter domination can dominate the relic abundance in large parts of the parameter space, including weak scale dark matter masses, and the allowed regions are highly dependent on the entire post-inflationary history. Moreover, for a very broad range of $\langle \sigma_{\rm ann} v \rangle_{\rm f}$ spanning over several decades, dark matter particles can start in chemical equilibrium early on and decouple during early matter domination, thereby rendering the relic abundance essentially independent of $\langle \sigma_{\rm ann} v \rangle_{\rm f}$. We briefly discuss connections to different observables as a possible means to test the elusive freeze-in scenario in this case.
[ { "created": "Tue, 3 Sep 2019 21:16:47 GMT", "version": "v1" }, { "created": "Thu, 13 Feb 2020 04:50:19 GMT", "version": "v2" } ]
2020-03-11
[ [ "Allahverdi", "Rouzbeh", "" ], [ "Osiński", "Jacek K.", "" ] ]
Freeze-out or freeze-in during a period of early matter domination can yield the correct dark matter abundance for small values of the velocity-averaged annihilation cross section, $\langle \sigma_{\rm ann} v \rangle_{\rm f} < 3 \times 10^{-26}$ cm$^3$ s$^{-1}$. However, in a generic non-standard thermal history, such a period is typically preceded by other phases. Here, we study production of dark matter in a simple post-inflationary history where a radiation-dominated phase after reheating is followed by an epoch of early matter domination. Focusing on the freeze-in regime, we show that dark matter production prior to early matter domination can dominate the relic abundance in large parts of the parameter space, including weak scale dark matter masses, and the allowed regions are highly dependent on the entire post-inflationary history. Moreover, for a very broad range of $\langle \sigma_{\rm ann} v \rangle_{\rm f}$ spanning over several decades, dark matter particles can start in chemical equilibrium early on and decouple during early matter domination, thereby rendering the relic abundance essentially independent of $\langle \sigma_{\rm ann} v \rangle_{\rm f}$. We briefly discuss connections to different observables as a possible means to test the elusive freeze-in scenario in this case.
hep-ph/9803215
Gabriela Barenboim
Gabriela Barenboim (U.Mainz), Nuria Rius (U.Valencia and IFIC)
Electroweak Phase Transitions in left-right symmetric models
20 pages, 5 figures (included), some comments added, typos corrected and new references included. Final version to appear in PRD
Phys.Rev. D58 (1998) 065010
10.1103/PhysRevD.58.065010
null
hep-ph
null
We study the finite-temperature effective potential of minimal left-right symmetric models containing a bidoublet and two triplets in the scalar sector. We perform a numerical analysis of the parameter space compatible with the requirement that baryon asymmetry is not washed out by sphaleron processes after the electroweak phase transition. We find that the spectrum of scalar particles for these acceptable cases is consistent with present experimental bounds.
[ { "created": "Mon, 2 Mar 1998 14:38:37 GMT", "version": "v1" }, { "created": "Wed, 17 Jun 1998 11:50:02 GMT", "version": "v2" } ]
2009-10-31
[ [ "Barenboim", "Gabriela", "", "U.Mainz" ], [ "Rius", "Nuria", "", "U.Valencia and IFIC" ] ]
We study the finite-temperature effective potential of minimal left-right symmetric models containing a bidoublet and two triplets in the scalar sector. We perform a numerical analysis of the parameter space compatible with the requirement that baryon asymmetry is not washed out by sphaleron processes after the electroweak phase transition. We find that the spectrum of scalar particles for these acceptable cases is consistent with present experimental bounds.
hep-ph/9710214
null
Eugene Golowich and Joachim Kambor
Two-loop Analysis of Axialvector Current Propagators in Chiral Perturbation Theory
51 pages, LaTeX, 7 figures
Phys.Rev. D58 (1998) 036004
10.1103/PhysRevD.58.036004
null
hep-ph
null
We perform a calculation of the isospin and hypercharge axialvector current propagators to two loops in SU(3)xSU(3) chiral perturbation theory. A large number of order p^6 divergent counterterms are fixed, and complete two-loop renormalized expressions for the pion and eta masses and decay constants are given. The calculated isospin and hypercharge axialvector polarization functions are used as input in new chiral sum rules, valid to second order in the light quark masses. Some phenomenological implications of these sum rules are considered.
[ { "created": "Wed, 1 Oct 1997 18:10:56 GMT", "version": "v1" } ]
2009-10-30
[ [ "Golowich", "Eugene", "" ], [ "Kambor", "Joachim", "" ] ]
We perform a calculation of the isospin and hypercharge axialvector current propagators to two loops in SU(3)xSU(3) chiral perturbation theory. A large number of order p^6 divergent counterterms are fixed, and complete two-loop renormalized expressions for the pion and eta masses and decay constants are given. The calculated isospin and hypercharge axialvector polarization functions are used as input in new chiral sum rules, valid to second order in the light quark masses. Some phenomenological implications of these sum rules are considered.
1907.05929
Elin Bergeaas Kuutmann
Rachid Benbrik, Elin Bergeaas Kuutmann, Diogo Buarque Franzosi, Venugopal Ellajosyula, Rikard Enberg, Gabriele Ferretti, Max Isacson, Yao-Bei Liu, Tanumoy Mandal, Thomas Mathisen, Stefano Moretti, Luca Panizzi
Signatures of vector-like top partners decaying into new neutral scalar or pseudoscalar bosons
50 pages, 21 figures, published in JHEP. v4 with an update of figure 14
JHEP 05 (2020) 028
10.1007/JHEP05(2020)028
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the phenomenology of models containing one Vector-Like Quark (VLQ), $t'$, which can decay into the Standard Model (SM) top quark, $t$, and a new spin-0 neutral boson, $S$, the latter being either a scalar or pseudoscalar state. We parametrise the underlying interactions in terms of a simplified model which enables us to capture possible Beyond the SM (BSM) scenarios. We discuss in particular three such scenarios: one where the SM state is supplemented by an additional scalar, one which builds upon a 2-Higgs Doublet Model (2HDM) framework and another which realises a Composite Higgs Model (CHM) through partial compositeness. Such exotic decays of the $t'$ can be competitive with decays into SM particles, leading to new possible discovery channels at the Large Hadron Collider (LHC). Assuming $t'$ pair production via strong interactions, we design signal regions optimised for one $t'\rightarrow S t$ transition (while being inclusive on the other \bar{t'} decay, and vice versa), followed by the decay of $S$ into the two very clean experimental signatures $S\rightarrow \gamma \gamma$ and $S\rightarrow Z(\rightarrow \ell^+\ell^-)\gamma$. We perform a dedicated signal-to-background analysis in both channels, by using Monte Carlo (MC) event simulations modelling the dynamics from the proton-proton to the detector level. Under the assumption of BR$(t' \rightarrow S t) = 100\%$, we are therefore able to realistically quantify the sensitivity of the LHC to both the $t'$ and $S$ masses, assuming both current and foreseen luminosities. This approach paves the way for the LHC experiments to surpass current VLQ search strategies based solely on $t'$ decays into SM bosons ($W^\pm, Z$, $h$).
[ { "created": "Fri, 12 Jul 2019 19:49:13 GMT", "version": "v1" }, { "created": "Tue, 30 Jul 2019 16:25:24 GMT", "version": "v2" }, { "created": "Mon, 27 Apr 2020 12:51:50 GMT", "version": "v3" }, { "created": "Wed, 13 May 2020 14:13:50 GMT", "version": "v4" } ]
2020-05-14
[ [ "Benbrik", "Rachid", "" ], [ "Kuutmann", "Elin Bergeaas", "" ], [ "Franzosi", "Diogo Buarque", "" ], [ "Ellajosyula", "Venugopal", "" ], [ "Enberg", "Rikard", "" ], [ "Ferretti", "Gabriele", "" ], [ "Isacson", "Max", "" ], [ "Liu", "Yao-Bei", "" ], [ "Mandal", "Tanumoy", "" ], [ "Mathisen", "Thomas", "" ], [ "Moretti", "Stefano", "" ], [ "Panizzi", "Luca", "" ] ]
We explore the phenomenology of models containing one Vector-Like Quark (VLQ), $t'$, which can decay into the Standard Model (SM) top quark, $t$, and a new spin-0 neutral boson, $S$, the latter being either a scalar or pseudoscalar state. We parametrise the underlying interactions in terms of a simplified model which enables us to capture possible Beyond the SM (BSM) scenarios. We discuss in particular three such scenarios: one where the SM state is supplemented by an additional scalar, one which builds upon a 2-Higgs Doublet Model (2HDM) framework and another which realises a Composite Higgs Model (CHM) through partial compositeness. Such exotic decays of the $t'$ can be competitive with decays into SM particles, leading to new possible discovery channels at the Large Hadron Collider (LHC). Assuming $t'$ pair production via strong interactions, we design signal regions optimised for one $t'\rightarrow S t$ transition (while being inclusive on the other \bar{t'} decay, and vice versa), followed by the decay of $S$ into the two very clean experimental signatures $S\rightarrow \gamma \gamma$ and $S\rightarrow Z(\rightarrow \ell^+\ell^-)\gamma$. We perform a dedicated signal-to-background analysis in both channels, by using Monte Carlo (MC) event simulations modelling the dynamics from the proton-proton to the detector level. Under the assumption of BR$(t' \rightarrow S t) = 100\%$, we are therefore able to realistically quantify the sensitivity of the LHC to both the $t'$ and $S$ masses, assuming both current and foreseen luminosities. This approach paves the way for the LHC experiments to surpass current VLQ search strategies based solely on $t'$ decays into SM bosons ($W^\pm, Z$, $h$).
1403.3394
Andreas Papaefstathiou
Massimiliano Grazzini, Andreas Papaefstathiou, Jennifer M. Smillie and Bryan R. Webber
Resummation of the transverse-energy distribution in Higgs boson production at the Large Hadron Collider
26 pages, 13 figures. Version to appear in JHEP
null
10.1007/JHEP09(2014)056
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the resummed hadronic transverse-energy ($E_T$) distribution due to initial-state QCD radiation in the production of a Standard Model Higgs boson of mass 126 GeV by gluon fusion at the Large Hadron Collider, with matching to next-to-leading order calculations at large $E_T$. Effects of hadronization, underlying event and limited detector acceptance are estimated using aMC@NLO with the Herwig++ and Pythia 8 event generators.
[ { "created": "Thu, 13 Mar 2014 20:00:01 GMT", "version": "v1" }, { "created": "Mon, 25 Aug 2014 10:58:10 GMT", "version": "v2" } ]
2015-06-19
[ [ "Grazzini", "Massimiliano", "" ], [ "Papaefstathiou", "Andreas", "" ], [ "Smillie", "Jennifer M.", "" ], [ "Webber", "Bryan R.", "" ] ]
We compute the resummed hadronic transverse-energy ($E_T$) distribution due to initial-state QCD radiation in the production of a Standard Model Higgs boson of mass 126 GeV by gluon fusion at the Large Hadron Collider, with matching to next-to-leading order calculations at large $E_T$. Effects of hadronization, underlying event and limited detector acceptance are estimated using aMC@NLO with the Herwig++ and Pythia 8 event generators.
hep-ph/0106112
Michael Lublinsky
M. Lublinsky
Scaling phenomena from non-linear evolution in high energy DIS
13 pages, 20 figures
Eur.Phys.J.C21:513-519,2001
10.1007/s100520100752
null
hep-ph
null
The numerical solutions of the non-linear evolution equation are shown to display the ``geometric'' scaling recently discovered in the experimental data. The phenomena hold both for proton and nucleus targets for all $x$ below $10^{-2}$ and $0.25 {\rm GeV^{2}}\le Q^2 \le 2.5\times10^3 {\rm GeV^{2}}$. The scaling is practically exact (few percent error) in the saturation region. In addition, an approximate scaling is found in the validity domain of the linear evolution where it holds with about 10% accuracy. Basing on the scaling phenomena we determine the saturation scale $Q_s(x)$ and study both its $x$-dependence and the atomic number dependence for the nuclei.
[ { "created": "Mon, 11 Jun 2001 12:20:50 GMT", "version": "v1" } ]
2009-01-07
[ [ "Lublinsky", "M.", "" ] ]
The numerical solutions of the non-linear evolution equation are shown to display the ``geometric'' scaling recently discovered in the experimental data. The phenomena hold both for proton and nucleus targets for all $x$ below $10^{-2}$ and $0.25 {\rm GeV^{2}}\le Q^2 \le 2.5\times10^3 {\rm GeV^{2}}$. The scaling is practically exact (few percent error) in the saturation region. In addition, an approximate scaling is found in the validity domain of the linear evolution where it holds with about 10% accuracy. Basing on the scaling phenomena we determine the saturation scale $Q_s(x)$ and study both its $x$-dependence and the atomic number dependence for the nuclei.
2106.01956
Tomohiro Abe
Tomohiro Abe
Early kinetic decoupling and a pseudo-Nambu-Goldstone dark matter model
20 pages, 3 figures, version accepted by PRD
Phys. Rev. D 104, 035025 (2021)
10.1103/PhysRevD.104.035025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the early kinetic decoupling effect in a pseudo-Nambu-Goldstone (pNG) dark matter (DM) model. The pNG DM scattering processes with particles in the thermal bath in the early Universe are suppressed by the small momentum transfer. As a result, kinetic equilibrium is not maintained, and the temperature of DM is different from the temperature of the thermal bath at the freeze-out era. This temperature difference affects the thermal relic abundance of DM. We investigate the early kinetic decoupling in the Higgs resonance region, 50 GeV $\lesssim m_\chi \lesssim m_h/2$, where $m_\chi$ is the mass of the DM, and $m_h/2 \simeq$ 62.5 GeV. We find that the DM-Higgs coupling determined to obtain the measured value of the DM energy density is underestimated in the literature. The enhancement in the coupling leads larger value of the Higgs invisible decay rate. It enlarges the capability to discover the DM signals from the decay of the Higgs bosons at collider experiments.
[ { "created": "Thu, 3 Jun 2021 16:03:50 GMT", "version": "v1" }, { "created": "Sat, 7 Aug 2021 04:24:23 GMT", "version": "v2" } ]
2021-09-01
[ [ "Abe", "Tomohiro", "" ] ]
We study the early kinetic decoupling effect in a pseudo-Nambu-Goldstone (pNG) dark matter (DM) model. The pNG DM scattering processes with particles in the thermal bath in the early Universe are suppressed by the small momentum transfer. As a result, kinetic equilibrium is not maintained, and the temperature of DM is different from the temperature of the thermal bath at the freeze-out era. This temperature difference affects the thermal relic abundance of DM. We investigate the early kinetic decoupling in the Higgs resonance region, 50 GeV $\lesssim m_\chi \lesssim m_h/2$, where $m_\chi$ is the mass of the DM, and $m_h/2 \simeq$ 62.5 GeV. We find that the DM-Higgs coupling determined to obtain the measured value of the DM energy density is underestimated in the literature. The enhancement in the coupling leads larger value of the Higgs invisible decay rate. It enlarges the capability to discover the DM signals from the decay of the Higgs bosons at collider experiments.
2302.13720
Victor Goncalves
Yuri N. Lima, Andr\'e V. Giannini, Victor P. Goncalves
Isolated photon production in $pp$ collisions at forward rapidities and high multiplicity events
9 pages, 6 figures. Improved version published in European Physical Journal A
null
10.1140/epja/s10050-024-01287-6
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of isolated photons in high multiplicity events is investigated considering the Color Glass Condensate (CGC) formalism. The associated cross-section for proton - proton collisions is estimated considering three distinct solutions of the Balitsky - Kovchegov (BK) equation and predictions for the normalized photon yield as a function of the multiplicities of co - produced charged particles are presented. We predict the increasing of the yield with the multiplicity, with the slope being smaller for larger rapidities. As the isolated photon production is not affected by the fragmentation process, a future experimental investigation of this process in current high energy hadronic colliders is ideal to test the treatment of high multiplicity events using the CGC formalism, previously applied only for the production of hadronic final states.
[ { "created": "Mon, 27 Feb 2023 12:33:50 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2024 11:49:45 GMT", "version": "v2" } ]
2024-03-13
[ [ "Lima", "Yuri N.", "" ], [ "Giannini", "André V.", "" ], [ "Goncalves", "Victor P.", "" ] ]
The production of isolated photons in high multiplicity events is investigated considering the Color Glass Condensate (CGC) formalism. The associated cross-section for proton - proton collisions is estimated considering three distinct solutions of the Balitsky - Kovchegov (BK) equation and predictions for the normalized photon yield as a function of the multiplicities of co - produced charged particles are presented. We predict the increasing of the yield with the multiplicity, with the slope being smaller for larger rapidities. As the isolated photon production is not affected by the fragmentation process, a future experimental investigation of this process in current high energy hadronic colliders is ideal to test the treatment of high multiplicity events using the CGC formalism, previously applied only for the production of hadronic final states.
hep-ph/0208180
Vladimir Miransky
V.A. Miransky
Dynamics of QCD in a Strong Magnetic Field
12 pages, 1 figure, Latex, Talk at Symposium and Workshop "Continuous Advances in QCD 2002/Arkadyfest, May 17-23, 2002
null
10.1142/9789812776310_0013
null
hep-ph
null
QCD in a strong magnetic field yields an example of a rich, sophisticated and controllable dynamics.
[ { "created": "Tue, 20 Aug 2002 14:58:26 GMT", "version": "v1" } ]
2017-08-23
[ [ "Miransky", "V. A.", "" ] ]
QCD in a strong magnetic field yields an example of a rich, sophisticated and controllable dynamics.
1205.0013
Jay Hubisz
Joshua Berger, Jay Hubisz, and Maxim Perelstein
A Fermionic Top Partner: Naturalness and the LHC
30 pages, 8 figures, 1 table; v2: Minor changes. Final version to appear in JHEP; v3: References added
null
10.1007/JHEP07(2012)016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Naturalness demands that the quadratic divergence of the one-loop top contribution to the Higgs mass be cancelled at a scale below 1 TeV. This can be achieved by introducing a fermionic (spin-1/2) top partner, as in, for example, Little Higgs models. In this paper, we study the phenomenology of a simple model realizing this mechanism. We present the current bounds on the model from precision electroweak fits, flavor physics, and direct searches at the LHC. The lower bound on the top partner mass from precision electroweak data is approximately 500 GeV, while the LHC bound with 5/fb of data at sqrt(s)=7 TeV is about 450 GeV. Given these bounds, the model can incorporate a 125 GeV Higgs with minimal fine-tuning of about 20%. We conclude that natural electroweak symmetry breaking with a fermionic top partner remains a viable possibility. We also compute the Higgs decay rates into gauge bosons, and find that significant, potentially observable deviations from the Standard Model predictions may occur.
[ { "created": "Mon, 30 Apr 2012 20:00:06 GMT", "version": "v1" }, { "created": "Fri, 29 Jun 2012 18:36:00 GMT", "version": "v2" }, { "created": "Fri, 4 Jan 2013 14:46:21 GMT", "version": "v3" } ]
2015-06-04
[ [ "Berger", "Joshua", "" ], [ "Hubisz", "Jay", "" ], [ "Perelstein", "Maxim", "" ] ]
Naturalness demands that the quadratic divergence of the one-loop top contribution to the Higgs mass be cancelled at a scale below 1 TeV. This can be achieved by introducing a fermionic (spin-1/2) top partner, as in, for example, Little Higgs models. In this paper, we study the phenomenology of a simple model realizing this mechanism. We present the current bounds on the model from precision electroweak fits, flavor physics, and direct searches at the LHC. The lower bound on the top partner mass from precision electroweak data is approximately 500 GeV, while the LHC bound with 5/fb of data at sqrt(s)=7 TeV is about 450 GeV. Given these bounds, the model can incorporate a 125 GeV Higgs with minimal fine-tuning of about 20%. We conclude that natural electroweak symmetry breaking with a fermionic top partner remains a viable possibility. We also compute the Higgs decay rates into gauge bosons, and find that significant, potentially observable deviations from the Standard Model predictions may occur.
hep-ph/9709219
Thomas Gajdosik
A. Bartl, E. Christova, T. Gajdosik, W. Majerotto
Electroweak dipole moment form factors of the top quark in supersymmetry
Footnote changed; 4 pages, LaTeX, 2 figures included as separate files, uses epsfig.sty and espcrc2.sty. Talk presented by A. Bartl at the XVI International Workshop on Weak Interaction and Neutrinos (WIN 97), Capri, Italy, 22-28 June, 1997. To appear in the Proceedings
Nucl.Phys.Proc.Suppl.66:75-78,1998
10.1016/S0920-5632(98)00013-9
HEPHY-PUB 672/97, UWThPh-1997-28, hep-ph/yymmnnn
hep-ph
null
We present a complete analysis of the electrtic and weak dipole moment form factors of the top quark within the Minimal Supersymmetric Standard Model with complex parameters. We include gluino, chargino, and neutralino exchange in the loops of the $\gamma t\bar{t}$ and $Z t\bar{t}$ vertices.
[ { "created": "Tue, 2 Sep 1997 15:54:37 GMT", "version": "v1" }, { "created": "Thu, 4 Dec 1997 13:16:58 GMT", "version": "v2" } ]
2011-01-25
[ [ "Bartl", "A.", "" ], [ "Christova", "E.", "" ], [ "Gajdosik", "T.", "" ], [ "Majerotto", "W.", "" ] ]
We present a complete analysis of the electrtic and weak dipole moment form factors of the top quark within the Minimal Supersymmetric Standard Model with complex parameters. We include gluino, chargino, and neutralino exchange in the loops of the $\gamma t\bar{t}$ and $Z t\bar{t}$ vertices.
2305.05052
Francesco Giovanni Celiberto
Francesco Giovanni Celiberto, Luigi Delle Rose, Michael Fucilla, Gabriele Gatto, Alessandro Papa
High-energy resummed Higgs-plus-jet distributions at NLL/NLO* with POWHEG+JETHAD
4 pages, 1 figure. Contribution to the 2023 QCD session of the 57th Rencontres de Moriond
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the inclusive production, at hadron colliders, of a Higgs boson and a jet widely separated in rapidity. Kinematic sectors explored fall into the so-called semi-hard regime, where both fixed-order and high-energy dynamics come into play. Therefore, we propose a first version of a matching procedure aimed at combining NLO fixed-order computations, as obtained from POWHEG, with the NLL resummation of energy logarithms via JETHAD. According to our knowledge, this represents a novel implementation of a matching in the context of the high-energy resummation at NLL and for rapidity-separated two-particle final states.
[ { "created": "Mon, 8 May 2023 21:14:44 GMT", "version": "v1" } ]
2023-05-10
[ [ "Celiberto", "Francesco Giovanni", "" ], [ "Rose", "Luigi Delle", "" ], [ "Fucilla", "Michael", "" ], [ "Gatto", "Gabriele", "" ], [ "Papa", "Alessandro", "" ] ]
We study the inclusive production, at hadron colliders, of a Higgs boson and a jet widely separated in rapidity. Kinematic sectors explored fall into the so-called semi-hard regime, where both fixed-order and high-energy dynamics come into play. Therefore, we propose a first version of a matching procedure aimed at combining NLO fixed-order computations, as obtained from POWHEG, with the NLL resummation of energy logarithms via JETHAD. According to our knowledge, this represents a novel implementation of a matching in the context of the high-energy resummation at NLL and for rapidity-separated two-particle final states.
1910.02094
Sebastian Pa{\ss}ehr
Mark D. Goodsell and Sebastian Pa{\ss}ehr
All two-loop scalar self-energies and tadpoles in general renormalisable field theories
76 pages, 5 figures
null
10.1140/epjc/s10052-020-7657-8
TTK-19-38
hep-ph
http://creativecommons.org/licenses/by/4.0/
We calculate the complete tadpoles and self-energies at the two-loop order for scalars in general renormalisable theories, a crucial component for calculating two-loop electroweak corrections to Higgs-boson masses or for any scalar beyond the Standard Model. We renormalise the amplitudes using mass-independent renormalisation schemes, based on both dimensional regularisation and dimensional reduction. The results are presented here in Feynman gauge, with expressions for all 121 self-energy and 25 tadpole diagrams given in terms of scalar and tensor integrals with the complete set of rules to reduce them to a minimal basis of scalar integrals for any physical kinematic configuration. In addition, we simplify the results to a set of only 16 tadpole and 58 self-energy topologies using relations in order to substitute the ghost and Goldstone-boson couplings that we derive. To facilitate their application, we also provide our results in electronic form as a new code TLDR. We test our results by applying them to the Standard Model and compare with analytic expressions in the literature.
[ { "created": "Fri, 4 Oct 2019 18:12:49 GMT", "version": "v1" } ]
2020-06-24
[ [ "Goodsell", "Mark D.", "" ], [ "Paßehr", "Sebastian", "" ] ]
We calculate the complete tadpoles and self-energies at the two-loop order for scalars in general renormalisable theories, a crucial component for calculating two-loop electroweak corrections to Higgs-boson masses or for any scalar beyond the Standard Model. We renormalise the amplitudes using mass-independent renormalisation schemes, based on both dimensional regularisation and dimensional reduction. The results are presented here in Feynman gauge, with expressions for all 121 self-energy and 25 tadpole diagrams given in terms of scalar and tensor integrals with the complete set of rules to reduce them to a minimal basis of scalar integrals for any physical kinematic configuration. In addition, we simplify the results to a set of only 16 tadpole and 58 self-energy topologies using relations in order to substitute the ghost and Goldstone-boson couplings that we derive. To facilitate their application, we also provide our results in electronic form as a new code TLDR. We test our results by applying them to the Standard Model and compare with analytic expressions in the literature.
hep-ph/9701240
A. Yates
T.W.B. Kibble, G. Lozano, A.J. Yates
Non-Abelian String Conductivity
19 pages, LaTeX, 3 figures, requires epsf.sty. Figure problems with postscript version corrected. Also available at http://euclid.tp.ph.ic.ac.uk/Papers/
Phys.Rev. D56 (1997) 1204-1214
10.1103/PhysRevD.56.1204
Imperial/TP/96-97/14, Heidelberg/HD-THEP-96-59
hep-ph astro-ph
null
We examine current-carrying configurations of cosmic strings in non-Abelian gauge theories. We study the solutions numerically and point out that the currents will be at best dynamically stable and not subject to any topological quantisation or conservation, as in conventional models of string superconduction. We suggest that non-Abelian string loops may be unable to support persistent currents in the absence of external fields. This will have relevance to vorton stability.
[ { "created": "Tue, 7 Jan 1997 15:34:27 GMT", "version": "v1" }, { "created": "Tue, 14 Jan 1997 17:30:23 GMT", "version": "v2" } ]
2009-10-30
[ [ "Kibble", "T. W. B.", "" ], [ "Lozano", "G.", "" ], [ "Yates", "A. J.", "" ] ]
We examine current-carrying configurations of cosmic strings in non-Abelian gauge theories. We study the solutions numerically and point out that the currents will be at best dynamically stable and not subject to any topological quantisation or conservation, as in conventional models of string superconduction. We suggest that non-Abelian string loops may be unable to support persistent currents in the absence of external fields. This will have relevance to vorton stability.
hep-ph/0503279
Andreas Gerhold
Andreas Gerhold
Aspects of cold dense quark matter
Ph.D. thesis, 121 pages, 18 figures
null
null
null
hep-ph
null
This thesis is devoted to properties of quark matter at high density and (comparatively) low temperature, which might exist in the interior of compact stars. The specific heat and the quark self energy in normal quark matter are discussed in detail. In particular higher order corrections to the known leading order results are obtained. Also the phenomenon of color superconductivity is discussed, with particular emphasis on the proof of gauge independence of the fermionic quasiparticle dispersion laws. Moreover, the expectation value of the gluon field in the 2SC and CFL phase is computed at leading order.
[ { "created": "Tue, 29 Mar 2005 14:31:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gerhold", "Andreas", "" ] ]
This thesis is devoted to properties of quark matter at high density and (comparatively) low temperature, which might exist in the interior of compact stars. The specific heat and the quark self energy in normal quark matter are discussed in detail. In particular higher order corrections to the known leading order results are obtained. Also the phenomenon of color superconductivity is discussed, with particular emphasis on the proof of gauge independence of the fermionic quasiparticle dispersion laws. Moreover, the expectation value of the gluon field in the 2SC and CFL phase is computed at leading order.
hep-ph/0612359
Tianjun Li
Tianjun Li
String Inspired Singlet Extensions of the Minimal Supersymmetric Standard Model
RevTex4, 5 pages, 2 tables, comments and references added, version to appear in PLB
Phys.Lett.B653:338-342,2007
10.1016/j.physletb.2007.08.027
null
hep-ph hep-th
null
The only allowed Higgs superpotential term at stringy tree level in the string derived Singlet Extensions of the Minimal Supersymmetric Standard Model (SEMSSM) is h S H_d H_u, which leads to an additional global U(1) symmetry in the Higgs potential. We propose the string inspired SEMSSM where the global U(1) symmetry is broken by the additional superpotential terms or supersymmetry breaking soft terms that can be obtained naturally due to the instanton effects or anomalous U(1)_A gauge symmetry. In these models, we can solve the \mu problem and the fine-tuning problem for the lightest CP-even Higgs boson mass in the MSSM, generate the baryon asymmetry via electroweak baryogenesis, and predict the new Higgs physics which can be tested at the LHC and ILC.
[ { "created": "Thu, 28 Dec 2006 18:17:02 GMT", "version": "v1" }, { "created": "Mon, 15 Jan 2007 09:49:48 GMT", "version": "v2" }, { "created": "Tue, 28 Aug 2007 17:33:02 GMT", "version": "v3" } ]
2008-11-26
[ [ "Li", "Tianjun", "" ] ]
The only allowed Higgs superpotential term at stringy tree level in the string derived Singlet Extensions of the Minimal Supersymmetric Standard Model (SEMSSM) is h S H_d H_u, which leads to an additional global U(1) symmetry in the Higgs potential. We propose the string inspired SEMSSM where the global U(1) symmetry is broken by the additional superpotential terms or supersymmetry breaking soft terms that can be obtained naturally due to the instanton effects or anomalous U(1)_A gauge symmetry. In these models, we can solve the \mu problem and the fine-tuning problem for the lightest CP-even Higgs boson mass in the MSSM, generate the baryon asymmetry via electroweak baryogenesis, and predict the new Higgs physics which can be tested at the LHC and ILC.
hep-ph/9912517
Martin Mojzis
Martin Mojzis, Joachim Kambor
Reordering of Baryon Chiral Perturbation Theory
9 pages, one reference added
Phys.Lett. B476 (2000) 344-348
10.1016/S0370-2693(00)00168-4
ZU-TH 41/99
hep-ph nucl-th
null
Reordering of the chiral perturbation series, proposed recently by Becher and Leutwyler in the framework of SU(2) baryonic ChPT, is applied to the SU(3) case. This results in improved convergence of the chiral expansion of static properties of the lowest lying baryon octet, which in most cases is quite impressive. Finite renormalization of coupling constants and the role it plays in the interpretation of effective field theories is discussed. Some future tests of the viability of the scheme are proposed too.
[ { "created": "Tue, 28 Dec 1999 00:02:50 GMT", "version": "v1" }, { "created": "Wed, 9 Feb 2000 11:52:27 GMT", "version": "v2" } ]
2009-10-31
[ [ "Mojzis", "Martin", "" ], [ "Kambor", "Joachim", "" ] ]
Reordering of the chiral perturbation series, proposed recently by Becher and Leutwyler in the framework of SU(2) baryonic ChPT, is applied to the SU(3) case. This results in improved convergence of the chiral expansion of static properties of the lowest lying baryon octet, which in most cases is quite impressive. Finite renormalization of coupling constants and the role it plays in the interpretation of effective field theories is discussed. Some future tests of the viability of the scheme are proposed too.
1608.06393
Yoshiharu Kawamura
Yugo Abe, Yuhei Goto, Yoshiharu Kawamura, and Yasunari Nishikawa
Conjugate boundary condition, hidden particles, and gauge-Higgs inflation
12 pages, typos corrected
Mod. Phys. Lett. A, Vol. 31, No. 35 (2016) 1650208
10.1142/S0217732316502084
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an idea that hidden particles can be separated according to gauge quantum numbers from the visible ones by the difference of boundary conditions on extra dimensions. We formulate 5-dimensional gauge theories yielding conjugate boundary conditions besides ordinary ones on $S^1/Z_2$, and examine physical implications concerning hidden particles on an extension of the standard model coexisting different types of boundary conditions. A model with conjugate boundary conditions is applied on a gauge-Higgs inflation scenario.
[ { "created": "Tue, 23 Aug 2016 06:15:06 GMT", "version": "v1" }, { "created": "Mon, 29 Aug 2016 08:37:46 GMT", "version": "v2" }, { "created": "Sun, 4 Sep 2016 23:50:20 GMT", "version": "v3" }, { "created": "Sat, 29 Oct 2016 05:58:01 GMT", "version": "v4" } ]
2016-11-01
[ [ "Abe", "Yugo", "" ], [ "Goto", "Yuhei", "" ], [ "Kawamura", "Yoshiharu", "" ], [ "Nishikawa", "Yasunari", "" ] ]
We propose an idea that hidden particles can be separated according to gauge quantum numbers from the visible ones by the difference of boundary conditions on extra dimensions. We formulate 5-dimensional gauge theories yielding conjugate boundary conditions besides ordinary ones on $S^1/Z_2$, and examine physical implications concerning hidden particles on an extension of the standard model coexisting different types of boundary conditions. A model with conjugate boundary conditions is applied on a gauge-Higgs inflation scenario.
2305.11106
Emmanuel de Oliveira
Edgar Huayra, Joao Vitor C. Lovato, Emmanuel G. de Oliveira
Valence and sea parton correlations in double parton scattering from data
8 pages, 1 figure, updated results, to be published in JHEP
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effective cross section of double parton scattering in proton collisions has been measured by many experiments with rather different results. Motivated by this fact, we assumed that the parton correlations in the transverse plane are different whether we have valence or sea partons. With this simple approach, we were able to fit the available data and found that sea parton pairs are more correlated in the transverse plane than valence--sea parton pairs.
[ { "created": "Thu, 18 May 2023 16:51:50 GMT", "version": "v1" }, { "created": "Mon, 25 Sep 2023 21:50:31 GMT", "version": "v2" } ]
2023-09-27
[ [ "Huayra", "Edgar", "" ], [ "Lovato", "Joao Vitor C.", "" ], [ "de Oliveira", "Emmanuel G.", "" ] ]
The effective cross section of double parton scattering in proton collisions has been measured by many experiments with rather different results. Motivated by this fact, we assumed that the parton correlations in the transverse plane are different whether we have valence or sea partons. With this simple approach, we were able to fit the available data and found that sea parton pairs are more correlated in the transverse plane than valence--sea parton pairs.
1510.04561
Tevong You
John Ellis and Tevong You
Sensitivities of Prospective Future e+e- Colliders to Decoupled New Physics
19 pages
null
10.1007/JHEP03(2016)089
KCL-PH-TH/2015-47, LCTS/2015-35, CERN-PH-TH/2015-244, Cavendish-HEP-15/09, DAMTP-2015-62
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the indirect sensitivities to decoupled new physics of prospective precision electroweak measurements, triple-gauge-coupling measurements and Higgs physics at future $e^+e^-$ colliders, with emphasis on the ILC250 and FCC-ee. The Standard Model effective field theory (SM EFT) is adopted as a model-independent approach for relating experimental precision projections to the scale of new physics, and we present prospective constraints on the Wilson coefficients of dimension-6 operators. We find that in a marginalised fit ILC250 EWPT measurements may be sensitive to new physics scales $\Lambda = \mathcal{O}(10)$~TeV, and FCC-ee EWPT measurements may be sensitive to $\Lambda = \mathcal{O}(30)$~TeV. The prospective sensitivities of Higgs and TGC measurements at the ILC250 (FCC-ee) are to $\Lambda = \mathcal{O}(1)$~TeV ($\Lambda = \mathcal{O}(2)$~TeV).
[ { "created": "Thu, 15 Oct 2015 14:51:27 GMT", "version": "v1" } ]
2016-04-20
[ [ "Ellis", "John", "" ], [ "You", "Tevong", "" ] ]
We explore the indirect sensitivities to decoupled new physics of prospective precision electroweak measurements, triple-gauge-coupling measurements and Higgs physics at future $e^+e^-$ colliders, with emphasis on the ILC250 and FCC-ee. The Standard Model effective field theory (SM EFT) is adopted as a model-independent approach for relating experimental precision projections to the scale of new physics, and we present prospective constraints on the Wilson coefficients of dimension-6 operators. We find that in a marginalised fit ILC250 EWPT measurements may be sensitive to new physics scales $\Lambda = \mathcal{O}(10)$~TeV, and FCC-ee EWPT measurements may be sensitive to $\Lambda = \mathcal{O}(30)$~TeV. The prospective sensitivities of Higgs and TGC measurements at the ILC250 (FCC-ee) are to $\Lambda = \mathcal{O}(1)$~TeV ($\Lambda = \mathcal{O}(2)$~TeV).
hep-ph/9903517
Yuval Grossman
Sven Bergmann, Yuval Grossman and Enrico Nardi
Neutrino propagation in matter with general interactions
14 pages, revtex, no figures. Final version to appear in PRD; a short discussion of the relevance of new tensor interactions for solar and supernova neutrinos has been added
Phys. Rev. D 60, 093008 (1999)
10.1103/PhysRevD.60.093008
WIS-99/11/Mar.-DPP, SLAC-PUB-8083, UdeA-PE-99/001
hep-ph
null
We present a general analysis of the effective potential for neutrino propagation in matter, assuming a generic set of Lorentz invariant non-derivative interactions. We find that in addition to the known vector and axial vector terms, in a polarized medium also tensor interactions can play an important role. We compute the effective potential arising from a tensor interaction. We show that the components of the tensor potential transverse to the direction of the neutrino propagation can induce a neutrino spin-flip, similar to the one induced by a transverse magnetic field.
[ { "created": "Mon, 29 Mar 1999 18:57:59 GMT", "version": "v1" }, { "created": "Wed, 14 Apr 1999 21:54:42 GMT", "version": "v2" }, { "created": "Thu, 30 Sep 1999 17:40:42 GMT", "version": "v3" } ]
2016-08-25
[ [ "Bergmann", "Sven", "" ], [ "Grossman", "Yuval", "" ], [ "Nardi", "Enrico", "" ] ]
We present a general analysis of the effective potential for neutrino propagation in matter, assuming a generic set of Lorentz invariant non-derivative interactions. We find that in addition to the known vector and axial vector terms, in a polarized medium also tensor interactions can play an important role. We compute the effective potential arising from a tensor interaction. We show that the components of the tensor potential transverse to the direction of the neutrino propagation can induce a neutrino spin-flip, similar to the one induced by a transverse magnetic field.
1512.05295
Kwang Sik Jeong
Tetsutaro Higaki, Kwang Sik Jeong, Naoya Kitajima, Fuminobu Takahashi
The QCD Axion from Aligned Axions and Diphoton Excess
11 pages; v3: typos corrected, references added, to appear in Physics Letters B
null
10.1016/j.physletb.2016.01.055
TU-1012,IPMU 15-0212, APCTP Pre2015-029
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the QCD axion can arise from many aligned axions with decay constants much smaller than the conventional axion window. If the typical decay constant is of {\cal O}{(100)} GeV to 1 TeV, one or more of the axions or saxions may account for the recently found diphoton excess at \sim 750 GeV. Our scenario predicts many axions and saxions coupled to gluons with decay constants of order the weak scale, and therefore many collider signatures by heavy axions and saxions will show up at different energy scales. In particular, if the inferred broad decay width is due to multiple axions or saxions, a non-trivial peak structure may become evident when more data is collected. We also discuss cosmological implications of the aligned QCD axion scenario. In the Appendix we give a possible UV completion and argue that the high quality of the Peccei-Quinn symmetry is naturally explained in our scenario.
[ { "created": "Wed, 16 Dec 2015 19:36:36 GMT", "version": "v1" }, { "created": "Mon, 21 Dec 2015 16:43:38 GMT", "version": "v2" }, { "created": "Thu, 28 Jan 2016 08:25:05 GMT", "version": "v3" } ]
2016-02-03
[ [ "Higaki", "Tetsutaro", "" ], [ "Jeong", "Kwang Sik", "" ], [ "Kitajima", "Naoya", "" ], [ "Takahashi", "Fuminobu", "" ] ]
We argue that the QCD axion can arise from many aligned axions with decay constants much smaller than the conventional axion window. If the typical decay constant is of {\cal O}{(100)} GeV to 1 TeV, one or more of the axions or saxions may account for the recently found diphoton excess at \sim 750 GeV. Our scenario predicts many axions and saxions coupled to gluons with decay constants of order the weak scale, and therefore many collider signatures by heavy axions and saxions will show up at different energy scales. In particular, if the inferred broad decay width is due to multiple axions or saxions, a non-trivial peak structure may become evident when more data is collected. We also discuss cosmological implications of the aligned QCD axion scenario. In the Appendix we give a possible UV completion and argue that the high quality of the Peccei-Quinn symmetry is naturally explained in our scenario.
hep-ph/0504205
Maciej Skrzypek
S. Jadach, M. Skrzypek
Non-Markovian Monte Carlo Algorithm for the Constrained Markovian Evolution in QCD
null
Acta Phys.Polon.B36:2979-3022,2005
null
IFJPAN-V-04-06, CERN-PH-TH/2005-065
hep-ph
null
We revisit the challenging problem of finding an efficient Monte Carlo (MC) algorithm solving the constrained evolution equations for the initial-state QCD radiation. The type of the parton (quark, gluon) and the energy fraction x of the parton exiting emission chain (entering hard process) are predefined, i.e. constrained throughout the evolution. Such a constraint is mandatory for any realistic MC for the initial state QCD parton shower. We add one important condition: the MC algorithm must not require the a priori knowledge of the full numerical exact solutions of the evolution equations, as is the case in the popular ``Markovian MC for backward evolution''. Our aim is to find at least one solution of this problem that would function in practice. Finding such a solution seems to be definitely within the reach of the currently available computer CPUs and the sophistication of the modern MC techniques. We describe in this work the first example of an efficient solution of this kind. Its numerical implementation is still restricted to the pure gluon-strahlung. As expected, it is not in the class of the so-called Markovian MCs. For this reason we refer to it as belonging to a class of non-Markovian MCs. We show that numerical results of our new MC algorithm agree very well (to 0.2%) with the results of the other MC program of our own (unconstrained Markovian) and another non-MC program QCDnum16. This provides a proof of the existence of the new class of MC techniques, to be exploited in the precision perturbative QCD calculations for the Large Hadron Collider.
[ { "created": "Fri, 22 Apr 2005 12:31:47 GMT", "version": "v1" } ]
2014-11-18
[ [ "Jadach", "S.", "" ], [ "Skrzypek", "M.", "" ] ]
We revisit the challenging problem of finding an efficient Monte Carlo (MC) algorithm solving the constrained evolution equations for the initial-state QCD radiation. The type of the parton (quark, gluon) and the energy fraction x of the parton exiting emission chain (entering hard process) are predefined, i.e. constrained throughout the evolution. Such a constraint is mandatory for any realistic MC for the initial state QCD parton shower. We add one important condition: the MC algorithm must not require the a priori knowledge of the full numerical exact solutions of the evolution equations, as is the case in the popular ``Markovian MC for backward evolution''. Our aim is to find at least one solution of this problem that would function in practice. Finding such a solution seems to be definitely within the reach of the currently available computer CPUs and the sophistication of the modern MC techniques. We describe in this work the first example of an efficient solution of this kind. Its numerical implementation is still restricted to the pure gluon-strahlung. As expected, it is not in the class of the so-called Markovian MCs. For this reason we refer to it as belonging to a class of non-Markovian MCs. We show that numerical results of our new MC algorithm agree very well (to 0.2%) with the results of the other MC program of our own (unconstrained Markovian) and another non-MC program QCDnum16. This provides a proof of the existence of the new class of MC techniques, to be exploited in the precision perturbative QCD calculations for the Large Hadron Collider.
hep-ph/0401240
Pasquale Di Bari
W. Buchmuller, P. Di Bari, M. Plumacher
Leptogenesis for Pedestrians
55 pages, 14 figures included
Annals Phys. 315 (2005) 305-351
10.1016/j.aop.2004.02.003
null
hep-ph
null
During the process of thermal leptogenesis temperature decreases by about one order of magnitude while the baryon asymmetry is generated. We present an analytical description of this process so that the dependence on the neutrino mass parameters becomes transparent. In the case of maximal CP asymmetry all decay and scattering rates in the plasma are determined by the mass M_1 of the decaying heavy Majorana neutrino, the effective light neutrino mass tilde{m}_1 and the absolute mass scale bar{m} of the light neutrinos. In the mass range suggested by neutrino oscillations, m_{sol} \simeq 8*10^{-3} eV \lesssim \tilde{m}_1 \lesssim m_{atm} \simeq 5*10^{-2} eV, leptogenesis is dominated just by decays and inverse decays. The effect of all other scattering processes lies within the theoretical uncertainty of present calculations. The final baryon asymmetry is dominantly produced at a temperature T_B which can be about one order of magnitude below the heavy neutrino mass M_1. We also derive an analytical expression for the upper bound on the light neutrino masses implied by successful leptogenesis.
[ { "created": "Fri, 30 Jan 2004 16:59:01 GMT", "version": "v1" } ]
2009-11-10
[ [ "Buchmuller", "W.", "" ], [ "Di Bari", "P.", "" ], [ "Plumacher", "M.", "" ] ]
During the process of thermal leptogenesis temperature decreases by about one order of magnitude while the baryon asymmetry is generated. We present an analytical description of this process so that the dependence on the neutrino mass parameters becomes transparent. In the case of maximal CP asymmetry all decay and scattering rates in the plasma are determined by the mass M_1 of the decaying heavy Majorana neutrino, the effective light neutrino mass tilde{m}_1 and the absolute mass scale bar{m} of the light neutrinos. In the mass range suggested by neutrino oscillations, m_{sol} \simeq 8*10^{-3} eV \lesssim \tilde{m}_1 \lesssim m_{atm} \simeq 5*10^{-2} eV, leptogenesis is dominated just by decays and inverse decays. The effect of all other scattering processes lies within the theoretical uncertainty of present calculations. The final baryon asymmetry is dominantly produced at a temperature T_B which can be about one order of magnitude below the heavy neutrino mass M_1. We also derive an analytical expression for the upper bound on the light neutrino masses implied by successful leptogenesis.
hep-ph/0608146
Cristian Villavicencio
C. Villavicencio and E.S. Fraga
QCD Effective action at high temperature and small chemical potential
3 pages. To appear in the proceedings of the 7th Conference on Strong & Electroweak Matter (SEWM06), BNL, May 2006
Nucl.Phys.A785:238-240,2007
10.1016/j.nuclphysa.2006.11.076
null
hep-ph
null
We present a construction of an effective Yang-Mills action for QCD, from the expansion of the fermionic determinant in terms of powers of the chemical potential at high temperature, for the case of massless quarks. We analyze this expansion in the perturbative region and find that it gives extra spurious information. We propose for the non-perturbative sector a simplified effective action which, in principle, contains only the relevant information.
[ { "created": "Mon, 14 Aug 2006 16:49:26 GMT", "version": "v1" } ]
2008-11-26
[ [ "Villavicencio", "C.", "" ], [ "Fraga", "E. S.", "" ] ]
We present a construction of an effective Yang-Mills action for QCD, from the expansion of the fermionic determinant in terms of powers of the chemical potential at high temperature, for the case of massless quarks. We analyze this expansion in the perturbative region and find that it gives extra spurious information. We propose for the non-perturbative sector a simplified effective action which, in principle, contains only the relevant information.
hep-ph/0604077
Frank J. Petriello
Giovanna Davatz, Fabian Stoeckli, Charalampos Anastasiou, Guenther Dissertori, Michael Dittmar, Kirill Melnikov, Frank Petriello
Combining Monte Carlo generators with next-to-next-to-leading order calculations: event reweighting for Higgs boson production at the LHC
18 pages, 14 figs
JHEP0607:037,2006
10.1088/1126-6708/2006/07/037
null
hep-ph
null
We study a phenomenological ansatz for merging next-to-next-to-leading order (NNLO) calculations with Monte Carlo event generators. We reweight them to match bin-integrated NNLO differential distributions. To test this procedure, we study the Higgs boson production cross-section at the LHC, for which a fully differential partonic NNLO calculation is available. We normalize PYTHIA and MC@NLO Monte Carlo events for Higgs production in the gluon fusion channel to reproduce the bin integrated NNLO double differential distribution in the transverse momentum and rapidity of the Higgs boson. These events are used to compute differential distributions for the photons in the pp \to H \to \gamma \gamma decay channel, and are compared to predictions from fixed-order perturbation theory at NNLO. We find agreement between the reweighted generators and the NNLO result in kinematic regions where we expect a good description using fixed-order perturbation theory. Kinematic boundaries where resummation is required are also modeled correctly using this procedure. We then use these events to compute distributions in the pp \to H \to W^+W^- \to l^+l^- \nu\bar{\nu} channel, for which an accurate description is needed for measurements at the LHC. We find that the final state lepton distributions obtained from PYTHIA are not significantly changed by the reweighting procedure.
[ { "created": "Fri, 7 Apr 2006 21:34:53 GMT", "version": "v1" } ]
2009-11-11
[ [ "Davatz", "Giovanna", "" ], [ "Stoeckli", "Fabian", "" ], [ "Anastasiou", "Charalampos", "" ], [ "Dissertori", "Guenther", "" ], [ "Dittmar", "Michael", "" ], [ "Melnikov", "Kirill", "" ], [ "Petriello", "Frank", "" ] ]
We study a phenomenological ansatz for merging next-to-next-to-leading order (NNLO) calculations with Monte Carlo event generators. We reweight them to match bin-integrated NNLO differential distributions. To test this procedure, we study the Higgs boson production cross-section at the LHC, for which a fully differential partonic NNLO calculation is available. We normalize PYTHIA and MC@NLO Monte Carlo events for Higgs production in the gluon fusion channel to reproduce the bin integrated NNLO double differential distribution in the transverse momentum and rapidity of the Higgs boson. These events are used to compute differential distributions for the photons in the pp \to H \to \gamma \gamma decay channel, and are compared to predictions from fixed-order perturbation theory at NNLO. We find agreement between the reweighted generators and the NNLO result in kinematic regions where we expect a good description using fixed-order perturbation theory. Kinematic boundaries where resummation is required are also modeled correctly using this procedure. We then use these events to compute distributions in the pp \to H \to W^+W^- \to l^+l^- \nu\bar{\nu} channel, for which an accurate description is needed for measurements at the LHC. We find that the final state lepton distributions obtained from PYTHIA are not significantly changed by the reweighting procedure.
hep-ph/9712289
Alexander V. Kuznetsov
A.V. Kuznetsov, N.V. Mikheev and L.A. Vassilevskaya
Photon decay gamma->nu anti-nu in an external magnetic field
8 pages, LaTeX, typos fixed, minor modifications, version accepted to Physics Letters B
Phys.Lett. B427 (1998) 105-108; Erratum-ibid. B438 (1998) 449
10.1016/S0370-2693(98)00170-1
YARU-HE-97/08
hep-ph astro-ph
null
The process of the photon decay into the neutrino - antineutrino pair in a magnetic field is investigated. The amplitude and the probability are analysed in the limits of relatively small and strong fields. The probability is suppressed by a factor (G_F m^2_e)^2 as compared with the probability of the pure electromagnetic process gamma -> e- e+. However, the process with neutrinos could play a role of an additional channel of stellar energy-loss.
[ { "created": "Sun, 7 Dec 1997 17:34:01 GMT", "version": "v1" }, { "created": "Fri, 20 Feb 1998 14:03:21 GMT", "version": "v2" } ]
2009-10-30
[ [ "Kuznetsov", "A. V.", "" ], [ "Mikheev", "N. V.", "" ], [ "Vassilevskaya", "L. A.", "" ] ]
The process of the photon decay into the neutrino - antineutrino pair in a magnetic field is investigated. The amplitude and the probability are analysed in the limits of relatively small and strong fields. The probability is suppressed by a factor (G_F m^2_e)^2 as compared with the probability of the pure electromagnetic process gamma -> e- e+. However, the process with neutrinos could play a role of an additional channel of stellar energy-loss.
hep-ph/9705376
Peter Landshoff
P V Landshoff
Introduction to thermal field theory
Lectures given in February 1997 at the IX Jorge Andre Swieca Summer School, Campos do Jordao, Brazil 13 pages plain tex, figures embedded with epsf [Sign error corrected in equation (16)]
null
null
DAMTP-97-51
hep-ph hep-th
null
Within the next few years experiments at RHIC and the LHC will seek to create in the laboratory a quark-gluon plasma, the phase of matter in which the Universe was initially created. It is believed that the plasma will survive long enough to reach thermal equilibrium. I give an introduction to the formalism of thermal field theory, the combination of statistical mechanics and quantum field theory needed to describe the plasma in thermal equilibrium, in a way that tries to keep close to the physics it describes.
[ { "created": "Wed, 21 May 1997 13:29:37 GMT", "version": "v1" }, { "created": "Mon, 18 Aug 1997 09:52:08 GMT", "version": "v2" } ]
2008-02-03
[ [ "Landshoff", "P V", "" ] ]
Within the next few years experiments at RHIC and the LHC will seek to create in the laboratory a quark-gluon plasma, the phase of matter in which the Universe was initially created. It is believed that the plasma will survive long enough to reach thermal equilibrium. I give an introduction to the formalism of thermal field theory, the combination of statistical mechanics and quantum field theory needed to describe the plasma in thermal equilibrium, in a way that tries to keep close to the physics it describes.
hep-ph/0511329
Stephen Godfrey
Stephen Godfrey (Carleton U) and Shou-hua Zhu (Peking U)
Study of V_LV_L\to t\bar{t} at the ILC Including O(alpha_s) QCD Corrections
Presented at the 2005 International Linear Collider Physics and Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO (Snowmass05), 4 pages, LaTeX, 6 postscript figures
null
null
ALCPG0427
hep-ph
null
In the event that the Higgs mass is large or that the electroweak interactions are strongly interacting at high energy, top quark couplings to longitudinal components of the weak gauge bosons could offer important clues to the underlying dynamics. It has been suggested that precision measurements of W_L W_L \to t\bar{t} and Z_L Z_L \to t\bar{t} might provide hints of new physics. In this paper we present results for O(alpha_s) QCD corrections to V_LV_L\to t\bar{t} scattering at the ILC. We find that corrections to cross sections can be as large as 30% and must be accounted for in any precision measurement of VV\to t\bar{t}.
[ { "created": "Tue, 29 Nov 2005 16:30:04 GMT", "version": "v1" }, { "created": "Tue, 29 Nov 2005 22:03:44 GMT", "version": "v2" } ]
2007-05-23
[ [ "Godfrey", "Stephen", "", "Carleton U" ], [ "Zhu", "Shou-hua", "", "Peking U" ] ]
In the event that the Higgs mass is large or that the electroweak interactions are strongly interacting at high energy, top quark couplings to longitudinal components of the weak gauge bosons could offer important clues to the underlying dynamics. It has been suggested that precision measurements of W_L W_L \to t\bar{t} and Z_L Z_L \to t\bar{t} might provide hints of new physics. In this paper we present results for O(alpha_s) QCD corrections to V_LV_L\to t\bar{t} scattering at the ILC. We find that corrections to cross sections can be as large as 30% and must be accounted for in any precision measurement of VV\to t\bar{t}.
2011.13425
Natsumi Ikeno
Natsumi Ikeno, Raquel Molina, Eulogio Oset
The $Z_{cs}(3985)$ as a threshold effect from the $\bar D_s^* D + \bar D_s D^*$ interaction
7 pages, 2 figures: The title is changed
Phys. Lett. B814 (2021) 136120
10.1016/j.physletb.2021.136120
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $e^+ e^- \to K^+ ( D_s^{*-} D^0 + D_s^- D^{*0})$ reaction recently measured at BESIII, from where a new $Z_{cs}$ state has been reported. We study the interaction of $\bar D_s D^*$ with the coupled channels $J/\psi K^-$, $K^{*-} \eta_c$, $D_s^- D^{*0}$, $D_s^{*-} D^0$ by means of an extension to the charm sector of the local hidden gauge approach. We find that the $D_s^- D^{*0}+ D_s^{*-} D^0$ combination couples to $J/\psi K^-$ and $K^{*-} \eta_c$, but the $D_s^- D^{*0}- D_s^{*-} D^0$ combination does not. The coupled channels help to build up strength in the $D_s^- D^{*0}+ D_s^{*-} D^0$ diagonal scattering matrix close to threshold and, although the interaction is not strong enough to produce a bound state or resonance, it is sufficient to produce a large accumulation of strength at the $\bar D_s D^*$ threshold in the $e^+ e^- \to K^+ ( D_s^{*-} D^0 + D_s^- D^{*0})$ reaction in agreement with experiment.
[ { "created": "Thu, 26 Nov 2020 18:31:25 GMT", "version": "v1" }, { "created": "Mon, 8 Feb 2021 19:29:56 GMT", "version": "v2" } ]
2021-02-10
[ [ "Ikeno", "Natsumi", "" ], [ "Molina", "Raquel", "" ], [ "Oset", "Eulogio", "" ] ]
We study the $e^+ e^- \to K^+ ( D_s^{*-} D^0 + D_s^- D^{*0})$ reaction recently measured at BESIII, from where a new $Z_{cs}$ state has been reported. We study the interaction of $\bar D_s D^*$ with the coupled channels $J/\psi K^-$, $K^{*-} \eta_c$, $D_s^- D^{*0}$, $D_s^{*-} D^0$ by means of an extension to the charm sector of the local hidden gauge approach. We find that the $D_s^- D^{*0}+ D_s^{*-} D^0$ combination couples to $J/\psi K^-$ and $K^{*-} \eta_c$, but the $D_s^- D^{*0}- D_s^{*-} D^0$ combination does not. The coupled channels help to build up strength in the $D_s^- D^{*0}+ D_s^{*-} D^0$ diagonal scattering matrix close to threshold and, although the interaction is not strong enough to produce a bound state or resonance, it is sufficient to produce a large accumulation of strength at the $\bar D_s D^*$ threshold in the $e^+ e^- \to K^+ ( D_s^{*-} D^0 + D_s^- D^{*0})$ reaction in agreement with experiment.
2403.11908
Sigtryggur Hauksson
Fran\c{c}ois Gelis, Sigtryggur Hauksson
Isotropization of a longitudinally expanding system of scalar fields in the 2PI formalism
39 pages, 11 figures
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by-nc-nd/4.0/
Motivated by isotropization of QCD matter in the initial stages of heavy-ion collisions, we consider a system of scalar fields that undergoes a boost invariant longitudinal expansion. We use the framework of the two-particle irreducible (2PI) effective action, which is close to the underlying quantum field theory, and resum self-energy corrections up to three loops. The resulting 2PI equations of motion are expressed in terms of the Milne coordinates to account for longitudinal expansion. By solving numerically these equations of motion, we can extract the occupation density and the effective mass generated by in-medium interactions. At the largest values of the coupling considered in this study, we observe the onset of isotropization both in the occupation number and in the momentum dependence of the effective mass.
[ { "created": "Mon, 18 Mar 2024 16:11:25 GMT", "version": "v1" } ]
2024-03-19
[ [ "Gelis", "François", "" ], [ "Hauksson", "Sigtryggur", "" ] ]
Motivated by isotropization of QCD matter in the initial stages of heavy-ion collisions, we consider a system of scalar fields that undergoes a boost invariant longitudinal expansion. We use the framework of the two-particle irreducible (2PI) effective action, which is close to the underlying quantum field theory, and resum self-energy corrections up to three loops. The resulting 2PI equations of motion are expressed in terms of the Milne coordinates to account for longitudinal expansion. By solving numerically these equations of motion, we can extract the occupation density and the effective mass generated by in-medium interactions. At the largest values of the coupling considered in this study, we observe the onset of isotropization both in the occupation number and in the momentum dependence of the effective mass.
0812.2776
Shamayita Ray
Joydeep Chakrabortty (Harish-Chandra Res. Inst.), Amol Dighe (Tata Inst.), Srubabati Goswami (Ahmedabad, Phys. Res. Lab), Shamayita Ray (Tata Inst.)
Renormalization group evolution of neutrino masses and mixing in the Type-III seesaw mechanism
40 pages, 4 figures, Revtex4. Uses axodraw.sty, accents.sty (included). The final version to be published in Nuclear Physics B. Major changes: Discussion of quasi-degenerate neutrinos and the corresponding figure added. A column added in Table III
Nucl.Phys.B820:116-147,2009
10.1016/j.nuclphysb.2009.05.016
TIFR/TH/08-56, HRI-P-08-12-001
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the standard model extended by heavy right handed fermions transforming as triplets under SU(2)$_L$, which generate neutrino masses through the Type-III seesaw mechanism. At energies below their respective mass scales, the heavy fields get sequentially decoupled to give an effective dimension-5 operator. Above their mass thresholds, these fields also participate in the renormalization of the wavefunctions, masses and coupling constants. We compute the renormalization group evolution of the effective neutrino mass matrix in this model, with particular emphasis on the threshold effects. The evolution equations are obtained in a basis of neutrino parameters where all the quantities are well-defined everywhere, including at $\theta_{13} = 0$. We also point out the important role of the threshold effects and Majorana phases in the evolution of mixing angles through illustrative examples.
[ { "created": "Mon, 15 Dec 2008 12:06:53 GMT", "version": "v1" }, { "created": "Mon, 1 Jun 2009 16:23:20 GMT", "version": "v2" } ]
2010-04-21
[ [ "Chakrabortty", "Joydeep", "", "Harish-Chandra Res. Inst." ], [ "Dighe", "Amol", "", "Tata\n Inst." ], [ "Goswami", "Srubabati", "", "Ahmedabad, Phys. Res. Lab" ], [ "Ray", "Shamayita", "", "Tata\n Inst." ] ]
We consider the standard model extended by heavy right handed fermions transforming as triplets under SU(2)$_L$, which generate neutrino masses through the Type-III seesaw mechanism. At energies below their respective mass scales, the heavy fields get sequentially decoupled to give an effective dimension-5 operator. Above their mass thresholds, these fields also participate in the renormalization of the wavefunctions, masses and coupling constants. We compute the renormalization group evolution of the effective neutrino mass matrix in this model, with particular emphasis on the threshold effects. The evolution equations are obtained in a basis of neutrino parameters where all the quantities are well-defined everywhere, including at $\theta_{13} = 0$. We also point out the important role of the threshold effects and Majorana phases in the evolution of mixing angles through illustrative examples.
2012.09874
Andrew Fowlie Assoc. Prof.
Shehu S. AbdusSalam, Fruzsina J. Agocs, Benjamin C. Allanach, Peter Athron, Csaba Bal\'azs, Emanuele Bagnaschi, Philip Bechtle, Oliver Buchmueller, Ankit Beniwal, Jihyun Bhom, Sanjay Bloor, Torsten Bringmann, Andy Buckley, Anja Butter, Jos\'e Eliel Camargo-Molina, Marcin Chrzaszcz, Jan Conrad, Jonathan M. Cornell, Matthias Danninger, Jorge de Blas, Albert De Roeck, Klaus Desch, Matthew Dolan, Herbert Dreiner, Otto Eberhardt, John Ellis, Ben Farmer, Marco Fedele, Henning Fl\"acher, Andrew Fowlie, Tom\'as E. Gonzalo, Philip Grace, Matthias Hamer, Will Handley, Julia Harz, Sven Heinemeyer, Sebastian Hoof, Selim Hotinli, Paul Jackson, Felix Kahlhoefer, Kamila Kowalska, Michael Kr\"amer, Anders Kvellestad, Miriam Lucio Martinez, Farvah Mahmoudi, Diego Martinez Santos, Gregory D. Martinez, Satoshi Mishima, Keith Olive, Ayan Paul, Markus Tobias Prim, Werner Porod, Are Raklev, Janina J. Renk, Christopher Rogan, Leszek Roszkowski, Roberto Ruiz de Austri, Kazuki Sakurai, Andre Scaffidi, Pat Scott, Enrico Maria Sessolo, Tim Stefaniak, Patrick St\"ocker, Wei Su, Sebastian Trojanowski, Roberto Trotta, Yue-Lin Sming Tsai, Jeriek Van den Abeele, Mauro Valli, Aaron C. Vincent, Georg Weiglein, Martin White, Peter Wienemann, Lei Wu, Yang Zhang
Simple and statistically sound recommendations for analysing physical theories
15 pages, 4 figures. extended discussions. closely matches version accepted for publication
Rep. Prog. Phys. 85 052201 (2022)
10.1088/1361-6633/ac60ac
PSI-PR-20-23, BONN-TH-2020-11, CP3-20-59, KCL-PH-TH/2020-75, P3H-20-080, TTP20-044, TUM-HEP-1310/20, IFT-UAM/CSIC-20-180, TTK-20-47, CERN-TH-2020-215, FTPI-MINN-20-36, UMN-TH-4005/20, HU-EP-20/37, DESY 20-222, ADP-20-33/T1143, Imperial/TP/2020/RT/04, UCI-TR-2020-19, gambit-review-2020
hep-ph astro-ph.CO hep-ex physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Physical theories that depend on many parameters or are tested against data from many different experiments pose unique challenges to statistical inference. Many models in particle physics, astrophysics and cosmology fall into one or both of these categories. These issues are often sidestepped with statistically unsound ad hoc methods, involving intersection of parameter intervals estimated by multiple experiments, and random or grid sampling of model parameters. Whilst these methods are easy to apply, they exhibit pathologies even in low-dimensional parameter spaces, and quickly become problematic to use and interpret in higher dimensions. In this article we give clear guidance for going beyond these procedures, suggesting where possible simple methods for performing statistically sound inference, and recommendations of readily-available software tools and standards that can assist in doing so. Our aim is to provide any physicists lacking comprehensive statistical training with recommendations for reaching correct scientific conclusions, with only a modest increase in analysis burden. Our examples can be reproduced with the code publicly available at https://doi.org/10.5281/zenodo.4322283.
[ { "created": "Thu, 17 Dec 2020 19:00:06 GMT", "version": "v1" }, { "created": "Mon, 11 Apr 2022 08:22:51 GMT", "version": "v2" } ]
2022-05-10
[ [ "AbdusSalam", "Shehu S.", "" ], [ "Agocs", "Fruzsina J.", "" ], [ "Allanach", "Benjamin C.", "" ], [ "Athron", "Peter", "" ], [ "Balázs", "Csaba", "" ], [ "Bagnaschi", "Emanuele", "" ], [ "Bechtle", "Philip", "" ], [ "Buchmueller", "Oliver", "" ], [ "Beniwal", "Ankit", "" ], [ "Bhom", "Jihyun", "" ], [ "Bloor", "Sanjay", "" ], [ "Bringmann", "Torsten", "" ], [ "Buckley", "Andy", "" ], [ "Butter", "Anja", "" ], [ "Camargo-Molina", "José Eliel", "" ], [ "Chrzaszcz", "Marcin", "" ], [ "Conrad", "Jan", "" ], [ "Cornell", "Jonathan M.", "" ], [ "Danninger", "Matthias", "" ], [ "de Blas", "Jorge", "" ], [ "De Roeck", "Albert", "" ], [ "Desch", "Klaus", "" ], [ "Dolan", "Matthew", "" ], [ "Dreiner", "Herbert", "" ], [ "Eberhardt", "Otto", "" ], [ "Ellis", "John", "" ], [ "Farmer", "Ben", "" ], [ "Fedele", "Marco", "" ], [ "Flächer", "Henning", "" ], [ "Fowlie", "Andrew", "" ], [ "Gonzalo", "Tomás E.", "" ], [ "Grace", "Philip", "" ], [ "Hamer", "Matthias", "" ], [ "Handley", "Will", "" ], [ "Harz", "Julia", "" ], [ "Heinemeyer", "Sven", "" ], [ "Hoof", "Sebastian", "" ], [ "Hotinli", "Selim", "" ], [ "Jackson", "Paul", "" ], [ "Kahlhoefer", "Felix", "" ], [ "Kowalska", "Kamila", "" ], [ "Krämer", "Michael", "" ], [ "Kvellestad", "Anders", "" ], [ "Martinez", "Miriam Lucio", "" ], [ "Mahmoudi", "Farvah", "" ], [ "Santos", "Diego Martinez", "" ], [ "Martinez", "Gregory D.", "" ], [ "Mishima", "Satoshi", "" ], [ "Olive", "Keith", "" ], [ "Paul", "Ayan", "" ], [ "Prim", "Markus Tobias", "" ], [ "Porod", "Werner", "" ], [ "Raklev", "Are", "" ], [ "Renk", "Janina J.", "" ], [ "Rogan", "Christopher", "" ], [ "Roszkowski", "Leszek", "" ], [ "de Austri", "Roberto Ruiz", "" ], [ "Sakurai", "Kazuki", "" ], [ "Scaffidi", "Andre", "" ], [ "Scott", "Pat", "" ], [ "Sessolo", "Enrico Maria", "" ], [ "Stefaniak", "Tim", "" ], [ "Stöcker", "Patrick", "" ], [ "Su", "Wei", "" ], [ "Trojanowski", "Sebastian", "" ], [ "Trotta", "Roberto", "" ], [ "Tsai", "Yue-Lin Sming", "" ], [ "Abeele", "Jeriek Van den", "" ], [ "Valli", "Mauro", "" ], [ "Vincent", "Aaron C.", "" ], [ "Weiglein", "Georg", "" ], [ "White", "Martin", "" ], [ "Wienemann", "Peter", "" ], [ "Wu", "Lei", "" ], [ "Zhang", "Yang", "" ] ]
Physical theories that depend on many parameters or are tested against data from many different experiments pose unique challenges to statistical inference. Many models in particle physics, astrophysics and cosmology fall into one or both of these categories. These issues are often sidestepped with statistically unsound ad hoc methods, involving intersection of parameter intervals estimated by multiple experiments, and random or grid sampling of model parameters. Whilst these methods are easy to apply, they exhibit pathologies even in low-dimensional parameter spaces, and quickly become problematic to use and interpret in higher dimensions. In this article we give clear guidance for going beyond these procedures, suggesting where possible simple methods for performing statistically sound inference, and recommendations of readily-available software tools and standards that can assist in doing so. Our aim is to provide any physicists lacking comprehensive statistical training with recommendations for reaching correct scientific conclusions, with only a modest increase in analysis burden. Our examples can be reproduced with the code publicly available at https://doi.org/10.5281/zenodo.4322283.
hep-ph/0110379
Jose Wudka
Bohdan Grzadkowski, Jose Wudka
Consistency bounds on the Higgs-boson mass
Talk presented at the Snowmass 2001 conference. 3 pages, 3 figures. Requires revtex4
eConf C010630 (2001) P101
null
IFT-37-0, UCRHEP-T324
hep-ph
null
In this talk we consider the modifications induced by heavy physics on the triviality and vacuum stability bounds on the Higgs-boson mass. We parameterize the heavy interactions using an effective Lagrangian and find that the triviality bound is essentially unaffected for weakly-coupled heavy physics. In contrast there are significant modifications in the stability bound that for a light Higgs boson require a scale of new physics of the order of a few TeV.
[ { "created": "Mon, 29 Oct 2001 21:08:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grzadkowski", "Bohdan", "" ], [ "Wudka", "Jose", "" ] ]
In this talk we consider the modifications induced by heavy physics on the triviality and vacuum stability bounds on the Higgs-boson mass. We parameterize the heavy interactions using an effective Lagrangian and find that the triviality bound is essentially unaffected for weakly-coupled heavy physics. In contrast there are significant modifications in the stability bound that for a light Higgs boson require a scale of new physics of the order of a few TeV.
1910.12357
Fazlollah Hajkarim
Fazlollah Hajkarim, J\"urgen Schaffner-Bielich
Thermal History of the Early Universe and Primordial Gravitational Waves from Induced Scalar Perturbations
10 pages, 6 figures
Phys. Rev. D 101, 043522 (2020)
10.1103/PhysRevD.101.043522
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the induced primordial gravitational waves (GW) coming from the effect of scalar perturbation on the tensor perturbation at the second order of cosmological perturbation theory. We use the evolution of the standard model degrees of freedom with respect to temperature in the early Universe to compute the induced gravitational waves bakcground. Our result shows that the spectrum of the induced GW is affected differently by the standard model degrees of freedom than the GW coming from first order tensor perturbation. This phenomenon is due to the presence of scalar perturbations as a source for tensor perturbations and it is effective around the quark gluon deconfinement and electroweak transition. In case of considering a scalar spectral index larger than one at small scales or a non-Gaussian curvature power spectrum this effect can be observed by gravitational wave observatories.
[ { "created": "Sun, 27 Oct 2019 21:34:19 GMT", "version": "v1" } ]
2020-02-19
[ [ "Hajkarim", "Fazlollah", "" ], [ "Schaffner-Bielich", "Jürgen", "" ] ]
We study the induced primordial gravitational waves (GW) coming from the effect of scalar perturbation on the tensor perturbation at the second order of cosmological perturbation theory. We use the evolution of the standard model degrees of freedom with respect to temperature in the early Universe to compute the induced gravitational waves bakcground. Our result shows that the spectrum of the induced GW is affected differently by the standard model degrees of freedom than the GW coming from first order tensor perturbation. This phenomenon is due to the presence of scalar perturbations as a source for tensor perturbations and it is effective around the quark gluon deconfinement and electroweak transition. In case of considering a scalar spectral index larger than one at small scales or a non-Gaussian curvature power spectrum this effect can be observed by gravitational wave observatories.
hep-ph/0610015
Jurgen Berges
J. Berges, Sz. Borsanyi
Progress in nonequilibrium quantum field theory III
Based on invited talk at SEWM06, 10 pages, appears in the proceedings
Nucl.Phys.A785:58-67,2007
10.1016/j.nuclphysa.2006.11.133
null
hep-ph
null
We review recent developments and open questions for the description of nonequilibrium quantum fields, continuing hep-ph/0302210 and hep-ph/0410330.
[ { "created": "Mon, 2 Oct 2006 07:31:37 GMT", "version": "v1" } ]
2008-11-26
[ [ "Berges", "J.", "" ], [ "Borsanyi", "Sz.", "" ] ]
We review recent developments and open questions for the description of nonequilibrium quantum fields, continuing hep-ph/0302210 and hep-ph/0410330.
0912.4675
Sebastian M. R. Frank DI
Helmut Eberl, Sebastian M.R. Frank, Walter Majerotto
CP Violating Asymmetry in Stop Decay into Bottom and Chargino
Version accepted for publication in Eur. Phys. J. C (8 pages, 8 figures)
Eur.Phys.J.C70:1017-1024,2010
10.1140/epjc/s10052-010-1501-5
HEPHY-PUB 882/09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the MSSM with complex parameters, loop corrections to the decay of a stop into a bottom quark and a chargino can lead to a CP violating decay rate asymmetry. We calculate this asymmetry at full one-loop level and perform a detailed numerical study, analyzing the dependence on the parameters and complex phases involved. If the stop can decay into a gluino, the self-energy and the vertex correction dominate due to the strong coupling. It is shown that the vertex contribution is always suppressed. We therefore give a simple approximate formula for the asymmetry. We account for the constraints on the parameters coming from several experimental limits. Asymmetries up to 25 percent are obtained. We also comment on the feasibility of measuring this asymmetry at the LHC.
[ { "created": "Wed, 23 Dec 2009 16:01:40 GMT", "version": "v1" }, { "created": "Fri, 18 Jun 2010 13:24:11 GMT", "version": "v2" }, { "created": "Mon, 6 Dec 2010 16:05:35 GMT", "version": "v3" } ]
2010-12-15
[ [ "Eberl", "Helmut", "" ], [ "Frank", "Sebastian M. R.", "" ], [ "Majerotto", "Walter", "" ] ]
In the MSSM with complex parameters, loop corrections to the decay of a stop into a bottom quark and a chargino can lead to a CP violating decay rate asymmetry. We calculate this asymmetry at full one-loop level and perform a detailed numerical study, analyzing the dependence on the parameters and complex phases involved. If the stop can decay into a gluino, the self-energy and the vertex correction dominate due to the strong coupling. It is shown that the vertex contribution is always suppressed. We therefore give a simple approximate formula for the asymmetry. We account for the constraints on the parameters coming from several experimental limits. Asymmetries up to 25 percent are obtained. We also comment on the feasibility of measuring this asymmetry at the LHC.
1211.4316
Balasubramanian Ananthanarayan
Gauhar Abbas, B.Ananthanarayan, Irinel Caprini, Jan Fischer
Perturbative expansion of the QCD Adler function improved by renormalization-group summation and analytic continuation in the Borel plane
15 pages latex using revtex, 4 figures; v2 corresponds to PRD version; compared to v1, power-correction estimates have been enlarged resulting in somewhat larger errors for alpha_S, relevant discussion has been provided, a reference has been added, minor typographical errors have been removed
Phys. Rev. D 87, 014008 (2013)
10.1103/PhysRevD.87.014008
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the large-order behaviour of a recently proposed renormalization-group-improved expansion of the Adler function in perturbative QCD, which sums in an analytically closed form the leading logarithms accessible from renormalization-group invariance. The expansion is first written as aneffective series in powers of the one-loop coupling, and its leading singularities in the Borel plane are shown to be identical to those of the standard "contour-improved" expansion. Applying the technique of conformal mappings for the analytic continuation in the Borel plane, we define a class of improved expansions, which implement both the renormalization-group invariance and the knowledge about the large-order behaviour of the series. Detailed numerical studies of specific models for the Adler function indicate that the new expansions have remarkable convergence properties up to high orders. Using these expansions for the determination of the strong coupling from the the hadronic width of the $\tau$ lepton we obtain, with a conservative estimate of the uncertainty due to the nonperturbative corrections, $\alpha_s(M_\tau^2)= 0.3189^{+ 0.0173}_{-0.0151}$, which translates to $\alpha_s(M_Z^2)= 0.1184^{+0.0021}_{-0.0018}$.
[ { "created": "Mon, 19 Nov 2012 07:07:10 GMT", "version": "v1" }, { "created": "Mon, 7 Jan 2013 15:17:23 GMT", "version": "v2" } ]
2013-01-08
[ [ "Abbas", "Gauhar", "" ], [ "Ananthanarayan", "B.", "" ], [ "Caprini", "Irinel", "" ], [ "Fischer", "Jan", "" ] ]
We examine the large-order behaviour of a recently proposed renormalization-group-improved expansion of the Adler function in perturbative QCD, which sums in an analytically closed form the leading logarithms accessible from renormalization-group invariance. The expansion is first written as aneffective series in powers of the one-loop coupling, and its leading singularities in the Borel plane are shown to be identical to those of the standard "contour-improved" expansion. Applying the technique of conformal mappings for the analytic continuation in the Borel plane, we define a class of improved expansions, which implement both the renormalization-group invariance and the knowledge about the large-order behaviour of the series. Detailed numerical studies of specific models for the Adler function indicate that the new expansions have remarkable convergence properties up to high orders. Using these expansions for the determination of the strong coupling from the the hadronic width of the $\tau$ lepton we obtain, with a conservative estimate of the uncertainty due to the nonperturbative corrections, $\alpha_s(M_\tau^2)= 0.3189^{+ 0.0173}_{-0.0151}$, which translates to $\alpha_s(M_Z^2)= 0.1184^{+0.0021}_{-0.0018}$.
0806.3880
Pran Nath
Tarek Ibrahim and Pran Nath
An MSSM Extension with a Mirror Fourth Generation, Neutrino Magnetic Moments and LHC Signatures
38 pages, 2 figures. Accepted for publication in Physical Review D
Phys.Rev.D78:075013,2008
10.1103/PhysRevD.78.075013
CERN-PH-TH/2008-139
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent analyses have shown that a sequential fourth generation can be consistent with precision electroweak data. We consider the possibility that the new generation could be a mirror generation with $V+A$ rather than $V-A$ interactions. Specifically we consider an extension of the minimal supersymmetric standard model with a light mirror generation (mirMSSM) . Implications of this extension are explored. One consequence is an enhancement of the tau neutrino magnetic moment by several orders of magnitude consistent with the current limits on the magnetic moment of the tau. The masses of the mirror generation arise due to electroweak symmetry breaking, and if a mirror generation exists its mass spectrum must lye below a TeV, and thus should be discovered at the LHC. Mirror particles and mirror sparticles produce many characteristic signatures which should be detectable at the LHC. Heavy higgs boson decays into mirror particles and an analysis of the forward-backward asymmetries can distinguish a mirror generation from a sequential fourth generation. The validity of the model can thus be tested at the LHC. A model of the type discussed here could arise from a more unified structure such as grand unification or strings where a mirror generation escapes the survival hypothesis, i.e., a generation and a mirror generation do not tie up to acquire a mass of size $M_{GUT}$ or $M_{string}$ due to a symmetry, and thus remain massless down to the electroweak scale.
[ { "created": "Tue, 24 Jun 2008 12:57:54 GMT", "version": "v1" }, { "created": "Fri, 19 Sep 2008 20:11:07 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ibrahim", "Tarek", "" ], [ "Nath", "Pran", "" ] ]
Recent analyses have shown that a sequential fourth generation can be consistent with precision electroweak data. We consider the possibility that the new generation could be a mirror generation with $V+A$ rather than $V-A$ interactions. Specifically we consider an extension of the minimal supersymmetric standard model with a light mirror generation (mirMSSM) . Implications of this extension are explored. One consequence is an enhancement of the tau neutrino magnetic moment by several orders of magnitude consistent with the current limits on the magnetic moment of the tau. The masses of the mirror generation arise due to electroweak symmetry breaking, and if a mirror generation exists its mass spectrum must lye below a TeV, and thus should be discovered at the LHC. Mirror particles and mirror sparticles produce many characteristic signatures which should be detectable at the LHC. Heavy higgs boson decays into mirror particles and an analysis of the forward-backward asymmetries can distinguish a mirror generation from a sequential fourth generation. The validity of the model can thus be tested at the LHC. A model of the type discussed here could arise from a more unified structure such as grand unification or strings where a mirror generation escapes the survival hypothesis, i.e., a generation and a mirror generation do not tie up to acquire a mass of size $M_{GUT}$ or $M_{string}$ due to a symmetry, and thus remain massless down to the electroweak scale.
1403.1782
Osamu Seto
Ki-Young Choi and Osamu Seto
X-ray line signal from decaying axino warm dark matter
8 pages, 2 figures, typos corrected, discussion and one more figure added, the final journal version
Phys. Lett. B 735, 92 (2014)
10.1016/j.physletb.2014.06.008
HGU-CAP-030
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider axino warm dark matter in a supersymmetric axion model with R-parity violation. In this scenario, axino with the mass $m_\axino\simeq 7$ keV can decay into photon and neutrino resulting in the X-ray line signal at $3.5$ keV, which might be the origin of unidentified X-ray emissions from galaxy clusters and Andromeda galaxy detected by the XMM-Newton X-ray observatory.
[ { "created": "Fri, 7 Mar 2014 15:35:05 GMT", "version": "v1" }, { "created": "Mon, 23 Jun 2014 19:22:42 GMT", "version": "v2" } ]
2015-06-19
[ [ "Choi", "Ki-Young", "" ], [ "Seto", "Osamu", "" ] ]
We consider axino warm dark matter in a supersymmetric axion model with R-parity violation. In this scenario, axino with the mass $m_\axino\simeq 7$ keV can decay into photon and neutrino resulting in the X-ray line signal at $3.5$ keV, which might be the origin of unidentified X-ray emissions from galaxy clusters and Andromeda galaxy detected by the XMM-Newton X-ray observatory.
1310.1051
Simon Badger
Simon Badger, Hjalte Frellesvig, Yang Zhang
A Two-Loop Five-Gluon Helicity Amplitude in QCD
31 pages, 7 figures. version 2 - fix typos and match with journal version
null
10.1007/JHEP12(2013)045
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the planar part of the two-loop five gluon amplitude with all helicities positive. To perform the calculation we develop a D-dimensional generalized unitarity procedure allowing us to reconstruct the amplitude by cutting into products of six-dimensional trees. We find a compact form for the integrand which only requires topologies with six or more propagators. We perform cross checks of the universal infra-red structure using numerical integration techniques.
[ { "created": "Thu, 3 Oct 2013 18:27:49 GMT", "version": "v1" }, { "created": "Sat, 18 Jul 2015 13:56:29 GMT", "version": "v2" } ]
2015-07-21
[ [ "Badger", "Simon", "" ], [ "Frellesvig", "Hjalte", "" ], [ "Zhang", "Yang", "" ] ]
We compute the planar part of the two-loop five gluon amplitude with all helicities positive. To perform the calculation we develop a D-dimensional generalized unitarity procedure allowing us to reconstruct the amplitude by cutting into products of six-dimensional trees. We find a compact form for the integrand which only requires topologies with six or more propagators. We perform cross checks of the universal infra-red structure using numerical integration techniques.
hep-ph/9602358
null
S. Loh, T.S. Biro, U. Mosel and M. H. Thoma
A Dynamical Model of Color Confinement
12 pages plus 5 figures
Phys.Lett. B387 (1996) 685-690
10.1016/0370-2693(96)01125-2
UGI-96-04
hep-ph nucl-th
null
A dynamical model of confinement based on a transport theoretical description of the Friedberg-Lee model is extended to explicit color degrees of freedom. The string tension is reproduced by an adiabatic string formation from the nucleon ground state. Color isovector oscillation modes of a $q\bar{q}$-system are investigated for a wide range of relative $q\bar{q}$-momenta and the dynamical impact of color confinement on the quark motion is shown.
[ { "created": "Wed, 21 Feb 1996 10:41:02 GMT", "version": "v1" } ]
2009-10-28
[ [ "Loh", "S.", "" ], [ "Biro", "T. S.", "" ], [ "Mosel", "U.", "" ], [ "Thoma", "M. H.", "" ] ]
A dynamical model of confinement based on a transport theoretical description of the Friedberg-Lee model is extended to explicit color degrees of freedom. The string tension is reproduced by an adiabatic string formation from the nucleon ground state. Color isovector oscillation modes of a $q\bar{q}$-system are investigated for a wide range of relative $q\bar{q}$-momenta and the dynamical impact of color confinement on the quark motion is shown.
1407.6700
Ruben Sandapen
M. R. Ahmady, S. Lord and R. Sandapen
The isospin asymmetry in $B \to K^* \mu^+ \mu^-$ using AdS/QCD
18 pages, 7 figures
Phys. Rev. D 90, 074010 (2014)
10.1103/PhysRevD.90.074010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the isospin asymmetry distribution in the rare dileptonic decay $B \to K^* \mu^+ \mu^-$, in the dimuon mass squared ($q^2$) region below the $J/\Psi$ resonance, using non-perturbative inputs as predicted by the anti-de Sitter/Quantum Chromodynamics (AdS/QCD) correspondence and by Sum Rules. We predict a positive asymmetry at $q^2=0$ which flips sign in the region $q^2 \in [1,2]~\mbox{GeV}^2$ to remain small ($\le 2\%$) and negative for larger $q^2$. While our predictions are distinct as $q^2 \to 0$, they become hardly model-dependent $q^2 \ge 4~\mbox{GeV}^2$. We compare our predictions to the most recent LHCb data.
[ { "created": "Thu, 24 Jul 2014 19:48:26 GMT", "version": "v1" } ]
2014-10-15
[ [ "Ahmady", "M. R.", "" ], [ "Lord", "S.", "" ], [ "Sandapen", "R.", "" ] ]
We compute the isospin asymmetry distribution in the rare dileptonic decay $B \to K^* \mu^+ \mu^-$, in the dimuon mass squared ($q^2$) region below the $J/\Psi$ resonance, using non-perturbative inputs as predicted by the anti-de Sitter/Quantum Chromodynamics (AdS/QCD) correspondence and by Sum Rules. We predict a positive asymmetry at $q^2=0$ which flips sign in the region $q^2 \in [1,2]~\mbox{GeV}^2$ to remain small ($\le 2\%$) and negative for larger $q^2$. While our predictions are distinct as $q^2 \to 0$, they become hardly model-dependent $q^2 \ge 4~\mbox{GeV}^2$. We compare our predictions to the most recent LHCb data.
hep-ph/0107049
Giacomo Morpurgo
G.Morpurgo (Universita` di Genova and INFN- Genova (Italy))
Comment on "Chiral symmetry and the intrinsic structure of the nucleon"- by D.B.Leinweber,A.W.Thomas and R.D.Young
3 pages, Latex
null
null
INFN-GEF-TH-July/2000
hep-ph
null
Some remarks are presented on a recent paper (Leinweber,Thomas and Young, Phys.Rev.Lett. 86, 5011, 2001). In particular a statement of the above paper on the fact that the ratio between the magnetic moments of proton and neutron should remain constant at -3/2, independent of the change of the quark mass is discussed on the basis of the general parameterization.
[ { "created": "Thu, 5 Jul 2001 14:37:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Morpurgo", "G.", "", "Universita` di Genova and INFN- Genova" ] ]
Some remarks are presented on a recent paper (Leinweber,Thomas and Young, Phys.Rev.Lett. 86, 5011, 2001). In particular a statement of the above paper on the fact that the ratio between the magnetic moments of proton and neutron should remain constant at -3/2, independent of the change of the quark mass is discussed on the basis of the general parameterization.
hep-ph/9910522
Andrija Rasin
Paul H. Frampton and Andrija Rasin
Nonabelian Discrete Symmetries, Fermion Mass Textures and Large Neutrino Mixing
15 pages, revtex, no figures. Shortened version, dirac neutrino mass and typos corrected, reference added
Phys.Lett.B478:424-433,2000
10.1016/S0370-2693(00)00276-8
null
hep-ph
null
Nonabelian discrete groups are an attractive tool to describe fermion masses and mixings. They have nonsinglet representations which seem particularly suitable for distinguishing the lighter generations from the heavier ones. Also, they do not suffer from the extra constraints a continuous group must obey, e.g. limits on extra particles. Some of the simplest groups are the nonabelian discrete subgroups of SO(3) and SU(2), the so called dihedral groups D_n and dicyclic groups Q_2n, which both have only singlet and doublet representations. After studying which vacuum expectation value (VEV) directions of representations of dihedral and dicyclic groups preserve which subgroups, we construct a simple model based on the group Q_6 \times Q_6. The model reproduces the masses and mixings of all quarks and leptons, including neutrinos. It has a large mixing angle in the mu - tau neutrino sector, in accordance with the recent SuperKamiokande results, while keeping a small quark mixing in the bottom - charm sector. The reason is similar to the one found in the literature based on the SU(5) group: the large_left_ handed mixing angle in the lepton sector corresponds to the large unphysical_right_ handed in the down quark sector. The large mixing is also responsible for the different hierarchies of the two heaviest families in the up and down sector, and can be summarized as the order of magnitude relation: m_s/m_b \sim tan(theta_\mu\tau) \sqrt{m_c/m_t}
[ { "created": "Wed, 27 Oct 1999 21:49:47 GMT", "version": "v1" }, { "created": "Mon, 29 Nov 1999 22:53:08 GMT", "version": "v2" } ]
2008-11-26
[ [ "Frampton", "Paul H.", "" ], [ "Rasin", "Andrija", "" ] ]
Nonabelian discrete groups are an attractive tool to describe fermion masses and mixings. They have nonsinglet representations which seem particularly suitable for distinguishing the lighter generations from the heavier ones. Also, they do not suffer from the extra constraints a continuous group must obey, e.g. limits on extra particles. Some of the simplest groups are the nonabelian discrete subgroups of SO(3) and SU(2), the so called dihedral groups D_n and dicyclic groups Q_2n, which both have only singlet and doublet representations. After studying which vacuum expectation value (VEV) directions of representations of dihedral and dicyclic groups preserve which subgroups, we construct a simple model based on the group Q_6 \times Q_6. The model reproduces the masses and mixings of all quarks and leptons, including neutrinos. It has a large mixing angle in the mu - tau neutrino sector, in accordance with the recent SuperKamiokande results, while keeping a small quark mixing in the bottom - charm sector. The reason is similar to the one found in the literature based on the SU(5) group: the large_left_ handed mixing angle in the lepton sector corresponds to the large unphysical_right_ handed in the down quark sector. The large mixing is also responsible for the different hierarchies of the two heaviest families in the up and down sector, and can be summarized as the order of magnitude relation: m_s/m_b \sim tan(theta_\mu\tau) \sqrt{m_c/m_t}
hep-ph/0302165
Peter Arnold
Peter Arnold, Guy D. Moore, and Laurence G. Yaffe
Transport coefficients in high temperature gauge theories: (II) Beyond leading log
38 pages, 6 figures
JHEP 0305:051,2003
10.1088/1126-6708/2003/05/051
null
hep-ph nucl-th
null
Results are presented of a full leading-order evaluation of the shear viscosity, flavor diffusion constants, and electrical conductivity in high temperature QCD and QED. The presence of Coulomb logarithms associated with gauge interactions imply that the leading-order results for transport coefficients may themselves be expanded in an infinite series in powers of 1/log(1/g); the utility of this expansion is also examined. A next-to-leading-log approximation is found to approximate the full leading-order result quite well as long as the Debye mass is less than the temperature.
[ { "created": "Tue, 18 Feb 2003 20:57:43 GMT", "version": "v1" }, { "created": "Tue, 6 May 2003 13:34:27 GMT", "version": "v2" } ]
2010-02-16
[ [ "Arnold", "Peter", "" ], [ "Moore", "Guy D.", "" ], [ "Yaffe", "Laurence G.", "" ] ]
Results are presented of a full leading-order evaluation of the shear viscosity, flavor diffusion constants, and electrical conductivity in high temperature QCD and QED. The presence of Coulomb logarithms associated with gauge interactions imply that the leading-order results for transport coefficients may themselves be expanded in an infinite series in powers of 1/log(1/g); the utility of this expansion is also examined. A next-to-leading-log approximation is found to approximate the full leading-order result quite well as long as the Debye mass is less than the temperature.
1809.09126
Da Liu
Da Liu, Ian Low and Zhewei Yin
Universal Relations in Composite Higgs Models
31 pages, 6 figures
null
10.1007/JHEP05(2019)170
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We initiate a phenomenological study of `universal relations' in composite Higgs models, which are dictated by nonlinear shift symmetries acting on the 125 GeV Higgs boson. These are relations among one Higgs couplings with two electroweak gauge bosons (HVV), two Higgses couplings with two electroweak gauge bosons (HHVV), one Higgs couplings with three electroweak gauge bosons (HVVV), as well as triple gauge boson couplings (TGC), which are all controlled by a single input parameter: the decay constant $f$ of the pseudo-Nambu-Goldstone Higgs boson. Assuming custodial invariance in strong sector, the relation is independent of the symmetry breaking pattern in the UV, for an arbitrary symmetric coset $G/H$. The complete list of corrections to HVV, HHVV, HVVV and TGC couplings in composite Higgs models is presented to all orders in $1/f$, and up to four-derivative level, without referring to a particular $G/H$. We then present several examples of universal relations in ratios of coefficients which could be extracted experimentally. Measuring the universal relation requires a precision sensitive to effects of dimension-8 operators in the effective Lagrangian and highlights the importance of verifying the tensor structure of HHVV interactions in the standard model, which remains untested to date.
[ { "created": "Mon, 24 Sep 2018 18:00:25 GMT", "version": "v1" } ]
2019-06-26
[ [ "Liu", "Da", "" ], [ "Low", "Ian", "" ], [ "Yin", "Zhewei", "" ] ]
We initiate a phenomenological study of `universal relations' in composite Higgs models, which are dictated by nonlinear shift symmetries acting on the 125 GeV Higgs boson. These are relations among one Higgs couplings with two electroweak gauge bosons (HVV), two Higgses couplings with two electroweak gauge bosons (HHVV), one Higgs couplings with three electroweak gauge bosons (HVVV), as well as triple gauge boson couplings (TGC), which are all controlled by a single input parameter: the decay constant $f$ of the pseudo-Nambu-Goldstone Higgs boson. Assuming custodial invariance in strong sector, the relation is independent of the symmetry breaking pattern in the UV, for an arbitrary symmetric coset $G/H$. The complete list of corrections to HVV, HHVV, HVVV and TGC couplings in composite Higgs models is presented to all orders in $1/f$, and up to four-derivative level, without referring to a particular $G/H$. We then present several examples of universal relations in ratios of coefficients which could be extracted experimentally. Measuring the universal relation requires a precision sensitive to effects of dimension-8 operators in the effective Lagrangian and highlights the importance of verifying the tensor structure of HHVV interactions in the standard model, which remains untested to date.
2212.12162
C. Anastasiou
Charalampos Anastasiou and George Sterman
Locally finite two-loop QCD amplitudes from IR universality for electroweak production
67 pages, 7 Tables, 12 Figures
null
10.1007/JHEP05(2023)242
YITP-SB-2022-43
hep-ph hep-th
http://creativecommons.org/licenses/by-nc-nd/4.0/
We describe the implementation of infrared subtractions for two-loop QCD corrections to quark-antiquark annihilation to electroweak final states. The subtractions are given as form-factor integrands whose integrals are known. The resulting subtracted amplitudes are amenable to efficient numerical integration. Our procedure is based on the universality of infrared singularities and requires a relatively limited set of subtractions, whose number grows as the number of two-loop diagrams, rather than with the number of singular regions of integration.
[ { "created": "Fri, 23 Dec 2022 05:56:18 GMT", "version": "v1" } ]
2023-06-21
[ [ "Anastasiou", "Charalampos", "" ], [ "Sterman", "George", "" ] ]
We describe the implementation of infrared subtractions for two-loop QCD corrections to quark-antiquark annihilation to electroweak final states. The subtractions are given as form-factor integrands whose integrals are known. The resulting subtracted amplitudes are amenable to efficient numerical integration. Our procedure is based on the universality of infrared singularities and requires a relatively limited set of subtractions, whose number grows as the number of two-loop diagrams, rather than with the number of singular regions of integration.
1601.01403
Hiroaki Matsuoka
H. Matsuoka (Kochi Univ., Japan), Y. Tsue (Kochi Univ., Japan), J. da Providencia (Univ. de Coimbra, Portugal), C. Providencia (Univ. de Coimbra, Portugal), M. Yamamura (Kansai Univ., Japan), H. Bohr (Danish Technical Univ., Denmark)
Spin Polarized versus Chiral Condensate in Quark Matter at Finite Temperature and Density
25 pages, 9 figures
null
10.1093/ptep/ptw055
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that the spin polarized condensate appears in quark matter at high baryon density and low temperature due to the tensor-type four-point interaction in the Nambu-Jona-Lasinio-type model as a low energy effective theory of quantum chromodynamics. It is indicated within this low energy effective model that the chiral symmetry is broken again by the spin polarized condensate as increasing the quark number density, while the chiral symmetry restoration occurs in which the chiral condensate disappears at a certain density.
[ { "created": "Thu, 7 Jan 2016 05:23:10 GMT", "version": "v1" }, { "created": "Tue, 12 Apr 2016 06:04:58 GMT", "version": "v2" } ]
2016-06-21
[ [ "Matsuoka", "H.", "", "Kochi Univ., Japan" ], [ "Tsue", "Y.", "", "Kochi Univ., Japan" ], [ "da Providencia", "J.", "", "Univ. de Coimbra, Portugal" ], [ "Providencia", "C.", "", "Univ. de Coimbra,\n Portugal" ], [ "Yamamura", "M.", "", "Kansai Univ., Japan" ], [ "Bohr", "H.", "", "Danish Technical\n Univ., Denmark" ] ]
It is shown that the spin polarized condensate appears in quark matter at high baryon density and low temperature due to the tensor-type four-point interaction in the Nambu-Jona-Lasinio-type model as a low energy effective theory of quantum chromodynamics. It is indicated within this low energy effective model that the chiral symmetry is broken again by the spin polarized condensate as increasing the quark number density, while the chiral symmetry restoration occurs in which the chiral condensate disappears at a certain density.
2305.03756
Matthias Koschnitzke
Aleksandr Chatrchyan, Cem Er\"oncel, Matthias Koschnitzke, G\'eraldine Servant
ALP dark matter with non-periodic potentials: parametric resonance, halo formation and gravitational signatures
50 pages and 22 figures in the main text, and 15 pages and 2 figures in appendices, v2: As published in JCAP
JCAP10(2023)068
10.1088/1475-7516/2023/10/068
DESY-23-060
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
Axion-like particles (ALPs) are leading candidates to explain the dark matter in the universe. Their production via the misalignment mechanism has been extensively studied for cosine potentials characteristic of pseudo-Nambu-Goldstone bosons. In this work we investigate ALPs with non-periodic potentials, which allow for large misalignment of the field from the minimum. As a result, the ALP can match the relic density of dark matter in a large part of the parameter space. Such potentials give rise to self-interactions which can trigger an exponential growth of fluctuations in the ALP field via parametric resonance, leading to the fragmentation of the field. We study these effects with both Floquet analysis and lattice simulations. Using the Press-Schechter formalism, we predict the halo mass function and halo spectrum arising from ALP dark matter. These halos can be dense enough to produce observable gravitational effects such as astrometric lensing, diffraction of gravitational wave signals from black hole mergers, photometric microlensing of highly magnified stars, perturbations of stars in the galactic disk or stellar streams. These effects would provide a probe of dark matter even if it does not couple to the Standard Model. They would not be observable for halos predicted for standard cold dark matter and for ALP dark matter in the standard misalignment mechanism. We determine the relevant regions of parameter space in the (ALP mass, decay constant)-plane and compare predictions in different axion fragmentation models.
[ { "created": "Fri, 5 May 2023 18:00:03 GMT", "version": "v1" }, { "created": "Fri, 27 Oct 2023 17:59:55 GMT", "version": "v2" } ]
2023-10-30
[ [ "Chatrchyan", "Aleksandr", "" ], [ "Eröncel", "Cem", "" ], [ "Koschnitzke", "Matthias", "" ], [ "Servant", "Géraldine", "" ] ]
Axion-like particles (ALPs) are leading candidates to explain the dark matter in the universe. Their production via the misalignment mechanism has been extensively studied for cosine potentials characteristic of pseudo-Nambu-Goldstone bosons. In this work we investigate ALPs with non-periodic potentials, which allow for large misalignment of the field from the minimum. As a result, the ALP can match the relic density of dark matter in a large part of the parameter space. Such potentials give rise to self-interactions which can trigger an exponential growth of fluctuations in the ALP field via parametric resonance, leading to the fragmentation of the field. We study these effects with both Floquet analysis and lattice simulations. Using the Press-Schechter formalism, we predict the halo mass function and halo spectrum arising from ALP dark matter. These halos can be dense enough to produce observable gravitational effects such as astrometric lensing, diffraction of gravitational wave signals from black hole mergers, photometric microlensing of highly magnified stars, perturbations of stars in the galactic disk or stellar streams. These effects would provide a probe of dark matter even if it does not couple to the Standard Model. They would not be observable for halos predicted for standard cold dark matter and for ALP dark matter in the standard misalignment mechanism. We determine the relevant regions of parameter space in the (ALP mass, decay constant)-plane and compare predictions in different axion fragmentation models.
0707.2838
Seungwon Baek
Seungwon Baek
A solution to B --> pi pi puzzle and B --> K K
12 pages, 2 figures, minor changes, references added
Phys.Lett.B659:265-269,2008
10.1016/j.physletb.2007.11.029
null
hep-ph
null
The large ratio of color-suppressed tree amplitude to color-allowed one in $B \to \pi \pi$ decays is difficult to understand within the Standard Model, which is known as the "$B \to \pi\pi$ puzzle". The two tree diagrams contain the up- and charm-quark component of penguin amplitude, $P_{uc}$, which cannot be separated by measuring $B \to \pi \pi$ decays alone. We show that the measurements of the branching ratio and direct CP asymmetry of $B^+ \to K^+ \bar{K^0}$ decay enable one to disentangle the $P_{uc}$ with two-fold ambiguity. One of the two degenerate solutions of the $P_{uc}$ can solve the $B \to \pi \pi$ puzzle by giving $|C/T|\sim 0.3$ which is consistent with the expectation in the Standard Model. We also show that the two solutions can be discriminated by the measurement of the indirect CP-asymmetry of $B^0 \to K^0 \ol{K^0}$. We point out that if the $B \to \pi \pi$ puzzle is solved in this way, the corresponding puzzle in $B \to \pi K$ decays should have a different origin.
[ { "created": "Thu, 19 Jul 2007 06:36:56 GMT", "version": "v1" }, { "created": "Thu, 26 Jul 2007 12:22:46 GMT", "version": "v2" } ]
2008-11-26
[ [ "Baek", "Seungwon", "" ] ]
The large ratio of color-suppressed tree amplitude to color-allowed one in $B \to \pi \pi$ decays is difficult to understand within the Standard Model, which is known as the "$B \to \pi\pi$ puzzle". The two tree diagrams contain the up- and charm-quark component of penguin amplitude, $P_{uc}$, which cannot be separated by measuring $B \to \pi \pi$ decays alone. We show that the measurements of the branching ratio and direct CP asymmetry of $B^+ \to K^+ \bar{K^0}$ decay enable one to disentangle the $P_{uc}$ with two-fold ambiguity. One of the two degenerate solutions of the $P_{uc}$ can solve the $B \to \pi \pi$ puzzle by giving $|C/T|\sim 0.3$ which is consistent with the expectation in the Standard Model. We also show that the two solutions can be discriminated by the measurement of the indirect CP-asymmetry of $B^0 \to K^0 \ol{K^0}$. We point out that if the $B \to \pi \pi$ puzzle is solved in this way, the corresponding puzzle in $B \to \pi K$ decays should have a different origin.
1710.10785
Shehu AbdusSalam
Shehu AbdusSalam
Testing Higgs boson scenarios in the phenomenological NMSSM
v3: major revisions, to appear in EPJC
null
10.1140/epjc/s10052-019-6953-7
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There could be another scalar in nature quasi-degenerate with the observed one (h125). This is possible in models such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The scenario(s) with a single Higgs boson can be compared to that with multiple ones, all near 125 GeV. In order to assess the extent to which the current set of collider, cold dark matter relic density and direct detection limits are capable of discriminating these scenarios, we perform, for the first-time, global fits of a weak-scale phenomenological NMSSM with 26 free parameters using the nested sampling implementation in PolyChord, a next-generation tool for Bayesian inference. The analyses indicate that the data used shows a moderate tendency for supporting the scenario with an additional scalar much lighter than h125 with mass distribution centred below the W-boson mass. More stringent constraints are, however, needed for decisive inference regarding an additional Higgs boson with mass much less than or near 125 GeV.
[ { "created": "Mon, 30 Oct 2017 06:45:09 GMT", "version": "v1" }, { "created": "Wed, 11 Jul 2018 12:37:29 GMT", "version": "v2" }, { "created": "Fri, 17 May 2019 12:35:37 GMT", "version": "v3" } ]
2019-05-23
[ [ "AbdusSalam", "Shehu", "" ] ]
There could be another scalar in nature quasi-degenerate with the observed one (h125). This is possible in models such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The scenario(s) with a single Higgs boson can be compared to that with multiple ones, all near 125 GeV. In order to assess the extent to which the current set of collider, cold dark matter relic density and direct detection limits are capable of discriminating these scenarios, we perform, for the first-time, global fits of a weak-scale phenomenological NMSSM with 26 free parameters using the nested sampling implementation in PolyChord, a next-generation tool for Bayesian inference. The analyses indicate that the data used shows a moderate tendency for supporting the scenario with an additional scalar much lighter than h125 with mass distribution centred below the W-boson mass. More stringent constraints are, however, needed for decisive inference regarding an additional Higgs boson with mass much less than or near 125 GeV.
0803.3609
Michael Durnev
M.A.Durnev
Quarkonia potential
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the quark-antiquark interactions obtained in the framework of the bootstrap method we construct a potential model, investigate the possibility of describing of heavy quarkonia and calculate the bottomonium spectrum. The potential of the interaction was obtained as a nonrelativistic limit of the relativistic quark-antiquark amplitudes Q{\bar Q} -> Q\bar Q.
[ { "created": "Tue, 25 Mar 2008 19:01:09 GMT", "version": "v1" } ]
2008-03-26
[ [ "Durnev", "M. A.", "" ] ]
Using the quark-antiquark interactions obtained in the framework of the bootstrap method we construct a potential model, investigate the possibility of describing of heavy quarkonia and calculate the bottomonium spectrum. The potential of the interaction was obtained as a nonrelativistic limit of the relativistic quark-antiquark amplitudes Q{\bar Q} -> Q\bar Q.
hep-ph/9709293
Ta-Pei Cheng
Ling-Fong Li and T. P. Cheng
The Proton Spin and Flavor Structure in the Chiral Quark Model
59 pages with table of contents, Lecture delivered at the Schladming Winter School (March 1997), to be published by Springer-Verlag under the title "Computing Particle Properties" (eds. C. B. Lang and H. Gausterer)
null
10.1007/BFb0106894
null
hep-ph
null
After a pedagogical review of the simple constituent quark model and deep inelastic sum rules, we describe how a quark sea as produced by the emission of internal Goldstone bosons by the valence quarks can account for the observed features of proton spin and flavor structures. Some issues concerning the strange quark content of the nucleon are also discussed.
[ { "created": "Tue, 9 Sep 1997 18:35:51 GMT", "version": "v1" } ]
2009-10-30
[ [ "Li", "Ling-Fong", "" ], [ "Cheng", "T. P.", "" ] ]
After a pedagogical review of the simple constituent quark model and deep inelastic sum rules, we describe how a quark sea as produced by the emission of internal Goldstone bosons by the valence quarks can account for the observed features of proton spin and flavor structures. Some issues concerning the strange quark content of the nucleon are also discussed.
1806.08271
Jose Bordes
Jose Bordes (1), H. M. Chan (2) and S. T. Tsou (3) ((1) Universitat de Valencia (Spain), (2) Rutherford Appleton Laboratory (United Kingdom), Mathematical Institute University of Oxford (United Kingdom)(3))
The $Z$ boson in the Framed Standard Model
21 pages, 2 figures
null
10.1142/S0217751X18501907
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The framed standard model (FSM), constructed initially for explaining the existence of three fermion generations and the hierarchical mass and mixing patterns of quarks and leptons, suggests also a "hidden sector" of particles including some dark matter candidates. It predicts in addition a new vector boson $G$, with mass of order TeV, which mixes with the $\gamma$ and $Z$ of the standard model yielding deviations from the standard mixing scheme, all calculable in terms of a single unknown parameter $m_G$. Given that standard mixing has been tested already to great accuracy by experiment, this could lead to contradictions, but it is shown here that for the three crucial and testable cases so far studied (i) $m_Z - m_W$, (ii) $\Gamma(Z \rightarrow \ell^ + \ell^-)$, (iii) $\Gamma(Z \rightarrow$ hadrons), the deviations are all within the present stringent experimental bounds provided $m_G > 1$ TeV, but should soon be detectable if experimental accuracy improves. This comes about because of some subtle cancellations, which might have a deeper reason that is not yet understood. By virtue of mixing, $G$ can be produced at the LHC and appear as a $\ell^+ \ell^-$ anomaly. If found, it will be of interest not only for its own sake but serve also as a window on to the "hidden sector" into which it will mostly decay, with dark matter candidates as most likely products.
[ { "created": "Thu, 21 Jun 2018 14:41:55 GMT", "version": "v1" }, { "created": "Fri, 22 Jun 2018 10:37:28 GMT", "version": "v2" }, { "created": "Thu, 4 Oct 2018 17:03:21 GMT", "version": "v3" } ]
2018-12-26
[ [ "Bordes", "Jose", "" ], [ "Chan", "H. M.", "" ], [ "Tsou", "S. T.", "" ] ]
The framed standard model (FSM), constructed initially for explaining the existence of three fermion generations and the hierarchical mass and mixing patterns of quarks and leptons, suggests also a "hidden sector" of particles including some dark matter candidates. It predicts in addition a new vector boson $G$, with mass of order TeV, which mixes with the $\gamma$ and $Z$ of the standard model yielding deviations from the standard mixing scheme, all calculable in terms of a single unknown parameter $m_G$. Given that standard mixing has been tested already to great accuracy by experiment, this could lead to contradictions, but it is shown here that for the three crucial and testable cases so far studied (i) $m_Z - m_W$, (ii) $\Gamma(Z \rightarrow \ell^ + \ell^-)$, (iii) $\Gamma(Z \rightarrow$ hadrons), the deviations are all within the present stringent experimental bounds provided $m_G > 1$ TeV, but should soon be detectable if experimental accuracy improves. This comes about because of some subtle cancellations, which might have a deeper reason that is not yet understood. By virtue of mixing, $G$ can be produced at the LHC and appear as a $\ell^+ \ell^-$ anomaly. If found, it will be of interest not only for its own sake but serve also as a window on to the "hidden sector" into which it will mostly decay, with dark matter candidates as most likely products.
1502.02503
Xun-Jie Xu
Xun-Jie Xu
Why Is The Neutrino Oscillation Formula Expanded In $\Delta m_{21}^{2}/\Delta m_{31}^{2}$ Still Accurate Near The Solar Resonance In Matter?
22 pages,7 figures. Some materials are removed for simplicity. Accepted by JHEP
null
10.1007/JHEP10(2015)090
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The conventional approximate formula for neutrino oscillation in matter which is obtained from the expansion in terms of the ratio of mass square differences $\alpha=\Delta m_{21}^{2}/\Delta m_{31}^{2}\approx0.03$, first proposed by Cervera, et al and Freund, turns out to be an accurate formula for accelerator neutrino experiments. Originally it required the neutrino energy to be well above the solar resonance to validate the expansion but it is found to be still very accurate when the formula is extrapolated to the resonance, which is practically important for the T2K experiment. This paper shows that the accuracy is guaranteed by cancellations of branch cut singularities and also, for the first time, analytically computes the actual error of the formula. The actual error implies that the original requirement can be safely removed in current experiments.
[ { "created": "Mon, 9 Feb 2015 14:39:20 GMT", "version": "v1" }, { "created": "Fri, 2 Oct 2015 18:44:57 GMT", "version": "v2" } ]
2015-10-16
[ [ "Xu", "Xun-Jie", "" ] ]
The conventional approximate formula for neutrino oscillation in matter which is obtained from the expansion in terms of the ratio of mass square differences $\alpha=\Delta m_{21}^{2}/\Delta m_{31}^{2}\approx0.03$, first proposed by Cervera, et al and Freund, turns out to be an accurate formula for accelerator neutrino experiments. Originally it required the neutrino energy to be well above the solar resonance to validate the expansion but it is found to be still very accurate when the formula is extrapolated to the resonance, which is practically important for the T2K experiment. This paper shows that the accuracy is guaranteed by cancellations of branch cut singularities and also, for the first time, analytically computes the actual error of the formula. The actual error implies that the original requirement can be safely removed in current experiments.
hep-ph/0606162
Alireza Haghpayma
A R. Haghpayma
Theta in a conventional correlated perturbative chiral quark model
4 pages, 2 tables
null
null
null
hep-ph
null
In a conventional covark model we constructed the Theta pentaquark wave function using vector diquarks and calculating the mass spectrum of this exotic pentaquark.
[ { "created": "Wed, 14 Jun 2006 16:11:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Haghpayma", "A R.", "" ] ]
In a conventional covark model we constructed the Theta pentaquark wave function using vector diquarks and calculating the mass spectrum of this exotic pentaquark.
hep-ph/0003257
Martin Maul
Paul Hoyer (NORDITA), Martin Maul (Lund U), Andreas Metz (Saclay)
Semi-Exclusive Production of Photons at HERA
11 pages, 7 figures, submitted to Eur. Phys. J. C, minor stylistic changes, references updated
Eur.Phys.J.C17:113-119,2000
10.1007/s100520000467
NORDITA-2000/20 HE, LU TP 00-09, DAPNIA/SPHN-00-11
hep-ph
null
We study the feasibility of measuring semi-exclusive photon production \gamma + p \to \gamma + Y at HERA. The cross section of photons produced at large transverse momenta, recoiling off an inclusive system Y of limited mass, can without photon isolation cuts be simply expressed in terms of hard pQCD subprocesses and standard target parton distributions. With the help of event generators we identify the kinematic region where quark and gluon fragmentation processes can be neglected. The cross section in this semi-exclusive region is large enough to be measured with an upgraded HERA luminosity of L = 100/pb. The subprocesses of lowest order in \alpha_s are suppressed at low recoil masses M_Y, compared to higher order gluon exchange, i.e. BFKL contributions. The distinct M_Y-dependence makes it possible to determine experimentally the kinematic range where the higher order processes dominate.
[ { "created": "Mon, 27 Mar 2000 09:35:43 GMT", "version": "v1" }, { "created": "Thu, 22 Jun 2000 17:43:13 GMT", "version": "v2" } ]
2011-09-13
[ [ "Hoyer", "Paul", "", "NORDITA" ], [ "Maul", "Martin", "", "Lund U" ], [ "Metz", "Andreas", "", "Saclay" ] ]
We study the feasibility of measuring semi-exclusive photon production \gamma + p \to \gamma + Y at HERA. The cross section of photons produced at large transverse momenta, recoiling off an inclusive system Y of limited mass, can without photon isolation cuts be simply expressed in terms of hard pQCD subprocesses and standard target parton distributions. With the help of event generators we identify the kinematic region where quark and gluon fragmentation processes can be neglected. The cross section in this semi-exclusive region is large enough to be measured with an upgraded HERA luminosity of L = 100/pb. The subprocesses of lowest order in \alpha_s are suppressed at low recoil masses M_Y, compared to higher order gluon exchange, i.e. BFKL contributions. The distinct M_Y-dependence makes it possible to determine experimentally the kinematic range where the higher order processes dominate.
hep-ph/0211451
Pierpaolo Mastrolia
P. Mastrolia (1 and 2), E. Remiddi (1 and 3) ((1) University of Bologna, (2) University of Karlsruhe, (3) INFN-Bologna)
The analytic value of a 3-loop sunrise graph in a particular kinematical configuration
9 pages, 3 figures
Nucl.Phys. B657 (2003) 397-406
10.1016/S0550-3213(03)00144-5
TTP02-39
hep-ph
null
We consider the scalar integral associated to the 3-loop sunrise graph with a massless line, two massive lines of equal mass $M$, a fourth line of mass equal to $Mx$, and the external invariant timelike and equal to the square of the fourth mass. We write the differential equation in $x$ satisfied by the integral, expand it in the continuous dimension $d$ around $d=4$ and solve the system of the resulting chained differential equations in closed analytic form, expressing the solutions in terms of Harmonic Polylogarithms. As a byproduct, we give the limiting values of the coefficients of the $(d-4)$ expansion at $x=1$ and $x=0$.
[ { "created": "Thu, 28 Nov 2002 20:22:34 GMT", "version": "v1" } ]
2009-11-07
[ [ "Mastrolia", "P.", "", "1 and 2" ], [ "Remiddi", "E.", "", "1 and 3" ] ]
We consider the scalar integral associated to the 3-loop sunrise graph with a massless line, two massive lines of equal mass $M$, a fourth line of mass equal to $Mx$, and the external invariant timelike and equal to the square of the fourth mass. We write the differential equation in $x$ satisfied by the integral, expand it in the continuous dimension $d$ around $d=4$ and solve the system of the resulting chained differential equations in closed analytic form, expressing the solutions in terms of Harmonic Polylogarithms. As a byproduct, we give the limiting values of the coefficients of the $(d-4)$ expansion at $x=1$ and $x=0$.
1903.09096
Allen Caldwell
Allen Caldwell, Gia Dvali
On the Gravitational Force on Anti-Matter
null
null
null
null
hep-ph gr-qc hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A number of experiments are currently underway on antimatter, particularly anti-hydrogen, to test whether the fundamental interactions behave the same way as for matter. Here we present a simple argument showing that a bound on a difference in gravitational forces exerted on matter and antimatter is already so severe that is goes well beyond the sensitivity of the above measurements.
[ { "created": "Thu, 21 Mar 2019 16:23:41 GMT", "version": "v1" } ]
2019-03-22
[ [ "Caldwell", "Allen", "" ], [ "Dvali", "Gia", "" ] ]
A number of experiments are currently underway on antimatter, particularly anti-hydrogen, to test whether the fundamental interactions behave the same way as for matter. Here we present a simple argument showing that a bound on a difference in gravitational forces exerted on matter and antimatter is already so severe that is goes well beyond the sensitivity of the above measurements.
0904.4042
Doyoun Kim
Deog Ki Hong and Doyoun Kim
Pseudo scalar contributions to light-by-light correction of muon g-2 in AdS/QCD
v3. 13 pages, 6 figures, slightly expanded and reorganized for clarity
Phys.Lett.B680:480-484,2009
10.1016/j.physletb.2009.09.026
PNUTP-09/A03 and SNUTP09-008
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have performed a holographic calculation of the hadronic contributions to the anomalous magnetic moment of the muon, using the gauge/gravity duality. We study a model of holographic QCD in the five dimensional AdS background with a hard-wall cutoff. Both 5D SU(2) and U(3) flavor gauge symmetries are considered for the neutral pion, eta and eta' contributions to the hadronic corrections. We find the total light-by-light contributions of pseudo scalars to the muon anomalous magnetic moment, a_mu=10.7 x 10^(-10), which is consistent with previous estimates, based on other approaches.
[ { "created": "Sun, 26 Apr 2009 17:52:26 GMT", "version": "v1" }, { "created": "Mon, 25 May 2009 12:13:58 GMT", "version": "v2" }, { "created": "Sun, 14 Jun 2009 16:13:26 GMT", "version": "v3" } ]
2009-10-06
[ [ "Hong", "Deog Ki", "" ], [ "Kim", "Doyoun", "" ] ]
We have performed a holographic calculation of the hadronic contributions to the anomalous magnetic moment of the muon, using the gauge/gravity duality. We study a model of holographic QCD in the five dimensional AdS background with a hard-wall cutoff. Both 5D SU(2) and U(3) flavor gauge symmetries are considered for the neutral pion, eta and eta' contributions to the hadronic corrections. We find the total light-by-light contributions of pseudo scalars to the muon anomalous magnetic moment, a_mu=10.7 x 10^(-10), which is consistent with previous estimates, based on other approaches.
2311.12766
Ian Jack
I. Jack
No-$\pi$ schemes for multi-coupling theories
63 pages, LaTeX, diagrams produced using tikz. Minor corrections made, note added
null
null
LTH1356
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We show that even $\zeta$-functions may be removed from the $\beta$-functions of general multi-coupling theories up to high loop order by means of coupling redefinitions. For theories whose $\beta$-function is determined by the anomalous dimensions of the fields, such as supersymmetric theories, this corresponds to a renormalisation scheme change to a momentum subtraction scheme.
[ { "created": "Tue, 21 Nov 2023 18:23:41 GMT", "version": "v1" }, { "created": "Mon, 4 Dec 2023 17:31:58 GMT", "version": "v2" } ]
2023-12-05
[ [ "Jack", "I.", "" ] ]
We show that even $\zeta$-functions may be removed from the $\beta$-functions of general multi-coupling theories up to high loop order by means of coupling redefinitions. For theories whose $\beta$-function is determined by the anomalous dimensions of the fields, such as supersymmetric theories, this corresponds to a renormalisation scheme change to a momentum subtraction scheme.
hep-ph/0407077
Susan Gardner
S. Gardner, V. Bernard, U.-G. Mei{\ss}ner
Radiative tritium beta-decay and the neutrino mass
11 pages, 4 eps figures; discussion, figure added
Phys.Lett. B598 (2004) 188-196
10.1016/j.physletb.2004.08.006
null
hep-ph nucl-ex nucl-th
null
The shape of the electron energy spectrum in 3H beta-decay permits a direct assay of the absolute scale of the neutrino mass; a highly accurate theoretical description of the electron energy spectrum is necessary to the empirical task. We update Sirlin's calculation of the outer radiative correction to nuclear beta-decay to take into account the non-zero energy resolution of the electron detector. In previous 3H beta-decay studies the outer radiative corrections were neglected all together; only Coulomb corrections to the spectrum were included. This neglect artificially pushes m_nu^2 < 0 in a potentially significant way. We present a computation of the theoretical spectrum appropriate to the extraction of the neutrino mass in the sub-eV regime.
[ { "created": "Tue, 6 Jul 2004 23:00:56 GMT", "version": "v1" }, { "created": "Wed, 14 Jul 2004 06:09:46 GMT", "version": "v2" }, { "created": "Mon, 9 Aug 2004 15:11:01 GMT", "version": "v3" } ]
2009-11-10
[ [ "Gardner", "S.", "" ], [ "Bernard", "V.", "" ], [ "Meißner", "U. -G.", "" ] ]
The shape of the electron energy spectrum in 3H beta-decay permits a direct assay of the absolute scale of the neutrino mass; a highly accurate theoretical description of the electron energy spectrum is necessary to the empirical task. We update Sirlin's calculation of the outer radiative correction to nuclear beta-decay to take into account the non-zero energy resolution of the electron detector. In previous 3H beta-decay studies the outer radiative corrections were neglected all together; only Coulomb corrections to the spectrum were included. This neglect artificially pushes m_nu^2 < 0 in a potentially significant way. We present a computation of the theoretical spectrum appropriate to the extraction of the neutrino mass in the sub-eV regime.