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2211.01906
Peihong Gu
Su-Ping Chen, Pei-Hong Gu
$U(1)_{Y'}$ universal seesaw
9 pages, 6 figures
null
10.1016/j.nuclphysb.2022.116057
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We extend the $SU(3)_c \times SU(2)_L \times U(1)_Y$ standard model by a $U(1)_{Y'}$ gauge symmetry. Three right-handed neutrinos are introduced to cancel the gauge anomaly. One Higgs singlet is responsible for spontaneously breaking the $U(1)_{Y'}$ symmetry while the standard model Higgs doublet does not carry any $U(1)_{Y'}$ charges. The down-type quarks, up-type quarks, charged leptons and neutral neutrinos obtain their Dirac masses through four types of dimension-5 operators constructed by the fermion doublets and singlets with the Higgs doublet and singlet. This effective theory is realized in three renormalizable contexts with heavy fermion singlets, scalar doublets and fermion doublets. The heavy fermion singlets and doublets for generating the neutrino masses also accommodate a successful Dirac leptogenesis to explain the baryon asymmetry in the universe.
[ { "created": "Thu, 3 Nov 2022 15:39:31 GMT", "version": "v1" } ]
2023-01-11
[ [ "Chen", "Su-Ping", "" ], [ "Gu", "Pei-Hong", "" ] ]
We extend the $SU(3)_c \times SU(2)_L \times U(1)_Y$ standard model by a $U(1)_{Y'}$ gauge symmetry. Three right-handed neutrinos are introduced to cancel the gauge anomaly. One Higgs singlet is responsible for spontaneously breaking the $U(1)_{Y'}$ symmetry while the standard model Higgs doublet does not carry any $U(1)_{Y'}$ charges. The down-type quarks, up-type quarks, charged leptons and neutral neutrinos obtain their Dirac masses through four types of dimension-5 operators constructed by the fermion doublets and singlets with the Higgs doublet and singlet. This effective theory is realized in three renormalizable contexts with heavy fermion singlets, scalar doublets and fermion doublets. The heavy fermion singlets and doublets for generating the neutrino masses also accommodate a successful Dirac leptogenesis to explain the baryon asymmetry in the universe.
1510.03092
Nobuchika Okada
Jason Carson and Nobuchika Okada
125 GeV Higgs boson mass from 5D gauge-Higgs unification
28 pages, 8 figures, revised version to be published in PTEP
Prog Theor Exp Phys (2018)
10.1093/ptep/pty018
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of a simple gauge-Higgs unification (GHU) scenario based on the gauge group SU(3)$\times$U(1)$^\prime$ in a 5-dimensional flat space-time, we investigate a possibility to reproduce the observed Higgs boson mass of around 125 GeV. We introduce bulk fermion multiplets with a bulk mass and a (half) periodic boundary condition. In our analysis, we adopt a low energy effective theoretical approach of the GHU scenario, where the running Higgs quartic coupling is required to vanish at the compactification scale. Under this "gauge-Higgs condition," we investigate the renormalization group evolution of the Higgs quartic coupling and find a relation between the bulk mass and the compactification scale so as to reproduce the 125 GeV Higgs boson mass. Through quantum corrections at the one-loop level, the bulk fermions contribute to the Higgs boson production and decay processes and deviate the Higgs boson signal strengths at the Large Hadron Collider (LHC) experiments from the Standard Model (SM) predictions. Employing the current experimental data which show the the Higgs boson signal strengths for a variety of Higgs decay modes are consistent with the SM predictions, we obtain lower mass bounds on the lightest mode of the bulk fermions.
[ { "created": "Sun, 11 Oct 2015 20:07:19 GMT", "version": "v1" }, { "created": "Mon, 10 Jul 2017 15:04:39 GMT", "version": "v2" }, { "created": "Mon, 5 Feb 2018 01:59:09 GMT", "version": "v3" } ]
2019-12-06
[ [ "Carson", "Jason", "" ], [ "Okada", "Nobuchika", "" ] ]
In the context of a simple gauge-Higgs unification (GHU) scenario based on the gauge group SU(3)$\times$U(1)$^\prime$ in a 5-dimensional flat space-time, we investigate a possibility to reproduce the observed Higgs boson mass of around 125 GeV. We introduce bulk fermion multiplets with a bulk mass and a (half) periodic boundary condition. In our analysis, we adopt a low energy effective theoretical approach of the GHU scenario, where the running Higgs quartic coupling is required to vanish at the compactification scale. Under this "gauge-Higgs condition," we investigate the renormalization group evolution of the Higgs quartic coupling and find a relation between the bulk mass and the compactification scale so as to reproduce the 125 GeV Higgs boson mass. Through quantum corrections at the one-loop level, the bulk fermions contribute to the Higgs boson production and decay processes and deviate the Higgs boson signal strengths at the Large Hadron Collider (LHC) experiments from the Standard Model (SM) predictions. Employing the current experimental data which show the the Higgs boson signal strengths for a variety of Higgs decay modes are consistent with the SM predictions, we obtain lower mass bounds on the lightest mode of the bulk fermions.
0705.4667
Daniele Montanino dr.
A. Mirizzi (MPI), D. Montanino (Salento U. & INFN, Lecce), P.D. Serpico (Fermilab)
Revisiting cosmological bounds on radiative neutrino lifetime
7 pages, 3 figures. Minor changes in the text, few references added. Matches the published version
Phys.Rev.D76:053007,2007
10.1103/PhysRevD.76.053007
FERMILAB-PUB-07-135-A; MPP-2007-63
hep-ph astro-ph
null
Neutrino oscillation experiments and direct bounds on absolute masses constrain neutrino mass differences to fall into the microwave energy range, for most of the allowed parameter space. As a consequence of these recent phenomenological advances, older constraints on radiative neutrino decays based on diffuse background radiations and assuming strongly hierarchical masses in the eV range are now outdated. We thus derive new bounds on the radiative neutrino lifetime using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of Cosmic Background Explorer. The lower bound on the lifetime is between a few x 10^19 s and 5 x 10^20 s, depending on the neutrino mass ordering and on the absolute mass scale. However, due to phase space limitations, the upper bound in terms of the effective magnetic moment mediating the decay is not better than ~ 10^-8 Bohr magnetons. We also comment about possible improvements of these limits, by means of recent diffuse infrared photon background data. We compare these bounds with pre-existing limits coming from laboratory or astrophysical arguments. We emphasize the complementarity of our results with others available in the literature.
[ { "created": "Thu, 31 May 2007 18:05:34 GMT", "version": "v1" }, { "created": "Thu, 27 Sep 2007 17:22:02 GMT", "version": "v2" } ]
2008-11-26
[ [ "Mirizzi", "A.", "", "MPI" ], [ "Montanino", "D.", "", "Salento U. & INFN, Lecce" ], [ "Serpico", "P. D.", "", "Fermilab" ] ]
Neutrino oscillation experiments and direct bounds on absolute masses constrain neutrino mass differences to fall into the microwave energy range, for most of the allowed parameter space. As a consequence of these recent phenomenological advances, older constraints on radiative neutrino decays based on diffuse background radiations and assuming strongly hierarchical masses in the eV range are now outdated. We thus derive new bounds on the radiative neutrino lifetime using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of Cosmic Background Explorer. The lower bound on the lifetime is between a few x 10^19 s and 5 x 10^20 s, depending on the neutrino mass ordering and on the absolute mass scale. However, due to phase space limitations, the upper bound in terms of the effective magnetic moment mediating the decay is not better than ~ 10^-8 Bohr magnetons. We also comment about possible improvements of these limits, by means of recent diffuse infrared photon background data. We compare these bounds with pre-existing limits coming from laboratory or astrophysical arguments. We emphasize the complementarity of our results with others available in the literature.
hep-ph/9608335
Shoichi Sasaki Rcnp
Hideo Suganuma (RCNP), Hiroko Ichie (RCNP), Hiroshi Toki (RCNP), Hideko Monden (TMU)
Recent Progress in Nonperturbative QCD Theory and Insight on Cosmological Phase Transition
Talk presented by H. Suganuma at International Workshop on ``Nuclear and Particle Cosmo Physics'', Jan. 1996, in Atami, Japan, 10 pages, Plain Tex, uses PHYZZX ( 9 figures - available on request from suganuma@rcnp.osaka-u.ac.jp )
null
null
null
hep-ph
null
The QCD phase transition at finite temperature is studied with the dual Ginzburg-Landau theory, which is the QCD effective theory based on the dual Higgs mechanism by QCD-monopole condensation. At high temperature, the confinement force is largely reduced by thermal effects, which leads to the swelling of hadrons. Simple formulae for the surface tension and the thickness of the phase boundary are derived from the shape of the effective potential at the critical temperature. We investigate also the process of the hadron-bubble formation in the early Universe.
[ { "created": "Thu, 15 Aug 1996 15:14:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Suganuma", "Hideo", "", "RCNP" ], [ "Ichie", "Hiroko", "", "RCNP" ], [ "Toki", "Hiroshi", "", "RCNP" ], [ "Monden", "Hideko", "", "TMU" ] ]
The QCD phase transition at finite temperature is studied with the dual Ginzburg-Landau theory, which is the QCD effective theory based on the dual Higgs mechanism by QCD-monopole condensation. At high temperature, the confinement force is largely reduced by thermal effects, which leads to the swelling of hadrons. Simple formulae for the surface tension and the thickness of the phase boundary are derived from the shape of the effective potential at the critical temperature. We investigate also the process of the hadron-bubble formation in the early Universe.
hep-ph/9711324
Jean Letessier
Jean Letessier, Jan Rafelski, Ahmed Tounsi
Formation and Evolution of the Quark-Gluon Plasma
Replaced for bad printing on US paper. 16 pages, LaTeX, 3 postscript figures
Phys.Lett. B333 (1994) 484-493
10.1016/0370-2693(94)90172-4
null
hep-ph nucl-th
null
Imposing an equilibrium between the thermal pressure of deconfined quarks and gluons and the dynamical compression pressure exercised by in-flowing nuclear matter, we study the initial thermal conditions reached in a quark-gluon plasma fireball formed in a relativistic heavy ion collision. We show that entropy is produced primarily in the pre-equilibrium stage of the reaction. We test our approach, comparing our results with the S-W/Pb collision results at 200 GeV A and find a surprising degree of agreement assuming about 50% stopping. We apply our method to a determination of the conditions in collisions of Au-Au at 11 GeV A and Pb-Pb at 157 GeV A, assuming full stopping of momentum, energy and baryon number. Our detailed results directly determine the spectral shape and abundance of (strange) hadrons and electromagnetic probes (photons, dileptons) produced in the collision, and we explore specific experimental consequences.
[ { "created": "Thu, 13 Nov 1997 18:01:34 GMT", "version": "v1" }, { "created": "Mon, 24 Nov 1997 10:59:47 GMT", "version": "v2" } ]
2009-10-30
[ [ "Letessier", "Jean", "" ], [ "Rafelski", "Jan", "" ], [ "Tounsi", "Ahmed", "" ] ]
Imposing an equilibrium between the thermal pressure of deconfined quarks and gluons and the dynamical compression pressure exercised by in-flowing nuclear matter, we study the initial thermal conditions reached in a quark-gluon plasma fireball formed in a relativistic heavy ion collision. We show that entropy is produced primarily in the pre-equilibrium stage of the reaction. We test our approach, comparing our results with the S-W/Pb collision results at 200 GeV A and find a surprising degree of agreement assuming about 50% stopping. We apply our method to a determination of the conditions in collisions of Au-Au at 11 GeV A and Pb-Pb at 157 GeV A, assuming full stopping of momentum, energy and baryon number. Our detailed results directly determine the spectral shape and abundance of (strange) hadrons and electromagnetic probes (photons, dileptons) produced in the collision, and we explore specific experimental consequences.
1505.06369
Yaofu Zhou
Yaofu Zhou
Constraining the Higgs Boson Coupling to Light Quarks in the $H\to ZZ$ Final States
7 pages, 5 figures, 3 tables
Phys. Rev. D 93, 013019 (2016)
10.1103/PhysRevD.93.013019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We constrain the Higgs boson (Yukawa) coupling to quarks in the first two generations in the $H\to ZZ$ final states. Deviation of these couplings from the Standard Model values leads to change in the Higgs boson width and in the cross sections of relevant processes. In the Higgs boson resonance region, an increased light Yukawa coupling leads to an increased Higgs boson width, which in turn leads to a decreased cross section. In the off-shell region, increased Yukawa couplings result in an enhancement of the Higgs boson signal through $q\bar{q}$ annihilation. With the assumption of scaling one Yukawa coupling at a time, this study is conceptually simple and yields results with the same order of magnitude as the tightest in the literature. The study is based on results published by the CMS experiment at the LHC in 2014, corresponding to integrated luminosities of $5.1\ifb$ at a centre-of-mass energy $\sqrt{s}=7\tev$ and $19.7\ifb$ at $8\tev$.
[ { "created": "Sat, 23 May 2015 19:37:02 GMT", "version": "v1" }, { "created": "Sun, 14 Feb 2016 00:22:20 GMT", "version": "v2" } ]
2016-02-16
[ [ "Zhou", "Yaofu", "" ] ]
We constrain the Higgs boson (Yukawa) coupling to quarks in the first two generations in the $H\to ZZ$ final states. Deviation of these couplings from the Standard Model values leads to change in the Higgs boson width and in the cross sections of relevant processes. In the Higgs boson resonance region, an increased light Yukawa coupling leads to an increased Higgs boson width, which in turn leads to a decreased cross section. In the off-shell region, increased Yukawa couplings result in an enhancement of the Higgs boson signal through $q\bar{q}$ annihilation. With the assumption of scaling one Yukawa coupling at a time, this study is conceptually simple and yields results with the same order of magnitude as the tightest in the literature. The study is based on results published by the CMS experiment at the LHC in 2014, corresponding to integrated luminosities of $5.1\ifb$ at a centre-of-mass energy $\sqrt{s}=7\tev$ and $19.7\ifb$ at $8\tev$.
1510.08069
Nikita Blinov
Nikita Blinov, Jonathan Kozaczuk, David E. Morrissey, Alejandro de la Puente
Compressing the Inert Doublet Model
32 pages, 9 figures. References added; other minor changes to match journal version
Phys. Rev. D 93, 035020 (2016)
10.1103/PhysRevD.93.035020
SLAC-PUB-16419
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Inert Doublet Model relies on a discrete symmetry to prevent couplings of the new scalars to Standard Model fermions. This stabilizes the lightest inert state, which can then contribute to the observed dark matter density. In the presence of additional approximate symmetries, the resulting spectrum of exotic scalars can be compressed. Here, we study the phenomenological and cosmological implications of this scenario. We derive new limits on the compressed Inert Doublet Model from LEP, and outline the prospects for exclusion and discovery of this model at dark matter experiments, the LHC, and future colliders.
[ { "created": "Tue, 27 Oct 2015 20:09:07 GMT", "version": "v1" }, { "created": "Tue, 23 Feb 2016 19:06:17 GMT", "version": "v2" } ]
2016-02-24
[ [ "Blinov", "Nikita", "" ], [ "Kozaczuk", "Jonathan", "" ], [ "Morrissey", "David E.", "" ], [ "de la Puente", "Alejandro", "" ] ]
The Inert Doublet Model relies on a discrete symmetry to prevent couplings of the new scalars to Standard Model fermions. This stabilizes the lightest inert state, which can then contribute to the observed dark matter density. In the presence of additional approximate symmetries, the resulting spectrum of exotic scalars can be compressed. Here, we study the phenomenological and cosmological implications of this scenario. We derive new limits on the compressed Inert Doublet Model from LEP, and outline the prospects for exclusion and discovery of this model at dark matter experiments, the LHC, and future colliders.
hep-ph/0204100
Junji Hisano
J. Hisano
Probing physics beyond the standard model from lepton sector
ICRR-Report-487-2002-5, 10 pages;Talk given in The Fifth KEK Topical Conference (KEKTC5), KEK, Tsukuba, Japan, November 2001
Nucl.Phys.Proc.Suppl. 111 (2002) 178-187
10.1016/S0920-5632(02)01703-6
null
hep-ph
null
In this review we discuss physics of the lepton sector, the anomalous dipole moment of muon, the charged lepton-flavor violation, and the electric dipole moments of charged leptons, from viewpoints of the minimal supersymmetric standard model and the extensions.
[ { "created": "Tue, 9 Apr 2002 08:28:11 GMT", "version": "v1" } ]
2009-11-07
[ [ "Hisano", "J.", "" ] ]
In this review we discuss physics of the lepton sector, the anomalous dipole moment of muon, the charged lepton-flavor violation, and the electric dipole moments of charged leptons, from viewpoints of the minimal supersymmetric standard model and the extensions.
2407.10560
Yannis Georis
J. de Vries, M. Drewes, Y. Georis, J. Klari\'c, V. Plakkot
Confronting the low-scale seesaw and leptogenesis with neutrinoless double beta decay
27 pages, 10 figures
null
null
null
hep-ph astro-ph.CO nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the impact of heavy neutrinos with masses in the MeV-GeV range on neutrinoless double beta decay ($0\nu\beta\beta$) in view of updated results for the lifetime of this process. Working in a minimal realistic extension of the Standard Model by two right-handed neutrino flavours, we show that the non-observation of $0\nu\beta\beta$ will impose strong bounds on the heavy neutrino properties that are complementary to the limits obtained from Big Bang Nucleosynthesis and collider searches. For an inverted mass hierarchy of the light neutrinos we find that improved limits on $0\nu\beta\beta$ from next-generation experiments will restrict the allowed parameter space for fixed mass splitting to narrow bands in the mass-mixing plane. Further combining this with the requirement to explain the baryon asymmetry of the universe via leptogenesis reduces these bands to windows in parameter space that are constrained in all directions and can be targeted by direct searches at accelerators. For a normal mass hierarchy, only parts of the parameter space can be probed by such experiments.
[ { "created": "Mon, 15 Jul 2024 09:20:00 GMT", "version": "v1" } ]
2024-07-16
[ [ "de Vries", "J.", "" ], [ "Drewes", "M.", "" ], [ "Georis", "Y.", "" ], [ "Klarić", "J.", "" ], [ "Plakkot", "V.", "" ] ]
We revisit the impact of heavy neutrinos with masses in the MeV-GeV range on neutrinoless double beta decay ($0\nu\beta\beta$) in view of updated results for the lifetime of this process. Working in a minimal realistic extension of the Standard Model by two right-handed neutrino flavours, we show that the non-observation of $0\nu\beta\beta$ will impose strong bounds on the heavy neutrino properties that are complementary to the limits obtained from Big Bang Nucleosynthesis and collider searches. For an inverted mass hierarchy of the light neutrinos we find that improved limits on $0\nu\beta\beta$ from next-generation experiments will restrict the allowed parameter space for fixed mass splitting to narrow bands in the mass-mixing plane. Further combining this with the requirement to explain the baryon asymmetry of the universe via leptogenesis reduces these bands to windows in parameter space that are constrained in all directions and can be targeted by direct searches at accelerators. For a normal mass hierarchy, only parts of the parameter space can be probed by such experiments.
hep-ph/9910437
Edward W. Kolb
Daniel J. H. Chung, Edward W. Kolb, Antonio Riotto, Igor I. Tkachev
Probing Planckian physics: resonant production of particles during inflation and features in the primordial power spectrum
19 pages, 11 eps figures
Phys.Rev. D62 (2000) 043508
10.1103/PhysRevD.62.043508
FNAL-Pub-99/308-A; CERN-TH/99-302
hep-ph astro-ph hep-th
null
The phenomenon of resonant production of particles {\it after} inflation has received much attention in the past few years. In a new application of resonant production of particles, we consider the effect of a resonance {\em during} inflation. We show that if the inflaton is coupled to a massive particle, resonant production of the particle during inflation modifies the evolution of the inflaton, and may leave an imprint in the form of sharp features in the primordial power spectrum. Precision measurements of microwave background anisotropies and large-scale structure surveys could be sensitive to the features, and probe the spectrum of particles as massive as the Planck scale.
[ { "created": "Thu, 21 Oct 1999 21:24:25 GMT", "version": "v1" } ]
2009-10-31
[ [ "Chung", "Daniel J. H.", "" ], [ "Kolb", "Edward W.", "" ], [ "Riotto", "Antonio", "" ], [ "Tkachev", "Igor I.", "" ] ]
The phenomenon of resonant production of particles {\it after} inflation has received much attention in the past few years. In a new application of resonant production of particles, we consider the effect of a resonance {\em during} inflation. We show that if the inflaton is coupled to a massive particle, resonant production of the particle during inflation modifies the evolution of the inflaton, and may leave an imprint in the form of sharp features in the primordial power spectrum. Precision measurements of microwave background anisotropies and large-scale structure surveys could be sensitive to the features, and probe the spectrum of particles as massive as the Planck scale.
1902.01984
Sheng-Quan Wang
Sheng-Quan Wang, Stanley J. Brodsky, Xing-Gang Wu, Leonardo Di Giustino
Thrust Distribution in Electron-Positron Annihilation using the Principle of Maximum Conformality
6 pages, 4 figures, v2: matches published version
Phys. Rev. D 99, 114020 (2019)
10.1103/PhysRevD.99.114020
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a comprehensive and self-consistent analysis for the thrust distribution by using the Principle of Maximum Conformality (PMC). By absorbing all nonconformal terms into the running coupling using PMC via renormalization group equation, the scale in the running coupling shows the correct physical behavior and the correct number of active flavors is determined. The resulting PMC predictions agree with the precise measurements for both the thrust differential distributions and the thrust mean values. Moreover, we provide a new remarkable way to determine the running of the coupling constant $\alpha_s(Q^2)$ from the measurement of the jet distributions in electron-positron annihilation at a single given value of the center-of-mass energy $\sqrt{s}$.
[ { "created": "Wed, 6 Feb 2019 00:21:11 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2019 23:50:54 GMT", "version": "v2" } ]
2019-07-03
[ [ "Wang", "Sheng-Quan", "" ], [ "Brodsky", "Stanley J.", "" ], [ "Wu", "Xing-Gang", "" ], [ "Di Giustino", "Leonardo", "" ] ]
We present a comprehensive and self-consistent analysis for the thrust distribution by using the Principle of Maximum Conformality (PMC). By absorbing all nonconformal terms into the running coupling using PMC via renormalization group equation, the scale in the running coupling shows the correct physical behavior and the correct number of active flavors is determined. The resulting PMC predictions agree with the precise measurements for both the thrust differential distributions and the thrust mean values. Moreover, we provide a new remarkable way to determine the running of the coupling constant $\alpha_s(Q^2)$ from the measurement of the jet distributions in electron-positron annihilation at a single given value of the center-of-mass energy $\sqrt{s}$.
hep-ph/9305284
David Bowser-Chao
Duane A. Dicus and Wayne W. Repko
Photon neutrino scattering
8 pages including figures; DOE-40200-014,CPP-14,MSUHEP 93/08. Figures, one style file, and latex file available by anonymous ftp to utaphy.ph.utexas.edu, in directory [anonymous.cpp-preprints.ggtonunu]
Phys.Rev. D48 (1993) 5106-5108
10.1103/PhysRevD.48.5106
null
hep-ph
null
The cross section for photon neutrino scattering is calculated in the standard model assuming that the neutrino is massless and that the center of mass energy is small compared to any charged lepton mass. Although the scattered photons can acquire a (parity violating) circular polarization of order unity, the cross section in this limit is highly suppressed.
[ { "created": "Tue, 18 May 1993 20:29:34 GMT", "version": "v1" } ]
2009-10-22
[ [ "Dicus", "Duane A.", "" ], [ "Repko", "Wayne W.", "" ] ]
The cross section for photon neutrino scattering is calculated in the standard model assuming that the neutrino is massless and that the center of mass energy is small compared to any charged lepton mass. Although the scattered photons can acquire a (parity violating) circular polarization of order unity, the cross section in this limit is highly suppressed.
1903.09249
Luciano Abreu
L. M. Abreu, E. B. S. Corr\^ea, C. A. Linhares and A. P. C. Malbouisson
Finite-volume and magnetic effects on the phase structure of the three-flavor Nambu--Jona-Lasinio model
27 pages; 9 figures; accepted for publication in Phys. Rev. D
Phys. Rev. D 99, 076001 (2019)
10.1103/PhysRevD.99.076001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we analyze the finite-volume and magnetic effects on the phase structure of a generalized version of Nambu--Jona-Lasinio model with three quark flavors. By making use of mean-field approximation and Schwinger's proper-time method in a toroidal topology with antiperiodic conditions, we investigate the gap equation solutions under the change of the size of compactified coordinates, strength of magnetic field, temperature and chemical potential. The 't Hooft interaction contributions are also evaluated. The thermodynamic behavior is strongly affected by the combined effects of relevant variables. The findings suggest that the broken phase is disfavored due to both increasing of temperature and chemical potential, and the drop of the cubic volume of size $L$, whereas it is stimulated with the augmentation of magnetic field. In particular, the reduction of $L$ (remarkably at $L\approx 0.5 - 3 $~fm) engenders a reduction of the constituent masses for $u,d,s$-quarks through a crossover phase transition to the their corresponding current quark masses. On the other hand, the presence of a magnetic background generates greater values constituent quark masses, inducing smaller sizes and greater temperatures at which the constituent quark masses drop to the respective current ones.
[ { "created": "Thu, 21 Mar 2019 21:52:20 GMT", "version": "v1" } ]
2019-04-09
[ [ "Abreu", "L. M.", "" ], [ "Corrêa", "E. B. S.", "" ], [ "Linhares", "C. A.", "" ], [ "Malbouisson", "A. P. C.", "" ] ]
In this work we analyze the finite-volume and magnetic effects on the phase structure of a generalized version of Nambu--Jona-Lasinio model with three quark flavors. By making use of mean-field approximation and Schwinger's proper-time method in a toroidal topology with antiperiodic conditions, we investigate the gap equation solutions under the change of the size of compactified coordinates, strength of magnetic field, temperature and chemical potential. The 't Hooft interaction contributions are also evaluated. The thermodynamic behavior is strongly affected by the combined effects of relevant variables. The findings suggest that the broken phase is disfavored due to both increasing of temperature and chemical potential, and the drop of the cubic volume of size $L$, whereas it is stimulated with the augmentation of magnetic field. In particular, the reduction of $L$ (remarkably at $L\approx 0.5 - 3 $~fm) engenders a reduction of the constituent masses for $u,d,s$-quarks through a crossover phase transition to the their corresponding current quark masses. On the other hand, the presence of a magnetic background generates greater values constituent quark masses, inducing smaller sizes and greater temperatures at which the constituent quark masses drop to the respective current ones.
1405.7482
Debajyoti Dutta
Kalpana Bora, Debajyoti Dutta, Pomita Ghoshal
Determining the Octant of $\theta_{23}$ at LBNE in conjunction with Reactor Experiments
18 pages, 36 figures in Mod.Phys.Lett.A, 2015
Mod.Phys.Lett.A 30, 1550066 (2015)
10.1142/S0217732315500662
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have explored the possibilities of resolving the $\theta_{23}$ octant degeneracy present in the newly planned Long-Baseline Neutrino Experiment (LBNE) by combining reactor data. Reactor experiments have already measured the third mixing angle $\theta_{13}$ very precisely and this precise measurenent of $\theta_{13}$ in turn helps in $\theta_{23}$ octant measurement. We have examined the octant sensitivity with and without reactor data and it improves if reactor data is added. The comparative study of octant sensitivities of 10kt and 35kt liquid argon Far Detectors, with and without the Near Detector, reveals that the sensitivity increases with an increase in detector mass. Also, the presence of the Near Detector improves the sensitivity. The effect of adding priors on octant determination is also studied in this work.
[ { "created": "Thu, 29 May 2014 07:39:10 GMT", "version": "v1" }, { "created": "Thu, 5 Feb 2015 08:50:04 GMT", "version": "v2" } ]
2015-05-28
[ [ "Bora", "Kalpana", "" ], [ "Dutta", "Debajyoti", "" ], [ "Ghoshal", "Pomita", "" ] ]
We have explored the possibilities of resolving the $\theta_{23}$ octant degeneracy present in the newly planned Long-Baseline Neutrino Experiment (LBNE) by combining reactor data. Reactor experiments have already measured the third mixing angle $\theta_{13}$ very precisely and this precise measurenent of $\theta_{13}$ in turn helps in $\theta_{23}$ octant measurement. We have examined the octant sensitivity with and without reactor data and it improves if reactor data is added. The comparative study of octant sensitivities of 10kt and 35kt liquid argon Far Detectors, with and without the Near Detector, reveals that the sensitivity increases with an increase in detector mass. Also, the presence of the Near Detector improves the sensitivity. The effect of adding priors on octant determination is also studied in this work.
1707.05343
Fredrick Olness
The xFitter Developers Team: V. Bertone, D. Britzger, S. Camarda, A. Cooper-Sarkar, A. Geiser, F. Giuli, A. Glazov, E. Godat, A. Kusina, A. Luszczak, F. Lyonnet, F. Olness, R. Placakyte, V. Radescu, I. Schienbein, O. Zenaiev
Impact of the heavy quark matching scales in PDF fits
18 pages, 12 figures. Updated to match published version
null
10.1140/epjc/s10052-017-5407-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the impact of displaced heavy quark matching scales in a global fit. The heavy quark matching scale $\mu_{m}$ determines at which energy scale $\mu$ the QCD theory transitions from $N_{F}$ to $N_{F}+1$ in the Variable Flavor Number Scheme (VFNS) for the evolution of the Parton Distribution Functions (PDFs) and strong coupling $\alpha_S(\mu)$. We study the variation of the matching scales, and their impact on a global PDF fit of the combined HERA data. As the choice of the matching scale $\mu_{m}$ effectively is a choice of scheme, this represents a theoretical uncertainty; ideally, we would like to see minimal dependence on this parameter. For the transition across the charm quark (from $N_{F}=3$ to $4$), we find a large $\mu_m=\mu_{c}$ dependence of the global fit $\chi^2$ at NLO, but this is significantly reduced at NNLO. For the transition across the bottom quark (from $N_{F}=4$ to $5$), we have a reduced $\mu_{m}=\mu_b$ dependence of the $\chi^2$ at both NLO and NNLO as compared to the charm. This feature is now implemented in xFitter 2.0.0, an open source QCD fit framework.
[ { "created": "Mon, 17 Jul 2017 18:08:33 GMT", "version": "v1" }, { "created": "Thu, 21 Dec 2017 20:04:29 GMT", "version": "v2" } ]
2017-12-25
[ [ "The xFitter Developers Team", "", "" ], [ "Bertone", "V.", "" ], [ "Britzger", "D.", "" ], [ "Camarda", "S.", "" ], [ "Cooper-Sarkar", "A.", "" ], [ "Geiser", "A.", "" ], [ "Giuli", "F.", "" ], [ "...
We investigate the impact of displaced heavy quark matching scales in a global fit. The heavy quark matching scale $\mu_{m}$ determines at which energy scale $\mu$ the QCD theory transitions from $N_{F}$ to $N_{F}+1$ in the Variable Flavor Number Scheme (VFNS) for the evolution of the Parton Distribution Functions (PDFs) and strong coupling $\alpha_S(\mu)$. We study the variation of the matching scales, and their impact on a global PDF fit of the combined HERA data. As the choice of the matching scale $\mu_{m}$ effectively is a choice of scheme, this represents a theoretical uncertainty; ideally, we would like to see minimal dependence on this parameter. For the transition across the charm quark (from $N_{F}=3$ to $4$), we find a large $\mu_m=\mu_{c}$ dependence of the global fit $\chi^2$ at NLO, but this is significantly reduced at NNLO. For the transition across the bottom quark (from $N_{F}=4$ to $5$), we have a reduced $\mu_{m}=\mu_b$ dependence of the $\chi^2$ at both NLO and NNLO as compared to the charm. This feature is now implemented in xFitter 2.0.0, an open source QCD fit framework.
hep-ph/9503249
null
N.I.Kochelev
Instanton Effects in $N\bar N$ Annihilation
11 pages, Latex
Chin.J.Phys. 34 (1996) 956-961
null
JINR-E2-95-99
hep-ph
null
It is shown that specific spin-flavour properties of the nonperturbative interaction between quarks induced by instantons allow us to explain the peculiarities of the OZI rule violation in $N \bar N$ annihilation. New experiments to test the instanton mechanism of the OZI rule violation are proposed.
[ { "created": "Tue, 7 Mar 1995 09:01:31 GMT", "version": "v1" }, { "created": "Tue, 14 Mar 1995 10:37:49 GMT", "version": "v2" } ]
2016-09-01
[ [ "Kochelev", "N. I.", "" ] ]
It is shown that specific spin-flavour properties of the nonperturbative interaction between quarks induced by instantons allow us to explain the peculiarities of the OZI rule violation in $N \bar N$ annihilation. New experiments to test the instanton mechanism of the OZI rule violation are proposed.
1412.3357
Manoj Mandal
M. C. Kumar, M. K. Mandal and V. Ravindran
Associated production of Higgs boson with vector boson at threshold N$^3$LO in QCD
14 pages, 3 figures
null
10.1007/JHEP03(2015)037
HRI-RECAPP-2014-027
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the results for the associated production of Higgs boson with vector boson computed at threshold N$^3$LO in QCD. We use the recently available result on the threshold contributions to the inclusive Drell-Yan production cross-section at third order in strong coupling constant. We have implemented it in the publicly available computer package vh@nnlo, thereby obtaining the numerical impact of threshold N$^3$LO contributions for the first time. We find that the inclusion of such corrections do reduce theoretical uncertainties resulting from the renormalization scale.
[ { "created": "Wed, 10 Dec 2014 16:32:18 GMT", "version": "v1" } ]
2015-06-23
[ [ "Kumar", "M. C.", "" ], [ "Mandal", "M. K.", "" ], [ "Ravindran", "V.", "" ] ]
We present the results for the associated production of Higgs boson with vector boson computed at threshold N$^3$LO in QCD. We use the recently available result on the threshold contributions to the inclusive Drell-Yan production cross-section at third order in strong coupling constant. We have implemented it in the publicly available computer package vh@nnlo, thereby obtaining the numerical impact of threshold N$^3$LO contributions for the first time. We find that the inclusion of such corrections do reduce theoretical uncertainties resulting from the renormalization scale.
hep-ph/0207049
Uleshchenko V. V. ofti off 337 fon
V. Uleshchenko, A. Szczurek
Nonpartonic effects in pion electroproduction in the HERMES kinematical region
A talk presented at DIS2002, 30 April - 4 May 2002, Cracow
Acta Phys.Polon. B33 (2002) 3299-3304
null
null
hep-ph
null
The presentation is concerned with higher twist corrections of nonpartonic origin to semi-inclusive observables in the kinematical region relevant for the HERMES experiment. We demonstrate a strong impact of the VDM-like interaction and the exclusive production of $\rho^0$ meson on the extraction of the $\bar d - \bar u$ asymmetry from charged pion DIS multiplicities. We also show that it is the exclusive-$\rho^0$ channel which accounts for the experimentally observed effect of the excess of charged over neutral pions produced at large $z$.
[ { "created": "Wed, 3 Jul 2002 13:40:28 GMT", "version": "v1" } ]
2007-05-23
[ [ "Uleshchenko", "V.", "" ], [ "Szczurek", "A.", "" ] ]
The presentation is concerned with higher twist corrections of nonpartonic origin to semi-inclusive observables in the kinematical region relevant for the HERMES experiment. We demonstrate a strong impact of the VDM-like interaction and the exclusive production of $\rho^0$ meson on the extraction of the $\bar d - \bar u$ asymmetry from charged pion DIS multiplicities. We also show that it is the exclusive-$\rho^0$ channel which accounts for the experimentally observed effect of the excess of charged over neutral pions produced at large $z$.
hep-ph/9608406
null
F. De Fazio
Heavy Quark Kinetic Energy in B Mesons by a QCD Relativistic Potential Model
Final Version, Accepted for Publication in Mod. Phys. Lett. A. Latex, 12 pages, 2 figures
Mod.Phys.Lett.A11:2693-2702,1996
10.1142/S0217732396002691
BARI-TH/96-233
hep-ph
null
The matrix element of the kinetic energy operator between B meson states is computed by means of a QCD relativistic potential model, with the result: $\mu_\pi^2=0.66 GeV^2$. A comparison with the outcome of other theoretical approaches and a discussion of the phenomenological implications of this result are carried out.
[ { "created": "Thu, 22 Aug 1996 10:01:46 GMT", "version": "v1" }, { "created": "Mon, 4 Nov 1996 16:03:42 GMT", "version": "v2" } ]
2011-01-25
[ [ "De Fazio", "F.", "" ] ]
The matrix element of the kinetic energy operator between B meson states is computed by means of a QCD relativistic potential model, with the result: $\mu_\pi^2=0.66 GeV^2$. A comparison with the outcome of other theoretical approaches and a discussion of the phenomenological implications of this result are carried out.
hep-ph/9405258
John McCurry
J. McCurry
Monoslepton production in hadronic collisions
SHEP-93/94-18. 20 pages including 10 uuencoded postscript figures. Uses LaTeX, epsf
null
null
null
hep-ph
null
Single sparticle creation in high energy collisions as a consequence explicit $R$-parity breaking, could be a rich source of highly spectacular signals at future colliders. One particular process, which could lead to a highly exotic leptonic signal at the LHC, is monoslepton production. In this paper we qualitatively discuss the constraints on the signal for this process and calculate the hadronic monoslepton production cross section, taking into account leading QCD corrections. Our results show the leading corrections could be quite significant at the proposed LHC operating energy.
[ { "created": "Tue, 10 May 1994 12:37:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "McCurry", "J.", "" ] ]
Single sparticle creation in high energy collisions as a consequence explicit $R$-parity breaking, could be a rich source of highly spectacular signals at future colliders. One particular process, which could lead to a highly exotic leptonic signal at the LHC, is monoslepton production. In this paper we qualitatively discuss the constraints on the signal for this process and calculate the hadronic monoslepton production cross section, taking into account leading QCD corrections. Our results show the leading corrections could be quite significant at the proposed LHC operating energy.
1306.6461
Berin Belma Sirvanli
Berin Belma Sirvanli
Lepton Asymmetries for the $B_s -> \gamma l^+ l^- $ Decay in a Family Nonuniversal Z' Model
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The exclusive $B_s -> \gamma l^+ l^- $ decay is analyzed in the framework of a family nonuniversal Z' model by calculating the differential branching ratio, double lepton polarizations and forward-backward asymmetries. Our results are compared against those of the Standard Model. The predictions of this work are hoped to can be tested in the near future at LHCb.
[ { "created": "Thu, 27 Jun 2013 10:36:42 GMT", "version": "v1" }, { "created": "Thu, 13 Mar 2014 13:50:34 GMT", "version": "v2" } ]
2014-03-17
[ [ "Sirvanli", "Berin Belma", "" ] ]
The exclusive $B_s -> \gamma l^+ l^- $ decay is analyzed in the framework of a family nonuniversal Z' model by calculating the differential branching ratio, double lepton polarizations and forward-backward asymmetries. Our results are compared against those of the Standard Model. The predictions of this work are hoped to can be tested in the near future at LHCb.
hep-ph/9510375
Robert D. Pisarski
Robert D. Pisarski
In a hot, chirally symmetric phase, $\pi^0$ doesn't go into $2 \gamma$, but $\pi^0 \sigma$ does
7 pages, LaTeX. To appear in: "From thermal field theory to neural networks, a day to remember Tanguy Altherr", World Scientific Publishing
null
10.1142/9789812830296_0005
BNL-RP-954
hep-ph nucl-th
null
In a constituent quark model at nonzero temperature, the amplitude for $\pi^0 \rightarrow 2 \gamma$ vanishes in a chirally symmetric phase, while that for $\pi^0 \sigma \rightarrow 2 \gamma$ does not.
[ { "created": "Mon, 23 Oct 1995 17:16:46 GMT", "version": "v1" } ]
2016-11-03
[ [ "Pisarski", "Robert D.", "" ] ]
In a constituent quark model at nonzero temperature, the amplitude for $\pi^0 \rightarrow 2 \gamma$ vanishes in a chirally symmetric phase, while that for $\pi^0 \sigma \rightarrow 2 \gamma$ does not.
0707.3907
Benno List
Michael Klasen, Benno List, Stephanie Hansmann-Menzemer and Rainer Mankel
Summary of the Heavy Flavor Working Group
17 pages, 3 figures, to appear in the Proceedings of the XV International Workshop on Deep-Inelastic Scattering and Related Subjectes, DIS 2007, April 16--20, 2007, Munich, Germany
null
null
LPSC 07-73
hep-ph
null
During the last year many important results have been achieved in heavy flavour physics: New measurements of charm and beauty production have been performed at HERA and the Tevatron. A wealth of new spectroscopy data with several new, unexpected states in the charmonium and the D_s systems has been collected and b to d gamma transitions have been established. The oscillation frequency in the B_s Bbar_s is now measured, and mixing in the D0 D0bar system has been observed. Theoretical progress in the areas of open heavy flavour production, quarkonium production and decays, and multiquark spectroscopy has been presented at this workshop.
[ { "created": "Thu, 26 Jul 2007 12:12:25 GMT", "version": "v1" } ]
2007-07-27
[ [ "Klasen", "Michael", "" ], [ "List", "Benno", "" ], [ "Hansmann-Menzemer", "Stephanie", "" ], [ "Mankel", "Rainer", "" ] ]
During the last year many important results have been achieved in heavy flavour physics: New measurements of charm and beauty production have been performed at HERA and the Tevatron. A wealth of new spectroscopy data with several new, unexpected states in the charmonium and the D_s systems has been collected and b to d gamma transitions have been established. The oscillation frequency in the B_s Bbar_s is now measured, and mixing in the D0 D0bar system has been observed. Theoretical progress in the areas of open heavy flavour production, quarkonium production and decays, and multiquark spectroscopy has been presented at this workshop.
1706.10025
Aaron Park
Aaron Park, Woosung Park, Su Houng Lee
Heptaquarks with two heavy antiquarks in a simple chromomagnetic model
14 pages, 11 figures, version to be published in prd
Phys. Rev. D 96, 034029 (2017)
10.1103/PhysRevD.96.034029
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the symmetry property and the stability of the heptaquark containing two identical heavy antiquarks using color-spin interaction. We construct the wave function of the heptaquark from the Pauli exclusion principle in the SU(3) breaking case. The stability of the heptaquark against the strong decay into one baryon and two mesons is discussed in a simple chromomagnetic model. We find that $q^2 s^3 \bar{s}^2$ with $I=0,S=\frac{5}{2}$ is the most stable heptaquark configuration that could be probed by reconstructing the $\Lambda+\phi+\phi$ invariant mass.
[ { "created": "Fri, 30 Jun 2017 05:34:22 GMT", "version": "v1" }, { "created": "Wed, 9 Aug 2017 23:45:46 GMT", "version": "v2" } ]
2017-09-06
[ [ "Park", "Aaron", "" ], [ "Park", "Woosung", "" ], [ "Lee", "Su Houng", "" ] ]
We investigate the symmetry property and the stability of the heptaquark containing two identical heavy antiquarks using color-spin interaction. We construct the wave function of the heptaquark from the Pauli exclusion principle in the SU(3) breaking case. The stability of the heptaquark against the strong decay into one baryon and two mesons is discussed in a simple chromomagnetic model. We find that $q^2 s^3 \bar{s}^2$ with $I=0,S=\frac{5}{2}$ is the most stable heptaquark configuration that could be probed by reconstructing the $\Lambda+\phi+\phi$ invariant mass.
hep-ph/0605044
Tetsuo Hyodo
Tetsuo Hyodo and Atsushi Hosaka (RCNP, Osaka Univ.)
Phenomenological study for the Theta+ and two-meson coupling
30 pages, 9 figures 9 tables, Talk given at International Workshop HNP06 at JAEA, Kizu, Japan, Feb. 16-18, 2006
null
null
null
hep-ph
null
We examine several assignments of spin and parity for the pentaquark Theta+ state (J^P=1/2^{+,-}, 3/2^{+,-}) in connection with phenomenology of known baryon resonances, using a general framework based on the flavor symmetry. Assuming that the Theta+ belongs to an antidecuplet representation which mixes with an octet, we calculate the mass spectra of the flavor partners of the Theta+ based on the SU(3) symmetry. The decay widths of the Theta+ and nucleon partners are analyzed for the consistency check of the mixing angle obtained from the masses. It is found that a suitable choice of the mixing angle successfully reproduces the observed masses of exotics, when their spin and parity are assigned to be J^P=3/2^-, together with other nonexotic resonances of J^P=3/2^-. The decay widths of Theta -> KN, N(1520) -> pi N, and N(1700) -> pi N are also reproduced simultaneously. We then evaluate two-meson couplings of Theta+, using experimental information of nucleon partners decaying into pi pi N channels, in which the two pions are in scalar- and vector-type correlations. We examine two assignments of spin and parity J^P=1/2^+ and 3/2^-, for which the experimental spectra of known resonances with exotic baryons are properly reproduced by an octet-antidecuplet representation mixing scheme. Using the obtained coupling constants, total cross sections of the reactions pi- p -> K- Theta+ and K+ p -> pi+ Theta+ are calculated. Substantial interference of two terms may occur in the reaction processes for the J^P=1/2^+ case, whereas the interference effect is rather small for the 3/2^- case.
[ { "created": "Thu, 4 May 2006 13:26:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hyodo", "Tetsuo", "", "RCNP, Osaka Univ." ], [ "Hosaka", "Atsushi", "", "RCNP, Osaka Univ." ] ]
We examine several assignments of spin and parity for the pentaquark Theta+ state (J^P=1/2^{+,-}, 3/2^{+,-}) in connection with phenomenology of known baryon resonances, using a general framework based on the flavor symmetry. Assuming that the Theta+ belongs to an antidecuplet representation which mixes with an octet, we calculate the mass spectra of the flavor partners of the Theta+ based on the SU(3) symmetry. The decay widths of the Theta+ and nucleon partners are analyzed for the consistency check of the mixing angle obtained from the masses. It is found that a suitable choice of the mixing angle successfully reproduces the observed masses of exotics, when their spin and parity are assigned to be J^P=3/2^-, together with other nonexotic resonances of J^P=3/2^-. The decay widths of Theta -> KN, N(1520) -> pi N, and N(1700) -> pi N are also reproduced simultaneously. We then evaluate two-meson couplings of Theta+, using experimental information of nucleon partners decaying into pi pi N channels, in which the two pions are in scalar- and vector-type correlations. We examine two assignments of spin and parity J^P=1/2^+ and 3/2^-, for which the experimental spectra of known resonances with exotic baryons are properly reproduced by an octet-antidecuplet representation mixing scheme. Using the obtained coupling constants, total cross sections of the reactions pi- p -> K- Theta+ and K+ p -> pi+ Theta+ are calculated. Substantial interference of two terms may occur in the reaction processes for the J^P=1/2^+ case, whereas the interference effect is rather small for the 3/2^- case.
hep-ph/9704376
Robert Fleischer
Andrzej J. Buras and Robert Fleischer
Quark mixing, CP violation and rare decays after the top quark discovery
180 pages, 35 figures, LaTeX. To appear in Heavy Flavours II, World Scientific (1997), Eds. A.J. Buras and M. Lindner. The complete paper is also available via anonymous ftp at ftp://www-ttp.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
Adv.Ser.Direct.HighEnergyPhys.15:65-238,1998
10.1142/9789812812667_0002
TUM-HEP-275/97, TTP97-15
hep-ph
null
We review the highlights of quark mixing, particle-antiparticle mixing, CP violation and rare K- and B-decays in the Standard Model. The top quark discovery, the precise measurement of its mass, the improved knowledge of the couplings $V_{cb}$ and $V_{ub}$, and the calculations of NLO short distance QCD corrections improved considerably the predictions for various decay rates, the determination of the couplings $V_{td}$ and $V_{ts}$ and of the complex phase in the Cabibbo-Kobayashi-Maskawa matrix. After presenting the general theoretical framework for weak decays, we discuss the following topics in detail: i) the CKM matrix, its most convenient parametrizations and the unitarity triangle, ii) the CP-violating parameter $\epsilon_K$ and $B^0_{d,s}-\bar B^0_{d,s}$ mixings, iii) the ratio $\epsilon'/\epsilon$, iv) the rare K-decays $K_L\to\pi^0e^+e^-$, $K^+\to\pi^+\nu\bar\nu$, $K_L\to\pi^0\nu\bar\nu$ and $K_L\to\mu^+\mu^-$, v) the radiative decays $B\to X_s\gamma$ and $B\to X_s l^+l^-$, vi) the rare B-decays $B\to X_{s,d}\nu\bar\nu$ and $B_{d,s}\to l^+l^-$, vii) CP violation in neutral and charged B-decays putting emphasis on clean determinations of the angles of the unitarity triangle, and viii) the role of electroweak penguins in B-decays. We present several future visions demonstrating very clearly the great potential of CP asymmetries in B-decays and of clean K-decays such as $K^+\to\pi^+\nu \bar\nu$ and $K_L\to\pi^0\nu\bar\nu$ in the determination of the CKM parameters and in decisive testing of the Standard Model. An outlook for the coming years ends our review.
[ { "created": "Tue, 22 Apr 1997 13:52:04 GMT", "version": "v1" } ]
2016-11-03
[ [ "Buras", "Andrzej J.", "" ], [ "Fleischer", "Robert", "" ] ]
We review the highlights of quark mixing, particle-antiparticle mixing, CP violation and rare K- and B-decays in the Standard Model. The top quark discovery, the precise measurement of its mass, the improved knowledge of the couplings $V_{cb}$ and $V_{ub}$, and the calculations of NLO short distance QCD corrections improved considerably the predictions for various decay rates, the determination of the couplings $V_{td}$ and $V_{ts}$ and of the complex phase in the Cabibbo-Kobayashi-Maskawa matrix. After presenting the general theoretical framework for weak decays, we discuss the following topics in detail: i) the CKM matrix, its most convenient parametrizations and the unitarity triangle, ii) the CP-violating parameter $\epsilon_K$ and $B^0_{d,s}-\bar B^0_{d,s}$ mixings, iii) the ratio $\epsilon'/\epsilon$, iv) the rare K-decays $K_L\to\pi^0e^+e^-$, $K^+\to\pi^+\nu\bar\nu$, $K_L\to\pi^0\nu\bar\nu$ and $K_L\to\mu^+\mu^-$, v) the radiative decays $B\to X_s\gamma$ and $B\to X_s l^+l^-$, vi) the rare B-decays $B\to X_{s,d}\nu\bar\nu$ and $B_{d,s}\to l^+l^-$, vii) CP violation in neutral and charged B-decays putting emphasis on clean determinations of the angles of the unitarity triangle, and viii) the role of electroweak penguins in B-decays. We present several future visions demonstrating very clearly the great potential of CP asymmetries in B-decays and of clean K-decays such as $K^+\to\pi^+\nu \bar\nu$ and $K_L\to\pi^0\nu\bar\nu$ in the determination of the CKM parameters and in decisive testing of the Standard Model. An outlook for the coming years ends our review.
1502.07716
Kei Yagyu
Shinya Kanemura, Mariko Kikuchi, Kei Yagyu
Fingerprinting the extended Higgs sector using one-loop corrected Higgs boson couplings and future precision measurements
Version published in Nuclear Physics B
null
10.1016/j.nuclphysb.2015.04.015
UT-HET 099
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate radiative corrections to a full set of coupling constants for the 125 GeV Higgs boson at the one-loop level in two Higgs doublet models with four types of Yukawa interaction under the softly-broken discrete $Z_2$ symmetry. The renormalization calculations are performed in the on-shell scheme, in which the gauge dependence in the mixing parameter which appears in the previous calculation is consistently avoided. We first show the details of our renormalizaton scheme, and present the complete set of the analytic formulae of the renormalized couplings. We then numerically demonstrate how the inner parameters of the model can be extracted by the future precision measurements of these couplings at the high luminosity LHC and the International Linear Collider.
[ { "created": "Thu, 26 Feb 2015 20:26:39 GMT", "version": "v1" }, { "created": "Fri, 17 Apr 2015 19:06:27 GMT", "version": "v2" } ]
2015-05-20
[ [ "Kanemura", "Shinya", "" ], [ "Kikuchi", "Mariko", "" ], [ "Yagyu", "Kei", "" ] ]
We calculate radiative corrections to a full set of coupling constants for the 125 GeV Higgs boson at the one-loop level in two Higgs doublet models with four types of Yukawa interaction under the softly-broken discrete $Z_2$ symmetry. The renormalization calculations are performed in the on-shell scheme, in which the gauge dependence in the mixing parameter which appears in the previous calculation is consistently avoided. We first show the details of our renormalizaton scheme, and present the complete set of the analytic formulae of the renormalized couplings. We then numerically demonstrate how the inner parameters of the model can be extracted by the future precision measurements of these couplings at the high luminosity LHC and the International Linear Collider.
hep-ph/0604065
Christian Bauer
Christian W. Bauer, Matthew D. Schwartz
Improving jet distributions with effective field theory
4 pages, 1 figure; typos corrected and notation updated to match hep-ph/0607296
Phys.Rev.Lett.97:142001,2006
10.1103/PhysRevLett.97.142001
LBNL-59964
hep-ph
null
We obtain perturbative expressions for jet distributions using soft-collinear effective theory (SCET). By matching SCET onto QCD at high energy, tree level matrix elements and higher order virtual corrections can be reproduced in SCET. The resulting operators are then evolved to lower scales, with additional operators being populated by required threshold matchings in the effective theory. We show that the renormalization group evolution and threshold matchings reproduce the Sudakov factors and splitting functions of QCD, and that the effective theory naturally combines QCD matrix elements and parton showers. The effective theory calculation is systematically improvable and any higher order perturbative effects can be included by a well defined procedure.
[ { "created": "Fri, 7 Apr 2006 19:30:39 GMT", "version": "v1" }, { "created": "Tue, 28 Nov 2006 14:48:13 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bauer", "Christian W.", "" ], [ "Schwartz", "Matthew D.", "" ] ]
We obtain perturbative expressions for jet distributions using soft-collinear effective theory (SCET). By matching SCET onto QCD at high energy, tree level matrix elements and higher order virtual corrections can be reproduced in SCET. The resulting operators are then evolved to lower scales, with additional operators being populated by required threshold matchings in the effective theory. We show that the renormalization group evolution and threshold matchings reproduce the Sudakov factors and splitting functions of QCD, and that the effective theory naturally combines QCD matrix elements and parton showers. The effective theory calculation is systematically improvable and any higher order perturbative effects can be included by a well defined procedure.
1001.3021
Konrad Tywoniuk
Nestor Armesto, Alexei B. Kaidalov, Carlos A. Salgado, Konrad Tywoniuk
A unitarized model of inclusive and diffractive DIS with Q2-evolution
22 pages, 12 figures
null
10.1103/PhysRevD.81.074002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the interplay of low-x physics and QCD scaling violations by extending the unified approach describing inclusive structure functions and diffractive production in $\gamma* p$ interactions proposed in previous papers, to large values of Q2. We describe the procedure of extracting, from the non-perturbative model, initial conditions for the QCD evolution that respect unitarity. Assuming Regge factorization of the diffractive structure function, a similar procedure is proposed for the calculation of hard diffraction. The results are in good agreement with experimental data on the proton structure function $F_2$ and the most recent data on the reduced diffractive cross section, $x_P \sigma_r^{\D(3)}$. Predictions for both $F_2$ and $F_L$ are presented in a wide kinematical range and compared to calculations within high-energy QCD.
[ { "created": "Mon, 18 Jan 2010 11:10:58 GMT", "version": "v1" } ]
2013-05-29
[ [ "Armesto", "Nestor", "" ], [ "Kaidalov", "Alexei B.", "" ], [ "Salgado", "Carlos A.", "" ], [ "Tywoniuk", "Konrad", "" ] ]
We discuss the interplay of low-x physics and QCD scaling violations by extending the unified approach describing inclusive structure functions and diffractive production in $\gamma* p$ interactions proposed in previous papers, to large values of Q2. We describe the procedure of extracting, from the non-perturbative model, initial conditions for the QCD evolution that respect unitarity. Assuming Regge factorization of the diffractive structure function, a similar procedure is proposed for the calculation of hard diffraction. The results are in good agreement with experimental data on the proton structure function $F_2$ and the most recent data on the reduced diffractive cross section, $x_P \sigma_r^{\D(3)}$. Predictions for both $F_2$ and $F_L$ are presented in a wide kinematical range and compared to calculations within high-energy QCD.
1006.5339
Nicolas Greiner
Nicolas Greiner, Alberto Guffanti, Jean-Philippe Guillet, Thomas Reiter, Juergen Reuter
NLO QCD corrections to 4 b-quark production
Contribution to the XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects, DIS 2010, April 19-23, 2010, Florence, Italy, 6 pages, 3 figures
PoS DIS2010:156,2010
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we present the recent calculation of the NLO QCD corrections to the production of four b-quarks induced by initial state quarks at the CERN LHC. We describe the details of the calculation using the GOLEM approach for the virtual corrections and MadEvent/MadDipole for the real emission part and present some results.
[ { "created": "Mon, 28 Jun 2010 13:06:43 GMT", "version": "v1" } ]
2010-11-19
[ [ "Greiner", "Nicolas", "" ], [ "Guffanti", "Alberto", "" ], [ "Guillet", "Jean-Philippe", "" ], [ "Reiter", "Thomas", "" ], [ "Reuter", "Juergen", "" ] ]
In this talk we present the recent calculation of the NLO QCD corrections to the production of four b-quarks induced by initial state quarks at the CERN LHC. We describe the details of the calculation using the GOLEM approach for the virtual corrections and MadEvent/MadDipole for the real emission part and present some results.
2204.05284
Luca Di Luzio
Luca Di Luzio, Ramona Gr\"ober, Paride Paradisi
Higgs physics confronts the $M_W$ anomaly
13 pages, 1 figure. Version to appear in Physics Letters B
null
10.1016/j.physletb.2022.137250
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The recent high-precision measurement of the $W$ mass by the CDF collaboration is in sharp tension with the Standard Model prediction as obtained by the electroweak fit. If confirmed, this finding can only be explained in terms of new physics effects. In this work, we point out a generic connection between the $M_W$ anomaly and Higgs physics observables such as $h\to\gamma\gamma, Z\gamma$ and the ratio $h\to ZZ/WW$. Moreover, we systematically classify new physics scenarios which can address the $M_W$ anomaly via a tree-level contribution to the $\hat T$ parameter. These include a real scalar triplet, a scalar quadruplet with the same hypercharge of the Higgs doublet, a $Z'$ boson, a vector triplet with unit hypercharge and a vector boson with the gauge quantum numbers of the Higgs doublet. These solutions to the $M_W$ anomaly are characterized by new physics states which are typically too heavy to be discovered in direct searches, but which might leave their imprints in Higgs physics.
[ { "created": "Mon, 11 Apr 2022 17:42:21 GMT", "version": "v1" }, { "created": "Mon, 18 Apr 2022 15:30:45 GMT", "version": "v2" }, { "created": "Mon, 13 Jun 2022 17:54:55 GMT", "version": "v3" } ]
2022-06-22
[ [ "Di Luzio", "Luca", "" ], [ "Gröber", "Ramona", "" ], [ "Paradisi", "Paride", "" ] ]
The recent high-precision measurement of the $W$ mass by the CDF collaboration is in sharp tension with the Standard Model prediction as obtained by the electroweak fit. If confirmed, this finding can only be explained in terms of new physics effects. In this work, we point out a generic connection between the $M_W$ anomaly and Higgs physics observables such as $h\to\gamma\gamma, Z\gamma$ and the ratio $h\to ZZ/WW$. Moreover, we systematically classify new physics scenarios which can address the $M_W$ anomaly via a tree-level contribution to the $\hat T$ parameter. These include a real scalar triplet, a scalar quadruplet with the same hypercharge of the Higgs doublet, a $Z'$ boson, a vector triplet with unit hypercharge and a vector boson with the gauge quantum numbers of the Higgs doublet. These solutions to the $M_W$ anomaly are characterized by new physics states which are typically too heavy to be discovered in direct searches, but which might leave their imprints in Higgs physics.
0901.3951
Baier
V. N. Baier and V. M. Katkov
Spectra of radiation and created particles at intermediate energy in oriented crystal taking into account energy loss
11 pages, 5 figures, report at "Channeling 2008" Workshop, Erice, Italy, October 2008
Int.J.Mod.Phys.A25S1:34-46,2010
10.1142/S0217751X1004989X
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spectral distribution of positron created by photon and the spectral distribution of photons radiated from electron in an oriented single crystal of intermediate thickness is calculated at intermediate energies. The energy loss of charged particles as well as photon absorption are taken into account. The used basic probabilities of processes include the action of field of axis as well as the multiple scattering of radiating electron or particles of the created pair (the Landau-Pomeranchuk-Migdal (LPM) effect)
[ { "created": "Mon, 26 Jan 2009 07:07:26 GMT", "version": "v1" } ]
2011-07-14
[ [ "Baier", "V. N.", "" ], [ "Katkov", "V. M.", "" ] ]
The spectral distribution of positron created by photon and the spectral distribution of photons radiated from electron in an oriented single crystal of intermediate thickness is calculated at intermediate energies. The energy loss of charged particles as well as photon absorption are taken into account. The used basic probabilities of processes include the action of field of axis as well as the multiple scattering of radiating electron or particles of the created pair (the Landau-Pomeranchuk-Migdal (LPM) effect)
1908.11256
Nicolas Chanon
Aurelien Carle, Nicolas Chanon, Stephane Perries
Prospects for Lorentz Invariance Violation searches with top pair production at the LHC and future hadron colliders
6 pages, 2 figures
null
10.1140/epjc/s10052-020-7715-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper investigates a signature of Lorentz invariance violation with the $t\bar{t}$ production at the LHC and future hadron colliders. Possible deviations from the Lorentz symmetry remain poorly constrained in the top quark sector. With a dedicated analysis of $t\bar{t}$ events produced at the LHC, bounds in the top sector can be improved by up to three orders of magnitude relative to Tevatron, the only measurement existing so far. The sensitivity will be even further enhanced at the HL-LHC and future colliders.
[ { "created": "Thu, 29 Aug 2019 14:30:04 GMT", "version": "v1" } ]
2020-03-18
[ [ "Carle", "Aurelien", "" ], [ "Chanon", "Nicolas", "" ], [ "Perries", "Stephane", "" ] ]
This paper investigates a signature of Lorentz invariance violation with the $t\bar{t}$ production at the LHC and future hadron colliders. Possible deviations from the Lorentz symmetry remain poorly constrained in the top quark sector. With a dedicated analysis of $t\bar{t}$ events produced at the LHC, bounds in the top sector can be improved by up to three orders of magnitude relative to Tevatron, the only measurement existing so far. The sensitivity will be even further enhanced at the HL-LHC and future colliders.
1106.4819
Bryan Zald\'ivar Montero
Yann Mambrini and Bryan Zald\'ivar
When LEP and Tevatron combined with WMAP and XENON100 shed light on the nature of Dark Matter
8 pages, 6 figures
null
10.1088/1475-7516/2011/10/023
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, several astrophysical data or would-be signals has been observed in different dark-matter oriented experiments. In each case, one could fit the data at the price of specific nature of the coupling between the Standard Model (SM) particles and a light Dark Matter candidate: hadrophobic (INTEGRAL, PAMELA) or leptophobic (WMAP Haze, dijet anomalies of CDF, FERMI Galactic Center observation). In this work, we show that when one takes into account the more recent LEP and Tevatron analysis, a light thermal fermionic Dark Matte (\lesssim 10 GeV) that couples to electrons is mainly ruled out if one combines the analysis with WMAP constraints. We also study the special case of scalar dark matter, using a mono-photon events simulation to constrain the coupling of dark matter to electron.
[ { "created": "Thu, 23 Jun 2011 20:00:11 GMT", "version": "v1" } ]
2015-05-28
[ [ "Mambrini", "Yann", "" ], [ "Zaldívar", "Bryan", "" ] ]
Recently, several astrophysical data or would-be signals has been observed in different dark-matter oriented experiments. In each case, one could fit the data at the price of specific nature of the coupling between the Standard Model (SM) particles and a light Dark Matter candidate: hadrophobic (INTEGRAL, PAMELA) or leptophobic (WMAP Haze, dijet anomalies of CDF, FERMI Galactic Center observation). In this work, we show that when one takes into account the more recent LEP and Tevatron analysis, a light thermal fermionic Dark Matte (\lesssim 10 GeV) that couples to electrons is mainly ruled out if one combines the analysis with WMAP constraints. We also study the special case of scalar dark matter, using a mono-photon events simulation to constrain the coupling of dark matter to electron.
1308.3767
Moslem Ahmadvand
M. Ahmadvand
Baryogenesis within the two-Higgs-doublet model in the Electroweak scale
10 pages, 3 figures, To be published in Int. J. Mod. Phys. A
Int. J. Mod. Phys. A. Vol. 29 (2014) 1450090
10.1142/S0217751X14500900
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The conventional baryogenesis mechanism is based on the one Higgs doublet within the standard model, at the electroweak scale $T\sim 100 GeV$. In this model the strong first order phase transition due to the spontaneous symmetry breaking imposes the folowing condition on the mass of the Higgs field: $m_H\lesssim 40 GeV$, which is contrary to the recently observed value $m_H\simeq 126 GeV$. In this paper we propose a baryogenesis mechanism within a two-Higgs-doublet model in which the phase transition occurs in one stage. This model is consistent with the observed mass of the Higgs. We obtain the true vacuum bubble wall velocity and thickness in this model. Then, we use nonlocal baryogenesis mechanism in which the interaction of fermions with the boundary of the expanding bubbles leads to CP violation and sphaleron mediated baryogenesis.
[ { "created": "Sat, 17 Aug 2013 08:51:52 GMT", "version": "v1" }, { "created": "Mon, 12 May 2014 19:44:56 GMT", "version": "v2" } ]
2014-05-27
[ [ "Ahmadvand", "M.", "" ] ]
The conventional baryogenesis mechanism is based on the one Higgs doublet within the standard model, at the electroweak scale $T\sim 100 GeV$. In this model the strong first order phase transition due to the spontaneous symmetry breaking imposes the folowing condition on the mass of the Higgs field: $m_H\lesssim 40 GeV$, which is contrary to the recently observed value $m_H\simeq 126 GeV$. In this paper we propose a baryogenesis mechanism within a two-Higgs-doublet model in which the phase transition occurs in one stage. This model is consistent with the observed mass of the Higgs. We obtain the true vacuum bubble wall velocity and thickness in this model. Then, we use nonlocal baryogenesis mechanism in which the interaction of fermions with the boundary of the expanding bubbles leads to CP violation and sphaleron mediated baryogenesis.
2101.03681
Chathuranga Sirimanna
Shanshan Cao, Chathuranga Sirimanna, Abhijit Majumder
The medium modification of high-virtuality partons
25 pages, 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The modification of the hard core of jets in a dense QCD medium is studied. In particular, we consider partons which possess a virtuality somewhat larger than the multiple scattering scale of the medium ($\hat{q} \tau$, where $\hat{q}$ is the transverse broadening jet transport coefficient, and $\tau$ is the formation length of a particular emission). We delineate the region of parameter space where the higher-twist approach is applicable, and derive the in-medium DGLAP evolution equation. We study a region in parameter space where this is the dominant mechanism of energy loss. We argue that such a regime is pervasive in most cases of jets in $A$-$A$ and future $e$-$A$ collisions, and controls the modification of the hard core of jets and the leading single particle spectrum at high transverse momentum ($p_\mathrm{T}$).
[ { "created": "Mon, 11 Jan 2021 02:55:49 GMT", "version": "v1" } ]
2021-01-12
[ [ "Cao", "Shanshan", "" ], [ "Sirimanna", "Chathuranga", "" ], [ "Majumder", "Abhijit", "" ] ]
The modification of the hard core of jets in a dense QCD medium is studied. In particular, we consider partons which possess a virtuality somewhat larger than the multiple scattering scale of the medium ($\hat{q} \tau$, where $\hat{q}$ is the transverse broadening jet transport coefficient, and $\tau$ is the formation length of a particular emission). We delineate the region of parameter space where the higher-twist approach is applicable, and derive the in-medium DGLAP evolution equation. We study a region in parameter space where this is the dominant mechanism of energy loss. We argue that such a regime is pervasive in most cases of jets in $A$-$A$ and future $e$-$A$ collisions, and controls the modification of the hard core of jets and the leading single particle spectrum at high transverse momentum ($p_\mathrm{T}$).
hep-ph/9807287
Mikko Vanttinen
M. V\"anttinen and L. Mankiewicz (TU Munich)
Exclusive $J/\psi$ photoproduction and gluon polarization
11 pages, Latex, psfig, 2 figures; v2: references and acknowledgement updated; v3: sign of asymmetry reversed, conclusions unchanged, to appear in Phys. Lett. B
Phys.Lett. B440 (1998) 157-162
10.1016/S0370-2693(98)01076-4
TUM/T39-98-21
hep-ph
null
In exclusive $J/\psi$ production by polarized photons incident on polarized protons, a finite polarization asymmetry arises because of $c\bar c$ Fermi-motion and binding-energy effects. The asymmetry depends on the polarized nonforward gluon distribution of the proton and thus gives information on gluon polarization in the proton. The analyzing power, however, is rather small.
[ { "created": "Wed, 8 Jul 1998 14:01:48 GMT", "version": "v1" }, { "created": "Tue, 4 Aug 1998 09:40:44 GMT", "version": "v2" }, { "created": "Fri, 16 Oct 1998 12:54:54 GMT", "version": "v3" } ]
2009-10-31
[ [ "Vänttinen", "M.", "", "TU Munich" ], [ "Mankiewicz", "L.", "", "TU Munich" ] ]
In exclusive $J/\psi$ production by polarized photons incident on polarized protons, a finite polarization asymmetry arises because of $c\bar c$ Fermi-motion and binding-energy effects. The asymmetry depends on the polarized nonforward gluon distribution of the proton and thus gives information on gluon polarization in the proton. The analyzing power, however, is rather small.
0910.2480
Gil Paz
Gil Paz
From A to Z': Combining Anomaly and Z' Mediation of Supersymmetry Breaking
Talk given at the 17th International Conference On Supersymmetry And The Unification Of Fundamental Interactions (SUSY 09), 5-10 Jun 2009, Boston, Massachusetts, USA
AIP Conf.Proc.1200:549-552,2010
10.1063/1.3327669
EFI 09-27
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Combining anomaly with Z' mediation allows us to solve the tachyonic slepton problem of the former and avoid fine tuning in the latter. We describe how the two mechanisms can be combined, and some of the phenomenology of such a joint scenario.
[ { "created": "Tue, 13 Oct 2009 21:41:56 GMT", "version": "v1" } ]
2015-05-14
[ [ "Paz", "Gil", "" ] ]
Combining anomaly with Z' mediation allows us to solve the tachyonic slepton problem of the former and avoid fine tuning in the latter. We describe how the two mechanisms can be combined, and some of the phenomenology of such a joint scenario.
1204.3772
Matteo Giordano
Matteo Giordano
Wilson-loop formalism for Reggeon exchange in soft high-energy scattering
A few misprints in the expressions for the relevant Wilson loops have been corrected. 55 pages, 7 figures
JHEP 1207 (2012) 109
10.1007/JHEP07(2012)109
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a nonperturbative expression for the non-vacuum, qqbar-Reggeon-exchange contribution to the meson-meson elastic scattering amplitude at high energy and low momentum transfer, in the framework of QCD. Describing the mesons in terms of colourless qqbar dipoles, the problem is reduced to the two-fermion-exchange contribution to the dipole-dipole scattering amplitudes, which is expressed as a path integral, over the trajectories of the exchanged fermions, of the expectation value of a certain Wilson loop. We also show how the resulting expression can be reconstructed from a corresponding quantity in the Euclidean theory, by means of analytic continuation. Finally, we make contact with previous work on Reggeon exchange in the gauge/gravity duality approach.
[ { "created": "Tue, 17 Apr 2012 11:51:09 GMT", "version": "v1" }, { "created": "Fri, 20 Jul 2012 10:43:14 GMT", "version": "v2" }, { "created": "Thu, 6 Dec 2012 13:55:59 GMT", "version": "v3" } ]
2015-06-04
[ [ "Giordano", "Matteo", "" ] ]
We derive a nonperturbative expression for the non-vacuum, qqbar-Reggeon-exchange contribution to the meson-meson elastic scattering amplitude at high energy and low momentum transfer, in the framework of QCD. Describing the mesons in terms of colourless qqbar dipoles, the problem is reduced to the two-fermion-exchange contribution to the dipole-dipole scattering amplitudes, which is expressed as a path integral, over the trajectories of the exchanged fermions, of the expectation value of a certain Wilson loop. We also show how the resulting expression can be reconstructed from a corresponding quantity in the Euclidean theory, by means of analytic continuation. Finally, we make contact with previous work on Reggeon exchange in the gauge/gravity duality approach.
1106.3028
Bin Pan
B. Pan
Meson Mass Spectrum of Heavy-Light Quarks Combinations with Dirac Equation
23 pages, 13 fig. v3, correct typo, add fig, add average data
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the Dirac equation to study the mass spectrum of mesons with heavy-light quark combinations. First we study the Dirac equation with spherically symmetry and funnel potential, and apply them on the hydrogen-like atom problem to check the correctness of our numerical program. Then we test the parameters in Olsson's paper. We show that Olsson's parameters are good in fitting the averaged central mass, but fail to get correct energy fine splitting. Finally we fit the mass spectrum data of D, D_s, B and B_s mesons with our parameters by solve the Dirac equation and funnel potential, calculate the energy splitting of the S and P states. Our parameters can fit the mass and fine splitting with errors in less than 7 MeV.
[ { "created": "Wed, 15 Jun 2011 17:18:51 GMT", "version": "v1" }, { "created": "Mon, 20 Jun 2011 15:22:49 GMT", "version": "v2" }, { "created": "Wed, 23 Nov 2011 16:41:37 GMT", "version": "v3" } ]
2011-11-24
[ [ "Pan", "B.", "" ] ]
We use the Dirac equation to study the mass spectrum of mesons with heavy-light quark combinations. First we study the Dirac equation with spherically symmetry and funnel potential, and apply them on the hydrogen-like atom problem to check the correctness of our numerical program. Then we test the parameters in Olsson's paper. We show that Olsson's parameters are good in fitting the averaged central mass, but fail to get correct energy fine splitting. Finally we fit the mass spectrum data of D, D_s, B and B_s mesons with our parameters by solve the Dirac equation and funnel potential, calculate the energy splitting of the S and P states. Our parameters can fit the mass and fine splitting with errors in less than 7 MeV.
hep-ph/0503125
Jorge Russo
Diego Chialva, Roberto Iengo and Jorge G. Russo
Cross sections for production of closed superstrings at high energy colliders in brane world models
18 pages, 3 figures. Reference added
Phys.Rev.D71:106009,2005
10.1103/PhysRevD.71.106009
UB-ECM-PF-05/05, SISSA-19/2005/EP
hep-ph hep-th
null
In brane world string models with large extra dimensions, there are processes where fermion and antifermion (or two gluons) can annihilate producing a light particle (e.g. gluon) carrying transverse momentum and a Kaluza-Klein graviton or an excited closed string that propagates in the extra dimensions. In high energy colliders, this process gives a missing momentum signature. We compute the total cross section for this process within the context of type II superstring theory in the presence of a D brane. This includes all missing energy sources for this string theory model up to s=8M_s^2, and it can be used to put new limits on the string scale M_s.
[ { "created": "Mon, 14 Mar 2005 14:55:28 GMT", "version": "v1" }, { "created": "Tue, 22 Mar 2005 17:59:17 GMT", "version": "v2" }, { "created": "Tue, 24 May 2005 10:52:14 GMT", "version": "v3" } ]
2014-11-18
[ [ "Chialva", "Diego", "" ], [ "Iengo", "Roberto", "" ], [ "Russo", "Jorge G.", "" ] ]
In brane world string models with large extra dimensions, there are processes where fermion and antifermion (or two gluons) can annihilate producing a light particle (e.g. gluon) carrying transverse momentum and a Kaluza-Klein graviton or an excited closed string that propagates in the extra dimensions. In high energy colliders, this process gives a missing momentum signature. We compute the total cross section for this process within the context of type II superstring theory in the presence of a D brane. This includes all missing energy sources for this string theory model up to s=8M_s^2, and it can be used to put new limits on the string scale M_s.
0808.3594
Patricia Magalh\~aes
P.C.Magalh\~aes and M.R. Robilotta
Elastic $K\pi$ amplitude: a simple model
13 pages, 4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a chiral model for the $J=0, I=1/2,$ elastic $K\p$ amplitude, suited to be employed in $D^+ \rar K^- \p^+ \p^+$ data analyses and valid between threshold and $1.5 $GeV. Although not as precise as other versions available in the literature, it is rather simple and incorporates the essential physics in this energy domain. In the case of the $K$-matrix approximation, the model allows the pole structure of the $K\p$ amplitude to be understood by solving a quadratic equation in $s$. We show that the solutions to this equation can be well approximated by polynomials of masses and coupling constants. This analytic structure allows a clear understanding why, depending on the values of one of the coupling constants, one may have one or two physical poles. The model yields a pole, associated with the $\k$, at $\sqrt{s}= (0.75 - i 0.24) $GeV.
[ { "created": "Tue, 26 Aug 2008 21:35:11 GMT", "version": "v1" } ]
2008-08-28
[ [ "Magalhães", "P. C.", "" ], [ "Robilotta", "M. R.", "" ] ]
We present a chiral model for the $J=0, I=1/2,$ elastic $K\p$ amplitude, suited to be employed in $D^+ \rar K^- \p^+ \p^+$ data analyses and valid between threshold and $1.5 $GeV. Although not as precise as other versions available in the literature, it is rather simple and incorporates the essential physics in this energy domain. In the case of the $K$-matrix approximation, the model allows the pole structure of the $K\p$ amplitude to be understood by solving a quadratic equation in $s$. We show that the solutions to this equation can be well approximated by polynomials of masses and coupling constants. This analytic structure allows a clear understanding why, depending on the values of one of the coupling constants, one may have one or two physical poles. The model yields a pole, associated with the $\k$, at $\sqrt{s}= (0.75 - i 0.24) $GeV.
0712.1227
Nora Brambilla
Nora Brambilla
Effective Field Theories for Heavy Quarkonium
Invited Plenary talk at The 20th European Conference on Few-Body Problems in Physics. September 10-14 2007. Pisa, Italy. To be published on Few-Body Systems
Few Body Syst.43:25-30,2008
10.1007/s00601-008-0204-z
null
hep-ph hep-th nucl-th
null
We briefly review how nonrelativistic effective field theories give us a definition of the QCD potentials and a coherent field theory derived quantum mechanical scheme to calculate the properties of bound states made by two or more heavy quarks. In this framework heavy quarkonium properties depend only on the QCD parameters (quark masses and $\als$) and nonpotential corrections are systematically accounted for. The relation between the form of the nonperturbative potentials and the low energy QCD dynamics is also discussed.
[ { "created": "Sun, 9 Dec 2007 15:36:56 GMT", "version": "v1" } ]
2009-01-08
[ [ "Brambilla", "Nora", "" ] ]
We briefly review how nonrelativistic effective field theories give us a definition of the QCD potentials and a coherent field theory derived quantum mechanical scheme to calculate the properties of bound states made by two or more heavy quarks. In this framework heavy quarkonium properties depend only on the QCD parameters (quark masses and $\als$) and nonpotential corrections are systematically accounted for. The relation between the form of the nonperturbative potentials and the low energy QCD dynamics is also discussed.
hep-ph/0602130
Zenro Hioki
Bohdan Grzadkowski (Warsaw U.), Zenro Hioki (U. Tokushima), Kazumasa Ohkuma (Fukui U. Tech.), Jose Wudka (UC Riverside)
New-Physics Search through gamma gamma -> t tbar -> lX/bX
LaTeX_2e, 10 pages, Talk presented by K. Ohkuma at the 7th International Symposium on Radiative Corrections (RADCOR2005), Shonan Village, Japan, October 2-7, 2005
null
10.1016/j.nuclphysbps.2006.03.028
IFT-03-06, FUT-06-01, UCRHEP-T404
hep-ph hep-ex
null
We probe optimal beam polarizations for new-physics search in top-quark and Higgs-boson sectors at Photon Linear Colliders (PLC). Expressing possible non-standard effects generated by SU(2)xU(1) gauge-invariant dimension-6 effective operators as anomalous top and Higgs couplings, we estimate expected statistical sensitivities of these couplings in gamma gamma -> t tbar -> lX/bX, using the optimal-observable method.
[ { "created": "Wed, 15 Feb 2006 03:29:17 GMT", "version": "v1" } ]
2012-07-04
[ [ "Grzadkowski", "Bohdan", "", "Warsaw U." ], [ "Hioki", "Zenro", "", "U. Tokushima" ], [ "Ohkuma", "Kazumasa", "", "Fukui U. Tech." ], [ "Wudka", "Jose", "", "UC Riverside" ] ]
We probe optimal beam polarizations for new-physics search in top-quark and Higgs-boson sectors at Photon Linear Colliders (PLC). Expressing possible non-standard effects generated by SU(2)xU(1) gauge-invariant dimension-6 effective operators as anomalous top and Higgs couplings, we estimate expected statistical sensitivities of these couplings in gamma gamma -> t tbar -> lX/bX, using the optimal-observable method.
1302.0669
Mamoru Matsunaga
Takaaki Hashimoto, Mamoru Matsunaga, and Kenta Yamamoto (Department of Physics Engineering, Mie University)
Quantization of hypercharge in gauge groups locally isomorphic but globally nonisomorphic to SU(3)_c X SU(2)_L X U(1)_Y
5 pages; typos fixed; to be published in Phys. Rev. D
null
10.1103/PhysRevD.87.077701
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Standard Model the hypercharges of quarks and leptons are not determined by the gauge group itself. In a recent paper [C. Hattori et al. Phys. Rev. D83, 015009 (2011)] it is shown that, if the direct product gauge group G_SM is slightly modified to the semidirect product group G'_SM, hypercharges are restricted to quantized values as n/6 mod Z (n = 0,1,3,4). In this brief paper, we examine all of the compact Lie groups locally isomorphic to G_SM, and show that G'_SM (or its isomorphisms) is the unique possibility that yields the correct hypercharge quantization.
[ { "created": "Mon, 4 Feb 2013 12:38:35 GMT", "version": "v1" }, { "created": "Mon, 8 Apr 2013 11:23:52 GMT", "version": "v2" } ]
2015-06-12
[ [ "Hashimoto", "Takaaki", "", "Department of\n Physics Engineering, Mie University" ], [ "Matsunaga", "Mamoru", "", "Department of\n Physics Engineering, Mie University" ], [ "Yamamoto", "Kenta", "", "Department of\n Physics Engineering, Mie University" ]...
In the Standard Model the hypercharges of quarks and leptons are not determined by the gauge group itself. In a recent paper [C. Hattori et al. Phys. Rev. D83, 015009 (2011)] it is shown that, if the direct product gauge group G_SM is slightly modified to the semidirect product group G'_SM, hypercharges are restricted to quantized values as n/6 mod Z (n = 0,1,3,4). In this brief paper, we examine all of the compact Lie groups locally isomorphic to G_SM, and show that G'_SM (or its isomorphisms) is the unique possibility that yields the correct hypercharge quantization.
hep-ph/0311238
Aurelien Barrau
A. Barrau, J. Grain, S.O. Alexeyev
Gauss-Bonnet Black Holes at the LHC : Beyond the Dimensionality of Space
Accepted by Phys. Lett. B
Phys.Lett.B584:114,2004
10.1016/j.physletb.2004.01.019
null
hep-ph astro-ph gr-qc hep-ex hep-th
null
The Gauss - Bonnet invariant is one of the most promising candidates for a quadratic curvature correction to the Einstein action in expansions of supersymmetric string theory. We study the evaporation of such Schwarzschild - Gauss - Bonnet black holes which could be formed at future colliders if the Planck scale is of order a TeV, as predicted by some modern brane world models. We show that, beyond the dimensionality of space, the corresponding coupling constant could be measured by the LHC. This opens new windows for physics investigation in spite of the possible screening of microphysics due to the event horizon.
[ { "created": "Wed, 19 Nov 2003 19:21:20 GMT", "version": "v1" }, { "created": "Mon, 12 Jan 2004 11:02:34 GMT", "version": "v2" } ]
2008-11-26
[ [ "Barrau", "A.", "" ], [ "Grain", "J.", "" ], [ "Alexeyev", "S. O.", "" ] ]
The Gauss - Bonnet invariant is one of the most promising candidates for a quadratic curvature correction to the Einstein action in expansions of supersymmetric string theory. We study the evaporation of such Schwarzschild - Gauss - Bonnet black holes which could be formed at future colliders if the Planck scale is of order a TeV, as predicted by some modern brane world models. We show that, beyond the dimensionality of space, the corresponding coupling constant could be measured by the LHC. This opens new windows for physics investigation in spite of the possible screening of microphysics due to the event horizon.
0904.2296
Schoeffel Laurent
Laurent Schoeffel
New measurement of charge asymmetry $x{F}_3$ from HERA
4 pages, 3 figures, proceedings of the International Workshop on Positrons at Jefferson Lab (March 25-27, 2009), Thomas Jefferson National Accelerator Facility, Newport News, VA
null
10.1063/1.3232034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After presenting the recent measurements of neutral current cross section in DIS at HERA, we explain the effect of the $\gamma-Z_0$ interference at the electro-weak scale, visible on these data. Then, the beam charge difference $x{F}_3$ is measured and the interference itself is extracted. Results are discussed in the context of perturbative QCD.
[ { "created": "Wed, 15 Apr 2009 12:38:54 GMT", "version": "v1" } ]
2015-05-13
[ [ "Schoeffel", "Laurent", "" ] ]
After presenting the recent measurements of neutral current cross section in DIS at HERA, we explain the effect of the $\gamma-Z_0$ interference at the electro-weak scale, visible on these data. Then, the beam charge difference $x{F}_3$ is measured and the interference itself is extracted. Results are discussed in the context of perturbative QCD.
hep-ph/9506418
null
A. Hebecker
The Electroweak Phase Transition
Ph.D. thesis, 70 pages LaTeX, figures not included, complete ps-file or hardcopy available from the Author
null
null
DESY T-95-02
hep-ph
null
The electroweak phase transition is investigated by means of the perturbatively calculated high temperature effective potential. An analytic result to order $g^4,\lambda^2$ is presented for the Abelian Higgs model, the SU(2)-Higgs model and the standard model and a complete on-shell renormalization at zero temperature is performed. Higher order corrections are found to increase the strength of the first order phase transition in the non-Abelian model, opposite to the Abelian case. This effect is traced back to the infrared contributions from the typical non-Abelian diagrams. The dependence of several phase transition parameters on the Higgs mass is analysed in detail. A new, gauge invariant, approach based on the composite field $\Phi^\dagger\Phi$ is introduced. This method, which supports the above Landau gauge results numerically, permits a conceptually simpler treatment of the thermodynamics of the phase transition. In particular, it enables a straightforward comparison with lattice data and the application of the Clausius-Clapeyron equation to the electroweak phase transition.
[ { "created": "Sun, 25 Jun 1995 10:21:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hebecker", "A.", "" ] ]
The electroweak phase transition is investigated by means of the perturbatively calculated high temperature effective potential. An analytic result to order $g^4,\lambda^2$ is presented for the Abelian Higgs model, the SU(2)-Higgs model and the standard model and a complete on-shell renormalization at zero temperature is performed. Higher order corrections are found to increase the strength of the first order phase transition in the non-Abelian model, opposite to the Abelian case. This effect is traced back to the infrared contributions from the typical non-Abelian diagrams. The dependence of several phase transition parameters on the Higgs mass is analysed in detail. A new, gauge invariant, approach based on the composite field $\Phi^\dagger\Phi$ is introduced. This method, which supports the above Landau gauge results numerically, permits a conceptually simpler treatment of the thermodynamics of the phase transition. In particular, it enables a straightforward comparison with lattice data and the application of the Clausius-Clapeyron equation to the electroweak phase transition.
0812.3262
Emidio Gabrielli
G. Degrassi, E. Gabrielli, and L. Trentadue
Flavor Changing Fermion-Graviton Vertices
21 pages, 2 figures. New results and two references added. To be published in PRD
Phys.Rev.D79:053004,2009
10.1103/PhysRevD.79.053004
null
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the flavor-changing quark-graviton vertex that is induced at the one-loop level when gravitational interactions are coupled to the standard model. Because of the conservation of the energy-momentum tensor the corresponding form factors turn out to be finite and gauge-invariant. Analytical expressions of the form factors are provided at leading order in the external masses. We show that flavor-changing interactions in gravity are local if the graviton is strictly massless while if the graviton has a small mass long-range interactions inducing a flavor-changing contribution in the Newton potential appear. Flavor-changing processes with massive spin-2 particles are also briefly discussed. These results can be generalized to the case of the lepton-graviton coupling.
[ { "created": "Wed, 17 Dec 2008 11:33:45 GMT", "version": "v1" }, { "created": "Wed, 11 Mar 2009 09:12:00 GMT", "version": "v2" } ]
2009-03-24
[ [ "Degrassi", "G.", "" ], [ "Gabrielli", "E.", "" ], [ "Trentadue", "L.", "" ] ]
We study the flavor-changing quark-graviton vertex that is induced at the one-loop level when gravitational interactions are coupled to the standard model. Because of the conservation of the energy-momentum tensor the corresponding form factors turn out to be finite and gauge-invariant. Analytical expressions of the form factors are provided at leading order in the external masses. We show that flavor-changing interactions in gravity are local if the graviton is strictly massless while if the graviton has a small mass long-range interactions inducing a flavor-changing contribution in the Newton potential appear. Flavor-changing processes with massive spin-2 particles are also briefly discussed. These results can be generalized to the case of the lepton-graviton coupling.
1404.3387
Anatoly Efremov
A.V. Efremov and J. Soffer
An analytical review of DSPIN-13
5 pages, no figures. Some chenges and correction in text. arXiv admin note: text overlap with arXiv:1211.0108
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A short analytical review of XV Workshop on High Energy Spin Physics (DSPIN-13) is given. All materials of the workshop, including all presented talks, list of participants and the pdf-file of Proceedings are available on the site http://theor.jinr.ru/~spin/2013/.
[ { "created": "Sun, 13 Apr 2014 14:47:49 GMT", "version": "v1" }, { "created": "Wed, 16 Apr 2014 08:48:35 GMT", "version": "v2" } ]
2014-04-17
[ [ "Efremov", "A. V.", "" ], [ "Soffer", "J.", "" ] ]
A short analytical review of XV Workshop on High Energy Spin Physics (DSPIN-13) is given. All materials of the workshop, including all presented talks, list of participants and the pdf-file of Proceedings are available on the site http://theor.jinr.ru/~spin/2013/.
2306.12382
Vivek Tiwari Kumar
Suraj Kumar Rai and Vivek Kumar Tiwari
Phase structure of the on-shell parametrized 2+1 flavor Polyakov quark-meson model
28 pages, 20 Figures. arXiv admin note: text overlap with arXiv:2211.11686, arXiv:2305.16180
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Augmenting the improved chiral effective potential of the on-shell renormalized 2+1 flavour quark-meson (RQM) model with the Polyakov-loop potential that accounts for the deconfinement transition,~we get the Quantum Chromodynamics (QCD) like framework of the renormalized Polyakov quark-meson (RPQM) model.~When the divergent quark one-loop vacuum term is included in the effective potential of the quark-meson (QM) model,~its tree level parameters or the parameters fixed by the use of meson curvature masses,~become inconsistent as the curvature masses involve the self energy evaluations at zero momentum.~Using the modified minimal subtraction method,~the consistent chiral effective potential for the RQM model has been calculated after relating the counterterms in the on-shell (OS) scheme to those in the $\overline{\text{MS}}$ scheme and finding the relations between the renormalized parameters of both the schemes where the physical (pole) masses of the $\pi, K, \eta$ and $\eta^{\prime}$ pseudo-scalar mesons and the scalar $\sigma$ meson,~the pion and kaon decay constants,~have been put into the relation of the running couplings and mass parameter.~Using the RPQM model and the PQM Model with different forms for the Polyakov-loop potentials in the presence or the absence of the quark back-reaction,~we have computed and compared the effect of the consistent quark one-loop correction and the quark back-reaction on the scaled chiral order parameter,~the QCD phase diagrams and the different thermodynamic quantities.~The results have been compared with the 2+1 flavor lattice QCD data from the Wuppertal-Budapest collaboration \{JHEP 09,73(2010); PLB 730,99(2014)\} and the HotQCD collaboration \{PRD 90,094503(2014)\}.
[ { "created": "Wed, 21 Jun 2023 17:02:01 GMT", "version": "v1" } ]
2023-06-22
[ [ "Rai", "Suraj Kumar", "" ], [ "Tiwari", "Vivek Kumar", "" ] ]
Augmenting the improved chiral effective potential of the on-shell renormalized 2+1 flavour quark-meson (RQM) model with the Polyakov-loop potential that accounts for the deconfinement transition,~we get the Quantum Chromodynamics (QCD) like framework of the renormalized Polyakov quark-meson (RPQM) model.~When the divergent quark one-loop vacuum term is included in the effective potential of the quark-meson (QM) model,~its tree level parameters or the parameters fixed by the use of meson curvature masses,~become inconsistent as the curvature masses involve the self energy evaluations at zero momentum.~Using the modified minimal subtraction method,~the consistent chiral effective potential for the RQM model has been calculated after relating the counterterms in the on-shell (OS) scheme to those in the $\overline{\text{MS}}$ scheme and finding the relations between the renormalized parameters of both the schemes where the physical (pole) masses of the $\pi, K, \eta$ and $\eta^{\prime}$ pseudo-scalar mesons and the scalar $\sigma$ meson,~the pion and kaon decay constants,~have been put into the relation of the running couplings and mass parameter.~Using the RPQM model and the PQM Model with different forms for the Polyakov-loop potentials in the presence or the absence of the quark back-reaction,~we have computed and compared the effect of the consistent quark one-loop correction and the quark back-reaction on the scaled chiral order parameter,~the QCD phase diagrams and the different thermodynamic quantities.~The results have been compared with the 2+1 flavor lattice QCD data from the Wuppertal-Budapest collaboration \{JHEP 09,73(2010); PLB 730,99(2014)\} and the HotQCD collaboration \{PRD 90,094503(2014)\}.
hep-ph/9704371
Ola Tornkvist
Antonio Riotto, Ola Tornkvist (Fermilab)
CP-Violating Solitons in the Minimal Supersymmetric Standard Model
revtex, 21 pages, 2 postscript figures, uses epsf.tex, aps.sty, prl.sty, preprint.sty
Phys. Rev. D 56, 3917 (1997)
10.1103/PhysRevD.56.3917
FERMILAB-Pub-97/102-A
hep-ph
null
We study non-topological and CP-violating static wall solutions in the framework of the Minimal Supersymmetric Standard Model. We show that such membranes, characterized by a non-trivial winding of the relative $U(1)$ phase of the two Higgs fields in the direction orthogonal to the wall, exist for small values of the mass of the CP-odd Higgs boson when loop corrections to the Higgs potential are included. Although their present-day existence is excluded by experimental bounds, we argue why they may have existed in the early universe with important cosmological consequences.
[ { "created": "Mon, 21 Apr 1997 23:01:33 GMT", "version": "v1" } ]
2016-08-25
[ [ "Riotto", "Antonio", "", "Fermilab" ], [ "Tornkvist", "Ola", "", "Fermilab" ] ]
We study non-topological and CP-violating static wall solutions in the framework of the Minimal Supersymmetric Standard Model. We show that such membranes, characterized by a non-trivial winding of the relative $U(1)$ phase of the two Higgs fields in the direction orthogonal to the wall, exist for small values of the mass of the CP-odd Higgs boson when loop corrections to the Higgs potential are included. Although their present-day existence is excluded by experimental bounds, we argue why they may have existed in the early universe with important cosmological consequences.
hep-ph/0510236
Sabine Hossenfelder
S. Hossenfelder
News about TeV-scale Black Holes
Talk given at the Quark Matter 2005, Budapest, Hungary, Aug. 2005
Nucl.Phys. A774 (2006) 865-868
10.1016/j.nuclphysa.2006.06.153
null
hep-ph
null
Collider produced black holes are the most exciting prediction from models with large extra dimensions. These black holes exist in an extreme region, in which gravity meets quantum field theory, particle physics, and thermodynamics. An investigation of the formation and decay processes can therefore provide us with important insights about the underlying theory and open a window to the understanding of Physics at the Planck scale. The production and the evaporation of TeV-scale black holes yields distinct signatures that have been examined closely during the last years, with analytical approaches as well as by use of numerical simulations. I present new results for the LHC, which take into account that, instead of a final decay, a black hole remnant can be left. This is a summary of the talk given at the Quark Matter 2005, Budapest, Hungary, Aug. 2005.
[ { "created": "Tue, 18 Oct 2005 19:12:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hossenfelder", "S.", "" ] ]
Collider produced black holes are the most exciting prediction from models with large extra dimensions. These black holes exist in an extreme region, in which gravity meets quantum field theory, particle physics, and thermodynamics. An investigation of the formation and decay processes can therefore provide us with important insights about the underlying theory and open a window to the understanding of Physics at the Planck scale. The production and the evaporation of TeV-scale black holes yields distinct signatures that have been examined closely during the last years, with analytical approaches as well as by use of numerical simulations. I present new results for the LHC, which take into account that, instead of a final decay, a black hole remnant can be left. This is a summary of the talk given at the Quark Matter 2005, Budapest, Hungary, Aug. 2005.
2208.12430
Adriana G. Menkara
Seong-Sik Kim, Hyun Min Lee, Adriana G. Menkara, Kimiko Yamashita
The $SU(2)_D$ lepton portals for muon $g-2$, $W$ boson mass and dark matter
6 pages, 2 figures, Proceeding for IDM 2022, 14th International Conference on Identification of Dark Matter, Vienna, Austria
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We propose a novel model which extends the Standard Model (SM) by introducing a $SU(2)_D$ gauge symmetry. In this model, a dark $SU(2)_D$ Higgs doublet and a Higgs bi-doublet can contribute to the muon $g-2$ anomaly and the $W$ boson mass, remaining in tune with the recent experimental results. At the same time, the isospin charged gauge boson of $SU(2)_D$ becomes a plausible candidate for Dark Matter(DM). We find that the resulting parameter space can fit the muon $g-2$, the $W$ boson mass and the DM constraints simultaneously.
[ { "created": "Fri, 26 Aug 2022 04:08:38 GMT", "version": "v1" } ]
2022-08-29
[ [ "Kim", "Seong-Sik", "" ], [ "Lee", "Hyun Min", "" ], [ "Menkara", "Adriana G.", "" ], [ "Yamashita", "Kimiko", "" ] ]
We propose a novel model which extends the Standard Model (SM) by introducing a $SU(2)_D$ gauge symmetry. In this model, a dark $SU(2)_D$ Higgs doublet and a Higgs bi-doublet can contribute to the muon $g-2$ anomaly and the $W$ boson mass, remaining in tune with the recent experimental results. At the same time, the isospin charged gauge boson of $SU(2)_D$ becomes a plausible candidate for Dark Matter(DM). We find that the resulting parameter space can fit the muon $g-2$, the $W$ boson mass and the DM constraints simultaneously.
hep-ph/9911498
Palash Baran Pal
Kaushik Bhattacharya and Palash B. Pal
Inverse beta-decay in magnetic fields
14 pages, LateX, with 3 embeded figures using epsf.sty
null
null
SINP/TNP/99-33
hep-ph
null
We calculate the cross section of the inverse beta decay process, $\nu_e+n\to p+e$, in a magnetic field which is much smaller than $m_p^2/e$. Using exact solutions of the Dirac equation in a constant magnetic field, we find that the cross section depends on the direction of the incident neutrino even when the initial neutron is assumed to be at rest. We discuss the implication of this result for pulsar kicks.
[ { "created": "Fri, 26 Nov 1999 06:53:49 GMT", "version": "v1" }, { "created": "Tue, 25 Apr 2000 09:14:15 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bhattacharya", "Kaushik", "" ], [ "Pal", "Palash B.", "" ] ]
We calculate the cross section of the inverse beta decay process, $\nu_e+n\to p+e$, in a magnetic field which is much smaller than $m_p^2/e$. Using exact solutions of the Dirac equation in a constant magnetic field, we find that the cross section depends on the direction of the incident neutrino even when the initial neutron is assumed to be at rest. We discuss the implication of this result for pulsar kicks.
0908.1968
Eduardo Pont\'on
Hooman Davoudiasl, Shrihari Gopalakrishna, Eduardo Ponton, Jose Santiago
Warped 5-Dimensional Models: Phenomenological Status and Experimental Prospects
References added. To appear in the focus issue on Extra Space Dimensions of the New Journal of Physics
New J.Phys.12:075011,2010
10.1088/1367-2630/12/7/075011
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Warped 5-dimensional models, based on the original Randall-Sundrum geometry, have been extended beyond their initial purpose of resolving the gauge hierarchy problem. Over the past decade, various ingredients have been added to their basic structure in order to provide natural and predictive models of flavor and also to address existing constraints from precision data. In this review, we examine the theoretical and experimental status of realistic models that accommodate current data, while addressing the hierarchy and flavor puzzles of the Standard Model. We also discuss the prospects for future discovery of the TeV-scale Kaluza-Klein states that are predicted to emerge in these models, and outline some of the challenges that the detection of such particles pose for experiments at the Large Hadron Collider.
[ { "created": "Thu, 13 Aug 2009 20:11:23 GMT", "version": "v1" }, { "created": "Fri, 23 Oct 2009 01:12:13 GMT", "version": "v2" } ]
2011-01-03
[ [ "Davoudiasl", "Hooman", "" ], [ "Gopalakrishna", "Shrihari", "" ], [ "Ponton", "Eduardo", "" ], [ "Santiago", "Jose", "" ] ]
Warped 5-dimensional models, based on the original Randall-Sundrum geometry, have been extended beyond their initial purpose of resolving the gauge hierarchy problem. Over the past decade, various ingredients have been added to their basic structure in order to provide natural and predictive models of flavor and also to address existing constraints from precision data. In this review, we examine the theoretical and experimental status of realistic models that accommodate current data, while addressing the hierarchy and flavor puzzles of the Standard Model. We also discuss the prospects for future discovery of the TeV-scale Kaluza-Klein states that are predicted to emerge in these models, and outline some of the challenges that the detection of such particles pose for experiments at the Large Hadron Collider.
1511.05561
Stefano Forte
Stefano Forte and Claudio Muselli
High energy resummation of transverse momentum distributions:Higgs in gluon fusion
28 pages, 6 figures, Final version published in JHEP: several typos corrected (including in equations)
null
10.1007/JHEP03(2016)122
TIF-UNIMI-2015-18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a general resummation formula for transverse-momentum distributions of hard processes at the leading logarithmic level in the high-energy limit, to all orders in the strong coupling. Our result is based on a suitable generalization of high-energy factorization theorems, whereby all-order resummation is reduced to the determination of the Born-level process but with incoming off-shell gluons. We validate our formula by applying it to Higgs production in gluon fusion in the infinite top mass limit. We check our result up to next-to-leading order by comparison to the high energy limit of the exact expression and to next-to-next-to leading by comparison to NNLL order trasverse momentum (Sudakov) resummation, and we predict the high-energy behaviour at next$^3$-to-leading order. We also show that the structure of the result in the small transverse momentum limit agrees to all orders with general constraints from Sudakov resummation.
[ { "created": "Tue, 17 Nov 2015 21:00:01 GMT", "version": "v1" }, { "created": "Thu, 16 Jun 2016 15:55:56 GMT", "version": "v2" } ]
2016-06-17
[ [ "Forte", "Stefano", "" ], [ "Muselli", "Claudio", "" ] ]
We derive a general resummation formula for transverse-momentum distributions of hard processes at the leading logarithmic level in the high-energy limit, to all orders in the strong coupling. Our result is based on a suitable generalization of high-energy factorization theorems, whereby all-order resummation is reduced to the determination of the Born-level process but with incoming off-shell gluons. We validate our formula by applying it to Higgs production in gluon fusion in the infinite top mass limit. We check our result up to next-to-leading order by comparison to the high energy limit of the exact expression and to next-to-next-to leading by comparison to NNLL order trasverse momentum (Sudakov) resummation, and we predict the high-energy behaviour at next$^3$-to-leading order. We also show that the structure of the result in the small transverse momentum limit agrees to all orders with general constraints from Sudakov resummation.
2003.11438
Victor Goncalves
V. P. Goncalves, B. D. Moreira
A phenomenological analysis of the nonperturbative QCD contributions for the photon wave function
8 pages, 6 figures. Improved version to be published in European Physical Journal C
null
10.1140/epjc/s10052-020-8043-2
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The photon -- induced interactions, present in $ep$, $eA$, $pp$, $pA$, $AA$ and $e^+ e^-$ collisions, are expressed within the color dipole approach in terms of the photon wave function, which describes the transition of the photon into a quark -- antiquark color dipole. Such quantity is usually calculated using perturbation theory assuming that long distance corrections associated to strong interactions can be neglected. In this paper we investigate the impact of these nonperturbative QCD (npQCD) corrections to the description of the photon wave function for dipoles of large size in several observables measured at HERA, LEP and LHC. We assume a phenomenological ansatz for the treatment of these npQCD corrections and constrain the free parameters of our model using the experimental data for the photoproduction cross section. The predictions for the $\gamma \gamma$ cross section, exclusive $\rho$ production in $ep$ collisions and the rapidity distribution for the $\rho$ production in $PbPb$ collisions are compared with the data. We demonstrate that the inclusion of the nonperturbative QCD corrections improves the description of processes that are dominated by large dipoles.
[ { "created": "Wed, 25 Mar 2020 15:02:37 GMT", "version": "v1" }, { "created": "Wed, 13 May 2020 15:24:58 GMT", "version": "v2" } ]
2020-06-24
[ [ "Goncalves", "V. P.", "" ], [ "Moreira", "B. D.", "" ] ]
The photon -- induced interactions, present in $ep$, $eA$, $pp$, $pA$, $AA$ and $e^+ e^-$ collisions, are expressed within the color dipole approach in terms of the photon wave function, which describes the transition of the photon into a quark -- antiquark color dipole. Such quantity is usually calculated using perturbation theory assuming that long distance corrections associated to strong interactions can be neglected. In this paper we investigate the impact of these nonperturbative QCD (npQCD) corrections to the description of the photon wave function for dipoles of large size in several observables measured at HERA, LEP and LHC. We assume a phenomenological ansatz for the treatment of these npQCD corrections and constrain the free parameters of our model using the experimental data for the photoproduction cross section. The predictions for the $\gamma \gamma$ cross section, exclusive $\rho$ production in $ep$ collisions and the rapidity distribution for the $\rho$ production in $PbPb$ collisions are compared with the data. We demonstrate that the inclusion of the nonperturbative QCD corrections improves the description of processes that are dominated by large dipoles.
2203.12169
Emanuele Mereghetti
Vincenzo Cirigliano, Zohreh Davoudi, Wouter Dekens, Jordy de Vries, Jonathan Engel, Xu Feng, Julia Gehrlein, Michael L. Graesser, Luk\'a\v{s} Gr\'af, Heiko Hergert, Luchang Jin, Emanuele Mereghetti, Amy Nicholson, Saori Pastore, Michael J. Ramsey-Musolf, Richard Ruiz, Martin Spinrath, Ubirajara van Kolck and Andr\'e Walker-Loud
Neutrinoless Double-Beta Decay: A Roadmap for Matching Theory to Experiment
Contribution to Snowmass 2021
null
null
LA-UR-22-22587
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observation of neutrino oscillations and hence non-zero neutrino masses provided a milestone in the search for physics beyond the Standard Model. But even though we now know that neutrinos are massive, the nature of neutrino masses, i.e., whether they are Dirac or Majorana, remains an open question. A smoking-gun signature of Majorana neutrinos is the observation of neutrinoless double-beta decay, a process that violates the lepton-number conservation of the Standard Model. This white paper focuses on the theoretical aspects of the neutrinoless double-beta decay program and lays out a roadmap for future developments. The roadmap is a multi-scale path starting from high-energy models of neutrinoless double-beta decay all the way to the low-energy nuclear many-body problem that needs to be solved to supplement measurements of the decay rate. The path goes through a systematic effective-field-theory description of the underlying processes at various scales and needs to be supplemented by lattice quantum chromodynamics input. The white paper also discusses the interplay between neutrinoless double-beta decay, experiments at the Large Hadron Collider and results from astrophysics and cosmology in probing simplified models of lepton-number violation at the TeV scale, and the generation of the matter-antimatter asymmetry via leptogenesis. This white paper is prepared for the topical groups TF11 (Theory of Neutrino Physics), TF05 (Lattice Gauge Theory), RF04 (Baryon and Lepton Number Violating Processes), NF03 (Beyond the Standard Model) and NF05 (Neutrino Properties) within the Theory Frontier, Rare Processes and Precision Frontier, and Neutrino Physics Frontier of the U.S. Community Study on the Future of Particle Physics (Snowmass 2021).
[ { "created": "Wed, 23 Mar 2022 03:26:30 GMT", "version": "v1" } ]
2022-03-24
[ [ "Cirigliano", "Vincenzo", "" ], [ "Davoudi", "Zohreh", "" ], [ "Dekens", "Wouter", "" ], [ "de Vries", "Jordy", "" ], [ "Engel", "Jonathan", "" ], [ "Feng", "Xu", "" ], [ "Gehrlein", "Julia", "" ], [ ...
The observation of neutrino oscillations and hence non-zero neutrino masses provided a milestone in the search for physics beyond the Standard Model. But even though we now know that neutrinos are massive, the nature of neutrino masses, i.e., whether they are Dirac or Majorana, remains an open question. A smoking-gun signature of Majorana neutrinos is the observation of neutrinoless double-beta decay, a process that violates the lepton-number conservation of the Standard Model. This white paper focuses on the theoretical aspects of the neutrinoless double-beta decay program and lays out a roadmap for future developments. The roadmap is a multi-scale path starting from high-energy models of neutrinoless double-beta decay all the way to the low-energy nuclear many-body problem that needs to be solved to supplement measurements of the decay rate. The path goes through a systematic effective-field-theory description of the underlying processes at various scales and needs to be supplemented by lattice quantum chromodynamics input. The white paper also discusses the interplay between neutrinoless double-beta decay, experiments at the Large Hadron Collider and results from astrophysics and cosmology in probing simplified models of lepton-number violation at the TeV scale, and the generation of the matter-antimatter asymmetry via leptogenesis. This white paper is prepared for the topical groups TF11 (Theory of Neutrino Physics), TF05 (Lattice Gauge Theory), RF04 (Baryon and Lepton Number Violating Processes), NF03 (Beyond the Standard Model) and NF05 (Neutrino Properties) within the Theory Frontier, Rare Processes and Precision Frontier, and Neutrino Physics Frontier of the U.S. Community Study on the Future of Particle Physics (Snowmass 2021).
1309.1934
Sayantan Choudhury
Sayantan Choudhury, Arnab Dasgupta
Galileogenesis: A new cosmophenomenological zip code for reheating through R-parity violating coupling
8 pages, 2 figures, Revision accepted by Nuclear Physics B
Nucl. Phys. B 882 (2014) pp. 195-204
10.1016/j.nuclphysb.2014.02.024
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we introduce an idea of leptogenesis scenario in higher derivative gravity induced DBI Galileon framework {\it aka Galileogenesis} in presence of one-loop R-parity violating couplings in the background of a low energy effective supergravity setup. We have studied extensively the detailed feature of reheating constraints and the cosmophenomenological consequences of thermal gravitino dark matter in light of PLANCK and PDG data. Finally we have also established a direct cosmological connection among dark matter relic abundance, reheating temperature and tensor-to-scalar ratio in the context of DBI Galileon inflation.
[ { "created": "Sun, 8 Sep 2013 07:32:19 GMT", "version": "v1" }, { "created": "Sun, 23 Feb 2014 16:53:45 GMT", "version": "v2" } ]
2014-03-20
[ [ "Choudhury", "Sayantan", "" ], [ "Dasgupta", "Arnab", "" ] ]
In this paper we introduce an idea of leptogenesis scenario in higher derivative gravity induced DBI Galileon framework {\it aka Galileogenesis} in presence of one-loop R-parity violating couplings in the background of a low energy effective supergravity setup. We have studied extensively the detailed feature of reheating constraints and the cosmophenomenological consequences of thermal gravitino dark matter in light of PLANCK and PDG data. Finally we have also established a direct cosmological connection among dark matter relic abundance, reheating temperature and tensor-to-scalar ratio in the context of DBI Galileon inflation.
1911.00328
Vedran Brdar
Cristina Benso, Vedran Brdar, Manfred Lindner, Werner Rodejohann
Prospects for Finding Sterile Neutrino Dark Matter at KATRIN
error in rescaling X-ray limits fixed; conclusions unchanged
Phys. Rev. D 100, 115035 (2019)
10.1103/PhysRevD.100.115035
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss under what circumstances a signal in upcoming laboratory searches for keV-scale sterile neutrinos would be compatible with those particles being a sizable part or all of dark matter. In the parameter space that will be experimentally accessible by KATRIN/TRISTAN, strong X-ray limits need to be relaxed and dark matter overproduction needs to be avoided. We discuss postponing the dark matter production to lower temperatures, a reduced sterile neutrino contribution to dark matter, and a reduction of the branching ratio in photons and active neutrinos through cancellation with a new physics diagram. Both the Dodelson-Widrow and the Shi-Fuller mechanisms for sterile neutrino dark matter production are considered. As a final exotic example, potential consequences of CPT violation are discussed.
[ { "created": "Fri, 1 Nov 2019 12:25:46 GMT", "version": "v1" }, { "created": "Fri, 20 Dec 2019 19:14:35 GMT", "version": "v2" }, { "created": "Fri, 24 Dec 2021 17:55:08 GMT", "version": "v3" } ]
2021-12-28
[ [ "Benso", "Cristina", "" ], [ "Brdar", "Vedran", "" ], [ "Lindner", "Manfred", "" ], [ "Rodejohann", "Werner", "" ] ]
We discuss under what circumstances a signal in upcoming laboratory searches for keV-scale sterile neutrinos would be compatible with those particles being a sizable part or all of dark matter. In the parameter space that will be experimentally accessible by KATRIN/TRISTAN, strong X-ray limits need to be relaxed and dark matter overproduction needs to be avoided. We discuss postponing the dark matter production to lower temperatures, a reduced sterile neutrino contribution to dark matter, and a reduction of the branching ratio in photons and active neutrinos through cancellation with a new physics diagram. Both the Dodelson-Widrow and the Shi-Fuller mechanisms for sterile neutrino dark matter production are considered. As a final exotic example, potential consequences of CPT violation are discussed.
hep-ph/0006112
Zhi-Zhong Xing
Zhi-zhong Xing
Can CPT Symmetry Be Tested With K^0 vs \bar{K}^0--> \pi^+\pi^-\pi^0 Decays?
RevTex 6 pages. Phys. Rev. D (in printing)
Phys.Rev. D62 (2000) 097901
10.1103/PhysRevD.62.097901
LMU-00-06
hep-ph hep-ex
null
We show that the CP-violating effect in K^0 vs \bar K^0-->\pi^+\pi^-\pi^0 decays differs from that in K_{\rm L}-->\pi^+\pi^-, K_{\rm L}-->\pi^0\pi^0 or the semileptonic K_{\rm L} transitions, if there exists CPT violation in K^0-\bar{K}^0 mixing. A delicate measurement of this difference in the KTeV experiment and at the \phi factory will provide a new test of CPT symmetry in the neutral kaon system.
[ { "created": "Mon, 12 Jun 2000 09:36:42 GMT", "version": "v1" }, { "created": "Thu, 13 Jul 2000 13:54:16 GMT", "version": "v2" } ]
2009-10-31
[ [ "Xing", "Zhi-zhong", "" ] ]
We show that the CP-violating effect in K^0 vs \bar K^0-->\pi^+\pi^-\pi^0 decays differs from that in K_{\rm L}-->\pi^+\pi^-, K_{\rm L}-->\pi^0\pi^0 or the semileptonic K_{\rm L} transitions, if there exists CPT violation in K^0-\bar{K}^0 mixing. A delicate measurement of this difference in the KTeV experiment and at the \phi factory will provide a new test of CPT symmetry in the neutral kaon system.
2106.02059
Davide Pagani
Davide Pagani, Hua-Sheng Shao, Ioannis Tsinikos, Marco Zaro
Automated EW corrections with isolated photons: $t \bar t \gamma$, $t \bar t \gamma\gamma$ and $t \gamma j$ as case studies
32 pages, 4 figures, 5 tables. This version matches the one published
JHEP09(2021)155
10.1007/JHEP09(2021)155
DESY 21-083, LU-TP 21-19, TIF-UNIMI-2021-7
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we compute for the first time the so-called Complete-NLO predictions for top-quark pair hadroproduction in association with at least one isolated photon ($ t \bar t \gamma$). We also compute NLO QCD+EW predictions for the similar case with at least two isolated photons ($ t \bar t \gamma\gamma$) and for single-top hadroproduction in association with at least one isolated photon. In addition, we complement our results with NLO QCD+EW predictions of the hadronic and leptonic decays of top-quark including an isolated photon. All these results have been obtained in a completely automated approach, by extending the capabilities of the MadGraph5_aMC@NLO framework and enabling the Complete-NLO predictions for processes with isolated photons in the final state. We discuss the technical details of the implementation, which involves a mixed EW renormalisation scheme for such processes.
[ { "created": "Thu, 3 Jun 2021 18:03:38 GMT", "version": "v1" }, { "created": "Fri, 1 Oct 2021 16:07:47 GMT", "version": "v2" } ]
2021-10-04
[ [ "Pagani", "Davide", "" ], [ "Shao", "Hua-Sheng", "" ], [ "Tsinikos", "Ioannis", "" ], [ "Zaro", "Marco", "" ] ]
In this work we compute for the first time the so-called Complete-NLO predictions for top-quark pair hadroproduction in association with at least one isolated photon ($ t \bar t \gamma$). We also compute NLO QCD+EW predictions for the similar case with at least two isolated photons ($ t \bar t \gamma\gamma$) and for single-top hadroproduction in association with at least one isolated photon. In addition, we complement our results with NLO QCD+EW predictions of the hadronic and leptonic decays of top-quark including an isolated photon. All these results have been obtained in a completely automated approach, by extending the capabilities of the MadGraph5_aMC@NLO framework and enabling the Complete-NLO predictions for processes with isolated photons in the final state. We discuss the technical details of the implementation, which involves a mixed EW renormalisation scheme for such processes.
1604.00925
Ye-Ling Zhou
Silvia Pascoli and Ye-Ling Zhou
The role of flavon cross couplings in leptonic flavour mixing
21 pages, 3 figures, typo corrected, published in JHEP
JHEP 06: 073, 2016
10.1007/JHEP06(2016)073
IPPP/16/19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In models with discrete flavour symmetries, flavons are critical to realise specific flavour structures. Leptonic flavour mixing originates from the misalignment of flavon vacuum expectation values which respect different residual symmetries in the charged lepton and neutrino sectors. Flavon cross couplings are usually forbidden, in order to protect these symmetries. Contrary to this approach, we show that cross couplings can play a key role and give raise to necessary corrections to flavour-mixing patterns, including a non-zero value for the reactor angle and CP violation. For definiteness, we present two models based on $A_4$. In the first model, all flavons are assumed to be real or pseudo-real, with 7 real degrees of freedom in the flavon sector in total. A sizable reactor angle associated with nearly maximal CP violation is achieved, and, as both originate from the same cross coupling, a sum rule results with a precise prediction for the value of the Dirac CP-violating phase. In the second model, the flavons are taken to be complex scalars, which can be connected with supersymmetric models and multi-Higgs models. The complexity properties of flavons provide new sources for generating the reactor angle. Models in this new approach introduce very few degrees of freedom beyond the Standard Model and can be more economical than those in the framework of extra dimension or supersymmetry.
[ { "created": "Mon, 4 Apr 2016 16:00:02 GMT", "version": "v1" }, { "created": "Mon, 13 Jun 2016 13:52:17 GMT", "version": "v2" } ]
2016-06-14
[ [ "Pascoli", "Silvia", "" ], [ "Zhou", "Ye-Ling", "" ] ]
In models with discrete flavour symmetries, flavons are critical to realise specific flavour structures. Leptonic flavour mixing originates from the misalignment of flavon vacuum expectation values which respect different residual symmetries in the charged lepton and neutrino sectors. Flavon cross couplings are usually forbidden, in order to protect these symmetries. Contrary to this approach, we show that cross couplings can play a key role and give raise to necessary corrections to flavour-mixing patterns, including a non-zero value for the reactor angle and CP violation. For definiteness, we present two models based on $A_4$. In the first model, all flavons are assumed to be real or pseudo-real, with 7 real degrees of freedom in the flavon sector in total. A sizable reactor angle associated with nearly maximal CP violation is achieved, and, as both originate from the same cross coupling, a sum rule results with a precise prediction for the value of the Dirac CP-violating phase. In the second model, the flavons are taken to be complex scalars, which can be connected with supersymmetric models and multi-Higgs models. The complexity properties of flavons provide new sources for generating the reactor angle. Models in this new approach introduce very few degrees of freedom beyond the Standard Model and can be more economical than those in the framework of extra dimension or supersymmetry.
hep-ph/0111112
Andreas Ringwald
A. Ringwald (DESY)
Possible detection of relic neutrinos and their mass
8 pages, 11 figures, needs icrc.cls (included). Invited so-called "Highlight Talk", to appear in the Proceedings of the 27th International Cosmic Ray Conference (ICRC 2001), Hamburg, Germany, August 2001
null
null
DESY 01-189
hep-ph astro-ph hep-ex
null
Recently the possibility was widely discussed that a large fraction of the highest energy cosmic rays may be decay products of Z bosons which were produced in the resonant annihilation of ultrahigh energy cosmic neutrinos on cosmological relic neutrinos. If one takes this so-called Z-burst scenario seriously, one may infer the mass of the heaviest relic neutrino as well as the necessary ultrahigh energy cosmic neutrino flux from a comparison of the predicted Z-burst spectrum with the observed cosmic ray spectrum.
[ { "created": "Fri, 9 Nov 2001 15:38:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ringwald", "A.", "", "DESY" ] ]
Recently the possibility was widely discussed that a large fraction of the highest energy cosmic rays may be decay products of Z bosons which were produced in the resonant annihilation of ultrahigh energy cosmic neutrinos on cosmological relic neutrinos. If one takes this so-called Z-burst scenario seriously, one may infer the mass of the heaviest relic neutrino as well as the necessary ultrahigh energy cosmic neutrino flux from a comparison of the predicted Z-burst spectrum with the observed cosmic ray spectrum.
1103.1881
Sho Iwamoto
Shoji Asai, Yuya Azuma, Motoi Endo, Koichi Hamaguchi, Sho Iwamoto
Stau Kinks at the LHC
19 pages, 4 figures; Version published in JHEP; abstract refined, reference added and several minor corrections in text
null
10.1007/JHEP12(2011)041
UT-11-06, IPMU-11-0033
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The kink signature of charged tracks is predicted in some SUSY models, and it is very characteristic signal at collider experiments. We study the kink signature at LHC using two models, SUSY models with a gravitino LSP and a stau NLSP, and R-parity violating SUSY models with a stau (N)LSP. We find that a large number of kink events can be discovered in a wide range of the SUSY parameters, when the decay length is O(10-10^5)mm. Model discrimination by identifying the daughter particles of the kink tracks is also discussed.
[ { "created": "Wed, 9 Mar 2011 21:01:00 GMT", "version": "v1" }, { "created": "Fri, 23 Dec 2011 18:24:37 GMT", "version": "v2" } ]
2015-05-27
[ [ "Asai", "Shoji", "" ], [ "Azuma", "Yuya", "" ], [ "Endo", "Motoi", "" ], [ "Hamaguchi", "Koichi", "" ], [ "Iwamoto", "Sho", "" ] ]
The kink signature of charged tracks is predicted in some SUSY models, and it is very characteristic signal at collider experiments. We study the kink signature at LHC using two models, SUSY models with a gravitino LSP and a stau NLSP, and R-parity violating SUSY models with a stau (N)LSP. We find that a large number of kink events can be discovered in a wide range of the SUSY parameters, when the decay length is O(10-10^5)mm. Model discrimination by identifying the daughter particles of the kink tracks is also discussed.
hep-ph/9406424
null
Gautam Bhattacharyya, Gustavo C. Branco and Debajyoti Choudhury
Radiative B-decay as a test of CKM unitarity
11 pages (Latex) + 4 postscript figures (compressed, tared, uuencoded) included at the end of the paper - [please check before printing that the uncompressed fig2.ps and fig3.ps files do not contain blank lines in the beginning], CERN-TH.7294/94, MPI-PhT/94-32
Phys.Lett.B336:487-493,1994; ERRATUM-ibid.B340:266,1994
10.1016/0370-2693(94)90562-2
null
hep-ph
null
We point out that $R \equiv Br(b\rightarrow d \gamma)/Br(b\rightarrow s \gamma)$ is a sensitive probe of possible violation of CKM unitarity. We compute $R$ in a minimal extension of the Standard Model containing an additional isosinglet charge ($-1/3$) quark, which leads to a deviation from CKM unitarity.
[ { "created": "Thu, 30 Jun 1994 16:53:05 GMT", "version": "v1" } ]
2010-11-01
[ [ "Bhattacharyya", "Gautam", "" ], [ "Branco", "Gustavo C.", "" ], [ "Choudhury", "Debajyoti", "" ] ]
We point out that $R \equiv Br(b\rightarrow d \gamma)/Br(b\rightarrow s \gamma)$ is a sensitive probe of possible violation of CKM unitarity. We compute $R$ in a minimal extension of the Standard Model containing an additional isosinglet charge ($-1/3$) quark, which leads to a deviation from CKM unitarity.
1412.8378
Josef Pradler
Haipeng An, Maxim Pospelov, Josef Pradler, Adam Ritz
Direct Detection Constraints on Dark Photon Dark Matter
10 pages, 4 figures; numerical bug in J-factor corrected; main results unchanged
Phys.Lett. B747 (2015) 331-338
10.1016/j.physletb.2015.06.018
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter detectors built primarily to probe elastic scattering of WIMPs on nuclei are also precise probes of light, weakly coupled particles that may be absorbed by the detector material. In this paper, we derive constraints on the minimal model of dark matter comprised of long-lived vector states V (dark photons) in the 0.01-100 keV mass range. The absence of an ionization signal in direct detection experiments such as XENON10 and XENON100 places a very strong constraint on the dark photon mixing angle, down to $O(10^{-15})$, assuming that dark photons comprise the dominant fraction of dark matter. This sensitivity to dark photon dark matter exceeds the indirect bounds derived from stellar energy loss considerations over a significant fraction of the available mass range. We also revisit indirect constraints from $V\to 3\gamma$ decay and show that limits from modifications to the cosmological ionization history are comparable to the updated limits from the diffuse gamma-ray flux.
[ { "created": "Mon, 29 Dec 2014 15:58:33 GMT", "version": "v1" }, { "created": "Wed, 10 Jun 2015 17:11:38 GMT", "version": "v2" }, { "created": "Wed, 22 Jul 2015 09:22:00 GMT", "version": "v3" } ]
2015-07-23
[ [ "An", "Haipeng", "" ], [ "Pospelov", "Maxim", "" ], [ "Pradler", "Josef", "" ], [ "Ritz", "Adam", "" ] ]
Dark matter detectors built primarily to probe elastic scattering of WIMPs on nuclei are also precise probes of light, weakly coupled particles that may be absorbed by the detector material. In this paper, we derive constraints on the minimal model of dark matter comprised of long-lived vector states V (dark photons) in the 0.01-100 keV mass range. The absence of an ionization signal in direct detection experiments such as XENON10 and XENON100 places a very strong constraint on the dark photon mixing angle, down to $O(10^{-15})$, assuming that dark photons comprise the dominant fraction of dark matter. This sensitivity to dark photon dark matter exceeds the indirect bounds derived from stellar energy loss considerations over a significant fraction of the available mass range. We also revisit indirect constraints from $V\to 3\gamma$ decay and show that limits from modifications to the cosmological ionization history are comparable to the updated limits from the diffuse gamma-ray flux.
hep-ph/9607290
Martin McDermott
W. Buchmuller, A. Hebecker and M.F. McDermott
Gluon Radiation in Diffractive Electroproduction
32 pages, 5 figures. Four equations are changed to account for a technical error. The qualitative discussion of the paper is not affected
Nucl.Phys.B487:283-310,1997; Erratum-ibid.B500:621-622,1997
10.1016/S0550-3213(96)00623-2
DESY 96-126, SLAC-PUB-7204
hep-ph
null
Order $\alpha_s$-corrections to the diffractive structure functions $F_L^D$ and $F_2^D$ at large $Q^2$ and small $x$ are evaluated in the semiclassical approach, where the initial proton is treated as a classical colour field. The diffractive final state contains a fast gluon in addition to a quark-antiquark pair. Two of these partons may have large transverse momentum. Our calculations lead to an intuitive picture of deep-inelastic diffractive processes which is very similar to Bjorken's aligned-jet model. Both diffractive structure functions contain leading twist contributions from high-$p_{\perp}$ jets.
[ { "created": "Thu, 11 Jul 1996 14:01:04 GMT", "version": "v1" }, { "created": "Mon, 4 Aug 1997 12:55:23 GMT", "version": "v2" } ]
2009-02-20
[ [ "Buchmuller", "W.", "" ], [ "Hebecker", "A.", "" ], [ "McDermott", "M. F.", "" ] ]
Order $\alpha_s$-corrections to the diffractive structure functions $F_L^D$ and $F_2^D$ at large $Q^2$ and small $x$ are evaluated in the semiclassical approach, where the initial proton is treated as a classical colour field. The diffractive final state contains a fast gluon in addition to a quark-antiquark pair. Two of these partons may have large transverse momentum. Our calculations lead to an intuitive picture of deep-inelastic diffractive processes which is very similar to Bjorken's aligned-jet model. Both diffractive structure functions contain leading twist contributions from high-$p_{\perp}$ jets.
1408.4575
Seong Chan Park
Carsten Rott, Kazunori Kohri, Seong Chan Park
Superheavy dark matter and IceCube neutrino signals:bounds on decaying dark matter
5 pages, 2 figures
Phys. Rev. D 92, 023529 (2015)
10.1103/PhysRevD.92.023529
KEK-Cosmo-153, KEK-TH 1761, KIAS-P14052
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Superheavy dark matter may show its presence in high energy neutrino signals detected on earth. From the latest results of IceCube, we could set the strongest lower bound on the lifetime of dark matter beyond 100 TeV around $10^{28} {\rm sec}$. The excess around a PeV is noticed and may be interpreted as the first signal of DM even though further confirmation and dedicated searches are invited.
[ { "created": "Wed, 20 Aug 2014 09:24:08 GMT", "version": "v1" }, { "created": "Mon, 27 Jul 2015 00:33:05 GMT", "version": "v2" } ]
2015-07-28
[ [ "Rott", "Carsten", "" ], [ "Kohri", "Kazunori", "" ], [ "Park", "Seong Chan", "" ] ]
Superheavy dark matter may show its presence in high energy neutrino signals detected on earth. From the latest results of IceCube, we could set the strongest lower bound on the lifetime of dark matter beyond 100 TeV around $10^{28} {\rm sec}$. The excess around a PeV is noticed and may be interpreted as the first signal of DM even though further confirmation and dedicated searches are invited.
0806.4886
Jerome de Favereau de Jeneret
J. de Favereau de Jeneret, S. Ovyn
Single top quark photoproduction at the LHC
null
Nucl.Phys.Proc.Suppl.179-180:277-284,2008
10.1016/j.nuclphysbps.2008.07.040
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
High-energy photon-proton interactions at the LHC offer interesting possibilities for the study of the electroweak sector up to TeV scale and searches for processes beyond the Standard Model. An analysis of the W associated single top photoproduction has been performed using the adapted MadGraph/MadEvent and CalcHEP programs interfaced to the Pythia generator and a fast detector simulation program. Event selection and suppression of main backgrounds have been studied. A comparable sensitivity to |V_{tb}| to those obtained using the standard single top production in pp collisions has been achieved already for 10 fb^{-1} of integrated luminosity. Photoproduction at the LHC provides also an attractive framework for observation of the anomalous production of single top due to Flavour-Changing Neutral Currents. The sensitivity to anomalous coupling parameters, k_{tu\gamma} and k_{tc\gamma} is presented and indicates that stronger limits can be placed on anomalous couplings after 1 fb^{-1}.
[ { "created": "Mon, 30 Jun 2008 13:18:03 GMT", "version": "v1" } ]
2008-11-26
[ [ "de Jeneret", "J. de Favereau", "" ], [ "Ovyn", "S.", "" ] ]
High-energy photon-proton interactions at the LHC offer interesting possibilities for the study of the electroweak sector up to TeV scale and searches for processes beyond the Standard Model. An analysis of the W associated single top photoproduction has been performed using the adapted MadGraph/MadEvent and CalcHEP programs interfaced to the Pythia generator and a fast detector simulation program. Event selection and suppression of main backgrounds have been studied. A comparable sensitivity to |V_{tb}| to those obtained using the standard single top production in pp collisions has been achieved already for 10 fb^{-1} of integrated luminosity. Photoproduction at the LHC provides also an attractive framework for observation of the anomalous production of single top due to Flavour-Changing Neutral Currents. The sensitivity to anomalous coupling parameters, k_{tu\gamma} and k_{tc\gamma} is presented and indicates that stronger limits can be placed on anomalous couplings after 1 fb^{-1}.
1008.5277
Wei Chao
Wei Chao and Yong-chao Zhang
The D0 Dimuon Charge Asymmetry and Baryon Asymmetry of the Universe
10 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The D0 collaboration has reported a 3.2 \sigma deviation from the Standard Model (SM) prediction in the like-sign dimuon charge asymmetry. New physics beyond the SM in B_s - \bar B_s mixing is needed to explain the data. In this paper, we investigate the possible extension of the SM with one generation color-triplet charged scalar as well as three generation Majorana fermions. We study the implications of the model on the D0's dimuon charge asymmetry as well as matter anti-matter asymmetry of the Universe.
[ { "created": "Tue, 31 Aug 2010 10:34:58 GMT", "version": "v1" } ]
2010-09-01
[ [ "Chao", "Wei", "" ], [ "Zhang", "Yong-chao", "" ] ]
The D0 collaboration has reported a 3.2 \sigma deviation from the Standard Model (SM) prediction in the like-sign dimuon charge asymmetry. New physics beyond the SM in B_s - \bar B_s mixing is needed to explain the data. In this paper, we investigate the possible extension of the SM with one generation color-triplet charged scalar as well as three generation Majorana fermions. We study the implications of the model on the D0's dimuon charge asymmetry as well as matter anti-matter asymmetry of the Universe.
1505.03149
Angelo Monteux
Angelo Monteux, Chang Sub Shin (NHETC, Rutgers University)
Thermal Goldstino Production with Low Reheating Temperatures
25 pages, 6 figures
Phys. Rev. D 92, 035002 (2015)
10.1103/PhysRevD.92.035002
RUNHETC-2015-03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss thermal production of (pseudo) goldstinos, the Goldstone fermions emerging from (multiple) SUSY breaking sectors, when the reheating temperature is well below the superpartner masses. In such a case, the production during matter-dominated era induced by inflaton decay stage is more important than after reheating. Depending on the SUSY breaking scale, goldstinos are produced by freeze-in or freeze-out mechanism via $1\to 2$ decays and inverse decays. We solve the Boltzmann equation for the momentum distribution function of the goldstino.In the freeze-out case, goldstinos maintain chemical equilibrium far after they are kinetically decoupled from the thermal bath, and consequently goldstinos with different momentum decouple at different temperatures. As a result their momentum distribution function shows a peculiar shape and the final yield is smaller than if kinetic equilibrium was assumed. We revisit the cosmological implications in both R-parity-conserving and R-parity-violating supersymmetric scenarios. For the former, thermally produced goldstinos can still be abundant enough to be dark matter at present times even if the reheating temperature is low, of order $1$ GeV. For the latter, if the reheating temperature is low, of order $0.1-1$ GeV, they are safe from the BBN constraints.
[ { "created": "Tue, 12 May 2015 20:00:28 GMT", "version": "v1" } ]
2015-08-12
[ [ "Monteux", "Angelo", "", "NHETC, Rutgers University" ], [ "Shin", "Chang Sub", "", "NHETC, Rutgers University" ] ]
We discuss thermal production of (pseudo) goldstinos, the Goldstone fermions emerging from (multiple) SUSY breaking sectors, when the reheating temperature is well below the superpartner masses. In such a case, the production during matter-dominated era induced by inflaton decay stage is more important than after reheating. Depending on the SUSY breaking scale, goldstinos are produced by freeze-in or freeze-out mechanism via $1\to 2$ decays and inverse decays. We solve the Boltzmann equation for the momentum distribution function of the goldstino.In the freeze-out case, goldstinos maintain chemical equilibrium far after they are kinetically decoupled from the thermal bath, and consequently goldstinos with different momentum decouple at different temperatures. As a result their momentum distribution function shows a peculiar shape and the final yield is smaller than if kinetic equilibrium was assumed. We revisit the cosmological implications in both R-parity-conserving and R-parity-violating supersymmetric scenarios. For the former, thermally produced goldstinos can still be abundant enough to be dark matter at present times even if the reheating temperature is low, of order $1$ GeV. For the latter, if the reheating temperature is low, of order $0.1-1$ GeV, they are safe from the BBN constraints.
hep-ph/9912445
Richard D. Ball
R.D. Ball and P.V. Landshoff
The Challenge of Small x
12 pages, 7 figures: contribution to Durham Phenomenology Workshop proceedings
J.Phys.G26:672-682,2000
10.1088/0954-3899/26/5/326
Edinburgh 99/21, DAMTP-1999-170
hep-ph
null
We review the current understanding of the behaviour of inclusive cross sections at small x and large Q^2 in terms of Altarelli-Parisi evolution, the BFKL equation, and Regge theory, asking in particular to what extent they are mutually consistent.
[ { "created": "Tue, 21 Dec 1999 15:04:41 GMT", "version": "v1" } ]
2010-03-25
[ [ "Ball", "R. D.", "" ], [ "Landshoff", "P. V.", "" ] ]
We review the current understanding of the behaviour of inclusive cross sections at small x and large Q^2 in terms of Altarelli-Parisi evolution, the BFKL equation, and Regge theory, asking in particular to what extent they are mutually consistent.
hep-ph/0005255
Ji Young Yu
E. A. Paschos (I. A. S., Princeton), L. Pasquali and J. Y. Yu (Dortmund U.)
Single Pion Production in Neutrino Reactions and Estimates for Charge-Exchange Effects
20 pages, 16 figures
Nucl.Phys. B588 (2000) 263-280
10.1016/S0550-3213(00)00486-7
DO-TH 00/10
hep-ph
null
We calculate single pion production by neutrinos in the resonance region. We consider both charged and neutral current reactions on free protons and neutrons. We present differential and total cross sections which can be compared with experiments. Then we use these results to calculate the spectra of the emerging pions including the Pauli suppression factor and rescattering corrections for reactions in heavy nuclei. Our results will be useful for studying single pion production and for investigating neutrino oscillations in future experiments.
[ { "created": "Thu, 25 May 2000 13:03:18 GMT", "version": "v1" } ]
2009-10-31
[ [ "Paschos", "E. A.", "", "I. A. S., Princeton" ], [ "Pasquali", "L.", "", "Dortmund U." ], [ "Yu", "J. Y.", "", "Dortmund U." ] ]
We calculate single pion production by neutrinos in the resonance region. We consider both charged and neutral current reactions on free protons and neutrons. We present differential and total cross sections which can be compared with experiments. Then we use these results to calculate the spectra of the emerging pions including the Pauli suppression factor and rescattering corrections for reactions in heavy nuclei. Our results will be useful for studying single pion production and for investigating neutrino oscillations in future experiments.
2004.08407
Alexandre Alves
Alexandre Alves, Alex Gomes Dias, and Roberto da Silva
The 7% Rule: A Maximum Entropy Prediction on New Decays of the Higgs Boson
12 pages, 5 figures. Version published in Nuclear Physics B
null
10.1016/j.nuclphysb.2020.115137
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The entropy of the Higgs boson decay probabilities distribution in the Standard Model (SM) is maximized for a Higgs mass value that is less than one standard deviation away from the current experimental measurement. This successful estimate of the Higgs mass encourages us to propose tests of the Maximum Entropy Principle (MEP) as a tool for theoretical inferences in other instances of Higgs physics. In this letter, we show that, irrespective of the extension of the SM predicting a new Higgs boson decay channel, its branching ratio can be inferred to be around 7% in such a way that the new entropy of decays still exhibits a maximum at the experimental Higgs mass. This 7% rule can be tested whenever a new Higgs decay channel is found. In order to illustrate the MEP predictions, we apply the MEP inference to Higgs portal models, Higgs-axion interactions, lepton flavour violating decays of the Higgs boson, and a dark gauge boson model.
[ { "created": "Fri, 17 Apr 2020 18:01:04 GMT", "version": "v1" }, { "created": "Wed, 12 Aug 2020 20:28:45 GMT", "version": "v2" } ]
2020-08-14
[ [ "Alves", "Alexandre", "" ], [ "Dias", "Alex Gomes", "" ], [ "da Silva", "Roberto", "" ] ]
The entropy of the Higgs boson decay probabilities distribution in the Standard Model (SM) is maximized for a Higgs mass value that is less than one standard deviation away from the current experimental measurement. This successful estimate of the Higgs mass encourages us to propose tests of the Maximum Entropy Principle (MEP) as a tool for theoretical inferences in other instances of Higgs physics. In this letter, we show that, irrespective of the extension of the SM predicting a new Higgs boson decay channel, its branching ratio can be inferred to be around 7% in such a way that the new entropy of decays still exhibits a maximum at the experimental Higgs mass. This 7% rule can be tested whenever a new Higgs decay channel is found. In order to illustrate the MEP predictions, we apply the MEP inference to Higgs portal models, Higgs-axion interactions, lepton flavour violating decays of the Higgs boson, and a dark gauge boson model.
hep-ph/9710206
Dalibor Kekez
Dubravko Klabucar and Dalibor Kekez
eta and eta' in a coupled Schwinger-Dyson and Bethe-Salpeter approach
30 pages, RevTeX, 2 eps figures, title changed, material reorganized, refereces updated; to appear in Phys. Rev. D
Phys. Rev. D 58, 096003 (1998)
10.1103/PhysRevD.58.096003
ZTF-97/R01
hep-ph nucl-th
null
Extending our earlier treatments of pi0, eta_c and eta_b, we study the eta-eta' system and its gamma-gamma decays using a model which is a leading version of the consistently coupled Schwinger-Dyson (SD) and Bethe-Salpeter (BS) approach. The electromagnetic interactions are incorporated through a (generalized) impulse approximation consistent with this bound-state approach, so that the Ward-Takahashi identities of QED are preserved when quarks are dynamically dressed. To overcome some of the limitations due to the ladder approximation, we introduce a minimal extension to the bound--state approach employed, so that the U_A(1) problem is avoided. Pointing out which of our predictions hold in the coupled SD-BS approach in general, and which are the consequences of the specific, chosen model, we present the results for the axial-current decay constants of eta_8, eta_0, and of their physical combinations eta and eta', the results for the gamma-gamma decay constants of eta_0 and eta_8, for the two-photon decay widths of eta and eta', and for the mixing-independent R-ratio constructed from them.
[ { "created": "Wed, 1 Oct 1997 16:17:23 GMT", "version": "v1" }, { "created": "Thu, 25 Jun 1998 10:36:03 GMT", "version": "v2" } ]
2016-08-25
[ [ "Klabucar", "Dubravko", "" ], [ "Kekez", "Dalibor", "" ] ]
Extending our earlier treatments of pi0, eta_c and eta_b, we study the eta-eta' system and its gamma-gamma decays using a model which is a leading version of the consistently coupled Schwinger-Dyson (SD) and Bethe-Salpeter (BS) approach. The electromagnetic interactions are incorporated through a (generalized) impulse approximation consistent with this bound-state approach, so that the Ward-Takahashi identities of QED are preserved when quarks are dynamically dressed. To overcome some of the limitations due to the ladder approximation, we introduce a minimal extension to the bound--state approach employed, so that the U_A(1) problem is avoided. Pointing out which of our predictions hold in the coupled SD-BS approach in general, and which are the consequences of the specific, chosen model, we present the results for the axial-current decay constants of eta_8, eta_0, and of their physical combinations eta and eta', the results for the gamma-gamma decay constants of eta_0 and eta_8, for the two-photon decay widths of eta and eta', and for the mixing-independent R-ratio constructed from them.
0801.0047
Vladimir Burdyuzha
V.Burdyuzha
When did vacuum energy of the Universe become cosmological constant?
3 pages. submitted to Phys. Letters
null
null
null
hep-ph
null
A quark-gluon phase transition in the Universe is researched after which vacuum (dark) energy has hardened and become cosmological constant. Before this a vacuum component of the Universe was changing by jumps during phase transitions since vacuum condensates of quantum fields carried a negative contribution in its positive density energy. This quintessence period of the Universe life took place during the first parts of a second when our Universe was losing high symmetry. Using Zel'dovich's formula the modern value of vacuum energy is also calculated. It is shown that a quantum chromodynamical vacuum which is characterized by pseudogoldstone bosons existed definitely when temperature of the Universe was T~150 MeV. Therefore there is a large probability that dark energy is vacuum energy.
[ { "created": "Sat, 29 Dec 2007 10:58:14 GMT", "version": "v1" } ]
2008-01-03
[ [ "Burdyuzha", "V.", "" ] ]
A quark-gluon phase transition in the Universe is researched after which vacuum (dark) energy has hardened and become cosmological constant. Before this a vacuum component of the Universe was changing by jumps during phase transitions since vacuum condensates of quantum fields carried a negative contribution in its positive density energy. This quintessence period of the Universe life took place during the first parts of a second when our Universe was losing high symmetry. Using Zel'dovich's formula the modern value of vacuum energy is also calculated. It is shown that a quantum chromodynamical vacuum which is characterized by pseudogoldstone bosons existed definitely when temperature of the Universe was T~150 MeV. Therefore there is a large probability that dark energy is vacuum energy.
0901.4101
Giulia Zanderighi
R. Keith Ellis, Kirill Melnikov, Giulia Zanderighi
Generalized unitarity at work: first NLO QCD results for hadronic W+3jet production
20 pages, 4 figures
JHEP 0904:077,2009
10.1088/1126-6708/2009/04/077
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the leading color, next-to-leading order QCD corrections to the dominant partonic channels for the production of a W boson in association with three jets at the Tevatron and the LHC. This is the first application of generalized unitarity for realistic one-loop calculations. The method performs well in this non-trivial test and offers great promise for the future.
[ { "created": "Tue, 27 Jan 2009 20:24:30 GMT", "version": "v1" } ]
2010-01-07
[ [ "Ellis", "R. Keith", "" ], [ "Melnikov", "Kirill", "" ], [ "Zanderighi", "Giulia", "" ] ]
We compute the leading color, next-to-leading order QCD corrections to the dominant partonic channels for the production of a W boson in association with three jets at the Tevatron and the LHC. This is the first application of generalized unitarity for realistic one-loop calculations. The method performs well in this non-trivial test and offers great promise for the future.
hep-ph/9503429
Ilya Royzen
I. Royzen
Theoretical Approach to Alignment Phenomenon
7 pages, LaTEX, 4 figures (available from the author upon request)
Mod.Phys.Lett. A9 (1994) 3517-3522
10.1142/S021773239400335X
Mod. Phys. Lett. A, vol. 9, no 38, (1994), p. 3517
hep-ph
null
An explanation of the puzzling alignment effect observed in cosmic ray experiments is suggested
[ { "created": "Thu, 23 Mar 1995 12:49:54 GMT", "version": "v1" } ]
2015-06-25
[ [ "Royzen", "I.", "" ] ]
An explanation of the puzzling alignment effect observed in cosmic ray experiments is suggested
1405.1185
Luca Rottoli
Luca Rottoli
Threshold resummation in SCET vs. direct QCD: a systematic comparison
110 pages, Master's thesis. Supervisors: S. Forte, G. Ridolfi
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a systematic comparison of soft-gluon resummation in SCET and in a standard "direct" QCD (dQCD) approach, both from an analytical and a phenomenological point of view. In particular, we concentrate on Higgs boson production in gluon-gluon fusion at a hadron collider. Using specifically a saddle point argument, we arrive at a detailed understanding of the quantitative differences between these two approaches.
[ { "created": "Tue, 6 May 2014 08:14:08 GMT", "version": "v1" } ]
2014-05-07
[ [ "Rottoli", "Luca", "" ] ]
We perform a systematic comparison of soft-gluon resummation in SCET and in a standard "direct" QCD (dQCD) approach, both from an analytical and a phenomenological point of view. In particular, we concentrate on Higgs boson production in gluon-gluon fusion at a hadron collider. Using specifically a saddle point argument, we arrive at a detailed understanding of the quantitative differences between these two approaches.
hep-ph/0307305
Peter Richardson
C.M. Harris (Cambridge), P. Richardson (CERN), and B.R. Webber (Cambridge and CERN)
CHARYBDIS: A Black Hole Event Generator
14 pages, 3 postscript figures. Program available from http://www.ippp.dur.ac.uk/montecarlo/leshouches/generators/charybdis/ . Footnote and two references added
JHEP0308:033,2003
10.1088/1126-6708/2003/08/033
Cavendish-HEP-03/12 CERN-TH/2003-170
hep-ph
null
CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator includes the extra-dimensional `grey-body' effects as well as the change in the temperature of the black hole as the decay progresses. Various options for modelling the Planck-scale terminal decay are provided.
[ { "created": "Thu, 24 Jul 2003 14:52:22 GMT", "version": "v1" }, { "created": "Tue, 29 Jul 2003 14:43:19 GMT", "version": "v2" } ]
2009-11-10
[ [ "Harris", "C. M.", "", "Cambridge" ], [ "Richardson", "P.", "", "CERN" ], [ "Webber", "B. R.", "", "Cambridge and CERN" ] ]
CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator includes the extra-dimensional `grey-body' effects as well as the change in the temperature of the black hole as the decay progresses. Various options for modelling the Planck-scale terminal decay are provided.
1302.6726
Alexei P. Martynenko
A.P. Martynenko (Samara State U. & Samara State Aerospace U.) and A.M. Trunin (Samara State Aerospace U.)
Relativistic corrections to \eta_c-pair production in high energy proton-proton collisions
12 pages, 3 figures
null
10.1016/j.physletb.2013.05.003
SSU-HEP-13/02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
On the basis of perturbative QCD and the relativistic quark model we calculate relativistic corrections to the double $\eta_c$ meson production in proton-proton interactions at LHC energies. Relativistic terms in the production amplitude connected with the relative motion of heavy quarks and the transformation law of the bound state wave functions to the reference frame of moving charmonia are taken into account. For the gluon and quark propagators entering the amplitude we use a truncated expansion in relative quark momenta up to the second order. Relativistic corrections to the quark bound state wave functions are considered by means of the Breit-like potential. It turns out that the examined effects decrease total nonrelativistic cross section more than two times and on 20 percents in the rapidity region of LHCb detector.
[ { "created": "Wed, 27 Feb 2013 11:25:40 GMT", "version": "v1" } ]
2015-06-15
[ [ "Martynenko", "A. P.", "", "Samara State U. & Samara State Aerospace U." ], [ "Trunin", "A. M.", "", "Samara State Aerospace U." ] ]
On the basis of perturbative QCD and the relativistic quark model we calculate relativistic corrections to the double $\eta_c$ meson production in proton-proton interactions at LHC energies. Relativistic terms in the production amplitude connected with the relative motion of heavy quarks and the transformation law of the bound state wave functions to the reference frame of moving charmonia are taken into account. For the gluon and quark propagators entering the amplitude we use a truncated expansion in relative quark momenta up to the second order. Relativistic corrections to the quark bound state wave functions are considered by means of the Breit-like potential. It turns out that the examined effects decrease total nonrelativistic cross section more than two times and on 20 percents in the rapidity region of LHCb detector.
1506.00254
Bumseok Kyae
Bumseok Kyae
Shifted focus point scenario from the minimal mixed mediation of SUSY breaking
4 pages, 1 figure, prepared for the proceedings of the 2nd Toyama International Workshop on Higgs as a Probe of New Physics (HPNP 2015), February 11-15, 2015
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We employ both the minimal gravity- and the minimal gauge mediations of supersymmetry breaking at the grand unified theory (GUT) scale in a single supergravity framework, assuming the gaugino masses are generated dominantly by the minimal gauge mediation effects. In such a "minimal mixed mediation model," a "focus point" of the soft Higgs mass parameter, m_{h_u}^2 emerges at 3-4 TeV energy scale, which is exactly the stop mass scale needed for explaining the 126 GeV Higgs boson mass without the "A-term" at the three loop level. As a result, m_{h_u}^2 in the MSSM can be quite insensitive to various trial stop masses at low energy, reducing the fine-tuning measures to be much smaller than 100 even for a 3-4 TeV low energy stop mass and -0.5 < A_t / m_0 < +0.1 at the GUT scale. The $\mu$ parameter is smaller than 600 GeV. The gluino mass is predicted to be about 1.7 TeV, which could readily be tested at LHC run2.
[ { "created": "Sun, 31 May 2015 16:50:23 GMT", "version": "v1" } ]
2015-06-02
[ [ "Kyae", "Bumseok", "" ] ]
We employ both the minimal gravity- and the minimal gauge mediations of supersymmetry breaking at the grand unified theory (GUT) scale in a single supergravity framework, assuming the gaugino masses are generated dominantly by the minimal gauge mediation effects. In such a "minimal mixed mediation model," a "focus point" of the soft Higgs mass parameter, m_{h_u}^2 emerges at 3-4 TeV energy scale, which is exactly the stop mass scale needed for explaining the 126 GeV Higgs boson mass without the "A-term" at the three loop level. As a result, m_{h_u}^2 in the MSSM can be quite insensitive to various trial stop masses at low energy, reducing the fine-tuning measures to be much smaller than 100 even for a 3-4 TeV low energy stop mass and -0.5 < A_t / m_0 < +0.1 at the GUT scale. The $\mu$ parameter is smaller than 600 GeV. The gluino mass is predicted to be about 1.7 TeV, which could readily be tested at LHC run2.
2210.12133
Darius Jurciukonis
Darius Jur\v{c}iukonis and Lu\'is Lavoura
The centers of discrete groups as stabilizers of Dark Matter
15 pages, no figures; v2: added references; v3: matches published version
Prog. Theor. Exp. Phys. 2023, 2, 023B02
10.1093/ptep/ptad004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The most usual option to stabilize Dark Matter (DM) is a $Z_2$ symmetry. In general, though, DM may be stabilized by any $Z_N$ with $N \ge 2$. We consider the way $Z_N$ is a subgroup of the internal-symmetry group $G$ of a model; we entertain the possibility that $Z_N$ is the center of $G$, yet $G$ is not of the form $Z_N \times G^\prime$, where $G^\prime$ is a group smaller (i.e. of lower order) than $G$. We examine all the discrete groups of order smaller than 2001 and we find that many of them cannot be written as the direct product of a cyclic group and some other group, yet they have a non-trivial center that might be used in Model Building to stabilize DM.
[ { "created": "Fri, 21 Oct 2022 17:43:44 GMT", "version": "v1" }, { "created": "Fri, 28 Oct 2022 14:45:21 GMT", "version": "v2" }, { "created": "Sat, 11 Feb 2023 17:03:35 GMT", "version": "v3" } ]
2023-02-14
[ [ "Jurčiukonis", "Darius", "" ], [ "Lavoura", "Luís", "" ] ]
The most usual option to stabilize Dark Matter (DM) is a $Z_2$ symmetry. In general, though, DM may be stabilized by any $Z_N$ with $N \ge 2$. We consider the way $Z_N$ is a subgroup of the internal-symmetry group $G$ of a model; we entertain the possibility that $Z_N$ is the center of $G$, yet $G$ is not of the form $Z_N \times G^\prime$, where $G^\prime$ is a group smaller (i.e. of lower order) than $G$. We examine all the discrete groups of order smaller than 2001 and we find that many of them cannot be written as the direct product of a cyclic group and some other group, yet they have a non-trivial center that might be used in Model Building to stabilize DM.
hep-ph/0112338
Naotoshi Okamura
M. Aoki (1), K. Hagiwara (1), Y. Hayato (1), T. Kobayashi (1), T. Nakaya (2), K. Nishikawa (2), and N. Okamura (3) ((1) KEK, (2) Kyoto Univ. (3) Virginia Tech)
Prospects of Very Long Base-Line Neutrino Oscillation Experiments with the KEK-JAERI High Intensity Proton Accelerator
65 pages, 22 figures, and 9 tables
Phys.Rev.D67:093004,2003
10.1103/PhysRevD.67.093004
KEK-TH-798, VPI-IPPAP-01-03
hep-ph hep-ex
null
We study physics potential of Very Long Base-Line (VLBL) Neutrino-Oscillation Experiments with the High Intensity Proton Accelerator (HIPA), which will be completed by the year 2007 in Tokai-village, Japan, as a joint project of KEK and JAERI (Japan Atomic Energy Research Institute). The HIPA 50 GeV proton beam will deliver neutrino beams of a few GeV range with the intensity about two orders of magnitude higher than the present KEK beam for K2K experiment. As a sequel to the proposed HIPA-to-Super-Kamiokande experiment, we study impacts of experiments with a 100 kton-level detector and the base-line length of a few-thousand km. The pulsed narrow-band nu_mu beams (NBB) allow us to measure the nu_mu to nu_e transition probability and the nu_mu survival probability through counting experiments at large water-Cerenkov detector. We study sensitivity of such experiments to the neutrino mass hierarchy, the mass-squared differences, the three angles, and one CP phase of the three-generation lepton-flavor-mixing matrix. We find that experiments at a distance between 1,000 and 2,000 km can determine the sign of the larger mass-squared difference (m_3^2-m_1^2) if the mixing between nu_e and nu_3 (the heaviest-or-lightest neutrino) is not too small; 2|U_{e3}|^2(1-|U_{e3}|^2) gsim 0.03. The CP phase can be constrained if the |U_{e3}| element is sufficiently large, 2|U_{e3}|^2(1-|U_{e3}|^2) gsim 0.06, and if the smaller mass-squared difference (m_2^2-m_1^2) and the U_{e2} element are in the prefered range of the large-mixing-angle solution of the solar-neutrino deficit. The magunitude | m_3^2-m_1^2| and the matrix element U_{mu 3} can be precisely measured, but we find little sensitivity to m_2^2-m_1^2 and the matrix element U_{e2}.
[ { "created": "Thu, 27 Dec 2001 16:23:38 GMT", "version": "v1" } ]
2008-11-26
[ [ "Aoki", "M.", "" ], [ "Hagiwara", "K.", "" ], [ "Hayato", "Y.", "" ], [ "Kobayashi", "T.", "" ], [ "Nakaya", "T.", "" ], [ "Nishikawa", "K.", "" ], [ "Okamura", "N.", "" ] ]
We study physics potential of Very Long Base-Line (VLBL) Neutrino-Oscillation Experiments with the High Intensity Proton Accelerator (HIPA), which will be completed by the year 2007 in Tokai-village, Japan, as a joint project of KEK and JAERI (Japan Atomic Energy Research Institute). The HIPA 50 GeV proton beam will deliver neutrino beams of a few GeV range with the intensity about two orders of magnitude higher than the present KEK beam for K2K experiment. As a sequel to the proposed HIPA-to-Super-Kamiokande experiment, we study impacts of experiments with a 100 kton-level detector and the base-line length of a few-thousand km. The pulsed narrow-band nu_mu beams (NBB) allow us to measure the nu_mu to nu_e transition probability and the nu_mu survival probability through counting experiments at large water-Cerenkov detector. We study sensitivity of such experiments to the neutrino mass hierarchy, the mass-squared differences, the three angles, and one CP phase of the three-generation lepton-flavor-mixing matrix. We find that experiments at a distance between 1,000 and 2,000 km can determine the sign of the larger mass-squared difference (m_3^2-m_1^2) if the mixing between nu_e and nu_3 (the heaviest-or-lightest neutrino) is not too small; 2|U_{e3}|^2(1-|U_{e3}|^2) gsim 0.03. The CP phase can be constrained if the |U_{e3}| element is sufficiently large, 2|U_{e3}|^2(1-|U_{e3}|^2) gsim 0.06, and if the smaller mass-squared difference (m_2^2-m_1^2) and the U_{e2} element are in the prefered range of the large-mixing-angle solution of the solar-neutrino deficit. The magunitude | m_3^2-m_1^2| and the matrix element U_{mu 3} can be precisely measured, but we find little sensitivity to m_2^2-m_1^2 and the matrix element U_{e2}.
hep-ph/0601026
Tetsuo Hyodo
T. Hyodo (1), Sourav Sarkar (2), A. Hosaka (1), E. Oset (2) ((1) RCNP, Osaka Univ., (2) IFIC, Valencia Univ.)
Coupling of \bar K*N to the Lambda(1520)
RevTeX4, 8 pages, 6 figures, Version to appear in Phys. Rev. C
Phys.Rev.C73:035209,2006; Erratum-ibid.C75:029901,2007
10.1103/PhysRevC.73.035209 10.1103/PhysRevC.75.029901
null
hep-ph
null
We study the coupling of the Lambda(1520)= Lambda* resonance to the \bar K* vector meson and nucleon. This coupling is not directly measured from the resonance decay, but is expected to be important in hyperon production reactions, in particular for the exotic Theta+ production. We compute the coupling in two different schemes, one in the chiral unitary model where the Lambda* is dominated by the quasibound state of mesons and baryons, and the other in the quark model where the resonance is a p-wave excitation in the three valence quarks. Although it is possible to construct both models such that they reproduce the \bar K N and pi Sigma decays, there is a significant difference between the Lambda* \bar K* N couplings in the two models. In the chiral unitary model $|g_{\Lambda^*\bar{K}^* N}| \sim 1.5$, while in the quark model $|g_{\Lambda^*\bar{K}^* N}| \sim 10$. The difference of the results stems from the different structure of the Lambda* in both models, and hence, an experimental determination of this coupling would shed light on the nature of the resonance.
[ { "created": "Wed, 4 Jan 2006 08:18:02 GMT", "version": "v1" }, { "created": "Wed, 22 Mar 2006 01:54:54 GMT", "version": "v2" } ]
2014-11-18
[ [ "Hyodo", "T.", "" ], [ "Sarkar", "Sourav", "" ], [ "Hosaka", "A.", "" ], [ "Oset", "E.", "" ] ]
We study the coupling of the Lambda(1520)= Lambda* resonance to the \bar K* vector meson and nucleon. This coupling is not directly measured from the resonance decay, but is expected to be important in hyperon production reactions, in particular for the exotic Theta+ production. We compute the coupling in two different schemes, one in the chiral unitary model where the Lambda* is dominated by the quasibound state of mesons and baryons, and the other in the quark model where the resonance is a p-wave excitation in the three valence quarks. Although it is possible to construct both models such that they reproduce the \bar K N and pi Sigma decays, there is a significant difference between the Lambda* \bar K* N couplings in the two models. In the chiral unitary model $|g_{\Lambda^*\bar{K}^* N}| \sim 1.5$, while in the quark model $|g_{\Lambda^*\bar{K}^* N}| \sim 10$. The difference of the results stems from the different structure of the Lambda* in both models, and hence, an experimental determination of this coupling would shed light on the nature of the resonance.
1611.05091
Cen Zhang
Cen Zhang
NLO predictions for SMEFT in the top-quark sector
Proceedings for the 38th International Conference on High Energy Physics (Chicago, USA), 5 pages, 5 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Predictions for the Standard Model Effective Field Theory at the next-to-leading order accuracy in QCD, including parton-shower effects, have started to become available in the MadGraph5_aMC@NLO framework. In this talk we summarize some recent results for $t\bar t$, single top, $t\bar tZ/\gamma$, and $t\bar tH$ production channels at dimension six.
[ { "created": "Tue, 15 Nov 2016 22:59:07 GMT", "version": "v1" } ]
2016-11-17
[ [ "Zhang", "Cen", "" ] ]
Predictions for the Standard Model Effective Field Theory at the next-to-leading order accuracy in QCD, including parton-shower effects, have started to become available in the MadGraph5_aMC@NLO framework. In this talk we summarize some recent results for $t\bar t$, single top, $t\bar tZ/\gamma$, and $t\bar tH$ production channels at dimension six.
hep-ph/0210393
Robert Foot
R. Foot
Are four neutrino models ruled out?
about 4 pages
Mod.Phys.Lett. A18 (2003) 2079-2082
10.1142/S0217732303011605
null
hep-ph
null
We show explicitly that four neutrino models of the 2+2 variety still provide an acceptable global fit to the solar, atmospheric and LSND neutrino data. The goodness of fit, defined in the usual way, is found to be 0.26 for the simplest such model. That is, we find that there is a 26% probability of obtaining a worse global fit to the neutrino data We also make some specific comments on the paper, ``Ruling out four-neutrino oscillation interpretations of the LSND anomaly'' [hep-ph/0207157], and explain why they reached drastically different conclusions.
[ { "created": "Tue, 29 Oct 2002 05:22:55 GMT", "version": "v1" } ]
2009-11-07
[ [ "Foot", "R.", "" ] ]
We show explicitly that four neutrino models of the 2+2 variety still provide an acceptable global fit to the solar, atmospheric and LSND neutrino data. The goodness of fit, defined in the usual way, is found to be 0.26 for the simplest such model. That is, we find that there is a 26% probability of obtaining a worse global fit to the neutrino data We also make some specific comments on the paper, ``Ruling out four-neutrino oscillation interpretations of the LSND anomaly'' [hep-ph/0207157], and explain why they reached drastically different conclusions.
0811.1175
Walter Winter
Walter Winter
Long baseline neutrino oscillations: Theoretical aspects
6 pages, 1 figure. Talk given at the NOW 2008 workshop, Otranto, Italy
Nucl.Phys.Proc.Suppl.188:151-157,2009
10.1016/j.nuclphysbps.2009.02.036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the measurement of the neutrino oscillation parameters at future long baseline experiments in terms of the motivation of the experiments, the quantities of interest from the theoretical point of view, the phenomenology of these experiments, and the experiment choice. We illustrate the oscillation physics potential of a neutrino factory, as a representative for the most challenging technologies. Finally, we point out that a future neutrino oscillation facility might also be affected by the unexpected.
[ { "created": "Fri, 7 Nov 2008 16:38:45 GMT", "version": "v1" } ]
2009-04-17
[ [ "Winter", "Walter", "" ] ]
We discuss the measurement of the neutrino oscillation parameters at future long baseline experiments in terms of the motivation of the experiments, the quantities of interest from the theoretical point of view, the phenomenology of these experiments, and the experiment choice. We illustrate the oscillation physics potential of a neutrino factory, as a representative for the most challenging technologies. Finally, we point out that a future neutrino oscillation facility might also be affected by the unexpected.
2305.09976
Yaroslav Krivenko-Emetov D
Yaroslav D. Krivenko-Emetov, Andriy I. Smetana
Chemical potential of a hadronic fireball in the freeze-out stage
17 pages, 9 figures, XXI UKRAINIAN SCIENTIFIC AND PRACTICAL CONFERENCE STUDENTS, GRADUATE STUDENTS AND YOUNG SCIENTISTS THEORETICAL AND APPLIED PROBLEMS PHYSICS, MATHEMATICS AND INFORMATICS (May 11 - 12, 2023, Kyiv, Ukraine). arXiv admin note: text overlap with arXiv:2301.00742
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This article explores the van der Waals gas model proposed to describe the hadronic stages of nuclear fireball evolution during the cooling stage. Two different models were proposed for the early and late stages of hadronization. At the initial stage, a two-component meson model consisting of $\pi^0$ and $\pi^+$ mesons was suggested, and at the later stage, a two-component nucleon model consisting of protons and neutrons was proposed. The interaction potential for both models was represented by a rectangular well, and the statistical sum was calculated using the saddle-point method. The analytic expressions for pressure and chemical potentials obtained from the model were compared with the corresponding numerical results of other authors obtained earlier using quantum chromodynamics (QCD) methods. The possibility of applying and using the effective chemical potential is also analyzed.
[ { "created": "Wed, 17 May 2023 06:15:47 GMT", "version": "v1" } ]
2023-05-18
[ [ "Krivenko-Emetov", "Yaroslav D.", "" ], [ "Smetana", "Andriy I.", "" ] ]
This article explores the van der Waals gas model proposed to describe the hadronic stages of nuclear fireball evolution during the cooling stage. Two different models were proposed for the early and late stages of hadronization. At the initial stage, a two-component meson model consisting of $\pi^0$ and $\pi^+$ mesons was suggested, and at the later stage, a two-component nucleon model consisting of protons and neutrons was proposed. The interaction potential for both models was represented by a rectangular well, and the statistical sum was calculated using the saddle-point method. The analytic expressions for pressure and chemical potentials obtained from the model were compared with the corresponding numerical results of other authors obtained earlier using quantum chromodynamics (QCD) methods. The possibility of applying and using the effective chemical potential is also analyzed.
hep-ph/0212245
K. S. Babu
K.S. Babu, Ilia Gogoladze and Kai Wang (Oklahoma State University)
Natural R-Parity, \mu-term, and Fermion Mass Hierarchy From Discrete Gauge Symmetries
22 pages, LaTeX
Nucl.Phys. B660 (2003) 322-342
10.1016/S0550-3213(03)00258-X
OSU-HEP-02-17
hep-ph
null
In the minimal supersymmetric Standard Model with seesaw neutrino masses we show how R-parity can emerge naturally as a discrete gauge symmetry. The same discrete symmetry explains the smallness of the \mu-term (the Higgsino mass parameter) via the Giudice--Masiero mechanism. The discrete gauge anomalies are cancelled by a discrete version of the Green--Schwarz mechanism. The simplest symmetry group is found to be Z_4 with a charge assignment that is compatible with grand unification. Several other Z_N gauge symmetries are found for N=10,12,18,36 etc, with some models employing discrete anomaly cancellation at higher Kac-Moody levels. Allowing for a flavor structure in Z_N, we show that the same gauge symmetry can also explain the observed hierarchy in the fermion masses and mixings.
[ { "created": "Tue, 17 Dec 2002 11:10:02 GMT", "version": "v1" } ]
2010-04-05
[ [ "Babu", "K. S.", "", "Oklahoma State University" ], [ "Gogoladze", "Ilia", "", "Oklahoma State University" ], [ "Wang", "Kai", "", "Oklahoma State University" ] ]
In the minimal supersymmetric Standard Model with seesaw neutrino masses we show how R-parity can emerge naturally as a discrete gauge symmetry. The same discrete symmetry explains the smallness of the \mu-term (the Higgsino mass parameter) via the Giudice--Masiero mechanism. The discrete gauge anomalies are cancelled by a discrete version of the Green--Schwarz mechanism. The simplest symmetry group is found to be Z_4 with a charge assignment that is compatible with grand unification. Several other Z_N gauge symmetries are found for N=10,12,18,36 etc, with some models employing discrete anomaly cancellation at higher Kac-Moody levels. Allowing for a flavor structure in Z_N, we show that the same gauge symmetry can also explain the observed hierarchy in the fermion masses and mixings.
hep-ph/9310349
Tom Gould
K.S. Babu, T.M. Gould, and I.Z. Rothstein
Closing the Windows on Mev Tau Neutrinos
8 pgs. LaTeX (1 uuencoded fig., also available on request), Bartol-930XXX, JHU-TIPAC-930026, UM-TH-93-26
Phys.Lett.B321:140-144,1994
10.1016/0370-2693(94)90340-9
null
hep-ph
null
In this note, we analyze various constraints on the ``visible'' decay modes of a massive $\tau $ neutrino, $\nu_\tau\rightarrow\nu^\prime\,\gamma $ and $\nu_\tau\rightarrow\nu^\prime\, e^+ e^-$, where $\nu^\prime$ is a light neutrino. The BEBC beam dump experiment provides model-independent constraints on these modes. The lifetime for the $\nu^\prime\, e^+e^-$ mode is constrained to be $\tau_{\nu^\prime\, e^+e^-} \ge 0.18~(m_{\nu_\tau}/MeV)~sec.$ We point out that the same experiment implies a similar constraint on the $\nu^\prime\,\gamma$ mode. This results in a new upper limit on the transition magnetic moment of $\nu_\tau$, $\mu_{\rm tran} \le 1.1 \times 10^{-9} (MeV/m_{\nu_\tau})^2 \mu_B $. Furthermore, a limit on the electric charge of $\nu_\tau$ may be obtained, $Q_{\nu_\tau} \le 4 \times 10^{-4}e$. Combining these constraints with those arising from supernova observations and primordial nucleosynthesis calculations, we show that these ``visible'' decays cannot be the dominant decay modes of the $\tau$ neutrino.
[ { "created": "Tue, 26 Oct 1993 03:47:52 GMT", "version": "v1" } ]
2008-11-26
[ [ "Babu", "K. S.", "" ], [ "Gould", "T. M.", "" ], [ "Rothstein", "I. Z.", "" ] ]
In this note, we analyze various constraints on the ``visible'' decay modes of a massive $\tau $ neutrino, $\nu_\tau\rightarrow\nu^\prime\,\gamma $ and $\nu_\tau\rightarrow\nu^\prime\, e^+ e^-$, where $\nu^\prime$ is a light neutrino. The BEBC beam dump experiment provides model-independent constraints on these modes. The lifetime for the $\nu^\prime\, e^+e^-$ mode is constrained to be $\tau_{\nu^\prime\, e^+e^-} \ge 0.18~(m_{\nu_\tau}/MeV)~sec.$ We point out that the same experiment implies a similar constraint on the $\nu^\prime\,\gamma$ mode. This results in a new upper limit on the transition magnetic moment of $\nu_\tau$, $\mu_{\rm tran} \le 1.1 \times 10^{-9} (MeV/m_{\nu_\tau})^2 \mu_B $. Furthermore, a limit on the electric charge of $\nu_\tau$ may be obtained, $Q_{\nu_\tau} \le 4 \times 10^{-4}e$. Combining these constraints with those arising from supernova observations and primordial nucleosynthesis calculations, we show that these ``visible'' decays cannot be the dominant decay modes of the $\tau$ neutrino.
1105.5801
Hao Ma
Hao Ma, Carlos A. Salgado and Konrad Tywoniuk
Medium-induced multi-photon radiation
5 pages, 1 figure. Proceedings of Hot Quarks 2010, La Londe Les Maures, France
J. Phys.: Conf. Ser. 270 012034, 2011
10.1088/1742-6596/270/1/012034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the spectrum of multi-photon radiation off a fast quark in medium in the BDMPS/ASW approach. We reproduce the medium-induced one-photon radiation spectrum in dipole approximation, and go on to calculate the two-photon radiation in the Moli\`{e}re limit. We find that in this limit the LPM effect holds for medium-induced two-photon ladder emission.
[ { "created": "Sun, 29 May 2011 16:37:07 GMT", "version": "v1" } ]
2015-05-28
[ [ "Ma", "Hao", "" ], [ "Salgado", "Carlos A.", "" ], [ "Tywoniuk", "Konrad", "" ] ]
We study the spectrum of multi-photon radiation off a fast quark in medium in the BDMPS/ASW approach. We reproduce the medium-induced one-photon radiation spectrum in dipole approximation, and go on to calculate the two-photon radiation in the Moli\`{e}re limit. We find that in this limit the LPM effect holds for medium-induced two-photon ladder emission.
hep-ph/0412227
Azad Ahmedov
R.Kh.Muradov and A.I.Ahmadov
Contribution superstring Z' boson on the polarization effects in proton-proton collisions
25 pages, 9 figures, LaTeX2e
Central Eur.J.Phys. 3 (2005) 433-455
10.2478/BF02475649
null
hep-ph
null
In this work we investigate the single- and the double- spin asymmetries at the collisions of polarized protons $pp \to (\gamma*, Z^0,Z')+X within the scope of QCD, electroweak interaction and superstring E_6 theory. The helicity amplitude method is used. Analytical expressions for the single- and the double- spin asymmetries are obtained and their dependence from the transverse momentum of lepton pair is investigated at the three different values of invariant masses of lepton pair. Has been extracted pure contribution coming from superstring Z' boson on the single- and double- spin asymmetries. The obtained results allow to investigate the spin structure of the proton.
[ { "created": "Thu, 16 Dec 2004 09:14:54 GMT", "version": "v1" }, { "created": "Fri, 8 Jul 2005 12:28:52 GMT", "version": "v2" } ]
2009-11-10
[ [ "Muradov", "R. Kh.", "" ], [ "Ahmadov", "A. I.", "" ] ]
In this work we investigate the single- and the double- spin asymmetries at the collisions of polarized protons $pp \to (\gamma*, Z^0,Z')+X within the scope of QCD, electroweak interaction and superstring E_6 theory. The helicity amplitude method is used. Analytical expressions for the single- and the double- spin asymmetries are obtained and their dependence from the transverse momentum of lepton pair is investigated at the three different values of invariant masses of lepton pair. Has been extracted pure contribution coming from superstring Z' boson on the single- and double- spin asymmetries. The obtained results allow to investigate the spin structure of the proton.
0810.2572
Cyrille Marquet
Cyrille Marquet
Heavy-quark energy loss in pQCD and SYM plasmas
5 pages, 2 figures, Proceedings of the IIIrd Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions (HotQuarks08), Estes Park, USA, August 18-23 2008
Eur.Phys.J.C62:15-20,2009
10.1140/epjc/s10052-009-1014-2
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider heavy-quark energy loss and pT-broadening in a strongly-coupled N=4 Super Yang Mills (SYM) plasma, and the problem of finite-extend matter is addressed. When expressed in terms of the appropriate saturation momentum, one finds identical parametric forms for the energy loss in pQCD and SYM theory, while pT-broadening is radiation dominated in SYM theory and multiple scattering dominated in pQCD.
[ { "created": "Tue, 14 Oct 2008 22:32:26 GMT", "version": "v1" } ]
2009-07-22
[ [ "Marquet", "Cyrille", "" ] ]
We consider heavy-quark energy loss and pT-broadening in a strongly-coupled N=4 Super Yang Mills (SYM) plasma, and the problem of finite-extend matter is addressed. When expressed in terms of the appropriate saturation momentum, one finds identical parametric forms for the energy loss in pQCD and SYM theory, while pT-broadening is radiation dominated in SYM theory and multiple scattering dominated in pQCD.
hep-ph/9608338
Wolfgang Schaefer
N. N. Nikolaev (1,2,3), W. Schaefer (2), B. G. Zakharov (3) ((1) ITKP Bonn, (2) IKP,KFA-Juelich, (3) Landau Inst.)
Diffractive DIS: back to triple-Regge phenomenology?
18 pages LaTeX, including 6 eps-figures, uses epsfig-macro, revised version: a factor of 1/3 in eq.(10) was corrected, and a more detailed discussion of the effect of the x_Pom-beta correlation added
null
null
KFA-IKP(Th)-1996-06
hep-ph
null
We discuss the factorization breaking effects caused by the contribution to large rapidity gap events from DIS on secondary reggeons. Based on the triple-Regge phenomenology of hadronic diffraction dissociation, we present estimates for the flux and structure function of the f reggeon. The kinematical x_Pom-beta correlation is shown to modify substantially the observed x_Pom dependence of the diffractive structure function. The secondary reggeon and x_Pom-beta correlation effects explain the recent H1 finding of the factorization breaking and resolve the apparent contradiction between the preliminary H1 results and predictions from the color dipole gBFKL approach. We suggest further tests of predictions for diffractive DIS from the gBFKL approach.
[ { "created": "Thu, 15 Aug 1996 16:00:34 GMT", "version": "v1" }, { "created": "Tue, 20 Aug 1996 14:13:30 GMT", "version": "v2" }, { "created": "Fri, 23 Aug 1996 11:49:04 GMT", "version": "v3" } ]
2008-02-03
[ [ "Nikolaev", "N. N.", "" ], [ "Schaefer", "W.", "" ], [ "Zakharov", "B. G.", "" ] ]
We discuss the factorization breaking effects caused by the contribution to large rapidity gap events from DIS on secondary reggeons. Based on the triple-Regge phenomenology of hadronic diffraction dissociation, we present estimates for the flux and structure function of the f reggeon. The kinematical x_Pom-beta correlation is shown to modify substantially the observed x_Pom dependence of the diffractive structure function. The secondary reggeon and x_Pom-beta correlation effects explain the recent H1 finding of the factorization breaking and resolve the apparent contradiction between the preliminary H1 results and predictions from the color dipole gBFKL approach. We suggest further tests of predictions for diffractive DIS from the gBFKL approach.
hep-ph/0204115
Hannes Jung
The Small x Collaboration: Bo Andersson, S. Baranov, J. Bartels, M. Ciafaloni, J. Collins, M. Davidsson, G. Gustafson, H. Jung, L. Joensson, M. Karlsson, M. Kimber, A. Kotikov, J. Kwiecinski, L. Loennblad, G. Miu, G. Salam, M.H. Seymour, T. Sjoestrand, N. Zotov
Small x Phenomenology: Summary and Status
4 tables, 10 figures
Eur.Phys.J.C25:77-101,2002
10.1007/s10052-002-0998-7
null
hep-ph
null
The aim of this paper is to summarize the general status of our understanding of small x physics. It is based on presentations and discussions at an informal meeting on this topic held in Lund, Sweden, in March 2001. This document also marks the founding of an informal collaboration between experimentalists and theoreticians with a special interest in small x physics. This paper is dedicated to the memory of Bo Andersson, who died unexpectedly from a heart attack on March 4th, 2002.
[ { "created": "Wed, 10 Apr 2002 07:29:10 GMT", "version": "v1" }, { "created": "Fri, 17 May 2002 12:15:42 GMT", "version": "v2" } ]
2019-08-17
[ [ "The Small x Collaboration", "", "" ], [ "Andersson", "Bo", "" ], [ "Baranov", "S.", "" ], [ "Bartels", "J.", "" ], [ "Ciafaloni", "M.", "" ], [ "Collins", "J.", "" ], [ "Davidsson", "M.", "" ], [ "...
The aim of this paper is to summarize the general status of our understanding of small x physics. It is based on presentations and discussions at an informal meeting on this topic held in Lund, Sweden, in March 2001. This document also marks the founding of an informal collaboration between experimentalists and theoreticians with a special interest in small x physics. This paper is dedicated to the memory of Bo Andersson, who died unexpectedly from a heart attack on March 4th, 2002.
1106.1997
Juan Rojo
Juan Rojo
Parton Distributions and LHC data
8 pages, 9 figures, proceedings of the "Rencontres de physique de la Vallee d'Aoste", La Thuile, March 2011
null
10.1393/ncc/i2012-11118-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this contribution we briefly report on the progress and open problems in parton distribution functions (PDFs), with emphasis on their implications for LHC phenomenology. Then we study the impact of the recent ATLAS and CMS W lepton asymmetry data on the NNPDF2.1 parton distributions. We show that these data provide the first constrains on PDFs from LHC measurements.
[ { "created": "Fri, 10 Jun 2011 09:55:00 GMT", "version": "v1" } ]
2022-03-02
[ [ "Rojo", "Juan", "" ] ]
In this contribution we briefly report on the progress and open problems in parton distribution functions (PDFs), with emphasis on their implications for LHC phenomenology. Then we study the impact of the recent ATLAS and CMS W lepton asymmetry data on the NNPDF2.1 parton distributions. We show that these data provide the first constrains on PDFs from LHC measurements.
2210.10017
Fayyazuddin Fayyazuddin
Fayyazuddin
W-exchange contribution in hadronic decays of bottom baryon
No figure
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The nonleptonic decays of \Lambda_{b} that are dominated by W exchange are studied. In particular, the decay modes \varLambda_{b}\to\varDelta^{0}D^{0},\varDelta^{-}D^{+},\Sigma^{*-}D_{s}^{+}, \Lambda_{b}\to\Sigma_{c}^{*+}\pi^{-},\Sigma_{c}^{*0}\pi^{0},\Xi_{c}^{*0}K^{0} and \varLambda_{b}\to\Sigma_{c}^{+}\pi^{-} are analyzed. In an another aspect, the decay \Lambda_{b}\to\Lambda_{c}^{+}\pi^{-} in the factorization anstaz is studied. It is shown that factorization contributes to parity-violating (s-wave) amplitude A only. Hence factorization gives asymmetry parameter \alpha=0. However, the dominant contribution to parity conserving (p-wave) amplitude B comes from W exchange, i.e., from the baryon pole, giving asymmetry parameter \alpha=-0.77.
[ { "created": "Tue, 18 Oct 2022 17:36:14 GMT", "version": "v1" }, { "created": "Tue, 17 Jan 2023 03:57:08 GMT", "version": "v2" }, { "created": "Mon, 28 Aug 2023 03:41:05 GMT", "version": "v3" } ]
2023-08-29
[ [ "Fayyazuddin", "", "" ] ]
The nonleptonic decays of \Lambda_{b} that are dominated by W exchange are studied. In particular, the decay modes \varLambda_{b}\to\varDelta^{0}D^{0},\varDelta^{-}D^{+},\Sigma^{*-}D_{s}^{+}, \Lambda_{b}\to\Sigma_{c}^{*+}\pi^{-},\Sigma_{c}^{*0}\pi^{0},\Xi_{c}^{*0}K^{0} and \varLambda_{b}\to\Sigma_{c}^{+}\pi^{-} are analyzed. In an another aspect, the decay \Lambda_{b}\to\Lambda_{c}^{+}\pi^{-} in the factorization anstaz is studied. It is shown that factorization contributes to parity-violating (s-wave) amplitude A only. Hence factorization gives asymmetry parameter \alpha=0. However, the dominant contribution to parity conserving (p-wave) amplitude B comes from W exchange, i.e., from the baryon pole, giving asymmetry parameter \alpha=-0.77.