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2303.07973
Eugen Dizer
Eugen Dizer and Zolt\'an Harman
Hadronic vacuum polarization correction to the bound-electron $g$ factor
null
null
10.1103/PhysRevA.108.042808
null
hep-ph physics.atom-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
The hadronic vacuum polarization correction to the $g$ factor of a bound electron is investigated theoretically. An effective hadronic Uehling potential obtained from measured cross sections of $e^- e^+$ annihilation into hadrons is employed to calculate $g$ factor corrections for low-lying hydrogenic levels. Analytical Dirac-Coulomb wave functions, as well as bound wave functions accounting for the finite nuclear radius are used. Closed formulas for the $g$ factor shift in case of a point-like nucleus are derived. In heavy ions, such effects are found to be much larger than for the free-electron $g$ factor.
[ { "created": "Tue, 14 Mar 2023 15:28:44 GMT", "version": "v1" } ]
2023-11-28
[ [ "Dizer", "Eugen", "" ], [ "Harman", "Zoltán", "" ] ]
The hadronic vacuum polarization correction to the $g$ factor of a bound electron is investigated theoretically. An effective hadronic Uehling potential obtained from measured cross sections of $e^- e^+$ annihilation into hadrons is employed to calculate $g$ factor corrections for low-lying hydrogenic levels. Analytical Dirac-Coulomb wave functions, as well as bound wave functions accounting for the finite nuclear radius are used. Closed formulas for the $g$ factor shift in case of a point-like nucleus are derived. In heavy ions, such effects are found to be much larger than for the free-electron $g$ factor.
hep-ph/9605427
null
A. Rossi
The stability of the MSW solution to the solar neutrino problem with respect to random matter density perturbations
latex file, 10 pages, including 8 postscript figures, Talk given at ``XXXIst Les Rencontres de Moriond- Electroweak Interactions and Unified Theories'', Les Arcs, France - March 16-23, 1996
null
null
FTUV/96-32; IFIC/96-37
hep-ph
null
We present a generalization of the resonant neutrino conversion in matter, including a random component in the matter density profile. The study is focused on the effect of such matter perturbations upon both large and small mixing angle MSW solutions to the solar neutrino problem. This is carried out both for the active-active $\nu_e \ra \nu_{\mu,\tau}$ as well as active-sterile $\nu_e \ra \nu_s$ conversion channels. We find that the small mixing MSW solution is much more stable (especially in $\delta m^2$) than the large mixing solution. Future solar neutrino experiments, such as Borexino, could probe solar matter density noise at the few percent level.
[ { "created": "Tue, 28 May 1996 20:31:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rossi", "A.", "" ] ]
We present a generalization of the resonant neutrino conversion in matter, including a random component in the matter density profile. The study is focused on the effect of such matter perturbations upon both large and small mixing angle MSW solutions to the solar neutrino problem. This is carried out both for the active-active $\nu_e \ra \nu_{\mu,\tau}$ as well as active-sterile $\nu_e \ra \nu_s$ conversion channels. We find that the small mixing MSW solution is much more stable (especially in $\delta m^2$) than the large mixing solution. Future solar neutrino experiments, such as Borexino, could probe solar matter density noise at the few percent level.
hep-ph/0601060
Zhi-Gang Wang
Zhi-Gang Wang, Shao-Long Wan, Wei-Min Yang
Axial form-factor and induced pseudoscalar form-factor of the nucleons
21 pages, 12 figures, revised version
Eur.Phys.J.C47:375-384,2006
10.1140/epjc/s2006-02570-2
null
hep-ph
null
In this article, we calculate the axial and the induced pseudoscalar form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ of the nucleons in the framework of the light-cone QCD sum-rules approach up to twist-6 three valence quark light-cone distribution amplitudes, and observe that the form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ at intermediate and large momentum transfers with $Q^2> 2 GeV^2$ have significant contributions from the end-point (soft) terms. The numerical values for the axial form-factor $G_A(t=-Q^2)$ are compatible with the experimental data and theoretical calculations, for example, the chiral quark models and lattice QCD. The numerical values for the induced pseudoscalar form-factor $G_P(t=-Q^2)$ are compatible with the calculation from the Bethe-Salpeter equation.
[ { "created": "Mon, 9 Jan 2006 10:22:57 GMT", "version": "v1" }, { "created": "Fri, 7 Apr 2006 01:40:35 GMT", "version": "v2" } ]
2009-01-07
[ [ "Wang", "Zhi-Gang", "" ], [ "Wan", "Shao-Long", "" ], [ "Yang", "Wei-Min", "" ] ]
In this article, we calculate the axial and the induced pseudoscalar form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ of the nucleons in the framework of the light-cone QCD sum-rules approach up to twist-6 three valence quark light-cone distribution amplitudes, and observe that the form-factors $G_A(t=-Q^2)$ and $G_P(t=-Q^2)$ at intermediate and large momentum transfers with $Q^2> 2 GeV^2$ have significant contributions from the end-point (soft) terms. The numerical values for the axial form-factor $G_A(t=-Q^2)$ are compatible with the experimental data and theoretical calculations, for example, the chiral quark models and lattice QCD. The numerical values for the induced pseudoscalar form-factor $G_P(t=-Q^2)$ are compatible with the calculation from the Bethe-Salpeter equation.
0809.3390
Gert Aarts
Gert Aarts (Swansea University), Nathan Laurie (Swansea University) and Anders Tranberg (University of Oulu)
Effective convergence of the 2PI-1/N expansion for nonequilibrium quantum fields
4 pages, 4 eps figures
Phys.Rev.D78:125028,2008
10.1103/PhysRevD.78.125028
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The 1/N expansion of the two-particle irreducible effective action offers a powerful approach to study quantum field dynamics far from equilibrium. We investigate the effective convergence of the 1/N expansion in the O(N) model by comparing results obtained numerically in 1+1 dimensions at leading, next-to-leading and next-to-next-to-leading order in 1/N as well as in the weak coupling limit. A comparison in classical statistical field theory, where exact numerical results are available, is made as well. We focus on early-time dynamics and quasi-particle properties far from equilibrium and observe rapid effective convergence already for moderate values of 1/N or the coupling.
[ { "created": "Fri, 19 Sep 2008 14:45:36 GMT", "version": "v1" } ]
2009-01-08
[ [ "Aarts", "Gert", "", "Swansea University" ], [ "Laurie", "Nathan", "", "Swansea University" ], [ "Tranberg", "Anders", "", "University of Oulu" ] ]
The 1/N expansion of the two-particle irreducible effective action offers a powerful approach to study quantum field dynamics far from equilibrium. We investigate the effective convergence of the 1/N expansion in the O(N) model by comparing results obtained numerically in 1+1 dimensions at leading, next-to-leading and next-to-next-to-leading order in 1/N as well as in the weak coupling limit. A comparison in classical statistical field theory, where exact numerical results are available, is made as well. We focus on early-time dynamics and quasi-particle properties far from equilibrium and observe rapid effective convergence already for moderate values of 1/N or the coupling.
hep-ph/0608171
Jan Martin Pawlowski
Holger Gies, Joerg Jaeckel, Jan M. Pawlowski and Christof Wetterich
Do Instantons Like a Colorful Background?
25 pages, 7 figures
Eur.Phys.J.C49:997-1010,2007
10.1140/epjc/s10052-006-0178-2
DESY 06-122, HD-THEP 06-17
hep-ph
null
We investigate chiral symmetry breaking and color symmetry breaking in QCD. The effective potential of the corresponding scalar condensates is discussed in the presence of non-perturbative contributions from the semiclassical one-instanton sector. We concentrate on a color singlet scalar background which can describe chiral condensation, as well as a color octet scalar background which can generate mass for the gluons. Whereas a non-vanishing singlet chiral field is favored by the instantons, we have found no indication for a preference of color octet backgrounds.
[ { "created": "Tue, 15 Aug 2006 15:05:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gies", "Holger", "" ], [ "Jaeckel", "Joerg", "" ], [ "Pawlowski", "Jan M.", "" ], [ "Wetterich", "Christof", "" ] ]
We investigate chiral symmetry breaking and color symmetry breaking in QCD. The effective potential of the corresponding scalar condensates is discussed in the presence of non-perturbative contributions from the semiclassical one-instanton sector. We concentrate on a color singlet scalar background which can describe chiral condensation, as well as a color octet scalar background which can generate mass for the gluons. Whereas a non-vanishing singlet chiral field is favored by the instantons, we have found no indication for a preference of color octet backgrounds.
hep-ph/0504012
Cecilia Jarlskog
C. Jarlskog
A comment on the lepton mixing matrix
null
null
null
null
hep-ph
null
A recent parameterisation scheme developed for the quark mixing matrix is shown to be easily applicable to the lepton mixing matrix as well.
[ { "created": "Sat, 2 Apr 2005 11:07:55 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jarlskog", "C.", "" ] ]
A recent parameterisation scheme developed for the quark mixing matrix is shown to be easily applicable to the lepton mixing matrix as well.
hep-ph/0406322
Sven Heinemeyer
K. Desch, E. Gross, S. Heinemeyer, G. Weiglein, L. Zivkovic
LHC/LC Interplay in the MSSM Higgs Sector
12 pages, 5 figures, minor modifications, version to appear in JHEP
JHEP 0409:062,2004
10.1088/1126-6708/2004/09/062
CERN-PH-TH/2004-101, DCPT/04/54, IPPP/04/27
hep-ph
null
The interplay of prospective experimental information from both the Large Hadron Collider (LHC) and the Linear Collider (LC) in the investigation of the MSSM Higgs sector is analyzed in the SPS~1a and SPS 1b benchmark scenarios. Combining LHC information on the heavy Higgs states of the MSSM with precise measurements of the mass and branching ratios of the lightest CP-even Higgs boson at the LC provides a sensitive consistency test of the MSSM. This allows to set bounds on the trilinear coupling A_t. In a scenario where LHC and LC only detect one light Higgs boson, the prospects for an indirect determination of M_A are investigated. In particular, the impact of the experimental errors of the other SUSY parameters is analyzed in detail. We find that a precision of about 20% (30%) can be achieved for M_A = 600 (800) GeV.
[ { "created": "Tue, 29 Jun 2004 12:10:52 GMT", "version": "v1" }, { "created": "Mon, 27 Sep 2004 16:35:51 GMT", "version": "v2" } ]
2010-02-03
[ [ "Desch", "K.", "" ], [ "Gross", "E.", "" ], [ "Heinemeyer", "S.", "" ], [ "Weiglein", "G.", "" ], [ "Zivkovic", "L.", "" ] ]
The interplay of prospective experimental information from both the Large Hadron Collider (LHC) and the Linear Collider (LC) in the investigation of the MSSM Higgs sector is analyzed in the SPS~1a and SPS 1b benchmark scenarios. Combining LHC information on the heavy Higgs states of the MSSM with precise measurements of the mass and branching ratios of the lightest CP-even Higgs boson at the LC provides a sensitive consistency test of the MSSM. This allows to set bounds on the trilinear coupling A_t. In a scenario where LHC and LC only detect one light Higgs boson, the prospects for an indirect determination of M_A are investigated. In particular, the impact of the experimental errors of the other SUSY parameters is analyzed in detail. We find that a precision of about 20% (30%) can be achieved for M_A = 600 (800) GeV.
2404.12019
Xin-Chen Duan
Xin-Chen Duan, Raymundo Ramos, Yue-Lin Sming Tsai
The relic density and temperature evolution of light dark sector
38 pages, 10 figures
null
null
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have developed a set of four fully coupled Boltzmann equations to precisely determine the relic density and temperature of dark matter by including three distinct sectors: dark matter, light scalar, and standard model sectors. The intricacies of heat transfer between DM and the SM sector through a light scalar particle are explored, inspired by stringent experimental constraints on the scalar-Higgs mixing angle and the DM-scalar coupling. Three distinct sectors emerge prior to DM freeze-out, requiring fully coupled Boltzmann equations to accurately compute relic density. Investigation of forbidden, resonance, and secluded DM scenarios demonstrates significant deviations between established methods and the novel approach with fully coupled Boltzmann equations. Despite increased computational demands, this emphasizes the need for improved precision in relic density calculations, underlining the importance of incorporating these equations in comprehensive analyses.
[ { "created": "Thu, 18 Apr 2024 09:12:46 GMT", "version": "v1" } ]
2024-04-19
[ [ "Duan", "Xin-Chen", "" ], [ "Ramos", "Raymundo", "" ], [ "Tsai", "Yue-Lin Sming", "" ] ]
We have developed a set of four fully coupled Boltzmann equations to precisely determine the relic density and temperature of dark matter by including three distinct sectors: dark matter, light scalar, and standard model sectors. The intricacies of heat transfer between DM and the SM sector through a light scalar particle are explored, inspired by stringent experimental constraints on the scalar-Higgs mixing angle and the DM-scalar coupling. Three distinct sectors emerge prior to DM freeze-out, requiring fully coupled Boltzmann equations to accurately compute relic density. Investigation of forbidden, resonance, and secluded DM scenarios demonstrates significant deviations between established methods and the novel approach with fully coupled Boltzmann equations. Despite increased computational demands, this emphasizes the need for improved precision in relic density calculations, underlining the importance of incorporating these equations in comprehensive analyses.
1807.02204
C. A. de S. Pires
J. G. Rodrigues, A. C. O. Santos, J. G. Ferreira Jr, C. A. de S. Pires
Neutrino masses, cosmological inflation and dark matter in a $U(1)_{B-L}$ model with type II seesaw mechanism
minor changes, 19 pages, 9 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we implement the type II seesaw mechanism into the framework of the $U(1)_{B-L}$ gauge model. As main gain, the right-handed neutrinos of the model get free to play the role of the dark matter of the universe. As side effect, the model realizes Higgs inflation without problem with loss of unitarity.
[ { "created": "Fri, 6 Jul 2018 00:23:25 GMT", "version": "v1" }, { "created": "Mon, 25 Mar 2019 13:58:06 GMT", "version": "v2" }, { "created": "Thu, 11 Jul 2019 22:32:23 GMT", "version": "v3" } ]
2019-07-15
[ [ "Rodrigues", "J. G.", "" ], [ "Santos", "A. C. O.", "" ], [ "Ferreira", "J. G.", "Jr" ], [ "Pires", "C. A. de S.", "" ] ]
In this work we implement the type II seesaw mechanism into the framework of the $U(1)_{B-L}$ gauge model. As main gain, the right-handed neutrinos of the model get free to play the role of the dark matter of the universe. As side effect, the model realizes Higgs inflation without problem with loss of unitarity.
hep-ph/9610208
null
Joao P. Silva (CFNUL) and L. Wolfenstein (CMU)
Detecting New Physics from CP-violating phase measurements in B decays
6 pages, Latex, no figures
Phys.Rev. D55 (1997) 5331-5333
10.1103/PhysRevD.55.5331
CFNUL/96-09 and CMU-HEP96-13
hep-ph
null
The standard CKM model can be tested and New Physics detected using only CP-violating phase measurements in B decays. This requires the measurement of a phase factor which is small in the Standard Model, in addition to the usual large phases $\beta$ and $\gamma$. We also point out that identifying violations of the unitarity of the CKM matrix is rather difficult, and cannot be done with phase measurements alone.
[ { "created": "Tue, 1 Oct 1996 13:50:07 GMT", "version": "v1" } ]
2016-09-06
[ [ "Silva", "Joao P.", "", "CFNUL" ], [ "Wolfenstein", "L.", "", "CMU" ] ]
The standard CKM model can be tested and New Physics detected using only CP-violating phase measurements in B decays. This requires the measurement of a phase factor which is small in the Standard Model, in addition to the usual large phases $\beta$ and $\gamma$. We also point out that identifying violations of the unitarity of the CKM matrix is rather difficult, and cannot be done with phase measurements alone.
hep-ph/9702328
Wolfgang Schweiger
G. Folberth, R. Rossmann and W. Schweiger (Graz U.)
Exclusive photo- and electroproduction of mesons in the GeV region
10 pages, LaTeX document, uses sprocl.sty style file, 5 embedded eps figures. Contribution presented by W. Schweiger at the DIQUARKS III Workshop, Turin, Italy, 28-30 Oct 1996
null
null
UNIGRAZ-UTP 12-02-97
hep-ph
null
We consider the reactions gamma p --> M B, with M B being either K+ Lambda, K+ Sigma0, or Pi n, within a diquark model which is based on perturbative QCD. The model parameters and the quark-diquark distribution amplitudes of the baryons are taken from previous investigations of electromagnetic baryon form factors and Compton-scattering off protons. Reasonable agreement with the few existing photoproduction data at large momentum transfer is found for meson distribution amplitudes compatible with the asymptotic one (proportional to x (1-x)). We present also first results for hard electroproduction of the K+ Lambda final state. Our predictions exhibit some characteristic features which could easily be tested in forthcoming electroproduction experiments.
[ { "created": "Thu, 13 Feb 1997 16:39:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Folberth", "G.", "", "Graz U." ], [ "Rossmann", "R.", "", "Graz U." ], [ "Schweiger", "W.", "", "Graz U." ] ]
We consider the reactions gamma p --> M B, with M B being either K+ Lambda, K+ Sigma0, or Pi n, within a diquark model which is based on perturbative QCD. The model parameters and the quark-diquark distribution amplitudes of the baryons are taken from previous investigations of electromagnetic baryon form factors and Compton-scattering off protons. Reasonable agreement with the few existing photoproduction data at large momentum transfer is found for meson distribution amplitudes compatible with the asymptotic one (proportional to x (1-x)). We present also first results for hard electroproduction of the K+ Lambda final state. Our predictions exhibit some characteristic features which could easily be tested in forthcoming electroproduction experiments.
hep-ph/9604385
Lorenzo Magnea
L. Magnea and E. Maina
QCD corrections to the production of a heavy quark pair plus a hard photon in $e^+ e^-$ annihilation
12 pages, 5 figures, LaTeX
Phys.Lett. B385 (1996) 395-403
10.1016/0370-2693(96)00888-X
DFTT 14/96, NORDITA 96/25-P
hep-ph
null
We present complete results for the $O(\alpha_s)$ corrections to the production of a heavy quark pair plus a hard photon, in $e^+ e^-$ annihilation, including both photon and $Z$ intermediate states. Virtual corrections are calculated analytically in $4 - 2 \epsilon$ dimensions, together with the soft approximation to the real emission diagrams. After cancellation of infrared divergences, real and virtual contributions are combined numerically to obtain the cross section for the production of two heavy quark jets plus a hard photon in next-to-leading order. The resulting fully differential cross section can be used to construct arbitrary distributions with the desired experimental cuts.
[ { "created": "Mon, 22 Apr 1996 16:25:13 GMT", "version": "v1" } ]
2009-10-28
[ [ "Magnea", "L.", "" ], [ "Maina", "E.", "" ] ]
We present complete results for the $O(\alpha_s)$ corrections to the production of a heavy quark pair plus a hard photon, in $e^+ e^-$ annihilation, including both photon and $Z$ intermediate states. Virtual corrections are calculated analytically in $4 - 2 \epsilon$ dimensions, together with the soft approximation to the real emission diagrams. After cancellation of infrared divergences, real and virtual contributions are combined numerically to obtain the cross section for the production of two heavy quark jets plus a hard photon in next-to-leading order. The resulting fully differential cross section can be used to construct arbitrary distributions with the desired experimental cuts.
1911.00345
Victor Goncalves
V. P. Goncalves, G. Sampaio dos Santos, C. R. Sena
Single inclusive jet photoproduction at very forward rapidities in $pp$ and $pPb$ collisions at the LHC
9 pages, 5 figures. arXiv admin note: text overlap with arXiv:1711.04497
null
10.1140/epjc/s10052-020-8095-3
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The particle production at very forward rapidities is expected to be sensitive to the non-linear effects in the QCD dynamics at high energies. In this paper we present, for the first time, the predictions of the Color Dipole formalism for the single inclusive jet photoproduction in $pp$ and $pPb$ collisions considering the very forward rapidities probed by the CMS-CASTOR calorimeter, which will be characterized by a jet in the rapidity range of $5.2 \le Y \le 6.6$, a rapidity gap in the rapidity range probed by the central CMS detector and one of the incident hadrons remaining intact in the final state. The transverse momentum distributions are estimated considering the more recent phenomenological models for the dipole-proton scattering amplitude, which are based on the Color Glass Condensate formalism and are able to describe the inclusive and exclusive $ep$ HERA data. Our results indicate that a future experimental analysis of this process is, in principle, feasible and useful to constrain the description of the QCD dynamics at high energies.
[ { "created": "Thu, 31 Oct 2019 10:17:27 GMT", "version": "v1" } ]
2020-07-15
[ [ "Goncalves", "V. P.", "" ], [ "Santos", "G. Sampaio dos", "" ], [ "Sena", "C. R.", "" ] ]
The particle production at very forward rapidities is expected to be sensitive to the non-linear effects in the QCD dynamics at high energies. In this paper we present, for the first time, the predictions of the Color Dipole formalism for the single inclusive jet photoproduction in $pp$ and $pPb$ collisions considering the very forward rapidities probed by the CMS-CASTOR calorimeter, which will be characterized by a jet in the rapidity range of $5.2 \le Y \le 6.6$, a rapidity gap in the rapidity range probed by the central CMS detector and one of the incident hadrons remaining intact in the final state. The transverse momentum distributions are estimated considering the more recent phenomenological models for the dipole-proton scattering amplitude, which are based on the Color Glass Condensate formalism and are able to describe the inclusive and exclusive $ep$ HERA data. Our results indicate that a future experimental analysis of this process is, in principle, feasible and useful to constrain the description of the QCD dynamics at high energies.
1101.1976
Archana Anandakrishnan
Archana Anandakrishnan and Stuart Raby
Gauge Coupling Unification in Heterotic String Models with Gauge Mediated SUSY Breaking
21 pages, 3 figures
Phys.Rev.D83:075008,2011
10.1103/PhysRevD.83.075008
OHSTPY-HEP-T-10-007
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the weak scale MSSM spectrum starting from a heterotic string theory compactified on an anisotropic orbifold. Supersymmetry breaking is mediated by vector-like exotics that arise naturally in heterotic string theories. The messengers that mediate SUSY breaking come in incomplete GUT multiplets and give rise to non-universal gaugino masses at the GUT scale. Models with non-universal gaugino masses at the GUT scale have the attractive feature of allowing for precision gauge coupling unification at the GUT scale with negligible contributions from threshold corrections near the unification scale. The unique features of the MSSM spectrum are light gluinos and also large mass differences between the lightest and the next-to-lightest neutralinos and charginos which could lead to interesting signatures at the colliders.
[ { "created": "Mon, 10 Jan 2011 21:31:51 GMT", "version": "v1" } ]
2011-04-22
[ [ "Anandakrishnan", "Archana", "" ], [ "Raby", "Stuart", "" ] ]
We calculate the weak scale MSSM spectrum starting from a heterotic string theory compactified on an anisotropic orbifold. Supersymmetry breaking is mediated by vector-like exotics that arise naturally in heterotic string theories. The messengers that mediate SUSY breaking come in incomplete GUT multiplets and give rise to non-universal gaugino masses at the GUT scale. Models with non-universal gaugino masses at the GUT scale have the attractive feature of allowing for precision gauge coupling unification at the GUT scale with negligible contributions from threshold corrections near the unification scale. The unique features of the MSSM spectrum are light gluinos and also large mass differences between the lightest and the next-to-lightest neutralinos and charginos which could lead to interesting signatures at the colliders.
hep-ph/0207258
Dr A. N. Mitra
A.N. Mitra
Minimum Of QCD Effective Action As Test Of QCD Confinement Parameter
LaTex file, 12 pages on dvi
null
null
null
hep-ph
null
A new approach to the non-perturbative regime of QCD is proposed by introducing a (non-hermitian) field $B$ related to the usual gluon field $A$ by $B_\mu$ = $(1+ \sigma \partial_m) A_\mu$ where $m$ goes to zero after differentiation, and $\sigma$ is a parameter which `runs' with momentum ($k$). An exact treatment yields a structure $[1/k^2 + 2\mu^2/k^4]$ for the gluon propagator, where $\sigma^2$ =$\pi k^4/9\mu^2\alpha_s$, showing $linear$ confinement in the instantaneous limit. This propagator was recently employed to evaluate some basic condensates and their temperature dependence (in the cosmological context), which were all reproduced for $\mu = 1GeV$ (termed the `confinement scale parameter'), in association with the QCD scale parameter $\Lambda_{qcd}= 200 MeV$ [hep-ph/0109278]. This paper seeks to provide a formal basis for the ratio $\Lambda_{qcd} / \mu$ by employing the minimality condition for the $integrated$ effective action $\Gamma$, up to the 2-loop level, using the Cornwall-Jackiw formalism for composite operators. To that end the mass function $m(p)$, determined via the Schwinger-Dyson equation (as a zero of the functional derivative of $\Gamma$ w.r.t $S_F'$), acts as a feeder, and the stationarity condition on $\Gamma$ as function of $\mu$ and $\alpha_s(\mu)$ gives the ratio $\Lambda /\mu$ = 0.246, in fair accord with the value 0.20 given above. Inclusion of a two-loop $\Gamma$ is crucial for the agreement. \\ Keywords: confinement scale, QCD effective action, minimality condition, $B$-field.
[ { "created": "Mon, 22 Jul 2002 07:13:51 GMT", "version": "v1" }, { "created": "Tue, 31 Dec 2002 19:13:23 GMT", "version": "v2" } ]
2007-05-23
[ [ "Mitra", "A. N.", "" ] ]
A new approach to the non-perturbative regime of QCD is proposed by introducing a (non-hermitian) field $B$ related to the usual gluon field $A$ by $B_\mu$ = $(1+ \sigma \partial_m) A_\mu$ where $m$ goes to zero after differentiation, and $\sigma$ is a parameter which `runs' with momentum ($k$). An exact treatment yields a structure $[1/k^2 + 2\mu^2/k^4]$ for the gluon propagator, where $\sigma^2$ =$\pi k^4/9\mu^2\alpha_s$, showing $linear$ confinement in the instantaneous limit. This propagator was recently employed to evaluate some basic condensates and their temperature dependence (in the cosmological context), which were all reproduced for $\mu = 1GeV$ (termed the `confinement scale parameter'), in association with the QCD scale parameter $\Lambda_{qcd}= 200 MeV$ [hep-ph/0109278]. This paper seeks to provide a formal basis for the ratio $\Lambda_{qcd} / \mu$ by employing the minimality condition for the $integrated$ effective action $\Gamma$, up to the 2-loop level, using the Cornwall-Jackiw formalism for composite operators. To that end the mass function $m(p)$, determined via the Schwinger-Dyson equation (as a zero of the functional derivative of $\Gamma$ w.r.t $S_F'$), acts as a feeder, and the stationarity condition on $\Gamma$ as function of $\mu$ and $\alpha_s(\mu)$ gives the ratio $\Lambda /\mu$ = 0.246, in fair accord with the value 0.20 given above. Inclusion of a two-loop $\Gamma$ is crucial for the agreement. \\ Keywords: confinement scale, QCD effective action, minimality condition, $B$-field.
1702.06996
Pier Paolo Giardino
Pier Paolo Giardino, Cen Zhang
Probing the top-quark width using the charge identification of $b$ jets
5 pages, 3 figures; V2: Journal version
Phys. Rev. D 96, 011901 (2017)
10.1103/PhysRevD.96.011901
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new method for measuring the top-quark width based on the on-/off-shell ratio of $b$-charge asymmetry in $pp\to Wbj$ production at the LHC. The charge asymmetry removes virtually all backgrounds and related uncertainties, while remaining systematic and theoretical uncertainties can be taken under control by the ratio of cross sections. Limited only by statistical error, in an optimistic scenario, we find that our approach leads to good precision at high integrated luminosity, at a few hundred MeV assuming 300-3000 fb$^{-1}$ at the LHC. The approach directly probes the total width, in such a way that model-dependence can be minimized. It is complementary to existing cross section measurements which always leave a degeneracy between the total rate and the branching ratio, and provides valuable information about the properties of the top quark. The proposal opens up new opportunities for precision top measurements using a $b$-charge identification algorithm.
[ { "created": "Wed, 22 Feb 2017 20:34:24 GMT", "version": "v1" }, { "created": "Thu, 20 Jul 2017 15:44:38 GMT", "version": "v2" } ]
2017-07-26
[ [ "Giardino", "Pier Paolo", "" ], [ "Zhang", "Cen", "" ] ]
We propose a new method for measuring the top-quark width based on the on-/off-shell ratio of $b$-charge asymmetry in $pp\to Wbj$ production at the LHC. The charge asymmetry removes virtually all backgrounds and related uncertainties, while remaining systematic and theoretical uncertainties can be taken under control by the ratio of cross sections. Limited only by statistical error, in an optimistic scenario, we find that our approach leads to good precision at high integrated luminosity, at a few hundred MeV assuming 300-3000 fb$^{-1}$ at the LHC. The approach directly probes the total width, in such a way that model-dependence can be minimized. It is complementary to existing cross section measurements which always leave a degeneracy between the total rate and the branching ratio, and provides valuable information about the properties of the top quark. The proposal opens up new opportunities for precision top measurements using a $b$-charge identification algorithm.
0706.3027
Olga Shekhovtsova
G. Pancheri, O.Shekhovtsova, G. Venanzoni
Final state radiation and a possibility to test a pion-photon interaction model near two-pion threshold
16 pages, 6 figures
J.Exp.Theor.Phys.106:470-480,2008
10.1134/S1063776108030072
null
hep-ph
null
Final state radiation in the process $e^+e^-\to\pi^+\pi^-$ is considered for the cuts used in the analysis of KLOE data at large angles. By means of a Monte Carlo event generator FEVA, effects of non-pointlike behaviour of pions are estimated in the framework of Resonance Perturbation Theory. An additional complication related with the $\phi$ meson intermediate state is taken into account and the corresponding contributions (the direct decay $\phi\to\pi^+\pi^-\gamma$ and the double resonance decay $\phi\to\rho^\pm\pi^\mp\to\pi^+\pi^-\gamma$) are added to FEVA. A method to test effects of non-pointlike behaviour of pions in a model-independent way is proposed.
[ { "created": "Wed, 20 Jun 2007 17:03:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pancheri", "G.", "" ], [ "Shekhovtsova", "O.", "" ], [ "Venanzoni", "G.", "" ] ]
Final state radiation in the process $e^+e^-\to\pi^+\pi^-$ is considered for the cuts used in the analysis of KLOE data at large angles. By means of a Monte Carlo event generator FEVA, effects of non-pointlike behaviour of pions are estimated in the framework of Resonance Perturbation Theory. An additional complication related with the $\phi$ meson intermediate state is taken into account and the corresponding contributions (the direct decay $\phi\to\pi^+\pi^-\gamma$ and the double resonance decay $\phi\to\rho^\pm\pi^\mp\to\pi^+\pi^-\gamma$) are added to FEVA. A method to test effects of non-pointlike behaviour of pions in a model-independent way is proposed.
hep-ph/0011333
null
Krishna Rajagopal (MIT) and Frank Wilczek (MIT)
The Condensed Matter Physics of QCD
91 pages. latex with sprocl.sty. 6 eps figures. To appear as Chapter 35 in the Festschrift in honor of B. L. Ioffe, "At the Frontier of Particle Physics / Handbook of QCD", M. Shifman, ed., (World Scientific). v2: References corrected
null
10.1142/9789812810458_0043
MIT-CTP-3049
hep-ph astro-ph cond-mat hep-th nucl-th
null
Important progress in understanding the behavior of hadronic matter at high density has been achieved recently, by adapting the techniques of condensed matter theory. At asymptotic densities, the combination of asymptotic freedom and BCS theory make a rigorous analysis possible. New phases of matter with remarkable properties are predicted. They provide a theoretical laboratory within which chiral symmetry breaking and confinement can be studied at weak coupling. They may also play a role in the description of neutron star interiors. We discuss the phase diagram of QCD as a function of temperature and density, and close with a look at possible astrophysical signatures.
[ { "created": "Mon, 27 Nov 2000 23:57:58 GMT", "version": "v1" }, { "created": "Wed, 13 Dec 2000 01:49:27 GMT", "version": "v2" } ]
2016-11-23
[ [ "Rajagopal", "Krishna", "", "MIT" ], [ "Wilczek", "Frank", "", "MIT" ] ]
Important progress in understanding the behavior of hadronic matter at high density has been achieved recently, by adapting the techniques of condensed matter theory. At asymptotic densities, the combination of asymptotic freedom and BCS theory make a rigorous analysis possible. New phases of matter with remarkable properties are predicted. They provide a theoretical laboratory within which chiral symmetry breaking and confinement can be studied at weak coupling. They may also play a role in the description of neutron star interiors. We discuss the phase diagram of QCD as a function of temperature and density, and close with a look at possible astrophysical signatures.
1011.3606
He Zhang
Werner Rodejohann, He Zhang
Higgs triplets at like-sign linear colliders and neutrino mixing
8 pages, 6 figures
Phys.Rev.D83:073005,2011
10.1103/PhysRevD.83.073005
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phenomenology of the type-II seesaw model at a linear e^-e^- collider. We show that the process e^-e^- \rightarrow alpha^-beta^- (alpha, beta = e, mu, tau being charged leptons) mediated by a doubly charged scalar is very sensitive to the neutrino parameters, in particular the absolute neutrino mass scale and the Majorana CP-violating phases. We identify the regions in parameter space in which appreciable collider signatures in the channel with two like-sign muons in the final state are possible. This includes Higgs triplet masses beyond the reach of the LHC.
[ { "created": "Tue, 16 Nov 2010 08:24:25 GMT", "version": "v1" } ]
2011-05-12
[ [ "Rodejohann", "Werner", "" ], [ "Zhang", "He", "" ] ]
We study the phenomenology of the type-II seesaw model at a linear e^-e^- collider. We show that the process e^-e^- \rightarrow alpha^-beta^- (alpha, beta = e, mu, tau being charged leptons) mediated by a doubly charged scalar is very sensitive to the neutrino parameters, in particular the absolute neutrino mass scale and the Majorana CP-violating phases. We identify the regions in parameter space in which appreciable collider signatures in the channel with two like-sign muons in the final state are possible. This includes Higgs triplet masses beyond the reach of the LHC.
2012.10893
Yu Zhang
Yu Zhang, Zhuo Yu, Qiang Yang, Mao Song, Gang Li, Ran Ding
Probing the $L_\mu-L_\tau$ gauge boson at electron colliders
12 pages, 10 figures. Accepted for publication in Physical Review D
Phys. Rev. D 103, 015008 (2021)
10.1103/PhysRevD.103.015008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the minimal $U(1)_{L_\mu-L_\tau}$ model with extra heavy vector-like leptons or charged scalars. By studying the kinetic mixing between $U(1)_{L_\mu-L_\tau}$ gauge boson $Z^\prime$ and standard model photon, which is absent at tree level and will arise at one loop level due to $\mu$, $\tau$ and new heavy charged leptons or scalars, the interesting behavior is shown. It can provide possibility for visible signatures of new heavy particles. We propose to search for $Z^\prime$ at electron collider experiments, such as Belle II, BESIII and future Super Tau Charm Factory (STCF), using the monophoton final state. The parameter space of $Z^\prime$ is probed, and scanned by its gauge coupling constant $g_{Z^\prime}$ and mass $m_{Z^\prime}$. We find that electron colliders have sensitivity to the previously unexplored parameter space for $Z^\prime$ with MeV-GeV mass. Future STCF experiments with $\sqrt s=2-7$ GeV can exclude the anomalous muon magnetic moment favored area when $m_{Z^\prime}<5$ GeV with the luminosity of 30 ab$^{-1}$. For $m_{Z^\prime} < 2m_\mu$, $g_{Z^\prime}$ can be down to $4.2\times 10^{-5}$ at 2 GeV STCF.
[ { "created": "Sun, 20 Dec 2020 11:33:48 GMT", "version": "v1" } ]
2021-01-13
[ [ "Zhang", "Yu", "" ], [ "Yu", "Zhuo", "" ], [ "Yang", "Qiang", "" ], [ "Song", "Mao", "" ], [ "Li", "Gang", "" ], [ "Ding", "Ran", "" ] ]
We investigate the minimal $U(1)_{L_\mu-L_\tau}$ model with extra heavy vector-like leptons or charged scalars. By studying the kinetic mixing between $U(1)_{L_\mu-L_\tau}$ gauge boson $Z^\prime$ and standard model photon, which is absent at tree level and will arise at one loop level due to $\mu$, $\tau$ and new heavy charged leptons or scalars, the interesting behavior is shown. It can provide possibility for visible signatures of new heavy particles. We propose to search for $Z^\prime$ at electron collider experiments, such as Belle II, BESIII and future Super Tau Charm Factory (STCF), using the monophoton final state. The parameter space of $Z^\prime$ is probed, and scanned by its gauge coupling constant $g_{Z^\prime}$ and mass $m_{Z^\prime}$. We find that electron colliders have sensitivity to the previously unexplored parameter space for $Z^\prime$ with MeV-GeV mass. Future STCF experiments with $\sqrt s=2-7$ GeV can exclude the anomalous muon magnetic moment favored area when $m_{Z^\prime}<5$ GeV with the luminosity of 30 ab$^{-1}$. For $m_{Z^\prime} < 2m_\mu$, $g_{Z^\prime}$ can be down to $4.2\times 10^{-5}$ at 2 GeV STCF.
hep-ph/0308280
Axel Weber
Axel Weber
Relativistic Bound States
9 pages, LaTeX, 3 pspicture diagrams, 3 postscript figures, uses aipxfm.sty. Talk delivered at the X Mexican School of Particles and Fields, Playa del Carmen, Mexico, 2002
AIP Conf.Proc. 670 (2003) 210-218
10.1063/1.1594337
null
hep-ph
null
In this contribution, I will give a brief survey of present techniques to treat the bound state problem in relativistic quantum field theories. In particular, I will discuss the Bethe-Salpeter equation, various quasi-potential equations, the Feynman-Schwinger representation, and similarity transformation methods for Hamiltonian approaches in light-front quantization. Finally, I will comment on a related similarity transformation in the usual equal-time quantized theory.
[ { "created": "Wed, 27 Aug 2003 14:04:33 GMT", "version": "v1" } ]
2009-11-10
[ [ "Weber", "Axel", "" ] ]
In this contribution, I will give a brief survey of present techniques to treat the bound state problem in relativistic quantum field theories. In particular, I will discuss the Bethe-Salpeter equation, various quasi-potential equations, the Feynman-Schwinger representation, and similarity transformation methods for Hamiltonian approaches in light-front quantization. Finally, I will comment on a related similarity transformation in the usual equal-time quantized theory.
hep-ph/9803309
Lisi Eligio
G.L. Fogli, E. Lisi, and D. Montanino (Bari U. & INFN, Bari)
Discriminating MSW solutions to the solar neutrino problem with flux-independent information at SuperKamiokande and SNO
10 pages (RevTeX) + 2 figures (postscript). Requires epsfig.sty
Phys.Lett.B434:333-339,1998
10.1016/S0370-2693(98)00678-9
BARI-TH/296-98
hep-ph astro-ph
null
The two possible Mikheyev-Smirnov-Wolfenstein (MSW) solutions of the solar neutrino problem (one at small and the other at large mixing angle), up to now tested mainly through absolute neutrino flux measurements, require flux-independent tests both for a decisive confirmation and for their discrimination. To this end, we perform a joint analysis of various flux-independent observables that can be measured at the SuperKamiokande and Sudbury Neutrino Observatory (SNO) experiments. In particular, we analyze the recent data collected at SuperKamiokande after 374 days of operation, work out the corresponding predictions for SNO, and study the interplay between SuperKamiokande and SNO observables. It is shown how, by using only flux-independent observables from SuperKamiokande and SNO, one can discriminate between the two MSW solutions and separate them from the no oscillation case.
[ { "created": "Wed, 11 Mar 1998 15:31:22 GMT", "version": "v1" } ]
2009-10-07
[ [ "Fogli", "G. L.", "", "Bari U. & INFN, Bari" ], [ "Lisi", "E.", "", "Bari U. & INFN, Bari" ], [ "Montanino", "D.", "", "Bari U. & INFN, Bari" ] ]
The two possible Mikheyev-Smirnov-Wolfenstein (MSW) solutions of the solar neutrino problem (one at small and the other at large mixing angle), up to now tested mainly through absolute neutrino flux measurements, require flux-independent tests both for a decisive confirmation and for their discrimination. To this end, we perform a joint analysis of various flux-independent observables that can be measured at the SuperKamiokande and Sudbury Neutrino Observatory (SNO) experiments. In particular, we analyze the recent data collected at SuperKamiokande after 374 days of operation, work out the corresponding predictions for SNO, and study the interplay between SuperKamiokande and SNO observables. It is shown how, by using only flux-independent observables from SuperKamiokande and SNO, one can discriminate between the two MSW solutions and separate them from the no oscillation case.
hep-ph/0609227
Michael Lublinsky
Alex Kovner and Michael Lublinsky
One gluon, two gluon: multigluon production via high energy evolution
32 pages, one reference corrected. to appear in JHEP
JHEP0611:083,2006
10.1088/1126-6708/2006/11/083
null
hep-ph
null
We develop an approach for calculating the inclusive multigluon production within the JIMWLK high energy evolution. We give a formal expression of multigluon cross section in terms of a generating functional for arbitrary number of gluons $n$. In the dipole limit the expression simplifies dramatically. We recover the previously known results for single and double gluon inclusive cross section and generalize those for arbitrary multigluon amplitude in terms of Feynman diagramms of Pomeron - like objects coupled to external rapidity dependent field $s(\eta)$. We confirm the conclusion that the AGK cutting rules in general are violated in multigluon production. However we present an argument to the effect that for doubly inclusive cross section the AGK diagramms give the leading contribution at high energy, while genuine violation only occurs for triple and higher inclusive gluon production. We discuss some general properties of our expressions and suggest a line of argument to simplify the approach further.
[ { "created": "Thu, 21 Sep 2006 19:30:42 GMT", "version": "v1" }, { "created": "Sat, 25 Nov 2006 02:03:28 GMT", "version": "v2" } ]
2009-11-11
[ [ "Kovner", "Alex", "" ], [ "Lublinsky", "Michael", "" ] ]
We develop an approach for calculating the inclusive multigluon production within the JIMWLK high energy evolution. We give a formal expression of multigluon cross section in terms of a generating functional for arbitrary number of gluons $n$. In the dipole limit the expression simplifies dramatically. We recover the previously known results for single and double gluon inclusive cross section and generalize those for arbitrary multigluon amplitude in terms of Feynman diagramms of Pomeron - like objects coupled to external rapidity dependent field $s(\eta)$. We confirm the conclusion that the AGK cutting rules in general are violated in multigluon production. However we present an argument to the effect that for doubly inclusive cross section the AGK diagramms give the leading contribution at high energy, while genuine violation only occurs for triple and higher inclusive gluon production. We discuss some general properties of our expressions and suggest a line of argument to simplify the approach further.
hep-ph/9909454
Yutaka Sakamura
Yutaka Sakamura
Spontaneous CP Violation in Large Extra Dimensions
LaTeX file, 9 page, 3 eps figures, some changes included
null
null
TIT/HEP-429
hep-ph
null
We show that in the context of large extra dimensions enough CP violation can be obtained from the spontaneous breaking in a simple non-SUSY model, which is usually considered not to cause the spontaneous CP violation. We estimate \epsilon_{K} in our scenario to be of order 10^{-3} consistent with the experimental value. We also propose a modification to the see-saw mechanism and axion scenario to match with our model.
[ { "created": "Tue, 21 Sep 1999 12:28:43 GMT", "version": "v1" }, { "created": "Mon, 29 Nov 1999 09:16:51 GMT", "version": "v2" } ]
2007-05-23
[ [ "Sakamura", "Yutaka", "" ] ]
We show that in the context of large extra dimensions enough CP violation can be obtained from the spontaneous breaking in a simple non-SUSY model, which is usually considered not to cause the spontaneous CP violation. We estimate \epsilon_{K} in our scenario to be of order 10^{-3} consistent with the experimental value. We also propose a modification to the see-saw mechanism and axion scenario to match with our model.
1301.4641
Peiwen Wu
Junjie Cao, Lei Wu, Peiwen Wu, Jin Min Yang
The Z+photon and diphoton decays of the Higgs boson as a joint probe of low energy SUSY models at LHC
28 pages, 6 figures
null
10.1007/JHEP09(2013)043
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In light of recent remarkable progress in Higgs search at the LHC, we study the rare decay process $h \to Z\gamma$ and show its correlation with the decay $h \to \gamma\gamma$ in low energy SUSY models such as CMSSM, MSSM, NMSSM and nMSSM. Under various experimental constraints, we scan the parameter space of each model, and present in the allowed parameter space the SUSY predictions on the $Z\gamma$ and $\gamma\gamma$ signal rates in the Higgs production at the LHC and future e+e- linear colliders. We have following observations: (i) Compared with the SM prediction, the $Z\gamma$ and $\gamma\gamma$ signal rates in the CMSSM are both slightly suppressed; (ii) In the MSSM, both the $Z\gamma$ and $\gamma\gamma$ rates can be either enhanced or suppressed, and in optimal case, the enhancement factors can reach 1.2 and 2 respectively; (iii) In the NMSSM, the $Z\gamma$ and $\gamma\gamma$ signal rates normalized by their SM predictions are strongly correlated, and vary from 0.2 to 2; (iv) In the nMSSM, the $Z\gamma$ and $\gamma\gamma$ rates are greatly reduced. Since the correlation behavior between the Z\gamma signal and the \gamma\gamma signal is so model-dependent, it may be used to distinguish the models in future experiments.
[ { "created": "Sun, 20 Jan 2013 09:18:13 GMT", "version": "v1" }, { "created": "Tue, 19 Mar 2013 06:34:05 GMT", "version": "v2" }, { "created": "Sun, 18 Aug 2013 11:27:08 GMT", "version": "v3" } ]
2015-06-12
[ [ "Cao", "Junjie", "" ], [ "Wu", "Lei", "" ], [ "Wu", "Peiwen", "" ], [ "Yang", "Jin Min", "" ] ]
In light of recent remarkable progress in Higgs search at the LHC, we study the rare decay process $h \to Z\gamma$ and show its correlation with the decay $h \to \gamma\gamma$ in low energy SUSY models such as CMSSM, MSSM, NMSSM and nMSSM. Under various experimental constraints, we scan the parameter space of each model, and present in the allowed parameter space the SUSY predictions on the $Z\gamma$ and $\gamma\gamma$ signal rates in the Higgs production at the LHC and future e+e- linear colliders. We have following observations: (i) Compared with the SM prediction, the $Z\gamma$ and $\gamma\gamma$ signal rates in the CMSSM are both slightly suppressed; (ii) In the MSSM, both the $Z\gamma$ and $\gamma\gamma$ rates can be either enhanced or suppressed, and in optimal case, the enhancement factors can reach 1.2 and 2 respectively; (iii) In the NMSSM, the $Z\gamma$ and $\gamma\gamma$ signal rates normalized by their SM predictions are strongly correlated, and vary from 0.2 to 2; (iv) In the nMSSM, the $Z\gamma$ and $\gamma\gamma$ rates are greatly reduced. Since the correlation behavior between the Z\gamma signal and the \gamma\gamma signal is so model-dependent, it may be used to distinguish the models in future experiments.
1704.03832
Gudrun Heinrich
S. Borowka, G. Heinrich, S. Jahn, S.P. Jones, M. Kerner, J. Schlenk
Multi-loop calculations: numerical methods and applications
10 pages, 3 figures, to appear in the proceedings of the 4th Computational Particle Physics Workshop, October 2016, Hayama, Japan; v2: references updated
null
10.1088/1742-6596/920/1/012003
CERN-TH-2017-051, IPPP/17/28, MPP-2017-62
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We briefly review numerical methods for calculations beyond one loop and then describe new developments within the method of sector decomposition in more detail. We also discuss applications to two-loop integrals involving several mass scales.
[ { "created": "Wed, 12 Apr 2017 16:46:38 GMT", "version": "v1" }, { "created": "Thu, 18 May 2017 08:16:53 GMT", "version": "v2" } ]
2017-11-22
[ [ "Borowka", "S.", "" ], [ "Heinrich", "G.", "" ], [ "Jahn", "S.", "" ], [ "Jones", "S. P.", "" ], [ "Kerner", "M.", "" ], [ "Schlenk", "J.", "" ] ]
We briefly review numerical methods for calculations beyond one loop and then describe new developments within the method of sector decomposition in more detail. We also discuss applications to two-loop integrals involving several mass scales.
hep-ph/9512342
Dam Son
F.L.Bezrukov, M.V.Libanov, D.T.Son, and S.V.Troitsky
Singular Classical Solutions and Tree Multiparticle Cross Sections in Scalar Theories
11 pages, one postcript figure; To appear in Proc. Xth Int. Workshop on high energy physics and quantum field theory, Zvenigorod, 1995
null
null
null
hep-ph
null
We consider the features of multiparticle tree cross sections in scalar theories in the framework of a semiclassical approach. These cross sections at large multiplicities have exponential form, and the properties of the exponent in different regimes are discussed.
[ { "created": "Mon, 18 Dec 1995 20:37:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bezrukov", "F. L.", "" ], [ "Libanov", "M. V.", "" ], [ "Son", "D. T.", "" ], [ "Troitsky", "S. V.", "" ] ]
We consider the features of multiparticle tree cross sections in scalar theories in the framework of a semiclassical approach. These cross sections at large multiplicities have exponential form, and the properties of the exponent in different regimes are discussed.
0809.2784
Jae-hyeon Park
Pyungwon Ko (KIAS), Jae-hyeon Park (INFN Padova), Masahiro Yamaguchi (Tohoku U)
Sflavor mixing map viewed from a high scale in supersymmetric SU(5)
40 pages, updated using phi_s from HFAG, conclusion unchanged
JHEP 0811:051,2008
10.1088/1126-6708/2008/11/051
KIAS-P07051, TU-814
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study flavor violation in a supersymmetric SU(5) grand unification scenario in a model-independent way employing mass insertions. We examine how the quark and the lepton sector observables restrict sfermion mixings. With a low soft scalar mass, a lepton flavor violating process provides a stringent constraint on the flavor structure of right-handed down-type squarks. In particular, mu -> e gamma turns out to be highly susceptible to the 1-3 and 2-3 mixings thereof, due to the radiative correction from the top Yukawa coupling to the scalar mass terms of 10. With a higher scalar mass around the optimal value, in contrast, the quark sector inputs such as B-meson mixings and hadron electric dipole moment, essentially determine the room for sfermion mixing. We also discuss the recent deviation observed in B_s mixing phase, projected sensitivity of forthcoming experiments, and ways to maintain the power of leptonic restrictions even after incorporating a solution to fix the incorrect quark-lepton mass relations.
[ { "created": "Tue, 16 Sep 2008 23:15:07 GMT", "version": "v1" }, { "created": "Sun, 28 Sep 2008 23:53:07 GMT", "version": "v2" } ]
2010-04-21
[ [ "Ko", "Pyungwon", "", "KIAS" ], [ "Park", "Jae-hyeon", "", "INFN Padova" ], [ "Yamaguchi", "Masahiro", "", "Tohoku U" ] ]
We study flavor violation in a supersymmetric SU(5) grand unification scenario in a model-independent way employing mass insertions. We examine how the quark and the lepton sector observables restrict sfermion mixings. With a low soft scalar mass, a lepton flavor violating process provides a stringent constraint on the flavor structure of right-handed down-type squarks. In particular, mu -> e gamma turns out to be highly susceptible to the 1-3 and 2-3 mixings thereof, due to the radiative correction from the top Yukawa coupling to the scalar mass terms of 10. With a higher scalar mass around the optimal value, in contrast, the quark sector inputs such as B-meson mixings and hadron electric dipole moment, essentially determine the room for sfermion mixing. We also discuss the recent deviation observed in B_s mixing phase, projected sensitivity of forthcoming experiments, and ways to maintain the power of leptonic restrictions even after incorporating a solution to fix the incorrect quark-lepton mass relations.
2406.10095
Wang Qing Prof
Zi-Kan Geng and Qing Wang
Calculation of the chiral Lagrangian coefficients with light vector mesons
34 pages, 2figures
null
null
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We calculate the coefficients in the effective chiral Lagrangian from QCD, which includes pseudo-scalar mesons and vector mesons (with hidden symmetry), up to O(p4). This encompasses both the normal and anomalous parts. Our work builds on a previous study that derived the chiral Lagrangian from first principles of QCD, where the low-energy coefficients are defined in terms of specific Green's functions in QCD. This research extends our earlier efforts that focused on calculating the low-energy coefficients of the chiral Lagrangian for pure pseudo-scalar mesons. This marks the first calculation of chiral Lagrangian coefficients for vector mesons from QCD, particularly for the important parameters a and g, which are typically considered inputs in existing literature. Notably, the regularization method used previously is inadequate for this broader scope. We find that cut-off regularization yields reasonable results for both pseudo-scalar mesons and vector mesons, though it has certain limitations. Finally, we demonstrate that our method aligns with the Weinberg sum rules.
[ { "created": "Fri, 14 Jun 2024 14:52:54 GMT", "version": "v1" } ]
2024-06-17
[ [ "Geng", "Zi-Kan", "" ], [ "Wang", "Qing", "" ] ]
We calculate the coefficients in the effective chiral Lagrangian from QCD, which includes pseudo-scalar mesons and vector mesons (with hidden symmetry), up to O(p4). This encompasses both the normal and anomalous parts. Our work builds on a previous study that derived the chiral Lagrangian from first principles of QCD, where the low-energy coefficients are defined in terms of specific Green's functions in QCD. This research extends our earlier efforts that focused on calculating the low-energy coefficients of the chiral Lagrangian for pure pseudo-scalar mesons. This marks the first calculation of chiral Lagrangian coefficients for vector mesons from QCD, particularly for the important parameters a and g, which are typically considered inputs in existing literature. Notably, the regularization method used previously is inadequate for this broader scope. We find that cut-off regularization yields reasonable results for both pseudo-scalar mesons and vector mesons, though it has certain limitations. Finally, we demonstrate that our method aligns with the Weinberg sum rules.
hep-ph/0003264
Rene Bellwied
R. Bellwied (Wayne State University), H. Caines (The Ohio State University), T.J. Humanic (The Ohio State University)
Time Dependence of Chemical Freeze-out in Relativistic Heavy Ion Collisions
10 pages, 7 postscript figures
Phys.Rev. C62 (2000) 054906
10.1103/PhysRevC.62.054906
WSU-NP-00-1
hep-ph
null
We investigate chemical and thermal freeze-out time dependencies for strange particle production for CERN SPS heavy ion collisions in the framework of a dynamical hadronic transport code. We show that the Lambda yield changes considerably after hadronization in the case of Pb+Pb collisions, whereas for smaller system sizes (e.g. S+S) the direct particle production dominates over production from inelastic rescattering. Chemical freeze-out times for strange baryons in Pb+Pb are smaller than for non-strange baryons, but they are still sufficiently long for hadronic rescattering to contribute significantly to the final Lambda yield. Based on inelastic and elastic cross section estimates we expect the trend of shorter freeze-out times (chemical and kinetic), and thus less particle production after hadronization, to continue for multi-strange baryons.
[ { "created": "Mon, 27 Mar 2000 20:16:04 GMT", "version": "v1" }, { "created": "Wed, 29 Mar 2000 01:43:37 GMT", "version": "v2" } ]
2009-10-31
[ [ "Bellwied", "R.", "", "Wayne State University" ], [ "Caines", "H.", "", "The Ohio State\n University" ], [ "Humanic", "T. J.", "", "The Ohio State University" ] ]
We investigate chemical and thermal freeze-out time dependencies for strange particle production for CERN SPS heavy ion collisions in the framework of a dynamical hadronic transport code. We show that the Lambda yield changes considerably after hadronization in the case of Pb+Pb collisions, whereas for smaller system sizes (e.g. S+S) the direct particle production dominates over production from inelastic rescattering. Chemical freeze-out times for strange baryons in Pb+Pb are smaller than for non-strange baryons, but they are still sufficiently long for hadronic rescattering to contribute significantly to the final Lambda yield. Based on inelastic and elastic cross section estimates we expect the trend of shorter freeze-out times (chemical and kinetic), and thus less particle production after hadronization, to continue for multi-strange baryons.
1408.2357
Achim G\"utlein
A. G\"utlein, G. Angloher, A. Bento, C. Bucci, L. Canonica, A. Erb, F. v. Feilitzsch, N. Ferreiro Iachellini, P. Gorla, D. Hauff, J. Jochum, M. Kiefer, H. Kluck, H. Kraus, J.-C. Lanfranchi, J. Loebell, A. M\"unster, F. Petricca, W. Potzel, F. Pr\"obst, F. Reindl, S. Roth, K. Rottler, C. Sailer, K. Sch\"affner, J. Schieck, S. Sch\"onert, W. Seidel, M. v. Sivers, L. Stodolsky, C. Strandhagen, R. Strauss, A. Tanzke, M. Uffinger, A. Ulrich, I. Usherov, S. Wawoczny, M. Willers, M. W\"ustrich, A. Z\"oller
Impact of Coherent Neutrino Nucleus Scattering on Direct Dark Matter Searches based on CaWO$_4$ Crystals
submitted to Astorparticle Physics
null
10.1016/j.astropartphys.2015.03.010
null
hep-ph physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Atmospheric and solar neutrinos scattering coherently off target nuclei will be an important background source for the next generation of direct dark matter searches. In this work we focus on calcium tungstate as target material. For comparison with existing works we calculate the neutrino floor indicating which sensitivities can be reached before the neutrino background appears. In addition, we investigate the sensitivities of future direct dark matter searches using CRESST-II like detectors. Extending previous works we take into account achievable energy resolutions and thresholds as well as beta and gamma backgrounds for this investigation. We show that an exploration of WIMP-nucleon cross sections below the neutrino floor is possible for exposures of $\gtrsim10$ kg-years or higher. In the third part we show that a first detection of coherent neutrino nucleus scattering of atmospheric and solar neutrinos using the same detectors and the backgrounds is feasible for exposures of $\gtrsim50$ kg-years.
[ { "created": "Mon, 11 Aug 2014 09:32:04 GMT", "version": "v1" }, { "created": "Tue, 17 Mar 2015 14:35:42 GMT", "version": "v2" } ]
2015-05-20
[ [ "Gütlein", "A.", "" ], [ "Angloher", "G.", "" ], [ "Bento", "A.", "" ], [ "Bucci", "C.", "" ], [ "Canonica", "L.", "" ], [ "Erb", "A.", "" ], [ "Feilitzsch", "F. v.", "" ], [ "Iachellini", "N. Ferreiro", "" ], [ "Gorla", "P.", "" ], [ "Hauff", "D.", "" ], [ "Jochum", "J.", "" ], [ "Kiefer", "M.", "" ], [ "Kluck", "H.", "" ], [ "Kraus", "H.", "" ], [ "Lanfranchi", "J. -C.", "" ], [ "Loebell", "J.", "" ], [ "Münster", "A.", "" ], [ "Petricca", "F.", "" ], [ "Potzel", "W.", "" ], [ "Pröbst", "F.", "" ], [ "Reindl", "F.", "" ], [ "Roth", "S.", "" ], [ "Rottler", "K.", "" ], [ "Sailer", "C.", "" ], [ "Schäffner", "K.", "" ], [ "Schieck", "J.", "" ], [ "Schönert", "S.", "" ], [ "Seidel", "W.", "" ], [ "Sivers", "M. v.", "" ], [ "Stodolsky", "L.", "" ], [ "Strandhagen", "C.", "" ], [ "Strauss", "R.", "" ], [ "Tanzke", "A.", "" ], [ "Uffinger", "M.", "" ], [ "Ulrich", "A.", "" ], [ "Usherov", "I.", "" ], [ "Wawoczny", "S.", "" ], [ "Willers", "M.", "" ], [ "Wüstrich", "M.", "" ], [ "Zöller", "A.", "" ] ]
Atmospheric and solar neutrinos scattering coherently off target nuclei will be an important background source for the next generation of direct dark matter searches. In this work we focus on calcium tungstate as target material. For comparison with existing works we calculate the neutrino floor indicating which sensitivities can be reached before the neutrino background appears. In addition, we investigate the sensitivities of future direct dark matter searches using CRESST-II like detectors. Extending previous works we take into account achievable energy resolutions and thresholds as well as beta and gamma backgrounds for this investigation. We show that an exploration of WIMP-nucleon cross sections below the neutrino floor is possible for exposures of $\gtrsim10$ kg-years or higher. In the third part we show that a first detection of coherent neutrino nucleus scattering of atmospheric and solar neutrinos using the same detectors and the backgrounds is feasible for exposures of $\gtrsim50$ kg-years.
2112.05766
David Curtin
Aaron Howe, Jack Setford, David Curtin, Christopher D. Matzner
How to search for Mirror Stars with Gaia
19 pages, 13 figures. Accepted for publication in JHEP; added various clarifications, references, typo fixes; no change in results or conclusions
null
null
null
hep-ph astro-ph.SR
http://creativecommons.org/licenses/by/4.0/
We show for the first time how to conduct a direct search for dark matter using Gaia observations. Its public astrometric data may contain the signals of mirror stars, exotic compact objects made of atomic dark matter with a tiny kinetic mixing between the dark and SM photon. Mirror stars capture small amounts of interstellar material in their cores, leading to characteristic optical/IR and X-ray emissions. We develop the detailed pipeline for conducting a mirror star search using data from Gaia and other stellar catalogues, and demonstrate our methodology by conducting a search for toy mirror stars with a simplified calculation of their optical/IR emissions over a wide range of mirror star and hidden sector parameters. We also obtain projected exclusion bounds on the abundance and properties of mirror stars if no candidates are found, demonstrating that Gaia is a new and uniquely powerful probe of atomic dark matter. Our study provides the blueprint for a realistic mirror star search that includes a more complete treatment of the captured interstellar gas in the future.
[ { "created": "Fri, 10 Dec 2021 19:00:01 GMT", "version": "v1" }, { "created": "Tue, 28 Jun 2022 16:39:17 GMT", "version": "v2" } ]
2022-06-29
[ [ "Howe", "Aaron", "" ], [ "Setford", "Jack", "" ], [ "Curtin", "David", "" ], [ "Matzner", "Christopher D.", "" ] ]
We show for the first time how to conduct a direct search for dark matter using Gaia observations. Its public astrometric data may contain the signals of mirror stars, exotic compact objects made of atomic dark matter with a tiny kinetic mixing between the dark and SM photon. Mirror stars capture small amounts of interstellar material in their cores, leading to characteristic optical/IR and X-ray emissions. We develop the detailed pipeline for conducting a mirror star search using data from Gaia and other stellar catalogues, and demonstrate our methodology by conducting a search for toy mirror stars with a simplified calculation of their optical/IR emissions over a wide range of mirror star and hidden sector parameters. We also obtain projected exclusion bounds on the abundance and properties of mirror stars if no candidates are found, demonstrating that Gaia is a new and uniquely powerful probe of atomic dark matter. Our study provides the blueprint for a realistic mirror star search that includes a more complete treatment of the captured interstellar gas in the future.
hep-ph/0005143
Xiang-Song Chen
X.S. Chen, X.B. Chen, Amand Faessler, Th. Gutsche, F. Wang
Renormalization of quark axial current in the chiral potential model
4 pages revtex, 5 eps figures
null
null
null
hep-ph
null
Non-conserved composite operators like the quark axial current have divergent matrix elements therefore must be renormalized. We explore how this can be done in quark model calculations where the systematic procedure of dimensional regularization and minimal subtraction is not applicable. We propose a most natural and convenient regularization scheme of cutting the intermediate quark states over which we sum in loop diagram calculations at a certain energy. We show that this scheme works perfectly for the quark axial current and we obtain the quark spin contribution to the proton spin: $\Delta_u=0.82$, $\Delta_d=-0.43$, $\Delta_s=-0.10$, which is in excellent agreement with experiments.
[ { "created": "Mon, 15 May 2000 20:06:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chen", "X. S.", "" ], [ "Chen", "X. B.", "" ], [ "Faessler", "Amand", "" ], [ "Gutsche", "Th.", "" ], [ "Wang", "F.", "" ] ]
Non-conserved composite operators like the quark axial current have divergent matrix elements therefore must be renormalized. We explore how this can be done in quark model calculations where the systematic procedure of dimensional regularization and minimal subtraction is not applicable. We propose a most natural and convenient regularization scheme of cutting the intermediate quark states over which we sum in loop diagram calculations at a certain energy. We show that this scheme works perfectly for the quark axial current and we obtain the quark spin contribution to the proton spin: $\Delta_u=0.82$, $\Delta_d=-0.43$, $\Delta_s=-0.10$, which is in excellent agreement with experiments.
hep-ph/0110147
Shouhua Zhu
Chao-Shang Huang, Wei Liao, Qi-shu Yan and Shou-hua Zhu
Rare decay $B\to X_sl^+l^-$ in a CP spontaneously broken two Higgs doublet model
27 pages, text updated, new numerical results included
Eur.Phys.J.C25:103-111,2002
10.1007/s10052-002-0972-4
null
hep-ph
null
The Higgs boson mass spectrum and couplings of neutral Higgs bosons to fermions are worked out i n a CP spontaneously broken two Higgs doublet model in the large tan$\beta$ case. The differential branching ratio, forward-backward asymmetry, CP asymmetry and lepton polarization for $B\to X_s l^+ l^-$ are computed. It is shown that effects of neutral Higgs bosons are quite significant when $\tan\beta$ is large. Especially, the CP violating normal polarization $P_N$ can be as large as several percents.
[ { "created": "Thu, 11 Oct 2001 08:08:32 GMT", "version": "v1" }, { "created": "Mon, 4 Mar 2002 14:02:27 GMT", "version": "v2" } ]
2009-01-07
[ [ "Huang", "Chao-Shang", "" ], [ "Liao", "Wei", "" ], [ "Yan", "Qi-shu", "" ], [ "Zhu", "Shou-hua", "" ] ]
The Higgs boson mass spectrum and couplings of neutral Higgs bosons to fermions are worked out i n a CP spontaneously broken two Higgs doublet model in the large tan$\beta$ case. The differential branching ratio, forward-backward asymmetry, CP asymmetry and lepton polarization for $B\to X_s l^+ l^-$ are computed. It is shown that effects of neutral Higgs bosons are quite significant when $\tan\beta$ is large. Especially, the CP violating normal polarization $P_N$ can be as large as several percents.
2201.06473
Snigdha Ghosh
Snigdha Ghosh, Nilanjan Chaudhuri, Sourav Sarkar and Pradip Roy
Electromagnetic spectral functions in hot and dense chirally imbalanced quark matter
Version Published in Physical Review D
Physical Review D 105, 096005 (2022)
10.1103/PhysRevD.105.096005
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The photon self-energy from chirally imbalanced quark matter is evaluated at finite temperature and density using the real time formulation of thermal field theory. The analytic structure is explored in detail exposing the cut structure which corresponds to a variety of physical scattering and decay processes in the medium and their thresholds. The mass of the quarks in the chiral symmetry broken phase are obtained from the gap equation of the Nambu--Jona-Lasinio model. It is found that, in presence of finite chiral chemical potential, the chiral condensate tends to get stronger at low temperature while the opposite is observed at high values of temperature. A continuous spectrum is obtained for the electromagnetic spectral function and this is purely a finite chiral chemical potential effect.
[ { "created": "Mon, 17 Jan 2022 15:34:25 GMT", "version": "v1" }, { "created": "Mon, 4 Apr 2022 07:26:24 GMT", "version": "v2" }, { "created": "Wed, 4 May 2022 15:53:24 GMT", "version": "v3" } ]
2022-05-05
[ [ "Ghosh", "Snigdha", "" ], [ "Chaudhuri", "Nilanjan", "" ], [ "Sarkar", "Sourav", "" ], [ "Roy", "Pradip", "" ] ]
The photon self-energy from chirally imbalanced quark matter is evaluated at finite temperature and density using the real time formulation of thermal field theory. The analytic structure is explored in detail exposing the cut structure which corresponds to a variety of physical scattering and decay processes in the medium and their thresholds. The mass of the quarks in the chiral symmetry broken phase are obtained from the gap equation of the Nambu--Jona-Lasinio model. It is found that, in presence of finite chiral chemical potential, the chiral condensate tends to get stronger at low temperature while the opposite is observed at high values of temperature. A continuous spectrum is obtained for the electromagnetic spectral function and this is purely a finite chiral chemical potential effect.
hep-ph/9903427
Jure Zupan
S. Fajfer, J. Zupan
The role of K^*_0(1430) in D->PK and \tau->KP\nu_\tau decays
17 pages, 2 figures, version as it appears in journal
Int.J.Mod.Phys. A14 (1999) 4161-4176
10.1142/S0217751X99001950
IJS-TP-99/08
hep-ph
null
We consider the scalar form factor in the weak current matrix element <P K| j_\mu |0>, P =\pi,\eta,\eta'. It obtains the contributions from the scalar meson resonance K^*_0(1430) and from the scalar projection of the vector meson K^*(892) resonance. We analyze decay amplitudes of the Cabibbo suppressed decays D->K P, P =\pi,\eta,\eta' using the factorization approach. The form factors of the relevant matrix elements are described by assuming the dominance of nearby resonances. The annihilation contribution in these decays arises from the matrix element <P K| j_\mu |0>. All the required parameters are experimentally known except the scalar meson K^*_0(1430) decay constant. We fit the decay amplitudes and we find that final state interaction improves the agreement with the experimental data. Then we extract bounds on scalar form factor parameters and compare them with the experimental data obtained in the analyses of K->\pi e\nu_e and K->\pi\mu\nu_\mu. The same scalar form factor is present in the \tau-> K P \nu_\tau decay, with P =\pi,\eta,\eta'. Using the obtained bounds we investigate the significance of the scalar meson form factor in the \tau-> K P \nu_\tau, P = \pi, \eta, \eta' decay rates and spectra. We find that the K^*_0(1430) scalar meson dominates in the \tau-> K \eta'\nu_\tau decay spectrum.
[ { "created": "Mon, 22 Mar 1999 15:13:15 GMT", "version": "v1" }, { "created": "Thu, 14 Oct 1999 07:10:01 GMT", "version": "v2" } ]
2009-10-31
[ [ "Fajfer", "S.", "" ], [ "Zupan", "J.", "" ] ]
We consider the scalar form factor in the weak current matrix element <P K| j_\mu |0>, P =\pi,\eta,\eta'. It obtains the contributions from the scalar meson resonance K^*_0(1430) and from the scalar projection of the vector meson K^*(892) resonance. We analyze decay amplitudes of the Cabibbo suppressed decays D->K P, P =\pi,\eta,\eta' using the factorization approach. The form factors of the relevant matrix elements are described by assuming the dominance of nearby resonances. The annihilation contribution in these decays arises from the matrix element <P K| j_\mu |0>. All the required parameters are experimentally known except the scalar meson K^*_0(1430) decay constant. We fit the decay amplitudes and we find that final state interaction improves the agreement with the experimental data. Then we extract bounds on scalar form factor parameters and compare them with the experimental data obtained in the analyses of K->\pi e\nu_e and K->\pi\mu\nu_\mu. The same scalar form factor is present in the \tau-> K P \nu_\tau decay, with P =\pi,\eta,\eta'. Using the obtained bounds we investigate the significance of the scalar meson form factor in the \tau-> K P \nu_\tau, P = \pi, \eta, \eta' decay rates and spectra. We find that the K^*_0(1430) scalar meson dominates in the \tau-> K \eta'\nu_\tau decay spectrum.
1210.7765
Konrad Tywoniuk
Jorge Casalderrey-Solana, Yacine Mehtar-Tani, Carlos A. Salgado and Konrad Tywoniuk
New picture of jet quenching dictated by color coherence
4 pages, 2 figures
null
10.1016/j.physletb.2013.07.046
CERN-PH-TH/2012-291; LU-TP 12-37
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new description of the jet quenching phenomenon observed in nuclear collisions at high energies in which coherent parton branching plays a central role. This picture is based on the appearance of a dynamically generated scale, the jet resolution scale, which controls the transverse resolution power of the medium to simultaneously propagating color probes. Since from the point of view of the medium all partonic jet fragments within this transverse distance act coherently as a single emitter, this scale allows us to rearrange the jet shower into effective emitters. We observe that in the kinematic regime of the LHC, the corresponding characteristic angle is comparable to the typical opening angle of high energy jets such that most of the jet energy is contained within a non-resolvable color coherent inner core. Thus, a sizable fraction of the jets are unresolved, losing energy as a single parton without modifications of their intra-jet structure. This new picture provides a consistent understanding of the present data on reconstructed jet observables and constitute the basis for future developments.
[ { "created": "Mon, 29 Oct 2012 18:23:41 GMT", "version": "v1" }, { "created": "Fri, 9 Nov 2012 13:36:10 GMT", "version": "v2" } ]
2015-06-11
[ [ "Casalderrey-Solana", "Jorge", "" ], [ "Mehtar-Tani", "Yacine", "" ], [ "Salgado", "Carlos A.", "" ], [ "Tywoniuk", "Konrad", "" ] ]
We propose a new description of the jet quenching phenomenon observed in nuclear collisions at high energies in which coherent parton branching plays a central role. This picture is based on the appearance of a dynamically generated scale, the jet resolution scale, which controls the transverse resolution power of the medium to simultaneously propagating color probes. Since from the point of view of the medium all partonic jet fragments within this transverse distance act coherently as a single emitter, this scale allows us to rearrange the jet shower into effective emitters. We observe that in the kinematic regime of the LHC, the corresponding characteristic angle is comparable to the typical opening angle of high energy jets such that most of the jet energy is contained within a non-resolvable color coherent inner core. Thus, a sizable fraction of the jets are unresolved, losing energy as a single parton without modifications of their intra-jet structure. This new picture provides a consistent understanding of the present data on reconstructed jet observables and constitute the basis for future developments.
1202.0106
Nodoka Yamanaka
Nodoka Yamanaka, Toru Sato and Takahiro Kubota
A reappraisal of two-loop contributions to the fermion electric dipole moments in R-parity violating supersymmetric models
4 pages, 2 figures
Phys.Rev. D85 (2012) 117701
10.1103/PhysRevD.85.117701
OU-HET 739
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reexamine the R-parity violating contribution to the fermion electric and chromo-electric dipole moments (EDM and cEDM) in the two-loop diagrams. It is found that the leading Barr-Zee type two-loop contribution is smaller than the result found in previous works, and that EDM experimental data provide looser limits on RPV couplings.
[ { "created": "Wed, 1 Feb 2012 06:46:19 GMT", "version": "v1" }, { "created": "Mon, 4 Jun 2012 09:26:29 GMT", "version": "v2" } ]
2012-06-20
[ [ "Yamanaka", "Nodoka", "" ], [ "Sato", "Toru", "" ], [ "Kubota", "Takahiro", "" ] ]
We reexamine the R-parity violating contribution to the fermion electric and chromo-electric dipole moments (EDM and cEDM) in the two-loop diagrams. It is found that the leading Barr-Zee type two-loop contribution is smaller than the result found in previous works, and that EDM experimental data provide looser limits on RPV couplings.
1007.2984
Igor Frolov
I. E. Frolov, V. Ch. Zhukovsky, and K. G. Klimenko
Chiral density waves in quark matter within the Nambu--Jona-Lasinio model in an external magnetic field
13 pages, 4 figures
Phys.Rev.D82:076002,2010
10.1103/PhysRevD.82.076002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A possibility of formation of static dual scalar and pseudoscalar density wave condensates in dense quark matter is considered for the Nambu--Jona-Lasinio model in an external magnetic field. Within a mean-field approximation, the effective potential of the theory is obtained and its minima are numerically studied; a phase diagram of the system is constructed. It is shown that the presence of a magnetic field favors the formation of spatially inhomogeneous condensate configurations at low temperatures and arbitrary non-zero values of the chemical potential.
[ { "created": "Sun, 18 Jul 2010 09:51:19 GMT", "version": "v1" }, { "created": "Fri, 20 Aug 2010 19:42:52 GMT", "version": "v2" }, { "created": "Mon, 11 Oct 2010 19:57:42 GMT", "version": "v3" } ]
2014-11-21
[ [ "Frolov", "I. E.", "" ], [ "Zhukovsky", "V. Ch.", "" ], [ "Klimenko", "K. G.", "" ] ]
A possibility of formation of static dual scalar and pseudoscalar density wave condensates in dense quark matter is considered for the Nambu--Jona-Lasinio model in an external magnetic field. Within a mean-field approximation, the effective potential of the theory is obtained and its minima are numerically studied; a phase diagram of the system is constructed. It is shown that the presence of a magnetic field favors the formation of spatially inhomogeneous condensate configurations at low temperatures and arbitrary non-zero values of the chemical potential.
0704.1961
Yi Liao
Yi Liao (Nankai U.)
Impact of spin-zero particle-photon interactions on light polarization in external magnetic fields
To appear in PLB, 10 pp, 0 figs; thanks to the anonymous referee for useful comments/suggestions. Main changes: (1)English hopefully improved. (2)The word `interference' deleted. (3)Results unchanged but discussions extended. (4)Quote Ref [26] where spin-zero particles with mixed parity appear. (5)Acknowledgements added
Phys.Lett.B650:257-261,2007
10.1016/j.physletb.2007.05.020
null
hep-ph hep-ex
null
If the recent PVLAS results on polarization changes of a linearly polarized laser beam passing through a magnetic field are interpreted by an axion-like particle, it is almost certain that it is not a standard QCD axion. Considering this, we study the general effective interactions of photons with spin-zero particles without restricting the latter to be a pseudo-scalar or a scalar, i.e., a parity eigenstate. At the lowest order in effective field theory, there are two dimension-5 interactions, each of which has previously been treated separately for a pseudo-scalar or a scalar particle. By following the evolution in an external magnetic field of the system of spin-zero particles and photons, we compute the changes in light polarization and the transition probability for two experimental set-ups: one-way propagation and round-trip propagation. While the first may be relevant for astrophysical sources of spin-zero particles, the second applies to laboratory optical experiments like PVLAS. In the one-way propagation, interesting phenomena can occur for special configurations of polarization where, for instance, transition occurs but light polarization does not change. For the round-trip propagation, however, the standard results of polarization changes for a pseudoscalar or a scalar are only modified by a factor that depends on the relative strength of the two interactions.
[ { "created": "Mon, 16 Apr 2007 09:38:32 GMT", "version": "v1" }, { "created": "Thu, 17 May 2007 03:15:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Liao", "Yi", "", "Nankai U." ] ]
If the recent PVLAS results on polarization changes of a linearly polarized laser beam passing through a magnetic field are interpreted by an axion-like particle, it is almost certain that it is not a standard QCD axion. Considering this, we study the general effective interactions of photons with spin-zero particles without restricting the latter to be a pseudo-scalar or a scalar, i.e., a parity eigenstate. At the lowest order in effective field theory, there are two dimension-5 interactions, each of which has previously been treated separately for a pseudo-scalar or a scalar particle. By following the evolution in an external magnetic field of the system of spin-zero particles and photons, we compute the changes in light polarization and the transition probability for two experimental set-ups: one-way propagation and round-trip propagation. While the first may be relevant for astrophysical sources of spin-zero particles, the second applies to laboratory optical experiments like PVLAS. In the one-way propagation, interesting phenomena can occur for special configurations of polarization where, for instance, transition occurs but light polarization does not change. For the round-trip propagation, however, the standard results of polarization changes for a pseudoscalar or a scalar are only modified by a factor that depends on the relative strength of the two interactions.
hep-ph/0503242
Aleksey I. Alekseev
Aleksey I. Alekseev
Synthetic Running Coupling of QCD
9 pages, 1 figure, 1 table, some minor corrections, references added, accepted for publication in Few-Body Systems
Few Body Syst. 40 (2006) 57-70
10.1007/s00601-006-0154-2
IHEP 2005-5
hep-ph
null
Based on a study of the analytic running coupling obtained from the standard perturbation theory results up to four-loop order, the QCD ``synthetic'' running coupling \alpha_{syn} is built. In so doing the perturbative time-like discontinuity is preserved and nonperturbative contributions not only remove the nonphysical singularities of the perturbation theory in the infrared region but also decrease rapidly in the ultraviolet region. In the framework of the approach, on the one hand, the running coupling is enhanced at zero and, on the other hand, the dynamical gluon mass m_g arises. Fixing the parameter which characterize the infrared enhancement corresponding to the string tension \sigma and normalization, say, at M_\tau completely define the synthetic running coupling. In this case the dynamical gluon mass appears to be fixed and the higher loop stabilization property of m_g is observed. For \sigma = (0.42 GeV)^2 and \alpha_{syn}(M^2_\tau) = 0.33 \pm 0.01 it is obtained that m_g = 530 \pm 80 MeV.
[ { "created": "Wed, 23 Mar 2005 17:20:30 GMT", "version": "v1" }, { "created": "Thu, 24 Nov 2005 19:35:44 GMT", "version": "v2" }, { "created": "Sun, 19 Feb 2006 14:42:47 GMT", "version": "v3" } ]
2009-11-11
[ [ "Alekseev", "Aleksey I.", "" ] ]
Based on a study of the analytic running coupling obtained from the standard perturbation theory results up to four-loop order, the QCD ``synthetic'' running coupling \alpha_{syn} is built. In so doing the perturbative time-like discontinuity is preserved and nonperturbative contributions not only remove the nonphysical singularities of the perturbation theory in the infrared region but also decrease rapidly in the ultraviolet region. In the framework of the approach, on the one hand, the running coupling is enhanced at zero and, on the other hand, the dynamical gluon mass m_g arises. Fixing the parameter which characterize the infrared enhancement corresponding to the string tension \sigma and normalization, say, at M_\tau completely define the synthetic running coupling. In this case the dynamical gluon mass appears to be fixed and the higher loop stabilization property of m_g is observed. For \sigma = (0.42 GeV)^2 and \alpha_{syn}(M^2_\tau) = 0.33 \pm 0.01 it is obtained that m_g = 530 \pm 80 MeV.
1405.7561
Shu-Min Zhao
Shu-Min Zhao, Tai-Fu Feng, Hai-Bin Zhang, Ben Yan, Xi-Jie Zhan
The corrections from one loop and two-loop Barr-Zee type diagrams to muon MDM in BLMSSM
35 pages, 10 figures
JHEP 1411(2014)119
10.1007/JHEP11(2014)119
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries(BLMSSM) and the Yukawa couplings between Higgs doublets and exotic quarks are considered, we study the one loop diagrams and the two-loop Barr-Zee type diagrams with a closed Fermi(scalar) loop between the vector Boson and Higgs. Using the effective Lagrangian method, we deduce the Wilson coefficients of dimension 6 operators contributing to the anomalous magnetic moment of muon, which satisfies the electromagnetic gauge invariance. In the numerical analysis, we consider the experiment constraints from Higgs and neutrino data. In some parameter space, the new physics contribution is large and even reaches $24\times10^{-10}$, which can remedy the deviation well.
[ { "created": "Thu, 29 May 2014 14:23:57 GMT", "version": "v1" }, { "created": "Sun, 13 Jul 2014 00:58:16 GMT", "version": "v2" }, { "created": "Mon, 29 Sep 2014 08:45:38 GMT", "version": "v3" } ]
2015-06-19
[ [ "Zhao", "Shu-Min", "" ], [ "Feng", "Tai-Fu", "" ], [ "Zhang", "Hai-Bin", "" ], [ "Yan", "Ben", "" ], [ "Zhan", "Xi-Jie", "" ] ]
In a supersymmetric extension of the standard model where baryon and lepton numbers are local gauge symmetries(BLMSSM) and the Yukawa couplings between Higgs doublets and exotic quarks are considered, we study the one loop diagrams and the two-loop Barr-Zee type diagrams with a closed Fermi(scalar) loop between the vector Boson and Higgs. Using the effective Lagrangian method, we deduce the Wilson coefficients of dimension 6 operators contributing to the anomalous magnetic moment of muon, which satisfies the electromagnetic gauge invariance. In the numerical analysis, we consider the experiment constraints from Higgs and neutrino data. In some parameter space, the new physics contribution is large and even reaches $24\times10^{-10}$, which can remedy the deviation well.
1212.1184
Bruno Werneck Mintz
Bruno W. Mintz, Rudnei O. Ramos, Juergen Schaffner-Bielich, Rainer Stiele
Phase diagram and surface tension in the three-flavor Polyakov-quark-meson model
17 pages, 6 figures. V2: typos fixed, references added
Phys. Rev. D 87, 036004 (2013)
10.1103/PhysRevD.87.036004
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain the in-medium effective potential of the three-flavor Polyakov-Quark-Meson model as a real function of real variables in the Polyakov loop variable, to allow for the study of all possible minima of the model. At finite quark chemical potential, the real and imaginary parts of the effective potential, in terms of the Polyakov loop variables, are made apparent, showing explicitly the fermion sign problem of the theory. The phase diagram and other equilibrium observables, obtained from the real part of the effective potential, are calculated in the mean-field approximation. The obtained results are compared to those found with the so-called saddle-point approach. Our procedure also allows the calculation of the surface tension between the chirally broken and confined phase, and the chirally restored and deconfined phase. The values of surface tension we find for low temperatures are very close to the ones recently found for two-flavor chiral models. Some consequences of our results for the early Universe, for heavy-ion collisions, and for proto-neutron stars are briefly discussed.
[ { "created": "Wed, 5 Dec 2012 21:29:10 GMT", "version": "v1" }, { "created": "Thu, 28 Feb 2013 14:10:05 GMT", "version": "v2" } ]
2013-03-01
[ [ "Mintz", "Bruno W.", "" ], [ "Ramos", "Rudnei O.", "" ], [ "Schaffner-Bielich", "Juergen", "" ], [ "Stiele", "Rainer", "" ] ]
We obtain the in-medium effective potential of the three-flavor Polyakov-Quark-Meson model as a real function of real variables in the Polyakov loop variable, to allow for the study of all possible minima of the model. At finite quark chemical potential, the real and imaginary parts of the effective potential, in terms of the Polyakov loop variables, are made apparent, showing explicitly the fermion sign problem of the theory. The phase diagram and other equilibrium observables, obtained from the real part of the effective potential, are calculated in the mean-field approximation. The obtained results are compared to those found with the so-called saddle-point approach. Our procedure also allows the calculation of the surface tension between the chirally broken and confined phase, and the chirally restored and deconfined phase. The values of surface tension we find for low temperatures are very close to the ones recently found for two-flavor chiral models. Some consequences of our results for the early Universe, for heavy-ion collisions, and for proto-neutron stars are briefly discussed.
1308.4652
Cem Salih Un
M. Adeel Ajaib, Ilia Gogoladze, Qaisar Shafi and Cem Salih Un
Higgs and Sparticle Masses from Yukawa Unified SO(10): A Snowmass White Paper
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss ways to probe t-b-tau Yukawa coupling unification condition at the Energy and Intensity frontiers. We consider non-universal soft supersymmetry breaking mass terms for gauginos related by the SO(10) grand unified theory (GUT). We have previously shown that t-b-tau Yukawa coupling unification prefers a mass of around 125 GeV for the Standard Model-like Higgs boson with all colored sparticle masses above 3 TeV. The well-known MSSM parameter tan(beta) is about 47-48 and neutralino-stau coannihilation yields the desired relic dark matter density.
[ { "created": "Wed, 21 Aug 2013 18:16:15 GMT", "version": "v1" } ]
2013-08-22
[ [ "Ajaib", "M. Adeel", "" ], [ "Gogoladze", "Ilia", "" ], [ "Shafi", "Qaisar", "" ], [ "Un", "Cem Salih", "" ] ]
We discuss ways to probe t-b-tau Yukawa coupling unification condition at the Energy and Intensity frontiers. We consider non-universal soft supersymmetry breaking mass terms for gauginos related by the SO(10) grand unified theory (GUT). We have previously shown that t-b-tau Yukawa coupling unification prefers a mass of around 125 GeV for the Standard Model-like Higgs boson with all colored sparticle masses above 3 TeV. The well-known MSSM parameter tan(beta) is about 47-48 and neutralino-stau coannihilation yields the desired relic dark matter density.
hep-ph/0010056
Tom Steele
T.G. Steele
Hoelder Inequalities and QCD Sum-Rule Bounds on the Masses of Light Quarks
3 pages, latex, write-up of talk presented at DPF 2000
Int.J.Mod.Phys. A16S1B (2001) 582-584
10.1142/S0217751X01007546
null
hep-ph
null
QCD Laplace Sum-Rules must satisfy a fundamental Hoelder inequality if they are to consistently represent an integrated hadronic spectral function. The Laplace sum-rules of pion currents is shown to violate this inequality unless the $u$ and $d$ quark masses are sufficiently large, placing a lower bound on $m_u+m_d$, the SU(2)-invariant combination of the light-quark masses.
[ { "created": "Fri, 6 Oct 2000 15:47:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Steele", "T. G.", "" ] ]
QCD Laplace Sum-Rules must satisfy a fundamental Hoelder inequality if they are to consistently represent an integrated hadronic spectral function. The Laplace sum-rules of pion currents is shown to violate this inequality unless the $u$ and $d$ quark masses are sufficiently large, placing a lower bound on $m_u+m_d$, the SU(2)-invariant combination of the light-quark masses.
hep-ph/0402065
David Tucker-Smith
David Tucker-Smith (Williams), Neal Weiner (Washington)
The Status of Inelastic Dark Matter
8 pages, 5 figures; updated to include CRESST results; version to appear in Phys.Rev.D
Phys.Rev. D72 (2005) 063509
10.1103/PhysRevD.72.063509
UW/PT 04/01
hep-ph
null
In light of recent positive results from the DAMA experiment, as well as new null results from CDMS Soudan, Edelweiss, ZEPLIN-I and CRESST, we reexamine the framework of inelastic dark matter with a standard halo. In this framework, which was originally introduced to reconcile tensions between CDMS and DAMA, dark matter particles can scatter off of nuclei only by making a transition to a nearly degenerate state that is roughly $100 \kev$ heavier. We find that recent data significantly constrains the parameter space of the framework, but that there are still regions consistent with all experimental results. Due to the enhanced annual modulation and dramatically different energy dependence in this scenario, we emphasize the need for greater information on the dates of data taking, and on the energy distribution of signal and background. We also study the specific case of ``mixed sneutrino'' dark matter, and isolate regions of parameter space which are cosmologically interesting for that particular model. A significant improvement in limits by heavy target experiments such as ZEPLIN or CRESST should be able to confirm or exclude the inelastic dark matter scenario in the near future. Within the mixed sneutrino model, an elastic scattering signature should be seen at upcoming germanium experiments, including future results from CDMS Soudan.
[ { "created": "Fri, 6 Feb 2004 19:19:21 GMT", "version": "v1" }, { "created": "Tue, 25 May 2004 18:16:32 GMT", "version": "v2" }, { "created": "Mon, 25 Jul 2005 15:56:59 GMT", "version": "v3" } ]
2009-11-10
[ [ "Tucker-Smith", "David", "", "Williams" ], [ "Weiner", "Neal", "", "Washington" ] ]
In light of recent positive results from the DAMA experiment, as well as new null results from CDMS Soudan, Edelweiss, ZEPLIN-I and CRESST, we reexamine the framework of inelastic dark matter with a standard halo. In this framework, which was originally introduced to reconcile tensions between CDMS and DAMA, dark matter particles can scatter off of nuclei only by making a transition to a nearly degenerate state that is roughly $100 \kev$ heavier. We find that recent data significantly constrains the parameter space of the framework, but that there are still regions consistent with all experimental results. Due to the enhanced annual modulation and dramatically different energy dependence in this scenario, we emphasize the need for greater information on the dates of data taking, and on the energy distribution of signal and background. We also study the specific case of ``mixed sneutrino'' dark matter, and isolate regions of parameter space which are cosmologically interesting for that particular model. A significant improvement in limits by heavy target experiments such as ZEPLIN or CRESST should be able to confirm or exclude the inelastic dark matter scenario in the near future. Within the mixed sneutrino model, an elastic scattering signature should be seen at upcoming germanium experiments, including future results from CDMS Soudan.
hep-ph/0206145
Johann Rafelski
Johann Rafelski (Arizona) and Jean Letessier (Paris 7)
Non-equilibrium Hadrochemistry in QGP Hadronization
To appear in the proceedings of Pan American Advanced Studies Institute on New States of Matter in Hadronic Interactions (PASI 2002), Campos do Jordao, Brazil, 7-18 Jan 2002; American Institute of Physics 2002 *v2 Contains UPDATED RHIC-130 chemical freeze-out analysis*
null
10.1063/1.1513695
null
hep-ph nucl-th
null
This survey offers an introductory tutorial for students of any age of the currently thriving field of hadrochemistry. We discuss the different chemical potentials, how the hadronic phase space is described and how one evaluates the abundance of hadrons at time of hadronization. We show that a rather accurate description of experimental data arises and we present results of fits to hadron yields at SPS and RHIC. We show that introduction of chemical non-equilibrium originating in a sudden hadronization of a QGP is favored strongly at SPS and is presently also emerging at RHIC. The low chemical freeze-out temperatures are consistent with the picture of single freeze-out scenario (chemical and thermal freeze-out coincide).
[ { "created": "Mon, 17 Jun 2002 10:49:45 GMT", "version": "v1" }, { "created": "Wed, 7 Aug 2002 21:01:12 GMT", "version": "v2" } ]
2009-11-07
[ [ "Rafelski", "Johann", "", "Arizona" ], [ "Letessier", "Jean", "", "Paris 7" ] ]
This survey offers an introductory tutorial for students of any age of the currently thriving field of hadrochemistry. We discuss the different chemical potentials, how the hadronic phase space is described and how one evaluates the abundance of hadrons at time of hadronization. We show that a rather accurate description of experimental data arises and we present results of fits to hadron yields at SPS and RHIC. We show that introduction of chemical non-equilibrium originating in a sudden hadronization of a QGP is favored strongly at SPS and is presently also emerging at RHIC. The low chemical freeze-out temperatures are consistent with the picture of single freeze-out scenario (chemical and thermal freeze-out coincide).
hep-ph/0209238
Erik Elfgren
Erik Elfgren
Heavy and Excited Leptons in the OPAL Detector?
85 pages, 38 figures, MSc thesis at Universite de Montreal
null
null
null
hep-ph
null
This M.Sc. thesis describes a search for exotic leptons. The search has been performed using data from the OPAL detector at the Large Electron Positron collider at CERN. The total integrated luminosity was 663 pb$^{-1}$ with center of mass energies in the range of 183-209 GeV. The work has been concentrated on the study of production of heavy leptons via the charged current channel and disintegration of the $W$ into two quarks. In particular, single production of heavy leptons in the mass region 100-170 GeV has been extensively studied. No evidence for any new particles has been found. The results translate into upper limits on the mixing between the heavy and the ordinary lepton for different heavy lepton masses. The limits on the mixing angles are generally improved in comparison with the nominal value $\zeta^2\sim 0.005$.
[ { "created": "Fri, 20 Sep 2002 13:05:16 GMT", "version": "v1" }, { "created": "Mon, 2 Dec 2002 13:31:05 GMT", "version": "v2" } ]
2007-05-23
[ [ "Elfgren", "Erik", "" ] ]
This M.Sc. thesis describes a search for exotic leptons. The search has been performed using data from the OPAL detector at the Large Electron Positron collider at CERN. The total integrated luminosity was 663 pb$^{-1}$ with center of mass energies in the range of 183-209 GeV. The work has been concentrated on the study of production of heavy leptons via the charged current channel and disintegration of the $W$ into two quarks. In particular, single production of heavy leptons in the mass region 100-170 GeV has been extensively studied. No evidence for any new particles has been found. The results translate into upper limits on the mixing between the heavy and the ordinary lepton for different heavy lepton masses. The limits on the mixing angles are generally improved in comparison with the nominal value $\zeta^2\sim 0.005$.
1702.03943
A. H. Rezaeian
Edmond Iancu, Amir H. Rezaeian
Elliptic flow from color-dipole orientation in pp and pA collisions
28 pages, 22 figures; v2: extended version, new discussion about the relation between elliptic flow and eccentricity, 8 new plots and some additional references added
Phys. Rev. D 95, 094003 (2017)
10.1103/PhysRevD.95.094003
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For ultrarelativistic proton-proton and proton-nucleus collisions, we perform an exploratory study of the contribution to the elliptic flow $v_2$ coming from the orientation of the momentum of the produced particles with respect to the reaction plane. Via the CGC factorization valid at high energies, this contribution is related to the orientation of a color dipole with respect to its impact parameter, which in turn probes the transverse inhomogeneity in the target. Using the McLerran-Venugopalan model (with impact-parameter dependence) as an effective description for the soft gluon distribution in the (proton or nuclear) target, we present a semi-analytic calculation of the dipole scattering amplitude, including its angular dependence. We find that the angular dependence is controlled by soft gluon exchanges and hence is genuinely non-perturbative. The effects of multiple scattering turn out to be essential (in particular, they change the sign of $v_2$). We find that sizable values for $v_2$, comparable to those observed in the LHC data and having a similar dependence upon the transverse momenta of the produced particles, can be easily generated via peripheral collisions. In particular, $v_2$ develops a peak at a transverse momentum which scales with the saturation momentum in the target.
[ { "created": "Mon, 13 Feb 2017 19:00:39 GMT", "version": "v1" }, { "created": "Mon, 20 Mar 2017 18:01:03 GMT", "version": "v2" } ]
2017-05-09
[ [ "Iancu", "Edmond", "" ], [ "Rezaeian", "Amir H.", "" ] ]
For ultrarelativistic proton-proton and proton-nucleus collisions, we perform an exploratory study of the contribution to the elliptic flow $v_2$ coming from the orientation of the momentum of the produced particles with respect to the reaction plane. Via the CGC factorization valid at high energies, this contribution is related to the orientation of a color dipole with respect to its impact parameter, which in turn probes the transverse inhomogeneity in the target. Using the McLerran-Venugopalan model (with impact-parameter dependence) as an effective description for the soft gluon distribution in the (proton or nuclear) target, we present a semi-analytic calculation of the dipole scattering amplitude, including its angular dependence. We find that the angular dependence is controlled by soft gluon exchanges and hence is genuinely non-perturbative. The effects of multiple scattering turn out to be essential (in particular, they change the sign of $v_2$). We find that sizable values for $v_2$, comparable to those observed in the LHC data and having a similar dependence upon the transverse momenta of the produced particles, can be easily generated via peripheral collisions. In particular, $v_2$ develops a peak at a transverse momentum which scales with the saturation momentum in the target.
2304.08509
Elias Bernreuther
Elias Bernreuther and Bogdan A. Dobrescu
Vectorlike leptons and long-lived bosons at the LHC
30 pages, 9 figures; v2: includes NLO cross sections in Figure 3, presentation improvements, more references, matches published version
JHEP 07 (2023) 079
10.1007/JHEP07(2023)079
Fermilab-Pub-23-151-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a renormalizable theory that includes a heavy weak-singlet vectorlike lepton, $\tau^\prime$, that decays into a pseudoscalar boson and a tau lepton. We show that this can be the dominant decay mode of $\tau^\prime$ provided the pseudoscalar couplings deviate from the case of a Nambu-Goldstone boson. For a range of parameters, the pseudoscalar is long-lived, and mainly decays into a photon pair at one loop, or into a tau pair at tree level. Electroweak production of $\tau^{\prime +} \tau^{\prime -}$ leads to a rich phenomenology at colliders, including signals with many taus or photons. We analyze in detail the LHC signal involving two prompt taus and two displaced photon pairs. Particularly interesting is the case where the pseudoscalar has a decay length of a few meters and thus would typically deposit energy in the muon chambers of the CMS or ATLAS detectors.
[ { "created": "Mon, 17 Apr 2023 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 29 Aug 2023 16:40:51 GMT", "version": "v2" } ]
2023-08-30
[ [ "Bernreuther", "Elias", "" ], [ "Dobrescu", "Bogdan A.", "" ] ]
We study a renormalizable theory that includes a heavy weak-singlet vectorlike lepton, $\tau^\prime$, that decays into a pseudoscalar boson and a tau lepton. We show that this can be the dominant decay mode of $\tau^\prime$ provided the pseudoscalar couplings deviate from the case of a Nambu-Goldstone boson. For a range of parameters, the pseudoscalar is long-lived, and mainly decays into a photon pair at one loop, or into a tau pair at tree level. Electroweak production of $\tau^{\prime +} \tau^{\prime -}$ leads to a rich phenomenology at colliders, including signals with many taus or photons. We analyze in detail the LHC signal involving two prompt taus and two displaced photon pairs. Particularly interesting is the case where the pseudoscalar has a decay length of a few meters and thus would typically deposit energy in the muon chambers of the CMS or ATLAS detectors.
1112.5954
Bjorn Garbrecht
Bjorn Garbrecht and Matti Herranen
Effective Theory of Resonant Leptogenesis in the Closed-Time-Path Approach
46 pages, typos corrected, clarifying details added
Nuclear Physics, Section B 861 (2012), pp. 17-52
10.1016/j.nuclphysb.2012.03.009
TTK 11-63
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe mixing scalar particles and Majorana fermions using Closed-Time-Path methods. From the Kadanoff-Baym equations, we obtain the charge asymmetry, that is generated from decays and inverse decays of the mixing particles. Within one single formalism, we thereby treat Leptogenesis from oscillations and recover as well the standard results for the asymmetry in Resonant Leptogenesis, which apply when the oscillation frequency is much larger than the decay rate. Analytic solutions for two mixing neutral particles in a constant-temperature background illustrate our results qualitatively. We also perform the modification of the kinetic equations that is necessary in order to take account of the expansion of the Universe and the washout of the asymmetry.
[ { "created": "Tue, 27 Dec 2011 12:05:30 GMT", "version": "v1" }, { "created": "Wed, 4 Apr 2012 19:43:51 GMT", "version": "v2" } ]
2012-06-26
[ [ "Garbrecht", "Bjorn", "" ], [ "Herranen", "Matti", "" ] ]
We describe mixing scalar particles and Majorana fermions using Closed-Time-Path methods. From the Kadanoff-Baym equations, we obtain the charge asymmetry, that is generated from decays and inverse decays of the mixing particles. Within one single formalism, we thereby treat Leptogenesis from oscillations and recover as well the standard results for the asymmetry in Resonant Leptogenesis, which apply when the oscillation frequency is much larger than the decay rate. Analytic solutions for two mixing neutral particles in a constant-temperature background illustrate our results qualitatively. We also perform the modification of the kinetic equations that is necessary in order to take account of the expansion of the Universe and the washout of the asymmetry.
1501.01761
R Saleh-Moghaddam
R. Saleh-Moghaddam, M. E. Zomorrodian
The properties of C-parameter and coupling constants
6 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we present the properties of the C-parameter which is one of event shape variables. We obtain the coupling constants both in the perturbative and in the non-perturbative part of the QCD theory. To achieve this we fit the dispersive model as well as the shape function model with our data. Our results are consistent with the QCD predictions. We explain more features of our results in the main text.
[ { "created": "Thu, 8 Jan 2015 08:15:08 GMT", "version": "v1" }, { "created": "Sun, 12 Apr 2015 11:08:02 GMT", "version": "v2" } ]
2015-04-14
[ [ "Saleh-Moghaddam", "R.", "" ], [ "Zomorrodian", "M. E.", "" ] ]
In this article, we present the properties of the C-parameter which is one of event shape variables. We obtain the coupling constants both in the perturbative and in the non-perturbative part of the QCD theory. To achieve this we fit the dispersive model as well as the shape function model with our data. Our results are consistent with the QCD predictions. We explain more features of our results in the main text.
2311.06949
Carlos Wagner
Carlos E.M. Wagner
Electroweak Baryogenesis and Higgs Physics
12 pages, 11 figures. Contributed to the LHEP special issue on Higgs physics, and beyond, after 10 years since the discovery
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the constraints on the Higgs sector coming from the requirement of the generation of the matter-antimatter asymmetry at the electroweak phase transition. These relate to both a strongly first order first transition, necessary for the preservation of the generated baryon asymmetry, as well as CP-violation, necessary for its generation. This scenario may lead to exotic decays of the Standard Model like Higgs, a deviation of the di-Higgs production cross section, or CP-violation in the Higgs sector. All these aspects are expected to be probed by the LHC as well as by electric dipole moment experiments, among others. Further phenomenological implications are discussed in this short review.
[ { "created": "Sun, 12 Nov 2023 20:26:12 GMT", "version": "v1" } ]
2023-11-14
[ [ "Wagner", "Carlos E. M.", "" ] ]
We discuss the constraints on the Higgs sector coming from the requirement of the generation of the matter-antimatter asymmetry at the electroweak phase transition. These relate to both a strongly first order first transition, necessary for the preservation of the generated baryon asymmetry, as well as CP-violation, necessary for its generation. This scenario may lead to exotic decays of the Standard Model like Higgs, a deviation of the di-Higgs production cross section, or CP-violation in the Higgs sector. All these aspects are expected to be probed by the LHC as well as by electric dipole moment experiments, among others. Further phenomenological implications are discussed in this short review.
1803.08689
Mikko Laine
M. Laine, P. Schicho, Y. Schroder
Soft thermal contributions to 3-loop gauge coupling
31 pages. v2: clarifications added, published version
JHEP 1805 (2018) 037
10.1007/JHEP05(2018)037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze 3-loop contributions to the gauge coupling felt by ultrasoft ("magnetostatic") modes in hot Yang-Mills theory. So-called soft/hard terms, originating from dimension-six operators within the soft effective theory, are shown to cancel 1097/1098 of the IR divergence found in a recent determination of the hard 3-loop contribution to the soft gauge coupling. The remaining 1/1098 originates from ultrasoft/hard contributions, induced by dimension-six operators in the ultrasoft effective theory. Soft 3-loop contributions are likewise computed, and are found to be IR divergent, rendering the ultrasoft gauge coupling non-perturbative at relative order O(alphas^{3/2}). We elaborate on the implications of these findings for effective theory studies of physical observables in thermal QCD.
[ { "created": "Fri, 23 Mar 2018 08:51:33 GMT", "version": "v1" }, { "created": "Wed, 16 May 2018 06:30:49 GMT", "version": "v2" } ]
2018-05-17
[ [ "Laine", "M.", "" ], [ "Schicho", "P.", "" ], [ "Schroder", "Y.", "" ] ]
We analyze 3-loop contributions to the gauge coupling felt by ultrasoft ("magnetostatic") modes in hot Yang-Mills theory. So-called soft/hard terms, originating from dimension-six operators within the soft effective theory, are shown to cancel 1097/1098 of the IR divergence found in a recent determination of the hard 3-loop contribution to the soft gauge coupling. The remaining 1/1098 originates from ultrasoft/hard contributions, induced by dimension-six operators in the ultrasoft effective theory. Soft 3-loop contributions are likewise computed, and are found to be IR divergent, rendering the ultrasoft gauge coupling non-perturbative at relative order O(alphas^{3/2}). We elaborate on the implications of these findings for effective theory studies of physical observables in thermal QCD.
hep-ph/0201258
Oscar Wallace Greenberg
O.W. Greenberg
CPT Violation Implies Violation of Lorentz Invariance
Minor changes in the published version
Phys.Rev.Lett.89:231602,2002
10.1103/PhysRevLett.89.231602
Univ. of Md. Preprint PP-02-027
hep-ph hep-th quant-ph
null
An interacting theory that violates CPT invariance necessarily violates Lorentz invariance. On the other hand, CPT invariance is not sufficient for out-of-cone Lorentz invariance. Theories that violate CPT by having different particle and antiparticle masses must be nonlocal.
[ { "created": "Mon, 28 Jan 2002 16:52:03 GMT", "version": "v1" }, { "created": "Tue, 5 Feb 2002 17:33:54 GMT", "version": "v2" }, { "created": "Tue, 3 Dec 2002 19:33:25 GMT", "version": "v3" } ]
2010-04-06
[ [ "Greenberg", "O. W.", "" ] ]
An interacting theory that violates CPT invariance necessarily violates Lorentz invariance. On the other hand, CPT invariance is not sufficient for out-of-cone Lorentz invariance. Theories that violate CPT by having different particle and antiparticle masses must be nonlocal.
1611.03653
Bernd-Jochen Schaefer
Ana Juri\v{c}i\'c and Bernd-Jochen Schaefer
Chiral Thermodynamics in a finite box
5 pages, 3 figures, Proceedings CPOD2016, Wroclaw, Poland
null
null
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Finite-volume modifications of the two-flavor chiral phase diagram are investigated within an effective quark-meson model in various mean-field approximations. The role of vacuum fluctuations and boundary conditions, their influence on higher cumulants and signatures of a possible pseudo-critical endpoint are amplified with smaller volumes.
[ { "created": "Fri, 11 Nov 2016 10:54:14 GMT", "version": "v1" } ]
2016-11-14
[ [ "Juričić", "Ana", "" ], [ "Schaefer", "Bernd-Jochen", "" ] ]
Finite-volume modifications of the two-flavor chiral phase diagram are investigated within an effective quark-meson model in various mean-field approximations. The role of vacuum fluctuations and boundary conditions, their influence on higher cumulants and signatures of a possible pseudo-critical endpoint are amplified with smaller volumes.
2112.15062
Guang-You Qin
Wen-Jing Xing, Guang-You Qin, Shanshan Cao
Perturbative and non-perturbative interactions between heavy quarks and quark-gluon plasma within a unified approach
9 pages, 5 figures
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
While perturbative QCD is sufficient for understanding the color, mass and energy dependences of parton energy loss and jet quenching at large transverse momentum in heavy-ion collisions, a simultaneous description of heavy flavor nuclear modification factor $R_\mathrm{AA}$ and elliptic flow coefficient $v_2$ at low and intermediate $p_\mathrm{T}$ still remains a challenge due to the effects from non-perturbative interactions. In this work, we extend the linear Boltzmann transport model by implementing a generalized Cornell-type potential that incorporates both short-range Yukawa interaction and long-range color confining interaction between heavy quarks and the QGP medium. Combining our new approach for heavy-quark-QGP interaction with a (3+1)-dimensional hydrodynamic model CLVisc for the QGP evolution and a hybrid fragmentation-coalescence model for heavy quark hadronization, we obtain a satisfactory description of heavy meson $R_\mathrm{AA}$ and $v_2$ from low to intermediate to high $p_\mathrm{T}$ observed at both RHIC and the LHC. By model-data-comparison, we extract for the first time the in-medium heavy quark potential from open heavy flavor measurements; the result is in agreement with the lattice QCD calculation. Our study indicates that while jet quenching at high $p_\mathrm{T}$ is dominated by perturbative QCD interactions, non-perturbative interactions are indispensible for understanding heavy flavor quenching and flow at low and intermediate $p_\mathrm{T}$.
[ { "created": "Thu, 30 Dec 2021 13:53:10 GMT", "version": "v1" } ]
2022-01-03
[ [ "Xing", "Wen-Jing", "" ], [ "Qin", "Guang-You", "" ], [ "Cao", "Shanshan", "" ] ]
While perturbative QCD is sufficient for understanding the color, mass and energy dependences of parton energy loss and jet quenching at large transverse momentum in heavy-ion collisions, a simultaneous description of heavy flavor nuclear modification factor $R_\mathrm{AA}$ and elliptic flow coefficient $v_2$ at low and intermediate $p_\mathrm{T}$ still remains a challenge due to the effects from non-perturbative interactions. In this work, we extend the linear Boltzmann transport model by implementing a generalized Cornell-type potential that incorporates both short-range Yukawa interaction and long-range color confining interaction between heavy quarks and the QGP medium. Combining our new approach for heavy-quark-QGP interaction with a (3+1)-dimensional hydrodynamic model CLVisc for the QGP evolution and a hybrid fragmentation-coalescence model for heavy quark hadronization, we obtain a satisfactory description of heavy meson $R_\mathrm{AA}$ and $v_2$ from low to intermediate to high $p_\mathrm{T}$ observed at both RHIC and the LHC. By model-data-comparison, we extract for the first time the in-medium heavy quark potential from open heavy flavor measurements; the result is in agreement with the lattice QCD calculation. Our study indicates that while jet quenching at high $p_\mathrm{T}$ is dominated by perturbative QCD interactions, non-perturbative interactions are indispensible for understanding heavy flavor quenching and flow at low and intermediate $p_\mathrm{T}$.
hep-ph/0608290
Jose Antonio Oller
Jose A. Oller, Luis Roca
Non-Perturbative Study of the Light Pseudoscalar Masses in Chiral Dynamics
26 pages, 9 figures. Original new material is included. Major rewriting when comparing with lattice QCD
Eur.Phys.J.A34:371-386,2007
10.1140/epja/i2006-10516-7
null
hep-ph hep-lat nucl-th
null
We perform a non-perturbative chiral study of the masses of the lightest pseudoscalar mesons. In the calculation of the self-energies we employ the S-wave meson-meson amplitudes taken from Unitary Chiral Perturbation Theory (UCHPT) that include the lightest nonet of scalar resonances. Values for the bare masses of pions and kaons are obtained, as well as an estimate of the mass of the \eta_8. The former are found to dominate the physical pseudoscalar masses. We then match to the self-energies from Chiral Perturbation Theory (CHPT) to O(p^4), and a robust relation between several O(p^4) CHPT counterterms is obtained. We also resum higher orders from our calculated self-energies. By taking into account values determined from previous chiral phenomenological studies of m_s/\hat{m} and 3L_7+L^r_8, we determine a tighter region of favoured values for the O(p^4) CHPT counterterms 2L^r_6-L^r_4 and 2L^r_8-L^r_5. This determination perfectly overlaps with the recent determinations to O(p^6) in CHPT. We warn about a likely reduction in the value of m_s/\hat{m} by higher loop diagrams and that this is not systematically accounted for by present lattice extrapolations. We also provide a favoured interval of values for m_s/\hat{m} and 3L_7+L^r_8.
[ { "created": "Mon, 28 Aug 2006 14:26:46 GMT", "version": "v1" }, { "created": "Sun, 2 Dec 2007 18:26:24 GMT", "version": "v2" } ]
2009-09-29
[ [ "Oller", "Jose A.", "" ], [ "Roca", "Luis", "" ] ]
We perform a non-perturbative chiral study of the masses of the lightest pseudoscalar mesons. In the calculation of the self-energies we employ the S-wave meson-meson amplitudes taken from Unitary Chiral Perturbation Theory (UCHPT) that include the lightest nonet of scalar resonances. Values for the bare masses of pions and kaons are obtained, as well as an estimate of the mass of the \eta_8. The former are found to dominate the physical pseudoscalar masses. We then match to the self-energies from Chiral Perturbation Theory (CHPT) to O(p^4), and a robust relation between several O(p^4) CHPT counterterms is obtained. We also resum higher orders from our calculated self-energies. By taking into account values determined from previous chiral phenomenological studies of m_s/\hat{m} and 3L_7+L^r_8, we determine a tighter region of favoured values for the O(p^4) CHPT counterterms 2L^r_6-L^r_4 and 2L^r_8-L^r_5. This determination perfectly overlaps with the recent determinations to O(p^6) in CHPT. We warn about a likely reduction in the value of m_s/\hat{m} by higher loop diagrams and that this is not systematically accounted for by present lattice extrapolations. We also provide a favoured interval of values for m_s/\hat{m} and 3L_7+L^r_8.
hep-ph/0005295
Shaouly Bar-Shalom
S. Bar-Shalom, G. Eilam and B. Mele
Sneutrino-Higgs mixing in WW and ZZ production in supersymmetry with R-parity violation
7 pages in revtex, 3 figures embadded in the text using epsfig. As will appear in Phys. Lett. B. The main change to the paper with respect to Version 1 was a correction to the numerical results due to an error detected in the scalar mass matrix
Phys.Lett. B500 (2001) 297-303
10.1016/S0370-2693(01)00076-4
ROME1-1295/00
hep-ph
null
We consider new s-channel scalar exchanges in e+e- -> ZZ,W+W- in supersymmetry with a small lepton number violation. We show that a small bilinear R-parity violating term which leads to sneutrino--Higgs mixing can give rise to a significant scalar resonance enhancement in e+e- -> ZZ,W+W-. We use the LEP2 measurements of the WW and ZZ cross-sections to place useful constraints on this scenario. We also find, under conservative assumptions on the relevant parameter space involved, that such an exchange of the sneutrino-like admixture in e+e- -> ZZ,W+W- may be accessible to a 500 GeV e+e- collider.
[ { "created": "Tue, 30 May 2000 08:30:13 GMT", "version": "v1" }, { "created": "Mon, 18 Dec 2000 16:17:24 GMT", "version": "v2" } ]
2009-10-31
[ [ "Bar-Shalom", "S.", "" ], [ "Eilam", "G.", "" ], [ "Mele", "B.", "" ] ]
We consider new s-channel scalar exchanges in e+e- -> ZZ,W+W- in supersymmetry with a small lepton number violation. We show that a small bilinear R-parity violating term which leads to sneutrino--Higgs mixing can give rise to a significant scalar resonance enhancement in e+e- -> ZZ,W+W-. We use the LEP2 measurements of the WW and ZZ cross-sections to place useful constraints on this scenario. We also find, under conservative assumptions on the relevant parameter space involved, that such an exchange of the sneutrino-like admixture in e+e- -> ZZ,W+W- may be accessible to a 500 GeV e+e- collider.
2112.08038
Pablo G. Ortega
Pablo G. Ortega, David R. Entem, Francisco Fernandez
The $Z_{cs}(3985)^-$ structure in a coupled-channels model
5 pages, 2 figures. Conference proceeding. Submitted to Suplemento de la Revista Mexicana de F\'isica, 19th International conference on hadron spectroscopy and structure in memoriam Simon Eidelman
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discovery of the $Z_c(3900)^\pm$ and $Z_b(10610)^\pm$ structures in the heavy quarkonium spectrum showed the need to incorporate hadron structures beyond the naive $qqq$ and $q\bar q$ systems in quark models. The new charged structure called $Z_{cs}(3985)^-$, spotted in the $K^+$ recoil-mass spectrum close to the $D^-_s D^{*0}/D^{*-}_sD^0$ threshold, is a new evidence in this line. In this work, we analyze the $Z_{cs}(3985)^-$ state, following the calculation of the $Z_c$ and $Z_b$ states using a chiral constituent quark model in a coupled-channels calculation, with all the parameters constrained from previous calculations. The pole structure of the S-matrix shows two virtual poles below the $D_s^-D^{*\,0}$ and $D_s^{*\,-}D^{*\,0}$ thresholds compatible with the $Z_{cs}(3985)^\pm$ and a new predicted $Z_{cs}(4110)^\pm$ structure, the SU(3) flavor partner of the $Z_c(4020)^\pm$. The $K^+$ recoil-mass spectrum is calculated in good agreement with LHCb and BESIII experimental data, with no fine tuning of the model parameters. Our results indicate that the $Z_{cs}(3985)^\pm$ and $Z_{cs}(4000)^\pm$ signals originate from the same virtual state.
[ { "created": "Wed, 15 Dec 2021 11:02:45 GMT", "version": "v1" } ]
2021-12-16
[ [ "Ortega", "Pablo G.", "" ], [ "Entem", "David R.", "" ], [ "Fernandez", "Francisco", "" ] ]
The discovery of the $Z_c(3900)^\pm$ and $Z_b(10610)^\pm$ structures in the heavy quarkonium spectrum showed the need to incorporate hadron structures beyond the naive $qqq$ and $q\bar q$ systems in quark models. The new charged structure called $Z_{cs}(3985)^-$, spotted in the $K^+$ recoil-mass spectrum close to the $D^-_s D^{*0}/D^{*-}_sD^0$ threshold, is a new evidence in this line. In this work, we analyze the $Z_{cs}(3985)^-$ state, following the calculation of the $Z_c$ and $Z_b$ states using a chiral constituent quark model in a coupled-channels calculation, with all the parameters constrained from previous calculations. The pole structure of the S-matrix shows two virtual poles below the $D_s^-D^{*\,0}$ and $D_s^{*\,-}D^{*\,0}$ thresholds compatible with the $Z_{cs}(3985)^\pm$ and a new predicted $Z_{cs}(4110)^\pm$ structure, the SU(3) flavor partner of the $Z_c(4020)^\pm$. The $K^+$ recoil-mass spectrum is calculated in good agreement with LHCb and BESIII experimental data, with no fine tuning of the model parameters. Our results indicate that the $Z_{cs}(3985)^\pm$ and $Z_{cs}(4000)^\pm$ signals originate from the same virtual state.
1307.0007
Simone Marzani
Mrinal Dasgupta, Alessandro Fregoso, Simone Marzani and Gavin P. Salam
Towards an understanding of jet substructure
52 pages, 18 figures. Version to be published in JHEP: added an Appendix about Y-trimming and addressed several points raised by the referee
JHEP09 (2013) 029
10.1007/JHEP09(2013)029
CERN-PH-TH/2013-145, DCPT/13/86, IPPP/13/43, LPN13-036, MAN/HEP/2013/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present first analytic, resummed calculations of the rates at which widespread jet substructure tools tag QCD jets. As well as considering trimming, pruning and the mass-drop tagger, we introduce modified tools with improved analytical and phenomenological behaviours. Most taggers have double logarithmic resummed structures. The modified mass-drop tagger is special in that it involves only single logarithms, and is free from a complex class of terms known as non-global logarithms. The modification of pruning brings an improved ability to discriminate between the different colour structures that characterise signal and background. As we outline in an extensive phenomenological discussion, these results provide valuable insight into the performance of existing tools and help lay robust foundations for future substructure studies.
[ { "created": "Fri, 28 Jun 2013 20:00:02 GMT", "version": "v1" }, { "created": "Thu, 5 Sep 2013 07:53:00 GMT", "version": "v2" } ]
2013-09-10
[ [ "Dasgupta", "Mrinal", "" ], [ "Fregoso", "Alessandro", "" ], [ "Marzani", "Simone", "" ], [ "Salam", "Gavin P.", "" ] ]
We present first analytic, resummed calculations of the rates at which widespread jet substructure tools tag QCD jets. As well as considering trimming, pruning and the mass-drop tagger, we introduce modified tools with improved analytical and phenomenological behaviours. Most taggers have double logarithmic resummed structures. The modified mass-drop tagger is special in that it involves only single logarithms, and is free from a complex class of terms known as non-global logarithms. The modification of pruning brings an improved ability to discriminate between the different colour structures that characterise signal and background. As we outline in an extensive phenomenological discussion, these results provide valuable insight into the performance of existing tools and help lay robust foundations for future substructure studies.
hep-ph/9606365
Osada Takeshi
T.Osada, S.Sano, and M.Biyajima
Coulomb and strong interactions for Bose-Einstein correlations
13 pages, Latex type, 9 figures. To appear Z.Phys.C
Z.Phys. C72 (1996) 285-290
10.1007/BF02909156
DPSU-95-10
hep-ph
null
We present an analytical formula for the Bose-Einstein correlations (BEC) which includes effects of both Coulomb and strong final stateinteractions (FSI). It was obtained by using Coulomb wave function together with the scattering partial wave amplitude of the strong interactions describing data on the $s$-wave phase shift. We have proved numerically that this method is equivalent to solving Schr\"{o}dinger equation with Coulomb and the $s$-wave strong interaction potentials. As an application we have analysed, using our formula which includes the degree of coherence and the long range correlation, the data for $e^+e^-$ annihilations. We have found that the degree of coherence present in our formula approaches approximately unity whereas the long range correlation parameter becomes approximately zero. These results suggest that the physical meanings of the fractional degree of coherence and the long range correlation observed in various other analyses can most probably be attributed to FSI.
[ { "created": "Wed, 19 Jun 1996 05:07:02 GMT", "version": "v1" } ]
2009-10-28
[ [ "Osada", "T.", "" ], [ "Sano", "S.", "" ], [ "Biyajima", "M.", "" ] ]
We present an analytical formula for the Bose-Einstein correlations (BEC) which includes effects of both Coulomb and strong final stateinteractions (FSI). It was obtained by using Coulomb wave function together with the scattering partial wave amplitude of the strong interactions describing data on the $s$-wave phase shift. We have proved numerically that this method is equivalent to solving Schr\"{o}dinger equation with Coulomb and the $s$-wave strong interaction potentials. As an application we have analysed, using our formula which includes the degree of coherence and the long range correlation, the data for $e^+e^-$ annihilations. We have found that the degree of coherence present in our formula approaches approximately unity whereas the long range correlation parameter becomes approximately zero. These results suggest that the physical meanings of the fractional degree of coherence and the long range correlation observed in various other analyses can most probably be attributed to FSI.
0708.3593
Tuhin Roy
Tuhin S. Roy, Martin Schmaltz
A hidden solution to the mu/B_mu problem in gauge mediation
minor clarifications, examples added, version to appear in PRD
Phys.Rev.D77:095008,2008
10.1103/PhysRevD.77.095008
BUHEP-07-06
hep-ph hep-th
null
We propose a solution to the mu/B_mu problem in gauge mediation. The novel feature of our solution is that it uses dynamics of the hidden sector, which is often present in models with dynamical supersymmetry breaking. We give an explicit example model of gauge mediation where a very simple messenger sector generates both mu and B_mu at one loop. The usual problem, that B_mu is then too large, is solved by strong renormalization effects from the hidden sector which suppress B_mu relative to mu. Our mechanism relies on an assumption about the signs of certain incalculable anomalous dimensions in the hidden sector. Making these assumptions not only allows us to solve the mu/B_mu problem but also leads to a characteristic superpartner spectrum which would be a smoking gun signal for our mechanism.
[ { "created": "Mon, 27 Aug 2007 19:01:26 GMT", "version": "v1" }, { "created": "Fri, 28 Mar 2008 16:33:02 GMT", "version": "v2" } ]
2008-11-26
[ [ "Roy", "Tuhin S.", "" ], [ "Schmaltz", "Martin", "" ] ]
We propose a solution to the mu/B_mu problem in gauge mediation. The novel feature of our solution is that it uses dynamics of the hidden sector, which is often present in models with dynamical supersymmetry breaking. We give an explicit example model of gauge mediation where a very simple messenger sector generates both mu and B_mu at one loop. The usual problem, that B_mu is then too large, is solved by strong renormalization effects from the hidden sector which suppress B_mu relative to mu. Our mechanism relies on an assumption about the signs of certain incalculable anomalous dimensions in the hidden sector. Making these assumptions not only allows us to solve the mu/B_mu problem but also leads to a characteristic superpartner spectrum which would be a smoking gun signal for our mechanism.
0909.3374
Andrei Shuvaev
M.G. Ryskin, A.G. Shuvaev
Higgs Boson as a Dilaton
12 pages, 1 figure
Phys.Atom.Nucl.73:965-970,2010
10.1134/S1063778810060104
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study possible phenomenological consequences of the recently proposed new approach to the Weinberg-Salam model. The electroweak theory is considered as a gravity and the Higgs particle is interpreted in it as a dilaton, without the usual potential of interaction in the Higgs sector. We have taken as a test the process of photons pair production, $e^+ + e^- \to Z + \gamma + \gamma$. In the framework of new formulation this reaction is mediated in the lowest order by the dilaton. The cross section is found to be rather small.
[ { "created": "Fri, 18 Sep 2009 07:45:33 GMT", "version": "v1" } ]
2014-11-20
[ [ "Ryskin", "M. G.", "" ], [ "Shuvaev", "A. G.", "" ] ]
We study possible phenomenological consequences of the recently proposed new approach to the Weinberg-Salam model. The electroweak theory is considered as a gravity and the Higgs particle is interpreted in it as a dilaton, without the usual potential of interaction in the Higgs sector. We have taken as a test the process of photons pair production, $e^+ + e^- \to Z + \gamma + \gamma$. In the framework of new formulation this reaction is mediated in the lowest order by the dilaton. The cross section is found to be rather small.
hep-ph/0210164
Zou BingSong
B. S. Zou (Institute of High Energy Physics, CAS, Beijing, China) and F. Hussain (Abdus Salam International Centre for Theoretical Physics, Trieste, Italy)
Covariant L-S Scheme for the effective N*NM couplings
Postscript file, 14 pages
Phys.Rev. C67 (2003) 015204
10.1103/PhysRevC.67.015204
BIHEP-TH-2002-29
hep-ph
null
For excited nucleon states $N^*$ of arbitrary spin coupling to nucleon (N) and meson (M), we propose a Lorentz covariant orbital-spin (L-S) scheme for the effective $N^*NM$ couplings. To be used for the partial wave analysis of various $N^*$ production and decay processes, it combines merits of two conventional schemes, {\sl i.e.}, covariant effective Lagrangian approach and multipole analysis with amplitudes expanded according to angular momentum L. As examples, explicit formulae are given for $N^*\to N\pi$, $N^*\to N\omega$ and $\psi\to N^*\bar N$ processes which are under current experimental studies.
[ { "created": "Thu, 10 Oct 2002 15:08:10 GMT", "version": "v1" } ]
2009-11-07
[ [ "Zou", "B. S.", "", "Institute of High Energy Physics, CAS, Beijing, China" ], [ "Hussain", "F.", "", "Abdus Salam International Centre for Theoretical Physics,\n Trieste, Italy" ] ]
For excited nucleon states $N^*$ of arbitrary spin coupling to nucleon (N) and meson (M), we propose a Lorentz covariant orbital-spin (L-S) scheme for the effective $N^*NM$ couplings. To be used for the partial wave analysis of various $N^*$ production and decay processes, it combines merits of two conventional schemes, {\sl i.e.}, covariant effective Lagrangian approach and multipole analysis with amplitudes expanded according to angular momentum L. As examples, explicit formulae are given for $N^*\to N\pi$, $N^*\to N\omega$ and $\psi\to N^*\bar N$ processes which are under current experimental studies.
hep-ph/9905413
Catherine Bourge
G. Borisov, F. Richard (LAL-Orsay)
Precise measurement of Higgs decay rate into WW* at future e^+e^- Linear Colliders
12 pages
null
null
LAL 99-26
hep-ph
null
Assuming a SM or MSSM scenario, one expects a light Higgs boson which could be studied in great detail with a LC operating at \sqrt s>m_h+m_Z. In the TESLA scenario, with 500 fb^-1 accumulated at \sqrt s = 350 GeV, about 10^5 hZ events could be produced through the Higgstrahlung process. At a future LC with a \sim 1 cm beam-pipe radius and a thin Si detector there will be excellent separation between the various flavours. With the high statistics available it will thus become possible to measure the various branching ratios with a few % error. Typically one expects 8 % precision on BR(h\to\bar cc), 6 % on BR(h\to gg) and \sim 1 % on \sigma(hZ) x BR(h\to\bar bb) access to BR(h\to WW^*) and, as explained in section 3, this measurement can give access to the Higgs total decay width and therefore to all partial widths. In particular one can precisely measure \Gamma(h\to\bar bb) and \Gamma(h\to\tau^+\tau^-) which have a high sensitivity to MSSM effects\cite{gunion} and therefore allow an essential test of the Higgs sector. If m_A < 1 TeV, it becomes possible to measure a significant deviation and, within MSSM, to give an indirect estimate of m_A thus extending the effective sensitivity above the discovery domain of LHC. In the following section we describe a detailed analysis on the measurement of BR(h\to WW^*).
[ { "created": "Thu, 20 May 1999 08:51:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Borisov", "G.", "", "LAL-Orsay" ], [ "Richard", "F.", "", "LAL-Orsay" ] ]
Assuming a SM or MSSM scenario, one expects a light Higgs boson which could be studied in great detail with a LC operating at \sqrt s>m_h+m_Z. In the TESLA scenario, with 500 fb^-1 accumulated at \sqrt s = 350 GeV, about 10^5 hZ events could be produced through the Higgstrahlung process. At a future LC with a \sim 1 cm beam-pipe radius and a thin Si detector there will be excellent separation between the various flavours. With the high statistics available it will thus become possible to measure the various branching ratios with a few % error. Typically one expects 8 % precision on BR(h\to\bar cc), 6 % on BR(h\to gg) and \sim 1 % on \sigma(hZ) x BR(h\to\bar bb) access to BR(h\to WW^*) and, as explained in section 3, this measurement can give access to the Higgs total decay width and therefore to all partial widths. In particular one can precisely measure \Gamma(h\to\bar bb) and \Gamma(h\to\tau^+\tau^-) which have a high sensitivity to MSSM effects\cite{gunion} and therefore allow an essential test of the Higgs sector. If m_A < 1 TeV, it becomes possible to measure a significant deviation and, within MSSM, to give an indirect estimate of m_A thus extending the effective sensitivity above the discovery domain of LHC. In the following section we describe a detailed analysis on the measurement of BR(h\to WW^*).
hep-ph/0602090
Sergey Kulagin
S. A. Kulagin and R. Petti
Phenomenology of lepton-nucleus DIS
6 pages, 5 figures, to appear in Proceedings of 4th International Workshop On Neutrino-Nucleus Interactions In The Few-GeV Region (NuInt05), 26-29 Sep. 2005, Okayama, Japan
Nucl.Phys.Proc.Suppl.159:180-185,2006
10.1016/j.nuclphysbps.2006.08.036
null
hep-ph
null
The results of recent phenomenological studies of unpolarized nuclear deep-inelastic scattering are discussed and applied to calculate neutrino charged-current structure functions and cross sections for a number of nuclei.
[ { "created": "Fri, 10 Feb 2006 13:38:41 GMT", "version": "v1" } ]
2014-11-18
[ [ "Kulagin", "S. A.", "" ], [ "Petti", "R.", "" ] ]
The results of recent phenomenological studies of unpolarized nuclear deep-inelastic scattering are discussed and applied to calculate neutrino charged-current structure functions and cross sections for a number of nuclei.
hep-ph/9401248
Mary Ann Rotondo
Kyungsik Kang
LEP Electroweak Physics
18 pages
null
null
Brown-HET-931
hep-ph
null
This is an overview of the electroweak physics achieved at LEP. After a brief review of the standard model and the calculation of the radiative corrections both in the MS and on-shell schemes, we introduce the Z decay parameters around the resonance energy and discuss the status of the standard model fits for them, along with some selected highlights of the measurements as well as new particle searches.
[ { "created": "Thu, 13 Jan 1994 20:01:34 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kang", "Kyungsik", "" ] ]
This is an overview of the electroweak physics achieved at LEP. After a brief review of the standard model and the calculation of the radiative corrections both in the MS and on-shell schemes, we introduce the Z decay parameters around the resonance energy and discuss the status of the standard model fits for them, along with some selected highlights of the measurements as well as new particle searches.
2005.03013
Matthias Neubert
Ze Long Liu (LANL), Bianka Mecaj (U. Mainz), Matthias Neubert (U. Mainz & Cornell), Xing Wang (U. Mainz) and Sean Fleming (U. Mainz & U. Arizona)
Renormalization and Scale Evolution of the Soft-Quark Soft Function
30 pages plus appendices and references, 6 figures
null
10.1007/JHEP07(2020)104
MITP/20-023
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Soft functions defined in terms of matrix elements of soft fields dressed by Wilson lines are central components of factorization theorems for cross sections and decay rates in collider and heavy-quark physics. While in many cases the relevant soft functions are defined in terms of gluon operators, at subleading order in power counting soft functions containing quark fields appear. We present a detailed discussion of the properties of the soft-quark soft function consisting of a quark propagator dressed by two finite-length Wilson lines connecting at one point. This function enters in the factorization theorem for the Higgs-boson decay amplitude of the $h\to\gamma\gamma$ process mediated by light-quark loops. We perform the renormalization of this soft function at one-loop order, derive its two-loop anomalous dimension and discuss solutions to its renormalization-group evolution equation in momentum space, in Laplace space and in the "diagonal space", where the evolution is strictly multiplicative.
[ { "created": "Wed, 6 May 2020 18:00:00 GMT", "version": "v1" } ]
2020-08-26
[ [ "Liu", "Ze Long", "", "LANL" ], [ "Mecaj", "Bianka", "", "U. Mainz" ], [ "Neubert", "Matthias", "", "U.\n Mainz & Cornell" ], [ "Wang", "Xing", "", "U. Mainz" ], [ "Fleming", "Sean", "", "U. Mainz & U.\n Arizona" ] ]
Soft functions defined in terms of matrix elements of soft fields dressed by Wilson lines are central components of factorization theorems for cross sections and decay rates in collider and heavy-quark physics. While in many cases the relevant soft functions are defined in terms of gluon operators, at subleading order in power counting soft functions containing quark fields appear. We present a detailed discussion of the properties of the soft-quark soft function consisting of a quark propagator dressed by two finite-length Wilson lines connecting at one point. This function enters in the factorization theorem for the Higgs-boson decay amplitude of the $h\to\gamma\gamma$ process mediated by light-quark loops. We perform the renormalization of this soft function at one-loop order, derive its two-loop anomalous dimension and discuss solutions to its renormalization-group evolution equation in momentum space, in Laplace space and in the "diagonal space", where the evolution is strictly multiplicative.
1212.4683
Roberto Iengo
Giorgio Calucci, Roberto Iengo
Lower bound for the ratio of charged wino tracks to charged lepton tracks at LHC
9 pages, abstract modified, improved explanations, new reference and wino track length corrected
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By using kinematical arguments we derive a theorem for the ratio: [production cross-section of charged-neutral wino pairs plus anything else] over [production cross-section of charged-neutral lepton pairs plus anything else]. We do that by working out the consequences of substituting the lepton pair with a wino pair, leaving untouched everything else of the interaction. We apply this result to the possible production of winos at LHC obtaining a lower bound for the ratio of the number of charged-winos over charged-leptons tracks and also find the average charged-wino track length, within a region in the relevant parameter space (e.g. available energy and mass).
[ { "created": "Wed, 19 Dec 2012 14:52:54 GMT", "version": "v1" }, { "created": "Tue, 15 Jan 2013 16:14:47 GMT", "version": "v2" } ]
2013-01-16
[ [ "Calucci", "Giorgio", "" ], [ "Iengo", "Roberto", "" ] ]
By using kinematical arguments we derive a theorem for the ratio: [production cross-section of charged-neutral wino pairs plus anything else] over [production cross-section of charged-neutral lepton pairs plus anything else]. We do that by working out the consequences of substituting the lepton pair with a wino pair, leaving untouched everything else of the interaction. We apply this result to the possible production of winos at LHC obtaining a lower bound for the ratio of the number of charged-winos over charged-leptons tracks and also find the average charged-wino track length, within a region in the relevant parameter space (e.g. available energy and mass).
hep-ph/9704327
null
Keiichi Akama, Kazuo Katsuura (Saitama Medical College) and Hidezumi Terazawa (Institute of Particle and Nuclear Studies, HEARO)
Has the Substructure of Quarks and Leptons Been Found also by the H1 and ZEUS Detectors at HERA?
7 pages, revtex, 2 Postscript figures
Phys.Rev.D56:2490-2494,1997
10.1103/PhysRevD.56.R2490
KEK Preprint 97-7, SMC-PHYS-153
hep-ph
null
The significant excess of events recently found by the H1 and ZEUS Collaborations at HERA in the deep-inelastic e^+ p scattering for high momentum-transfers squared Q^2>15000 GeV^2 over the expectation of the standard model can be explained by either one of the following possible consequences of the substructure of quarks and leptons: 1) production of leptoquarks (Phi), 2) exchange of an excited Z boson (Z'), 3) intrinsic form factors of quarks (or leptons), 4) intrinsic anomalous magnetic moments of quarks, 5) production of excited quarks (q^*), and 6) that of excited positrons (e^*+). The masses of these new particles are estimated to be m(Phi) = 280-440 GeV, m(Z') = 210-250 GeV, m(q^*) = 120-140 GeV, and m(e^*+) = 300-370 GeV, although the possibilities 2) and 5) are excluded by the currently available experimental constraints.
[ { "created": "Tue, 15 Apr 1997 10:57:22 GMT", "version": "v1" }, { "created": "Thu, 17 Apr 1997 04:57:21 GMT", "version": "v2" }, { "created": "Thu, 24 Apr 1997 03:57:52 GMT", "version": "v3" }, { "created": "Sat, 31 May 1997 11:15:10 GMT", "version": "v4" } ]
2009-12-30
[ [ "Akama", "Keiichi", "", "Saitama Medical College" ], [ "Katsuura", "Kazuo", "", "Saitama Medical College" ], [ "Terazawa", "Hidezumi", "", "Institute of Particle and Nuclear Studies, HEARO" ] ]
The significant excess of events recently found by the H1 and ZEUS Collaborations at HERA in the deep-inelastic e^+ p scattering for high momentum-transfers squared Q^2>15000 GeV^2 over the expectation of the standard model can be explained by either one of the following possible consequences of the substructure of quarks and leptons: 1) production of leptoquarks (Phi), 2) exchange of an excited Z boson (Z'), 3) intrinsic form factors of quarks (or leptons), 4) intrinsic anomalous magnetic moments of quarks, 5) production of excited quarks (q^*), and 6) that of excited positrons (e^*+). The masses of these new particles are estimated to be m(Phi) = 280-440 GeV, m(Z') = 210-250 GeV, m(q^*) = 120-140 GeV, and m(e^*+) = 300-370 GeV, although the possibilities 2) and 5) are excluded by the currently available experimental constraints.
hep-ph/0104124
V. J. Kolhinen
K.J. Eskola, V.J. Kolhinen, R. Vogt
Obtaining the nuclear gluon distribution from heavy quark decays to lepton pairs in p$A$ collisions
19 pages, 6 figures
Nucl.Phys. A696 (2001) 729-746
10.1016/S0375-9474(01)01221-0
JYFL-6/01
hep-ph nucl-th
null
We have studied how lepton pairs from decays of heavy-flavoured mesons produced in p$A$ collisions can be used to determine the modifications of the gluon distribution in the nucleus. Since heavy quark production is dominated by the $gg$ channel, the ratio of correlated lepton pair cross sections from $D\bar D$ and $B\bar B$ decays in p$A$ and pp collisions directly reflects the ratio $R_g^A \equiv f_g^A/f_g^p$. We have numerically calculated the lepton pair cross sections from these decays in pp and p$A$ collisions at SPS, RHIC and LHC energies. We find that ratio of the p$A$ to pp cross sections agrees quite well with the input $R_g^A.$ Thus, sufficiently accurate measurements could be used to determine the nuclear modification of the gluon distribution over a greater range of $x$ and $Q^2$ than presently available, putting strong constraints on models.
[ { "created": "Thu, 12 Apr 2001 10:41:56 GMT", "version": "v1" } ]
2009-11-07
[ [ "Eskola", "K. J.", "" ], [ "Kolhinen", "V. J.", "" ], [ "Vogt", "R.", "" ] ]
We have studied how lepton pairs from decays of heavy-flavoured mesons produced in p$A$ collisions can be used to determine the modifications of the gluon distribution in the nucleus. Since heavy quark production is dominated by the $gg$ channel, the ratio of correlated lepton pair cross sections from $D\bar D$ and $B\bar B$ decays in p$A$ and pp collisions directly reflects the ratio $R_g^A \equiv f_g^A/f_g^p$. We have numerically calculated the lepton pair cross sections from these decays in pp and p$A$ collisions at SPS, RHIC and LHC energies. We find that ratio of the p$A$ to pp cross sections agrees quite well with the input $R_g^A.$ Thus, sufficiently accurate measurements could be used to determine the nuclear modification of the gluon distribution over a greater range of $x$ and $Q^2$ than presently available, putting strong constraints on models.
hep-ph/9509426
Bernd Schlei
B.R. Schlei, U. Ornik, M. Pl\"umer, D. Strottman and R.M. Weiner
Hydrodynamical analysis of single inclusive spectra and Bose-Einstein correlations for $Pb+Pb$ at 160 AGeV
13 pages, 5 Postscript figures (attached to this file as compressed and uuencoded Postscript file)
Phys.Lett. B376 (1996) 212-219
10.1016/0370-2693(96)00202-X
LAUR-95-3232
hep-ph
null
We present the first analysis of preliminary data for $Pb+Pb$ at 160 $AGeV$ using 3+1-dimensional relativistic hydrodynamics. We find excellent agreement with the rapidity spectra of negative hadrons and the correlation measurements. The data indicates a large amount of stopping; $65\%$ of the invariant energy of the collision is thermalized and $73\%$ of the baryons are contained in the central fireball. Within our model this implies that a quark-gluon-plasma of lifetime 3.4 $fm/c$ was formed.
[ { "created": "Fri, 29 Sep 1995 19:20:46 GMT", "version": "v1" }, { "created": "Mon, 2 Oct 1995 17:17:20 GMT", "version": "v2" }, { "created": "Thu, 12 Oct 1995 16:03:10 GMT", "version": "v3" } ]
2009-10-28
[ [ "Schlei", "B. R.", "" ], [ "Ornik", "U.", "" ], [ "Plümer", "M.", "" ], [ "Strottman", "D.", "" ], [ "Weiner", "R. M.", "" ] ]
We present the first analysis of preliminary data for $Pb+Pb$ at 160 $AGeV$ using 3+1-dimensional relativistic hydrodynamics. We find excellent agreement with the rapidity spectra of negative hadrons and the correlation measurements. The data indicates a large amount of stopping; $65\%$ of the invariant energy of the collision is thermalized and $73\%$ of the baryons are contained in the central fireball. Within our model this implies that a quark-gluon-plasma of lifetime 3.4 $fm/c$ was formed.
2205.03140
Luca Di Luzio
Federica Devoto, Simone Devoto, Luca Di Luzio, Giovanni Ridolfi
False vacuum decay: an introductory review
106 pages, 12 Figures. Invited review for Journal of Physics G. Minor corrections and references added. Matches published version
J. Phys. G: Nucl. Part. Phys. 49 103001 (2022)
10.1088/1361-6471/ac7f24
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We review the description of tunnelling phenomena in the semi-classical approximation in ordinary quantum mechanics and in quantum field theory. In particular, we describe in detail the calculation, up to the first quantum corrections, of the decay probability per unit time of a metastable ground state. We apply the relevant formalism to the case of the standard model of electroweak interactions, whose ground state is metastable for sufficiently large values of the top quark mass. Finally, we discuss the impact of gravitational interactions on the calculation of the tunnelling rate.
[ { "created": "Fri, 6 May 2022 11:10:21 GMT", "version": "v1" }, { "created": "Wed, 27 Jul 2022 06:29:01 GMT", "version": "v2" } ]
2022-08-30
[ [ "Devoto", "Federica", "" ], [ "Devoto", "Simone", "" ], [ "Di Luzio", "Luca", "" ], [ "Ridolfi", "Giovanni", "" ] ]
We review the description of tunnelling phenomena in the semi-classical approximation in ordinary quantum mechanics and in quantum field theory. In particular, we describe in detail the calculation, up to the first quantum corrections, of the decay probability per unit time of a metastable ground state. We apply the relevant formalism to the case of the standard model of electroweak interactions, whose ground state is metastable for sufficiently large values of the top quark mass. Finally, we discuss the impact of gravitational interactions on the calculation of the tunnelling rate.
hep-ph/9501252
Frank Dodd Smith
Frank D. Smith, Jr.
Gravity and the Standard Model with 130 GeV Truth Quark from D4-D5-E6 Model using 3x3 Octonion Matrices
108 pages, latex. Revised with respect to lattice structure to use HyperDiamond lattice. Added references. Some minor revisions
null
null
THEP-95-1
hep-ph
null
The D4-D5-E6 model of gravity and the Standard Model with a 130 GeV truth quark is constructed using 3x3 matrices of octonions. The model has both continuum and lattice versions. The lattice version uses HyperDiamond lattice structure.
[ { "created": "Mon, 9 Jan 1995 05:57:21 GMT", "version": "v1" }, { "created": "Wed, 1 Mar 1995 06:18:38 GMT", "version": "v2" } ]
2012-08-27
[ [ "Smith,", "Frank D.", "Jr." ] ]
The D4-D5-E6 model of gravity and the Standard Model with a 130 GeV truth quark is constructed using 3x3 matrices of octonions. The model has both continuum and lattice versions. The lattice version uses HyperDiamond lattice structure.
1510.04530
Josef Pradler
Haipeng An, Kaixuan Ni, Maxim Pospelov, Josef Pradler, Adam Ritz
Direct detection prospects of dark vectors with xenon-based dark matter experiments
5 pages, 1 figure; proceedings of the European Physical Society Conference on High Energy Physics 2015 (EPS-HEP 2015), Vienna, Austria; reference added
PoS(EPS-HEP2015)397
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter experiments primarily search for the scattering of WIMPs on target nuclei of well shielded underground detectors. The results from liquid scintillator experiments furthermore provide precise probes of very light and very weakly coupled particles that may be absorbed by electrons. In these proceedings we summarize previously obtained constraints on long-lived dark matter vector particles $V$ (dark photons) in the $0.01-100$ keV mass range. In addition, we provide a first projected sensitivity reach for the upcoming XENON1T dark matter search to detect dark photons.
[ { "created": "Thu, 15 Oct 2015 13:38:14 GMT", "version": "v1" }, { "created": "Fri, 16 Oct 2015 07:19:34 GMT", "version": "v2" } ]
2015-10-19
[ [ "An", "Haipeng", "" ], [ "Ni", "Kaixuan", "" ], [ "Pospelov", "Maxim", "" ], [ "Pradler", "Josef", "" ], [ "Ritz", "Adam", "" ] ]
Dark matter experiments primarily search for the scattering of WIMPs on target nuclei of well shielded underground detectors. The results from liquid scintillator experiments furthermore provide precise probes of very light and very weakly coupled particles that may be absorbed by electrons. In these proceedings we summarize previously obtained constraints on long-lived dark matter vector particles $V$ (dark photons) in the $0.01-100$ keV mass range. In addition, we provide a first projected sensitivity reach for the upcoming XENON1T dark matter search to detect dark photons.
hep-ph/0107159
Per Osland
A.A. Babich (Gomel), P. Osland (Bergen), A.A. Pankov (Gomel, Trieste), N. Paver (Trieste)
New physics signatures at a Linear Collider: model-independent analysis from `conventional' polarized observables
13 pages, including 3 figures
Phys.Lett.B518:128-136,2001
10.1016/S0370-2693(01)01047-4
null
hep-ph
null
We discuss four-fermion contact-interaction searches in the processes e^+e^-\to\mu^+\mu^-, c{\bar c} and b{\bar b} at a future e^+e^- Linear Collider with c.m. energy \sqrt{s}=0.5 TeV and with both beams longitudinally polarized. Our analysis is based on the measurements of familiar polarized observables such as the total cross section and the forward-backward/left-right asymmetries, and accounts for the general set of contact interaction couplings as independent, non-zero, parameters thus avoiding simplifying, model-dependent, assumptions. We derive the corresponding model-independent constraints on the above-mentioned coupling constants, and evaluate the corresponding reach at the Linear Collider, emphasizing the role of beam polarization. We compare the results with a model-dependent procedure where only one coupling is varied at a time.
[ { "created": "Fri, 13 Jul 2001 20:05:34 GMT", "version": "v1" } ]
2011-01-25
[ [ "Babich", "A. A.", "", "Gomel" ], [ "Osland", "P.", "", "Bergen" ], [ "Pankov", "A. A.", "", "Gomel, Trieste" ], [ "Paver", "N.", "", "Trieste" ] ]
We discuss four-fermion contact-interaction searches in the processes e^+e^-\to\mu^+\mu^-, c{\bar c} and b{\bar b} at a future e^+e^- Linear Collider with c.m. energy \sqrt{s}=0.5 TeV and with both beams longitudinally polarized. Our analysis is based on the measurements of familiar polarized observables such as the total cross section and the forward-backward/left-right asymmetries, and accounts for the general set of contact interaction couplings as independent, non-zero, parameters thus avoiding simplifying, model-dependent, assumptions. We derive the corresponding model-independent constraints on the above-mentioned coupling constants, and evaluate the corresponding reach at the Linear Collider, emphasizing the role of beam polarization. We compare the results with a model-dependent procedure where only one coupling is varied at a time.
hep-ph/0512180
German Rodrigo
Henryk Czyz, Agnieszka Grzelinska, Johann H. Kuhn, German Rodrigo
Electron-positron annihilation into three pions and the radiative return
8 pages, 8 figures. Final version to appear in Eur. Phys. J. C
Eur.Phys.J.C47:617-624,2006
10.1140/epjc/s2006-02614-7
IFIC/05-38, TTP05-28
hep-ph
null
The Monte Carlo event generator PHOKHARA, which simulates hadron and muon production at electron-positron colliders through radiative return, has been extended to final states with three pions. A model for the form factor based on generalized vector dominance has been employed, which is consistent with presently available experimental observations.
[ { "created": "Wed, 14 Dec 2005 14:48:56 GMT", "version": "v1" }, { "created": "Tue, 20 Jun 2006 15:40:17 GMT", "version": "v2" } ]
2009-01-07
[ [ "Czyz", "Henryk", "" ], [ "Grzelinska", "Agnieszka", "" ], [ "Kuhn", "Johann H.", "" ], [ "Rodrigo", "German", "" ] ]
The Monte Carlo event generator PHOKHARA, which simulates hadron and muon production at electron-positron colliders through radiative return, has been extended to final states with three pions. A model for the form factor based on generalized vector dominance has been employed, which is consistent with presently available experimental observations.
0705.0794
Gui-Jun Ding
Gui-Jun Ding, Mu-Lin Yan
Unparticle Physics in DIS
13 pages, 6 figures
Phys.Rev.D76:075005,2007
10.1103/PhysRevD.76.075005
null
hep-ph
null
The unparticle stuff scenario related to the notrivial IR fixed point in 4D-conformal field theory is recently suggested by Georgi. We illustrate its physical effects in Deep Inelastic Scattering (DIS) process. A possible signal of unparticle related to parity violation asymmetry in DIS is investigated. It is found out that the behavior of this parity violation signal is sensitive to the value of the scale dimension $d_{\cal U}$ of unpaticle.
[ { "created": "Sun, 6 May 2007 09:55:06 GMT", "version": "v1" }, { "created": "Wed, 9 May 2007 17:40:26 GMT", "version": "v2" }, { "created": "Mon, 20 Aug 2007 17:34:21 GMT", "version": "v3" } ]
2008-11-26
[ [ "Ding", "Gui-Jun", "" ], [ "Yan", "Mu-Lin", "" ] ]
The unparticle stuff scenario related to the notrivial IR fixed point in 4D-conformal field theory is recently suggested by Georgi. We illustrate its physical effects in Deep Inelastic Scattering (DIS) process. A possible signal of unparticle related to parity violation asymmetry in DIS is investigated. It is found out that the behavior of this parity violation signal is sensitive to the value of the scale dimension $d_{\cal U}$ of unpaticle.
hep-ph/9509395
Mariano Quiros
M. Quir\'os
Bounds on the Higgs mass in the Standard Model and the Minimal Supersymmetric Standard Model
13 pages, latex + sprocl + psfig.sty, 6 uuencoded figures. Based on talk given at the International Workshop on Elementary Particle Physics: Present and Future, Valencia, June 5 to 9, 1995
null
null
IEM-FT-115/95
hep-ph
null
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the {\bf Standard Model} can develop a non-standard minimum for values of the field much larger than the weak scale. In those cases the standard minimum becomes metastable and the possibility of decay to the non-standard one arises. Comparison of the decay rate to the non-standard minimum at finite (and zero) temperature with the corresponding expansion rate of the Universe allows to identify the region, in the ($M_H$, $M_t$) plane, where the Higgs field is sitting at the standard electroweak minimum. In the {\bf Minimal Supersymmetric Standard Model}, approximate analytical expressions for the Higgs mass spectrum and couplings are worked out, providing an excellent approximation to the numerical results which include all next-to-leading-log corrections. An appropriate treatment of squark decoupling allows to consider large values of the stop and/or sbottom mixing parameters and thus fix a reliable upper bound on the mass of the lightest CP-even Higgs boson mass. The discovery of the Higgs boson at LEP~2 might put an upper bound (below the Planck scale) on the scale of new physics $\Lambda$ and eventually disentangle between the Standard Model and the Minimal Supersymmetric Standard Model.
[ { "created": "Tue, 26 Sep 1995 15:35:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Quirós", "M.", "" ] ]
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the {\bf Standard Model} can develop a non-standard minimum for values of the field much larger than the weak scale. In those cases the standard minimum becomes metastable and the possibility of decay to the non-standard one arises. Comparison of the decay rate to the non-standard minimum at finite (and zero) temperature with the corresponding expansion rate of the Universe allows to identify the region, in the ($M_H$, $M_t$) plane, where the Higgs field is sitting at the standard electroweak minimum. In the {\bf Minimal Supersymmetric Standard Model}, approximate analytical expressions for the Higgs mass spectrum and couplings are worked out, providing an excellent approximation to the numerical results which include all next-to-leading-log corrections. An appropriate treatment of squark decoupling allows to consider large values of the stop and/or sbottom mixing parameters and thus fix a reliable upper bound on the mass of the lightest CP-even Higgs boson mass. The discovery of the Higgs boson at LEP~2 might put an upper bound (below the Planck scale) on the scale of new physics $\Lambda$ and eventually disentangle between the Standard Model and the Minimal Supersymmetric Standard Model.
1311.0552
Ho-Meoyng Choi
Ho-Meoyng Choi and Chueng-Ryong Ji
Light-front zero-mode issue on the vector meson decay constant
6 pages, talk presented at Light Cone 2013, Skiathos, Greece, 20-24 May 2013
null
10.1007/s00601-013-0789-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the light-front zero-mode issue in the light-front quark model (LFQM) prediction of a vector meson decay constant from the perspective of the vacuum fluctuation consistent with the chiral symmetry of QCD. We extend the exactly solvable manifestly covariant Bethe-Salpeter model calculation to the more phenomenologically accessible realistic LFQM and present a self-consistent covariant description of the vector meson decay constant analyzing the twist-2 and twist-3 quark-antiquark distribution amplitudes with even chirality.
[ { "created": "Mon, 4 Nov 2013 00:41:45 GMT", "version": "v1" }, { "created": "Fri, 20 Dec 2013 08:54:42 GMT", "version": "v2" } ]
2015-06-17
[ [ "Choi", "Ho-Meoyng", "" ], [ "Ji", "Chueng-Ryong", "" ] ]
We discuss the light-front zero-mode issue in the light-front quark model (LFQM) prediction of a vector meson decay constant from the perspective of the vacuum fluctuation consistent with the chiral symmetry of QCD. We extend the exactly solvable manifestly covariant Bethe-Salpeter model calculation to the more phenomenologically accessible realistic LFQM and present a self-consistent covariant description of the vector meson decay constant analyzing the twist-2 and twist-3 quark-antiquark distribution amplitudes with even chirality.
0902.3820
Albert Villanova del Moral
A. Villanova del Moral
Lepton flavour violating stau decays versus seesaw parameters: correlations and expected number of events for both seesaw type-I and II
10 pages, 6 figures, 1 table, to appear in the proceedings of DISCRETE'08 Symposium on Prospects in the Physics of Discrete Symmetries, 11-16 December 2008, Valencia, Spain; some comments added
J.Phys.Conf.Ser.171:012074,2009
10.1088/1742-6596/171/1/012074
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In minimal supergravity (mSugra), the neutrino sector is related to the slepton sector by means of the renormalization group equations. This opens a door to indirectly test the neutrino sector via measurements at the LHC. Concretely, for the simplest seesaw type-I, we present the correlations between seesaw parameters and ratio of stau lepton flavour violating (LFV) branching ratios. We find some simple, extreme scenarios for the unknown right-handed parameters, where ratios of LFV rates correlate with neutrino oscillation parameters. On the other hand, we scan the mSugra parameter space, for both seesaw type-I and II, to find regions where LFV stau decays can be maximized, while respecting low-energy experimental bounds. We estimate the expected number of events at the LHC for a sample luminosity of L = 100 fb^{-1}.
[ { "created": "Sun, 22 Feb 2009 20:26:10 GMT", "version": "v1" }, { "created": "Wed, 25 Feb 2009 11:38:08 GMT", "version": "v2" } ]
2009-07-22
[ [ "del Moral", "A. Villanova", "" ] ]
In minimal supergravity (mSugra), the neutrino sector is related to the slepton sector by means of the renormalization group equations. This opens a door to indirectly test the neutrino sector via measurements at the LHC. Concretely, for the simplest seesaw type-I, we present the correlations between seesaw parameters and ratio of stau lepton flavour violating (LFV) branching ratios. We find some simple, extreme scenarios for the unknown right-handed parameters, where ratios of LFV rates correlate with neutrino oscillation parameters. On the other hand, we scan the mSugra parameter space, for both seesaw type-I and II, to find regions where LFV stau decays can be maximized, while respecting low-energy experimental bounds. We estimate the expected number of events at the LHC for a sample luminosity of L = 100 fb^{-1}.
1807.04964
Avirup Ghosh
Avirup Ghosh, Tanmoy Mondal and Biswarup Mukhopadhyaya
Right sneutrino with $\Delta\,L\,=\,2$ masses as non-thermal dark matter
15 pages, 12 figure, 1 Table, Version matches the version published in Physical Review D
Phys. Rev. D 99, 035018 (2019)
10.1103/PhysRevD.99.035018
HRI-RECAPP-2018-005, KIAS-P19011
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider MSSM with right-chiral neutrino superfields with Majorana masses, where the lightest right-handed sneutrino dominated scalars constitutes non-thermal dark matter (DM). The $\Delta\,L=2$ masses are subject to severe constraints coming from freeze-in relic density of such DM candidates as well as from sterile neutrino $\textit{freeze-in}$. In addition, big-bang Nucleosynthesis and $\textit{freeze-out}$ of the next-to-lightest superparticle shrink the viable parameter space of such a scenario. We examine various $\Delta\,L=2$ mass terms for families other than that $\Delta\,L=2$ masses are difficult to reconcile with a right-sneutrino DM, unless there is either (a) a hierarchy of about 3 orders of magnitudes among various supersymmetry-breaking mass parameters, or, (b) strong cancellation between the higgsino mass and the trilinear supersymmetry breaking mass parameter for sneutrinos.
[ { "created": "Fri, 13 Jul 2018 08:18:37 GMT", "version": "v1" }, { "created": "Sat, 23 Feb 2019 14:13:09 GMT", "version": "v2" } ]
2019-02-26
[ [ "Ghosh", "Avirup", "" ], [ "Mondal", "Tanmoy", "" ], [ "Mukhopadhyaya", "Biswarup", "" ] ]
We consider MSSM with right-chiral neutrino superfields with Majorana masses, where the lightest right-handed sneutrino dominated scalars constitutes non-thermal dark matter (DM). The $\Delta\,L=2$ masses are subject to severe constraints coming from freeze-in relic density of such DM candidates as well as from sterile neutrino $\textit{freeze-in}$. In addition, big-bang Nucleosynthesis and $\textit{freeze-out}$ of the next-to-lightest superparticle shrink the viable parameter space of such a scenario. We examine various $\Delta\,L=2$ mass terms for families other than that $\Delta\,L=2$ masses are difficult to reconcile with a right-sneutrino DM, unless there is either (a) a hierarchy of about 3 orders of magnitudes among various supersymmetry-breaking mass parameters, or, (b) strong cancellation between the higgsino mass and the trilinear supersymmetry breaking mass parameter for sneutrinos.
hep-ph/9812416
Dmitry Ostrovsky
A.V. Leonidov (1,2), D.M. Ostrovsky (1) ((1) Theoretical Department, Lebedev Physics Institute, Moscow, Russia; (2) Service de Physique Theorique, C.E.Saclay, Gif-sur-Yvette, France)
Angular pattern of minijet transverse energy flow in hadron and nuclear collisions
25 LaTeX pages, 11 figures embedded with epsf; expanded version
Eur.Phys.J.C16:683-693,2000; Phys.Atom.Nucl.65:886-897,2002; Yad.Fiz.65:918-929,2002
10.1134/1.1481483
FIAN/TD-28/98, SPhT-98/145
hep-ph nucl-th
null
The azimuthal asymmetry of minijet system produced at the early stage of nucleon-nucleon and nuclear collisions in a central rapidity window is studied. We show that in pp collisions the minijet transverse energy production in a central rapidity window is essentially unbalanced in azimuth due to asymmetric contributions in which only one minijet hits the acceptance window. We further study the angular pattern of transverse energy flow generated by semihard degrees of freedom at the early stage of high energy nuclear collisions and its dependence on the number of semihard collisions in the models both including and neglecting soft contributions to the inelastic cross section at RHIC and LHC energies as well as on the choice of the infrared cutoff.
[ { "created": "Thu, 17 Dec 1998 17:26:33 GMT", "version": "v1" }, { "created": "Tue, 25 Jan 2000 09:38:31 GMT", "version": "v2" }, { "created": "Wed, 26 Jan 2000 11:47:11 GMT", "version": "v3" } ]
2011-09-13
[ [ "Leonidov", "A. V.", "" ], [ "Ostrovsky", "D. M.", "" ] ]
The azimuthal asymmetry of minijet system produced at the early stage of nucleon-nucleon and nuclear collisions in a central rapidity window is studied. We show that in pp collisions the minijet transverse energy production in a central rapidity window is essentially unbalanced in azimuth due to asymmetric contributions in which only one minijet hits the acceptance window. We further study the angular pattern of transverse energy flow generated by semihard degrees of freedom at the early stage of high energy nuclear collisions and its dependence on the number of semihard collisions in the models both including and neglecting soft contributions to the inelastic cross section at RHIC and LHC energies as well as on the choice of the infrared cutoff.
2201.05398
Farid Taghinavaz
S. M. A. Tabatabaee Mehr, F. Taghinavaz
Chiral phase transition of a dense, magnetized and rotating quark matter
18 pages, 15 figures, 5 tables, comments are welcome
null
10.1016/j.aop.2023.169357
null
hep-ph hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
We investigate the chiral symmetry restoration/breaking of a dense, magnetized and rotating quark matter within the Nambu Jona-Lasinio model including $N_f=2$ and $N_c=3$ numbers of flavors and colors, respectively. Imposing the spectral boundary conditions, as well as the positiveness of energy levels, lead to a correlation between the magnetic and rotation fields such that strongly magnetized plasma can not rotate anymore. We solve the gap equation at zero and finite temperature. At finite temperature and baryon chemical potential $\mu_B$, we sketch the phase diagrams $T_c(\mu_B)$ and $T_c(R\Omega)$ in different cases. As a result, we always observe inverse-rotational catalysis mean to decrease $T_c$ by increasing $R\Omega$. But the magnetic field has a more complex structure in the phase diagram. For slowly rotating plasma, we find that $T_c$ decreases by increasing $eB$, while in the fast rotating plasma we see that $T_c$ increases by increasing $eB$. Also, we locate exactly the position of Critical End Point by solving the equations of first and second derivatives of effective action with respect to the order parameters, simultaneously.
[ { "created": "Fri, 14 Jan 2022 11:24:23 GMT", "version": "v1" }, { "created": "Wed, 6 Apr 2022 07:56:48 GMT", "version": "v2" } ]
2023-06-14
[ [ "Mehr", "S. M. A. Tabatabaee", "" ], [ "Taghinavaz", "F.", "" ] ]
We investigate the chiral symmetry restoration/breaking of a dense, magnetized and rotating quark matter within the Nambu Jona-Lasinio model including $N_f=2$ and $N_c=3$ numbers of flavors and colors, respectively. Imposing the spectral boundary conditions, as well as the positiveness of energy levels, lead to a correlation between the magnetic and rotation fields such that strongly magnetized plasma can not rotate anymore. We solve the gap equation at zero and finite temperature. At finite temperature and baryon chemical potential $\mu_B$, we sketch the phase diagrams $T_c(\mu_B)$ and $T_c(R\Omega)$ in different cases. As a result, we always observe inverse-rotational catalysis mean to decrease $T_c$ by increasing $R\Omega$. But the magnetic field has a more complex structure in the phase diagram. For slowly rotating plasma, we find that $T_c$ decreases by increasing $eB$, while in the fast rotating plasma we see that $T_c$ increases by increasing $eB$. Also, we locate exactly the position of Critical End Point by solving the equations of first and second derivatives of effective action with respect to the order parameters, simultaneously.
1806.07896
Michael Baker
Michael J. Baker, Andrea Thamm
Leptonic WIMP Coannihilation and the Current Dark Matter Search Strategy
26 pages, 10 figures, v2: version matched to journal (JHEP)
null
10.1007/JHEP10(2018)187
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the extent to which models of Weakly Interacting Massive Particle (WIMP) Dark Matter (DM) at and above the electroweak scale can be probed conclusively in future high energy and astroparticle physics experiments. We consider simplified models with bino-like dark matter and slepton-like coannihilation partners, and find that perturbative models yield the observed relic abundance up to at least 10 TeV. We emphasise that coannihilation can either increase or decrease the dark matter relic abundance. We compute the sensitivity of direct detection experiments to DM-nucleus scattering, consider indirect detection bounds and estimate the sensitivity of future proton colliders to slepton pair production. We find that current and future experiments will be able to probe the Dirac DM models up to at least 10 TeV. However, current and future searches will not be sensitive to models of Majorana dark matter for masses above 2 or 4 TeV, for one or ten coannihilation partners respectively, leaving around 70 % of the parameter space unconstrained. This demonstrates the need for new experimental ideas to access models of coannihilating Majorana dark matter.
[ { "created": "Wed, 20 Jun 2018 18:00:01 GMT", "version": "v1" }, { "created": "Wed, 13 Feb 2019 11:43:06 GMT", "version": "v2" } ]
2019-02-14
[ [ "Baker", "Michael J.", "" ], [ "Thamm", "Andrea", "" ] ]
We discuss the extent to which models of Weakly Interacting Massive Particle (WIMP) Dark Matter (DM) at and above the electroweak scale can be probed conclusively in future high energy and astroparticle physics experiments. We consider simplified models with bino-like dark matter and slepton-like coannihilation partners, and find that perturbative models yield the observed relic abundance up to at least 10 TeV. We emphasise that coannihilation can either increase or decrease the dark matter relic abundance. We compute the sensitivity of direct detection experiments to DM-nucleus scattering, consider indirect detection bounds and estimate the sensitivity of future proton colliders to slepton pair production. We find that current and future experiments will be able to probe the Dirac DM models up to at least 10 TeV. However, current and future searches will not be sensitive to models of Majorana dark matter for masses above 2 or 4 TeV, for one or ten coannihilation partners respectively, leaving around 70 % of the parameter space unconstrained. This demonstrates the need for new experimental ideas to access models of coannihilating Majorana dark matter.
1504.07538
Mohamed Abu-Shady
M. Abu-Shady
Heavy Quarkonia and Bc-Mesons in the Cornell Potential with Harmonic Oscillator Potential in the N-dimensional Schrodinger Equation
5 pages, 3 Tables
International Journal of Applied Mathematics and Theoretical Physics 2, 16-20 (2016)
10.11648/j.ijamtp.20160202.11
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy quarkonia, Bc-meson, and CS-meson masses are calculated within the framework of the N-dimensional radial Schrodinger equation. The Cornell potential is extended by including the harmonic oscillator potential. The energy eigenvalues and the corresponding wave functions are calculated in the N-dimensional space using the Nikiforov-Uvarov (NV) method. The energy eigenvalues are obtained in the three-dimensional space. The mass of spectra of charmonium, bottomonium, and mesons are calculated. The effect of dimensionality number on the mass of quarkonium is investigated. A comparison with other theoretical approaches is discussed. The obtained results are in good agreement with experimental data. We conclude that the dimensionality number plays an important role in studying the spectra of quarkonium masses. The modified Cornell potential provides a good description of the spectra of quarkonium masses.
[ { "created": "Mon, 27 Apr 2015 15:12:08 GMT", "version": "v1" }, { "created": "Fri, 5 Jun 2015 21:14:21 GMT", "version": "v2" }, { "created": "Thu, 16 Jul 2015 16:30:38 GMT", "version": "v3" }, { "created": "Thu, 20 Oct 2016 08:10:11 GMT", "version": "v4" } ]
2016-10-21
[ [ "Abu-Shady", "M.", "" ] ]
Heavy quarkonia, Bc-meson, and CS-meson masses are calculated within the framework of the N-dimensional radial Schrodinger equation. The Cornell potential is extended by including the harmonic oscillator potential. The energy eigenvalues and the corresponding wave functions are calculated in the N-dimensional space using the Nikiforov-Uvarov (NV) method. The energy eigenvalues are obtained in the three-dimensional space. The mass of spectra of charmonium, bottomonium, and mesons are calculated. The effect of dimensionality number on the mass of quarkonium is investigated. A comparison with other theoretical approaches is discussed. The obtained results are in good agreement with experimental data. We conclude that the dimensionality number plays an important role in studying the spectra of quarkonium masses. The modified Cornell potential provides a good description of the spectra of quarkonium masses.
hep-ph/0609189
Matteo Beccaria
M. Beccaria, G. Macorini, F.M. Renard and C. Verzegnassi
The relevance of virtual electroweak effects in the overall $t$-channel single top production at LHC
15 pages, 7 eps figures
null
null
PTA/06-20
hep-ph
null
We compute the complete one loop electroweak effects in the MSSM for the eight processes of single top (and single antitop) production in the $t$-channel at hadron colliders, generalizing a previous analysis performed for the dominant $dt$ final state. The results are quite similar for all processes, showing an impressively large Standard Model effect and a generally modest genuine SUSY contribution in the mSUGRA scenario. The one loop effect on the total rate is shown and the possibility of measuring it at LHC is discussed.
[ { "created": "Tue, 19 Sep 2006 10:09:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Beccaria", "M.", "" ], [ "Macorini", "G.", "" ], [ "Renard", "F. M.", "" ], [ "Verzegnassi", "C.", "" ] ]
We compute the complete one loop electroweak effects in the MSSM for the eight processes of single top (and single antitop) production in the $t$-channel at hadron colliders, generalizing a previous analysis performed for the dominant $dt$ final state. The results are quite similar for all processes, showing an impressively large Standard Model effect and a generally modest genuine SUSY contribution in the mSUGRA scenario. The one loop effect on the total rate is shown and the possibility of measuring it at LHC is discussed.
hep-ph/9805267
Otto Kong
Otto C. W. Kong (Rochester U.)
Standard-Model-like Chiral Spectra and the Origin of the Families
summary of IUKT seminar, in latex with lamuphys.sty
null
null
UR-1528, ER/40685/916
hep-ph
null
We outline our approach to understand the family structure through the idea of a SM-like chiral fermion spectrum, one that is derivable from anomaly cancellation conditions in the same way as the one family SM, under an extended symmetry, which after breaking to the SM symmetry yields the three families as the residual chiral content. An example of a relatively simple scalar sector which gives an acceptable symmetry breaking pattern and naturally hierarchical quark mass matrices is also discussed for a successful $SU(4)_A\otimes SU(3)_C\otimes SU(2)_L\otimes U(1)_X$ model. This is a summary of a seminar given at the 37th IUKT winter school, for the proceedings.
[ { "created": "Fri, 8 May 1998 21:08:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kong", "Otto C. W.", "", "Rochester U." ] ]
We outline our approach to understand the family structure through the idea of a SM-like chiral fermion spectrum, one that is derivable from anomaly cancellation conditions in the same way as the one family SM, under an extended symmetry, which after breaking to the SM symmetry yields the three families as the residual chiral content. An example of a relatively simple scalar sector which gives an acceptable symmetry breaking pattern and naturally hierarchical quark mass matrices is also discussed for a successful $SU(4)_A\otimes SU(3)_C\otimes SU(2)_L\otimes U(1)_X$ model. This is a summary of a seminar given at the 37th IUKT winter school, for the proceedings.
1401.6747
Zhiyang Law
Z. Y. Law, A. H. Chan, and C. H. Oh
A quantum field theoretical model of neutrino oscillation without external wave packets
32 pages, 10 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a general and consistent model of neutrino oscillation based on the quantum field theoretical description of the neutrino production and detection processes. Emphasis is placed on the locality of the interactions of these processes, where on top of the usual application of the four fermion local Hamiltonian, we assume that weak interactions switched on only when the wave functions of the particles involved are overlapping and switched off upon their separation. A key assumption in our treatment is that the wave packet sizes of the particles, in particular, the neutrino producing source particles and the neutrino absorbing detector particles, are taken to be negligible compared with their mean free path in their respective medium. With this assumption, and taking into considerations of the finite time of neutrino production, neutrino wave packets with well-defined edges are generated. This fact, together with the locality of weak interactions, enable us to relate the propagation time to the propagation distance, thus doing away with the ad hoc time averaging procedure normally employing in derivations of neutrino oscillation formula. No assumptions on the particular forms of particle wave functions; for example, Gaussians, need to be made. A good feature of our approach is that the neutrino oscillation formula is automatically normalised if the in-going states of the production and detection processes are normalised. We also show that causality and unitarity cannot both be satisfied in virtual neutrino models.
[ { "created": "Mon, 27 Jan 2014 06:11:30 GMT", "version": "v1" }, { "created": "Mon, 3 Mar 2014 04:07:53 GMT", "version": "v2" } ]
2014-03-04
[ [ "Law", "Z. Y.", "" ], [ "Chan", "A. H.", "" ], [ "Oh", "C. H.", "" ] ]
We develop a general and consistent model of neutrino oscillation based on the quantum field theoretical description of the neutrino production and detection processes. Emphasis is placed on the locality of the interactions of these processes, where on top of the usual application of the four fermion local Hamiltonian, we assume that weak interactions switched on only when the wave functions of the particles involved are overlapping and switched off upon their separation. A key assumption in our treatment is that the wave packet sizes of the particles, in particular, the neutrino producing source particles and the neutrino absorbing detector particles, are taken to be negligible compared with their mean free path in their respective medium. With this assumption, and taking into considerations of the finite time of neutrino production, neutrino wave packets with well-defined edges are generated. This fact, together with the locality of weak interactions, enable us to relate the propagation time to the propagation distance, thus doing away with the ad hoc time averaging procedure normally employing in derivations of neutrino oscillation formula. No assumptions on the particular forms of particle wave functions; for example, Gaussians, need to be made. A good feature of our approach is that the neutrino oscillation formula is automatically normalised if the in-going states of the production and detection processes are normalised. We also show that causality and unitarity cannot both be satisfied in virtual neutrino models.
1308.2823
Pouya Bakhti
Pouya Bakhti, Yasaman Farzan
Constraining Super-light Sterile Neutrino Scenario by JUNO and RENO-50
12 pages, 5 figures
null
10.1007/JHEP10(2013)200
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Super-light Sterile Neutrino Scenario (SSNS) has been proposed in the literature to explain the suppression of the upturn in the low energy solar data. In this scenario, the mass splitting between the new mass eigenstate, $\nu_0$ and the standard $\nu_1$ is of order of $\Delta m_{01}^2\sim 10^{-5}$ eV$^2$. Reactor neutrino experiments with baseline larger than $\sim$20 km can help us to probe this scenario. We study the potential of upcoming JUNO and RENO-50 reactor experiments for discovering the superlight sterile neutrino or constraining its mixing parameters. We study the dependence of sensitivity to the SNSS and find that the proposed JUNO setup is very close to the optimal setup for probing the SSNS.
[ { "created": "Tue, 13 Aug 2013 11:14:55 GMT", "version": "v1" }, { "created": "Sat, 26 Oct 2013 11:30:44 GMT", "version": "v2" } ]
2015-06-16
[ [ "Bakhti", "Pouya", "" ], [ "Farzan", "Yasaman", "" ] ]
The Super-light Sterile Neutrino Scenario (SSNS) has been proposed in the literature to explain the suppression of the upturn in the low energy solar data. In this scenario, the mass splitting between the new mass eigenstate, $\nu_0$ and the standard $\nu_1$ is of order of $\Delta m_{01}^2\sim 10^{-5}$ eV$^2$. Reactor neutrino experiments with baseline larger than $\sim$20 km can help us to probe this scenario. We study the potential of upcoming JUNO and RENO-50 reactor experiments for discovering the superlight sterile neutrino or constraining its mixing parameters. We study the dependence of sensitivity to the SNSS and find that the proposed JUNO setup is very close to the optimal setup for probing the SSNS.
1901.01205
Rama Krishnan
R. Krishnan
Fully constrained mass matrix: Can symmetries alone determine the flavon vacuum alignments?
17 pages, 3 figures
Phys. Rev. D 101, 075004 (2020)
10.1103/PhysRevD.101.075004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the representation theory of finite groups, it was recently shown that a fully constrained complex-symmetric mass matrix can be conveniently mapped into a sextet of $\Sigma(72\times3)$. In this paper, we introduce an additional flavor group $X_{24}$ in the model so that the vacuum alignment of the $\Sigma(72\times3)$ sextet is determined not only by the symmetries of $\Sigma(72\times3)$ but also by that of $X_{24}$. We define several flavons which transform as multiplets under $\Sigma(72\times3)$ as well as $X_{24}$. The vacuum alignment of each of these flavons is obtained as a simultaneous invariant eigenstate of specific elements of the groups $\Sigma(72\times3)$ and $X_{24}$; i.e.,~the vacuum alignment is fully determined by its residual symmetries. These flavons couple together uniquely resulting in the fully constrained sextet of $\Sigma(72\times3)$. Through this work we propose a general formalism in which the flavor symmetry group ($G_f$) is obtained as the direct product, $G_f=G_r \times G_x$. Fermions transform nontrivially only under $G_r$ while they remain invariant under $G_x$. Flavons, on the other hand, transform nontrivially under both $G_r$ and $G_x$. The vacuum alignment of each flavon multiplet transforming irreducibly under $G_r \times G_x$ is uniquely identified by its corresponding residual symmetry (a subgroup of $G_r \times G_x$). Several such flavons couple together to form an effective multiple of $G_r$ which remains invariant under $G_x$. This effective multiplet couples to the fermions.
[ { "created": "Fri, 4 Jan 2019 16:48:21 GMT", "version": "v1" }, { "created": "Sun, 5 Apr 2020 04:43:18 GMT", "version": "v2" } ]
2020-04-08
[ [ "Krishnan", "R.", "" ] ]
In the framework of the representation theory of finite groups, it was recently shown that a fully constrained complex-symmetric mass matrix can be conveniently mapped into a sextet of $\Sigma(72\times3)$. In this paper, we introduce an additional flavor group $X_{24}$ in the model so that the vacuum alignment of the $\Sigma(72\times3)$ sextet is determined not only by the symmetries of $\Sigma(72\times3)$ but also by that of $X_{24}$. We define several flavons which transform as multiplets under $\Sigma(72\times3)$ as well as $X_{24}$. The vacuum alignment of each of these flavons is obtained as a simultaneous invariant eigenstate of specific elements of the groups $\Sigma(72\times3)$ and $X_{24}$; i.e.,~the vacuum alignment is fully determined by its residual symmetries. These flavons couple together uniquely resulting in the fully constrained sextet of $\Sigma(72\times3)$. Through this work we propose a general formalism in which the flavor symmetry group ($G_f$) is obtained as the direct product, $G_f=G_r \times G_x$. Fermions transform nontrivially only under $G_r$ while they remain invariant under $G_x$. Flavons, on the other hand, transform nontrivially under both $G_r$ and $G_x$. The vacuum alignment of each flavon multiplet transforming irreducibly under $G_r \times G_x$ is uniquely identified by its corresponding residual symmetry (a subgroup of $G_r \times G_x$). Several such flavons couple together to form an effective multiple of $G_r$ which remains invariant under $G_x$. This effective multiplet couples to the fermions.
1505.07113
Andrey Katz
Nathaniel Craig, Andrey Katz
The Fraternal WIMP Miracle
22 pages, 6 figures. v2: Relic abundance calculations revised and improved, citations added. Conclusions largely unchanged. v3: Minor changes, accepted by JCAP
JCAP 1510 (2015) 10, 054
10.1088/1475-7516/2015/10/054
CERN-PH-TH-2015-125
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We identify and analyze thermal dark matter candidates in the fraternal twin Higgs model and its generalizations. The relic abundance of fraternal twin dark matter is set by twin weak interactions, with a scale tightly tied to the weak scale of the Standard Model by naturalness considerations. As such, the dark matter candidates benefit from a "fraternal WIMP miracle," reproducing the observed dark matter abundance for dark matter masses between 50 and 150 GeV. However, the couplings dominantly responsible for dark matter annihilation do not lead to interactions with the visible sector. The direct detection rate is instead set via fermionic Higgs portal interactions, which are likewise constrained by naturalness considerations but parametrically weaker than those leading to dark matter annihilation. The predicted direct detection cross section is close to current LUX bounds and presents an opportunity for the next generation of direct detection experiments.
[ { "created": "Tue, 26 May 2015 20:00:30 GMT", "version": "v1" }, { "created": "Mon, 13 Jul 2015 14:08:18 GMT", "version": "v2" }, { "created": "Mon, 1 Feb 2016 14:42:26 GMT", "version": "v3" } ]
2016-02-02
[ [ "Craig", "Nathaniel", "" ], [ "Katz", "Andrey", "" ] ]
We identify and analyze thermal dark matter candidates in the fraternal twin Higgs model and its generalizations. The relic abundance of fraternal twin dark matter is set by twin weak interactions, with a scale tightly tied to the weak scale of the Standard Model by naturalness considerations. As such, the dark matter candidates benefit from a "fraternal WIMP miracle," reproducing the observed dark matter abundance for dark matter masses between 50 and 150 GeV. However, the couplings dominantly responsible for dark matter annihilation do not lead to interactions with the visible sector. The direct detection rate is instead set via fermionic Higgs portal interactions, which are likewise constrained by naturalness considerations but parametrically weaker than those leading to dark matter annihilation. The predicted direct detection cross section is close to current LUX bounds and presents an opportunity for the next generation of direct detection experiments.
0711.3813
Xiang Liu
Xiang Liu and Bo Zhang
What can we learn from the decay of $ N_X(1625)$ in molecule picture?
6 pages, 3 figures, 2 tables. The title changed. More discussion added
Eur.Phys.J.C54:253-258,2008
10.1140/epjc/s10052-008-0527-4
null
hep-ph hep-ex nucl-ex nucl-th
null
Considering two molecular state assumptions, i.e. S-wave $\bar{\Lambda}-K^-$ and S-wave $\bar{\Sigma}^0-K^-$ molecular states, we study the possible decays of $\bar N_X(1625)$ that include $\bar N_X(1625)\to K^{-}\bar{\Lambda}, \pi^{0}\bar{p}, \eta\bar{p}, \pi^{-}\bar{n}$. Our results indicate: (1) if $\bar N_{X}(1625)$ is $\bar{\Lambda}-K^-$ molecular state, $K^{-}\bar{\Lambda}$ is the main decay modes of $\bar N_{X}(1625)$, and the branching ratios of the rest decay modes are tiny; (2) if $\bar N_{X}(1625)$ is $\bar{\Sigma}^0-K^-$ molecular state, the branching ratio of $\bar N_{X}(1625)\to K^{-}\bar{\Lambda}$ is one or two order smaller than that of $\bar N_{X}(1625)\to \pi^{0}\bar{p}, \eta\bar{p}, \pi^{-}\bar{n}$. Thus the search for $\bar N_X(1625)\to \pi^{0}\bar{p}, \eta\bar{p}, \pi^{-}\bar{n}$ will be helpful to shed light on the nature of $\bar N_X(1625)$.
[ { "created": "Sat, 24 Nov 2007 04:29:23 GMT", "version": "v1" }, { "created": "Wed, 12 Dec 2007 14:56:46 GMT", "version": "v2" } ]
2008-11-26
[ [ "Liu", "Xiang", "" ], [ "Zhang", "Bo", "" ] ]
Considering two molecular state assumptions, i.e. S-wave $\bar{\Lambda}-K^-$ and S-wave $\bar{\Sigma}^0-K^-$ molecular states, we study the possible decays of $\bar N_X(1625)$ that include $\bar N_X(1625)\to K^{-}\bar{\Lambda}, \pi^{0}\bar{p}, \eta\bar{p}, \pi^{-}\bar{n}$. Our results indicate: (1) if $\bar N_{X}(1625)$ is $\bar{\Lambda}-K^-$ molecular state, $K^{-}\bar{\Lambda}$ is the main decay modes of $\bar N_{X}(1625)$, and the branching ratios of the rest decay modes are tiny; (2) if $\bar N_{X}(1625)$ is $\bar{\Sigma}^0-K^-$ molecular state, the branching ratio of $\bar N_{X}(1625)\to K^{-}\bar{\Lambda}$ is one or two order smaller than that of $\bar N_{X}(1625)\to \pi^{0}\bar{p}, \eta\bar{p}, \pi^{-}\bar{n}$. Thus the search for $\bar N_X(1625)\to \pi^{0}\bar{p}, \eta\bar{p}, \pi^{-}\bar{n}$ will be helpful to shed light on the nature of $\bar N_X(1625)$.
1501.02181
Kazem Azizi
K. Azizi, A. Turkan, H. Sundu, E. Veli Veliev, E. Yazici
Thermal behaviors of light unflavored tensor mesons in the framework of QCD sum rule
4 Pages and 1 Table, Prepared for the proceeding of the 4th International Conference on Hadron Physics (TROIA'14)
J.Phys.Conf.Ser. 562 (2014) 1, 012016
10.1088/1742-6596/562/1/012016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, we investigate the sensitivity of the masses and decay constants of the light $f_{2}(1270)$ and $a_{2}(1320)$ tensor mesons to the temperature using QCD sum rule approach. In our calculations, we take into account the additional operators appearing in operator product expansion at finite temperature. It is obtained that at deconfinement temperature the decay constants and masses decrease with amount of $6\%$ and $96\%$ compared to their vacuum values, respectively. Our results on the masses at zero temperature are consistent with the vacuum sum rules predictions as well as the experimental data.
[ { "created": "Fri, 9 Jan 2015 15:50:41 GMT", "version": "v1" } ]
2015-01-12
[ [ "Azizi", "K.", "" ], [ "Turkan", "A.", "" ], [ "Sundu", "H.", "" ], [ "Veliev", "E. Veli", "" ], [ "Yazici", "E.", "" ] ]
In this study, we investigate the sensitivity of the masses and decay constants of the light $f_{2}(1270)$ and $a_{2}(1320)$ tensor mesons to the temperature using QCD sum rule approach. In our calculations, we take into account the additional operators appearing in operator product expansion at finite temperature. It is obtained that at deconfinement temperature the decay constants and masses decrease with amount of $6\%$ and $96\%$ compared to their vacuum values, respectively. Our results on the masses at zero temperature are consistent with the vacuum sum rules predictions as well as the experimental data.
hep-ph/9710219
Alexander V. Kuznetsov
A.A. Gvozdev, A.V. Kuznetsov, N.V. Mikheev, L.A. Vassilevskaya
Neutrino transitions nu -> nu gamma, nu -> nu e+ e- in a strong magnetic field as a possible origin of cosmological gamma-burst
9 pages, Latex, uses sprocl.sty. Talk presented at the International Workshop on Non-Accelerator New Physics (NANP-97), Dubna, Russia, July 7-11, 1997, to appear in the Proceedings
Phys.Atom.Nucl.61:1031-1034,1998
null
YARU-HE-97/07
hep-ph
null
The high energy neutrino transitions with the photon and electron-positron pair creation in a strong magnetic field in the framework of the Standard Model are investigated. The process probabilities and the mean values of the neutrino energy and momentum loss are presented. The asymmetry of outgoing neutrinos, as a possible source of sufficient recoil ``kick'' velocity of a remnant and the emission of e+ e- pairs and gamma-quanta in a ``polar cap'' region of a remnant, as a possible origin of cosmological gamma-burst are discussed.
[ { "created": "Thu, 2 Oct 1997 08:18:18 GMT", "version": "v1" } ]
2014-11-17
[ [ "Gvozdev", "A. A.", "" ], [ "Kuznetsov", "A. V.", "" ], [ "Mikheev", "N. V.", "" ], [ "Vassilevskaya", "L. A.", "" ] ]
The high energy neutrino transitions with the photon and electron-positron pair creation in a strong magnetic field in the framework of the Standard Model are investigated. The process probabilities and the mean values of the neutrino energy and momentum loss are presented. The asymmetry of outgoing neutrinos, as a possible source of sufficient recoil ``kick'' velocity of a remnant and the emission of e+ e- pairs and gamma-quanta in a ``polar cap'' region of a remnant, as a possible origin of cosmological gamma-burst are discussed.
1404.1538
Ichiro Oda
Ichiro Oda and Takahiko Tomoyose
Quadratic Chaotic Inflation from Higgs Inflation
Added some sentences to the final section for clarification
null
null
DPUR/TH/40
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Stimulated with the recent discovery of B-mode by BICEP2, we discuss the relation between a Higgs inflation and a chaotic inflation with quadratic potential. Starting with a generalized Higgs inflation model, we derive a condition for obtaining the quadratic chaotic inflation. It is shown that the running of the Higgs self-coupling constant in the Jordan frame plays a decisive role when the generalized Higgs inflation model coincides with the Higgs inflation model in a small-field limit.
[ { "created": "Sun, 6 Apr 2014 01:41:26 GMT", "version": "v1" }, { "created": "Wed, 9 Apr 2014 20:17:14 GMT", "version": "v2" }, { "created": "Mon, 2 Jun 2014 00:05:35 GMT", "version": "v3" } ]
2014-06-03
[ [ "Oda", "Ichiro", "" ], [ "Tomoyose", "Takahiko", "" ] ]
Stimulated with the recent discovery of B-mode by BICEP2, we discuss the relation between a Higgs inflation and a chaotic inflation with quadratic potential. Starting with a generalized Higgs inflation model, we derive a condition for obtaining the quadratic chaotic inflation. It is shown that the running of the Higgs self-coupling constant in the Jordan frame plays a decisive role when the generalized Higgs inflation model coincides with the Higgs inflation model in a small-field limit.
hep-ph/0608161
Jeff Forshaw
J.R. Forshaw, R. Sandapen, G. Shaw
Further success of the colour dipole model
28 pages, 26 figures. Several corrections in response to referee report
JHEP0611:025,2006
10.1088/1126-6708/2006/11/025
null
hep-ph
null
We confront a very wide body of HERA diffractive electroproduction data with the predictions of the colour dipole model. We focus upon three different parameterisations of the dipole scattering cross-section and find good agreement for all observables. There can be no doubting the success of the dipole scattering approach and more precise observations are needed in order to expose its limitations.
[ { "created": "Mon, 14 Aug 2006 21:32:37 GMT", "version": "v1" }, { "created": "Mon, 16 Oct 2006 12:37:29 GMT", "version": "v2" } ]
2009-11-11
[ [ "Forshaw", "J. R.", "" ], [ "Sandapen", "R.", "" ], [ "Shaw", "G.", "" ] ]
We confront a very wide body of HERA diffractive electroproduction data with the predictions of the colour dipole model. We focus upon three different parameterisations of the dipole scattering cross-section and find good agreement for all observables. There can be no doubting the success of the dipole scattering approach and more precise observations are needed in order to expose its limitations.
hep-ph/9611433
John Collins
John C. Collins, Leonid Frankfurt, Mark Strikman
Factorization for hard exclusive electroproduction of mesons in QCD
50 pages, revtex, figures included, uses epsf.sty. Correction of citations, and of predictions for meson production
Phys.Rev. D56 (1997) 2982-3006
10.1103/PhysRevD.56.2982
CERN-TH/96-314, PSU/TH/168
hep-ph
null
We formulate and prove a QCD factorization theorem for hard exclusive electroproduction of mesons in QCD. The proof is valid for the leading power in Q and all logarithms. This generalizes previous work on vector meson production in the diffractive region of small x. The amplitude is expressed in terms of off-diagonal generalizations of the usual parton densities. The full theorem applies to all kinds of meson and not just to vector mesons. The parton densities used include not only the ordinary parton density, but also the helicity density (g_1 or $\Delta q$) and the transversity density ($h_1$ or $\delta q$), and these can be probed by measuring the polarization of the produced mesons with unpolarized protons.
[ { "created": "Tue, 26 Nov 1996 17:50:47 GMT", "version": "v1" }, { "created": "Fri, 20 Dec 1996 10:41:13 GMT", "version": "v2" }, { "created": "Tue, 24 Jun 1997 17:05:56 GMT", "version": "v3" }, { "created": "Mon, 28 Jul 1997 17:07:19 GMT", "version": "v4" } ]
2009-10-30
[ [ "Collins", "John C.", "" ], [ "Frankfurt", "Leonid", "" ], [ "Strikman", "Mark", "" ] ]
We formulate and prove a QCD factorization theorem for hard exclusive electroproduction of mesons in QCD. The proof is valid for the leading power in Q and all logarithms. This generalizes previous work on vector meson production in the diffractive region of small x. The amplitude is expressed in terms of off-diagonal generalizations of the usual parton densities. The full theorem applies to all kinds of meson and not just to vector mesons. The parton densities used include not only the ordinary parton density, but also the helicity density (g_1 or $\Delta q$) and the transversity density ($h_1$ or $\delta q$), and these can be probed by measuring the polarization of the produced mesons with unpolarized protons.
1410.5241
Wolfgang Lucha
Wolfgang Lucha, Franz F. Sch\"oberl
The Spinless Relativistic Yukawa Problem
10 pages
Int. J. Mod. Phys. A 29 (2014) 1450195
10.1142/S0217751X14501954
HEPHY-PUB 941/14
hep-ph math-ph math.MP nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Noticing renewed or increasing interest in the possibility to describe semirelativistic bound states (of either spin-zero constituents or, upon confining oneself to spin-averaged features, constituents with nonzero spin) by means of the spinless Salpeter equation generalizing the Schr\"odinger equation towards incorporation of effects caused by relativistic kinematics, we revisit this problem for interactions between bound-state constituents of Yukawa shape, by recalling and applying several well-known tools enabling to constrain the resulting spectra.
[ { "created": "Mon, 20 Oct 2014 12:14:35 GMT", "version": "v1" } ]
2014-12-11
[ [ "Lucha", "Wolfgang", "" ], [ "Schöberl", "Franz F.", "" ] ]
Noticing renewed or increasing interest in the possibility to describe semirelativistic bound states (of either spin-zero constituents or, upon confining oneself to spin-averaged features, constituents with nonzero spin) by means of the spinless Salpeter equation generalizing the Schr\"odinger equation towards incorporation of effects caused by relativistic kinematics, we revisit this problem for interactions between bound-state constituents of Yukawa shape, by recalling and applying several well-known tools enabling to constrain the resulting spectra.