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2306.00079
Hongkai Liu
Tao Han, Ian M. Lewis, Hongkai Liu, Zhen Liu, Xing Wang
A Guide to Diagnosing Colored Resonances at Hadron Colliders
45 pages, 13 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a comprehensive study on how to distinguish the properties of heavy dijet resonances at hadron colliders. A variety of spins, chiral couplings, charges, and QCD color representations are considered. Distinguishing the different color representations is particularly difficult at hadron colliders. To determine the QCD color structure, we consider a third jet radiated in a resonant dijet event. We show that the relative rates of three-jet versus two-jet processes are sensitive to the color representation of the resonance. We also show analytically that the antennae radiation pattern of soft radiation depends on the color structure of dijet events and develops an observable that is sensitive to the antennae patterns. Finally, we exploit a Convolutional Neural Network with Machine Learning techniques to differentiate the radiation patterns from different colored resonances and find encouraging results to discriminate them. We demonstrate our results numerically at a 14 TeV LHC, and the methodology presented here should be applicable to other future hadron colliders.
[ { "created": "Wed, 31 May 2023 18:00:43 GMT", "version": "v1" } ]
2023-06-05
[ [ "Han", "Tao", "" ], [ "Lewis", "Ian M.", "" ], [ "Liu", "Hongkai", "" ], [ "Liu", "Zhen", "" ], [ "Wang", "Xing", "" ] ]
We present a comprehensive study on how to distinguish the properties of heavy dijet resonances at hadron colliders. A variety of spins, chiral couplings, charges, and QCD color representations are considered. Distinguishing the different color representations is particularly difficult at hadron colliders. To determine the QCD color structure, we consider a third jet radiated in a resonant dijet event. We show that the relative rates of three-jet versus two-jet processes are sensitive to the color representation of the resonance. We also show analytically that the antennae radiation pattern of soft radiation depends on the color structure of dijet events and develops an observable that is sensitive to the antennae patterns. Finally, we exploit a Convolutional Neural Network with Machine Learning techniques to differentiate the radiation patterns from different colored resonances and find encouraging results to discriminate them. We demonstrate our results numerically at a 14 TeV LHC, and the methodology presented here should be applicable to other future hadron colliders.
1007.1891
Roberto Bonciani
R. Bonciani, G. Degrassi, A. Vicini
On the Generalized Harmonic Polylogarithms of One Complex Variable
25 pages, 1 figure
Comput.Phys.Commun.182:1253-1264,2011
10.1016/j.cpc.2011.02.011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe how to compute numerically in the complex plain a set of Generalized Harmonic Polylogarithms (GHPLs) with square roots in the weights, using the C++/GiNaC numerical routines of Vollinga and Weinzierl. As an example, we provide the numerical values of the NLO electroweak light-fermion corrections to the Higgs boson production in gluon fusion in the case of complex W and Z masses.
[ { "created": "Mon, 12 Jul 2010 12:43:28 GMT", "version": "v1" } ]
2011-04-05
[ [ "Bonciani", "R.", "" ], [ "Degrassi", "G.", "" ], [ "Vicini", "A.", "" ] ]
We describe how to compute numerically in the complex plain a set of Generalized Harmonic Polylogarithms (GHPLs) with square roots in the weights, using the C++/GiNaC numerical routines of Vollinga and Weinzierl. As an example, we provide the numerical values of the NLO electroweak light-fermion corrections to the Higgs boson production in gluon fusion in the case of complex W and Z masses.
2006.08546
Jose Manuel S\'anchez Vel\'azquez
Daniel E. Borrajo Guti\'errez, Jose A. R. Cembranos, Luis J. Garay and Jose M. S\'anchez Vel\'azquez
Derivative couplings in gravitational production in the early universe
24 pages, 6 figures
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational particle production in the early universe is due to the coupling of matter fields to curvature. This coupling may include derivative terms that modify the kinetic term. The most general first order action contains derivative couplings to the curvature scalar and to the traceless Ricci tensor, which can be dominant in the case of (pseudo-)Nambu-Goldstone bosons or disformal scalars, such as branons. In the presence of these derivative couplings, the density of produced particles for the adiabatic regime in the de Sitter phase (which mimics inflation) is constant in time and decays with the inverse effective mass (which in turn depends on the coupling to the curvature scalar). In the reheating phase following inflation, the presence of derivative couplings to the background curvature modifies in a nontrivial way the gravitational production even in the perturbative regime. We also show that the two couplings -- to the curvature scalar and to the traceless Ricci tensor -- are drastically different, specially for large masses. In this regime, the production becomes highly sensitive to the former coupling while it becomes independent of the latter.
[ { "created": "Mon, 15 Jun 2020 17:03:00 GMT", "version": "v1" } ]
2020-06-16
[ [ "Gutiérrez", "Daniel E. Borrajo", "" ], [ "Cembranos", "Jose A. R.", "" ], [ "Garay", "Luis J.", "" ], [ "Velázquez", "Jose M. Sánchez", "" ] ]
Gravitational particle production in the early universe is due to the coupling of matter fields to curvature. This coupling may include derivative terms that modify the kinetic term. The most general first order action contains derivative couplings to the curvature scalar and to the traceless Ricci tensor, which can be dominant in the case of (pseudo-)Nambu-Goldstone bosons or disformal scalars, such as branons. In the presence of these derivative couplings, the density of produced particles for the adiabatic regime in the de Sitter phase (which mimics inflation) is constant in time and decays with the inverse effective mass (which in turn depends on the coupling to the curvature scalar). In the reheating phase following inflation, the presence of derivative couplings to the background curvature modifies in a nontrivial way the gravitational production even in the perturbative regime. We also show that the two couplings -- to the curvature scalar and to the traceless Ricci tensor -- are drastically different, specially for large masses. In this regime, the production becomes highly sensitive to the former coupling while it becomes independent of the latter.
1907.13034
Juraj Klari\'c
Marco Drewes, Juraj Klari\'c, Philipp Klose
On Lepton Number Violation in Heavy Neutrino Decays at Colliders
14 pages plus appendix, 1 figure: Matches version accepted for publication in JHEP
J. High Energ. Phys. (2019) 2019: 32
10.1007/JHEP11(2019)032
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the perspective to observe lepton number violating signatures from heavy Majorana neutrino decays at colliders in view of the requirement to explain the light neutrino masses via the seesaw mechanism. In the minimal model with only two heavy neutrinos and in the $\nu$MSM one can identify three distinct regions in the mass-mixing plane. For Majorana masses above the electroweak scale the branching ratio for lepton number violating processes at the LHC is generically suppressed. For masses well below the electroweak scale that are probed in displaced vertex searches or at fixed target experiments lepton number violation is the rule and can only be avoided at the cost of fine tuning. In between there is a mass regime where both possibilities coexist. In models with more than two heavy neutrinos the larger parameter space allows for more freedom, but our results remain qualitatively correct unless there is a mass degeneracy amongst more than two of the heavy neutrinos.
[ { "created": "Tue, 30 Jul 2019 15:47:13 GMT", "version": "v1" }, { "created": "Wed, 30 Oct 2019 09:43:55 GMT", "version": "v2" } ]
2019-11-20
[ [ "Drewes", "Marco", "" ], [ "Klarić", "Juraj", "" ], [ "Klose", "Philipp", "" ] ]
We study the perspective to observe lepton number violating signatures from heavy Majorana neutrino decays at colliders in view of the requirement to explain the light neutrino masses via the seesaw mechanism. In the minimal model with only two heavy neutrinos and in the $\nu$MSM one can identify three distinct regions in the mass-mixing plane. For Majorana masses above the electroweak scale the branching ratio for lepton number violating processes at the LHC is generically suppressed. For masses well below the electroweak scale that are probed in displaced vertex searches or at fixed target experiments lepton number violation is the rule and can only be avoided at the cost of fine tuning. In between there is a mass regime where both possibilities coexist. In models with more than two heavy neutrinos the larger parameter space allows for more freedom, but our results remain qualitatively correct unless there is a mass degeneracy amongst more than two of the heavy neutrinos.
0801.4887
Giulia Pancheri Dr.
R.M. Godbole (Bangalore), A. Grau (Granada U.), G. Pancheri (INFN Frascati), Y.N. Srivastava (INFN and Perugia U.)
Large rapidity gaps survival probabilities at LHC
6 pages, 2 figures, to be published in the Proceedings of International Symposium on Multiparticle Dynamics 2007, Berkeley 2-9 August 2007
Acta Phys.Polon.Supp.1:651-656,2008
null
LNF-08-2(P) 30 gennaio 2008
hep-ph
null
We calculate the probability of large rapidity gaps in high energy hadronic collisions using a model based on QCD mini-jets and soft gluon emission down into the infrared region. Comparing with other models we find a remarkable agreement among most predictions.
[ { "created": "Thu, 31 Jan 2008 15:17:19 GMT", "version": "v1" } ]
2009-01-16
[ [ "Godbole", "R. M.", "", "Bangalore" ], [ "Grau", "A.", "", "Granada U." ], [ "Pancheri", "G.", "", "INFN\n Frascati" ], [ "Srivastava", "Y. N.", "", "INFN and Perugia U." ] ]
We calculate the probability of large rapidity gaps in high energy hadronic collisions using a model based on QCD mini-jets and soft gluon emission down into the infrared region. Comparing with other models we find a remarkable agreement among most predictions.
hep-ph/0112215
Alexei Yu. Illarionov
A. Yu. Illarionov, A. G. Litvinenko and G. I. Lykasov
Polarization Phenomena in Fragmentation of Deuterons to Pions and Non-Nucleon Degrees of Freedom in the Deuteron
3 pages, 2 figures, uses epsfig.sty and wrapfig.sty, Talk given at 9th International Workshop on High-Energy Spin Physics (SPIN 01), Dubna, Russia, 2-7 Aug 2001 minor revisions in the text, reference added
null
null
null
hep-ph nucl-th
null
The fragmentation of deuterons into pions emitted forward in the kinematic region forbidden for free nucleon-nucleon collisions is analyzed. It is shown that the inclusion of the non-nucleon degrees of freedom in a deuteron allows to describe the experimental data about inclusive pion spectrum rather satisfactory and improves the description of data concerning the deuteron analyzing power T_{20}. The experimental data show the positive sign and very small values, less than 0.2, of T_{20} what can't be reproduced by the calculations ignoring these degrees of freedom.
[ { "created": "Sun, 16 Dec 2001 11:40:48 GMT", "version": "v1" }, { "created": "Sun, 23 Dec 2001 18:18:08 GMT", "version": "v2" } ]
2007-05-23
[ [ "Illarionov", "A. Yu.", "" ], [ "Litvinenko", "A. G.", "" ], [ "Lykasov", "G. I.", "" ] ]
The fragmentation of deuterons into pions emitted forward in the kinematic region forbidden for free nucleon-nucleon collisions is analyzed. It is shown that the inclusion of the non-nucleon degrees of freedom in a deuteron allows to describe the experimental data about inclusive pion spectrum rather satisfactory and improves the description of data concerning the deuteron analyzing power T_{20}. The experimental data show the positive sign and very small values, less than 0.2, of T_{20} what can't be reproduced by the calculations ignoring these degrees of freedom.
hep-ph/0006063
V. Gogohia
V. Gogohia
Structure of the Yang-Mills vacuum in the zero modes enhancement quantum model
16 pages, no figures, no tables, to appear in Phys. Lett. B
Phys.Lett.B485:162-170,2000
10.1016/S0370-2693(00)00698-5
null
hep-ph hep-th
null
We have formulated new quantum model of the QCD vacuum using the effective potential approach for composite operators. It is based on the existence and importance of such kind of the nonperturbative, topologically nontrivial excitations of gluon field configurations, which can be effectively correctly described by the $q^{-4}$-type behavior of the full gluon propagator in the deep infrared domain. The ultraviolet part of the full gluon propagator was approximated by the asymptotic freedom to-leading order perturbative logarithm term of the running coupling constant. Despite the vacuum energy density remains badly divergent, we have formulated a method how to establish a finite (in the ultraviolet limit) relation between the two scale parameters of our model. We have expressed the asymptotic scale parameter as $pure number$ times the nonperturbative scale, which is inevitably contained in any realistic Ansatz for the full gluon propagator.
[ { "created": "Wed, 7 Jun 2000 11:12:47 GMT", "version": "v1" } ]
2011-08-17
[ [ "Gogohia", "V.", "" ] ]
We have formulated new quantum model of the QCD vacuum using the effective potential approach for composite operators. It is based on the existence and importance of such kind of the nonperturbative, topologically nontrivial excitations of gluon field configurations, which can be effectively correctly described by the $q^{-4}$-type behavior of the full gluon propagator in the deep infrared domain. The ultraviolet part of the full gluon propagator was approximated by the asymptotic freedom to-leading order perturbative logarithm term of the running coupling constant. Despite the vacuum energy density remains badly divergent, we have formulated a method how to establish a finite (in the ultraviolet limit) relation between the two scale parameters of our model. We have expressed the asymptotic scale parameter as $pure number$ times the nonperturbative scale, which is inevitably contained in any realistic Ansatz for the full gluon propagator.
hep-ph/9908312
Ma Bo-Qiang
Bo-Qiang Ma (IHEP, Academia Sinica, Beijing, China)
High Precision Test of QCD at Beijing Electron Positron Collider
6 page Latex file, to be published in High Energy Phys. Nucl. Phys. 23 (1999) 922-925
High Energy Phys.Nucl.Phys. 23 (1999) 922-925
null
Revised BIHEP-TH-96-24
hep-ph hep-ex
null
The generalized Crewther relation relates the cross section ratio $R=\sigma(e^+e^- \to {\rm hadrons})/\sigma(e^+e^- \to {\mu}^+ {\mu}^-)$ in $e^+e^-$ annihilation with the Bjorken sum rule or the Gross-Llewellyn Smith sum rule in deep inelastic scattering and provides a fundamental connection for observables in Quantum Chromodynamics (QCD) without scale or scheme ambiguities. The ratio $R$ can be measured at the upgrated Bejing Electron Positron Collider or the $\tau$-Charm factory with higher precision and thus can be served for a high precision test of QCD in the Standard Model.
[ { "created": "Tue, 10 Aug 1999 03:11:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ma", "Bo-Qiang", "", "IHEP, Academia Sinica, Beijing, China" ] ]
The generalized Crewther relation relates the cross section ratio $R=\sigma(e^+e^- \to {\rm hadrons})/\sigma(e^+e^- \to {\mu}^+ {\mu}^-)$ in $e^+e^-$ annihilation with the Bjorken sum rule or the Gross-Llewellyn Smith sum rule in deep inelastic scattering and provides a fundamental connection for observables in Quantum Chromodynamics (QCD) without scale or scheme ambiguities. The ratio $R$ can be measured at the upgrated Bejing Electron Positron Collider or the $\tau$-Charm factory with higher precision and thus can be served for a high precision test of QCD in the Standard Model.
hep-ph/9711442
Robert Peschanski
A.Bialas, H.Navelet and R.Peschanski
The QCD triple Pomeron coupling from string amplitudes
12 pages, 1 .eps figure, LaTeX
Phys.Rev.D57:6585-6589,1998
10.1103/PhysRevD.57.6585
null
hep-ph hep-th
null
Using the recent solution of the triple Pomeron coupling in the QCD dipole picture as a closed string amplitude with six legs, its analytical form in terms of hypergeometric functions and numerical value are derived.
[ { "created": "Mon, 24 Nov 1997 17:05:14 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bialas", "A.", "" ], [ "Navelet", "H.", "" ], [ "Peschanski", "R.", "" ] ]
Using the recent solution of the triple Pomeron coupling in the QCD dipole picture as a closed string amplitude with six legs, its analytical form in terms of hypergeometric functions and numerical value are derived.
2303.07119
Felix Hekhorn
Andrea Barontini, Alessandro Candido, Juan M. Cruz-Martinez, Felix Hekhorn, Christopher Schwan
Theory prediction in PDF fitting
5 pages, 2 figures; submitted to ACAT 2022 proceedings
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Continuously comparing theory predictions to experimental data is a common task in analysis of particle physics such as fitting parton distribution functions (PDFs). However, typically, both the computation of scattering amplitudes and the evolution of candidate PDFs from the fitting scale to the process scale are non-trivial, computing intesive tasks. We develop a new stack of software tools that aim to facilitate the theory predictions by computing FastKernel (FK) tables that reduce the theory computation to a linear algebra operation. Specifically, I present PineAPPL, our workhorse for grid operations, EKO, a new DGLAP solver, and yadism, a new DIS library. Alongside, I review several projects that become available with the new tools.
[ { "created": "Mon, 13 Mar 2023 13:51:30 GMT", "version": "v1" } ]
2023-03-14
[ [ "Barontini", "Andrea", "" ], [ "Candido", "Alessandro", "" ], [ "Cruz-Martinez", "Juan M.", "" ], [ "Hekhorn", "Felix", "" ], [ "Schwan", "Christopher", "" ] ]
Continuously comparing theory predictions to experimental data is a common task in analysis of particle physics such as fitting parton distribution functions (PDFs). However, typically, both the computation of scattering amplitudes and the evolution of candidate PDFs from the fitting scale to the process scale are non-trivial, computing intesive tasks. We develop a new stack of software tools that aim to facilitate the theory predictions by computing FastKernel (FK) tables that reduce the theory computation to a linear algebra operation. Specifically, I present PineAPPL, our workhorse for grid operations, EKO, a new DGLAP solver, and yadism, a new DIS library. Alongside, I review several projects that become available with the new tools.
1609.06231
Hiroshi Okada
Kingman Cheung, Hiroyuki Ishida, Hiroshi Okada
Accommodation of the Dirac Phase in the Krauss-Nasri-Trodden Model
20 pages, 4 tables, 3 figures; update version
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate one of the radiative models, Kraus-Nasri-Trodden model, with the maximal value of Dirac CP violating phase, $\delta$ is -\pi/2 (or equivalently 3\pi/2), which is preferred in not only recent long baseline experiments but also the global fit of neutrino oscillation data. We show that our predicted region of the \mu-e conversion rate can be searched in the future experiments without conflicting lepton-flavor violation and dark matter constraints.
[ { "created": "Tue, 20 Sep 2016 15:54:10 GMT", "version": "v1" }, { "created": "Mon, 6 Feb 2017 14:40:22 GMT", "version": "v2" } ]
2017-02-07
[ [ "Cheung", "Kingman", "" ], [ "Ishida", "Hiroyuki", "" ], [ "Okada", "Hiroshi", "" ] ]
We investigate one of the radiative models, Kraus-Nasri-Trodden model, with the maximal value of Dirac CP violating phase, $\delta$ is -\pi/2 (or equivalently 3\pi/2), which is preferred in not only recent long baseline experiments but also the global fit of neutrino oscillation data. We show that our predicted region of the \mu-e conversion rate can be searched in the future experiments without conflicting lepton-flavor violation and dark matter constraints.
0709.4662
Michael Durnev
S. M. Gerasyuta, M. A. Durnev
Spectroscopy of new c,b-mesons
21 pages
null
null
null
hep-ph
null
Masses of the lowest multiplets of c,b-mesons in S- and P-wave states with quantum numbers JPC: 0-+, 1--, 0++, 1+-, 1++, 2++ are obtained with the help of dispersion N/D method of heavy quark effective theory. The results are in a good agreement with experimental data. Radiative decay widths for some states mentioned above were calculated.
[ { "created": "Fri, 28 Sep 2007 18:04:17 GMT", "version": "v1" } ]
2007-10-01
[ [ "Gerasyuta", "S. M.", "" ], [ "Durnev", "M. A.", "" ] ]
Masses of the lowest multiplets of c,b-mesons in S- and P-wave states with quantum numbers JPC: 0-+, 1--, 0++, 1+-, 1++, 2++ are obtained with the help of dispersion N/D method of heavy quark effective theory. The results are in a good agreement with experimental data. Radiative decay widths for some states mentioned above were calculated.
hep-ph/9903352
Roland Rosenfelder
R. Rosenfelder
Proton Polarization Shifts in Electronic and Muonic Hydrogen
8 pages, LATEX, no figures, discussion improved and references updated, final version accepted for publication in Phys. Lett. B
Phys.Lett. B463 (1999) 317-322
10.1016/S0370-2693(99)00937-5
PSI-PR-99-11
hep-ph
null
The contribution of virtual excitations to the energy levels of electronic and muonic hydrogen is investigated combining a model-independent approach for the main part with quark model predictions for the remaining corrections. Precise values for the polarization shifts are obtained in the long-wavelength dipole approximation by numerically integrating over measured total photoabsorption cross sections. These unretarded results are considerably reduced by including retardation effects in an approximate way since the average momentum transfer (together with the mean excitation energy) turns out to be larger than usually assumed. Transverse and seagull contributions are estimated in a simple harmonic oscillator quark model and found to be non-negligible. Possible uncertainties and improvements of the final results are discussed.
[ { "created": "Mon, 15 Mar 1999 13:13:45 GMT", "version": "v1" }, { "created": "Mon, 30 Aug 1999 14:36:00 GMT", "version": "v2" } ]
2009-10-31
[ [ "Rosenfelder", "R.", "" ] ]
The contribution of virtual excitations to the energy levels of electronic and muonic hydrogen is investigated combining a model-independent approach for the main part with quark model predictions for the remaining corrections. Precise values for the polarization shifts are obtained in the long-wavelength dipole approximation by numerically integrating over measured total photoabsorption cross sections. These unretarded results are considerably reduced by including retardation effects in an approximate way since the average momentum transfer (together with the mean excitation energy) turns out to be larger than usually assumed. Transverse and seagull contributions are estimated in a simple harmonic oscillator quark model and found to be non-negligible. Possible uncertainties and improvements of the final results are discussed.
0708.0812
Peter Arnold
Peter Arnold
Quark-Gluon Plasmas and Thermalization
40 pages; based on lectures given at X Hadron Physics in Florianopolis, SC, Brazil, March 26-31, 2007 [another small typo fixed]
Int.J.Mod.Phys.E16:2555-2594,2007
10.1142/S021830130700832X
null
hep-ph nucl-th
null
In these lectures, I will attempt a pedagogical and qualitative introduction to the theory of equilibrium and thermalization of quark-gluon plasmas. I assume only that the reader is familiar with quantum field theory at zero temperature and with QCD as the theory of the strong interactions. I focus on the limit of small alpha_s, which in principle should be relevant at extremely high temperature because of asymptotic freedom, and in any case provides a clean theoretical context in which to discuss a variety of phenomena. Topics discussed include the basic equilibrium formalism for finite-temperature quantum field theory, Debye screening, electric deconfinement, magnetic confinement, dimensional reduction, plasma waves, kinetic theory, hydrodynamic properties such as viscosity, the Landau-Pomeranchuk-Migdal effect, thermalization in (arbitrarily high energy) heavy ion collisions, and QCD plasma instabilities.
[ { "created": "Mon, 6 Aug 2007 19:02:13 GMT", "version": "v1" }, { "created": "Tue, 21 Aug 2007 15:13:05 GMT", "version": "v2" }, { "created": "Tue, 4 Sep 2007 17:39:09 GMT", "version": "v3" }, { "created": "Mon, 14 Jan 2008 22:06:38 GMT", "version": "v4" } ]
2008-11-26
[ [ "Arnold", "Peter", "" ] ]
In these lectures, I will attempt a pedagogical and qualitative introduction to the theory of equilibrium and thermalization of quark-gluon plasmas. I assume only that the reader is familiar with quantum field theory at zero temperature and with QCD as the theory of the strong interactions. I focus on the limit of small alpha_s, which in principle should be relevant at extremely high temperature because of asymptotic freedom, and in any case provides a clean theoretical context in which to discuss a variety of phenomena. Topics discussed include the basic equilibrium formalism for finite-temperature quantum field theory, Debye screening, electric deconfinement, magnetic confinement, dimensional reduction, plasma waves, kinetic theory, hydrodynamic properties such as viscosity, the Landau-Pomeranchuk-Migdal effect, thermalization in (arbitrarily high energy) heavy ion collisions, and QCD plasma instabilities.
hep-ph/0301223
Don Colladay
Don Colladay
Theoretical Overview of Lorentz and CPT Violation
9 pages, to appear in the proceedings for 31st Coral Gables Conference, Ft. Lauderdale, Florida
AIP Conf.Proc. 672 (2003) 65-73
10.1063/1.1594393
null
hep-ph
null
In this talk, I discuss some recent theoretical progress concerning the Lorentz- and CPT-violating extension of the standard model. The results summarized include the development of an explicit connection between noncommutative field theory and the standard model extension, placement of new bounds in the photon sector, calculation of one-loop renormalization beta functions in QED, and an analysis of field redefinitions.
[ { "created": "Sat, 25 Jan 2003 20:38:13 GMT", "version": "v1" } ]
2009-11-10
[ [ "Colladay", "Don", "" ] ]
In this talk, I discuss some recent theoretical progress concerning the Lorentz- and CPT-violating extension of the standard model. The results summarized include the development of an explicit connection between noncommutative field theory and the standard model extension, placement of new bounds in the photon sector, calculation of one-loop renormalization beta functions in QED, and an analysis of field redefinitions.
0710.1150
Francisco Yndurain
R. Kaminski, J. R. Pelaez and F. J. Yndurain
The pion-pion scattering amplitude. III: Improving the analysis with forward dispersion relations and Roy equations
Plain TeX. 29 figures. Version to be published in PRD, with improved P and F waves
Phys.Rev.D77:054015,2008
10.1103/PhysRevD.77.054015
FTUAM 07-11
hep-ph
null
We complete and improve the fits to experimental $\pi\pi$ scattering amplitudes, both at low and high energies, that we performed in the previous papers of this series. We then verify that the corresponding amplitudes satisfy analyticity requirements, in the form of partial wave analyticity at low energies, forward dispersion relations (FDR) at all energies, and Roy equations below$\bar{K}K$ threshold; the first by construction, the last two, inside experimental errors. Then we repeat the fits including as constraints FDR and Roy equations. The ensuing central values of the various scattering amplitudes verify very accurately FDR and, especially, Roy equations, and change very little from what we found by just fitting data, with the exception of the D2 wave phase shift, for which one parameter moves by $1.5 \sigma$. These improved parametrizations therefore provide a reliable representation of pion-pion amplitudes with which one can test various physical relations. We also present a list of low energy parameters and other observables. In particular, we find $a_0^{(0)}=0.223\pm0.009 M^{-1}_\pi$, $a_0^{(2)}=-0.0444\pm0.0045 M^{-1}_\pi$ and $\delta_0^{(0)}(m^2_K)-\delta_0^{(2)}(m^2_K)=50.9\pm1.2^{\rm o}$.
[ { "created": "Fri, 5 Oct 2007 08:53:45 GMT", "version": "v1" }, { "created": "Wed, 9 Jan 2008 10:00:22 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kaminski", "R.", "" ], [ "Pelaez", "J. R.", "" ], [ "Yndurain", "F. J.", "" ] ]
We complete and improve the fits to experimental $\pi\pi$ scattering amplitudes, both at low and high energies, that we performed in the previous papers of this series. We then verify that the corresponding amplitudes satisfy analyticity requirements, in the form of partial wave analyticity at low energies, forward dispersion relations (FDR) at all energies, and Roy equations below$\bar{K}K$ threshold; the first by construction, the last two, inside experimental errors. Then we repeat the fits including as constraints FDR and Roy equations. The ensuing central values of the various scattering amplitudes verify very accurately FDR and, especially, Roy equations, and change very little from what we found by just fitting data, with the exception of the D2 wave phase shift, for which one parameter moves by $1.5 \sigma$. These improved parametrizations therefore provide a reliable representation of pion-pion amplitudes with which one can test various physical relations. We also present a list of low energy parameters and other observables. In particular, we find $a_0^{(0)}=0.223\pm0.009 M^{-1}_\pi$, $a_0^{(2)}=-0.0444\pm0.0045 M^{-1}_\pi$ and $\delta_0^{(0)}(m^2_K)-\delta_0^{(2)}(m^2_K)=50.9\pm1.2^{\rm o}$.
1506.08167
Denis Rosenthal
Thomas Mannel, Alexei A. Pivovarov, Denis Rosenthal
Inclusive weak decays of heavy hadrons with power suppressed terms at NLO
32 pages, 17 figures
Phys. Rev. D 92, 054025 (2015)
10.1103/PhysRevD.92.054025
SI-HEP-2015-15, QFET-2015-18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the heavy quark expansion techniques for the heavy hadron weak decays we analytically compute the coefficient of the power suppressed dimension five chromo-magnetic operator at next-to-leading order of QCD perturbation theory with the full dependence on the final state quark mass. We present explicit expressions for the total width of inclusive semileptonic decays including the power suppressed terms and for a few moments of decay differential distributions. One of the important phenomenological applications of our results is precision analysis of the decays of bottom mesons to charmed final states and extraction of the numerical value for the CKM matrix entry |V_{cb}|.
[ { "created": "Fri, 26 Jun 2015 17:37:28 GMT", "version": "v1" } ]
2015-09-30
[ [ "Mannel", "Thomas", "" ], [ "Pivovarov", "Alexei A.", "" ], [ "Rosenthal", "Denis", "" ] ]
Within the heavy quark expansion techniques for the heavy hadron weak decays we analytically compute the coefficient of the power suppressed dimension five chromo-magnetic operator at next-to-leading order of QCD perturbation theory with the full dependence on the final state quark mass. We present explicit expressions for the total width of inclusive semileptonic decays including the power suppressed terms and for a few moments of decay differential distributions. One of the important phenomenological applications of our results is precision analysis of the decays of bottom mesons to charmed final states and extraction of the numerical value for the CKM matrix entry |V_{cb}|.
2311.00743
Stefano Forte
Richard D. Ball, Alessandro Candido, Juan Cruz-Martinez, Stefano Forte, Tommaso Giani, Felix Hekhorn, Giacomo Magni, Emanuele R. Nocera, Juan Rojo and Roy Stegeman
The intrinsic charm quark valence distribution of the proton
11 pages, 11 figures. PDF files available for download in LHAPDF format from https://nnpdf.mi.infn.it/nnpdf4-0-charm-asymmetry-study/ Final version, to be published in PRD (letters). Figures 2, 6 and 7 added. Fit without imposing the charm valence sum rule added. Various small clarifications
null
null
Edinburgh 2023/22, TIF-UNIMI-2023-28, Nikhef 2023-012, CERN-TH-2023-196
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a first quantitative indication that the wave function of the proton contains unequal distributions of charm quarks and antiquarks, i.e. a nonvanishing intrinsic valence charm distribution. A significant nonvanishing valence component cannot be perturbatively generated, hence our results reinforce previous evidence that the proton contains an intrinsic (i.e., not radiatively generated) charm quark component. We establish our result through a determination of the parton distribution functions (PDFs) of charm quarks and antiquarks in the proton. We propose two novel experimental probes of this intrinsic charm valence component: D-meson asymmetries in Z+c-jet production at the LHCb experiment, and flavor-tagged structure functions at the Electron-Ion Collider.
[ { "created": "Wed, 1 Nov 2023 18:00:00 GMT", "version": "v1" }, { "created": "Fri, 3 Nov 2023 08:52:42 GMT", "version": "v2" }, { "created": "Fri, 15 Mar 2024 10:23:15 GMT", "version": "v3" } ]
2024-03-18
[ [ "Ball", "Richard D.", "" ], [ "Candido", "Alessandro", "" ], [ "Cruz-Martinez", "Juan", "" ], [ "Forte", "Stefano", "" ], [ "Giani", "Tommaso", "" ], [ "Hekhorn", "Felix", "" ], [ "Magni", "Giacomo", "" ]...
We provide a first quantitative indication that the wave function of the proton contains unequal distributions of charm quarks and antiquarks, i.e. a nonvanishing intrinsic valence charm distribution. A significant nonvanishing valence component cannot be perturbatively generated, hence our results reinforce previous evidence that the proton contains an intrinsic (i.e., not radiatively generated) charm quark component. We establish our result through a determination of the parton distribution functions (PDFs) of charm quarks and antiquarks in the proton. We propose two novel experimental probes of this intrinsic charm valence component: D-meson asymmetries in Z+c-jet production at the LHCb experiment, and flavor-tagged structure functions at the Electron-Ion Collider.
2111.08040
Shohei Okawa
Shohei Okawa, Maxim Pospelov, Adam Ritz
Long-range axion forces and hadronic CP violation
9 pages, 2 figures; v2: references added, version published in PRD
Phys. Rev. D 105, 075003 (2022)
10.1103/PhysRevD.105.075003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Axions and other pseudoscalar fields comprise an interesting class of ultralight dark matter candidates, that may independently play a role in solving the strong $CP$ problem. In the presence of $CP$-violating sources, these pseudoscalar fields can develop a coherent non-derivative coupling to nucleons, $\bar g_{aNN}$, thus mediating `mass-mass' and `mass-spin' forces in matter that can be probed experimentally. We revisit the non-perturbative generation of these $CP$-odd axion forces, and refine estimates of $\bar g_{aNN}$ generated by the EDMs and color EDMs of quarks. We also revisit the Standard Model contribution to $CP$-odd axion couplings generated by the phase of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.
[ { "created": "Mon, 15 Nov 2021 19:01:28 GMT", "version": "v1" }, { "created": "Fri, 8 Apr 2022 15:06:54 GMT", "version": "v2" } ]
2022-04-11
[ [ "Okawa", "Shohei", "" ], [ "Pospelov", "Maxim", "" ], [ "Ritz", "Adam", "" ] ]
Axions and other pseudoscalar fields comprise an interesting class of ultralight dark matter candidates, that may independently play a role in solving the strong $CP$ problem. In the presence of $CP$-violating sources, these pseudoscalar fields can develop a coherent non-derivative coupling to nucleons, $\bar g_{aNN}$, thus mediating `mass-mass' and `mass-spin' forces in matter that can be probed experimentally. We revisit the non-perturbative generation of these $CP$-odd axion forces, and refine estimates of $\bar g_{aNN}$ generated by the EDMs and color EDMs of quarks. We also revisit the Standard Model contribution to $CP$-odd axion couplings generated by the phase of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.
2312.04627
Kristjan Kannike
Nico Benincasa, Andrzej Hryczuk, Kristjan Kannike, Maxim Laletin
Phase Transitions and Gravitational Waves in a Model of $\mathbb{Z}_{3}$ Scalar Dark Matter
37 pages, 5 figures, references added, version accepted in JHEP
JHEP 02 (2024) 207
10.1007/JHEP02(2024)207
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theories with more than one scalar field often exhibit phase transitions producing potentially detectable gravitational wave (GW) signal. In this work we study the semi-annihilating $\mathbb{Z}_3$ dark matter model, whose dark sector comprises an inert doublet and a complex singlet, and assess its prospects in future GW detectors. Without imposing limits from requirement of providing a viable dark matter candidate, i.e. taking into account only other experimental and theoretical constraints, we find that the first order phase transition in this model can be strong enough to lead to a detectable signal. However, direct detection and the dark matter thermal relic density constraint calculated with the state-of-the-art method including the impact of early kinetic decoupling, very strongly limit the parameter space of the model explaining all of dark matter and providing observable GW peak amplitude. Extending the analysis to underabundant dark matter thus reveals region with detectable GWs from a single-step or multi-step phase transition.
[ { "created": "Thu, 7 Dec 2023 19:00:01 GMT", "version": "v1" }, { "created": "Thu, 7 Mar 2024 08:38:31 GMT", "version": "v2" } ]
2024-03-08
[ [ "Benincasa", "Nico", "" ], [ "Hryczuk", "Andrzej", "" ], [ "Kannike", "Kristjan", "" ], [ "Laletin", "Maxim", "" ] ]
Theories with more than one scalar field often exhibit phase transitions producing potentially detectable gravitational wave (GW) signal. In this work we study the semi-annihilating $\mathbb{Z}_3$ dark matter model, whose dark sector comprises an inert doublet and a complex singlet, and assess its prospects in future GW detectors. Without imposing limits from requirement of providing a viable dark matter candidate, i.e. taking into account only other experimental and theoretical constraints, we find that the first order phase transition in this model can be strong enough to lead to a detectable signal. However, direct detection and the dark matter thermal relic density constraint calculated with the state-of-the-art method including the impact of early kinetic decoupling, very strongly limit the parameter space of the model explaining all of dark matter and providing observable GW peak amplitude. Extending the analysis to underabundant dark matter thus reveals region with detectable GWs from a single-step or multi-step phase transition.
hep-ph/9707505
Yoshio Koide
Yoshio Koide
Neutrino Masses and Mixings in a Universal Seesaw Mass Matrix Model
19 pages (Latex file)
Phys.Rev. D57 (1998) 5836-5843
10.1103/PhysRevD.57.5836
US-97-05
hep-ph
null
Neutrino masses and mixings are investigated on the basis of a universal seesaw mass matrix model, in which quark (except for top) and charged lepton mass matrices M_f and neutrino mass matrix M_\nu are given by M_f \simeq m_L M_F^{-1} m_R and M_\nu \simeq m_L M_F^{-1} m_L^T (F=N), respectively. For a simple model which can successfully describe quark masses and mixings, we find that the observed neutrino data (except for the solar neutrino data) are favor to the intermediate mass scales O(m_R) = 10^{11} GeV and O(M_F)= 10^{13} GeV together with O(m_L)= 10^2 GeV. In spite of the largesse of O(m_R), the observed top quark mass can be consistently understood from the would-be seesaw mass matrix with these mass scales.
[ { "created": "Tue, 29 Jul 1997 11:44:10 GMT", "version": "v1" } ]
2009-10-30
[ [ "Koide", "Yoshio", "" ] ]
Neutrino masses and mixings are investigated on the basis of a universal seesaw mass matrix model, in which quark (except for top) and charged lepton mass matrices M_f and neutrino mass matrix M_\nu are given by M_f \simeq m_L M_F^{-1} m_R and M_\nu \simeq m_L M_F^{-1} m_L^T (F=N), respectively. For a simple model which can successfully describe quark masses and mixings, we find that the observed neutrino data (except for the solar neutrino data) are favor to the intermediate mass scales O(m_R) = 10^{11} GeV and O(M_F)= 10^{13} GeV together with O(m_L)= 10^2 GeV. In spite of the largesse of O(m_R), the observed top quark mass can be consistently understood from the would-be seesaw mass matrix with these mass scales.
1709.10084
Keith Pedersen
Keith Pedersen and Zack Sullivan
Spherical harmonics for multiparticle final states
12 pages, 4 figures. Talk presented at the APS Division of Particles and Fields Meeting (DPF 2017), July 31-August 4, 2017, Fermilab. C170731
null
null
IIT-CAPP-17-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine collider physics via the spectral power H_l, which utilizes much more detector information than sequential jet reconstruction. We use H_l to define a novel jet definition and use it to reconstruct both e+e- > qqg and e+e > tt final states. We find that a significant amount of pileup can be trivially subtracted from H_l jets, provided that the "shape" of pileup can be determined ahead of time. Finally, we find that future progress with H_l jets will require the addition of degrees of freedom accounting for jet "shape" (e.g. radial energy distribution). This should allow the measurement of jet shapes using much more information than traditional techniques.
[ { "created": "Thu, 28 Sep 2017 17:48:53 GMT", "version": "v1" } ]
2017-09-29
[ [ "Pedersen", "Keith", "" ], [ "Sullivan", "Zack", "" ] ]
We examine collider physics via the spectral power H_l, which utilizes much more detector information than sequential jet reconstruction. We use H_l to define a novel jet definition and use it to reconstruct both e+e- > qqg and e+e > tt final states. We find that a significant amount of pileup can be trivially subtracted from H_l jets, provided that the "shape" of pileup can be determined ahead of time. Finally, we find that future progress with H_l jets will require the addition of degrees of freedom accounting for jet "shape" (e.g. radial energy distribution). This should allow the measurement of jet shapes using much more information than traditional techniques.
1501.00173
Mansoor Ur Rehman
Waqas Ahmed, Ommair Ishaque and Mansoor Ur Rehman
Quantum Smearing in Hybrid Inflation with Chaotic Potentials
14 pages, 25 figures (typos fixed)
Int. J. Mod. Phys. D 25, 1650035 (2016)
10.1142/S0218271816500358
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the impact of one-loop radiative corrections in a non-supersymmetric model of hybrid inflation with chaotic (polynomial-like) potential, $V_0 + \lambda_p \phi^p$. These corrections can arise from the possible couplings of inflaton with other fields which may play active role in the reheating process. The tree-level predictions of these models are shown to lie outside of the Planck's latest bounds on the scalar spectral index $n_s$ and the tensor to scalar ratio $r$. However, the radiatively corrected version of these models, $ V_0 + \lambda_p \phi^p + A \phi^4 \ln \phi$, is fully consistent with the Planck's data. More specifically, fermionic radiative correction ($A<0$) reduces the tensor to scalar ratio significantly and a red-tilted spectral index $n_s<1$, consistent with Planck's data, is obtained even for sub-Planckian field-values.
[ { "created": "Wed, 31 Dec 2014 17:07:09 GMT", "version": "v1" }, { "created": "Tue, 13 Jan 2015 07:35:08 GMT", "version": "v2" }, { "created": "Sun, 7 Jun 2015 04:16:18 GMT", "version": "v3" } ]
2018-07-03
[ [ "Ahmed", "Waqas", "" ], [ "Ishaque", "Ommair", "" ], [ "Rehman", "Mansoor Ur", "" ] ]
We study the impact of one-loop radiative corrections in a non-supersymmetric model of hybrid inflation with chaotic (polynomial-like) potential, $V_0 + \lambda_p \phi^p$. These corrections can arise from the possible couplings of inflaton with other fields which may play active role in the reheating process. The tree-level predictions of these models are shown to lie outside of the Planck's latest bounds on the scalar spectral index $n_s$ and the tensor to scalar ratio $r$. However, the radiatively corrected version of these models, $ V_0 + \lambda_p \phi^p + A \phi^4 \ln \phi$, is fully consistent with the Planck's data. More specifically, fermionic radiative correction ($A<0$) reduces the tensor to scalar ratio significantly and a red-tilted spectral index $n_s<1$, consistent with Planck's data, is obtained even for sub-Planckian field-values.
hep-ph/9310358
Georg Weiglein
G. Weiglein, R. Scharf, M. B\"ohm
Reduction of general two-loop self-energies to standard scalar integrals
LaTex, 32 pages, (+ 7 figures available from the authors as ps-files), to appear in Nuclear Physics B
Nucl.Phys. B416 (1994) 606-644
10.1016/0550-3213(94)90325-5
null
hep-ph
null
We present a method for reducing general two-loop self-energies to standard scalar integrals in massive gauge theories with special emphasis on the electroweak Standard Model. It includes the tensor integral reduction for all two-loop integrals appearing in self-energy calculations. The results are valid for arbitrary values of the invariant momentum $p^2$, all particle masses, the space-time dimension $D$ and the gauge parameters $\xi _i \; (i = \gamma , Z, W)$. The algebraic structure of the results clearly displays the gauge dependence of the considered quantities and allows to perform very stringent checks. We explicitly verify Slavnov-Taylor identities by calculating several thousand Feynman-diagrams and adding them up algebraically. As an application we calculate the light fermion contributions to the two-loop gauge boson self-energies of the electroweak SM. We study their gauge dependence and discuss the occurring standard integrals.
[ { "created": "Wed, 27 Oct 1993 11:33:50 GMT", "version": "v1" } ]
2009-10-22
[ [ "Weiglein", "G.", "" ], [ "Scharf", "R.", "" ], [ "Böhm", "M.", "" ] ]
We present a method for reducing general two-loop self-energies to standard scalar integrals in massive gauge theories with special emphasis on the electroweak Standard Model. It includes the tensor integral reduction for all two-loop integrals appearing in self-energy calculations. The results are valid for arbitrary values of the invariant momentum $p^2$, all particle masses, the space-time dimension $D$ and the gauge parameters $\xi _i \; (i = \gamma , Z, W)$. The algebraic structure of the results clearly displays the gauge dependence of the considered quantities and allows to perform very stringent checks. We explicitly verify Slavnov-Taylor identities by calculating several thousand Feynman-diagrams and adding them up algebraically. As an application we calculate the light fermion contributions to the two-loop gauge boson self-energies of the electroweak SM. We study their gauge dependence and discuss the occurring standard integrals.
hep-ph/0504213
Mustafa Savci
T. M. Aliev, V. Bashiry and M. Savci (Middle East Technical University-Ankara-Turkey)
Exclusive (B -> rho l^+ l^-) decay and Polarized lepton pair forward--backward asymmetries
23 pages, 12 figures, LaTeX formatted
Phys.Rev. D73 (2006) 034013
10.1103/PhysRevD.73.034013
metu-phys-hep-05-12
hep-ph
null
The polarized lepton pair forward-backward asymmetries in (B -> rho l^+ l^-) decay using a general, model independent form of the effective Hamiltonian is studied. The general expression for nine double-polarization forward-backward asymmetries are calculated. The study of the forward-backward asymmetries of the doubly-polarized lepton pair proves to be very useful tool in looking for new physics beyond the standard model.
[ { "created": "Sat, 23 Apr 2005 14:55:13 GMT", "version": "v1" } ]
2015-06-25
[ [ "Aliev", "T. M.", "", "Middle East Technical\n University-Ankara-Turkey" ], [ "Bashiry", "V.", "", "Middle East Technical\n University-Ankara-Turkey" ], [ "Savci", "M.", "", "Middle East Technical\n University-Ankara-Turkey" ] ]
The polarized lepton pair forward-backward asymmetries in (B -> rho l^+ l^-) decay using a general, model independent form of the effective Hamiltonian is studied. The general expression for nine double-polarization forward-backward asymmetries are calculated. The study of the forward-backward asymmetries of the doubly-polarized lepton pair proves to be very useful tool in looking for new physics beyond the standard model.
hep-ph/9903383
Nicolaj Merenkov
M.I.Konchatnij, N.P.Merenkov (National Science Centre "Kharkov Institute of Physics and Technology")
Scanning of hadron cross-section at DAFNE by analysis of initial-state radiative events
6p. (Submitted to JETP Lett.)
JETP Lett. 69 (1999) 811-818
10.1134/1.568095
null
hep-ph
null
The initial-state radiative events in electron-positron annihilation into hadrons at DAFNE have been considered. The coresponding cross-section with the full first order radiative correction has been calculated. The analytical calculations take into account the realistic angular acceptance and energy cut of DAFNE photon detector.
[ { "created": "Wed, 17 Mar 1999 14:03:35 GMT", "version": "v1" } ]
2009-10-31
[ [ "Konchatnij", "M. I.", "", "National Science Centre \"Kharkov\n Institute of Physics and Technology\"" ], [ "Merenkov", "N. P.", "", "National Science Centre \"Kharkov\n Institute of Physics and Technology\"" ] ]
The initial-state radiative events in electron-positron annihilation into hadrons at DAFNE have been considered. The coresponding cross-section with the full first order radiative correction has been calculated. The analytical calculations take into account the realistic angular acceptance and energy cut of DAFNE photon detector.
hep-ph/0601128
Leszek Motyka
J. Bartels, S. Bondarenko, K. Kutak and L. Motyka
Exclusive Higgs boson production at the LHC: hard rescattering corrections
28 pages, 9 figures
Phys.Rev.D73:093004,2006
10.1103/PhysRevD.73.093004
DESY 06-003
hep-ph
null
We examine, as a correction to the central exclusive Higgs boson production in $pp$ collisions at the LHC, the rescattering of gluonic ladders off the proton. As usual, at the lowest order the hard part of this process can be described as a fusion of two hard gluonic ladders. We calculate corrections to this hard amplitude which are due to rescattering of these ladders. These corrections, which contain high mass diffractive excitations of the proton, have not yet been taken into account by the usual soft survival probabilities. We find that the correction due to the exchange of a single hard rescattering is negative, large and infrared sensitive. As a first step towards a more reliable description we therefore replace the rescattering exchange by a unitarized amplitude using the BK equation which generates the saturation scale $Q_s(x)$. We also include a soft gap survival probability factor. We discuss the results and outline possible future strategies.
[ { "created": "Tue, 17 Jan 2006 11:16:03 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bartels", "J.", "" ], [ "Bondarenko", "S.", "" ], [ "Kutak", "K.", "" ], [ "Motyka", "L.", "" ] ]
We examine, as a correction to the central exclusive Higgs boson production in $pp$ collisions at the LHC, the rescattering of gluonic ladders off the proton. As usual, at the lowest order the hard part of this process can be described as a fusion of two hard gluonic ladders. We calculate corrections to this hard amplitude which are due to rescattering of these ladders. These corrections, which contain high mass diffractive excitations of the proton, have not yet been taken into account by the usual soft survival probabilities. We find that the correction due to the exchange of a single hard rescattering is negative, large and infrared sensitive. As a first step towards a more reliable description we therefore replace the rescattering exchange by a unitarized amplitude using the BK equation which generates the saturation scale $Q_s(x)$. We also include a soft gap survival probability factor. We discuss the results and outline possible future strategies.
1106.6199
Benjamin Fuks
Jeremy Andrea, Benjamin Fuks, Fabio Maltoni
Monotops at the LHC
4 pages, 3 figures, 1 table; version accepted by PRD
null
10.1103/PhysRevD.84.074025
CP3-11-21; IPHC-PHENO-11-03
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore scenarios where top quarks may be produced singly in association with missing energy, a very distinctive signature, which in analogy with monojets, we dub monotops. We find that monotops can be produced in a variety of modes, typically characterized by baryon number violating or flavor changing neutral interactions. We build a simplified model that encompasses all the possible (tree-level) production mechanisms and study the LHC sensitiveness to a few representative scenarios by considering fully hadronic top decays. We find that constraints on such exotic models can already be set with one inverse femtobarn of integrated luminosity collected at seven TeV.
[ { "created": "Thu, 30 Jun 2011 12:05:58 GMT", "version": "v1" }, { "created": "Mon, 10 Oct 2011 13:36:28 GMT", "version": "v2" } ]
2013-05-29
[ [ "Andrea", "Jeremy", "" ], [ "Fuks", "Benjamin", "" ], [ "Maltoni", "Fabio", "" ] ]
We explore scenarios where top quarks may be produced singly in association with missing energy, a very distinctive signature, which in analogy with monojets, we dub monotops. We find that monotops can be produced in a variety of modes, typically characterized by baryon number violating or flavor changing neutral interactions. We build a simplified model that encompasses all the possible (tree-level) production mechanisms and study the LHC sensitiveness to a few representative scenarios by considering fully hadronic top decays. We find that constraints on such exotic models can already be set with one inverse femtobarn of integrated luminosity collected at seven TeV.
hep-ph/0010094
Klaus Werner
H. Drescher, J. Aichelin, and K. Werner
Multiplicity of different hadrons in e+e-, pp, and AA collisions
5 pages and 6 figures
null
null
SUBATECH 00-21
hep-ph nucl-th
null
Employing the recently developed neXus model, we compare the yields of different hadrons in ultra-relativistic collisions: electron-positron annihilation at 91 GeV, proton-proton scattering at 17 GeV and nucleus-nucleus collisions at 17 GeV (SPS) and 200 GeV (RHIC). Plotting the yields as a function of the hadron masses, we find very surprising results: we observe that the spectra are practically identical for e+e- at 91 GeV and central nucleus-nucleus reactions at SPS and RHIC energies, whereas the spectrum for proton-proton scattering is somewhat steeper. All have the form one expects if the particles were emitted by a canonical system which is characterized by a temperature and chemical potentials. These identical forms have, however, different origins: in e+e- and pp the exponential shape it is due to the statistical behavior of string fragmentation, which has absolutely nothing to do with thermalization, in AA it is caused by phase space. The fact that e+e- and nuclear results agree is pure coincidence. Surprisingly the results for pp and e+e- differ, although here the production mechanism is identical. In pp collisions we see directly that the string energy is very limited and hence the high mass baryons are suppressed. We conclude that it is practically impossible to draw conclusions from hadronic yields about the reaction mechanism.
[ { "created": "Tue, 10 Oct 2000 16:18:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Drescher", "H.", "" ], [ "Aichelin", "J.", "" ], [ "Werner", "K.", "" ] ]
Employing the recently developed neXus model, we compare the yields of different hadrons in ultra-relativistic collisions: electron-positron annihilation at 91 GeV, proton-proton scattering at 17 GeV and nucleus-nucleus collisions at 17 GeV (SPS) and 200 GeV (RHIC). Plotting the yields as a function of the hadron masses, we find very surprising results: we observe that the spectra are practically identical for e+e- at 91 GeV and central nucleus-nucleus reactions at SPS and RHIC energies, whereas the spectrum for proton-proton scattering is somewhat steeper. All have the form one expects if the particles were emitted by a canonical system which is characterized by a temperature and chemical potentials. These identical forms have, however, different origins: in e+e- and pp the exponential shape it is due to the statistical behavior of string fragmentation, which has absolutely nothing to do with thermalization, in AA it is caused by phase space. The fact that e+e- and nuclear results agree is pure coincidence. Surprisingly the results for pp and e+e- differ, although here the production mechanism is identical. In pp collisions we see directly that the string energy is very limited and hence the high mass baryons are suppressed. We conclude that it is practically impossible to draw conclusions from hadronic yields about the reaction mechanism.
hep-ph/9908485
Dan-Olof Riska
T. A. Lahde, C. Nyfalt, D. O. Riska
Spectra and M1 Decay Widths of Heavy-Light Mesons
Accepted version
Nucl.Phys. A674 (2000) 141-167
10.1016/S0375-9474(00)00154-8
null
hep-ph
null
The M1 decay widths of charm and bottom mesons and their excited states are sensitive to the relativistic aspect of the quark current operators and obtain a significant contribution from the interaction current that is associated with the scalar confining interaction between heavy quarks ($Q$) and light antiquarks ($\bar q$). Consequently they provide direct evidence on the latter. The spectra and the M1 transition widths of the $D$, $D_s$ and $B$, $B_s$ mesons and their orbital excitations are calculated here within the framework of the Blankenbecler-Sugar equation, which allows a covariant treatment, while retaining a formal similarity to the nonrelativistic approach. The hyperfine interaction in the $Q\bar q$ mesons is modeled by screened gluon exchange, which shares many features with the instanton induced interaction. The quality of the model is tested by calculation of the spectra and M1 decay widths of charmonium.
[ { "created": "Fri, 27 Aug 1999 09:52:26 GMT", "version": "v1" }, { "created": "Tue, 22 Feb 2000 11:28:20 GMT", "version": "v2" } ]
2009-10-31
[ [ "Lahde", "T. A.", "" ], [ "Nyfalt", "C.", "" ], [ "Riska", "D. O.", "" ] ]
The M1 decay widths of charm and bottom mesons and their excited states are sensitive to the relativistic aspect of the quark current operators and obtain a significant contribution from the interaction current that is associated with the scalar confining interaction between heavy quarks ($Q$) and light antiquarks ($\bar q$). Consequently they provide direct evidence on the latter. The spectra and the M1 transition widths of the $D$, $D_s$ and $B$, $B_s$ mesons and their orbital excitations are calculated here within the framework of the Blankenbecler-Sugar equation, which allows a covariant treatment, while retaining a formal similarity to the nonrelativistic approach. The hyperfine interaction in the $Q\bar q$ mesons is modeled by screened gluon exchange, which shares many features with the instanton induced interaction. The quality of the model is tested by calculation of the spectra and M1 decay widths of charmonium.
1708.04072
Andrew Akeroyd
A.G. Akeroyd, Chuan-Hung Chen
Constraint on the branching ratio of B_c \to tau nu from LEP1 and consequences for R(D(*)) anomaly
14 pages, 4 figures, a reference and two sentences added
Phys. Rev. D 96, 075011 (2017)
10.1103/PhysRevD.96.075011
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently there has been interest in the correlation between R(D*) and the branching ratio (BR) of $B_c \to \tau \nu$ in models with a charged scalar H^\pm. Any enhancement of R(D*) by $H^\pm$ alone (in order to agree with current data) also enhances $BR(B_c \to \tau \nu$), for which there has been no direct search at hadron colliders. We show that LEP data taken at the Z peak requires BR($B_c \to \tau \nu$) < 10%, and this constraint is significantly stronger than the recent constraint BR($B_c \to \tau \nu$) < 30% from considering the lifetime of B_c. In order to respect this new constraint, any explanation of the R(D) and R(D*) anomaly in terms of $H^\pm$ alone would require the future measurements of R(D*) to be even closer to the Standard Model prediction. A stronger limit on BR($B_c \to \tau \nu$) (or its first measurement) would be obtained if the L3 collaboration used all its data taken at the Z peak.
[ { "created": "Mon, 14 Aug 2017 10:53:36 GMT", "version": "v1" }, { "created": "Wed, 23 Aug 2017 09:58:52 GMT", "version": "v2" } ]
2017-10-18
[ [ "Akeroyd", "A. G.", "" ], [ "Chen", "Chuan-Hung", "" ] ]
Recently there has been interest in the correlation between R(D*) and the branching ratio (BR) of $B_c \to \tau \nu$ in models with a charged scalar H^\pm. Any enhancement of R(D*) by $H^\pm$ alone (in order to agree with current data) also enhances $BR(B_c \to \tau \nu$), for which there has been no direct search at hadron colliders. We show that LEP data taken at the Z peak requires BR($B_c \to \tau \nu$) < 10%, and this constraint is significantly stronger than the recent constraint BR($B_c \to \tau \nu$) < 30% from considering the lifetime of B_c. In order to respect this new constraint, any explanation of the R(D) and R(D*) anomaly in terms of $H^\pm$ alone would require the future measurements of R(D*) to be even closer to the Standard Model prediction. A stronger limit on BR($B_c \to \tau \nu$) (or its first measurement) would be obtained if the L3 collaboration used all its data taken at the Z peak.
1903.02286
S. Weinzierl
Robin Baumeister, Daniel Mediger, Julia Pe\v{c}ovnik, Stefan Weinzierl
On the vanishing of certain cuts or residues of loop integrals with higher powers of the propagators
19 pages, v2: version to be published
Phys. Rev. D 99, 096023 (2019)
10.1103/PhysRevD.99.096023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from two-loops, there are Feynman integrals with higher powers of the propagators. They arise from self-energy insertions on internal lines. Within the loop-tree duality approach or within methods based on numerical unitarity one needs (among other things) the residue when a raised propagator goes on-shell. We show that for renormalised quantities in the on-shell scheme these residues can be made to vanish already at the integrand level.
[ { "created": "Wed, 6 Mar 2019 10:19:25 GMT", "version": "v1" }, { "created": "Tue, 7 May 2019 16:20:40 GMT", "version": "v2" } ]
2019-05-29
[ [ "Baumeister", "Robin", "" ], [ "Mediger", "Daniel", "" ], [ "Pečovnik", "Julia", "" ], [ "Weinzierl", "Stefan", "" ] ]
Starting from two-loops, there are Feynman integrals with higher powers of the propagators. They arise from self-energy insertions on internal lines. Within the loop-tree duality approach or within methods based on numerical unitarity one needs (among other things) the residue when a raised propagator goes on-shell. We show that for renormalised quantities in the on-shell scheme these residues can be made to vanish already at the integrand level.
hep-ph/9809377
Matthias Neubert
Matthias Neubert (CERN)
Theoretical Status of B -> Xs gamma Decays
6 pages, 1 figure, uses ltwol2e.sty (included); to appear in the Proceedings of the 29th International Conference on High Energy Physics (Vancouver)
null
null
CERN-TH/98-301
hep-ph
null
We review the theoretical understanding of the branching ratio and photon-energy spectrum in B -> Xs gamma decays at next-to-leading order in QCD, including consistently the effects of Fermi motion. For the Standard Model, we obtain B(B -> Xs gamma)=(3.29 +- 0.33)*10^{-4} for the total branching ratio, and B(B -> Xs gamma)=(2.85+0.34-0.40)*10^{-4} if a cut E_gamma > 2.1 GeV is applied on the photon energy, as done in the recent CLEO analysis. A precise measurement of the photon spectrum would help reducing the theoretical uncertainty and yield important information on the momentum distribution of b quarks inside B mesons.
[ { "created": "Mon, 14 Sep 1998 15:37:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Neubert", "Matthias", "", "CERN" ] ]
We review the theoretical understanding of the branching ratio and photon-energy spectrum in B -> Xs gamma decays at next-to-leading order in QCD, including consistently the effects of Fermi motion. For the Standard Model, we obtain B(B -> Xs gamma)=(3.29 +- 0.33)*10^{-4} for the total branching ratio, and B(B -> Xs gamma)=(2.85+0.34-0.40)*10^{-4} if a cut E_gamma > 2.1 GeV is applied on the photon energy, as done in the recent CLEO analysis. A precise measurement of the photon spectrum would help reducing the theoretical uncertainty and yield important information on the momentum distribution of b quarks inside B mesons.
hep-ph/0409248
Koichi Hamaguchi
Koichi Hamaguchi, Yoshitaka Kuno, Tsuyoshi Nakaya, Mihoko M. Nojiri
A study of late decaying charged particles at future colliders
22 pages, 9 figures. v2: Comments and references are added
Phys.Rev.D70:115007,2004
10.1103/PhysRevD.70.115007
YITP-04-50, DESY-04-179
hep-ph hep-ex
null
In models where the gravitino is the lightest supersymmetric particle (LSP), the next-to-lightest supersymmetric particle (NLSP) is long-lived. We consider an important charged NLSP candidate, the scalar tau $\tilde{\tau}$. Slow charged NLSPs may be produced at future colliders and they may be stopped in a massive stopper which simultaneously serves as a detector for the NLSP and its decay products. We found the number of events at a 1 kton to O(10) kton detector could be significant enough to study the NLSP decays with lifetime shorter than $10^{10}$ sec at the LHC. The performance of existing 1 kton detectors may be good enough to do such studies at the LHC, if they can be placed close to the ATLAS/CMS detectors. At a future $e^- e^-$ collider, scalar electrons $\tilde{e}^-$s are copiously produced. Slow NLSPs may be produced from the $\tilde{e}^-$ decay. The number of stopped NLSPs at a future linear collider could be large enough to study rare decay modes of the NLSP.
[ { "created": "Tue, 21 Sep 2004 14:49:21 GMT", "version": "v1" }, { "created": "Fri, 24 Sep 2004 14:35:42 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hamaguchi", "Koichi", "" ], [ "Kuno", "Yoshitaka", "" ], [ "Nakaya", "Tsuyoshi", "" ], [ "Nojiri", "Mihoko M.", "" ] ]
In models where the gravitino is the lightest supersymmetric particle (LSP), the next-to-lightest supersymmetric particle (NLSP) is long-lived. We consider an important charged NLSP candidate, the scalar tau $\tilde{\tau}$. Slow charged NLSPs may be produced at future colliders and they may be stopped in a massive stopper which simultaneously serves as a detector for the NLSP and its decay products. We found the number of events at a 1 kton to O(10) kton detector could be significant enough to study the NLSP decays with lifetime shorter than $10^{10}$ sec at the LHC. The performance of existing 1 kton detectors may be good enough to do such studies at the LHC, if they can be placed close to the ATLAS/CMS detectors. At a future $e^- e^-$ collider, scalar electrons $\tilde{e}^-$s are copiously produced. Slow NLSPs may be produced from the $\tilde{e}^-$ decay. The number of stopped NLSPs at a future linear collider could be large enough to study rare decay modes of the NLSP.
hep-ph/9801404
Tim
T.S.Evans, T.W.B.Kibble, D.A.Steer
Wick's Theorem for non-symmetric normal ordered products and contractions
17 pages
J.Math.Phys. 39 (1998) 5726-5738
10.1063/1.532589
Imperial/TP/97-98/16 DAMTP-97-149
hep-ph
null
We consider arbitrary splits of field operators into two parts, and use the corresponding definition of normal ordering introduced by Evans and Steer. In this case the normal ordered products and contractions have none of the special symmetry properties assumed in existing proofs of Wick's theorem. Despite this, we prove that Wick's theorem still holds in its usual form as long as the contraction is a c-number. Wick's theorem is thus shown to be much more general than existing derivations suggest, and we discuss possible simplifying applications of this result.
[ { "created": "Fri, 23 Jan 1998 14:36:34 GMT", "version": "v1" } ]
2016-09-06
[ [ "Evans", "T. S.", "" ], [ "Kibble", "T. W. B.", "" ], [ "Steer", "D. A.", "" ] ]
We consider arbitrary splits of field operators into two parts, and use the corresponding definition of normal ordering introduced by Evans and Steer. In this case the normal ordered products and contractions have none of the special symmetry properties assumed in existing proofs of Wick's theorem. Despite this, we prove that Wick's theorem still holds in its usual form as long as the contraction is a c-number. Wick's theorem is thus shown to be much more general than existing derivations suggest, and we discuss possible simplifying applications of this result.
1805.06988
Cherepanov Vladimir
Vladimir Cherepanov, Alexander Zotz
Kinematic reconstruction of $Z/H \rightarrow \tau\tau$ decay in proton-proton collisions
null
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The knowledge of $\tau$ lepton kinematic and kinematic of the $\tau$ pair in the decay $Z/H \rightarrow \tau\tau$ is essential for various analysis at LHC. However, the reconstruction of the whole kinematic of the $\tau$ decay is a challenging task, since in every $\tau$ decay at least one neutrino is present in the final state which escapes detection. In this paper a kinematic technique (Global Event Fit) to estimate the momentum escaped with neutrinos and hence the full momentum of the $\tau$ lepton pair is described. The algorithm is based on iterative minimization of the likelihood with constrains derived from all available kinematic information on the decay. The method requires the direction of at least one $\tau$ lepton to be well defined and therefore the method can be applied to the decays $Z/H \rightarrow \tau\tau \rightarrow X + a_{1}\nu$ with $a_{1}$ resonance decaying into three charged pions.
[ { "created": "Thu, 17 May 2018 23:11:19 GMT", "version": "v1" }, { "created": "Mon, 5 Nov 2018 05:14:32 GMT", "version": "v2" } ]
2018-11-06
[ [ "Cherepanov", "Vladimir", "" ], [ "Zotz", "Alexander", "" ] ]
The knowledge of $\tau$ lepton kinematic and kinematic of the $\tau$ pair in the decay $Z/H \rightarrow \tau\tau$ is essential for various analysis at LHC. However, the reconstruction of the whole kinematic of the $\tau$ decay is a challenging task, since in every $\tau$ decay at least one neutrino is present in the final state which escapes detection. In this paper a kinematic technique (Global Event Fit) to estimate the momentum escaped with neutrinos and hence the full momentum of the $\tau$ lepton pair is described. The algorithm is based on iterative minimization of the likelihood with constrains derived from all available kinematic information on the decay. The method requires the direction of at least one $\tau$ lepton to be well defined and therefore the method can be applied to the decays $Z/H \rightarrow \tau\tau \rightarrow X + a_{1}\nu$ with $a_{1}$ resonance decaying into three charged pions.
2311.09330
Maksim Nekrasov L
M. L. Nekrasov
Coulomb-nuclear interference in elastic proton scattering in the eikonal approach
v2: significantly reduced text; v3: added discussion of ambiguity of $O(\alpha)$-approximation of amplitude, 12 pages
Phys.Lett.B 849 (2024) 138485
10.1016/j.physletb.2024.138485
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We find exact solution in the Cahn eikonal model, which describes Coulomb-nuclear interference in elastic scattering of charged hadrons. The cases of both point-like and extended particles equipped with electromagnetic form factors are considered. According to the solution obtained the Coulomb-nuclear contributions are not exponentiated and cannot be added to the Coulomb phase. At the same time, the $O(\alpha)$-approximation of the amplitude is ambiguous, which makes it unsuitable for data processing.
[ { "created": "Wed, 15 Nov 2023 19:37:02 GMT", "version": "v1" }, { "created": "Thu, 14 Dec 2023 18:28:11 GMT", "version": "v2" }, { "created": "Thu, 25 Jan 2024 10:32:50 GMT", "version": "v3" } ]
2024-02-06
[ [ "Nekrasov", "M. L.", "" ] ]
We find exact solution in the Cahn eikonal model, which describes Coulomb-nuclear interference in elastic scattering of charged hadrons. The cases of both point-like and extended particles equipped with electromagnetic form factors are considered. According to the solution obtained the Coulomb-nuclear contributions are not exponentiated and cannot be added to the Coulomb phase. At the same time, the $O(\alpha)$-approximation of the amplitude is ambiguous, which makes it unsuitable for data processing.
0710.5534
Mahiko Suzuki
Mahiko Suzuki
Inelastic final-state interaction
The published version. One figure corrected
Phys.Rev.D77:054021,2008
10.1103/PhysRevD.77.054021
null
hep-ph
null
The final-state interaction in multichannel decay processes is sytematically studied with application to B decay in mind. Since the final-state inteaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like "Watson's theorem" holds for experimentally observed final states. We first examine in detail the two-channel problem as a toy-model to clarify the issues and to remedy common mistakes made in earlier literature. Realistic multichannel problems are too challenging for quantitative analysis. To cope with mathematical complexity, we introduce a method of approximation that is applicable to the case where one prominant inelastic channel dominates over all others. We illustrate this approximation method in the amplitude of the decay B to pi K fed by the intermediate states of a charmed meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonethless we are able to obtain some insight in the issue and draw useful conclusions on general fearyres on the strong phases.
[ { "created": "Mon, 29 Oct 2007 21:03:50 GMT", "version": "v1" }, { "created": "Mon, 3 Dec 2007 22:21:58 GMT", "version": "v2" }, { "created": "Sat, 12 Apr 2008 22:00:04 GMT", "version": "v3" }, { "created": "Tue, 15 Apr 2008 17:03:29 GMT", "version": "v4" } ]
2008-11-26
[ [ "Suzuki", "Mahiko", "" ] ]
The final-state interaction in multichannel decay processes is sytematically studied with application to B decay in mind. Since the final-state inteaction is intrinsically interwoven with the decay interaction in this case, no simple phase theorem like "Watson's theorem" holds for experimentally observed final states. We first examine in detail the two-channel problem as a toy-model to clarify the issues and to remedy common mistakes made in earlier literature. Realistic multichannel problems are too challenging for quantitative analysis. To cope with mathematical complexity, we introduce a method of approximation that is applicable to the case where one prominant inelastic channel dominates over all others. We illustrate this approximation method in the amplitude of the decay B to pi K fed by the intermediate states of a charmed meson pair. Even with our approximation we need more accurate information of strong interactions than we have now. Nonethless we are able to obtain some insight in the issue and draw useful conclusions on general fearyres on the strong phases.
1605.00542
Jeremie Quevillon
Abdelhak Djouadi, John Ellis and J\'er\'emie Quevillon
Interference Effects in the Decays of Spin-Zero Resonances into $\gamma \gamma$ and $t\bar{t}$
31 pages, v2 contains additional comments
null
10.1007/JHEP07(2016)105
CERN-TH/2016-095, KCL-PH-TH/2016-20, LPT-Orsay--16--39
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider interference effects in the production via gluon fusion in LHC collisions at 13 TeV and decays into $\gamma \gamma$ and $t {\bar t}$ final states of one or two putative new resonant states $\Phi$, assumed here to be scalar and/or pseudo scalar particles. Although our approach is general, we use for our numerical analysis the example of the putative $750$ GeV state for which a slight excess was observed in the initial LHC $13$ TeV data. We revisit previous calculations of the interferences between the heavy-fermion loop-induced $gg \to \Phi \to \gamma \gamma$ signal and the continuum $gg\to \gamma\gamma$ QCD background, which can alter the production rate as well as modify the line-shape and apparent mass. We find a modest enhancement by $\sim 20$% under favorable circumstances, for a large $\Phi$ width. The effect of interference on the apparent scalar-pseudoscalar mass difference in a two-Higgs-doublet model is found to be also modest. An exploratory study indicates that similar effects are to be expected in the $gg \to \Phi \to Z \gamma$ channel. In this and other models with a large $\Phi$ total width, the dominant $\Phi$ decays are expected to be into $t \bar t$ final states. We therefore also study the effects of interference of the $gg\to \Phi \to t\bar t$ signal with the $gg\to t \bar t$ continuum QCD background and show that in the presence of standard fermions only in the $gg\to \Phi$ loops, it is destructive causing a dip in the $t \bar t$ mass distribution. Including additional vector-like quarks leads to a different picture as peaks followed by dips can then occur. We use the absence of such effects in ATLAS and CMS data to constrain models of the production and decays of the $\Phi$ state(s).
[ { "created": "Mon, 2 May 2016 16:12:37 GMT", "version": "v1" }, { "created": "Tue, 26 Jul 2016 10:36:34 GMT", "version": "v2" } ]
2016-08-24
[ [ "Djouadi", "Abdelhak", "" ], [ "Ellis", "John", "" ], [ "Quevillon", "Jérémie", "" ] ]
We consider interference effects in the production via gluon fusion in LHC collisions at 13 TeV and decays into $\gamma \gamma$ and $t {\bar t}$ final states of one or two putative new resonant states $\Phi$, assumed here to be scalar and/or pseudo scalar particles. Although our approach is general, we use for our numerical analysis the example of the putative $750$ GeV state for which a slight excess was observed in the initial LHC $13$ TeV data. We revisit previous calculations of the interferences between the heavy-fermion loop-induced $gg \to \Phi \to \gamma \gamma$ signal and the continuum $gg\to \gamma\gamma$ QCD background, which can alter the production rate as well as modify the line-shape and apparent mass. We find a modest enhancement by $\sim 20$% under favorable circumstances, for a large $\Phi$ width. The effect of interference on the apparent scalar-pseudoscalar mass difference in a two-Higgs-doublet model is found to be also modest. An exploratory study indicates that similar effects are to be expected in the $gg \to \Phi \to Z \gamma$ channel. In this and other models with a large $\Phi$ total width, the dominant $\Phi$ decays are expected to be into $t \bar t$ final states. We therefore also study the effects of interference of the $gg\to \Phi \to t\bar t$ signal with the $gg\to t \bar t$ continuum QCD background and show that in the presence of standard fermions only in the $gg\to \Phi$ loops, it is destructive causing a dip in the $t \bar t$ mass distribution. Including additional vector-like quarks leads to a different picture as peaks followed by dips can then occur. We use the absence of such effects in ATLAS and CMS data to constrain models of the production and decays of the $\Phi$ state(s).
2012.05891
Jiaming Zheng
Hong-Jian He, Yu-Chen Wang, Jiaming Zheng
GeV Scale Inelastic Dark Matter with Dark Photon Mediator via Direct Detection and Cosmological/Laboratory Constraints
14pp, PRD published version. Results and Conclusions unchanged, only minor refinements. The importance of Migdal bound on inelastic DM is stressed. References added
Phys. Rev. D 104 (2021) 115033, no.11
10.1103/PhysRevD.104.115033
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new candidate of GeV scale inelastic dark matter (DM). Our construction has an anomaly-free $U(1)_X^{}$ gauge group with dark photon mediator, and can realize either scalar or fermionic inelastic DM. It is highly predictive and testable. We study the scattering rate of light inelastic DM with electrons in the XENON1T experiment and with nuclei in the XENON1T, CRESST-III, CDEX-1B and DarkSide-50 experiments. We resolve the recent XENON1T anomaly via electron recoil detection. Combining the XENON1T constraints from both electron recoils and nuclear recoils (including Migdal effect), we predict the inelastic DM mass $\lesssim 1.5$GeV. We further analyze the bounds by the DM relic abundance, the lifetime of the heavier DM component, and laboratory constraints, from which we identify the viable parameter space for the future probe. This provides an important benchmark for the theories and experimental tests of GeV scale inelastic DM.
[ { "created": "Thu, 10 Dec 2020 18:52:23 GMT", "version": "v1" }, { "created": "Fri, 8 Jan 2021 04:34:52 GMT", "version": "v2" }, { "created": "Sat, 1 Jan 2022 06:38:12 GMT", "version": "v3" } ]
2022-01-04
[ [ "He", "Hong-Jian", "" ], [ "Wang", "Yu-Chen", "" ], [ "Zheng", "Jiaming", "" ] ]
We propose a new candidate of GeV scale inelastic dark matter (DM). Our construction has an anomaly-free $U(1)_X^{}$ gauge group with dark photon mediator, and can realize either scalar or fermionic inelastic DM. It is highly predictive and testable. We study the scattering rate of light inelastic DM with electrons in the XENON1T experiment and with nuclei in the XENON1T, CRESST-III, CDEX-1B and DarkSide-50 experiments. We resolve the recent XENON1T anomaly via electron recoil detection. Combining the XENON1T constraints from both electron recoils and nuclear recoils (including Migdal effect), we predict the inelastic DM mass $\lesssim 1.5$GeV. We further analyze the bounds by the DM relic abundance, the lifetime of the heavier DM component, and laboratory constraints, from which we identify the viable parameter space for the future probe. This provides an important benchmark for the theories and experimental tests of GeV scale inelastic DM.
1302.6246
C.-P. Yuan
Jun Gao, Marco Guzzi, Joey Huston, Hung-Liang Lai, Zhao Li, Pavel Nadolsky, Jon Pumplin, Daniel Stump, and C.-P. Yuan
The CT10 NNLO Global Analysis of QCD
46 pages, 28 figures, and 2 tables
Phys. Rev. D 89, 033009 (2014)
10.1103/PhysRevD.89.033009
SMU-HEP-12-23
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present next-to-next-to-leading order (NNLO) parton distribution functions (PDFs) from the CTEQ-TEA group. The CT10NNLO PDF fit is based on essentially the same global data sets used in the CT10 and CT10W NLO PDF analyses. After exploring the goodness of the fits to the HERA combined data and the Tevatron jet data, we present various predictions at NNLO accuracy for both existing and forthcoming precision measurements from the CERN Large Hadron Collider. The range of variations in the gluon distribution introduced by correlated systematic effects in inclusive jet production is also examined.
[ { "created": "Mon, 25 Feb 2013 21:01:23 GMT", "version": "v1" }, { "created": "Tue, 19 Aug 2014 22:05:19 GMT", "version": "v2" } ]
2014-08-21
[ [ "Gao", "Jun", "" ], [ "Guzzi", "Marco", "" ], [ "Huston", "Joey", "" ], [ "Lai", "Hung-Liang", "" ], [ "Li", "Zhao", "" ], [ "Nadolsky", "Pavel", "" ], [ "Pumplin", "Jon", "" ], [ "Stump", "Dani...
We present next-to-next-to-leading order (NNLO) parton distribution functions (PDFs) from the CTEQ-TEA group. The CT10NNLO PDF fit is based on essentially the same global data sets used in the CT10 and CT10W NLO PDF analyses. After exploring the goodness of the fits to the HERA combined data and the Tevatron jet data, we present various predictions at NNLO accuracy for both existing and forthcoming precision measurements from the CERN Large Hadron Collider. The range of variations in the gluon distribution introduced by correlated systematic effects in inclusive jet production is also examined.
hep-ph/0502011
Ling-Fong Li
Ling-Fong Li, (Carnegie Mellon University)
Vector Goldstone Boson and Lorentz Invariance
Talk presented at "Miami 2004: A topical conference on elementary particle physics and cosmology" Miami, Florida, Dec 15-19, 2004
null
null
null
hep-ph
null
Spontanous symmetry breaking usually gives spin 0 Goldstone bosons for the case of internal symmetries and spin 1/2 fermions for the supersymmetry. The spontaneous breaking of higher dimensional Lorentz symmetry can give vector Goldstone boson in 4-dimension.
[ { "created": "Tue, 1 Feb 2005 19:15:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Li", "Ling-Fong", "" ] ]
Spontanous symmetry breaking usually gives spin 0 Goldstone bosons for the case of internal symmetries and spin 1/2 fermions for the supersymmetry. The spontaneous breaking of higher dimensional Lorentz symmetry can give vector Goldstone boson in 4-dimension.
hep-ph/0507249
Makiko Nio
T. Kinoshita (Cornell.U) and M. Nio (RIKEN)
Improved $\alpha^4$ Term of the Electron Anomalous Magnetic Moment
64 pages and 10 figures. Eq.(16) is corrected. Comments are added after Eq.(40)
Phys.Rev.D73:013003,2006
10.1103/PhysRevD.73.013003
null
hep-ph
null
We report a new value of electron $g-2$, or $a_e$, from 891 Feynman diagrams of order $\alpha^4$. The FORTRAN codes of 373 diagrams containing closed electron loops have been verified by at least two independent formulations. For the remaining 518 diagrams, which have no closed lepton loop, verification by a second formulation is not yet attempted because of the enormous amount of additional work required. However, these integrals have structures that allow extensive cross-checking as well as detailed comparison with lower-order diagrams through the renormalization procedure. No algebraic error has been uncovered for them. The numerical evaluation of the entire $\alpha^4$ term by the integration routine VEGAS gives $-1.7283 (35) (\alpha/\pi)^4$, where the uncertainty is obtained by careful examination of error estimates by VEGAS. This leads to $a_e = 1 159 652 175.86 (0.10) (0.26) (8.48) \times 10^{-12}$, where the uncertainties come from the $\alpha^4$ term, the estimated uncertainty of $\alpha^5$ term, and the inverse fine structure constant, $\alpha^{-1} = 137.036 000 3 (10)$, measured by atom interferometry combined with a frequency comb technique, respectively. The inverse fine structure constant $\alpha^{-1} (a_e)$ derived from the theory and the Seattle measurement of $a_e$ is $137.035 998 83 (51)$.
[ { "created": "Thu, 21 Jul 2005 07:20:02 GMT", "version": "v1" }, { "created": "Mon, 21 Nov 2005 05:17:15 GMT", "version": "v2" } ]
2011-02-16
[ [ "Kinoshita", "T.", "", "Cornell.U" ], [ "Nio", "M.", "", "RIKEN" ] ]
We report a new value of electron $g-2$, or $a_e$, from 891 Feynman diagrams of order $\alpha^4$. The FORTRAN codes of 373 diagrams containing closed electron loops have been verified by at least two independent formulations. For the remaining 518 diagrams, which have no closed lepton loop, verification by a second formulation is not yet attempted because of the enormous amount of additional work required. However, these integrals have structures that allow extensive cross-checking as well as detailed comparison with lower-order diagrams through the renormalization procedure. No algebraic error has been uncovered for them. The numerical evaluation of the entire $\alpha^4$ term by the integration routine VEGAS gives $-1.7283 (35) (\alpha/\pi)^4$, where the uncertainty is obtained by careful examination of error estimates by VEGAS. This leads to $a_e = 1 159 652 175.86 (0.10) (0.26) (8.48) \times 10^{-12}$, where the uncertainties come from the $\alpha^4$ term, the estimated uncertainty of $\alpha^5$ term, and the inverse fine structure constant, $\alpha^{-1} = 137.036 000 3 (10)$, measured by atom interferometry combined with a frequency comb technique, respectively. The inverse fine structure constant $\alpha^{-1} (a_e)$ derived from the theory and the Seattle measurement of $a_e$ is $137.035 998 83 (51)$.
hep-ph/9406288
Pene
M.B. Gavela, M. Lozano, J. Orloff, O.P\`ene
Standard Model CP-violation and Baryon asymmetry Part I: Zero Temperature
38 pages, CERN-TH.7262/94, LPTHE-Orsay-94/48, HD-THEP-94-19, FAMNSE-12-94, NSF-ITP-94-64
Nucl.Phys.B430:345-381,1994
10.1016/0550-3213(94)00409-9
null
hep-ph astro-ph
null
We consider quantum effects in a world with two coexisting symmetry phases, unbroken and spontaneously broken, as a result of a first order phase transition. The discrete symmetries of the problem are discussed in general. We compute the exact two-point Green function for a free fermion, when a thin wall separates the two phases. The Dirac propagator displays both massive and massless poles, and new CP-even phases resulting from the fermion reflection on the wall. We discuss the possible quark-antiquark CP asymmetries produced in the Standard Model(SM) for the academic $T=0$ case. General arguments indicate that an effect first appears at order $\alpha_W$ in the reflection amplitude, as the wall acts as a source of momentum and the on-shell one-loop self-energy cannot be renormalized away. The asymmetries stem from the interference of the SM CP-odd couplings and the CP-even phases in the propagator. We perform a toy computation that indicates the type of GIM cancellations of the problem. The behaviour can be expressed in terms of two unitarity triangles.
[ { "created": "Sat, 11 Jun 1994 18:33:05 GMT", "version": "v1" } ]
2010-11-01
[ [ "Gavela", "M. B.", "" ], [ "Lozano", "M.", "" ], [ "Orloff", "J.", "" ], [ "Pène", "O.", "" ] ]
We consider quantum effects in a world with two coexisting symmetry phases, unbroken and spontaneously broken, as a result of a first order phase transition. The discrete symmetries of the problem are discussed in general. We compute the exact two-point Green function for a free fermion, when a thin wall separates the two phases. The Dirac propagator displays both massive and massless poles, and new CP-even phases resulting from the fermion reflection on the wall. We discuss the possible quark-antiquark CP asymmetries produced in the Standard Model(SM) for the academic $T=0$ case. General arguments indicate that an effect first appears at order $\alpha_W$ in the reflection amplitude, as the wall acts as a source of momentum and the on-shell one-loop self-energy cannot be renormalized away. The asymmetries stem from the interference of the SM CP-odd couplings and the CP-even phases in the propagator. We perform a toy computation that indicates the type of GIM cancellations of the problem. The behaviour can be expressed in terms of two unitarity triangles.
1505.02996
Sho Iwamoto
Jonathan L. Feng, Sho Iwamoto, Yael Shadmi, Shlomit Tarem
Long-Lived Sleptons at the LHC and a 100 TeV Proton Collider
24 pages, 9 figures, revised to match published version
null
10.1007/JHEP12(2015)166
UCI-TR-2015-02
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the prospects for long-lived charged particle (LLCP) searches at current and future LHC runs and at a 100 TeV pp collider, using Drell-Yan slepton pair production as an example. Because momentum measurements become more challenging for very energetic particles, we carefully treat the expected momentum resolution. At the same time, a novel feature of 100 TeV collisions is the significant energy loss of energetic muons in detectors. We use this to help discriminate between muons and LLCPs. We find that the 14 TeV LHC with an integrated luminosity of 3 ab$^{-1}$ can probe LLCP slepton masses up to 1.2 TeV, and a 100 TeV pp collider with 3 ab$^{-1}$ can probe LLCP slepton masses up to 4 TeV, using time-of-flight measurements. These searches will have striking implications for dark matter, with the LHC definitively testing the possibility of slepton-neutralino co-annihilating WIMP dark matter, and with the LHC and future hadron colliders having a strong potential for discovering LLCPs in models with superWIMP dark matter.
[ { "created": "Tue, 12 May 2015 13:19:29 GMT", "version": "v1" }, { "created": "Sun, 14 Feb 2016 08:18:11 GMT", "version": "v2" } ]
2016-02-16
[ [ "Feng", "Jonathan L.", "" ], [ "Iwamoto", "Sho", "" ], [ "Shadmi", "Yael", "" ], [ "Tarem", "Shlomit", "" ] ]
We study the prospects for long-lived charged particle (LLCP) searches at current and future LHC runs and at a 100 TeV pp collider, using Drell-Yan slepton pair production as an example. Because momentum measurements become more challenging for very energetic particles, we carefully treat the expected momentum resolution. At the same time, a novel feature of 100 TeV collisions is the significant energy loss of energetic muons in detectors. We use this to help discriminate between muons and LLCPs. We find that the 14 TeV LHC with an integrated luminosity of 3 ab$^{-1}$ can probe LLCP slepton masses up to 1.2 TeV, and a 100 TeV pp collider with 3 ab$^{-1}$ can probe LLCP slepton masses up to 4 TeV, using time-of-flight measurements. These searches will have striking implications for dark matter, with the LHC definitively testing the possibility of slepton-neutralino co-annihilating WIMP dark matter, and with the LHC and future hadron colliders having a strong potential for discovering LLCPs in models with superWIMP dark matter.
1505.04444
Jaime Varela
Peter W. Graham, Surjeet Rajendran, Jaime Varela
Dark Matter Triggers of Supernovae
16 pages, 3 figures
Phys. Rev. D 92, 063007 (2015)
10.1103/PhysRevD.92.063007
null
hep-ph astro-ph.CO astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\odot}$ rules out primordial black holes with masses $\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large space-time volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.
[ { "created": "Sun, 17 May 2015 19:53:11 GMT", "version": "v1" } ]
2015-09-16
[ [ "Graham", "Peter W.", "" ], [ "Rajendran", "Surjeet", "" ], [ "Varela", "Jaime", "" ] ]
The transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. For sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. The shape of the observed distribution of white dwarfs with masses up to $1.25 M_{\odot}$ rules out primordial black holes with masses $\sim 10^{19}$ gm - $10^{20}$ gm as a dominant constituent of the local dark matter density. Black holes with masses as large as $10^{24}$ gm will be excluded if recent observations by the NuStar collaboration of a population of white dwarfs near the galactic center are confirmed. Black holes in the mass range $10^{20}$ gm - $10^{22}$ gm are also constrained by the observed supernova rate, though these bounds are subject to astrophysical uncertainties. These bounds can be further strengthened through measurements of white dwarf binaries in gravitational wave observatories. The mechanism proposed in this paper can constrain a variety of other dark matter scenarios such as Q balls, annihilation/collision of large composite states of dark matter and models of dark matter where the accretion of dark matter leads to the formation of compact cores within the star. White dwarfs, with their astronomical lifetimes and sizes, can thus act as large space-time volume detectors enabling a unique probe of the properties of dark matter, especially of dark matter candidates that have low number density. This mechanism also raises the intriguing possibility that a class of supernova may be triggered through rare events induced by dark matter rather than the conventional mechanism of accreting white dwarfs that explode upon reaching the Chandrasekhar mass.
hep-ph/0108217
Georgi Dvali
Gia Dvali and Matias Zaldarriaga
Changing alpha With Time: Implications For Fifth-Force-Type Experiments And Quintessence
7 pages, Latex
Phys.Rev.Lett. 88 (2002) 091303
10.1103/PhysRevLett.88.091303
NYU-TH/01/08/07
hep-ph astro-ph hep-th
null
If the recent observations suggesting a time variation of the fine structure constant are correct, they imply the existence of an ultra light scalar particle. This particle inevitably couples to nucleons through the \alpha-dependence of their masses and thus mediates an isotope-dependent long-range force. The strength of the coupling is within a couple of orders of magnitude from the existing experimental bounds for such forces. The new force can be potentially measured in the precision experimental tests of the equivalence principle. Due to an interesting coincidence of the required time-scales, the scalar filed in question can at the same time play the role of a quintessence field.
[ { "created": "Sun, 26 Aug 2001 20:26:32 GMT", "version": "v1" } ]
2009-11-07
[ [ "Dvali", "Gia", "" ], [ "Zaldarriaga", "Matias", "" ] ]
If the recent observations suggesting a time variation of the fine structure constant are correct, they imply the existence of an ultra light scalar particle. This particle inevitably couples to nucleons through the \alpha-dependence of their masses and thus mediates an isotope-dependent long-range force. The strength of the coupling is within a couple of orders of magnitude from the existing experimental bounds for such forces. The new force can be potentially measured in the precision experimental tests of the equivalence principle. Due to an interesting coincidence of the required time-scales, the scalar filed in question can at the same time play the role of a quintessence field.
1810.06795
Stefano Profumo
Nicolas Fernandez and Stefano Profumo
Comment on "keV Neutrino Dark Matter in a Fast Expanding Universe" by Biswas et al
null
Physics Letters B, 789 (2019) 603-604
10.1016/j.physletb.2018.12.057
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Biswas et al. found that the thermal relic density of a dark matter particle freezing out while the universe's energy density is dominated by a non-standard extra component $\phi$, whose energy density redshifts faster than radiation, can be greatly suppressed. Here we show that this result, which contradicts extensive previous literature, is incorrect: the mistake lies with the assumption that the (decoupled) extra component $\phi$ contributes to the entropic degrees of freedom relevant for dark matter freeze out. If this were the case, a completely different approach would be needed to calculate the dark matter relic abundance, with dramatically different results.
[ { "created": "Tue, 16 Oct 2018 02:54:55 GMT", "version": "v1" } ]
2019-01-14
[ [ "Fernandez", "Nicolas", "" ], [ "Profumo", "Stefano", "" ] ]
Biswas et al. found that the thermal relic density of a dark matter particle freezing out while the universe's energy density is dominated by a non-standard extra component $\phi$, whose energy density redshifts faster than radiation, can be greatly suppressed. Here we show that this result, which contradicts extensive previous literature, is incorrect: the mistake lies with the assumption that the (decoupled) extra component $\phi$ contributes to the entropic degrees of freedom relevant for dark matter freeze out. If this were the case, a completely different approach would be needed to calculate the dark matter relic abundance, with dramatically different results.
2307.03526
Alexander Korchin
Sw. Banerjee, A.Yu. Korchin, E. Richter-Was, Z. Was
Electron-positron, parton-parton and photon-photon production of $\tau$-lepton pairs: anomalous magnetic and electric dipole moments spin effects
30 pages, 5 figures; v2: introduction and summary are extended, radiative corrections are included in subsection 2.1 in framework of improved Born approximation; several references added, misprints corrected, corresponds to published version
Phys. Rev. D 109 (1), 013002 (2024)
10.1103/PhysRevD.109.013002
IFJPAN-IV-2023-3
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Anomalous contributions to the electric and magnetic dipole moments of the $\tau$ lepton from new physics scenarios have brought renewed interest in the development of new charge-parity violating signatures in $\tau$-pair production at Belle II energies, and also at higher energies of the Large Hadron Collider and the Future Circular Collider. In this paper, we discuss the effects of spin correlations, including transverse degrees of freedom, in the $\tau$-pair production and decay. These studies include calculating analytical formulas, obtaining numerical results, and building semi-realistic observables sensitive to the transverse spin correlations induced by the dipole moments of the $\tau$ lepton. The effects of such anomalous contributions to the dipole moments are introduced on top of precision simulations of $e^-e^+ \to \tau^-\tau^+$, $q\bar{q} \to \tau^-\tau^+$ and $\gamma\gamma \to \tau^-\tau^+$ processes, involving multi-body final states. The $\tau$ decays are simulated along with radiative corrections, in particular electroweak box contributions of $WW$ and $ZZ$ exchanges are taken into account. Respective extensions of the Standard Model amplitudes and the reweighting algorithms are implemented into the KKMC Monte Carlo, which is used to simulate $\tau$-pair production in $e^-e^+$ collisions, and the TauSpinner program, which is used to reweight events with $\tau$ pair produced in $pp$ collisions.
[ { "created": "Fri, 7 Jul 2023 11:28:24 GMT", "version": "v1" }, { "created": "Thu, 18 Jul 2024 08:31:21 GMT", "version": "v2" } ]
2024-07-19
[ [ "Banerjee", "Sw.", "" ], [ "Korchin", "A. Yu.", "" ], [ "Richter-Was", "E.", "" ], [ "Was", "Z.", "" ] ]
Anomalous contributions to the electric and magnetic dipole moments of the $\tau$ lepton from new physics scenarios have brought renewed interest in the development of new charge-parity violating signatures in $\tau$-pair production at Belle II energies, and also at higher energies of the Large Hadron Collider and the Future Circular Collider. In this paper, we discuss the effects of spin correlations, including transverse degrees of freedom, in the $\tau$-pair production and decay. These studies include calculating analytical formulas, obtaining numerical results, and building semi-realistic observables sensitive to the transverse spin correlations induced by the dipole moments of the $\tau$ lepton. The effects of such anomalous contributions to the dipole moments are introduced on top of precision simulations of $e^-e^+ \to \tau^-\tau^+$, $q\bar{q} \to \tau^-\tau^+$ and $\gamma\gamma \to \tau^-\tau^+$ processes, involving multi-body final states. The $\tau$ decays are simulated along with radiative corrections, in particular electroweak box contributions of $WW$ and $ZZ$ exchanges are taken into account. Respective extensions of the Standard Model amplitudes and the reweighting algorithms are implemented into the KKMC Monte Carlo, which is used to simulate $\tau$-pair production in $e^-e^+$ collisions, and the TauSpinner program, which is used to reweight events with $\tau$ pair produced in $pp$ collisions.
2211.05390
Hai-Bing Fu
Zai-Hui Wu, Hai-Bing Fu, Tao Zhong, Dong Huang, Dan-Dan Hu, Xing-Gang Wu
$a_0(980)$-meson twist-2 distribution amplitude within the QCD sum rules and investigation of $D \to a_0(980) (\to\eta\pi) e^+\nu_e$
14 pages, 6 figures, more discussions added, accepted for publication in Nuclear Physics A
Nuclear Physics A 1036 (2023) 122671
10.1016/j.nuclphysa.2023.122671
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, moments of $a_0(980)$-meson twist-2 light-cone distribution amplitudes were deeply researched by using QCD sum rules approach within background field theory. Up to 9th-order accuracy, we present $\langle\xi_{2;a_0}^n\rangle|_{\mu_0}$ at the initial scale $\mu_0 = 1~{\rm GeV}$, i.e. $\langle\xi^1_{2;a_0}\rangle|_{\mu_0} = -0.307(43)$, $\langle\xi^3_{2;a_0}\rangle|_{\mu_0} = -0.181(34)$, $\langle\xi^5_{2;a_0}\rangle|_{\mu_0} = -0.078(28)$, $\langle\xi^7_{2;a_0}\rangle|_{\mu_0} = -0.049(26)$, $\langle\xi^9_{2;a_0}\rangle|_{\mu_0} = -0.036(24)$, respectively. An improved light-cone harmonic oscillator model for $a_0(980)$-meson twist-2 light-cone distribution amplitudes is adopted, where its parameters are fixed by using the least squares method based on the $\langle\xi_{2;a_0}^n\rangle|_{\mu_0}$, and their goodness of fit reach to $95.4\%$. Then, we calculate the $D\to a_0(980)$ transition form factors within the light-cone sum rules approach, and at largest recoil point, we obtain $f_+^{D\to a_0}(0) = 1.058^{+0.068}_{-0.035}$ and $f_-^{D\to a_0}(0) = 0.764^{+0.044}_{-0.036}$. As a further application, the branching fractions of the $D\to a_0(980)\ell\bar\nu_\ell$ semileptonic decays are given. Taking the decay $a_0(980)\to \eta\pi$ into consideration, we obtain ${\cal B}(D^0 \to a_0(980)^- (\to \eta \pi^-) e^+\nu_e) =(1.330^{+0.216}_{-0.134})\times10^{-4}$, ${\cal B}(D^+\to a_0(980)^0(\to \eta \pi^0)e^+\nu_e)=(1.675^{+0.272}_{-0.169})\times10^{-4}$, which are consistent with the BESIII collaboration and PDG data within errors. Finally, we present the angle observables of forward-backward asymmetries, $q^2$-differential flat terms and lepton polarization asymmetry of the semileptonic decay $D\to a_0(980)\ell\bar\nu_\ell$.
[ { "created": "Thu, 10 Nov 2022 07:46:05 GMT", "version": "v1" }, { "created": "Wed, 3 May 2023 02:41:25 GMT", "version": "v2" } ]
2023-05-17
[ [ "Wu", "Zai-Hui", "" ], [ "Fu", "Hai-Bing", "" ], [ "Zhong", "Tao", "" ], [ "Huang", "Dong", "" ], [ "Hu", "Dan-Dan", "" ], [ "Wu", "Xing-Gang", "" ] ]
In this paper, moments of $a_0(980)$-meson twist-2 light-cone distribution amplitudes were deeply researched by using QCD sum rules approach within background field theory. Up to 9th-order accuracy, we present $\langle\xi_{2;a_0}^n\rangle|_{\mu_0}$ at the initial scale $\mu_0 = 1~{\rm GeV}$, i.e. $\langle\xi^1_{2;a_0}\rangle|_{\mu_0} = -0.307(43)$, $\langle\xi^3_{2;a_0}\rangle|_{\mu_0} = -0.181(34)$, $\langle\xi^5_{2;a_0}\rangle|_{\mu_0} = -0.078(28)$, $\langle\xi^7_{2;a_0}\rangle|_{\mu_0} = -0.049(26)$, $\langle\xi^9_{2;a_0}\rangle|_{\mu_0} = -0.036(24)$, respectively. An improved light-cone harmonic oscillator model for $a_0(980)$-meson twist-2 light-cone distribution amplitudes is adopted, where its parameters are fixed by using the least squares method based on the $\langle\xi_{2;a_0}^n\rangle|_{\mu_0}$, and their goodness of fit reach to $95.4\%$. Then, we calculate the $D\to a_0(980)$ transition form factors within the light-cone sum rules approach, and at largest recoil point, we obtain $f_+^{D\to a_0}(0) = 1.058^{+0.068}_{-0.035}$ and $f_-^{D\to a_0}(0) = 0.764^{+0.044}_{-0.036}$. As a further application, the branching fractions of the $D\to a_0(980)\ell\bar\nu_\ell$ semileptonic decays are given. Taking the decay $a_0(980)\to \eta\pi$ into consideration, we obtain ${\cal B}(D^0 \to a_0(980)^- (\to \eta \pi^-) e^+\nu_e) =(1.330^{+0.216}_{-0.134})\times10^{-4}$, ${\cal B}(D^+\to a_0(980)^0(\to \eta \pi^0)e^+\nu_e)=(1.675^{+0.272}_{-0.169})\times10^{-4}$, which are consistent with the BESIII collaboration and PDG data within errors. Finally, we present the angle observables of forward-backward asymmetries, $q^2$-differential flat terms and lepton polarization asymmetry of the semileptonic decay $D\to a_0(980)\ell\bar\nu_\ell$.
1908.11619
Josef Jur\'a\v{n}
Mikul\'a\v{s} Gintner and Josef Jur\'a\v{n}
A case study about the mass exclusion limits for the BSM vector resonances with the direct couplings to the third quark generation
22 pages, 14 figures, 8 tables
Eur. Phys. J. C 80 (2020) 161
10.1140/epjc/s10052-020-7732-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The upper bounds that the LHC measurements searching for heavy resonances beyond the Standard model set on the resonance production cross sections are not universal. They depend on various characteristics of the resonance under consideration, like its mass, spin, and its interaction pattern. Their validity are also limited by the assumptions and approximations applied to their calculations. The bounds are typically used to derive the mass exclusion limits for the new resonances. In our work, we address some of the issues that emerge when deriving the mass exclusion limits for the strongly coupled composite $SU(2)_{L+R}$ vector resonance triplet which would interact directly to the third quark generation only. We investigate the restrictions on the applicability of the generally used limit-obtaining procedure to this particular type of vector resonances. We demonstrate that, in this case, it is necessary to consider the bottom quark partonic contents of the proton. Eventually, we find the mass exclusion limits for this resonance triplet for some representative subsets of the parameter space.
[ { "created": "Fri, 30 Aug 2019 09:51:00 GMT", "version": "v1" }, { "created": "Mon, 24 Feb 2020 14:26:27 GMT", "version": "v2" } ]
2020-02-25
[ [ "Gintner", "Mikuláš", "" ], [ "Juráň", "Josef", "" ] ]
The upper bounds that the LHC measurements searching for heavy resonances beyond the Standard model set on the resonance production cross sections are not universal. They depend on various characteristics of the resonance under consideration, like its mass, spin, and its interaction pattern. Their validity are also limited by the assumptions and approximations applied to their calculations. The bounds are typically used to derive the mass exclusion limits for the new resonances. In our work, we address some of the issues that emerge when deriving the mass exclusion limits for the strongly coupled composite $SU(2)_{L+R}$ vector resonance triplet which would interact directly to the third quark generation only. We investigate the restrictions on the applicability of the generally used limit-obtaining procedure to this particular type of vector resonances. We demonstrate that, in this case, it is necessary to consider the bottom quark partonic contents of the proton. Eventually, we find the mass exclusion limits for this resonance triplet for some representative subsets of the parameter space.
1711.04558
Yuki Kamiya
Yuki Kamiya and Tetsuo Hyodo
Structure of hadron resonances with a nearby zero of the amplitude
7 pages, 3 figures, v2: published version
Phys. Rev. D 97, 054019 (2018)
10.1103/PhysRevD.97.054019
YITP-17-118
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the relation between the analytic structure of the scattering amplitude and the origin of an eigenstate represented by a pole of the amplitude.If the eigenstate is not dynamically generated by the interaction in the channel of interest, the residue of the pole vanishes in the zero coupling limit. Based on the topological nature of the phase of the scattering amplitude, we show that the pole must encounter with the Castillejo-Dalitz-Dyson (CDD) zero in this limit. It is concluded that the dynamical component of the eigenstate is small if a CDD zero exists near the eigenstate pole. We show that the line shape of the resonance is distorted from the Breit-Wigner form as an observable consequence of the nearby CDD zero. Finally, studying the positions of poles and CDD zeros of the KbarN-piSigma amplitude, we discuss the origin of the eigenstates in the Lambda(1405) region.
[ { "created": "Mon, 13 Nov 2017 13:01:39 GMT", "version": "v1" }, { "created": "Sat, 31 Mar 2018 12:54:45 GMT", "version": "v2" } ]
2018-04-03
[ [ "Kamiya", "Yuki", "" ], [ "Hyodo", "Tetsuo", "" ] ]
We discuss the relation between the analytic structure of the scattering amplitude and the origin of an eigenstate represented by a pole of the amplitude.If the eigenstate is not dynamically generated by the interaction in the channel of interest, the residue of the pole vanishes in the zero coupling limit. Based on the topological nature of the phase of the scattering amplitude, we show that the pole must encounter with the Castillejo-Dalitz-Dyson (CDD) zero in this limit. It is concluded that the dynamical component of the eigenstate is small if a CDD zero exists near the eigenstate pole. We show that the line shape of the resonance is distorted from the Breit-Wigner form as an observable consequence of the nearby CDD zero. Finally, studying the positions of poles and CDD zeros of the KbarN-piSigma amplitude, we discuss the origin of the eigenstates in the Lambda(1405) region.
hep-ph/0702180
Abhijit Samanta
Abhijit Samanta, Sudeb Bhattacharya, Ambar Ghosal, Kamales Kar, Debasish Majumdar, Amitava Raychaudhuri
A GEANT-based study of atmospheric neutrino oscillation parameters at INO
8 pages, 13 figures, a new figure added, version accepted in IJMPA
Int.J.Mod.Phys.A23:233-245,2008
10.1142/S0217751X08037968
null
hep-ph
null
We have studied the dependence of the allowed space of the atmospheric neutrino oscillation parameters on the time of exposure for a magnetized Iron CALorimeter (ICAL) detector at the India-based Neutrino Observatory (INO). We have performed a Monte Carlo simulation for a 50 kTon ICAL detector generating events by the neutrino generator NUANCE and simulating the detector response by GEANT. A chi-square analysis for the ratio of the up-going and down-going neutrinos as a function of $L/E$ is performed and the allowed regions at 90% and 99% CL are displayed. These results are found to be better than the current experimental results of MINOS and Super-K. The possibilities of further improvement have also been discussed.
[ { "created": "Sun, 18 Feb 2007 16:09:43 GMT", "version": "v1" }, { "created": "Tue, 6 Mar 2007 13:30:55 GMT", "version": "v2" }, { "created": "Fri, 4 Jan 2008 07:20:53 GMT", "version": "v3" } ]
2008-11-26
[ [ "Samanta", "Abhijit", "" ], [ "Bhattacharya", "Sudeb", "" ], [ "Ghosal", "Ambar", "" ], [ "Kar", "Kamales", "" ], [ "Majumdar", "Debasish", "" ], [ "Raychaudhuri", "Amitava", "" ] ]
We have studied the dependence of the allowed space of the atmospheric neutrino oscillation parameters on the time of exposure for a magnetized Iron CALorimeter (ICAL) detector at the India-based Neutrino Observatory (INO). We have performed a Monte Carlo simulation for a 50 kTon ICAL detector generating events by the neutrino generator NUANCE and simulating the detector response by GEANT. A chi-square analysis for the ratio of the up-going and down-going neutrinos as a function of $L/E$ is performed and the allowed regions at 90% and 99% CL are displayed. These results are found to be better than the current experimental results of MINOS and Super-K. The possibilities of further improvement have also been discussed.
1403.7947
Michael Eides
Michael I. Eides and Valery A. Shelyuto
Hard Nonlogarithmic Corrections of Order $m\alpha^7$ to Hyperfine Splitting in Positronium
10 pages, 8 fugures
Phys. Rev. D 89, 111301 (2014)
10.1103/PhysRevD.89.111301
UK/14-02
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider hard three-loop nonlogarithmic corrections of order $m\alpha^7$ to hyperfine splitting in positronium. All these contributions are generated by the graphs with photon and/or electron loop radiative insertions in the two-photon exchange diagrams. We calculate contributions of six gauge invariant sets of diagrams. The total result for all these diagrams is $\Delta E=-1.2917(1)m\alpha^7/\pi^3=-5.672$ kHz.
[ { "created": "Mon, 31 Mar 2014 11:14:15 GMT", "version": "v1" } ]
2014-07-09
[ [ "Eides", "Michael I.", "" ], [ "Shelyuto", "Valery A.", "" ] ]
We consider hard three-loop nonlogarithmic corrections of order $m\alpha^7$ to hyperfine splitting in positronium. All these contributions are generated by the graphs with photon and/or electron loop radiative insertions in the two-photon exchange diagrams. We calculate contributions of six gauge invariant sets of diagrams. The total result for all these diagrams is $\Delta E=-1.2917(1)m\alpha^7/\pi^3=-5.672$ kHz.
hep-ph/0003001
Xin HengGuo
S. Ying
Virtual Color Superconductivity--Status and Perspective
5 pages, Latex (World Scientific style file included). Talk given on the "Symposium on the Frontiers of Physics at Millennium", Beijing, China, Oct. 8-10, 2000. Minor changes, references added
null
null
FDUTP-00-03-01
hep-ph hep-lat hep-th nucl-th
null
The status of our understanding of the properties and manifestations of color superconductivity at zero and low density is briefly reviewed. Future possibility is highlighted.
[ { "created": "Wed, 1 Mar 2000 00:47:53 GMT", "version": "v1" }, { "created": "Wed, 15 Mar 2000 02:12:42 GMT", "version": "v2" } ]
2007-05-23
[ [ "Ying", "S.", "" ] ]
The status of our understanding of the properties and manifestations of color superconductivity at zero and low density is briefly reviewed. Future possibility is highlighted.
hep-ph/9601308
Fyodor V. Tkachov
Fyodor V. Tkachov
Measuring Multijet Structure of Hadronic Energy Flow Or What IS A Jet?
PostScript, 94 pp (US Letter), 18 PS files, ftkachov@ms2.inr.ac.ru
Int.J.Mod.Phys. A12 (1997) 5411-5529
10.1142/S0217751X97002899
FERMILAB-PUB-95/191-T
hep-ph hep-ex
null
Ambiguities of jet algorithms are reinterpreted as instability wrt small variations of input. Optimal stability occurs for observables possessing property of calorimetric continuity (C-continuity) predetermined by kinematical structure of calorimetric detectors. The so-called C-correlators form a basic class of such observables and fit naturally into QFT framework, allowing systematic theoretical studies. A few rules generate other C-continuous observables. The resulting C-algebra correctly quantifies any feature of multijet structure such as the "number of jets" and mass spectra of "multijet substates". The new observables are physically equivalent to traditional ones but can be computed from final states bypassing jet algorithms which reemerge as a tool of approximate computation of C-observables from data with all ambiguities under analytical control and an optimal recombination criterion minimizing approximation errors.
[ { "created": "Fri, 19 Jan 1996 12:44:24 GMT", "version": "v1" } ]
2009-10-28
[ [ "Tkachov", "Fyodor V.", "" ] ]
Ambiguities of jet algorithms are reinterpreted as instability wrt small variations of input. Optimal stability occurs for observables possessing property of calorimetric continuity (C-continuity) predetermined by kinematical structure of calorimetric detectors. The so-called C-correlators form a basic class of such observables and fit naturally into QFT framework, allowing systematic theoretical studies. A few rules generate other C-continuous observables. The resulting C-algebra correctly quantifies any feature of multijet structure such as the "number of jets" and mass spectra of "multijet substates". The new observables are physically equivalent to traditional ones but can be computed from final states bypassing jet algorithms which reemerge as a tool of approximate computation of C-observables from data with all ambiguities under analytical control and an optimal recombination criterion minimizing approximation errors.
hep-ph/9805361
Goran Senjanovic
Goran Senjanovic
Rochelle salt: a prototype of particle physics
9 pages, uses sprocl.sty, plenary talk given at the International Workshop COSMO97 on Particle Physics and the Early Universe, 15-19 September 1997, Ambleside, Lake District, England, to be published in the Proceedings. References added
null
10.1142/9789814447263_0062
IC/98/48
hep-ph
null
Rochelle salt has a remarkable characteristic of becoming more ordered for a range of high temperatures before melting. In the particle physics language this means more symmetry breaking for high T. In many realistic field theories this is a perfectly consistent scenario which has profound consequences in the early universe. In particular it implies that there may be no domain wall and monopole problems, and it may also play an important role in baryogenesis if CP and P are broken spontaneously. In the case of the monopole problem this may require a large background charge of the universe. The natural candidates for this background charge are a possible lepton number in the neutrino sea or global continous R-charges in supersymmetric theories.
[ { "created": "Mon, 18 May 1998 18:31:44 GMT", "version": "v1" }, { "created": "Tue, 19 May 1998 13:18:34 GMT", "version": "v2" } ]
2016-10-26
[ [ "Senjanovic", "Goran", "" ] ]
Rochelle salt has a remarkable characteristic of becoming more ordered for a range of high temperatures before melting. In the particle physics language this means more symmetry breaking for high T. In many realistic field theories this is a perfectly consistent scenario which has profound consequences in the early universe. In particular it implies that there may be no domain wall and monopole problems, and it may also play an important role in baryogenesis if CP and P are broken spontaneously. In the case of the monopole problem this may require a large background charge of the universe. The natural candidates for this background charge are a possible lepton number in the neutrino sea or global continous R-charges in supersymmetric theories.
2012.00032
Konstantinos Rigatos
Nick Evans, Konstantinos S. Rigatos
Chiral symmetry breaking and confinement: separating the scales
9 pages, 2 figures, 1 table, v2: added commentary, v3: minor corrections, added references
Phys. Rev. D 103, 094022 (2021)
10.1103/PhysRevD.103.094022
null
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review arguments that chiral symmetry breaking is triggered when the quark bilinear condensate's dimension passes through one ($\gamma=1$). This is supported by gap equations and more recently holographic models. Confinement may then be a separate property of the pure Yang-Mills theory below the scale of the dynamically generated quark mass, occurring at the scale of the pole in the deep IR running. Here, we use perturbative results for the running of the gauge coupling and $\gamma$ in asymptotically free SU($N_c$) gauge theories with matter in higher dimension representations to seek the best candidate theories where confinement and chiral symmetry breaking can be maximally separated. For example, SU(2) gauge theory with a single Weyl quark in the $S_3$ (dimension 4) representation may have a factor of 20 separation in scale. Such a theory could be simulated on the lattice to test the separation. We also propose studying multi-representation theories where the higher dimension representation forms a condensate at one scale that can be quite separate from the condensation scale of the second representation matter. The confinement scale would presumably be below the second scale. For example, SU(3) gauge theory with a Weyl adjoint fermion and ten fundamental quarks may have a separation of a factor of 20 also.
[ { "created": "Mon, 30 Nov 2020 19:00:09 GMT", "version": "v1" }, { "created": "Mon, 14 Dec 2020 10:37:33 GMT", "version": "v2" }, { "created": "Wed, 19 May 2021 07:38:40 GMT", "version": "v3" } ]
2021-05-26
[ [ "Evans", "Nick", "" ], [ "Rigatos", "Konstantinos S.", "" ] ]
We review arguments that chiral symmetry breaking is triggered when the quark bilinear condensate's dimension passes through one ($\gamma=1$). This is supported by gap equations and more recently holographic models. Confinement may then be a separate property of the pure Yang-Mills theory below the scale of the dynamically generated quark mass, occurring at the scale of the pole in the deep IR running. Here, we use perturbative results for the running of the gauge coupling and $\gamma$ in asymptotically free SU($N_c$) gauge theories with matter in higher dimension representations to seek the best candidate theories where confinement and chiral symmetry breaking can be maximally separated. For example, SU(2) gauge theory with a single Weyl quark in the $S_3$ (dimension 4) representation may have a factor of 20 separation in scale. Such a theory could be simulated on the lattice to test the separation. We also propose studying multi-representation theories where the higher dimension representation forms a condensate at one scale that can be quite separate from the condensation scale of the second representation matter. The confinement scale would presumably be below the second scale. For example, SU(3) gauge theory with a Weyl adjoint fermion and ten fundamental quarks may have a separation of a factor of 20 also.
hep-ph/9401339
Kiselev
V.V. Kiselev
Scaling law for the $\Upsilon(4S) \to B \bar B$ and $\psi(3770) \to D \bar D$ decay constants from effective sum rules
14 pages, 1 Fig., Standard LATEX
Mod.Phys.Lett.A10:2113-2124,1995
10.1142/S021773239500226X
IHEP 94-3 (Protvino1994)
hep-ph
null
Sum rules for exclusive production of heavy meson pairs in $e^+e^-$ annihilation are used to evaluate the $\Upsilon(4S) \to B \bar B$ and $\psi(3770) \to D \bar D$ decay widths. Infinitely heavy quark limit is discussed, so that scaling law for the quarkonium-meson coupling constant is derived. A value of the $B\bar B$ pair contribution into the leptonic constant $f_{\Upsilon(4S)}$ is estimated.
[ { "created": "Thu, 27 Jan 1994 07:19:23 GMT", "version": "v1" } ]
2011-07-19
[ [ "Kiselev", "V. V.", "" ] ]
Sum rules for exclusive production of heavy meson pairs in $e^+e^-$ annihilation are used to evaluate the $\Upsilon(4S) \to B \bar B$ and $\psi(3770) \to D \bar D$ decay widths. Infinitely heavy quark limit is discussed, so that scaling law for the quarkonium-meson coupling constant is derived. A value of the $B\bar B$ pair contribution into the leptonic constant $f_{\Upsilon(4S)}$ is estimated.
0911.2092
Gilad Perez
Gilad Perez
Brief Introduction to Flavor Physics
15 pages, 6 Figs., submitted to Springer Proceedings in Physics
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the standard model (SM) quark flavor sector. We study its structure in a spurionic, symmetry oriented approach. The SM picture of flavor and CP violation is now experimentally verified, hence strong bounds on beyond the SM flavor structure follow. We show how to parametrically derive such bounds, in a model independent manner, via minimal flavor violation power counting. This min-review summarizes lectures given at the ISSCSMB '08 international school. It aims to give basic tools to understand how flavor and CP violation occur in the SM and its extensions. It should be particularly useful for non-expert students who have mastered other aspects of the SM dynamics.
[ { "created": "Wed, 11 Nov 2009 09:45:05 GMT", "version": "v1" } ]
2009-11-12
[ [ "Perez", "Gilad", "" ] ]
We consider the standard model (SM) quark flavor sector. We study its structure in a spurionic, symmetry oriented approach. The SM picture of flavor and CP violation is now experimentally verified, hence strong bounds on beyond the SM flavor structure follow. We show how to parametrically derive such bounds, in a model independent manner, via minimal flavor violation power counting. This min-review summarizes lectures given at the ISSCSMB '08 international school. It aims to give basic tools to understand how flavor and CP violation occur in the SM and its extensions. It should be particularly useful for non-expert students who have mastered other aspects of the SM dynamics.
1309.6575
Arshad Momen
M. Onirban Islam, Md. Galib Hassan and M. Arshad Momen
Charged Scalar Pair Production in Strong-Field Photon-Photon Interaction
8 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Following the pioneering work of H. Reiss [1], we provide a covariant calculation of the charged scalar particle pair production. The calculation is facilitated by the use of two-dimensional Bessel functions and light-font coordinates.
[ { "created": "Wed, 25 Sep 2013 17:04:35 GMT", "version": "v1" } ]
2013-09-26
[ [ "Islam", "M. Onirban", "" ], [ "Hassan", "Md. Galib", "" ], [ "Momen", "M. Arshad", "" ] ]
Following the pioneering work of H. Reiss [1], we provide a covariant calculation of the charged scalar particle pair production. The calculation is facilitated by the use of two-dimensional Bessel functions and light-font coordinates.
hep-ph/9907448
Iain Stewart
Iain W. Stewart (Caltech)
Applications of Chiral Perturbation Theory in Reactions with Heavy Particles
Ph.D. thesis, 170 pages
null
null
CALT-68-2233
hep-ph nucl-th
null
Effective field theory techniques are used to describe the interaction of heavy hadrons in a model independent way. Predictability is obtained by exploiting the symmetries of QCD. Heavy hadron chiral perturbation theory is reviewed and used to describe $D^*$ decays. The phenomenologically important $D^*D\pi$ coupling is extracted from data working to first order in the chiral and heavy quark symmetry breaking parameters. A method is described for determining $|V_{ub}|$ from exclusive semileptonic $B$ and $D$ decays with 10% uncertainty. An effective field theory for two-nucleon systems is then discussed. The large S-wave scattering lengths necessitate expanding around a non-trivial fixed point. A detailed discussion of the interplay between renormalization and the power counting is given. In power counting pion interactions with nucleons it is useful to consider three classes of pion: potential, radiation, and soft. A power counting for massive radiation is developed. Finally, it is shown that the leading terms in the effective theory for nucleon-nucleon interactions are invariant under Wigner's SU(4) spin-isospin symmetry in the infinite scattering length limit.
[ { "created": "Wed, 21 Jul 1999 22:19:07 GMT", "version": "v1" } ]
2007-05-23
[ [ "Stewart", "Iain W.", "", "Caltech" ] ]
Effective field theory techniques are used to describe the interaction of heavy hadrons in a model independent way. Predictability is obtained by exploiting the symmetries of QCD. Heavy hadron chiral perturbation theory is reviewed and used to describe $D^*$ decays. The phenomenologically important $D^*D\pi$ coupling is extracted from data working to first order in the chiral and heavy quark symmetry breaking parameters. A method is described for determining $|V_{ub}|$ from exclusive semileptonic $B$ and $D$ decays with 10% uncertainty. An effective field theory for two-nucleon systems is then discussed. The large S-wave scattering lengths necessitate expanding around a non-trivial fixed point. A detailed discussion of the interplay between renormalization and the power counting is given. In power counting pion interactions with nucleons it is useful to consider three classes of pion: potential, radiation, and soft. A power counting for massive radiation is developed. Finally, it is shown that the leading terms in the effective theory for nucleon-nucleon interactions are invariant under Wigner's SU(4) spin-isospin symmetry in the infinite scattering length limit.
2007.14788
Javier Monta\~no Dom\'inguez
A. C. B. Machado, J. Monta\~no, V. Pleitez, and M. C. Rodriguez
Radiative neutrino masses and exotic right-handed neutrinos
18 pages, 7 figures, corrected typos. arXiv admin note: text overlap with arXiv:1705.01009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an extension of the standard electroweak model with three Higgs doublets and global $B-L$ and $\mathbb{Z}_2$ symmetries. Two of the scalar doublets are inert due to the $\mathbb{Z}_2$ symmetry. We calculated all the mass spectra in the scalar and lepton sectors and accommodate the leptonic mixing matrix as well. We also include an analysis of the scalar sector, showing that the potential is limited from below, and we obtain the masses of the scalar sector. Furthermore we consider the effects of the model on the anaomalous magnetic dipole of charged leptons and the $\mu\to e\gamma$ decay. We also present the SUSY version of the model with global $B-L$.
[ { "created": "Mon, 27 Jul 2020 22:28:37 GMT", "version": "v1" }, { "created": "Tue, 6 Oct 2020 14:47:12 GMT", "version": "v2" } ]
2020-10-08
[ [ "Machado", "A. C. B.", "" ], [ "Montaño", "J.", "" ], [ "Pleitez", "V.", "" ], [ "Rodriguez", "M. C.", "" ] ]
We consider an extension of the standard electroweak model with three Higgs doublets and global $B-L$ and $\mathbb{Z}_2$ symmetries. Two of the scalar doublets are inert due to the $\mathbb{Z}_2$ symmetry. We calculated all the mass spectra in the scalar and lepton sectors and accommodate the leptonic mixing matrix as well. We also include an analysis of the scalar sector, showing that the potential is limited from below, and we obtain the masses of the scalar sector. Furthermore we consider the effects of the model on the anaomalous magnetic dipole of charged leptons and the $\mu\to e\gamma$ decay. We also present the SUSY version of the model with global $B-L$.
hep-ph/0410262
Daniel Gomez Dumm
D. Gomez Dumm, N. N. Scoccola
Characteristics of the chiral phase transition in nonlocal quark models
19 pages, 5 figures. Figures 1 and 2 modified, references added, minor changes in the presentation and in the discussion of results. Accepted for publication in Phys. Rev. C
Phys.Rev. C72 (2005) 014909
10.1103/PhysRevC.72.014909
null
hep-ph
null
The characteristics of the chiral phase transition are analyzed within the framework of chiral quark models with nonlocal interactions in the mean field approximation. In the chiral limit, we develop a semi-analytic framework which allows us to explicitly determine the phase transition curve, the position of the critical points, some relevant critical exponents, etc. For the case of finite current quark masses, we show the behavior of various thermodynamical and chiral response functions across the phase transition.
[ { "created": "Tue, 19 Oct 2004 14:25:15 GMT", "version": "v1" }, { "created": "Thu, 30 Jun 2005 15:24:10 GMT", "version": "v2" } ]
2009-11-10
[ [ "Dumm", "D. Gomez", "" ], [ "Scoccola", "N. N.", "" ] ]
The characteristics of the chiral phase transition are analyzed within the framework of chiral quark models with nonlocal interactions in the mean field approximation. In the chiral limit, we develop a semi-analytic framework which allows us to explicitly determine the phase transition curve, the position of the critical points, some relevant critical exponents, etc. For the case of finite current quark masses, we show the behavior of various thermodynamical and chiral response functions across the phase transition.
hep-ph/9510328
null
Pilar Hernandez, Raman Sundrum (Harvard University)
Lattice Chiral Gauge Theory with Finely-Grained Fermions
10 pages, LateX, no figures. An important reference to Frolov and Slavnov has been added and a confusing typo corrected
null
null
HUTP-95/A038
hep-ph hep-lat
null
We discuss the problem of formulating the continuum limit of chiral gauge theories ($\chi$GT) in the absence of an explicitly gauge-invariant regulator for the fermions. A solution is proposed which is independent of the details of the regulator, wherein one considers two cutoff scales, $\Lambda_f >> \Lambda_b$, for the fermions and the gauge bosons respectively. Our recent non-perturbative lattice construction in which the fermions live on a finer lattice than do the gauge bosons, is seen to be an example of such a scheme, providing a finite algorithm for simulating $\chi$GT. The essential difference with previous (one-cutoff) lattice schemes is clarified: in our formulation the breakage of gauge invariance is small, $O(\Lambda^2_b/\Lambda^2_f)$, and vanishes in the continuum limit. Finally, we argue against 2-D models being significant testing grounds for 4-D regulators of $\chi$GT.
[ { "created": "Wed, 18 Oct 1995 00:25:31 GMT", "version": "v1" }, { "created": "Fri, 3 Nov 1995 21:29:09 GMT", "version": "v2" } ]
2008-02-03
[ [ "Hernandez", "Pilar", "", "Harvard University" ], [ "Sundrum", "Raman", "", "Harvard University" ] ]
We discuss the problem of formulating the continuum limit of chiral gauge theories ($\chi$GT) in the absence of an explicitly gauge-invariant regulator for the fermions. A solution is proposed which is independent of the details of the regulator, wherein one considers two cutoff scales, $\Lambda_f >> \Lambda_b$, for the fermions and the gauge bosons respectively. Our recent non-perturbative lattice construction in which the fermions live on a finer lattice than do the gauge bosons, is seen to be an example of such a scheme, providing a finite algorithm for simulating $\chi$GT. The essential difference with previous (one-cutoff) lattice schemes is clarified: in our formulation the breakage of gauge invariance is small, $O(\Lambda^2_b/\Lambda^2_f)$, and vanishes in the continuum limit. Finally, we argue against 2-D models being significant testing grounds for 4-D regulators of $\chi$GT.
0812.4748
Tomoi Koide
T. Kodama and T. Koide
Dynamical Origin of Power Spectra
22 pages, 7 figures, prepared for the European Physical Journal A - Hadrons and Nuclei
Eur.Phys.J.A40:289-297,2009
10.1140/epja/i2009-10796-3
null
hep-ph cond-mat.stat-mech nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a possible origin of Tsallis' statistics from the correlation among constituents which reduces the phase space of the system. We also show that in the system of coupled linear harmonic oscillators can exhibit a Tsallis type behavior.
[ { "created": "Sat, 27 Dec 2008 15:36:14 GMT", "version": "v1" } ]
2014-11-18
[ [ "Kodama", "T.", "" ], [ "Koide", "T.", "" ] ]
We discuss a possible origin of Tsallis' statistics from the correlation among constituents which reduces the phase space of the system. We also show that in the system of coupled linear harmonic oscillators can exhibit a Tsallis type behavior.
hep-ph/9611259
Nikolai Uraltsev
N. Uraltsev
Theoretical Aspects of the Heavy Quark Expansion
18 pages, 2 Figures in the text; LaTeX. Invited lecture presented at the Workshop "Beauty `96", Rome, 17-21 June 1996; Minor stylistic changes, typos corrected, a double reference deleted; to appear in Proc. "Beauty `96" (Nucl. Instrum. & Methods A, 1996)
Nucl.Instrum.Meth.A384:17-25,1996
10.1016/S0168-9002(96)01082-0
CERN-TH/96-298, UND-HEP-96-BIG03
hep-ph
null
I give a brief outline of the theoretical framework for the modern treatment of the strong interaction effects in heavy quark decays, based on first principles of QCD. This model-independent approach is required to meet the precision of current and future experiments. Applications to a few problems of particular practical interest are reviewed, including the precise determination of V_{cb} and V_{ub}. I emphasize the peculiarities of simultaneously accounting for the perturbative and power-suppressed effects necessary for accurate predictions.
[ { "created": "Thu, 7 Nov 1996 04:10:13 GMT", "version": "v1" }, { "created": "Sun, 15 Dec 1996 18:48:51 GMT", "version": "v2" } ]
2014-11-17
[ [ "Uraltsev", "N.", "" ] ]
I give a brief outline of the theoretical framework for the modern treatment of the strong interaction effects in heavy quark decays, based on first principles of QCD. This model-independent approach is required to meet the precision of current and future experiments. Applications to a few problems of particular practical interest are reviewed, including the precise determination of V_{cb} and V_{ub}. I emphasize the peculiarities of simultaneously accounting for the perturbative and power-suppressed effects necessary for accurate predictions.
1804.03361
Zachary Matthews
Shivani Gupta, Zachary M. Matthews, Pankaj Sharma, Anthony G. Williams
The Effect of a Light Sterile Neutrino at NO$\nu$A and DUNE
9 pages, 19 figures, updated for latest journal submission
Phys. Rev. D 98, 035042 (2018)
10.1103/PhysRevD.98.035042
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Now that the NOvA experiment is approaching two years run time and has released some preliminary data, some constraints for the oscillation parameters can be inferred. Currently the best fits for NOvA are three separate results, the reason they are indistinct is that they produce almost degenerate probability curves. It has been postulated that these degeneracies can be resolved by running antineutrinos at NOvA and/or combining its data with T2K. However, this degeneracy resolution power can be compromised if sterile neutrinos are present due to additional degrees of freedom that can significantly alter the oscillation probability for any of the current best fits. We aim to investigate this degradation in predictive power and the effect of the DUNE experiment on it. Now that the NOvA experiment has been running for a few years and has released some preliminary data, some constraints for the oscillation parameters can be inferred. The best fits for NOvA include three degenerate results, the reason they are indistinct is that they produce almost degenerate probability curves. It has been postulated that these degeneracies can be resolved by running antineutrinos at NOvA and/or combining its data with T2K. However, this degeneracy resolution power can be compromised if sterile neutrinos are present due to additional degrees of freedom that can significantly alter the oscillation probability for any of these best fits. We aim to investigate this degradation in predictive power and the effect of the DUNE experiment on it. In light of the 2018 NOvA data we also consider the same fits but with theta_{23}=45 to see if the sensitivity results are different.
[ { "created": "Tue, 10 Apr 2018 06:32:43 GMT", "version": "v1" }, { "created": "Fri, 10 Aug 2018 07:51:50 GMT", "version": "v2" } ]
2018-09-12
[ [ "Gupta", "Shivani", "" ], [ "Matthews", "Zachary M.", "" ], [ "Sharma", "Pankaj", "" ], [ "Williams", "Anthony G.", "" ] ]
Now that the NOvA experiment is approaching two years run time and has released some preliminary data, some constraints for the oscillation parameters can be inferred. Currently the best fits for NOvA are three separate results, the reason they are indistinct is that they produce almost degenerate probability curves. It has been postulated that these degeneracies can be resolved by running antineutrinos at NOvA and/or combining its data with T2K. However, this degeneracy resolution power can be compromised if sterile neutrinos are present due to additional degrees of freedom that can significantly alter the oscillation probability for any of the current best fits. We aim to investigate this degradation in predictive power and the effect of the DUNE experiment on it. Now that the NOvA experiment has been running for a few years and has released some preliminary data, some constraints for the oscillation parameters can be inferred. The best fits for NOvA include three degenerate results, the reason they are indistinct is that they produce almost degenerate probability curves. It has been postulated that these degeneracies can be resolved by running antineutrinos at NOvA and/or combining its data with T2K. However, this degeneracy resolution power can be compromised if sterile neutrinos are present due to additional degrees of freedom that can significantly alter the oscillation probability for any of these best fits. We aim to investigate this degradation in predictive power and the effect of the DUNE experiment on it. In light of the 2018 NOvA data we also consider the same fits but with theta_{23}=45 to see if the sensitivity results are different.
hep-ph/9510395
Megevand Ariel
Roberto Fiore, Luis Masperi, Ariel Megevand
Strings With Axionic Content and Baryogenesis
12 pages
Mod.Phys.Lett. A11 (1996) 1847-1860
10.1142/S0217732396001843
null
hep-ph astro-ph
null
We describe different electroweak strings with axionic content, including non-topological configurations calculated numerically, and show their possible influence on baryogenesis indicating that they may constitute a mechanism competitive to that of bubble nucleation with two Higgs-doublets.
[ { "created": "Tue, 24 Oct 1995 16:11:03 GMT", "version": "v1" } ]
2009-10-28
[ [ "Fiore", "Roberto", "" ], [ "Masperi", "Luis", "" ], [ "Megevand", "Ariel", "" ] ]
We describe different electroweak strings with axionic content, including non-topological configurations calculated numerically, and show their possible influence on baryogenesis indicating that they may constitute a mechanism competitive to that of bubble nucleation with two Higgs-doublets.
hep-ph/0404147
Sergey Goloskokov
S.V. Goloskokov
Spin effects in diffractive $ Q \bar Q$ production at BNL eRHIC
Some modifications of the text and graphs were done. Title is modified slightly. To be published in Phys. Rev. D
Phys.Rev.D70:034011,2004
10.1103/PhysRevD.70.034011
null
hep-ph
null
We discuss quark-antiquark leptoproduction within a QCD two-gluon exchange model at small $x$. The double spin asymmetries for longitudinally polarized leptons and transversely polarized protons in diffractive $Q \bar Q$ production are analysed at eRHIC energies. The predicted $A_{lT}$ asymmetry is large and can be used to obtain information on the polarized generalized gluon distributions in the proton.
[ { "created": "Mon, 19 Apr 2004 13:03:44 GMT", "version": "v1" }, { "created": "Fri, 23 Apr 2004 05:51:47 GMT", "version": "v2" }, { "created": "Wed, 16 Jun 2004 07:25:29 GMT", "version": "v3" } ]
2014-11-17
[ [ "Goloskokov", "S. V.", "" ] ]
We discuss quark-antiquark leptoproduction within a QCD two-gluon exchange model at small $x$. The double spin asymmetries for longitudinally polarized leptons and transversely polarized protons in diffractive $Q \bar Q$ production are analysed at eRHIC energies. The predicted $A_{lT}$ asymmetry is large and can be used to obtain information on the polarized generalized gluon distributions in the proton.
hep-ph/9806395
Frank Wilczek
Frank Wilczek
From Notes to Chords in QCD
LaTeX, 13 pages, 1 figure. Reference added. Will appear in Proceedings of QCD at Finite Baryon Density Conference, April 1998, Universitaet Bielefeld, Germany
Nucl.Phys. A642 (1998) 1-13
10.1016/S0375-9474(98)00493-X
IASSNS-HEP98-56
hep-ph astro-ph hep-lat hep-th
null
After a very brief overview recollecting the `classic' parts of QCD, that is its application to describe hard processes and static properties of hadrons, I survey recent work -- some very recent -- on QCD at non-zero temperature and density. At finite temperature and zero density there is a compelling theoretical framework allowing us to predict highly specific, non-trivial dependence of the phase structure on the number of flavors and colors. Several aspects have been rigorously, and successfully, tested against massive numerical realizations of the microscopic theory. The theoretical description of high density is nowhere near as mature, but some intriguing possibilities have been put forward. The color/flavor locked state recently proposed for three flavors has many remarkable features connected to its basic symmetry structure, notably including chiral symmetry re-breaking and the existence (unlike for two flavors) of a gauge invariant order parameter. I survey potential applications to heavy ion collisions, astrophysics, and cosmology. A noteworthy possibility is that stellar explosions are powered by release of QCD latent heat.
[ { "created": "Wed, 17 Jun 1998 18:16:39 GMT", "version": "v1" }, { "created": "Thu, 25 Jun 1998 12:27:37 GMT", "version": "v2" } ]
2009-10-31
[ [ "Wilczek", "Frank", "" ] ]
After a very brief overview recollecting the `classic' parts of QCD, that is its application to describe hard processes and static properties of hadrons, I survey recent work -- some very recent -- on QCD at non-zero temperature and density. At finite temperature and zero density there is a compelling theoretical framework allowing us to predict highly specific, non-trivial dependence of the phase structure on the number of flavors and colors. Several aspects have been rigorously, and successfully, tested against massive numerical realizations of the microscopic theory. The theoretical description of high density is nowhere near as mature, but some intriguing possibilities have been put forward. The color/flavor locked state recently proposed for three flavors has many remarkable features connected to its basic symmetry structure, notably including chiral symmetry re-breaking and the existence (unlike for two flavors) of a gauge invariant order parameter. I survey potential applications to heavy ion collisions, astrophysics, and cosmology. A noteworthy possibility is that stellar explosions are powered by release of QCD latent heat.
1003.2447
Sean Tulin
Kfir Blum, Cedric Delaunay, Marta Losada, Yosef Nir, Sean Tulin
CP violation Beyond the MSSM: Baryogenesis and Electric Dipole Moments
33 pages, 6 figures
JHEP 1005:101,2010
10.1007/JHEP05(2010)101
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study electroweak baryogenesis and electric dipole moments in the presence of the two leading-order, non-renormalizable operators in the Higgs sector of the MSSM. Significant qualitative and quantitative differences from MSSM baryogenesis arise due to the presence of new CP-violating phases and to the relaxation of constraints on the supersymmetric spectrum (in particular, both stops can be light). We find: (1) spontaneous baryogenesis, driven by a change in the phase of the Higgs vevs across the bubble wall, becomes possible; (2) the top and stop CP-violating sources can become effective; (3) baryogenesis is viable in larger parts of parameter space, alleviating the well-known fine-tuning associated with MSSM baryogenesis. Nevertheless, electric dipole moments should be measured if experimental sensitivities are improved by about one order of magnitude.
[ { "created": "Thu, 11 Mar 2010 23:40:19 GMT", "version": "v1" } ]
2015-03-13
[ [ "Blum", "Kfir", "" ], [ "Delaunay", "Cedric", "" ], [ "Losada", "Marta", "" ], [ "Nir", "Yosef", "" ], [ "Tulin", "Sean", "" ] ]
We study electroweak baryogenesis and electric dipole moments in the presence of the two leading-order, non-renormalizable operators in the Higgs sector of the MSSM. Significant qualitative and quantitative differences from MSSM baryogenesis arise due to the presence of new CP-violating phases and to the relaxation of constraints on the supersymmetric spectrum (in particular, both stops can be light). We find: (1) spontaneous baryogenesis, driven by a change in the phase of the Higgs vevs across the bubble wall, becomes possible; (2) the top and stop CP-violating sources can become effective; (3) baryogenesis is viable in larger parts of parameter space, alleviating the well-known fine-tuning associated with MSSM baryogenesis. Nevertheless, electric dipole moments should be measured if experimental sensitivities are improved by about one order of magnitude.
hep-ph/0405005
Osamu Yasuda
Osamu Yasuda
New plots and parameter degeneracies in neutrino oscillations
29 pages, 12 sets of figures. For "Focus on Neutrino Physics" issue of New Journal of Physics
New J.Phys. 6 (2004) 83
10.1088/1367-2630/6/1/083
null
hep-ph
null
It is shown that eightfold degeneracy in neutrino oscillations is easily seen by plotting constant probabilities in the $(\sin^22\theta_{13}, 1/s^2_{23})$ plane. Using this plot, we discuss how an additional long baseline measurement resolves degeneracies after the JPARC experiment measures the oscillation probabilities $P(\nu_\mu\to\nu_e)$ and $P(\bar{\nu}_\mu\to\bar{\nu}_e)$ at $|\Delta m^2_{31}|L/4E=\pi/2$. By measuring $P(\nu_\mu\to\nu_e)$ or $P(\bar{\nu}_\mu\to\bar{\nu}_e)$, the sgn($\Delta m_{31}^2$) ambiguity is resolved better at longer baselines and the $\delta\leftrightarrow\pi-\delta$ ambiguity is resolved better when $||\Delta m^2_{31}|L/4E-\pi/2|$ is larger. The $\theta_{23}$ ambiguity may be resolved as a byproduct if $||\Delta m^2_{31}|L/4E-\pi|$ is small and the CP phase $\delta$ turns out to satisfy $|\cos(\delta +|\Delta m^2_{31}|L/4E)|\sim1$. It is pointed out that the low energy option ($E\sim$1GeV) at the off-axis NuMI experiment may be useful in resolving these ambiguities. The $\nu_e\to\nu_\tau$ channel offers a promising possibility which may potentially resolve all the ambiguities.
[ { "created": "Sun, 2 May 2004 09:54:47 GMT", "version": "v1" } ]
2009-11-10
[ [ "Yasuda", "Osamu", "" ] ]
It is shown that eightfold degeneracy in neutrino oscillations is easily seen by plotting constant probabilities in the $(\sin^22\theta_{13}, 1/s^2_{23})$ plane. Using this plot, we discuss how an additional long baseline measurement resolves degeneracies after the JPARC experiment measures the oscillation probabilities $P(\nu_\mu\to\nu_e)$ and $P(\bar{\nu}_\mu\to\bar{\nu}_e)$ at $|\Delta m^2_{31}|L/4E=\pi/2$. By measuring $P(\nu_\mu\to\nu_e)$ or $P(\bar{\nu}_\mu\to\bar{\nu}_e)$, the sgn($\Delta m_{31}^2$) ambiguity is resolved better at longer baselines and the $\delta\leftrightarrow\pi-\delta$ ambiguity is resolved better when $||\Delta m^2_{31}|L/4E-\pi/2|$ is larger. The $\theta_{23}$ ambiguity may be resolved as a byproduct if $||\Delta m^2_{31}|L/4E-\pi|$ is small and the CP phase $\delta$ turns out to satisfy $|\cos(\delta +|\Delta m^2_{31}|L/4E)|\sim1$. It is pointed out that the low energy option ($E\sim$1GeV) at the off-axis NuMI experiment may be useful in resolving these ambiguities. The $\nu_e\to\nu_\tau$ channel offers a promising possibility which may potentially resolve all the ambiguities.
hep-ph/0305315
Jonathan L. Rosner
Jonathan L. Rosner
Theoretical Issues in $b$ Physics
18 pages, LaTeX, 4 figures, invited talk presented at LHC 2003 Symposium, Fermilab, May 1-3, 2003. Proceedings to be published by Springer-Verlag. Two figures and one CP asymmetry updated; more direct use made of CP asymmetry information in B -> K pi decays
Eur.Phys.J.C34:s365-s374,2004
10.1140/epjcd/s2004-04-036-4
EFI 03-26
hep-ph
null
Examples are given of some current questions in $b$ physics to which LHC experiments may provide answers. These include (i) the precise determination of parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix; (ii) measurements of CKM phases using B decays to CP eigenstates; (iii) the search for direct CP asymmetries in B decays; (iv) rare radiative B decays; (v) the study of $B_s$ properties and decays, (vi) excited states of $B$ and $B_s$ mesons, and (vii) the search for heavier quarks which could mix with the $b$ quark.
[ { "created": "Wed, 28 May 2003 20:24:43 GMT", "version": "v1" }, { "created": "Sat, 31 May 2003 21:03:41 GMT", "version": "v2" }, { "created": "Sun, 22 Jun 2003 22:07:49 GMT", "version": "v3" }, { "created": "Thu, 26 Jun 2003 22:00:18 GMT", "version": "v4" }, { "c...
2010-11-23
[ [ "Rosner", "Jonathan L.", "" ] ]
Examples are given of some current questions in $b$ physics to which LHC experiments may provide answers. These include (i) the precise determination of parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix; (ii) measurements of CKM phases using B decays to CP eigenstates; (iii) the search for direct CP asymmetries in B decays; (iv) rare radiative B decays; (v) the study of $B_s$ properties and decays, (vi) excited states of $B$ and $B_s$ mesons, and (vii) the search for heavier quarks which could mix with the $b$ quark.
1506.02964
Julian Heeck
Jean-Marie Fr\`ere, Julian Heeck, Simon Mollet
Triangle Inequalities for Majorana-Neutrino Magnetic Moments
10 pages, 1 figure. Extended discussion of sterile neutrinos; accepted by PRD
Phys. Rev. D 92, 053002 (2015)
10.1103/PhysRevD.92.053002
ULB-TH/15-08
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electromagnetic properties of neutrinos, if ever observed, could help to decide the Dirac versus Majorana nature of neutrinos. We show that the magnetic moments of Majorana neutrinos have to fulfill triangle inequalities, $|\mu_{\nu_\tau}|^2 \leq |\mu_{\nu_\mu}|^2 +|\mu_{\nu_e}|^2$ and cyclic permutations, which do not hold for Dirac neutrinos. Observing a violation of these inequalities, e.g. by measuring the magnetic moment of $\nu_\tau$ at SHiP, would thus strongly hint either at the Dirac nature of neutrinos or at the presence of at least one extra light sterile mode.
[ { "created": "Tue, 9 Jun 2015 15:36:17 GMT", "version": "v1" }, { "created": "Tue, 1 Sep 2015 08:13:17 GMT", "version": "v2" } ]
2015-09-10
[ [ "Frère", "Jean-Marie", "" ], [ "Heeck", "Julian", "" ], [ "Mollet", "Simon", "" ] ]
Electromagnetic properties of neutrinos, if ever observed, could help to decide the Dirac versus Majorana nature of neutrinos. We show that the magnetic moments of Majorana neutrinos have to fulfill triangle inequalities, $|\mu_{\nu_\tau}|^2 \leq |\mu_{\nu_\mu}|^2 +|\mu_{\nu_e}|^2$ and cyclic permutations, which do not hold for Dirac neutrinos. Observing a violation of these inequalities, e.g. by measuring the magnetic moment of $\nu_\tau$ at SHiP, would thus strongly hint either at the Dirac nature of neutrinos or at the presence of at least one extra light sterile mode.
hep-ph/0005159
Martti Raidal
G. Barenboim, K. Huitu and M. Raidal
Flavour Violation in SUSY SU(5) GUT at Large tan beta
22 pages, 7 figures
Phys.Rev.D63:055006,2001
10.1103/PhysRevD.63.055006
UCRHEP-T276, HIP-2000-23/TH, MZ-TH/00-20
hep-ph
null
We study flavour violation in the minimal SUSY SU(5) GUT assuming all the third generation Yukawa couplings to be due to the renormalizable physics above GUT scale. At large $\tan\beta,$ as suggested by Yukawa unification in SU(5), sizable flavour violation in the left (right) slepton (down squark) sector is induced due to renormalization effects of down type Yukawa couplings between GUT and Planck scales in addition to the flavour violation in the right slepton sector. The new flavour physics contribution to $K-\bar K,$ $B-\bar B$ mixing is small but might be of phenomenological interest in the case of $b\to s\gamma.$ The sign of the latter contribution is the same as the sign of the dominant chargino contribution, thus making the constraints on SUSY scale coming from $b\to s\gamma$ somewhat more restrictive. The most important feature of the considered scenario is the large rate of lepton flavour violation. Given the present experimental constraints, the $\mu\to e\gamma$ and $\mu-e$ conversion branching ratios are above the sensitivity of the planned experiments unless the SUSY scale is pushed above one TeV.
[ { "created": "Wed, 17 May 2000 00:51:01 GMT", "version": "v1" } ]
2014-11-17
[ [ "Barenboim", "G.", "" ], [ "Huitu", "K.", "" ], [ "Raidal", "M.", "" ] ]
We study flavour violation in the minimal SUSY SU(5) GUT assuming all the third generation Yukawa couplings to be due to the renormalizable physics above GUT scale. At large $\tan\beta,$ as suggested by Yukawa unification in SU(5), sizable flavour violation in the left (right) slepton (down squark) sector is induced due to renormalization effects of down type Yukawa couplings between GUT and Planck scales in addition to the flavour violation in the right slepton sector. The new flavour physics contribution to $K-\bar K,$ $B-\bar B$ mixing is small but might be of phenomenological interest in the case of $b\to s\gamma.$ The sign of the latter contribution is the same as the sign of the dominant chargino contribution, thus making the constraints on SUSY scale coming from $b\to s\gamma$ somewhat more restrictive. The most important feature of the considered scenario is the large rate of lepton flavour violation. Given the present experimental constraints, the $\mu\to e\gamma$ and $\mu-e$ conversion branching ratios are above the sensitivity of the planned experiments unless the SUSY scale is pushed above one TeV.
hep-ph/9712234
Piotr Chankowski
P.H. Chankowski, J. Ellis, S. Pokorski
The fine-tuning price of LEP
13 pages, 5 figures. Two references added, one corrected. A typo corrected
Phys.Lett.B423:327-336,1998
10.1016/S0370-2693(98)00060-4
CERN-TH/97-343, IFT-97/19
hep-ph
null
We quantify the amount of fine tuning of input parameters of the Minimal Supersymmetric Extension of the Standard Model (MSSM) that is needed to respect the lower limits on sparticle and Higgs masses imposed by precision electroweak measurements at LEP, measurements of $b\to X_s\gamma$, and searches at LEP 2. If universal input scalar masses are assumed in a gravity-mediated scenario, a factor of $\gappeq180$ is required at $\tan\beta\sim1.65$, decreasing to $\sim20$ at $\tan\beta\sim10$. The amount of fine tuning is not greatly reduced if non-universal input scalar Higgs masses are allowed, but may be significantly reduced if some theoretical relations between MSSM parameters are assumed.
[ { "created": "Tue, 2 Dec 1997 13:30:04 GMT", "version": "v1" }, { "created": "Wed, 17 Dec 1997 11:43:21 GMT", "version": "v2" } ]
2009-09-11
[ [ "Chankowski", "P. H.", "" ], [ "Ellis", "J.", "" ], [ "Pokorski", "S.", "" ] ]
We quantify the amount of fine tuning of input parameters of the Minimal Supersymmetric Extension of the Standard Model (MSSM) that is needed to respect the lower limits on sparticle and Higgs masses imposed by precision electroweak measurements at LEP, measurements of $b\to X_s\gamma$, and searches at LEP 2. If universal input scalar masses are assumed in a gravity-mediated scenario, a factor of $\gappeq180$ is required at $\tan\beta\sim1.65$, decreasing to $\sim20$ at $\tan\beta\sim10$. The amount of fine tuning is not greatly reduced if non-universal input scalar Higgs masses are allowed, but may be significantly reduced if some theoretical relations between MSSM parameters are assumed.
1701.01947
Vadim Lensky
Vadim Lensky, Vladimir Pascalutsa, Marc Vanderhaeghen, Chung Wen Kao
Spin-dependent sum rules connecting real and virtual Compton scattering verified
21 pages, 4 figures, RevTeX 4, typos corrected, matches published version
Phys. Rev. D 95, 074001 (2017)
10.1103/PhysRevD.95.074001
MITP/16-119
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a detailed derivation of the two sum rules relating the spin polarizabilities measured in real, virtual, and doubly-virtual Compton scattering. For example, the polarizability $\delta_{LT}$, accessed in inclusive electron scattering, is related to the spin polarizability $\gamma_{E1E1}$ and the slope of generalized polarizabilities $P^{(M1,M1)1}-P^{(L1,L1)1}$, measured in, respectively, the real and the virtual Compton scattering. We verify these sum rules in different variants of chiral perturbation theory, discuss their empirical verification for the proton, and prospect their use in studies of the nucleon spin structure.
[ { "created": "Sun, 8 Jan 2017 11:46:30 GMT", "version": "v1" }, { "created": "Mon, 3 Apr 2017 16:27:05 GMT", "version": "v2" } ]
2017-04-04
[ [ "Lensky", "Vadim", "" ], [ "Pascalutsa", "Vladimir", "" ], [ "Vanderhaeghen", "Marc", "" ], [ "Kao", "Chung Wen", "" ] ]
We present a detailed derivation of the two sum rules relating the spin polarizabilities measured in real, virtual, and doubly-virtual Compton scattering. For example, the polarizability $\delta_{LT}$, accessed in inclusive electron scattering, is related to the spin polarizability $\gamma_{E1E1}$ and the slope of generalized polarizabilities $P^{(M1,M1)1}-P^{(L1,L1)1}$, measured in, respectively, the real and the virtual Compton scattering. We verify these sum rules in different variants of chiral perturbation theory, discuss their empirical verification for the proton, and prospect their use in studies of the nucleon spin structure.
hep-ph/9809510
Kimball A. Milton
K. A. Milton, I. L. Solovtsov, and O. P. Solovtsova
The Bjorken Sum Rule in the Analytic Approach to Perturbative QCD
12 pages, 3 eps figures, uses elsart.cls
Phys.Lett. B439 (1998) 421-427
10.1016/S0370-2693(98)01053-3
OKHEP-98-03
hep-ph
null
Results of applying analytic perturbation theory (APT) to the Bjorken sum rule are presented. We study the third-order QCD correction within the analytic approach and investigate its renormalization scheme dependence. We demonstrate that, in the framework of the method, theoretical predictions of the Bjorken sum rule are, practically, scheme independent for the entire interval of momentum transfer.
[ { "created": "Wed, 23 Sep 1998 20:31:13 GMT", "version": "v1" } ]
2009-10-31
[ [ "Milton", "K. A.", "" ], [ "Solovtsov", "I. L.", "" ], [ "Solovtsova", "O. P.", "" ] ]
Results of applying analytic perturbation theory (APT) to the Bjorken sum rule are presented. We study the third-order QCD correction within the analytic approach and investigate its renormalization scheme dependence. We demonstrate that, in the framework of the method, theoretical predictions of the Bjorken sum rule are, practically, scheme independent for the entire interval of momentum transfer.
2207.08415
Surender Verma Ph. D.
Labh Singh, Monal Kashav and Surender Verma
Gauged $U(1)_{L_{\mu}-L_{\tau}}$ Symmetry and two-zero Textures of Inverse Neutrino Mass Matrix in light of Muon ($g-2$)
13 pages, 5 figures
null
10.1142/S0217732322502029
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the framework of anomaly free $U(1)_{L_{\mu}-L_{\tau}}$ model, charged scalar fields give rise to massive gauge boson ($Z_{\mu\tau}$) through spontaneous symmetry breaking. $Z_{\mu\tau}$ leads to one loop contribution to the muon anomalous magnetic moment. These scalar fields may, also, appear in the structure of right-handed neutrino mass matrix, thus, connecting the possible explanation of muon ($g-2$) and low energy neutrino phenomenology through $vevs$ associated with the scalar fields. In the present work, we consider textures of inverse neutrino mass matrix ($M_{\nu}^{-1}$) wherein any two elements of the mass matrix are zero. In this ansatz, with Dirac neutrino mass matrix diagonal, the zero(s) of right-handed Majorana neutrino mass matrix correspond to zero(s) in the low energy effective neutrino mass matrix (within Type-I seesaw). We have realized two such textures of $M_{\nu}^{-1}$ accommodating the muon ($g-2$) and low energy neutrino phenomenology. The requirement of successful explanation of muon ($g-2$), further, constrain the allowed parameter space of the model and results in sharp correlations amongst neutrino mixing angles, $CP$ invariants and effective Majorana mass ($M_{ee}$). The model explains muon ($g-2$) for $M_{Z_{\mu\tau}}$ in the range ($0.035$ GeV-$0.100$ GeV) and $g_{\mu\tau}\approx\mathcal{O}(10^{-4}$) which is found to be consistent with constraints coming from the experiments like CCFR, COHERENT, BABAR, NA62 and NA64.
[ { "created": "Mon, 18 Jul 2022 07:48:25 GMT", "version": "v1" } ]
2023-01-25
[ [ "Singh", "Labh", "" ], [ "Kashav", "Monal", "" ], [ "Verma", "Surender", "" ] ]
In the framework of anomaly free $U(1)_{L_{\mu}-L_{\tau}}$ model, charged scalar fields give rise to massive gauge boson ($Z_{\mu\tau}$) through spontaneous symmetry breaking. $Z_{\mu\tau}$ leads to one loop contribution to the muon anomalous magnetic moment. These scalar fields may, also, appear in the structure of right-handed neutrino mass matrix, thus, connecting the possible explanation of muon ($g-2$) and low energy neutrino phenomenology through $vevs$ associated with the scalar fields. In the present work, we consider textures of inverse neutrino mass matrix ($M_{\nu}^{-1}$) wherein any two elements of the mass matrix are zero. In this ansatz, with Dirac neutrino mass matrix diagonal, the zero(s) of right-handed Majorana neutrino mass matrix correspond to zero(s) in the low energy effective neutrino mass matrix (within Type-I seesaw). We have realized two such textures of $M_{\nu}^{-1}$ accommodating the muon ($g-2$) and low energy neutrino phenomenology. The requirement of successful explanation of muon ($g-2$), further, constrain the allowed parameter space of the model and results in sharp correlations amongst neutrino mixing angles, $CP$ invariants and effective Majorana mass ($M_{ee}$). The model explains muon ($g-2$) for $M_{Z_{\mu\tau}}$ in the range ($0.035$ GeV-$0.100$ GeV) and $g_{\mu\tau}\approx\mathcal{O}(10^{-4}$) which is found to be consistent with constraints coming from the experiments like CCFR, COHERENT, BABAR, NA62 and NA64.
1302.4823
Gulsheen Ahuja
Manmohan Gupta and Gulsheen Ahuja
Flavor mixings and textures of the fermion mass matrices
100 pages, 19 figures
Int. Jour. Mod. Phys. A, 27, (2012) 1230033
10.1142/S0217751X12300335
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A comprehensive review of several aspects of fermion mixing phenomenon and texture specific mass matrices have been presented. Regarding fermion mixings, implications of unitarity and certain new developments for the CKM paradigm have been discussed. In the leptonic sector, the question of possibility of CP violation has been discussed in detail from the unitarity triangle perspective. In the case of texture specific mass matrices, the issues of viability of Fritzsch-like as well as non Fritzsch-like mass matrices have been detailed for both the quark and leptonic sectors. The relationship of textures, naturalness and weak basis rotations has also been looked into. The issue of the compatibility of texture specific mass matrices with the SO(10) based GUT mass matrices has also been discussed.
[ { "created": "Wed, 20 Feb 2013 06:53:43 GMT", "version": "v1" } ]
2015-06-15
[ [ "Gupta", "Manmohan", "" ], [ "Ahuja", "Gulsheen", "" ] ]
A comprehensive review of several aspects of fermion mixing phenomenon and texture specific mass matrices have been presented. Regarding fermion mixings, implications of unitarity and certain new developments for the CKM paradigm have been discussed. In the leptonic sector, the question of possibility of CP violation has been discussed in detail from the unitarity triangle perspective. In the case of texture specific mass matrices, the issues of viability of Fritzsch-like as well as non Fritzsch-like mass matrices have been detailed for both the quark and leptonic sectors. The relationship of textures, naturalness and weak basis rotations has also been looked into. The issue of the compatibility of texture specific mass matrices with the SO(10) based GUT mass matrices has also been discussed.
hep-ph/0607138
Joseph Conlon
Joseph P. Conlon
Seeing the Invisible Axion in the Sparticle Spectrum
4 pages, REVTeX
Phys.Rev.Lett.97:261802,2006
10.1103/PhysRevLett.97.261802
DAMTP-2006-55
hep-ph
null
I describe how under favourable circumstances the invisible axion may manifest its existence at the LHC through the sparticle spectrum; in particular through a gluino \sim \ln (M_P/m_{3/2}) times heavier than other gauginos.
[ { "created": "Wed, 12 Jul 2006 15:25:36 GMT", "version": "v1" } ]
2008-11-26
[ [ "Conlon", "Joseph P.", "" ] ]
I describe how under favourable circumstances the invisible axion may manifest its existence at the LHC through the sparticle spectrum; in particular through a gluino \sim \ln (M_P/m_{3/2}) times heavier than other gauginos.
1212.2321
Danny van Dyk
Christoph Bobeth, Gudrun Hiller, Danny van Dyk
General Analysis of B -> K^(*) l^+ l^- Decays at Low Recoil
17 pages, 4 figures. v2: Clarifications added, bug in mu_b handling in Fig 1 corrected. v3: 1/mb terms in tensor amplitudes clarified and sign of A_{t perp} corrected. Conclusions unchanged. v4: Corrected relation (signs) between the definition of tensor operators and appendix C; all numerics and conclusions unchanged
Phys.Rev. D87 (2013) 034016
10.1103/PhysRevD.87.034016
DO-TH 12/16, EOS-2012-02, SI-HEP-2012-21, QFET-2012-02
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the angular distributions of B -> K^* (-> K pi) l^+ l^- and B -> K l^+ l^- decays in the region of low hadronic recoil in a model-independent way by taking into account the complete set of dimension-six operators [sbar Gamma b][lbar Gamma' l]. We obtain several novel low-recoil observables with high sensitivity to non-standard-model Dirac structures, including CP-asymmetries which do not require flavor tagging. The transversity observables H_T^(1,3,4,5) are found to be insensitive to hadronic matrix elements and their uncertainties even when considering the complete set of operators. In the most general scenario we show that the low recoil operator product expansion can be probed at the few-percent level using the angular observable J_7. Higher sensitivities are possible assuming no tensor contributions, specifically by testing the low-recoil relation |H_T^(1)|=1. We explicitly demonstrate the gain in reach of the low-recoil observables in accessing the ratio |C_9/C_10| compared to the forward-backward asymmetry, and probing CP-violating right-handed currents Im C_10'. We give updated Standard Model predictions for key observables in B -> K^(*) l^+ l^- decays.
[ { "created": "Tue, 11 Dec 2012 07:54:57 GMT", "version": "v1" }, { "created": "Thu, 7 Feb 2013 13:27:16 GMT", "version": "v2" }, { "created": "Wed, 31 Jul 2013 15:51:39 GMT", "version": "v3" }, { "created": "Mon, 8 Feb 2016 15:49:43 GMT", "version": "v4" } ]
2016-02-09
[ [ "Bobeth", "Christoph", "" ], [ "Hiller", "Gudrun", "" ], [ "van Dyk", "Danny", "" ] ]
We analyze the angular distributions of B -> K^* (-> K pi) l^+ l^- and B -> K l^+ l^- decays in the region of low hadronic recoil in a model-independent way by taking into account the complete set of dimension-six operators [sbar Gamma b][lbar Gamma' l]. We obtain several novel low-recoil observables with high sensitivity to non-standard-model Dirac structures, including CP-asymmetries which do not require flavor tagging. The transversity observables H_T^(1,3,4,5) are found to be insensitive to hadronic matrix elements and their uncertainties even when considering the complete set of operators. In the most general scenario we show that the low recoil operator product expansion can be probed at the few-percent level using the angular observable J_7. Higher sensitivities are possible assuming no tensor contributions, specifically by testing the low-recoil relation |H_T^(1)|=1. We explicitly demonstrate the gain in reach of the low-recoil observables in accessing the ratio |C_9/C_10| compared to the forward-backward asymmetry, and probing CP-violating right-handed currents Im C_10'. We give updated Standard Model predictions for key observables in B -> K^(*) l^+ l^- decays.
1011.1371
Davide Meloni
D. Meloni, S. Morisi and E. Peinado
Neutrino phenomenology and stable dark matter with A4
7 pages, 2 figures, minor changes to match the version to appear in PLB
Phys.Lett.B697:339-342,2011
10.1016/j.physletb.2011.02.019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model based on the A4 non-abelian discrete symmetry leading to a predictive five-parameter neutrino mass matrix and providing a stable dark matter candidate. We found an interesting correlation among the atmospheric and the reactor angles which predicts theta_23 ~ pi/4 for very small reactor angle and deviation from maximal atmospheric mixing for large theta_13. Only normal neutrino mass spectrum is possible and the effective mass entering the neutrinoless double beta decay rate is constrained to be |m_ee| > 4 10^{-4} eV.
[ { "created": "Fri, 5 Nov 2010 11:35:48 GMT", "version": "v1" }, { "created": "Mon, 7 Feb 2011 16:00:14 GMT", "version": "v2" } ]
2011-04-20
[ [ "Meloni", "D.", "" ], [ "Morisi", "S.", "" ], [ "Peinado", "E.", "" ] ]
We present a model based on the A4 non-abelian discrete symmetry leading to a predictive five-parameter neutrino mass matrix and providing a stable dark matter candidate. We found an interesting correlation among the atmospheric and the reactor angles which predicts theta_23 ~ pi/4 for very small reactor angle and deviation from maximal atmospheric mixing for large theta_13. Only normal neutrino mass spectrum is possible and the effective mass entering the neutrinoless double beta decay rate is constrained to be |m_ee| > 4 10^{-4} eV.
2304.05089
Zebin Qiu
Zebin Qiu and Muneto Nitta
Quasicrystals in QCD
19 pages, 6 figures
null
10.1007/JHEP05(2023)170
null
hep-ph hep-th nucl-th
http://creativecommons.org/licenses/by/4.0/
We study the ground state of the low energy dense QCD with the assumption of chiral condensates of quarks. Under an external magnetic field, mesons could form soliton lattices via the chiral anomaly. For such scenarios, we present a unified description of pions and $\eta$ meson with a $U(2)$ field in the framework of the chiral perturbation theory. Our result shows the ground state is a mixture of the magnetized domain walls formed by neutral pion $\pi^0$ and $\eta$ meson when they coexist. The winding number of the ground state would alter according to the strength of the magnetic field. When the magnetic field is strong or the chemical potential is large, the proportion of the mixture is determined by the decay constants and the contributions to the anomalous action of $\pi^0$ and $\eta$ meson. The resulting configuration is either a mixed soliton lattice or a quasicrystal which could be dubbed a ``chiral soliton quasicrystal''.
[ { "created": "Tue, 11 Apr 2023 09:35:02 GMT", "version": "v1" } ]
2023-06-07
[ [ "Qiu", "Zebin", "" ], [ "Nitta", "Muneto", "" ] ]
We study the ground state of the low energy dense QCD with the assumption of chiral condensates of quarks. Under an external magnetic field, mesons could form soliton lattices via the chiral anomaly. For such scenarios, we present a unified description of pions and $\eta$ meson with a $U(2)$ field in the framework of the chiral perturbation theory. Our result shows the ground state is a mixture of the magnetized domain walls formed by neutral pion $\pi^0$ and $\eta$ meson when they coexist. The winding number of the ground state would alter according to the strength of the magnetic field. When the magnetic field is strong or the chemical potential is large, the proportion of the mixture is determined by the decay constants and the contributions to the anomalous action of $\pi^0$ and $\eta$ meson. The resulting configuration is either a mixed soliton lattice or a quasicrystal which could be dubbed a ``chiral soliton quasicrystal''.
hep-ph/0107026
Ed Stoeffhaas
O. J. P. Eboli, E. M. Gregores, and F. Halzen
Soft Color Enhancement of the Production of J/psi's by Neutrinos
7 pages, Revtex, 4 postscript figures, uses epsfig.sty
Phys.Rev.D64:093015,2001
10.1103/PhysRevD.64.093015
MADPH-01-1233, IFT-P.048/2001
hep-ph
null
We calculate the production of J/psi mesons by neutrino-nucleon collisions in fixed target experiments. Soft color, often referred to as color evaporation effects, enhance production cross sections due to the contribution of color octet states. Though still small, J/\psi production may be observable in present and future experiments like NuTeV and muon colliders.
[ { "created": "Tue, 3 Jul 2001 17:10:01 GMT", "version": "v1" } ]
2011-03-23
[ [ "Eboli", "O. J. P.", "" ], [ "Gregores", "E. M.", "" ], [ "Halzen", "F.", "" ] ]
We calculate the production of J/psi mesons by neutrino-nucleon collisions in fixed target experiments. Soft color, often referred to as color evaporation effects, enhance production cross sections due to the contribution of color octet states. Though still small, J/\psi production may be observable in present and future experiments like NuTeV and muon colliders.
2006.07675
Chandan Mondal
Mohammad Ahmady, Satvir Kaur, Chandan Mondal, Ruben Sandapen
Light-front holographic radiative transition form factors for light mesons
20 pages, 5 figures; Revised version that specifies the differences between the holographic meson wave function and other models. References updated, results unchanged. Accepted by PRD
Phys. Rev. D 102, 034021 (2020)
10.1103/PhysRevD.102.034021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We predict the $\mathcal{V} \to \mathcal{P} \gamma$ decay widths and the $\mathcal{V} \to \mathcal{P} \gamma^{*}$ transition form factors, where $\mathcal{V}=(\rho, \omega, K^*, \phi)$ and $\mathcal{P}= (\pi,K, \eta,\eta^\prime)$, using spin-improved holographic light-front wavefunctions for the mesons. We find excellent agreement with the available data for both the decay widths and the timelike transition form factors extracted from the leptonic conversion decays $\mathcal{V} \to \mathcal{P} l^+ l^-$.
[ { "created": "Sat, 13 Jun 2020 16:32:24 GMT", "version": "v1" }, { "created": "Fri, 24 Jul 2020 16:04:18 GMT", "version": "v2" } ]
2020-08-21
[ [ "Ahmady", "Mohammad", "" ], [ "Kaur", "Satvir", "" ], [ "Mondal", "Chandan", "" ], [ "Sandapen", "Ruben", "" ] ]
We predict the $\mathcal{V} \to \mathcal{P} \gamma$ decay widths and the $\mathcal{V} \to \mathcal{P} \gamma^{*}$ transition form factors, where $\mathcal{V}=(\rho, \omega, K^*, \phi)$ and $\mathcal{P}= (\pi,K, \eta,\eta^\prime)$, using spin-improved holographic light-front wavefunctions for the mesons. We find excellent agreement with the available data for both the decay widths and the timelike transition form factors extracted from the leptonic conversion decays $\mathcal{V} \to \mathcal{P} l^+ l^-$.
1004.2770
Gennady Lykasov I
J.Cleymans, G.I.Lykasov, A.N.Sissakian, A.S.Sorin, O.V.Teryaev
Duality of thermal and dynamical descriptions in particle interactions
8 pages, 1 figure
null
null
0022524
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a duality between the statistical and standard (dynamical) distributions of partons in the nucleons. The temperature parameter entering into the statistical form for the quark distributions is estimated. It is found that this effective temperature is practically the same for the dependence on logitudinal and transverse momenta and, it is close to the freeze-out temperature in high energy heavy-ion collisions.
[ { "created": "Fri, 16 Apr 2010 07:35:50 GMT", "version": "v1" } ]
2010-04-19
[ [ "Cleymans", "J.", "" ], [ "Lykasov", "G. I.", "" ], [ "Sissakian", "A. N.", "" ], [ "Sorin", "A. S.", "" ], [ "Teryaev", "O. V.", "" ] ]
We suggest a duality between the statistical and standard (dynamical) distributions of partons in the nucleons. The temperature parameter entering into the statistical form for the quark distributions is estimated. It is found that this effective temperature is practically the same for the dependence on logitudinal and transverse momenta and, it is close to the freeze-out temperature in high energy heavy-ion collisions.
hep-ph/0010207
Masayasu Harada
Masayasu Harada and Koichi Yamawaki
Vector Manifestation of the Chiral Symmetry
4 pages, No figures. A discussion for finite temperature and/or density is added. This is the version to appear in Physical Review Letters
Phys.Rev.Lett. 86 (2001) 757-760
10.1103/PhysRevLett.86.757
DPNU-00-38
hep-ph hep-th nucl-th
null
We propose ``vector manifestation (VM)'' of the Wigner realization of the chiral symmetry in which the symmetry is restored at the critical point by the massless degenerate pion (and its flavor partners) and rho meson (and its flavor partners) as the chiral partner, in sharp contrast to the traditional manifestation \'a la linear sigma model where the symmetry is restored by the degenerate pion and scalar meson. The application to the chiral phase transition of the large Nf QCD is performed using the hidden local symmetry Lagrangian. Combined with the Wilsonian matching proposed recently, the VM determines the critical number of massless flavors Nf \simeq 5 without much ambiguity.
[ { "created": "Wed, 18 Oct 2000 13:43:19 GMT", "version": "v1" }, { "created": "Tue, 24 Oct 2000 11:35:18 GMT", "version": "v2" }, { "created": "Tue, 28 Nov 2000 06:37:11 GMT", "version": "v3" } ]
2009-10-31
[ [ "Harada", "Masayasu", "" ], [ "Yamawaki", "Koichi", "" ] ]
We propose ``vector manifestation (VM)'' of the Wigner realization of the chiral symmetry in which the symmetry is restored at the critical point by the massless degenerate pion (and its flavor partners) and rho meson (and its flavor partners) as the chiral partner, in sharp contrast to the traditional manifestation \'a la linear sigma model where the symmetry is restored by the degenerate pion and scalar meson. The application to the chiral phase transition of the large Nf QCD is performed using the hidden local symmetry Lagrangian. Combined with the Wilsonian matching proposed recently, the VM determines the critical number of massless flavors Nf \simeq 5 without much ambiguity.
hep-ph/0109221
Daniel Boer
Daniel Boer (Vrije U., Amsterdam)
Theoretical aspects of transversity observables
4 pages, uses espcrc2.sty, Talk presented at the "International Workshop on the Spin Structure of the Proton and Polarized Collider Physics", ECT*, Trento, Italy, July 23-28, 2001
Nucl.Phys.Proc.Suppl. 105 (2002) 76-79
10.1016/S0920-5632(01)01955-7
VUTH 01-19
hep-ph
null
Theoretical aspects of transversity observables are reviewed. The main focus is on two leading twist transversity single spin asymmetries, one arising from the Collins effect and one from the interference fragmentation functions. Electron-positron annihilation experiments which are required to obtain these fragmentation functions are discussed, as well as the issues of factorization, evolution and Sudakov factors for the relevant observables. These theoretical considerations pinpoint the most realistic scenarios towards measurements of transversity.
[ { "created": "Mon, 24 Sep 2001 17:19:17 GMT", "version": "v1" } ]
2009-11-07
[ [ "Boer", "Daniel", "", "Vrije U., Amsterdam" ] ]
Theoretical aspects of transversity observables are reviewed. The main focus is on two leading twist transversity single spin asymmetries, one arising from the Collins effect and one from the interference fragmentation functions. Electron-positron annihilation experiments which are required to obtain these fragmentation functions are discussed, as well as the issues of factorization, evolution and Sudakov factors for the relevant observables. These theoretical considerations pinpoint the most realistic scenarios towards measurements of transversity.
1507.05657
Herm\`es B\'elusca-Ma\"ito
Hermes Belusca-Maito (Laboratoire de Physique Th\'eorique, Universit\'e Paris-Sud XI, Orsay, France)
Higgs Couplings in an Effective Theory Framework
4 pages, 3 figures. Proceedings of the 2014 Journ\'ees des Jeunes Chercheurs (JJC 2014), 7-13 December 2014, Le Lazaret, S\`ete, France (http://jjc2014.sciencesconf.org/). Based on arXiv:1404.5343 by the same author
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The study of the properties of the scalar boson recently discovered at the LHC (ATLAS and CMS experiments) may allow us to know whether it is well described by the Standard Model. In the case where deviations from SM predictions are present, this would be an evidence for the presence of new physics. We focus on the study of the Higgs couplings to matter in a model-independent approach by introducing a dimension-6 effective Lagrangian that includes both CP-even and CP-odd effective couplings. Constraints are set on some of these coefficients using experimental data from ATLAS and CMS as well as electroweak precision measurements from LEP, SLC and Tevatron. These data meaningfully constrain CP-even and some CP-odd couplings.
[ { "created": "Mon, 20 Jul 2015 21:11:28 GMT", "version": "v1" } ]
2015-07-22
[ [ "Belusca-Maito", "Hermes", "", "Laboratoire de Physique Théorique,\n Université Paris-Sud XI, Orsay, France" ] ]
The study of the properties of the scalar boson recently discovered at the LHC (ATLAS and CMS experiments) may allow us to know whether it is well described by the Standard Model. In the case where deviations from SM predictions are present, this would be an evidence for the presence of new physics. We focus on the study of the Higgs couplings to matter in a model-independent approach by introducing a dimension-6 effective Lagrangian that includes both CP-even and CP-odd effective couplings. Constraints are set on some of these coefficients using experimental data from ATLAS and CMS as well as electroweak precision measurements from LEP, SLC and Tevatron. These data meaningfully constrain CP-even and some CP-odd couplings.
hep-ph/9811235
Kingman Cheung
David Bowser-Chao, Kingman Cheung, and Wai-Yee Keung
Phase Effect of A General Two-Higgs-Doublet Model in $b\to s\gamma$
LaTeX 17 pages, 3 figures
Phys.Rev.D59:115006,1999
10.1103/PhysRevD.59.115006
UIC-HEP/97-4, UCD-HEP-98-30, UTEXAS-HEP-97-7
hep-ph
null
In a general two-Higgs-doublet model (2HDM), without the {\it ad hoc} discrete symmetries to prevent tree-level flavor-changing-neutral currents, an extra phase angle in the charged-Higgs-fermion coupling is allowed. We show that the charged-Higgs amplitude interferes destructively or constructively with the standard model amplitude depending crucially on this phase angle. The popular model I and II are special cases of our analysis. As a result of this phase angle the severe constraint on the charged-Higgs boson mass imposed by the inclusive rate of $b\to s\gamma$ from CLEO can be relaxed. We also examine the effects of this phase angle on the neutron electric dipole moment. Furthermore, we also discuss other constraints on the charged-Higgs-fermion couplings coming from measurements of $B^0-\bar{B^0}$ mixing, $\rho_0$, and $R_b$.
[ { "created": "Tue, 3 Nov 1998 19:39:45 GMT", "version": "v1" } ]
2009-09-01
[ [ "Bowser-Chao", "David", "" ], [ "Cheung", "Kingman", "" ], [ "Keung", "Wai-Yee", "" ] ]
In a general two-Higgs-doublet model (2HDM), without the {\it ad hoc} discrete symmetries to prevent tree-level flavor-changing-neutral currents, an extra phase angle in the charged-Higgs-fermion coupling is allowed. We show that the charged-Higgs amplitude interferes destructively or constructively with the standard model amplitude depending crucially on this phase angle. The popular model I and II are special cases of our analysis. As a result of this phase angle the severe constraint on the charged-Higgs boson mass imposed by the inclusive rate of $b\to s\gamma$ from CLEO can be relaxed. We also examine the effects of this phase angle on the neutron electric dipole moment. Furthermore, we also discuss other constraints on the charged-Higgs-fermion couplings coming from measurements of $B^0-\bar{B^0}$ mixing, $\rho_0$, and $R_b$.
2305.19854
Anatolii Egorov
Anatolii Iu. Egorov and Victor T. Kim
Next-to-leading BFKL evolution for dijets with large rapidity separation at different LHC energies
8 pages, 5 figures
Phys. Rev. D 108, 014010 (2023)
10.1103/PhysRevD.108.014010
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The calculations based on the next-to-leading logarithm (NLL) approximation for the Balitsky-Fadin-Kuraev-Lipatov (BKFL) evolution are presented for the Mueller-Navelet (MN) dijet production cross section, as well as for their ratios at different collision energies. The MN dijet denotes the jet pair consists of jets, which were selected with $p_{\perp} > p_{\perp\min}$ and with maximal rapidity separation in the event. The NLL BFKL predictions for the MN cross sections are given for the $pp$ collisions at $\sqrt{s}=2.76$, $8$, and $13$ TeV, for $p_{\perp\min} = 20$ and $35$ GeV. The results are in agreement with the measurement by the CMS experiment in $pp$ collisions at $\sqrt{s}=2.76$ TeV and $p_{\perp\min} = 35$ GeV within the theoretical and experimental uncertainties. The predictions of the NLL BFKL calculation of ratios of the MN cross sections at different collision energies and $p_{\perp\min}$ are also presented.
[ { "created": "Wed, 31 May 2023 13:42:54 GMT", "version": "v1" }, { "created": "Thu, 1 Jun 2023 13:33:12 GMT", "version": "v2" }, { "created": "Thu, 13 Jul 2023 08:34:33 GMT", "version": "v3" } ]
2023-07-14
[ [ "Egorov", "Anatolii Iu.", "" ], [ "Kim", "Victor T.", "" ] ]
The calculations based on the next-to-leading logarithm (NLL) approximation for the Balitsky-Fadin-Kuraev-Lipatov (BKFL) evolution are presented for the Mueller-Navelet (MN) dijet production cross section, as well as for their ratios at different collision energies. The MN dijet denotes the jet pair consists of jets, which were selected with $p_{\perp} > p_{\perp\min}$ and with maximal rapidity separation in the event. The NLL BFKL predictions for the MN cross sections are given for the $pp$ collisions at $\sqrt{s}=2.76$, $8$, and $13$ TeV, for $p_{\perp\min} = 20$ and $35$ GeV. The results are in agreement with the measurement by the CMS experiment in $pp$ collisions at $\sqrt{s}=2.76$ TeV and $p_{\perp\min} = 35$ GeV within the theoretical and experimental uncertainties. The predictions of the NLL BFKL calculation of ratios of the MN cross sections at different collision energies and $p_{\perp\min}$ are also presented.
0808.2055
Anzhong Wang
Anzhong Wang and N.O. Santos
The hierarchy problem, radion mass, localization of gravity and 4D effective Newtonian potential in string theory on $S^{1}/Z_{2}$
Considerably extended, Revtex4, 19 pages, 5 figures, published in IJMPA, 25, 1661-1698 (2010)
null
10.1142/S0217751X10047890
null
hep-ph astro-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a systematical study of brane worlds in string theory on $S^{1}/Z_{2}$. Starting with the toroidal compactification of the NS/NS sector in (D+d) dimensions, we first obtain an effective $D$-dimensional action, and then compactify one of the $(D-1)$ spatial dimensions by introducing two orbifold branes as its boundaries. By combining the Gauss-Codacci and Lanczos equations, we write down explicitly the general gravitational field equations on each of the two branes, while using distribution theory we express the matter field equations on the branes in terms of the discontinuities of the first derivatives of the matter fields. Afterwards, we address three important issues: (i) the hierarchy problem; (ii) the radion mass; and (iii) the localization of gravity, the 4-dimensional Newtonian effective potential and the Yukawa corrections due to the gravitational high-order Kaluza-Klein (KK) modes. With a very conservative estimation, we find that the radion mass is of the order of $10^{-2} GeV$. The gravity is localized on the visible brane, and the spectrum of the gravitational KK modes is discrete and can be of the order of TeV. The corrections to the 4-dimensional Newtonian potential from the higher order of gravitational KK modes are exponentially suppressed and can be safely neglected in current experiments. In an appendix, we also present a systematical and pedagogical study of the Gauss-Codacci equations and Israel's junction conditions across a (D-1)-dimensional hypersurface, which can be either spacelike or timelike.
[ { "created": "Thu, 14 Aug 2008 20:01:13 GMT", "version": "v1" }, { "created": "Fri, 10 Jul 2009 19:02:51 GMT", "version": "v2" }, { "created": "Sun, 18 Jul 2010 16:12:45 GMT", "version": "v3" } ]
2015-05-13
[ [ "Wang", "Anzhong", "" ], [ "Santos", "N. O.", "" ] ]
We present a systematical study of brane worlds in string theory on $S^{1}/Z_{2}$. Starting with the toroidal compactification of the NS/NS sector in (D+d) dimensions, we first obtain an effective $D$-dimensional action, and then compactify one of the $(D-1)$ spatial dimensions by introducing two orbifold branes as its boundaries. By combining the Gauss-Codacci and Lanczos equations, we write down explicitly the general gravitational field equations on each of the two branes, while using distribution theory we express the matter field equations on the branes in terms of the discontinuities of the first derivatives of the matter fields. Afterwards, we address three important issues: (i) the hierarchy problem; (ii) the radion mass; and (iii) the localization of gravity, the 4-dimensional Newtonian effective potential and the Yukawa corrections due to the gravitational high-order Kaluza-Klein (KK) modes. With a very conservative estimation, we find that the radion mass is of the order of $10^{-2} GeV$. The gravity is localized on the visible brane, and the spectrum of the gravitational KK modes is discrete and can be of the order of TeV. The corrections to the 4-dimensional Newtonian potential from the higher order of gravitational KK modes are exponentially suppressed and can be safely neglected in current experiments. In an appendix, we also present a systematical and pedagogical study of the Gauss-Codacci equations and Israel's junction conditions across a (D-1)-dimensional hypersurface, which can be either spacelike or timelike.
0806.1254
Jun-Feng Sun
Junfeng Sun, Yueling Yang, Wenjie Du, Huilan Ma
Study of Bc -> BP,BV Decays with QCD Factorization
revtex4; Published Fri Jun 6, 2008
Phys.Rev.D77:114004,2008
10.1103/PhysRevD.77.114004
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The Bc -> BP,BV decays are studied with the QCD factorization approach (where P and V denote pseudoscalar and vector mesons, respectively). Considering the contributions of both current-current and penguin operators, the amplitudes of branching ratios are estimated at the leading approximation. We find that the contributions of the penguin operators are very small due to the serious suppression by the CKM elements. The most promising decay modes are Bc -> Bs Pi, Bs rho, which might be easily detected at hadron colliders.
[ { "created": "Sat, 7 Jun 2008 01:42:46 GMT", "version": "v1" } ]
2008-11-26
[ [ "Sun", "Junfeng", "" ], [ "Yang", "Yueling", "" ], [ "Du", "Wenjie", "" ], [ "Ma", "Huilan", "" ] ]
The Bc -> BP,BV decays are studied with the QCD factorization approach (where P and V denote pseudoscalar and vector mesons, respectively). Considering the contributions of both current-current and penguin operators, the amplitudes of branching ratios are estimated at the leading approximation. We find that the contributions of the penguin operators are very small due to the serious suppression by the CKM elements. The most promising decay modes are Bc -> Bs Pi, Bs rho, which might be easily detected at hadron colliders.
1405.7651
Dorival Goncalves
Malte Buschmann, Christoph Englert, Dorival Goncalves, Tilman Plehn, Michael Spannowsky
Resolving the Higgs-Gluon Coupling with Jets
12 pages, 9 figures, 2 tables
Phys. Rev. D 90, 013010 (2014)
10.1103/PhysRevD.90.013010
IPPP/14/50, DCPT/14/100
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Standard Model the Higgs coupling to gluons is almost entirely induced by top quark loops. We derive the logarithmic structure of Higgs production in association with two jets. Just like in the one-jet case the transverse momentum distributions exhibit logarithms of the top quark mass and can be used to test the nature of the loop-induced Higgs coupling to gluons. Using Higgs decays to W bosons and to tau leptons we show how the corresponding analyses hugely benefit from the second jet in the relevant signal rate as well as in the background rejection.
[ { "created": "Thu, 29 May 2014 18:47:26 GMT", "version": "v1" } ]
2014-07-16
[ [ "Buschmann", "Malte", "" ], [ "Englert", "Christoph", "" ], [ "Goncalves", "Dorival", "" ], [ "Plehn", "Tilman", "" ], [ "Spannowsky", "Michael", "" ] ]
In the Standard Model the Higgs coupling to gluons is almost entirely induced by top quark loops. We derive the logarithmic structure of Higgs production in association with two jets. Just like in the one-jet case the transverse momentum distributions exhibit logarithms of the top quark mass and can be used to test the nature of the loop-induced Higgs coupling to gluons. Using Higgs decays to W bosons and to tau leptons we show how the corresponding analyses hugely benefit from the second jet in the relevant signal rate as well as in the background rejection.
2408.01138
Amit Chakraborty
Camellia Bose, Amit Chakraborty, Shreecheta Chowdhury, and Saunak Dutta
Interplay of Traditional Methods and Machine Learning Algorithms for Tagging Boosted Objects
35 pages, 13 figures, 1 table; Invited Review article, published in EPJ Special Topics
null
10.1140/epjs/s11734-024-01256-6
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Interest in deep learning in collider physics has been growing in recent years, specifically in applying these methods in jet classification, anomaly detection, particle identification etc. Among those, jet classification using neural networks is one of the well-established areas. In this review, we discuss different tagging frameworks available to tag boosted objects, especially boosted Higgs boson and top quark, at the Large Hadron Collider (LHC). Our aim is to study the interplay of traditional jet substructure based methods with the state-of-the-art machine learning ones. In this methodology, we would gain some interpretability of those machine learning methods, and which in turn helps to propose hybrid taggers relevant for tagging of those boosted objects belonging to both Standard Model (SM) and physics beyond the SM.
[ { "created": "Fri, 2 Aug 2024 09:31:28 GMT", "version": "v1" } ]
2024-08-05
[ [ "Bose", "Camellia", "" ], [ "Chakraborty", "Amit", "" ], [ "Chowdhury", "Shreecheta", "" ], [ "Dutta", "Saunak", "" ] ]
Interest in deep learning in collider physics has been growing in recent years, specifically in applying these methods in jet classification, anomaly detection, particle identification etc. Among those, jet classification using neural networks is one of the well-established areas. In this review, we discuss different tagging frameworks available to tag boosted objects, especially boosted Higgs boson and top quark, at the Large Hadron Collider (LHC). Our aim is to study the interplay of traditional jet substructure based methods with the state-of-the-art machine learning ones. In this methodology, we would gain some interpretability of those machine learning methods, and which in turn helps to propose hybrid taggers relevant for tagging of those boosted objects belonging to both Standard Model (SM) and physics beyond the SM.
1807.05683
Gauhar Abbas
Gauhar Abbas
A new solution of the fermionic mass hierarchy of the standard model
12 pages, 1 figures, neutrino masses, mixing and flavour bounds are derived. To be published in Int.J.Mod.Phys.A
Int.J.Mod.Phys.A Vol. 36 (2021) 2150090
10.1142/S0217751X21500901
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new mechanism for solving the fermionic masses and mixing hierarchies of the standard model through a minimal symmetry $\mathcal{Z}_2 \times \mathcal{Z}_5$. The mechanism is also capable of explaining the neutrino masses and mixing parameters. The phenomenological bounds arising from kaon mixing are also derived on the parameter space of the model.
[ { "created": "Mon, 16 Jul 2018 05:20:04 GMT", "version": "v1" }, { "created": "Thu, 6 Sep 2018 16:53:06 GMT", "version": "v2" }, { "created": "Mon, 1 Oct 2018 07:01:22 GMT", "version": "v3" }, { "created": "Wed, 3 Apr 2019 10:18:44 GMT", "version": "v4" }, { "crea...
2021-08-03
[ [ "Abbas", "Gauhar", "" ] ]
We present a new mechanism for solving the fermionic masses and mixing hierarchies of the standard model through a minimal symmetry $\mathcal{Z}_2 \times \mathcal{Z}_5$. The mechanism is also capable of explaining the neutrino masses and mixing parameters. The phenomenological bounds arising from kaon mixing are also derived on the parameter space of the model.
1502.05712
Philipp Grothaus
Philipp Grothaus, Seng Pei Liew and Kazuki Sakurai
A closer look at a hint of SUSY at the 8 TeV LHC
v2: 20 pages, 10 figures, corrections in one sbottom model, more models investigated and extended results section, references added
null
null
KCL-PH-TH/2015-07, LCTS/2015-03, UT-15-06
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recent CMS analysis has reported the observation of an excess in the invariant mass distribution of the opposite-sign same-flavour lepton pair, which can be interpreted as a kinematic edge due to new physics. Using collider simulation tools, we recast relevant LHC search results reported by ATLAS and CMS collaborations in order to determine constraints on supersymmetric models that could produce the observed features. In particular, we focus on models involving cascade decays of light-flavour squarks and sbottoms. We find no favourable supersymmetry scenario within our exploration that could explain the origin of the excess when other LHC constraints are taken into account.
[ { "created": "Thu, 19 Feb 2015 21:00:12 GMT", "version": "v1" }, { "created": "Fri, 20 Mar 2015 15:25:11 GMT", "version": "v2" } ]
2015-03-23
[ [ "Grothaus", "Philipp", "" ], [ "Liew", "Seng Pei", "" ], [ "Sakurai", "Kazuki", "" ] ]
A recent CMS analysis has reported the observation of an excess in the invariant mass distribution of the opposite-sign same-flavour lepton pair, which can be interpreted as a kinematic edge due to new physics. Using collider simulation tools, we recast relevant LHC search results reported by ATLAS and CMS collaborations in order to determine constraints on supersymmetric models that could produce the observed features. In particular, we focus on models involving cascade decays of light-flavour squarks and sbottoms. We find no favourable supersymmetry scenario within our exploration that could explain the origin of the excess when other LHC constraints are taken into account.
hep-ph/9601207
Rolf Dahm
Rolf Dahm (Institute of Nuclear Physics, University Mainz, Germany)
Relativistic SU(4) and Quaternions
20 pages, LaTeX2e. Talk given at the `International Conference on the Theory of the Electron' 1995, Cuautitlan, Mexico. To appear in the proceedings, eds. J. Keller, Z. Oziewicz. (Files kapproc.cls (Kluwer) + 1 postscript figure included, selfextracting during first run with LaTeX2e)
Advances in Applied Clifford Algebras 7(S) 1996 337-356
null
null
hep-ph hep-th nucl-th
null
A classification of hadrons and their interactions at low energies according to SU(4) allows to identify combinations of the fifteen mesons $\pi$, $\omega$ and $\rho$ within the spin-isospin decomposition of the regular representation \rhdmulti{15}. Chirally symmetric SU(2)$\times$SU(2) hadron interactions are then associated with transformations of a subgroup of SU(4). Nucleon and Delta resonance states are represented by a symmetric third rank tensor \rhdmulti{20} whose spin-isospin decomposition leads to $4\oplus 16$ `tower states' also known from the large-N$_c$ limit of QCD. Towards a relativistic hadron theory, we consider possible generalizations of the stereographic projection {\bf S}$^{2}$ $\to$ {\bf C} and the related complex spinorial calculus {\it on the basis of the division algebras with unit element}. Such a geometrical framework leads directly to transformations in a quaternionic projective `plane' and the related symmetry group SL(2,{\bf H}). In exploiting the Lie algebra isomorphism sl(2,{\bf H}) $\cong$ su$*$(4) $\cong$ so(5,1), we focus on the Lie algebra su$*$(4) to construct quaternionic Dirac-like spinors, the associated Clifford algebra and the relation to SU(4) by Weyl's unitary trick. The algebra so(5,1) contains the de Sitter-algebra so(4,1) which can be contracted to the algebra of the Poincar\'e group.
[ { "created": "Wed, 3 Jan 1996 17:35:10 GMT", "version": "v1" } ]
2013-06-13
[ [ "Dahm", "Rolf", "", "Institute of Nuclear Physics, University Mainz, Germany" ] ]
A classification of hadrons and their interactions at low energies according to SU(4) allows to identify combinations of the fifteen mesons $\pi$, $\omega$ and $\rho$ within the spin-isospin decomposition of the regular representation \rhdmulti{15}. Chirally symmetric SU(2)$\times$SU(2) hadron interactions are then associated with transformations of a subgroup of SU(4). Nucleon and Delta resonance states are represented by a symmetric third rank tensor \rhdmulti{20} whose spin-isospin decomposition leads to $4\oplus 16$ `tower states' also known from the large-N$_c$ limit of QCD. Towards a relativistic hadron theory, we consider possible generalizations of the stereographic projection {\bf S}$^{2}$ $\to$ {\bf C} and the related complex spinorial calculus {\it on the basis of the division algebras with unit element}. Such a geometrical framework leads directly to transformations in a quaternionic projective `plane' and the related symmetry group SL(2,{\bf H}). In exploiting the Lie algebra isomorphism sl(2,{\bf H}) $\cong$ su$*$(4) $\cong$ so(5,1), we focus on the Lie algebra su$*$(4) to construct quaternionic Dirac-like spinors, the associated Clifford algebra and the relation to SU(4) by Weyl's unitary trick. The algebra so(5,1) contains the de Sitter-algebra so(4,1) which can be contracted to the algebra of the Poincar\'e group.