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0912.0972
Jernej Kamenik
Ilja Dorsner, Svjetlana Fajfer, Jernej F. Kamenik and Nejc Kosnik
Light colored scalars from grand unification and the forward-backward asymmetry in top quark pair production
12 pages, 13 figures, version as published
Phys.Rev.D81:055009,2010
10.1103/PhysRevD.81.055009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The experimental results on the t bar t production cross section at the Tevatron are well described by the QCD contributions within the standard model, while the recent measurement of the forward-backward asymmetry cannot be accounted for within this framework. We consider light colored scalars appearing in a particular SU(5) GUT model within the 45-dimensional Higgs representation. A virtue of the model is that it connects the presence of a light colored SU(2) singlet (Delta_6) and a color octet weak doublet (Delta_1) with bounds on the proton lifetime, which constrain the parameter space of both scalars. We find that both the t bar t production cross section and the forward-backward asymmetry can be accommodated simultaneously within this model. The experimental results prefer a region for the mass of Delta_6 around 400 GeV, while Delta_1 is then constrained to have a mass around the TeV scale as well. We analyze possible experimental signatures and find that Delta_6 associated top production could be probed in the t bar t + jets final states at Tevatron and the LHC.
[ { "created": "Mon, 7 Dec 2009 17:59:07 GMT", "version": "v1" }, { "created": "Thu, 17 Jun 2010 07:49:22 GMT", "version": "v2" } ]
2010-06-18
[ [ "Dorsner", "Ilja", "" ], [ "Fajfer", "Svjetlana", "" ], [ "Kamenik", "Jernej F.", "" ], [ "Kosnik", "Nejc", "" ] ]
The experimental results on the t bar t production cross section at the Tevatron are well described by the QCD contributions within the standard model, while the recent measurement of the forward-backward asymmetry cannot be accounted for within this framework. We consider light colored scalars appearing in a particular SU(5) GUT model within the 45-dimensional Higgs representation. A virtue of the model is that it connects the presence of a light colored SU(2) singlet (Delta_6) and a color octet weak doublet (Delta_1) with bounds on the proton lifetime, which constrain the parameter space of both scalars. We find that both the t bar t production cross section and the forward-backward asymmetry can be accommodated simultaneously within this model. The experimental results prefer a region for the mass of Delta_6 around 400 GeV, while Delta_1 is then constrained to have a mass around the TeV scale as well. We analyze possible experimental signatures and find that Delta_6 associated top production could be probed in the t bar t + jets final states at Tevatron and the LHC.
hep-ph/0311026
Yasunori Fujii
Yasunori Fujii
Oklo Constraint on the Time-Variability of the Fine-Structure Constant
19 pages, 2 jpg and 10 eps figures, delivered at Astrophysics, Clocks and Fundamental Constants, 16-18 June 2003, Bad Honnef, Germany, to be published in Lecture Notes in Physics, Springer. v2 revises jpg files, adds 2 footnotes and 2 references
null
10.1007/b13178
null
hep-ph
null
The Oklo phenomenon, natural fission reactors which had taken place in Gabon about 2 billion years ago, provides one of the most stringent constraints on the possible time-variability of the fine-structure constant $\alpha$. We first review briefly what it is and how reliable it is in constraining $\alpha$. We then compare the result with a more recent result on the nonzero change of $\alpha$ obtained from the observation of the QSO absorption lines. We suggest a possible way to make these results consistent with each other in terms of the behavior of a scalar field which is expected to be responsible for the acceleration of the universe.
[ { "created": "Mon, 3 Nov 2003 15:20:49 GMT", "version": "v1" }, { "created": "Mon, 17 Nov 2003 02:04:28 GMT", "version": "v2" } ]
2017-08-23
[ [ "Fujii", "Yasunori", "" ] ]
The Oklo phenomenon, natural fission reactors which had taken place in Gabon about 2 billion years ago, provides one of the most stringent constraints on the possible time-variability of the fine-structure constant $\alpha$. We first review briefly what it is and how reliable it is in constraining $\alpha$. We then compare the result with a more recent result on the nonzero change of $\alpha$ obtained from the observation of the QSO absorption lines. We suggest a possible way to make these results consistent with each other in terms of the behavior of a scalar field which is expected to be responsible for the acceleration of the universe.
1906.09742
Mohamed Abu-Shady
M. Abu-Shady and A. N. Ikot
Dissociation of Nucleon and Heavy-Baryon in an Anisotropic Hot and Dense QCD Media Using Nikiforov-Uvarov Method
24 pages, 11 figures, 2 Tables
null
null
null
hep-ph nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
By using the Nikiforov-Uvarov method, the hyper-radial Schrodinger equation is analytically solved, in which the real modified potential is employed at finite temperature and baryon chemical potential. The eigenvalue of energy and corresponding wave function are obtained in the isotropic and anisotropic media in hot and dense media. The present results show that the binding energy of nucleon and some heavy baryon decrease strongly in hot medium and decreases slightly with increasing baryon chemical potential. In addition, binding energy for each baryon is more bound in an anisotropic medium in comparison with its value in an isotropic medium. The dissociation of temperature of each baryon is above a critical temperature and it increases in the anisotropic medium. The dissociation of temperature is slightly decreased in the hot medium when the baryon of chemical potential is considered. A comparison is studied with the available studies. We conclude that the present study provides a good description of the nucleon and some heavy baryon in hot and dense media in the isotropic and anisotropic systems.
[ { "created": "Mon, 24 Jun 2019 06:48:29 GMT", "version": "v1" }, { "created": "Sun, 3 Nov 2019 09:02:01 GMT", "version": "v2" } ]
2019-11-05
[ [ "Abu-Shady", "M.", "" ], [ "Ikot", "A. N.", "" ] ]
By using the Nikiforov-Uvarov method, the hyper-radial Schrodinger equation is analytically solved, in which the real modified potential is employed at finite temperature and baryon chemical potential. The eigenvalue of energy and corresponding wave function are obtained in the isotropic and anisotropic media in hot and dense media. The present results show that the binding energy of nucleon and some heavy baryon decrease strongly in hot medium and decreases slightly with increasing baryon chemical potential. In addition, binding energy for each baryon is more bound in an anisotropic medium in comparison with its value in an isotropic medium. The dissociation of temperature of each baryon is above a critical temperature and it increases in the anisotropic medium. The dissociation of temperature is slightly decreased in the hot medium when the baryon of chemical potential is considered. A comparison is studied with the available studies. We conclude that the present study provides a good description of the nucleon and some heavy baryon in hot and dense media in the isotropic and anisotropic systems.
1412.5147
Tigran Kalaydzhyan
Tigran Kalaydzhyan and Edward Shuryak
Gravity waves generated by sounds from big bang phase transitions
13 pages. Published version
Phys. Rev. D 91, 083502 (2015)
10.1103/PhysRevD.91.083502
null
hep-ph astro-ph.CO hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inhomogeneities associated with the cosmological QCD and electroweak phase transitions produce hydrodynamical perturbations, longitudinal sounds and rotations. It has been demonstrated by Hindmarsh et al. that the sounds produce gravity waves (GW) well after the phase transition is over. We further argue that, under certain conditions, an inverse acoustic cascade may occur and move sound perturbations from the (UV) momentum scale at which the sound is originally produced to much smaller (IR) momenta. The weak turbulence regime of this cascade is studied via the Boltzmann equation, possessing stationary power and time-dependent self-similar solutions. We suggest certain indices for the strong turbulence regime as well, into which the cascade eventually proceeds. Finally, we point out that two on-shell sound waves can produce one on-shell gravity wave, and we evaluate the rate of the process using a standard sound loop diagram.
[ { "created": "Tue, 16 Dec 2014 20:10:18 GMT", "version": "v1" }, { "created": "Wed, 14 Jan 2015 22:00:46 GMT", "version": "v2" }, { "created": "Fri, 3 Apr 2015 22:27:44 GMT", "version": "v3" } ]
2015-04-08
[ [ "Kalaydzhyan", "Tigran", "" ], [ "Shuryak", "Edward", "" ] ]
Inhomogeneities associated with the cosmological QCD and electroweak phase transitions produce hydrodynamical perturbations, longitudinal sounds and rotations. It has been demonstrated by Hindmarsh et al. that the sounds produce gravity waves (GW) well after the phase transition is over. We further argue that, under certain conditions, an inverse acoustic cascade may occur and move sound perturbations from the (UV) momentum scale at which the sound is originally produced to much smaller (IR) momenta. The weak turbulence regime of this cascade is studied via the Boltzmann equation, possessing stationary power and time-dependent self-similar solutions. We suggest certain indices for the strong turbulence regime as well, into which the cascade eventually proceeds. Finally, we point out that two on-shell sound waves can produce one on-shell gravity wave, and we evaluate the rate of the process using a standard sound loop diagram.
hep-ph/0405264
Mikhail Dubinin
E. Akhmetzyanova (1), M. Dolgopolov (1), M. Dubinin (2) ((1) Samara State Univ., (2) Inst.of Nucl.Phys., Moscow State Univ.)
Higgs Bosons in the Two-Doublet Model with CP Violation
36 pages, 5 tables, 9 figures. References added, minor changes in the text, misprint in the g_{hH^+H^-}, page 22, corrected, 'direct' diagonalization procedure described in section 3.1
Phys.Rev.D71:075008,2005
10.1103/PhysRevD.71.075008
null
hep-ph
null
We consider the effective two-Higgs-doublet potential with complex parameters, when the CP invariance is broken both explicitly and spontaneously. Diagonal mass term in the local minimum of the potential is constructed for the physical basis of Higgs fields, keeping explicitly the limiting case of CP-conservation if the parameters are taken real. For special case of the two-doublet Higgs sector of the minimal supersymmetric model, when CP invariance is violated by the Higgs bosons interaction with scalar quarks of the third generation, we calculate by means of the effective pothential method the Higgs boson masses and evaluate the two-fermion Higgs boson decay widths and the widths of rare one-loop mediated decays H -> \gamma \gamma, H -> gg.
[ { "created": "Wed, 26 May 2004 15:23:43 GMT", "version": "v1" }, { "created": "Wed, 6 Oct 2004 20:53:39 GMT", "version": "v2" } ]
2011-07-19
[ [ "Akhmetzyanova", "E.", "" ], [ "Dolgopolov", "M.", "" ], [ "Dubinin", "M.", "" ] ]
We consider the effective two-Higgs-doublet potential with complex parameters, when the CP invariance is broken both explicitly and spontaneously. Diagonal mass term in the local minimum of the potential is constructed for the physical basis of Higgs fields, keeping explicitly the limiting case of CP-conservation if the parameters are taken real. For special case of the two-doublet Higgs sector of the minimal supersymmetric model, when CP invariance is violated by the Higgs bosons interaction with scalar quarks of the third generation, we calculate by means of the effective pothential method the Higgs boson masses and evaluate the two-fermion Higgs boson decay widths and the widths of rare one-loop mediated decays H -> \gamma \gamma, H -> gg.
2207.09355
Johannes Braathen
Henning Bahl, Johannes Braathen, Georg Weiglein
External-leg corrections as an origin of large logarithms
8 pages, 2 figures. Contribution to the proceedings of the conference "Loops and Legs in Quantum Field Theory - LL2022," 25-30 April, 2022, Ettal, Germany
null
null
DESY-22-114
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Obtaining precise theoretical predictions for both production and decay processes of heavy new particles is of great importance to constrain the allowed parameter spaces of Beyond-the-Standard-Model (BSM) theories, and to properly assess the sensitivity for discoveries and for discriminating between different possible BSM scenarios. In this context, it is well known that large logarithmic corrections can appear in the presence of widely separated mass scales. We point out the existence of a new type of possible large, Sudakov-like, logarithms in external-leg corrections of heavy scalars. To the difference of usual Sudakov logarithms, these can furthermore potentially be enhanced by large trilinear couplings. Such large logarithms are associated with infrared singularities and we review several techniques to address these at one loop. In addition to this discussion, we also present the derivation of the two-loop corrections containing this type of large logarithms, pointing out in this context the importance of adopting an on-shell renormalisation scheme. Finally, we illustrate our calculations and examine the possible magnitude of these corrections for a simple scalar toy model as well as for decay processes involving heavy stop quarks in the Minimal Supersymmetric Standard Model and a heavy Higgs boson in the Next-to-Two-Higgs-Doublet Model.
[ { "created": "Tue, 19 Jul 2022 16:02:03 GMT", "version": "v1" } ]
2022-07-20
[ [ "Bahl", "Henning", "" ], [ "Braathen", "Johannes", "" ], [ "Weiglein", "Georg", "" ] ]
Obtaining precise theoretical predictions for both production and decay processes of heavy new particles is of great importance to constrain the allowed parameter spaces of Beyond-the-Standard-Model (BSM) theories, and to properly assess the sensitivity for discoveries and for discriminating between different possible BSM scenarios. In this context, it is well known that large logarithmic corrections can appear in the presence of widely separated mass scales. We point out the existence of a new type of possible large, Sudakov-like, logarithms in external-leg corrections of heavy scalars. To the difference of usual Sudakov logarithms, these can furthermore potentially be enhanced by large trilinear couplings. Such large logarithms are associated with infrared singularities and we review several techniques to address these at one loop. In addition to this discussion, we also present the derivation of the two-loop corrections containing this type of large logarithms, pointing out in this context the importance of adopting an on-shell renormalisation scheme. Finally, we illustrate our calculations and examine the possible magnitude of these corrections for a simple scalar toy model as well as for decay processes involving heavy stop quarks in the Minimal Supersymmetric Standard Model and a heavy Higgs boson in the Next-to-Two-Higgs-Doublet Model.
1206.0676
Fedor Pavlov
Fedor Pavlov
Relativistic Correction to the First Moment of the Spin-Dependent Structure Function of the Deuteron $\Gamma_1^D(Q^2)$ in the Light-Cone Formalism
34 pages, 6 figures, an extended version of the paper published in Journal of Experimental and Theoretical Physics, 2012
Journal of Experimental and Theoretical Physics, 2012, Vol. 114, No. 6, pp. 946-954
10.1134/S106377611206012X
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The deuteron is considered as a superposition of two-nucleon Fock states with the invariant mass depending on the relative momentum in a proton-neutron pair. The condition of the transversality of the polarization vectors should be imposed at the Fock component level and these vectors depend on the invariant mass of the Fock component. Such "running" longitudinal polarization vector was not used in early estimates of relativistic effects. The technique for the calculation of the average helicity of the proton in the deuteron has been considered in the light-cone variables. A receipt has been proposed for the consistent calculation of relativistic nuclear corrections to the average helicity of the proton in the deuteron and to the first moment of the spin-dependent structure function of the deuteron.
[ { "created": "Mon, 4 Jun 2012 16:47:48 GMT", "version": "v1" }, { "created": "Tue, 5 Jun 2012 12:44:17 GMT", "version": "v2" }, { "created": "Thu, 7 Jun 2012 11:16:57 GMT", "version": "v3" } ]
2015-06-05
[ [ "Pavlov", "Fedor", "" ] ]
The deuteron is considered as a superposition of two-nucleon Fock states with the invariant mass depending on the relative momentum in a proton-neutron pair. The condition of the transversality of the polarization vectors should be imposed at the Fock component level and these vectors depend on the invariant mass of the Fock component. Such "running" longitudinal polarization vector was not used in early estimates of relativistic effects. The technique for the calculation of the average helicity of the proton in the deuteron has been considered in the light-cone variables. A receipt has been proposed for the consistent calculation of relativistic nuclear corrections to the average helicity of the proton in the deuteron and to the first moment of the spin-dependent structure function of the deuteron.
1704.01867
Anirban Kundu
Swagata Ghosh, Rashidul Islam, and Anirban Kundu
Scattering unitarity with effective dimension-6 operators
19 pages, 3 figures. The section on results substantially extended. Final version accepted for publication
null
10.1088/1361-6471/aa9873
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effects of physics beyond the Standard Model may be parametrized by a set of higher-dimensional operators leading to an effective theory. The introduction of these operators makes the theory nonrenormalizable, and one may reasonably expect a violation of unitarity in $2\to 2$ scattering processes,depending on the values of the Wilson coefficients of the higher dimensional operators. Bounds on these coefficients may be obtained from demanding that there be no such unitarity violation below the scale of the effective theory. We show, at the lowest level, how the new operators affect the scattering amplitudes with longitudinal gauge bosons, scalars, and $t\bar{t}$ in the final state, and find that one may expect a violation of unitarity even at the LHC energies with small values of some of the new Wilson coefficients. For most of the others, such a violation needs large coefficients, indicating nonperturbative physics for the ultraviolet-complete theory, although a proper treatment necessitates the inclusion of even higher-dimensional operators. However, deviations from the Standard Model expectations may be observed with even smaller values for these coefficients. We find that $WW \to WW$, $WW\to ZZ$, and $ZZ\to hh$ scatterings are the best possible channels to probe unitarity violations.
[ { "created": "Thu, 6 Apr 2017 14:44:51 GMT", "version": "v1" }, { "created": "Mon, 6 Nov 2017 16:00:04 GMT", "version": "v2" } ]
2018-01-17
[ [ "Ghosh", "Swagata", "" ], [ "Islam", "Rashidul", "" ], [ "Kundu", "Anirban", "" ] ]
The effects of physics beyond the Standard Model may be parametrized by a set of higher-dimensional operators leading to an effective theory. The introduction of these operators makes the theory nonrenormalizable, and one may reasonably expect a violation of unitarity in $2\to 2$ scattering processes,depending on the values of the Wilson coefficients of the higher dimensional operators. Bounds on these coefficients may be obtained from demanding that there be no such unitarity violation below the scale of the effective theory. We show, at the lowest level, how the new operators affect the scattering amplitudes with longitudinal gauge bosons, scalars, and $t\bar{t}$ in the final state, and find that one may expect a violation of unitarity even at the LHC energies with small values of some of the new Wilson coefficients. For most of the others, such a violation needs large coefficients, indicating nonperturbative physics for the ultraviolet-complete theory, although a proper treatment necessitates the inclusion of even higher-dimensional operators. However, deviations from the Standard Model expectations may be observed with even smaller values for these coefficients. We find that $WW \to WW$, $WW\to ZZ$, and $ZZ\to hh$ scatterings are the best possible channels to probe unitarity violations.
hep-ph/9808283
Robin Stuart
Timo van Ritbergen and Robin G. Stuart
Complete 2-loop Quantum Electrodynamic Contributions to the Muon Lifetime in the Fermi Model
5 pages REVTeX. 2 figures. Uses axodraw.sty. References added, minor changes in text. To be published in Phys. Rev. Lett
Phys.Rev.Lett.82:488-491,1999
10.1103/PhysRevLett.82.488
UM-TH-98-15
hep-ph
null
The complete 2-loop quantum electrodynamic corrections to the muon lifetime are calculated in the Fermi theory. The exact result for the effects of virtual and real photons, virtual electrons, muons as well as e+e- pair creation is Delta Gamma_QED = Gamma_0(alpha/pi)^2[(156815/5184)-(1036/27)zeta(2)-(895/36)zeta(3) +(67/8)zeta(4)+53zeta(2)ln(2)] = Gamma_0(alpha/pi)^2(6.743) where Gamma_0 is the tree-level width. The theoretical error in the value of the Fermi coupling constant, G_F, is now rendered negligible compared to the experimental uncertainty coming from the measurement of the muon lifetime. The overall error in G_F is then roughly halved giving G_F = (1.16637 +/- 0.00001) x 10^(-5) GeV^(-2).
[ { "created": "Mon, 10 Aug 1998 17:57:35 GMT", "version": "v1" }, { "created": "Mon, 7 Dec 1998 09:54:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "van Ritbergen", "Timo", "" ], [ "Stuart", "Robin G.", "" ] ]
The complete 2-loop quantum electrodynamic corrections to the muon lifetime are calculated in the Fermi theory. The exact result for the effects of virtual and real photons, virtual electrons, muons as well as e+e- pair creation is Delta Gamma_QED = Gamma_0(alpha/pi)^2[(156815/5184)-(1036/27)zeta(2)-(895/36)zeta(3) +(67/8)zeta(4)+53zeta(2)ln(2)] = Gamma_0(alpha/pi)^2(6.743) where Gamma_0 is the tree-level width. The theoretical error in the value of the Fermi coupling constant, G_F, is now rendered negligible compared to the experimental uncertainty coming from the measurement of the muon lifetime. The overall error in G_F is then roughly halved giving G_F = (1.16637 +/- 0.00001) x 10^(-5) GeV^(-2).
hep-ph/9808261
Anjan Joshipura
Anjan S. Joshipura
Gravitationally violated U(1) symmetry and neutrino anomalies
12 pages, LATEX
Phys.Rev.D60:053002,1999
10.1103/PhysRevD.60.053002
PRL-TH-98/009
hep-ph
null
The current searches for neutrino oscillations seem to suggest an approximate $L_e-L_\m-L_{\tau}$ flavor symmetry. This symmetry implies a pair of degenerate neutrinos with mass $m_0$ and large leptonic mixing. We explore the possibility that gravitational interactions break this global symmetry. The Planck scale suppressed breaking of the $L_e-L_\m-L_{\tau}$ symmetry is shown to lead to the right amount of splitting among the degenerate neutrinos needed in order to solve the solar neutrino problem. The common mass $m_0$ of the pair can be identified with the atmospheric neutrino scale. A concrete model is proposed in which smallness of $m_0$ and hierarchy in the solar and atmospheric neutrino scales get linked to hierarchies in the weak, grand unification and the Planck scales.
[ { "created": "Fri, 7 Aug 1998 12:59:27 GMT", "version": "v1" } ]
2008-11-26
[ [ "Joshipura", "Anjan S.", "" ] ]
The current searches for neutrino oscillations seem to suggest an approximate $L_e-L_\m-L_{\tau}$ flavor symmetry. This symmetry implies a pair of degenerate neutrinos with mass $m_0$ and large leptonic mixing. We explore the possibility that gravitational interactions break this global symmetry. The Planck scale suppressed breaking of the $L_e-L_\m-L_{\tau}$ symmetry is shown to lead to the right amount of splitting among the degenerate neutrinos needed in order to solve the solar neutrino problem. The common mass $m_0$ of the pair can be identified with the atmospheric neutrino scale. A concrete model is proposed in which smallness of $m_0$ and hierarchy in the solar and atmospheric neutrino scales get linked to hierarchies in the weak, grand unification and the Planck scales.
1211.4471
Jan L\"ucker
Jan Luecker and Christian S. Fischer
The phase diagram of N_f=2 and N_f=2+1 QCD from quark and gluon propagators
5 pages, 3 figures. FAIRNESS 2012 proceedings
null
10.1088/1742-6596/426/1/012021
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we present results for the propagators and the phase diagram of QCD, obtained from a truncated set of Dyson-Schwinger equations at finite temperature T and quark chemical potential mu. We include back-coupling effects of the dressed quark and gluon propagators, which also allows us to study the influence of strange quarks. For the phase diagram we find a critical end-point at mu/T = 1.9 and coinciding chiral and deconfinement phase transitions.
[ { "created": "Mon, 19 Nov 2012 15:57:10 GMT", "version": "v1" } ]
2015-06-12
[ [ "Luecker", "Jan", "" ], [ "Fischer", "Christian S.", "" ] ]
In this talk we present results for the propagators and the phase diagram of QCD, obtained from a truncated set of Dyson-Schwinger equations at finite temperature T and quark chemical potential mu. We include back-coupling effects of the dressed quark and gluon propagators, which also allows us to study the influence of strange quarks. For the phase diagram we find a critical end-point at mu/T = 1.9 and coinciding chiral and deconfinement phase transitions.
hep-ph/0604225
Bohdan Grzadkowski
Bohdan Grzadkowski, Jose Wudka
5-Dimensional Difficulties of Gauge-Higgs Unifications
some wording modified
Phys.Rev.Lett.97:211602,2006
10.1103/PhysRevLett.97.211602
IFT-06-07, UCRHEP-T411
hep-ph hep-th
null
We consider 5 dimensional gauge theories where the 5th direction is compactified on the orbifold S^1/Z_2, and where the 5th components of the gauge bosons play the role of the Standard Model Higgs boson (gauge-Higgs unification). The gauge symmetry breaking is realized through the appropriate orbifold boundary conditions and through the Hosotani mechanism. We show that for {\em any such theory} the assumption that the low-energy vector-boson spectrum consists of the W^\pm, Z and \gamma only, is inconsistent with the experimental requirements \sin^2\theta_W\simeq 1/4 and \rho\equiv m_W^2/(m_Z^2\cos^2\theta_w)=1.
[ { "created": "Wed, 26 Apr 2006 09:46:15 GMT", "version": "v1" }, { "created": "Tue, 16 May 2006 07:49:08 GMT", "version": "v2" } ]
2008-11-26
[ [ "Grzadkowski", "Bohdan", "" ], [ "Wudka", "Jose", "" ] ]
We consider 5 dimensional gauge theories where the 5th direction is compactified on the orbifold S^1/Z_2, and where the 5th components of the gauge bosons play the role of the Standard Model Higgs boson (gauge-Higgs unification). The gauge symmetry breaking is realized through the appropriate orbifold boundary conditions and through the Hosotani mechanism. We show that for {\em any such theory} the assumption that the low-energy vector-boson spectrum consists of the W^\pm, Z and \gamma only, is inconsistent with the experimental requirements \sin^2\theta_W\simeq 1/4 and \rho\equiv m_W^2/(m_Z^2\cos^2\theta_w)=1.
1107.2472
Ulrich Ellwanger
Ulrich Ellwanger, Gregory Espitalier-Noel and Cyril Hugonie
Naturalness and Fine Tuning in the NMSSM: Implications of Early LHC Results
19 pages, 10 figures, bounds from Susy searches with ~1/fb included
JHEP 09 (2011) 105
10.1007/JHEP09(2011)105
LPT Orsay 11-63; L2C 11-; LUPM 11-002
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the fine tuning in the parameter space of the semi-constrained NMSSM, where most soft Susy breaking parameters are universal at the GUT scale. We discuss the dependence of the fine tuning on the soft Susy breaking parameters M_1/2 and m0, and on the Higgs masses in NMSSM specific scenarios involving large singlet-doublet Higgs mixing or dominant Higgs-to-Higgs decays. Whereas these latter scenarios allow a priori for considerably less fine tuning than the constrained MSSM, the early LHC results rule out a large part of the parameter space of the semi-constrained NMSSM corresponding to low values of the fine tuning.
[ { "created": "Wed, 13 Jul 2011 06:59:41 GMT", "version": "v1" }, { "created": "Mon, 12 Sep 2011 10:07:07 GMT", "version": "v2" } ]
2015-05-28
[ [ "Ellwanger", "Ulrich", "" ], [ "Espitalier-Noel", "Gregory", "" ], [ "Hugonie", "Cyril", "" ] ]
We study the fine tuning in the parameter space of the semi-constrained NMSSM, where most soft Susy breaking parameters are universal at the GUT scale. We discuss the dependence of the fine tuning on the soft Susy breaking parameters M_1/2 and m0, and on the Higgs masses in NMSSM specific scenarios involving large singlet-doublet Higgs mixing or dominant Higgs-to-Higgs decays. Whereas these latter scenarios allow a priori for considerably less fine tuning than the constrained MSSM, the early LHC results rule out a large part of the parameter space of the semi-constrained NMSSM corresponding to low values of the fine tuning.
hep-ph/0607089
Basarab Nicolescu
Regina F. Avila, Pierre Gauron, Basarab Nicolescu
How can the Odderon be detected at RHIC and LHC
14 pages, 16 figures, two typographical errors corrected and acknowledgments added
Eur.Phys.J.C49:581-592,2007
10.1140/epjc/s10052-006-0074-9
null
hep-ph
null
The Odderon remains an elusive object, 33 years after its invention. The Odderon is now a fundamental object in QCD and CGC and it has to be found experimentally if QCD and CGC are right. In the present paper, we show how to find it at RHIC and LHC. The most spectacular signature of the Odderon is the predicted difference between the differential cross-sections for proton-proton and antiproton-proton at high s and moderate t. The experiment can be done by using the STAR detector at RHIC and by combining these future data with the already present UA4/2 data. The Odderon could also be found by ATLAS exeperiment at LHC by performing a high-precision measurement of the real part of the hadron elastic scattering amplitude at small t.
[ { "created": "Sat, 8 Jul 2006 17:25:03 GMT", "version": "v1" }, { "created": "Fri, 28 Jul 2006 11:48:25 GMT", "version": "v2" }, { "created": "Mon, 11 Dec 2006 17:25:18 GMT", "version": "v3" }, { "created": "Thu, 21 Dec 2006 17:21:55 GMT", "version": "v4" } ]
2011-09-13
[ [ "Avila", "Regina F.", "" ], [ "Gauron", "Pierre", "" ], [ "Nicolescu", "Basarab", "" ] ]
The Odderon remains an elusive object, 33 years after its invention. The Odderon is now a fundamental object in QCD and CGC and it has to be found experimentally if QCD and CGC are right. In the present paper, we show how to find it at RHIC and LHC. The most spectacular signature of the Odderon is the predicted difference between the differential cross-sections for proton-proton and antiproton-proton at high s and moderate t. The experiment can be done by using the STAR detector at RHIC and by combining these future data with the already present UA4/2 data. The Odderon could also be found by ATLAS exeperiment at LHC by performing a high-precision measurement of the real part of the hadron elastic scattering amplitude at small t.
hep-ph/0509335
Gouranga Nayak
Gouranga C. Nayak (SUNY, Stony Brook) and J. Smith (SUNY, Stony Brook)
J/Psi and Psi' Polarizations in Polarized Proton-Proton Collisions at the RHIC
Final version, To appear in Phys. Rev. D
Phys.Rev.D73:014007,2006
10.1103/PhysRevD.73.014007
YITP-SB-05-32
hep-ph hep-ex nucl-ex nucl-th
null
We study inclusive heavy quarkonium production with definite polarizations in polarized proton-proton collisions using the non-relativistic QCD color-octet mechanism. We present results for rapidity distributions of cross sections and spin asymmetries for the production of J/psi and psi' with specific polarizations in polarized p-p collisions at \sqrt s = 200 GeV and 500 GeV at the RHIC within the PHENIX detector acceptance range.
[ { "created": "Wed, 28 Sep 2005 19:43:56 GMT", "version": "v1" }, { "created": "Wed, 7 Dec 2005 22:31:18 GMT", "version": "v2" } ]
2011-03-23
[ [ "Nayak", "Gouranga C.", "", "SUNY, Stony Brook" ], [ "Smith", "J.", "", "SUNY, Stony Brook" ] ]
We study inclusive heavy quarkonium production with definite polarizations in polarized proton-proton collisions using the non-relativistic QCD color-octet mechanism. We present results for rapidity distributions of cross sections and spin asymmetries for the production of J/psi and psi' with specific polarizations in polarized p-p collisions at \sqrt s = 200 GeV and 500 GeV at the RHIC within the PHENIX detector acceptance range.
hep-ph/9612444
Morimitsu Tanimoto
Morimitsu Tanimoto
Prediction on CP Violation in Long Baseline Neutrino Oscillation Experiments
23 pages, LaTex file, 4 figures included using epsfig fig.3 and 4 are added. To be published in PTP
Prog.Theor.Phys.97:901-912,1997
10.1143/PTP.97.901
EHU-96-12 Revised
hep-ph
null
We predict CP violation in the long baseline accelerator experiments taking into consideration the recent LSND data and the atmospheric neutrino data. The estimated upper bound of CP violation is 0.006, which may be observable in the long baseline accelerator experiments. It is found that the upper bound increases to 0.01 if the LSND data is excluded. The matter effect, which is not CP invariant, is found to be very small in the case we consider.
[ { "created": "Sat, 21 Dec 1996 07:57:24 GMT", "version": "v1" }, { "created": "Sat, 7 Jun 1997 08:36:33 GMT", "version": "v2" } ]
2014-11-17
[ [ "Tanimoto", "Morimitsu", "" ] ]
We predict CP violation in the long baseline accelerator experiments taking into consideration the recent LSND data and the atmospheric neutrino data. The estimated upper bound of CP violation is 0.006, which may be observable in the long baseline accelerator experiments. It is found that the upper bound increases to 0.01 if the LSND data is excluded. The matter effect, which is not CP invariant, is found to be very small in the case we consider.
1504.07242
Are R. Raklev
L. A. Dal, A. R. Raklev
An Alternative Formation Model for Antideuterons from Dark Matter
19 pages, 15 figures, C++ code with parametrised cross sections can be found in the ancillary folder, v2 fixes important missing references
Phys. Rev. D 91, 123536 (2015)
10.1103/PhysRevD.91.123536
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Antideuterons are a potential messenger for dark matter annihilation or decay in our own galaxy, with very low backgrounds expected from astrophysical processes. The standard coalescence model of antideuteron formation, while simple to implement, is shown to be under considerable strain by recent data from the LHC. We suggest a new empirically based model, with only one free parameter, which is better able to cope with these data, and we explore the consequences of the model for dark matter searches.
[ { "created": "Mon, 27 Apr 2015 20:00:57 GMT", "version": "v1" }, { "created": "Thu, 13 Aug 2015 15:32:08 GMT", "version": "v2" } ]
2015-08-14
[ [ "Dal", "L. A.", "" ], [ "Raklev", "A. R.", "" ] ]
Antideuterons are a potential messenger for dark matter annihilation or decay in our own galaxy, with very low backgrounds expected from astrophysical processes. The standard coalescence model of antideuteron formation, while simple to implement, is shown to be under considerable strain by recent data from the LHC. We suggest a new empirically based model, with only one free parameter, which is better able to cope with these data, and we explore the consequences of the model for dark matter searches.
hep-ph/0211225
Ana Gabriela Grunfeld
L. Epele, H. Fanchiotti and A. G. Grunfeld
The Ideal Mixing Departure in Vector Meson Physics
12 pages incl. 1 figure
Eur.Phys.J.C30:97-101,2004
10.1140/epjc/s2003-01250-1
LA PLATA-TH-02/06
hep-ph
null
In this work we study the departure for the ideal $\phi-\omega$ mixing angle in the frame of the Nambu-Jona-Lasinio model. We have shown that in that context, the flavour symmetry breaking is unable to produce the shifting in the mixing angle. We introduce a nonet symmetry breaking in the neutral vector sector to regulate the non-strange content of the $\phi$ meson. The phenomenon is well reproduced by our proposal.
[ { "created": "Thu, 14 Nov 2002 17:30:22 GMT", "version": "v1" } ]
2011-09-13
[ [ "Epele", "L.", "" ], [ "Fanchiotti", "H.", "" ], [ "Grunfeld", "A. G.", "" ] ]
In this work we study the departure for the ideal $\phi-\omega$ mixing angle in the frame of the Nambu-Jona-Lasinio model. We have shown that in that context, the flavour symmetry breaking is unable to produce the shifting in the mixing angle. We introduce a nonet symmetry breaking in the neutral vector sector to regulate the non-strange content of the $\phi$ meson. The phenomenon is well reproduced by our proposal.
hep-ph/0509043
Wojciech Krolikowski
Wojciech Krolikowski
Predicting the tauon mass as well as the ratio of electron and muon masses
1+7 pages
null
null
IFT-05/21
hep-ph
null
Treating the Koide equation and another efficient charged-lepton mass formula (having the form of a mass sum rule) as a system of two mathematically independent algebraic equations for three charged-lepton masses, we predict the tauon mass as well as the ratio of electron and muon masses, both consistent with experiment.
[ { "created": "Tue, 6 Sep 2005 10:13:43 GMT", "version": "v1" } ]
2007-05-23
[ [ "Krolikowski", "Wojciech", "" ] ]
Treating the Koide equation and another efficient charged-lepton mass formula (having the form of a mass sum rule) as a system of two mathematically independent algebraic equations for three charged-lepton masses, we predict the tauon mass as well as the ratio of electron and muon masses, both consistent with experiment.
hep-ph/0202195
Reinhard Alkofer
C. S. Fischer, R. Alkofer and H. Reinhardt
The Elusiveness of Infrared Critical Exponents in Landau Gauge Yang--Mills Theories
30 pages, REVTEX4 style, 11 figures
Phys.Rev.D65:094008,2002
10.1103/PhysRevD.65.094008
UNITU-THEP-06/2002
hep-ph hep-lat hep-th nucl-th
null
We solve a truncated system of coupled Dyson-Schwinger equations for the gluon and ghost propagators in SU($N_c$) Yang-Mills theories in Faddeev-Popov quantization on a four-torus. This compact space-time manifold provides an efficient mean to solve the gluon and ghost Dyson-Schwinger equations without any angular approximations. We verify that analytically two power-like solutions in the very far infrared seem possible. However, only one of these solutions can be matched to a numerical solution for non-vanishing momenta. For a bare ghost-gluon vertex this implies that the gluon propagator is only weakly infrared vanishing, $D_{gl}(k^2) \propto (k^2)^{2\kappa -1}$, $\kappa \approx 0.595$, and the ghost propagator is infrared singular, $D_{gh}(k^2) \propto (k^2)^{-\kappa -1}$. For non-vanishing momenta our solutions are in agreement with the results of recent SU(2) Monte-Carlo lattice calculations. The running coupling possesses an infrared fixed point. We obtain $\alpha(0) = 8.92/N_c$ for all gauge groups SU($N_c$). Above one GeV the running coupling rapidly approaches its perturbative form.
[ { "created": "Wed, 20 Feb 2002 15:32:56 GMT", "version": "v1" } ]
2008-11-26
[ [ "Fischer", "C. S.", "" ], [ "Alkofer", "R.", "" ], [ "Reinhardt", "H.", "" ] ]
We solve a truncated system of coupled Dyson-Schwinger equations for the gluon and ghost propagators in SU($N_c$) Yang-Mills theories in Faddeev-Popov quantization on a four-torus. This compact space-time manifold provides an efficient mean to solve the gluon and ghost Dyson-Schwinger equations without any angular approximations. We verify that analytically two power-like solutions in the very far infrared seem possible. However, only one of these solutions can be matched to a numerical solution for non-vanishing momenta. For a bare ghost-gluon vertex this implies that the gluon propagator is only weakly infrared vanishing, $D_{gl}(k^2) \propto (k^2)^{2\kappa -1}$, $\kappa \approx 0.595$, and the ghost propagator is infrared singular, $D_{gh}(k^2) \propto (k^2)^{-\kappa -1}$. For non-vanishing momenta our solutions are in agreement with the results of recent SU(2) Monte-Carlo lattice calculations. The running coupling possesses an infrared fixed point. We obtain $\alpha(0) = 8.92/N_c$ for all gauge groups SU($N_c$). Above one GeV the running coupling rapidly approaches its perturbative form.
2406.02097
Fanrong Xu
Shuge Zeng, Fanrong Xu, Yu Gu
The Benchmark Mode $\Omega_c \to \Omega^-\pi^+$ and Its Related Processes
19 pages, 2 figures, 4 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The benchmark mode $\Omega_c^0\to \Omega^- \pi^+$, which receives purely factorization contribution, is of great importance among all the decay channels of $\Omega_c^0$ decays. In this work, within the framework of non-relativistic quark model (NRQM), we calculate all the 6 baryon transition form factors involving $\frac12 ^+\to \frac32 ^+$ decays. The absolute branching fractions of non-leptonic decays $\Omega_c^0\to \Omega^- \pi^+$, $\Omega_c^0\to \Omega^- \rho^+$ and $\Omega_c^0\to \Xi^- \pi^+$ as well as semi-leptonic decays $\Omega_c^0\to \Omega^- \ell^+ \nu_{\ell} \; (\ell=e,\mu)$ are calculated although they cannot be measured directly by current experiment. Based on the prediction $\mathcal{B}(\Omega_c^0\to\Omega^-\pi^+)=3.43\%$ in our work, we further predict the ratios between interested modes and the benchmark mode, giving $R(\Xi^-\pi^+)=0.156$, $R(\Omega^-\rho^+)=5.33$, $R(\Omega^- e^+\nu_e)=1.18$ and $R(\Omega^- \mu^+\nu_\mu)=1.11$. The predictions on $\Omega_c^0\to \Xi^-\pi^+$ and $\Omega_c^0\to \Omega^- e^+\nu$ agree well with recent measured ratios reported by LHCb in 2023 and ALICE in 2024, respectively.
[ { "created": "Tue, 4 Jun 2024 08:27:24 GMT", "version": "v1" } ]
2024-06-05
[ [ "Zeng", "Shuge", "" ], [ "Xu", "Fanrong", "" ], [ "Gu", "Yu", "" ] ]
The benchmark mode $\Omega_c^0\to \Omega^- \pi^+$, which receives purely factorization contribution, is of great importance among all the decay channels of $\Omega_c^0$ decays. In this work, within the framework of non-relativistic quark model (NRQM), we calculate all the 6 baryon transition form factors involving $\frac12 ^+\to \frac32 ^+$ decays. The absolute branching fractions of non-leptonic decays $\Omega_c^0\to \Omega^- \pi^+$, $\Omega_c^0\to \Omega^- \rho^+$ and $\Omega_c^0\to \Xi^- \pi^+$ as well as semi-leptonic decays $\Omega_c^0\to \Omega^- \ell^+ \nu_{\ell} \; (\ell=e,\mu)$ are calculated although they cannot be measured directly by current experiment. Based on the prediction $\mathcal{B}(\Omega_c^0\to\Omega^-\pi^+)=3.43\%$ in our work, we further predict the ratios between interested modes and the benchmark mode, giving $R(\Xi^-\pi^+)=0.156$, $R(\Omega^-\rho^+)=5.33$, $R(\Omega^- e^+\nu_e)=1.18$ and $R(\Omega^- \mu^+\nu_\mu)=1.11$. The predictions on $\Omega_c^0\to \Xi^-\pi^+$ and $\Omega_c^0\to \Omega^- e^+\nu$ agree well with recent measured ratios reported by LHCb in 2023 and ALICE in 2024, respectively.
1402.1189
Michael Spannowsky
Davison E. Soper and Michael Spannowsky
Finding physics signals with event deconstruction
17 pages, 4 figures
null
10.1103/PhysRevD.89.094005
IPPP/14/04, DCPT/14/08
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a matrix element based reconstruction method called event deconstruction. The method uses information from the hard matrix element and a parton shower to assign probabilities to whether a final state was initiated by a signal or background process. We apply this method in the signal process of a Z' decaying to boosted top quarks in an all hadronic final state and discuss envisioned improvements of the method. We find that event deconstruction can considerably improve on existing reconstruction techniques.
[ { "created": "Wed, 5 Feb 2014 21:32:01 GMT", "version": "v1" } ]
2014-08-14
[ [ "Soper", "Davison E.", "" ], [ "Spannowsky", "Michael", "" ] ]
We develop a matrix element based reconstruction method called event deconstruction. The method uses information from the hard matrix element and a parton shower to assign probabilities to whether a final state was initiated by a signal or background process. We apply this method in the signal process of a Z' decaying to boosted top quarks in an all hadronic final state and discuss envisioned improvements of the method. We find that event deconstruction can considerably improve on existing reconstruction techniques.
1305.3823
Marlene Nahrgang
Marlene Nahrgang, Joerg Aichelin, Pol Bernard Gossiaux, Klaus Werner
Azimuthal correlations of heavy quarks in Pb+Pb collisions at LHC ($\sqrt{s}=2.76$ TeV)
final, published version
Phys. Rev. C 90, 024907 (2014)
10.1103/PhysRevC.90.024907
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the azimuthal correlations of heavy quarks in Pb+Pb collisions with $\sqrt{s}=2.76$ TeV at LHC. Due to the interaction with the medium heavy quarks and antiquarks are deflected from their original direction and the initial correlation of the pair is broadened. We investigate this effect for different transverse momentum classes. Low-momentum heavy-quark pairs lose their leading order back-to-back initial correlation, while a significant residual correlation survives at large momenta. Due to the larger acquired average deflection from their original directions the azimuthal correlations of heavy-quark pairs are broadened more efficiently in a purely collisional energy loss mechanism compared to including radiative corrections. This discriminatory feature survives when next-to-leading order production processes are included.
[ { "created": "Thu, 16 May 2013 14:43:05 GMT", "version": "v1" }, { "created": "Thu, 14 Aug 2014 18:38:53 GMT", "version": "v2" } ]
2014-08-27
[ [ "Nahrgang", "Marlene", "" ], [ "Aichelin", "Joerg", "" ], [ "Gossiaux", "Pol Bernard", "" ], [ "Werner", "Klaus", "" ] ]
In this paper we study the azimuthal correlations of heavy quarks in Pb+Pb collisions with $\sqrt{s}=2.76$ TeV at LHC. Due to the interaction with the medium heavy quarks and antiquarks are deflected from their original direction and the initial correlation of the pair is broadened. We investigate this effect for different transverse momentum classes. Low-momentum heavy-quark pairs lose their leading order back-to-back initial correlation, while a significant residual correlation survives at large momenta. Due to the larger acquired average deflection from their original directions the azimuthal correlations of heavy-quark pairs are broadened more efficiently in a purely collisional energy loss mechanism compared to including radiative corrections. This discriminatory feature survives when next-to-leading order production processes are included.
hep-ph/0409357
Cristina Volpe
C. Volpe (Institut de Physique Nucl\'eaire Orsay, France)
Physics potential of beta-beams
4 pages, 1 figure, Proceedings to "INPC04"
Nucl.Phys. A752 (2005) 38-41
10.1016/j.nuclphysa.2005.02.025
null
hep-ph
null
Beta-beams is a novel concept for the production of neutrino beams exploiting boosted radioactive ions which decay through beta-decay. Here we describe a project, currently under investigation, where such beams are used to address the issue of CP violation in the lepton sector. We also mention the interest of having low-energy beta-beams. The connection to projects for the production of very intense exotic ion beams, like EURISOL, is emphasized.
[ { "created": "Thu, 30 Sep 2004 11:25:48 GMT", "version": "v1" } ]
2009-11-10
[ [ "Volpe", "C.", "", "Institut de Physique Nucléaire Orsay, France" ] ]
Beta-beams is a novel concept for the production of neutrino beams exploiting boosted radioactive ions which decay through beta-decay. Here we describe a project, currently under investigation, where such beams are used to address the issue of CP violation in the lepton sector. We also mention the interest of having low-energy beta-beams. The connection to projects for the production of very intense exotic ion beams, like EURISOL, is emphasized.
hep-ph/9901272
null
T. Csorgo and B. Lorstad
Invariant Buda-Lund Particle Interferometry
20 pages, LaTeX, sprocl.sty, epsfig.sty, 2 eps figures, Proc. Correlations and Fluctuations'98, Matrahaza, Hungary, June 14-21, 1998, (World Scientific, Singapore, 1999, ed. T.Csorgo, S. Hegyi, G. Jancso and R. C. Hwa) p. 108
Proc. CF'98 (WSCI 1999 ed. T. Csorgo et al), p. 108
null
KFKI - 1998 - 06/A
hep-ph
null
The invariant Buda-Lund parameterization of the two-particle Bose-Einstein correlation functions is presented, its derivation is summarized. In its particular multi-variate Gaussian limiting case, the invariant Buda - Lund parameterization is compared to the Bertsch-Pratt and Yano-Koonin-Podgoretskii parameterizations, advantages and shortcomings are discussed. The invariant Buda-Lund parameterizations are given also for non-Gaussian multi-variate distributions, including damped oscillations in the like-particle correlation function, that are similar to the oscillating intensity correlations of binary stars in stellar interferometry. A separation between the pion and the proton source is also estimated in the Buda - Lund hydro framework, the result is utilized to extract the mean proper time of particle emission with the help of fits to E877 data on non-identical particle correlations by Miskowiec.
[ { "created": "Mon, 11 Jan 1999 23:51:45 GMT", "version": "v1" } ]
2007-05-23
[ [ "Csorgo", "T.", "" ], [ "Lorstad", "B.", "" ] ]
The invariant Buda-Lund parameterization of the two-particle Bose-Einstein correlation functions is presented, its derivation is summarized. In its particular multi-variate Gaussian limiting case, the invariant Buda - Lund parameterization is compared to the Bertsch-Pratt and Yano-Koonin-Podgoretskii parameterizations, advantages and shortcomings are discussed. The invariant Buda-Lund parameterizations are given also for non-Gaussian multi-variate distributions, including damped oscillations in the like-particle correlation function, that are similar to the oscillating intensity correlations of binary stars in stellar interferometry. A separation between the pion and the proton source is also estimated in the Buda - Lund hydro framework, the result is utilized to extract the mean proper time of particle emission with the help of fits to E877 data on non-identical particle correlations by Miskowiec.
1304.0850
Evgenij Martynov
A. Alkin, O. Kovalenko and E. Martynov
Can the "standard" unitarized Regge models describe the TOTEM data?
11 pages, 7 figures, typos are corrected, minor corrections in the text, No changes in results and conclusion. To appear in EPL
null
10.1209/0295-5075/102/31001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The standard Regge poles are considered as inputs for two unitarization methods: eikonal and U-matrix. It is shown that only models with three input pomerons and two input odderons can describe the high energy data on $pp$ and $\bar pp$ elastic scattering including the new data from Tevatron and LHC. However, it seems that the both considered models (eikonal and U-matrix) require a further modification (e.g., to explore nonlinear reggeon trajectories and/or nonexponential vertex functions) for a more satisfactory description of the data at 19.0 GeV$\leq \sqrt{s}\leq$ 7 TeV and 0.01 $\leq |t|\leq $14.2 GeV$^{2}$.
[ { "created": "Wed, 3 Apr 2013 06:35:24 GMT", "version": "v1" }, { "created": "Tue, 7 May 2013 16:32:58 GMT", "version": "v2" } ]
2015-06-15
[ [ "Alkin", "A.", "" ], [ "Kovalenko", "O.", "" ], [ "Martynov", "E.", "" ] ]
The standard Regge poles are considered as inputs for two unitarization methods: eikonal and U-matrix. It is shown that only models with three input pomerons and two input odderons can describe the high energy data on $pp$ and $\bar pp$ elastic scattering including the new data from Tevatron and LHC. However, it seems that the both considered models (eikonal and U-matrix) require a further modification (e.g., to explore nonlinear reggeon trajectories and/or nonexponential vertex functions) for a more satisfactory description of the data at 19.0 GeV$\leq \sqrt{s}\leq$ 7 TeV and 0.01 $\leq |t|\leq $14.2 GeV$^{2}$.
hep-ph/0003323
Robert Fleischer
Andrzej J. Buras, Robert Fleischer
Constraints on the CKM Angle $\gamma$ and Strong Phases from $B\to\pi K$ Decays
18 pages, LaTeX, 8 figures
Eur.Phys.J.C16:97-104,2000
10.1007/s100520050006
DESY 00-051, TUM-HEP-367/00
hep-ph
null
As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. In this paper, we reconsider this approach in the light of recent CLEO data, which look very interesting. In particular, the results for the corresponding CP-averaged branching ratios are in favour of strong constraints on $\gamma$, where the second quadrant is preferred. Such a situation would be in conflict with the standard analysis of the unitarity triangle. Moreover, constraints on a CP-conserving strong phase $\delta_n$ are in favour of a negative value of $\cos\delta_n$, which would be in conflict with the factorization expectation. In addition, there seems to be an interesting discrepancy with the bounds that are implied by the charged $B\to\pi K$ system: whereas these decays favour a range for $\gamma$ that is similar to that of the neutral modes, they point towards a positive value of $\cos\delta_c$, which would be in conflict with the expectation of equal signs for $\cos\delta_n$ and $\cos\delta_c$. If future data should confirm this ``puzzle'', it may be an indication for new-physics contributions to the electroweak penguin sector, or a manifestation of large non-factorizable SU(3)-breaking effects.
[ { "created": "Fri, 31 Mar 2000 15:34:44 GMT", "version": "v1" } ]
2008-11-26
[ [ "Buras", "Andrzej J.", "" ], [ "Fleischer", "Robert", "" ] ]
As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. In this paper, we reconsider this approach in the light of recent CLEO data, which look very interesting. In particular, the results for the corresponding CP-averaged branching ratios are in favour of strong constraints on $\gamma$, where the second quadrant is preferred. Such a situation would be in conflict with the standard analysis of the unitarity triangle. Moreover, constraints on a CP-conserving strong phase $\delta_n$ are in favour of a negative value of $\cos\delta_n$, which would be in conflict with the factorization expectation. In addition, there seems to be an interesting discrepancy with the bounds that are implied by the charged $B\to\pi K$ system: whereas these decays favour a range for $\gamma$ that is similar to that of the neutral modes, they point towards a positive value of $\cos\delta_c$, which would be in conflict with the expectation of equal signs for $\cos\delta_n$ and $\cos\delta_c$. If future data should confirm this ``puzzle'', it may be an indication for new-physics contributions to the electroweak penguin sector, or a manifestation of large non-factorizable SU(3)-breaking effects.
1901.07414
Gui-Jun Ding
Jun-Nan Lu, Gui-Jun Ding
Dihedral flavor group as the key to understand quark and lepton flavor mixing
22 pages, 3 figures
null
null
USTC-ICTS-19-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have studied the lepton and quark mixing patterns which can be derived from the dihedral group $D_n$ in combination with CP symmetry. The left-handed lepton and quark doublets are assigned to the direct sum of a singlet and a doublet of $D_n$. A unified description of the observed structure of the quark and lepton mixing can be achieved if the flavor group $D_n$ and CP are broken to $Z_2\times CP$ in neutrino, charged lepton, up quark and down quark sectors, and the minimal group is $D_{14}$. We also consider another scenario in which the residual symmetry of the charged lepton and up quark sector is $Z_2$ while $Z_2\times CP$ remains preserved by the neutrino and down quark mass matrices. Then $D_7$ can give the experimentally favored values of CKM and PMNS mixing matrices.
[ { "created": "Tue, 22 Jan 2019 15:30:53 GMT", "version": "v1" } ]
2019-01-23
[ [ "Lu", "Jun-Nan", "" ], [ "Ding", "Gui-Jun", "" ] ]
We have studied the lepton and quark mixing patterns which can be derived from the dihedral group $D_n$ in combination with CP symmetry. The left-handed lepton and quark doublets are assigned to the direct sum of a singlet and a doublet of $D_n$. A unified description of the observed structure of the quark and lepton mixing can be achieved if the flavor group $D_n$ and CP are broken to $Z_2\times CP$ in neutrino, charged lepton, up quark and down quark sectors, and the minimal group is $D_{14}$. We also consider another scenario in which the residual symmetry of the charged lepton and up quark sector is $Z_2$ while $Z_2\times CP$ remains preserved by the neutrino and down quark mass matrices. Then $D_7$ can give the experimentally favored values of CKM and PMNS mixing matrices.
1411.3007
Alexander Mitov
Michal Czakon, Paul Fiedler and Alexander Mitov
Resolving the Tevatron Top Quark Forward-Backward Asymmetry Puzzle: Fully Differential Next-to-Next-to-Leading-Order Calculation
6 pages, 4 figures. Published journal version: title extended and few clarifications added
Phys. Rev. Lett. 115, 052001 (2015)
10.1103/PhysRevLett.115.052001
Cavendish-HEP-14/10, TTK-14-32
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine the dominant missing Standard Model (SM) contribution to the top quark pair forward-backward asymmetry at the Tevatron. Contrary to past expectations, we find a large, around 27%, shift relative to the well-known value of the inclusive asymmetry in next-to-leading order (NLO) QCD. Combining all known Standard Model corrections, we find that AFB^{SM} = 0.095 +- 0.007. This value is in agreement with the latest D0 measurement [V. M. Abazov et al. (D0 Collaboration), Phys. Rev. D 90, 072011 (2014)] AFB^{D0} = 0.106+- 0.03 and about 1.5 sigma below that of CDF [T. Aaltonen et al. (CDF Collaboration), Phys. Rev. D 87, 092002 (2013)] AFB^{CDF} =0.164 +- 0.047. Our result is derived from a fully differential calculation of the next-to-next-to leading order (NNLO) QCD corrections to inclusive top pair production at hadron colliders and includes - without any approximation - all partonic channels contributing to this process. This is the first complete fully differential calculation in NNLO QCD of a two-to-two scattering process with all coloured partons.
[ { "created": "Tue, 11 Nov 2014 22:45:33 GMT", "version": "v1" }, { "created": "Wed, 29 Jul 2015 12:23:17 GMT", "version": "v2" } ]
2015-07-30
[ [ "Czakon", "Michal", "" ], [ "Fiedler", "Paul", "" ], [ "Mitov", "Alexander", "" ] ]
We determine the dominant missing Standard Model (SM) contribution to the top quark pair forward-backward asymmetry at the Tevatron. Contrary to past expectations, we find a large, around 27%, shift relative to the well-known value of the inclusive asymmetry in next-to-leading order (NLO) QCD. Combining all known Standard Model corrections, we find that AFB^{SM} = 0.095 +- 0.007. This value is in agreement with the latest D0 measurement [V. M. Abazov et al. (D0 Collaboration), Phys. Rev. D 90, 072011 (2014)] AFB^{D0} = 0.106+- 0.03 and about 1.5 sigma below that of CDF [T. Aaltonen et al. (CDF Collaboration), Phys. Rev. D 87, 092002 (2013)] AFB^{CDF} =0.164 +- 0.047. Our result is derived from a fully differential calculation of the next-to-next-to leading order (NNLO) QCD corrections to inclusive top pair production at hadron colliders and includes - without any approximation - all partonic channels contributing to this process. This is the first complete fully differential calculation in NNLO QCD of a two-to-two scattering process with all coloured partons.
2406.19129
Savely G. Karshenboim
Savely G. Karshenboim
Laboratory constraint on the electric charge of the neutron and the neutrino
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit constraints on the electric charge of the neutron and neutrino as well as on e_p+e_e. We consider phenomenological constraints based on laboratory study of the electrical neutrality of subatomic, atomic, and molecular species under assumption of the conservation of the electric charge in the beta decay, that relates e_p+e_e, e_n, and e_nu. Some previously published constraints utilized an additional assumption e_nu=0, which we do not. We dismiss a cosmological constraint at the level of 10^-35 e utilized by PDG in their Review of particle properties as a controversial one which makes the laboratory constraints on e_nu dominant. The phenomenological constraints from the laboratory experiments are obtained as e_p+e_e=(0.2\pm2.6)10^-21 e, e_n=(-0.4\pm1.1)10^-21 e, and e_nu=(0.6\pm3.2)10^{-21} e. The ones on e_p+e_e and e_n are at the same level as the PDG constraints, while our e_nu constraint is several orders of magnitude weaker than the controversial cosmological result dominated in the PDG constraint, but several orders of magnitude stronger than the other individual e_nu constraints considered by PDG. We also consider consistency of the phenomenological constraints and the SM. The SM ignores the neutrino mass term and cannot describe the neutrino oscillations which makes it not a complete theory but a part of it. We demonstrate that the condition of the cancellation of the triangle anomaly within the complete theory does not disagree with the phenomenological constraints since different extensions of the SM may produce different additional contributions to the anomaly. In particular, we consider a minimal extension of the SM, where leptons (nu,e) are treated the same ways as quarks, which sets e_p+e_e=0 and allows for numerical strengthening the constraint on e_n and e_nu, which is e_n=-e_nu=(-0.4\pm1.0)10^-21 e.
[ { "created": "Thu, 27 Jun 2024 12:28:45 GMT", "version": "v1" } ]
2024-06-28
[ [ "Karshenboim", "Savely G.", "" ] ]
We revisit constraints on the electric charge of the neutron and neutrino as well as on e_p+e_e. We consider phenomenological constraints based on laboratory study of the electrical neutrality of subatomic, atomic, and molecular species under assumption of the conservation of the electric charge in the beta decay, that relates e_p+e_e, e_n, and e_nu. Some previously published constraints utilized an additional assumption e_nu=0, which we do not. We dismiss a cosmological constraint at the level of 10^-35 e utilized by PDG in their Review of particle properties as a controversial one which makes the laboratory constraints on e_nu dominant. The phenomenological constraints from the laboratory experiments are obtained as e_p+e_e=(0.2\pm2.6)10^-21 e, e_n=(-0.4\pm1.1)10^-21 e, and e_nu=(0.6\pm3.2)10^{-21} e. The ones on e_p+e_e and e_n are at the same level as the PDG constraints, while our e_nu constraint is several orders of magnitude weaker than the controversial cosmological result dominated in the PDG constraint, but several orders of magnitude stronger than the other individual e_nu constraints considered by PDG. We also consider consistency of the phenomenological constraints and the SM. The SM ignores the neutrino mass term and cannot describe the neutrino oscillations which makes it not a complete theory but a part of it. We demonstrate that the condition of the cancellation of the triangle anomaly within the complete theory does not disagree with the phenomenological constraints since different extensions of the SM may produce different additional contributions to the anomaly. In particular, we consider a minimal extension of the SM, where leptons (nu,e) are treated the same ways as quarks, which sets e_p+e_e=0 and allows for numerical strengthening the constraint on e_n and e_nu, which is e_n=-e_nu=(-0.4\pm1.0)10^-21 e.
0707.3893
Massimo Mannarelli
Massimo Mannarelli and Cristina Manuel
Jet-induced gauge field instabilities in the quark-gluon plasma: A kinetic theory approach
13 pages, 6 figures
Phys.Rev.D77:054018,2008
10.1103/PhysRevD.77.054018
null
hep-ph
null
We discuss the properties of the collective modes of a system composed by a thermalized quark-gluon plasma traversed by a relativistic jet of partons. The transport equations obeyed by the components of the plasma and of the jet are studied in the Vlasov approximation. Assuming that the partons in the jet can be described with a tsunami-like distribution function we derive the expressions of the dispersion law of the collective modes. Then the behavior of the unstable gauge modes of the system is analyzed for various values of the velocity of the jet, of the momentum of the collective modes and of the angle between these two quantities. We find that the most unstable modes are those with momentum orthogonal to the velocity of the jet and that these instabilities appear when the velocity of the jet is higher than a threshold value, which depends on the plasma and jet frequencies. The results obtained within the Vlasov approximation are compared with the corresponding results obtained using a chromohydrodynamical approach.The effect we discuss here suggests a possible collective mechanism for the description of the jet quenching phenomena in heavy ion collisions.
[ { "created": "Thu, 26 Jul 2007 10:35:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mannarelli", "Massimo", "" ], [ "Manuel", "Cristina", "" ] ]
We discuss the properties of the collective modes of a system composed by a thermalized quark-gluon plasma traversed by a relativistic jet of partons. The transport equations obeyed by the components of the plasma and of the jet are studied in the Vlasov approximation. Assuming that the partons in the jet can be described with a tsunami-like distribution function we derive the expressions of the dispersion law of the collective modes. Then the behavior of the unstable gauge modes of the system is analyzed for various values of the velocity of the jet, of the momentum of the collective modes and of the angle between these two quantities. We find that the most unstable modes are those with momentum orthogonal to the velocity of the jet and that these instabilities appear when the velocity of the jet is higher than a threshold value, which depends on the plasma and jet frequencies. The results obtained within the Vlasov approximation are compared with the corresponding results obtained using a chromohydrodynamical approach.The effect we discuss here suggests a possible collective mechanism for the description of the jet quenching phenomena in heavy ion collisions.
0803.0631
Marco Regis
Marco Regis
Photons from Dark Matter in a (non-Universal) Extra Dimension model
11 pages, 6 figures; title modified, 1 reference added
Phys.Lett.B663:250-254,2008
10.1016/j.physletb.2008.03.070
null
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the multi-wavelength signal induced by pairs annihilations at the Galactic center (GC) of a recently proposed dark matter (DM) candidate. The weakly interacting massive particle (WIMP) candidate, named A_, is the first Kaluza-Klein mode of a five dimensional Abelian gauge boson. Electroweak precision tests and the DM cosmological bound constrain its mass and pair annihilation rate in small ranges, leading to precise predictions of indirect signals from what concerns the particle physics side. The related multi-wavelength emission is expected to be faint, unless a significant enhancement of the DM density is present at the GC. We find that in this case, and depending on few additional assumptions, the next generation of gamma-ray and wide-field radio observations can test the model, possibly even with the detection of the induced monochromatic gamma-ray emission.
[ { "created": "Wed, 5 Mar 2008 11:01:46 GMT", "version": "v1" }, { "created": "Fri, 9 May 2008 17:34:42 GMT", "version": "v2" } ]
2008-11-26
[ [ "Regis", "Marco", "" ] ]
We study the multi-wavelength signal induced by pairs annihilations at the Galactic center (GC) of a recently proposed dark matter (DM) candidate. The weakly interacting massive particle (WIMP) candidate, named A_, is the first Kaluza-Klein mode of a five dimensional Abelian gauge boson. Electroweak precision tests and the DM cosmological bound constrain its mass and pair annihilation rate in small ranges, leading to precise predictions of indirect signals from what concerns the particle physics side. The related multi-wavelength emission is expected to be faint, unless a significant enhancement of the DM density is present at the GC. We find that in this case, and depending on few additional assumptions, the next generation of gamma-ray and wide-field radio observations can test the model, possibly even with the detection of the induced monochromatic gamma-ray emission.
hep-ph/9905569
Parameswaran Nair
D. Metaxas and V.P. Nair
Plasmon interactions in the quark-gluon plasma
12 pages, LaTeX, minor typos corrected, discussion added
Int.J.Mod.Phys. A16 (2001) 1249-1260
10.1142/S0217751X01002737
CCNY-HEP 99/4
hep-ph
null
Yang-Mills theory at finite temperature is rewritten as a theory of plasmons which provides a Hamiltonian framework for perturbation theory with resummation of hard thermal loops.
[ { "created": "Mon, 31 May 1999 15:52:28 GMT", "version": "v1" }, { "created": "Tue, 6 Jul 1999 17:57:06 GMT", "version": "v2" } ]
2015-06-25
[ [ "Metaxas", "D.", "" ], [ "Nair", "V. P.", "" ] ]
Yang-Mills theory at finite temperature is rewritten as a theory of plasmons which provides a Hamiltonian framework for perturbation theory with resummation of hard thermal loops.
hep-ph/9702204
Jose Luis Cortes
Mario Atance, Jose Luis Cortes and Igor G. Irastorza
An extension of the standard model with a single coupling parameter
13 pages, Latex file, 1 Figure
Phys.Lett. B403 (1997) 80-85
10.1016/S0370-2693(97)00511-X
DFTUZ 97/01
hep-ph
null
We show that it is possible to find an extension of the matter content of the standard model with a unification of gauge and Yukawa couplings reproducing their known values. The perturbative renormalizability of the model with a single coupling and the requirement to accomodate the known properties of the standard model fix the masses and couplings of the additional particles. The implications on the parameters of the standard model are discussed.
[ { "created": "Fri, 31 Jan 1997 11:52:01 GMT", "version": "v1" } ]
2009-10-30
[ [ "Atance", "Mario", "" ], [ "Cortes", "Jose Luis", "" ], [ "Irastorza", "Igor G.", "" ] ]
We show that it is possible to find an extension of the matter content of the standard model with a unification of gauge and Yukawa couplings reproducing their known values. The perturbative renormalizability of the model with a single coupling and the requirement to accomodate the known properties of the standard model fix the masses and couplings of the additional particles. The implications on the parameters of the standard model are discussed.
hep-ph/0312208
Ivan Sotsky Mr
T. Shishkina, I. Sotsky
Helicity amplitude method for two electron positron pairs photoproduction
7 pages, 1 figer
null
null
null
hep-ph
null
We present the matrix element of gamma gamma ->4l process with four charge particles in final state. The constructions are performed in frame of Standard Model of electroweak interaction using the helicity amplitude method . Every possible polarization state of initial and final particles are considered and analyzed.
[ { "created": "Tue, 16 Dec 2003 12:02:58 GMT", "version": "v1" }, { "created": "Wed, 31 Dec 2003 14:44:11 GMT", "version": "v2" }, { "created": "Mon, 30 Aug 2004 08:35:21 GMT", "version": "v3" }, { "created": "Mon, 3 Apr 2006 16:06:31 GMT", "version": "v4" } ]
2007-05-23
[ [ "Shishkina", "T.", "" ], [ "Sotsky", "I.", "" ] ]
We present the matrix element of gamma gamma ->4l process with four charge particles in final state. The constructions are performed in frame of Standard Model of electroweak interaction using the helicity amplitude method . Every possible polarization state of initial and final particles are considered and analyzed.
hep-ph/0109202
Guenter Sigl
G. Sigl (Institut d'Astrophysique de Paris, CNRS)
Ultrahigh Energy Neutrinos and Cosmic Rays as Probes of New Physics
44 latex pages, 8 postscript figures included; based on lectures given at summer schools in Kopenhagen and Parma (2001). for reviews see also http://www.iap.fr/users/sigl/uhecrpub.html
null
null
null
hep-ph astro-ph
null
Cosmic high energy neutrinos are inextricably linked to the origin of cosmic rays which is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a considerable increase of statistics at the highest energies and a combination with gamma-ray and neutrino astrophysics will put strong constraints on these theoretical models. The detection of ultra high energy neutrinos in particular is made likely by new experimental techniques and will open an important new channel. We give an overview over this quickly evolving field with special emphasize on new experimental ideas and possibilities for probing new physics beyond the electroweak scale.
[ { "created": "Fri, 21 Sep 2001 17:48:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sigl", "G.", "", "Institut d'Astrophysique de Paris, CNRS" ] ]
Cosmic high energy neutrinos are inextricably linked to the origin of cosmic rays which is one of the major unresolved questions in astrophysics. In particular, the highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from conventional shock acceleration to particle physics beyond the Standard Model and processes taking place at the earliest moments of our Universe. Furthermore, many new experimental activities promise a considerable increase of statistics at the highest energies and a combination with gamma-ray and neutrino astrophysics will put strong constraints on these theoretical models. The detection of ultra high energy neutrinos in particular is made likely by new experimental techniques and will open an important new channel. We give an overview over this quickly evolving field with special emphasize on new experimental ideas and possibilities for probing new physics beyond the electroweak scale.
1005.5136
Krzysztof Rolbiecki
Terrance Figy, Krzysztof Rolbiecki, Yudi Santoso
Tau-Sneutrino NLSP and Multilepton Signatures at the LHC
25 pages, 6 figures, minor changes to match the version published in Phys.Rev.D
Phys.Rev.D82:075016,2010
10.1103/PhysRevD.82.075016
IPPP/10/37, DCPT/10/74, CERN-PH-TH/2010-107
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In models with gravitino as the lightest supersymmetric particle(LSP), the next to lightest supersymmetric particle (NLSP) can have a long lifetime and appear stable in collider experiments. We study the leptonic signatures of such a scenario with tau-sneutrino as the NLSP, which is realized in the non-universal Higgs masses scenario. We focus on an interesting trilepton signature with two like-sign taus and an electron or a muon of opposite sign. The neutralinos and charginos are quite heavy in the model considered, and the trilepton signal comes mostly from the slepton-sneutrino production. We identify the relevant backgrounds, taking into account tau decays, and devise a set of cuts to optimize this trilepton signal. We simulate signal and backgrounds at the LHC with 14 TeV center-of-mass energy. Although the sleptons in this model are relatively light, O(100 GeV), discovery is more demanding compared to typical neutralino LSP scenarios. The trilepton signal requires large amount of accumulated data, at least ~80 fb^-1, at the CM energy of 14 TeV.
[ { "created": "Thu, 27 May 2010 18:01:47 GMT", "version": "v1" }, { "created": "Thu, 28 Oct 2010 12:59:56 GMT", "version": "v2" } ]
2010-11-03
[ [ "Figy", "Terrance", "" ], [ "Rolbiecki", "Krzysztof", "" ], [ "Santoso", "Yudi", "" ] ]
In models with gravitino as the lightest supersymmetric particle(LSP), the next to lightest supersymmetric particle (NLSP) can have a long lifetime and appear stable in collider experiments. We study the leptonic signatures of such a scenario with tau-sneutrino as the NLSP, which is realized in the non-universal Higgs masses scenario. We focus on an interesting trilepton signature with two like-sign taus and an electron or a muon of opposite sign. The neutralinos and charginos are quite heavy in the model considered, and the trilepton signal comes mostly from the slepton-sneutrino production. We identify the relevant backgrounds, taking into account tau decays, and devise a set of cuts to optimize this trilepton signal. We simulate signal and backgrounds at the LHC with 14 TeV center-of-mass energy. Although the sleptons in this model are relatively light, O(100 GeV), discovery is more demanding compared to typical neutralino LSP scenarios. The trilepton signal requires large amount of accumulated data, at least ~80 fb^-1, at the CM energy of 14 TeV.
hep-ph/9403337
Chris Lassig
C. C. Lassig and R. R. Volkas
Phenomenology of the Two Higgs Doublet Sector of a Quark-Lepton Symmetric Model
17 pages + 2 figures all in uuencoded compressed file, REVTeX 3.0, UM-P-94/21, OZ-94/8
Phys.Rev. D51 (1995) 285-288
10.1103/PhysRevD.51.285
null
hep-ph
null
In the simplest examples of models with a discrete quark-lepton symmetry, an electroweak symmetry breaking sector with more than one Higgs doublet is necessary to obtain the correct mass relations between quarks and leptons. A two Higgs doublet model has flavour-nonconserving Yukawa couplings, which are proportional to the masses of the quark-lepton symmetric partners of the fermions. We describe how flavour changing leptonic decays can occur, with branching ratios not far beyond that currently measureable, enabling investigation of the phenomenology of such models.
[ { "created": "Wed, 23 Mar 1994 04:12:39 GMT", "version": "v1" } ]
2009-10-28
[ [ "Lassig", "C. C.", "" ], [ "Volkas", "R. R.", "" ] ]
In the simplest examples of models with a discrete quark-lepton symmetry, an electroweak symmetry breaking sector with more than one Higgs doublet is necessary to obtain the correct mass relations between quarks and leptons. A two Higgs doublet model has flavour-nonconserving Yukawa couplings, which are proportional to the masses of the quark-lepton symmetric partners of the fermions. We describe how flavour changing leptonic decays can occur, with branching ratios not far beyond that currently measureable, enabling investigation of the phenomenology of such models.
hep-ph/9611380
Gabor Cynolter
G. Cynolter and G. Pocsik
Vector Condensate Model of Electroweak Interactions
9p Latex, no figure, the original postscript file is replaced by the LaTeX src file
Heavy Ion Phys. 5 (1997) 19-25
10.1007/BF03157991
ITP-Budapest 518
hep-ph
null
Motivated by the fact that the Higgs is not seen, we have proposed a version of the standard model where the scalar doublet is replaced by a vector doublet and its neutral member forms a nonvanishing condensate. Gauge fields are coupled to the new vector fields B in a gauge invariant way leading to mass terms for the gauge fields by condensation. B-particles become massive because of their self interactions. Fermion and gauge field couplings are standard. Low energy charged current phenomenology fixes the condensate. Fermion masses are coming from the condensation and B-particle-fermion couplings. The Kobayashi-Maskawa description is unchanged. The model has a low mementum scale of about 2 TeV. For instance, from tree-graph unitarity at a scale of 1 TeV the minimum mass of a charged B-particle is 369 GeV. Such B-particles are shown to copiously produced at high-energy linear $e^+e^-$ colliders. The model survives the test of oblique radiative corrections. To each momentum scale there exists a range of B masses where the S, T parameters are compatible with the experiment. For instance, at a scale of 1 TeV from the S parameter the minimum mass of a charged (neutral) B is 200-350 GeV (400-550 GeV).
[ { "created": "Wed, 20 Nov 1996 17:39:21 GMT", "version": "v1" }, { "created": "Thu, 19 Dec 1996 13:08:30 GMT", "version": "v2" } ]
2022-02-23
[ [ "Cynolter", "G.", "" ], [ "Pocsik", "G.", "" ] ]
Motivated by the fact that the Higgs is not seen, we have proposed a version of the standard model where the scalar doublet is replaced by a vector doublet and its neutral member forms a nonvanishing condensate. Gauge fields are coupled to the new vector fields B in a gauge invariant way leading to mass terms for the gauge fields by condensation. B-particles become massive because of their self interactions. Fermion and gauge field couplings are standard. Low energy charged current phenomenology fixes the condensate. Fermion masses are coming from the condensation and B-particle-fermion couplings. The Kobayashi-Maskawa description is unchanged. The model has a low mementum scale of about 2 TeV. For instance, from tree-graph unitarity at a scale of 1 TeV the minimum mass of a charged B-particle is 369 GeV. Such B-particles are shown to copiously produced at high-energy linear $e^+e^-$ colliders. The model survives the test of oblique radiative corrections. To each momentum scale there exists a range of B masses where the S, T parameters are compatible with the experiment. For instance, at a scale of 1 TeV from the S parameter the minimum mass of a charged (neutral) B is 200-350 GeV (400-550 GeV).
1102.3116
Eugenio Del Nobile
Eugenio Del Nobile and Francesco Sannino (CP3-Origins)
Dark Matter Effective Theory
Few typos corrected; Phenomenological section added with an application of the effective operators to dark matter direct detection searches
Int.J.Mod.Phys. A27 (2012) 1250065
10.1142/S0217751X12500650
null
hep-ph astro-ph.HE hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We organize the effective (self)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter cutoff scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting dark matter induced flavor-changing operators. Our general framework allows for model independent investigations of dark matter properties.
[ { "created": "Tue, 15 Feb 2011 16:13:25 GMT", "version": "v1" }, { "created": "Wed, 18 Apr 2012 08:07:56 GMT", "version": "v2" } ]
2012-04-26
[ [ "Del Nobile", "Eugenio", "", "CP3-Origins" ], [ "Sannino", "Francesco", "", "CP3-Origins" ] ]
We organize the effective (self)interaction terms for complex scalar dark matter candidates which are either an isosinglet, isodoublet or an isotriplet with respect to the weak interactions. The classification has been performed ordering the operators in inverse powers of the dark matter cutoff scale. We assume Lorentz invariance, color and charge neutrality. We also introduce potentially interesting dark matter induced flavor-changing operators. Our general framework allows for model independent investigations of dark matter properties.
hep-ph/9312333
Bern
Z. Bern, G. Chalmers, L. Dixon, and D. A. Kosower
One-Loop N Gluon Amplitudes with Maximal Helicity Violation via Collinear Limits
12 pages (including figures), (cut down to meet PRL space requirements and some improvements included), SLAC--PUB--6409
Phys.Rev.Lett.72:2134-2137,1994
10.1103/PhysRevLett.72.2134
null
hep-ph hep-th
null
We present a conjecture for the $n$-gluon one-loop amplitudes with maximal helicity violation. The conjecture emerges from the powerful requirement that the amplitudes have the correct behavior in the collinear limits of external momenta. One implication is that the corresponding amplitudes where three or more gluon legs are replaced by photons vanish for $n>4$.
[ { "created": "Fri, 24 Dec 1993 01:28:21 GMT", "version": "v1" }, { "created": "Tue, 1 Feb 1994 08:43:07 GMT", "version": "v2" } ]
2010-11-15
[ [ "Bern", "Z.", "" ], [ "Chalmers", "G.", "" ], [ "Dixon", "L.", "" ], [ "Kosower", "D. A.", "" ] ]
We present a conjecture for the $n$-gluon one-loop amplitudes with maximal helicity violation. The conjecture emerges from the powerful requirement that the amplitudes have the correct behavior in the collinear limits of external momenta. One implication is that the corresponding amplitudes where three or more gluon legs are replaced by photons vanish for $n>4$.
hep-ph/0611352
Fedor Bezrukov
Fedor Bezrukov, Mikhail Shaposhnikov
Searching for dark matter sterile neutrino in laboratory
RevTex, 6 pages, 1 figure. Journal version accepted in Phys.Rev.D
Phys.Rev.D75:053005,2007
10.1103/PhysRevD.75.053005
null
hep-ph
null
If the dark matter of the Universe is made of sterile neutrinos with the mass in keV region they can be searched for with the help of X-ray satellites. We discuss the prospects of laboratory experiments that can be competitive and complimentary to Space missions. We argue that the detailed study of beta decays of tritium and other nuclei with the help of Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) can potentially enter into interesting parameter range and even supersede the current astronomical bounds on the properties of dark matter sterile neutrino.
[ { "created": "Tue, 28 Nov 2006 13:53:57 GMT", "version": "v1" }, { "created": "Tue, 13 Feb 2007 11:21:40 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bezrukov", "Fedor", "" ], [ "Shaposhnikov", "Mikhail", "" ] ]
If the dark matter of the Universe is made of sterile neutrinos with the mass in keV region they can be searched for with the help of X-ray satellites. We discuss the prospects of laboratory experiments that can be competitive and complimentary to Space missions. We argue that the detailed study of beta decays of tritium and other nuclei with the help of Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) can potentially enter into interesting parameter range and even supersede the current astronomical bounds on the properties of dark matter sterile neutrino.
1803.10391
Takuya Tatsuishi
Tatsuo Kobayashi, Kentaro Tanaka, and Takuya H. Tatsuishi
Neutrino mixing from finite modular groups
20 pages, 5 figures
Phys. Rev. D 98, 016004 (2018)
10.1103/PhysRevD.98.016004
HPHOU-18-002
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the lepton flavor models, whose flavor symmetries are finite subgroups of the modular group such as $S_3$ and $A_4$. In our models, couplings are also nontrivial representations of these groups and modular functions of the modulus. We study the possibilities that these models realize realistic values of neutrino masses and lepton mixing angles.
[ { "created": "Wed, 28 Mar 2018 02:37:18 GMT", "version": "v1" }, { "created": "Tue, 10 Jul 2018 08:17:32 GMT", "version": "v2" } ]
2018-07-11
[ [ "Kobayashi", "Tatsuo", "" ], [ "Tanaka", "Kentaro", "" ], [ "Tatsuishi", "Takuya H.", "" ] ]
We study the lepton flavor models, whose flavor symmetries are finite subgroups of the modular group such as $S_3$ and $A_4$. In our models, couplings are also nontrivial representations of these groups and modular functions of the modulus. We study the possibilities that these models realize realistic values of neutrino masses and lepton mixing angles.
hep-ph/9410293
null
B. Blok, R. Dikeman and M. Shifman
Calculation of 1/m^3 terms in the total semileptonic width of D mesons.
Final version accepted for publication in Physical Review D (19 pages, 5 figures appended as two PS files at the end of the LATEX file)
Phys.Rev. D51 (1995) 6167-6176
10.1103/PhysRevD.51.6167
TPI-MINN-94/23-T, UMN-TH-1261, Technion-PH-94-8
hep-ph
null
We calculate the 1/$m^3_c$ corrections in the inclusive semileptonic widths of $D$ mesons. We show that these are due to the novel penguin type operators that appear at this level in the transition operator. Taking into account the nonperturbative corrections leads to the predicted value of the semileptonic width significantly lower than the experimental value. The $1/m^3_c$ worsen the situation or at the very least, within uncertainty, give small contribution. We indicate possible ways out. It seems most probable that violations of duality are noticeable in the energy range characteristic to the inclusive decays in the charm family. Theoretically these deviations are related to divergence of the high-order terms in the power expansion in the inverse heavy quark mass.
[ { "created": "Fri, 14 Oct 1994 19:05:00 GMT", "version": "v1" }, { "created": "Tue, 28 Mar 1995 19:47:52 GMT", "version": "v2" } ]
2009-10-28
[ [ "Blok", "B.", "" ], [ "Dikeman", "R.", "" ], [ "Shifman", "M.", "" ] ]
We calculate the 1/$m^3_c$ corrections in the inclusive semileptonic widths of $D$ mesons. We show that these are due to the novel penguin type operators that appear at this level in the transition operator. Taking into account the nonperturbative corrections leads to the predicted value of the semileptonic width significantly lower than the experimental value. The $1/m^3_c$ worsen the situation or at the very least, within uncertainty, give small contribution. We indicate possible ways out. It seems most probable that violations of duality are noticeable in the energy range characteristic to the inclusive decays in the charm family. Theoretically these deviations are related to divergence of the high-order terms in the power expansion in the inverse heavy quark mass.
1101.4895
Christopher Coleman-Smith
Christopher E. Coleman-Smith, Steffen A. Bass, Dinesh K. Srivastava
Implementing the LPM effect in a parton cascade model
4 pages, 1 figure. A proceeding of ICPAGQP 2010
null
10.1016/j.nuclphysa.2011.05.071
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Parton Cascade Models (PCM), which describe the full time-evolution of a system of quarks and gluons using pQCD interactions are ideally suited for the description of jet production, including the emission, evolution and energy-loss of the full parton shower in a hot and dense QCD medium. The Landau-Pomeranchuk-Migdal (LPM) effect, the quantum interference of parton wave functions due to repeated scatterings against the background medium, is likely the dominant in-medium effect affecting jet suppression. We have implemented a probabilistic implementation of the LPM effect within the PCM which can be validated against previously derived analytical calculations by Baier et al (BDMPS-Z). Presented at the 6th International Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP 2010).
[ { "created": "Tue, 25 Jan 2011 18:52:06 GMT", "version": "v1" } ]
2015-05-27
[ [ "Coleman-Smith", "Christopher E.", "" ], [ "Bass", "Steffen A.", "" ], [ "Srivastava", "Dinesh K.", "" ] ]
Parton Cascade Models (PCM), which describe the full time-evolution of a system of quarks and gluons using pQCD interactions are ideally suited for the description of jet production, including the emission, evolution and energy-loss of the full parton shower in a hot and dense QCD medium. The Landau-Pomeranchuk-Migdal (LPM) effect, the quantum interference of parton wave functions due to repeated scatterings against the background medium, is likely the dominant in-medium effect affecting jet suppression. We have implemented a probabilistic implementation of the LPM effect within the PCM which can be validated against previously derived analytical calculations by Baier et al (BDMPS-Z). Presented at the 6th International Conference on Physics and Astrophysics of Quark Gluon Plasma (ICPAQGP 2010).
hep-ph/0509346
Joaquim Prades
Joaquim Prades (Granada), Elvira Gamiz (Glasgow) and Ignazio Scimemi (Valencia)
Charged Kaon K^+ --> 3 pi CP Violating Asymmetries vs epsilon'_K / epsilon_K
Invited talk given by J.P. at QCD'05, 4-8 July Montpellier, France
null
null
CAFPE-64/05, IFIC/05-49, UG-FT-194/05
hep-ph
null
We present the next-to-leading order full results in Chiral Perturbation Theory for the charged Kaon K --> 3 pi slope g CP violating asymmetries. We discuss the constraints that a measurement of these asymmetries would impose on the Standard Model results of epsilon_K' and search for new physics. We also study the kind of information that such measurement can provide on Im G_8, Im (e^2 G_E) and higher order weak couplings.
[ { "created": "Thu, 29 Sep 2005 13:22:52 GMT", "version": "v1" } ]
2016-09-06
[ [ "Prades", "Joaquim", "", "Granada" ], [ "Gamiz", "Elvira", "", "Glasgow" ], [ "Scimemi", "Ignazio", "", "Valencia" ] ]
We present the next-to-leading order full results in Chiral Perturbation Theory for the charged Kaon K --> 3 pi slope g CP violating asymmetries. We discuss the constraints that a measurement of these asymmetries would impose on the Standard Model results of epsilon_K' and search for new physics. We also study the kind of information that such measurement can provide on Im G_8, Im (e^2 G_E) and higher order weak couplings.
hep-ph/9409301
null
Pran Nath and R.Arnowitt
Event Rates in Dark Matter Detectors For Neutralinos Including Constraints From The $b\rightarrow s\gamma$ Decay
9 pages Latex+1page of figs(hard copy available on request),CERN-TH.7363/94, NUB-TH-3099/94,CTP-TAMU-38/94
Phys.Rev.Lett.74:4592-4595,1995
10.1103/PhysRevLett.74.4592
null
hep-ph
null
Event rates for dark matter detectors in neutralino--nucleus scattering are studied for supergravity unified models, including the constraint arising from the $b\rightarrow s\gamma$ experiment. The recent experimental measurement of this decay by the CLEO Collaboration leads to strong constraints on the SUSY particle spectrum,and also significantly affects the event rates in dark matter detectors. The analysis given here uses the accurate method for the computation of the relic density and leads to a dip in the event rate when the neutralino mass is $\sim M_Z/2$ due to the $Z$-pole, and similar results hold when the neutralino mass is $\sim m_h/2$ due to the Higgs pole . Implication of these results for dark matter detectors are discussed.
[ { "created": "Tue, 13 Sep 1994 17:03:44 GMT", "version": "v1" } ]
2009-09-25
[ [ "Nath", "Pran", "" ], [ "Arnowitt", "R.", "" ] ]
Event rates for dark matter detectors in neutralino--nucleus scattering are studied for supergravity unified models, including the constraint arising from the $b\rightarrow s\gamma$ experiment. The recent experimental measurement of this decay by the CLEO Collaboration leads to strong constraints on the SUSY particle spectrum,and also significantly affects the event rates in dark matter detectors. The analysis given here uses the accurate method for the computation of the relic density and leads to a dip in the event rate when the neutralino mass is $\sim M_Z/2$ due to the $Z$-pole, and similar results hold when the neutralino mass is $\sim m_h/2$ due to the Higgs pole . Implication of these results for dark matter detectors are discussed.
hep-ph/0210144
Michael Klasen
Michael Klasen
J/Psi production in direct and resolved gamma gamma collisions
Talk presented at the RADCOR/LL 2002 conference. 5 pages, 3 postscript figures
Nucl.Phys.Proc.Suppl. 116 (2003) 141-145
10.1016/S0920-5632(03)80159-7
null
hep-ph
null
The production of J/Psi mesons in gamma gamma collisions allows for a test of factorization in color-octet processes as predicted by NRQCD and observed at the Tevatron. We calculate the cross sections for J/Psi production with direct and resolved photons, including also the feed-down from chi_{cJ} and Psi' decays. Our NRQCD predictions are nicely confirmed by recent data from the DELPHI collaboration at CERN LEP2.
[ { "created": "Wed, 9 Oct 2002 14:29:43 GMT", "version": "v1" } ]
2009-11-07
[ [ "Klasen", "Michael", "" ] ]
The production of J/Psi mesons in gamma gamma collisions allows for a test of factorization in color-octet processes as predicted by NRQCD and observed at the Tevatron. We calculate the cross sections for J/Psi production with direct and resolved photons, including also the feed-down from chi_{cJ} and Psi' decays. Our NRQCD predictions are nicely confirmed by recent data from the DELPHI collaboration at CERN LEP2.
hep-ph/0212089
Joaquim Inacio da Silva Marcos
J.I. Silva-Marcos
On the Reduction of CP Violation Phases
10 pages, LaTeX 2e
null
null
null
hep-ph
null
We describe a method that is used to reduce, significantly, the number of CP violating complex phases in the Yukawa parameters. With this Reduction of Complex Phases (RCP) we obtain only one CP violating complex phase in the case where the neutrinos have an (effective) $3\times 3$ Majorana mass matrix. For the See Saw extension of the SM with three righthanded neutrinos, and in connection with CP violation in leptogenis, we reduce the usual 6 complex phases to only 2.
[ { "created": "Thu, 5 Dec 2002 19:45:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Silva-Marcos", "J. I.", "" ] ]
We describe a method that is used to reduce, significantly, the number of CP violating complex phases in the Yukawa parameters. With this Reduction of Complex Phases (RCP) we obtain only one CP violating complex phase in the case where the neutrinos have an (effective) $3\times 3$ Majorana mass matrix. For the See Saw extension of the SM with three righthanded neutrinos, and in connection with CP violation in leptogenis, we reduce the usual 6 complex phases to only 2.
hep-ph/0309294
Mahiko Suzuki
Sandip Pakvasa and Mahiko Suzuki
On the hidden charm state at 3872 MeV
10 pages, 1 eps figure, and 1 Table in Revtex. A comment with two references is added on mixing between a charmonium and a molecule
Phys.Lett.B579:67-73,2004
10.1016/j.physletb.2003.11.005
null
hep-ph hep-ex
null
We discuss some puzzling aspects of the narrow hidden charm resonance that was recently discovered by the Belle Collaboration at mass 3872 MeV. In order to determine its quantum numbers, a crucial piece of information is the spin of the dipion in the decay final state pi^+pi^-J/psi. We give the angular distributions and correlations of the final particles in the decay which will give this information about the nature of this resonance.
[ { "created": "Thu, 25 Sep 2003 17:28:01 GMT", "version": "v1" }, { "created": "Tue, 30 Sep 2003 19:09:23 GMT", "version": "v2" } ]
2008-11-26
[ [ "Pakvasa", "Sandip", "" ], [ "Suzuki", "Mahiko", "" ] ]
We discuss some puzzling aspects of the narrow hidden charm resonance that was recently discovered by the Belle Collaboration at mass 3872 MeV. In order to determine its quantum numbers, a crucial piece of information is the spin of the dipion in the decay final state pi^+pi^-J/psi. We give the angular distributions and correlations of the final particles in the decay which will give this information about the nature of this resonance.
hep-ph/9810515
Hsien-Hung Shih
Hsien-Hung Shih, Shih-Chang Lee, Hsiang-nan Li
The $\Lambda_b\to pl{\bar\nu}$ decay in perturbative QCD
22 pages in Latex file, 6 figures in postscript files, figure fig6.ps changed
Phys.Rev. D59 (1999) 094014
10.1103/PhysRevD.59.094014
NCKU-HEP-98-10
hep-ph
null
We develop perturbative QCD factorization theorems for the exclusive semileptonic heavy baryon decay $\Lambda_b \to pl{\bar\nu}$, in which the relevant hadronic form factor is expressed as the convolution of a hard subamplitude with the $\Lambda_b$ baryon wave function and the proton wave function. The specific evolution scale for the proton wave function, determined from the best fit to the data of the proton form factor, is adopted. The Sudakov resummation for a heavy-light system (the $\Lambda_b$ baryon) and the quark-level decay diagrams with at least one hard gluon attaching the $b$ quark, which were ignored in the literature, are incorporated. It turns out that these additional ingredients are important: the neglect of the former and the latter reduces the results of the form factor by factors 1.5 and 3, respectively. We present the predictions of the form factor and of the proton energy spectrum for the various choices of the parameter involved in the $\Lambda_b$ baryon wave function.
[ { "created": "Thu, 29 Oct 1998 03:31:33 GMT", "version": "v1" }, { "created": "Fri, 30 Oct 1998 06:57:57 GMT", "version": "v2" } ]
2009-10-31
[ [ "Shih", "Hsien-Hung", "" ], [ "Lee", "Shih-Chang", "" ], [ "Li", "Hsiang-nan", "" ] ]
We develop perturbative QCD factorization theorems for the exclusive semileptonic heavy baryon decay $\Lambda_b \to pl{\bar\nu}$, in which the relevant hadronic form factor is expressed as the convolution of a hard subamplitude with the $\Lambda_b$ baryon wave function and the proton wave function. The specific evolution scale for the proton wave function, determined from the best fit to the data of the proton form factor, is adopted. The Sudakov resummation for a heavy-light system (the $\Lambda_b$ baryon) and the quark-level decay diagrams with at least one hard gluon attaching the $b$ quark, which were ignored in the literature, are incorporated. It turns out that these additional ingredients are important: the neglect of the former and the latter reduces the results of the form factor by factors 1.5 and 3, respectively. We present the predictions of the form factor and of the proton energy spectrum for the various choices of the parameter involved in the $\Lambda_b$ baryon wave function.
0707.2878
Saurabh D. Rindani
P.S. Bhupal Dev, A. Djouadi, R.M. Godbole, M.M. M\"uhlleitner, S.D. Rindani
Determining the CP properties of the Higgs boson
4 pages, revtex, uses axodraw (style file included in the submission)
Phys.Rev.Lett.100:051801,2008
10.1103/PhysRevLett.100.051801
IISc-CHEP/7/07, CERN-PH-TH/2007-115, LPT-ORSAY-07-49, LAPTH-1194/07
hep-ph
null
The search and the probe of the fundamental properties of Higgs boson(s) and, in particular, the determination of their charge conjugation and parity (CP) quantum numbers, is one of the main tasks of future high-energy colliders. We demonstrate that the CP properties of a Standard Model-like Higgs particle can be unambiguously assessed by measuring just the total cross section and the top polarization in associated Higgs production with top quark pairs in e+e- collisions.
[ { "created": "Thu, 19 Jul 2007 12:19:41 GMT", "version": "v1" } ]
2008-11-26
[ [ "Dev", "P. S. Bhupal", "" ], [ "Djouadi", "A.", "" ], [ "Godbole", "R. M.", "" ], [ "Mühlleitner", "M. M.", "" ], [ "Rindani", "S. D.", "" ] ]
The search and the probe of the fundamental properties of Higgs boson(s) and, in particular, the determination of their charge conjugation and parity (CP) quantum numbers, is one of the main tasks of future high-energy colliders. We demonstrate that the CP properties of a Standard Model-like Higgs particle can be unambiguously assessed by measuring just the total cross section and the top polarization in associated Higgs production with top quark pairs in e+e- collisions.
hep-ph/0202128
Matthias Neubert
Matthias Neubert, Ben D. Pecjak (Cornell University)
Higher-Order Corrections to QCD Factorization in B->pi K,pi pi Decays
19 pages, 2 figures, journal version published in JHEP
JHEP 0202 (2002) 028
10.1088/1126-6708/2002/02/028
CLNS-02/1777
hep-ph
null
The renormalon calculus is used to calculate the terms of order $\beta_0^{n-1}\alpha_s^n$ in the perturbative expansions of the Wilson coefficients and hard-scattering kernels entering the QCD factorization formula for hadronic B-meson decays into two light pseudoscalar mesons. The asymptotic behavior of the expansions is analyzed, and a minimal model of power corrections arising from soft ``non-factorizable'' gluon exchange to the B->pi K,pi pi decay amplitudes is obtained, which takes into account the structure of the leading and subleading infrared renormalon singularities. Whereas the resulting power corrections are generally very small, some of the strong-interaction phases of the hard-scattering kernels receive sizeable two-loop corrections. The implications of these findings on CP asymmetries and branching ratios are investigated.
[ { "created": "Thu, 14 Feb 2002 20:16:02 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2002 21:03:55 GMT", "version": "v2" } ]
2009-11-07
[ [ "Neubert", "Matthias", "", "Cornell University" ], [ "Pecjak", "Ben D.", "", "Cornell University" ] ]
The renormalon calculus is used to calculate the terms of order $\beta_0^{n-1}\alpha_s^n$ in the perturbative expansions of the Wilson coefficients and hard-scattering kernels entering the QCD factorization formula for hadronic B-meson decays into two light pseudoscalar mesons. The asymptotic behavior of the expansions is analyzed, and a minimal model of power corrections arising from soft ``non-factorizable'' gluon exchange to the B->pi K,pi pi decay amplitudes is obtained, which takes into account the structure of the leading and subleading infrared renormalon singularities. Whereas the resulting power corrections are generally very small, some of the strong-interaction phases of the hard-scattering kernels receive sizeable two-loop corrections. The implications of these findings on CP asymmetries and branching ratios are investigated.
hep-ph/9701371
Vladislav Korotkov
V.Korotkov, W.-D.Nowak
Summary of Physics Prospects for Polarized Nucleon-Nucleon Scattering at HERA-N
18 pages, Latex-2e, elsart.sty, epsfig.sty, rotating.sty, 12 .eps figures. Invited talk presented by W.-D. Nowak at the 2nd ELFE Workshop (St. Malo, September 1996)
Nucl.Phys. A622 (1997) 78c-94c
10.1016/S0375-9474(97)00334-5
DESY 97-004
hep-ph
null
The physics scope of polarized nucleon-nucleon collisions originating from an internal polarized target in the HERA proton beam is summarized. Based on 240 pb^{-1} integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are given over a wide (x_F, p_T)-range for a variety of inclusive and exclusive final states. By measuring single spin asymmetries unique information can be obtained on higher twist contributions and their p_T-dependence. From double spin asymmetries in both photon and J/psi production it appears possible to measure the polarized gluon distribution in the range 0.1 < x_{gluon} < 0.4 with a good statistical accuracy. Drell-Yan pair production asymmetries in doubly longitudinal mode, measurable in the mass range 3-10 GeV, allow discrimination between different parametrizations of the polarized light sea quark distributions. In doubly transverse mode access to the quark transversity distribution might become possible. Statistically significant results can be expected in the elastic channel.
[ { "created": "Fri, 24 Jan 1997 14:51:10 GMT", "version": "v1" } ]
2016-09-06
[ [ "Korotkov", "V.", "" ], [ "Nowak", "W. -D.", "" ] ]
The physics scope of polarized nucleon-nucleon collisions originating from an internal polarized target in the HERA proton beam is summarized. Based on 240 pb^{-1} integrated luminosity at 40 GeV c.m. energy, statistical sensitivities are given over a wide (x_F, p_T)-range for a variety of inclusive and exclusive final states. By measuring single spin asymmetries unique information can be obtained on higher twist contributions and their p_T-dependence. From double spin asymmetries in both photon and J/psi production it appears possible to measure the polarized gluon distribution in the range 0.1 < x_{gluon} < 0.4 with a good statistical accuracy. Drell-Yan pair production asymmetries in doubly longitudinal mode, measurable in the mass range 3-10 GeV, allow discrimination between different parametrizations of the polarized light sea quark distributions. In doubly transverse mode access to the quark transversity distribution might become possible. Statistically significant results can be expected in the elastic channel.
hep-ph/0405191
Ulrich Baur
U. Baur and D. Wackeroth
Electroweak Radiative Corrections to pp/ppbar -> W+/- -> l+/- nu Beyond the Pole Approximation
25 pages, revtex, 8 figures, 3 tables
Phys.Rev.D70:073015,2004
10.1103/PhysRevD.70.073015
UB-HET-04-01
hep-ph
null
We present a calculation of the complete electroweak O(alpha) corrections to pp/ppbar -> W+/- -> l+/- nu (l=e, mu) in the Standard Model of electroweak interactions, focusing on those corrections which do not contribute in the pole approximation. We study in detail the effect of these corrections on the transverse mass distribution, the W-width measurement, and the transverse mass ratio and cross section ratio of W and Z bosons.
[ { "created": "Wed, 19 May 2004 19:53:35 GMT", "version": "v1" } ]
2011-03-23
[ [ "Baur", "U.", "" ], [ "Wackeroth", "D.", "" ] ]
We present a calculation of the complete electroweak O(alpha) corrections to pp/ppbar -> W+/- -> l+/- nu (l=e, mu) in the Standard Model of electroweak interactions, focusing on those corrections which do not contribute in the pole approximation. We study in detail the effect of these corrections on the transverse mass distribution, the W-width measurement, and the transverse mass ratio and cross section ratio of W and Z bosons.
hep-ph/0011047
Douglas Ross
J.R. Forshaw, D.A. Ross, A. Sabio-Vera
Solving the BFKL Equation with Running Coupling
11 pages, 2 figs
Phys.Lett.B498:149-155,2001
10.1016/S0370-2693(00)01386-1
MC-TH-00/11, Cavendish-HEP-2000/11
hep-ph
null
We describe a formalism for solving the BFKL equation with a coupling that runs for momenta above a certain infrared cutoff. By suitably choosing matching conditions proper account is taken of the fact that the BFKL diffusion implies that the solution in the infrared (fixed coupling) regime depends upon the solution in the ultraviolet (running coupling) regime and vice versa. Expanding the BFKL kernel to a given order in the ratio of the transverse momenta allows arbitrary accuracy to be achieved.
[ { "created": "Fri, 3 Nov 2000 10:33:47 GMT", "version": "v1" }, { "created": "Thu, 30 Nov 2000 17:10:18 GMT", "version": "v2" } ]
2008-11-26
[ [ "Forshaw", "J. R.", "" ], [ "Ross", "D. A.", "" ], [ "Sabio-Vera", "A.", "" ] ]
We describe a formalism for solving the BFKL equation with a coupling that runs for momenta above a certain infrared cutoff. By suitably choosing matching conditions proper account is taken of the fact that the BFKL diffusion implies that the solution in the infrared (fixed coupling) regime depends upon the solution in the ultraviolet (running coupling) regime and vice versa. Expanding the BFKL kernel to a given order in the ratio of the transverse momenta allows arbitrary accuracy to be achieved.
hep-ph/0410155
Ulrich Haisch
Paolo Gambino, Ulrich Haisch and Mikolaj Misiak
Determining the sign of the b -> s gamma amplitude
Journal version, references added, minor modifications. 4 pages, 2 figures
Phys.Rev.Lett.94:061803,2005
10.1103/PhysRevLett.94.061803
null
hep-ph hep-ex
null
The latest Belle and BaBar measurements of the inclusive B -> X_s l^+ l^- branching ratio have smaller errors and lower central values than the previous ones. We point out that these results indicate that the sign of the b -> s gamma amplitude is the same as in the SM. This underscores the importance of B -> X_s l^+ l^- in searches for new physics, and may be relevant for neutralino dark matter analyses within the MSSM.
[ { "created": "Mon, 11 Oct 2004 16:29:53 GMT", "version": "v1" }, { "created": "Mon, 14 Feb 2005 14:29:01 GMT", "version": "v2" } ]
2008-11-26
[ [ "Gambino", "Paolo", "" ], [ "Haisch", "Ulrich", "" ], [ "Misiak", "Mikolaj", "" ] ]
The latest Belle and BaBar measurements of the inclusive B -> X_s l^+ l^- branching ratio have smaller errors and lower central values than the previous ones. We point out that these results indicate that the sign of the b -> s gamma amplitude is the same as in the SM. This underscores the importance of B -> X_s l^+ l^- in searches for new physics, and may be relevant for neutralino dark matter analyses within the MSSM.
hep-ph/0502059
Mitsuru Kakizaki
Mitsuru Kakizaki, Shigeki Matsumoto, Yoshio Sato, Masato Senami
Significant effects of second KK particles on LKP dark matter physics
12 pages, 5 figures. Comments and references added
Phys.Rev. D71 (2005) 123522
10.1103/PhysRevD.71.123522
null
hep-ph
null
We point out that Kaluza-Klein (KK) dark matter physics is drastically affected by second KK particles. In this work various interesting phenomena caused by the second KK modes are discussed. In particular, we reevaluate the annihilation cross section and thermal relic density of the KK dark matter quantitatively in universal extra dimensions, in which all the standard model particles propagate. In these models, the first KK mode of $B$ boson is a viable dark matter candidate by virtue of KK-parity. We demonstrate that the KK dark matter annihilation cross section can be enhanced, compared with the tree level cross section mediated only by first KK particles. The dark matter mass consistent with the WMAP observation is increased.
[ { "created": "Mon, 7 Feb 2005 18:10:00 GMT", "version": "v1" }, { "created": "Fri, 17 Jun 2005 10:49:19 GMT", "version": "v2" } ]
2009-11-11
[ [ "Kakizaki", "Mitsuru", "" ], [ "Matsumoto", "Shigeki", "" ], [ "Sato", "Yoshio", "" ], [ "Senami", "Masato", "" ] ]
We point out that Kaluza-Klein (KK) dark matter physics is drastically affected by second KK particles. In this work various interesting phenomena caused by the second KK modes are discussed. In particular, we reevaluate the annihilation cross section and thermal relic density of the KK dark matter quantitatively in universal extra dimensions, in which all the standard model particles propagate. In these models, the first KK mode of $B$ boson is a viable dark matter candidate by virtue of KK-parity. We demonstrate that the KK dark matter annihilation cross section can be enhanced, compared with the tree level cross section mediated only by first KK particles. The dark matter mass consistent with the WMAP observation is increased.
hep-ph/9709225
Saurabh D. Rindani
P. Poulose and Saurabh D. Rindani
Electric dipole moment of top quark and CP-violating asymmetries in gamma gamma -> t tbar
17 pages, LaTeX, 3 figures in postscript files (included), macros file included
Phys.Rev.D57:5444-5452,1998; Erratum-ibid.D61:119902,2000
10.1103/PhysRevD.57.5444 10.1103/PhysRevD.61.119902
PRL-TH-97/25
hep-ph
null
CP-violating asymmetries due to a possible electric dipole interaction of the top quark in the production and subsequent decay of top quark-top antiquark pair in photon-photon collisions are studied. The asymmetries defined can be used to determine the imaginary part of the electric dipole form factors. A gamma-gamma collider with photon beams generated from laser back-scattering off electron beams with an integrated geometric luminosity of 20 fb^{-1} can put a limit of the order of 10^{-17} e cm on the imaginary part of the electric dipole form factor of the top quark if the electron beams have longitudinal polarization and the laser beams have circular polarization.
[ { "created": "Wed, 3 Sep 1997 04:24:54 GMT", "version": "v1" } ]
2014-11-17
[ [ "Poulose", "P.", "" ], [ "Rindani", "Saurabh D.", "" ] ]
CP-violating asymmetries due to a possible electric dipole interaction of the top quark in the production and subsequent decay of top quark-top antiquark pair in photon-photon collisions are studied. The asymmetries defined can be used to determine the imaginary part of the electric dipole form factors. A gamma-gamma collider with photon beams generated from laser back-scattering off electron beams with an integrated geometric luminosity of 20 fb^{-1} can put a limit of the order of 10^{-17} e cm on the imaginary part of the electric dipole form factor of the top quark if the electron beams have longitudinal polarization and the laser beams have circular polarization.
0704.1839
Vladimir Makarenko
V. Makarenko
ALHEP symbolic algebra program for high-energy physics
33 pages, 4 figures
null
null
null
hep-ph
null
ALHEP is the symbolic algebra program for high-energy physics. It deals with amplitudes calculation, matrix element squaring, Wick theorem, dimensional regularization, tensor reduction of loop integrals and simplification of final expressions. The program output includes: Fortran code for differential cross section, Mathematica files to view results and intermediate steps and TeX source for Feynman diagrams. The PYTHIA interface is available. The project website http://www.hep.by/alhep contains up-to-date executables, manual and script examples.
[ { "created": "Fri, 13 Apr 2007 23:02:17 GMT", "version": "v1" } ]
2007-05-23
[ [ "Makarenko", "V.", "" ] ]
ALHEP is the symbolic algebra program for high-energy physics. It deals with amplitudes calculation, matrix element squaring, Wick theorem, dimensional regularization, tensor reduction of loop integrals and simplification of final expressions. The program output includes: Fortran code for differential cross section, Mathematica files to view results and intermediate steps and TeX source for Feynman diagrams. The PYTHIA interface is available. The project website http://www.hep.by/alhep contains up-to-date executables, manual and script examples.
2403.13529
Nilavjyoti Hazarika
Nilavjyoti Hazarika, Paramita Deka and Kalpana Bora
Scalar Dark Matter and Stability of Higgs Vacuum within a Minimal SO(10) GUT Model
17 pages, 6 figures, 1 table
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we delve to investigate a feasible range of dark matter (DM) masses within a non-supersymmetric $SO(10)$ Grand Unified Theory (GUT) scalar dark matter model, in freeze-out scenario. This model includes a singlet scalar denoted as S and an inert doublet represented by $\phi$. Being part of SO(10), the quantum numbers of DM particles are assigned and hence we know their nature. These fields are odd under a discrete $Z_2$ matter parity $(-1)^{3(B-L)}$. The dark matter with mass 300 $\leq M_{DM} \leq$ 1000 GeV emerges as a mixture of the $Z_2$-odd scalar singlet $S$ and the neutral element of the doublet $\phi$, both residing within a \textbf{16}-dim scalar representation of $SO(10)$. In this work we consider a real scalar \textbf{S} belonging to \textbf{16} of SO(10) as DM. We also investigate the one-loop vacuum stability through the solution of Renormalization Group Equations (RGEs) for the model's parameters. Subsequently, we scrutinize the model's predictions within the confines of contemporary theoretical and experimental restrictions. In addition to achieving vacuum stability in the SO(10) framework, the DM mass is found to lie in the previously unaddressed (theoretically) intermediate mass region of 300$\leqslant$ MDM $\leqslant$ 1000 GeV which also adheres to many current phenomenological constraints, like recent direct experimental bounds from XENON1T, indirect detection bounds from Fermi-LAT experiment, Higgs invisible decay and Electroweak Precision Test. The stability of the electroweak vacuum is seen to be present up to the Planck scale. These model predictions possess the potential for future validation through dark matter search experiments, as they are testable in future DM search experiments, along with the added feature that the model is a part of an elegant grand unified theory.
[ { "created": "Wed, 20 Mar 2024 12:02:10 GMT", "version": "v1" } ]
2024-03-21
[ [ "Hazarika", "Nilavjyoti", "" ], [ "Deka", "Paramita", "" ], [ "Bora", "Kalpana", "" ] ]
In this work, we delve to investigate a feasible range of dark matter (DM) masses within a non-supersymmetric $SO(10)$ Grand Unified Theory (GUT) scalar dark matter model, in freeze-out scenario. This model includes a singlet scalar denoted as S and an inert doublet represented by $\phi$. Being part of SO(10), the quantum numbers of DM particles are assigned and hence we know their nature. These fields are odd under a discrete $Z_2$ matter parity $(-1)^{3(B-L)}$. The dark matter with mass 300 $\leq M_{DM} \leq$ 1000 GeV emerges as a mixture of the $Z_2$-odd scalar singlet $S$ and the neutral element of the doublet $\phi$, both residing within a \textbf{16}-dim scalar representation of $SO(10)$. In this work we consider a real scalar \textbf{S} belonging to \textbf{16} of SO(10) as DM. We also investigate the one-loop vacuum stability through the solution of Renormalization Group Equations (RGEs) for the model's parameters. Subsequently, we scrutinize the model's predictions within the confines of contemporary theoretical and experimental restrictions. In addition to achieving vacuum stability in the SO(10) framework, the DM mass is found to lie in the previously unaddressed (theoretically) intermediate mass region of 300$\leqslant$ MDM $\leqslant$ 1000 GeV which also adheres to many current phenomenological constraints, like recent direct experimental bounds from XENON1T, indirect detection bounds from Fermi-LAT experiment, Higgs invisible decay and Electroweak Precision Test. The stability of the electroweak vacuum is seen to be present up to the Planck scale. These model predictions possess the potential for future validation through dark matter search experiments, as they are testable in future DM search experiments, along with the added feature that the model is a part of an elegant grand unified theory.
1712.06572
Luca Di Luzio
Luca Di Luzio, Matthew Kirk, Alexander Lenz
One constraint to kill them all?
12 pages, 5 figures. To appear in PRD, matches the published version up to the title
Phys. Rev. D 97, 095035 (2018)
10.1103/PhysRevD.97.095035
IPPP/17/106
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many new physics models that explain the intriguing anomalies in the $b$-quark flavour sector are severely constrained by $B_s$-mixing, for which the Standard Model prediction and experiment agreed well until recently. The most recent FLAG average of lattice results for the non-perturbative matrix elements points, however, in the direction of a small discrepancy in this observable. Using up-to-date inputs from standard sources such as PDG, FLAG and one of the two leading CKM fitting groups to determine $\Delta M_s^{\rm SM}$, we find a severe reduction of the allowed parameter space of $Z'$ and leptoquark models explaining the $B$-anomalies. Remarkably, in the former case the upper bound on the $Z'$ mass approaches dangerously close to the energy scales already probed by the LHC. We finally identify some model building directions in order to alleviate the tension with $B_s$-mixing.
[ { "created": "Mon, 18 Dec 2017 18:33:22 GMT", "version": "v1" }, { "created": "Tue, 15 May 2018 09:20:20 GMT", "version": "v2" } ]
2018-05-30
[ [ "Di Luzio", "Luca", "" ], [ "Kirk", "Matthew", "" ], [ "Lenz", "Alexander", "" ] ]
Many new physics models that explain the intriguing anomalies in the $b$-quark flavour sector are severely constrained by $B_s$-mixing, for which the Standard Model prediction and experiment agreed well until recently. The most recent FLAG average of lattice results for the non-perturbative matrix elements points, however, in the direction of a small discrepancy in this observable. Using up-to-date inputs from standard sources such as PDG, FLAG and one of the two leading CKM fitting groups to determine $\Delta M_s^{\rm SM}$, we find a severe reduction of the allowed parameter space of $Z'$ and leptoquark models explaining the $B$-anomalies. Remarkably, in the former case the upper bound on the $Z'$ mass approaches dangerously close to the energy scales already probed by the LHC. We finally identify some model building directions in order to alleviate the tension with $B_s$-mixing.
hep-ph/0301220
Chris Quigg
Gabriela Barenboim and Chris Quigg
Neutrino Observatories Can Characterize Cosmic Sources and Neutrino Properties
9 RevTeX pages, 4 figures
Phys.Rev.D67:073024,2003
10.1103/PhysRevD.67.073024
FERMILAB-Pub-03/018-T, NSF-ITP-03-08
hep-ph astro-ph
null
Neutrino telescopes that measure relative fluxes of ultrahigh-energy $\nu_{e}, \nu_{\mu}, \nu_{\tau}$ can give information about the location and characteristics of sources, about neutrino mixing, and can test for neutrino instability and for departures from CPT invariance in the neutrino sector. We investigate consequences of neutrino mixing for the neutrino flux arriving at Earth, and consider how terrestrial measurements can characterize distant sources. We contrast mixtures that arise from neutrino oscillations with those signaling neutrino decays. We stress the importance of measuring $\nu_{e}, \nu_{\mu}, \nu_{\tau}$ fluxes in neutrino observatories.
[ { "created": "Fri, 24 Jan 2003 19:19:19 GMT", "version": "v1" } ]
2009-05-05
[ [ "Barenboim", "Gabriela", "" ], [ "Quigg", "Chris", "" ] ]
Neutrino telescopes that measure relative fluxes of ultrahigh-energy $\nu_{e}, \nu_{\mu}, \nu_{\tau}$ can give information about the location and characteristics of sources, about neutrino mixing, and can test for neutrino instability and for departures from CPT invariance in the neutrino sector. We investigate consequences of neutrino mixing for the neutrino flux arriving at Earth, and consider how terrestrial measurements can characterize distant sources. We contrast mixtures that arise from neutrino oscillations with those signaling neutrino decays. We stress the importance of measuring $\nu_{e}, \nu_{\mu}, \nu_{\tau}$ fluxes in neutrino observatories.
1203.1320
Sean Tulin
Moira I. Gresham, Ian-Woo Kim, Sean Tulin, Kathryn M. Zurek
Confronting Top AFB with Parity Violation Constraints
4 pages
null
10.1103/PhysRevD.86.034029
MCTP-12-06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the implications of low-energy precision tests of parity violation on t-channel mediator models explaining the top AFB excess measured by CDF and D0. Flavor-violating u-t or d-t couplings of new scalar or vector mediators generate at one-loop an anomalous contribution to the nuclear weak charge. As a result, atomic parity violation constraints disfavor at >3 sigma t-channel models that give rise to a greater than 20% AFB at the parton level for M_tt > 450 GeV while not producing too large a top cross-section. Even stronger constraints are expected through future measurements of the proton weak charge by the Q-Weak experiment.
[ { "created": "Tue, 6 Mar 2012 21:00:02 GMT", "version": "v1" } ]
2013-05-30
[ [ "Gresham", "Moira I.", "" ], [ "Kim", "Ian-Woo", "" ], [ "Tulin", "Sean", "" ], [ "Zurek", "Kathryn M.", "" ] ]
We consider the implications of low-energy precision tests of parity violation on t-channel mediator models explaining the top AFB excess measured by CDF and D0. Flavor-violating u-t or d-t couplings of new scalar or vector mediators generate at one-loop an anomalous contribution to the nuclear weak charge. As a result, atomic parity violation constraints disfavor at >3 sigma t-channel models that give rise to a greater than 20% AFB at the parton level for M_tt > 450 GeV while not producing too large a top cross-section. Even stronger constraints are expected through future measurements of the proton weak charge by the Q-Weak experiment.
0707.0320
Wu-Ki Tung
Wu-Ki Tung, H.L. Lai, J. Pumplin, P. Nadolsky, and C.-P. Yuan
Heavy Quark Mass Effects in PQCD and Heavy Flavor Parton Distributions
Contribution to the proceedings of the DIS2007 Workshop, Munich, Germany, April, 2007
null
10.1142/9789812706706_0022
null
hep-ph
null
The systematic treatment of heavy quark mass effects in DIS in current CTEQ global analysis is summarized. Applications of this treatment to the comparison between theory and experimental data on DIS charm production are described. The possibility of intrinsic charm in the nucleon is studied. The issue of determining the charm mass in global analysis is discussed.
[ { "created": "Mon, 2 Jul 2007 22:19:16 GMT", "version": "v1" } ]
2017-08-23
[ [ "Tung", "Wu-Ki", "" ], [ "Lai", "H. L.", "" ], [ "Pumplin", "J.", "" ], [ "Nadolsky", "P.", "" ], [ "Yuan", "C. -P.", "" ] ]
The systematic treatment of heavy quark mass effects in DIS in current CTEQ global analysis is summarized. Applications of this treatment to the comparison between theory and experimental data on DIS charm production are described. The possibility of intrinsic charm in the nucleon is studied. The issue of determining the charm mass in global analysis is discussed.
hep-ph/9802362
Philipp Haegler
P. Haegler, A. Schaefer
Evolution Equations for Higher Moments of Angular Momentum Distributions
10 pages in LaTeX with 1 eps-figure; missing \Psi in eq.(10) added; p.7/8: short paragraph dropped, one definition added
Phys.Lett.B430:179-185,1998
10.1016/S0370-2693(98)00414-6
University Regensburg preprint : TPR-98-08
hep-ph
null
Based on a sumrule for the nucleon spin we expand quark and gluon orbital angular momentum operators and derive an evolution matrix for higher moments of the corresponding distributions. In combination with the spin-dependent DGLAP-matrix we find a complete set of spin and orbital angular momentum evolution equations.
[ { "created": "Thu, 19 Feb 1998 14:32:53 GMT", "version": "v1" }, { "created": "Wed, 7 Oct 1998 13:29:20 GMT", "version": "v2" } ]
2014-11-17
[ [ "Haegler", "P.", "" ], [ "Schaefer", "A.", "" ] ]
Based on a sumrule for the nucleon spin we expand quark and gluon orbital angular momentum operators and derive an evolution matrix for higher moments of the corresponding distributions. In combination with the spin-dependent DGLAP-matrix we find a complete set of spin and orbital angular momentum evolution equations.
0805.3007
Kevin Black
K.M. Black
Randall-Sundrum Gravitons and Black Holes at the LHC
for Moriond QCD proceedings 2008, correcting refrences
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Models predicting the existence of extra spatial dimensions offer compelling and novel solutions to outstanding problems of the Standard Model. In such models, our universe exists on a 4 dimensional brane embedded in a larger dimensional space time. By allowing gravity to propagate in the bulk the gravitational coupling could be comparable with the other gauge interactions thus removing the hierarchy problem. The phenomenology of these models could have dramatic observable effects at the LHC includingthe production and decay of gravitons and mini black holes. In this note we summarize feasibility studies for the discovery of strong gravitational interactions at the LHC.
[ { "created": "Tue, 20 May 2008 05:48:17 GMT", "version": "v1" }, { "created": "Sat, 24 May 2008 01:29:21 GMT", "version": "v2" } ]
2008-05-24
[ [ "Black", "K. M.", "" ] ]
Models predicting the existence of extra spatial dimensions offer compelling and novel solutions to outstanding problems of the Standard Model. In such models, our universe exists on a 4 dimensional brane embedded in a larger dimensional space time. By allowing gravity to propagate in the bulk the gravitational coupling could be comparable with the other gauge interactions thus removing the hierarchy problem. The phenomenology of these models could have dramatic observable effects at the LHC includingthe production and decay of gravitons and mini black holes. In this note we summarize feasibility studies for the discovery of strong gravitational interactions at the LHC.
hep-ph/0606319
Kacper Zalewski
A. Bialas, W. Czyz and K. Zalewski
The Renyi entropy H_2 as a rigorous, measurable lower bound for the entropy of the interaction region in multiparticle production processes
Eur. Phys. J. C in print, 17 pages, 5 figures
Eur.Phys.J.C48:215-221,2006
10.1140/epjc/s2006-02623-6
null
hep-ph
null
A model-independent lower bound on the entropy S of the multiparticle system produced in high energy collisions, provided by the Renyi entropy H_2, is shown to be very effective. Estimates show that the ratio H_2/S remains close to one half for all realistic values of the parameters.
[ { "created": "Fri, 30 Jun 2006 13:06:21 GMT", "version": "v1" } ]
2009-01-07
[ [ "Bialas", "A.", "" ], [ "Czyz", "W.", "" ], [ "Zalewski", "K.", "" ] ]
A model-independent lower bound on the entropy S of the multiparticle system produced in high energy collisions, provided by the Renyi entropy H_2, is shown to be very effective. Estimates show that the ratio H_2/S remains close to one half for all realistic values of the parameters.
1006.2548
Alfredo Raya
Alfredo Raya and Edward Reyes
Fermion Condensate and Vacuum Current Density Induced by Homogeneous and Inhomogeneous Magnetic Fields in (2+1)-Dimensions
8 pages, 2 figures. Accepted for publication in Phys. Rev. D
Phys.Rev.D82:016004,2010
10.1103/PhysRevD.82.016004
null
hep-ph cond-mat.supr-con hep-th math-ph math.MP
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the condensate and the vacuum current density induced by external static magnetic fields in (2+1)-dimensions. At the perturbative level, we consider an exponentially decaying magnetic field along one cartesian coordinate. Non-perturbatively, we obtain the fermion propagator in the presence of a uniform magnetic field by solving the Schwinger-Dyson equation in the rainbow-ladder approximation. In the large flux limit, we observe that both these quantities, either perturbative (inhomogeneous) and non-perturbative (homogeneous), are proportional to the external field, in agreement with early expectations.
[ { "created": "Sun, 13 Jun 2010 17:17:15 GMT", "version": "v1" } ]
2014-11-21
[ [ "Raya", "Alfredo", "" ], [ "Reyes", "Edward", "" ] ]
We calculate the condensate and the vacuum current density induced by external static magnetic fields in (2+1)-dimensions. At the perturbative level, we consider an exponentially decaying magnetic field along one cartesian coordinate. Non-perturbatively, we obtain the fermion propagator in the presence of a uniform magnetic field by solving the Schwinger-Dyson equation in the rainbow-ladder approximation. In the large flux limit, we observe that both these quantities, either perturbative (inhomogeneous) and non-perturbative (homogeneous), are proportional to the external field, in agreement with early expectations.
1312.0517
Norbert Kaiser
N. Kaiser and S. Petschauer
Radiative corrections to the charged pion-pair production process {\boldmath$\pi^-\gamma\to \pi^+\pi^-\pi^-$} at low energies
19 pages, 17 figures, accepted for publication in Eur. Phys. J. A
null
10.1140/epja/i2013-13159-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the one-photon loop radiative corrections to the charged pion-pair production process $\pi^-\gamma\to\pi^+\pi^-\pi^-$. In the low-energy region this reaction is governed by the chiral pion-pion interaction. The pertinent set of 42 irreducible photon-loop diagrams is calculated by using the package FeynCalc. Electromagnetic counterterms with two independent low-energy constants $\widehat k_1$ and $\widehat k_2$ are included in order to remove the ultraviolet divergences generated by the photon-loops. Infrared finiteness of the virtual radiative corrections is achieved by including soft photon radiation below an energy cut-off $\lambda$. The purely electromagnetic interaction of the charged pions mediated by one-photon exchange is also taken into account. The radiative corrections to the total cross section (in the isospin limit) vary between $+10\%$ close to threshold and about $-1\%$ at a center-of-mass energy of $7m_\pi$. The largest contribution comes from the simple one-photon exchange. Radiative corrections to the $\pi^+\pi^-$ and $\pi^-\pi^-$ mass spectra are studied as well. The Coulomb singularity of the final-state interaction produces a kink in the dipion mass spectra. The virtual radiative corrections to elastic $\pi^-\pi^-$ scattering are derived additionally.
[ { "created": "Mon, 2 Dec 2013 17:00:40 GMT", "version": "v1" } ]
2015-06-18
[ [ "Kaiser", "N.", "" ], [ "Petschauer", "S.", "" ] ]
We calculate the one-photon loop radiative corrections to the charged pion-pair production process $\pi^-\gamma\to\pi^+\pi^-\pi^-$. In the low-energy region this reaction is governed by the chiral pion-pion interaction. The pertinent set of 42 irreducible photon-loop diagrams is calculated by using the package FeynCalc. Electromagnetic counterterms with two independent low-energy constants $\widehat k_1$ and $\widehat k_2$ are included in order to remove the ultraviolet divergences generated by the photon-loops. Infrared finiteness of the virtual radiative corrections is achieved by including soft photon radiation below an energy cut-off $\lambda$. The purely electromagnetic interaction of the charged pions mediated by one-photon exchange is also taken into account. The radiative corrections to the total cross section (in the isospin limit) vary between $+10\%$ close to threshold and about $-1\%$ at a center-of-mass energy of $7m_\pi$. The largest contribution comes from the simple one-photon exchange. Radiative corrections to the $\pi^+\pi^-$ and $\pi^-\pi^-$ mass spectra are studied as well. The Coulomb singularity of the final-state interaction produces a kink in the dipion mass spectra. The virtual radiative corrections to elastic $\pi^-\pi^-$ scattering are derived additionally.
hep-ph/9902218
Shang-Yung Wang
S.-Y. Wang, D. Boyanovsky, H.J. de Vega, D.-S. Lee, and Y.J. Ng
Damping Rates and Mean Free Paths of Soft Fermion Collective Excitations in a Hot Fermion-Gauge-Scalar Theory
REVTeX, 19 pages, 4 eps figures, published version
Phys.Rev. D61 (2000) 065004
10.1103/PhysRevD.61.065004
null
hep-ph
null
We study the transport coefficients, damping rates and mean free paths of soft fermion collective excitations in a hot fermion-gauge-scalar plasma with the goal of understanding the main physical mechanisms that determine transport of chirality in scenarios of non-local electroweak baryogenesis. The focus is on identifying the different transport coefficients for the different branches of soft collective excitations of the fermion spectrum. These branches correspond to collective excitations with opposite ratios of chirality to helicity and different dispersion relations. By combining results from the hard thermal loop (HTL) resummation program with a novel mechanism of fermion damping through heavy scalar decay, we obtain a robust description of the different damping rates and mean free paths for the soft collective excitations to leading order in HTL and lowest order in the Yukawa coupling. The space-time evolution of wave packets of collective excitations unambiguously reveals the respective mean free paths. We find that whereas both the gauge and scalar contribution to the damping rates are different for the different branches, the difference of mean free paths for both branches is mainly determined by the decay of the heavy scalar into a hard fermion and a soft collective excitation. We argue that these mechanisms are robust and are therefore relevant for non-local scenarios of baryogenesis either in the Standard Model or extensions thereof.
[ { "created": "Mon, 1 Feb 1999 22:56:08 GMT", "version": "v1" }, { "created": "Thu, 24 Feb 2000 03:48:13 GMT", "version": "v2" } ]
2007-05-23
[ [ "Wang", "S. -Y.", "" ], [ "Boyanovsky", "D.", "" ], [ "de Vega", "H. J.", "" ], [ "Lee", "D. -S.", "" ], [ "Ng", "Y. J.", "" ] ]
We study the transport coefficients, damping rates and mean free paths of soft fermion collective excitations in a hot fermion-gauge-scalar plasma with the goal of understanding the main physical mechanisms that determine transport of chirality in scenarios of non-local electroweak baryogenesis. The focus is on identifying the different transport coefficients for the different branches of soft collective excitations of the fermion spectrum. These branches correspond to collective excitations with opposite ratios of chirality to helicity and different dispersion relations. By combining results from the hard thermal loop (HTL) resummation program with a novel mechanism of fermion damping through heavy scalar decay, we obtain a robust description of the different damping rates and mean free paths for the soft collective excitations to leading order in HTL and lowest order in the Yukawa coupling. The space-time evolution of wave packets of collective excitations unambiguously reveals the respective mean free paths. We find that whereas both the gauge and scalar contribution to the damping rates are different for the different branches, the difference of mean free paths for both branches is mainly determined by the decay of the heavy scalar into a hard fermion and a soft collective excitation. We argue that these mechanisms are robust and are therefore relevant for non-local scenarios of baryogenesis either in the Standard Model or extensions thereof.
2111.15079
Si-Qiang Luo
Si-Qiang Luo, Tian-Wei Wu, Ming-Zhu Liu, Li-Sheng Geng, and Xiang Liu
Triple-charm molecular states composed of $D^*D^*D$ and $D^*D^*D^*$
12 pages, 3 figures, 6 tables. Published version in Phys. Rev. D
Phys. Rev. D 105, 074033 (2022)
10.1103/PhysRevD.105.074033
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the newly observed $T_{cc}^+$ state, we systematically investigate the $S$-wave triple-charm molecular states composed of $D^*D^*D$ and $D^*D^*D^*$. We employ the one-boson-exchange model to derive the interactions between $D(D^*)$ and $D^*$ and solve the three-body Schr\"odinger equations with the Gaussian expansion method. The $S$-$D$ mixing and coupled channel effects are carefully assessed in our study. Our results show that the $I(J^P)=\frac{1}{2}(0^-,1^-,2^-)$ $D^*D^*D$ and $I(J^P)=\frac{1}{2}(0^-,1^-,2^-,3^-)$ $D^*D^*D^*$ systems could form bound states, which can be viewed as three-body hadronic molecules. We present not only the binding energies of the three-body bound states, but also the root-mean-square radii of $D $-$D^*$ and $D^*$-$D^*$, which further corroborate the molecular nature of these states. These predictions could be tested in the future at LHC or HL-LHC.
[ { "created": "Tue, 30 Nov 2021 02:48:26 GMT", "version": "v1" }, { "created": "Thu, 7 Apr 2022 06:24:23 GMT", "version": "v2" }, { "created": "Thu, 28 Apr 2022 17:28:10 GMT", "version": "v3" } ]
2022-04-29
[ [ "Luo", "Si-Qiang", "" ], [ "Wu", "Tian-Wei", "" ], [ "Liu", "Ming-Zhu", "" ], [ "Geng", "Li-Sheng", "" ], [ "Liu", "Xiang", "" ] ]
Inspired by the newly observed $T_{cc}^+$ state, we systematically investigate the $S$-wave triple-charm molecular states composed of $D^*D^*D$ and $D^*D^*D^*$. We employ the one-boson-exchange model to derive the interactions between $D(D^*)$ and $D^*$ and solve the three-body Schr\"odinger equations with the Gaussian expansion method. The $S$-$D$ mixing and coupled channel effects are carefully assessed in our study. Our results show that the $I(J^P)=\frac{1}{2}(0^-,1^-,2^-)$ $D^*D^*D$ and $I(J^P)=\frac{1}{2}(0^-,1^-,2^-,3^-)$ $D^*D^*D^*$ systems could form bound states, which can be viewed as three-body hadronic molecules. We present not only the binding energies of the three-body bound states, but also the root-mean-square radii of $D $-$D^*$ and $D^*$-$D^*$, which further corroborate the molecular nature of these states. These predictions could be tested in the future at LHC or HL-LHC.
2207.14186
Smita Chakraborty
Smita Chakraborty and Leif L\"onnblad
Impact of string interactions on the space-time evolution of hadronic vertices
13 pages, 5 figures
null
10.1140/epjc/s10052-023-11652-2
LU-TP-22-50, MCnet-22-12
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We investigate the space-time picture of string evolution and hadron production in a fully string-based model for high energy collisions involving heavy ions. We find that although the density strings is quite large at the time of hadronization in a central heavy ion collision, the initial overlap between them right after the collisions is not necessarily large. We also find that when including string--string interactions using the so-called shoving model, the density of strings is decreased which should dampen the rapid increase in string tension in the rope hadronization with multiplicity that we found in a previous paper.
[ { "created": "Thu, 28 Jul 2022 15:55:07 GMT", "version": "v1" } ]
2023-06-21
[ [ "Chakraborty", "Smita", "" ], [ "Lönnblad", "Leif", "" ] ]
We investigate the space-time picture of string evolution and hadron production in a fully string-based model for high energy collisions involving heavy ions. We find that although the density strings is quite large at the time of hadronization in a central heavy ion collision, the initial overlap between them right after the collisions is not necessarily large. We also find that when including string--string interactions using the so-called shoving model, the density of strings is decreased which should dampen the rapid increase in string tension in the rope hadronization with multiplicity that we found in a previous paper.
hep-ph/0211327
Renard Fernand Michel
G.J. Gounaris, J. Layssac and F.M. Renard
The processes $e^-e^+\to\gamma\gamma, Z \gamma, ZZ$ in SM and MSSM
Short version (16 pages and 9 figures) of the paper hep-ph/0207273, to appear in Phy.Rev.D. e-mail: renard@lpm.univ-montp2.fr
Phys.Rev.D67:013012,2003
10.1103/PhysRevD.67.013012
null
hep-ph
null
We present the results of a complete analysis of the one loop electroweak corrections to $e^-e^+\to\gamma\gamma, ~Z\gamma, ~ZZ$ in the Standard (SM) and the Minimal Supersymmetric Standard Model (MSSM). A special emphasis is put on the high energy behaviour of the various helicity amplitudes and the way the logarithmic structure is generated. The large magnitude of these effects, which induce striking differences between the SM and MSSM cases at high energies, offers the possibility of making global tests which could check the consistency of these models, and even decide whether any additional new physics is required.
[ { "created": "Thu, 21 Nov 2002 08:30:57 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gounaris", "G. J.", "" ], [ "Layssac", "J.", "" ], [ "Renard", "F. M.", "" ] ]
We present the results of a complete analysis of the one loop electroweak corrections to $e^-e^+\to\gamma\gamma, ~Z\gamma, ~ZZ$ in the Standard (SM) and the Minimal Supersymmetric Standard Model (MSSM). A special emphasis is put on the high energy behaviour of the various helicity amplitudes and the way the logarithmic structure is generated. The large magnitude of these effects, which induce striking differences between the SM and MSSM cases at high energies, offers the possibility of making global tests which could check the consistency of these models, and even decide whether any additional new physics is required.
hep-ph/9502255
null
A.Dobado and M.T.Urdiales
DETERMINATION OF THE ELECTROWEAK CHIRAL-LAGRANGIAN PARAMETERS AT THE LHC
59 pages,latex, figures available on request
Z.Phys.C71:659-672,1996
10.1007/BF02907028
FT/UCM/19/94,FT/UAM/29/94
hep-ph
null
In this work we report on the results obtained in a detailed and systematical study of the possibility to measure the parameters appearing in the electroweak chiral lagrangian. The main novelty of our approach is that we do not use the Equivalence Theorem and therefore we work explicitly with all the gauge boson degrees of freedom.
[ { "created": "Wed, 8 Feb 1995 17:56:58 GMT", "version": "v1" } ]
2015-04-27
[ [ "Dobado", "A.", "" ], [ "Urdiales", "M. T.", "" ] ]
In this work we report on the results obtained in a detailed and systematical study of the possibility to measure the parameters appearing in the electroweak chiral lagrangian. The main novelty of our approach is that we do not use the Equivalence Theorem and therefore we work explicitly with all the gauge boson degrees of freedom.
hep-ph/0012204
Matthias Neubert
Matthias Neubert (Cornell University)
Lectures on the Theory of Non-leptonic B Decays
53 pages, 12 figures. Invited lectures presented at the Theoretical Advanced Study Institute (TASI 2000), Boulder, Colorado, June 2000, and at the 5th International Workshop on Particle Physics Phenomenology, Taitung, Taiwan, November 2000
null
10.1142/9789812799982_0002
CLNS 00/1712
hep-ph
null
These notes provide a pedagogical introduction to the theory of non-leptonic heavy-meson decays recently proposed by Beneke, Buchalla, Sachrajda and myself. We provide a rigorous basis for factorization for a large class of non-leptonic two-body B-meson decays in the heavy-quark limit. The resulting factorization formula incorporates elements of the naive factorization approach and the hard-scattering approach, and allows us to compute systematically radiative (``non-factorizable'') corrections to naive factorization for decays such as B->D+pi and B->pi+pi.
[ { "created": "Fri, 15 Dec 2000 21:11:28 GMT", "version": "v1" } ]
2017-08-23
[ [ "Neubert", "Matthias", "", "Cornell University" ] ]
These notes provide a pedagogical introduction to the theory of non-leptonic heavy-meson decays recently proposed by Beneke, Buchalla, Sachrajda and myself. We provide a rigorous basis for factorization for a large class of non-leptonic two-body B-meson decays in the heavy-quark limit. The resulting factorization formula incorporates elements of the naive factorization approach and the hard-scattering approach, and allows us to compute systematically radiative (``non-factorizable'') corrections to naive factorization for decays such as B->D+pi and B->pi+pi.
hep-ph/0006007
Fulvia De Fazio
F. De Fazio, M.R. Pennington
Radiative $\phi$$-$meson decays and $\eta$-$\eta^\prime$ mixing: a QCD sum rule analysis
Latex, 15 pages, 3figures. Some typos corrected
JHEP 0007:051,2000
10.1088/1126-6708/2000/07/051
DPT/00/14
hep-ph
null
The radiative transitions $\phi \to \eta \gamma$ and $\phi \to \eta^\prime \gamma$ are analysed using QCD sum-rules. The results we obtain for ${\cal B}(\phi \to \eta \gamma)=(1.15 \pm 0.2) 10^{-2}$ and ${\cal B}(\phi \to \eta^\prime \gamma)=(1.18 \pm 0.4) 10^{-4}$ are in very good agreement with existing experimental data. The related issue of $\eta-\eta^\prime$ mixing is discussed and we give predictions for the $\eta$ and $\eta^\prime$ decay constants in the framework of a mixing scheme in the quark-flavour basis.
[ { "created": "Thu, 1 Jun 2000 12:16:09 GMT", "version": "v1" }, { "created": "Fri, 4 Aug 2000 08:23:01 GMT", "version": "v2" }, { "created": "Tue, 31 Jul 2001 10:43:11 GMT", "version": "v3" } ]
2015-06-25
[ [ "De Fazio", "F.", "" ], [ "Pennington", "M. R.", "" ] ]
The radiative transitions $\phi \to \eta \gamma$ and $\phi \to \eta^\prime \gamma$ are analysed using QCD sum-rules. The results we obtain for ${\cal B}(\phi \to \eta \gamma)=(1.15 \pm 0.2) 10^{-2}$ and ${\cal B}(\phi \to \eta^\prime \gamma)=(1.18 \pm 0.4) 10^{-4}$ are in very good agreement with existing experimental data. The related issue of $\eta-\eta^\prime$ mixing is discussed and we give predictions for the $\eta$ and $\eta^\prime$ decay constants in the framework of a mixing scheme in the quark-flavour basis.
hep-ph/0108044
Alexei P. Martynenko
E.V.Cherednikova, R.N.Faustov, A.P.Martynenko
Proton polarizability contribution to the hyperfine splitting in muonic hydrogen
10 pages (revtex), 5 figures
Nucl.Phys. A703 (2002) 365-377
10.1016/S0375-9474(01)01461-0
SSU-HEP-01/07
hep-ph
null
The contribution of the proton polarizability to the ground state hyperfine splitting in muonic hydrogen is evaluated on the basis of modern experimental and theoretical results on the proton polarized structure functions. The value of this correction is equal to 4.6(8)\cdot 10^{-4} times the Fermi splitting E_F.
[ { "created": "Sat, 4 Aug 2001 09:35:57 GMT", "version": "v1" }, { "created": "Sat, 6 Jul 2002 15:23:41 GMT", "version": "v2" } ]
2009-11-07
[ [ "Cherednikova", "E. V.", "" ], [ "Faustov", "R. N.", "" ], [ "Martynenko", "A. P.", "" ] ]
The contribution of the proton polarizability to the ground state hyperfine splitting in muonic hydrogen is evaluated on the basis of modern experimental and theoretical results on the proton polarized structure functions. The value of this correction is equal to 4.6(8)\cdot 10^{-4} times the Fermi splitting E_F.
1904.07593
Hidetoshi Taya
Xu-Guang Huang, Mamoru Matsuo, Hidetoshi Taya
Spontaneous generation of spin current from the vacuum by strong electric fields
v2: 16 pages, 5 figures; discussions and references added
Prog Theor Exp Phys (2019)
10.1093/ptep/ptz112
null
hep-ph cond-mat.mes-hall cond-mat.mtrl-sci hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss spontaneous spin current generation from the vacuum by strong electric fields as a result of interplay between the Schwinger mechanism and a spin-orbit coupling. By considering a homogeneous slow strong electric field superimposed by a fast weak transverse electric field, we explicitly evaluate the vacuum expectation value of a spin current (the Bargmann-Wigner spin current) by numerically solving the Dirac equation. We show that a non-vanishing spin current polarized in the direction perpendicular to the electric fields flows mostly in the longitudinal direction. We also find that a relativistic effect due to the helicity conservation affects direction/polarization of spin current.
[ { "created": "Tue, 16 Apr 2019 11:08:01 GMT", "version": "v1" }, { "created": "Mon, 9 Sep 2019 10:58:06 GMT", "version": "v2" } ]
2019-11-20
[ [ "Huang", "Xu-Guang", "" ], [ "Matsuo", "Mamoru", "" ], [ "Taya", "Hidetoshi", "" ] ]
We discuss spontaneous spin current generation from the vacuum by strong electric fields as a result of interplay between the Schwinger mechanism and a spin-orbit coupling. By considering a homogeneous slow strong electric field superimposed by a fast weak transverse electric field, we explicitly evaluate the vacuum expectation value of a spin current (the Bargmann-Wigner spin current) by numerically solving the Dirac equation. We show that a non-vanishing spin current polarized in the direction perpendicular to the electric fields flows mostly in the longitudinal direction. We also find that a relativistic effect due to the helicity conservation affects direction/polarization of spin current.
1504.02540
Frank J. Petriello
Radja Boughezal, Xiaohui Liu and Frank Petriello
The N-jettiness soft function at next-to-next-to-leading order
22 pages, 19 figures
Phys. Rev. D 91, 094035 (2015)
10.1103/PhysRevD.91.094035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a general framework for the calculation of soft functions for SCET_I observables through next-to-next-to-leading order (NNLO) in the strong coupling constant. As an example of our formalism we show how it can be used to obtain the complete NNLO soft function for the $N$-jettiness event shape variable. We present numerical results for two examples with phenomenological impact: the one-jettiness soft function for both electron-proton and proton-proton collisions.
[ { "created": "Fri, 10 Apr 2015 02:41:47 GMT", "version": "v1" } ]
2015-06-03
[ [ "Boughezal", "Radja", "" ], [ "Liu", "Xiaohui", "" ], [ "Petriello", "Frank", "" ] ]
We present a general framework for the calculation of soft functions for SCET_I observables through next-to-next-to-leading order (NNLO) in the strong coupling constant. As an example of our formalism we show how it can be used to obtain the complete NNLO soft function for the $N$-jettiness event shape variable. We present numerical results for two examples with phenomenological impact: the one-jettiness soft function for both electron-proton and proton-proton collisions.
2304.09736
Sergi Gonz\`alez-Sol\'is
JPAC Collaboration: M. Albaladejo, S. Gonz\`alez-Sol\'is, \L. Bibrzycki, C. Fern\'andez-Ram\'irez, N. Hammoud, V. Mathieu, M. Mikhasenko, G. Monta\~na, R. J. Perry, A. Pilloni, A. Rodas, W. A. Smith, A. Szczepaniak, D. Winney
Khuri-Treiman analysis of $J/\psi\to\pi^{+}\pi^{-}\pi^{0}$
20 pages, 9 figures
null
10.1103/PhysRevD.108.014035
null
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
We study the decay $J/\psi\to\pi^{+}\pi^{-}\pi^{0}$ within the framework of the Khuri-Treiman equations. We find that the BESIII experimental di-pion mass distribution in the $\rho(770)$-region is well reproduced with a once-subtracted $P$-wave amplitude. Furthermore, we show that $F$-wave contributions to the amplitude improve the description of the data in the $\pi\pi$ mass region around 1.5 GeV. We also present predictions for the $J/\psi\to\pi^{0}\gamma^{*}$ transition form factor.
[ { "created": "Wed, 19 Apr 2023 15:22:17 GMT", "version": "v1" } ]
2023-08-09
[ [ "JPAC Collaboration", "", "" ], [ "Albaladejo", "M.", "" ], [ "Gonzàlez-Solís", "S.", "" ], [ "Bibrzycki", "Ł.", "" ], [ "Fernández-Ramírez", "C.", "" ], [ "Hammoud", "N.", "" ], [ "Mathieu", "V.", "" ], [ "Mikhasenko", "M.", "" ], [ "Montaña", "G.", "" ], [ "Perry", "R. J.", "" ], [ "Pilloni", "A.", "" ], [ "Rodas", "A.", "" ], [ "Smith", "W. A.", "" ], [ "Szczepaniak", "A.", "" ], [ "Winney", "D.", "" ] ]
We study the decay $J/\psi\to\pi^{+}\pi^{-}\pi^{0}$ within the framework of the Khuri-Treiman equations. We find that the BESIII experimental di-pion mass distribution in the $\rho(770)$-region is well reproduced with a once-subtracted $P$-wave amplitude. Furthermore, we show that $F$-wave contributions to the amplitude improve the description of the data in the $\pi\pi$ mass region around 1.5 GeV. We also present predictions for the $J/\psi\to\pi^{0}\gamma^{*}$ transition form factor.
hep-ph/9608363
null
N.V.Krasnikov
The masses of vector supermultiplet and of the Higgs supertriplet in supersymmetric SU(5) model
11 pages, latex, no figures
Phys.Lett. B392 (1997) 365-370
10.1016/S0370-2693(96)01593-6
Preprint INR 869a/96
hep-ph
null
The masses of vector supermultiplet and of the Higgs supertriplet in standard supersymmetric SU(5) model are calculated. Taking into account uncertainties related with the initial coupling constants and threshold corrections we find that in supersymmetric SU(5) model the scale of the supersymmetry breaking could be up to 50 Tev. We find that in the extensions of the standard SU(5) supersymmetric model it is possible to increase the supersymmetry breaking scale up to $O(10^{12})$ Gev. In standard supersymmetric SU(5) model it is possible to increase the GUT scale up to $5 \cdot 10^{17}$ Gev provided that the masses of chiral superoctets and supertriplets are $m_{3,8} \sim O(10^{13}) Gev$. We also propose SU(5) supersymmetric model with 6 light superdoublets and superoctet with a mass $O(10^{9})$ Gev.
[ { "created": "Mon, 19 Aug 1996 11:31:15 GMT", "version": "v1" } ]
2009-10-28
[ [ "Krasnikov", "N. V.", "" ] ]
The masses of vector supermultiplet and of the Higgs supertriplet in standard supersymmetric SU(5) model are calculated. Taking into account uncertainties related with the initial coupling constants and threshold corrections we find that in supersymmetric SU(5) model the scale of the supersymmetry breaking could be up to 50 Tev. We find that in the extensions of the standard SU(5) supersymmetric model it is possible to increase the supersymmetry breaking scale up to $O(10^{12})$ Gev. In standard supersymmetric SU(5) model it is possible to increase the GUT scale up to $5 \cdot 10^{17}$ Gev provided that the masses of chiral superoctets and supertriplets are $m_{3,8} \sim O(10^{13}) Gev$. We also propose SU(5) supersymmetric model with 6 light superdoublets and superoctet with a mass $O(10^{9})$ Gev.
hep-ph/9908234
Richard F. Lebed
Richard F. Lebed
QCD Constraints on Form Factor Shapes
8 pages, 3 eps figures, presented at ``Exclusive & Semi-exclusive Processes at High Momentum Transfer,'' Jefferson Lab, Newport News, VA, May 20-22, 1999
null
null
JLAB-THY 99-19
hep-ph
null
This talk presents an introduction to the use of dispersion relations to constrain the shapes of hadronic form factors consistent with QCD. The applications described include methods for studying |V_{cb}| and |V_{ub}|, the strange quark mass, and the pion charge radius.
[ { "created": "Tue, 3 Aug 1999 14:05:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lebed", "Richard F.", "" ] ]
This talk presents an introduction to the use of dispersion relations to constrain the shapes of hadronic form factors consistent with QCD. The applications described include methods for studying |V_{cb}| and |V_{ub}|, the strange quark mass, and the pion charge radius.
2008.08604
Nathaniel Craig
Tianji Cai, Junyi Cheng, Katy Craig, Nathaniel Craig
Linearized Optimal Transport for Collider Events
16 pages, 5 figures
Phys. Rev. D 102, 116019 (2020)
10.1103/PhysRevD.102.116019
null
hep-ph hep-ex stat.ML
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We introduce an efficient framework for computing the distance between collider events using the tools of Linearized Optimal Transport (LOT). This preserves many of the advantages of the recently-introduced Energy Mover's Distance, which quantifies the "work" required to rearrange one event into another, while significantly reducing the computational cost. It also furnishes a Euclidean embedding amenable to simple machine learning algorithms and visualization techniques, which we demonstrate in a variety of jet tagging examples. The LOT approximation lowers the threshold for diverse applications of the theory of optimal transport to collider physics.
[ { "created": "Wed, 19 Aug 2020 18:00:09 GMT", "version": "v1" } ]
2021-01-04
[ [ "Cai", "Tianji", "" ], [ "Cheng", "Junyi", "" ], [ "Craig", "Katy", "" ], [ "Craig", "Nathaniel", "" ] ]
We introduce an efficient framework for computing the distance between collider events using the tools of Linearized Optimal Transport (LOT). This preserves many of the advantages of the recently-introduced Energy Mover's Distance, which quantifies the "work" required to rearrange one event into another, while significantly reducing the computational cost. It also furnishes a Euclidean embedding amenable to simple machine learning algorithms and visualization techniques, which we demonstrate in a variety of jet tagging examples. The LOT approximation lowers the threshold for diverse applications of the theory of optimal transport to collider physics.
hep-ph/9602272
A. A. Pivovarov
N.V. Krasnikov, A.A. Pivovarov
Renormalization schemes and renormalons
Latex, 18 pages, two tables
Mod.Phys.Lett. A11 (1996) 835-852
10.1142/S0217732396000849
Preprint INR 915/96
hep-ph
null
We describe some ways how higher order corrections can reveal themselves if integrated over the infrared region. We show that in different renormalization group (RG) schemes and for some observables one has no factorial divergences. We argue that for treating things in the infrared region it is preferable to start with a RG scheme without the infrared Landau pole in the running coupling constant. The uncertainties for the $\tau$ lepton width resulting from accounting for higher order corrections are discussed.
[ { "created": "Mon, 12 Feb 1996 10:13:17 GMT", "version": "v1" } ]
2015-06-25
[ [ "Krasnikov", "N. V.", "" ], [ "Pivovarov", "A. A.", "" ] ]
We describe some ways how higher order corrections can reveal themselves if integrated over the infrared region. We show that in different renormalization group (RG) schemes and for some observables one has no factorial divergences. We argue that for treating things in the infrared region it is preferable to start with a RG scheme without the infrared Landau pole in the running coupling constant. The uncertainties for the $\tau$ lepton width resulting from accounting for higher order corrections are discussed.
1608.00574
Susanne Westhoff
Stefan Berge and Susanne Westhoff
Observing the Top Energy Asymmetry at the LHC
16 pages, 5 figures, 2 tables, identical with version published in PRD
Phys. Rev. D 95, 014035 (2017)
10.1103/PhysRevD.95.014035
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The top-antitop energy asymmetry is a promising observable of the charge asymmetry in jet-associated top-quark pair production at the LHC. We present new predictions of the energy asymmetry in proton-proton collisions at 13 TeV, including QCD corrections at the next-to-leading perturbative order. The effect of QCD corrections on the observable is moderate. With suitable phase-space cuts, the asymmetry can be enhanced at the cost of reducing the cross section. For instance, for a cross section of $1\,\text{pb}$ after cuts, we predict an energy asymmetry of $-6.5^{\,+0.1}_{\,-0.2}\%$ at the next-to-leading order in QCD. We also investigate scale uncertainties and parton-shower effects, which partially cancel in the normalized asymmetry. Our results provide a sound basis for a measurement of the energy asymmetry at the LHC during run II.
[ { "created": "Mon, 1 Aug 2016 20:00:00 GMT", "version": "v1" }, { "created": "Tue, 28 Feb 2017 08:56:51 GMT", "version": "v2" } ]
2017-03-01
[ [ "Berge", "Stefan", "" ], [ "Westhoff", "Susanne", "" ] ]
The top-antitop energy asymmetry is a promising observable of the charge asymmetry in jet-associated top-quark pair production at the LHC. We present new predictions of the energy asymmetry in proton-proton collisions at 13 TeV, including QCD corrections at the next-to-leading perturbative order. The effect of QCD corrections on the observable is moderate. With suitable phase-space cuts, the asymmetry can be enhanced at the cost of reducing the cross section. For instance, for a cross section of $1\,\text{pb}$ after cuts, we predict an energy asymmetry of $-6.5^{\,+0.1}_{\,-0.2}\%$ at the next-to-leading order in QCD. We also investigate scale uncertainties and parton-shower effects, which partially cancel in the normalized asymmetry. Our results provide a sound basis for a measurement of the energy asymmetry at the LHC during run II.
0810.4380
Pankaj Jain
Avijit K. Ganguly, Pankaj Jain, Subhayan Mandal
Photon & Axion Oscillation In a Magnetized Medium: A Covariant Treatment
16 pages, no figures
Phys.Rev.D79:115014,2009
10.1103/PhysRevD.79.115014
MMV/No/08-10-15
hep-ph astro-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Pseudoscalar particles, with almost zero mass and very weak coupling to the visible matter, arise in many extensions of the standard model of particle physics. Their mixing with photons in the presence of an external magnetic field leads to many interesting astrophysical and cosmological consequences. This mixing depends on the medium properties, the momentum of the photon and the background magnetic field. Here we give a general treatment of pseudoscalar-photon oscillations in a background magnetic field, taking the Faraday term into account. We give predictions valid in all regimes, under the assumption that the frequency of the wave is much higher than the plasma frequency of the medium. At sufficiently high frequencies, the Faraday effect is negligible and we reproduce the standard pseudoscalar-photon mixing phenomenon. However at low frequencies, where Faraday effect is important, the mixing formulae are considerably modified. We explicitly compute the contribution due to the longitudinal mode of the photon and show that it is negligible.
[ { "created": "Fri, 24 Oct 2008 05:02:52 GMT", "version": "v1" } ]
2009-08-03
[ [ "Ganguly", "Avijit K.", "" ], [ "Jain", "Pankaj", "" ], [ "Mandal", "Subhayan", "" ] ]
Pseudoscalar particles, with almost zero mass and very weak coupling to the visible matter, arise in many extensions of the standard model of particle physics. Their mixing with photons in the presence of an external magnetic field leads to many interesting astrophysical and cosmological consequences. This mixing depends on the medium properties, the momentum of the photon and the background magnetic field. Here we give a general treatment of pseudoscalar-photon oscillations in a background magnetic field, taking the Faraday term into account. We give predictions valid in all regimes, under the assumption that the frequency of the wave is much higher than the plasma frequency of the medium. At sufficiently high frequencies, the Faraday effect is negligible and we reproduce the standard pseudoscalar-photon mixing phenomenon. However at low frequencies, where Faraday effect is important, the mixing formulae are considerably modified. We explicitly compute the contribution due to the longitudinal mode of the photon and show that it is negligible.
1010.2869
Karl Schilcher
N.F. Nasrallah and K. Schilcher
New Sum Rule Determination of the Nucleon Mass
7 pages
null
null
MZ-TH/10-37
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new QCD calculation of the mass of the nucleon is presented. It makes use of a polynomial kernel in the dispersion integrals tailored to practically eliminate the contribution of the unknown 1/2+ and 1/2- continuum. This approach avoids the arbitrariness and other drawbacks attached to the Borel kernel used in previous sum rules calculations. Our method yields stable results for the nucleon mass and coupling for standard values of the condensates. The prediction of the nucleon mass m_{N}=(0.945 \pm .045) GeV is in good agreement with experiment.
[ { "created": "Thu, 14 Oct 2010 09:48:05 GMT", "version": "v1" }, { "created": "Tue, 2 Nov 2010 10:38:49 GMT", "version": "v2" } ]
2010-11-03
[ [ "Nasrallah", "N. F.", "" ], [ "Schilcher", "K.", "" ] ]
A new QCD calculation of the mass of the nucleon is presented. It makes use of a polynomial kernel in the dispersion integrals tailored to practically eliminate the contribution of the unknown 1/2+ and 1/2- continuum. This approach avoids the arbitrariness and other drawbacks attached to the Borel kernel used in previous sum rules calculations. Our method yields stable results for the nucleon mass and coupling for standard values of the condensates. The prediction of the nucleon mass m_{N}=(0.945 \pm .045) GeV is in good agreement with experiment.
hep-ph/9804368
Jose Herman
G. Lopez Castro(1), R. Martinez(2) and J. H. Munoz(1,3) ((1)CINVESTAV-IPN/Mexico; (2)U. Nacional/Colombia; (3) U. del Tolima/Colombia)
FCNC in leptonic and semileptonic decays of D mesons in a general two-Higgs doublet model
latex, 10 pages, to appear in Phys. Rev. D
Phys.Rev. D58 (1998) 033003
10.1103/PhysRevD.58.033003
null
hep-ph
null
Large long-distance standard model effects in FCNC semileptonic D decays can make observable these processes in future measurements. Eventual disagreements in this sector and/or the observation of lepton family violating (LFV) D decays would require an explanatio beyond the SM framework. In this paper we confront present experimental data on leptonic and semileptonic FCNC and LFV D meson decays with a version of the two-Higgs doublet model that allows these effects to occur at tree- level. The stringent bounds on the parameters of the model are obtained from D^0 --> l^+l'^- and D --> pi l^+l'^- decays. The consistency of the model requires that the branching fractions of D --> V l^+l'^- decays should be below the 10^{-9} level.
[ { "created": "Thu, 23 Apr 1998 02:12:26 GMT", "version": "v1" } ]
2009-10-31
[ [ "Castro", "G. Lopez", "" ], [ "Martinez", "R.", "" ], [ "Munoz", "J. H.", "" ] ]
Large long-distance standard model effects in FCNC semileptonic D decays can make observable these processes in future measurements. Eventual disagreements in this sector and/or the observation of lepton family violating (LFV) D decays would require an explanatio beyond the SM framework. In this paper we confront present experimental data on leptonic and semileptonic FCNC and LFV D meson decays with a version of the two-Higgs doublet model that allows these effects to occur at tree- level. The stringent bounds on the parameters of the model are obtained from D^0 --> l^+l'^- and D --> pi l^+l'^- decays. The consistency of the model requires that the branching fractions of D --> V l^+l'^- decays should be below the 10^{-9} level.
hep-ph/0405247
Borut Paul Kersevan
Borut Paul Kersevan, Elzbieta Richter-Was
The Monte Carlo Event Generator AcerMC 2.0 with Interfaces to PYTHIA 6.2 and HERWIG 6.5
Updated version of the AcerMC manual adapted to the changes and upgrades in the code
null
10.1016/j.cpc.2012.10.032
TPJU-6/2004
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The AcerMC Monte Carlo generator is dedicated to the generation of Standard Model background processes which were recognised as critical for the searches at LHC, and generation of which was either unavailable or not straightforward so far. The program itself provides a library of the massive matrix elements (coded by MADGRAPH) and native phase space modules for generation of a set of selected processes. The hard process event can be completed by the initial and final state radiation, hadronisation and decays through the existing interface with either PYTHIA, HERWIG or ARIADNE event generators and (optionally) TAUOLA and PHOTOS. Interfaces to all these packages are provided in the distribution version. The matrix element codes have been derived with the help of the MADGRAPH package. The phase-space generation is based on the multi-channel self-optimising approach using the modified Kajantie-Byckling formalism for phase space construction and further smoothing of the phase space was obtained by using a modified ac-VEGAS algorithm.
[ { "created": "Tue, 25 May 2004 09:54:56 GMT", "version": "v1" }, { "created": "Thu, 17 May 2012 12:57:25 GMT", "version": "v2" }, { "created": "Mon, 12 Nov 2012 16:08:35 GMT", "version": "v3" } ]
2012-11-15
[ [ "Kersevan", "Borut Paul", "" ], [ "Richter-Was", "Elzbieta", "" ] ]
The AcerMC Monte Carlo generator is dedicated to the generation of Standard Model background processes which were recognised as critical for the searches at LHC, and generation of which was either unavailable or not straightforward so far. The program itself provides a library of the massive matrix elements (coded by MADGRAPH) and native phase space modules for generation of a set of selected processes. The hard process event can be completed by the initial and final state radiation, hadronisation and decays through the existing interface with either PYTHIA, HERWIG or ARIADNE event generators and (optionally) TAUOLA and PHOTOS. Interfaces to all these packages are provided in the distribution version. The matrix element codes have been derived with the help of the MADGRAPH package. The phase-space generation is based on the multi-channel self-optimising approach using the modified Kajantie-Byckling formalism for phase space construction and further smoothing of the phase space was obtained by using a modified ac-VEGAS algorithm.
hep-ph/0108198
Chi-Sing Lam
C.S. Lam
Neutrino Oscillations in Extra Dimensions
Plenary talk given at the International Conference on Flavor Physics, May 31-June 6, 2001, Zhang-Jia-Jie, China. More references provided in this new version
null
10.1142/9789812777379_0012
null
hep-ph
null
The characteristics and phenomenology of neutrino oscillation in extra dimensions are briefly reviewed
[ { "created": "Thu, 23 Aug 2001 18:57:25 GMT", "version": "v1" }, { "created": "Fri, 31 Aug 2001 17:14:51 GMT", "version": "v2" } ]
2017-08-23
[ [ "Lam", "C. S.", "" ] ]
The characteristics and phenomenology of neutrino oscillation in extra dimensions are briefly reviewed
2308.12543
Da-Cheng Yan
Da-Cheng Yan (Changzhou U.), Zhou Rui (NCUST, Taiyuan), Yan Yan (Changzhou U.), Ya Li (Nanjing Agricultural U.)
Study of four-body decays $B_{(s)} \to (\pi\pi)(\pi\pi)$ in the perturbative QCD approach
24 pages, 4 figures. Several new references are added. arXiv admin note: text overlap with arXiv:2204.01092, arXiv:2107.10684
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we make a systematical study on the four-body $B_{(s)} \to (\pi\pi)(\pi\pi)$ decays in the perturbative QCD approach, where the $\pi\pi$ invariant mass spectra are dominated by the vector resonance $\rho(770)$ and the scalar resonance $f_0(980)$. We improve the Gengenbauer moments for the longitudinal $P$-wave two-pion distribution amplitudes (DAs) by fitting the PQCD factorization formulas to measured branching ratios of three-body and four-body $B$ decays. With the fitted Gegenbauer moments, we make predictions for the branching ratios and direct $CP$ asymmetries of four-body $B_{(s)} \to (\pi\pi)(\pi\pi)$ decays. We extract the branching ratios of two-body $B_{(s)} \to \rho\rho$ from the corresponding four-body decay modes and calculate the relevant polarization fractions. We find that the ${\cal B}(B^0 \to \rho^+\rho^-)$ is consistent with the previous theoretical predictions and data. The leading-order PQCD calculations of the ${\cal B}(B^+\to \rho^+\rho^0)$, ${\cal B}(B^0\to \rho^0\rho^0)$ and the $f_0(B^0\to \rho^0\rho^0)$ are a bit lower than the experimental measurements, which should be further examined. In addition, the "true" and "fake" triple-product asymmetries (TPAs) in the $B_{(s)}\to (\pi\pi)(\pi\pi)$ decays are also analyzed. The sizable averaged TPA ${\cal A}_{\text{T-true}}^{1, \text{ave}}=25.26\%$ of the color-suppressed decay $B^0\to \rho^0\rho^0 \to (\pi^+\pi^-)(\pi^+\pi^-)$ is predicted for the first time, which deviates a lot from the so-called "true" TPA $\mathcal{A}_\text{T-true}^1=7.92\%$ due to the large direct $CP$ violation. A large "fake" TPA $\mathcal{A}_\text{T-fake}^1=24.96\%$ of the decay $B^0\to \rho^0\rho^0 \to (\pi^+\pi^-)(\pi^+\pi^-)$ is also found, which indicates the significance of the final-state interactions. The predictions in this work can be tested by LHCb and Belle-II experiments in the near future.
[ { "created": "Thu, 24 Aug 2023 03:58:23 GMT", "version": "v1" }, { "created": "Fri, 1 Sep 2023 00:15:41 GMT", "version": "v2" } ]
2023-09-04
[ [ "Yan", "Da-Cheng", "", "Changzhou U." ], [ "Rui", "Zhou", "", "NCUST, Taiyuan" ], [ "Yan", "Yan", "", "Changzhou U." ], [ "Li", "Ya", "", "Nanjing Agricultural U." ] ]
In this work, we make a systematical study on the four-body $B_{(s)} \to (\pi\pi)(\pi\pi)$ decays in the perturbative QCD approach, where the $\pi\pi$ invariant mass spectra are dominated by the vector resonance $\rho(770)$ and the scalar resonance $f_0(980)$. We improve the Gengenbauer moments for the longitudinal $P$-wave two-pion distribution amplitudes (DAs) by fitting the PQCD factorization formulas to measured branching ratios of three-body and four-body $B$ decays. With the fitted Gegenbauer moments, we make predictions for the branching ratios and direct $CP$ asymmetries of four-body $B_{(s)} \to (\pi\pi)(\pi\pi)$ decays. We extract the branching ratios of two-body $B_{(s)} \to \rho\rho$ from the corresponding four-body decay modes and calculate the relevant polarization fractions. We find that the ${\cal B}(B^0 \to \rho^+\rho^-)$ is consistent with the previous theoretical predictions and data. The leading-order PQCD calculations of the ${\cal B}(B^+\to \rho^+\rho^0)$, ${\cal B}(B^0\to \rho^0\rho^0)$ and the $f_0(B^0\to \rho^0\rho^0)$ are a bit lower than the experimental measurements, which should be further examined. In addition, the "true" and "fake" triple-product asymmetries (TPAs) in the $B_{(s)}\to (\pi\pi)(\pi\pi)$ decays are also analyzed. The sizable averaged TPA ${\cal A}_{\text{T-true}}^{1, \text{ave}}=25.26\%$ of the color-suppressed decay $B^0\to \rho^0\rho^0 \to (\pi^+\pi^-)(\pi^+\pi^-)$ is predicted for the first time, which deviates a lot from the so-called "true" TPA $\mathcal{A}_\text{T-true}^1=7.92\%$ due to the large direct $CP$ violation. A large "fake" TPA $\mathcal{A}_\text{T-fake}^1=24.96\%$ of the decay $B^0\to \rho^0\rho^0 \to (\pi^+\pi^-)(\pi^+\pi^-)$ is also found, which indicates the significance of the final-state interactions. The predictions in this work can be tested by LHCb and Belle-II experiments in the near future.
hep-ph/9612446
Robert Fleischer
Robert Fleischer
CP Violation and the Role of Electroweak Penguins in Non-leptonic B Decays
Invited review article for publication in International Journal of Modern Physics A. 62 pages, LaTeX, 16 figures. The complete paper is also available via anonymous ftp at ftp://www-ttp.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/
Int.J.Mod.Phys.A12:2459-2522,1997
10.1142/S0217751X97001432
TTP96-58
hep-ph
null
The phenomenon of CP violation in the B system and strategies for extracting CKM phases are reviewed. We focus both on general aspects and on some recent developments including CP-violating asymmetries in B_d decays, the B_s system in light of a possible width difference $\Delta\Gamma_s$, charged B decays, and SU(3) relations among certain transition amplitudes. In order to describe the relevant non-leptonic B decays, low energy effective Hamiltonians calculated beyond the leading logarithmic approximation are used. Special emphasis is given to the role of electroweak penguin operators in such transitions. These effects are analyzed both within a general framework and more specifically in view of the theoretical cleanliness of methods to determine CKM phases. Strategies for obtaining insights into the world of electroweak penguins are discussed.
[ { "created": "Sun, 22 Dec 1996 11:45:09 GMT", "version": "v1" } ]
2014-11-17
[ [ "Fleischer", "Robert", "" ] ]
The phenomenon of CP violation in the B system and strategies for extracting CKM phases are reviewed. We focus both on general aspects and on some recent developments including CP-violating asymmetries in B_d decays, the B_s system in light of a possible width difference $\Delta\Gamma_s$, charged B decays, and SU(3) relations among certain transition amplitudes. In order to describe the relevant non-leptonic B decays, low energy effective Hamiltonians calculated beyond the leading logarithmic approximation are used. Special emphasis is given to the role of electroweak penguin operators in such transitions. These effects are analyzed both within a general framework and more specifically in view of the theoretical cleanliness of methods to determine CKM phases. Strategies for obtaining insights into the world of electroweak penguins are discussed.
1811.01941
Sergey Koshkarev
Sergey Koshkarev and Stefan Groote
Resolving the SELEX-LHCb double-charm baryon conflict: the impact of intrinsic heavy-quark hadroproduction and supersymmetric light-front holographic QCD
6 pages; Baldin seminar 2018. arXiv admin note: substantial text overlap with arXiv:1709.09903, arXiv:1803.07034
null
10.1051/epjconf/201920408007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we review the hadroproduction mechanisms of double-charm baryons for the different experimental environments and reinterpret the SELEX and LHCb results.
[ { "created": "Mon, 5 Nov 2018 13:02:08 GMT", "version": "v1" } ]
2019-05-01
[ [ "Koshkarev", "Sergey", "" ], [ "Groote", "Stefan", "" ] ]
In this paper we review the hadroproduction mechanisms of double-charm baryons for the different experimental environments and reinterpret the SELEX and LHCb results.
1206.5685
Zhi-Gang Wang
Zhi-Gang Wang
Radiative transitions among the vector and scalar heavy quarkonium states with covariant light-front quark model
11 pages, 7 figures
Int.J.Theor.Phys.53(2014)1022-1032
10.1007/s10773-013-1895-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we study the radiative transitions among the vector and scalar heavy quarkonium states with the covariant light-front quark model. In calculations, we observe that the radiative decay widths are sensitive to the constituent quark masses and the shape parameters of the wave-functions, and reproduce the experimental data with suitable parameters.
[ { "created": "Mon, 25 Jun 2012 14:03:17 GMT", "version": "v1" }, { "created": "Wed, 19 Sep 2012 09:36:49 GMT", "version": "v2" }, { "created": "Thu, 13 Dec 2012 13:17:47 GMT", "version": "v3" }, { "created": "Mon, 25 Mar 2013 09:15:42 GMT", "version": "v4" }, { "created": "Thu, 27 Jun 2013 08:09:29 GMT", "version": "v5" }, { "created": "Wed, 28 Aug 2013 02:36:30 GMT", "version": "v6" }, { "created": "Sun, 22 Sep 2013 11:38:29 GMT", "version": "v7" } ]
2014-01-28
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we study the radiative transitions among the vector and scalar heavy quarkonium states with the covariant light-front quark model. In calculations, we observe that the radiative decay widths are sensitive to the constituent quark masses and the shape parameters of the wave-functions, and reproduce the experimental data with suitable parameters.
0707.3292
Jihn E. Kim
Jihn E. Kim
GMSB at a stable vacuum and MSSM without exotics from heterotic string
17 pages, references and DOI added
Phys.Lett.B656:207-213,2007
10.1016/j.physletb.2007.09.027
SNUTP 07-010
hep-ph
null
We show that it is possible to introduce the confining hidden sector gauge group SU(5)' with the chiral matter 10 plus 5-bar, which are neutral under the standard model gauge group, toward a gauge mediated supersymmetry breaking (GMSB) in a Z_{12-I} orbifold compactification of E_8xE_8 heterotic string. Three families of MSSM result without exotics. We also find a desirable matter parity P (or R-parity) assignment. We note that this model contains the spectrum of the Lee-Weinberg model which has a nice solution of the mu problem.
[ { "created": "Mon, 23 Jul 2007 19:40:44 GMT", "version": "v1" }, { "created": "Wed, 29 Aug 2007 23:11:11 GMT", "version": "v2" }, { "created": "Mon, 8 Oct 2007 02:08:50 GMT", "version": "v3" } ]
2008-11-26
[ [ "Kim", "Jihn E.", "" ] ]
We show that it is possible to introduce the confining hidden sector gauge group SU(5)' with the chiral matter 10 plus 5-bar, which are neutral under the standard model gauge group, toward a gauge mediated supersymmetry breaking (GMSB) in a Z_{12-I} orbifold compactification of E_8xE_8 heterotic string. Three families of MSSM result without exotics. We also find a desirable matter parity P (or R-parity) assignment. We note that this model contains the spectrum of the Lee-Weinberg model which has a nice solution of the mu problem.
1309.3534
Satoshi Nakamura
S X Nakamura (YITP, Kyoto Univ.), H Kamano (RCNP, Osaka Univ.), T S H Lee (Argonne Nat'l Lab), T Sato (Osaka Univ.)
Neutrino induced meson productions in forward limit
4 pages, 3 figures, Contribution to the proceedings of International Workshop on Neutrino Factories, Super Beams and Beta Beams (NUFACT 2013), August 19-24 2013, Beijing, China
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study neutrino-induced meson productions off the nucleon in the forward limit by applying the PCAC hypothesis to our dynamical coupled-channels (DCC) model. The DCC model reasonably describes pi N, gamma N -> pi N, eta N, K Lambda, K Sigma data in the resonance region. We give a prediction for nu N -> pi N, pi pi N, eta N, K Lambda, K Sigma$ reactions cross sections. We compare our results with those from the Rein-Sehgal model, and find a significant difference.
[ { "created": "Fri, 13 Sep 2013 18:32:13 GMT", "version": "v1" } ]
2013-09-16
[ [ "Nakamura", "S X", "", "YITP, Kyoto Univ." ], [ "Kamano", "H", "", "RCNP, Osaka Univ." ], [ "Lee", "T S H", "", "Argonne Nat'l Lab" ], [ "Sato", "T", "", "Osaka Univ." ] ]
We study neutrino-induced meson productions off the nucleon in the forward limit by applying the PCAC hypothesis to our dynamical coupled-channels (DCC) model. The DCC model reasonably describes pi N, gamma N -> pi N, eta N, K Lambda, K Sigma data in the resonance region. We give a prediction for nu N -> pi N, pi pi N, eta N, K Lambda, K Sigma$ reactions cross sections. We compare our results with those from the Rein-Sehgal model, and find a significant difference.
2208.11146
Richard Woodard
S. Katuwal (U. Florida), S. P. Miao (NCKU, Taiwan) and R. P. Woodard (U. Florida)
Reheating with Effective Potentials
24 pages, 11 figures, uses LaTeX2e, Version 2 has 2 small typos corrected to reflect the published version
JCAP 11 (2022) 026
10.1088/1475-7516/2022/11/026
UFIFT-QG-22-02
hep-ph astro-ph.CO gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We consider reheating for a charged inflaton which is minimally coupled to electromagnetism. The evolution of such an inflaton induces a time-dependent mass for the photon. We show how the massive photon propagator can be expressed as a spatial Fourier mode sum involving three different sorts of mode functions, just like the constant mass case. We develop accurate analytic approximations for these mode functions, and use them to approximate the effective force exerted on the inflaton $0$-mode. This effective force allows one to simply compute the evolution of the inflaton $0$-mode and to follow the progress of reheating.
[ { "created": "Tue, 23 Aug 2022 18:15:52 GMT", "version": "v1" }, { "created": "Mon, 14 Nov 2022 15:25:56 GMT", "version": "v2" } ]
2022-11-15
[ [ "Katuwal", "S.", "", "U. Florida" ], [ "Miao", "S. P.", "", "NCKU, Taiwan" ], [ "Woodard", "R. P.", "", "U. Florida" ] ]
We consider reheating for a charged inflaton which is minimally coupled to electromagnetism. The evolution of such an inflaton induces a time-dependent mass for the photon. We show how the massive photon propagator can be expressed as a spatial Fourier mode sum involving three different sorts of mode functions, just like the constant mass case. We develop accurate analytic approximations for these mode functions, and use them to approximate the effective force exerted on the inflaton $0$-mode. This effective force allows one to simply compute the evolution of the inflaton $0$-mode and to follow the progress of reheating.
1808.02500
Sudip Jana
Enrico Bertuzzo, Sudip Jana, Pedro A. N. Machado and Renata Zukanovich Funchal
Neutrino Masses and Mixings Dynamically Generated by a Light Dark Sector
7 pages, 1 figure, published version in Phys. Lett. B
Physics Letters B 791 (2019) 210-214
10.1016/j.physletb.2019.02.023
FERMILAB-PUB-18-381-T, OSU-HEP-18-05
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrinos may be the harbingers of new dark sectors, since the renormalizable neutrino portal allows for their interactions with hidden new physics. We propose here to use this fact to connect the generation of neutrino masses to a light dark sector, charged under a new $U(1)_{\cal D}$ dark gauge symmetry. We introduce the minimal number of dark fields to obtain an anomaly free theory with spontaneous breaking of the dark symmetry, and obtain automatically the inverse seesaw Lagrangian. In addition, the so-called $\mu$-term of the inverse seesaw is dynamically generated and technically natural in this framework. As a bonus, the new light dark gauge boson can provide a possible explanation to the MiniBooNE anomaly.
[ { "created": "Tue, 7 Aug 2018 18:01:03 GMT", "version": "v1" }, { "created": "Tue, 5 Mar 2019 09:14:31 GMT", "version": "v2" } ]
2019-03-06
[ [ "Bertuzzo", "Enrico", "" ], [ "Jana", "Sudip", "" ], [ "Machado", "Pedro A. N.", "" ], [ "Funchal", "Renata Zukanovich", "" ] ]
Neutrinos may be the harbingers of new dark sectors, since the renormalizable neutrino portal allows for their interactions with hidden new physics. We propose here to use this fact to connect the generation of neutrino masses to a light dark sector, charged under a new $U(1)_{\cal D}$ dark gauge symmetry. We introduce the minimal number of dark fields to obtain an anomaly free theory with spontaneous breaking of the dark symmetry, and obtain automatically the inverse seesaw Lagrangian. In addition, the so-called $\mu$-term of the inverse seesaw is dynamically generated and technically natural in this framework. As a bonus, the new light dark gauge boson can provide a possible explanation to the MiniBooNE anomaly.
hep-ph/0610350
Yaobei Liu liuyaobei
Yao-Bei Liu, Jie-Fen Shen, Xue-Lei Wang
Effects of little Higgs models on single top production at the $e^{-}\gamma$ colliders
10pages, 4 figures
null
null
null
hep-ph
null
In the framework of the littlest Higgs($LH$) model and the littlest Higgs model with T-parity($LHT$), We investigate the single top production process $e^{-}\gamma\to \nu_{e}b\bar{t}$, and calculate the corrections of these two models to the cross section of this process. We find that in the reasonable parameter space, the correction terms for the tree-level $Wtb$ couplings coming from the $LHT$ model can generate significantly corrections to the cross section of this process, which might be detected in the future high energy linear $e^{+}e^{-}$ collider($ILC$) experiments. However, the contributions of the new gauge boson $W^{\pm}_{H}$ predicted by the $LH$ model to this process is very small.
[ { "created": "Thu, 26 Oct 2006 08:32:21 GMT", "version": "v1" }, { "created": "Tue, 6 Feb 2007 04:49:04 GMT", "version": "v2" } ]
2007-05-23
[ [ "Liu", "Yao-Bei", "" ], [ "Shen", "Jie-Fen", "" ], [ "Wang", "Xue-Lei", "" ] ]
In the framework of the littlest Higgs($LH$) model and the littlest Higgs model with T-parity($LHT$), We investigate the single top production process $e^{-}\gamma\to \nu_{e}b\bar{t}$, and calculate the corrections of these two models to the cross section of this process. We find that in the reasonable parameter space, the correction terms for the tree-level $Wtb$ couplings coming from the $LHT$ model can generate significantly corrections to the cross section of this process, which might be detected in the future high energy linear $e^{+}e^{-}$ collider($ILC$) experiments. However, the contributions of the new gauge boson $W^{\pm}_{H}$ predicted by the $LH$ model to this process is very small.