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hep-ph/9908343
Michael Gronau
Michael Gronau
CP Violation and B Physics
12 pages, SLAC-PUB-8221, Invited talk given at the 1999 Conference on Kaon Physics, Chicago, IL, June 21-26, 1999
null
null
null
hep-ph
null
This is a quick review of CP non-conservation in $B$ physics. Several methods are described for testing the Kobayashi-Maskawa single phase origin of CP violation in B decays, pointing out some limitations due to hadronic uncertainties. A few characteristic signatures of new physics in B decay asymmetries are listed.
[ { "created": "Thu, 12 Aug 1999 21:04:14 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gronau", "Michael", "" ] ]
This is a quick review of CP non-conservation in $B$ physics. Several methods are described for testing the Kobayashi-Maskawa single phase origin of CP violation in B decays, pointing out some limitations due to hadronic uncertainties. A few characteristic signatures of new physics in B decay asymmetries are listed.
hep-ph/0110392
Isabela Porto Cavalcante
Isabela P. Cavalcante and J. S\'a Borges
Crossing Symmetry Violation of Unitarized Pion-Pion Amplitude in the Resonance Region
6 pages, 4 figures
J.Phys.G28:1351-1358,2002
10.1088/0954-3899/28/6/315
null
hep-ph
null
Pion-pion scattering amplitude obtained from one-loop Chiral Perturbation Theory (ChPT) is crossing symmetric, however the corresponding partial wave amplitudes do not respect exact unitarity relation. There are different approaches to get unitarized partial wave amplitudes from ChPT. Here we consider the inverse amplitude method (IAM) that is often used to fit pion-pion phase shifts to experimental data, by adjusting free parameters. We measure the amount of crossing symmetry violation (CSV) in this case and we show that crossing symmetry is badly violated by the IAM unitarized ChPT amplitude in the resonance region. Important CSV also occurs when all free parameters are set equal to zero.
[ { "created": "Tue, 30 Oct 2001 20:05:57 GMT", "version": "v1" } ]
2008-11-26
[ [ "Cavalcante", "Isabela P.", "" ], [ "Borges", "J. Sá", "" ] ]
Pion-pion scattering amplitude obtained from one-loop Chiral Perturbation Theory (ChPT) is crossing symmetric, however the corresponding partial wave amplitudes do not respect exact unitarity relation. There are different approaches to get unitarized partial wave amplitudes from ChPT. Here we consider the inverse amplitude method (IAM) that is often used to fit pion-pion phase shifts to experimental data, by adjusting free parameters. We measure the amount of crossing symmetry violation (CSV) in this case and we show that crossing symmetry is badly violated by the IAM unitarized ChPT amplitude in the resonance region. Important CSV also occurs when all free parameters are set equal to zero.
hep-ph/0203173
Huo WuJun
W.J. Huo and T.F. Feng (IHEP, Cas)
Constraints of the fourth generation from $g_\mu -2$
7 pages, 3 figures, to appear in Phys. Lett. B
null
null
null
hep-ph
null
We investigate the newly observed muon $g_\mu -2$ anomaly in the framework of a sequential fourth generation model with a heavy fourth neutrino, $\nu'$. We find that $g_\mu -2$ can exclude most values of $m_{\nu'}$ and put a very stringent constraint on the existence of the fourth generation. We also obtain bounds of a $4\times 4$ leptonic mixing matrix elements, $V_{2\nu'}$ if it really exists.
[ { "created": "Mon, 18 Mar 2002 16:31:17 GMT", "version": "v1" }, { "created": "Wed, 20 Mar 2002 12:53:29 GMT", "version": "v2" } ]
2007-05-23
[ [ "Huo", "W. J.", "", "IHEP, Cas" ], [ "Feng", "T. F.", "", "IHEP, Cas" ] ]
We investigate the newly observed muon $g_\mu -2$ anomaly in the framework of a sequential fourth generation model with a heavy fourth neutrino, $\nu'$. We find that $g_\mu -2$ can exclude most values of $m_{\nu'}$ and put a very stringent constraint on the existence of the fourth generation. We also obtain bounds of a $4\times 4$ leptonic mixing matrix elements, $V_{2\nu'}$ if it really exists.
hep-ph/0610178
Pavel Fileviez Perez
David Emmanuel-Costa, Pavel Fileviez Perez, Ricardo Gonzalez Felipe
Natural Gauge and Gravitational Coupling Unification and the Superpartner Masses
8 pages, 4 figures, version accepted in Physics Letters B
Phys.Lett.B648:60-63,2007
10.1016/j.physletb.2007.02.061
null
hep-ph hep-ex hep-th
null
The possibility to achieve unification at the string scale in the context of the simplest supersymmetric grand unified theory is investigated. We find conservative upper bounds on the superpartner masses consistent with the unification of gauge and gravitational couplings, M_{\tilde G} < 5 TeV and M_{\tilde f} < 3 \times 10^7 GeV, for the superparticles with spin one-half and zero, respectively. These bounds hint towards the possibility that this supersymmetric scenario could be tested at future colliders, and in particular, at the forthcoming LHC.
[ { "created": "Sat, 14 Oct 2006 14:33:13 GMT", "version": "v1" }, { "created": "Thu, 15 Feb 2007 15:31:29 GMT", "version": "v2" } ]
2007-05-23
[ [ "Emmanuel-Costa", "David", "" ], [ "Perez", "Pavel Fileviez", "" ], [ "Felipe", "Ricardo Gonzalez", "" ] ]
The possibility to achieve unification at the string scale in the context of the simplest supersymmetric grand unified theory is investigated. We find conservative upper bounds on the superpartner masses consistent with the unification of gauge and gravitational couplings, M_{\tilde G} < 5 TeV and M_{\tilde f} < 3 \times 10^7 GeV, for the superparticles with spin one-half and zero, respectively. These bounds hint towards the possibility that this supersymmetric scenario could be tested at future colliders, and in particular, at the forthcoming LHC.
2205.02912
Serdar Spor
A. Senol, S. Spor, E. Gurkanli, V. Cetinkaya, H. Denizli, M. K\"oksal
Model-independent study on the anomalous $ZZ\gamma$ and $Z\gamma\gamma$ couplings at the future muon collider
21 pages, 9 figures
European Physical Journal Plus, (2022) 137:1354
10.1140/epjp/s13360-022-03569-8
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this study, we investigate the potential of $\mu^{-} \mu^{+}\to Z\gamma \to \nu\bar{\nu}\gamma$ process at the future muon collider with a center-of-mass energy of 3 TeV to examine the anomalous $ZZ\gamma$ and $Z\gamma\gamma$ neutral triple gauge couplings defining $CP$-conserving $C_{\widetilde{B}W}/{\Lambda^4}$ coupling and three $CP$-violating $C_{BB}/{\Lambda^4}$, $C_{BW}/{\Lambda^4}$, $C_{WW}/{\Lambda^4}$ couplings. All signal and relevant background events are generated in MadGraph and passed through Pythia for parton showering and hadronization. Detector effects are also considered via tuned muon detector cards in Delphes. The effects of systematic uncertainties of $0\%$, $3\%$ and $5\%$ on the sensitivities are studied. The best sensitivities obtained from the process $\mu^{-} \mu^{+}\to Z\gamma \to \nu\bar{\nu}\gamma$ are $[-6.53;6.64]\times10^{-2}$ TeV$^{-4}$ on $CP$-conserving $C_{\widetilde{B}W}/{\Lambda^4}$ coupling and $[-2.47;2.47]\times10^{-2}$ TeV$^{-4}$, $[-8.46;8.46]\times10^{-2}$ TeV$^{-4}$ and $[-2.20;2.20]\times10^{-1}$ TeV$^{-4}$ on $CP$-conserving $C_{BB}/{\Lambda^4}$, $C_{BW}/{\Lambda^4}$, $C_{WW}/{\Lambda^4}$ couplings , respectively. Our obtained results on the anomalous neutral gauge couplings set more stringent sensitivity, ranging between 5 and 15 times than the current experimental results while slightly better than the phenomenological studies at future pp colliders such as the HL-LHC, the HE-LHC and the FCC-hh, respectively. On the other hand, we can see that the bounds on the anomalous neutral gauge couplings expected to be obtained for the future $e^{-}e^{+}$ colliders such as the CLIC are roughly 2 times better than our results.
[ { "created": "Thu, 5 May 2022 20:36:02 GMT", "version": "v1" }, { "created": "Sat, 17 Dec 2022 14:35:38 GMT", "version": "v2" } ]
2022-12-20
[ [ "Senol", "A.", "" ], [ "Spor", "S.", "" ], [ "Gurkanli", "E.", "" ], [ "Cetinkaya", "V.", "" ], [ "Denizli", "H.", "" ], [ "Köksal", "M.", "" ] ]
In this study, we investigate the potential of $\mu^{-} \mu^{+}\to Z\gamma \to \nu\bar{\nu}\gamma$ process at the future muon collider with a center-of-mass energy of 3 TeV to examine the anomalous $ZZ\gamma$ and $Z\gamma\gamma$ neutral triple gauge couplings defining $CP$-conserving $C_{\widetilde{B}W}/{\Lambda^4}$ coupling and three $CP$-violating $C_{BB}/{\Lambda^4}$, $C_{BW}/{\Lambda^4}$, $C_{WW}/{\Lambda^4}$ couplings. All signal and relevant background events are generated in MadGraph and passed through Pythia for parton showering and hadronization. Detector effects are also considered via tuned muon detector cards in Delphes. The effects of systematic uncertainties of $0\%$, $3\%$ and $5\%$ on the sensitivities are studied. The best sensitivities obtained from the process $\mu^{-} \mu^{+}\to Z\gamma \to \nu\bar{\nu}\gamma$ are $[-6.53;6.64]\times10^{-2}$ TeV$^{-4}$ on $CP$-conserving $C_{\widetilde{B}W}/{\Lambda^4}$ coupling and $[-2.47;2.47]\times10^{-2}$ TeV$^{-4}$, $[-8.46;8.46]\times10^{-2}$ TeV$^{-4}$ and $[-2.20;2.20]\times10^{-1}$ TeV$^{-4}$ on $CP$-conserving $C_{BB}/{\Lambda^4}$, $C_{BW}/{\Lambda^4}$, $C_{WW}/{\Lambda^4}$ couplings , respectively. Our obtained results on the anomalous neutral gauge couplings set more stringent sensitivity, ranging between 5 and 15 times than the current experimental results while slightly better than the phenomenological studies at future pp colliders such as the HL-LHC, the HE-LHC and the FCC-hh, respectively. On the other hand, we can see that the bounds on the anomalous neutral gauge couplings expected to be obtained for the future $e^{-}e^{+}$ colliders such as the CLIC are roughly 2 times better than our results.
1910.05711
Graciela B. Gelmini
Graciela B. Gelmini
Blois 2019: highlights and outlook
13 pages, 5 figures, blois.cls file necessary for typeset. Summary talk to be published in the proceedings of the conference
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is an idiosyncratic account of the main results presented at the 31st Rencontres de Blois, which took place from June 2nd to June 7th, 2019 in the Castle of Blois, France.
[ { "created": "Sun, 13 Oct 2019 08:39:26 GMT", "version": "v1" } ]
2019-10-15
[ [ "Gelmini", "Graciela B.", "" ] ]
This is an idiosyncratic account of the main results presented at the 31st Rencontres de Blois, which took place from June 2nd to June 7th, 2019 in the Castle of Blois, France.
hep-ph/0412121
Sangyong Jeon
Sangyong Jeon
The Boltzmann Equation in Classical and Quantum Field Theory
22 pages, 3 eps figures. Version to appear in Physical Review C
Phys.Rev. C72 (2005) 014907
10.1103/PhysRevC.72.014907
null
hep-ph
null
Improving upon the previous treatment by Mueller and Son, we derive the Boltzmann equation that results from a classical scalar field theory. This is obtained by starting from the corresponding quantum field theory and taking the classical limit with particular emphasis on the path integral and perturbation theory. A previously overlooked Van-Vleck determinant is shown to control the tadpole type of self-energy that can still appear in the classical perturbation theory. Further comments on the validity of the approximations and possible applications are also given.
[ { "created": "Wed, 8 Dec 2004 21:52:53 GMT", "version": "v1" }, { "created": "Tue, 18 Jan 2005 17:45:04 GMT", "version": "v2" }, { "created": "Mon, 18 Jul 2005 15:31:13 GMT", "version": "v3" } ]
2009-11-10
[ [ "Jeon", "Sangyong", "" ] ]
Improving upon the previous treatment by Mueller and Son, we derive the Boltzmann equation that results from a classical scalar field theory. This is obtained by starting from the corresponding quantum field theory and taking the classical limit with particular emphasis on the path integral and perturbation theory. A previously overlooked Van-Vleck determinant is shown to control the tadpole type of self-energy that can still appear in the classical perturbation theory. Further comments on the validity of the approximations and possible applications are also given.
1904.08016
Astrid Nathalie Hiller Blin
A. N. Hiller Blin, V. Mokeev, M. Albaladejo, C. Fern\'andez-Ram\'irez, V. Mathieu, A. Pilloni, A.Szczepaniak, V. D. Burkert, V. V. Chesnokov, A. A. Golubenko, M. Vanderhaeghen
Nucleon resonance contributions to unpolarised inclusive electron scattering
null
Phys. Rev. C 100, 035201 (2019)
10.1103/PhysRevC.100.035201
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first CLAS12 experiments will provide high-precision data on inclusive electron scattering observables at a photon virtuality $Q^2$ ranging from 0.05 GeV$^2$ to 12 GeV$^2$ and center-of-mass energies $W$ up to 4 GeV. In view of this endeavour, we present the modeling of the resonant contributions to the inclusive electron scattering observables. As input, we use the existing CLAS electrocoupling results obtained from exclusive meson electroproduction data off protons, and evaluate for the first time the resonant contributions based on the experimental results on the nucleon resonance electroexcitation. The uncertainties are given by the data and duly propagated through a Monte Carlo approach. In this way, we obtain estimates for the resonant contributions, important for insight into the nucleon parton distributions in the resonance region and for the studies of quark-hadron duality.
[ { "created": "Tue, 16 Apr 2019 23:30:41 GMT", "version": "v1" } ]
2019-09-11
[ [ "Blin", "A. N. Hiller", "" ], [ "Mokeev", "V.", "" ], [ "Albaladejo", "M.", "" ], [ "Fernández-Ramírez", "C.", "" ], [ "Mathieu", "V.", "" ], [ "Pilloni", "A.", "" ], [ "Szczepaniak", "A.", "" ], [ "Burkert", "V. D.", "" ], [ "Chesnokov", "V. V.", "" ], [ "Golubenko", "A. A.", "" ], [ "Vanderhaeghen", "M.", "" ] ]
The first CLAS12 experiments will provide high-precision data on inclusive electron scattering observables at a photon virtuality $Q^2$ ranging from 0.05 GeV$^2$ to 12 GeV$^2$ and center-of-mass energies $W$ up to 4 GeV. In view of this endeavour, we present the modeling of the resonant contributions to the inclusive electron scattering observables. As input, we use the existing CLAS electrocoupling results obtained from exclusive meson electroproduction data off protons, and evaluate for the first time the resonant contributions based on the experimental results on the nucleon resonance electroexcitation. The uncertainties are given by the data and duly propagated through a Monte Carlo approach. In this way, we obtain estimates for the resonant contributions, important for insight into the nucleon parton distributions in the resonance region and for the studies of quark-hadron duality.
1212.5604
Yang Bai
Yang Bai, Vernon Barger, Lisa L. Everett and Gabe Shaughnessy
2HDM Portal Dark Matter: LHC data and the Fermi-LAT 135 GeV Line
6 pages, 4 figures
Phys.Rev.D88:015008,2013
10.1103/PhysRevD.88.015008
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a two Higgs doublet model augmented by a scalar dark matter particle that provides an excellent fit to the LHC Higgs data and the Fermi-LAT 135 GeV line. The heavy CP-even Higgs boson, which predominantly mediates annihilation and scattering, must have a coupling to weak gauge bosons at or below percent level to suppress the continuum gamma-ray spectrum below the limit from the Fermi-LAT data and the anti-proton spectrum constrained by the PAMELA data. Discovering or excluding this CP-even Higgs boson at the LHC with a mass between 265 and 280 GeV and an enhanced diphoton branching ratio is crucial to test this scenario.
[ { "created": "Fri, 21 Dec 2012 21:00:02 GMT", "version": "v1" } ]
2013-07-30
[ [ "Bai", "Yang", "" ], [ "Barger", "Vernon", "" ], [ "Everett", "Lisa L.", "" ], [ "Shaughnessy", "Gabe", "" ] ]
We study a two Higgs doublet model augmented by a scalar dark matter particle that provides an excellent fit to the LHC Higgs data and the Fermi-LAT 135 GeV line. The heavy CP-even Higgs boson, which predominantly mediates annihilation and scattering, must have a coupling to weak gauge bosons at or below percent level to suppress the continuum gamma-ray spectrum below the limit from the Fermi-LAT data and the anti-proton spectrum constrained by the PAMELA data. Discovering or excluding this CP-even Higgs boson at the LHC with a mass between 265 and 280 GeV and an enhanced diphoton branching ratio is crucial to test this scenario.
hep-ph/0002257
Craig Tyler
Craig Tyler, Angela V. Olinto (Chicago, USA), Guenter Sigl (DARC, CNRS, Obs.Paris-Meudon, France)
Cosmic Neutrinos and New Physics beyond the Electroweak Scale
14 latex pages, uses revtex; final version as appears in PRD
Phys.Rev. D63 (2001) 055001
10.1103/PhysRevD.63.055001
null
hep-ph astro-ph
null
New physics beyond the electroweak scale may increase weak interaction cross sections beyond the Standard Model predictions. Such cross sections can be expected within theories that solve the hierarchy problem of known interactions with a unification scale in the TeV range. We derive constraints on these cross sections from the flux of neutrinos expected from cosmic ray interactions with the microwave background and the non-observation of horizontal air showers. We also discuss how this limit can be improved by upcoming cosmic ray and neutrino experiments, and how the energy dependence of the new interactions can be probed by these experiments.
[ { "created": "Thu, 24 Feb 2000 22:37:52 GMT", "version": "v1" }, { "created": "Fri, 19 Jan 2001 00:39:57 GMT", "version": "v2" } ]
2009-10-31
[ [ "Tyler", "Craig", "", "Chicago, USA" ], [ "Olinto", "Angela V.", "", "Chicago, USA" ], [ "Sigl", "Guenter", "", "DARC,\n CNRS, Obs.Paris-Meudon, France" ] ]
New physics beyond the electroweak scale may increase weak interaction cross sections beyond the Standard Model predictions. Such cross sections can be expected within theories that solve the hierarchy problem of known interactions with a unification scale in the TeV range. We derive constraints on these cross sections from the flux of neutrinos expected from cosmic ray interactions with the microwave background and the non-observation of horizontal air showers. We also discuss how this limit can be improved by upcoming cosmic ray and neutrino experiments, and how the energy dependence of the new interactions can be probed by these experiments.
1901.09552
Antonio Enrique C\'arcamo Hern\'andez
A. E. C\'arcamo Hern\'andez, Sergey Kovalenko, Roman Pasechnik, Ivan Schmidt
Phenomenology of an extended IDM with loop-generated fermion mass hierarchies
Version accepted for publication in EPJC. arXiv admin note: text overlap with arXiv:1901.02764
null
10.1140/epjc/s10052-019-7101-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a comprehensive analysis of the most distinctive and important phenomenological implications of the recently proposed mechanism of sequential loop generation of strong hierarchies in the Standard Model (SM) fermion mass spectra. This mechanism is consistently realized at the level of renormalizable interactions in an extended variant of the Inert Higgs Doublet model, possessing the additional $Z_{2}^{(1)}\times Z_{2}^{(2)}$ discrete and $U_{1X}$ gauge family symmetries, while the matter sectors of the SM are extended by means of $SU_{2L}$-singlet scalars, heavy vector-like leptons and quarks, as well as right-handed neutrinos. We thoroughly analyze the most stringent constraints on the model parameter space, coming from the $Z^{\prime }$ collider searches, related to the anomaly in lepton universality, and the muon anomalous magnetic moment, as well as provide benchmark points for further tests of the model and discuss possible "standard candle" signatures relevant for future explorations.
[ { "created": "Mon, 28 Jan 2019 08:53:19 GMT", "version": "v1" }, { "created": "Fri, 5 Jul 2019 17:09:30 GMT", "version": "v2" } ]
2019-09-04
[ [ "Hernández", "A. E. Cárcamo", "" ], [ "Kovalenko", "Sergey", "" ], [ "Pasechnik", "Roman", "" ], [ "Schmidt", "Ivan", "" ] ]
We perform a comprehensive analysis of the most distinctive and important phenomenological implications of the recently proposed mechanism of sequential loop generation of strong hierarchies in the Standard Model (SM) fermion mass spectra. This mechanism is consistently realized at the level of renormalizable interactions in an extended variant of the Inert Higgs Doublet model, possessing the additional $Z_{2}^{(1)}\times Z_{2}^{(2)}$ discrete and $U_{1X}$ gauge family symmetries, while the matter sectors of the SM are extended by means of $SU_{2L}$-singlet scalars, heavy vector-like leptons and quarks, as well as right-handed neutrinos. We thoroughly analyze the most stringent constraints on the model parameter space, coming from the $Z^{\prime }$ collider searches, related to the anomaly in lepton universality, and the muon anomalous magnetic moment, as well as provide benchmark points for further tests of the model and discuss possible "standard candle" signatures relevant for future explorations.
hep-ph/0510188
Thorsten Renk
Thorsten Renk
The influence of flow on the jet quenching power in heavy-ion collisions
Contribution to QM'2005 poster session proceedings, section 3
Acta Phys.Hung. A27 (2006) 263-266
10.1556/APH.27.2006.2-3.19
null
hep-ph
null
The flow pattern and evolution of the medium created in ultrarelativistic heavy ion collisions can have significant influence on the energy loss of hard partons traversing the medium. We demonstrate that within a range of assumptions for longitudinal and transverse flow which are all compatible with the measured hadronic single particle distributions, the quenching power of the medium can vary within almost a factor five. Thus, the choice of the medium evolution is one of the biggest uncertainties in jet quenching calculations and needs to be addressed with some care.
[ { "created": "Fri, 14 Oct 2005 09:50:23 GMT", "version": "v1" } ]
2009-11-11
[ [ "Renk", "Thorsten", "" ] ]
The flow pattern and evolution of the medium created in ultrarelativistic heavy ion collisions can have significant influence on the energy loss of hard partons traversing the medium. We demonstrate that within a range of assumptions for longitudinal and transverse flow which are all compatible with the measured hadronic single particle distributions, the quenching power of the medium can vary within almost a factor five. Thus, the choice of the medium evolution is one of the biggest uncertainties in jet quenching calculations and needs to be addressed with some care.
hep-ph/0005284
Xiaolin Chen
Wei Liu, Hanqing Zheng and Xiao-Lin Chen
A Numerical Analysis to the {$\pi$} and {K} Coupled--Channel Scalar Form-factor
8 pages, Latex, 3 figures. Minor changes and one reference added
Commun.Theor.Phys. 35 (2001) 543-546
10.1088/0253-6102/35/5/543
null
hep-ph
null
A numerical analysis to the scalar form-factor in the $\pi\pi$ and KK coupled--channel system is made by solving the coupled-channel dispersive integral equations, using the iteration method. The solutions are found not unique. Physical application to the $\pi\pi$ central production in the $pp\to pp\pi\pi$ process is discussed based upon the numerical solutions we found.
[ { "created": "Mon, 29 May 2000 15:09:40 GMT", "version": "v1" }, { "created": "Sat, 22 Jul 2000 02:54:14 GMT", "version": "v2" } ]
2018-01-17
[ [ "Liu", "Wei", "" ], [ "Zheng", "Hanqing", "" ], [ "Chen", "Xiao-Lin", "" ] ]
A numerical analysis to the scalar form-factor in the $\pi\pi$ and KK coupled--channel system is made by solving the coupled-channel dispersive integral equations, using the iteration method. The solutions are found not unique. Physical application to the $\pi\pi$ central production in the $pp\to pp\pi\pi$ process is discussed based upon the numerical solutions we found.
hep-ph/0701070
Hisakazu Minakata
Hisakazu Minakata
Neutrinos; Opportunities and Strategies in the Future
Comments 27 pages, 13 figures, Combined and slightly expanded written version of the invited talks given at International Conference ``Heavy Quarks and Leptons'', Munich, Germany, October 16-20, 2006, and Second World Summit on ``Physics Beyond the Standard Model'', Galapagos Islands, Ecuador, June 22-25, 2006 (post-deadline version)
ECONFC0610161:036,2006
null
null
hep-ph
null
I try to give an overview of future prospects of the experimental exploration of the unknowns in the neutrino mass pattern and the lepton flavor mixing. Because of the nature of the lectures on which this manuscript is based, I give some pedagogical discussions to prepare for the presentation in the later part. I start from measuring \theta_{13} by reactors and accelerators as a prerequisite for proceeding to search for leptonic CP violation. I then discuss how CP violation can be uncovered, and how the neutrino mass hierarchy can be determined. I do these by resolving so called the ``parameter degeneracy'' which is necessary anyway if one wants to seek precision measurement of the lepton mixing parameters. As a concrete setting for resolving the degeneracy I introduce the Tokai-to-Kamioka-Korea two detector complex which receives neutrino superbeam from J-PARC, sometimes dubbed as ``T2KK''. It is shown that T2KK is able to resolve all the eight-fold parameter degeneracy in a wide range of the lepton mixing parameters. I also discuss an alternative way for lifting the \theta_{23} octant degeneracy by reactor-accelerator combined method. Finally, I discuss by taking some examples how some theoretically or phenomenologically motivated ideas can be tested experimentally.
[ { "created": "Wed, 10 Jan 2007 12:52:21 GMT", "version": "v1" } ]
2008-11-26
[ [ "Minakata", "Hisakazu", "" ] ]
I try to give an overview of future prospects of the experimental exploration of the unknowns in the neutrino mass pattern and the lepton flavor mixing. Because of the nature of the lectures on which this manuscript is based, I give some pedagogical discussions to prepare for the presentation in the later part. I start from measuring \theta_{13} by reactors and accelerators as a prerequisite for proceeding to search for leptonic CP violation. I then discuss how CP violation can be uncovered, and how the neutrino mass hierarchy can be determined. I do these by resolving so called the ``parameter degeneracy'' which is necessary anyway if one wants to seek precision measurement of the lepton mixing parameters. As a concrete setting for resolving the degeneracy I introduce the Tokai-to-Kamioka-Korea two detector complex which receives neutrino superbeam from J-PARC, sometimes dubbed as ``T2KK''. It is shown that T2KK is able to resolve all the eight-fold parameter degeneracy in a wide range of the lepton mixing parameters. I also discuss an alternative way for lifting the \theta_{23} octant degeneracy by reactor-accelerator combined method. Finally, I discuss by taking some examples how some theoretically or phenomenologically motivated ideas can be tested experimentally.
1506.05575
Soodeh Zarepour
S. Mohammad Zebarjad and Soodeh Zarepour
Two-body decay widths of lowest lying and next-to-lowest lying scalar and pseudoscalar mesons in generalized linear sigma model
21 pages, 12 figures
Int. J. Mod. Phys. A 30, 1550134, 2015
10.1142/S0217751X15501341
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Two-body decay widths of lowest lying and next-to-lowest lying scalar and pseudoscalar mesons are studied in Generalized Linear Sigma Model (GLSM) of low-energy QCD. This model which considers mixing between "two quark" and "four quark" chiral nonets has been employed to investigate various decays and scatterings in low energy region of QCD. In this paper, $\Gamma[f_0(980) \rightarrow K \bar{K}]$ and $\Gamma[a_0(980) \rightarrow K \bar{K}]$ are obtained and it is shown that two-body decay widths of lowest lying mesons are well predicted by this model while for the next-to-lowest lying mesons, only some of the decay widths agree with the experimental results. We have compared the predicted decay widths in GLSM with the results obtained in single nonet linear sigma model (SNLSM) to indicate that chiral nonet mixing greatly improves the predictions of SNLSM for decay widths.
[ { "created": "Thu, 18 Jun 2015 07:51:57 GMT", "version": "v1" } ]
2015-07-28
[ [ "Zebarjad", "S. Mohammad", "" ], [ "Zarepour", "Soodeh", "" ] ]
Two-body decay widths of lowest lying and next-to-lowest lying scalar and pseudoscalar mesons are studied in Generalized Linear Sigma Model (GLSM) of low-energy QCD. This model which considers mixing between "two quark" and "four quark" chiral nonets has been employed to investigate various decays and scatterings in low energy region of QCD. In this paper, $\Gamma[f_0(980) \rightarrow K \bar{K}]$ and $\Gamma[a_0(980) \rightarrow K \bar{K}]$ are obtained and it is shown that two-body decay widths of lowest lying mesons are well predicted by this model while for the next-to-lowest lying mesons, only some of the decay widths agree with the experimental results. We have compared the predicted decay widths in GLSM with the results obtained in single nonet linear sigma model (SNLSM) to indicate that chiral nonet mixing greatly improves the predictions of SNLSM for decay widths.
hep-ph/0112240
Kai Hencken
Kai Hencken
Coherent electromagnetic processes in relativistic heavy ion collisions
10 pages, invited talk presented at the Workshop on Electromagnetic Probes of Fundamental Physics, Oct. 16-21, 2001, Erice, Italy
null
null
null
hep-ph
null
Using the strong electromagnetic fields in peripheral heavy ion collisions gives rise to a number of interesting possibilities of applications in both photon-photon and photon-hadron physics. We look at the theoretical foundations of the equivalent photon approximation and the specific problems in the heavy ion case. The interesting physics processes that can be studied in this way are outlined. Electron positron pair production plays a special role. We look at multiple pair production and Coulomb corrections as typical strong field effects. But electron positron pair production is also an important loss process and has some practical applications.
[ { "created": "Tue, 18 Dec 2001 13:40:37 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hencken", "Kai", "" ] ]
Using the strong electromagnetic fields in peripheral heavy ion collisions gives rise to a number of interesting possibilities of applications in both photon-photon and photon-hadron physics. We look at the theoretical foundations of the equivalent photon approximation and the specific problems in the heavy ion case. The interesting physics processes that can be studied in this way are outlined. Electron positron pair production plays a special role. We look at multiple pair production and Coulomb corrections as typical strong field effects. But electron positron pair production is also an important loss process and has some practical applications.
hep-ph/0506110
Andrej Arbuzov
A. Arbuzov, D. Bardin, S. Bondarenko, P. Christova, L. Kalinovskaya, G. Nanava, and R. Sadykov
One-loop corrections to the Drell-Yan process in SANC (I). The charged current case
extended version submitted to EPJC
Eur.Phys.J.C46:407-412,2006; Erratum-ibid.C50:505,2007; Erratum-ibid.C50:505-505,2007
10.1140/epjc/s2006-02505-y 10.1140/epjc/s10052-007-0225-7
null
hep-ph
null
Radiative corrections to the charged current Drell-Yan processes are revisited. Complete one-loop electroweak corrections are calculated within the automatic SANC system. Electroweak scheme dependence and the choice of the factorization scale are discussed. Comparisons with earlier calculations are presented.
[ { "created": "Sat, 11 Jun 2005 07:37:43 GMT", "version": "v1" }, { "created": "Mon, 9 Jan 2006 12:24:56 GMT", "version": "v2" } ]
2008-11-26
[ [ "Arbuzov", "A.", "" ], [ "Bardin", "D.", "" ], [ "Bondarenko", "S.", "" ], [ "Christova", "P.", "" ], [ "Kalinovskaya", "L.", "" ], [ "Nanava", "G.", "" ], [ "Sadykov", "R.", "" ] ]
Radiative corrections to the charged current Drell-Yan processes are revisited. Complete one-loop electroweak corrections are calculated within the automatic SANC system. Electroweak scheme dependence and the choice of the factorization scale are discussed. Comparisons with earlier calculations are presented.
2109.07674
Zhongyi Zhang
Manuel Drees, Meng Shi, Zhongyi Zhang
Machine Learning Optimized Search for the $Z'$ from $U(1)_{L_\mu-L_\tau}$ at the LHC
39 pages, 10 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extending the Standard Model (SM) by a $U(1)_{L_\mu-L_\tau}$ group gives potentially significant new contributions to $g_\mu-2$, allows the construction of realistic neutrino mass matrices, incorporates lepton universality violation, and offers an anomaly-free mediator for a Dark Matter (DM) sector. In a recent analysis we showed that published LHC searches are not very sensitive to this model. Here we apply several Machine Learning (ML) algorithms in order to distinguish this model from the SM using simulated LHC data. In particular, we optimize the $3\mu$-signal, which has a considerably larger cross section than the $4\mu$-signal. Furthermore, since the $2$-muon plus missing $E_T$ final state gets contributions from diagrams involving DM particles, we optimize it as well. We find greatly improved sensitivity, which already for $36$ fb$^{-1}$ of data exceeds the combination of published LHC and non-LHC results. We also emphasize the usefulness of Boosted Decision Trees which, unlike Neural Networks, easily allow to extract additional information from the data which directly connect to the theoretical model through feature importance. The same scheme could be used to analyze other models.
[ { "created": "Thu, 16 Sep 2021 02:33:07 GMT", "version": "v1" }, { "created": "Thu, 17 Feb 2022 00:27:21 GMT", "version": "v2" } ]
2022-02-18
[ [ "Drees", "Manuel", "" ], [ "Shi", "Meng", "" ], [ "Zhang", "Zhongyi", "" ] ]
Extending the Standard Model (SM) by a $U(1)_{L_\mu-L_\tau}$ group gives potentially significant new contributions to $g_\mu-2$, allows the construction of realistic neutrino mass matrices, incorporates lepton universality violation, and offers an anomaly-free mediator for a Dark Matter (DM) sector. In a recent analysis we showed that published LHC searches are not very sensitive to this model. Here we apply several Machine Learning (ML) algorithms in order to distinguish this model from the SM using simulated LHC data. In particular, we optimize the $3\mu$-signal, which has a considerably larger cross section than the $4\mu$-signal. Furthermore, since the $2$-muon plus missing $E_T$ final state gets contributions from diagrams involving DM particles, we optimize it as well. We find greatly improved sensitivity, which already for $36$ fb$^{-1}$ of data exceeds the combination of published LHC and non-LHC results. We also emphasize the usefulness of Boosted Decision Trees which, unlike Neural Networks, easily allow to extract additional information from the data which directly connect to the theoretical model through feature importance. The same scheme could be used to analyze other models.
hep-ph/9508363
null
Zhenjun Xiao and Xuelei Wang
Pseudo-Goldstone Bosons in Technicolor Models and the Phenomenology
31 pages, latex, no macros, 2 figures, hard copies are available upon request. Invited talk Given at CCAST Seminar of Precision Test of the Standard Model and Superhigh Energy Physics, Beijing, P.R.China, April 18 to May 17, 1995; to appear in the Proceedings
null
null
HNU-TH-95/16
hep-ph
null
In this report we present a review of recent developments in the TC/ETC theories, concentrating on the theoretical estimations and the phenomenological analysis about the Non-Oblique corrections on the $Zb\overline{b}$ vertex from ETC dynamics and Pseudo-Goldstone Bosons. The relevant studies about the vertex corrections on other processes from the PGBs were also considered.
[ { "created": "Thu, 24 Aug 1995 13:32:50 GMT", "version": "v1" } ]
2009-09-25
[ [ "Xiao", "Zhenjun", "" ], [ "Wang", "Xuelei", "" ] ]
In this report we present a review of recent developments in the TC/ETC theories, concentrating on the theoretical estimations and the phenomenological analysis about the Non-Oblique corrections on the $Zb\overline{b}$ vertex from ETC dynamics and Pseudo-Goldstone Bosons. The relevant studies about the vertex corrections on other processes from the PGBs were also considered.
1505.07764
Wolfgang Hollik
Wolfgang Gregor Hollik
Neutrinos Meet Supersymmetry: Quantum Aspects of of Neutrinophysics in Supersymmetric Theories
PhD thesis; contains results of arXiv:1412.4585, arXiv:1411.3549 and arXiv:1407.2814
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We address the influence of quantum corrections to neutrino masses and mixings and discuss the possibilities to completely generate the flavor mixing irrespective of any tree-level flavor model. Furthermore, we describe a new class of vacua with a new minimum appearing in the standard Higgs direction. The results hint towards a charge and color breaking global minimum and therefore extend existing bounds at tree-level. Finally, we combine the discussion of vacuum stability in the MSSM with the right-handed neutrino extension. The supersymmetric version of the seesaw mechanism rescues the potential and also does not induce further instabilities neither at the SUSY scale nor at the scale of heavy neutrinos, as long as both scales are well separated. Moreover, we resolve a degeneracy in name space.
[ { "created": "Thu, 28 May 2015 17:29:31 GMT", "version": "v1" } ]
2015-05-29
[ [ "Hollik", "Wolfgang Gregor", "" ] ]
We address the influence of quantum corrections to neutrino masses and mixings and discuss the possibilities to completely generate the flavor mixing irrespective of any tree-level flavor model. Furthermore, we describe a new class of vacua with a new minimum appearing in the standard Higgs direction. The results hint towards a charge and color breaking global minimum and therefore extend existing bounds at tree-level. Finally, we combine the discussion of vacuum stability in the MSSM with the right-handed neutrino extension. The supersymmetric version of the seesaw mechanism rescues the potential and also does not induce further instabilities neither at the SUSY scale nor at the scale of heavy neutrinos, as long as both scales are well separated. Moreover, we resolve a degeneracy in name space.
1001.0104
Alexander Snigirev
A.M. Snigirev
Possible indication to the QCD evolution of double parton distributions?
5 pages, 1 figure, revtex4, Clarifications, Ref. added, Fig. redrawn, accepted in Phys. Rev. D
Phys.Rev.D81:065014,2010
10.1103/PhysRevD.81.065014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For the first time the process-independent parameter of double parton scattering, $\sigma_{\rm eff}^{\rm exp}$, has been measured newly in the D0 experiment at the three different resolution scales.If we interpret the measurement as a decrease of the effective cross section with a growth of the resolution scale it can indicate the QCD evolution of double parton distributions.
[ { "created": "Thu, 31 Dec 2009 08:09:24 GMT", "version": "v1" }, { "created": "Sat, 9 Jan 2010 10:04:41 GMT", "version": "v2" }, { "created": "Fri, 5 Feb 2010 11:31:25 GMT", "version": "v3" } ]
2010-04-29
[ [ "Snigirev", "A. M.", "" ] ]
For the first time the process-independent parameter of double parton scattering, $\sigma_{\rm eff}^{\rm exp}$, has been measured newly in the D0 experiment at the three different resolution scales.If we interpret the measurement as a decrease of the effective cross section with a growth of the resolution scale it can indicate the QCD evolution of double parton distributions.
2204.06948
Priyanka Lamba
Mathew Thomas Arun, Priyanka Lamba, and Sudhir K. Vempati
Restricting $q^2 l^2$ operators from $\pi^0 \rightarrow \mu e$
21 pages, 1 figure
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper we consider semileptonic lepton flavor violating operators of the type $q^2l^2$ in low energy effective theory (LEFT). At the chiral scale, we match these operators to chiral perturbation theory ($\chi$PT) and place constraints from the process $\pi^0\rightarrow \mu^+ \,\, e^-$. These bounds are shown to depend on the chiral nature of the operators. The scalar operators are significantly more constrained compared to the vector operators. We then compare the limits from $\mu \to e$ conversion in Nuclei and show that the limits on scalar operators are within an order of magnitude of the corresponding limits from $\mu \to e$ conversion in Ti. On the other hand, the limits on vector operators are however much weaker. Towards the end, we evolve the LEFT operators to W-boson mass scale using RGE, and match them to the Standard Model effective field theory (SMEFT) operators. We, then, derive the constraints on the parameter space of Leptoquark models that could generate these SMEFT operators at tree level.
[ { "created": "Thu, 14 Apr 2022 13:19:08 GMT", "version": "v1" } ]
2022-04-15
[ [ "Arun", "Mathew Thomas", "" ], [ "Lamba", "Priyanka", "" ], [ "Vempati", "Sudhir K.", "" ] ]
In this paper we consider semileptonic lepton flavor violating operators of the type $q^2l^2$ in low energy effective theory (LEFT). At the chiral scale, we match these operators to chiral perturbation theory ($\chi$PT) and place constraints from the process $\pi^0\rightarrow \mu^+ \,\, e^-$. These bounds are shown to depend on the chiral nature of the operators. The scalar operators are significantly more constrained compared to the vector operators. We then compare the limits from $\mu \to e$ conversion in Nuclei and show that the limits on scalar operators are within an order of magnitude of the corresponding limits from $\mu \to e$ conversion in Ti. On the other hand, the limits on vector operators are however much weaker. Towards the end, we evolve the LEFT operators to W-boson mass scale using RGE, and match them to the Standard Model effective field theory (SMEFT) operators. We, then, derive the constraints on the parameter space of Leptoquark models that could generate these SMEFT operators at tree level.
hep-ph/0210130
Maria E. Tejeda-Yeomans
George Sterman and Maria E. Tejeda-Yeomans (SUNY, Stony Brook)
Multi-loop Amplitudes and Resummation
14 pages, LateX2e using elsart.cls (included). Typographical errors corrected and expansion in renormalized coupling clarified. Thanks added to Z. Bern and L. Dixon for critical readings of the original version
Phys.Lett.B552:48-56,2003
10.1016/S0370-2693(02)03100-3
YITP-SB-02-56
hep-ph
null
We explore the relation between resummation and explicit multi-loop calculations for QCD hard-scattering amplitudes. We describe how the factorization properties of amplitudes lead to the exponentiation of double and single poles at each order of perturbation theory. For these amplitudes, previously-observed relations between single and double poles in different 2 to 2 processes can now be interpreted in terms of universal functions associated with external partons and process-dependent anomalous dimensions that describe coherent soft radiation. Catani's proposal for multiple poles in dimensionally-continued amplitudes emerges naturally.
[ { "created": "Tue, 8 Oct 2002 18:29:37 GMT", "version": "v1" }, { "created": "Thu, 10 Oct 2002 20:46:56 GMT", "version": "v2" }, { "created": "Wed, 6 Apr 2005 17:23:55 GMT", "version": "v3" } ]
2014-11-17
[ [ "Sterman", "George", "", "SUNY, Stony Brook" ], [ "Tejeda-Yeomans", "Maria E.", "", "SUNY, Stony Brook" ] ]
We explore the relation between resummation and explicit multi-loop calculations for QCD hard-scattering amplitudes. We describe how the factorization properties of amplitudes lead to the exponentiation of double and single poles at each order of perturbation theory. For these amplitudes, previously-observed relations between single and double poles in different 2 to 2 processes can now be interpreted in terms of universal functions associated with external partons and process-dependent anomalous dimensions that describe coherent soft radiation. Catani's proposal for multiple poles in dimensionally-continued amplitudes emerges naturally.
hep-ph/0508238
Bernd Kniehl
Bernd A. Kniehl, Anatoly V. Kotikov
Calculating four-loop tadpoles with one non-zero mass
12 pages, 3 figures
Phys.Lett. B638 (2006) 531-537
10.1016/j.physletb.2006.04.057
DESY 05-153
hep-ph
null
An efficient method to calculate tadpole diagrams is proposed. Its capability is demonstrated by analytically evaluating two four-loop tadpole diagrams of current interest in the literature, including their $O(\epsilon)$ terms in $D=4-2\epsilon$ space-time dimensions.
[ { "created": "Tue, 23 Aug 2005 09:34:32 GMT", "version": "v1" }, { "created": "Tue, 18 Jul 2006 18:39:49 GMT", "version": "v2" } ]
2009-11-11
[ [ "Kniehl", "Bernd A.", "" ], [ "Kotikov", "Anatoly V.", "" ] ]
An efficient method to calculate tadpole diagrams is proposed. Its capability is demonstrated by analytically evaluating two four-loop tadpole diagrams of current interest in the literature, including their $O(\epsilon)$ terms in $D=4-2\epsilon$ space-time dimensions.
1201.1236
Marek G\'o\'zd\'z
Marek G\'o\'zd\'z and W. A. Kami\'nski
Suppression of $0\nu 2\beta$ Decay from CP Violation
I've decided to move the collection of my papers to arXiv for easier access. Proceedings of the Nuclear Physics Workshop in Kazimierz Dolny, Poland, 2006
Int. J. Mod. Phys. E 16 (2007) 561
10.1142/S0218301307005995
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observed phenomenon of neutrino oscillations is interpreted as the proof that neutrinos must have mass. As this is true for the neutrinos in the mass basis, the mass matrix in the flavor (weak) basis may still contain zeros. This can happen if the CP violating phases, usually neglected, come into play and result in suppression of processes which half-life depends on the masses of $\nu_e$, $\nu_\mu$, or $\nu_\tau$. In the present paper we investigate the possibility of such suppression of the neutrinoless double beta decay ($0\nu2\beta$).
[ { "created": "Thu, 5 Jan 2012 18:00:27 GMT", "version": "v1" } ]
2015-06-03
[ [ "Góźdź", "Marek", "" ], [ "Kamiński", "W. A.", "" ] ]
The observed phenomenon of neutrino oscillations is interpreted as the proof that neutrinos must have mass. As this is true for the neutrinos in the mass basis, the mass matrix in the flavor (weak) basis may still contain zeros. This can happen if the CP violating phases, usually neglected, come into play and result in suppression of processes which half-life depends on the masses of $\nu_e$, $\nu_\mu$, or $\nu_\tau$. In the present paper we investigate the possibility of such suppression of the neutrinoless double beta decay ($0\nu2\beta$).
2312.15518
Jin-Wen Kang
Jin-Wen Kang, Sa Wang, Lei Wang, Ben-Wei Zhang
Phenomenological study of the angle between jet axes in heavy-ion collisions
8 pages, 7 figures
null
null
null
hep-ph hep-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
This paper presents a phenomenological study on the angle between the Standard and the Winner-Take-All (WTA) jet axes ($\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$) in high-energy nuclear collisions. The $p$+$p$ baseline is provided by the Pythia8 event generator. The in-medium jet propagation is simulated by the linear Boltzmann transport (LBT) model, which considers both the elastic and inelastic jet-medium interactions. Our theoretical results calculated by the LBT model show that the $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ distribution in Pb+Pb at $\sqrt{s}=5.02$ TeV is narrower than that in $p$+$p$, which agrees well with the recent ALICE measurements. The narrowing of $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ seems to violate the $p_T$-broadening nature of the jet quenching effect, usually explained by the influence of "selection bias". However, the physical details still need to be fully understood. Utilizing a matching-jet method to track the jet evolution in the QGP to remove the selection bias in the Monte Carlo simulations, we observe that the $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ distribution becomes broader due to the jet-medium interactions. At the same time, by rescaling the quark/gluon-jet fractions in Pb+Pb collisions to be the same as that in $p$+$p$, we find that the fraction change may not significantly influence the modification pattern of jet $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$. On the other hand, the selected jet sample in A+A collisions has a significantly narrower initial $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ distribution than the $p$+$p$ baseline, and such a biased comparison between $p$+$p$ and A+A conceals the actual jet-broadening effect in the experimental measurements. The investigations presented in this paper will deepen our understanding of the relationship between the actual intra-jet modifications in the QGP and the experimental observations.
[ { "created": "Sun, 24 Dec 2023 16:03:23 GMT", "version": "v1" } ]
2023-12-27
[ [ "Kang", "Jin-Wen", "" ], [ "Wang", "Sa", "" ], [ "Wang", "Lei", "" ], [ "Zhang", "Ben-Wei", "" ] ]
This paper presents a phenomenological study on the angle between the Standard and the Winner-Take-All (WTA) jet axes ($\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$) in high-energy nuclear collisions. The $p$+$p$ baseline is provided by the Pythia8 event generator. The in-medium jet propagation is simulated by the linear Boltzmann transport (LBT) model, which considers both the elastic and inelastic jet-medium interactions. Our theoretical results calculated by the LBT model show that the $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ distribution in Pb+Pb at $\sqrt{s}=5.02$ TeV is narrower than that in $p$+$p$, which agrees well with the recent ALICE measurements. The narrowing of $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ seems to violate the $p_T$-broadening nature of the jet quenching effect, usually explained by the influence of "selection bias". However, the physical details still need to be fully understood. Utilizing a matching-jet method to track the jet evolution in the QGP to remove the selection bias in the Monte Carlo simulations, we observe that the $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ distribution becomes broader due to the jet-medium interactions. At the same time, by rescaling the quark/gluon-jet fractions in Pb+Pb collisions to be the same as that in $p$+$p$, we find that the fraction change may not significantly influence the modification pattern of jet $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$. On the other hand, the selected jet sample in A+A collisions has a significantly narrower initial $\Delta R_{{\rm axis}}^{{\rm WTA-Std}}$ distribution than the $p$+$p$ baseline, and such a biased comparison between $p$+$p$ and A+A conceals the actual jet-broadening effect in the experimental measurements. The investigations presented in this paper will deepen our understanding of the relationship between the actual intra-jet modifications in the QGP and the experimental observations.
1511.00935
Girish Kumar
Girish Kumar and Namit Mahajan
Asymmetries and observables for $\Lambda_b\rightarrow \Lambda \ell^+\ell^-$
8 pages, 1 figure
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The semi-leptonic baryonic $b\to s$ decay, $\Lambda_b\rightarrow \Lambda \ell^+\ell^-$, has been studied and new angular observables and asymmetries have been proposed which can test the presence of new physics beyond the standard model.
[ { "created": "Tue, 3 Nov 2015 14:53:38 GMT", "version": "v1" } ]
2015-11-04
[ [ "Kumar", "Girish", "" ], [ "Mahajan", "Namit", "" ] ]
The semi-leptonic baryonic $b\to s$ decay, $\Lambda_b\rightarrow \Lambda \ell^+\ell^-$, has been studied and new angular observables and asymmetries have been proposed which can test the presence of new physics beyond the standard model.
1510.06550
Shuichiro Funatsu
Shuichiro Funatsu, Hisaki Hatanaka, Yutaka Hosotani
$H\to Z\gamma$ in the gauge-Higgs unification
35 pages, 7 figures, typo corrected
Phys. Rev. D 92, 115003 (2015)
10.1103/PhysRevD.92.115003
OU-HET 872, KIAS-P15044
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay rate of the Higgs decay $H \to Z \gamma$ is evaluated at the one-loop level in the $SO(5)\times U(1)$ gauge-Higgs unification. Although an infinite number of loops with Kaluza-Klein states contribute to the decay amplitude, there appears the cancellation among the loops, and the decay rate is found to be finite and non-zero. It is found that the decay rate is well approximated by the decay rate in the standard model multiplied by $\cos^2\theta_H$, where $\theta_H$ is the Aharonov-Bohm phase induced by the vacuum expectation value of an extra-dimensional component of the gauge field.
[ { "created": "Thu, 22 Oct 2015 09:42:54 GMT", "version": "v1" }, { "created": "Thu, 3 Dec 2015 12:56:46 GMT", "version": "v2" }, { "created": "Sat, 3 Sep 2016 20:09:12 GMT", "version": "v3" } ]
2016-09-06
[ [ "Funatsu", "Shuichiro", "" ], [ "Hatanaka", "Hisaki", "" ], [ "Hosotani", "Yutaka", "" ] ]
The decay rate of the Higgs decay $H \to Z \gamma$ is evaluated at the one-loop level in the $SO(5)\times U(1)$ gauge-Higgs unification. Although an infinite number of loops with Kaluza-Klein states contribute to the decay amplitude, there appears the cancellation among the loops, and the decay rate is found to be finite and non-zero. It is found that the decay rate is well approximated by the decay rate in the standard model multiplied by $\cos^2\theta_H$, where $\theta_H$ is the Aharonov-Bohm phase induced by the vacuum expectation value of an extra-dimensional component of the gauge field.
hep-ph/9611406
Nicolas Pott
Oliver Baer, Nicolas Pott (TU Munich)
1/m_b^2 correction to the left-right lepton polarization asymmetry in the decay B -> X_s mu^+ mu^-
8 pages, 2 figures included. Uses epsf.sty and rotate.sty. To appear in Physical Review D. The complete postscript file is also available from URL ftp://feynman.t30.physik.tu-muenchen.de/pub/preprints/ tum_t31_98_96.ps.gz
Phys.Rev.D55:1684-1687,1997
10.1103/PhysRevD.55.1684
TUM-T31-98/96
hep-ph
null
Using a known result by Falk et al. for the 1/m_b^2 correction to the dilepton invariant mass spectrum in the decay B \rightarrow X_s \mu^+ \mu^-, we calculate the 1/m_b^2 correction to the left-right muon polarization asymmetry in this decay. Employing an up-to-date range of values for the non-perturbative parameter \lambda_1, we find that the correction is much smaller than it should have been expected from the previous work by Falk et al.
[ { "created": "Mon, 25 Nov 1996 09:26:10 GMT", "version": "v1" } ]
2011-01-27
[ [ "Baer", "Oliver", "", "TU Munich" ], [ "Pott", "Nicolas", "", "TU Munich" ] ]
Using a known result by Falk et al. for the 1/m_b^2 correction to the dilepton invariant mass spectrum in the decay B \rightarrow X_s \mu^+ \mu^-, we calculate the 1/m_b^2 correction to the left-right muon polarization asymmetry in this decay. Employing an up-to-date range of values for the non-perturbative parameter \lambda_1, we find that the correction is much smaller than it should have been expected from the previous work by Falk et al.
1707.08965
Raymond Co
Raymond T. Co and Keisuke Harigaya
Gravitino Production Suppressed by Dynamics of Sgoldstino
23 pages, 3 figures; v2: discussions added and one figure updated, matches version published in JHEP
JHEP 1710 (2017) 207
10.1007/JHEP10(2017)207
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In supersymmetric theories, the gravitino is abundantly produced in the early Universe from thermal scattering, resulting in a strong upper bound on the reheat temperature after inflation. We point out that the gravitino problem may be absent or very mild due to the early dynamics of a supersymmetry breaking field, i.e. a sgoldstino. In models of low scale mediation, the field value of the sgoldstino determines the mediation scale and is in general different in the early Universe from the present one. A large initial field value since the era of the inflationary reheating suppresses the gravitino production significantly. We investigate in detail the cosmological evolution of the sgoldstino and show that the reheat temperature may be much higher than the conventional upper bound, restoring the compatibility with thermal leptogenesis.
[ { "created": "Thu, 27 Jul 2017 18:00:01 GMT", "version": "v1" }, { "created": "Wed, 15 Nov 2017 20:39:27 GMT", "version": "v2" } ]
2017-11-22
[ [ "Co", "Raymond T.", "" ], [ "Harigaya", "Keisuke", "" ] ]
In supersymmetric theories, the gravitino is abundantly produced in the early Universe from thermal scattering, resulting in a strong upper bound on the reheat temperature after inflation. We point out that the gravitino problem may be absent or very mild due to the early dynamics of a supersymmetry breaking field, i.e. a sgoldstino. In models of low scale mediation, the field value of the sgoldstino determines the mediation scale and is in general different in the early Universe from the present one. A large initial field value since the era of the inflationary reheating suppresses the gravitino production significantly. We investigate in detail the cosmological evolution of the sgoldstino and show that the reheat temperature may be much higher than the conventional upper bound, restoring the compatibility with thermal leptogenesis.
1711.10779
Kenji Morita
Kenji Morita, Chihiro Sasaki, Pok Man Lo, Krzysztof Redlich
Overlap between Lattice QCD and HRG with in-medium effects and parity doubling
9 pages, 5 figures. To appear in Proceedings of Strangeness in Quark Matter 2017
null
10.1051/epjconf/201817105001
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the fluctuations and correlations involving baryon number in hot hadronic matter with modified masses of negative-parity baryons, in the context of the hadron resonance gas. Temperature-dependent masses are adopted from the recent lattice QCD results and from a chiral effective model which implements the parity doubling structure with respect to the chiral symmetry. Confronting the baryon number susceptibility, baryon-charge correlation, and baryon-strangeness correlation and their ratios with the lattice QCD data, we show that the strong downward mass shift in hyperons can accidentally reproduce some correlation ratios, however it also tends to overshoot the individual fluctuations and correlations. This indicates, that in order to correctly account for the influence of the chiral symmetry restoration on the fluctuation observables, a consistent framework of in-medium effects beyond hadron mass shifts is required.
[ { "created": "Wed, 29 Nov 2017 11:28:24 GMT", "version": "v1" } ]
2018-03-14
[ [ "Morita", "Kenji", "" ], [ "Sasaki", "Chihiro", "" ], [ "Lo", "Pok Man", "" ], [ "Redlich", "Krzysztof", "" ] ]
We investigate the fluctuations and correlations involving baryon number in hot hadronic matter with modified masses of negative-parity baryons, in the context of the hadron resonance gas. Temperature-dependent masses are adopted from the recent lattice QCD results and from a chiral effective model which implements the parity doubling structure with respect to the chiral symmetry. Confronting the baryon number susceptibility, baryon-charge correlation, and baryon-strangeness correlation and their ratios with the lattice QCD data, we show that the strong downward mass shift in hyperons can accidentally reproduce some correlation ratios, however it also tends to overshoot the individual fluctuations and correlations. This indicates, that in order to correctly account for the influence of the chiral symmetry restoration on the fluctuation observables, a consistent framework of in-medium effects beyond hadron mass shifts is required.
hep-ph/9206233
Dave Bennett
David P. Bennett, Albert Stebbins, and Francois R. Bouchet
The Implications of the COBE-DMR Results for Cosmic Strings
8 pages, 1 figure (included). UCRL-JC-110803
Astrophys.J.399:L5-L8,1992
10.1086/186592
null
hep-ph astro-ph
null
We compare the anisotropies in the cosmic microwave background radiation measured by the COBE experiment to the predictions of cosmic strings. We use an analytic model for the $\Delta T/T$ power spectrum that is based on our previous numerical simulations to show that the COBE results imply a value for the string mass per unit length, $\mu$ under the assumption that cosmic strings are the source of the measured anisotropy. We find $G\mu = 1.5\pm 0.5 \times 10^{-6}$ which is consistent with the value of $\mu$ thought to be required for cosmic strings to seed galaxy formation.
[ { "created": "Thu, 18 Jun 1992 23:32:58 GMT", "version": "v1" } ]
2009-10-22
[ [ "Bennett", "David P.", "" ], [ "Stebbins", "Albert", "" ], [ "Bouchet", "Francois R.", "" ] ]
We compare the anisotropies in the cosmic microwave background radiation measured by the COBE experiment to the predictions of cosmic strings. We use an analytic model for the $\Delta T/T$ power spectrum that is based on our previous numerical simulations to show that the COBE results imply a value for the string mass per unit length, $\mu$ under the assumption that cosmic strings are the source of the measured anisotropy. We find $G\mu = 1.5\pm 0.5 \times 10^{-6}$ which is consistent with the value of $\mu$ thought to be required for cosmic strings to seed galaxy formation.
hep-ph/9601201
null
J.Bartels, J.R.Forshaw, H.Lotter, M.Wusthoff
Diffractive Production of Vector Mesons at Large t
13 pages plus 3 figures (uuencoded)
Phys.Lett.B375:301-309,1996
10.1016/0370-2693(96)00203-1
DESY-95-253, MC-TH-95/23, ANL-HEP-PR-95-89
hep-ph
null
The cross section for elastic vector meson production in photon-proton interactions at large $t$ is considered using the exact analytic solution of the BFKL equation in the azimuthally symmetric $n=0$ limit. We use a non-relativistic model for the vector meson production and find a small shrinkage in the $t$-distribution with increasing energy.
[ { "created": "Tue, 2 Jan 1996 14:03:54 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bartels", "J.", "" ], [ "Forshaw", "J. R.", "" ], [ "Lotter", "H.", "" ], [ "Wusthoff", "M.", "" ] ]
The cross section for elastic vector meson production in photon-proton interactions at large $t$ is considered using the exact analytic solution of the BFKL equation in the azimuthally symmetric $n=0$ limit. We use a non-relativistic model for the vector meson production and find a small shrinkage in the $t$-distribution with increasing energy.
1408.0222
Alexander Lenz
Alexander Lenz, David Hodges, Daniel Hulme, Sandra Kvedaraite, Jack Richings, Jian Shen Woo and Philip Waite
Investigating bounds on decoherence in quantum mechanics via B and D-mixing
10 pages, Reference added, agrees with the published version in Nucl. Phys. B
Nuclear Physics B 888 (2014) 129-136
10.1016/j.nuclphysb.2014.09.007
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate bounds on decoherence in quantum mechanics by studying $B$ and $D$-mixing observables, making use of many precise new measurements, particularly from the LHC and B factories. In that respect we show that the stringent bounds obtained by a different group in 2013 rely on unjustified assumptions. Finally, we point out which experimental measurements could improve the decoherence bounds considerably.
[ { "created": "Fri, 1 Aug 2014 16:21:57 GMT", "version": "v1" }, { "created": "Wed, 1 Oct 2014 12:47:23 GMT", "version": "v2" } ]
2016-05-03
[ [ "Lenz", "Alexander", "" ], [ "Hodges", "David", "" ], [ "Hulme", "Daniel", "" ], [ "Kvedaraite", "Sandra", "" ], [ "Richings", "Jack", "" ], [ "Woo", "Jian Shen", "" ], [ "Waite", "Philip", "" ] ]
We investigate bounds on decoherence in quantum mechanics by studying $B$ and $D$-mixing observables, making use of many precise new measurements, particularly from the LHC and B factories. In that respect we show that the stringent bounds obtained by a different group in 2013 rely on unjustified assumptions. Finally, we point out which experimental measurements could improve the decoherence bounds considerably.
2002.07610
Luis Roca
Guan-Ying Wang, Luis Roca, En Wang, Wei-Hong Liang, Eulogio Oset
Signatures of the two $K_1(1270)$ poles in $D^+\to \nu e^+ V P$ decay
7 pages, 3 figures
null
10.1140/epjc/s10052-020-7939-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze theoretically the $D^+\to \nu e^+ \rho \bar K$ and $D^+\to \nu e^+ \bar K^* \pi$ decays to see the feasibility to check the double pole nature of the axial-vector resonance $K_1(1270)$ predicted by the unitary extensions of chiral perturbation theory (UChPT). Indeed, within UChPT the $K_1(1270)$ is dynamically generated from the interaction of a vector and a pseudoscalar meson, and two poles are obtained for the quantum numbers of this resonance. The lower mass pole couples dominantly to $K^*\pi$ and the higher mass pole to $\rho K$, therefore we can expect that different reactions weighing differently these channels in the production mechanisms enhance one or the other pole. We show that the different final $VP$ channels in $D^+\to \nu e^+ V P$ weigh differently both poles, and this is reflected in the shape of the final vector-pseudoscalar invariant mass distributions. Therefore, we conclude that these decays are suitable to distinguish experimentally the predicted double pole of the $K_1(1270)$ resonance.
[ { "created": "Tue, 18 Feb 2020 14:51:46 GMT", "version": "v1" } ]
2020-06-24
[ [ "Wang", "Guan-Ying", "" ], [ "Roca", "Luis", "" ], [ "Wang", "En", "" ], [ "Liang", "Wei-Hong", "" ], [ "Oset", "Eulogio", "" ] ]
We analyze theoretically the $D^+\to \nu e^+ \rho \bar K$ and $D^+\to \nu e^+ \bar K^* \pi$ decays to see the feasibility to check the double pole nature of the axial-vector resonance $K_1(1270)$ predicted by the unitary extensions of chiral perturbation theory (UChPT). Indeed, within UChPT the $K_1(1270)$ is dynamically generated from the interaction of a vector and a pseudoscalar meson, and two poles are obtained for the quantum numbers of this resonance. The lower mass pole couples dominantly to $K^*\pi$ and the higher mass pole to $\rho K$, therefore we can expect that different reactions weighing differently these channels in the production mechanisms enhance one or the other pole. We show that the different final $VP$ channels in $D^+\to \nu e^+ V P$ weigh differently both poles, and this is reflected in the shape of the final vector-pseudoscalar invariant mass distributions. Therefore, we conclude that these decays are suitable to distinguish experimentally the predicted double pole of the $K_1(1270)$ resonance.
0704.1724
Marco Ruggieri
M. Ruggieri
Inhomogeneous color superconductivity and the cooling of compact stars
4 pages, 1 figure, uses aiproc style. Talk given at "Quark confinement and the hadron spectrum", Ponta Delgada, Acores, Portugal, 2-7 September 2006
AIPConf.Proc.892:495-498,2007
10.1063/1.2714452
null
hep-ph
null
In this talk I discuss the inhomogeneous (LOFF) color superconductive phases of Quantum Chromodynamics (QCD). In particular, I show the effect of a core of LOFF phase on the cooling of a compact star.
[ { "created": "Fri, 13 Apr 2007 09:28:14 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ruggieri", "M.", "" ] ]
In this talk I discuss the inhomogeneous (LOFF) color superconductive phases of Quantum Chromodynamics (QCD). In particular, I show the effect of a core of LOFF phase on the cooling of a compact star.
0801.1826
Michelangelo Mangano
M. Raidal, A. van der Schaaf, I. Bigi, M.L. Mangano, Y. Semertzidis, S. Abel, S. Albino, S. Antusch, E. Arganda, B. Bajc, S. Banerjee, C. Biggio, M. Blanke, W. Bonivento, G.C. Branco, D. Bryman, A.J. Buras, L. Calibbi, A. Ceccucci, P.H. Chankowski, S. Davidson, A. Deandrea, D.P. DeMille, F. Deppisch, M. Diaz, B. Duling, M. Felcini, W. Fetscher, D.K. Ghosh, M. Giffels, G. Giudice, E. Goudzovskij, T. Han, P.G. Harris, M.J. Herrero, J. Hisano, R.J. Holt, K. Huitu, A. Ibarra, O. Igonkina, A. Ilakovac, J. Imazato, G. Isidori, F.R. Joaquim, M. Kadastik, Y. Kajiyama, S.F. King, K. Kirch, M.G. Kozlov, M. Krawczyk, T. Kress, O. Lebedev, A. Lusiani, E. Ma, G. Marchiori, I. Masina, G. Moreau, T. Mori, M. Muntel, F. Nesti, C.J.G. Onderwater, P. Paradisi, S.T. Petcov, M. Picariello, V. Porretti, A. Poschenrieder, M. Pospelov, L. Rebane, M.N. Rebelo, A. Ritz, L. Roberts, A. Romanino, A. Rossi, R. Rueckl, G. Senjanovic, N. Serra, T. Shindou, Y. Takanishi, C. Tarantino, A.M. Teixeira, E. Torrente-Lujan, K.J. Turzynski, T.E.J. Underwood, S.K. Vempati, O. Vives
Flavour physics of leptons and dipole moments
Report of Working Group 3 of the CERN Workshop ``Flavour in the era of the LHC'', Geneva, Switzerland, November 2005 -- March 2007
Eur.Phys.J.C57:13-182,2008
10.1140/epjc/s10052-008-0715-2
null
hep-ph hep-ex
null
This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
[ { "created": "Fri, 11 Jan 2008 19:25:25 GMT", "version": "v1" } ]
2008-12-18
[ [ "Raidal", "M.", "" ], [ "van der Schaaf", "A.", "" ], [ "Bigi", "I.", "" ], [ "Mangano", "M. L.", "" ], [ "Semertzidis", "Y.", "" ], [ "Abel", "S.", "" ], [ "Albino", "S.", "" ], [ "Antusch", "S.", "" ], [ "Arganda", "E.", "" ], [ "Bajc", "B.", "" ], [ "Banerjee", "S.", "" ], [ "Biggio", "C.", "" ], [ "Blanke", "M.", "" ], [ "Bonivento", "W.", "" ], [ "Branco", "G. C.", "" ], [ "Bryman", "D.", "" ], [ "Buras", "A. J.", "" ], [ "Calibbi", "L.", "" ], [ "Ceccucci", "A.", "" ], [ "Chankowski", "P. H.", "" ], [ "Davidson", "S.", "" ], [ "Deandrea", "A.", "" ], [ "DeMille", "D. P.", "" ], [ "Deppisch", "F.", "" ], [ "Diaz", "M.", "" ], [ "Duling", "B.", "" ], [ "Felcini", "M.", "" ], [ "Fetscher", "W.", "" ], [ "Ghosh", "D. K.", "" ], [ "Giffels", "M.", "" ], [ "Giudice", "G.", "" ], [ "Goudzovskij", "E.", "" ], [ "Han", "T.", "" ], [ "Harris", "P. G.", "" ], [ "Herrero", "M. J.", "" ], [ "Hisano", "J.", "" ], [ "Holt", "R. J.", "" ], [ "Huitu", "K.", "" ], [ "Ibarra", "A.", "" ], [ "Igonkina", "O.", "" ], [ "Ilakovac", "A.", "" ], [ "Imazato", "J.", "" ], [ "Isidori", "G.", "" ], [ "Joaquim", "F. R.", "" ], [ "Kadastik", "M.", "" ], [ "Kajiyama", "Y.", "" ], [ "King", "S. F.", "" ], [ "Kirch", "K.", "" ], [ "Kozlov", "M. G.", "" ], [ "Krawczyk", "M.", "" ], [ "Kress", "T.", "" ], [ "Lebedev", "O.", "" ], [ "Lusiani", "A.", "" ], [ "Ma", "E.", "" ], [ "Marchiori", "G.", "" ], [ "Masina", "I.", "" ], [ "Moreau", "G.", "" ], [ "Mori", "T.", "" ], [ "Muntel", "M.", "" ], [ "Nesti", "F.", "" ], [ "Onderwater", "C. J. G.", "" ], [ "Paradisi", "P.", "" ], [ "Petcov", "S. T.", "" ], [ "Picariello", "M.", "" ], [ "Porretti", "V.", "" ], [ "Poschenrieder", "A.", "" ], [ "Pospelov", "M.", "" ], [ "Rebane", "L.", "" ], [ "Rebelo", "M. N.", "" ], [ "Ritz", "A.", "" ], [ "Roberts", "L.", "" ], [ "Romanino", "A.", "" ], [ "Rossi", "A.", "" ], [ "Rueckl", "R.", "" ], [ "Senjanovic", "G.", "" ], [ "Serra", "N.", "" ], [ "Shindou", "T.", "" ], [ "Takanishi", "Y.", "" ], [ "Tarantino", "C.", "" ], [ "Teixeira", "A. M.", "" ], [ "Torrente-Lujan", "E.", "" ], [ "Turzynski", "K. J.", "" ], [ "Underwood", "T. E. J.", "" ], [ "Vempati", "S. K.", "" ], [ "Vives", "O.", "" ] ]
This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
hep-ph/0111179
John F. Gunion
U. Ellwanger (Lab. Physique), J.F. Gunion (U.C. Davis) and C. Hugonie (Durham)
Establishing a No-Lose Theorem for NMSSM Higgs Boson Discovery at the LHC
20 pages, 3 tables. revisions for final publication included
null
null
UCD-2001-13
hep-ph
null
We scan the parameter space of the NMSSM for the observability of at least one Higgs boson at the LHC with $300\fbi$ integrated luminosity, taking the present LEP2 constraints into account. We restrict the scan to those regions of parameter space for which Higgs boson decays to other Higgs bosons and/or supersymmetric particles are kinematically forbidden. We find that if $WW$-fusion detection modes for a light Higgs boson are not taken into account, then there are still significant regions in the scanned portion of the NMSSM parameter space where no Higgs boson can be observed at the $5\sigma$ level, despite the recent improvements in ATLAS and CMS procedures and techniques and even if we combine all non-fusion discovery channels. However, if the $WW$-fusion detection modes are included using the current theoretical study estimates, then we find that for all scanned points at least one of the NMSSM Higgs bosons will be detected. If the estimated $300\fbi$ significances for ATLAS and CMS are combined, one can also achieve $5\sigma$ signals after combining just the non-$WW$-fusion channels signals. We present the parameters of several particularly difficult points, and discuss the complementary roles played by different modes. We conclude that the LHC will discover at least one NMSSM Higgs boson unless there are large branching ratios for decays to SUSY particles and/or to other Higgs bosons.
[ { "created": "Wed, 14 Nov 2001 19:27:58 GMT", "version": "v1" }, { "created": "Wed, 12 Dec 2001 19:35:57 GMT", "version": "v2" }, { "created": "Thu, 14 Feb 2002 22:58:15 GMT", "version": "v3" } ]
2007-05-23
[ [ "Ellwanger", "U.", "", "Lab. Physique" ], [ "Gunion", "J. F.", "", "U.C. Davis" ], [ "Hugonie", "C.", "", "Durham" ] ]
We scan the parameter space of the NMSSM for the observability of at least one Higgs boson at the LHC with $300\fbi$ integrated luminosity, taking the present LEP2 constraints into account. We restrict the scan to those regions of parameter space for which Higgs boson decays to other Higgs bosons and/or supersymmetric particles are kinematically forbidden. We find that if $WW$-fusion detection modes for a light Higgs boson are not taken into account, then there are still significant regions in the scanned portion of the NMSSM parameter space where no Higgs boson can be observed at the $5\sigma$ level, despite the recent improvements in ATLAS and CMS procedures and techniques and even if we combine all non-fusion discovery channels. However, if the $WW$-fusion detection modes are included using the current theoretical study estimates, then we find that for all scanned points at least one of the NMSSM Higgs bosons will be detected. If the estimated $300\fbi$ significances for ATLAS and CMS are combined, one can also achieve $5\sigma$ signals after combining just the non-$WW$-fusion channels signals. We present the parameters of several particularly difficult points, and discuss the complementary roles played by different modes. We conclude that the LHC will discover at least one NMSSM Higgs boson unless there are large branching ratios for decays to SUSY particles and/or to other Higgs bosons.
hep-ph/9802432
Daniel De Florian
D. de Florian (CERN), M. Stratmann (Durham Univ.), W. Vogelsang (CERN)
Polarized Lambda-Baryon Production in pp Collisions
11 pages, LaTeX, 2 figures, uses epsfig and amssymb styles
Phys.Rev.Lett. 81 (1998) 530-533
10.1103/PhysRevLett.81.530
CERN-TH/98-56, DTP/98/06
hep-ph
null
We study the production of longitudinally polarized Lambda-baryons in single-spin pp collisions at RHIC and HERA-N as a means of determining the spin-dependent Lambda fragmentation functions. It is shown that a measurement of the rapidity distribution of the Lambda's would provide an excellent way of clearly discriminating between various recently suggested sets of polarized Lambda fragmentation functions that are all compatible with present e^+e^- data. We also address the main theoretical uncertainties, which appear to be well under control.
[ { "created": "Thu, 26 Feb 1998 13:47:27 GMT", "version": "v1" } ]
2009-10-31
[ [ "de Florian", "D.", "", "CERN" ], [ "Stratmann", "M.", "", "Durham Univ." ], [ "Vogelsang", "W.", "", "CERN" ] ]
We study the production of longitudinally polarized Lambda-baryons in single-spin pp collisions at RHIC and HERA-N as a means of determining the spin-dependent Lambda fragmentation functions. It is shown that a measurement of the rapidity distribution of the Lambda's would provide an excellent way of clearly discriminating between various recently suggested sets of polarized Lambda fragmentation functions that are all compatible with present e^+e^- data. We also address the main theoretical uncertainties, which appear to be well under control.
hep-ph/9702267
Sarira Sahu
Sarira Sahu
Neutrino propagation in a random magnetic field
11 pages
Phys.Rev. D56 (1997) 4378-4383
10.1103/PhysRevD.56.4378
PRL-TH-97
hep-ph
null
The active-sterile neutrino conversion probability is calculated for neutrino propagating in a medium in the presence of random magnetic field fluctuations. Necessary condition for the probability to be positive definite is obtained. Using this necessary condition we put constraint on the neutrino magnetic moment from active-sterile electron neutrino conversion in the early universe hot plasma and in supernova.
[ { "created": "Wed, 5 Feb 1997 18:06:57 GMT", "version": "v1" } ]
2009-10-30
[ [ "Sahu", "Sarira", "" ] ]
The active-sterile neutrino conversion probability is calculated for neutrino propagating in a medium in the presence of random magnetic field fluctuations. Necessary condition for the probability to be positive definite is obtained. Using this necessary condition we put constraint on the neutrino magnetic moment from active-sterile electron neutrino conversion in the early universe hot plasma and in supernova.
hep-ph/0001076
shunzo Kumano
S. Kumano (Saga University)
Flavor asymmetry in polarized proton-deuteron Drell-Yan process
1+6 pages LATEX, sprocl.sty, amsmath.sty, epsfig.sty, wrapfig.sty, 2 eps figures. Talk at the RCNP-TMU Symposium on "Spins in Nuclear and Hadronic Reactions", Tokyo, Japan, Oct.26-28, 1999, to be published in proceedings. Complete postscript file is available at http://www-hs.phys.saga-u.ac.jp Email: kumanos@cc.saga-u.ac.jp
null
10.1142/9789812792297_0029
SAGA-HE-157-00
hep-ph hep-ex nucl-th
null
We discuss the possibility of finding polarized antiquark flavor asymmetry in Drell-Yan processes. We find that the difference between polarized proton-proton and proton-deuteron Drell-Yan cross sections should provide valuable information on the polarized flavor asymmetry. Numerical results indicate that the asymmetry effects are conspicuous especially in the large-x_F region. Our analysis is important for the transversity distributions because the flavor asymmetry cannot be found by inclusive lepton scattering and W-production processes.
[ { "created": "Tue, 11 Jan 2000 01:44:40 GMT", "version": "v1" } ]
2017-08-23
[ [ "Kumano", "S.", "", "Saga University" ] ]
We discuss the possibility of finding polarized antiquark flavor asymmetry in Drell-Yan processes. We find that the difference between polarized proton-proton and proton-deuteron Drell-Yan cross sections should provide valuable information on the polarized flavor asymmetry. Numerical results indicate that the asymmetry effects are conspicuous especially in the large-x_F region. Our analysis is important for the transversity distributions because the flavor asymmetry cannot be found by inclusive lepton scattering and W-production processes.
1602.08105
Mikko Laine
Seyong Kim, M. Laine
Rapid thermal co-annihilation through bound states in QCD
26 pages. v3: clarifications and references added
JHEP 1607 (2016) 143
10.1007/JHEP07(2016)143
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The co-annihilation rate of heavy particles close to thermal equilibrium, which plays a role in many classic dark matter scenarios, can be "simulated" in QCD by considering the pair annihilation rate of a heavy quark and antiquark at a temperature of a few hundred MeV. We show that the so-called Sommerfeld factors, parameterizing the rate, can be defined and measured non-perturbatively within the NRQCD framework. Lattice measurements indicate a modest suppression in the octet channel, in reasonable agreement with perturbation theory, and a large enhancement in the singlet channel, much above the perturbative prediction. The additional enhancement is suggested to originate from bound state formation and subsequent decay. Making use of a Green's function based method to incorporate thermal corrections in perturbative co-annihilation rate computations, we show that qualitative agreement with lattice data can be found once thermally broadened bound states are accounted for. We suggest that our formalism may also be applicable to specific dark matter models which have complicated bound state structures.
[ { "created": "Thu, 25 Feb 2016 21:00:26 GMT", "version": "v1" }, { "created": "Thu, 3 Mar 2016 05:24:02 GMT", "version": "v2" }, { "created": "Tue, 2 Aug 2016 06:57:35 GMT", "version": "v3" } ]
2016-08-03
[ [ "Kim", "Seyong", "" ], [ "Laine", "M.", "" ] ]
The co-annihilation rate of heavy particles close to thermal equilibrium, which plays a role in many classic dark matter scenarios, can be "simulated" in QCD by considering the pair annihilation rate of a heavy quark and antiquark at a temperature of a few hundred MeV. We show that the so-called Sommerfeld factors, parameterizing the rate, can be defined and measured non-perturbatively within the NRQCD framework. Lattice measurements indicate a modest suppression in the octet channel, in reasonable agreement with perturbation theory, and a large enhancement in the singlet channel, much above the perturbative prediction. The additional enhancement is suggested to originate from bound state formation and subsequent decay. Making use of a Green's function based method to incorporate thermal corrections in perturbative co-annihilation rate computations, we show that qualitative agreement with lattice data can be found once thermally broadened bound states are accounted for. We suggest that our formalism may also be applicable to specific dark matter models which have complicated bound state structures.
hep-ph/0407087
Sheldon Lee Glashow
Sheldon Lee Glashow
Atmospheric Neutrino Constraints on Lorentz Violation
3 pages
null
null
null
hep-ph
null
Sensitive tests of Lorentz invariance can emerge from the study of neutrino oscillations, particularly for atmospheric neutrinos where the effect is conveniently near-maximal and has been observed over a wide range of energies. We assume these oscillations to be described in terms of two neutrinos with different masses and (possibly) different maximal attainable velocities (MAVs). It suffices to examine limiting cases in which neutrino velocity eigenstates coincide with either their mass or flavor eigenstates. We display the modified mu to tau neutrino transition probability for each case. Data on atmospheric neutrino oscillations at the highest observed energies and pathlengths can yield constraints on neutrino MAV differences (i.e., tests of special relativity) more restrictive than any that have been obtained to date on analogous Lorentz-violating parameters in other sectors of particle physics.
[ { "created": "Wed, 7 Jul 2004 15:54:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Glashow", "Sheldon Lee", "" ] ]
Sensitive tests of Lorentz invariance can emerge from the study of neutrino oscillations, particularly for atmospheric neutrinos where the effect is conveniently near-maximal and has been observed over a wide range of energies. We assume these oscillations to be described in terms of two neutrinos with different masses and (possibly) different maximal attainable velocities (MAVs). It suffices to examine limiting cases in which neutrino velocity eigenstates coincide with either their mass or flavor eigenstates. We display the modified mu to tau neutrino transition probability for each case. Data on atmospheric neutrino oscillations at the highest observed energies and pathlengths can yield constraints on neutrino MAV differences (i.e., tests of special relativity) more restrictive than any that have been obtained to date on analogous Lorentz-violating parameters in other sectors of particle physics.
1801.05862
Thomas A. Trainor
Thomas A. Trainor
Glauber-model analysis of 5 TeV $\bf p$-Pb centrality compared to a two-component (soft + hard) model of hadron production in high-energy nuclear collisions
24 pages, 25 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A recent study of 5 TeV $p$-Pb centrality combined a Glauber model of $p$-Pb collision geometry with an assumption of linear scaling between $n_{ch}$ (charge) integrated within some $\eta$ acceptance and the number of nucleon participants $N_{part}$. The study concluded that $N_{part}$ increases to nearly 16 in central collisions, and the high-$p_t$ region of $p$-Pb $p_t$ spectra rescaled by the Glauber-estimated number of $p$-N binary collisions remains consistent with a $p$-$p$ spectrum for the same energy, independent of $p$-Pb centrality. However, the relation between $N_{part}$ and $n_{ch}$ derived from a two-component (soft + hard) model (TCM) study of ensemble-mean $\bar p_t$ data for the same system is quite different. This article reports a detailed analysis of the Glauber study and the question of centrality in $p$-A collisions. The Glauber centrality model is compared with the $\bar p_t$ TCM to understand the sources of major differences. The assumption of linear proportionality between $n_{ch}$ and $N_{part}$ is found to be inconsistent with $\bar p_t$ data. Properties of the convolution integral relating a differential cross section and hadron production model to an event distribution on $n_{ch}$ are examined. An alternative differential-cross-section distribution is inferred from charge-multiplicity data, and the upper limit on $N_{part}$ is estimated to be near 8. The TCM centrality model is then applied to $p_t$ spectrum ratios to predict results for $p$-Pb spectra. The spectrum TCM is tested with identified-pion spectra from 5 TeV $p$-Pb collisions and the result is consistent with previous $p$-$p$ TCM results. A TCM prediction that the spectrum ratio at high $p_t$ should increase to 14 for central $p$-Pb collisions due to quadratic dependence of dijet production on $n_{ch}$ is consistent with $\bar p_t$ data from the same system.
[ { "created": "Wed, 17 Jan 2018 20:53:17 GMT", "version": "v1" } ]
2018-01-19
[ [ "Trainor", "Thomas A.", "" ] ]
A recent study of 5 TeV $p$-Pb centrality combined a Glauber model of $p$-Pb collision geometry with an assumption of linear scaling between $n_{ch}$ (charge) integrated within some $\eta$ acceptance and the number of nucleon participants $N_{part}$. The study concluded that $N_{part}$ increases to nearly 16 in central collisions, and the high-$p_t$ region of $p$-Pb $p_t$ spectra rescaled by the Glauber-estimated number of $p$-N binary collisions remains consistent with a $p$-$p$ spectrum for the same energy, independent of $p$-Pb centrality. However, the relation between $N_{part}$ and $n_{ch}$ derived from a two-component (soft + hard) model (TCM) study of ensemble-mean $\bar p_t$ data for the same system is quite different. This article reports a detailed analysis of the Glauber study and the question of centrality in $p$-A collisions. The Glauber centrality model is compared with the $\bar p_t$ TCM to understand the sources of major differences. The assumption of linear proportionality between $n_{ch}$ and $N_{part}$ is found to be inconsistent with $\bar p_t$ data. Properties of the convolution integral relating a differential cross section and hadron production model to an event distribution on $n_{ch}$ are examined. An alternative differential-cross-section distribution is inferred from charge-multiplicity data, and the upper limit on $N_{part}$ is estimated to be near 8. The TCM centrality model is then applied to $p_t$ spectrum ratios to predict results for $p$-Pb spectra. The spectrum TCM is tested with identified-pion spectra from 5 TeV $p$-Pb collisions and the result is consistent with previous $p$-$p$ TCM results. A TCM prediction that the spectrum ratio at high $p_t$ should increase to 14 for central $p$-Pb collisions due to quadratic dependence of dijet production on $n_{ch}$ is consistent with $\bar p_t$ data from the same system.
1205.4038
Bin He
Bin He, Nobuchika Okada and Qaisar Shafi
125 GeV Higgs, Type III Seesaw and Gauge-Higgs Unification
null
null
10.1016/j.physletb.2012.08.012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, both the ATLAS and CMS experiments have observed an excess of events that could be the first evidence for a 125 GeV Higgs boson. This is a few GeV below the (absolute) vacuum stability bound on the Higgs mass in the Standard Model (SM), assuming a Planck mass ultraviolet (UV) cutoff. In this paper, we study some implications of a 125 GeV Higgs boson for new physics in terms of the vacuum stability bound. We first consider the seesaw extension of the SM and find that in type III seesaw, the vacuum stability bound on the Higgs mass can be as low as 125 GeV for the seesaw scale around a TeV. Next we dicuss some alternative new physics models which provide an effective ultraviolet cutoff lower than the Planck mass. An effective cutoff \Lambda \simeq 10^{11} GeV leads to a vacuum stability bound on the Higgs mass of 125 GeV. In a gauge-Higgs unification scenario with five-dimensional flat spacetime, the so-called gauge-Higgs condition allows us to predict a Higgs mass of 125 GeV, with the compactification scale of the extra-dimension being identified as the cutoff scale \Lambda \simeq 10^{11} GeV. Identifying the compactification scale with the unification scale of the SM SU(2) gauge coupling and the top quark Yukawa coupling yields a Higgs mass of 121\pm 2 GeV.
[ { "created": "Thu, 17 May 2012 20:13:44 GMT", "version": "v1" }, { "created": "Thu, 31 May 2012 04:52:48 GMT", "version": "v2" } ]
2015-06-05
[ [ "He", "Bin", "" ], [ "Okada", "Nobuchika", "" ], [ "Shafi", "Qaisar", "" ] ]
Recently, both the ATLAS and CMS experiments have observed an excess of events that could be the first evidence for a 125 GeV Higgs boson. This is a few GeV below the (absolute) vacuum stability bound on the Higgs mass in the Standard Model (SM), assuming a Planck mass ultraviolet (UV) cutoff. In this paper, we study some implications of a 125 GeV Higgs boson for new physics in terms of the vacuum stability bound. We first consider the seesaw extension of the SM and find that in type III seesaw, the vacuum stability bound on the Higgs mass can be as low as 125 GeV for the seesaw scale around a TeV. Next we dicuss some alternative new physics models which provide an effective ultraviolet cutoff lower than the Planck mass. An effective cutoff \Lambda \simeq 10^{11} GeV leads to a vacuum stability bound on the Higgs mass of 125 GeV. In a gauge-Higgs unification scenario with five-dimensional flat spacetime, the so-called gauge-Higgs condition allows us to predict a Higgs mass of 125 GeV, with the compactification scale of the extra-dimension being identified as the cutoff scale \Lambda \simeq 10^{11} GeV. Identifying the compactification scale with the unification scale of the SM SU(2) gauge coupling and the top quark Yukawa coupling yields a Higgs mass of 121\pm 2 GeV.
1702.05890
Qi Chen
Qi Chen and De-fu Hou
The HTL resumed propagators in the light cone gauge
18pages,6figures
null
10.1088/1674-1137/42/4/043102
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The expression of the HTL resumed gluon propagator in the light cone gauge is derived. In the real time mechanism, using the Mandelstam Leibbrant prescription of $(n\cdot K)^{-1}$, we calculate the transverse and longitudinal parts of the gluon HTL self-energy and prove the transverse and longitudinal parts do not have divergence. We also calculate the quark self energy in the HTL approximation, and find it gauge independent. We analytically calculate the damping rates of the hard quark and gluon with this HTL resumed gluon propagator.
[ { "created": "Mon, 20 Feb 2017 08:21:18 GMT", "version": "v1" }, { "created": "Mon, 3 Jul 2017 19:15:20 GMT", "version": "v2" } ]
2018-04-18
[ [ "Chen", "Qi", "" ], [ "Hou", "De-fu", "" ] ]
The expression of the HTL resumed gluon propagator in the light cone gauge is derived. In the real time mechanism, using the Mandelstam Leibbrant prescription of $(n\cdot K)^{-1}$, we calculate the transverse and longitudinal parts of the gluon HTL self-energy and prove the transverse and longitudinal parts do not have divergence. We also calculate the quark self energy in the HTL approximation, and find it gauge independent. We analytically calculate the damping rates of the hard quark and gluon with this HTL resumed gluon propagator.
hep-ph/0302195
Alexei Prokudin
R. Fiore, L.L. Jenkovszky, F. Paccanoni, A. Prokudin
The Pomeron In Exclusive Vector Meson Production
12 pages, 13 figures
Phys.Rev. D68 (2003) 014005
10.1103/PhysRevD.68.014005
DFCAL-TH 03/3
hep-ph
null
An earlier developed model for vector meson photoproduction, based on a dipole Pomeron exchange, is extended to electroproduction. Universality of the non linear Pomeron trajectory is tested by fitting the model to ZEUS and H1 data as well as to CDF data on $\bar pp$ elastic scattering.
[ { "created": "Fri, 21 Feb 2003 11:06:43 GMT", "version": "v1" } ]
2009-11-10
[ [ "Fiore", "R.", "" ], [ "Jenkovszky", "L. L.", "" ], [ "Paccanoni", "F.", "" ], [ "Prokudin", "A.", "" ] ]
An earlier developed model for vector meson photoproduction, based on a dipole Pomeron exchange, is extended to electroproduction. Universality of the non linear Pomeron trajectory is tested by fitting the model to ZEUS and H1 data as well as to CDF data on $\bar pp$ elastic scattering.
2401.11423
Yao-Bei Liu
Jin-Zhong Han, Yao-Bei Liu, Shi-Yu Xu
Pair production of the singlet vector-like B quark at the CLIC
17 pages, 6 figures. arXiv admin note: text overlap with arXiv:2112.15044
Eur. Phys. J. C 84, 61 (2024)
10.1140/epjc/s10052-023-12362-5
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Vector-like quarks~(VLQs) are a common feature of many scenarios of new physics beyond the Standard Model~(SM), which generally decay into a SM third-generation quark with a SM gauge boson, or a Higgs boson. The presence of a new exotic decay mode of VLQs will reduce the branching ratios of these standard decay modes and thus relax the current mass exclusion limits from LHC experiments. Based on a model-independent framework, we investigate the prospect of discovering the pair production of the weak-singlet VLQ-$B$ at the future 3-TeV Compact Linear Collider~(CLIC), by focusing on the final states including one $Z$ boson and four $b$-jets via two types of modes: $Z\to \ell^{+}\ell^{-}$ and $Z\to \nu\bar{\nu}$. By performing a rapid detector simulation of the signal and background events, and considering the initial state radiation and beamstrahlung effects, the exclusion limit at the 95\% confidence level and the $5\sigma$ discovery prospects are respectively obtained on the branching ratio of $B\to bZ$ and the VLQ-$B$ masses at the future 3-TeV CLIC with an integrated luminosity of 5 ab$^{-1}$.
[ { "created": "Sun, 21 Jan 2024 08:03:33 GMT", "version": "v1" } ]
2024-01-23
[ [ "Han", "Jin-Zhong", "" ], [ "Liu", "Yao-Bei", "" ], [ "Xu", "Shi-Yu", "" ] ]
Vector-like quarks~(VLQs) are a common feature of many scenarios of new physics beyond the Standard Model~(SM), which generally decay into a SM third-generation quark with a SM gauge boson, or a Higgs boson. The presence of a new exotic decay mode of VLQs will reduce the branching ratios of these standard decay modes and thus relax the current mass exclusion limits from LHC experiments. Based on a model-independent framework, we investigate the prospect of discovering the pair production of the weak-singlet VLQ-$B$ at the future 3-TeV Compact Linear Collider~(CLIC), by focusing on the final states including one $Z$ boson and four $b$-jets via two types of modes: $Z\to \ell^{+}\ell^{-}$ and $Z\to \nu\bar{\nu}$. By performing a rapid detector simulation of the signal and background events, and considering the initial state radiation and beamstrahlung effects, the exclusion limit at the 95\% confidence level and the $5\sigma$ discovery prospects are respectively obtained on the branching ratio of $B\to bZ$ and the VLQ-$B$ masses at the future 3-TeV CLIC with an integrated luminosity of 5 ab$^{-1}$.
hep-ph/0104289
Fulvia De Fazio
F. De Fazio and M.R. Pennington
Probing the structure of $f_0(980)$ through radiative $\phi$ decays
Latex, 11 pages, 2 eps figures. Final version to apper in Physics Letters B
Phys.Lett.B521:15-21,2001
10.1016/S0370-2693(01)01200-X
DCPT/01/34 - IPPP/01/17; BARI-TH/413-2001
hep-ph
null
We consider the radiative transition $\phi \to f_0 \gamma$, which is a sensitive probe of the nature of the $f_0(980)$ particle. Using the QCD sum-rule technique, we estimate the branching ratio of such decay mode to be: ${\cal B}(\phi \to f_0 \gamma)=(2.7 \pm 1.1) ~ 10^{-4}$, in fair agreement with present experimental data. As for the structure of the $f_0$, the result suggests a sizeable $s {\bar s}$ component; however, this result does not exclude the possibility of further components and allows a more complex structure than indicated by the naive quark model.
[ { "created": "Fri, 27 Apr 2001 15:10:37 GMT", "version": "v1" }, { "created": "Mon, 11 Jun 2001 08:40:44 GMT", "version": "v2" } ]
2010-05-28
[ [ "De Fazio", "F.", "" ], [ "Pennington", "M. R.", "" ] ]
We consider the radiative transition $\phi \to f_0 \gamma$, which is a sensitive probe of the nature of the $f_0(980)$ particle. Using the QCD sum-rule technique, we estimate the branching ratio of such decay mode to be: ${\cal B}(\phi \to f_0 \gamma)=(2.7 \pm 1.1) ~ 10^{-4}$, in fair agreement with present experimental data. As for the structure of the $f_0$, the result suggests a sizeable $s {\bar s}$ component; however, this result does not exclude the possibility of further components and allows a more complex structure than indicated by the naive quark model.
1812.10380
Chowdhury Aminul Islam
Chowdhury Aminul Islam, Aritra Bandyopadhyay, Pradip K. Roy and Sourav Sarkar
Spectral function and dilepton rate from a strongly magnetised hot and dense medium in the light of mean field models
18 pages, 17 figures, title slightly changed, matches with the published version
Phys. Rev. D 99, 094028 (2019)
10.1103/PhysRevD.99.094028
TIFR/TH/18-53
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have calculated the electromagnetic spectral function (SF) vis-\`{a}-vis the dilepton rate (DR) by evaluating the one-loop photon polarisation tensor for a strongly magnetised hot and dense medium. The calculation is performed in the ambit of mean field models namely Nambu\textendash Jona-Lasinio (NJL) and its Polyakov loop extended version (PNJL) in the lowest Landau level approximation. These models allow for a dynamical generation of quark mass which, evidently, gets affected in the presence of a magnetised medium. We have shown that the strength of the SF gets boosted because of the presence of dynamical quarks in lieu of the current quarks. It increases as we increase the magnetic field for a given value of temperature in both NJL and PNJL models. This increment is further reflected in the DR which is enhanced as compared to the Born rate for certain values of invariant masses. We also discuss the impact of chemical potential on DR within the present scenario.
[ { "created": "Wed, 26 Dec 2018 17:04:39 GMT", "version": "v1" }, { "created": "Thu, 7 Feb 2019 14:40:09 GMT", "version": "v2" }, { "created": "Wed, 24 Apr 2019 09:52:30 GMT", "version": "v3" } ]
2019-05-29
[ [ "Islam", "Chowdhury Aminul", "" ], [ "Bandyopadhyay", "Aritra", "" ], [ "Roy", "Pradip K.", "" ], [ "Sarkar", "Sourav", "" ] ]
We have calculated the electromagnetic spectral function (SF) vis-\`{a}-vis the dilepton rate (DR) by evaluating the one-loop photon polarisation tensor for a strongly magnetised hot and dense medium. The calculation is performed in the ambit of mean field models namely Nambu\textendash Jona-Lasinio (NJL) and its Polyakov loop extended version (PNJL) in the lowest Landau level approximation. These models allow for a dynamical generation of quark mass which, evidently, gets affected in the presence of a magnetised medium. We have shown that the strength of the SF gets boosted because of the presence of dynamical quarks in lieu of the current quarks. It increases as we increase the magnetic field for a given value of temperature in both NJL and PNJL models. This increment is further reflected in the DR which is enhanced as compared to the Born rate for certain values of invariant masses. We also discuss the impact of chemical potential on DR within the present scenario.
hep-ph/9703220
null
R. Alemany (CERN), M. Davier (LAL, Orsay), A. Hocker (LAL, Orsay)
Improved Determination of the Hadronic Contribution to the Muon (g-2) and to alpha(M_Z**2) Using new Data from Hadronic Tau Decays
23 pages, LaTex, 6 figures, Paper submitted to Zeitschrift fuer Physik C
Eur.Phys.J.C2:123-135,1998
10.1007/s100520050127
LAL 97-02
hep-ph
null
We have reevaluated the hadronic contribution to the anomalous magnetic moment of the muon (g-2) and to the running of the QED fine structure constant alpha(s) at s=M_Z**2. We incorporated new data from hadronic tau decays, recently published by the ALEPH Collaboration. In addition, compared to previous analyses, we use more extensive e+e- annihilation data sets. The integration over the total hadronic cross section is performed using experimental data up to 40 GeV and results from perturbative QCD above 40 GeV. The improvement from tau data concerns mainly the pion form factor, where the uncertainty in the corresponding integral could be reduced by more than a factor of two. We obtain for the lowest order hadronic vacuum polarization graph a_mu(had) = (695.0 +/- 15.0) x 10^{-10} and delta(alpha(M_Z**2))(had) = (280.9 +/- 6.3) x 10^{-4} using e+e- data only. The corresponding results for combined e+e- and tau data are a_mu(had) = (701.1 +/- 9.4) x 10^{-10} and delta(alpha(M_Z**2))(had) = (281.7 +/- 6.2) x 10^{-4}, where the latter is calculated using the contribution from the five lightest quarks.
[ { "created": "Mon, 3 Mar 1997 23:45:45 GMT", "version": "v1" }, { "created": "Wed, 5 Mar 1997 13:51:48 GMT", "version": "v2" } ]
2008-11-26
[ [ "Alemany", "R.", "", "CERN" ], [ "Davier", "M.", "", "LAL, Orsay" ], [ "Hocker", "A.", "", "LAL, Orsay" ] ]
We have reevaluated the hadronic contribution to the anomalous magnetic moment of the muon (g-2) and to the running of the QED fine structure constant alpha(s) at s=M_Z**2. We incorporated new data from hadronic tau decays, recently published by the ALEPH Collaboration. In addition, compared to previous analyses, we use more extensive e+e- annihilation data sets. The integration over the total hadronic cross section is performed using experimental data up to 40 GeV and results from perturbative QCD above 40 GeV. The improvement from tau data concerns mainly the pion form factor, where the uncertainty in the corresponding integral could be reduced by more than a factor of two. We obtain for the lowest order hadronic vacuum polarization graph a_mu(had) = (695.0 +/- 15.0) x 10^{-10} and delta(alpha(M_Z**2))(had) = (280.9 +/- 6.3) x 10^{-4} using e+e- data only. The corresponding results for combined e+e- and tau data are a_mu(had) = (701.1 +/- 9.4) x 10^{-10} and delta(alpha(M_Z**2))(had) = (281.7 +/- 6.2) x 10^{-4}, where the latter is calculated using the contribution from the five lightest quarks.
0804.3668
Shinya Matsuzaki
Kazumoto Haba, Shinya Matsuzaki, and Koichi Yamawaki
$S$ Parameter in the Holographic Walking/Conformal Technicolor
typo, a version to be published in Progress of Theoretical Physics
Prog. Theor. Phys. 120 (2008), 691
10.1143/PTP.120.691
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explicitly calculate the $S$ parameter in entire parameter space of the holographic walking/conformal technicolor (W/C TC), based on the deformation of the holographic QCD by varying the anomalous dimension from $\gamma_m \simeq 0$ through $\gamma_m \simeq 1$ continuously. The $S$ parameter is given as a positive monotonic function of $\xi$ which is fairly insensitive to $\gamma_m$ and continuously vanishes as $S \sim \xi^2 \to 0$ when $\xi \to 0$, where $\xi$ is the vacuum expectation value of the bulk scalar field at the infrared boundary of the 5th dimension $z=z_m$ and is related to the mass of (techni-) $\rho$ meson ($M_\rho$) and the decay constant ($f_\pi$) as $\xi \sim f_\pi z_m \sim f_\pi/M_\rho$ for $\xi \ll 1$. However, although $\xi$ is related to the techni-fermion condensate $\condense$, we find no particular suppression of $\xi$ and hence of $S$ due to large $\gamma_m$, based on the correct identification of the renormalization-point dependence of $\condense$ in contrast to the literature. Then we argue possible behaviors of $f_\pi/M_\rho$ as $\condense \to 0$ near the conformal window characterized by the Banks-Zaks infrared fixed point in more explicit dynamics with $\gamma_m \simeq 1$. It is a curious coincidence that the result from ladder Schwinger-Dyson and Bethe-Salpeter equations well fits in the parameter space obtained in this paper. When $f_\pi/M_\rho \to 0$ is realized, the holography suggests a novel possibility that $f_\pi$ vanishes much faster than the dynamical mass $m$ does.
[ { "created": "Wed, 23 Apr 2008 19:19:09 GMT", "version": "v1" }, { "created": "Mon, 4 Aug 2008 09:08:52 GMT", "version": "v2" }, { "created": "Tue, 2 Sep 2008 09:40:53 GMT", "version": "v3" }, { "created": "Tue, 9 Sep 2008 01:54:36 GMT", "version": "v4" } ]
2008-12-23
[ [ "Haba", "Kazumoto", "" ], [ "Matsuzaki", "Shinya", "" ], [ "Yamawaki", "Koichi", "" ] ]
We explicitly calculate the $S$ parameter in entire parameter space of the holographic walking/conformal technicolor (W/C TC), based on the deformation of the holographic QCD by varying the anomalous dimension from $\gamma_m \simeq 0$ through $\gamma_m \simeq 1$ continuously. The $S$ parameter is given as a positive monotonic function of $\xi$ which is fairly insensitive to $\gamma_m$ and continuously vanishes as $S \sim \xi^2 \to 0$ when $\xi \to 0$, where $\xi$ is the vacuum expectation value of the bulk scalar field at the infrared boundary of the 5th dimension $z=z_m$ and is related to the mass of (techni-) $\rho$ meson ($M_\rho$) and the decay constant ($f_\pi$) as $\xi \sim f_\pi z_m \sim f_\pi/M_\rho$ for $\xi \ll 1$. However, although $\xi$ is related to the techni-fermion condensate $\condense$, we find no particular suppression of $\xi$ and hence of $S$ due to large $\gamma_m$, based on the correct identification of the renormalization-point dependence of $\condense$ in contrast to the literature. Then we argue possible behaviors of $f_\pi/M_\rho$ as $\condense \to 0$ near the conformal window characterized by the Banks-Zaks infrared fixed point in more explicit dynamics with $\gamma_m \simeq 1$. It is a curious coincidence that the result from ladder Schwinger-Dyson and Bethe-Salpeter equations well fits in the parameter space obtained in this paper. When $f_\pi/M_\rho \to 0$ is realized, the holography suggests a novel possibility that $f_\pi$ vanishes much faster than the dynamical mass $m$ does.
hep-ph/0603230
Bjorn Garbrecht
K. R. S. Balaji and Bjorn Garbrecht
Perturbative and Nonperturbative Contributions to a Simple Model for Baryogenesis
11 pages, 3 figures
Phys.Lett. B638 (2006) 320-324
10.1016/j.physletb.2006.05.080
MCGILL-01-06, MAN/HEP/2006/4
hep-ph
null
Single field baryogenesis, a scenario for Dirac leptogenesis sourced by a time-dependent scalar condensate, is studied. We compare the creation of the charge asymmetry by the perturbative decay of the condensate with the nonperturbative decay, a process of particle production commonly known in the context of inflation as preheating. The nonperturbative channel dominates when the coupling of the scalar field to leptons is sufficiently large.
[ { "created": "Tue, 28 Mar 2006 18:52:39 GMT", "version": "v1" }, { "created": "Thu, 6 Jul 2006 17:02:47 GMT", "version": "v2" } ]
2009-11-11
[ [ "Balaji", "K. R. S.", "" ], [ "Garbrecht", "Bjorn", "" ] ]
Single field baryogenesis, a scenario for Dirac leptogenesis sourced by a time-dependent scalar condensate, is studied. We compare the creation of the charge asymmetry by the perturbative decay of the condensate with the nonperturbative decay, a process of particle production commonly known in the context of inflation as preheating. The nonperturbative channel dominates when the coupling of the scalar field to leptons is sufficiently large.
1712.08387
Pedro Fernando Simoes Costa
Pedro Costa, M\'arcio Ferreira, Constan\c{c}a Provid\^encia
Magnetized QCD phase diagram: critical end points for the strange quark phase transition driven by external magnetic fields
Contribution to the proceedings of Hadron 2017 - XVII International Conference on Hadron Spectroscopy and Structure, September 25th-29th 2017, Salamanca, Spain
null
10.22323/1.310.0161
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we examine possible effects of an external magnetic field in the strongly interacting matter phase diagram. The study is performed using the Polyakov-Nambu-Jona-Lasinio model. Possible consequences of the inverse magnetic catalysis effect on the phase diagram at both finite chemical potential and temperature are analyzed. We devote special emphasis on how the location of the multiple critical end points (CEPs) change in a magnetized medium: the presence of an external magnetic field induces several CEPs in the strange sector, which arise due to the multiple phase transitions that the strange quark undergoes. We also study the deconfinement transition which turns out to be less sensitive to the external magnetic field when compared to the quark phase transitions. The crossover nature of the deconfinement is preserved over the whole phase diagram.
[ { "created": "Fri, 22 Dec 2017 10:37:29 GMT", "version": "v1" } ]
2022-09-21
[ [ "Costa", "Pedro", "" ], [ "Ferreira", "Márcio", "" ], [ "Providência", "Constança", "" ] ]
In this work we examine possible effects of an external magnetic field in the strongly interacting matter phase diagram. The study is performed using the Polyakov-Nambu-Jona-Lasinio model. Possible consequences of the inverse magnetic catalysis effect on the phase diagram at both finite chemical potential and temperature are analyzed. We devote special emphasis on how the location of the multiple critical end points (CEPs) change in a magnetized medium: the presence of an external magnetic field induces several CEPs in the strange sector, which arise due to the multiple phase transitions that the strange quark undergoes. We also study the deconfinement transition which turns out to be less sensitive to the external magnetic field when compared to the quark phase transitions. The crossover nature of the deconfinement is preserved over the whole phase diagram.
2108.03482
Chandan Mondal
Mohammad Ahmady, Satvir Kaur, Sugee Lee MacKay, Chandan Mondal, Ruben Sandapen
Hadron spectroscopy using the light-front holographic Schr\"odinger equation and the 't Hooft equation
28 pages, 10 figures, 8 tables; added hadron spectroscopy with an alternative longitudinal potential, expanded discussion, version to appear in PRD
Phys. Rev. D 104, 074013 (2021)
10.1103/PhysRevD.104.074013
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Light-front holographic QCD provides a successful first approximation to hadron spectroscopy in the chiral limit of $(3+1)$-dim light-front QCD, where a holographic Schr\"odinger-like equation, with an emerging confining scale, $\kappa$, governs confinement in the transverse direction. In its supersymmetric formulation, light-front holography predicts that each baryon has two superpartners: a meson and a tetraquark, with their degenerate masses being generated by the same scale, $\kappa$. In nature, this mass degeneracy is lifted by chiral symmetry breaking and longitudinal confinement. In this paper, we show that the latter can be successfully captured by the 't Hooft equation of $(1+1)$-dim, large $N_c$, QCD. Together, the holographic Schr\"odinger equation and the 't Hooft equation, provide a good global description of the data across the full hadron spectrum with a universal $\kappa$.
[ { "created": "Sat, 7 Aug 2021 16:25:41 GMT", "version": "v1" }, { "created": "Tue, 5 Oct 2021 15:07:27 GMT", "version": "v2" } ]
2021-10-20
[ [ "Ahmady", "Mohammad", "" ], [ "Kaur", "Satvir", "" ], [ "MacKay", "Sugee Lee", "" ], [ "Mondal", "Chandan", "" ], [ "Sandapen", "Ruben", "" ] ]
Light-front holographic QCD provides a successful first approximation to hadron spectroscopy in the chiral limit of $(3+1)$-dim light-front QCD, where a holographic Schr\"odinger-like equation, with an emerging confining scale, $\kappa$, governs confinement in the transverse direction. In its supersymmetric formulation, light-front holography predicts that each baryon has two superpartners: a meson and a tetraquark, with their degenerate masses being generated by the same scale, $\kappa$. In nature, this mass degeneracy is lifted by chiral symmetry breaking and longitudinal confinement. In this paper, we show that the latter can be successfully captured by the 't Hooft equation of $(1+1)$-dim, large $N_c$, QCD. Together, the holographic Schr\"odinger equation and the 't Hooft equation, provide a good global description of the data across the full hadron spectrum with a universal $\kappa$.
1111.2604
Alex Drlica-Wagner
R.C. Cotta, A. Drlica-Wagner, S. Murgia, E.D. Bloom, J.L. Hewett, and T.G. Rizzo
Constraints on the pMSSM from LAT Observations of Dwarf Spheroidal Galaxies
24 pages, 9 figures, submitted to JCAP
JCAP 1204 (2012) 016
10.1088/1475-7516/2012/04/016
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of ~71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (m_LSP < 50 GeV) annihilating into tau-pairs and heavier LSPs annihilating into b-bbar. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.
[ { "created": "Thu, 10 Nov 2011 21:00:02 GMT", "version": "v1" } ]
2013-01-04
[ [ "Cotta", "R. C.", "" ], [ "Drlica-Wagner", "A.", "" ], [ "Murgia", "S.", "" ], [ "Bloom", "E. D.", "" ], [ "Hewett", "J. L.", "" ], [ "Rizzo", "T. G.", "" ] ]
We examine the ability for the Large Area Telescope (LAT) to constrain Minimal Supersymmetric Standard Model (MSSM) dark matter through a combined analysis of Milky Way dwarf spheroidal galaxies. We examine the Lightest Supersymmetric Particles (LSPs) for a set of ~71k experimentally valid supersymmetric models derived from the phenomenological-MSSM (pMSSM). We find that none of these models can be excluded at 95% confidence by the current analysis; nevertheless, many lie within the predicted reach of future LAT analyses. With two years of data, we find that the LAT is currently most sensitive to light LSPs (m_LSP < 50 GeV) annihilating into tau-pairs and heavier LSPs annihilating into b-bbar. Additionally, we find that future LAT analyses will be able to probe some LSPs that form a sub-dominant component of dark matter. We directly compare the LAT results to direct detection experiments and show the complementarity of these search methods.
2401.08305
Hang Li
Hang Li and P. Wang
Nonlocal QED and lepton g-2 anomalies
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum electrodynamics is generally extended to a nonlocal QED by introducing the correlation functions. The gauge link is introduced to guarantee that the nonlocal QED is locally U(1) gauge invariant. The corresponding Feynman rules as well as the proof of Ward-Takahashi identity are presented. As an example, the anomalous magnetic moments of leptons are studied in nonlocal QED. At one-loop level, besides the ordinary diagrams, there are many additional Feynman diagrams which are generated from the gauge link. It shows the nonlocal QED can provide a reasonable explanation for lepton g-2 anomalies.
[ { "created": "Tue, 16 Jan 2024 12:04:20 GMT", "version": "v1" } ]
2024-01-17
[ [ "Li", "Hang", "" ], [ "Wang", "P.", "" ] ]
Quantum electrodynamics is generally extended to a nonlocal QED by introducing the correlation functions. The gauge link is introduced to guarantee that the nonlocal QED is locally U(1) gauge invariant. The corresponding Feynman rules as well as the proof of Ward-Takahashi identity are presented. As an example, the anomalous magnetic moments of leptons are studied in nonlocal QED. At one-loop level, besides the ordinary diagrams, there are many additional Feynman diagrams which are generated from the gauge link. It shows the nonlocal QED can provide a reasonable explanation for lepton g-2 anomalies.
1301.3033
Rafal Maciula
Rafal Maciula, Antoni Szczurek
Open charm production at the LHC - $k_{t}$-factorization approach
27 pages, 33 figures
null
10.1103/PhysRevD.87.094022
null
hep-ph hep-ex nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss inclusive production of open charm in proton-proton scattering at LHC. The calculation is performed within the $k_t$-factorization approach. Different models of unintegrated gluon distributions (UGDF) from the literature are used. The theoretical transverse momentum as well as (pseudo)rapidity distributions of charmed mesons are compared with recent experimental data of ATLAS, ALICE and LHCb collaborations. Only the calculation with Kimber-Martin-Ryskin (KMR) UGDF gives results comparable to experimental ones. All other popular models of UGDF significantly underpredict experimental data. Several sources of uncertainties of the theoretical predictions are also studied in details. In addition we discuss correlations between $D$ and $\bar D$ mesons. Good description of experimental distribution in invariant mass and in relative azimuthal angle between $D$ and $\bar D$ mesons is achieved for the KMR UGDF. The considered correlation observables measured by the LHCb experiment were not discussed in other approaches in the literature.
[ { "created": "Mon, 14 Jan 2013 16:20:24 GMT", "version": "v1" } ]
2013-05-29
[ [ "Maciula", "Rafal", "" ], [ "Szczurek", "Antoni", "" ] ]
We discuss inclusive production of open charm in proton-proton scattering at LHC. The calculation is performed within the $k_t$-factorization approach. Different models of unintegrated gluon distributions (UGDF) from the literature are used. The theoretical transverse momentum as well as (pseudo)rapidity distributions of charmed mesons are compared with recent experimental data of ATLAS, ALICE and LHCb collaborations. Only the calculation with Kimber-Martin-Ryskin (KMR) UGDF gives results comparable to experimental ones. All other popular models of UGDF significantly underpredict experimental data. Several sources of uncertainties of the theoretical predictions are also studied in details. In addition we discuss correlations between $D$ and $\bar D$ mesons. Good description of experimental distribution in invariant mass and in relative azimuthal angle between $D$ and $\bar D$ mesons is achieved for the KMR UGDF. The considered correlation observables measured by the LHCb experiment were not discussed in other approaches in the literature.
hep-ph/9511267
James M. Johnson
Suraj N. Gupta and James M. Johnson
Bc spectroscopy in a quantum-chromodynamic potential model
10 page ReVTeX paper
Phys.Rev.D53:312-314,1996
10.1103/PhysRevD.53.312
null
hep-ph
null
We have investigated $B_c$ spectroscopy with the use of a quantum-chromodynamic potential model which was recently used by us for the light-heavy quarkonia. We give our predictions for the energy levels and the $E$1 transition widths. We also find, rather surprisingly, that although $B_c$ is not a light-heavy system, the heavy quark effective theory with the inclusion of the $m_b^{-1}$ and $m_b^{-1}\ln m_b$ corrections is as successful for $B_c$ as it is for $B$ and $B_s$.
[ { "created": "Wed, 8 Nov 1995 19:00:16 GMT", "version": "v1" } ]
2011-01-27
[ [ "Gupta", "Suraj N.", "" ], [ "Johnson", "James M.", "" ] ]
We have investigated $B_c$ spectroscopy with the use of a quantum-chromodynamic potential model which was recently used by us for the light-heavy quarkonia. We give our predictions for the energy levels and the $E$1 transition widths. We also find, rather surprisingly, that although $B_c$ is not a light-heavy system, the heavy quark effective theory with the inclusion of the $m_b^{-1}$ and $m_b^{-1}\ln m_b$ corrections is as successful for $B_c$ as it is for $B$ and $B_s$.
1412.5815
Shoaib Munir
Nils-Erik Bomark, Stefano Moretti, Shoaib Munir and Leszek Roszkowski
Revisiting a light NMSSM pseudoscalar at the LHC
6 pages, 3 figures; Proceedings of "Prospects for Charged Higgs Discovery at Colliders (CHARGED 2014)", September 2014, Uppsala, Sweden. Typos and references corrected
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discovery of a light, singlet-like pseudoscalar Higgs boson, $A_1$, of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) could provide a hallmark signature of non-minimal supersymmetry. We review here the potential of the LHC to probe such a light $A_1$ in the decays of one of the heavier scalar Higgs bosons of the NMSSM. We find the production of pairs of the $A_1$, with a mass below 60 GeV or so, via decays of the two lightest scalar states to be especially promising, for an integrated luminosity as low as 30/fb. For heavier masses, the decay of the heaviest scalar into a $Z$ boson and an $A_1$ could lead to its detection at the LHC.
[ { "created": "Thu, 18 Dec 2014 11:31:33 GMT", "version": "v1" }, { "created": "Wed, 18 Feb 2015 08:01:35 GMT", "version": "v2" } ]
2015-02-19
[ [ "Bomark", "Nils-Erik", "" ], [ "Moretti", "Stefano", "" ], [ "Munir", "Shoaib", "" ], [ "Roszkowski", "Leszek", "" ] ]
The discovery of a light, singlet-like pseudoscalar Higgs boson, $A_1$, of the Next-to-Minimal Supersymmetric Standard Model (NMSSM) could provide a hallmark signature of non-minimal supersymmetry. We review here the potential of the LHC to probe such a light $A_1$ in the decays of one of the heavier scalar Higgs bosons of the NMSSM. We find the production of pairs of the $A_1$, with a mass below 60 GeV or so, via decays of the two lightest scalar states to be especially promising, for an integrated luminosity as low as 30/fb. For heavier masses, the decay of the heaviest scalar into a $Z$ boson and an $A_1$ could lead to its detection at the LHC.
2304.09004
Jun Zeng
Zhi-Fu Deng, Chao Han, Wei Wang, Jun Zeng, Jia-Lu Zhang
Light-cone distribution amplitudes of a light baryon in large-momentum effective theory
19 pages, 2 figures
null
10.1007/JHEP07(2023)191
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Momentum distributions of quarks/gluons inside a light baryon in a hard exclusive process are encoded in the light-cone distribution amplitudes (LCDAs). In this work, we point out that the leading twist LCDAs of a light baryon can be obtained through a simulation of a quasi-distribution amplitude calculable on lattice QCD within the framework of the large-momentum effective theory. We calculate the one-loop perturbative contributions to LCDA and quasi-distribution amplitudes and explicitly demonstrate the factorization of quasi-distribution amplitudes at the one-loop level. Based on the perturbative results, we derive the matching kernel in the $\overline{\rm MS}$ scheme and regularization-invariant momentum-subtraction scheme. Our result provides a first step to obtaining the LCDA from first principle lattice QCD calculations in the future.
[ { "created": "Tue, 18 Apr 2023 14:14:39 GMT", "version": "v1" } ]
2023-08-09
[ [ "Deng", "Zhi-Fu", "" ], [ "Han", "Chao", "" ], [ "Wang", "Wei", "" ], [ "Zeng", "Jun", "" ], [ "Zhang", "Jia-Lu", "" ] ]
Momentum distributions of quarks/gluons inside a light baryon in a hard exclusive process are encoded in the light-cone distribution amplitudes (LCDAs). In this work, we point out that the leading twist LCDAs of a light baryon can be obtained through a simulation of a quasi-distribution amplitude calculable on lattice QCD within the framework of the large-momentum effective theory. We calculate the one-loop perturbative contributions to LCDA and quasi-distribution amplitudes and explicitly demonstrate the factorization of quasi-distribution amplitudes at the one-loop level. Based on the perturbative results, we derive the matching kernel in the $\overline{\rm MS}$ scheme and regularization-invariant momentum-subtraction scheme. Our result provides a first step to obtaining the LCDA from first principle lattice QCD calculations in the future.
hep-ph/9607469
Saul Youssef
David Jaffe and Saul Youssef
Bayesian estimate of the effect of B^0B^0bar mixing measurements on the CKM matrix elements
Nine pages
Comput.Phys.Commun.101:206,1997
10.1016/S0010-4655(96)00171-3
FSU-SCRI-96-61
hep-ph hep-ex
null
A method employing Bayesian statistics is used to incorporate recent experimental results on BdBdbar and BsBsbar mixing into a measurement of the Cabibbo-Kobayashi-Maskawa matrix elements. The neutral B meson mixing results yield a slight improvement in the estimation of Vtd.
[ { "created": "Tue, 30 Jul 1996 14:14:24 GMT", "version": "v1" } ]
2010-11-23
[ [ "Jaffe", "David", "" ], [ "Youssef", "Saul", "" ] ]
A method employing Bayesian statistics is used to incorporate recent experimental results on BdBdbar and BsBsbar mixing into a measurement of the Cabibbo-Kobayashi-Maskawa matrix elements. The neutral B meson mixing results yield a slight improvement in the estimation of Vtd.
1211.2429
Ilya F. Ginzburg
Ilya F. Ginzburg
Singularities in the single lepton energy spectrum for precise measuring mass and spin of Dark Matter particles at the e^+e^- Linear Collider
6 pages, 3 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider models in which stability of Dark Matter particles $D$ is ensured by the conservation of the new quantum number, called D-parity here. Our models contain also charged $D$-odd particle $D^\pm$. Here I propose the method for precision measuring masses and spin of $D$-particles via the study of energy distribution of single lepton ($e$ or $\mu$) in the process $\epe\to D^+D^-\to DDW^+W^-$ with the observable states {\it dijet + lepton} ($\mu$ or $e$) + {\it nothing}. To determine precisely masses of $D$ and $D^\pm$, it is sufficient to measure the singular points in the lepton energy distributions (upper edge and kinks or peak). After this, even a rough measuring of corresponding cross section allows to determine the spin of $D$ particles. This approach is free from the difficulties of a well-known methods of measuring the masses via the edges of the energy distribution of dijets, representing $W$, which obliged by inaccuracies in measuring the energies of individual jets.
[ { "created": "Sun, 11 Nov 2012 15:03:10 GMT", "version": "v1" } ]
2012-11-13
[ [ "Ginzburg", "Ilya F.", "" ] ]
We consider models in which stability of Dark Matter particles $D$ is ensured by the conservation of the new quantum number, called D-parity here. Our models contain also charged $D$-odd particle $D^\pm$. Here I propose the method for precision measuring masses and spin of $D$-particles via the study of energy distribution of single lepton ($e$ or $\mu$) in the process $\epe\to D^+D^-\to DDW^+W^-$ with the observable states {\it dijet + lepton} ($\mu$ or $e$) + {\it nothing}. To determine precisely masses of $D$ and $D^\pm$, it is sufficient to measure the singular points in the lepton energy distributions (upper edge and kinks or peak). After this, even a rough measuring of corresponding cross section allows to determine the spin of $D$ particles. This approach is free from the difficulties of a well-known methods of measuring the masses via the edges of the energy distribution of dijets, representing $W$, which obliged by inaccuracies in measuring the energies of individual jets.
hep-ph/0209166
Alexander Khodjamirian
Alexander Khodjamirian
QCD Sum Rules - a Working Tool for Hadronic Physics
Latex, ws-procs9x6 style, 22 pages, 7 figures; talk given at Continuous Advances in QCD 2002/ ARKADYFEST (honoring the 60th birthday of Arkady Vainshtein),Minneapolis, Minnesota, 17-23 May 2002, to be published in the Proceedings
null
10.1142/9789812776310_0004
TTP02-23
hep-ph
null
QCD sum rules are overviewed with an emphasize on the practical applications of this method to the physics of light and heavy hadrons.
[ { "created": "Sun, 15 Sep 2002 13:57:48 GMT", "version": "v1" } ]
2017-08-23
[ [ "Khodjamirian", "Alexander", "" ] ]
QCD sum rules are overviewed with an emphasize on the practical applications of this method to the physics of light and heavy hadrons.
0811.0306
Oleg Veretin
B. A. Kniehl, A. V. Kotikov, O. L. Veretin
Irrational constants in positronium decays
Presented at 9th Workshop on Elementary Particle Theory: Loops and Legs in Quantum Field Theory, Sondershausen, 20-25 Apr 2008. 6 pages, 3 figures
null
10.1016/j.nuclphysbps.2008.09.075
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We establish irrational constants, that contribute to the positronium lifetime at $O(\alpha)$ and $O(\alpha^2)$ order. In particular we show, that a new type of constants appear, which are not related to Euler--Zagier sums or multiple $\zeta$ values.
[ { "created": "Mon, 3 Nov 2008 14:15:29 GMT", "version": "v1" } ]
2009-11-13
[ [ "Kniehl", "B. A.", "" ], [ "Kotikov", "A. V.", "" ], [ "Veretin", "O. L.", "" ] ]
We establish irrational constants, that contribute to the positronium lifetime at $O(\alpha)$ and $O(\alpha^2)$ order. In particular we show, that a new type of constants appear, which are not related to Euler--Zagier sums or multiple $\zeta$ values.
1310.2256
Ayres Freitas
A. Freitas
Two-loop fermionic electroweak corrections to the Z-boson width and production rate
7 pages; v2: few typos fixed and minor corrections of numbers in tables
Phys. Lett. B 730 (2014) 50-52
10.1016/j.physletb.2014.01.017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Improved predictions for the Z-boson decay width and the hadronic Z-peak cross-section within the Standard Model are presented, based on a complete calculation of electroweak two-loop corrections with closed fermion loops. Compared to previous partial results, the predictions for the Z width and hadronic cross-section shift by about 0.6 MeV and 0.004 nb, respectively. Compact parametrization formulae are provided, which approximate the full results to better than 4 ppm.
[ { "created": "Tue, 8 Oct 2013 20:02:52 GMT", "version": "v1" }, { "created": "Sat, 4 Jan 2014 19:13:35 GMT", "version": "v2" } ]
2014-01-24
[ [ "Freitas", "A.", "" ] ]
Improved predictions for the Z-boson decay width and the hadronic Z-peak cross-section within the Standard Model are presented, based on a complete calculation of electroweak two-loop corrections with closed fermion loops. Compared to previous partial results, the predictions for the Z width and hadronic cross-section shift by about 0.6 MeV and 0.004 nb, respectively. Compact parametrization formulae are provided, which approximate the full results to better than 4 ppm.
2404.19197
Yuan-Zhen Li
Yuan-Zhen Li, Michael J. Ramsey-Musolf, Jiang-Hao Yu
Does the Electron EDM Preclude Electroweak Baryogenesis ?
6 pages, 3 figures
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electroweak baryogenesis (EWBG) constitutes a theoretically compelling and experimentally testable mechanism for explaining the origin of the baryon asymmetry of the universe (BAU). New results for the electric dipole moment (EDM) of the electron place significant constraints on the beyond Standard Model CP-violation needed for successful EWBG. We show how new developments in EWBG quantum transport theory that include CP-violating sources first order in gradients imply more relaxed EDM constraints than implied by previous approximation formulations. Consequently, EWBG remains viable even in light of present EDM bounds. We also illustrate how these developments enable a more realistic treatment of CP-conserving interactions that can also have a decisive impact on the predicted BAU.
[ { "created": "Tue, 30 Apr 2024 01:49:02 GMT", "version": "v1" } ]
2024-05-02
[ [ "Li", "Yuan-Zhen", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Yu", "Jiang-Hao", "" ] ]
Electroweak baryogenesis (EWBG) constitutes a theoretically compelling and experimentally testable mechanism for explaining the origin of the baryon asymmetry of the universe (BAU). New results for the electric dipole moment (EDM) of the electron place significant constraints on the beyond Standard Model CP-violation needed for successful EWBG. We show how new developments in EWBG quantum transport theory that include CP-violating sources first order in gradients imply more relaxed EDM constraints than implied by previous approximation formulations. Consequently, EWBG remains viable even in light of present EDM bounds. We also illustrate how these developments enable a more realistic treatment of CP-conserving interactions that can also have a decisive impact on the predicted BAU.
2405.04145
Zhi-Gang Wang
Zhi-Gang Wang
The ground states and first radial excitations of the vector tetraquark states with explicit P-waves via the QCD sum rules
12 pages, 4 figures
Chin. Phys. C48 (2024) 103103
10.1088/1674-1137/ad5ae5
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we choose the diquark-antidiquark type four-quark currents with an explicit P-wave between the diquark and antidiquark pairs to study the ground states and first radial excitations of the hidden-charm tetraquark states with the quantum numbers $J^{PC}=1^{--}$. And we obtain the lowest vector tetraquark masses and make possible assignments of the existing $Y$ states. There indeed exists a hidden-charm tetraquark state with the $J^{PC}=1^{--}$ at the energy about $4.75\,\rm{GeV}$ as the first radial excitation to account for the BESIII data.
[ { "created": "Tue, 7 May 2024 09:22:21 GMT", "version": "v1" }, { "created": "Tue, 4 Jun 2024 13:45:32 GMT", "version": "v2" } ]
2024-08-13
[ [ "Wang", "Zhi-Gang", "" ] ]
In this work, we choose the diquark-antidiquark type four-quark currents with an explicit P-wave between the diquark and antidiquark pairs to study the ground states and first radial excitations of the hidden-charm tetraquark states with the quantum numbers $J^{PC}=1^{--}$. And we obtain the lowest vector tetraquark masses and make possible assignments of the existing $Y$ states. There indeed exists a hidden-charm tetraquark state with the $J^{PC}=1^{--}$ at the energy about $4.75\,\rm{GeV}$ as the first radial excitation to account for the BESIII data.
1202.1297
Thomas A. Ryttov
Thomas A. Ryttov and Robert Shrock
Comparison of Some Exact and Perturbative Results for a Supersymmetric SU($N_c$) Gauge Theory
16 pages, 3 figures
Phys. Rev. D85, 076009 (2012)
10.1103/PhysRevD.85.076009
YITP-SB-11-23
hep-ph hep-lat hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider vectorial, asymptotically free ${\cal N}=1$ supersymmetric SU($N_c$) gauge theories with $N_f$ copies of massless chiral super fields in various representations and study how perturbative predictions for the lower boundary of the infrared conformal phase, as a function of $N_f$, compare with exact results. We make use of two-loop and three-loop calculations of the beta function and anomalous dimension of the quadratic chiral super field operator product for this purpose. The specific chiral superfield contents that we consider are $N_f$ copies of (i) $F+\bar F$, (ii) $Adj$, (iii) $S_2+\bar S_2$, and (iv) $A_2 + \bar A_2$, where $F$, $Adj$, $S_2$, and $A_2$ denote, respectively, the fundamental, adjoint, and symmetric and antisymmetric rank-2 tensor representations. We find that perturbative results slightly overestimate the value of $N_{f,cr}$ relative to the respective exact results for these representations, i.e., slightly underestimate the interval in $N_f$ for which the theory has infrared conformal behavior. Our results provide a measure of how closely perturbative calculations reproduce exact results for these theories.
[ { "created": "Mon, 6 Feb 2012 21:19:19 GMT", "version": "v1" } ]
2012-04-26
[ [ "Ryttov", "Thomas A.", "" ], [ "Shrock", "Robert", "" ] ]
We consider vectorial, asymptotically free ${\cal N}=1$ supersymmetric SU($N_c$) gauge theories with $N_f$ copies of massless chiral super fields in various representations and study how perturbative predictions for the lower boundary of the infrared conformal phase, as a function of $N_f$, compare with exact results. We make use of two-loop and three-loop calculations of the beta function and anomalous dimension of the quadratic chiral super field operator product for this purpose. The specific chiral superfield contents that we consider are $N_f$ copies of (i) $F+\bar F$, (ii) $Adj$, (iii) $S_2+\bar S_2$, and (iv) $A_2 + \bar A_2$, where $F$, $Adj$, $S_2$, and $A_2$ denote, respectively, the fundamental, adjoint, and symmetric and antisymmetric rank-2 tensor representations. We find that perturbative results slightly overestimate the value of $N_{f,cr}$ relative to the respective exact results for these representations, i.e., slightly underestimate the interval in $N_f$ for which the theory has infrared conformal behavior. Our results provide a measure of how closely perturbative calculations reproduce exact results for these theories.
hep-ph/9911348
Christoph Greub
C. Greub (Bern)
Theory of rare B meson decays
14 pages including 8 postscript figures
null
null
BUTP-99/22
hep-ph
null
I review the NLO QCD calculations of the branching ratio for B--> X_s gamma in the SM. Including the leading electromagnetic corrections, one obtaines BR(B-> X_s gamma)=(3.32 +- 0.30)*10^{-4}. Confronting theory with the newest data, an updated value for |V_{ts}| is obtained: |V_{ts}|=0.037 +- 0.007. Theoretical progress on the photon energy spectrum is also discussed. The inclusive FCNC semileptonic decays in the SM are briefly summarized. Furthermore, B--> X_s gamma is considered in 2HDMs and in different SUSY scenarios. QCD corrections are shown to be crucial.
[ { "created": "Sat, 13 Nov 1999 20:53:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Greub", "C.", "", "Bern" ] ]
I review the NLO QCD calculations of the branching ratio for B--> X_s gamma in the SM. Including the leading electromagnetic corrections, one obtaines BR(B-> X_s gamma)=(3.32 +- 0.30)*10^{-4}. Confronting theory with the newest data, an updated value for |V_{ts}| is obtained: |V_{ts}|=0.037 +- 0.007. Theoretical progress on the photon energy spectrum is also discussed. The inclusive FCNC semileptonic decays in the SM are briefly summarized. Furthermore, B--> X_s gamma is considered in 2HDMs and in different SUSY scenarios. QCD corrections are shown to be crucial.
1101.6044
Edi Halyo
Edi Halyo
Supersymmetry Breaking by the Right-Handed Tau Neutrino
20 pages
null
null
SU-ITP-11/01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We describe supersymmetry breaking by the F-term of a heavy right-handed tau neutrino with a VEV. Due to the the tau neutrino Yukawa coupling, the neutralino, chargino and scalar mass matrices and the weak currents are modified. In addition, there are new cubic and quartic scalar and trilinear R parity violating interactions. For large $\tan \beta$ these effects may be quite large. The scenario requires low energy supersymmetry breaking with generic values of $F \sim 10^{10}$~GeV.
[ { "created": "Mon, 31 Jan 2011 18:15:40 GMT", "version": "v1" } ]
2011-02-01
[ [ "Halyo", "Edi", "" ] ]
We describe supersymmetry breaking by the F-term of a heavy right-handed tau neutrino with a VEV. Due to the the tau neutrino Yukawa coupling, the neutralino, chargino and scalar mass matrices and the weak currents are modified. In addition, there are new cubic and quartic scalar and trilinear R parity violating interactions. For large $\tan \beta$ these effects may be quite large. The scenario requires low energy supersymmetry breaking with generic values of $F \sim 10^{10}$~GeV.
1408.2964
Jan Uphoff
Jan Uphoff, Oliver Fochler, Zhe Xu, Carsten Greiner
Elastic and radiative heavy quark interactions in ultra-relativistic heavy-ion collisions
18 pages, 18 figures
null
10.1088/0954-3899/42/11/115106
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Elastic and radiative heavy quark interactions with light partons are studied with the partonic transport description BAMPS (Boltzmann Approach to MultiParton Scatterings). After calculating the cross section of radiative processes for finite masses in the improved Gunion-Bertsch approximation and verifying this calculation by comparing to the exact result, we study elastic and radiative heavy quark energy loss in a static medium of quarks and gluons. Furthermore, the full 3+1D space-time evolution of gluons, light quarks, and heavy quarks in ultra-relativistic heavy-ion collisions at the BNL Relativistic Heavy-Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC) are calculated with BAMPS including elastic and radiative heavy flavor interactions. Treating light and heavy particles on the same footing in the same framework, we find that the experimentally measured nuclear modification factor of charged hadrons and D mesons at the LHC can be simultaneously described. In addition, we calculate the heavy flavor evolution with an improved screening procedure from hard-thermal-loop calculations and confront the results with experimental data of the nuclear modification factor and the elliptic flow of heavy flavor particles at RHIC and LHC.
[ { "created": "Wed, 13 Aug 2014 10:19:53 GMT", "version": "v1" } ]
2015-10-28
[ [ "Uphoff", "Jan", "" ], [ "Fochler", "Oliver", "" ], [ "Xu", "Zhe", "" ], [ "Greiner", "Carsten", "" ] ]
Elastic and radiative heavy quark interactions with light partons are studied with the partonic transport description BAMPS (Boltzmann Approach to MultiParton Scatterings). After calculating the cross section of radiative processes for finite masses in the improved Gunion-Bertsch approximation and verifying this calculation by comparing to the exact result, we study elastic and radiative heavy quark energy loss in a static medium of quarks and gluons. Furthermore, the full 3+1D space-time evolution of gluons, light quarks, and heavy quarks in ultra-relativistic heavy-ion collisions at the BNL Relativistic Heavy-Ion Collider (RHIC) and the CERN Large Hadron Collider (LHC) are calculated with BAMPS including elastic and radiative heavy flavor interactions. Treating light and heavy particles on the same footing in the same framework, we find that the experimentally measured nuclear modification factor of charged hadrons and D mesons at the LHC can be simultaneously described. In addition, we calculate the heavy flavor evolution with an improved screening procedure from hard-thermal-loop calculations and confront the results with experimental data of the nuclear modification factor and the elliptic flow of heavy flavor particles at RHIC and LHC.
1001.4082
Gavin Salam
Andrea Banfi, Gavin P. Salam and Giulia Zanderighi
Phenomenology of event shapes at hadron colliders
70 pages, 25 figures, additional material available from http://www.lpthe.jussieu.fr/~salam/pp-event-shapes/
JHEP 1006:038,2010
10.1007/JHEP06(2010)038
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results for matched distributions of a range of dijet event shapes at hadron colliders, combining next-to-leading logarithmic (NLL) accuracy in the resummation exponent, next-to-next-to leading logarithmic (NNLL) accuracy in its expansion and next-to-leading order (NLO) accuracy in a pure alpha_s expansion. This is the first time that such a matching has been carried out for hadronic final-state observables at hadron colliders. We compare our results to Monte Carlo predictions, with and without matching to multi-parton tree-level fixed-order calculations. These studies suggest that hadron-collider event shapes have significant scope for constraining both perturbative and non-perturbative aspects of hadron-collider QCD. The differences between various calculational methods also highlight the limits of relying on simultaneous variations of renormalisation and factorisation scale in making reliable estimates of uncertainties in QCD predictions. We also discuss the sensitivity of event shapes to the topology of multi-jet events, which are expected to appear in many New Physics scenarios.
[ { "created": "Fri, 22 Jan 2010 21:02:52 GMT", "version": "v1" } ]
2014-11-20
[ [ "Banfi", "Andrea", "" ], [ "Salam", "Gavin P.", "" ], [ "Zanderighi", "Giulia", "" ] ]
We present results for matched distributions of a range of dijet event shapes at hadron colliders, combining next-to-leading logarithmic (NLL) accuracy in the resummation exponent, next-to-next-to leading logarithmic (NNLL) accuracy in its expansion and next-to-leading order (NLO) accuracy in a pure alpha_s expansion. This is the first time that such a matching has been carried out for hadronic final-state observables at hadron colliders. We compare our results to Monte Carlo predictions, with and without matching to multi-parton tree-level fixed-order calculations. These studies suggest that hadron-collider event shapes have significant scope for constraining both perturbative and non-perturbative aspects of hadron-collider QCD. The differences between various calculational methods also highlight the limits of relying on simultaneous variations of renormalisation and factorisation scale in making reliable estimates of uncertainties in QCD predictions. We also discuss the sensitivity of event shapes to the topology of multi-jet events, which are expected to appear in many New Physics scenarios.
1401.7327
Pavel Fileviez Perez
Pavel Fileviez Perez, Sogee Spinner
The Higgs Mass and the Stueckelberg Mechanism in Supersymmetry
to appear in Physical Review D
Phys. Rev. D 89, 095004 (2014)
10.1103/PhysRevD.89.095004
null
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a class of theories where the mass of the lightest Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) can be larger than the Z gauge boson mass at tree level. In this context the MSSM fields feel a new force, whose corresponding gauge boson attains its mass through the Stueckelberg mechanism. We show how one can achieve a Higgs mass around 126 GeV without assuming a heavy stop spectrum or a large stop trilinear term. The application of this class of models to the conservation of R-parity is also discussed.
[ { "created": "Tue, 28 Jan 2014 21:00:27 GMT", "version": "v1" }, { "created": "Thu, 17 Apr 2014 21:09:34 GMT", "version": "v2" } ]
2014-05-14
[ [ "Perez", "Pavel Fileviez", "" ], [ "Spinner", "Sogee", "" ] ]
We investigate a class of theories where the mass of the lightest Higgs boson of the Minimal Supersymmetric Standard Model (MSSM) can be larger than the Z gauge boson mass at tree level. In this context the MSSM fields feel a new force, whose corresponding gauge boson attains its mass through the Stueckelberg mechanism. We show how one can achieve a Higgs mass around 126 GeV without assuming a heavy stop spectrum or a large stop trilinear term. The application of this class of models to the conservation of R-parity is also discussed.
1707.07155
Seyed Yaser Ayazi
Seyed Yaser Ayazi and Saeid Paktinat Mehdiabadi
The s-Channel Single Top Quark Production as a Constraint for $W'$ Boson Contribution
10 pages, 6 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An analysis is performed to constrain the $W'$ boson production using the measurement of the s-channel single top quark production cross section. Both phenomenological and statistical approaches are examined and results are presented. In the best case, $W'$ bosons that interact only to the right-handed fermions are excluded below 1390 GeV. To our knowledge, it is the first time that the measured cross section of the s-channel single top quark production from the colliders is used to rule out part of the phase space of the $W'$ boson.
[ { "created": "Sat, 22 Jul 2017 12:52:14 GMT", "version": "v1" } ]
2017-07-25
[ [ "Ayazi", "Seyed Yaser", "" ], [ "Mehdiabadi", "Saeid Paktinat", "" ] ]
An analysis is performed to constrain the $W'$ boson production using the measurement of the s-channel single top quark production cross section. Both phenomenological and statistical approaches are examined and results are presented. In the best case, $W'$ bosons that interact only to the right-handed fermions are excluded below 1390 GeV. To our knowledge, it is the first time that the measured cross section of the s-channel single top quark production from the colliders is used to rule out part of the phase space of the $W'$ boson.
hep-ph/9611369
Sin Kyu Kang
Kyungsik Kang, Sin Kyu Kang, Jihn E. Kim, and Pyungwon Ko
Almost maximally broken permutation symmetry for neutrino mass matrix
9 pages, RevTex, no figures
Mod.Phys.Lett. A12 (1997) 1175-1184
10.1142/S0217732397001205
Brown-HET-1062 and SNUTP 96-011
hep-ph
null
Assuming three light neutrinos are Majorana particles, we propose mass matrix ansatz for the charged leptons and Majorana neutrinos with family symmetry $S_{3} $ broken into $S_{1}$ and $S_{2}$, respectively. Each matrix has three parameters, which are fixed by measured charged lepton masses, differences of squared neutrino masses relevant to the solar and the atmospheric neutrino puzzles, and the masses of three light Majorana neutrinos as a candidate for hot dark matter with $\sum |m_{\nu}| \sim 6 eV$. The resulting neutrino mixing is compatible with the data for the current upper limit, $ < m_{\nu_e} >_{th} < 0.8 eV$, of neutrino-less double beta decay experiments, and the current data for various types of neutrino oscillation experiments. One solution of our model predicts that $\nu_{\mu} \rightarrow \nu_{\tau}$ oscillation probability is about $< 0.008$ with $\Delta m^{2} \sim 10^{-2} eV^2$, which may not be accessible at CHORUS and other ongoing experiments.
[ { "created": "Tue, 19 Nov 1996 20:43:23 GMT", "version": "v1" } ]
2009-10-30
[ [ "Kang", "Kyungsik", "" ], [ "Kang", "Sin Kyu", "" ], [ "Kim", "Jihn E.", "" ], [ "Ko", "Pyungwon", "" ] ]
Assuming three light neutrinos are Majorana particles, we propose mass matrix ansatz for the charged leptons and Majorana neutrinos with family symmetry $S_{3} $ broken into $S_{1}$ and $S_{2}$, respectively. Each matrix has three parameters, which are fixed by measured charged lepton masses, differences of squared neutrino masses relevant to the solar and the atmospheric neutrino puzzles, and the masses of three light Majorana neutrinos as a candidate for hot dark matter with $\sum |m_{\nu}| \sim 6 eV$. The resulting neutrino mixing is compatible with the data for the current upper limit, $ < m_{\nu_e} >_{th} < 0.8 eV$, of neutrino-less double beta decay experiments, and the current data for various types of neutrino oscillation experiments. One solution of our model predicts that $\nu_{\mu} \rightarrow \nu_{\tau}$ oscillation probability is about $< 0.008$ with $\Delta m^{2} \sim 10^{-2} eV^2$, which may not be accessible at CHORUS and other ongoing experiments.
2009.04782
Martin Rohrmoser
Martin Rohrmoser, Krzysztof Kutak, Andreas van Hameren, Wies{\l}aw P{\l}aczek, Konrad Tywoniuk
In-medium transverse momentum broadening effects on di-jet observables
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy ion collisions at high energies can be used as an interesting way to recreate and study the medium of the quark-gluon plasma (QGP). We particularly investigate the jets produced in hard binary collisions and their interactions with a tentative medium. These jets were obtained numerically from the Monte-Carlo simulations of hard collisions using the KATIE-algorithm [1], where parton momenta within the colliding nucleons were describe by means of unintegrated parton distribution functions (uPDF). We evolved these jets within a medium that contains both, transverse kicks (yielding a broadening in momentum transvers to the jet-axis) as well as medium induced radiation within the MINCAS-algorithm [2] following the works of [3,4]. We produce qualitative results for the decorrelation of dijets. In particular, we study deviations from a transverse momentum broadening that follows a Gaussian distribution. [1] A. van Hameren, Comput.Phys.Commun. 224 (2018) 371-380 [2] K. Kutak, W. P{\l}aczek, R. Straka, Eur.Phys.J. C79 (2019) no.4, 317 [3] J.-P. Blaizot, F. Dominguez, E. Iancu, Y. Mehtar-Tani, JHEP 1301 (2013) 143 [4] J.-P. Blaizot, F. Dominguez, E. Iancu, Y. Mehtar-Tani, JHEP 1406 (2014) 075
[ { "created": "Thu, 10 Sep 2020 11:35:21 GMT", "version": "v1" } ]
2020-09-11
[ [ "Rohrmoser", "Martin", "" ], [ "Kutak", "Krzysztof", "" ], [ "van Hameren", "Andreas", "" ], [ "Płaczek", "Wiesław", "" ], [ "Tywoniuk", "Konrad", "" ] ]
Heavy ion collisions at high energies can be used as an interesting way to recreate and study the medium of the quark-gluon plasma (QGP). We particularly investigate the jets produced in hard binary collisions and their interactions with a tentative medium. These jets were obtained numerically from the Monte-Carlo simulations of hard collisions using the KATIE-algorithm [1], where parton momenta within the colliding nucleons were describe by means of unintegrated parton distribution functions (uPDF). We evolved these jets within a medium that contains both, transverse kicks (yielding a broadening in momentum transvers to the jet-axis) as well as medium induced radiation within the MINCAS-algorithm [2] following the works of [3,4]. We produce qualitative results for the decorrelation of dijets. In particular, we study deviations from a transverse momentum broadening that follows a Gaussian distribution. [1] A. van Hameren, Comput.Phys.Commun. 224 (2018) 371-380 [2] K. Kutak, W. P{\l}aczek, R. Straka, Eur.Phys.J. C79 (2019) no.4, 317 [3] J.-P. Blaizot, F. Dominguez, E. Iancu, Y. Mehtar-Tani, JHEP 1301 (2013) 143 [4] J.-P. Blaizot, F. Dominguez, E. Iancu, Y. Mehtar-Tani, JHEP 1406 (2014) 075
hep-ph/0302162
Pierpaolo Mastrolia
P. Mastrolia (1,2) and E. Remiddi (1,3) ((1) University of Bologna, (2) University of Karlsruhe, (3) INFN-Bologna)
Two-Loop Form Factors in QED
13 pages, 1 figure
Nucl.Phys.B664:341-356,2003
10.1016/S0550-3213(03)00405-X
TTP-03-05
hep-ph
null
We evaluate the on shell form factors of the electron for arbitrary momentum transfer and finite electron mass, at two loops in QED, by integrating the corresponding dispersion relations, which involve the imaginary parts known since a long time. The infrared divergences are parameterized in terms of a fictitious small photon mass. The result is expressed in terms of Harmonic Polylogarithms of maximum weight 4. The expansions for small and large momentum transfer are also given
[ { "created": "Tue, 18 Feb 2003 19:05:12 GMT", "version": "v1" } ]
2008-11-26
[ [ "Mastrolia", "P.", "" ], [ "Remiddi", "E.", "" ] ]
We evaluate the on shell form factors of the electron for arbitrary momentum transfer and finite electron mass, at two loops in QED, by integrating the corresponding dispersion relations, which involve the imaginary parts known since a long time. The infrared divergences are parameterized in terms of a fictitious small photon mass. The result is expressed in terms of Harmonic Polylogarithms of maximum weight 4. The expansions for small and large momentum transfer are also given
2201.06580
Ruth Sch\"afer
Torben Ferber, Anastasiia Filimonova, Ruth Sch\"afer, Susanne Westhoff
Displaced or invisible? ALPs from $B$ decays at Belle II
30 pages, 12 figures, 1 table
null
10.1007/JHEP04(2023)131
P3H-22-005, Nikhef 2022-001
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
At colliders, neutral long-lived particles can be detected through displaced decay products or as missing energy. Which search strategy is better depends on the particle's decay length just as on the detector properties. We investigate the complementarity of displaced and invisible signatures for the Belle II experiment. Focusing on axion-like particles $a$ produced from meson decays, we present a new search strategy for two-body decays $B^+ \to K^+ a, a\to E\!\!\!/$ with missing energy $E\!\!\!/$. With $50\,$ab$^{-1}$ of data, Belle II can probe light invisible resonances with branching ratio $\mathcal{B}(B^+\to K^+ a) \gtrsim 10^{-7}$ and decay length $c\tau_a \gtrsim 1\,$m. For axion-like particles, we expect the sensitivity of $B^+ \to K^+ E\!\!\!/$ to small couplings to improve by up to two orders of magnitude compared to previous searches at collider and fixed-target experiments. For sub-GeV particles, $B^+ \to K^+ E\!\!\!/$ at Belle II and searches at beam-dump experiments are most sensitive; for heavier particles, searches for displaced vertices at Belle II, long-lived particle experiments at the LHC, and future fixed-target experiments can probe the smallest couplings.
[ { "created": "Mon, 17 Jan 2022 19:00:01 GMT", "version": "v1" }, { "created": "Wed, 14 Jun 2023 13:52:42 GMT", "version": "v2" } ]
2023-06-16
[ [ "Ferber", "Torben", "" ], [ "Filimonova", "Anastasiia", "" ], [ "Schäfer", "Ruth", "" ], [ "Westhoff", "Susanne", "" ] ]
At colliders, neutral long-lived particles can be detected through displaced decay products or as missing energy. Which search strategy is better depends on the particle's decay length just as on the detector properties. We investigate the complementarity of displaced and invisible signatures for the Belle II experiment. Focusing on axion-like particles $a$ produced from meson decays, we present a new search strategy for two-body decays $B^+ \to K^+ a, a\to E\!\!\!/$ with missing energy $E\!\!\!/$. With $50\,$ab$^{-1}$ of data, Belle II can probe light invisible resonances with branching ratio $\mathcal{B}(B^+\to K^+ a) \gtrsim 10^{-7}$ and decay length $c\tau_a \gtrsim 1\,$m. For axion-like particles, we expect the sensitivity of $B^+ \to K^+ E\!\!\!/$ to small couplings to improve by up to two orders of magnitude compared to previous searches at collider and fixed-target experiments. For sub-GeV particles, $B^+ \to K^+ E\!\!\!/$ at Belle II and searches at beam-dump experiments are most sensitive; for heavier particles, searches for displaced vertices at Belle II, long-lived particle experiments at the LHC, and future fixed-target experiments can probe the smallest couplings.
hep-ph/0301123
Matthias Neubert
S.W. Bosch (Cornell), R.J. Hill (SLAC), B.O. Lange (Cornell), M. Neubert (Cornell)
Factorization and Sudakov Resummation in Leptonic Radiative B Decay
20 pages, 5 figures; several references added or updated, extended discussion of the new elements of the factorization proof, typo in eq.(6) fixed; version to appear in Phys. Rev. D
Phys.Rev.D67:094014,2003
10.1103/PhysRevD.67.094014
CLNS-03/1817, SLAC-PUB-9625
hep-ph
null
Soft-collinear effective theory is used to prove factorization of the B->gamma+l+nu decay amplitude at leading power in Lambda/m_b, including a demonstration of the absence of non-valence Fock states and of the finiteness of the convolution integral in the factorization formula. Large logarithms entering the hard-scattering kernel are resummed by performing a two-step perturbative matching onto the low-energy effective theory, and by solving evolution equations derived from the renormalization properties of the leading-order B-meson light-cone distribution amplitude. As a byproduct, the evolution equation for heavy-collinear current operators in soft-collinear effective theory is derived.
[ { "created": "Thu, 16 Jan 2003 21:47:35 GMT", "version": "v1" }, { "created": "Mon, 7 Apr 2003 15:46:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bosch", "S. W.", "", "Cornell" ], [ "Hill", "R. J.", "", "SLAC" ], [ "Lange", "B. O.", "", "Cornell" ], [ "Neubert", "M.", "", "Cornell" ] ]
Soft-collinear effective theory is used to prove factorization of the B->gamma+l+nu decay amplitude at leading power in Lambda/m_b, including a demonstration of the absence of non-valence Fock states and of the finiteness of the convolution integral in the factorization formula. Large logarithms entering the hard-scattering kernel are resummed by performing a two-step perturbative matching onto the low-energy effective theory, and by solving evolution equations derived from the renormalization properties of the leading-order B-meson light-cone distribution amplitude. As a byproduct, the evolution equation for heavy-collinear current operators in soft-collinear effective theory is derived.
1711.07464
Dipyaman Pramanik
Sandhya Choubey, Debajyoti Dutta, Dipyaman Pramanik
Measuring the Sterile Neutrino CP Phase at DUNE and T2HK
Published in EPJ C with minor corrections
Eur.Phys.J. C78 (2018) no.4, 339
10.1140/epjc/s10052-018-5816-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CP phases associated with the sterile neutrino cannot be measured in the dedicated short-baseline experiments being built to test the sterile neutrino hypothesis. On the other hand, these phases can be measured in long-baseline experiments, even though the main goal of these experiments is not to test or measure sterile neutrino parameters. In particular, the sterile neutrino phase $\delta_{24}$ affects the charged-current electron appearance data in long-baseline experiment. In this paper we show for the first time how well the sterile neutrino phase $\delta_{24}$ can be measured by the next-generation long-baseline experiments DUNE, T2HK (and T2HKK). We also show the expected precision with which this sterile phase can be measured by combining the DUNE data with data from T2HK or T2HKK. We also present the sensitivity of these experiments to the sterile mixing angles, both by themselves, as well as when DUNE is combined with T2HK or T2HKK.
[ { "created": "Mon, 20 Nov 2017 18:56:12 GMT", "version": "v1" }, { "created": "Wed, 22 Nov 2017 14:56:56 GMT", "version": "v2" }, { "created": "Sun, 6 May 2018 10:31:33 GMT", "version": "v3" } ]
2018-05-08
[ [ "Choubey", "Sandhya", "" ], [ "Dutta", "Debajyoti", "" ], [ "Pramanik", "Dipyaman", "" ] ]
The CP phases associated with the sterile neutrino cannot be measured in the dedicated short-baseline experiments being built to test the sterile neutrino hypothesis. On the other hand, these phases can be measured in long-baseline experiments, even though the main goal of these experiments is not to test or measure sterile neutrino parameters. In particular, the sterile neutrino phase $\delta_{24}$ affects the charged-current electron appearance data in long-baseline experiment. In this paper we show for the first time how well the sterile neutrino phase $\delta_{24}$ can be measured by the next-generation long-baseline experiments DUNE, T2HK (and T2HKK). We also show the expected precision with which this sterile phase can be measured by combining the DUNE data with data from T2HK or T2HKK. We also present the sensitivity of these experiments to the sterile mixing angles, both by themselves, as well as when DUNE is combined with T2HK or T2HKK.
hep-ph/0309116
Matthias Burkardt
Matthias Burkardt (New Mexico State University)
Some Inequalities for the Generalized Parton Distribution E(x,0,t)
3 pages
Phys.Lett. B582 (2004) 151-156
10.1016/j.physletb.2003.12.058
null
hep-ph
null
We discuss some constraints on the $x$ and $t$-dependence of $E(x,0,t)$ that arise from positivity bounds in the impact parameter representation. In addition, we show that $E(x,0,0)$ for the nucleon vanishes for $x\to 1$ at least as rapidly as $(1-x)^4$. Finally we provide an inequality that limits the contribution from $E$ to the angular momentum sum rule.
[ { "created": "Wed, 10 Sep 2003 21:56:53 GMT", "version": "v1" } ]
2009-11-10
[ [ "Burkardt", "Matthias", "", "New Mexico State University" ] ]
We discuss some constraints on the $x$ and $t$-dependence of $E(x,0,t)$ that arise from positivity bounds in the impact parameter representation. In addition, we show that $E(x,0,0)$ for the nucleon vanishes for $x\to 1$ at least as rapidly as $(1-x)^4$. Finally we provide an inequality that limits the contribution from $E$ to the angular momentum sum rule.
0807.4815
Yu-Feng Zhou
Yu-Feng Zhou
Mixing-induced CP violating sources for electroweak baryogenesis
3 pages, 2 figures. Talk given at the 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY08) June 16 - 21, 2008, Seoul, Korea. To appear in the proceedings
AIP Conf.Proc.1078:506-508,2009
10.1063/1.3052010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The effects of flavor mixing in electroweak baryogenesis is investigated in a generalized semiclassical WKB approach. Through calculating the nonadiabatic corrections to the particle currents it is shown that extra CP violation sources arise from the off-diagonal part of the equation of motion of particles moving inside the bubble wall. The numerical importance of the mixing-induced source is discussed in the Minimal Supersymmetric Standard Model and compared with the source term induced by semiclassical force.
[ { "created": "Wed, 30 Jul 2008 09:20:04 GMT", "version": "v1" } ]
2009-02-02
[ [ "Zhou", "Yu-Feng", "" ] ]
The effects of flavor mixing in electroweak baryogenesis is investigated in a generalized semiclassical WKB approach. Through calculating the nonadiabatic corrections to the particle currents it is shown that extra CP violation sources arise from the off-diagonal part of the equation of motion of particles moving inside the bubble wall. The numerical importance of the mixing-induced source is discussed in the Minimal Supersymmetric Standard Model and compared with the source term induced by semiclassical force.
2209.09290
Gongjun Choi
Gongjun Choi, Tsutomu T. Yanagida
High Quality Axion in Supersymmetric Models
27 pages,1 figure, 2 tables. v3: version accepted by JHEP
null
10.1007/JHEP12(2022)067
CERN-TH-2022-149
hep-ph hep-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
In this work, we discuss how the use of the symmetries well motivated in physics beyond the Standard model (BSM) can guarantee the high quality axions. We avoid to introduce symmetries only useful for addressing the axion quality problem. Rather, we rely on symmetries well motivated by other issues in BSM: supersymmetry, $U(1)_{\rm B-L}$ and the discrete R-symmetry $Z_{NR}$. We show that the interplay among these guarantees the high quality of the axion even for the gravitino mass and axion decay constant as large as $m_{3/2}=\mathcal{O}(10){\rm TeV}$ and $F_{a}=\mathcal{O}(10^{15}){\rm GeV}$ respectively. The key point of this work relies on the observation that the MSSM contribution to the mixed anomalies $Z_{NR}-[SU(2)_{L}]^{2}$ and $Z_{NR}-[SU(3)_{c}]^{2}$ is not enough for gauging $Z_{NR}$ for $N\neq6$, which necessitates the introduction of new matter fields. We make the introduction to achieve zero mixed anomalies, which logically supports a desired large enough $N$ for $Z_{NR}$. This mechanism effectively makes $Z_{NR}$ equal to $U(1)_{R}$ and thus offers a logically complete solution to the axion quality problem.
[ { "created": "Mon, 19 Sep 2022 18:29:11 GMT", "version": "v1" }, { "created": "Mon, 17 Oct 2022 16:02:01 GMT", "version": "v2" }, { "created": "Mon, 12 Dec 2022 13:32:14 GMT", "version": "v3" } ]
2023-01-04
[ [ "Choi", "Gongjun", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
In this work, we discuss how the use of the symmetries well motivated in physics beyond the Standard model (BSM) can guarantee the high quality axions. We avoid to introduce symmetries only useful for addressing the axion quality problem. Rather, we rely on symmetries well motivated by other issues in BSM: supersymmetry, $U(1)_{\rm B-L}$ and the discrete R-symmetry $Z_{NR}$. We show that the interplay among these guarantees the high quality of the axion even for the gravitino mass and axion decay constant as large as $m_{3/2}=\mathcal{O}(10){\rm TeV}$ and $F_{a}=\mathcal{O}(10^{15}){\rm GeV}$ respectively. The key point of this work relies on the observation that the MSSM contribution to the mixed anomalies $Z_{NR}-[SU(2)_{L}]^{2}$ and $Z_{NR}-[SU(3)_{c}]^{2}$ is not enough for gauging $Z_{NR}$ for $N\neq6$, which necessitates the introduction of new matter fields. We make the introduction to achieve zero mixed anomalies, which logically supports a desired large enough $N$ for $Z_{NR}$. This mechanism effectively makes $Z_{NR}$ equal to $U(1)_{R}$ and thus offers a logically complete solution to the axion quality problem.
2010.15993
Eduardo Rojas
Bruno El-Bennich, G. E. R. Zambrano, Eduardo Rojas
The Podolsky propagator in gap and bound-state equations
12 pages, 6 figures
Phys. Rev. D 103, 076008 (2021)
10.1103/PhysRevD.103.076008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on the Generalized Quantum Electrodynamics expression for the Podolsky propagator, which preserves gauge invariance for massive photons, we propose a model for the massive gluon propagator that reproduces well-known features of established strong-interaction models in the framework of the Dyson-Schwinger equation. By adjusting the Podolsky mass and the coupling strength we thus construct a model with simple analytical properties known from perturbative theory, yet well suited to describe a confining interaction. We obtain solutions of the Dyson-Schwinger equation for the quark at space-like momenta on the real axis as well as on the complex plane and solving the bound-state problem with the Bethe-Salpeter equation yields masses and weak decay constants of the $\pi, K$ and $\eta_c$ in excellent agreement with experimental values, while the $D$ and $D_s$ are reasonably well described. The analytical simplicity of this effective interaction has the potential to be useful for phenomenological applications and may facilitate calculations in Minkowski space.
[ { "created": "Thu, 29 Oct 2020 23:44:43 GMT", "version": "v1" }, { "created": "Mon, 1 Mar 2021 20:32:13 GMT", "version": "v2" } ]
2021-04-21
[ [ "El-Bennich", "Bruno", "" ], [ "Zambrano", "G. E. R.", "" ], [ "Rojas", "Eduardo", "" ] ]
Based on the Generalized Quantum Electrodynamics expression for the Podolsky propagator, which preserves gauge invariance for massive photons, we propose a model for the massive gluon propagator that reproduces well-known features of established strong-interaction models in the framework of the Dyson-Schwinger equation. By adjusting the Podolsky mass and the coupling strength we thus construct a model with simple analytical properties known from perturbative theory, yet well suited to describe a confining interaction. We obtain solutions of the Dyson-Schwinger equation for the quark at space-like momenta on the real axis as well as on the complex plane and solving the bound-state problem with the Bethe-Salpeter equation yields masses and weak decay constants of the $\pi, K$ and $\eta_c$ in excellent agreement with experimental values, while the $D$ and $D_s$ are reasonably well described. The analytical simplicity of this effective interaction has the potential to be useful for phenomenological applications and may facilitate calculations in Minkowski space.
hep-ph/0509307
Zhang Xiao-Bing
Xiao-Bing Zhang and Xue-Qian Li
Density dependence of quark masses and stability of color-flavor locked phases
4 figures, to be appeared in PRD
Phys.Rev.D72:054021,2005
10.1103/PhysRevD.72.054021
null
hep-ph
null
Considering the density dependence of quark masses, we investigate the color-flavor-locked matter and its stability relative to the ( unpaired ) strange quark matter. We find that, when the current mass of strange quark $m_s$ is small, the strange quark matter remains stable for the moderate baryon densities. When $m_s$ is large, the gapless phase of the color-flavor-locked matter is found to be difficult to be stable. A schematic phase diagram of three-flavor quark matter is presented, in which the color-flavor-locked phase region is suppressed in comparison with the previous results.
[ { "created": "Tue, 27 Sep 2005 15:31:12 GMT", "version": "v1" } ]
2014-11-18
[ [ "Zhang", "Xiao-Bing", "" ], [ "Li", "Xue-Qian", "" ] ]
Considering the density dependence of quark masses, we investigate the color-flavor-locked matter and its stability relative to the ( unpaired ) strange quark matter. We find that, when the current mass of strange quark $m_s$ is small, the strange quark matter remains stable for the moderate baryon densities. When $m_s$ is large, the gapless phase of the color-flavor-locked matter is found to be difficult to be stable. A schematic phase diagram of three-flavor quark matter is presented, in which the color-flavor-locked phase region is suppressed in comparison with the previous results.
2006.14681
Nan Li
Yu-Chen Ding, Nan Li, Chun-Cheng Wei and Yu-Feng Zhou
The high energy window of probing dark matter with cosmic-ray antideuterium and antihelium
22 pages, 12 figures; to appear on Chin. Phys. C
null
10.1088/1674-1137/abf13a
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Cosmic-ray (CR) anti-nuclei are often considered as important observables for dark matter (DM) indirect detections at low kinetic energies below GeV per nucleon. Since the primary CR fluxes drop quickly towards high energies, the secondary anti-nuclei in CR are expected to be significantly suppressed in high energy regions ($\gtrsim 100$ GeV per nucleon). If DM particles are heavy, the annihilation productions of DM can be highly boosted, thus the fluxes of anti-nuclei produced by DM annihilations may exceed the secondary background at high energies, which opens a high energy window for DM indirect detections. We investigate the possibility of detecting heavy DM particles which annihilate into high energy anti-nuclei. We use Monte-Carlo generators $\texttt{PYTHIA}$, $\texttt{EPOS-LHC}$ and $\texttt{DPMJET}$ and the coalescence model to simulate the production of anti-nuclei, and constrain the DM annihilation cross sections by using the AMS-02 and HAWC antiproton data and the HESS galactic center gamma-ray data. We find that the conclusion depends on the choice of DM density profiles. For the "Cored" type profile with a DM particle mass $\gtrsim 10$ TeV, the contributions from DM annihilations can exceed the secondary background in high energy regions, which opens the high energy window. While for the "Cuspy" type profile, the excess disappears.
[ { "created": "Thu, 25 Jun 2020 20:19:17 GMT", "version": "v1" }, { "created": "Tue, 30 Mar 2021 12:47:07 GMT", "version": "v2" } ]
2021-07-07
[ [ "Ding", "Yu-Chen", "" ], [ "Li", "Nan", "" ], [ "Wei", "Chun-Cheng", "" ], [ "Zhou", "Yu-Feng", "" ] ]
Cosmic-ray (CR) anti-nuclei are often considered as important observables for dark matter (DM) indirect detections at low kinetic energies below GeV per nucleon. Since the primary CR fluxes drop quickly towards high energies, the secondary anti-nuclei in CR are expected to be significantly suppressed in high energy regions ($\gtrsim 100$ GeV per nucleon). If DM particles are heavy, the annihilation productions of DM can be highly boosted, thus the fluxes of anti-nuclei produced by DM annihilations may exceed the secondary background at high energies, which opens a high energy window for DM indirect detections. We investigate the possibility of detecting heavy DM particles which annihilate into high energy anti-nuclei. We use Monte-Carlo generators $\texttt{PYTHIA}$, $\texttt{EPOS-LHC}$ and $\texttt{DPMJET}$ and the coalescence model to simulate the production of anti-nuclei, and constrain the DM annihilation cross sections by using the AMS-02 and HAWC antiproton data and the HESS galactic center gamma-ray data. We find that the conclusion depends on the choice of DM density profiles. For the "Cored" type profile with a DM particle mass $\gtrsim 10$ TeV, the contributions from DM annihilations can exceed the secondary background in high energy regions, which opens the high energy window. While for the "Cuspy" type profile, the excess disappears.
2209.09517
Bo Feng
Bo Feng
Generation Function For One-loop Tensor Reduction
38 Pages
null
10.1088/1572-9494/aca253
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
For loop integrals, the reduction is the standard method. Having an efficient way to find reduction coefficients is an important topic in scattering amplitudes. In this paper, we present the generation functions of reduction coefficients for general one-loop integrals with arbitrary tensor rank.
[ { "created": "Tue, 20 Sep 2022 07:24:36 GMT", "version": "v1" } ]
2023-02-22
[ [ "Feng", "Bo", "" ] ]
For loop integrals, the reduction is the standard method. Having an efficient way to find reduction coefficients is an important topic in scattering amplitudes. In this paper, we present the generation functions of reduction coefficients for general one-loop integrals with arbitrary tensor rank.
0805.2677
Mauro Anselmino
M. Anselmino, M. Boglione, U. D'Alesio, A. Kotzinian, S. Melis, F. Murgia, A. Prokudin and C. Turk
Sivers Effect for Pion and Kaon Production in Semi-Inclusive Deep Inelastic Scattering
16 pages, 19 figures; v2: no changes in results and conclusions; some sentences rephrased, few paragraphs (and references) added; a new table (table 2) with individual chi^2 per data points added; figures for JLab at 6 GeV removed; matches the version published on Eur. Phys. J. A
Eur.Phys.J.A39:89-100,2009
10.1140/epja/i2008-10697-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Sivers effect in the transverse single spin asymmetries (SSA) for pion and kaon production in semi-inclusive deep inelastic scattering (SIDIS) processes. We perform a fit of A^sin(phi_h-phi_S)_UT which, by including recent high statistics experimental data for pion and kaon production from HERMES and COMPASS Collaborations, allows a new determination of the Sivers distribution functions for quarks and antiquarks with u, d and s flavours. Estimates for forthcoming SIDIS experiments at COMPASS and JLab are given.
[ { "created": "Sat, 17 May 2008 15:13:54 GMT", "version": "v1" }, { "created": "Fri, 9 Jan 2009 12:00:41 GMT", "version": "v2" } ]
2009-02-19
[ [ "Anselmino", "M.", "" ], [ "Boglione", "M.", "" ], [ "D'Alesio", "U.", "" ], [ "Kotzinian", "A.", "" ], [ "Melis", "S.", "" ], [ "Murgia", "F.", "" ], [ "Prokudin", "A.", "" ], [ "Turk", "C.", "" ] ]
We study the Sivers effect in the transverse single spin asymmetries (SSA) for pion and kaon production in semi-inclusive deep inelastic scattering (SIDIS) processes. We perform a fit of A^sin(phi_h-phi_S)_UT which, by including recent high statistics experimental data for pion and kaon production from HERMES and COMPASS Collaborations, allows a new determination of the Sivers distribution functions for quarks and antiquarks with u, d and s flavours. Estimates for forthcoming SIDIS experiments at COMPASS and JLab are given.
2108.01486
Mohammad Sharifian
Mohammad Sharifian, Moslem Zarei, Mehdi Abdi, Marco Peloso, and Sabino Matarrese
Probing Virtual ALPs by Precision Phase Measurements: Time-Varying Magnetic Field Background
26 pages, 8 figures
https://iopscience.iop.org/article/10.1088/1475-7516/2023/04/036
10.1088/1475-7516/2023/04/036
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an experimental scheme for detecting the effects of off-shell axion-like particles (ALPs) through optical cavities. In this proposed experiment, linearly polarized photons are pumped into an optical cavity where an external time-dependent magnetic field is present. The magnetic field mediates an interaction between the cavity photons and ALPs giving rise to a modification in the phase of the cavity photons. The time-dependent nature of the external magnetic field prompts a novel amplification effect which significantly enhances this phase modification. A detection scheme is then proposed to identify such axion-induced phase shifts. We find that the phase modification is considerably sensitive to the photon-ALPs coupling constants $g_{a\gamma\gamma}$ for the range of ALPs mass $3.1\:\mu\textrm{eV}\leqslant m_a \leqslant 44.4\:\mu\textrm{eV}$.
[ { "created": "Tue, 3 Aug 2021 13:24:07 GMT", "version": "v1" }, { "created": "Thu, 13 Apr 2023 12:27:14 GMT", "version": "v2" } ]
2023-04-14
[ [ "Sharifian", "Mohammad", "" ], [ "Zarei", "Moslem", "" ], [ "Abdi", "Mehdi", "" ], [ "Peloso", "Marco", "" ], [ "Matarrese", "Sabino", "" ] ]
We propose an experimental scheme for detecting the effects of off-shell axion-like particles (ALPs) through optical cavities. In this proposed experiment, linearly polarized photons are pumped into an optical cavity where an external time-dependent magnetic field is present. The magnetic field mediates an interaction between the cavity photons and ALPs giving rise to a modification in the phase of the cavity photons. The time-dependent nature of the external magnetic field prompts a novel amplification effect which significantly enhances this phase modification. A detection scheme is then proposed to identify such axion-induced phase shifts. We find that the phase modification is considerably sensitive to the photon-ALPs coupling constants $g_{a\gamma\gamma}$ for the range of ALPs mass $3.1\:\mu\textrm{eV}\leqslant m_a \leqslant 44.4\:\mu\textrm{eV}$.
1011.2185
Thomas G. Rizzo
Thomas G. Rizzo
Transverse Beam Polarization as an Alternate View into New Physics at CLIC
16 pages, 8 figures. Based on a talk given at the International Workshop on Linear Colliders, CERN, Geneva, Switzerland, 18-22 Oct 2010; typos corrected
null
null
SLAC-PUB-14280
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In $e^+e^-$ collisions, transverse beam polarization can be a useful tool in studying the properties of particles associated with new physics beyond the Standard Model(SM). However, unlike in the case of measurements associated with longitudinal polarization, the formation of azimuthal asymmetries used to probe this physics in the case of transverse polarization requires both $e^\pm$ beams to be simultaneously polarized. In this paper we discuss the further use of transverse polarization as a probe of new physics models at a high energy, $\sqrt s=3$ TeV version of CLIC. In particular, we show ($i$) how measurements of the sign of these asymmetries is sufficient to discriminate the production of spin-0 supersymmetric states from the spin-1/2 Kaluza-Klein excitations of Universal Extra Dimensions. Simultaneously, the contribution to this asymmetry arising from the potentially large SM $W^+W^-$ background can be made negligibly small. We then show ($ii$) how measurements of such asymmetries and their associated angular distributions on the peak of a new resonant $Z'$-like state can be used to extract precision information on the $Z'$ couplings to the SM fermions.
[ { "created": "Tue, 9 Nov 2010 20:17:04 GMT", "version": "v1" }, { "created": "Mon, 3 Jan 2011 15:24:43 GMT", "version": "v2" } ]
2011-01-04
[ [ "Rizzo", "Thomas G.", "" ] ]
In $e^+e^-$ collisions, transverse beam polarization can be a useful tool in studying the properties of particles associated with new physics beyond the Standard Model(SM). However, unlike in the case of measurements associated with longitudinal polarization, the formation of azimuthal asymmetries used to probe this physics in the case of transverse polarization requires both $e^\pm$ beams to be simultaneously polarized. In this paper we discuss the further use of transverse polarization as a probe of new physics models at a high energy, $\sqrt s=3$ TeV version of CLIC. In particular, we show ($i$) how measurements of the sign of these asymmetries is sufficient to discriminate the production of spin-0 supersymmetric states from the spin-1/2 Kaluza-Klein excitations of Universal Extra Dimensions. Simultaneously, the contribution to this asymmetry arising from the potentially large SM $W^+W^-$ background can be made negligibly small. We then show ($ii$) how measurements of such asymmetries and their associated angular distributions on the peak of a new resonant $Z'$-like state can be used to extract precision information on the $Z'$ couplings to the SM fermions.
2407.19418
Zhan Sun
Cong Li, Ying-Zhao Jiang, and Zhan Sun
Studies of $Z$ boson decay into double $\Upsilon$ mesons at the NLO QCD accuracy
30 pages, 3 figures, and 3 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we employ the nonrelativistic QCD factorization to conduct a comprehensive examination of the $Z$ boson decay into a pair of $\Upsilon$ mesons, achieving accuracy at the next-to-leading-order (NLO) in $\alpha_s$. Our calculations demonstrate that the QED diagrams are indispensable in comparison to the pure QCD diagrams, and the implementation of QCD corrections markedly enhance the QCD results, whereas it substantially diminish the QED results. To ensure consistency with the experimental methodology, we have taken into account the feed-down transitions originating from higher excited states, which exhibit significant relevance. Combining all the contributions, we arrive at the NLO prediction of $\mathcal{B}_{Z \to \Upsilon(nS)+\Upsilon(mS)} \sim 10^{-11}$, which is notably lower than the upper limits set by CMS.
[ { "created": "Sun, 28 Jul 2024 07:38:36 GMT", "version": "v1" } ]
2024-07-30
[ [ "Li", "Cong", "" ], [ "Jiang", "Ying-Zhao", "" ], [ "Sun", "Zhan", "" ] ]
In this paper, we employ the nonrelativistic QCD factorization to conduct a comprehensive examination of the $Z$ boson decay into a pair of $\Upsilon$ mesons, achieving accuracy at the next-to-leading-order (NLO) in $\alpha_s$. Our calculations demonstrate that the QED diagrams are indispensable in comparison to the pure QCD diagrams, and the implementation of QCD corrections markedly enhance the QCD results, whereas it substantially diminish the QED results. To ensure consistency with the experimental methodology, we have taken into account the feed-down transitions originating from higher excited states, which exhibit significant relevance. Combining all the contributions, we arrive at the NLO prediction of $\mathcal{B}_{Z \to \Upsilon(nS)+\Upsilon(mS)} \sim 10^{-11}$, which is notably lower than the upper limits set by CMS.
1809.02788
Pervez Hoodbhoy
Pervez Hoodbhoy
Augmenting the Gauge-Gravity Correspondence to include Hadron Polarizabilities
11 pages, explanations added, results unchanged
Phys. Rev. D 98, 086017 (2018)
10.1103/PhysRevD.98.086017
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
ADS/CFT models have achieved considerable success in describing hadronic properties such as masses and Regge trajectories. Even if the minimal vertex that couples photons to structureless spin-zero fields is used, one still ends up with electromagnetic form factors of hadrons that are in fair to good agreement with experiment. However, contradicting both experiment and intuition, this minimal model gives zero for hadronic electric and magnetic polarizabilities. We show here that if effective vertices are used, and axial and vector mesons are allowed to propagate as intermediate states, then the static polarizabilities can in principle be computed from ADS/CFT.
[ { "created": "Sat, 8 Sep 2018 11:38:36 GMT", "version": "v1" }, { "created": "Sun, 23 Sep 2018 12:48:30 GMT", "version": "v2" } ]
2018-10-24
[ [ "Hoodbhoy", "Pervez", "" ] ]
ADS/CFT models have achieved considerable success in describing hadronic properties such as masses and Regge trajectories. Even if the minimal vertex that couples photons to structureless spin-zero fields is used, one still ends up with electromagnetic form factors of hadrons that are in fair to good agreement with experiment. However, contradicting both experiment and intuition, this minimal model gives zero for hadronic electric and magnetic polarizabilities. We show here that if effective vertices are used, and axial and vector mesons are allowed to propagate as intermediate states, then the static polarizabilities can in principle be computed from ADS/CFT.
1009.1468
Eugene Levin
Andrey Kormilitzin and Eugene Levin
Non-linear equation: energy conservation and impact parameter dependence
24 pp. 8 figures in eps files
Nucl.Phys.A849:98-119,2011
10.1016/j.nuclphysa.2010.11.005
TAUP 2920/10
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we address two questions: how energy conservation affects the solution to the non-linear equation, and how impact parameter dependence influences the inclusive production. Answering the first question we solve the modified BK equation which takes into account energy conservation. In spite of the fact that we used the simplified kernel, we believe that the main result of the paper: the small ($\leq 40%$) suppression of the inclusive productiondue to energy conservation, reflects a general feature. This result leads us to believe that the small value of the nuclear modification factor is of a non-perturbative nature. In the solution a new scale appears $Q_{fr} = Q_s \exp(-1/(2 \bas))$ and the production of dipoles with the size larger than $2/Q_{fr}$ is suppressed. Therefore, we can expect that the typical temperature for hadron production is about $Q_{fr}$ ($ T \approx Q_{fr}$). The simplified equation allows us to obtain a solution to Balitsky-Kovchegov equation taking into account the impact parameter dependence. We show that the impact parameter ($b$) dependence can be absorbed into the non-perturbative $b$ dependence of the saturation scale. The solution of the BK equation, as well as of the modified BK equation without $b$ dependence, is only accurate up to $\pm 25%$.
[ { "created": "Wed, 8 Sep 2010 07:41:46 GMT", "version": "v1" } ]
2011-01-17
[ [ "Kormilitzin", "Andrey", "" ], [ "Levin", "Eugene", "" ] ]
In this paper we address two questions: how energy conservation affects the solution to the non-linear equation, and how impact parameter dependence influences the inclusive production. Answering the first question we solve the modified BK equation which takes into account energy conservation. In spite of the fact that we used the simplified kernel, we believe that the main result of the paper: the small ($\leq 40%$) suppression of the inclusive productiondue to energy conservation, reflects a general feature. This result leads us to believe that the small value of the nuclear modification factor is of a non-perturbative nature. In the solution a new scale appears $Q_{fr} = Q_s \exp(-1/(2 \bas))$ and the production of dipoles with the size larger than $2/Q_{fr}$ is suppressed. Therefore, we can expect that the typical temperature for hadron production is about $Q_{fr}$ ($ T \approx Q_{fr}$). The simplified equation allows us to obtain a solution to Balitsky-Kovchegov equation taking into account the impact parameter dependence. We show that the impact parameter ($b$) dependence can be absorbed into the non-perturbative $b$ dependence of the saturation scale. The solution of the BK equation, as well as of the modified BK equation without $b$ dependence, is only accurate up to $\pm 25%$.
hep-ph/0504076
Naomichi Suzuki
N. Suzuki and M. Biyajima
Transverse momentum distribution with radial flow in relativistic diffusion model
7 pages, 5 figures and 6 tables
Int.J.Mod.Phys. E16 (2007) 133-148
10.1142/S0218301307005582
null
hep-ph
null
Large transverse momentum distributions of identified particles observed at RHIC are analyzed by a relativistic stochastic model in the three dimensional (non-Euclidean) rapidity space. A distribution function obtained from the model is Gaussian-like in radial rapidity. It can well describe observed transverse momentum $p_T$ distributions. Estimation of radial flow is made from the analysis of $p_T$ distributions for $\bar{p}$ in Au + Au Collisions. Temperatures are estimated from observed large $p_T$ distributions under the assumption that the distribution function approaches to the Maxwell-Boltzmann distribution in the lower momentum limit. Power-law behavior of large $p_T$ distribution is also derived from the model.
[ { "created": "Mon, 11 Apr 2005 11:29:43 GMT", "version": "v1" } ]
2015-06-25
[ [ "Suzuki", "N.", "" ], [ "Biyajima", "M.", "" ] ]
Large transverse momentum distributions of identified particles observed at RHIC are analyzed by a relativistic stochastic model in the three dimensional (non-Euclidean) rapidity space. A distribution function obtained from the model is Gaussian-like in radial rapidity. It can well describe observed transverse momentum $p_T$ distributions. Estimation of radial flow is made from the analysis of $p_T$ distributions for $\bar{p}$ in Au + Au Collisions. Temperatures are estimated from observed large $p_T$ distributions under the assumption that the distribution function approaches to the Maxwell-Boltzmann distribution in the lower momentum limit. Power-law behavior of large $p_T$ distribution is also derived from the model.
1606.03099
Giovanna Cottin
B. C. Allanach, Marcin Badziak, Giovanna Cottin, Nishita Desai, Cyril Hugonie and Robert Ziegler
Prompt Signals and Displaced Vertices in Sparticle Searches for Next-to-Minimal Gauge Mediated Supersymmetric Models
18 pages, 12 figures, 4 tables. Version accepted for publication in EPJC
null
10.1140/epjc/s10052-016-4330-3
CAVENDISH-HEP-16/10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the LHC phenomenology of the next-to-minimal model of gauge-mediated supersymmetry breaking (NMGMSB), both for Run I and Run II. The Higgs phenomenology of the model is consistent with observations: a 125 GeV Standard Model-like Higgs which mixes with singlet-like state of mass around 90 GeV that provides a 2$\sigma$ excess at LEP II. The model possesses regions of parameter space where a longer-lived lightest neutralino decays in the detector into a gravitino and a $b-$jet pair or a tau pair. We investigate current lower bounds on sparticle masses and the discovery potential of the model, both via conventional sparticle searches and via searches for displaced vertices. The strongest bound from searches for promptly decaying sparticles yields a lower limit on the gluino mass of 1080 GeV. An analysis of 100 fb$^{-1}$ from Run II, on the other hand, is expected to be sensitive up to 1900 GeV. The displaced vertex searches from Run I suffer from a very low signal efficiency, mainly due to the presence of $b-$quarks in the final state. We show how the displaced vertex cuts might be relaxed in order to improve signal efficiency, while simultaneous prompt objects can be used to cut down background. We find that a combined search strategy with both prompt and displaced cuts potentially has a far better sensitivity to this model than either set alone, motivating a fully fledged experimental study.
[ { "created": "Thu, 9 Jun 2016 20:00:19 GMT", "version": "v1" }, { "created": "Tue, 21 Jun 2016 13:15:23 GMT", "version": "v2" }, { "created": "Mon, 22 Aug 2016 14:43:00 GMT", "version": "v3" } ]
2016-09-21
[ [ "Allanach", "B. C.", "" ], [ "Badziak", "Marcin", "" ], [ "Cottin", "Giovanna", "" ], [ "Desai", "Nishita", "" ], [ "Hugonie", "Cyril", "" ], [ "Ziegler", "Robert", "" ] ]
We study the LHC phenomenology of the next-to-minimal model of gauge-mediated supersymmetry breaking (NMGMSB), both for Run I and Run II. The Higgs phenomenology of the model is consistent with observations: a 125 GeV Standard Model-like Higgs which mixes with singlet-like state of mass around 90 GeV that provides a 2$\sigma$ excess at LEP II. The model possesses regions of parameter space where a longer-lived lightest neutralino decays in the detector into a gravitino and a $b-$jet pair or a tau pair. We investigate current lower bounds on sparticle masses and the discovery potential of the model, both via conventional sparticle searches and via searches for displaced vertices. The strongest bound from searches for promptly decaying sparticles yields a lower limit on the gluino mass of 1080 GeV. An analysis of 100 fb$^{-1}$ from Run II, on the other hand, is expected to be sensitive up to 1900 GeV. The displaced vertex searches from Run I suffer from a very low signal efficiency, mainly due to the presence of $b-$quarks in the final state. We show how the displaced vertex cuts might be relaxed in order to improve signal efficiency, while simultaneous prompt objects can be used to cut down background. We find that a combined search strategy with both prompt and displaced cuts potentially has a far better sensitivity to this model than either set alone, motivating a fully fledged experimental study.
1109.6667
Qiang Yuan
Xiao-Jun Bi, Peng-Fei Yin, Zhao-Huan Yu, Qiang Yuan
Constraints and tests of the OPERA superluminal neutrinos
5 pages (2 column), 4 figures; published in Phys. Rev. Lett
Phys. Rev. Lett. 107, 241802 (2011)
10.1103/PhysRevLett.107.241802
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The superluminal neutrinos detected by OPERA indicates Lorentz invariance violation (LIV) of the neutrino sector at the order of $10^{-5}$. We study the implications of the result in this work. We find that such a large LIV implied by OPERA data will make the neutrino production process $\pi \to \mu + \nu_\mu$ kinematically forbidden for neutrino energy greater than about 5 GeV. The OPERA detection of neutrinos at 40 GeV can constrain the LIV parameter to be smaller than $3\times 10^{-7}$. Furthermore the neutrino decay in the LIV framework will modify the neutrino spectrum greatly. The atmospheric neutrino spectrum measured by IceCube can constrain the LIV parameter to the level of $10^{-12}$. The future detection of astrophysical neutrinos of Galactic sources is expected to be able to give even stronger constraint on the LIV parameter of neutrinos.
[ { "created": "Thu, 29 Sep 2011 20:33:57 GMT", "version": "v1" }, { "created": "Mon, 3 Oct 2011 17:04:29 GMT", "version": "v2" }, { "created": "Mon, 12 Dec 2011 06:19:44 GMT", "version": "v3" } ]
2015-03-19
[ [ "Bi", "Xiao-Jun", "" ], [ "Yin", "Peng-Fei", "" ], [ "Yu", "Zhao-Huan", "" ], [ "Yuan", "Qiang", "" ] ]
The superluminal neutrinos detected by OPERA indicates Lorentz invariance violation (LIV) of the neutrino sector at the order of $10^{-5}$. We study the implications of the result in this work. We find that such a large LIV implied by OPERA data will make the neutrino production process $\pi \to \mu + \nu_\mu$ kinematically forbidden for neutrino energy greater than about 5 GeV. The OPERA detection of neutrinos at 40 GeV can constrain the LIV parameter to be smaller than $3\times 10^{-7}$. Furthermore the neutrino decay in the LIV framework will modify the neutrino spectrum greatly. The atmospheric neutrino spectrum measured by IceCube can constrain the LIV parameter to the level of $10^{-12}$. The future detection of astrophysical neutrinos of Galactic sources is expected to be able to give even stronger constraint on the LIV parameter of neutrinos.
1909.07387
Ningqiang Song
Amit Bhoonah, Joseph Bramante, Ningqiang Song
Superradiant Searches for Dark Photons in Two Stage Atomic Transitions
43 pages, 11 figures. Added discussions on decoherence effects and the sensitivity corresponding to larger target number density. Matched published version
Phys. Rev. D 101, 055040 (2020)
10.1103/PhysRevD.101.055040
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a new mechanism to discover dark photon fields, by resonantly triggering two photon transitions in cold gas preparations. Using coherently prepared cold parahydrogen, coupling sensitivity for sub-meV mass dark photon fields can be advanced by orders of magnitude, with a modified light-shining-through-wall setup. We calculate the effect of a background dark photon field on the dipole moment and corresponding transition rate of cold parahydrogen pumped into its first vibrational excited state by counter-propagating laser beams. The nonlinear amplification of two photon emission triggered by dark photons in a cold parahydrogen sample is numerically simulated to obtain the expected dark photon coupling sensitivity.
[ { "created": "Mon, 16 Sep 2019 18:00:00 GMT", "version": "v1" }, { "created": "Thu, 19 Mar 2020 21:48:16 GMT", "version": "v2" } ]
2020-04-08
[ [ "Bhoonah", "Amit", "" ], [ "Bramante", "Joseph", "" ], [ "Song", "Ningqiang", "" ] ]
We study a new mechanism to discover dark photon fields, by resonantly triggering two photon transitions in cold gas preparations. Using coherently prepared cold parahydrogen, coupling sensitivity for sub-meV mass dark photon fields can be advanced by orders of magnitude, with a modified light-shining-through-wall setup. We calculate the effect of a background dark photon field on the dipole moment and corresponding transition rate of cold parahydrogen pumped into its first vibrational excited state by counter-propagating laser beams. The nonlinear amplification of two photon emission triggered by dark photons in a cold parahydrogen sample is numerically simulated to obtain the expected dark photon coupling sensitivity.
1609.01605
Teppei Kitahara
Teppei Kitahara, Yasuhiro Yamamoto
Protophobic Light Vector Boson as a Mediator to the Dark Sector
7 pages, 7 figures; version published in PRD
Phys. Rev. D 95, 015008 (2017)
10.1103/PhysRevD.95.015008
OU-HET-909, TTP16-036
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observation of a protophobic 16.7 MeV vector boson has been reported by a $^8$Be nuclear transition experiment. Such a new particle could mediate between the Standard Model and a dark sector, which includes the dark matter. In this paper, we show some simple models of the dark matter which satisfy the thermal relic abundance under the current experimental bounds from the direct and the indirect detections. In a model, it is found that an appropriate self-scattering cross section to solve the small scale structure puzzles can be achieved.
[ { "created": "Tue, 6 Sep 2016 15:25:44 GMT", "version": "v1" }, { "created": "Thu, 12 Jan 2017 13:54:36 GMT", "version": "v2" } ]
2017-01-13
[ [ "Kitahara", "Teppei", "" ], [ "Yamamoto", "Yasuhiro", "" ] ]
The observation of a protophobic 16.7 MeV vector boson has been reported by a $^8$Be nuclear transition experiment. Such a new particle could mediate between the Standard Model and a dark sector, which includes the dark matter. In this paper, we show some simple models of the dark matter which satisfy the thermal relic abundance under the current experimental bounds from the direct and the indirect detections. In a model, it is found that an appropriate self-scattering cross section to solve the small scale structure puzzles can be achieved.
hep-ph/0412214
Sven Heinemeyer
S. Heinemeyer, W. Hollik, G. Weiglein
Electroweak Precision Observables in the Minimal Supersymmetric Standard Model
145 pages, lots of figures
Phys.Rept.425:265-368,2006
10.1016/j.physrep.2005.12.002
CERN-PH-TH/2004-224, DCPT/04/162, IPPP/04/81, MPP-2004-145
hep-ph
null
The current status of electroweak precision observables in the Minimal Supersymmetric Standard Model (MSSM) is reviewed. We focus in particular on the $W$ boson mass, M_W, the effective leptonic weak mixing angle, sin^2 theta_eff, the anomalous magnetic moment of the muon, (g-2)_\mu, and the lightest CP-even MSSM Higgs boson mass, m_h. We summarize the current experimental situation and the status of the theoretical evaluations. An estimate of the current theoretical uncertainties from unknown higher-order corrections and from the experimental errors of the input parameters is given. We discuss future prospects for both the experimental accuracies and the precision of the theoretical predictions. Confronting the precision data with the theory predictions within the unconstrained MSSM and within specific SUSY-breaking scenarios, we analyse how well the data are described by the theory. The mSUGRA scenario with cosmological constraints yields a very good fit to the data, showing a clear preference for a relatively light mass scale of the SUSY particles. The constraints on the parameter space from the precision data is discussed, and it is shown that the prospective accuracy at the next generation of colliders will enhance the sensitivity of the precision tests very significantly.
[ { "created": "Wed, 15 Dec 2004 14:59:19 GMT", "version": "v1" } ]
2010-12-16
[ [ "Heinemeyer", "S.", "" ], [ "Hollik", "W.", "" ], [ "Weiglein", "G.", "" ] ]
The current status of electroweak precision observables in the Minimal Supersymmetric Standard Model (MSSM) is reviewed. We focus in particular on the $W$ boson mass, M_W, the effective leptonic weak mixing angle, sin^2 theta_eff, the anomalous magnetic moment of the muon, (g-2)_\mu, and the lightest CP-even MSSM Higgs boson mass, m_h. We summarize the current experimental situation and the status of the theoretical evaluations. An estimate of the current theoretical uncertainties from unknown higher-order corrections and from the experimental errors of the input parameters is given. We discuss future prospects for both the experimental accuracies and the precision of the theoretical predictions. Confronting the precision data with the theory predictions within the unconstrained MSSM and within specific SUSY-breaking scenarios, we analyse how well the data are described by the theory. The mSUGRA scenario with cosmological constraints yields a very good fit to the data, showing a clear preference for a relatively light mass scale of the SUSY particles. The constraints on the parameter space from the precision data is discussed, and it is shown that the prospective accuracy at the next generation of colliders will enhance the sensitivity of the precision tests very significantly.