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1608.06597
Luis Flores
L. J. Flores and O. G. Miranda
Matter neutrino oscillations, an approximation in a parametrization-free framework
6 pages, 2 figures, To be published in Journal of Physics Conference Series (IOP). Joint Proceedings of the XV Mexican Workshop on Particles and Fields & the XXX Annual Meeting of the Division of Particles and Fields of the Mexican Physical Society
null
10.1088/1742-6596/761/1/012041
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino oscillations are one of the most studied and successful phenomena since the establishment of the solar neutrino problem in late 1960's. In this work we discuss the exact expressions for the probability P_{\alpha\beta} in a constant density medium, in terms of the standard vacuum parameters and the medium density. Besides of being compact, these expressions are independent of any particular parametrization, which could be helpful in the application of unitary tests of the mixing matrix. In addition, we introduce a new approximation on P_{\alpha\beta} and compare it with the most commonly used, discussing their main differences.
[ { "created": "Tue, 23 Aug 2016 18:08:40 GMT", "version": "v1" } ]
2016-11-23
[ [ "Flores", "L. J.", "" ], [ "Miranda", "O. G.", "" ] ]
Neutrino oscillations are one of the most studied and successful phenomena since the establishment of the solar neutrino problem in late 1960's. In this work we discuss the exact expressions for the probability P_{\alpha\beta} in a constant density medium, in terms of the standard vacuum parameters and the medium density. Besides of being compact, these expressions are independent of any particular parametrization, which could be helpful in the application of unitary tests of the mixing matrix. In addition, we introduce a new approximation on P_{\alpha\beta} and compare it with the most commonly used, discussing their main differences.
2106.01212
Manuel Masip
Miguel Guti\'errez, Gerardo Hern\'andez-Tom\'e, Jos\'e I. Illana, Manuel Masip
Neutrino events within muon bundles at neutrino telescopes
19 pages, version to appear in Astroparticle Physics
null
10.1016/j.astropartphys.2021.102646
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The atmospheric neutrino flux includes a component from the prompt decay of charmed hadrons that becomes significant only at $E\ge 10$ TeV. At these energies, however, the diffuse flux of cosmic neutrinos discovered by IceCube seems to be larger than the atmospheric one. Here we study the possibility to detect a neutrino interaction in down-going atmospheric events at km$^3$ telescopes. The neutrino signal will always appear together with a muon bundle that reveals its atmospheric origin and, generically, it implies an increase in the detector activity with the slant depth. We propose a simple algorithm that could separate these events from regular muon bundles.
[ { "created": "Wed, 2 Jun 2021 14:59:17 GMT", "version": "v1" }, { "created": "Mon, 6 Sep 2021 08:45:17 GMT", "version": "v2" } ]
2021-09-15
[ [ "Gutiérrez", "Miguel", "" ], [ "Hernández-Tomé", "Gerardo", "" ], [ "Illana", "José I.", "" ], [ "Masip", "Manuel", "" ] ]
The atmospheric neutrino flux includes a component from the prompt decay of charmed hadrons that becomes significant only at $E\ge 10$ TeV. At these energies, however, the diffuse flux of cosmic neutrinos discovered by IceCube seems to be larger than the atmospheric one. Here we study the possibility to detect a neutrino interaction in down-going atmospheric events at km$^3$ telescopes. The neutrino signal will always appear together with a muon bundle that reveals its atmospheric origin and, generically, it implies an increase in the detector activity with the slant depth. We propose a simple algorithm that could separate these events from regular muon bundles.
1103.1627
Fabrizio Nesti
Miha Nemevsek, Fabrizio Nesti, Goran Senjanovi\'c, Yue Zhang
First Limits on Left-Right Symmetry Scale from LHC Data
4 pages, added references
Phys.Rev.D83:115014,2011
10.1103/PhysRevD.83.115014
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the early Large Hadron Collider data to set the lower limit on the scale of Left-Right symmetry, by searching for the right-handed charged gauge boson $W_R$ via the final state with two leptons and two jets, for 33/pb integrated luminosity and 7 TeV center-of-mass energy. In the absence of a signal beyond the Standard Model background, we set the bound M_WR > 1.4 TeV at 95% C.L.. This result is obtained for a range of right-handed neutrino masses of the order of few 100 GeV, assuming no accidental cancelation in right-handed lepton mixings.
[ { "created": "Tue, 8 Mar 2011 20:56:04 GMT", "version": "v1" }, { "created": "Mon, 28 Mar 2011 19:47:56 GMT", "version": "v2" } ]
2011-06-28
[ [ "Nemevsek", "Miha", "" ], [ "Nesti", "Fabrizio", "" ], [ "Senjanović", "Goran", "" ], [ "Zhang", "Yue", "" ] ]
We use the early Large Hadron Collider data to set the lower limit on the scale of Left-Right symmetry, by searching for the right-handed charged gauge boson $W_R$ via the final state with two leptons and two jets, for 33/pb integrated luminosity and 7 TeV center-of-mass energy. In the absence of a signal beyond the Standard Model background, we set the bound M_WR > 1.4 TeV at 95% C.L.. This result is obtained for a range of right-handed neutrino masses of the order of few 100 GeV, assuming no accidental cancelation in right-handed lepton mixings.
hep-ph/0207284
Christopher Smith
Christopher Smith
Very low energy matching of effective meson theories with QCD
6 pages, 2 eps figures
null
null
null
hep-ph
null
A simple matching procedure is proposed to extract constraints on effective meson theories. In this way, a QCD prediction for the pion decay constant is found, F(pi)=2 m(pi)/pi, i.e. approximately 90MeV. The same procedure also determines other mesonic observables, like the decay width of the sigma meson to two photons. Finally, some information which can be gained about the hadronic light-by-light contributions to the muon anomalous moment are briefly commented.
[ { "created": "Tue, 23 Jul 2002 14:59:03 GMT", "version": "v1" } ]
2007-05-23
[ [ "Smith", "Christopher", "" ] ]
A simple matching procedure is proposed to extract constraints on effective meson theories. In this way, a QCD prediction for the pion decay constant is found, F(pi)=2 m(pi)/pi, i.e. approximately 90MeV. The same procedure also determines other mesonic observables, like the decay width of the sigma meson to two photons. Finally, some information which can be gained about the hadronic light-by-light contributions to the muon anomalous moment are briefly commented.
hep-ph/9703449
Vadim Guzey
L.L.Frankfurt (1), A.Freund (2), V.Guzey (2), M. Strikman (2)((1) Physics Department, Tel-Aviv University, (2) Department of Physics, Penn State University)
Nondiagonal Parton Distributions in the Leading Logarithmic Approximation
20 pages, RevTex. Final version with updated figures. Published in Phys. Lett. B
Phys.Lett.B418:345-354,1998; Erratum-ibid.B429:414,1998
10.1016/S0370-2693(97)01152-0
null
hep-ph
null
In this paper we make predictions for nondiagonal parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA, solve the nondiagonal GLAP evolution equations with a modified version of the CTEQ-package and comment on the range of applicability of the LLA in the asymmetric regime. We show that the nondiagonal gluon distribution $g(x_{1},x_{2},t,\mu^2)$ can be well approximated at small $x$ by the conventional gluon density $xG(x,\mu^2)$. Keywords: Hard Diffractive Scattering, Nondiagonal distributions, Evolution
[ { "created": "Fri, 28 Mar 1997 07:05:31 GMT", "version": "v1" }, { "created": "Thu, 10 Apr 1997 12:46:36 GMT", "version": "v2" }, { "created": "Tue, 14 Oct 1997 03:22:16 GMT", "version": "v3" }, { "created": "Mon, 27 Oct 1997 03:06:20 GMT", "version": "v4" }, { "c...
2014-11-17
[ [ "Frankfurt", "L. L.", "" ], [ "Freund", "A.", "" ], [ "Guzey", "V.", "" ], [ "Strikman", "M.", "" ] ]
In this paper we make predictions for nondiagonal parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA, solve the nondiagonal GLAP evolution equations with a modified version of the CTEQ-package and comment on the range of applicability of the LLA in the asymmetric regime. We show that the nondiagonal gluon distribution $g(x_{1},x_{2},t,\mu^2)$ can be well approximated at small $x$ by the conventional gluon density $xG(x,\mu^2)$. Keywords: Hard Diffractive Scattering, Nondiagonal distributions, Evolution
1207.4358
Ruben Sandapen
J. R. Forshaw and R. Sandapen
An AdS/QCD holographic wavefunction for the rho meson
4 pages, 3 figures, to appear in the Proceedings of 20th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2012), Bonn, Germany, 26-30 March 2012
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use an AdS/QCD holographic wavefunction to generate predictions for the rate of diffractive {\rho}-meson electroproduction that are in reasonable agreement with data collected at the HERA electron-proton collider.
[ { "created": "Wed, 18 Jul 2012 12:36:20 GMT", "version": "v1" } ]
2012-07-19
[ [ "Forshaw", "J. R.", "" ], [ "Sandapen", "R.", "" ] ]
We use an AdS/QCD holographic wavefunction to generate predictions for the rate of diffractive {\rho}-meson electroproduction that are in reasonable agreement with data collected at the HERA electron-proton collider.
0710.3819
Marina-Aura Dariescu
Ciprian Dariescu and Marina-Aura Dariescu
B \to K^{*} \gamma Decay within MSSM
7 pages, 3 figures, International Conference on Hadron Physics TROIA'07, Canakkale, Turkey, 30 August -- 03 September 2007
null
null
null
hep-ph
null
The paper deals with a next-to-leading order analysis of the radiative $B \to K^* \gamma$ decay. Working in a PQCD approach, we compute the correction to the essential form factor, coming from a single gluon exchange with the spectator. We investigate the supersymmetry effects on the branching ratio and direct CP asymmetry and constrain the squark mixing parameter $(\delta_{23}^d)_{LR}$.
[ { "created": "Sat, 20 Oct 2007 06:08:22 GMT", "version": "v1" } ]
2007-10-23
[ [ "Dariescu", "Ciprian", "" ], [ "Dariescu", "Marina-Aura", "" ] ]
The paper deals with a next-to-leading order analysis of the radiative $B \to K^* \gamma$ decay. Working in a PQCD approach, we compute the correction to the essential form factor, coming from a single gluon exchange with the spectator. We investigate the supersymmetry effects on the branching ratio and direct CP asymmetry and constrain the squark mixing parameter $(\delta_{23}^d)_{LR}$.
hep-ph/0305026
Thomas Dent
Thomas Dent (Aristotle University of Thessaloniki)
Varying alpha, thresholds and extra dimensions
24 pages, minor edits, slight change in observational numbers from Murphy et al., added remarks on long-range forces
null
10.1016/j.nuclphysb.2003.10.047
UT-STPD-2-03
hep-ph astro-ph gr-qc hep-th
null
We consider variations of coupling strengths and mass ratios in and beyond the Standard Model, in the light of various mechanisms of mass generation. In four-dimensional unified models, heavy quark and superparticle thresholds and the electron mass can completely alter the (testable) relation between Delta ln alpha and Delta ln mu, where mu \equiv m_p/m_e. In extra-dimensional models where a compactification scale below the fundamental scale is varying, definite predictions may result even without unification; we examine some models with Scherk-Schwarz supersymmetry-breaking.
[ { "created": "Fri, 2 May 2003 19:57:41 GMT", "version": "v1" }, { "created": "Tue, 26 Aug 2003 20:51:16 GMT", "version": "v2" } ]
2015-06-25
[ [ "Dent", "Thomas", "", "Aristotle University of Thessaloniki" ] ]
We consider variations of coupling strengths and mass ratios in and beyond the Standard Model, in the light of various mechanisms of mass generation. In four-dimensional unified models, heavy quark and superparticle thresholds and the electron mass can completely alter the (testable) relation between Delta ln alpha and Delta ln mu, where mu \equiv m_p/m_e. In extra-dimensional models where a compactification scale below the fundamental scale is varying, definite predictions may result even without unification; we examine some models with Scherk-Schwarz supersymmetry-breaking.
0812.1212
Dmitri Diakonov
Dmitri Diakonov and Victor Petrov (St. Petersburg NPI)
Exotic baryon resonances in the Skyrme model
Contributed to "The Multi-facet of Skyrmions" edited by G. Brown and M. Rho for World Scientific Publishing Co, 33 p
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We outline how one can understand the Skyrme model from the modern perspective. We review the quantization of the SU(3) rotations of the Skyrmion, leading to the exotic baryons that cannot be made of three quarks. It is shown that in the limit of large number of colours the lowest-mass exotic baryons can be studied from the kaon-Skyrmion scattering amplitudes, an approach known after Callan and Klebanov. We follow this approach and find, both analytically and numerically, a strong Theta+ resonance in the scattering amplitude that is traced to the rotational mode. The Skyrme model does predict an exotic resonance Theta+ but grossly overestimates the width. To understand better the factors affecting the width, it is computed by several methods giving, however, identical results. In particular, we show that insofar as the width is small, it can be found from the transition axial constant. The physics leading to a narrow Theta+ resonance is briefly reviewed and affirmed.
[ { "created": "Fri, 5 Dec 2008 20:38:24 GMT", "version": "v1" } ]
2008-12-08
[ [ "Diakonov", "Dmitri", "", "St. Petersburg NPI" ], [ "Petrov", "Victor", "", "St. Petersburg NPI" ] ]
We outline how one can understand the Skyrme model from the modern perspective. We review the quantization of the SU(3) rotations of the Skyrmion, leading to the exotic baryons that cannot be made of three quarks. It is shown that in the limit of large number of colours the lowest-mass exotic baryons can be studied from the kaon-Skyrmion scattering amplitudes, an approach known after Callan and Klebanov. We follow this approach and find, both analytically and numerically, a strong Theta+ resonance in the scattering amplitude that is traced to the rotational mode. The Skyrme model does predict an exotic resonance Theta+ but grossly overestimates the width. To understand better the factors affecting the width, it is computed by several methods giving, however, identical results. In particular, we show that insofar as the width is small, it can be found from the transition axial constant. The physics leading to a narrow Theta+ resonance is briefly reviewed and affirmed.
1401.5609
Zhao-Feng Kang
Jun Guo and Zhaofeng Kang
Higgs Naturalness and Dark Matter Stability by Scale Invariance
Journal version, with a major revision. Discussions on phenomenologies of scale invariant 2HDM+S are substantially changed
null
10.1016/j.nuclphysb.2015.07.014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Extending the spacetime symmetries of standard model (SM) by scale invariance (SI) may address the Higgs naturalness problem. In this article we attempt to embed accidental dark matter (DM) into SISM, requiring that the symmetry protecting DM stability is accidental due to the model structure rather than imposed by hand. In this framework, if the light SM-like Higgs boson is the pseudo Goldstone boson of SI spontaneously breaking, we can even pine down the model, two-Higgs-doublets plus a real singlet: The singlet is the DM candidate and the extra Higgs doublet triggers electroweak symmetry breaking via the Coleman-Weinberg mechanism; Moreover, it dominates DM dynamics. We study spontaneously breaking of SI using the Gillard-Weinberg approach and find that the second doublet should acquire vacuum expectation value near the weak scale. Moreover, its components should acquire masses around 380 GeV except for a light CP-odd Higgs boson. Based on these features, we explore viable ways to achieve the correct relic density of DM, facing stringent constraints from direct detections of DM. For instance, DM annihilates into $b\bar b$ near the SM-like Higgs boson pole, or into a pair of CP-odd Higgs boson with mass above that pole.
[ { "created": "Wed, 22 Jan 2014 10:10:21 GMT", "version": "v1" }, { "created": "Mon, 31 Mar 2014 13:29:49 GMT", "version": "v2" }, { "created": "Fri, 7 Aug 2015 15:11:33 GMT", "version": "v3" } ]
2015-12-09
[ [ "Guo", "Jun", "" ], [ "Kang", "Zhaofeng", "" ] ]
Extending the spacetime symmetries of standard model (SM) by scale invariance (SI) may address the Higgs naturalness problem. In this article we attempt to embed accidental dark matter (DM) into SISM, requiring that the symmetry protecting DM stability is accidental due to the model structure rather than imposed by hand. In this framework, if the light SM-like Higgs boson is the pseudo Goldstone boson of SI spontaneously breaking, we can even pine down the model, two-Higgs-doublets plus a real singlet: The singlet is the DM candidate and the extra Higgs doublet triggers electroweak symmetry breaking via the Coleman-Weinberg mechanism; Moreover, it dominates DM dynamics. We study spontaneously breaking of SI using the Gillard-Weinberg approach and find that the second doublet should acquire vacuum expectation value near the weak scale. Moreover, its components should acquire masses around 380 GeV except for a light CP-odd Higgs boson. Based on these features, we explore viable ways to achieve the correct relic density of DM, facing stringent constraints from direct detections of DM. For instance, DM annihilates into $b\bar b$ near the SM-like Higgs boson pole, or into a pair of CP-odd Higgs boson with mass above that pole.
2207.03767
Jiaqi Chen
Jiaqi Chen, Bo Feng
Module Intersection and Uniform Formula for Iterative Reduction of One-loop Integrals
20 pages
null
10.1007/JHEP02(2023)178
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper, we develop an iterative sector-level reduction strategy for Feynman integrals, which bases on module intersection in the Baikov representation and auxiliary vector for tensor structure. Using this strategy we have studied the reduction of general one-loop integrals, i.e., integrals having arbitrary tensor structures and arbitrary power for propagators. Inspired by these studies, a uniform and compact formula that iteratively reduces all one-loop integrals has been written down, where messy polynomials in integration-by-parts (IBP) relations have organized themselves to Gram determinants.
[ { "created": "Fri, 8 Jul 2022 09:14:47 GMT", "version": "v1" } ]
2023-03-22
[ [ "Chen", "Jiaqi", "" ], [ "Feng", "Bo", "" ] ]
In this paper, we develop an iterative sector-level reduction strategy for Feynman integrals, which bases on module intersection in the Baikov representation and auxiliary vector for tensor structure. Using this strategy we have studied the reduction of general one-loop integrals, i.e., integrals having arbitrary tensor structures and arbitrary power for propagators. Inspired by these studies, a uniform and compact formula that iteratively reduces all one-loop integrals has been written down, where messy polynomials in integration-by-parts (IBP) relations have organized themselves to Gram determinants.
0806.3450
Marc Gillioz
Marc Gillioz
One light composite Higgs boson facing electroweak precision tests
15 pages, 4 figures; v2: figures and discussion improved, references added; v3: minor changes, final version to appear in PRD
Phys.Rev.D80:055003,2009
10.1103/PhysRevD.80.055003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study analytically and numerically the bounds imposed by the electroweak precision tests on a minimal composite Higgs model. The model is based on spontaneous SO(5)/SO(4) breaking, so that an approximate custodial symmetry is preserved. The Higgs arises as a pseudo-Goldstone boson at a scale below the electroweak symmetry breaking scale. We show that one can satisfy the electroweak precision constraints without much fine-tuning. This is the case if the left-handed top quark is fully composite, which gives a mass spectrum within the reach of the LHC. However a composite top quark is strongly disfavoured by flavour physics. The alternative is to have a singlet top partner at a scale much lighter than the rest of the composite fermions. In this case the top partner would be light enough to be produced significantly at the LHC.
[ { "created": "Fri, 20 Jun 2008 19:55:03 GMT", "version": "v1" }, { "created": "Fri, 28 Nov 2008 13:00:36 GMT", "version": "v2" }, { "created": "Fri, 10 Jul 2009 11:20:52 GMT", "version": "v3" } ]
2010-04-30
[ [ "Gillioz", "Marc", "" ] ]
We study analytically and numerically the bounds imposed by the electroweak precision tests on a minimal composite Higgs model. The model is based on spontaneous SO(5)/SO(4) breaking, so that an approximate custodial symmetry is preserved. The Higgs arises as a pseudo-Goldstone boson at a scale below the electroweak symmetry breaking scale. We show that one can satisfy the electroweak precision constraints without much fine-tuning. This is the case if the left-handed top quark is fully composite, which gives a mass spectrum within the reach of the LHC. However a composite top quark is strongly disfavoured by flavour physics. The alternative is to have a singlet top partner at a scale much lighter than the rest of the composite fermions. In this case the top partner would be light enough to be produced significantly at the LHC.
hep-ph/9308330
null
Duane A. Dicus and Chung Kao
Production of $Z$ Boson Pairs at Photon Linear Colliders
18 pages in REVTEX, Figures available upon request, DOE-ER40757-024,CPP-93-24 and FSU-HEP-930808
Phys.Rev. D49 (1994) 1265-1271
10.1103/PhysRevD.49.1265
null
hep-ph
null
The $ZZ$ pair production rate in high energy $\gamma \gamma$ collisions is evaluated with photons from laser backscattering. We find that searching for the Standard Model Higgs boson with a mass up to, or slightly larger than, 400 GeV via the $ZZ$ final state is possible via photon fusion with backscattered laser photons at a linear $e^+e^-$ collider with energies in the range 600 GeV $< \sqrt{s_{e^+e^-}} <$ 1000 GeV.
[ { "created": "Tue, 24 Aug 1993 18:50:41 GMT", "version": "v1" } ]
2009-10-22
[ [ "Dicus", "Duane A.", "" ], [ "Kao", "Chung", "" ] ]
The $ZZ$ pair production rate in high energy $\gamma \gamma$ collisions is evaluated with photons from laser backscattering. We find that searching for the Standard Model Higgs boson with a mass up to, or slightly larger than, 400 GeV via the $ZZ$ final state is possible via photon fusion with backscattered laser photons at a linear $e^+e^-$ collider with energies in the range 600 GeV $< \sqrt{s_{e^+e^-}} <$ 1000 GeV.
0806.3875
Markos Maniatis
A. Brandenburg, M. Maniatis, M.M. Weber, Peter M. Zerwas
Squarks and gluinos at a TeV e+e- collider: Testing the identity of Yukawa and gauge couplings in SUSY-QCD
14 pages, 13 figures
Eur.Phys.J.C58:291-300,2008
10.1140/epjc/s10052-008-0770-8
DESY 08-076, HD-THEP-08-13, PITHA 08/12
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supersymmetry predicts the identity of Yukawa and gauge couplings in the QCD sector: quark-squark-gluino = squark-squark-gluon = quark-quark-gluon. We examine whether the quark-squark-gluino Yukawa coupling can be determined, by methods complementary to LHC, by analyzing squark-gluino final states at a TeV e+e- collider.
[ { "created": "Tue, 24 Jun 2008 16:20:35 GMT", "version": "v1" } ]
2008-12-18
[ [ "Brandenburg", "A.", "" ], [ "Maniatis", "M.", "" ], [ "Weber", "M. M.", "" ], [ "Zerwas", "Peter M.", "" ] ]
Supersymmetry predicts the identity of Yukawa and gauge couplings in the QCD sector: quark-squark-gluino = squark-squark-gluon = quark-quark-gluon. We examine whether the quark-squark-gluino Yukawa coupling can be determined, by methods complementary to LHC, by analyzing squark-gluino final states at a TeV e+e- collider.
hep-ph/9603386
D. R. T. Jones
I. Jack, D.R.T. Jones and C.G. North
$N=1$ supersymmetry and the three loop anomalous dimension for the chiral superfield
18 pages. Uses Harvmac. Revised version includes discussion of the special case of the Wess-Zumino model
Nucl.Phys.B473:308-322,1996
10.1016/0550-3213(96)00269-6
LTH 368
hep-ph hep-th
null
We calculate the three loop anomalous dimension for a general $N=1$ supersymmetric gauge theory. The result is used to probe the possible existence of renormalisation invariant relationships between the Yukawa and gauge couplings.
[ { "created": "Fri, 22 Mar 1996 14:53:12 GMT", "version": "v1" }, { "created": "Wed, 3 Apr 1996 14:22:53 GMT", "version": "v2" } ]
2008-11-26
[ [ "Jack", "I.", "" ], [ "Jones", "D. R. T.", "" ], [ "North", "C. G.", "" ] ]
We calculate the three loop anomalous dimension for a general $N=1$ supersymmetric gauge theory. The result is used to probe the possible existence of renormalisation invariant relationships between the Yukawa and gauge couplings.
1412.3589
Monika Blanke
Monika Blanke
Flavoured Dark Matter Beyond MFV
proceedings of Flavorful Ways to New Physics - FWNP, 28-31 October 2014, Freudenstadt - Lauterbad, Germany
null
null
CERN-PH-TH-2014-257, TTP14-037
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review a model of quark flavoured dark matter with new flavour violating interactions. This simplified model describes Dirac fermionic dark matter that is charged under a new U(3) flavour symmetry and couples to right-handed down quarks via a scalar mediator. The corresponding coupling matrix is assumed to be the only new source of flavour violation, which we refer to as the Dark Minimal Flavour Violation (DMFV) hypothesis. This ansatz ensures the stability of dark matter. We discuss the phenomenology of the simplest DMFV model in flavour violating observables, LHC searches, and direct dark matter detection experiments. Especially interesting is the non-trivial interplay between the constraints from the different sectors.
[ { "created": "Thu, 11 Dec 2014 10:08:46 GMT", "version": "v1" } ]
2014-12-12
[ [ "Blanke", "Monika", "" ] ]
We review a model of quark flavoured dark matter with new flavour violating interactions. This simplified model describes Dirac fermionic dark matter that is charged under a new U(3) flavour symmetry and couples to right-handed down quarks via a scalar mediator. The corresponding coupling matrix is assumed to be the only new source of flavour violation, which we refer to as the Dark Minimal Flavour Violation (DMFV) hypothesis. This ansatz ensures the stability of dark matter. We discuss the phenomenology of the simplest DMFV model in flavour violating observables, LHC searches, and direct dark matter detection experiments. Especially interesting is the non-trivial interplay between the constraints from the different sectors.
2405.02619
Zhen-Hua Zhang
Zhao-Sai Jia, Gang Li, Pan-Pan Shi, and Zhen-Hua Zhang
Production of hidden-heavy and double-heavy hadronic molecules at the $Z$ factory of CEPC
24 pages, 10 figures, published version
Phys. Rev. D 110 (2024) 014031
10.1103/PhysRevD.110.014031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With a clean environment and high collision energy, the Circular Electron Positron Collider (CEPC) would be an excellent facility for heavy flavor physics. Using the Monte Carlo event generator Pythia, we simulate the production of the charmed (bottom) hadron pairs in the electron-positron collisions at the $Z$ factory of CEPC, and the inclusive production rates for typical candidates of the hidden/double-charm and hidden/double-bottom $S$-wave hadronic molecules are estimated at an order-of-magnitude level with the final state interactions after the hadron pair production. The predicted cross sections for the hidden-charm meson-meson molecules $X(3872)$ and $Z_c(3900)$ are at $\rm{pb}$ level, which are about two to three orders of magnitude larger than the production cross sections for the double-charm meson-meson molecules $T_{cc}$ and $T_{cc}^{*}$, as the double-charmed ones require the production of two pairs of $c\bar{c}$ from the $Z$ boson decay. The production cross sections for the hidden-charm pentaquark states $P_{c}$ and $P_{cs}$ as meson-baryon molecules are a few to tens of fb, which are about one magnitude larger than those of the possible hidden-charm baryon-antibaryon and double-charm meson-baryon molecules. In the bottom sector, the production cross sections for the $Z_b$ states as $B^{(*)}\bar{B}^{*}$ molecules are about tens to hundreds of fb, indicating $10^6$ - $10^7$ events from a two-year operation of CEPC, and the expected events from the double-bottom molecules are about 2 - 5 orders of magnitude smaller than the $Z_b$ states. Our results shows great prospects of probing heavy exotic hadrons at CEPC.
[ { "created": "Sat, 4 May 2024 09:35:13 GMT", "version": "v1" }, { "created": "Fri, 9 Aug 2024 04:26:55 GMT", "version": "v2" } ]
2024-08-12
[ [ "Jia", "Zhao-Sai", "" ], [ "Li", "Gang", "" ], [ "Shi", "Pan-Pan", "" ], [ "Zhang", "Zhen-Hua", "" ] ]
With a clean environment and high collision energy, the Circular Electron Positron Collider (CEPC) would be an excellent facility for heavy flavor physics. Using the Monte Carlo event generator Pythia, we simulate the production of the charmed (bottom) hadron pairs in the electron-positron collisions at the $Z$ factory of CEPC, and the inclusive production rates for typical candidates of the hidden/double-charm and hidden/double-bottom $S$-wave hadronic molecules are estimated at an order-of-magnitude level with the final state interactions after the hadron pair production. The predicted cross sections for the hidden-charm meson-meson molecules $X(3872)$ and $Z_c(3900)$ are at $\rm{pb}$ level, which are about two to three orders of magnitude larger than the production cross sections for the double-charm meson-meson molecules $T_{cc}$ and $T_{cc}^{*}$, as the double-charmed ones require the production of two pairs of $c\bar{c}$ from the $Z$ boson decay. The production cross sections for the hidden-charm pentaquark states $P_{c}$ and $P_{cs}$ as meson-baryon molecules are a few to tens of fb, which are about one magnitude larger than those of the possible hidden-charm baryon-antibaryon and double-charm meson-baryon molecules. In the bottom sector, the production cross sections for the $Z_b$ states as $B^{(*)}\bar{B}^{*}$ molecules are about tens to hundreds of fb, indicating $10^6$ - $10^7$ events from a two-year operation of CEPC, and the expected events from the double-bottom molecules are about 2 - 5 orders of magnitude smaller than the $Z_b$ states. Our results shows great prospects of probing heavy exotic hadrons at CEPC.
hep-ph/0404093
Shunzo Kumano
M. Hirai (RIKEN), S. Kumano and T.-H. Nagai (Saga University)
Nuclear parton distribution functions and their uncertainties
9 pages, REVTeX, 23 eps files, Phys. Rev. C in press. Nuclear PDF library is available at http://hs.phys.saga-u.ac.jp/nuclp.html
Phys.Rev.C70:044905,2004
10.1103/PhysRevC.70.044905
SAGA-HE-197-04
hep-ph hep-ex nucl-ex nucl-th
null
We analyze experimental data of nuclear structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross section ratios for obtaining optimum parton distribution functions (PDFs) in nuclei. Then, uncertainties of the nuclear PDFs are estimated by the Hessian method. Valence-quark distributions are determined by the F_2 data at large x; however, the small-x part is not obvious from the data. On the other hand, the antiquark distributions are determined well at x~0.01 from the F_2 data and at x~0.1 by the Drell-Yan data; however, the large-x behavior is not clear. Gluon distributions cannot be fixed by the present data and they have large uncertainties in the whole x region. Parametrization results are shown in comparison with the data. We provide a useful code for calculating nuclear PDFs at given x and Q^2.
[ { "created": "Fri, 9 Apr 2004 15:06:09 GMT", "version": "v1" }, { "created": "Thu, 15 Jul 2004 01:03:48 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hirai", "M.", "", "RIKEN" ], [ "Kumano", "S.", "", "Saga University" ], [ "Nagai", "T. -H.", "", "Saga University" ] ]
We analyze experimental data of nuclear structure-function ratios F_2^A/F_2^{A'} and Drell-Yan cross section ratios for obtaining optimum parton distribution functions (PDFs) in nuclei. Then, uncertainties of the nuclear PDFs are estimated by the Hessian method. Valence-quark distributions are determined by the F_2 data at large x; however, the small-x part is not obvious from the data. On the other hand, the antiquark distributions are determined well at x~0.01 from the F_2 data and at x~0.1 by the Drell-Yan data; however, the large-x behavior is not clear. Gluon distributions cannot be fixed by the present data and they have large uncertainties in the whole x region. Parametrization results are shown in comparison with the data. We provide a useful code for calculating nuclear PDFs at given x and Q^2.
1209.5798
Alexander Mitov
Alexander Mitov and George Sterman
Final state interactions in single- and multi-particle inclusive cross sections for hadronic collisions
18 pages, 6 figures
null
10.1103/PhysRevD.86.114038
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the role of low momentum transfer (soft) interactions between high-transverse momentum heavy particles and beam remnants (spectators) in hadronic collisions. Such final-state interactions are power suppressed for single-particle inclusive cross sections whenever that particle is accompanied by a recoiling high-p_T partner whose momentum is not fixed. An example is the single-top inclusive cross section in top pair production. Final-state soft interactions in multi-particle inclusive cross sections, including transverse momentum distributions, however, produce leading power corrections in the absence of hard recoiling radiation. Nonperturbative corrections due to scattering from spectators are generically suppressed by powers of \Lambda/p'_T, where \Lambda is a hadronic scale, and p'_T is the largest transverse momentum of radiation recoiling against the particles whose momenta are observed.
[ { "created": "Wed, 26 Sep 2012 00:06:15 GMT", "version": "v1" } ]
2013-05-30
[ [ "Mitov", "Alexander", "" ], [ "Sterman", "George", "" ] ]
We study the role of low momentum transfer (soft) interactions between high-transverse momentum heavy particles and beam remnants (spectators) in hadronic collisions. Such final-state interactions are power suppressed for single-particle inclusive cross sections whenever that particle is accompanied by a recoiling high-p_T partner whose momentum is not fixed. An example is the single-top inclusive cross section in top pair production. Final-state soft interactions in multi-particle inclusive cross sections, including transverse momentum distributions, however, produce leading power corrections in the absence of hard recoiling radiation. Nonperturbative corrections due to scattering from spectators are generically suppressed by powers of \Lambda/p'_T, where \Lambda is a hadronic scale, and p'_T is the largest transverse momentum of radiation recoiling against the particles whose momenta are observed.
0811.2211
Andrea Wulzer Dr
Giuliano Panico, Andrea Wulzer
Nucleon Form Factors from 5D Skyrmions
30 pages, 6 figures; v2: References added and typos corrected; v3: Version published in Nucl. Phys. A
Nucl.Phys.A825:91-114,2009
10.1016/j.nuclphysa.2009.04.004
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Several aspects of hadron physics are well described by a simple 5D effective field theory. Baryons arise in this scenario as "large" (and therefore calculable) 5D skyrmions. We extend and refine the existing analysis of this 5D soliton, which is fairly non-trivial due to the need of numerical methods. We perform the complete quantization of those collective coordinates which are relevant for computing the static observables like the nucleon form factors. We compare the result with simple expectations about large-N_c QCD and with the experimental data. An agreement within 30% is found.
[ { "created": "Thu, 13 Nov 2008 20:27:28 GMT", "version": "v1" }, { "created": "Thu, 8 Jan 2009 15:47:56 GMT", "version": "v2" }, { "created": "Sat, 16 May 2009 12:16:40 GMT", "version": "v3" } ]
2010-04-15
[ [ "Panico", "Giuliano", "" ], [ "Wulzer", "Andrea", "" ] ]
Several aspects of hadron physics are well described by a simple 5D effective field theory. Baryons arise in this scenario as "large" (and therefore calculable) 5D skyrmions. We extend and refine the existing analysis of this 5D soliton, which is fairly non-trivial due to the need of numerical methods. We perform the complete quantization of those collective coordinates which are relevant for computing the static observables like the nucleon form factors. We compare the result with simple expectations about large-N_c QCD and with the experimental data. An agreement within 30% is found.
2111.13916
Dimitri Colferai Prof
Dimitri Colferai
Is BFKL factorization valid for Mueller-Tang jets?
8 pages, 10 figures, proceedings of the conference Low-x 2021
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The perturbative QCD description of high-energy hadroproduction of two hard jets separated by a large rapidity gap void of emission (also called Mueller-Tang jets) is based on a factorization formula of BFKL type that represents exchanges of colour-singlet objects among the external particles. This formula resums to all perturbative orders a certain class of Feynman diagrams that are supposed to dominate the cross-section in the Regge limit. However, the explicit calculations at next-to-leading logarithmic order questions the validity of such factorization when an IR safe jet algorithm is used to reconstruct jets. We show the origin of such violation of factorization, and quantify its impact for LHC phenomenology. In this connection, we estimate the impact of other contributions to the cross-section that are not included in the Mueller-Tang factorization formula -- colour non-singlet exchanges -- that, at low rapidity separation, compete with the singlet ones.
[ { "created": "Sat, 27 Nov 2021 14:54:02 GMT", "version": "v1" } ]
2021-11-30
[ [ "Colferai", "Dimitri", "" ] ]
The perturbative QCD description of high-energy hadroproduction of two hard jets separated by a large rapidity gap void of emission (also called Mueller-Tang jets) is based on a factorization formula of BFKL type that represents exchanges of colour-singlet objects among the external particles. This formula resums to all perturbative orders a certain class of Feynman diagrams that are supposed to dominate the cross-section in the Regge limit. However, the explicit calculations at next-to-leading logarithmic order questions the validity of such factorization when an IR safe jet algorithm is used to reconstruct jets. We show the origin of such violation of factorization, and quantify its impact for LHC phenomenology. In this connection, we estimate the impact of other contributions to the cross-section that are not included in the Mueller-Tang factorization formula -- colour non-singlet exchanges -- that, at low rapidity separation, compete with the singlet ones.
hep-ph/0311278
Krzysztof Golec-Biernat
K. Golec-Biernat
Saturation and Diffractive DIS
6 pages, presented at the XXXIII International Symposium on Multiparticle Dynamics, Krakow, Poland, 5-11 September 2003
ActaPhys.Polon.B35:497-502,2004
null
null
hep-ph
null
We review QCD based descriptions of diffractive deep inelastic scattering emphasizing the role of models with parton saturation. These models provide natural explanation of such experimentally observed facts as the constant ratio of diffractive and total DIS cross sections as a function of the Bjorken variable x and Regge factorization of diffractive parton distributions.
[ { "created": "Fri, 21 Nov 2003 20:44:31 GMT", "version": "v1" }, { "created": "Sat, 22 Nov 2003 19:26:09 GMT", "version": "v2" } ]
2008-11-26
[ [ "Golec-Biernat", "K.", "" ] ]
We review QCD based descriptions of diffractive deep inelastic scattering emphasizing the role of models with parton saturation. These models provide natural explanation of such experimentally observed facts as the constant ratio of diffractive and total DIS cross sections as a function of the Bjorken variable x and Regge factorization of diffractive parton distributions.
hep-ph/0011364
Abdelhak Djouadi
A. Djouadi and Y. Mambrini (LPMT Montpellier)
Three-Body Decays of Top and Bottom Squarks
24 pages with 4 psfigures, latex
Phys.Rev.D63:115005,2001
10.1103/PhysRevD.63.115005
PM/00-41
hep-ph
null
We investigate the decays of third generation scalar quarks in the Minimal Supersymmetric extension of the Standard Model, focusing on the three-body modes. We calculate the partial widths of the decays of heavier top and bottom squarks into the lighter ones and a fermion pair [through virtual vector boson, Higgs boson or gaugino exchanges] and the partial widths of the three-body decays of both top squarks into bottom quarks and a pair of fermion and scalar fermion [we consider the case of lighter $\tilde{\tau}$ or $\tilde{b}$ states] and into a bottom quark, the lightest neutralino and a $W$ or a charged Higgs boson $H^\pm$. Some of these decay modes are shown to have substantial branching ratios in some areas of the parameter space.
[ { "created": "Wed, 29 Nov 2000 14:56:03 GMT", "version": "v1" } ]
2011-01-27
[ [ "Djouadi", "A.", "", "LPMT Montpellier" ], [ "Mambrini", "Y.", "", "LPMT Montpellier" ] ]
We investigate the decays of third generation scalar quarks in the Minimal Supersymmetric extension of the Standard Model, focusing on the three-body modes. We calculate the partial widths of the decays of heavier top and bottom squarks into the lighter ones and a fermion pair [through virtual vector boson, Higgs boson or gaugino exchanges] and the partial widths of the three-body decays of both top squarks into bottom quarks and a pair of fermion and scalar fermion [we consider the case of lighter $\tilde{\tau}$ or $\tilde{b}$ states] and into a bottom quark, the lightest neutralino and a $W$ or a charged Higgs boson $H^\pm$. Some of these decay modes are shown to have substantial branching ratios in some areas of the parameter space.
hep-ph/0101310
Gerasyuta
S.M. Gerasyuta, D.V. Ivanov
Charmed baryons in bootstrap quark model
21 pages, LaTeX
Nuovo Cim. A112 (1999) 261-276
10.1007/BF03035848
null
hep-ph
null
In the framework of dispersion relation technique the relativistic three-quark equations including heavy quarks are found. The approximate solutions of the relativistic three-particles equations based on the extraction of leading singularities of amplitudes are obtained. The mass values of S-wave multiplets of charmed baryons are calculated.
[ { "created": "Sun, 28 Jan 2001 18:06:03 GMT", "version": "v1" } ]
2009-11-07
[ [ "Gerasyuta", "S. M.", "" ], [ "Ivanov", "D. V.", "" ] ]
In the framework of dispersion relation technique the relativistic three-quark equations including heavy quarks are found. The approximate solutions of the relativistic three-particles equations based on the extraction of leading singularities of amplitudes are obtained. The mass values of S-wave multiplets of charmed baryons are calculated.
1611.08115
Samuel Wallon
R. Boussarie, B. Pire, L.Szymanowski, S. Wallon
Accessing Generalized Parton Distributions in Exclusive Photoproduction of a $\gamma \rho$ Pair with a Large Invariant Mass
4 pages, 4 figures, proceedings of "Diffraction 2016", International Workshop on Diffraction in High-Energy Physics, Acireale (Catania, Sicily), Sept. 2-8, 2016; to be published in the conference proceedings by AIP. arXiv admin note: substantial text overlap with arXiv:1609.05144
null
10.1063/1.4977164
CPHT-PC051.112016, LPT-Orsay-16-80
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose and study the photoproduction of a $\gamma\,\rho$ pair with a large invariant mass and a small transverse momentum of the final nucleon, as a way to access generalized parton distributions. In the kinematics of JLab 12-GeV, we demonstrate the feasibility of this measurement.
[ { "created": "Thu, 24 Nov 2016 09:35:29 GMT", "version": "v1" } ]
2017-04-05
[ [ "Boussarie", "R.", "" ], [ "Pire", "B.", "" ], [ "Szymanowski", "L.", "" ], [ "Wallon", "S.", "" ] ]
We propose and study the photoproduction of a $\gamma\,\rho$ pair with a large invariant mass and a small transverse momentum of the final nucleon, as a way to access generalized parton distributions. In the kinematics of JLab 12-GeV, we demonstrate the feasibility of this measurement.
2208.14608
Takuma Nishibuchi
Takuma Nishibuchi and Tetsuo Hyodo
Nature of excited $\Xi$ baryons with threshold effects
4 pages, Proceedings of the 14th International Conference on Hypernuclear and Strange Particle Physics (HYP2022), 27 June to 1 July 2022. v2: modified the right panel of the figure2
null
10.1051/epjconf/202227110002
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Spectroscopy of excited baryons with strangeness $S=-2$ is stimulated by recent experimental developments. Here we focus on the $\Xi(1620)$ which locates close to the $\bar{K}\Lambda$ threshold. To take into account the threshold effects, we construct the coupled-channels meson-baryon scattering amplitude where the $\Xi(1620)$ appears as a resonance. We demonstrate that the $\bar{K}\Lambda$ threshold effects distort the peak of the $\Xi(1620)$ resonance from the simple Breit-Wigner distribution.
[ { "created": "Wed, 31 Aug 2022 03:02:25 GMT", "version": "v1" }, { "created": "Fri, 14 Oct 2022 01:18:10 GMT", "version": "v2" } ]
2022-11-30
[ [ "Nishibuchi", "Takuma", "" ], [ "Hyodo", "Tetsuo", "" ] ]
Spectroscopy of excited baryons with strangeness $S=-2$ is stimulated by recent experimental developments. Here we focus on the $\Xi(1620)$ which locates close to the $\bar{K}\Lambda$ threshold. To take into account the threshold effects, we construct the coupled-channels meson-baryon scattering amplitude where the $\Xi(1620)$ appears as a resonance. We demonstrate that the $\bar{K}\Lambda$ threshold effects distort the peak of the $\Xi(1620)$ resonance from the simple Breit-Wigner distribution.
1003.1070
Shinya Matsuzaki
M.Harada, S.Matsuzaki, and K.Yamawaki
Integrating out Holographic QCD back to Hidden Local Symmetry
To appear in proceedings of SCGT09, Nagoya, Japan, 8 pages
null
10.1142/9789814329521_0007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a previously proposed gauge-invariant method to integrate out infinite towers of vector and axialvector mesons arising as Kaluza-Klein (KK) modes in a class of holographic models of QCD (HQCD). We demonstrate that HQCD can be reduced to the chiral perturbation theory (ChPT) with the hidden local symmetry (HLS) (so-called HLS-ChPT) having only the lowest KK mode identified as the HLS gauge boson, and the Nambu-Goldstone bosons. The ${\cal O} (p^4)$ terms in the HLS-ChPT are completely determined by integrating out infinite towers of vector/axialvector mesons in HQCD: Effects of higher KK modes are fully included in the coefficients. As an example, we apply our method to the Sakai-Sugimoto model.
[ { "created": "Thu, 4 Mar 2010 16:05:07 GMT", "version": "v1" } ]
2017-08-23
[ [ "Harada", "M.", "" ], [ "Matsuzaki", "S.", "" ], [ "Yamawaki", "K.", "" ] ]
We develop a previously proposed gauge-invariant method to integrate out infinite towers of vector and axialvector mesons arising as Kaluza-Klein (KK) modes in a class of holographic models of QCD (HQCD). We demonstrate that HQCD can be reduced to the chiral perturbation theory (ChPT) with the hidden local symmetry (HLS) (so-called HLS-ChPT) having only the lowest KK mode identified as the HLS gauge boson, and the Nambu-Goldstone bosons. The ${\cal O} (p^4)$ terms in the HLS-ChPT are completely determined by integrating out infinite towers of vector/axialvector mesons in HQCD: Effects of higher KK modes are fully included in the coefficients. As an example, we apply our method to the Sakai-Sugimoto model.
1303.1345
Chung-Lin Shan
Sen Miao, Chung-Lin Shan, and Yu-Feng Zhou
Model-Independent Identification of Inelastic WIMPs from Direct Dark Matter Detection Experiments
37 pages, 13 figures (95 eps plots); v2: revised version, compacted for publication
IJMPA 29:1450014, 2014
10.1142/S0217751X14500146
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we introduce model-independent data analysis procedures for identifying inelastic WIMP-nucleus scattering as well as for reconstructing the mass and the mass splitting of inelastic WIMPs simultaneously and separately. Our simulations show that, with O(50) observed WIMP signals from one experiment, one could already distinguish the inelastic WIMP scattering scenarios from the elastic one. By combining two or more data sets with positive signals, the WIMP mass and the mass splitting could even be reconstructed with statistical uncertainties of less than a factor of two.
[ { "created": "Wed, 6 Mar 2013 15:01:03 GMT", "version": "v1" }, { "created": "Thu, 20 Feb 2014 18:29:07 GMT", "version": "v2" } ]
2014-02-21
[ [ "Miao", "Sen", "" ], [ "Shan", "Chung-Lin", "" ], [ "Zhou", "Yu-Feng", "" ] ]
In this paper, we introduce model-independent data analysis procedures for identifying inelastic WIMP-nucleus scattering as well as for reconstructing the mass and the mass splitting of inelastic WIMPs simultaneously and separately. Our simulations show that, with O(50) observed WIMP signals from one experiment, one could already distinguish the inelastic WIMP scattering scenarios from the elastic one. By combining two or more data sets with positive signals, the WIMP mass and the mass splitting could even be reconstructed with statistical uncertainties of less than a factor of two.
2009.13773
Yuichi Uesaka
Takashi Shimomura, Yuichi Uesaka
Kinematical distributions of coherent neutrino trident production in gauged $L_\mu-L_\tau$ model
27 pages, 10 figures, 3 tables
Phys. Rev. D 103, 035022 (2021)
10.1103/PhysRevD.103.035022
UME-PP-015
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the distributions of energy, opening angle and invariant mass in muonic neutrino trident production processes, $\nu_\mu \to \nu_\mu \mu \overline{\mu}$, in a minimal gauged $U(1)_{L_\mu - L_\tau}$ model, in which the discrepancy of anomalous magnetic moment of muon can be solved. It is known that the total cross sections of the neutrino trident production are degenerate in new physics parameters, the new gauge coupling and gauge boson mass, and therefore other observables are needed to determine these parameters. From numerical analyses, we find that the muon energy and invariant mass distributions show the differences among the new physics parameter sets with which the total cross sections have the same value, while the anti-muon energy and opening angle distributions are not sensitive to the parameters.
[ { "created": "Tue, 29 Sep 2020 04:13:49 GMT", "version": "v1" } ]
2021-03-03
[ [ "Shimomura", "Takashi", "" ], [ "Uesaka", "Yuichi", "" ] ]
We analyze the distributions of energy, opening angle and invariant mass in muonic neutrino trident production processes, $\nu_\mu \to \nu_\mu \mu \overline{\mu}$, in a minimal gauged $U(1)_{L_\mu - L_\tau}$ model, in which the discrepancy of anomalous magnetic moment of muon can be solved. It is known that the total cross sections of the neutrino trident production are degenerate in new physics parameters, the new gauge coupling and gauge boson mass, and therefore other observables are needed to determine these parameters. From numerical analyses, we find that the muon energy and invariant mass distributions show the differences among the new physics parameter sets with which the total cross sections have the same value, while the anti-muon energy and opening angle distributions are not sensitive to the parameters.
1807.05604
Jinfeng Liao
Shuzhe Shi, Hui Zhang, Defu Hou, Jinfeng Liao
Chiral Magnetic Effect in Isobaric Collisions from Anomalous-Viscous Fluid Dynamics (AVFD)
4 pages, 3 figures, contribution to QM2018 conference proceedings
null
10.1016/j.nuclphysa.2018.10.007
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The isobaric collision experiment at RHIC provides the unique opportunity to detect the possible signal of Chiral Magnetic Effect (CME) in heavy ion collisions. The idea is to contrast the correlation observables of the two colliding systems that supposedly have identical flow-driven background contributions while quite different CME signal contributions due to the 10% variation in their nuclear charge and thus magnetic field strength. With the recently developed quantitative simulation tool for computing CME signal, the Anomalous-Viscous Fluid Dynamics (AVFD), we demonstrate that a joint (multiplicity + elliptic-flow) event selection is crucial for this purpose. We further propose to use the absolute difference between RuRu and ZrZr events (after using identical event selection) for detecting CME signal and make predictions for the correlation observables.
[ { "created": "Sun, 15 Jul 2018 20:18:02 GMT", "version": "v1" } ]
2019-02-20
[ [ "Shi", "Shuzhe", "" ], [ "Zhang", "Hui", "" ], [ "Hou", "Defu", "" ], [ "Liao", "Jinfeng", "" ] ]
The isobaric collision experiment at RHIC provides the unique opportunity to detect the possible signal of Chiral Magnetic Effect (CME) in heavy ion collisions. The idea is to contrast the correlation observables of the two colliding systems that supposedly have identical flow-driven background contributions while quite different CME signal contributions due to the 10% variation in their nuclear charge and thus magnetic field strength. With the recently developed quantitative simulation tool for computing CME signal, the Anomalous-Viscous Fluid Dynamics (AVFD), we demonstrate that a joint (multiplicity + elliptic-flow) event selection is crucial for this purpose. We further propose to use the absolute difference between RuRu and ZrZr events (after using identical event selection) for detecting CME signal and make predictions for the correlation observables.
2107.11948
Alexander Gramolin
Alexander V. Gramolin, Arne Wickenbrock, Deniz Aybas, Hendrik Bekker, Dmitry Budker, Gary P. Centers, Nataniel L. Figueroa, Derek F. Jackson Kimball, and Alexander O. Sushkov
Spectral signatures of axionlike dark matter
Our Python code is available at https://github.com/gramolin/lineshape
Phys. Rev. D 105, 035029 (2022)
10.1103/PhysRevD.105.035029
null
hep-ph astro-ph.CO hep-ex physics.atom-ph
http://creativecommons.org/licenses/by/4.0/
We derive spectral line shapes of the expected signal for a haloscope experiment searching for axionlike dark matter. The knowledge of these line shapes is needed to optimize an experimental design and data analysis procedure. We extend the previously known results for the axion-photon and axion-gluon couplings to the case of gradient (axion-fermion) coupling. A unique feature of the gradient interaction is its dependence not only on magnitudes but also on directions of velocities of galactic halo particles, which leads to the directional sensitivity of the corresponding haloscope. We also discuss the daily and annual modulations of the gradient signal caused by the Earth's rotational and orbital motions. In the case of detection, these periodic modulations will be an important confirmation that the signal is sourced by axionlike particles in the halo of our Galaxy.
[ { "created": "Mon, 26 Jul 2021 03:59:59 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2022 18:01:45 GMT", "version": "v2" } ]
2022-02-28
[ [ "Gramolin", "Alexander V.", "" ], [ "Wickenbrock", "Arne", "" ], [ "Aybas", "Deniz", "" ], [ "Bekker", "Hendrik", "" ], [ "Budker", "Dmitry", "" ], [ "Centers", "Gary P.", "" ], [ "Figueroa", "Nataniel L.", ...
We derive spectral line shapes of the expected signal for a haloscope experiment searching for axionlike dark matter. The knowledge of these line shapes is needed to optimize an experimental design and data analysis procedure. We extend the previously known results for the axion-photon and axion-gluon couplings to the case of gradient (axion-fermion) coupling. A unique feature of the gradient interaction is its dependence not only on magnitudes but also on directions of velocities of galactic halo particles, which leads to the directional sensitivity of the corresponding haloscope. We also discuss the daily and annual modulations of the gradient signal caused by the Earth's rotational and orbital motions. In the case of detection, these periodic modulations will be an important confirmation that the signal is sourced by axionlike particles in the halo of our Galaxy.
2201.09949
Fiona Kirk
Fiona Kirk
Leptophilic New Physics and the Cabibbo Angle Anomaly
5 pages, 3 figures, Contribution to the 32nd Rencontres de Blois
null
null
PSI-PR-22-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Cabibbo Angle Anomaly, an apparent deficit in first-row CKM unitarity, can be addressed by leptophilic Standard Model extensions that generate new contributions to the Fermi constant and affect the determination of the CKM element $V_{ud}$. We focus on simplified models with this property, including the Standard Model extended by vectorlike leptons, by the singly charged scalar singlet, or by a leptophilic $Z'$ boson.
[ { "created": "Mon, 24 Jan 2022 20:57:35 GMT", "version": "v1" } ]
2022-01-26
[ [ "Kirk", "Fiona", "" ] ]
The Cabibbo Angle Anomaly, an apparent deficit in first-row CKM unitarity, can be addressed by leptophilic Standard Model extensions that generate new contributions to the Fermi constant and affect the determination of the CKM element $V_{ud}$. We focus on simplified models with this property, including the Standard Model extended by vectorlike leptons, by the singly charged scalar singlet, or by a leptophilic $Z'$ boson.
0801.0743
Iain W. Stewart
Ambar Jain, Ignazio Scimemi, Iain W. Stewart
Two-loop Jet-Function and Jet-Mass for Top Quarks
25 pages, some typos corrected in text and references; 1 figure replaced
Phys.Rev.D77:094008,2008
10.1103/PhysRevD.77.094008
MIT-CTP 3916
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute the two-loop heavy quark jet-function in the heavy quark limit. This is one of the key ingredients in next-to-next-to-leading order (NNLO) and next-to-next-to-leading-log order (NNLL) computations of the invariant mass distribution of top-jets at a future e+e- collider. The shape of the top invariant mass distribution is affected by large logs which we compute at NNLL order. Exploiting the non-abelian exponentiation theorem, a definition of the top jet-mass is given which is transitive and whose renormalization group evolution is determined by the cusp-anomalous dimension to all orders in perturbation theory. Relations of the jet-mass to the pole, MSbar, and 1S masses are presented at two-loop order.
[ { "created": "Mon, 7 Jan 2008 20:43:32 GMT", "version": "v1" }, { "created": "Mon, 16 Jun 2008 15:11:03 GMT", "version": "v2" } ]
2008-11-26
[ [ "Jain", "Ambar", "" ], [ "Scimemi", "Ignazio", "" ], [ "Stewart", "Iain W.", "" ] ]
We compute the two-loop heavy quark jet-function in the heavy quark limit. This is one of the key ingredients in next-to-next-to-leading order (NNLO) and next-to-next-to-leading-log order (NNLL) computations of the invariant mass distribution of top-jets at a future e+e- collider. The shape of the top invariant mass distribution is affected by large logs which we compute at NNLL order. Exploiting the non-abelian exponentiation theorem, a definition of the top jet-mass is given which is transitive and whose renormalization group evolution is determined by the cusp-anomalous dimension to all orders in perturbation theory. Relations of the jet-mass to the pole, MSbar, and 1S masses are presented at two-loop order.
2204.02826
Francesco Giuli Dr.
Francesco Giuli
Precision measurements of the Lepton-Charge and Forward-Backward Drell-Yan Asymmetries to Enhance the Sensitivity to Broad Resonances of New Gauge Sectors
5 pages, 4 figures, contribution to the 2022 QCD session of the 56th Rencontres de Moriond
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the impact of future measurements of lepton-charge and forward-backward asymmetries in Drell-Yan processes in regions of transverse and invariant masses near the Standard Model gauge bosons peaks to improve the Parton Distribution Functions uncertainties. We study the implications on $W^{'}$ and $Z^{'}$ searches following the reduction of these uncertainties. We find that the sensitivity to the Beyond the Standard Model states is greatly increased with respect to the case of base Parton Distribution Functions sets, thereby enabling one to set more stringent limits on (or indeed discover) such new particles.
[ { "created": "Wed, 6 Apr 2022 13:38:47 GMT", "version": "v1" } ]
2022-04-07
[ [ "Giuli", "Francesco", "" ] ]
We study the impact of future measurements of lepton-charge and forward-backward asymmetries in Drell-Yan processes in regions of transverse and invariant masses near the Standard Model gauge bosons peaks to improve the Parton Distribution Functions uncertainties. We study the implications on $W^{'}$ and $Z^{'}$ searches following the reduction of these uncertainties. We find that the sensitivity to the Beyond the Standard Model states is greatly increased with respect to the case of base Parton Distribution Functions sets, thereby enabling one to set more stringent limits on (or indeed discover) such new particles.
2111.15655
G\'abor B\'ir\'o
G\'abor B\'ir\'o and Bence Tank\'o-Bartalis and Gergely G\'abor Barnaf\"oldi
Studying Hadronization by Machine Learning Techniques
null
null
null
null
hep-ph cs.LG
http://creativecommons.org/licenses/by/4.0/
Hadronization is a non-perturbative process, which theoretical description can not be deduced from first principles. Modeling hadron formation requires several assumptions and various phenomenological approaches. Utilizing state-of-the-art Computer Vision and Deep Learning algorithms, it is eventually possible to train neural networks to learn non-linear and non-perturbative features of the physical processes. In this study, results of two ResNet networks are presented by investigating global and kinematical quantities, indeed jet- and event-shape variables. The widely used Lund string fragmentation model is applied as a baseline in $\sqrt{s}= 7$ TeV proton-proton collisions to predict the most relevant observables at further LHC energies.
[ { "created": "Tue, 30 Nov 2021 18:38:32 GMT", "version": "v1" }, { "created": "Mon, 10 Jan 2022 09:06:44 GMT", "version": "v2" } ]
2022-01-11
[ [ "Bíró", "Gábor", "" ], [ "Tankó-Bartalis", "Bence", "" ], [ "Barnaföldi", "Gergely Gábor", "" ] ]
Hadronization is a non-perturbative process, which theoretical description can not be deduced from first principles. Modeling hadron formation requires several assumptions and various phenomenological approaches. Utilizing state-of-the-art Computer Vision and Deep Learning algorithms, it is eventually possible to train neural networks to learn non-linear and non-perturbative features of the physical processes. In this study, results of two ResNet networks are presented by investigating global and kinematical quantities, indeed jet- and event-shape variables. The widely used Lund string fragmentation model is applied as a baseline in $\sqrt{s}= 7$ TeV proton-proton collisions to predict the most relevant observables at further LHC energies.
hep-ph/9805209
Andrei Linde
I. Tkachev, S. Khlebnikov, L. Kofman, and A. Linde
Cosmic strings from preheating
6 pages, 7 figures, revtex. Computer generated movies illustrating string production can be found at http://www.physics.purdue.edu/~tkachev/movies.html and at http://physics.stanford.edu/~linde
Phys.Lett.B440:262-268,1998
10.1016/S0370-2693(98)01094-6
PURD-TH-98-07, UH-IfA-98-30, SU-ITP-98-32
hep-ph astro-ph gr-qc hep-th
null
We investigate nonthermal phase transitions that may occur after post-inflationary preheating in a simple model of a two-component scalar field with the effective potential $\lambda (\phi_i^2 - {\rm v}^2)^2/4$, where $\phi_1$ is identified with the inflaton field. We use three-dimensional lattice simulations to investigate the full nonlinear dynamics of the model. Fluctuations of the fields generated during and after preheating temporarily make the effective potential convex in the $\phi_1$ direction. The subsequent nonthermal phase transition with symmetry breaking leads to formation of cosmic strings even for ${\rm v} \gg 10^{16}$ GeV. This mechanism of string formation, in a modulated (by the oscillating field $\phi_{1}$) phase transition, is different from the usual Kibble mechanism.
[ { "created": "Mon, 4 May 1998 23:51:23 GMT", "version": "v1" }, { "created": "Tue, 5 May 1998 00:00:45 GMT", "version": "v2" } ]
2009-09-29
[ [ "Tkachev", "I.", "" ], [ "Khlebnikov", "S.", "" ], [ "Kofman", "L.", "" ], [ "Linde", "A.", "" ] ]
We investigate nonthermal phase transitions that may occur after post-inflationary preheating in a simple model of a two-component scalar field with the effective potential $\lambda (\phi_i^2 - {\rm v}^2)^2/4$, where $\phi_1$ is identified with the inflaton field. We use three-dimensional lattice simulations to investigate the full nonlinear dynamics of the model. Fluctuations of the fields generated during and after preheating temporarily make the effective potential convex in the $\phi_1$ direction. The subsequent nonthermal phase transition with symmetry breaking leads to formation of cosmic strings even for ${\rm v} \gg 10^{16}$ GeV. This mechanism of string formation, in a modulated (by the oscillating field $\phi_{1}$) phase transition, is different from the usual Kibble mechanism.
1106.3253
Enrico Bertuzzo Dr
Enrico Bertuzzo
On the MSSM with hierarchical squark masses and a heavier Higgs boson
8 pages, 5 figures, proceedings of the LC10 workshop
null
10.1393/ncc/i2011-11010-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the contest of supersymmetric extensions of the Standard Model, we consider a spectrum in which the lightest Higgs boson has mass between 200 and 300 GeV and the first two generations of squarks have masses above 20 TeV, considering the Higgs boson mass and the Supersymmetric Flavour Problem as related naturalness problems. After the analysis of some models in which the previous spectrum can be naturally realised, we consider the phenomenological consequences for the LHC and for Dark Matter.
[ { "created": "Thu, 16 Jun 2011 15:16:01 GMT", "version": "v1" } ]
2011-11-10
[ [ "Bertuzzo", "Enrico", "" ] ]
In the contest of supersymmetric extensions of the Standard Model, we consider a spectrum in which the lightest Higgs boson has mass between 200 and 300 GeV and the first two generations of squarks have masses above 20 TeV, considering the Higgs boson mass and the Supersymmetric Flavour Problem as related naturalness problems. After the analysis of some models in which the previous spectrum can be naturally realised, we consider the phenomenological consequences for the LHC and for Dark Matter.
0802.2162
Kirtiman Ghosh
Kirtiman Ghosh, Anindya Datta
Probing two Universal Extra Dimensions at International Linear Collider
8 pages, 3 figures. Minor changes and typos corrected. Refs added
Phys.Lett.B665:369-373,2008
10.1016/j.physletb.2008.06.042
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss collider signatures of (1,1)-th Kaluza-Klein (KK) mode vector bosons in the framework of two universal extra dimension model, at a future electron-positron collider. Production of the (1,1)-th KK mode of electro-weak vector bosons (B(1,1), W3(1,1)), are considered in association with a hard photon. Without caring about the decay products of those vector bosons, one can measure the masses of these particles just by looking at the photon energy distribution. Once produced these particles dominantly decay to a pair of jets or to a pair of top quarks. Thus we look for a pair of jets or a pair of top quarks in association with a photon. Upto the kinematic limit of the collider, signals from the B(1,1) production and decay in both the above mentioned channels are greater than the $5\sigma$ fluctuation of the Standard Model background. However, the number of events from W3(1,1) production and decay is smaller and its detection prospect is not very good.
[ { "created": "Fri, 15 Feb 2008 09:21:21 GMT", "version": "v1" }, { "created": "Tue, 21 Apr 2009 10:08:09 GMT", "version": "v2" } ]
2009-04-21
[ [ "Ghosh", "Kirtiman", "" ], [ "Datta", "Anindya", "" ] ]
We discuss collider signatures of (1,1)-th Kaluza-Klein (KK) mode vector bosons in the framework of two universal extra dimension model, at a future electron-positron collider. Production of the (1,1)-th KK mode of electro-weak vector bosons (B(1,1), W3(1,1)), are considered in association with a hard photon. Without caring about the decay products of those vector bosons, one can measure the masses of these particles just by looking at the photon energy distribution. Once produced these particles dominantly decay to a pair of jets or to a pair of top quarks. Thus we look for a pair of jets or a pair of top quarks in association with a photon. Upto the kinematic limit of the collider, signals from the B(1,1) production and decay in both the above mentioned channels are greater than the $5\sigma$ fluctuation of the Standard Model background. However, the number of events from W3(1,1) production and decay is smaller and its detection prospect is not very good.
hep-ph/0507152
Daniel Maitre
D. Maitre
HPL, a Mathematica implementation of the harmonic polylogarithms
24 pages, Latex, the package can be downloaded at http://krone.physik.unizh.ch/~maitreda/HPL/, typos corrected, one example changed
Comput.Phys.Commun. 174 (2006) 222-240
10.1016/j.cpc.2005.10.008
null
hep-ph
null
In this paper, we present an implementation of the harmonic polylogarithm of Remiddi and Vermaseren for Mathematica. It contains an implementation of the product algebra, the derivative properties, series expansion and numerical evaluation. The analytic continuation has been treated carefully, allowing the user to keep the control over the definition of the sign of the imaginary parts. Many options enables the user to adapt the behavior of the package to his specific problem.
[ { "created": "Wed, 13 Jul 2005 11:26:17 GMT", "version": "v1" }, { "created": "Mon, 18 Jul 2005 08:50:59 GMT", "version": "v2" } ]
2009-11-11
[ [ "Maitre", "D.", "" ] ]
In this paper, we present an implementation of the harmonic polylogarithm of Remiddi and Vermaseren for Mathematica. It contains an implementation of the product algebra, the derivative properties, series expansion and numerical evaluation. The analytic continuation has been treated carefully, allowing the user to keep the control over the definition of the sign of the imaginary parts. Many options enables the user to adapt the behavior of the package to his specific problem.
1305.6103
Zhenjun Xiao
Wei Bai, Min Liu, Ying-Ying Fan, Wen-Fei Wang, Shan Cheng, and Zhen-Jun Xiao
Revisiting $K\pi$ puzzle in the pQCD factorization approach
11 pages, 2 pdf figures. to be published in Chinese Physics C; several typos removed
Chin.Phys. C38 (2014) 033101
10.1088/1674-1137/38/3/033101
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we calculated the branching ratios and direct CP violation of the four $B\to K\pi$ decays with the inclusion of all currently known next-to-leading order (NLO) contributions by employing the perturbative QCD (pQCD) factorization approach. We found that (a) Besides the 10% enhancement from the NLO vertex corrections, the quark-loops and magnetic penguins, the NLO contributions to the form factors can provide an additional $\sim 15%$ enhancement to the branching ratios, and lead to a very good agreement with the data; (b) The NLO pQCD predictions are $\acp^{dir}(B^0\to K^+\pi^-)=(-6.5\pm 3.1)%$ and $\acp^{dir}(B^+\to K^+ \pi^0)=(2.2\pm 2.0)%$, become well consistent with the data due to the inclusion of the NLO contributions.
[ { "created": "Mon, 27 May 2013 04:37:07 GMT", "version": "v1" }, { "created": "Wed, 29 May 2013 16:09:15 GMT", "version": "v2" } ]
2014-08-19
[ [ "Bai", "Wei", "" ], [ "Liu", "Min", "" ], [ "Fan", "Ying-Ying", "" ], [ "Wang", "Wen-Fei", "" ], [ "Cheng", "Shan", "" ], [ "Xiao", "Zhen-Jun", "" ] ]
In this paper, we calculated the branching ratios and direct CP violation of the four $B\to K\pi$ decays with the inclusion of all currently known next-to-leading order (NLO) contributions by employing the perturbative QCD (pQCD) factorization approach. We found that (a) Besides the 10% enhancement from the NLO vertex corrections, the quark-loops and magnetic penguins, the NLO contributions to the form factors can provide an additional $\sim 15%$ enhancement to the branching ratios, and lead to a very good agreement with the data; (b) The NLO pQCD predictions are $\acp^{dir}(B^0\to K^+\pi^-)=(-6.5\pm 3.1)%$ and $\acp^{dir}(B^+\to K^+ \pi^0)=(2.2\pm 2.0)%$, become well consistent with the data due to the inclusion of the NLO contributions.
2302.04191
Pritam Palit
Pritam Palit and Sujay Shil
Probing Electroweak Phase Transition in Singlet scalar extension of Standard Model at HL-LHC through $bbZZ$ channel using parameterized machine learning
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, the collider signature of the heavy Higgs boson at $14$ TeV HL-LHC is studied, where heavy Higgs boson decays into a pair of standard model Higgs boson, which further decays to $bbZZ$ state and subsequently to $bb\ell^{+} \ell^{-}\nu_{\ell} \nu_{\ell}$ final state. To study this, we consider singlet scalar extension of the standard model and considered the parameter space and mass of the heavy Higgs such that it prefers the strong first order electroweak phase transition. The study is done following the $bbZZ$ analysis of CMS Collaboration and further using parameterized machine learning for final discrimination which simplifies the training process along with an improved discrimination between signal and background over the range of benchmark points. Despite the lower branching fractions, this channel can be a potential probe of the electroweak phase transition with the data sets collected by the CMS and ATLAS experiments in the $14$ TeV HL-LHC with $3$ $\rm{ab}^{-1}$ of integrated luminosity and a production of resonant di-Higgs signal can be potentially discovered.
[ { "created": "Wed, 8 Feb 2023 16:59:39 GMT", "version": "v1" } ]
2023-02-09
[ [ "Palit", "Pritam", "" ], [ "Shil", "Sujay", "" ] ]
In this paper, the collider signature of the heavy Higgs boson at $14$ TeV HL-LHC is studied, where heavy Higgs boson decays into a pair of standard model Higgs boson, which further decays to $bbZZ$ state and subsequently to $bb\ell^{+} \ell^{-}\nu_{\ell} \nu_{\ell}$ final state. To study this, we consider singlet scalar extension of the standard model and considered the parameter space and mass of the heavy Higgs such that it prefers the strong first order electroweak phase transition. The study is done following the $bbZZ$ analysis of CMS Collaboration and further using parameterized machine learning for final discrimination which simplifies the training process along with an improved discrimination between signal and background over the range of benchmark points. Despite the lower branching fractions, this channel can be a potential probe of the electroweak phase transition with the data sets collected by the CMS and ATLAS experiments in the $14$ TeV HL-LHC with $3$ $\rm{ab}^{-1}$ of integrated luminosity and a production of resonant di-Higgs signal can be potentially discovered.
hep-ph/0206020
Nima Arkani-Hamed
N. Arkani-Hamed, A.G. Cohen, T. Gregoire, E. Katz, A.E. Nelson, J.G. Wacker
The Minimal Moose for a Little Higgs
15 pages. References added. Included clarifying comments on the origin of quartic couplings, and on power-counting. More elegant model for generating Higgs potential from top Yukawa coupling presented
JHEP 0208:021,2002
10.1088/1126-6708/2002/08/021
HUTP-02/A016, BUHEP-02-24,UW/PT-01/09
hep-ph hep-th
null
Recently a new class of theories of electroweak symmetry breaking have been constructed. These models, based on deconstruction and the physics of theory space, provide the first alternative to weak-scale supersymmetry with naturally light Higgs fields and perturbative new physics at the TeV scale. The Higgs is light because it is a pseudo-Goldstone boson, and the quadratically divergent contributions to the Higgs mass are cancelled by new TeV scale ``partners'' of the {\em same} statistics. In this paper we present the minimal theory space model of electroweak symmetry breaking, with two sites and four link fields, and the minimal set of fermions. There are very few parameters and degrees of freedom beyond the Standard Model. Below a TeV, we have the Standard Model with two light Higgs doublets, and an additional complex scalar weak triplet and singlet. At the TeV scale, the new particles that cancel the 1-loop quadratic divergences in the Higgs mass are revealed. The entire Higgs potential needed for electroweak symmetry breaking--the quartic couplings as well as the familiar negative mass squared--can be generated by the top Yukawa coupling, providing a novel link between the physics of flavor and electroweak symmetry breaking.
[ { "created": "Mon, 3 Jun 2002 20:31:42 GMT", "version": "v1" }, { "created": "Mon, 17 Jun 2002 21:10:55 GMT", "version": "v2" } ]
2011-01-13
[ [ "Arkani-Hamed", "N.", "" ], [ "Cohen", "A. G.", "" ], [ "Gregoire", "T.", "" ], [ "Katz", "E.", "" ], [ "Nelson", "A. E.", "" ], [ "Wacker", "J. G.", "" ] ]
Recently a new class of theories of electroweak symmetry breaking have been constructed. These models, based on deconstruction and the physics of theory space, provide the first alternative to weak-scale supersymmetry with naturally light Higgs fields and perturbative new physics at the TeV scale. The Higgs is light because it is a pseudo-Goldstone boson, and the quadratically divergent contributions to the Higgs mass are cancelled by new TeV scale ``partners'' of the {\em same} statistics. In this paper we present the minimal theory space model of electroweak symmetry breaking, with two sites and four link fields, and the minimal set of fermions. There are very few parameters and degrees of freedom beyond the Standard Model. Below a TeV, we have the Standard Model with two light Higgs doublets, and an additional complex scalar weak triplet and singlet. At the TeV scale, the new particles that cancel the 1-loop quadratic divergences in the Higgs mass are revealed. The entire Higgs potential needed for electroweak symmetry breaking--the quartic couplings as well as the familiar negative mass squared--can be generated by the top Yukawa coupling, providing a novel link between the physics of flavor and electroweak symmetry breaking.
1612.01192
Tanumoy Mandal
Tanumoy Mandal
Exclusion limits on a scalar decaying to photons and distinguishing its production mechanisms
18 pages, 10 figures, 2 tables. Matches with the published version
Adv.High Energy Phys. 2018 (2018) 9150617
10.1155/2018/9150617
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
LHC run-II has a great potential to search for new resonances in the diphoton channel. Latest 13 TeV data already put stringent limits on the cross sections in the diphoton channel assuming the resonance is produced through the gluon-gluon fusion. Many beyond the Standard Model (SM) theories predict TeV-scale scalars, which copiously decay to diphotons. Apart from the gluon-gluon fusion production, these scalars can also be dominantly produced in other ways too at the LHC namely through the quark-quark fusion or the gauge boson fusions like the photon-photon, photon-$Z$, $WW$ or $ZZ$ fusions. In this paper, we use an effective field theory approach where a heavy scalar can be produced in various ways and recast the latest ATLAS diphoton resonance search to put model-independent limits on its mass and effective couplings to the SM particles. If a new scalar is discovered at the LHC, it would be very important to identify its production mechanism in order to probe the nature of the underlying theory. We show that combining various kinematic variables in a multivariate analysis can be very powerful to distinguish different production mechanisms one from the other.
[ { "created": "Sun, 4 Dec 2016 22:03:28 GMT", "version": "v1" }, { "created": "Fri, 12 Jan 2018 10:57:44 GMT", "version": "v2" } ]
2018-01-15
[ [ "Mandal", "Tanumoy", "" ] ]
LHC run-II has a great potential to search for new resonances in the diphoton channel. Latest 13 TeV data already put stringent limits on the cross sections in the diphoton channel assuming the resonance is produced through the gluon-gluon fusion. Many beyond the Standard Model (SM) theories predict TeV-scale scalars, which copiously decay to diphotons. Apart from the gluon-gluon fusion production, these scalars can also be dominantly produced in other ways too at the LHC namely through the quark-quark fusion or the gauge boson fusions like the photon-photon, photon-$Z$, $WW$ or $ZZ$ fusions. In this paper, we use an effective field theory approach where a heavy scalar can be produced in various ways and recast the latest ATLAS diphoton resonance search to put model-independent limits on its mass and effective couplings to the SM particles. If a new scalar is discovered at the LHC, it would be very important to identify its production mechanism in order to probe the nature of the underlying theory. We show that combining various kinematic variables in a multivariate analysis can be very powerful to distinguish different production mechanisms one from the other.
1004.0549
Jinshu Huang
Jinshu Huang, Gongru Lu, Wei Xu, Shuaiwei Wang
Associated production of a neutral top-Higgs with a heavy-quark pair in the \gamma\gamma collisions at ILC
4 pages, 4 figures, some references are added
Chin. Phys. C34:1057-1060, 2010
10.1088/1674-1137/34/8/004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have studied the associated production processes of a neutral top-Higgs in the topcolor assisted technicolor model with a pair of heavy quarks in \gamma\gamma collisions at the International Linear Collider (ILC). We find that the cross section for t\bar{t}h_t in \gamma\gamma collisions is at the level of a few fb with the c.m. energy \sqrt{s}=1000 GeV, which is consistent with the results of the cross section of t\bar{t}H in the standard model and the cross section of t\bar{t}h in the minimal supersymmetric standard modeland the little Higgs models. It should be distinct that hundreds of to thousands of h_t per year can be produced at the ILC, this process of \gamma\gamma \to t\bar{t}h_t is really interesting in testing the standard model and searching the signs of technicolor.
[ { "created": "Mon, 5 Apr 2010 01:26:59 GMT", "version": "v1" }, { "created": "Fri, 25 Jun 2010 09:28:06 GMT", "version": "v2" } ]
2015-05-18
[ [ "Huang", "Jinshu", "" ], [ "Lu", "Gongru", "" ], [ "Xu", "Wei", "" ], [ "Wang", "Shuaiwei", "" ] ]
We have studied the associated production processes of a neutral top-Higgs in the topcolor assisted technicolor model with a pair of heavy quarks in \gamma\gamma collisions at the International Linear Collider (ILC). We find that the cross section for t\bar{t}h_t in \gamma\gamma collisions is at the level of a few fb with the c.m. energy \sqrt{s}=1000 GeV, which is consistent with the results of the cross section of t\bar{t}H in the standard model and the cross section of t\bar{t}h in the minimal supersymmetric standard modeland the little Higgs models. It should be distinct that hundreds of to thousands of h_t per year can be produced at the ILC, this process of \gamma\gamma \to t\bar{t}h_t is really interesting in testing the standard model and searching the signs of technicolor.
0811.3050
Alfredo Raya
A. Bashir, A. Raya and S. Sanchez-Madrigal
Gauge Covariance Relations and the Fermion Propagator in Maxwell-Chern-Simons QED3
13 pages, 4 figures. Published version. V2, References corrected
J.Phys.A41:505401,2008
10.1088/1751-8113/41/50/505401
UMSNH-IFM-F-2008-32
hep-ph cond-mat.mes-hall hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the gauge covariance of the fermion propagator in Maxwell-Chern-Simons planar quantum electrodynamics (QED$_3$) considering four-component spinors with parity-even and parity-odd mass terms both for fermions and photons. Starting with its tree level expression in the Landau gauge, we derive a non perturbative expression for this propagator in an arbitrary covariant gauge by means of its Landau-Khalatnikov-Fradkin transformation (LKFT). We compare our findings in the weak coupling regime with the direct one-loop calculation of the two-point Green function and observe perfect agreement up to a gauge independent term. We also reproduce results derived in earlier works as special cases of our findings.
[ { "created": "Wed, 19 Nov 2008 04:26:07 GMT", "version": "v1" }, { "created": "Sun, 30 Nov 2008 20:38:24 GMT", "version": "v2" } ]
2008-12-18
[ [ "Bashir", "A.", "" ], [ "Raya", "A.", "" ], [ "Sanchez-Madrigal", "S.", "" ] ]
We study the gauge covariance of the fermion propagator in Maxwell-Chern-Simons planar quantum electrodynamics (QED$_3$) considering four-component spinors with parity-even and parity-odd mass terms both for fermions and photons. Starting with its tree level expression in the Landau gauge, we derive a non perturbative expression for this propagator in an arbitrary covariant gauge by means of its Landau-Khalatnikov-Fradkin transformation (LKFT). We compare our findings in the weak coupling regime with the direct one-loop calculation of the two-point Green function and observe perfect agreement up to a gauge independent term. We also reproduce results derived in earlier works as special cases of our findings.
hep-ph/9602249
null
E.Chikovani (1), V.Kartvelishvili (1,2), R.Shanidze (1), G.Shaw (2). ((1) - HEPI, Tbilisi, Georgia; (2) - University of Manchester, UK)
Bound States of Two Gluinos at the Tevatron and LHC
LaTeX, 14 pages, 1 table, 5 figures. Submitted to Phys. Rev. D
Phys.Rev.D53:6653-6657,1996
10.1103/PhysRevD.53.6653
MC-TH-96/06
hep-ph
null
We calculate the production cross-sections for the vector and pseudoscalar bound states of two gluinos. It is shown that existing and future colliders imply a realistic chance of observing gluinonium as a narrow peak in the two-jet invariant mass spectrum. With an integrated luminosity of 0.2 fb$^{-1}$ at the Tevatron, and the high efficiency for tagging heavy quark jets at CDF, one should be able to detect vector gluinonium for gluino masses up to about 170 GeV; or up to about 260 GeV for an upgraded Tevatron with a centre of mass energy of 2 TeV and an integrated luminosity of 1 fb$^{-1}$. The significantly higher energy and luminosity of LHC should allow pseudoscalar gluinonium to be detected for gluino masses up to about 1500 GeV for an assumed luminosity of 200 fb$^{-1}$. These results are insensitive to the details of supersymmetry models, provided that R-parity is conserved and the gluinos are lighter than the squarks. In addition, gluinonium detection implies a relatively accurate measure of the gluino mass, which is difficult to determine by other means.
[ { "created": "Wed, 7 Feb 1996 18:32:30 GMT", "version": "v1" }, { "created": "Thu, 8 Feb 1996 18:55:46 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chikovani", "E.", "", "- HEPI, Tbilisi, Georgia;" ], [ "Kartvelishvili", "V.", "", "- HEPI, Tbilisi, Georgia;", "- University of Manchester, UK" ], [ "Shanidze", "R.", "", "- HEPI, Tbilisi, Georgia;" ], [ "Shaw", "G.", "", "- Univers...
We calculate the production cross-sections for the vector and pseudoscalar bound states of two gluinos. It is shown that existing and future colliders imply a realistic chance of observing gluinonium as a narrow peak in the two-jet invariant mass spectrum. With an integrated luminosity of 0.2 fb$^{-1}$ at the Tevatron, and the high efficiency for tagging heavy quark jets at CDF, one should be able to detect vector gluinonium for gluino masses up to about 170 GeV; or up to about 260 GeV for an upgraded Tevatron with a centre of mass energy of 2 TeV and an integrated luminosity of 1 fb$^{-1}$. The significantly higher energy and luminosity of LHC should allow pseudoscalar gluinonium to be detected for gluino masses up to about 1500 GeV for an assumed luminosity of 200 fb$^{-1}$. These results are insensitive to the details of supersymmetry models, provided that R-parity is conserved and the gluinos are lighter than the squarks. In addition, gluinonium detection implies a relatively accurate measure of the gluino mass, which is difficult to determine by other means.
2206.14722
Debasish Borah
Debasish Borah, Arnab Dasgupta
Large Neutrino Asymmetry from TeV Scale Leptogenesis
11 pages, 6 captioned figures, matches version published in Phys. Rev. D
Phys. Rev. D108, 035015 (2023)
10.1103/PhysRevD.108.035015
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study a class of leptogenesis scenarios with decay or scattering being the source of lepton asymmetry, which can not only give rise to the observed baryon asymmetry in the universe but also can leave behind a large remnant neutrino asymmetry. Such large neutrino asymmetry can not only be probed at future cosmic microwave background (CMB) experiments but is also motivating due to its possible role in solving the recently reported anomalies in $^4{\rm He}$ measurements. Additionally, such large neutrino asymmetry also offers the possibility of cogenesis if dark matter is in the form of a sterile neutrino resonantly produced in the early universe via Shi-Fuller mechanism. Considering $1 \rightarrow 2, 1 \rightarrow 3$ as well as $2 \rightarrow 2$ processes to be responsible for generating the asymmetries, we show that only TeV scale leptogenesis preferably of $1 \rightarrow N \, (N \geq 3)$ type can generate the required lepton asymmetry around sphaleron temperature while also generating a large neutrino asymmetry $\sim \mathcal{O}(10^{-2})$ by the epoch of the big bang nucleosynthesis. While such low scale leptogenesis can have tantalising detection prospects at laboratory experiments, the indication of a large neutrino asymmetry provides a complementary indirect signature.
[ { "created": "Wed, 29 Jun 2022 15:42:27 GMT", "version": "v1" }, { "created": "Fri, 11 Aug 2023 17:28:27 GMT", "version": "v2" } ]
2023-08-14
[ [ "Borah", "Debasish", "" ], [ "Dasgupta", "Arnab", "" ] ]
We study a class of leptogenesis scenarios with decay or scattering being the source of lepton asymmetry, which can not only give rise to the observed baryon asymmetry in the universe but also can leave behind a large remnant neutrino asymmetry. Such large neutrino asymmetry can not only be probed at future cosmic microwave background (CMB) experiments but is also motivating due to its possible role in solving the recently reported anomalies in $^4{\rm He}$ measurements. Additionally, such large neutrino asymmetry also offers the possibility of cogenesis if dark matter is in the form of a sterile neutrino resonantly produced in the early universe via Shi-Fuller mechanism. Considering $1 \rightarrow 2, 1 \rightarrow 3$ as well as $2 \rightarrow 2$ processes to be responsible for generating the asymmetries, we show that only TeV scale leptogenesis preferably of $1 \rightarrow N \, (N \geq 3)$ type can generate the required lepton asymmetry around sphaleron temperature while also generating a large neutrino asymmetry $\sim \mathcal{O}(10^{-2})$ by the epoch of the big bang nucleosynthesis. While such low scale leptogenesis can have tantalising detection prospects at laboratory experiments, the indication of a large neutrino asymmetry provides a complementary indirect signature.
hep-ph/9905544
Oliver Martin
O. Martin
Transverse Double-Spin Asymmetries for Dimuon Production in pp Collisions
3 pages, 4 figures, talk given at DIS99, requires npb.sty, one reference corrected
Nucl.Phys.Proc.Suppl. 79 (1999) 623-625
10.1016/S0920-5632(99)00802-6
null
hep-ph
null
We calculate the transverse double-spin asymmetry for the production of dimuons in pp collisions as function of the dimuon rapidity and mass to next-to-leading accuracy in the strong coupling. Predictions for BNL-RHIC and HERA-N are made by assuming a saturation of Soffer's inequality at a low hadronic input scale. It seems unlikely that transversity can be measured in dimuon production at RHIC.
[ { "created": "Sat, 29 May 1999 18:29:52 GMT", "version": "v1" }, { "created": "Mon, 25 Oct 1999 14:03:09 GMT", "version": "v2" } ]
2009-10-31
[ [ "Martin", "O.", "" ] ]
We calculate the transverse double-spin asymmetry for the production of dimuons in pp collisions as function of the dimuon rapidity and mass to next-to-leading accuracy in the strong coupling. Predictions for BNL-RHIC and HERA-N are made by assuming a saturation of Soffer's inequality at a low hadronic input scale. It seems unlikely that transversity can be measured in dimuon production at RHIC.
hep-ph/9701297
null
B.O.Kerbikov, D.S.Kuzmenko, Yu.A.Simonov
Effective Quark Lagrangian in the Instanton Vacuum with Nonzero Modes Included
5 pages
Pisma Zh.Eksp.Teor.Fiz. 65 (1997) 128; JETP Lett. 65 (1997) 137-141
10.1134/1.567303
null
hep-ph
null
A new approach to effective theory of quarks in the instanton vacuum is presented. Exact equations for the quark propagator and Lagrangian are derived which contain contributions of all quark modes with known coefficients. The resulting effective Lagrangian differs from the standard one and resembles that of the Nambu-Jona-Lasinio model.
[ { "created": "Wed, 15 Jan 1997 12:42:57 GMT", "version": "v1" } ]
2009-10-30
[ [ "Kerbikov", "B. O.", "" ], [ "Kuzmenko", "D. S.", "" ], [ "Simonov", "Yu. A.", "" ] ]
A new approach to effective theory of quarks in the instanton vacuum is presented. Exact equations for the quark propagator and Lagrangian are derived which contain contributions of all quark modes with known coefficients. The resulting effective Lagrangian differs from the standard one and resembles that of the Nambu-Jona-Lasinio model.
hep-ph/0310236
Andrzej Wereszczynski
Andrzej Wereszczynski
Universality of the Linear Potential in Effective Models for the Low Energy QCD coupled with the Dilaton Field
10 pages
Phys.Lett.B570:260-264,2003
10.1016/j.physletb.2003.07.054
null
hep-ph
null
QCD motivated effective models coupled with the cosmological dilaton field are analyzed. It is shown that all models possess confining solutions with the linear potential of confinement even thought such solutions are not observed in the original effective theory. In case of the Pagels-Tomboulis model analytical solutions are explicit found.
[ { "created": "Mon, 20 Oct 2003 11:37:58 GMT", "version": "v1" } ]
2009-12-30
[ [ "Wereszczynski", "Andrzej", "" ] ]
QCD motivated effective models coupled with the cosmological dilaton field are analyzed. It is shown that all models possess confining solutions with the linear potential of confinement even thought such solutions are not observed in the original effective theory. In case of the Pagels-Tomboulis model analytical solutions are explicit found.
1903.04172
Abdel Nasser Tawfik
Abdel Nasser Tawfik (Nile U., ECTP & WLCAPP, Cairo)
Transverse Momentum Spectra of Pions at LHC Energies
7 pages, 1 figure, submitted to AHEP (special issue)
Advances High Energy Phys, 2019, 4604608 (2019)
10.1155/2019/4604608
ECTP-2018-02, WLCAPP-2018-02
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to characterize the transverse momentum spectra of positive pions measured in the ALICE experiment, two thermal approaches are utilized; one is based on degeneracy of non-perfect Bose-Einstein gas and the other imposes an {\it ad-hoc} finite pion-chemical potential. The inclusion of missing haron states and the out-of-chemical equilibrium greatly contribute to the excellent characterization of pion production. The excellent reproduction of the experimental data can be understood as a manifestation of not-yet-regarded anomalous pion-production, which likely contribute to the long-standing debate on the {\it "anomalous"} proton-to-pion ratios at top RHIC and LHC energies.
[ { "created": "Mon, 11 Mar 2019 08:35:20 GMT", "version": "v1" } ]
2019-06-07
[ [ "Tawfik", "Abdel Nasser", "", "Nile U., ECTP & WLCAPP, Cairo" ] ]
In order to characterize the transverse momentum spectra of positive pions measured in the ALICE experiment, two thermal approaches are utilized; one is based on degeneracy of non-perfect Bose-Einstein gas and the other imposes an {\it ad-hoc} finite pion-chemical potential. The inclusion of missing haron states and the out-of-chemical equilibrium greatly contribute to the excellent characterization of pion production. The excellent reproduction of the experimental data can be understood as a manifestation of not-yet-regarded anomalous pion-production, which likely contribute to the long-standing debate on the {\it "anomalous"} proton-to-pion ratios at top RHIC and LHC energies.
hep-ph/0107113
Peschanski
M. Boonekamp (Saclay, Exp.), R. Peschanski (Saclay, Th.) and C. Royon (Saclay, Exp., BNL, Texas U. at Arlington)
Inclusive Higgs boson and dijet production via Double Pomeron exchange
6pages, 4 figures
Phys.Rev.Lett.87:251806,2001
10.1103/PhysRevLett.87.251806
null
hep-ph
null
We evaluate Higgs boson and dijet cross-sections at the Tevatron collider via Double Pomeron exchange when accompanying particles in the central region are taken into account. Such {\it inclusive} processes, normalized to the observed dijet rate observed at run I, noticeably increase the predictions for tagged (anti)protons in the run II with respect to {\it exclusive} ones, with the potentiality of Higgs boson detection.
[ { "created": "Tue, 10 Jul 2001 14:51:17 GMT", "version": "v1" } ]
2008-11-26
[ [ "Boonekamp", "M.", "", "Saclay, Exp." ], [ "Peschanski", "R.", "", "Saclay, Th." ], [ "Royon", "C.", "", "Saclay, Exp., BNL, Texas U. at Arlington" ] ]
We evaluate Higgs boson and dijet cross-sections at the Tevatron collider via Double Pomeron exchange when accompanying particles in the central region are taken into account. Such {\it inclusive} processes, normalized to the observed dijet rate observed at run I, noticeably increase the predictions for tagged (anti)protons in the run II with respect to {\it exclusive} ones, with the potentiality of Higgs boson detection.
1704.01720
Soumitra Nandi
Soumitra Nandi
Theory update on the inlcusive determination of $|V_{cb}|$
7 pages, 1 figure, presented at CKM 2016 , TIFR Mumbai, India
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk I update the precision determination of the CKM element $|V_{cb}|$ from the inclusive decay $B\to X_c\ell\nu_{\ell}$.
[ { "created": "Thu, 6 Apr 2017 06:15:59 GMT", "version": "v1" } ]
2017-04-07
[ [ "Nandi", "Soumitra", "" ] ]
In this talk I update the precision determination of the CKM element $|V_{cb}|$ from the inclusive decay $B\to X_c\ell\nu_{\ell}$.
0906.1979
Soumya Rao
Eduard Masso, Subhendra Mohanty and Soumya Rao
Dipolar Dark Matter
23 pages, 8 figures
Phys.Rev.D80:036009,2009
10.1103/PhysRevD.80.036009
Preprint UAB-FT-663, PRL-TH/AP-09/1
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If dark matter (DM) has non-zero direct or transition, electric or magnetic dipole moment then it can scatter nucleons electromagnetically in direct detection experiments. Using the results from experiments like XENON, CDMS, DAMA and COGENT we put bounds on the electric and magnetic dipole moments of DM. If DM consists of Dirac fermions with direct dipole moments, then DM of mass less than 10 GeV is consistent with the DAMA signal and with null results of other experiments. If on the other hand DM consists of Majorana fermions then they can have only non-zero transition moments between different mass eigenstates. We find that Majorana fermions with mass m_\chi > 38 GeV and mass splitting of the order of (50-200) keV can explain the DAMA signal and the null observations from other experiments and in addition give the observed relic density of DM by dipole-mediated annihilation. This parameter space for the mass and for dipole moments is allowed by limits from L3 but may have observable signals at LHC.
[ { "created": "Wed, 10 Jun 2009 17:21:12 GMT", "version": "v1" } ]
2009-09-02
[ [ "Masso", "Eduard", "" ], [ "Mohanty", "Subhendra", "" ], [ "Rao", "Soumya", "" ] ]
If dark matter (DM) has non-zero direct or transition, electric or magnetic dipole moment then it can scatter nucleons electromagnetically in direct detection experiments. Using the results from experiments like XENON, CDMS, DAMA and COGENT we put bounds on the electric and magnetic dipole moments of DM. If DM consists of Dirac fermions with direct dipole moments, then DM of mass less than 10 GeV is consistent with the DAMA signal and with null results of other experiments. If on the other hand DM consists of Majorana fermions then they can have only non-zero transition moments between different mass eigenstates. We find that Majorana fermions with mass m_\chi > 38 GeV and mass splitting of the order of (50-200) keV can explain the DAMA signal and the null observations from other experiments and in addition give the observed relic density of DM by dipole-mediated annihilation. This parameter space for the mass and for dipole moments is allowed by limits from L3 but may have observable signals at LHC.
hep-ph/9802307
Fyodor V. Tkachov
Fyodor V. Tkachov
Perturbation theory with unstable fundamental fields
PS 8 pp. Final must-have version 16 Nov 98: many clarifications (NB: expanded remark 6 at end) thanks to relaxed formfactor. More at http://www.inr.ac.ru/~ftkachov/unstable/index.htm
Proc. XXXIII PNPI Winter School on Nuclear and Particle Physics, ed. Ya.I.Azimov et al., S.Petersburg, PNPI, 1999, pp.166-181
null
F5T-98/01
hep-ph
null
The difficulties of perturbation theory associated with unstable fundamental fields (such as the lack of exact gauge invariance in each order) are cured if one constructs perturbative expansion directly for probabilities interpreted as distributions in kinematic variables. Such an expansion is made possible by the powerful method of non-Euclidean asymptotic operation [hep-ph/9703424].
[ { "created": "Thu, 12 Feb 1998 09:32:22 GMT", "version": "v1" }, { "created": "Sun, 5 Apr 1998 13:49:12 GMT", "version": "v2" }, { "created": "Sun, 26 Apr 1998 06:28:51 GMT", "version": "v3" }, { "created": "Thu, 7 May 1998 22:56:09 GMT", "version": "v4" }, { "cre...
2007-05-23
[ [ "Tkachov", "Fyodor V.", "" ] ]
The difficulties of perturbation theory associated with unstable fundamental fields (such as the lack of exact gauge invariance in each order) are cured if one constructs perturbative expansion directly for probabilities interpreted as distributions in kinematic variables. Such an expansion is made possible by the powerful method of non-Euclidean asymptotic operation [hep-ph/9703424].
hep-ph/9303210
null
F. Buccella, F. Lombardi, G. Miele and P. Santorelli
Nonleptonic Cabibbo Favoured $B$-Decays and $CP$-Asymmetries for Charmed Final Hadron States in Isgur and Wise Theory
CERNTEX, 17 pages, DSF-92/23, INFN-NA-IV-92/23
Z.Phys.C59:437-444,1993
10.1007/BF01498623
null
hep-ph
null
The Cabibbo allowed non-leptonic $B$-decays in two hadrons are studied, within the factorization hypothesis, in the framework of Isgur and Wise theory for the matrix elements of the $\Delta B=-\Delta C=\pm 1$ weak currents. The $SU(2)_{HF}$ symmetry relates $|\Delta B|=1$ to $|\Delta C|=1$ currents, which have been measured in the semileptonic strange decays of charmed particles. By assuming colour screening and allowing for $SU(3)$ invariant contributions from the annihilation terms with charmed final states one is able to comply with the present experimental knowledge.\\ The $CP$ violating asymmetries in neutral $B$ decays are given for charmed final states in terms of the $K-M$ angles. With the central values found for the annihilation parameters there is a destructive (constructive) interference between the direct and annihilation terms in the Cabibbo allowed (doubly forbidden) amplitudes for the decays into $D^{0}(D^{*0})\pi^0$ and $D^0\rho^0$ so that they may be of the same order. This would imply large asymmetries, for which however our present knowledge on the amplitudes does not allow to predict even their sign.\\ We have better confidence in our predictions for the charged final states than the neutral ones and can draw the conclusion that the detection of the corresponding asymmetries requires, at least, $10^6$ tagged neutral $B$-particles.
[ { "created": "Wed, 3 Mar 1993 13:13:00 GMT", "version": "v1" } ]
2010-11-01
[ [ "Buccella", "F.", "" ], [ "Lombardi", "F.", "" ], [ "Miele", "G.", "" ], [ "Santorelli", "P.", "" ] ]
The Cabibbo allowed non-leptonic $B$-decays in two hadrons are studied, within the factorization hypothesis, in the framework of Isgur and Wise theory for the matrix elements of the $\Delta B=-\Delta C=\pm 1$ weak currents. The $SU(2)_{HF}$ symmetry relates $|\Delta B|=1$ to $|\Delta C|=1$ currents, which have been measured in the semileptonic strange decays of charmed particles. By assuming colour screening and allowing for $SU(3)$ invariant contributions from the annihilation terms with charmed final states one is able to comply with the present experimental knowledge.\\ The $CP$ violating asymmetries in neutral $B$ decays are given for charmed final states in terms of the $K-M$ angles. With the central values found for the annihilation parameters there is a destructive (constructive) interference between the direct and annihilation terms in the Cabibbo allowed (doubly forbidden) amplitudes for the decays into $D^{0}(D^{*0})\pi^0$ and $D^0\rho^0$ so that they may be of the same order. This would imply large asymmetries, for which however our present knowledge on the amplitudes does not allow to predict even their sign.\\ We have better confidence in our predictions for the charged final states than the neutral ones and can draw the conclusion that the detection of the corresponding asymmetries requires, at least, $10^6$ tagged neutral $B$-particles.
hep-ph/0205084
Wai-Yee Keung
Darwin Chang, We-Fu Chang, and Wai-Yee Keung
New constraint from Electric Dipole Moments on chargino baryogenesis in MSSM
17 pages, 6 figures (Expanded version)
Phys.Rev.D66:116008,2002
10.1103/PhysRevD.66.116008
null
hep-ph
null
A commonly accepted mechanism of generating baryon asymmetry in the minimal supersymmetric standard model (MSSM) depends on the CP violating relative phase between the gaugino mass and the Higgsino mu term. The direct constraint on this phase comes from the limit of electric dipole moments (EDM) of various light fermions. To avoid such a constraint, a scheme which assumes the first two generation sfermions are very heavy is usually evoked to suppress the one-loop EDM contributions. We point out that under such a scheme the most severe constraint may come from a new contribution to the electric dipole moments of the electron, the neutron or atoms via the chargino sector at the two-loop level. As a result, the allowed parameter space for baryogenesis in MSSM is severely constrained, independent of masses of the first two generation sfermions.
[ { "created": "Wed, 8 May 2002 23:19:23 GMT", "version": "v1" }, { "created": "Tue, 4 Jun 2002 02:55:54 GMT", "version": "v2" }, { "created": "Thu, 12 Sep 2002 20:58:36 GMT", "version": "v3" } ]
2009-09-01
[ [ "Chang", "Darwin", "" ], [ "Chang", "We-Fu", "" ], [ "Keung", "Wai-Yee", "" ] ]
A commonly accepted mechanism of generating baryon asymmetry in the minimal supersymmetric standard model (MSSM) depends on the CP violating relative phase between the gaugino mass and the Higgsino mu term. The direct constraint on this phase comes from the limit of electric dipole moments (EDM) of various light fermions. To avoid such a constraint, a scheme which assumes the first two generation sfermions are very heavy is usually evoked to suppress the one-loop EDM contributions. We point out that under such a scheme the most severe constraint may come from a new contribution to the electric dipole moments of the electron, the neutron or atoms via the chargino sector at the two-loop level. As a result, the allowed parameter space for baryogenesis in MSSM is severely constrained, independent of masses of the first two generation sfermions.
0901.4187
Roman Pasechnik
R. S. Pasechnik, A. Szczurek, O. V. Teryaev
Elastic double diffractive production of axial-vector \chi_c(1^{++}) mesons and the Landau-Yang theorem
14 pages, 5 figures, a numerical error corrected, discussions extended, conclusions unchanged
Phys.Lett.B680:62-71,2009
10.1016/j.physletb.2009.08.035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss exclusive elastic double diffractive axial-vector \chi_c(1^{+}) meson production in proton-antiproton collisions at the Tevatron. The amplitude for the process is derived within the k_t-factorisation approach with unintegrated gluon distribution functions (UGDFs). We show that the famous Landau-Yang theorem is not applicable in the case of off-shell gluons. Differential cross sections for different UGDFs are calculated. We compare exclusive production of \chi_c(1^+) and \chi_c(0^+). The contribution of \chi_c(1^+) to the J/\Psi + \gamma channel is smaller than that of the \chi_c(0^+) decay, but not negligible and can be measured. The numerical value of the ratio of the both contributions is almost independent of UGDFs modeling.
[ { "created": "Tue, 27 Jan 2009 07:28:50 GMT", "version": "v1" }, { "created": "Tue, 7 Apr 2009 20:06:09 GMT", "version": "v2" } ]
2009-09-28
[ [ "Pasechnik", "R. S.", "" ], [ "Szczurek", "A.", "" ], [ "Teryaev", "O. V.", "" ] ]
We discuss exclusive elastic double diffractive axial-vector \chi_c(1^{+}) meson production in proton-antiproton collisions at the Tevatron. The amplitude for the process is derived within the k_t-factorisation approach with unintegrated gluon distribution functions (UGDFs). We show that the famous Landau-Yang theorem is not applicable in the case of off-shell gluons. Differential cross sections for different UGDFs are calculated. We compare exclusive production of \chi_c(1^+) and \chi_c(0^+). The contribution of \chi_c(1^+) to the J/\Psi + \gamma channel is smaller than that of the \chi_c(0^+) decay, but not negligible and can be measured. The numerical value of the ratio of the both contributions is almost independent of UGDFs modeling.
hep-ph/0703188
Davor Horvatic
D. Blaschke, D. Horvatic, D. Klabucar, A. E. Radzhabov
Separable Dyson-Schwinger model at zero and finite T
9 pages, 4 figures, abbreviated version of hep-ph/0703115, published in proceedings of "Progress in Quark Models", Bled, Slovenia, July 10-17, 2006, editors B. Golli, M. Rosina and S. Sirca, available at www-f1.ijs.si/Bled2006/book.pdf
proc. Bled Workshops in Physics, Vol. 7, No. 1 (2006) 20
null
null
hep-ph nucl-th
null
Theoretical understanding of experimental results from relativistic heavy-ion collisions requires a microscopic approach to the behavior of QCD n-point functions at finite temperatures, as given by the hierarchy of Dyson-Schwinger equations, properly generalized within the Matsubara formalism. The technical complexity of related finite-temperature calculations however mandates modeling. We present a model where the QCD interaction in the infrared, nonperturbative domain, is modeled by a separable form. Results for the mass spectrum of light quark flavors at finite temperature are presented.
[ { "created": "Sun, 18 Mar 2007 04:40:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Blaschke", "D.", "" ], [ "Horvatic", "D.", "" ], [ "Klabucar", "D.", "" ], [ "Radzhabov", "A. E.", "" ] ]
Theoretical understanding of experimental results from relativistic heavy-ion collisions requires a microscopic approach to the behavior of QCD n-point functions at finite temperatures, as given by the hierarchy of Dyson-Schwinger equations, properly generalized within the Matsubara formalism. The technical complexity of related finite-temperature calculations however mandates modeling. We present a model where the QCD interaction in the infrared, nonperturbative domain, is modeled by a separable form. Results for the mass spectrum of light quark flavors at finite temperature are presented.
hep-ph/0301021
Vitaly Velizhanin
A.V. Kotikov (JINR, Dubna), L.N. Lipatov and V.N. Velizhanin (St. Petersburg, INP)
Anomalous dimensions of Wilson operators in N=4 SYM theory
LaTeX file, 10 pages, no figures
Phys.Lett. B557 (2003) 114-120
10.1016/S0370-2693(03)00184-9
null
hep-ph hep-th
null
We present the results of two-loop calculations of the anomalous dimension matrix for the Wilson twist-2 operators in the N=4 Supersymmetric Yang-Mills theory for polarized and unpolarized cases. This matrix can be transformed to a triangle form by the same similarity transformation as in the leading order. The eigenvalues of the anomalous dimension matrix are expressed in terms of an universal function with its argument shifted by integer numbers. In the conclusion we discuss relations between the weak and strong coupling regimes in the framework of the AdS/CFT correspondence.
[ { "created": "Sun, 5 Jan 2003 18:00:33 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kotikov", "A. V.", "", "JINR, Dubna" ], [ "Lipatov", "L. N.", "", "St.\n Petersburg, INP" ], [ "Velizhanin", "V. N.", "", "St.\n Petersburg, INP" ] ]
We present the results of two-loop calculations of the anomalous dimension matrix for the Wilson twist-2 operators in the N=4 Supersymmetric Yang-Mills theory for polarized and unpolarized cases. This matrix can be transformed to a triangle form by the same similarity transformation as in the leading order. The eigenvalues of the anomalous dimension matrix are expressed in terms of an universal function with its argument shifted by integer numbers. In the conclusion we discuss relations between the weak and strong coupling regimes in the framework of the AdS/CFT correspondence.
1409.2497
Jihn E. Kim
Jihn E. Kim, Yannis Semertzidis, Shinji Tsujikawa
Bosonic Coherent Motions in the Universe
15 pages, 7 figures
Front. Phys. 2 (2014) 60, 3 (2015) 04 (E)
10.3389/fphy.2014.00060, 10.3389/fphy.2015.00004
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We mini-review the role of fundamental spin-0 bosons as bosonic coherent motion (BCM) in the Universe. The fundamental spin-0 bosons have the potential to account for the baryon number generation, cold dark matter (CDM) via BCM, dark energy, and inflation. Among these, here we focus on the CDM possibility because it can be experimentally tested with the current experimental techniques. We also comment briefly on the panoply of the other roles of spin-0 bosons.
[ { "created": "Mon, 8 Sep 2014 20:00:16 GMT", "version": "v1" }, { "created": "Sat, 18 Oct 2014 05:16:56 GMT", "version": "v2" } ]
2015-01-29
[ [ "Kim", "Jihn E.", "" ], [ "Semertzidis", "Yannis", "" ], [ "Tsujikawa", "Shinji", "" ] ]
We mini-review the role of fundamental spin-0 bosons as bosonic coherent motion (BCM) in the Universe. The fundamental spin-0 bosons have the potential to account for the baryon number generation, cold dark matter (CDM) via BCM, dark energy, and inflation. Among these, here we focus on the CDM possibility because it can be experimentally tested with the current experimental techniques. We also comment briefly on the panoply of the other roles of spin-0 bosons.
1910.05889
Hui Luo
Qingjun Jin and Hui Luo
Analytic Form of the Three-loop Four-gluon Scattering Amplitudes in Yang-Mills Theory
6 pages, 4 figures, comments are welcome
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present analytic forms of three-loop four-gluon planar amplitudes in pure Yang-Mills theory in this letter. Gauge invariant bases and a set of proper master integrals are chosen such that the amplitudes are explicitly invariant under cyclic permutations of external particles. The $D$-dimensional unitarity method and integration-by-parts reductions with cut conditions are performed to determine the coefficients of the master integrals. Helicity amplitudes in the conventional dimension regularization scheme are obtained by setting gauge invariant bases to helicity configurations. After renormalizing the ultraviolet divergences, remaining divergences of the amplitudes agree with known infrared divergence structures exactly. Our results provide an essential piece of three-loop amplitudes required for the ${\rm N^3LO}$ order corrections to the production of two jets at hadron colliders.
[ { "created": "Mon, 14 Oct 2019 02:01:24 GMT", "version": "v1" } ]
2019-10-15
[ [ "Jin", "Qingjun", "" ], [ "Luo", "Hui", "" ] ]
We present analytic forms of three-loop four-gluon planar amplitudes in pure Yang-Mills theory in this letter. Gauge invariant bases and a set of proper master integrals are chosen such that the amplitudes are explicitly invariant under cyclic permutations of external particles. The $D$-dimensional unitarity method and integration-by-parts reductions with cut conditions are performed to determine the coefficients of the master integrals. Helicity amplitudes in the conventional dimension regularization scheme are obtained by setting gauge invariant bases to helicity configurations. After renormalizing the ultraviolet divergences, remaining divergences of the amplitudes agree with known infrared divergence structures exactly. Our results provide an essential piece of three-loop amplitudes required for the ${\rm N^3LO}$ order corrections to the production of two jets at hadron colliders.
hep-ph/9605274
Matthias Neubert
Maria Girone (Bari) and Matthias Neubert (CERN)
Measuring $\alpha_s(Q^2)$ in $\tau$ Decays
12 pages, 7 figures appended, to appear in the Proceedings of Les Rencontres de Physique de la Vall\'ee d'Aoste (La Thuile, Italy, March 1996), and Second Workshop on Continuous Advances in QCD (Minneapolis, Minnesota, March 1996)
null
null
BARI-TH/96-236, CERN-TH/96-125
hep-ph
null
The decay rate of the $\tau$ lepton into hadrons of invariant mass smaller than $Q\gg\Lambda_{\rm QCD}$ can be calculated in QCD using the OPE. Using experimental data on the hadronic mass distribution, the running coupling constant $\alpha_s(Q^2)$ is extracted in the range $0.85~\mbox{GeV}<Q<m_\tau$, where its value changes by about a factor~2. At $Q=m_\tau$, the result is $\alpha_s(m_\tau^2)=0.33\pm 0.03$, corresponding to $\alpha_s(m_Z^2)=0.119\pm 0.004$. The running of the coupling constant is in excellent agreement with the QCD prediction based on the three-loop $\beta$-function.
[ { "created": "Fri, 10 May 1996 17:37:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Girone", "Maria", "", "Bari" ], [ "Neubert", "Matthias", "", "CERN" ] ]
The decay rate of the $\tau$ lepton into hadrons of invariant mass smaller than $Q\gg\Lambda_{\rm QCD}$ can be calculated in QCD using the OPE. Using experimental data on the hadronic mass distribution, the running coupling constant $\alpha_s(Q^2)$ is extracted in the range $0.85~\mbox{GeV}<Q<m_\tau$, where its value changes by about a factor~2. At $Q=m_\tau$, the result is $\alpha_s(m_\tau^2)=0.33\pm 0.03$, corresponding to $\alpha_s(m_Z^2)=0.119\pm 0.004$. The running of the coupling constant is in excellent agreement with the QCD prediction based on the three-loop $\beta$-function.
hep-ph/9507413
Kurt Riesselmann
Kurt Riesselmann (Techn. Univ. Munich)
Large uncertainties in the cross section of elastic $ W_L^+ W_L^- $ scattering
30 pages, Revtex using epsf, uuencoded, packed Postscript figures. The analysis has been updated to include the 3-loop running coupling. Four figures updated, one figure added to show the maximal energy allowed as a function of the Higgs mass. Final version as to appear in Phys. Rev. D
Phys.Rev.D53:6226-6240,1996
10.1103/PhysRevD.53.6226
TUM-HEP-223/95
hep-ph
null
The amplitudes for $2\rightarrow 2$ scattering processes involving longitudinally polarized gauge bosons $( W_L^\pm, Z_L )$ and the Higgs boson are analyzed up to two loops. Assuming $M_H >> M_W$, the trilinear Higgs coupling, $\lambda v$, is dominant for energies of $\sqrt{s}$ < 1.5 -- 2 $M_H$. For larger values of $\sqrt{s}$, the quartic coupling, $\lambda$, becomes dominant, allowing for a simpler calculation of higher-order corrections. The high-energy amplitudes display a large logarithmic dependence on $\sqrt{s}$ which can be resummed using renormalization group techniques. The resummation of leading-log terms is sufficient for Higgs masses of less than 350 GeV. For 350 < $M_H$ < 450 GeV, a next-to-leading-log resummation is necessary. For even larger values of $M_H$, the perturbative approach fails completely since two-loop terms become in magnitude larger than one-loop terms. Choosing the $\overline{{\rm MS}}$ renormalization scheme instead of the OMS scheme, the coefficients of the perturbative series increase in magnitude, making the breakdown of perturbation theory even more apparent. In conclusion, the Standard Model cross sections presented here have very large uncertainties if $M_H\gtrsim 450$ GeV and $\sqrt{s} \gtrsim 2 M_H$, reducing the sensitivity to contributions from new physics significantly.
[ { "created": "Tue, 25 Jul 1995 21:46:24 GMT", "version": "v1" }, { "created": "Tue, 25 Jul 1995 22:06:07 GMT", "version": "v2" }, { "created": "Tue, 23 Jan 1996 22:16:54 GMT", "version": "v3" } ]
2011-08-17
[ [ "Riesselmann", "Kurt", "", "Techn. Univ. Munich" ] ]
The amplitudes for $2\rightarrow 2$ scattering processes involving longitudinally polarized gauge bosons $( W_L^\pm, Z_L )$ and the Higgs boson are analyzed up to two loops. Assuming $M_H >> M_W$, the trilinear Higgs coupling, $\lambda v$, is dominant for energies of $\sqrt{s}$ < 1.5 -- 2 $M_H$. For larger values of $\sqrt{s}$, the quartic coupling, $\lambda$, becomes dominant, allowing for a simpler calculation of higher-order corrections. The high-energy amplitudes display a large logarithmic dependence on $\sqrt{s}$ which can be resummed using renormalization group techniques. The resummation of leading-log terms is sufficient for Higgs masses of less than 350 GeV. For 350 < $M_H$ < 450 GeV, a next-to-leading-log resummation is necessary. For even larger values of $M_H$, the perturbative approach fails completely since two-loop terms become in magnitude larger than one-loop terms. Choosing the $\overline{{\rm MS}}$ renormalization scheme instead of the OMS scheme, the coefficients of the perturbative series increase in magnitude, making the breakdown of perturbation theory even more apparent. In conclusion, the Standard Model cross sections presented here have very large uncertainties if $M_H\gtrsim 450$ GeV and $\sqrt{s} \gtrsim 2 M_H$, reducing the sensitivity to contributions from new physics significantly.
1305.2331
Manlio De Domenico
Manlio De Domenico, Mariangela Settimo, Simone Riggi and Eric Bertin
Reinterpreting the development of extensive air showers initiated by nuclei and photons
21 pages, 4 tables, 8 figures
JCAP07 (2013) 050
10.1088/1475-7516/2013/07/050
null
hep-ph astro-ph.HE astro-ph.IM
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultra-high energy cosmic rays (UHECRs) interacting with the atmosphere generate extensive air showers (EAS) of secondary particles. The depth corresponding to the maximum development of the shower, $\Xmax$, is a well-known observable for determining the nature of the primary cosmic ray which initiated the cascade process. In this paper, we present an empirical model to describe the distribution of $\Xmax$ for EAS initiated by nuclei, in the energy range from $10^{17}$ eV up to $10^{21}$ eV, and by photons, in the energy range from $10^{17}$ eV up to $10^{19.6}$ eV. Our model adopts the generalized Gumbel distribution motivated by the relationship between the generalized Gumbel statistics and the distribution of the sum of non-identically distributed variables in dissipative stochastic systems. We provide an analytical expression for describing the $\Xmax$ distribution for photons and for nuclei, and for their first two statistical moments, namely $\langle \Xmax\rangle$ and $\sigma^{2}(\Xmax)$. The impact of the hadronic interaction model is investigated in detail, even in the case of the most up-to-date models accounting for LHC observations. We also briefly discuss the differences with a more classical approach and an application to the experimental data based on information theory.
[ { "created": "Fri, 10 May 2013 12:50:06 GMT", "version": "v1" }, { "created": "Wed, 31 Jul 2013 16:20:10 GMT", "version": "v2" } ]
2013-08-01
[ [ "De Domenico", "Manlio", "" ], [ "Settimo", "Mariangela", "" ], [ "Riggi", "Simone", "" ], [ "Bertin", "Eric", "" ] ]
Ultra-high energy cosmic rays (UHECRs) interacting with the atmosphere generate extensive air showers (EAS) of secondary particles. The depth corresponding to the maximum development of the shower, $\Xmax$, is a well-known observable for determining the nature of the primary cosmic ray which initiated the cascade process. In this paper, we present an empirical model to describe the distribution of $\Xmax$ for EAS initiated by nuclei, in the energy range from $10^{17}$ eV up to $10^{21}$ eV, and by photons, in the energy range from $10^{17}$ eV up to $10^{19.6}$ eV. Our model adopts the generalized Gumbel distribution motivated by the relationship between the generalized Gumbel statistics and the distribution of the sum of non-identically distributed variables in dissipative stochastic systems. We provide an analytical expression for describing the $\Xmax$ distribution for photons and for nuclei, and for their first two statistical moments, namely $\langle \Xmax\rangle$ and $\sigma^{2}(\Xmax)$. The impact of the hadronic interaction model is investigated in detail, even in the case of the most up-to-date models accounting for LHC observations. We also briefly discuss the differences with a more classical approach and an application to the experimental data based on information theory.
hep-ph/9907574
Emidio Gabrielli
E. Gabrielli, V.A. Ilyin and B. Mele
Bounds on anomalous gamma-gamma-H and Z-gamma-H couplings at future e-gamma linear colliders
LaTeX, 6 pages, To appear in the proceedings of the International Workshop on Linear Colliders, Sitges, Barcellona, Spain, April 28 - May 5, (1999)
null
null
null
hep-ph
null
We study the bounds on the anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices that can be obtained via the process e-gamma-->e H. We consider the representative case of an intermediate Higgs mass production of MH=120 GeV and for a center of mass energy of Sqrt{S}=500 GeV and Sqrt{S}=1500 GeV. We use a model independent analysis based on SU(2)xU(1) invariant operators of dimension 6 added to the Standard Model lagrangian. We find that this process provides an excelent way to put strong constraints both in the sector of CP-even and CP-odd anomalous couplings contribution to the gamma-gamma-H and Z-gamma-H vertices.
[ { "created": "Fri, 30 Jul 1999 22:26:36 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gabrielli", "E.", "" ], [ "Ilyin", "V. A.", "" ], [ "Mele", "B.", "" ] ]
We study the bounds on the anomalous contributions to the gamma-gamma-H and Z-gamma-H vertices that can be obtained via the process e-gamma-->e H. We consider the representative case of an intermediate Higgs mass production of MH=120 GeV and for a center of mass energy of Sqrt{S}=500 GeV and Sqrt{S}=1500 GeV. We use a model independent analysis based on SU(2)xU(1) invariant operators of dimension 6 added to the Standard Model lagrangian. We find that this process provides an excelent way to put strong constraints both in the sector of CP-even and CP-odd anomalous couplings contribution to the gamma-gamma-H and Z-gamma-H vertices.
2207.02874
Drona Vatsyayan
Arnau Bas i Beneito, Juan Herrero-Garc\'ia and Drona Vatsyayan
Multi-component Dark Sectors: Symmetries, Asymmetries and Conversions
31 pages, 11 figures, 3 tables; Version published in JHEP
J. High Energ. Phys. 2022, 75 (2022)
10.1007/JHEP10(2022)075
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the relic abundance of several stable particles from a generic dark sector, including the possible presence of dark asymmetries. After discussing the different possibilities for stabilising multi-component dark matter, we analyse the final relic abundance of the symmetric and asymmetric dark matter components, paying special attention to the role of the unavoidable conversions between dark matter states. We find an exponential dependence of the asymmetries of the heavier components on annihilations and conversions. We conclude that having similar symmetric and asymmetric components is a natural outcome in many scenarios of multi-component dark matter. This has novel phenomenological implications, which we briefly discuss.
[ { "created": "Wed, 6 Jul 2022 18:00:03 GMT", "version": "v1" }, { "created": "Wed, 19 Oct 2022 09:10:40 GMT", "version": "v2" } ]
2022-10-20
[ [ "Beneito", "Arnau Bas i", "" ], [ "Herrero-García", "Juan", "" ], [ "Vatsyayan", "Drona", "" ] ]
We study the relic abundance of several stable particles from a generic dark sector, including the possible presence of dark asymmetries. After discussing the different possibilities for stabilising multi-component dark matter, we analyse the final relic abundance of the symmetric and asymmetric dark matter components, paying special attention to the role of the unavoidable conversions between dark matter states. We find an exponential dependence of the asymmetries of the heavier components on annihilations and conversions. We conclude that having similar symmetric and asymmetric components is a natural outcome in many scenarios of multi-component dark matter. This has novel phenomenological implications, which we briefly discuss.
hep-ph/9811435
null
K. Takayama and M. Oka
Hyperon Non-leptonic Weak Decays in the Chiral Perturbation Theory II
20 pages, LaTeX file, 1 figure, with epsf.sty
null
null
TIT/HEP-406/NP
hep-ph nucl-th
null
Hyperon non-leptonic weak decay amplitudes are studied in the chiral perturbation theory. The weak interaction vertices caused by the four quark operators are substituted by the products of the hadronic currents and by the phenomenologically introduced weak Hamiltonian of hadron operators. Our study suggests the improvement of the theoretical prediction for the weak decay amplitudes.
[ { "created": "Mon, 23 Nov 1998 11:03:36 GMT", "version": "v1" } ]
2007-05-23
[ [ "Takayama", "K.", "" ], [ "Oka", "M.", "" ] ]
Hyperon non-leptonic weak decay amplitudes are studied in the chiral perturbation theory. The weak interaction vertices caused by the four quark operators are substituted by the products of the hadronic currents and by the phenomenologically introduced weak Hamiltonian of hadron operators. Our study suggests the improvement of the theoretical prediction for the weak decay amplitudes.
0810.2168
Qun Wang
Hao-jie Xu, Qun Wang
An Abelian Ward identity and the vertex corrections to the color superconducting gap
RevTex 4, 11 pages, 4 figures
Chin.Phys.C33:753-758,2009
10.1088/1674-1137/33/9/008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive an Abelian-like Ward identity in color superconducting phase and calculate vertex corrections to the color superconducting gap. Making use of the Ward identity, we show that subleading order contributions to the gap from vertices are absent for gapped excitations.
[ { "created": "Mon, 13 Oct 2008 07:54:40 GMT", "version": "v1" } ]
2015-05-13
[ [ "Xu", "Hao-jie", "" ], [ "Wang", "Qun", "" ] ]
We derive an Abelian-like Ward identity in color superconducting phase and calculate vertex corrections to the color superconducting gap. Making use of the Ward identity, we show that subleading order contributions to the gap from vertices are absent for gapped excitations.
2108.00461
Xin-Li Sheng
Xin-Li Sheng
Improved quark coalescence model for spin alignments of vector mesons
4 pages, Contribution to the Proceedings of the 19th International Conference on Strangeness in Quark Matter, SQM 2021
null
10.1051/epjconf/202225911013
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We propose an improved quark coalescence model for spin alignment of vector mesons by spin density matrix with phase space dependence. Within this model we propose an understanding of spin alignments of vector mesons $\phi$ and $K^{*0}$ in the static limit: a large positive deviation of $\rho_{00}$ for $\phi$ mesons from $1/3$ may come from the electric part of the vector $\phi$ field, while a negative deviation of $\rho_{00}$ for $K^{*0}$ mesons may come from the electric part of vorticity fields. In the low-$p_T$ region, $\rho_{00}$ for $K^{*0}$ mesons is proportional to $p_T^2$, which is qualitatively agree with experimental results.
[ { "created": "Sun, 1 Aug 2021 14:24:36 GMT", "version": "v1" } ]
2022-02-16
[ [ "Sheng", "Xin-Li", "" ] ]
We propose an improved quark coalescence model for spin alignment of vector mesons by spin density matrix with phase space dependence. Within this model we propose an understanding of spin alignments of vector mesons $\phi$ and $K^{*0}$ in the static limit: a large positive deviation of $\rho_{00}$ for $\phi$ mesons from $1/3$ may come from the electric part of the vector $\phi$ field, while a negative deviation of $\rho_{00}$ for $K^{*0}$ mesons may come from the electric part of vorticity fields. In the low-$p_T$ region, $\rho_{00}$ for $K^{*0}$ mesons is proportional to $p_T^2$, which is qualitatively agree with experimental results.
2403.15269
Erdenebulgan Lkhagvadorj
Ki-Young Choi, Erdenebulgan Lkhagvadorj, and Satyabrata Mahapatra
Gravitational Wave Sourced by Decay of Massive Particle from Primordial Black Hole evaporation
19 pages, 5 figures; matches the version published in JCAP
JCAP 07(2024)064
10.1088/1475-7516/2024/07/064
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this article, we investigate the stochastic gravitational waves (GWs) spectrum, resulting from the emission of gravitons through bremsstrahlung, in the decay of particles produced by Hawking radiation. Although particle decays inevitably entail the emission of graviton due to bremsstrahlung, the associated decay width is notably suppressed due to the Planck scale suppression in the coupling of matter fields to gravitons. Consequently, the relic abundance of such GWs constituted of these gravitons undergoes a corresponding reduction. However, we demonstrate that super-heavy particles, reaching masses as high as Planck scale, can emerge naturally in the Hawking radiation of evaporating primordial black holes (PBHs) and can compensate for this suppression. In addition, we also discuss the stochastic gravitational waves constituted out of the gravitons directly radiated from such evaporating PBHs. When the super-heavy particle decays promptly after its production, then the corresponding GW spectrum remains subdominant to the one arising from direct PBH evaporation. However, if this particle is long-lived and decays after PBH evaporation, then the resulting GWs produced in these two processes have two distinct spectra with their peaks at extremely high frequencies, providing avenues for proposed ultra-high frequency gravitational wave detectors. We also show that such gravitational waves contribute significantly to substantial dark radiation, which can be probed with the enhanced sensitivity of future experiments.
[ { "created": "Fri, 22 Mar 2024 15:08:11 GMT", "version": "v1" }, { "created": "Mon, 29 Jul 2024 04:06:24 GMT", "version": "v2" } ]
2024-07-30
[ [ "Choi", "Ki-Young", "" ], [ "Lkhagvadorj", "Erdenebulgan", "" ], [ "Mahapatra", "Satyabrata", "" ] ]
In this article, we investigate the stochastic gravitational waves (GWs) spectrum, resulting from the emission of gravitons through bremsstrahlung, in the decay of particles produced by Hawking radiation. Although particle decays inevitably entail the emission of graviton due to bremsstrahlung, the associated decay width is notably suppressed due to the Planck scale suppression in the coupling of matter fields to gravitons. Consequently, the relic abundance of such GWs constituted of these gravitons undergoes a corresponding reduction. However, we demonstrate that super-heavy particles, reaching masses as high as Planck scale, can emerge naturally in the Hawking radiation of evaporating primordial black holes (PBHs) and can compensate for this suppression. In addition, we also discuss the stochastic gravitational waves constituted out of the gravitons directly radiated from such evaporating PBHs. When the super-heavy particle decays promptly after its production, then the corresponding GW spectrum remains subdominant to the one arising from direct PBH evaporation. However, if this particle is long-lived and decays after PBH evaporation, then the resulting GWs produced in these two processes have two distinct spectra with their peaks at extremely high frequencies, providing avenues for proposed ultra-high frequency gravitational wave detectors. We also show that such gravitational waves contribute significantly to substantial dark radiation, which can be probed with the enhanced sensitivity of future experiments.
hep-ph/0311103
Mattias Marklund
Padma K. Shukla, Mattias Marklund, Gert Brodin and Lennart Stenflo
Nonlinear Propagation of Incoherent Photons in a Radiation Background
4 pages, 2 figures, uses revtex4
Phys.Lett.A330:131-136,2004
10.1016/j.physleta.2004.07.073
null
hep-ph astro-ph
null
The nonlinear propagation of intense incoherent photons in a photon gas is considered. The photon-photon interactions are governed by a pair of equations comprising a wave-kinetic equation for the incoherent photons in the presence of the slowly varying energy density perturbations of sound-like waves, and an equation for the latter waves in a background where the photon coupling is caused by quantum electrodynamical effects. The coupled equations are used to derive a dispersion relation, which admits new classes of modulational instabilities of incoherent photons. The present instabilities can lead to fragmentation of broadband short photon pulses in astrophysical and laboratory settings.
[ { "created": "Sat, 8 Nov 2003 09:56:20 GMT", "version": "v1" } ]
2008-11-26
[ [ "Shukla", "Padma K.", "" ], [ "Marklund", "Mattias", "" ], [ "Brodin", "Gert", "" ], [ "Stenflo", "Lennart", "" ] ]
The nonlinear propagation of intense incoherent photons in a photon gas is considered. The photon-photon interactions are governed by a pair of equations comprising a wave-kinetic equation for the incoherent photons in the presence of the slowly varying energy density perturbations of sound-like waves, and an equation for the latter waves in a background where the photon coupling is caused by quantum electrodynamical effects. The coupled equations are used to derive a dispersion relation, which admits new classes of modulational instabilities of incoherent photons. The present instabilities can lead to fragmentation of broadband short photon pulses in astrophysical and laboratory settings.
1809.06235
Partha Pratim Bhaduri
Partha Pratim Bhaduri, Nicolas Borghini, Amaresh Jaiswal, Michael Strickland
Anisotropic escape mechanism and elliptic flow of bottomonia
7 pages, 5 figures; extensively revised text, significant new results
Phys. Rev. C 100, 051901 (2019)
10.1103/PhysRevC.100.051901
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the role of anisotropic escape in generating the elliptic flow of bottomonia produced in ultrarelativistic heavy-ion collisions. We implement temperature-dependent decay widths for the various bottomonium states, to calculate their survival probability when traversing through the anisotropic hot medium formed in non-central collisions. We employ the recently developed 3+1d quasiparticle anisotropic hydrodynamic simulation to model the space-time evolution of the quark-gluon plasma. We provide a quantitative prediction for transverse momentum dependence of bottomonium elliptic flow and nuclear modification factor for Pb$\,+\,$Pb collisions in $\sqrt{s_{\rm NN}}=2.76$ TeV at the Large Hadron Collider.
[ { "created": "Mon, 17 Sep 2018 14:24:47 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2019 16:09:58 GMT", "version": "v2" } ]
2019-11-20
[ [ "Bhaduri", "Partha Pratim", "" ], [ "Borghini", "Nicolas", "" ], [ "Jaiswal", "Amaresh", "" ], [ "Strickland", "Michael", "" ] ]
We study the role of anisotropic escape in generating the elliptic flow of bottomonia produced in ultrarelativistic heavy-ion collisions. We implement temperature-dependent decay widths for the various bottomonium states, to calculate their survival probability when traversing through the anisotropic hot medium formed in non-central collisions. We employ the recently developed 3+1d quasiparticle anisotropic hydrodynamic simulation to model the space-time evolution of the quark-gluon plasma. We provide a quantitative prediction for transverse momentum dependence of bottomonium elliptic flow and nuclear modification factor for Pb$\,+\,$Pb collisions in $\sqrt{s_{\rm NN}}=2.76$ TeV at the Large Hadron Collider.
1503.00532
Felix Karbstein
Felix Karbstein, Rashid Shaisultanov
Photon propagation in slowly varying inhomogeneous electromagnetic fields
15 pages, 1 figure; typo fixed in first line of Eq. (12)
Phys. Rev. D 91, 085027 (2015)
10.1103/PhysRevD.91.085027
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from the Heisenberg-Euler effective Lagrangian, we determine the photon current and photon polarization tensor in inhomogeneous, slowly varying electromagnetic fields. To this end, we consider background field configurations varying in both space and time, paying special attention to the tensor structure. As a main result, we obtain compact analytical expressions for the photon polarization tensor in realistic Gaussian laser pulses, as generated in the focal spots of high-intensity lasers. These expressions are of utmost importance for the investigation of quantum vacuum nonlinearities in realistic high-intensity laser experiments.
[ { "created": "Mon, 2 Mar 2015 14:14:16 GMT", "version": "v1" }, { "created": "Thu, 23 Apr 2015 06:56:25 GMT", "version": "v2" }, { "created": "Wed, 1 Jun 2022 10:17:53 GMT", "version": "v3" } ]
2022-06-02
[ [ "Karbstein", "Felix", "" ], [ "Shaisultanov", "Rashid", "" ] ]
Starting from the Heisenberg-Euler effective Lagrangian, we determine the photon current and photon polarization tensor in inhomogeneous, slowly varying electromagnetic fields. To this end, we consider background field configurations varying in both space and time, paying special attention to the tensor structure. As a main result, we obtain compact analytical expressions for the photon polarization tensor in realistic Gaussian laser pulses, as generated in the focal spots of high-intensity lasers. These expressions are of utmost importance for the investigation of quantum vacuum nonlinearities in realistic high-intensity laser experiments.
hep-ph/9911217
Huo Wujun
Yu-feng Liu, Wu-jun Huo and Jinyan Zeng
Connection between closeness of classical orbits and the factorization of radial Schr\"{o}dinger equation
14 pages, no figures
Phys.Rev.A58:862,1998
10.1103/PhysRevA.58.862
null
hep-ph quant-ph
null
It was shown that the Runge-Lenz vector for a hydrogen atom is equivalent to the raising and lowering operators derived from the factorization of radial Schr\"{o}dinger equation. Similar situation exists for an isotropic harmonic oscillator. It seems that there may exist intimate relation between the closeness of classical orbits and the factorization of radial Schr\"{o}dinger equation. Some discussion was made about the factorization of a 1D Schr\"{o}dinger equation.
[ { "created": "Wed, 3 Nov 1999 11:35:45 GMT", "version": "v1" }, { "created": "Thu, 25 Nov 1999 03:56:56 GMT", "version": "v2" } ]
2010-11-19
[ [ "Liu", "Yu-feng", "" ], [ "Huo", "Wu-jun", "" ], [ "Zeng", "Jinyan", "" ] ]
It was shown that the Runge-Lenz vector for a hydrogen atom is equivalent to the raising and lowering operators derived from the factorization of radial Schr\"{o}dinger equation. Similar situation exists for an isotropic harmonic oscillator. It seems that there may exist intimate relation between the closeness of classical orbits and the factorization of radial Schr\"{o}dinger equation. Some discussion was made about the factorization of a 1D Schr\"{o}dinger equation.
1807.06524
Chung Wen Kao
Chung-Wen Kao, Dong-Jing Yang, Wen-Chen Chang
Charged Kaon multiplicities of Semi-inclusive DIS off the deuteron target
Contributed talk at the XXVI International Workshop on Deep Inelastic Scattering and Related Subjects at Kobe university, Kobe, Japan from April 16 to April 20, 2018
null
null
CYCU-HEP-18-05
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the results of the charged kaon multiplicities off the deuteron target from HERMES and COMPASS experiments. The discrepancy of the two data sets cannot be explained by different $Q^2$ values. Furthermore we examine the empirical parametrization of the fragmentation functions, DSS2017, and find that the agreement between the theoretical predictions and the HERMES data is less satisfactory as claimed.
[ { "created": "Tue, 17 Jul 2018 16:09:32 GMT", "version": "v1" } ]
2018-07-18
[ [ "Kao", "Chung-Wen", "" ], [ "Yang", "Dong-Jing", "" ], [ "Chang", "Wen-Chen", "" ] ]
We investigate the results of the charged kaon multiplicities off the deuteron target from HERMES and COMPASS experiments. The discrepancy of the two data sets cannot be explained by different $Q^2$ values. Furthermore we examine the empirical parametrization of the fragmentation functions, DSS2017, and find that the agreement between the theoretical predictions and the HERMES data is less satisfactory as claimed.
1012.5362
Xiang Liu
Dian-Yong Chen, Jun He and Xiang Liu
Nonresonant explanation for the Y(4260) structure observed in the $e^+e^-\to J/\psi\pi^+\pi^-$ process
7 pages, 4 figures, 4 tables. Final version accepted for publication in Physical Review D
Phys.Rev.D83:054021,2011
10.1103/PhysRevD.83.054021
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we proposed a nonresonant explanation for the Y(4260) structure observed in the $e^+e^-\to J/\psi\pi^+\pi^-$ process, i.e., Y(4260) is not a genuine resonance. Our result indicates that the Y(4260) structure can be reproduced by the interference of production amplitudes of the $e^+e^-\to J/\psi\pi^+\pi^-$ processes via direct $e^+e^-$ annihilation and through intermediate charmonia $\psi(4160)/\psi(4415)$. Besides describing Y(4260) line shape in $e^+e^-\to J/\psi\pi^+\pi^-$ well, such a nonresonant explanation for the Y(4260) structure naturally answers why there is no evidence of Y(4260) in the exclusive open-charm decay channel and $R$-value scan.
[ { "created": "Fri, 24 Dec 2010 08:29:54 GMT", "version": "v1" }, { "created": "Fri, 21 Jan 2011 04:11:07 GMT", "version": "v2" }, { "created": "Tue, 15 Feb 2011 06:53:25 GMT", "version": "v3" }, { "created": "Mon, 28 Feb 2011 13:20:06 GMT", "version": "v4" } ]
2011-03-16
[ [ "Chen", "Dian-Yong", "" ], [ "He", "Jun", "" ], [ "Liu", "Xiang", "" ] ]
In this work, we proposed a nonresonant explanation for the Y(4260) structure observed in the $e^+e^-\to J/\psi\pi^+\pi^-$ process, i.e., Y(4260) is not a genuine resonance. Our result indicates that the Y(4260) structure can be reproduced by the interference of production amplitudes of the $e^+e^-\to J/\psi\pi^+\pi^-$ processes via direct $e^+e^-$ annihilation and through intermediate charmonia $\psi(4160)/\psi(4415)$. Besides describing Y(4260) line shape in $e^+e^-\to J/\psi\pi^+\pi^-$ well, such a nonresonant explanation for the Y(4260) structure naturally answers why there is no evidence of Y(4260) in the exclusive open-charm decay channel and $R$-value scan.
1902.05737
Dian-Yong Chen
Qi Wu, Dian-Yong Chen, Xue-Jia Fan, and Gang Li
Production of $Z_c(3900$) and $Z_c(4020)$ in $B_c$ decay
6 pages, 2 figures and 2 tables, EPJC published version
Eur.Phys.J. C79 (2019) no.3, 265
10.1140/epjc/s10052-019-6784-6
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present work, we propose to search the charmonium-like states $Z_c(3900$) and $Z_c(4020)$ in the $B_c$ decay. In an effective Lagrangian approach, the branching ratios of $B_c^+ \to Z_c(3900)^+ \pi^0$ and $B_c^+\to Z_c (4020)^+ \pi^0$ are estimated to be of order of $10^{-4}$ and $10^{-7}$, respectively. The large production rate of $Z_c(3900)$ could provide an important source of the production of $Z_c(3900)$ from the semi-exclusive decay of $b$-flavored hadrons reported by D0 Collaboration, which can be tested by the exclusive measurements in LHCb.
[ { "created": "Fri, 15 Feb 2019 09:38:40 GMT", "version": "v1" }, { "created": "Thu, 28 Mar 2019 11:16:25 GMT", "version": "v2" } ]
2019-03-29
[ [ "Wu", "Qi", "" ], [ "Chen", "Dian-Yong", "" ], [ "Fan", "Xue-Jia", "" ], [ "Li", "Gang", "" ] ]
In the present work, we propose to search the charmonium-like states $Z_c(3900$) and $Z_c(4020)$ in the $B_c$ decay. In an effective Lagrangian approach, the branching ratios of $B_c^+ \to Z_c(3900)^+ \pi^0$ and $B_c^+\to Z_c (4020)^+ \pi^0$ are estimated to be of order of $10^{-4}$ and $10^{-7}$, respectively. The large production rate of $Z_c(3900)$ could provide an important source of the production of $Z_c(3900)$ from the semi-exclusive decay of $b$-flavored hadrons reported by D0 Collaboration, which can be tested by the exclusive measurements in LHCb.
1309.4770
Peinado Eduardo
D. Aristizabal Sierra, Chee Sheng Fong, Enrico Nardi and Eduardo Peinado
Cloistered Baryogenesis
18 pages, 2 figures; V2 references added, accepted for publication in JCAP
null
10.1088/1475-7516/2014/02/013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cosmological matter-antimatter asymmetry can arise from the baryon number conserving CP asymmetry in two body decays of heavy particles, when the two final states carry equal and opposite baryon number, and one couples directly or indirectly to electroweak sphalerons so that its baryon asymmetry gets partly reprocessed into a lepton asymmetry, while the other remains chemically decoupled from the thermal bath with its baryon content frozen. After sphaleron switchoff the decay of the decoupled particles inject in the thermal plasma an unbalanced baryon asymmetry, giving rise to baryogenesis. We highlight the features of this mechanism in a type-I seesaw model extended by adding a new colored scalar coupled to the heavy Majorana neutrinos. If the colored scalar has an O(TeV) mass, it would leave at the LHC a characteristic signature throughout all layers of the detectors.
[ { "created": "Wed, 18 Sep 2013 20:00:00 GMT", "version": "v1" }, { "created": "Tue, 28 Jan 2014 11:33:22 GMT", "version": "v2" } ]
2014-02-12
[ [ "Sierra", "D. Aristizabal", "" ], [ "Fong", "Chee Sheng", "" ], [ "Nardi", "Enrico", "" ], [ "Peinado", "Eduardo", "" ] ]
The cosmological matter-antimatter asymmetry can arise from the baryon number conserving CP asymmetry in two body decays of heavy particles, when the two final states carry equal and opposite baryon number, and one couples directly or indirectly to electroweak sphalerons so that its baryon asymmetry gets partly reprocessed into a lepton asymmetry, while the other remains chemically decoupled from the thermal bath with its baryon content frozen. After sphaleron switchoff the decay of the decoupled particles inject in the thermal plasma an unbalanced baryon asymmetry, giving rise to baryogenesis. We highlight the features of this mechanism in a type-I seesaw model extended by adding a new colored scalar coupled to the heavy Majorana neutrinos. If the colored scalar has an O(TeV) mass, it would leave at the LHC a characteristic signature throughout all layers of the detectors.
hep-ph/9503453
David Bowser-Chao
P. Agrawal, D. Bowser-Chao, and J. Pumplin
Optimized Top Quark Analysis with the Decision Tree
17 pages, uses revtex macros, postscript figures in .uu format, or available from the Authors.
Phys.Rev. D52 (1995) 6309-6315
10.1103/PhysRevD.52.6309
MSU-HEP/50327
hep-ph
null
We present an optimized and physically motivated method for separating top quark signal events from background events at the Tevatron. For the top quark signal $t\bar t \to e/\mu + 4$ jets, we show how to reject all but $25\%$ of the background in a data sample while retaining $80\%$ of the signal, without introducing bias into the subsequent mass measurement. The technique used is the Binary Decision Tree. Combining this highly efficient procedure for signal identification with a novel algorithm for top quark reconstruction, we propose a powerful new way to measure the top quark mass.
[ { "created": "Tue, 28 Mar 1995 01:55:42 GMT", "version": "v1" }, { "created": "Tue, 28 Mar 1995 16:11:01 GMT", "version": "v2" } ]
2009-10-28
[ [ "Agrawal", "P.", "" ], [ "Bowser-Chao", "D.", "" ], [ "Pumplin", "J.", "" ] ]
We present an optimized and physically motivated method for separating top quark signal events from background events at the Tevatron. For the top quark signal $t\bar t \to e/\mu + 4$ jets, we show how to reject all but $25\%$ of the background in a data sample while retaining $80\%$ of the signal, without introducing bias into the subsequent mass measurement. The technique used is the Binary Decision Tree. Combining this highly efficient procedure for signal identification with a novel algorithm for top quark reconstruction, we propose a powerful new way to measure the top quark mass.
1912.09164
Mari\'an Koles\'ar
Mari\'an Koles\'ar, Jaroslav \v{R}\'iha
Application of Bayesian statistics to $\eta$-meson decay constant in $\chi$PT
Presented at "QCD 19", Montpellier, France, July 4, 2019. 4 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay constant of the $\eta$-meson in the framework of 'resummed' chiral perturbation theory is discussed. A theoretical prediction is compared to the available determinations. Compatibility of these determinations with the latest fits of the SU(3) low energy coupling constants is investigated. Preliminary results for the obtained constraints on the low energy coupling constants $L^r_5$ and $L^r_4$, using Bayesian statistical approach, are presented.
[ { "created": "Thu, 19 Dec 2019 12:45:44 GMT", "version": "v1" } ]
2019-12-20
[ [ "Kolesár", "Marián", "" ], [ "Říha", "Jaroslav", "" ] ]
The decay constant of the $\eta$-meson in the framework of 'resummed' chiral perturbation theory is discussed. A theoretical prediction is compared to the available determinations. Compatibility of these determinations with the latest fits of the SU(3) low energy coupling constants is investigated. Preliminary results for the obtained constraints on the low energy coupling constants $L^r_5$ and $L^r_4$, using Bayesian statistical approach, are presented.
hep-ph/0312041
Bo-Qiang Ma
Bin Wu and Bo-Qiang Ma
The 27-plet Baryons from Chiral Soliton Models
4 pages in Revtex format, 1 figure, version to appear in PRD
Phys.Rev. D69 (2004) 077501
10.1103/PhysRevD.69.077501
null
hep-ph hep-ex nucl-ex nucl-th
null
We use the perturbation method to calculate the masses and widths for 27-plet baryons with spin 3/2 from chiral soliton models. According to the masses and quantum numbers, we find all the candidates for non-exotic members of 27-plet. The calculation of the widths shows that these candidates manifest an approximate symmetry of the 27 representation of the SU(3) group, and the quantum numbers of $\Xi(1950)$ seem to be $I(J^P)={1/2}({3/2}^+)$. Up to leading order of the strange quark mass, we find that the exotic members have widths much larger than those of the anti-decuplet members.
[ { "created": "Tue, 2 Dec 2003 23:32:36 GMT", "version": "v1" }, { "created": "Tue, 24 Feb 2004 00:40:28 GMT", "version": "v2" } ]
2009-11-10
[ [ "Wu", "Bin", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We use the perturbation method to calculate the masses and widths for 27-plet baryons with spin 3/2 from chiral soliton models. According to the masses and quantum numbers, we find all the candidates for non-exotic members of 27-plet. The calculation of the widths shows that these candidates manifest an approximate symmetry of the 27 representation of the SU(3) group, and the quantum numbers of $\Xi(1950)$ seem to be $I(J^P)={1/2}({3/2}^+)$. Up to leading order of the strange quark mass, we find that the exotic members have widths much larger than those of the anti-decuplet members.
1011.5304
Patrick Draper
Marcela Carena, Patrick Draper, Sven Heinemeyer, Tao Liu, Carlos E.M. Wagner, Georg Weiglein
Probing the Higgs Sector of High-Scale SUSY-Breaking Models at the Tevatron
14 pages
Phys.Rev.D83:055007,2011
10.1103/PhysRevD.83.055007
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A canonical signature of the Minimal Supersymmetric Standard Model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and Standard Model (SM)-like couplings to the electroweak gauge bosons. In this note we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY)-breaking, including the Constrained MSSM (CMSSM), minimal Gauge Mediated SUSY-breaking (mGMSB), and minimal Anomaly Mediated SUSY-breaking (mAMSB). We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb^-1 per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb^-1, our projection shows that evidence at the 3-sigma level for the light Higgs boson could be expected in extended regions of parameter space.
[ { "created": "Wed, 24 Nov 2010 05:39:44 GMT", "version": "v1" } ]
2011-03-22
[ [ "Carena", "Marcela", "" ], [ "Draper", "Patrick", "" ], [ "Heinemeyer", "Sven", "" ], [ "Liu", "Tao", "" ], [ "Wagner", "Carlos E. M.", "" ], [ "Weiglein", "Georg", "" ] ]
A canonical signature of the Minimal Supersymmetric Standard Model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and Standard Model (SM)-like couplings to the electroweak gauge bosons. In this note we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY)-breaking, including the Constrained MSSM (CMSSM), minimal Gauge Mediated SUSY-breaking (mGMSB), and minimal Anomaly Mediated SUSY-breaking (mAMSB). We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb^-1 per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb^-1, our projection shows that evidence at the 3-sigma level for the light Higgs boson could be expected in extended regions of parameter space.
2001.03031
Vincent Theeuwes
Anna Kulesza, Leszek Motyka, Daniel Schwartl\"ander, Tomasz Stebel, Vincent Theeuwes
Associated top quark pair production with a heavy boson: differential cross sections at NLO+NNLL accuracy
28 pages, 23 figures; Published version
Eur. Phys. J. C (2020) 80: 428
10.1140/epjc/s10052-020-7987-6
MS-TP-20-01
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present theoretical predictions for selected differential cross sections for the process $pp \to t \bar{t} B$ at the LHC, where $B$ can be a Higgs ($H$), a $Z$ or a $W$ boson. The predictions are calculated in the direct QCD framework up to the next-to-next-leading logarithmic (NNLL) accuracy and matched to the complete NLO results including QCD and electroweak effects. Additionally, results for the total cross sections are provided. The calculations deliver a significant improvement of the theoretical predictions, especially for the $t \bar{t} H$ and the $t \bar{t} Z$ production. In these cases, predictions for both the total and differential cross sections are remarkably stable with respect to the central scale choice and carry a substantially reduced scale uncertainty in comparison with the complete NLO predictions.
[ { "created": "Thu, 9 Jan 2020 14:48:19 GMT", "version": "v1" }, { "created": "Fri, 22 May 2020 10:49:45 GMT", "version": "v2" } ]
2020-05-25
[ [ "Kulesza", "Anna", "" ], [ "Motyka", "Leszek", "" ], [ "Schwartländer", "Daniel", "" ], [ "Stebel", "Tomasz", "" ], [ "Theeuwes", "Vincent", "" ] ]
We present theoretical predictions for selected differential cross sections for the process $pp \to t \bar{t} B$ at the LHC, where $B$ can be a Higgs ($H$), a $Z$ or a $W$ boson. The predictions are calculated in the direct QCD framework up to the next-to-next-leading logarithmic (NNLL) accuracy and matched to the complete NLO results including QCD and electroweak effects. Additionally, results for the total cross sections are provided. The calculations deliver a significant improvement of the theoretical predictions, especially for the $t \bar{t} H$ and the $t \bar{t} Z$ production. In these cases, predictions for both the total and differential cross sections are remarkably stable with respect to the central scale choice and carry a substantially reduced scale uncertainty in comparison with the complete NLO predictions.
hep-ph/9209236
null
P. Gondolo, G. Gelmini and S. Sarkar
Cosmic Neutrinos from Unstable Relic Particles
21pp, 11 figures available on request, PHYZZX, UCLA/91/TEP/31 (revised)
Nucl.Phys.B392:111-136,1993
10.1016/0550-3213(93)90199-Y
null
hep-ph
null
We derive constraints on the relic abundance of a generic particle of mass $\sim~1-10^{14}$ TeV which decays into neutrinos at cosmological epochs, using data from the Fr\'ejus and IMB nucleon decay detectors and the Fly's Eye air shower array. The lifetime of such unstable particles which may constitute the dark matter today is bounded to be greater than $\sim~10^{14}-10^{18}$ yr, depending on the mass. For lifetimes shorter than the age of the universe, neutrino energy losses due to scattering and the expansion redshift become important and set limits to the ability of neutrino observatories to probe the early universe.
[ { "created": "Tue, 15 Sep 1992 14:58:00 GMT", "version": "v1" } ]
2011-02-16
[ [ "Gondolo", "P.", "" ], [ "Gelmini", "G.", "" ], [ "Sarkar", "S.", "" ] ]
We derive constraints on the relic abundance of a generic particle of mass $\sim~1-10^{14}$ TeV which decays into neutrinos at cosmological epochs, using data from the Fr\'ejus and IMB nucleon decay detectors and the Fly's Eye air shower array. The lifetime of such unstable particles which may constitute the dark matter today is bounded to be greater than $\sim~10^{14}-10^{18}$ yr, depending on the mass. For lifetimes shorter than the age of the universe, neutrino energy losses due to scattering and the expansion redshift become important and set limits to the ability of neutrino observatories to probe the early universe.
hep-ph/0610343
Mar Bastero-Gil
Mar Bastero-Gil Arjun Berera
Warm inflation dynamics in the low temperature regime
13 pages, 2 eps figures
Phys.Rev.D76:043515,2007
10.1103/PhysRevD.76.043515
UG-FT-211/06, CAFPE-81/06
hep-ph astro-ph
null
Warm inflation scenarios are studied with the dissipative coefficient computed in the equilibrium approximation. Use is made of the analytical expressions available in the low temperature regime with focus on the possibility of achieving strong dissipation within this approximation. Two different types of models are examined: monomial or equivalently chaotic type potentials, and hybrid like models where the energy density during inflation is dominated by the false vacuum. In both cases dissipation is shown to typically increase during inflation and bring the system into the strong dissipative regime. Observational consequences are explored for the amplitude of the primordial spectrum and the spectral index, which translate into constraints on the number of fields mediating the dissipative mechanism, and the number of light degrees of freedom produced during inflation. This paper furthers the foundational development of warm inflation dynamics from first principles quantum field theory by calculating conservative lower bound estimates on dissipative effects during inflation using the well established thermal equilibrium approximation. This approximation does not completely represent the actual physical system and earlier work has shown relaxing both the equilibrium and low temperature constraints can substantially enlarge the warm inflation regime, but these improvements still need further theoretical development.
[ { "created": "Wed, 25 Oct 2006 17:36:51 GMT", "version": "v1" } ]
2008-11-26
[ [ "Berera", "Mar Bastero-Gil Arjun", "" ] ]
Warm inflation scenarios are studied with the dissipative coefficient computed in the equilibrium approximation. Use is made of the analytical expressions available in the low temperature regime with focus on the possibility of achieving strong dissipation within this approximation. Two different types of models are examined: monomial or equivalently chaotic type potentials, and hybrid like models where the energy density during inflation is dominated by the false vacuum. In both cases dissipation is shown to typically increase during inflation and bring the system into the strong dissipative regime. Observational consequences are explored for the amplitude of the primordial spectrum and the spectral index, which translate into constraints on the number of fields mediating the dissipative mechanism, and the number of light degrees of freedom produced during inflation. This paper furthers the foundational development of warm inflation dynamics from first principles quantum field theory by calculating conservative lower bound estimates on dissipative effects during inflation using the well established thermal equilibrium approximation. This approximation does not completely represent the actual physical system and earlier work has shown relaxing both the equilibrium and low temperature constraints can substantially enlarge the warm inflation regime, but these improvements still need further theoretical development.
hep-ph/0503271
Subir Sarkar
Subir Sarkar (Oxford)
Measuring the cosmological density perturbation
6 pages, 4 figures; Talk at Workshop on `The Density Perturbation in the Universe', Athens, June 2004 (references added, no change in text)
Nucl.Phys.Proc.Suppl.148:1-6,2005
10.1016/j.nuclphysbps.2005.04.044
null
hep-ph astro-ph
null
Precision measurements of anisotropies in the cosmic microwave background and of the clustering of large-scale structure have supposedly confirmed that the primordial density perturbation has a (nearly) scale-invariant spectrum. However this conclusion is based on assumptions about the world model and the nature of the dark matter. Physical models of inflation suggest that the spectrum may not in fact be scale-free, which would imply rather different cosmological parameters on the basis of the same observational data.
[ { "created": "Mon, 28 Mar 2005 19:57:06 GMT", "version": "v1" }, { "created": "Fri, 1 Apr 2005 10:14:16 GMT", "version": "v2" } ]
2011-02-16
[ [ "Sarkar", "Subir", "", "Oxford" ] ]
Precision measurements of anisotropies in the cosmic microwave background and of the clustering of large-scale structure have supposedly confirmed that the primordial density perturbation has a (nearly) scale-invariant spectrum. However this conclusion is based on assumptions about the world model and the nature of the dark matter. Physical models of inflation suggest that the spectrum may not in fact be scale-free, which would imply rather different cosmological parameters on the basis of the same observational data.
hep-ph/9708473
Andre Rouge
Andre Rouge (LPNHE Ecole Polytechnique-IN2P3/CNRS)
Isospin constraints on the $\tau\to K\bar Kn\pi\nu$ decay mode
7 pages, Latex, 3 PostScript figures, to appear in Z. Phys. C
Eur.Phys.J.C4:265-268,1998
10.1007/s100520050203
X-LPNHE 97/08
hep-ph
null
The construction of the complete isospin relations and inequalities between the possible charge configurations of a $\tau\to K\bar Kn\pi\nu$ decay mode is presented. Detailed applications to the cases of two and three pions are given.
[ { "created": "Wed, 27 Aug 1997 12:55:10 GMT", "version": "v1" }, { "created": "Tue, 7 Oct 1997 14:30:52 GMT", "version": "v2" } ]
2011-09-13
[ [ "Rouge", "Andre", "", "LPNHE Ecole Polytechnique-IN2P3/CNRS" ] ]
The construction of the complete isospin relations and inequalities between the possible charge configurations of a $\tau\to K\bar Kn\pi\nu$ decay mode is presented. Detailed applications to the cases of two and three pions are given.
hep-ph/9705363
Patrick O'Donnell
Harry J. Lipkin, Patrick J. O'Donnell
Hyperfine Interactions in Charm and Bottom Systems
10 pages, plain Latex, no figures. A new isospin argument has been added
Phys.Lett. B409 (1997) 412-416
10.1016/S0370-2693(97)00884-8
TAUP 2424-97, WIS-97/12/MAY-PH, UTPT-97-11
hep-ph
null
Hyperfine interactions in the light meson and baryon sectors are generalized to the charm and bottom systems. It is pointed out that an attempt to increase the value of the wave function at the origin to account for the unusual ratio of $\Lambda_{b}$ to the $B^0$ lifetimes could spoil the good agreement among the baryon and meson hyperfine mass-splitting. Including spin effects and taking phase space differences into account we predict that the decay rate of the $\Lambda_{b}$ can be increased relative to that of the $B^0$ meson by about 7%.
[ { "created": "Tue, 20 May 1997 19:16:35 GMT", "version": "v1" }, { "created": "Wed, 16 Jul 1997 16:15:48 GMT", "version": "v2" } ]
2009-10-30
[ [ "Lipkin", "Harry J.", "" ], [ "O'Donnell", "Patrick J.", "" ] ]
Hyperfine interactions in the light meson and baryon sectors are generalized to the charm and bottom systems. It is pointed out that an attempt to increase the value of the wave function at the origin to account for the unusual ratio of $\Lambda_{b}$ to the $B^0$ lifetimes could spoil the good agreement among the baryon and meson hyperfine mass-splitting. Including spin effects and taking phase space differences into account we predict that the decay rate of the $\Lambda_{b}$ can be increased relative to that of the $B^0$ meson by about 7%.
2011.03550
Sang Eon Park
Sang Eon Park, Dylan Rankin, Silviu-Marian Udrescu, Mikaeel Yunus, Philip Harris
Quasi Anomalous Knowledge: Searching for new physics with embedded knowledge
25 pages, 9 figures
J. High Energ. Phys. 2021, 30 (2021)
10.1007/JHEP06(2021)030
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Discoveries of new phenomena often involve a dedicated search for a hypothetical physics signature. Recently, novel deep learning techniques have emerged for anomaly detection in the absence of a signal prior. However, by ignoring signal priors, the sensitivity of these approaches is significantly reduced. We present a new strategy dubbed Quasi Anomalous Knowledge (QUAK), whereby we introduce alternative signal priors that capture some of the salient features of new physics signatures, allowing for the recovery of sensitivity even when the alternative signal is incorrect. This approach can be applied to a broad range of physics models and neural network architectures. In this paper, we apply QUAK to anomaly detection of new physics events at the CERN Large Hadron Collider utilizing variational autoencoders with normalizing flow.
[ { "created": "Fri, 6 Nov 2020 19:00:02 GMT", "version": "v1" }, { "created": "Sun, 21 Mar 2021 06:44:16 GMT", "version": "v2" }, { "created": "Tue, 8 Jun 2021 18:22:18 GMT", "version": "v3" }, { "created": "Fri, 11 Jun 2021 17:28:38 GMT", "version": "v4" } ]
2021-06-14
[ [ "Park", "Sang Eon", "" ], [ "Rankin", "Dylan", "" ], [ "Udrescu", "Silviu-Marian", "" ], [ "Yunus", "Mikaeel", "" ], [ "Harris", "Philip", "" ] ]
Discoveries of new phenomena often involve a dedicated search for a hypothetical physics signature. Recently, novel deep learning techniques have emerged for anomaly detection in the absence of a signal prior. However, by ignoring signal priors, the sensitivity of these approaches is significantly reduced. We present a new strategy dubbed Quasi Anomalous Knowledge (QUAK), whereby we introduce alternative signal priors that capture some of the salient features of new physics signatures, allowing for the recovery of sensitivity even when the alternative signal is incorrect. This approach can be applied to a broad range of physics models and neural network architectures. In this paper, we apply QUAK to anomaly detection of new physics events at the CERN Large Hadron Collider utilizing variational autoencoders with normalizing flow.
hep-ph/0612178
Justyna Jankiewicz
Justyna Jankiewicz
Numerical Evaluation of some Parameters for a Model of Neutral Kaons
LaTeX2e, 29 pages, 17 figures, new section, new figures, new comments and references added, several stylistic improvements, Acta Physica Polonica B - in press
ActaPhys.Polon.B38:2471-2488,2007
null
null
hep-ph hep-ex
null
Using the Mathematica program we calculate numerically the difference of the diagonal matrix elements of the time dependent effective Hamiltonian for the neutral K meson complex. We consider the exactly solvable neutral K meson model based on the one-pole approximation for the mass density. The so-called Khalfin's Theorem is numerically examined. Some characteristic parameters for this system are also calculated. The results of all calculations are presented in the graphical form. The calculations are made assuming the total system is CPT -- invariant and CP -- noninvariant.
[ { "created": "Thu, 14 Dec 2006 11:42:31 GMT", "version": "v1" }, { "created": "Tue, 19 Dec 2006 07:48:26 GMT", "version": "v2" }, { "created": "Thu, 21 Jun 2007 19:21:58 GMT", "version": "v3" } ]
2008-11-26
[ [ "Jankiewicz", "Justyna", "" ] ]
Using the Mathematica program we calculate numerically the difference of the diagonal matrix elements of the time dependent effective Hamiltonian for the neutral K meson complex. We consider the exactly solvable neutral K meson model based on the one-pole approximation for the mass density. The so-called Khalfin's Theorem is numerically examined. Some characteristic parameters for this system are also calculated. The results of all calculations are presented in the graphical form. The calculations are made assuming the total system is CPT -- invariant and CP -- noninvariant.
hep-ph/0608051
Karol Kampf
Karol Kampf, Jiri Novotny, Jaroslav Trnka
On different lagrangian formalisms for vector resonances within chiral perturbation theory
34 pages, 3 figures
Eur.Phys.J.C50:385-403,2007
10.1140/epjc/s10052-006-0171-9
null
hep-ph
null
We study the relation of vector Proca field formalism and antisymmetric tensor field formalism for spin-one resonances in the context of the large N_C inspired chiral resonance Lagrangian systematically up to the order O(p6) and give a transparent prescription for the transition from vector to antisymmetric tensor Lagrangian and vice versa. We also discuss the possibility to describe the spin-one resonances using an alternative "mixed" first order formalism, which includes both types of fields simultaneously, and compare this one with the former two. We also briefly comment on the compatibility of the above lagrangian formalisms with the high-energy constraints for concrete VVP correlator.
[ { "created": "Fri, 4 Aug 2006 12:28:34 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kampf", "Karol", "" ], [ "Novotny", "Jiri", "" ], [ "Trnka", "Jaroslav", "" ] ]
We study the relation of vector Proca field formalism and antisymmetric tensor field formalism for spin-one resonances in the context of the large N_C inspired chiral resonance Lagrangian systematically up to the order O(p6) and give a transparent prescription for the transition from vector to antisymmetric tensor Lagrangian and vice versa. We also discuss the possibility to describe the spin-one resonances using an alternative "mixed" first order formalism, which includes both types of fields simultaneously, and compare this one with the former two. We also briefly comment on the compatibility of the above lagrangian formalisms with the high-energy constraints for concrete VVP correlator.
2306.00368
Arnab Dasgupta
Debasish Borah, Arnab Dasgupta and Daniel Stolarski
Dynamical Inflation Stimulated Cogenesis
22 pages, 6 figures, Published version
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/publicdomain/zero/1.0/
We propose a minimal setup that realises dynamical inflection point inflation, and, using the same field content, generates neutrino masses, a baryon asymmetry of the universe, and dark matter. A dark $SU(2)_D$ gauge sector with a dark scalar doublet playing the role of inflaton is considered along with several doublet and singlet fermions sufficient to realise multiple inflection points in the inflaton potential. The singlet fermions couple to SM leptons and generate neutrino masses via the inverse seesaw mechanism. Those fermions also decay asymmetrically and out of equilibrium, generating a baryon asymmetry via leptogenesis. Some of the fermion doublets are dark matter, and they are produced via inflaton decay and freeze-in annihilation of the same fermions that generate the lepton asymmetry. Reheating, leptogenesis, and dark matter are all at the TeV scale.
[ { "created": "Thu, 1 Jun 2023 06:00:38 GMT", "version": "v1" }, { "created": "Wed, 14 Feb 2024 05:50:44 GMT", "version": "v2" } ]
2024-02-15
[ [ "Borah", "Debasish", "" ], [ "Dasgupta", "Arnab", "" ], [ "Stolarski", "Daniel", "" ] ]
We propose a minimal setup that realises dynamical inflection point inflation, and, using the same field content, generates neutrino masses, a baryon asymmetry of the universe, and dark matter. A dark $SU(2)_D$ gauge sector with a dark scalar doublet playing the role of inflaton is considered along with several doublet and singlet fermions sufficient to realise multiple inflection points in the inflaton potential. The singlet fermions couple to SM leptons and generate neutrino masses via the inverse seesaw mechanism. Those fermions also decay asymmetrically and out of equilibrium, generating a baryon asymmetry via leptogenesis. Some of the fermion doublets are dark matter, and they are produced via inflaton decay and freeze-in annihilation of the same fermions that generate the lepton asymmetry. Reheating, leptogenesis, and dark matter are all at the TeV scale.
2312.10125
Federica Capellino
Federica Capellino, Andrea Dubla, Stefan Floerchinger, Eduardo Grossi, Andreas Kirchner, Silvia Masciocchi
Hydrodynamization of charm quarks in heavy-ion collisions
4 pages, 2 figures, Contribution to Quark Matter 2023. arXiv admin note: substantial text overlap with arXiv:2307.15580
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
Heavy quarks (i.e. charm and beauty) in heavy-ion collisions are initially produced out of kinetic equilibrium via hard partonic scattering processes. However, recent measurements of anisotropic flow of charmed hadrons pose the question regarding the thermalization of heavy quarks in the quark-gluon plasma (QGP). Exploiting a mapping between transport theory and fluid dynamics, we develop a fluid-dynamic description for charm quarks and show results for charm-hadron momentum distributions. Inspired by recent Lattice-QCD (LQCD) calculations, we show that a late hydrodynamization within the lifetime of the QGP is possible also for beauty quarks.
[ { "created": "Fri, 15 Dec 2023 14:17:33 GMT", "version": "v1" } ]
2023-12-19
[ [ "Capellino", "Federica", "" ], [ "Dubla", "Andrea", "" ], [ "Floerchinger", "Stefan", "" ], [ "Grossi", "Eduardo", "" ], [ "Kirchner", "Andreas", "" ], [ "Masciocchi", "Silvia", "" ] ]
Heavy quarks (i.e. charm and beauty) in heavy-ion collisions are initially produced out of kinetic equilibrium via hard partonic scattering processes. However, recent measurements of anisotropic flow of charmed hadrons pose the question regarding the thermalization of heavy quarks in the quark-gluon plasma (QGP). Exploiting a mapping between transport theory and fluid dynamics, we develop a fluid-dynamic description for charm quarks and show results for charm-hadron momentum distributions. Inspired by recent Lattice-QCD (LQCD) calculations, we show that a late hydrodynamization within the lifetime of the QGP is possible also for beauty quarks.
0801.1980
Michael Trusov
I.M.Narodetskii, M.A.Trusov, A.I.Veselov
Charm and bottom baryons in nonperturbative quark dynamics
Contributed talk at the session of Russian Academy of Sciences "Physics of Fundamental Interactions", ITEP, Moscow, November 26-30, 2007
Phys.Atom.Nucl.72:536-540,2009
10.1134/S1063778809030193
null
hep-ph
null
We use the Field Correlator Method in QCD to calculate the masses of $\Sigma_c$, $\Xi_c$ and recently observed $\Sigma_b$, $\Xi_b$ baryons and their orbital excitations.
[ { "created": "Sun, 13 Jan 2008 19:47:02 GMT", "version": "v1" } ]
2009-04-17
[ [ "Narodetskii", "I. M.", "" ], [ "Trusov", "M. A.", "" ], [ "Veselov", "A. I.", "" ] ]
We use the Field Correlator Method in QCD to calculate the masses of $\Sigma_c$, $\Xi_c$ and recently observed $\Sigma_b$, $\Xi_b$ baryons and their orbital excitations.
hep-ph/0104243
Andrew Akeroyd
A.G. Akeroyd, A.Arhrib and M. Capdequi Peyran\`ere
Supersymmetric enhancement of associated ZA^0 production at e^+e^- colliders
10 pages, LaTex, 4 figures, figures changed and differ from published version. Conclusions slightly altered
Phys.Rev.D64:075007,2001; Erratum-ibid.D65:099903,2002
10.1103/PhysRevD.64.075007 10.1103/PhysRevD.65.099903
null
hep-ph
null
We study the associated production of the A^0 neutral CP-odd Higgs boson with a neutral gauge boson Z in high energy e^+ e^- collisions at the one loop level. We present a detailed discussion for the total cross-section predicted in the context of the Minimal Supersymmetric Standard Model (MSSM) and make a comparison with the non-SUSY Two Higgs Doublet Model (THDM). We show that the MSSM cross-section may be enhanced compared to that for the THDM.
[ { "created": "Tue, 24 Apr 2001 12:53:21 GMT", "version": "v1" }, { "created": "Wed, 11 Jul 2001 02:54:38 GMT", "version": "v2" }, { "created": "Wed, 29 May 2002 14:17:12 GMT", "version": "v3" } ]
2014-11-17
[ [ "Akeroyd", "A. G.", "" ], [ "Arhrib", "A.", "" ], [ "Peyranère", "M. Capdequi", "" ] ]
We study the associated production of the A^0 neutral CP-odd Higgs boson with a neutral gauge boson Z in high energy e^+ e^- collisions at the one loop level. We present a detailed discussion for the total cross-section predicted in the context of the Minimal Supersymmetric Standard Model (MSSM) and make a comparison with the non-SUSY Two Higgs Doublet Model (THDM). We show that the MSSM cross-section may be enhanced compared to that for the THDM.
2001.04773
Neil Barrie Dr.
Neil D. Barrie
Big Bounce Baryogenesis
20 pages, 3 figures; revised version, consistent with that published in JCAP
null
10.1088/1475-7516/2020/08/008
IPMU19-0169
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the possibility of an Ekpyrotic contraction phase harbouring a mechanism for Baryogenesis. A Chern-Simons coupling between the fast-rolling Ekpyrotic scalar and the Standard Model Hypercharge gauge field enables the generation of a non-zero helicity during the contraction phase. The baryon number subsequently produced at the Electroweak Phase Transition is consistent with observation for a range of couplings and bounce scales. Simultaneously, the gauge field production during the contraction provides the seeds for galactic magnetic fields and sources gravitational waves, which may provide additional avenues for observational confirmation.
[ { "created": "Tue, 14 Jan 2020 13:48:17 GMT", "version": "v1" }, { "created": "Tue, 18 Aug 2020 03:05:32 GMT", "version": "v2" } ]
2020-08-19
[ [ "Barrie", "Neil D.", "" ] ]
We explore the possibility of an Ekpyrotic contraction phase harbouring a mechanism for Baryogenesis. A Chern-Simons coupling between the fast-rolling Ekpyrotic scalar and the Standard Model Hypercharge gauge field enables the generation of a non-zero helicity during the contraction phase. The baryon number subsequently produced at the Electroweak Phase Transition is consistent with observation for a range of couplings and bounce scales. Simultaneously, the gauge field production during the contraction provides the seeds for galactic magnetic fields and sources gravitational waves, which may provide additional avenues for observational confirmation.
2201.00681
Shota Nakagawa
Kwang Sik Jeong, Kohei Matsukawa, Shota Nakagawa, and Fuminobu Takahashi
Cosmological effects of Peccei-Quinn symmetry breaking on QCD axion dark matter
28 pages, 16 figures
null
10.1088/1475-7516/2022/03/026
PNUTP-22-A11, TU-1143
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study cosmological effects of explicit Peccei-Quinn breaking on the QCD axion dark matter. We find that the axion abundance decreases or increases significantly depending on the initial position, even for a tiny Peccei-Quinn breaking that satisfies the experimental bound of the neutron electric dipole measurements. If the axion first starts to oscillate around a wrong vacuum and if it gets trapped there until the false vacuum disappears due to non-perturbative QCD effects, its abundance increases significantly and is independent of the decay constant $f_a$, as first pointed out in [JHEP 06 (2016) 150]. Thus, the axion produced by the trapping mechanism can explain dark matter even when the decay constant is close to the lower limit due to stellar cooling arguments. On the other hand, if the axion starts to oscillate about a potential minimum close to the low-energy vacuum, its abundance is significantly reduced because of the adiabatic suppression mechanism. This relaxes the upper limit of the axion window to large values of $f_a$. We also discuss how the axionic isocurvature perturbation is affected by the Peccei-Quinn breaking term, and show that it can be suppressed in both regimes. In particular, the isocurvature bound on the inflation scale is relaxed by many orders of magnitudes for $f_a \lesssim 10^{11}{\rm GeV}$ compared to the conventional scenario.
[ { "created": "Mon, 3 Jan 2022 14:44:19 GMT", "version": "v1" } ]
2022-03-30
[ [ "Jeong", "Kwang Sik", "" ], [ "Matsukawa", "Kohei", "" ], [ "Nakagawa", "Shota", "" ], [ "Takahashi", "Fuminobu", "" ] ]
We study cosmological effects of explicit Peccei-Quinn breaking on the QCD axion dark matter. We find that the axion abundance decreases or increases significantly depending on the initial position, even for a tiny Peccei-Quinn breaking that satisfies the experimental bound of the neutron electric dipole measurements. If the axion first starts to oscillate around a wrong vacuum and if it gets trapped there until the false vacuum disappears due to non-perturbative QCD effects, its abundance increases significantly and is independent of the decay constant $f_a$, as first pointed out in [JHEP 06 (2016) 150]. Thus, the axion produced by the trapping mechanism can explain dark matter even when the decay constant is close to the lower limit due to stellar cooling arguments. On the other hand, if the axion starts to oscillate about a potential minimum close to the low-energy vacuum, its abundance is significantly reduced because of the adiabatic suppression mechanism. This relaxes the upper limit of the axion window to large values of $f_a$. We also discuss how the axionic isocurvature perturbation is affected by the Peccei-Quinn breaking term, and show that it can be suppressed in both regimes. In particular, the isocurvature bound on the inflation scale is relaxed by many orders of magnitudes for $f_a \lesssim 10^{11}{\rm GeV}$ compared to the conventional scenario.
1410.8459
Andreas Crivellin
Jason Aebischer, Andreas Crivellin and Christoph Greub
1-loop SQCD corrections to the decay of top-squarks to charm and neutralino in the generic MSSM
25 pages, 7 figures
null
10.1103/PhysRevD.91.035010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we calculate the 1-loop supersymmetric QCD (SQCD) corrections to the decay $\tilde u_1\to c \tilde\chi^0_1$ in the MSSM with generic flavour structure. This decay mode is phenomenologically important if the mass difference between the lightest squark $\tilde u_1$ (which is assumed to be mainly stop-like) and the neutralino LSP $\tilde \chi^0_1$ is smaller than the top mass. In such a scenario $\tilde u_1\to t \tilde\chi^0_1$ is kinematically not allowed and searches for $\tilde u_1\to W b \tilde\chi^0_1$ and $\tilde u_1\to c \tilde\chi^0_1$ are performed. A large decay rate for $\tilde u_1\to c \tilde\chi^0_1$ can weaken the LHC bounds from $\tilde u_1\to W b \chi^0_1$ which are usually obtained under the assumption ${\rm Br}[\tilde u_1\to W b \chi^0_1]=100\%$. We find the SQCD corrections enhance $\Gamma[\tilde u_1\to c \tilde\chi^0_1]$ by approximately 10\% if the flavour-violation originates from bilinear terms. If flavour-violation originates from trilinear terms, the effect can be $\pm 50\%$ or more, depending on the sign of $A^t$. We note that connecting a theory of SUSY breaking to LHC observables, the shift from the $\overline{\rm DR}$ to the on-shell mass is numerically very important for light stop decays.
[ { "created": "Thu, 30 Oct 2014 17:37:12 GMT", "version": "v1" } ]
2015-06-23
[ [ "Aebischer", "Jason", "" ], [ "Crivellin", "Andreas", "" ], [ "Greub", "Christoph", "" ] ]
In this article we calculate the 1-loop supersymmetric QCD (SQCD) corrections to the decay $\tilde u_1\to c \tilde\chi^0_1$ in the MSSM with generic flavour structure. This decay mode is phenomenologically important if the mass difference between the lightest squark $\tilde u_1$ (which is assumed to be mainly stop-like) and the neutralino LSP $\tilde \chi^0_1$ is smaller than the top mass. In such a scenario $\tilde u_1\to t \tilde\chi^0_1$ is kinematically not allowed and searches for $\tilde u_1\to W b \tilde\chi^0_1$ and $\tilde u_1\to c \tilde\chi^0_1$ are performed. A large decay rate for $\tilde u_1\to c \tilde\chi^0_1$ can weaken the LHC bounds from $\tilde u_1\to W b \chi^0_1$ which are usually obtained under the assumption ${\rm Br}[\tilde u_1\to W b \chi^0_1]=100\%$. We find the SQCD corrections enhance $\Gamma[\tilde u_1\to c \tilde\chi^0_1]$ by approximately 10\% if the flavour-violation originates from bilinear terms. If flavour-violation originates from trilinear terms, the effect can be $\pm 50\%$ or more, depending on the sign of $A^t$. We note that connecting a theory of SUSY breaking to LHC observables, the shift from the $\overline{\rm DR}$ to the on-shell mass is numerically very important for light stop decays.
1606.09555
Juan Helo
L. Gonzales, J.C. Helo, M. Hirsch, S.G. Kovalenko
Scalar-mediated double beta decay and LHC
14 pages, 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The decay rate of neutrinoless double beta decay could be dominated by short-range diagrams involving heavy scalar particles ("topology-II" diagrams). Examples are diagrams with diquarks, leptoquarks or charged scalars. Here, we compare the discovery potential for lepton number violating signals at the LHC with constraints from dijet and leptoquark searches and the sensitivity of double beta decay experiments, using three example models. We note that already with 20/fb the LHC will test interesting parts of the parameter space of these models, not excluded by current limits on double beta decay.
[ { "created": "Thu, 30 Jun 2016 16:24:04 GMT", "version": "v1" } ]
2016-07-01
[ [ "Gonzales", "L.", "" ], [ "Helo", "J. C.", "" ], [ "Hirsch", "M.", "" ], [ "Kovalenko", "S. G.", "" ] ]
The decay rate of neutrinoless double beta decay could be dominated by short-range diagrams involving heavy scalar particles ("topology-II" diagrams). Examples are diagrams with diquarks, leptoquarks or charged scalars. Here, we compare the discovery potential for lepton number violating signals at the LHC with constraints from dijet and leptoquark searches and the sensitivity of double beta decay experiments, using three example models. We note that already with 20/fb the LHC will test interesting parts of the parameter space of these models, not excluded by current limits on double beta decay.