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hep-ph/0005051
Rudolf Baier
D. Ahrensmeier, R. Baier, M. Dirks (Faculty of Physics, University of Bielefeld, Germany)
Resonant decay of parity odd bubbles in hot hadronic matter
11 pages latex file with 4 gif - figures. Uses elsart.cls (included)
Phys.Lett. B484 (2000) 58-63
10.1016/S0370-2693(00)00636-5
BI-TP 2000/12
hep-ph
null
We investigate the decay of metastable states with broken CP-symmetry which have recently been proposed by Kharzeev, Pisarski and Tytgat to form in hot hadronic matter. We consider the efficiency of the amplification of the $\eta'$-field via parametric resonance, taking the backreaction into account. For times of the order $t\approx 10 fm$, we find a particle density of about $0.7/fm^3$ and a correlation length of $\xi_{max}\approx 2.5 fm$. The corresponding momentum spectra show a non-thermal behaviour.
[ { "created": "Fri, 5 May 2000 17:13:12 GMT", "version": "v1" } ]
2009-10-31
[ [ "Ahrensmeier", "D.", "", "Faculty of Physics, University of\n Bielefeld, Germany" ], [ "Baier", "R.", "", "Faculty of Physics, University of\n Bielefeld, Germany" ], [ "Dirks", "M.", "", "Faculty of Physics, University of\n Bielefeld, Germany" ] ]
We investigate the decay of metastable states with broken CP-symmetry which have recently been proposed by Kharzeev, Pisarski and Tytgat to form in hot hadronic matter. We consider the efficiency of the amplification of the $\eta'$-field via parametric resonance, taking the backreaction into account. For times of the order $t\approx 10 fm$, we find a particle density of about $0.7/fm^3$ and a correlation length of $\xi_{max}\approx 2.5 fm$. The corresponding momentum spectra show a non-thermal behaviour.
2401.14742
Jordan Gu\'e
Jordan Gu\'e, Aur\'elien Hees and Peter Wolf
Violation of the equivalence principle induced by oscillating rest mass and transition frequency, and its detection in atom interferometers
30 pages, 7 figures, 2 tables
null
null
null
hep-ph astro-ph.CO gr-qc physics.atom-ph
http://creativecommons.org/licenses/by/4.0/
We present a theoretical investigation of the expected experimental signals produced by freely falling atoms with time oscillating mass and transition frequency. These oscillations could be produced in a variety of models, in particular, models of scalar dark matter (DM) non universally coupled to the standard matter (SM) such as axion-like particles (ALP) and dilatons. Performing complete and rigorous calculations, we show that, on one hand, two different atomic species would accelerate at a different rate, and on the other hand, they would produce a non-zero differential phase shift in atom interferometers (AI). The former would produce observable signals in equivalence principle tests like the recent MICROSCOPE mission, and we provide a corresponding sensitivity estimate, showing that MICROSCOPE can reach beyond the best existing searches in the ALP case. We also compare the expected sensitivity of two future AI experiments, namely the AION-10 gradiometer and an isotope differential AI considered for MAGIS-100, that we will refer to as SPID. We show that the SPID setup would be more sensitive to these dark matter fields compared to the gradiometer one, assuming equivalent experimental parameters.
[ { "created": "Fri, 26 Jan 2024 10:05:11 GMT", "version": "v1" }, { "created": "Wed, 15 May 2024 07:59:19 GMT", "version": "v2" } ]
2024-05-16
[ [ "Gué", "Jordan", "" ], [ "Hees", "Aurélien", "" ], [ "Wolf", "Peter", "" ] ]
We present a theoretical investigation of the expected experimental signals produced by freely falling atoms with time oscillating mass and transition frequency. These oscillations could be produced in a variety of models, in particular, models of scalar dark matter (DM) non universally coupled to the standard matter (SM) such as axion-like particles (ALP) and dilatons. Performing complete and rigorous calculations, we show that, on one hand, two different atomic species would accelerate at a different rate, and on the other hand, they would produce a non-zero differential phase shift in atom interferometers (AI). The former would produce observable signals in equivalence principle tests like the recent MICROSCOPE mission, and we provide a corresponding sensitivity estimate, showing that MICROSCOPE can reach beyond the best existing searches in the ALP case. We also compare the expected sensitivity of two future AI experiments, namely the AION-10 gradiometer and an isotope differential AI considered for MAGIS-100, that we will refer to as SPID. We show that the SPID setup would be more sensitive to these dark matter fields compared to the gradiometer one, assuming equivalent experimental parameters.
1008.0306
Vadim Naumov
Dmitry V. Naumov, Vadim A. Naumov, (Dubna, JINR)
A diagrammatic treatment of neutrino oscillations
27 pages,7 figures, iopart class. Includes minor corrections made in proofs. References updated
J.Phys.G37:105014,2010
10.1088/0954-3899/37/10/105014
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a covariant wave-packet approach to neutrino flavor transitions in vacuum. The approach is based on the technique of macroscopic Feynman diagrams describing the lepton number violating processes of production and absorption of virtual massive neutrinos at the macroscopically separated space-time regions ("source" and "detector"). Accordingly, the flavor transitions are a result of interference of the diagrams with neutrinos of different masses in the intermediate states. The statistically averaged probability of the process is representable as a multidimensional integral of the product of the factors which describe the differential flux density of massless neutrinos from the source, differential cross section of the neutrino interaction with the detector and a dimensionless factor responsible for the flavor transition. The conditions are analyzed under which the last factor can be treated as the flavor transition probability in the usual quantum-mechanical sense.
[ { "created": "Mon, 2 Aug 2010 13:54:50 GMT", "version": "v1" }, { "created": "Tue, 24 Aug 2010 10:39:02 GMT", "version": "v2" } ]
2014-11-21
[ [ "Naumov", "Dmitry V.", "" ], [ "Naumov", "Vadim A.", "" ] ]
We present a covariant wave-packet approach to neutrino flavor transitions in vacuum. The approach is based on the technique of macroscopic Feynman diagrams describing the lepton number violating processes of production and absorption of virtual massive neutrinos at the macroscopically separated space-time regions ("source" and "detector"). Accordingly, the flavor transitions are a result of interference of the diagrams with neutrinos of different masses in the intermediate states. The statistically averaged probability of the process is representable as a multidimensional integral of the product of the factors which describe the differential flux density of massless neutrinos from the source, differential cross section of the neutrino interaction with the detector and a dimensionless factor responsible for the flavor transition. The conditions are analyzed under which the last factor can be treated as the flavor transition probability in the usual quantum-mechanical sense.
1102.4422
Michael Klasen
J. Debove, B. Fuks, M. Klasen
Joint Resummation for Gaugino Pair Production at Hadron Colliders
21 pages, 5 figures, 1 table
null
10.1016/j.nuclphysb.2011.03.015
IPHC-PHENO-11-01, LPSC 11-031, MS-TP-11-02
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate direct gaugino pair production at hadron colliders at next-to-leading order of perturbative QCD, resumming simultaneously large logarithms in the small transverse-momentum and threshold regions to next-to-leading logarithmic accuracy. Numerical predictions are presented for transverse momentum and invariant mass spectra as well as for total cross sections and compared to results obtained at fixed order and with pure transverse-momentum and threshold resummation. We find that our new results are in general in good agreement with the previous ones, but often even more precise.
[ { "created": "Tue, 22 Feb 2011 07:17:21 GMT", "version": "v1" } ]
2015-05-27
[ [ "Debove", "J.", "" ], [ "Fuks", "B.", "" ], [ "Klasen", "M.", "" ] ]
We calculate direct gaugino pair production at hadron colliders at next-to-leading order of perturbative QCD, resumming simultaneously large logarithms in the small transverse-momentum and threshold regions to next-to-leading logarithmic accuracy. Numerical predictions are presented for transverse momentum and invariant mass spectra as well as for total cross sections and compared to results obtained at fixed order and with pure transverse-momentum and threshold resummation. We find that our new results are in general in good agreement with the previous ones, but often even more precise.
hep-ph/0010307
Volodymyr Magas
V.K. Magas, L.P. Csernai and D.D. Strottman
The initial state of ultra-relativistic heavy ion collision
28 pages, 9 figures. The presentation has been changed considerably. Some parts of the model have been reformulated, what led to modifications in several equations: (20-38), Apps. A, B. All the figures have been changed from 100 GeV/nucl initial energy to the achieved RHIC energy of 65 GeV/nucl. The last subplots in the Figs. 3, 4, 5, 6 present E=T^{00} in the laboratory frame now, instead of the energy density in the local rest frame, e, shown in the initial version. We also added the App. C to clarify the transformation from space-time to lightcone coordinates and back
Phys.Rev. C64 (2001) 014901
10.1103/PhysRevC.64.014901
null
hep-ph
null
A model for energy, pressure and flow velocity distributions at the beginning of ultra-relativistic heavy ion collisions is presented, which can be used as an initial condition for hydrodynamic calculations. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field, produced in the collision. The typical field strength (string tension) for RHIC energies is about 5-12 GeV/fm, what allows us to talk about "string ropes". The results show that a QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. Such initial conditions may lead to the creation of "antiflow" or "third flow component".
[ { "created": "Thu, 26 Oct 2000 16:20:40 GMT", "version": "v1" }, { "created": "Mon, 5 Mar 2001 15:32:53 GMT", "version": "v2" } ]
2009-10-31
[ [ "Magas", "V. K.", "" ], [ "Csernai", "L. P.", "" ], [ "Strottman", "D. D.", "" ] ]
A model for energy, pressure and flow velocity distributions at the beginning of ultra-relativistic heavy ion collisions is presented, which can be used as an initial condition for hydrodynamic calculations. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field, produced in the collision. The typical field strength (string tension) for RHIC energies is about 5-12 GeV/fm, what allows us to talk about "string ropes". The results show that a QGP forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. Such initial conditions may lead to the creation of "antiflow" or "third flow component".
2401.05162
Kazem Azizi
S. S. Agaev, K. Azizi, H. Sundu
Heavy axial-vector structures $bb\overline{c}\overline{c}$
9 Pages and 5 Figures
null
null
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
The fully heavy axial-vector diquark-antidiquark structures $bb\overline{c} \overline{c}$ are explored by means of the QCD sum rule method. They are modeled as four-quark mesons $T_{\mathrm{1}}$ and $T_{\mathrm{2}}$ composed of $b^{T}C\sigma _{\mu \nu }\gamma _{5}b$, $\overline{c}\gamma ^{\nu }C \overline{c}^{T}$ and $b^{T}C\gamma _{\mu }\gamma _{5}b$, $\overline{c}C \overline{c}^{T}$ diquarks, respectively. The spectroscopic parameters of the tetraquarks $T_{\mathrm{1}}$ and $T_{\mathrm{2}}$ are determined in the context of the QCD two-point sum rule method. Results obtained for masses of these states $m_{1} =(12715\pm 86)~\mathrm{MeV}$ and $m_{2}=(13383\pm 92)~ \mathrm{MeV}$ are used to fix their strong decay channels. The full width $ \Gamma (T_{\mathrm{1}})$ of the diquark-antidiquark state $T_{\mathrm{1}}$ is estimated by considering the processes $T_{\mathrm{1}} \to B_{c}^{-}B_{c}^{\ast -}$ and $T_{\mathrm{1}} \to B_{c}^{\ast -}B_{c}^{\ast -} $. The decays to mesons $B_{c}^{-}B_{c}^{\ast -}$, $B_{c}^{-}(2S)B_{c}^{ \ast -}$ and $B_{c}^{\ast -}B_{c}^{\ast -}$ are employed to evaluate $\Gamma (T_{\mathrm{2}})$. Results obtained for the widths $\Gamma (T_{\mathrm{1} })=(44.3\pm 8.8)~\mathrm{MeV}$ and $\Gamma (T_{\mathrm{2}})=(82.5\pm 13.7)~ \mathrm{MeV}$ of these tetraquarks in conjunction with their masses are useful for future experimental studies of fully heavy resonances.
[ { "created": "Wed, 10 Jan 2024 13:56:39 GMT", "version": "v1" }, { "created": "Tue, 12 Mar 2024 06:09:39 GMT", "version": "v2" } ]
2024-03-13
[ [ "Agaev", "S. S.", "" ], [ "Azizi", "K.", "" ], [ "Sundu", "H.", "" ] ]
The fully heavy axial-vector diquark-antidiquark structures $bb\overline{c} \overline{c}$ are explored by means of the QCD sum rule method. They are modeled as four-quark mesons $T_{\mathrm{1}}$ and $T_{\mathrm{2}}$ composed of $b^{T}C\sigma _{\mu \nu }\gamma _{5}b$, $\overline{c}\gamma ^{\nu }C \overline{c}^{T}$ and $b^{T}C\gamma _{\mu }\gamma _{5}b$, $\overline{c}C \overline{c}^{T}$ diquarks, respectively. The spectroscopic parameters of the tetraquarks $T_{\mathrm{1}}$ and $T_{\mathrm{2}}$ are determined in the context of the QCD two-point sum rule method. Results obtained for masses of these states $m_{1} =(12715\pm 86)~\mathrm{MeV}$ and $m_{2}=(13383\pm 92)~ \mathrm{MeV}$ are used to fix their strong decay channels. The full width $ \Gamma (T_{\mathrm{1}})$ of the diquark-antidiquark state $T_{\mathrm{1}}$ is estimated by considering the processes $T_{\mathrm{1}} \to B_{c}^{-}B_{c}^{\ast -}$ and $T_{\mathrm{1}} \to B_{c}^{\ast -}B_{c}^{\ast -} $. The decays to mesons $B_{c}^{-}B_{c}^{\ast -}$, $B_{c}^{-}(2S)B_{c}^{ \ast -}$ and $B_{c}^{\ast -}B_{c}^{\ast -}$ are employed to evaluate $\Gamma (T_{\mathrm{2}})$. Results obtained for the widths $\Gamma (T_{\mathrm{1} })=(44.3\pm 8.8)~\mathrm{MeV}$ and $\Gamma (T_{\mathrm{2}})=(82.5\pm 13.7)~ \mathrm{MeV}$ of these tetraquarks in conjunction with their masses are useful for future experimental studies of fully heavy resonances.
hep-ph/9706231
Darrell Tonge
C.J. Maxwell (Centre for Particle Theory, Durham)
Large-order Behaviour of the QCD Adler D-function in Planar Approximation
10 pages, uses LaTeX
Phys.Lett. B409 (1997) 382-386
10.1016/S0370-2693(97)00860-5
DTP/97/40
hep-ph
null
We consider the structure of the leading ultra-violet (UV) renormalon singularity associated with the QCD vacuum polarization Adler D-function, in the approximation that only planar Feynman diagrams are retained. This ``planar approximation'' results in some simplifications, in particular three of the four potential contributions from four-fermion operators are shown to be absent. We are able to obtain a fully normalized result for the leading $n\to\infty$ behaviour of the portion of perturbative coefficients proportional to $N_f^{n-r} N^r$, for SU(N) QCD with $N_f$ quark flavours.
[ { "created": "Tue, 3 Jun 1997 14:54:56 GMT", "version": "v1" } ]
2016-09-06
[ [ "Maxwell", "C. J.", "", "Centre for Particle Theory, Durham" ] ]
We consider the structure of the leading ultra-violet (UV) renormalon singularity associated with the QCD vacuum polarization Adler D-function, in the approximation that only planar Feynman diagrams are retained. This ``planar approximation'' results in some simplifications, in particular three of the four potential contributions from four-fermion operators are shown to be absent. We are able to obtain a fully normalized result for the leading $n\to\infty$ behaviour of the portion of perturbative coefficients proportional to $N_f^{n-r} N^r$, for SU(N) QCD with $N_f$ quark flavours.
hep-ph/0510251
Daijiro Suematsu
Daijiro Suematsu
Nonthermal production of baryon and dark matter
16 pages, to be published in Astroparticle Physics
Astropart.Phys.24:511-519,2006
10.1016/j.astropartphys.2005.10.003
KANAZAWA-05-08
hep-ph
null
We study nonthermal production of baryon and dark matter. If we extend the MSSM by introducing some singlet chiral superfields so as to enlarge the conserved global symmetry, the abundance of the baryon and the dark matter in the universe may be explained as the charge asymmetry of that symmetry. In such a case, the baryon energy density and the dark matter energy density in the present universe can be correlated each other and take the similar order values naturally.
[ { "created": "Wed, 19 Oct 2005 13:07:34 GMT", "version": "v1" } ]
2011-05-23
[ [ "Suematsu", "Daijiro", "" ] ]
We study nonthermal production of baryon and dark matter. If we extend the MSSM by introducing some singlet chiral superfields so as to enlarge the conserved global symmetry, the abundance of the baryon and the dark matter in the universe may be explained as the charge asymmetry of that symmetry. In such a case, the baryon energy density and the dark matter energy density in the present universe can be correlated each other and take the similar order values naturally.
hep-ph/0610002
Roman Nevzorov
S.F. King, S. Moretti, R. Nevzorov
E$_6$SSM
Presented at XXXIII International Conference on High Energy Physics (ICHEP'06), Moscow, Russia, 26 July - 2 August and at Cairo International Conference on High Energy Physics (CICHEP II), Cairo, Egypt, 14-17 January 2006
AIPConf.Proc.881:138-143,2007
10.1063/1.2435288
SHEP-06-30
hep-ph
null
In this talk we discuss an $E_6$ inspired supersymmetric (SUSY) model with an extra $U(1)_{N}$ gauge symmetry under which right-handed neutrinos have zero charge. In this exceptional supersymmetric standard model (E$_6$SSM) the $\mu$-term is generated dynamically after the electroweak symmetry breaking. We specify the particle content of the model and argue that the presence of a $Z'$ and exotic particles predicted by E$_6$SSM allows the lightest Higgs boson to be significantly heavier than in the MSSM and NMSSM. Other possible manifestations of E$_6$SSM at the LHC are also discussed.
[ { "created": "Mon, 2 Oct 2006 14:43:23 GMT", "version": "v1" } ]
2008-11-26
[ [ "King", "S. F.", "" ], [ "Moretti", "S.", "" ], [ "Nevzorov", "R.", "" ] ]
In this talk we discuss an $E_6$ inspired supersymmetric (SUSY) model with an extra $U(1)_{N}$ gauge symmetry under which right-handed neutrinos have zero charge. In this exceptional supersymmetric standard model (E$_6$SSM) the $\mu$-term is generated dynamically after the electroweak symmetry breaking. We specify the particle content of the model and argue that the presence of a $Z'$ and exotic particles predicted by E$_6$SSM allows the lightest Higgs boson to be significantly heavier than in the MSSM and NMSSM. Other possible manifestations of E$_6$SSM at the LHC are also discussed.
1907.11714
Gui-Jun Ding
Gui-Jun Ding, Stephen F. King, Xiang-Gan Liu
Modular $A_4$ Symmetry Models of Neutrinos and Charged Leptons
35 pages, 9 figures. arXiv admin note: text overlap with arXiv:1903.12588
null
10.1007/JHEP09(2019)074
USTC-ICTS-19-16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a comprehensive analysis of neutrino mass and lepton mixing in theories with $A_4$ modular symmetry, where the only flavon field is the single modulus field $\tau$, and all masses and Yukawa couplings are modular forms. Similar to previous analyses, we discuss all the simplest neutrino sectors arising from both the Weinberg operator and the type I seesaw mechanism, with lepton doublets and right-handed neutrinos assumed to be triplets of $A_4$. Unlike previous analyses, we allow right-handed charged leptons to transform as all combinations of $\mathbf{1}$, $\mathbf{1}'$ and $\mathbf{1}''$ representations of $A_4$, using the simplest different modular weights to break the degeneracy, leading to ten different charged lepton Yukawa matrices, instead of the usual one. This implies ten different Weinberg models and thirty different type I seesaw models, which we analyse in detail. We find that fourteen models for both NO and IO neutrino mass ordering can accommodate the data, as compared to one in previous analyses, providing many new possibilities.
[ { "created": "Fri, 26 Jul 2019 10:11:01 GMT", "version": "v1" } ]
2019-10-02
[ [ "Ding", "Gui-Jun", "" ], [ "King", "Stephen F.", "" ], [ "Liu", "Xiang-Gan", "" ] ]
We present a comprehensive analysis of neutrino mass and lepton mixing in theories with $A_4$ modular symmetry, where the only flavon field is the single modulus field $\tau$, and all masses and Yukawa couplings are modular forms. Similar to previous analyses, we discuss all the simplest neutrino sectors arising from both the Weinberg operator and the type I seesaw mechanism, with lepton doublets and right-handed neutrinos assumed to be triplets of $A_4$. Unlike previous analyses, we allow right-handed charged leptons to transform as all combinations of $\mathbf{1}$, $\mathbf{1}'$ and $\mathbf{1}''$ representations of $A_4$, using the simplest different modular weights to break the degeneracy, leading to ten different charged lepton Yukawa matrices, instead of the usual one. This implies ten different Weinberg models and thirty different type I seesaw models, which we analyse in detail. We find that fourteen models for both NO and IO neutrino mass ordering can accommodate the data, as compared to one in previous analyses, providing many new possibilities.
hep-ph/9902365
Johann Rafelski
Johann Rafelski and Jean Letessier (Department of Physics, University of Arizona, Tucson, AZ and LPTHE-Universite Paris 7, France)
Hadron Freeze-out and QGP Hadronization
10 pages including 7 tables. Presented at the 15th Winter Workshop on Nuclear Dynamics, Park City, UT, January 1999, proceedings to be published by Kluwer Academic Press (1999) W. Bauer and G. Westfall, Eds
null
null
null
hep-ph
null
Abundances and $m_\bot$-spectra of strange and other hadronic particles emanating from central 158-200 A GeV reactions between nuclei are found to originate from a thermally equilibrated, deconfined source in chemical non-equilibrium. Physical freeze-out parameters and physical conditions (pressure, specific energy, entropy, and strangeness) are evaluated. Five properties of the source we obtain are as expected for direct hadron emission (hadronization) from a deconfined quark-gluon plasma phase.
[ { "created": "Tue, 16 Feb 1999 20:11:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rafelski", "Johann", "", "Department of Physics, University\n of Arizona, Tucson, AZ and LPTHE-Universite Paris 7, France" ], [ "Letessier", "Jean", "", "Department of Physics, University\n of Arizona, Tucson, AZ and LPTHE-Universite Paris 7, France" ] ]
Abundances and $m_\bot$-spectra of strange and other hadronic particles emanating from central 158-200 A GeV reactions between nuclei are found to originate from a thermally equilibrated, deconfined source in chemical non-equilibrium. Physical freeze-out parameters and physical conditions (pressure, specific energy, entropy, and strangeness) are evaluated. Five properties of the source we obtain are as expected for direct hadron emission (hadronization) from a deconfined quark-gluon plasma phase.
1110.5526
Jean Cleymans
J. Cleymans and D. Worku
The Tsallis Distribution in Proton-Proton Collisions at $\sqrt{s}$ = 0.9 TeV at the LHC
15 pages, 7 figures. arXiv admin note: substantial text overlap with arXiv:1106.3405
null
10.1088/0954-3899/39/2/025006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Tsallis distribution has been used recently to fit the transverse momentum distributions of identified particles by the STAR and PHENIX collaborations at the Relativistic Heavy Ion Collider and by the ALICE and CMS collaborations at the Large Hadron Collider. Theoretical issues are clarified concerning the thermodynamic consistency of the Tsallis distribution in the particular case of relativistic high energy quantum distributions. An improved form is proposed for describing the transverse momentum distribution and fits are presented together with estimates of the parameter $q$ and the temperature $T$.
[ { "created": "Tue, 25 Oct 2011 15:07:55 GMT", "version": "v1" } ]
2015-05-30
[ [ "Cleymans", "J.", "" ], [ "Worku", "D.", "" ] ]
The Tsallis distribution has been used recently to fit the transverse momentum distributions of identified particles by the STAR and PHENIX collaborations at the Relativistic Heavy Ion Collider and by the ALICE and CMS collaborations at the Large Hadron Collider. Theoretical issues are clarified concerning the thermodynamic consistency of the Tsallis distribution in the particular case of relativistic high energy quantum distributions. An improved form is proposed for describing the transverse momentum distribution and fits are presented together with estimates of the parameter $q$ and the temperature $T$.
2101.08275
Simon Knapen
Simon Knapen, Jonathan Kozaczuk, Tongyan Lin
Dark matter-electron scattering in dielectrics
13 pages, 7 figures
Phys. Rev. D 104, 015031 (2021)
10.1103/PhysRevD.104.015031
CERN-TH-2021-013
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A number of direct detection experiments are searching for electron excitations created by scattering of sub-GeV dark matter. We present an alternate formulation of dark matter-electron scattering in terms of the dielectric response of a material. For dark matter which couples to electrons, this approach automatically accounts for in-medium screening effects, which were not included in previous rate calculations for semiconductor targets. We show that the screening effects appear for both scalar and vector mediators. The result is a non-negligible reduction of reach for direct detection experiments which use dielectric materials as targets. We also explore different determinations of the dielectric response, including first-principles density functional theory (DFT) calculations and a data-driven analytic approximation using a Mermin oscillator model.
[ { "created": "Wed, 20 Jan 2021 19:00:03 GMT", "version": "v1" } ]
2021-08-04
[ [ "Knapen", "Simon", "" ], [ "Kozaczuk", "Jonathan", "" ], [ "Lin", "Tongyan", "" ] ]
A number of direct detection experiments are searching for electron excitations created by scattering of sub-GeV dark matter. We present an alternate formulation of dark matter-electron scattering in terms of the dielectric response of a material. For dark matter which couples to electrons, this approach automatically accounts for in-medium screening effects, which were not included in previous rate calculations for semiconductor targets. We show that the screening effects appear for both scalar and vector mediators. The result is a non-negligible reduction of reach for direct detection experiments which use dielectric materials as targets. We also explore different determinations of the dielectric response, including first-principles density functional theory (DFT) calculations and a data-driven analytic approximation using a Mermin oscillator model.
hep-ph/0512214
Cong-Feng Qiao
Gang Hao, Cong-Feng Qiao (GUCAS) and Ai-Lin Zhang (SHU)
0^-+ Trigluon Glueball and its Implication for a Recent BES Observation
14 text pages; 2 eps-form figures.To appear in Phys.Lett.B
Phys.Lett.B642:53-61,2006
10.1016/j.physletb.2006.09.031
GUCAS-SPS-05-06
hep-ph
null
We calculate the mass of $0^{-+}$ triple-valence-gluon resonance, the trigluon glueball, with QCD sum rules. Its mass is found to be approximately in the region between 1.9 GeV and 2.7 GeV with some theoretical uncertainties. Moreover, it is likely that the new BES measurement of the $p \bar{p}$ enhancement near threshold in the $J/\psi$ decays exhibits the behavior of this trigluon state. Our analyzes favor the baryonium-gluonium mixing picture for the BES observation.
[ { "created": "Fri, 16 Dec 2005 09:23:57 GMT", "version": "v1" }, { "created": "Mon, 27 Feb 2006 13:35:19 GMT", "version": "v2" }, { "created": "Wed, 20 Sep 2006 12:39:32 GMT", "version": "v3" } ]
2008-11-26
[ [ "Hao", "Gang", "", "GUCAS" ], [ "Qiao", "Cong-Feng", "", "GUCAS" ], [ "Zhang", "Ai-Lin", "", "SHU" ] ]
We calculate the mass of $0^{-+}$ triple-valence-gluon resonance, the trigluon glueball, with QCD sum rules. Its mass is found to be approximately in the region between 1.9 GeV and 2.7 GeV with some theoretical uncertainties. Moreover, it is likely that the new BES measurement of the $p \bar{p}$ enhancement near threshold in the $J/\psi$ decays exhibits the behavior of this trigluon state. Our analyzes favor the baryonium-gluonium mixing picture for the BES observation.
hep-ph/9511236
V. A. Rubakov
V.A.Rubakov
Non-Perturbative Aspects of Multiparticle Production
14 pages, LaTeX; to appear in Proceedings of 2nd Rencontres du Vietnam, October 1995
null
null
null
hep-ph
null
Processes with multiparticle final states in weakly coupled theories, both with and without instantons, cannot be studied perturbatively at most interesting energies and multiplicities. Semiclassical approaches to the calculation of their cross sections are reviewed.
[ { "created": "Sat, 4 Nov 1995 13:35:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rubakov", "V. A.", "" ] ]
Processes with multiparticle final states in weakly coupled theories, both with and without instantons, cannot be studied perturbatively at most interesting energies and multiplicities. Semiclassical approaches to the calculation of their cross sections are reviewed.
2407.10950
Joe Davighi
Sebastiano Covone, Joe Davighi, Gino Isidori, Marko Pesut
Flavour Deconstructing the Composite Higgs
36 pages, 4 figures, 1 table
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a flavour non-universal extension of the Standard Model combined with the idea of Higgs compositeness. At the TeV scale, the gauge groups $SU(2)_R$ and $U(1)_{B-L}$ are assumed to act in a non-universal manner on light- and third-generation fermions, while the Higgs emerges as a pseudo Nambu-Goldstone boson of the spontaneous global symmetry breaking $Sp(4)\to SU(2)_L\times SU(2)_R^{[3]}$, attributed to new strong dynamics. The flavour deconstruction means the couplings of the light families to the composite sector (and therefore the pNGB Higgs) are suppressed by powers of a heavy mass scale (from which the Higgs is nevertheless shielded by compositeness), explaining the flavour puzzle. We present a detailed analysis of the radiatively generated Higgs potential, showing how this intrinsically-flavoured framework has the ingredients to justify the unavoidable tuning in the Higgs potential necessary to separate electroweak and composite scales. This happens for large enough values of the $SU(2)_R^{[3]}$ gauge coupling and light enough flavoured gauge bosons resulting from the deconstruction, whose phenomenology is also investigated. The model is compatible with current experimental bounds and predicts new states at the TeV scale, which are within the reach of near future experimental searches.
[ { "created": "Mon, 15 Jul 2024 17:47:34 GMT", "version": "v1" } ]
2024-07-16
[ [ "Covone", "Sebastiano", "" ], [ "Davighi", "Joe", "" ], [ "Isidori", "Gino", "" ], [ "Pesut", "Marko", "" ] ]
We present a flavour non-universal extension of the Standard Model combined with the idea of Higgs compositeness. At the TeV scale, the gauge groups $SU(2)_R$ and $U(1)_{B-L}$ are assumed to act in a non-universal manner on light- and third-generation fermions, while the Higgs emerges as a pseudo Nambu-Goldstone boson of the spontaneous global symmetry breaking $Sp(4)\to SU(2)_L\times SU(2)_R^{[3]}$, attributed to new strong dynamics. The flavour deconstruction means the couplings of the light families to the composite sector (and therefore the pNGB Higgs) are suppressed by powers of a heavy mass scale (from which the Higgs is nevertheless shielded by compositeness), explaining the flavour puzzle. We present a detailed analysis of the radiatively generated Higgs potential, showing how this intrinsically-flavoured framework has the ingredients to justify the unavoidable tuning in the Higgs potential necessary to separate electroweak and composite scales. This happens for large enough values of the $SU(2)_R^{[3]}$ gauge coupling and light enough flavoured gauge bosons resulting from the deconstruction, whose phenomenology is also investigated. The model is compatible with current experimental bounds and predicts new states at the TeV scale, which are within the reach of near future experimental searches.
1910.11558
Lokesh Kumar
Abhirikshma Nandi, Lokesh Kumar, and Natasha Sharma
Constraining the Particle Production Mechanism in Au+Au Collisions at $\sqrt{s_{NN}}=$ 7.7, 27, and 200 GeV Using A Multi Phase Transport Model
16 pages with 8 captioned figures. The updated version is modified in accordance with the published version
Phys. Rev. C 102, 024902 (2020)
10.1103/PhysRevC.102.024902
null
hep-ph nucl-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the production of pions, kaons, and (anti)protons in A Multi Phase Transport (AMPT) Model in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 27, and 200 GeV. We present the centrality and energy dependence of various bulk observables such as invariant yields as a function of transverse momentum $p_T$, particle yields $dN/dy$, average transverse momentum $\langle p_T \rangle$, and various particle ratios, and compare them with experimental data. Both default and string melting (SM) versions of the AMPT model are used with three different sets of initial conditions. We observe that neither the default nor the SM version of the model could consistently describe the centrality dependence of all observables at the above energies with any one set of initial conditions. The energy dependence behavior of the experimental observables for 0--5\% central collisions is in general better described by the default AMPT model using the modified HIJING parameters for Lund string fragmentation and 3mb parton scattering cross-section. In addition, the kaon production as well as the $K/\pi$ ratio at 7.7 GeV are under predicted by the AMPT model.
[ { "created": "Fri, 25 Oct 2019 07:45:30 GMT", "version": "v1" }, { "created": "Fri, 21 Aug 2020 05:14:02 GMT", "version": "v2" } ]
2020-08-24
[ [ "Nandi", "Abhirikshma", "" ], [ "Kumar", "Lokesh", "" ], [ "Sharma", "Natasha", "" ] ]
We study the production of pions, kaons, and (anti)protons in A Multi Phase Transport (AMPT) Model in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 27, and 200 GeV. We present the centrality and energy dependence of various bulk observables such as invariant yields as a function of transverse momentum $p_T$, particle yields $dN/dy$, average transverse momentum $\langle p_T \rangle$, and various particle ratios, and compare them with experimental data. Both default and string melting (SM) versions of the AMPT model are used with three different sets of initial conditions. We observe that neither the default nor the SM version of the model could consistently describe the centrality dependence of all observables at the above energies with any one set of initial conditions. The energy dependence behavior of the experimental observables for 0--5\% central collisions is in general better described by the default AMPT model using the modified HIJING parameters for Lund string fragmentation and 3mb parton scattering cross-section. In addition, the kaon production as well as the $K/\pi$ ratio at 7.7 GeV are under predicted by the AMPT model.
hep-ph/0211412
Nigel Glover
E.W.N. Glover
Progress in NNLO calculations for scattering processes
Latex 9 pages, 2 postscript embedded figures, JHEP class, Based on invited talks at 6th International Symposium on Radiative Corrections, Application of Quantum Field Theory to Phenomenology (RADCOR 2002) and 6th Zeuthen Workshop on Elementary Particle Theory (Loops and Legs in Quantum Field Theory) Kloster Banz, Germany, 8th - 13th Sep 2002 and 14th Topical Conference on Hadron Collider Physics (HCP 2002), Karlsruhe, Germany, 29th Sep - 4th Oct 2002
Nucl.Phys.Proc.Suppl.116:3-7,2003
10.1016/S0920-5632(03)80133-0
IPPP/02/73
hep-ph
null
The various motivations for improving the perturbative prediction to next-to-next-to-leading order (NNLO) for basic scattering processes in proton-(anti)proton, electron-proton and electron-positron scattering are discussed in detail. Recent progress in the field of next-to-next-to-leading order calculations is reviewed.
[ { "created": "Tue, 26 Nov 2002 15:50:13 GMT", "version": "v1" } ]
2008-11-26
[ [ "Glover", "E. W. N.", "" ] ]
The various motivations for improving the perturbative prediction to next-to-next-to-leading order (NNLO) for basic scattering processes in proton-(anti)proton, electron-proton and electron-positron scattering are discussed in detail. Recent progress in the field of next-to-next-to-leading order calculations is reviewed.
hep-ph/9801307
David Kaiser
David Kaiser (Harvard University)
Larger Domains from Resonant Decay of Disoriented Chiral Condensates
4pp, 2 figs, Revtex. Minor revisions, conclusions unchanged
Phys.Rev. D59 (1999) 117901
10.1103/PhysRevD.59.117901
HUTP-97/A107
hep-ph nucl-th
null
The decay of disoriented chiral condensates into soft pions is considered within the context of a linear sigma model. Unlike earlier analytic studies, which focused on the production of pions as the sigma field rolled down toward its new equilibrium value, here we focus on the amplification of long-wavelength pion modes due to parametric resonance as the sigma field oscillates around the minimum of its potential. This process can create larger domains of pion fluctuations than the usual spinodal decomposition process, and hence may provide a viable experimental signature for chiral symmetry breaking in relativistic heavy ion collisions; it may also better explain physically the large growth of domains found in several numerical simulations.
[ { "created": "Wed, 14 Jan 1998 21:43:35 GMT", "version": "v1" }, { "created": "Tue, 17 Nov 1998 00:51:22 GMT", "version": "v2" } ]
2009-10-31
[ [ "Kaiser", "David", "", "Harvard University" ] ]
The decay of disoriented chiral condensates into soft pions is considered within the context of a linear sigma model. Unlike earlier analytic studies, which focused on the production of pions as the sigma field rolled down toward its new equilibrium value, here we focus on the amplification of long-wavelength pion modes due to parametric resonance as the sigma field oscillates around the minimum of its potential. This process can create larger domains of pion fluctuations than the usual spinodal decomposition process, and hence may provide a viable experimental signature for chiral symmetry breaking in relativistic heavy ion collisions; it may also better explain physically the large growth of domains found in several numerical simulations.
1908.08455
Claude Amsler
Claude Amsler
Nucleon-antinucleon annihilation at LEAR
27 pages, 29 figures, Invited talk at the ECT* workshop on Antiproton-nucleus interactions and related phenomena
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This report is a historical review of the salient results in low energy antiproton-proton and antineutron-proton annihilation obtained at the Low Energy Antiproton Ring (LEAR), which was operated at CERN between 1983 and 1996. The intention is to provide guidelines for future experiments at the CERN AD/ELENA complex and elsewhere. In the spirit of this workshop, hadron spectroscopy - one of the cornerstones at LEAR - is briefly mentioned, while emphasis is put on the annihilation mechanism on one and two nucleons, the final state multiplicity distributions and the contributions from quarks, in particular in annihilation channels involving strangeness.
[ { "created": "Thu, 22 Aug 2019 15:32:22 GMT", "version": "v1" } ]
2019-08-23
[ [ "Amsler", "Claude", "" ] ]
This report is a historical review of the salient results in low energy antiproton-proton and antineutron-proton annihilation obtained at the Low Energy Antiproton Ring (LEAR), which was operated at CERN between 1983 and 1996. The intention is to provide guidelines for future experiments at the CERN AD/ELENA complex and elsewhere. In the spirit of this workshop, hadron spectroscopy - one of the cornerstones at LEAR - is briefly mentioned, while emphasis is put on the annihilation mechanism on one and two nucleons, the final state multiplicity distributions and the contributions from quarks, in particular in annihilation channels involving strangeness.
0912.4338
Hua-Xing Chen
Hua-Xing Chen, V. Dmitrasinovic, Atsushi Hosaka
Baryon Fields with U_L(3) \times U_R(3) Chiral Symmetry: Axial Currents of Nucleons and Hyperons
one typo correction, and accepted by PRD
Phys.Rev.D81:054002,2010
10.1103/PhysRevD.81.054002
null
hep-ph
http://creativecommons.org/licenses/publicdomain/
We use the conventional F and D octet and decimet generator matrices to reformulate chiral properties of local (non-derivative) and one-derivative non-local fields of baryons consisting of three quarks with flavor SU(3) symmetry that were expressed in SU(3) tensor form in Ref. [12]. We show explicitly the chiral transformations of the [(6,3)\oplus(3,6)] chiral multiplet in the "SU(3) particle basis", for the first time to our knowledge, as well as those of the (3,\bar{3}) \oplus (\bar{3}, 3), (8,1) \oplus (1,8) multiplets, which have been recorded before in Refs. [4,5]. We derive the vector and axial-vector Noether currents, and show explicitly that their zeroth (charge-like) components close the SU_L(3) \times SU_R(3) chiral algebra. We use these results to study the effects of mixing of (three-quark) chiral multiplets on the axial current matrix elements of hyperons and nucleons. We show, in particular, that there is a strong correlation, indeed a definite relation between the flavor-singlet (i.e. the zeroth), the isovector (the third) and the eighth flavor component of the axial current, which is in decent agreement with the measured ones.
[ { "created": "Tue, 22 Dec 2009 08:33:22 GMT", "version": "v1" }, { "created": "Tue, 2 Mar 2010 03:48:35 GMT", "version": "v2" } ]
2010-04-21
[ [ "Chen", "Hua-Xing", "" ], [ "Dmitrasinovic", "V.", "" ], [ "Hosaka", "Atsushi", "" ] ]
We use the conventional F and D octet and decimet generator matrices to reformulate chiral properties of local (non-derivative) and one-derivative non-local fields of baryons consisting of three quarks with flavor SU(3) symmetry that were expressed in SU(3) tensor form in Ref. [12]. We show explicitly the chiral transformations of the [(6,3)\oplus(3,6)] chiral multiplet in the "SU(3) particle basis", for the first time to our knowledge, as well as those of the (3,\bar{3}) \oplus (\bar{3}, 3), (8,1) \oplus (1,8) multiplets, which have been recorded before in Refs. [4,5]. We derive the vector and axial-vector Noether currents, and show explicitly that their zeroth (charge-like) components close the SU_L(3) \times SU_R(3) chiral algebra. We use these results to study the effects of mixing of (three-quark) chiral multiplets on the axial current matrix elements of hyperons and nucleons. We show, in particular, that there is a strong correlation, indeed a definite relation between the flavor-singlet (i.e. the zeroth), the isovector (the third) and the eighth flavor component of the axial current, which is in decent agreement with the measured ones.
2209.10996
Tania Robens
Tania Robens
Two-Real-Singlet-Model Benchmark Planes
21 pages, 14 figures; extension of Whitepaper presented at arXiv:2205.14486; v2: slightly changed phrasing of abstract to clarify this is not a Snowmass Whitepaper; v3: minor changes, corresponds to published journal version
Symmetry 2023, 15(1), 27
10.3390/sym15010027
RBI-ThPhys-2022-35
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this manuscript, I briefly review the Benchmark Planes in the Two-Real-Singlet Model (TRSM), a model that enhances the Standard Model (SM) scalar sector by two real singlets that obey a Z2 x Z2' symmetry. In this model, all fields acquire a vacuum expectation value, such that the model contains in total 3 CP-even neutral scalars that can interact with each other. All interactions with SM-like particles are inherited from the SM-like doublet via mixing. I remind the readers of the previously proposed benchmark planes, and briefly discuss possible production at future Higgs factories, as well as regions in a more generic scan of the model. For these, I also discuss the use of the W-boson mass as a precision observable to determine allowed/ excluded regions in the models parameter space. This work builds on a whitepaper submitted to the Snowmass process.
[ { "created": "Thu, 22 Sep 2022 13:27:08 GMT", "version": "v1" }, { "created": "Fri, 23 Sep 2022 16:37:21 GMT", "version": "v2" }, { "created": "Fri, 27 Jan 2023 13:10:53 GMT", "version": "v3" } ]
2023-01-30
[ [ "Robens", "Tania", "" ] ]
In this manuscript, I briefly review the Benchmark Planes in the Two-Real-Singlet Model (TRSM), a model that enhances the Standard Model (SM) scalar sector by two real singlets that obey a Z2 x Z2' symmetry. In this model, all fields acquire a vacuum expectation value, such that the model contains in total 3 CP-even neutral scalars that can interact with each other. All interactions with SM-like particles are inherited from the SM-like doublet via mixing. I remind the readers of the previously proposed benchmark planes, and briefly discuss possible production at future Higgs factories, as well as regions in a more generic scan of the model. For these, I also discuss the use of the W-boson mass as a precision observable to determine allowed/ excluded regions in the models parameter space. This work builds on a whitepaper submitted to the Snowmass process.
0907.2379
Enrique Fernandez-Martinez
Sandhya Choubey, Pilar Coloma, Andrea Donini and Enrique Fernandez-Martinez
Optimized Two-Baseline Beta-Beam Experiment
17 pages, 3 eps figures. Minor changes, matches version accepted in JHEP
JHEP 0912:020,2009
10.1088/1126-6708/2009/12/020
IFT-UAM/CSIC-09-33, MPP-2009-118, EUROnu-WP6-09-07, CUP-TH-09-01
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a realistic Beta-Beam experiment with four source ions and two baselines for the best possible sensitivity to theta_{13}, CP violation and mass hierarchy. Neutrinos from 18Ne and 6He with Lorentz boost gamma=350 are detected in a 500 kton water Cerenkov detector at a distance L=650 km (first oscillation peak) from the source. Neutrinos from 8B and 8Li are detected in a 50 kton magnetized iron detector at a distance L=7000 km (magic baseline) from the source. Since the decay ring requires a tilt angle of 34.5 degrees to send the beam to the magic baseline, the far end of the ring has a maximum depth of d=2132 m for magnetic field strength of 8.3 T, if one demands that the fraction of ions that decay along the straight sections of the racetrack geometry decay ring (called livetime) is 0.3. We alleviate this problem by proposing to trade reduction of the livetime of the decay ring with the increase in the boost factor of the ions, such that the number of events at the detector remains almost the same. This allows to substantially reduce the maximum depth of the decay ring at the far end, without significantly compromising the sensitivity of the experiment to the oscillation parameters. We take 8B and 8Li with gamma=390 and 656 respectively, as these are the largest possible boost factors possible with the envisaged upgrades of the SPS at CERN. This allows us to reduce d of the decay ring by a factor of 1.7 for 8.3 T magnetic field. Increase of magnetic field to 15 T would further reduce d to 738 m only. We study the sensitivity reach of this two baseline two storage ring Beta-Beam experiment, and compare it with the corresponding reach of the other proposed facilities.
[ { "created": "Tue, 14 Jul 2009 17:35:38 GMT", "version": "v1" }, { "created": "Wed, 4 Nov 2009 13:19:46 GMT", "version": "v2" } ]
2009-12-15
[ [ "Choubey", "Sandhya", "" ], [ "Coloma", "Pilar", "" ], [ "Donini", "Andrea", "" ], [ "Fernandez-Martinez", "Enrique", "" ] ]
We propose a realistic Beta-Beam experiment with four source ions and two baselines for the best possible sensitivity to theta_{13}, CP violation and mass hierarchy. Neutrinos from 18Ne and 6He with Lorentz boost gamma=350 are detected in a 500 kton water Cerenkov detector at a distance L=650 km (first oscillation peak) from the source. Neutrinos from 8B and 8Li are detected in a 50 kton magnetized iron detector at a distance L=7000 km (magic baseline) from the source. Since the decay ring requires a tilt angle of 34.5 degrees to send the beam to the magic baseline, the far end of the ring has a maximum depth of d=2132 m for magnetic field strength of 8.3 T, if one demands that the fraction of ions that decay along the straight sections of the racetrack geometry decay ring (called livetime) is 0.3. We alleviate this problem by proposing to trade reduction of the livetime of the decay ring with the increase in the boost factor of the ions, such that the number of events at the detector remains almost the same. This allows to substantially reduce the maximum depth of the decay ring at the far end, without significantly compromising the sensitivity of the experiment to the oscillation parameters. We take 8B and 8Li with gamma=390 and 656 respectively, as these are the largest possible boost factors possible with the envisaged upgrades of the SPS at CERN. This allows us to reduce d of the decay ring by a factor of 1.7 for 8.3 T magnetic field. Increase of magnetic field to 15 T would further reduce d to 738 m only. We study the sensitivity reach of this two baseline two storage ring Beta-Beam experiment, and compare it with the corresponding reach of the other proposed facilities.
2205.08604
Mario W. Barela
Mario W. Barela and J. Monta\~no-Dom\'inguez
Constraints on exotic particle masses from flavor violating charged lepton decays and the role of interference
null
null
10.1103/PhysRevD.106.055013
null
hep-ph hep-ex
http://creativecommons.org/licenses/by-sa/4.0/
Together with any Beyond the Standard Model ultraviolet complete, renormalizable model, one or several exotic particles are usually hypothesized. $C\!P$-even neutral and doubly-charged scalars are common, well known examples which can contribute to the seven 3-body Charged Lepton Flavor Violating decays. The experimental bounds on each Branching Ratio within this set of processes provide a good test for new physics that can induce powerful constraints on relevant parameter spaces. This is specially true for a third species of particle which, unlike the previous two, is a rare feature of renormalizable models: a doubly charged vector bilepton. We show how these purely leptonic bounds can indeed induce relevant exclusion regions for the corresponding particles masses, stronger than what have been considered in the literature for the alternative flavor conserving case, and examine how interference effects can influence these regions in a non-trivial way.
[ { "created": "Tue, 17 May 2022 19:49:05 GMT", "version": "v1" }, { "created": "Fri, 20 May 2022 20:37:49 GMT", "version": "v2" }, { "created": "Tue, 21 Jun 2022 19:30:04 GMT", "version": "v3" }, { "created": "Mon, 8 Aug 2022 18:32:53 GMT", "version": "v4" } ]
2022-10-05
[ [ "Barela", "Mario W.", "" ], [ "Montaño-Domínguez", "J.", "" ] ]
Together with any Beyond the Standard Model ultraviolet complete, renormalizable model, one or several exotic particles are usually hypothesized. $C\!P$-even neutral and doubly-charged scalars are common, well known examples which can contribute to the seven 3-body Charged Lepton Flavor Violating decays. The experimental bounds on each Branching Ratio within this set of processes provide a good test for new physics that can induce powerful constraints on relevant parameter spaces. This is specially true for a third species of particle which, unlike the previous two, is a rare feature of renormalizable models: a doubly charged vector bilepton. We show how these purely leptonic bounds can indeed induce relevant exclusion regions for the corresponding particles masses, stronger than what have been considered in the literature for the alternative flavor conserving case, and examine how interference effects can influence these regions in a non-trivial way.
2406.16803
Toni M\"akel\"a
Wolfgang Altmannshofer, Toni M\"akel\"a, Subir Sarkar, Sebastian Trojanowski, Keping Xie, Bei Zhou
Discovering neutrino tridents at the Large Hadron Collider
19 pages, 11 figures
null
null
FERMILAB-PUB-24-0294-T, MSUHEP-24-007
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Neutrino trident production of di-lepton pairs is well recognized as a sensitive probe of both electroweak physics and physics beyond the Standard Model. Although a rare process, it could be significantly boosted by such new physics, and it also allows the electroweak theory to be tested in a new regime. We demonstrate that the forward neutrino physics program at the Large Hadron Collider offers a promising opportunity to measure for the first time, dimuon neutrino tridents with a statistical significance exceeding $5\sigma$. We present predictions for various proposed experiments and outline a specific experimental strategy to identify the signal and mitigate backgrounds, based on "reverse tracking" dimuon pairs in the FASER$\nu$2 detector. We also discuss prospects for constraining beyond Standard Model contributions to neutrino trident rates at high energies.
[ { "created": "Mon, 24 Jun 2024 17:14:31 GMT", "version": "v1" } ]
2024-06-26
[ [ "Altmannshofer", "Wolfgang", "" ], [ "Mäkelä", "Toni", "" ], [ "Sarkar", "Subir", "" ], [ "Trojanowski", "Sebastian", "" ], [ "Xie", "Keping", "" ], [ "Zhou", "Bei", "" ] ]
Neutrino trident production of di-lepton pairs is well recognized as a sensitive probe of both electroweak physics and physics beyond the Standard Model. Although a rare process, it could be significantly boosted by such new physics, and it also allows the electroweak theory to be tested in a new regime. We demonstrate that the forward neutrino physics program at the Large Hadron Collider offers a promising opportunity to measure for the first time, dimuon neutrino tridents with a statistical significance exceeding $5\sigma$. We present predictions for various proposed experiments and outline a specific experimental strategy to identify the signal and mitigate backgrounds, based on "reverse tracking" dimuon pairs in the FASER$\nu$2 detector. We also discuss prospects for constraining beyond Standard Model contributions to neutrino trident rates at high energies.
2204.08820
Ananya Mukherjee
Ananya Mukherjee, Nimmala Narendra
Retrieving Inverse Seesaw parameter space for Dirac Phase Leptogenesis
28 pages, 12 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work addresses the viability of \textit {Dirac phase leptogenesis}, in a scenario where the light Majorana neutrinos acquire masses by the inverse seesaw (ISS) mechanism. We show that, a successful leptogenesis in the ISS, driven (only) by the Dirac CP phase can be achieved with the involvement of an unorthodox form of the rotational matrix $R = e^{i{\bf A}} \,\,\,(e^{{\bf A}})$ in the Casas-Ibarra parametrisation. This particular structure of $R$ turns out to be an artefact in explaining the observed baryon asymmetry of the Universe in a pure ISS scenario. We detail here the confined regions of the $R$ matrix parameter space, essential for a successful leptogenesis. The $R$-matrix parameter space assists in rescuing the ISS parameter space needed for successful leptogenesis. This finding is otherwise unprecedented in the ISS set up. Making use of the resulted $R$ matrix parameter space we have calculated the branching ratio for the LFV decay $\mu \rightarrow e\gamma$. This accounts for an indirect probe of the $R$-matrix parameter space. The branching ratio obtained from the leptogenesis parameter space surpasses the existing bound on the branching ratio that resulted in a scenario of combined effect of linear and inverse seesaw. We also report here that, for $R = e^{i{\bf A}}$ choice leptogenesis demands the Dirac CP phase ($\delta$) to oscillate around $\pi/2$, although for the later choice the constraint on $\delta$ is much relaxed.
[ { "created": "Tue, 19 Apr 2022 11:41:12 GMT", "version": "v1" } ]
2022-04-20
[ [ "Mukherjee", "Ananya", "" ], [ "Narendra", "Nimmala", "" ] ]
This work addresses the viability of \textit {Dirac phase leptogenesis}, in a scenario where the light Majorana neutrinos acquire masses by the inverse seesaw (ISS) mechanism. We show that, a successful leptogenesis in the ISS, driven (only) by the Dirac CP phase can be achieved with the involvement of an unorthodox form of the rotational matrix $R = e^{i{\bf A}} \,\,\,(e^{{\bf A}})$ in the Casas-Ibarra parametrisation. This particular structure of $R$ turns out to be an artefact in explaining the observed baryon asymmetry of the Universe in a pure ISS scenario. We detail here the confined regions of the $R$ matrix parameter space, essential for a successful leptogenesis. The $R$-matrix parameter space assists in rescuing the ISS parameter space needed for successful leptogenesis. This finding is otherwise unprecedented in the ISS set up. Making use of the resulted $R$ matrix parameter space we have calculated the branching ratio for the LFV decay $\mu \rightarrow e\gamma$. This accounts for an indirect probe of the $R$-matrix parameter space. The branching ratio obtained from the leptogenesis parameter space surpasses the existing bound on the branching ratio that resulted in a scenario of combined effect of linear and inverse seesaw. We also report here that, for $R = e^{i{\bf A}}$ choice leptogenesis demands the Dirac CP phase ($\delta$) to oscillate around $\pi/2$, although for the later choice the constraint on $\delta$ is much relaxed.
2010.01068
Valentin Hirschi Dr
Zeno Capatti, Valentin Hirschi, Andrea Pelloni, Ben Ruijl
Local Unitarity: a representation of differential cross-sections that is locally free of infrared singularities at any order
88 pages
null
10.1007/JHEP04(2021)104
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a novel representation of differential scattering cross-sections that locally realises the direct cancellation of infrared singularities exhibited by its so-called real-emission and virtual degrees of freedom. We take advantage of the Loop-Tree Duality representation of each individual forward-scattering diagram and we prove that the ensuing expression is locally free of infrared divergences, applies at any perturbative order and for any process without initial-state collinear singularities. Divergences for loop momenta with large magnitudes are regulated using local ultraviolet counterterms that reproduce the usual Lagrangian renormalisation procedure of quantum field theories. Our representation is especially suited for a numerical implementation and we demonstrate its practical potential by computing fully numerically and without any IR counterterm the next-to-leading order accurate differential cross-section for the process $e^+ e^- \rightarrow d \bar{d}$. We also show first results beyond next-to-leading order by computing interference terms part of the N4LO-accurate inclusive cross-section of a $1\rightarrow 2+X$ scalar scattering process.
[ { "created": "Fri, 2 Oct 2020 15:47:50 GMT", "version": "v1" }, { "created": "Thu, 15 Oct 2020 15:53:06 GMT", "version": "v2" }, { "created": "Mon, 3 May 2021 10:21:32 GMT", "version": "v3" } ]
2021-05-04
[ [ "Capatti", "Zeno", "" ], [ "Hirschi", "Valentin", "" ], [ "Pelloni", "Andrea", "" ], [ "Ruijl", "Ben", "" ] ]
We propose a novel representation of differential scattering cross-sections that locally realises the direct cancellation of infrared singularities exhibited by its so-called real-emission and virtual degrees of freedom. We take advantage of the Loop-Tree Duality representation of each individual forward-scattering diagram and we prove that the ensuing expression is locally free of infrared divergences, applies at any perturbative order and for any process without initial-state collinear singularities. Divergences for loop momenta with large magnitudes are regulated using local ultraviolet counterterms that reproduce the usual Lagrangian renormalisation procedure of quantum field theories. Our representation is especially suited for a numerical implementation and we demonstrate its practical potential by computing fully numerically and without any IR counterterm the next-to-leading order accurate differential cross-section for the process $e^+ e^- \rightarrow d \bar{d}$. We also show first results beyond next-to-leading order by computing interference terms part of the N4LO-accurate inclusive cross-section of a $1\rightarrow 2+X$ scalar scattering process.
1710.08416
Claudio Muselli
Simone Zoia and Claudio Muselli
High Energy Resummation of Jet Observables
31 pages, 6 figures
null
10.1007/JHEP12(2017)097
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we investigate the extension of high energy resummation at LLx accuracy to jet observables. In particular, we present the high energy resummed expression of the transverse momentum distribution of the outgoing parton in the general partonic process $g(q) + g(q) \to g(q) + X$. In order to reach this result, several new ideas are introduced and exploited. First we prove that LLx resummation is achieved by dressing with hard radiation an off-shell gluon initiated LO process even if its on-shell limit is vanishing or trivial. Then we present a gauge-invariant framework where these calculations can be performed by using the modern helicity techniques. Finally, we show a possible way to restore gluon indistinguishability in the final state, which is otherwise lost in the resummation procedure, at all orders in $\alpha_s$ at LLx. All partonic channels are then resummed and cross-checked against fixed-order calculations up to $\mathcal{O}(\alpha_s^3)$
[ { "created": "Mon, 23 Oct 2017 18:00:00 GMT", "version": "v1" } ]
2018-01-17
[ [ "Zoia", "Simone", "" ], [ "Muselli", "Claudio", "" ] ]
In this paper we investigate the extension of high energy resummation at LLx accuracy to jet observables. In particular, we present the high energy resummed expression of the transverse momentum distribution of the outgoing parton in the general partonic process $g(q) + g(q) \to g(q) + X$. In order to reach this result, several new ideas are introduced and exploited. First we prove that LLx resummation is achieved by dressing with hard radiation an off-shell gluon initiated LO process even if its on-shell limit is vanishing or trivial. Then we present a gauge-invariant framework where these calculations can be performed by using the modern helicity techniques. Finally, we show a possible way to restore gluon indistinguishability in the final state, which is otherwise lost in the resummation procedure, at all orders in $\alpha_s$ at LLx. All partonic channels are then resummed and cross-checked against fixed-order calculations up to $\mathcal{O}(\alpha_s^3)$
hep-ph/9909501
Tommy Ohlsson
Martin Freund and Tommy Ohlsson
Matter Enhanced Neutrino Oscillations with a Realistic Earth Density Profile
8 pages, 5 figures (PostScript), MPLA LaTeX
Mod.Phys.Lett. A15 (2000) 867-874
10.1142/S0217732300000864
TUM-HEP-360/99
hep-ph
null
We have investigated matter enhanced neutrino oscillations with a mantle-core-mantle step function and a realistic Earth matter density profile in both a two and a three neutrino scenario. We found that the realistic Earth matter density profile can be well approximated with the mantle-core-mantle step function and that there could be an influence on the oscillation channel $\nu_\mu \to \nu_\tau$ due to resonant enhancement of one of the mixing angles.
[ { "created": "Fri, 24 Sep 1999 09:05:44 GMT", "version": "v1" }, { "created": "Fri, 30 Jun 2000 19:07:08 GMT", "version": "v2" } ]
2009-10-31
[ [ "Freund", "Martin", "" ], [ "Ohlsson", "Tommy", "" ] ]
We have investigated matter enhanced neutrino oscillations with a mantle-core-mantle step function and a realistic Earth matter density profile in both a two and a three neutrino scenario. We found that the realistic Earth matter density profile can be well approximated with the mantle-core-mantle step function and that there could be an influence on the oscillation channel $\nu_\mu \to \nu_\tau$ due to resonant enhancement of one of the mixing angles.
1810.09040
Warren W. Buck
W. W. Buck and Stinson Lee
Another Look at Flavor
6 pages, 2 figures, 3 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new suggestion for organizing the charged pseudo scalar mesons is presented. The simple Non-relativistic (NR) potential model employs a single value of the light quark mass and determines the potential coupling constant directly from the charged pseudo scalar mesons, pion and kaon, experimental charge radii values. All other constituent quark masses are directly dependent on the light quark mass value. The model compares features of the traditional approaches to the NR quark model as well as that of a Relativistic quark model. We explore the possibility of introducing flavor as a dynamic quantum number.
[ { "created": "Sun, 21 Oct 2018 23:08:20 GMT", "version": "v1" } ]
2018-10-23
[ [ "Buck", "W. W.", "" ], [ "Lee", "Stinson", "" ] ]
A new suggestion for organizing the charged pseudo scalar mesons is presented. The simple Non-relativistic (NR) potential model employs a single value of the light quark mass and determines the potential coupling constant directly from the charged pseudo scalar mesons, pion and kaon, experimental charge radii values. All other constituent quark masses are directly dependent on the light quark mass value. The model compares features of the traditional approaches to the NR quark model as well as that of a Relativistic quark model. We explore the possibility of introducing flavor as a dynamic quantum number.
1207.1165
Tomohiro Takesako
Masahiro Kawasaki and Tomohiro Takesako
Stochastic Approach to Flat Direction during Inflation
17 pages, 4 figures, v2: minor corrections made, published in JCAP
null
10.1088/1475-7516/2012/08/031
ICRR-Report-617-2012-6; IPMU 12-0139
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the time evolution of a flat and non-flat direction system during inflation. In order to take into account quantum noises in the analysis, we base on stochastic formalism and solve coupled Langevin equations numerically. We focus on a class of models in which tree-level Hubble-induced mass is not generated. Although the non-flat directions can block the growth of the flat direction's variance in principle, the blocking effects are suppressed by the effective masses of the non-flat directions. We find that the fate of the flat direction during inflation is determined by one-loop radiative corrections and non-renormalizable terms as usually considered, if we remove the zero-point fluctuation from the noise terms.
[ { "created": "Thu, 5 Jul 2012 05:42:26 GMT", "version": "v1" }, { "created": "Wed, 29 Aug 2012 00:29:51 GMT", "version": "v2" } ]
2015-06-05
[ [ "Kawasaki", "Masahiro", "" ], [ "Takesako", "Tomohiro", "" ] ]
We revisit the time evolution of a flat and non-flat direction system during inflation. In order to take into account quantum noises in the analysis, we base on stochastic formalism and solve coupled Langevin equations numerically. We focus on a class of models in which tree-level Hubble-induced mass is not generated. Although the non-flat directions can block the growth of the flat direction's variance in principle, the blocking effects are suppressed by the effective masses of the non-flat directions. We find that the fate of the flat direction during inflation is determined by one-loop radiative corrections and non-renormalizable terms as usually considered, if we remove the zero-point fluctuation from the noise terms.
hep-ph/9908219
null
David H Lyth (Lancaster)
Constraints on TeV-scale hybrid inflation and comments on non-hybrid alternatives
15 pages, one ref added in V2
Phys.Lett. B466 (1999) 85-94
10.1016/S0370-2693(99)01089-8
LANCS-TH/9915
hep-ph astro-ph
null
During hybrid inflation, the slowly-rolling inflaton field has a significant coupling to the trigger field which is responsible for most of the potential. Barring a fine-tuned accidental cancellation, this coupling induces a minimal one-loop contribution to the inflaton potential. The requirement that this contribution be not too large constrains a wide class of hybrid inflation models. Assuming that the inflaton perturbation generates structure in the Universe, the inflaton field and/or the trigger field after inflation have to be bigger than $10^9\GeV$. This and other results make hybrid inflation at or below the TeV scale problematical. (There is no problem with hybrid inflation at the high energy scales normally considered.) `New' and thermal inflation seem to be viable alternatives for inflation at or below the TeV scale, including the case that quantum gravity is at the TeV scale. In any case, supersymmetry is needed required during inflation, in order to protect a scalar mass.
[ { "created": "Mon, 2 Aug 1999 16:04:46 GMT", "version": "v1" }, { "created": "Mon, 4 Oct 1999 17:04:12 GMT", "version": "v2" } ]
2009-10-31
[ [ "Lyth", "David H", "", "Lancaster" ] ]
During hybrid inflation, the slowly-rolling inflaton field has a significant coupling to the trigger field which is responsible for most of the potential. Barring a fine-tuned accidental cancellation, this coupling induces a minimal one-loop contribution to the inflaton potential. The requirement that this contribution be not too large constrains a wide class of hybrid inflation models. Assuming that the inflaton perturbation generates structure in the Universe, the inflaton field and/or the trigger field after inflation have to be bigger than $10^9\GeV$. This and other results make hybrid inflation at or below the TeV scale problematical. (There is no problem with hybrid inflation at the high energy scales normally considered.) `New' and thermal inflation seem to be viable alternatives for inflation at or below the TeV scale, including the case that quantum gravity is at the TeV scale. In any case, supersymmetry is needed required during inflation, in order to protect a scalar mass.
1703.04765
Aleksey Rusov
Alexander Khodjamirian, Aleksey V. Rusov
$B_{s}\to K \ell \nu_\ell$ and $B_{(s)} \to \pi (K) \ell^+\ell^-$ decays at large recoil and CKM matrix elements
21 pages, 4 figures, 5 tables, a few comments and references addded, version accepted for publication in JHEP
null
10.1007/JHEP08(2017)112
SI-HEP-2017-03, QFET-2017-03
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide hadronic input for the $B$-meson semileptonic transitions to a light pseudoscalar meson at large recoil. The $B_s\to K$ form factor calculated from QCD light-cone sum rule is updated, to be used for a $|V_{ub}|$ determination from the $B_s\to K \ell \nu$ width. Furthermore, we calculate the hadronic input for the binned observables of $B \to \pi \ell^+ \ell^-$ and $B \to K \ell^+ \ell^-$. In addition to the form factors, the nonlocal hadronic matrix elements are obtained, combining QCD factorization and light-cone sum rules with hadronic dispersion relations. We emphasize that, due to nonlocal effects, the ratio of branching fractions of these decays is not sufficient for an accurate extraction of the $|V_{td}/V_{ts}|$ ratio. Instead, we suggest to determine the Wolfenstein parameters $A,\rho,\eta$ of the CKM matrix, combining the branching fractions of $B \to K \ell^+ \ell^-$ and $B \to \pi \ell^+ \ell^-$ with the direct $CP$-asymmetry in the latter decay. We also obtain the hadronic matrix elements for a yet unexplored channel $B_s \to K \ell^+ \ell^-$.
[ { "created": "Tue, 14 Mar 2017 22:15:39 GMT", "version": "v1" }, { "created": "Tue, 8 Aug 2017 12:35:17 GMT", "version": "v2" } ]
2017-09-13
[ [ "Khodjamirian", "Alexander", "" ], [ "Rusov", "Aleksey V.", "" ] ]
We provide hadronic input for the $B$-meson semileptonic transitions to a light pseudoscalar meson at large recoil. The $B_s\to K$ form factor calculated from QCD light-cone sum rule is updated, to be used for a $|V_{ub}|$ determination from the $B_s\to K \ell \nu$ width. Furthermore, we calculate the hadronic input for the binned observables of $B \to \pi \ell^+ \ell^-$ and $B \to K \ell^+ \ell^-$. In addition to the form factors, the nonlocal hadronic matrix elements are obtained, combining QCD factorization and light-cone sum rules with hadronic dispersion relations. We emphasize that, due to nonlocal effects, the ratio of branching fractions of these decays is not sufficient for an accurate extraction of the $|V_{td}/V_{ts}|$ ratio. Instead, we suggest to determine the Wolfenstein parameters $A,\rho,\eta$ of the CKM matrix, combining the branching fractions of $B \to K \ell^+ \ell^-$ and $B \to \pi \ell^+ \ell^-$ with the direct $CP$-asymmetry in the latter decay. We also obtain the hadronic matrix elements for a yet unexplored channel $B_s \to K \ell^+ \ell^-$.
1109.6187
Samuel Wallon
Samuel Wallon
A short review of the theory of hard exclusive processes
27 pages, 18 figures, Invited review talk presented at the workshop "30 years of strong interactions", Spa, Belgium, 6-8 April 2011
null
10.1007/s00601-012-0308-3
LPT 11-81
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We first present an introduction to the theory of hard exclusive processes. We then illustrate this theory by a few selected examples. The last part is devoted to the most recent developments in the asymptotical energy limit.
[ { "created": "Wed, 28 Sep 2011 12:42:17 GMT", "version": "v1" } ]
2015-05-30
[ [ "Wallon", "Samuel", "" ] ]
We first present an introduction to the theory of hard exclusive processes. We then illustrate this theory by a few selected examples. The last part is devoted to the most recent developments in the asymptotical energy limit.
1810.10573
{\AA}smund Folkestad
Aasmund Folkestad and Jens O. Andersen
Thermodynamics and phase diagrams of Polyakov-loop extended chiral models
23 pages and 22 figures. v2: minor edits, including new figure and fixing typos
Phys. Rev. D 99, 054006 (2019)
10.1103/PhysRevD.99.054006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the thermodynamics and phase diagrams of two-flavor quantum chromodynamics using the Polyakov-loop extended quark-meson (PQM) model and the Pisarski-Skokov chiral matrix ($\chi M$) model. At temperatures up to $T\approx2T_c$ and baryon chemical potentials up to $\mu_B=400\ \rm{MeV}$, both models show reasonable agreement with the pressure, energy density, and interaction measure as calculated on the lattice. The Polyakov loop is found to rise significantly faster with temperature in models than on the lattice. In the low-temperature and high baryon density regime, the two models predict different states of matter; The PQM model predicts a confined and chirally restored phase, while the $\chi M$ model predicts a deconfined and chirally restored phase. At finite isospin density and zero baryon density, the onset of pion condensation at $T=0$ is at $\mu_I={1\over2}m_{\pi}$, and the transition is second order at all temperatures. The transition temperature for pion condensation coincides with that of the chiral transition for values of the isospin chemical potential larger than approximately $110\ \rm{MeV}$. In the $\chi M$ model they also coincide with the transition temperature for deconfinement. The results are in good overall agreement with recent lattice simulations of the $\mu_I$--$T$ phase diagram.
[ { "created": "Wed, 24 Oct 2018 18:41:45 GMT", "version": "v1" }, { "created": "Mon, 15 Apr 2019 20:22:45 GMT", "version": "v2" } ]
2019-04-17
[ [ "Folkestad", "Aasmund", "" ], [ "Andersen", "Jens O.", "" ] ]
We study the thermodynamics and phase diagrams of two-flavor quantum chromodynamics using the Polyakov-loop extended quark-meson (PQM) model and the Pisarski-Skokov chiral matrix ($\chi M$) model. At temperatures up to $T\approx2T_c$ and baryon chemical potentials up to $\mu_B=400\ \rm{MeV}$, both models show reasonable agreement with the pressure, energy density, and interaction measure as calculated on the lattice. The Polyakov loop is found to rise significantly faster with temperature in models than on the lattice. In the low-temperature and high baryon density regime, the two models predict different states of matter; The PQM model predicts a confined and chirally restored phase, while the $\chi M$ model predicts a deconfined and chirally restored phase. At finite isospin density and zero baryon density, the onset of pion condensation at $T=0$ is at $\mu_I={1\over2}m_{\pi}$, and the transition is second order at all temperatures. The transition temperature for pion condensation coincides with that of the chiral transition for values of the isospin chemical potential larger than approximately $110\ \rm{MeV}$. In the $\chi M$ model they also coincide with the transition temperature for deconfinement. The results are in good overall agreement with recent lattice simulations of the $\mu_I$--$T$ phase diagram.
1604.05569
Kristian McDonald
Amine Ahriche, Kristian L. McDonald and Salah Nasri
The Scale-Invariant Scotogenic Model
21 pages, 8 figures; v2 JHEP version
null
10.1007/JHEP06(2016)182
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a minimal scale-invariant implementation of the scotogenic model and show that viable electroweak symmetry breaking can occur while simultaneously generating one-loop neutrino masses and the dark matter relic abundance. The model predicts the existence of a singlet scalar (dilaton) that plays the dual roles of triggering electroweak symmetry breaking and sourcing lepton number violation. Important constraints are studied, including those from lepton flavor violating effects and dark matter direct-detection experiments. The latter turn out to be somewhat severe, already excluding large regions of parameter space. None the less, viable regions of parameter space are found, corresponding to dark matter masses below (roughly) 10 GeV and above 200 GeV.
[ { "created": "Tue, 19 Apr 2016 13:58:01 GMT", "version": "v1" }, { "created": "Mon, 22 Aug 2016 06:43:08 GMT", "version": "v2" } ]
2016-08-23
[ [ "Ahriche", "Amine", "" ], [ "McDonald", "Kristian L.", "" ], [ "Nasri", "Salah", "" ] ]
We investigate a minimal scale-invariant implementation of the scotogenic model and show that viable electroweak symmetry breaking can occur while simultaneously generating one-loop neutrino masses and the dark matter relic abundance. The model predicts the existence of a singlet scalar (dilaton) that plays the dual roles of triggering electroweak symmetry breaking and sourcing lepton number violation. Important constraints are studied, including those from lepton flavor violating effects and dark matter direct-detection experiments. The latter turn out to be somewhat severe, already excluding large regions of parameter space. None the less, viable regions of parameter space are found, corresponding to dark matter masses below (roughly) 10 GeV and above 200 GeV.
2406.00218
Olcyr Sumensari
Olcyr Sumensari
Looking for New Physics Through the Exclusive $b\to s\nu\bar{\nu}$ Modes
Contribution to the 2024 Electroweak session of the 58th Rencontres de Moriond. Based on arXiv:2301.06990 and arXiv:2309.02246
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The Belle-II experiment has recently measured $\mathcal{B}(B^+\to K^+\nu\bar{\nu})$, which appears to be almost $3\sigma$ larger than its Standard Model (SM) prediction. In this talk, I will critically revisit the status of the SM predictions for the $B\to K^{(\ast)}\nu\bar{\nu}$ decays, and discuss the interpretation of the recent Belle-II measurement in terms of a general Effective Field Theory, as well as concrete models of physics beyond the SM.
[ { "created": "Fri, 31 May 2024 22:34:59 GMT", "version": "v1" } ]
2024-06-04
[ [ "Sumensari", "Olcyr", "" ] ]
The Belle-II experiment has recently measured $\mathcal{B}(B^+\to K^+\nu\bar{\nu})$, which appears to be almost $3\sigma$ larger than its Standard Model (SM) prediction. In this talk, I will critically revisit the status of the SM predictions for the $B\to K^{(\ast)}\nu\bar{\nu}$ decays, and discuss the interpretation of the recent Belle-II measurement in terms of a general Effective Field Theory, as well as concrete models of physics beyond the SM.
1305.0920
Guillaume Drieu La Rochelle Mr
Guillaume Drieu La Rochelle
Higgs couplings as a probe of New Physics
4p, Proceeding for HPNP 2013, Toyama, Feb. 2013; based on arXiv:1210.8120
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the Higgs boson decay processes and its production and provide a parameterisation tailored for testing models of new physics. The choice of a particular parameterisation depends on a non-obvious balance of quantity and quality of the available experimental data, envisaged purpose for the parameterisation and degree of model independence. At present only simple parameterisations with a limited number of fit parameters can be performed, but this situation will improve with the forthcoming experimental LHC data. It is therefore important that different approaches are considered and that the most detailed information is made available to allow testing the different aspects of the Higgs boson physics and the possible hints beyond the Standard Model.
[ { "created": "Sat, 4 May 2013 13:16:19 GMT", "version": "v1" } ]
2013-05-07
[ [ "La Rochelle", "Guillaume Drieu", "" ] ]
We consider the Higgs boson decay processes and its production and provide a parameterisation tailored for testing models of new physics. The choice of a particular parameterisation depends on a non-obvious balance of quantity and quality of the available experimental data, envisaged purpose for the parameterisation and degree of model independence. At present only simple parameterisations with a limited number of fit parameters can be performed, but this situation will improve with the forthcoming experimental LHC data. It is therefore important that different approaches are considered and that the most detailed information is made available to allow testing the different aspects of the Higgs boson physics and the possible hints beyond the Standard Model.
1209.5379
A. Tawfik
A. Tawfik (Egyptian Ctr. Theor. Phys., Cairo), E. Gamal (Egyptian Ctr. Theor. Phys., Cairo) and A. G. Shalaby (Benha U.)
Particle Production at RHIC and LHC Energies
7 pages, 4 eps figures
null
null
ECTP-2012-07
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of different particle species is recently measured in $Pb-Pb$ collisions by the ALICE experiment at $\sqrt{s}=7 $TeV. This motivates the use of various bosons and baryons measured at lower center-of-mass energies in comparing their ratios to the hadron resonance (HRG) gas model and PYTHIA event generator. It is found that the particle-to-antiparticle ratios are perfectly reproduce by means of HRG and PYTHIA at RHIC and LHC energies. The kaon-to-pion and proton-to-pion ratios are entirely overestimated by the HRG model. The PYTHIA event generator obviously underestimates the kaon-to-pion ratio and simultaneously reproduces the proton-to-pion ratio, almost perfectly, especially at LHC energy. While matter-to-antimatter and non-strange abundances are partly in line with predictions from the HRG model, it is found in the ALICE experiment that the measured baryon ratios are suppressed by a factor of $\sim1.5$. The strange abundances are overestimated in the HRG model.
[ { "created": "Mon, 24 Sep 2012 19:47:51 GMT", "version": "v1" } ]
2012-09-27
[ [ "Tawfik", "A.", "", "Egyptian Ctr. Theor. Phys., Cairo" ], [ "Gamal", "E.", "", "Egyptian Ctr.\n Theor. Phys., Cairo" ], [ "Shalaby", "A. G.", "", "Benha U." ] ]
The production of different particle species is recently measured in $Pb-Pb$ collisions by the ALICE experiment at $\sqrt{s}=7 $TeV. This motivates the use of various bosons and baryons measured at lower center-of-mass energies in comparing their ratios to the hadron resonance (HRG) gas model and PYTHIA event generator. It is found that the particle-to-antiparticle ratios are perfectly reproduce by means of HRG and PYTHIA at RHIC and LHC energies. The kaon-to-pion and proton-to-pion ratios are entirely overestimated by the HRG model. The PYTHIA event generator obviously underestimates the kaon-to-pion ratio and simultaneously reproduces the proton-to-pion ratio, almost perfectly, especially at LHC energy. While matter-to-antimatter and non-strange abundances are partly in line with predictions from the HRG model, it is found in the ALICE experiment that the measured baryon ratios are suppressed by a factor of $\sim1.5$. The strange abundances are overestimated in the HRG model.
1401.3004
Jan Piclum
Peter Marquard, Jan H. Piclum, Dirk Seidel and Matthias Steinhauser
Three-loop matching of the vector current
6 pages, 3 figures
Phys. Rev. D 89, 034027 (2014)
10.1103/PhysRevD.89.034027
DESY-13-253, LPN14-003, SFB/CPP-14-03, SI-HEP-2014-01, TTP14-002, TTK-14-01, TUM-HEP-922/14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We evaluate the three-loop corrections to the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and non-relativistic QCD. The result is presented in the MSbar scheme where large perturbative corrections are observed. The implications on the threshold production of top quark pairs are briefly discussed.
[ { "created": "Mon, 13 Jan 2014 21:00:54 GMT", "version": "v1" } ]
2014-03-05
[ [ "Marquard", "Peter", "" ], [ "Piclum", "Jan H.", "" ], [ "Seidel", "Dirk", "" ], [ "Steinhauser", "Matthias", "" ] ]
We evaluate the three-loop corrections to the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and non-relativistic QCD. The result is presented in the MSbar scheme where large perturbative corrections are observed. The implications on the threshold production of top quark pairs are briefly discussed.
1312.6610
Simone Biondini
Simone Biondini, Orlando Panella, Giulia Pancheri, Yogendra Srivastava and Livio Fan\`o
Searching Doubly Charged Leptons at Present and Future Colliders
8 pages, 4 figures, submitted as a proceeding for the LC13 Conference (ECT*, Trento), updated bibliography
IL NUOVO CIMENTO Vol. 37 C, N. 2, March-April 2014
10.1393/ncc/i2014-11740-4
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production at the LHC of exotic excited leptons of charge $Q = +2e$ is considered. Such states are predicted in composite models with extended isospin multiplets ($I_{W}=1$ and $I_{W}=3/2$). The coupling among these doubly charged leptons and Standard Model fermions may occurs either via gauge or contact interactions. In the former case the decay channels are more constrained. We study the production cross section at the LHC of $L^{++}$ ($pp \rightarrow L^{++} \, \ell^{-}$) and focus on the leptonic signature deriving from the subsequent decays $L^{++} \rightarrow W^{+} \ell^{+} \rightarrow \ell^{+} \ \ell^{+} \, \nu_l $. The invariant mass distribution of the like-sign dilepton exhibits a sharp end-point corresponding to excited doubly charged lepton mass $m^{*}$. A preliminary study for the production of doubly charged leptons at the future linear colliders, by considering the process $e^{-} e^{-} \rightarrow L_{e}^{--} \, \nu_{e}$, is carried out. Both the contact and gauge interaction mechanisms are investigated and compared.
[ { "created": "Mon, 23 Dec 2013 17:17:47 GMT", "version": "v1" }, { "created": "Tue, 14 Jan 2014 18:29:15 GMT", "version": "v2" }, { "created": "Thu, 20 Feb 2014 17:13:53 GMT", "version": "v3" } ]
2014-06-26
[ [ "Biondini", "Simone", "" ], [ "Panella", "Orlando", "" ], [ "Pancheri", "Giulia", "" ], [ "Srivastava", "Yogendra", "" ], [ "Fanò", "Livio", "" ] ]
The production at the LHC of exotic excited leptons of charge $Q = +2e$ is considered. Such states are predicted in composite models with extended isospin multiplets ($I_{W}=1$ and $I_{W}=3/2$). The coupling among these doubly charged leptons and Standard Model fermions may occurs either via gauge or contact interactions. In the former case the decay channels are more constrained. We study the production cross section at the LHC of $L^{++}$ ($pp \rightarrow L^{++} \, \ell^{-}$) and focus on the leptonic signature deriving from the subsequent decays $L^{++} \rightarrow W^{+} \ell^{+} \rightarrow \ell^{+} \ \ell^{+} \, \nu_l $. The invariant mass distribution of the like-sign dilepton exhibits a sharp end-point corresponding to excited doubly charged lepton mass $m^{*}$. A preliminary study for the production of doubly charged leptons at the future linear colliders, by considering the process $e^{-} e^{-} \rightarrow L_{e}^{--} \, \nu_{e}$, is carried out. Both the contact and gauge interaction mechanisms are investigated and compared.
hep-ph/9812298
Jose Illana
W. Hollik (1,2), J.I. Illana (3), S. Rigolin (4), C. Schappacher (1), D. St\"ockinger (1) ((1) U. Karlsruhe, (2) CERN, (3) DESY-Zeuthen, (4) U. Autonoma Madrid)
Top Dipole Form Factors and Loop-induced CP-violation in Supersymmetry
43 pages LaTeX. PS figures included with epsf.sty. Labels `N' and `T' in Tables 2,3 exchanged
Nucl.Phys.B551:3-40,1999; Erratum-ibid.B557:407-409,1999
10.1016/S0550-3213(99)00201-1
null
hep-ph
null
The one-loop Minimal Supersymmetric Standard Model (MSSM) contributions to the weak and electromagnetic dipole form factors of the top quark are presented. Far from the Z peak, they are not sufficient to account for all the new physics effects. In the context of the calculation of the process e^+e^- -> t tbar to one loop in the MSSM, we compare the impact on the phenomenology of the CP-violating dipole form factors of the top quark with the contribution from CP-violating box graphs. Some exemplificative observables are analyzed and the relevance of both the contributions is pointed out. The one-loop expressions for the electromagnetic and weak dipole form factors in a general renormalizable theory and the SM and MSSM couplings and conventions are also given.
[ { "created": "Wed, 9 Dec 1998 17:03:48 GMT", "version": "v1" }, { "created": "Wed, 7 Jul 1999 08:44:06 GMT", "version": "v2" }, { "created": "Wed, 31 Oct 2001 11:25:46 GMT", "version": "v3" } ]
2014-11-17
[ [ "Hollik", "W.", "" ], [ "Illana", "J. I.", "" ], [ "Rigolin", "S.", "" ], [ "Schappacher", "C.", "" ], [ "Stöckinger", "D.", "" ] ]
The one-loop Minimal Supersymmetric Standard Model (MSSM) contributions to the weak and electromagnetic dipole form factors of the top quark are presented. Far from the Z peak, they are not sufficient to account for all the new physics effects. In the context of the calculation of the process e^+e^- -> t tbar to one loop in the MSSM, we compare the impact on the phenomenology of the CP-violating dipole form factors of the top quark with the contribution from CP-violating box graphs. Some exemplificative observables are analyzed and the relevance of both the contributions is pointed out. The one-loop expressions for the electromagnetic and weak dipole form factors in a general renormalizable theory and the SM and MSSM couplings and conventions are also given.
hep-ph/0204103
Peter Minkowski
Peter Minkowski and Sonja Kabana
Stable quark stars beyond neutran stars : can they account for the missing matter ?
5 pages, 2 figures, contribution to Strange Quark Matter conference, Frankfurt, Germany, Sept. 2001
J.Phys.G28:2063-2068,2002
10.1088/0954-3899/28/7/372
null
hep-ph
null
The structure of a spherically symmetric stable dark 'star' is discussed, at zero temperature, containing 1) a core of quarks in the deconfined phase and antileptons 2) a shell of hadrons in particular $n$, $p$, $\Lambda$ and $\Sigma^-$ and leptons or antileptons and 3) a shell of hydrogen in the superfluid phase. If the superfluid hydrogen phase goes over into the electromagnetic plasma phase at densities well below one atom / $(10 fm)^{3}$, as is usually assumed, the hydrogen shell is insignificant for the mass and the radius of the 'star'. These quantities are then determined approximatively : mass = 1.8 solar masses and radius = 9.2 km. On the contrary if densities of the order of one atom / $(10 fm)^{3}$ do form a stable hydrogen superfluid phase, we find a large range of possible masses from 1.8 to 375 solar masses. The radii vary accordingly from 9 to 1200 km.
[ { "created": "Tue, 9 Apr 2002 14:35:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Minkowski", "Peter", "" ], [ "Kabana", "Sonja", "" ] ]
The structure of a spherically symmetric stable dark 'star' is discussed, at zero temperature, containing 1) a core of quarks in the deconfined phase and antileptons 2) a shell of hadrons in particular $n$, $p$, $\Lambda$ and $\Sigma^-$ and leptons or antileptons and 3) a shell of hydrogen in the superfluid phase. If the superfluid hydrogen phase goes over into the electromagnetic plasma phase at densities well below one atom / $(10 fm)^{3}$, as is usually assumed, the hydrogen shell is insignificant for the mass and the radius of the 'star'. These quantities are then determined approximatively : mass = 1.8 solar masses and radius = 9.2 km. On the contrary if densities of the order of one atom / $(10 fm)^{3}$ do form a stable hydrogen superfluid phase, we find a large range of possible masses from 1.8 to 375 solar masses. The radii vary accordingly from 9 to 1200 km.
1807.05288
Shikha Chaurasia
Christopher D. Carone, Shikha Chaurasia, and Tangereen V. B. Claringbold
Dark sector portal with vector-like leptons and flavor sequestering
24 pages, 5 figures
Phys. Rev. D 99, 015009 (2019)
10.1103/PhysRevD.99.015009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider models with fermionic dark matter that transforms under a non-Abelian dark gauge group. Exotic, vector-like leptons that also transform under the dark gauge group can mix with standard model leptons after spontaneous symmetry breaking and serve as a portal between the dark and visible sectors. We show in an explicit, renormalizable model based on a dark SU(2) gauge group how this can lead to adequate dark matter annihilation to a standard model lepton flavor so that the correct relic density is obtained. We identify a discrete symmetry that allows mass mixing between the vector-like fermions and a single standard model lepton flavor, while preventing mixing between these fields and the remaining standard model leptons. This flavor sequestering avoids unwanted lepton-flavor-violating effects, substantially relaxing constraints on the mass scale of the vector-like states. We discuss aspects of the phenomenology of the model, including direct detection of the dark matter.
[ { "created": "Fri, 13 Jul 2018 21:38:31 GMT", "version": "v1" } ]
2019-01-09
[ [ "Carone", "Christopher D.", "" ], [ "Chaurasia", "Shikha", "" ], [ "Claringbold", "Tangereen V. B.", "" ] ]
We consider models with fermionic dark matter that transforms under a non-Abelian dark gauge group. Exotic, vector-like leptons that also transform under the dark gauge group can mix with standard model leptons after spontaneous symmetry breaking and serve as a portal between the dark and visible sectors. We show in an explicit, renormalizable model based on a dark SU(2) gauge group how this can lead to adequate dark matter annihilation to a standard model lepton flavor so that the correct relic density is obtained. We identify a discrete symmetry that allows mass mixing between the vector-like fermions and a single standard model lepton flavor, while preventing mixing between these fields and the remaining standard model leptons. This flavor sequestering avoids unwanted lepton-flavor-violating effects, substantially relaxing constraints on the mass scale of the vector-like states. We discuss aspects of the phenomenology of the model, including direct detection of the dark matter.
hep-ph/9708374
null
Damien M. Pierce, Jens Erler
chi^2 Analysis of Supersymmetric Models
11 pages, 13 figures. Talk given by D.M.P. at the 5th International Conference on Supersymmetries in Physics (SUSY 97), Philadelphia, Pennsylvania, May 27-31, 1997
Nucl.Phys.Proc.Suppl. 62 (1998) 97-107
10.1016/S0920-5632(97)00647-6
SLAC-PUB-7633
hep-ph
null
We discuss the results of a global fit to precision data in supersymmetric models. We consider both gravity- and gauge-mediated models. As the superpartner spectrum becomes light, the global fit to the data typically results in larger values of chi^2. We indicate the regions of parameter space which are excluded by the data. We discuss the additional effect of the B(B --> X_s\gamma) measurement. Our analysis excludes chargino masses below MZ in the simplest gauge-mediated model with mu>0, with stronger constraints for larger values of tan beta.
[ { "created": "Sat, 16 Aug 1997 02:03:23 GMT", "version": "v1" } ]
2009-10-30
[ [ "Pierce", "Damien M.", "" ], [ "Erler", "Jens", "" ] ]
We discuss the results of a global fit to precision data in supersymmetric models. We consider both gravity- and gauge-mediated models. As the superpartner spectrum becomes light, the global fit to the data typically results in larger values of chi^2. We indicate the regions of parameter space which are excluded by the data. We discuss the additional effect of the B(B --> X_s\gamma) measurement. Our analysis excludes chargino masses below MZ in the simplest gauge-mediated model with mu>0, with stronger constraints for larger values of tan beta.
hep-ph/0109090
null
Yosef Nir
CP Violation - A New Era
58 pages, 1 Postscript figure, lectures at the 55th Scottish Universities Summer School in Physics, St. Andrews, Scotland, August 7-23, 2001
null
null
WIS/18/01-Aug-DPP
hep-ph
null
We give a pedagogical review of the theory of CP violation with emphasis on the implications of recent experimental results. The review includes: (i) A detailed description of how CP violation arises in the Standard Model and in its extension that allows for neutrino masses; (ii) The formalism of CP violation in meson decays and its application to various K decays (\epsilon_K, \epsilon^\prime and K\to\pi\nu\nu), D decays (D\to K\pi and D\to KK) and B decays (B\to\ell\nu X, B\to\psi K_S and B\to\pi\pi, including a discussion of the `penguin pollution' problem); (iii) Supersymmetry: the CP problems and the use of CP violation as a probe of the mechanism of dynamical supersymmetry breaking.
[ { "created": "Tue, 11 Sep 2001 06:34:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nir", "Yosef", "" ] ]
We give a pedagogical review of the theory of CP violation with emphasis on the implications of recent experimental results. The review includes: (i) A detailed description of how CP violation arises in the Standard Model and in its extension that allows for neutrino masses; (ii) The formalism of CP violation in meson decays and its application to various K decays (\epsilon_K, \epsilon^\prime and K\to\pi\nu\nu), D decays (D\to K\pi and D\to KK) and B decays (B\to\ell\nu X, B\to\psi K_S and B\to\pi\pi, including a discussion of the `penguin pollution' problem); (iii) Supersymmetry: the CP problems and the use of CP violation as a probe of the mechanism of dynamical supersymmetry breaking.
hep-ph/9909470
Narison Stephan
Stephan Narison (Univ. Montpellier)
Gluonia, Scalar and Hybrid Mesons in QCD
Latex2e sources 10 pages. Plenary talk given at Hadrons 99 (Beijing)
Nucl.Phys. A675 (2000) 54c-63c
10.1016/S0375-9474(00)00214-1
Montpellier preprint PM/99-September
hep-ph hep-ex hep-lat nucl-th
null
For some experimental guidelines of the next millenium, I review the determinations of the masses, decays and mixings of the gluonia, scalar and hybrid mesons from QCD spectral sum rules and low-energy theorems, and compare them with the lattice.
[ { "created": "Wed, 22 Sep 1999 14:38:42 GMT", "version": "v1" } ]
2009-10-31
[ [ "Narison", "Stephan", "", "Univ. Montpellier" ] ]
For some experimental guidelines of the next millenium, I review the determinations of the masses, decays and mixings of the gluonia, scalar and hybrid mesons from QCD spectral sum rules and low-energy theorems, and compare them with the lattice.
hep-ph/9605432
Sreerup Raychaudhuri
Amitava Datta, Aseshkrishna Datta and Sreerup Raychaudhuri
Virtual LSPs at e+ e- Colliders
51 pages, LaTeX plus 13 postscript figures included using epsfig in uuencoded and compressed form, minor comments added
Eur.Phys.J.C1:375-393,1998
10.1007/BF01245828
TIFR/TH/96-27
hep-ph
null
Currently popular search strategies for supersymmetric particles may be significantly affected due to relatively light sneutrinos which decay dominantly into invisible channels. In certain cases the second lightest neutralino may also decay invisibly leading to two extra carriers of missing energy (in addition to the lightest supersymmetric particle (LSP)) -- the virtual LSPs (VLSPs). It is shown that if the sneutrino masses happen to be in the small but experimentally allowed range ~ 45 - 55 GeV, these particles together with neutralino pairs may contribute significantly to the missing energy in the process e+ e- ---> \gamma + missing energy at LEP-2 energies as an enhancement over the Standard Model or the conventional MSSM predictions. It is further shown that a much larger region of the parameter space can be scanned at a high luminosity e+ e- collider at 500 GeV like the proposed NLC machine. Moreover this process can play a complementary role to direct chargino searches at LEP-2 and NLC which may fail due to a near mass degeneracy of the chargino and the sneutrino. Formulae for the cross sections taking into account full mixings of the charginos and the neutralinos are derived. The signal remains observable even in the context of more restricted models based on N=1 SUGRA with common scalar and gaugino masses. The effect of soft photon brehmsstrahlung on the signal is also discussed briefly.
[ { "created": "Thu, 30 May 1996 13:10:29 GMT", "version": "v1" }, { "created": "Tue, 9 Jul 1996 11:42:05 GMT", "version": "v2" } ]
2015-06-25
[ [ "Datta", "Amitava", "" ], [ "Datta", "Aseshkrishna", "" ], [ "Raychaudhuri", "Sreerup", "" ] ]
Currently popular search strategies for supersymmetric particles may be significantly affected due to relatively light sneutrinos which decay dominantly into invisible channels. In certain cases the second lightest neutralino may also decay invisibly leading to two extra carriers of missing energy (in addition to the lightest supersymmetric particle (LSP)) -- the virtual LSPs (VLSPs). It is shown that if the sneutrino masses happen to be in the small but experimentally allowed range ~ 45 - 55 GeV, these particles together with neutralino pairs may contribute significantly to the missing energy in the process e+ e- ---> \gamma + missing energy at LEP-2 energies as an enhancement over the Standard Model or the conventional MSSM predictions. It is further shown that a much larger region of the parameter space can be scanned at a high luminosity e+ e- collider at 500 GeV like the proposed NLC machine. Moreover this process can play a complementary role to direct chargino searches at LEP-2 and NLC which may fail due to a near mass degeneracy of the chargino and the sneutrino. Formulae for the cross sections taking into account full mixings of the charginos and the neutralinos are derived. The signal remains observable even in the context of more restricted models based on N=1 SUGRA with common scalar and gaugino masses. The effect of soft photon brehmsstrahlung on the signal is also discussed briefly.
hep-ph/9810373
Helen Bukina
E.N. Bukina, V.M. Dubovik and V.S. Zamiralov
Generalized Gordon Identities, Hara Theorem and Weak Radiative Hyperon Decays
LaTex, 7 pages, 2 tables added, text also changed
Phys.Lett. B449 (1999) 93-96
10.1016/S0370-2693(99)00045-3
null
hep-ph
null
It is shown that an alternative form of the parity-nonconserving (PNC) transition electromagnetic current resolves partly a puzzle with the Hara theorem. New formulation of it has allowed PNC weak radiative hyperon transitions of the charged hyperons $\Sigma^{+} \Rightarrow p + \gamma $ and $\Xi^{-} \Rightarrow \Sigma^{-} + \gamma $ revealing hitherto unseen transition toroid dipole moment.
[ { "created": "Thu, 15 Oct 1998 15:59:53 GMT", "version": "v1" }, { "created": "Thu, 29 Oct 1998 11:56:32 GMT", "version": "v2" } ]
2009-10-31
[ [ "Bukina", "E. N.", "" ], [ "Dubovik", "V. M.", "" ], [ "Zamiralov", "V. S.", "" ] ]
It is shown that an alternative form of the parity-nonconserving (PNC) transition electromagnetic current resolves partly a puzzle with the Hara theorem. New formulation of it has allowed PNC weak radiative hyperon transitions of the charged hyperons $\Sigma^{+} \Rightarrow p + \gamma $ and $\Xi^{-} \Rightarrow \Sigma^{-} + \gamma $ revealing hitherto unseen transition toroid dipole moment.
hep-ph/0010166
Elena Boglione
M. Anselmino, M. Boglione, F. Murgia
Lambda and Lambda-bar polarization as a measurement of distribution and fragmentation functions
Talk presented by M. Boglione at the "Second Workshop on Physics with an Electron Polarized Light Ion Collider", MIT, Sept. 14-16, 2000
AIP Conf.Proc. 588 (2001) 255-259
10.1063/1.1413164
null
hep-ph
null
A combined analysis of the polarization vector of the Lambda baryons produced in DIS processes may give a relevant insight of the hadronization process which governs the transition from partons to physical hadrons and precise indications on the mechanisms of $spin$ transfer from partons to hadrons. We give here a short review of some interesting results.
[ { "created": "Mon, 16 Oct 2000 15:00:16 GMT", "version": "v1" } ]
2015-06-25
[ [ "Anselmino", "M.", "" ], [ "Boglione", "M.", "" ], [ "Murgia", "F.", "" ] ]
A combined analysis of the polarization vector of the Lambda baryons produced in DIS processes may give a relevant insight of the hadronization process which governs the transition from partons to physical hadrons and precise indications on the mechanisms of $spin$ transfer from partons to hadrons. We give here a short review of some interesting results.
1612.09146
Alessio Maiezza
Alessio Maiezza, Goran Senjanovi\'c and Juan Carlos Vasquez
Higgs Sector of the Left-Right Symmetric Theory
Added references, version to appear in PRD
Phys. Rev. D 95, 095004 (2017)
10.1103/PhysRevD.95.095004
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform an in-depth analysis of the Higgs sector in the Minimal Left-Right Symmetric Model and compute the scalar mass spectrum and associated mixings, offering simple physical and symmetry arguments in support of our findings. We identify the tree-level quartic and cubic potential couplings in terms of the physical states and compute the quantum corrections for the latter ones. The deviations from the Standard Model prediction of the cubic Higgs doublet coupling are considered. Moreover we discuss the possible implications concerning the stability of the potential under the renormalization-group-equations evolution. In particular we examine three possible energy scales of parity restoration: LHC reach, next hadronic collider and very high energy relevant for grand unification.
[ { "created": "Thu, 29 Dec 2016 13:56:06 GMT", "version": "v1" }, { "created": "Tue, 17 Jan 2017 12:25:01 GMT", "version": "v2" }, { "created": "Wed, 19 Apr 2017 10:35:22 GMT", "version": "v3" } ]
2017-05-17
[ [ "Maiezza", "Alessio", "" ], [ "Senjanović", "Goran", "" ], [ "Vasquez", "Juan Carlos", "" ] ]
We perform an in-depth analysis of the Higgs sector in the Minimal Left-Right Symmetric Model and compute the scalar mass spectrum and associated mixings, offering simple physical and symmetry arguments in support of our findings. We identify the tree-level quartic and cubic potential couplings in terms of the physical states and compute the quantum corrections for the latter ones. The deviations from the Standard Model prediction of the cubic Higgs doublet coupling are considered. Moreover we discuss the possible implications concerning the stability of the potential under the renormalization-group-equations evolution. In particular we examine three possible energy scales of parity restoration: LHC reach, next hadronic collider and very high energy relevant for grand unification.
hep-ph/0108032
Nicholas Tracas
G.K. Leontaris, A. Prikas, A. Spanou, N.D. Tracas and N.D. Vlachos
On the stability of nontopological solitons in supersymmetric extensions of the Standard Model: A Numerical Approach
Plain LaTex, 13 Figures
null
null
IOA-TH.10/01, NTUA 06/01
hep-ph
null
In various supersymmetric extensions of the Standard Model there appear non-topological solitons due to the existence of U(1) global symmetries associated with Baryon and/or Lepton quantum numbers. Trilinear couplings (A-terms) in the scalar potential break explicitly the U(1) invariance. We investigate numerically the stability of these objects in the case that this breaking is small. We find that stable configurations, oscillating though, can still appear. Other relevant properties are also examined.
[ { "created": "Fri, 3 Aug 2001 08:35:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Leontaris", "G. K.", "" ], [ "Prikas", "A.", "" ], [ "Spanou", "A.", "" ], [ "Tracas", "N. D.", "" ], [ "Vlachos", "N. D.", "" ] ]
In various supersymmetric extensions of the Standard Model there appear non-topological solitons due to the existence of U(1) global symmetries associated with Baryon and/or Lepton quantum numbers. Trilinear couplings (A-terms) in the scalar potential break explicitly the U(1) invariance. We investigate numerically the stability of these objects in the case that this breaking is small. We find that stable configurations, oscillating though, can still appear. Other relevant properties are also examined.
hep-ph/0407282
Alexander Lenz
V.M.Braun and A.Lenz
On the SU(3) Symmetry-Breaking Corrections to Meson Distribution Amplitudes
15 pages,4 figures
Phys.Rev. D70 (2004) 074020
10.1103/PhysRevD.70.074020
null
hep-ph
null
We consider constraints on the momentum fraction of the $K$ and $K^*$ meson carried by the strange quark that follow from exact operator identities, similar to those for the divergence of the quark part of the QCD energy-momentum tensor. The existing QCD sum rule estimates are reanalyzed in this context. Our conclusions essentially support the constituent quark-model picture where the momentum fraction is roughly proportional to the constituent quark mass, but the asymmetry turns out to be smaller compared to the naive quark model estimates. As a byproduct of this study, we calculate the SU(3)-breaking quark-antiquark-gluon matrix elements that determine the leading conformal spin contributions to the asymmetry in twist-four distribution amplitudes of strange mesons $K$ and $K^*$, and also update the estimate for the SU(3) breaking for the quark-antiquark-gluon vacuum condensate.
[ { "created": "Fri, 23 Jul 2004 12:39:29 GMT", "version": "v1" } ]
2009-11-10
[ [ "Braun", "V. M.", "" ], [ "Lenz", "A.", "" ] ]
We consider constraints on the momentum fraction of the $K$ and $K^*$ meson carried by the strange quark that follow from exact operator identities, similar to those for the divergence of the quark part of the QCD energy-momentum tensor. The existing QCD sum rule estimates are reanalyzed in this context. Our conclusions essentially support the constituent quark-model picture where the momentum fraction is roughly proportional to the constituent quark mass, but the asymmetry turns out to be smaller compared to the naive quark model estimates. As a byproduct of this study, we calculate the SU(3)-breaking quark-antiquark-gluon matrix elements that determine the leading conformal spin contributions to the asymmetry in twist-four distribution amplitudes of strange mesons $K$ and $K^*$, and also update the estimate for the SU(3) breaking for the quark-antiquark-gluon vacuum condensate.
0801.2048
Petros Draggiotis
Petros Draggiotis
Numerical Implementation of Generalized Unitarity
10 pages, 1 figure
null
null
null
hep-ph
null
We present a numerical implementation of generalized unitarity. We will show that we are able to obtain the box coefficients of any 1 loop gluonic amplitude, for an arbitrary helicity configuration and for any number of external particles.
[ { "created": "Mon, 14 Jan 2008 15:14:19 GMT", "version": "v1" } ]
2008-01-15
[ [ "Draggiotis", "Petros", "" ] ]
We present a numerical implementation of generalized unitarity. We will show that we are able to obtain the box coefficients of any 1 loop gluonic amplitude, for an arbitrary helicity configuration and for any number of external particles.
2108.06716
Qin Qin
Qin Qin, Yu-Ji Shi, Wei Wang, Guo-He Yang, Fu-Sheng Yu and Ruilin Zhu
Inclusive approach to hunt for the beauty-charmed baryons $\Xi_{bc}$
6 pages, 3 figures
Phys.Rev.D 105 (2022) 3, L031902
10.1103/PhysRevD.105.L031902
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
With a distinctive internal structure from all established hadrons, the beauty-charmed baryons $\Xi_{bc}$ can provide us with new points of view to decipher the strong interaction. In this work, we point out that the inclusive $\Xi_{bc} \to \Xi_{cc}^{++}+X$ decay is a golden channel for the experimental discovery of $\Xi_{bc}$ at the LHC. A unique feature of this process is that the $\Xi_{cc}^{++}$ is displaced, which greatly reduces the combinatorial background. A feasibility analysis is performed on the $\Xi_{bc}^+$ search, which is expected to have a longer lifetime than $\Xi_{bc}^0$ and thus a better displacement resolution. The $\Xi_{bc}^+ \to \Xi_{cc}^{++}+X$ branching ratio is calculated within the heavy diquark effective theory. Combining the $\Xi_{bc}$ production rate and the $\Xi_{cc}^{++}$ detection efficiency, we anticipate that hundreds of signal events will be collected during LHCb Run 3.
[ { "created": "Sun, 15 Aug 2021 10:48:06 GMT", "version": "v1" }, { "created": "Thu, 10 Feb 2022 10:54:20 GMT", "version": "v2" } ]
2022-02-11
[ [ "Qin", "Qin", "" ], [ "Shi", "Yu-Ji", "" ], [ "Wang", "Wei", "" ], [ "Yang", "Guo-He", "" ], [ "Yu", "Fu-Sheng", "" ], [ "Zhu", "Ruilin", "" ] ]
With a distinctive internal structure from all established hadrons, the beauty-charmed baryons $\Xi_{bc}$ can provide us with new points of view to decipher the strong interaction. In this work, we point out that the inclusive $\Xi_{bc} \to \Xi_{cc}^{++}+X$ decay is a golden channel for the experimental discovery of $\Xi_{bc}$ at the LHC. A unique feature of this process is that the $\Xi_{cc}^{++}$ is displaced, which greatly reduces the combinatorial background. A feasibility analysis is performed on the $\Xi_{bc}^+$ search, which is expected to have a longer lifetime than $\Xi_{bc}^0$ and thus a better displacement resolution. The $\Xi_{bc}^+ \to \Xi_{cc}^{++}+X$ branching ratio is calculated within the heavy diquark effective theory. Combining the $\Xi_{bc}$ production rate and the $\Xi_{cc}^{++}$ detection efficiency, we anticipate that hundreds of signal events will be collected during LHCb Run 3.
hep-ph/9511399
Hans Lotter
J.Bartels, H.Lotter, M.Vogt
A Numerical Estimate of the Small-$k_T$ Region in the BFKL Pomeron
15 pages, latex, 9 figures ,revised version, some discussion added, one reference added, two figures removed, final version to be published in Phys. Lett. B
Phys.Lett.B373:215-222,1996
10.1016/0370-2693(96)00115-3
DESY-95-224
hep-ph
null
A computer study is performed to estimate the influence of the small-$k_T$ region in the BFKL evolution equation. We consider the small-x region of the deep inelastic structure function $F_2$ and show that the magnitude of the small-$k_T$ region depends on $Q^2$ and $x_B$. We suggest that the width of the $\log k_T^2$-distribution in the final state may serve as an additional footprint of BFKL dynamics. For diffractive dissociation it is shown that the contribution of the infrared region is large - even for large $Q^2$. This contribution becomes smaller only if restrictions on the final state are imposed.
[ { "created": "Thu, 23 Nov 1995 14:45:56 GMT", "version": "v1" }, { "created": "Tue, 16 Jan 1996 18:43:44 GMT", "version": "v2" } ]
2014-11-17
[ [ "Bartels", "J.", "" ], [ "Lotter", "H.", "" ], [ "Vogt", "M.", "" ] ]
A computer study is performed to estimate the influence of the small-$k_T$ region in the BFKL evolution equation. We consider the small-x region of the deep inelastic structure function $F_2$ and show that the magnitude of the small-$k_T$ region depends on $Q^2$ and $x_B$. We suggest that the width of the $\log k_T^2$-distribution in the final state may serve as an additional footprint of BFKL dynamics. For diffractive dissociation it is shown that the contribution of the infrared region is large - even for large $Q^2$. This contribution becomes smaller only if restrictions on the final state are imposed.
2002.05332
Xiaoyan Wang
Xiao-Yan Wang and Xiang-Jun Chen
The stochastic model of neutrino oscillation
6 pages, 0 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutrino oscillation is phenomenon of random transition from a flavor state of neutrino to another, and should obey quantum statistics theory, and constitutes Markoffian process. The process is depicted by method of CTRW (continuous time random walk), and the time-evolution formula of flavor distribution of neutrino beam has been established. The simulation with Markoffian model for solar and cosmic ray neutrino indicates neutrino oscillation will arrive at equilibrium flavor distribution of three-fold maximum if propagation time is long enough, which is consistent to the data of SK and SNO experiments.
[ { "created": "Thu, 13 Feb 2020 04:12:53 GMT", "version": "v1" } ]
2020-02-14
[ [ "Wang", "Xiao-Yan", "" ], [ "Chen", "Xiang-Jun", "" ] ]
Neutrino oscillation is phenomenon of random transition from a flavor state of neutrino to another, and should obey quantum statistics theory, and constitutes Markoffian process. The process is depicted by method of CTRW (continuous time random walk), and the time-evolution formula of flavor distribution of neutrino beam has been established. The simulation with Markoffian model for solar and cosmic ray neutrino indicates neutrino oscillation will arrive at equilibrium flavor distribution of three-fold maximum if propagation time is long enough, which is consistent to the data of SK and SNO experiments.
2205.09356
Jacob Christy
J. G. Christy, Jason Kumar, Arvind Rajaraman
Indirect Detection of Low-mass Dark Matter Through the $\pi^0$ and $\eta$ Windows
13 pages, 5 figures, 1 table; updated to match version accepted by Physical Review D
null
10.1103/PhysRevD.106.123021
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the search for gamma-rays produced by the annihilation or decay of low-mass dark matter which couples to quarks. In this scenario, most of the photons are produced from the decays of $\pi^0$ or $\eta$ mesons. These decays produce distinctly different photon signatures due to the difference in meson mass. We assess the ability of the future MeV-range observatories to constrain the hadronic final states produced by dark matter annihilation or decay from the shape of the resulting photon spectrum. We then comment on how this information can be used to determine properties of the dark matter coupling to the quark current, based on the approximate symmetries of low-energy QCD.
[ { "created": "Thu, 19 May 2022 07:27:07 GMT", "version": "v1" }, { "created": "Thu, 19 Jan 2023 02:40:38 GMT", "version": "v2" } ]
2023-01-20
[ [ "Christy", "J. G.", "" ], [ "Kumar", "Jason", "" ], [ "Rajaraman", "Arvind", "" ] ]
We consider the search for gamma-rays produced by the annihilation or decay of low-mass dark matter which couples to quarks. In this scenario, most of the photons are produced from the decays of $\pi^0$ or $\eta$ mesons. These decays produce distinctly different photon signatures due to the difference in meson mass. We assess the ability of the future MeV-range observatories to constrain the hadronic final states produced by dark matter annihilation or decay from the shape of the resulting photon spectrum. We then comment on how this information can be used to determine properties of the dark matter coupling to the quark current, based on the approximate symmetries of low-energy QCD.
0912.1781
V Braguta
V.V. Braguta
Mass of nonrelativistic meson from leading twist distribution amplitudes
4 pages
Phys.Atom.Nucl.74:86-89,2011
10.1134/S1063778811010108
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper distribution amplitudes of pseudoscalar and vector nonrelativistic mesons are considered. Using equations of motion for the distribution amplitudes, it is derived relations which allow one to calculate the masses of nonrelativistic pseudoscalar and vector meson if the leading twist distribution amplitudes are known. These relations can be also rewritten as relations between the masses of nonrelativistic mesons and infinite series of QCD operators, what can be considered as an exact version of Gremm-Kapustin relation in NRQCD.
[ { "created": "Wed, 9 Dec 2009 16:07:26 GMT", "version": "v1" } ]
2011-03-17
[ [ "Braguta", "V. V.", "" ] ]
In this paper distribution amplitudes of pseudoscalar and vector nonrelativistic mesons are considered. Using equations of motion for the distribution amplitudes, it is derived relations which allow one to calculate the masses of nonrelativistic pseudoscalar and vector meson if the leading twist distribution amplitudes are known. These relations can be also rewritten as relations between the masses of nonrelativistic mesons and infinite series of QCD operators, what can be considered as an exact version of Gremm-Kapustin relation in NRQCD.
2403.03356
Mary Alberg
Mary Alberg and Gerald A. Miller
Quark Counting, Drell-Yan West, and the Pion Wave Function
6 pages, 2 figures
null
null
NT@UW-24-2
hep-ph nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
The relation between the pion's quark distribution function, $q(x)$, its light-front wave function, and the elastic charge form factor, $F(\Delta^2)$ is explored. The square of the leading-twist pion wave function at a special probe scale, $\zeta_H$, is determined using models and Poincare covariance from realistic results for $q(x)$. This wave function is then used to compute form factors with the result that the Drell-Yan-West and quark counting relationships are not satisfied. A new relationship between $q(x)$ and $F(\Delta^2)$ is proposed.
[ { "created": "Tue, 5 Mar 2024 22:50:07 GMT", "version": "v1" } ]
2024-03-07
[ [ "Alberg", "Mary", "" ], [ "Miller", "Gerald A.", "" ] ]
The relation between the pion's quark distribution function, $q(x)$, its light-front wave function, and the elastic charge form factor, $F(\Delta^2)$ is explored. The square of the leading-twist pion wave function at a special probe scale, $\zeta_H$, is determined using models and Poincare covariance from realistic results for $q(x)$. This wave function is then used to compute form factors with the result that the Drell-Yan-West and quark counting relationships are not satisfied. A new relationship between $q(x)$ and $F(\Delta^2)$ is proposed.
hep-ph/0505098
Petra Haefliger
Luisa Sabrina Stark, Petra Hafliger, Adrian Biland and Felicitas Pauss
Impact of A0 on the mSUGRA parameter space
2 pages, contribution to the proceedings of the XXXXth Rencontres de Moriond, La Thuile, March 2005
null
null
null
hep-ph
null
In mSUGRA models the lightest supersymmetric particle (assumed to be the lightest neutralino) provides an excellent cold dark matter (CDM) candidate. The supersymmetric parameter space is significantly reduced, if the limits on the CDM relic density, obtained from WMAP data, are used. Assuming a vanishing trilinear scalar coupling A0 and fixed values of tan(beta), these limits result in narrow lines of allowed regions in the m0-m12 plane, the so called WMAP strips. In this analysis the trilinear coupling A0 has been varied within +/-4TeV resulting in largely extended areas in the m0-m12 plane which are no longer excluded.
[ { "created": "Thu, 12 May 2005 09:22:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Stark", "Luisa Sabrina", "" ], [ "Hafliger", "Petra", "" ], [ "Biland", "Adrian", "" ], [ "Pauss", "Felicitas", "" ] ]
In mSUGRA models the lightest supersymmetric particle (assumed to be the lightest neutralino) provides an excellent cold dark matter (CDM) candidate. The supersymmetric parameter space is significantly reduced, if the limits on the CDM relic density, obtained from WMAP data, are used. Assuming a vanishing trilinear scalar coupling A0 and fixed values of tan(beta), these limits result in narrow lines of allowed regions in the m0-m12 plane, the so called WMAP strips. In this analysis the trilinear coupling A0 has been varied within +/-4TeV resulting in largely extended areas in the m0-m12 plane which are no longer excluded.
1611.00428
Ricardo Landim
Ricardo G. Landim and Elcio Abdalla
Metastable dark energy
15 pages, 3 figures, references added. Accepted for publication in PLB
Phys. Lett. B 764 (2017) 271-276
10.1016/j.physletb.2016.11.044
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We build a model of metastable dark energy, in which the observed vacuum energy is the value of the scalar potential at the false vacuum. The scalar potential is given by a sum of even self-interactions up to order six. The deviation from the Minkowski vacuum is due to a term suppressed by the Planck scale. The decay time of the metastable vacuum can easily accommodate a mean life time compatible with the age of the universe. The metastable dark energy is also embedded into a model with $SU(2)_R$ symmetry. The dark energy doublet and the dark matter doublet naturally interact with each other. A three-body decay of the dark energy particle into (cold and warm) dark matter can be as long as large fraction of the age of the universe, if the mediator is massive enough, the lower bound being at intermediate energy level some orders below the grand unification scale. Such a decay shows a different form of interaction between dark matter and dark energy, and the model opens a new window to investigate the dark sector from the point-of-view of particle physics.
[ { "created": "Wed, 2 Nov 2016 00:06:10 GMT", "version": "v1" }, { "created": "Tue, 22 Nov 2016 18:54:12 GMT", "version": "v2" } ]
2016-12-02
[ [ "Landim", "Ricardo G.", "" ], [ "Abdalla", "Elcio", "" ] ]
We build a model of metastable dark energy, in which the observed vacuum energy is the value of the scalar potential at the false vacuum. The scalar potential is given by a sum of even self-interactions up to order six. The deviation from the Minkowski vacuum is due to a term suppressed by the Planck scale. The decay time of the metastable vacuum can easily accommodate a mean life time compatible with the age of the universe. The metastable dark energy is also embedded into a model with $SU(2)_R$ symmetry. The dark energy doublet and the dark matter doublet naturally interact with each other. A three-body decay of the dark energy particle into (cold and warm) dark matter can be as long as large fraction of the age of the universe, if the mediator is massive enough, the lower bound being at intermediate energy level some orders below the grand unification scale. Such a decay shows a different form of interaction between dark matter and dark energy, and the model opens a new window to investigate the dark sector from the point-of-view of particle physics.
1007.4207
Branimir Zauner
S. Ceci, M. Korolija and B. Zauner
Model Independent Extraction of S-Matrix Poles from Experimental Data
4 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By separating data points close to a resonance into intervals, and fitting all possible intervals to a simple pole with constant coherently added background, we obtained a substantial number of convergent fits. After a carefully chosen set of statistical constraints was imposed, we calculated the average of a resonance pole position from the statistically acceptable results. We used this method to find pole positions of Z and N(1440) resonances, and to show that the strong discrepancy between the old and new measurements of the Upsilon(11020) mass stems from specious comparison of the Upsilon(11020) pole with its Breit-Wigner mass.
[ { "created": "Fri, 23 Jul 2010 20:14:17 GMT", "version": "v1" } ]
2010-07-27
[ [ "Ceci", "S.", "" ], [ "Korolija", "M.", "" ], [ "Zauner", "B.", "" ] ]
By separating data points close to a resonance into intervals, and fitting all possible intervals to a simple pole with constant coherently added background, we obtained a substantial number of convergent fits. After a carefully chosen set of statistical constraints was imposed, we calculated the average of a resonance pole position from the statistically acceptable results. We used this method to find pole positions of Z and N(1440) resonances, and to show that the strong discrepancy between the old and new measurements of the Upsilon(11020) mass stems from specious comparison of the Upsilon(11020) pole with its Breit-Wigner mass.
1106.5909
Fuming Liu
Fu-Ming Liu, Klaus Werner
On QGP Formation in pp Collisions at 7 TeV
4pages, 5figs, submitted to the Proceedings of the 22nd International Conference on Ultra-relativistic Nucleus-Nucleus Collision (Quark Matter 2011), 23 - 28 May 2011, Annecy, France
null
10.1088/0954-3899/38/12/124183
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The possibility of QGP formation in central pp collisions at ultra-high collision energy is discussed. Centrality-dependent $\pt$-spectra and (pseudo)rapidity spectra of thermal photons (charged hadrons) from pp collisions at 7 TeV are presented (addressed). Minimal-bias $\pt$-spectrum of direct photons and charged hadrons is compared under the framework with and without hydrodynamical evolution process.
[ { "created": "Wed, 29 Jun 2011 11:27:16 GMT", "version": "v1" } ]
2015-05-28
[ [ "Liu", "Fu-Ming", "" ], [ "Werner", "Klaus", "" ] ]
The possibility of QGP formation in central pp collisions at ultra-high collision energy is discussed. Centrality-dependent $\pt$-spectra and (pseudo)rapidity spectra of thermal photons (charged hadrons) from pp collisions at 7 TeV are presented (addressed). Minimal-bias $\pt$-spectrum of direct photons and charged hadrons is compared under the framework with and without hydrodynamical evolution process.
2106.07272
Jun He Prof.
Shu-Yi Kong, Jun-Tao Zhu, Dan Song, Jun He
Heavy-strange meson molecules and possible candidates $D^*_{s0}(2317)$, $D_{s1}(2460)$, and $X_0(2900)$
8 pages,5 figure
null
10.1103/PhysRevD.104.094012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we systematically investigate the heavy-strange meson systems, $D^{(*)}K^{(*)}/\bar{B}^{(*)}K^{(*)}$ and $\bar{D}^{(*)}K^{(*)}/B^{(*)}K^{(*)}$, to study possible molecules in a quasipotenial Bethe-Salpter equation approach together with the one-boson exchange model. The potential is achieved with the help of the hidden-gauge Lagrangians. Molecular states are found from all six $S$-wave isoscalar interactions of $D^{(*)}K^{(*)}$ or $\bar{B}^{(*)}K^{(*)}$. The charmed-strange mesons $D^*_{s0}(2317)$ and $D_{s1}(2460)$ can be related to the ${D}K$ and $D^*K$ states with spin parities $0^+$ and $1^+$, respectively. In the current model, the $\bar{B}K^*$ molecular state with $1^+$ is the best candidate of the recent observed $B_{sJ}(6158)$. Four molecular states are produced from the interactions of $\bar{D}^{(*)}K^{(*)}$ or $B^{(*)}K^{(*)}$. The relation between the $\bar{D}^*{K}^*$ molecular state with $0^+$ and the $X_0(2900)$ is also discussed. No isovector molecular states are found from the interactions considered. The current results are helpful to understand the internal structure of $D^*_{s0}(2317)$, $D_{s1}(2460)$, $X_0(2900)$, and new $B_{sJ}$ states. The experimental research for more heavy-strange meson molecules is suggested.
[ { "created": "Mon, 14 Jun 2021 09:48:40 GMT", "version": "v1" }, { "created": "Tue, 26 Oct 2021 01:45:53 GMT", "version": "v2" } ]
2021-11-24
[ [ "Kong", "Shu-Yi", "" ], [ "Zhu", "Jun-Tao", "" ], [ "Song", "Dan", "" ], [ "He", "Jun", "" ] ]
In this work, we systematically investigate the heavy-strange meson systems, $D^{(*)}K^{(*)}/\bar{B}^{(*)}K^{(*)}$ and $\bar{D}^{(*)}K^{(*)}/B^{(*)}K^{(*)}$, to study possible molecules in a quasipotenial Bethe-Salpter equation approach together with the one-boson exchange model. The potential is achieved with the help of the hidden-gauge Lagrangians. Molecular states are found from all six $S$-wave isoscalar interactions of $D^{(*)}K^{(*)}$ or $\bar{B}^{(*)}K^{(*)}$. The charmed-strange mesons $D^*_{s0}(2317)$ and $D_{s1}(2460)$ can be related to the ${D}K$ and $D^*K$ states with spin parities $0^+$ and $1^+$, respectively. In the current model, the $\bar{B}K^*$ molecular state with $1^+$ is the best candidate of the recent observed $B_{sJ}(6158)$. Four molecular states are produced from the interactions of $\bar{D}^{(*)}K^{(*)}$ or $B^{(*)}K^{(*)}$. The relation between the $\bar{D}^*{K}^*$ molecular state with $0^+$ and the $X_0(2900)$ is also discussed. No isovector molecular states are found from the interactions considered. The current results are helpful to understand the internal structure of $D^*_{s0}(2317)$, $D_{s1}(2460)$, $X_0(2900)$, and new $B_{sJ}$ states. The experimental research for more heavy-strange meson molecules is suggested.
hep-ph/9712209
Andrei Davydychev
F.A. Berends, A.I. Davydychev and N.I. Ussyukina
Threshold and pseudothreshold values of the sunset diagram
11 pages, plain LaTeX
Phys.Lett. B426 (1998) 95-104
10.1016/S0370-2693(98)00166-X
INLO-PUB-12/97
hep-ph
null
Analytic results for the threshold and pseudothreshold values of the sunset diagram with arbitrary masses are obtained in terms of dilogarithms of ratios of the masses.
[ { "created": "Sun, 30 Nov 1997 20:04:30 GMT", "version": "v1" } ]
2009-10-30
[ [ "Berends", "F. A.", "" ], [ "Davydychev", "A. I.", "" ], [ "Ussyukina", "N. I.", "" ] ]
Analytic results for the threshold and pseudothreshold values of the sunset diagram with arbitrary masses are obtained in terms of dilogarithms of ratios of the masses.
2101.04887
Gi-Chol Cho
Sachiho Abe, Gi-Chol Cho and Kentarou Mawatari
Probing a degenerate-scalar scenario in a pseudoscalar dark-matter model
18 pages, 8 figures. version accepted for publication in Phys. Rev. D
Phys. Rev. D 104, 035023 (2021)
10.1103/PhysRevD.104.035023
OCHA-PP-362
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study a pseudoscalar dark-matter model arising from a complex singlet extension of the standard model (SM), and show that the dark-matter--nucleon scattering is suppressed when two CP-even scalars are degenerate. In such a degenerate-scalar scenario we explore the model parameter space which satisfies constraints from the direct detection experiments and the relic density of dark matter. In addition, we discuss a possibility to verify such a scenario by using the recoil mass technique at the International Linear Collider. We find that a pair of states separated by 0.2 GeV can be distinguished from the single SM-like Higgs state at 5$\sigma$ with integrated luminosity of 2 ab$^{-1}$.
[ { "created": "Wed, 13 Jan 2021 05:38:30 GMT", "version": "v1" }, { "created": "Fri, 6 Aug 2021 02:20:07 GMT", "version": "v2" } ]
2021-09-01
[ [ "Abe", "Sachiho", "" ], [ "Cho", "Gi-Chol", "" ], [ "Mawatari", "Kentarou", "" ] ]
We study a pseudoscalar dark-matter model arising from a complex singlet extension of the standard model (SM), and show that the dark-matter--nucleon scattering is suppressed when two CP-even scalars are degenerate. In such a degenerate-scalar scenario we explore the model parameter space which satisfies constraints from the direct detection experiments and the relic density of dark matter. In addition, we discuss a possibility to verify such a scenario by using the recoil mass technique at the International Linear Collider. We find that a pair of states separated by 0.2 GeV can be distinguished from the single SM-like Higgs state at 5$\sigma$ with integrated luminosity of 2 ab$^{-1}$.
hep-ph/0304271
Michael Klasen
Michael Klasen
J/\psi Production in Direct and Resolved Photon Collisions
Talk presented at the QCD Moriond 2003 conference. 4 pages, 3 postscript figures
null
null
null
hep-ph
null
The production of J/Psi mesons in photon photon collisions allows for a test of factorization in color-octet processes as predicted by NRQCD and observed at the Tevatron. We calculate the cross sections for J/Psi production with direct and resolved photons, including also the feed-down from chi_{cJ} and Psi' decays. Our NRQCD predictions are nicely confirmed by recent data from the DELPHI collaboration at CERN LEP2.
[ { "created": "Tue, 29 Apr 2003 13:20:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Klasen", "Michael", "" ] ]
The production of J/Psi mesons in photon photon collisions allows for a test of factorization in color-octet processes as predicted by NRQCD and observed at the Tevatron. We calculate the cross sections for J/Psi production with direct and resolved photons, including also the feed-down from chi_{cJ} and Psi' decays. Our NRQCD predictions are nicely confirmed by recent data from the DELPHI collaboration at CERN LEP2.
1907.08966
Sankagiri Uma Sankar
Mohammad Nizam, Jaydeep Datta, Ali Ajmi and S. Uma Sankar
Matter vs Vacuum oscillations in Atmospheric Neutrinos
Accepted for publication in Nucl. Phys. B
Nucl. Phys. B \textbf{961} (2020), 115251
10.1016/j.nuclphysb.2020.115251
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Atmospheric neutrinos travel very long distances through earth matter. It is expected that the matter effects lead to significant changes in the neutrino survival and oscillation probabilities. Initial analysis of atmospheric neutrino data by the Super- Kamiokande collaboration is done using the vacuum oscillation hypothesis, which provided a good fit to the data. In this work, we did a study to differentiate the effects of vacuum oscillations and matter modified oscillations in the atmospheric neutrino data. We find that magnetized iron detector, ICAL at INO, can make a 3 sigma discrimination between vacuum oscillations and matter oscillations, for both normal and inverted hierarchies, in ten years.
[ { "created": "Sun, 21 Jul 2019 12:43:52 GMT", "version": "v1" }, { "created": "Tue, 24 Nov 2020 15:00:06 GMT", "version": "v2" } ]
2022-09-07
[ [ "Nizam", "Mohammad", "" ], [ "Datta", "Jaydeep", "" ], [ "Ajmi", "Ali", "" ], [ "Sankar", "S. Uma", "" ] ]
Atmospheric neutrinos travel very long distances through earth matter. It is expected that the matter effects lead to significant changes in the neutrino survival and oscillation probabilities. Initial analysis of atmospheric neutrino data by the Super- Kamiokande collaboration is done using the vacuum oscillation hypothesis, which provided a good fit to the data. In this work, we did a study to differentiate the effects of vacuum oscillations and matter modified oscillations in the atmospheric neutrino data. We find that magnetized iron detector, ICAL at INO, can make a 3 sigma discrimination between vacuum oscillations and matter oscillations, for both normal and inverted hierarchies, in ten years.
hep-ph/0210255
Michael Dine
Michael Dine
String Theory, Unification and Supersymmetry
Talk at the First International Conference on String Phenomenology, Oxford. 19 pages
null
10.1142/9789812704917_0010
scipp-02/20
hep-ph
null
One cannot yet point to any firm string prediction. While many approximate string ground states are known with interesting properties, we do not have any argument that one or another describes what we observe around us, and for reasons which appear fundamental we do not know how to systematically determine even any rough quantitative properties. I argue here that we should examine large classes of string ground states, trying to determine whether features such as low energy supersymmetry, the pattern of supersymmetry breaking, the presence of axions, large dimensions, or others might be generic.
[ { "created": "Thu, 17 Oct 2002 18:45:17 GMT", "version": "v1" } ]
2017-08-23
[ [ "Dine", "Michael", "" ] ]
One cannot yet point to any firm string prediction. While many approximate string ground states are known with interesting properties, we do not have any argument that one or another describes what we observe around us, and for reasons which appear fundamental we do not know how to systematically determine even any rough quantitative properties. I argue here that we should examine large classes of string ground states, trying to determine whether features such as low energy supersymmetry, the pattern of supersymmetry breaking, the presence of axions, large dimensions, or others might be generic.
hep-ph/9711463
Mannque Rho
Tae-Sun Park, Kuniharu Kubodera, Dong-Pil Min and Mannque Rho
Effective Field Theory for Low-Energy Two-Nucleon Systems
4 pages, RevTeX, two eps files. Slightly modified. To appear in Rapid Communication Section of Phys. Rev. C
Phys.Rev.C58:637-640,1998
10.1103/PhysRevC.58.637
SNUTP97-160
hep-ph nucl-th
null
We illustrate how effective field theories work in nuclear physics by using an effective Lagrangian in which all other degrees of freedom than the nucleonic one have been integrated out to calculate the low-energy properties of two-nucleon systems, viz, the deuteron properties, the np 1S0 scattering amplitude and the M1 transition amplitude entering into the radiative np capture process. Exploiting a finite cut-off regularization procedure, we find all the two-nucleon low-energy properties to be accurately described with little cut-off dependence, in consistency with the general philosophy of effective field theories.
[ { "created": "Tue, 25 Nov 1997 13:01:59 GMT", "version": "v1" }, { "created": "Tue, 23 Jun 1998 13:51:31 GMT", "version": "v2" } ]
2008-11-26
[ [ "Park", "Tae-Sun", "" ], [ "Kubodera", "Kuniharu", "" ], [ "Min", "Dong-Pil", "" ], [ "Rho", "Mannque", "" ] ]
We illustrate how effective field theories work in nuclear physics by using an effective Lagrangian in which all other degrees of freedom than the nucleonic one have been integrated out to calculate the low-energy properties of two-nucleon systems, viz, the deuteron properties, the np 1S0 scattering amplitude and the M1 transition amplitude entering into the radiative np capture process. Exploiting a finite cut-off regularization procedure, we find all the two-nucleon low-energy properties to be accurately described with little cut-off dependence, in consistency with the general philosophy of effective field theories.
hep-ph/0509248
Francesco Giacosa
F. Giacosa, Th. Gutsche, V. E. Lyubovitskij and Amand Faessler
Scalar nonet quarkonia and the scalar glueball: mixing and decays in an effective chiral approach
Erroneous duplicate of hep-ph/0509247
null
null
null
hep-ph
null
Erroneous duplicate of hep-ph/0509247 removed by arXiv admin
[ { "created": "Thu, 22 Sep 2005 22:10:45 GMT", "version": "v1" }, { "created": "Mon, 26 Sep 2005 23:46:05 GMT", "version": "v2" } ]
2007-05-23
[ [ "Giacosa", "F.", "" ], [ "Gutsche", "Th.", "" ], [ "Lyubovitskij", "V. E.", "" ], [ "Faessler", "Amand", "" ] ]
Erroneous duplicate of hep-ph/0509247 removed by arXiv admin
hep-ph/0105039
Leszek Motyka
J. Kwiecinski, A.D. Martin, L. Motyka and J. Outhwaite
Azimuthal decorrelation of forward and backward jets at the Tevatron
1+9 pages, 6 eps figures; the final version to appear in Phys. Lett. B; one reference added, the use of effective rapidity and the need for BFKL resummmation for small azimuthal angles better motivated
Phys.Lett. B514 (2001) 355-360
10.1016/S0370-2693(01)00813-9
IPPP/01/21, DCTP/01/42
hep-ph
null
We analyse the azimuthal decorrelation of Mueller-Navelet dijets produced in the collisions at Tevatron energies using a BFKL framework which incorporates dominant subleading effects. We show that these effects significantly reduce the decorrelation yet they are still insufficient to give satisfactory description of experimental data. However a good description of the data is obtained after incorporating within formalism the effective rapidity defined by Del Duca and Schmidt.
[ { "created": "Fri, 4 May 2001 09:19:34 GMT", "version": "v1" }, { "created": "Wed, 20 Jun 2001 08:10:14 GMT", "version": "v2" } ]
2009-11-07
[ [ "Kwiecinski", "J.", "" ], [ "Martin", "A. D.", "" ], [ "Motyka", "L.", "" ], [ "Outhwaite", "J.", "" ] ]
We analyse the azimuthal decorrelation of Mueller-Navelet dijets produced in the collisions at Tevatron energies using a BFKL framework which incorporates dominant subleading effects. We show that these effects significantly reduce the decorrelation yet they are still insufficient to give satisfactory description of experimental data. However a good description of the data is obtained after incorporating within formalism the effective rapidity defined by Del Duca and Schmidt.
1708.03642
Josef Pradler
Haipeng An, Maxim Pospelov, Josef Pradler, Adam Ritz
Directly Detecting MeV-scale Dark Matter via Solar Reflection
6 pages, 4 figures; improved treatment of reflection process; limits strengthened, conclusions otherwise unchanged
Phys. Rev. Lett. 120, 141801 (2018)
10.1103/PhysRevLett.120.141801
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If dark matter (DM) particles are lighter than a few MeV/$c^2$ and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass vs. cross section parameter space, $\{m_e, \sigma_e\}$, the "reflected" component of the DM flux is far more energetic than the endpoint of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of $10-10^3$ eV. After numerically simulating the small reflected component of the DM flux, we calculate its subsequent signal due to scattering on detector electrons, deriving new constraints on $\sigma_e$ in the MeV and sub-MeV range using existing data from the XENON10/100, LUX, PandaX-II, and XENON1T experiments, as well as making projections for future low threshold direct detection experiments.
[ { "created": "Fri, 11 Aug 2017 18:00:25 GMT", "version": "v1" }, { "created": "Wed, 11 Apr 2018 13:08:10 GMT", "version": "v2" }, { "created": "Fri, 16 Nov 2018 08:15:53 GMT", "version": "v3" } ]
2018-11-19
[ [ "An", "Haipeng", "" ], [ "Pospelov", "Maxim", "" ], [ "Pradler", "Josef", "" ], [ "Ritz", "Adam", "" ] ]
If dark matter (DM) particles are lighter than a few MeV/$c^2$ and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass vs. cross section parameter space, $\{m_e, \sigma_e\}$, the "reflected" component of the DM flux is far more energetic than the endpoint of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of $10-10^3$ eV. After numerically simulating the small reflected component of the DM flux, we calculate its subsequent signal due to scattering on detector electrons, deriving new constraints on $\sigma_e$ in the MeV and sub-MeV range using existing data from the XENON10/100, LUX, PandaX-II, and XENON1T experiments, as well as making projections for future low threshold direct detection experiments.
2211.16150
Koichi Hattori
Koichi Hattori, Daiki Suenaga, Kei Suzuki, and Shigehiro Yasui
Dirac Kondo effect under magnetic catalysis
Extended discussions and appendices. To appear in PRB
null
10.1103/PhysRevB.108.245110
null
hep-ph cond-mat.mes-hall cond-mat.str-el hep-lat nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
We develop a mean-field theory of a novel Kondo effect emerging in systems without a Fermi surface, which instead emerges under strong magnetic fields. We determine the magnitude of the Kondo condensate which is a particle pairing composed of conducting Dirac fermions and localized impurities. We focus on the competition between the Kondo effect and the energy gap formation that stems from the pairing among the Dirac fermions leading to the dynamical chiral symmetry breaking. We find that this competition induces a quantum critical point. We also investigate finite-temperature effects. This system at vanishing fermion density can be studied with Monte Carlo lattice simulations which do not suffer from the sign problem.
[ { "created": "Tue, 29 Nov 2022 12:24:36 GMT", "version": "v1" }, { "created": "Sat, 2 Dec 2023 05:26:59 GMT", "version": "v2" } ]
2023-12-07
[ [ "Hattori", "Koichi", "" ], [ "Suenaga", "Daiki", "" ], [ "Suzuki", "Kei", "" ], [ "Yasui", "Shigehiro", "" ] ]
We develop a mean-field theory of a novel Kondo effect emerging in systems without a Fermi surface, which instead emerges under strong magnetic fields. We determine the magnitude of the Kondo condensate which is a particle pairing composed of conducting Dirac fermions and localized impurities. We focus on the competition between the Kondo effect and the energy gap formation that stems from the pairing among the Dirac fermions leading to the dynamical chiral symmetry breaking. We find that this competition induces a quantum critical point. We also investigate finite-temperature effects. This system at vanishing fermion density can be studied with Monte Carlo lattice simulations which do not suffer from the sign problem.
1201.2563
Jennifer Girrbach
Andrzej J. Buras and Jennifer Girrbach
Completing NLO QCD Corrections for Tree Level Non-Leptonic Delta F = 1 Decays Beyond the Standard Model
24 pages, 6 figures
null
10.1007/JHEP02(2012)143
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In various extensions of the Standard Model (SM) tree level non-leptonic decays of hadrons receive contributions from new heavy gauge bosons and scalars. Prominent examples are the right-handed W' bosons in left-right symmetric models and charged Higgs (H^\pm) particles in models with extended scalar sector like two Higgs doublet models and supersymmetric models. Even in the case of decays with four different quark flavours involved, to which penguin operators cannot contribute, twenty linearly independent operators, instead of two in the SM, have to be considered. Anticipating the important role of such decays at the LHCb, KEKB and Super-B in Rome and having in mind future improved lattice computations, we complete the existing NLO QCD formulae for these processes by calculating O(alpha_s) corrections to matching conditions for the Wilson coefficients of all contributing operators in the NDR-\bar{MS} scheme. This allows to reduce certain unphysical scale and renormalization scheme dependences in the existing NLO calculations. Our results can also be applied to models with tree-level heavy neutral gauge boson and scalar exchanges in Delta F = 1 transitions and constitute an important part of NLO analyses of those non-leptonic decays to which also penguin operators contribute.
[ { "created": "Thu, 12 Jan 2012 13:45:36 GMT", "version": "v1" } ]
2015-06-03
[ [ "Buras", "Andrzej J.", "" ], [ "Girrbach", "Jennifer", "" ] ]
In various extensions of the Standard Model (SM) tree level non-leptonic decays of hadrons receive contributions from new heavy gauge bosons and scalars. Prominent examples are the right-handed W' bosons in left-right symmetric models and charged Higgs (H^\pm) particles in models with extended scalar sector like two Higgs doublet models and supersymmetric models. Even in the case of decays with four different quark flavours involved, to which penguin operators cannot contribute, twenty linearly independent operators, instead of two in the SM, have to be considered. Anticipating the important role of such decays at the LHCb, KEKB and Super-B in Rome and having in mind future improved lattice computations, we complete the existing NLO QCD formulae for these processes by calculating O(alpha_s) corrections to matching conditions for the Wilson coefficients of all contributing operators in the NDR-\bar{MS} scheme. This allows to reduce certain unphysical scale and renormalization scheme dependences in the existing NLO calculations. Our results can also be applied to models with tree-level heavy neutral gauge boson and scalar exchanges in Delta F = 1 transitions and constitute an important part of NLO analyses of those non-leptonic decays to which also penguin operators contribute.
2104.10324
Ernest Ma
Ernest Ma (UC Riverside)
Gauged Lepton Number, Dirac Neutrinos, Dark Matter, and Muon $g-2$
10 pages, 1 figure
null
10.1016/j.physletb.2021.136402
UCRHEP-T613 (Apr 2021)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lepton number is promoted to an $U(1)_L$ gauge symmetry in a simple extension of the standard model. The spontaneous breaking of $U(1)_L$ by three units allows a conserved $Z_3^L$ lepton symmetry to remain, guaranteeing that neutrinos are Dirac fermions, which acquire naturally small masses from a previously proposed mechanism. Dark matter appears as a singlet scalar, with dark symmetry $Z_3^D$ derivable from $Z_3^L$. Muon $g-2$ may be explained.
[ { "created": "Wed, 21 Apr 2021 02:48:14 GMT", "version": "v1" } ]
2021-06-02
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
Lepton number is promoted to an $U(1)_L$ gauge symmetry in a simple extension of the standard model. The spontaneous breaking of $U(1)_L$ by three units allows a conserved $Z_3^L$ lepton symmetry to remain, guaranteeing that neutrinos are Dirac fermions, which acquire naturally small masses from a previously proposed mechanism. Dark matter appears as a singlet scalar, with dark symmetry $Z_3^D$ derivable from $Z_3^L$. Muon $g-2$ may be explained.
hep-ph/0603168
Nils Manuel Bezares Roder
Nils M. Bezares-Roder, Hemwati Nandan
Spontaneous Symmetry Breakdown and Critical Perspectives of Higgs Mechanism
13 pages, no figures. Final version based on original to appear in the Indian Journal of Physics
Indian J.Phys.82:69-93,2008
null
null
hep-ph
null
The foundations of the mass generation mechanism of particles are reviewed. The Spontaneous Symmetry Breaking (SSB) process within the standard model (SM) and the minimal supersymmetric standard model (MSSM) is used to explore the present status of the Higgs Mechanism along with the constraints in detecting the Higgs particles in experiments. The possible explanations and generalizations for the case that the Higgs particles should not appear or to couple the Higgs Mechanism (because of their gravitational nature of interaction) are also iscussed in detail in view of the Higgs field gravity.
[ { "created": "Tue, 21 Mar 2006 21:50:54 GMT", "version": "v1" }, { "created": "Mon, 19 Feb 2007 15:00:00 GMT", "version": "v2" }, { "created": "Thu, 25 Oct 2007 08:40:02 GMT", "version": "v3" }, { "created": "Mon, 14 Apr 2008 13:22:03 GMT", "version": "v4" } ]
2009-07-07
[ [ "Bezares-Roder", "Nils M.", "" ], [ "Nandan", "Hemwati", "" ] ]
The foundations of the mass generation mechanism of particles are reviewed. The Spontaneous Symmetry Breaking (SSB) process within the standard model (SM) and the minimal supersymmetric standard model (MSSM) is used to explore the present status of the Higgs Mechanism along with the constraints in detecting the Higgs particles in experiments. The possible explanations and generalizations for the case that the Higgs particles should not appear or to couple the Higgs Mechanism (because of their gravitational nature of interaction) are also iscussed in detail in view of the Higgs field gravity.
hep-ph/0603202
Veronique Bernard
V\'eronique Bernard, Micaela Oertel, Emilie Passemar, Jan Stern
K^L_{mu3} decay: A Stringent Test of Right-Handed Quark Currents
15 pp, 3 eps figs, Comment on the charged Kaon mode and few refs added
Phys.Lett.B638:480-486,2006
10.1016/j.physletb.2006.05.079
null
hep-ph hep-ex
null
Clean tests of a small admixture of right-handed quark currents directly coupled to the standard W are still lacking. We show that such non-standard couplings can be significantly constrained measuring the value of the scalar Kpi form factor at the Callan-Treiman point to a few percent. A realistic prospect of such a measurement in K^L_{mu3} decay based on an accurate dispersive representation of the scalar form factor is presented. The inadequacy of the currently used linear parametrisation is explained and illustrated using recent KTeV data. We briefly comment on the charged Kaon mode.
[ { "created": "Fri, 24 Mar 2006 20:29:24 GMT", "version": "v1" }, { "created": "Thu, 4 May 2006 18:36:48 GMT", "version": "v2" } ]
2010-11-05
[ [ "Bernard", "Véronique", "" ], [ "Oertel", "Micaela", "" ], [ "Passemar", "Emilie", "" ], [ "Stern", "Jan", "" ] ]
Clean tests of a small admixture of right-handed quark currents directly coupled to the standard W are still lacking. We show that such non-standard couplings can be significantly constrained measuring the value of the scalar Kpi form factor at the Callan-Treiman point to a few percent. A realistic prospect of such a measurement in K^L_{mu3} decay based on an accurate dispersive representation of the scalar form factor is presented. The inadequacy of the currently used linear parametrisation is explained and illustrated using recent KTeV data. We briefly comment on the charged Kaon mode.
hep-ph/9803363
A. A. Penin
A.A.Penin and A.A.Pivovarov
Next-to-next-to-leading order vacuum polarization function of heavy quark near threshold and sum rules for $b \bar b$ system
12 pages Latex, misprints in the formulae for the nonrelativistic Green function are corrected
Phys.Lett. B435 (1998) 413-419
10.1016/S0370-2693(98)00803-X
preprint TTP98-13
hep-ph
null
A correlator of the vector current of a heavy quark is computed analytically near threshold in the next-to-next-to-leading order in perturbative and relativistic expansion that includes $\al_s^2$, $\al_sv$ and $v^2$ corrections in the coupling constant and velocity of the heavy quark to the nonrelativistic Coulomb approximation. Based on this result, the numerical values of the $b$-quark pole mass and the strong coupling constant are determined from the analysis of sum rules for the $\Upsilon$ system. The next-to-next-to-leading corrections are found to be of order of next-to-leading ones.
[ { "created": "Mon, 16 Mar 1998 19:46:05 GMT", "version": "v1" }, { "created": "Thu, 19 Mar 1998 20:00:28 GMT", "version": "v2" }, { "created": "Fri, 27 Mar 1998 16:00:41 GMT", "version": "v3" }, { "created": "Mon, 6 Apr 1998 10:26:17 GMT", "version": "v4" } ]
2009-10-31
[ [ "Penin", "A. A.", "" ], [ "Pivovarov", "A. A.", "" ] ]
A correlator of the vector current of a heavy quark is computed analytically near threshold in the next-to-next-to-leading order in perturbative and relativistic expansion that includes $\al_s^2$, $\al_sv$ and $v^2$ corrections in the coupling constant and velocity of the heavy quark to the nonrelativistic Coulomb approximation. Based on this result, the numerical values of the $b$-quark pole mass and the strong coupling constant are determined from the analysis of sum rules for the $\Upsilon$ system. The next-to-next-to-leading corrections are found to be of order of next-to-leading ones.
0802.0026
Michelangelo Mangano
Michelangelo L. Mangano
Understanding the Standard Model, as a bridge to the discovery of new phenomena at the LHC
Contribution to ``Perspectives on the LHC'', G. Kane and A. Pierce, editors
Int.J.Mod.Phys.A23:3833-3848,2008
10.1142/S0217751X08042353
CERN-PH-TH/98-019
hep-ph hep-ex hep-th
null
I discuss the basic elements of the process that will lead to the discovery of possible new phenomena at the LHC. We review the status of the tools available to model the Standard Model backgrounds, and the role that such tools can play in the discovery phase, and in the exploration of the features and parameters of such new phenomena.
[ { "created": "Thu, 31 Jan 2008 22:40:04 GMT", "version": "v1" }, { "created": "Sat, 2 Feb 2008 07:50:57 GMT", "version": "v2" } ]
2009-01-06
[ [ "Mangano", "Michelangelo L.", "" ] ]
I discuss the basic elements of the process that will lead to the discovery of possible new phenomena at the LHC. We review the status of the tools available to model the Standard Model backgrounds, and the role that such tools can play in the discovery phase, and in the exploration of the features and parameters of such new phenomena.
2107.10683
Xiao-Dong Cheng Xiao-Dong Cheng
Xiao-Dong Cheng, Ru-Min Wang, Xing-Bo Yuan
Effect of $K^0-\bar{K}^0$ Mixing on CP and CPT Violations in $B_{c}^{\pm}\rightarrow B^{\pm} K_{S,L}^{0}$ Decays
32 pages,2 figures
null
10.1103/PhysRevD.104.093005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The large data sample of the $B_c$ meson collected at the LHC experiment and the HL-LHC experiment provides us the opportunity to study the $B_c$ decays and the related physics. In this paper, we investigate the effect of $K^0-\bar{K}^0$ mixing on the the branching ratios, CP violations and CPT violations in the $B_{c}^{\pm}\rightarrow B^{\pm} K_{S,L}^{0}$ decays. We find that some of the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0\rightarrow f_{B^{\pm}} f_{K_{S,L}^0}$ decay chains have large branching ratios, whose maximum value can exceed the order of $10^{-6}$, the minimum number of $B_c^\pm$ events times efficiency for observing the decays at three standard deviations (3$\sigma$) level is about $ 10^6$. We study the CP asymmetries in the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0$ decays and find that the CP asymmetries can exceed the order of $10^{-3}$, which are dominated by $K^0-\bar{K}^0$ mixing. We give the most promising processes to observe the CP violations and the ranges of the numbers of $B_c^\pm$ events-times-efficiency needed to observe the CP asymmetries at a significance of 3$\sigma$ in these decays. We investigate the possibility to constraint the CPT violation parameter $z$ in the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0\rightarrow f_{B^{\pm}} f_{K_{S,L}^0}$ decays and give the most promising processes to constraint the parameter $z$.
[ { "created": "Thu, 22 Jul 2021 13:41:55 GMT", "version": "v1" }, { "created": "Thu, 23 Sep 2021 10:13:26 GMT", "version": "v2" } ]
2021-11-24
[ [ "Cheng", "Xiao-Dong", "" ], [ "Wang", "Ru-Min", "" ], [ "Yuan", "Xing-Bo", "" ] ]
The large data sample of the $B_c$ meson collected at the LHC experiment and the HL-LHC experiment provides us the opportunity to study the $B_c$ decays and the related physics. In this paper, we investigate the effect of $K^0-\bar{K}^0$ mixing on the the branching ratios, CP violations and CPT violations in the $B_{c}^{\pm}\rightarrow B^{\pm} K_{S,L}^{0}$ decays. We find that some of the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0\rightarrow f_{B^{\pm}} f_{K_{S,L}^0}$ decay chains have large branching ratios, whose maximum value can exceed the order of $10^{-6}$, the minimum number of $B_c^\pm$ events times efficiency for observing the decays at three standard deviations (3$\sigma$) level is about $ 10^6$. We study the CP asymmetries in the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0$ decays and find that the CP asymmetries can exceed the order of $10^{-3}$, which are dominated by $K^0-\bar{K}^0$ mixing. We give the most promising processes to observe the CP violations and the ranges of the numbers of $B_c^\pm$ events-times-efficiency needed to observe the CP asymmetries at a significance of 3$\sigma$ in these decays. We investigate the possibility to constraint the CPT violation parameter $z$ in the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0\rightarrow f_{B^{\pm}} f_{K_{S,L}^0}$ decays and give the most promising processes to constraint the parameter $z$.
hep-ph/0607004
Junegone Chay
Junegone Chay, Chul Kim, Adam K. Leibovich, Jure Zupan
Semi-inclusive hadronic B decays in the endpoint region
31 pages, 7 figures
Phys.Rev.D74:074022,2006
10.1103/PhysRevD.74.074022
null
hep-ph
null
We consider in the soft-collinear effective theory semi-inclusive hadronic B decays, B-> XM, in which an energetic light meson M near the endpoint recoils against an inclusive jet X. We focus on a subset of decays where the spectator quark from the B meson ends up in the jet. The branching ratios and direct CP asymmetries are computed to next-to-leading order accuracy in alpha_s and to leading order in 1/m_b. The contribution of charming penguins is extensively discussed, and a method to extract it in semi-inclusive decays is suggested. Subleading 1/m_b corrections and SU(3) breaking effects are discussed.
[ { "created": "Sat, 1 Jul 2006 01:17:34 GMT", "version": "v1" } ]
2008-11-26
[ [ "Chay", "Junegone", "" ], [ "Kim", "Chul", "" ], [ "Leibovich", "Adam K.", "" ], [ "Zupan", "Jure", "" ] ]
We consider in the soft-collinear effective theory semi-inclusive hadronic B decays, B-> XM, in which an energetic light meson M near the endpoint recoils against an inclusive jet X. We focus on a subset of decays where the spectator quark from the B meson ends up in the jet. The branching ratios and direct CP asymmetries are computed to next-to-leading order accuracy in alpha_s and to leading order in 1/m_b. The contribution of charming penguins is extensively discussed, and a method to extract it in semi-inclusive decays is suggested. Subleading 1/m_b corrections and SU(3) breaking effects are discussed.
hep-ph/0304295
Vladimir Vechernin
V. V. Vechernin and R. S. Kolevatov (St.Petersburg State University)
Simple Cellular Model of Long-Range Multiplicity and $p_t$ Correlations in High-Energy Nuclear Collisions
15 pages, LaTeX, 5 figures in PostScript, Russian version will appear in the journal "Vestnik SPbU"
null
null
SPbU-IP-03-07
hep-ph
null
A simple cellular model for the description of the long-range multiplicity and $p_t$ correlations in high-energy nuclear collisions originating from the string fusion model is proposed. Three versions of the model: without fusion, with local and with global string fusion are formulated. A Gauss approximation which enables explicit analytical calculations of the correlation functions in some asymptotic cases in the framework of the model is developed. The assumptions of the model and the validity of a Gauss approximation are checked up in the simplest (no fusion) case when the explicit solution of the model can be found. The role of a size of cells is analysed. The modification of the results in the case of non-Poissonian distributions is also discussed.
[ { "created": "Wed, 30 Apr 2003 15:59:16 GMT", "version": "v1" } ]
2007-05-23
[ [ "Vechernin", "V. V.", "", "St.Petersburg State University" ], [ "Kolevatov", "R. S.", "", "St.Petersburg State University" ] ]
A simple cellular model for the description of the long-range multiplicity and $p_t$ correlations in high-energy nuclear collisions originating from the string fusion model is proposed. Three versions of the model: without fusion, with local and with global string fusion are formulated. A Gauss approximation which enables explicit analytical calculations of the correlation functions in some asymptotic cases in the framework of the model is developed. The assumptions of the model and the validity of a Gauss approximation are checked up in the simplest (no fusion) case when the explicit solution of the model can be found. The role of a size of cells is analysed. The modification of the results in the case of non-Poissonian distributions is also discussed.
1603.01366
Millie McDonald
A. J. Brennan, M. F. McDonald, J. Gramling and T. D. Jacques
Collide and Conquer: Constraints on Simplified Dark Matter Models using Mono-X Collider Searches
32 pages, 8 figures; v2: minor changes, conclusion unchanged, matches published version
JHEP05(2016)112
10.1007/JHEP05(2016)112
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
The use of simplified models as a tool for interpreting dark matter collider searches has become increasingly prevalent, and while early Run II results are beginning to appear, we look to see what further information can be extracted from the Run I dataset. We consider three `standard' simplified models that couple quarks to fermionic singlet dark matter: an $s$-channel vector mediator with vector or axial-vector couplings, and a $t$-channel scalar mediator. Upper limits on the couplings are calculated and compared across three alternate channels, namely mono-jet, mono-$Z$ (leptonic) and mono-$W/Z$ (hadronic). The strongest limits are observed in the mono-jet channel, however the computational simplicity and absence of significant $t$-channel model width effects in the mono-boson channels make these a straightforward and competitive alternative. We also include a comparison with relic density and direct detection constraints.
[ { "created": "Fri, 4 Mar 2016 07:27:26 GMT", "version": "v1" }, { "created": "Tue, 24 May 2016 05:35:50 GMT", "version": "v2" } ]
2016-05-25
[ [ "Brennan", "A. J.", "" ], [ "McDonald", "M. F.", "" ], [ "Gramling", "J.", "" ], [ "Jacques", "T. D.", "" ] ]
The use of simplified models as a tool for interpreting dark matter collider searches has become increasingly prevalent, and while early Run II results are beginning to appear, we look to see what further information can be extracted from the Run I dataset. We consider three `standard' simplified models that couple quarks to fermionic singlet dark matter: an $s$-channel vector mediator with vector or axial-vector couplings, and a $t$-channel scalar mediator. Upper limits on the couplings are calculated and compared across three alternate channels, namely mono-jet, mono-$Z$ (leptonic) and mono-$W/Z$ (hadronic). The strongest limits are observed in the mono-jet channel, however the computational simplicity and absence of significant $t$-channel model width effects in the mono-boson channels make these a straightforward and competitive alternative. We also include a comparison with relic density and direct detection constraints.
hep-ph/9503240
Halperin Igor
Igor Halperin
Quantum KAM Technique and Yang-Mills Quantum Mechanics
26 pages, latex, no figures
Annals Phys. 244 (1995) 445-475
10.1006/aphy.1995.1119
TECHNION-PHYS-95-1
hep-ph hep-th
null
We study a quantum analogue of the iterative perturbation theory by Kolmogorov used in the proof of the Kolmogorov-Arnold-Moser (KAM) theorem. The method is based on sequent canonical transformations with a "running" coupling constant $ \lm,\lm^{2},\lm^{4} $ etc. The proposed scheme, as its classical predecessor, is "superconvergent" in the sense that after the n-th step, a theory is solved to the accuracy of order $ \lm^{2^{n-1}} $. It is shown that the Kolmogorov technique corresponds to an infinite resummation of the usual perturbative series. The corresponding expansion is convergent for the quantum anharmonic oscillator due to the fact that it turns out to be identical to the Pade series. The method is easily generalizable to many-dimensional cases. The Kolmogorov technique is further applied to a non-perturbative treatment of Yang-Mills quantum mechanics. A controllable expansion for the wave function near the origin is constructed. For large fields, we build an asymptotic adiabatic expansion in inverse powers of the field. This asymptotic solution contains arbitrary constants which are not fixed by the boundary conditions at infinity. To find them, we approximately match the two expansions in an intermediate region. We also discuss some analogies between this problem and the method of QCD sum rules.
[ { "created": "Mon, 6 Mar 1995 16:10:33 GMT", "version": "v1" } ]
2015-06-25
[ [ "Halperin", "Igor", "" ] ]
We study a quantum analogue of the iterative perturbation theory by Kolmogorov used in the proof of the Kolmogorov-Arnold-Moser (KAM) theorem. The method is based on sequent canonical transformations with a "running" coupling constant $ \lm,\lm^{2},\lm^{4} $ etc. The proposed scheme, as its classical predecessor, is "superconvergent" in the sense that after the n-th step, a theory is solved to the accuracy of order $ \lm^{2^{n-1}} $. It is shown that the Kolmogorov technique corresponds to an infinite resummation of the usual perturbative series. The corresponding expansion is convergent for the quantum anharmonic oscillator due to the fact that it turns out to be identical to the Pade series. The method is easily generalizable to many-dimensional cases. The Kolmogorov technique is further applied to a non-perturbative treatment of Yang-Mills quantum mechanics. A controllable expansion for the wave function near the origin is constructed. For large fields, we build an asymptotic adiabatic expansion in inverse powers of the field. This asymptotic solution contains arbitrary constants which are not fixed by the boundary conditions at infinity. To find them, we approximately match the two expansions in an intermediate region. We also discuss some analogies between this problem and the method of QCD sum rules.
hep-ph/0007046
Tord Riemann
M. Jack (1), A. Hoefer (1), A. Leike (2), T. Riemann (1) ((1) DESY, (2) LMU Munich)
Predictions for Fermion Pair Production at e+e- Colliders
10 pages, 1 table, 2 figures, uses npb.sty, to appear in the proceedings of Zeuthen Workshop: Loops and Legs in Quantum Field Theory, 9-14 April, Bastei, Germany
Nucl.Phys.Proc.Suppl.89:15-24,2000
10.1016/S0920-5632(00)00816-1
DESY 00-073
hep-ph
null
We discuss the status and some ongoing upgrades of the ZFITTER program for applications at e+e- colliders LEP1/SLC, LEP2, GigaZ, and TESLA. The inclusion of top quark pair production is under work.
[ { "created": "Wed, 5 Jul 2000 15:06:20 GMT", "version": "v1" } ]
2011-01-13
[ [ "Jack", "M.", "" ], [ "Hoefer", "A.", "" ], [ "Leike", "A.", "" ], [ "Riemann", "T.", "" ] ]
We discuss the status and some ongoing upgrades of the ZFITTER program for applications at e+e- colliders LEP1/SLC, LEP2, GigaZ, and TESLA. The inclusion of top quark pair production is under work.
hep-ph/0407300
Bodo Geyer
B. Geyer, D. Robaschik and J. Eilers
Target mass corrections for virtual Compton scattering at twist-2 and generalized, non-forward Wandzura-Wilczek and Callan-Gross relations
32 pages, Latex 2e, adding two relations (VI.39/40), removing some misprints and changing few notations, adjusting trace terms
Nucl.Phys. B704 (2005) 279-331
10.1016/j.nuclphysb.2004.10.041
null
hep-ph hep-th
null
The off-cone Compton operator of twist-2 is Fourier transformed using a general procedure which is applicable, in principle, to any QCD tensor operator of definite (geometric) twist. That method allows, after taking the non-forward matrix elements, to separate quite effectively their imaginary part and to reveal some hidden structure in terms of appropriately defined variables, including generalized Nachtmann variables. In this way, without using the equations of motion, generalizations of the Wandzura-Wilzcek relation and of the mass-corrected Callan-Gross relation to the non-forward scattering, having the same shape as in the forward case, are obtained. In addition, new relations for those structure functions which vanish in the forward case are derived. These structure functions are written in terms of iterated generalized parton distributions of $n$-th order.
[ { "created": "Tue, 27 Jul 2004 07:39:07 GMT", "version": "v1" }, { "created": "Tue, 10 Aug 2004 10:51:42 GMT", "version": "v2" } ]
2009-11-10
[ [ "Geyer", "B.", "" ], [ "Robaschik", "D.", "" ], [ "Eilers", "J.", "" ] ]
The off-cone Compton operator of twist-2 is Fourier transformed using a general procedure which is applicable, in principle, to any QCD tensor operator of definite (geometric) twist. That method allows, after taking the non-forward matrix elements, to separate quite effectively their imaginary part and to reveal some hidden structure in terms of appropriately defined variables, including generalized Nachtmann variables. In this way, without using the equations of motion, generalizations of the Wandzura-Wilzcek relation and of the mass-corrected Callan-Gross relation to the non-forward scattering, having the same shape as in the forward case, are obtained. In addition, new relations for those structure functions which vanish in the forward case are derived. These structure functions are written in terms of iterated generalized parton distributions of $n$-th order.
2107.10852
Wouter Dekens
Wouter Dekens, Lorenzo Andreoli, Jordy de Vries, Emanuele Mereghetti, and Femke Oosterhof
A low-energy perspective on the minimal left-right symmetric model
42 pages plus appendices. Published version
null
10.1007/JHEP11(2021)127
LA-UR-21-26789
hep-ph
http://creativecommons.org/licenses/by/4.0/
We perform a global analysis of the low-energy phenomenology of the minimal left-right symmetric model (mLRSM) with parity symmetry. We match the mLRSM to the Standard Model Effective Field Theory Lagrangian at the left-right-symmetry breaking scale and perform a comprehensive fit to low-energy data including mesonic, neutron, and nuclear $\beta$-decay processes, $\Delta F=1$ and $\Delta F=2$ CP-even and -odd processes in the bottom and strange sectors, and electric dipole moments (EDMs) of nucleons, nuclei, and atoms. We fit the Cabibbo-Kobayashi-Maskawa and mLRSM parameters simultaneously and determine a lower bound on the mass of the right-handed $W_R$ boson. In models where a Peccei-Quinn mechanism provides a solution to the strong CP problem, we obtain $M_{W_R} \gtrsim 5.5$ TeV at $95\%$ C.L. which can be significantly improved with next-generation EDM experiments. In the $P$-symmetric mLRSM without a Peccei-Quinn mechanism we obtain a more stringent constraint $M_{W_R} \gtrsim 17$ TeV at $95\%$ C.L., which is difficult to improve with low-energy measurements alone. In all cases, the additional scalar fields of the mLRSM are required to be a few times heavier than the right-handed gauge bosons. We consider a recent discrepancy in tests of first-row unitarity of the CKM matrix. We find that, while TeV-scale $W_R$ bosons can alleviate some of the tension found in the $V_{ud,us}$ determinations, a solution to the discrepancy is disfavored when taking into account other low-energy observables within the mLRSM.
[ { "created": "Thu, 22 Jul 2021 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 31 Aug 2021 13:54:02 GMT", "version": "v2" }, { "created": "Fri, 3 Dec 2021 10:13:01 GMT", "version": "v3" } ]
2021-12-08
[ [ "Dekens", "Wouter", "" ], [ "Andreoli", "Lorenzo", "" ], [ "de Vries", "Jordy", "" ], [ "Mereghetti", "Emanuele", "" ], [ "Oosterhof", "Femke", "" ] ]
We perform a global analysis of the low-energy phenomenology of the minimal left-right symmetric model (mLRSM) with parity symmetry. We match the mLRSM to the Standard Model Effective Field Theory Lagrangian at the left-right-symmetry breaking scale and perform a comprehensive fit to low-energy data including mesonic, neutron, and nuclear $\beta$-decay processes, $\Delta F=1$ and $\Delta F=2$ CP-even and -odd processes in the bottom and strange sectors, and electric dipole moments (EDMs) of nucleons, nuclei, and atoms. We fit the Cabibbo-Kobayashi-Maskawa and mLRSM parameters simultaneously and determine a lower bound on the mass of the right-handed $W_R$ boson. In models where a Peccei-Quinn mechanism provides a solution to the strong CP problem, we obtain $M_{W_R} \gtrsim 5.5$ TeV at $95\%$ C.L. which can be significantly improved with next-generation EDM experiments. In the $P$-symmetric mLRSM without a Peccei-Quinn mechanism we obtain a more stringent constraint $M_{W_R} \gtrsim 17$ TeV at $95\%$ C.L., which is difficult to improve with low-energy measurements alone. In all cases, the additional scalar fields of the mLRSM are required to be a few times heavier than the right-handed gauge bosons. We consider a recent discrepancy in tests of first-row unitarity of the CKM matrix. We find that, while TeV-scale $W_R$ bosons can alleviate some of the tension found in the $V_{ud,us}$ determinations, a solution to the discrepancy is disfavored when taking into account other low-energy observables within the mLRSM.
hep-ph/0305007
Josef Dubicki
J. E. Dubicki, C. D. Froggatt (Dept. of Physics and Astronomy, University of Glasgow)
Supersymmetric Grand Unification with a Fourth Generation?
Minor changes. Version to appear in Phys. Lett. B
Phys.Lett. B567 (2003) 46-52
10.1016/j.physletb.2003.06.017
GUTPA/03/04/01
hep-ph
null
The possibility of incorporating a chiral fourth generation into a SUSY-GUT is investigated. Precision fits to electroweak observables require us to introduce light supersymmetric particles, with masses less than mZ. These particles might also provide decay channels for fourth generation quarks of mass ~ 100 GeV. We also require tan(beta) to lie in the range 1.50 <~ tan(beta) <~ 1.75 and obtain an upper limit on the lightest Higgs boson mass in the MSSM4 of 152 GeV.
[ { "created": "Thu, 1 May 2003 12:33:45 GMT", "version": "v1" }, { "created": "Thu, 19 Jun 2003 15:07:03 GMT", "version": "v2" } ]
2009-11-10
[ [ "Dubicki", "J. E.", "", "Dept. of Physics and Astronomy,\n University of Glasgow" ], [ "Froggatt", "C. D.", "", "Dept. of Physics and Astronomy,\n University of Glasgow" ] ]
The possibility of incorporating a chiral fourth generation into a SUSY-GUT is investigated. Precision fits to electroweak observables require us to introduce light supersymmetric particles, with masses less than mZ. These particles might also provide decay channels for fourth generation quarks of mass ~ 100 GeV. We also require tan(beta) to lie in the range 1.50 <~ tan(beta) <~ 1.75 and obtain an upper limit on the lightest Higgs boson mass in the MSSM4 of 152 GeV.
1204.6532
Daisuke Satow
Daisuke Satow, Yoshimasa Hidaka
Off-diagonal kinetic theory in ultrasoft momentum region at high temperature
15 pages, 8 figures
Phys. Rev. D 85:116009, 2012
10.1103/PhysRevD.85.116009
RIKEN-QHP-23; RIKEN-MP-44; KUNS-2399
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive a linearized kinetic equation for fermionic excitations with an ultrasoft momentum, g^2T, from the Kadanoff-Baym equation in a Yukawa model and quantum electrodynamics (QED) at extremely high T, where g is the coupling constant. We show that this equation is equivalent to the self-consistent equation in the resummed perturbation theory used in the analysis of the fermion spectrum with the ultrasoft momentum. Furthermore, we derive the equation that determines the n-point function with external lines for a pair of fermions and (n-2) bosons with ultrasoft momenta in QED.
[ { "created": "Mon, 30 Apr 2012 01:02:58 GMT", "version": "v1" } ]
2012-06-25
[ [ "Satow", "Daisuke", "" ], [ "Hidaka", "Yoshimasa", "" ] ]
We derive a linearized kinetic equation for fermionic excitations with an ultrasoft momentum, g^2T, from the Kadanoff-Baym equation in a Yukawa model and quantum electrodynamics (QED) at extremely high T, where g is the coupling constant. We show that this equation is equivalent to the self-consistent equation in the resummed perturbation theory used in the analysis of the fermion spectrum with the ultrasoft momentum. Furthermore, we derive the equation that determines the n-point function with external lines for a pair of fermions and (n-2) bosons with ultrasoft momenta in QED.
1301.4095
Heikki M\"antysaari
T. Lappi, H. M\"antysaari
J/Psi production in ultraperipheral Pb+Pb and p+Pb collisions at energies available at the CERN Large Hadron Collider
6 pages, 5 figures. RevTeX. v2: references added, corrected a numerical error (small effect on coherent cross section), conclusions unchanged. v3: references updated, published in Phys. Rev. C
Phys.Rev. C87 (2013) 032201
10.1103/PhysRevC.87.032201
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute cross sections for incoherent and coherent diffractive J/Psi production in ultraperipheral nucleus-nucleus and proton-nucleus collisions using two different dipole models fitted to HERA data. We obtain a reasonably good description of the available ALICE data for coherent J/\Psi production and present our prediction for the incoherent cross section. We also find that while the normalization of the cross section depends quite strongly on the dipole model and vector meson wave function used, the rapidity dependence is very well constrained.
[ { "created": "Thu, 17 Jan 2013 13:49:00 GMT", "version": "v1" }, { "created": "Tue, 22 Jan 2013 12:40:10 GMT", "version": "v2" }, { "created": "Wed, 10 Apr 2013 11:32:09 GMT", "version": "v3" } ]
2013-04-11
[ [ "Lappi", "T.", "" ], [ "Mäntysaari", "H.", "" ] ]
We compute cross sections for incoherent and coherent diffractive J/Psi production in ultraperipheral nucleus-nucleus and proton-nucleus collisions using two different dipole models fitted to HERA data. We obtain a reasonably good description of the available ALICE data for coherent J/\Psi production and present our prediction for the incoherent cross section. We also find that while the normalization of the cross section depends quite strongly on the dipole model and vector meson wave function used, the rapidity dependence is very well constrained.
1011.4417
Mikhail Ivanov
Stanislav Dubnicka, Anna Z. Dubnickova, Mikhail A. Ivanov, Juergen G. Koerner, Gozyal G. Saidullaeva
A relativistic quark model with infrared confinement and the tetraquark state
3 pages, 2 figures, talk given at the conference "Quark Confinement and the Hadron Spectrum", Madrid, 30/Aug-3/Sept, 2010
AIP Conf.Proc.1343:385-387,2011
10.1063/1.3575037
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the consequences of treating the X(3872) meson as a tetraquark bound state. As dynamical framework we employ a relativistic constituent quark model which includes infrared confinement in an effective way. We calculate the hadronic decay widths of the observed channels. For reasonable values of the size parameter of the X(3872) we find consistency with the available experimental data.
[ { "created": "Fri, 19 Nov 2010 13:04:56 GMT", "version": "v1" } ]
2011-07-08
[ [ "Dubnicka", "Stanislav", "" ], [ "Dubnickova", "Anna Z.", "" ], [ "Ivanov", "Mikhail A.", "" ], [ "Koerner", "Juergen G.", "" ], [ "Saidullaeva", "Gozyal G.", "" ] ]
We explore the consequences of treating the X(3872) meson as a tetraquark bound state. As dynamical framework we employ a relativistic constituent quark model which includes infrared confinement in an effective way. We calculate the hadronic decay widths of the observed channels. For reasonable values of the size parameter of the X(3872) we find consistency with the available experimental data.
hep-ph/0507004
Piotr Niezurawski
P. Niezurawski
Final results for the SM Higgs-boson production at the Photon Collider
Presented at the International Linear Collider Workshop LCWS05, Stanford, USA
null
null
null
hep-ph
null
Feasibility of the precise measurement of the SM Higgs-boson production cross section gamma+gamma->h->b+bbar at the Photon Collider is studied in detail for M_h=120-160 GeV. All relevant experimental and theoretical issues, which could affect the measurement, are taken into account. The study is based on the realistic gamma-gamma luminosity spectra simulation. The heavy-quark background gamma+gamma->Q+Qbar(+g) is estimated using the NLO QCD results. Other background processes, which were neglected in earlier analyses, are also studied: gamma+gamma->W+W, gamma+gamma->tau+tau and light-quark pair production gamma+gamma->q+qbar. The contribution from the so-called overlaying events, gamma+gamma->hadrons, is taken into account. The non-zero beam crossing angle and the finite size of colliding bunches are included in the event generation. The detector simulation and realistic b-tagging are used. Criteria of event selection are optimized separately for each considered Higgs-boson mass. In spite of the significant background contribution and deterioration of the invariant mass resolution due to overlaying events, precise measurement of the Higgs-boson production cross section is still possible. For the Standard-Model Higgs boson with mass of 120 to 160 GeV the corresponding partial width Gamma(h->gamma+gamma)BR(h->b+bbar) can be measured with a statistical accuracy of 2.1-7.7% after one year of the Photon Collider running. The systematic uncertainties of the measurement are estimated to be of the order of 2%.
[ { "created": "Fri, 1 Jul 2005 01:21:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Niezurawski", "P.", "" ] ]
Feasibility of the precise measurement of the SM Higgs-boson production cross section gamma+gamma->h->b+bbar at the Photon Collider is studied in detail for M_h=120-160 GeV. All relevant experimental and theoretical issues, which could affect the measurement, are taken into account. The study is based on the realistic gamma-gamma luminosity spectra simulation. The heavy-quark background gamma+gamma->Q+Qbar(+g) is estimated using the NLO QCD results. Other background processes, which were neglected in earlier analyses, are also studied: gamma+gamma->W+W, gamma+gamma->tau+tau and light-quark pair production gamma+gamma->q+qbar. The contribution from the so-called overlaying events, gamma+gamma->hadrons, is taken into account. The non-zero beam crossing angle and the finite size of colliding bunches are included in the event generation. The detector simulation and realistic b-tagging are used. Criteria of event selection are optimized separately for each considered Higgs-boson mass. In spite of the significant background contribution and deterioration of the invariant mass resolution due to overlaying events, precise measurement of the Higgs-boson production cross section is still possible. For the Standard-Model Higgs boson with mass of 120 to 160 GeV the corresponding partial width Gamma(h->gamma+gamma)BR(h->b+bbar) can be measured with a statistical accuracy of 2.1-7.7% after one year of the Photon Collider running. The systematic uncertainties of the measurement are estimated to be of the order of 2%.
hep-ph/9806463
Liliana Micu
L. Micu (NIPNE-HH, Bucharest)
Meson electromagnetic form factors in a relativistic quark model
11 pages, LaTeX, 1 eps figure, submitted to Physics Letters B
null
null
FT 435-98-06
hep-ph
null
The main assumption of the model is that in soft processes mesons behave like systems made of valence quarks and an effective vacuum- like field. The 4-momentum of the latter represents the relativistic generalization of the potential energy. The electromagnetic form factors are expressed in terms of the overlap integral of the initial and final wave functions written under the form of Lorentz covariant distribution of quark momenta. The calculation is fully Lorentz covariant and the form factors of the charged mesons are normalized to unity at t=0.
[ { "created": "Wed, 24 Jun 1998 11:35:12 GMT", "version": "v1" } ]
2007-05-23
[ [ "Micu", "L.", "", "NIPNE-HH, Bucharest" ] ]
The main assumption of the model is that in soft processes mesons behave like systems made of valence quarks and an effective vacuum- like field. The 4-momentum of the latter represents the relativistic generalization of the potential energy. The electromagnetic form factors are expressed in terms of the overlap integral of the initial and final wave functions written under the form of Lorentz covariant distribution of quark momenta. The calculation is fully Lorentz covariant and the form factors of the charged mesons are normalized to unity at t=0.
hep-ph/9903392
Stefan Scherer
S. Scherer, S. A. Bass, M. Belkacem, M. Bleicher, J. Brachmann, A. Dumitru, C. Ernst, L. Gerland, N. Hammon, M. Hofmann, J. Konopka, L. Neise, M. Reiter, S. Schramm, S. Soff, C. Spieles, H. Weber, D. Zschiesche, J.A. Maruhn, H. St\"ocker, W. Greiner (J. W. Goethe-Universit\"at, Frankfurt am Main, Germany, Duke University, Durham, USA, Yale University, New Haven, USA, Lawrence Berkeley Laboratory, Berkeley, USA)
Physics opportunities at RHIC and LHC
Proceedings of the Klaus Kinder-Geiger Day
null
10.1063/1.59576
null
hep-ph
null
Nonequilibrium models (three-fluid hydrodynamics, UrQMD, and quark molecular dynamics) are used to discuss the uniqueness of often proposed experimental signatures for quark matter formation in relativistic heavy ion collisions from the SPS via RHIC to LHC. It is demonstrated that these models -- although they do treat the most interesting early phase of the collisions quite differently (thermalizing QGP vs. coherent color fields with virtual particles) -- all yield a reasonable agreement with a large variety of the available heavy ion data. Hadron/hyperon yields, including $J/\Psi$ meson production/suppression, strange matter formation, dileptons, and directed flow (bounce-off and squeeze-out) are investigated. Observations of interesting phenomena in dense matter are reported. However, we emphasize the need for systematic future measurements to search for simultaneous irregularities in the excitation functions of several observables in order to come close to pinning the properties of hot, dense QCD matter from data. The role of future experiments with the STAR and ALICE detectors is pointed out.
[ { "created": "Thu, 18 Mar 1999 18:03:32 GMT", "version": "v1" } ]
2009-10-31
[ [ "Scherer", "S.", "", "J. W. Goethe-Universität, Frankfurt am\n Main, Germany, Duke University, Durham, USA, Yale University, New Haven, USA,\n Lawrence Berkeley Laboratory, Berkeley, USA" ], [ "Bass", "S. A.", "", "J. W. Goethe-Universität, Frankfurt am\n Main, Germany, Duke...
Nonequilibrium models (three-fluid hydrodynamics, UrQMD, and quark molecular dynamics) are used to discuss the uniqueness of often proposed experimental signatures for quark matter formation in relativistic heavy ion collisions from the SPS via RHIC to LHC. It is demonstrated that these models -- although they do treat the most interesting early phase of the collisions quite differently (thermalizing QGP vs. coherent color fields with virtual particles) -- all yield a reasonable agreement with a large variety of the available heavy ion data. Hadron/hyperon yields, including $J/\Psi$ meson production/suppression, strange matter formation, dileptons, and directed flow (bounce-off and squeeze-out) are investigated. Observations of interesting phenomena in dense matter are reported. However, we emphasize the need for systematic future measurements to search for simultaneous irregularities in the excitation functions of several observables in order to come close to pinning the properties of hot, dense QCD matter from data. The role of future experiments with the STAR and ALICE detectors is pointed out.
1801.07682
Aurore Courtoy
Federico Alberto Ceccopieri, Aurore Courtoy, Santiago Noguera, Sergio Scopetta
Pion nucleus Drell-Yan process and parton transverse momentum in the pion
13 pages, 8 figures
null
10.1140/epjc/s10052-018-6115-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a thorough analysis of unpolarized Drell-Yan (DY) pair production in pion-nucleus scattering. On the nucleus side, we use nuclear parton distributions along with parametrisations of the nucleon partonic transverse distribution available in the literature. Partonic longitudinal and transverse distributions of the pion are those obtained in a recent calculation in a Nambu-Jona Lasinio (NJL) framework, with Pauli-Villars regularization. The scale of the NJL model is fixed by a comparison between NLO predictions based on NJL evolved pion distributions and rapidity differential DY cross sections data. The resulting distributions are then used to describe, up to next-to-leading logarithmic accuracy, the transverse momentum spectrum of dilepton pairs up to a transverse momentum of 2 GeV. With no additional parameters, fair agreement is found with available pion-nucleus data, confirming the virtues of the NJL description of pion parton structure. We find sizable evolution effects on the shape of the distributions and on the generated average transverse momentum of the dilepton pair. We discuss the possibility of extracting details on pion unpolarized transverse momentum dependent parton distribution from pion nucleus DY data. In this respect, the region of low invariant mass of the lepton pair appears to be favored to discriminate between different descriptions of the non-perturbative pion transverse structure.
[ { "created": "Tue, 23 Jan 2018 18:06:19 GMT", "version": "v1" }, { "created": "Fri, 18 May 2018 20:07:40 GMT", "version": "v2" } ]
2018-08-29
[ [ "Ceccopieri", "Federico Alberto", "" ], [ "Courtoy", "Aurore", "" ], [ "Noguera", "Santiago", "" ], [ "Scopetta", "Sergio", "" ] ]
We present a thorough analysis of unpolarized Drell-Yan (DY) pair production in pion-nucleus scattering. On the nucleus side, we use nuclear parton distributions along with parametrisations of the nucleon partonic transverse distribution available in the literature. Partonic longitudinal and transverse distributions of the pion are those obtained in a recent calculation in a Nambu-Jona Lasinio (NJL) framework, with Pauli-Villars regularization. The scale of the NJL model is fixed by a comparison between NLO predictions based on NJL evolved pion distributions and rapidity differential DY cross sections data. The resulting distributions are then used to describe, up to next-to-leading logarithmic accuracy, the transverse momentum spectrum of dilepton pairs up to a transverse momentum of 2 GeV. With no additional parameters, fair agreement is found with available pion-nucleus data, confirming the virtues of the NJL description of pion parton structure. We find sizable evolution effects on the shape of the distributions and on the generated average transverse momentum of the dilepton pair. We discuss the possibility of extracting details on pion unpolarized transverse momentum dependent parton distribution from pion nucleus DY data. In this respect, the region of low invariant mass of the lepton pair appears to be favored to discriminate between different descriptions of the non-perturbative pion transverse structure.
2304.05942
Hyun Min Lee
Hyun Min Lee
Self-resonant Dark Matter
7 pages, 4 figures. v2: Typos corrected. To appear in the proceedings for the 19th Rencontres du Vietnam Theory Meeting Experiment (TMEX) 2023, ICISE, Quoy Nhon, Vietnam, Jan 5-11, 2023
null
null
null
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
We present a review on the self-resonant dark matter scenarios where multiple components of dark matter give rise to a resonant condition in the $u$-channel diagrams for their comparable masses. In this case, there is no need of lighter mediators for enhancing the self-scattering and annihilation cross sections for dark matter. We discuss the velocity-dependent self-scattering for the small-scale problems, the relic density of self-resonant dark matter, and the observable signatures in indirect and detection experiments.
[ { "created": "Wed, 12 Apr 2023 16:05:37 GMT", "version": "v1" }, { "created": "Fri, 14 Apr 2023 10:34:37 GMT", "version": "v2" } ]
2023-04-17
[ [ "Lee", "Hyun Min", "" ] ]
We present a review on the self-resonant dark matter scenarios where multiple components of dark matter give rise to a resonant condition in the $u$-channel diagrams for their comparable masses. In this case, there is no need of lighter mediators for enhancing the self-scattering and annihilation cross sections for dark matter. We discuss the velocity-dependent self-scattering for the small-scale problems, the relic density of self-resonant dark matter, and the observable signatures in indirect and detection experiments.
1907.05177
Guang-Juan Wang
Guang-Juan Wang, Lu Meng, and Shi-Lin Zhu
Spectrum of the fully-heavy tetraquark state $QQ\bar Q' \bar Q'$
13 pages, 6 figures
Phys. Rev. D 100, 096013 (2019)
10.1103/PhysRevD.100.096013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we systematically calculate the mass spectra of the $S$-wave fully heavy tetraquark states $bb\bar b\bar b$, $cc\bar c\bar c$, and $bb\bar c\bar c$ in two nonrelativistic quark models. A tetraquark state may be an admixture of a $6_c-\bar 6_c$ state and a $\bar 3_c-3_c$ one, where $6_c-\bar 6_c$($\bar 3_c-3_c$) denotes the color configuration with a $6_c$ ($\bar 3_c$) diquark and a $\bar 6_c$ ($3_c$) antidiquark. For the tetraquark states $bb\bar b\bar b$ and $cc\bar c\bar c$ with $J^{PC}={0^{++}}$, the $6_c-\bar 6_c$ state is lower than the $\bar 3_c-3_c$ one in both the two quark models, while the order of the $bb\bar c\bar c$ states depend on models. The $6_c-\bar 6_c$ and $\bar 3_c-3_c$ mixing effects are induced by the hyperfine interactions between the diquark and antidiquark, while the contributions from the one-gluon-exchange (OGE) Coulomb or the linear confinement potentials vanish for the $QQ\bar Q'\bar Q'$ system. With the couple-channel effects, we obtain the similar mass spectra. The numerical results show that the ground $QQ\bar Q'\bar Q'$ ($Q=b,c$ and $Q'=b,c$) tetraquark states are located above the corresponding scattering states, which indicates that there may not exist a bound state in the scheme of the two quark models.
[ { "created": "Thu, 11 Jul 2019 13:17:24 GMT", "version": "v1" } ]
2019-11-27
[ [ "Wang", "Guang-Juan", "" ], [ "Meng", "Lu", "" ], [ "Zhu", "Shi-Lin", "" ] ]
In this work, we systematically calculate the mass spectra of the $S$-wave fully heavy tetraquark states $bb\bar b\bar b$, $cc\bar c\bar c$, and $bb\bar c\bar c$ in two nonrelativistic quark models. A tetraquark state may be an admixture of a $6_c-\bar 6_c$ state and a $\bar 3_c-3_c$ one, where $6_c-\bar 6_c$($\bar 3_c-3_c$) denotes the color configuration with a $6_c$ ($\bar 3_c$) diquark and a $\bar 6_c$ ($3_c$) antidiquark. For the tetraquark states $bb\bar b\bar b$ and $cc\bar c\bar c$ with $J^{PC}={0^{++}}$, the $6_c-\bar 6_c$ state is lower than the $\bar 3_c-3_c$ one in both the two quark models, while the order of the $bb\bar c\bar c$ states depend on models. The $6_c-\bar 6_c$ and $\bar 3_c-3_c$ mixing effects are induced by the hyperfine interactions between the diquark and antidiquark, while the contributions from the one-gluon-exchange (OGE) Coulomb or the linear confinement potentials vanish for the $QQ\bar Q'\bar Q'$ system. With the couple-channel effects, we obtain the similar mass spectra. The numerical results show that the ground $QQ\bar Q'\bar Q'$ ($Q=b,c$ and $Q'=b,c$) tetraquark states are located above the corresponding scattering states, which indicates that there may not exist a bound state in the scheme of the two quark models.
1803.07832
Grzegorz Wilk
Grzegorz Wilk and Zbigniew W{\l}odarczyk
Some intriguing aspects of multiparticle production processes
Review article, to be published in Int. J. Mod. Phys. A (2018), 50 pages
Int. J. Mod. Phys. A33 (2018) 1830008
10.1142/S0217751X18300089
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiparticle production processes provide valuable information about the mechanism of the conversion of the initial energy of projectiles into a number of secondaries by measuring their multiplicity distributions and their distributions in phase space. They therefore serve as a reference point for more involved measurements. Distributions in phase space are usually investigated using the statistical approach, very successful in general but failing in cases of small colliding systems, small multiplicities, and at the edges of the allowed phase space, in which cases the underlying dynamical effects competing with the statistical distributions take over. We discuss an alternative approach, which applies to the whole phase space without detailed knowledge of dynamics. It is based on a modification of the usual statistics by generalizing it to a superstatistical form. We stress particularly the scaling and self-similar properties of such an approach manifesting themselves as the phenomena of the log-periodic oscillations and oscillations of temperature caused by sound waves in hadronic matter. Concerning the multiplicity distributions we discuss in detail the phenomenon of the oscillatory behaviour of the modified combinants apparently observed in experimental data.
[ { "created": "Wed, 21 Mar 2018 10:17:57 GMT", "version": "v1" } ]
2018-04-12
[ [ "Wilk", "Grzegorz", "" ], [ "Włodarczyk", "Zbigniew", "" ] ]
Multiparticle production processes provide valuable information about the mechanism of the conversion of the initial energy of projectiles into a number of secondaries by measuring their multiplicity distributions and their distributions in phase space. They therefore serve as a reference point for more involved measurements. Distributions in phase space are usually investigated using the statistical approach, very successful in general but failing in cases of small colliding systems, small multiplicities, and at the edges of the allowed phase space, in which cases the underlying dynamical effects competing with the statistical distributions take over. We discuss an alternative approach, which applies to the whole phase space without detailed knowledge of dynamics. It is based on a modification of the usual statistics by generalizing it to a superstatistical form. We stress particularly the scaling and self-similar properties of such an approach manifesting themselves as the phenomena of the log-periodic oscillations and oscillations of temperature caused by sound waves in hadronic matter. Concerning the multiplicity distributions we discuss in detail the phenomenon of the oscillatory behaviour of the modified combinants apparently observed in experimental data.