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hep-ph/9307256
Drew Peterson
Stephen Godfrey and K. Andrew Peterson
Single $W$-Boson Production in $e\gamma$ Collisions
Talk at The 2nd International Workshop on Physics and Experiment with Linear $e^+e^-$\ Colliders, Waikoloa, Hawaii, Apr. 26-30, 1993, 4 pages, latex with epsfig and worldsci, OCIP/C-93-08
null
null
null
hep-ph
null
We studied single $W$ boson production in high energy $e\gamma$ collisions and the sensitivity of various observables to the $WW\gamma$ vertex. We included gauge boson decay to final state fermions and all contributions to the same final state. The contributions of the non-resonant diagrams and their interference with the resonant gauge boson production diagrams give significant contributions which should not be neglected. We present results for $W$ production at a 500 GeV $e^+e^-$ collider with the photon spectra obtained from a backscattered laser.
[ { "created": "Tue, 13 Jul 1993 04:01:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Godfrey", "Stephen", "" ], [ "Peterson", "K. Andrew", "" ] ]
We studied single $W$ boson production in high energy $e\gamma$ collisions and the sensitivity of various observables to the $WW\gamma$ vertex. We included gauge boson decay to final state fermions and all contributions to the same final state. The contributions of the non-resonant diagrams and their interference with the resonant gauge boson production diagrams give significant contributions which should not be neglected. We present results for $W$ production at a 500 GeV $e^+e^-$ collider with the photon spectra obtained from a backscattered laser.
hep-ph/9803394
null
Arjun Berera, Marcelo Gleiser, Rudnei O. Ramos
Strong Dissipative Behavior in Quantum Field Theory
45 pages, 5 figures, Latex, In press Phys. Rev. D, minor corrections
Phys.Rev.D58:123508,1998
10.1103/PhysRevD.58.123508
VAND-TH-98-02,DART-HEP-98/02,IF/UERJ-98/10
hep-ph astro-ph cond-mat gr-qc hep-th
null
We study under which conditions an overdamped regime can be attained in the dynamic evolution of a quantum field configuration. Using a real-time formulation of finite temperature field theory, we compute the effective evolution equation of a scalar field configuration, quadratically interacting with a given set of other scalar fields. We then show that, in the overdamped regime, the dissipative kernel in the field equation of motion is closely related to the shear viscosity coefficient, as computed in scalar field theory at finite temperature. The effective dynamics is equivalent to a time-dependent Ginzburg-Landau description of the approach to equilibrium in phenomenological theories of phase transitions. Applications of our results, including a recently proposed inflationary scenario called ``warm inflation'', are discussed.
[ { "created": "Thu, 19 Mar 1998 22:51:37 GMT", "version": "v1" }, { "created": "Tue, 31 Mar 1998 21:49:08 GMT", "version": "v2" }, { "created": "Tue, 14 Apr 1998 02:25:23 GMT", "version": "v3" }, { "created": "Wed, 30 Sep 1998 01:31:18 GMT", "version": "v4" } ]
2011-05-05
[ [ "Berera", "Arjun", "" ], [ "Gleiser", "Marcelo", "" ], [ "Ramos", "Rudnei O.", "" ] ]
We study under which conditions an overdamped regime can be attained in the dynamic evolution of a quantum field configuration. Using a real-time formulation of finite temperature field theory, we compute the effective evolution equation of a scalar field configuration, quadratically interacting with a given set of other scalar fields. We then show that, in the overdamped regime, the dissipative kernel in the field equation of motion is closely related to the shear viscosity coefficient, as computed in scalar field theory at finite temperature. The effective dynamics is equivalent to a time-dependent Ginzburg-Landau description of the approach to equilibrium in phenomenological theories of phase transitions. Applications of our results, including a recently proposed inflationary scenario called ``warm inflation'', are discussed.
hep-ph/9706457
Martin Beneke
M. Beneke (CERN)
Renormalon Phenomenology: Questions and Directions
8 pages, LaTeX (To appear in the Proceedings of the Fifth International Workshop on `Deep Inelastic Scattering and QCD' (DIS'97), Chicago, IL, April 1997)
null
10.1063/1.53696
CERN-TH/97-134
hep-ph
null
A qualitative (and selective) discussion of current activities and problems in the field is given.
[ { "created": "Mon, 23 Jun 1997 14:19:57 GMT", "version": "v1" } ]
2009-10-30
[ [ "Beneke", "M.", "", "CERN" ] ]
A qualitative (and selective) discussion of current activities and problems in the field is given.
1511.07452
A. H. Rezaeian
Tolga Altinoluk, N\'estor Armesto, Guillaume Beuf, Amir H. Rezaeian
Diffractive Dijet Production in Deep Inelastic Scattering and Photon-Hadron Collisions in the Color Glass Condensate
15 pages, 10 figures; v2: a clarifying Appendix added, 3 new plots added, references added. The version to appear in PLB
Phys.Lett.B758:373-383,2016
10.1016/j.physletb.2016.05.032
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study exclusive dijet production in coherent diffractive processes in deep inelastic scattering and real (and virtual) photon-hadron ($\gamma^{(*)}$-h) collisions in the Color Glass Condensate formalism at leading order. We show that the diffractive dijet cross section is sensitive to the color-dipole orientation in the transverse plane, and is a good probe of possible correlations between the $q\bar{q}$-dipole transverse separation vector $\r$ and the dipole impact parameter $\b$. We also investigate the diffractive dijet azimuthal angle correlations and $t$-distributions in $\gamma^{(*)}$-h collisions and show that they are sensitive to gluon saturation effects in the small-$x$ region. In particular, we show that the $t$-distribution of diffractive dijet photo-production off a proton target exhibits a dip-type structure in the saturation region. This effect is similar to diffractive vector meson production. Besides, at variance with the inclusive case, the effect of saturation leads to stronger azimuthal correlations between the jets.
[ { "created": "Mon, 23 Nov 2015 21:01:09 GMT", "version": "v1" }, { "created": "Thu, 12 May 2016 14:56:30 GMT", "version": "v2" } ]
2016-05-24
[ [ "Altinoluk", "Tolga", "" ], [ "Armesto", "Néstor", "" ], [ "Beuf", "Guillaume", "" ], [ "Rezaeian", "Amir H.", "" ] ]
We study exclusive dijet production in coherent diffractive processes in deep inelastic scattering and real (and virtual) photon-hadron ($\gamma^{(*)}$-h) collisions in the Color Glass Condensate formalism at leading order. We show that the diffractive dijet cross section is sensitive to the color-dipole orientation in the transverse plane, and is a good probe of possible correlations between the $q\bar{q}$-dipole transverse separation vector $\r$ and the dipole impact parameter $\b$. We also investigate the diffractive dijet azimuthal angle correlations and $t$-distributions in $\gamma^{(*)}$-h collisions and show that they are sensitive to gluon saturation effects in the small-$x$ region. In particular, we show that the $t$-distribution of diffractive dijet photo-production off a proton target exhibits a dip-type structure in the saturation region. This effect is similar to diffractive vector meson production. Besides, at variance with the inclusive case, the effect of saturation leads to stronger azimuthal correlations between the jets.
hep-ph/0604200
Barbara Jager
Barbara Jager, Carlo Oleari, Dieter Zeppenfeld
Next-to-leading order QCD corrections to Z boson pair production via vector-boson fusion
12 pages, 4 figures
Phys.Rev.D73:113006,2006
10.1103/PhysRevD.73.113006
Bicocca-FT-06-7, KA-TP-04-2006, SFB/CPP-06-20
hep-ph
null
Vector-boson fusion processes are an important tool for the study of electroweak symmetry breaking at hadron colliders, since they allow to distinguish a light Higgs boson scenario from strong weak boson scattering. We here consider the channels WW->ZZ and ZZ->ZZ as part of electroweak Z boson pair production in association with two tagging jets. We present the calculation of the NLO QCD corrections to the cross sections for p p -> e+ e- mu+ mu- + 2 jets and p p -> e+ e- nu_mu nubar_mu + 2 jets via vector-boson fusion at order alpha_s alpha^6, which is performed in the form a NLO parton-level Monte Carlo program. The corrections to the integrated cross sections are found to be modest, while the shapes of some kinematical distributions change appreciably at NLO. Residual scale uncertainties typically are at the few percent level.
[ { "created": "Mon, 24 Apr 2006 12:48:56 GMT", "version": "v1" } ]
2008-11-26
[ [ "Jager", "Barbara", "" ], [ "Oleari", "Carlo", "" ], [ "Zeppenfeld", "Dieter", "" ] ]
Vector-boson fusion processes are an important tool for the study of electroweak symmetry breaking at hadron colliders, since they allow to distinguish a light Higgs boson scenario from strong weak boson scattering. We here consider the channels WW->ZZ and ZZ->ZZ as part of electroweak Z boson pair production in association with two tagging jets. We present the calculation of the NLO QCD corrections to the cross sections for p p -> e+ e- mu+ mu- + 2 jets and p p -> e+ e- nu_mu nubar_mu + 2 jets via vector-boson fusion at order alpha_s alpha^6, which is performed in the form a NLO parton-level Monte Carlo program. The corrections to the integrated cross sections are found to be modest, while the shapes of some kinematical distributions change appreciably at NLO. Residual scale uncertainties typically are at the few percent level.
hep-ph/0211354
G. Moreau
H. K. Dreiner, G. Moreau
Status of a Supersymmetric Flavour Violating Solution to the Solar Neutrino Puzzle with Three Generations
17 pages, Latex file
Phys.Rev. D67 (2003) 055005
10.1103/PhysRevD.67.055005
null
hep-ph
null
We present a general study of a three neutrino flavour transition model based on the supersymmetric interactions which violate R-parity. These interactions induce flavour violating scattering reactions between solar matter and neutrinos. The model does not contain any vacuum mass or mixing angle for the first generation neutrino. Instead, the effective mixing in the first generation is induced via the new interactions. The model provides a natural interpretation of the atmospheric neutrino anomaly, and is consistent with reactor experiments. We determine all R-parity violating couplings which can contribute to the effective neutrino oscillations, and summarize the present laboratory bounds. Independent of the specific nature of the (supersymmetric) flavour violating model, the experimental data on the solar neutrino rates and the recoil electron energy spectrum are inconsistent with the theoretical predictions. The confidence level of the $\chi^2$-analysis ranges between $\sim 10^{-4}$ and $\sim 10^{-3}$. The incompatibility, is due to the new SNO results, and excludes the present model. We conclude that a non-vanishing vacuum mixing angle for the first generation neutrino is necessary in our model. We expect this also to apply to the solutions based on other flavour violating interactions having constraints of the same order of magnitude.
[ { "created": "Fri, 22 Nov 2002 13:56:14 GMT", "version": "v1" } ]
2009-11-07
[ [ "Dreiner", "H. K.", "" ], [ "Moreau", "G.", "" ] ]
We present a general study of a three neutrino flavour transition model based on the supersymmetric interactions which violate R-parity. These interactions induce flavour violating scattering reactions between solar matter and neutrinos. The model does not contain any vacuum mass or mixing angle for the first generation neutrino. Instead, the effective mixing in the first generation is induced via the new interactions. The model provides a natural interpretation of the atmospheric neutrino anomaly, and is consistent with reactor experiments. We determine all R-parity violating couplings which can contribute to the effective neutrino oscillations, and summarize the present laboratory bounds. Independent of the specific nature of the (supersymmetric) flavour violating model, the experimental data on the solar neutrino rates and the recoil electron energy spectrum are inconsistent with the theoretical predictions. The confidence level of the $\chi^2$-analysis ranges between $\sim 10^{-4}$ and $\sim 10^{-3}$. The incompatibility, is due to the new SNO results, and excludes the present model. We conclude that a non-vanishing vacuum mixing angle for the first generation neutrino is necessary in our model. We expect this also to apply to the solutions based on other flavour violating interactions having constraints of the same order of magnitude.
hep-ph/0009168
Andrew Kirk
A. Kirk
The mixing of the f0(1370), f0(1500) and f0(1710) and the search for the scalar glueball
4 pages, Latex, 1 Figure. Talk given at ICHEP2000, Osaka, Japan
null
null
BHAM-HEP/00-01
hep-ph
null
For the first time a complete data set of the two-body decays of the f0(1370), f0(1500) and f0(1710) into all pseudoscalar mesons is available. The implications of these data for the flavour content for these three f0 states is studied. We find that they are in accord with the hypothesis that the scalar glueball of lattice QCD mixes with the qqbar nonet that also exists in its immediate vicinity. We show that this solution also is compatible with the relative production strengths of the f0(1370), f0(1500) and f0(1710) in pp central production, ppbar annihilations and J/psi radiative decays.
[ { "created": "Thu, 14 Sep 2000 11:55:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kirk", "A.", "" ] ]
For the first time a complete data set of the two-body decays of the f0(1370), f0(1500) and f0(1710) into all pseudoscalar mesons is available. The implications of these data for the flavour content for these three f0 states is studied. We find that they are in accord with the hypothesis that the scalar glueball of lattice QCD mixes with the qqbar nonet that also exists in its immediate vicinity. We show that this solution also is compatible with the relative production strengths of the f0(1370), f0(1500) and f0(1710) in pp central production, ppbar annihilations and J/psi radiative decays.
hep-ph/0204330
Viktor Nikonov
A.V. Anisovich, V.V. Anisovich, M.A. Matveev, V.A. Nikonov
Two-photon partial widths of tensor mesons
37 pages, 7 figures, epsfig
Phys.Atom.Nucl.66:914-927,2003; Yad.Fiz.66:946-959,2003
10.1134/1.1577914
null
hep-ph
null
We calculate partial widths of the gamma-gamma decay of the tensor q\bar q states a_2(1320), f_2(1270), f_2(1525), their radial excitations a_2(1660), f_2(1640), f_2(1800) as well as ^3F_2 q\bar q states. Calculations are performed in the framework of the same approach which was used before for the study of radiative decays f_0(980) -> gamma-gamma, a_0(980) -> gamma-gamma and phi(1020) -> gamma-f_0(980): the assumption made is that of q\bar q structure of f_0(980) and a_0(980) [A.V. Anisovich et al., Phys. Lett. B 456, 80 (1999); Eur. Phys. J. A 12, 103 (2001)]. The description of the decay partial widths for a_2(1320), f_2(1270), f_2(1525) and f_0(980), a_0(980) is reached with the approximately equal radial wave functions, thus giving a strong argument in favour of the fact that these scalar and tensor mesons are to be classified as members of the same P-wave q\bar q multiplet.
[ { "created": "Mon, 29 Apr 2002 08:47:55 GMT", "version": "v1" } ]
2014-11-17
[ [ "Anisovich", "A. V.", "" ], [ "Anisovich", "V. V.", "" ], [ "Matveev", "M. A.", "" ], [ "Nikonov", "V. A.", "" ] ]
We calculate partial widths of the gamma-gamma decay of the tensor q\bar q states a_2(1320), f_2(1270), f_2(1525), their radial excitations a_2(1660), f_2(1640), f_2(1800) as well as ^3F_2 q\bar q states. Calculations are performed in the framework of the same approach which was used before for the study of radiative decays f_0(980) -> gamma-gamma, a_0(980) -> gamma-gamma and phi(1020) -> gamma-f_0(980): the assumption made is that of q\bar q structure of f_0(980) and a_0(980) [A.V. Anisovich et al., Phys. Lett. B 456, 80 (1999); Eur. Phys. J. A 12, 103 (2001)]. The description of the decay partial widths for a_2(1320), f_2(1270), f_2(1525) and f_0(980), a_0(980) is reached with the approximately equal radial wave functions, thus giving a strong argument in favour of the fact that these scalar and tensor mesons are to be classified as members of the same P-wave q\bar q multiplet.
hep-ph/0702016
Larry McLerran
Larry McLerran
Some Comments About The High Energy Limit of QCD
null
Acta Phys.Polon.B37:3237-3252,2006
null
null
hep-ph
null
I argue that the physics of the scattering of very high energy strongly interacting particles is controlled by a new, universal form of matter, the Color Glass Condensate. This matter is the dominant contribution to the low x part of a hadron wavefunction. In collisions, this matter almost instantaneously turns into a Glasma. The Glasma initially has strong longitudinal color electric and magnetic fields, with topological charge. These fields melt into gluons. Due to instabilities, quantum noise is converted into classical turbulence, which may be responsible for the early thermalization seen in heavy ion collisions at RHIC.
[ { "created": "Thu, 1 Feb 2007 15:47:07 GMT", "version": "v1" } ]
2009-04-22
[ [ "McLerran", "Larry", "" ] ]
I argue that the physics of the scattering of very high energy strongly interacting particles is controlled by a new, universal form of matter, the Color Glass Condensate. This matter is the dominant contribution to the low x part of a hadron wavefunction. In collisions, this matter almost instantaneously turns into a Glasma. The Glasma initially has strong longitudinal color electric and magnetic fields, with topological charge. These fields melt into gluons. Due to instabilities, quantum noise is converted into classical turbulence, which may be responsible for the early thermalization seen in heavy ion collisions at RHIC.
hep-ph/0109081
Yu. A. Simonov
Yu.A.Simonov (ITEP)
Perturbative expansions in QCD and analytic properties of alpha_s
38 pages, no figures
Phys.Atom.Nucl.65:135-152,2002; Yad.Fiz.65:140-157,2002
10.1134/1.1446565
null
hep-ph
null
It is shown that analytic properties of standard QCD perturbation theory contradict known spectral properties,and contain in particular IR generated ghost poles and cuts. As an outcome the rigorous background perturbation theory is developed and its analytic properties are shown to be in agreement with general requirements. In a limiting case of large Nc, when QCD amplitudes contain only pole singularities, the strong coupling constant alpha_s(Q) is shown to be also meromorfic function of external momenta. Some simple models and examples are given when nonperturbative beta function and alpha_s(Q) can be written explicitly. General form of amplitudes at large Nc is given in the framework of background perturbation theory and its correspondence with standard perturbation theory at large momenta is demonstrated in the example of e^+e^- annihilation. For time-like momenta the background coupling constant differs drastically from the standard one but the background series averaged over energy intervals has the same (AF) asymptotics at large momenta as in the standard perturbation theory.
[ { "created": "Mon, 10 Sep 2001 14:31:52 GMT", "version": "v1" } ]
2011-07-19
[ [ "Simonov", "Yu. A.", "", "ITEP" ] ]
It is shown that analytic properties of standard QCD perturbation theory contradict known spectral properties,and contain in particular IR generated ghost poles and cuts. As an outcome the rigorous background perturbation theory is developed and its analytic properties are shown to be in agreement with general requirements. In a limiting case of large Nc, when QCD amplitudes contain only pole singularities, the strong coupling constant alpha_s(Q) is shown to be also meromorfic function of external momenta. Some simple models and examples are given when nonperturbative beta function and alpha_s(Q) can be written explicitly. General form of amplitudes at large Nc is given in the framework of background perturbation theory and its correspondence with standard perturbation theory at large momenta is demonstrated in the example of e^+e^- annihilation. For time-like momenta the background coupling constant differs drastically from the standard one but the background series averaged over energy intervals has the same (AF) asymptotics at large momenta as in the standard perturbation theory.
1409.8526
Johann Felix von Soden-Fraunhofen
Johann Felix von Soden-Fraunhofen
GoSam 2.0: a tool for automated one-loop calculations
7 pages, 5 figures; contribution to the proceedings of the conference "ACAT 2014 (Advanced Computing and Analysis Techniques in physics)", Prague, Czech Republic, September 2014
null
null
MPP-2014-358
hep-ph
http://creativecommons.org/licenses/by/3.0/
We present the version 2.0 of the program package GoSam, which is a public program package to compute one-loop QCD and/or electroweak corrections to multi-particle processes within and beyond the Standard Model. The extended version of the Binoth-Les-Houches-Accord interface to Monte Carlo programs is also implemented. This allows a large flexibility regarding the combination of the code with various Monte Carlo programs to produce fully differential NLO results, including the possibility of parton showering and hadronisation. We illustrate the wide range of applicability of the code by showing phenomenological results for multi-particle processes at NLO, both within and beyond the Standard Model.
[ { "created": "Tue, 30 Sep 2014 12:56:39 GMT", "version": "v1" } ]
2014-10-01
[ [ "von Soden-Fraunhofen", "Johann Felix", "" ] ]
We present the version 2.0 of the program package GoSam, which is a public program package to compute one-loop QCD and/or electroweak corrections to multi-particle processes within and beyond the Standard Model. The extended version of the Binoth-Les-Houches-Accord interface to Monte Carlo programs is also implemented. This allows a large flexibility regarding the combination of the code with various Monte Carlo programs to produce fully differential NLO results, including the possibility of parton showering and hadronisation. We illustrate the wide range of applicability of the code by showing phenomenological results for multi-particle processes at NLO, both within and beyond the Standard Model.
0909.2413
Kazem Azizi
T. M. Aliev, K. Azizi, M. Savc{\i}
Magnetic dipole moment of the light tensor mesons in light cone QCD sum rules
12 Pages and 1 Table
null
10.1088/0954-3899/37/7/075008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The magnetic dipole moments of the light tensor mesons $f_2$, $a_2$ and strange $K_2^{\ast 0} (1430)$ tensor meson are calculated in the framework of the light cone QCD sum rules. It is observed that the values of the magnetic dipole moment for the charged tensor particles are considerably different from zero. These values are very close to zero for the light neutral $f_2$ and $a_2$ tensor mesons, while it has a small nonzero value for the neutral strange $K_2^{\ast 0} (1430)$ tensor meson.
[ { "created": "Sun, 13 Sep 2009 11:27:29 GMT", "version": "v1" }, { "created": "Tue, 20 Apr 2010 19:32:18 GMT", "version": "v2" } ]
2015-05-14
[ [ "Aliev", "T. M.", "" ], [ "Azizi", "K.", "" ], [ "Savcı", "M.", "" ] ]
The magnetic dipole moments of the light tensor mesons $f_2$, $a_2$ and strange $K_2^{\ast 0} (1430)$ tensor meson are calculated in the framework of the light cone QCD sum rules. It is observed that the values of the magnetic dipole moment for the charged tensor particles are considerably different from zero. These values are very close to zero for the light neutral $f_2$ and $a_2$ tensor mesons, while it has a small nonzero value for the neutral strange $K_2^{\ast 0} (1430)$ tensor meson.
2401.08737
Gilad Perez
Jay Hubisz, Shaked Ironi, Gilad Perez, Rogerio Rosenfeld
A Note on the Quality of Dilatonic Ultralight Dark Matter
6 pages
null
null
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
Dilatons are pseudo-Nambu-Goldstone bosons arising from the breaking of conformal invariance. In this letter we point out that in general a dilaton mass has a power-law dependence on a small parameter related to the explicit breaking of conformal invariance whereas the ratio between the ultraviolet and infrared scales in the theory are exponentially related to the same parameter. We show that this scaling results in a separation between the dilaton mass and the infrared scale that can not be arbitrary large. Therefore a small dilaton mass necessarily is associated to a secluded conformal sector. We argue that the fact that the dilaton field must have a small displacement from the minimum of its effective potential generated near the infrared scale precludes a cosmologically interesting amount of dilatonic dark matter to be produced by a misalignment mechanism in the early Universe.
[ { "created": "Tue, 16 Jan 2024 18:28:59 GMT", "version": "v1" } ]
2024-01-18
[ [ "Hubisz", "Jay", "" ], [ "Ironi", "Shaked", "" ], [ "Perez", "Gilad", "" ], [ "Rosenfeld", "Rogerio", "" ] ]
Dilatons are pseudo-Nambu-Goldstone bosons arising from the breaking of conformal invariance. In this letter we point out that in general a dilaton mass has a power-law dependence on a small parameter related to the explicit breaking of conformal invariance whereas the ratio between the ultraviolet and infrared scales in the theory are exponentially related to the same parameter. We show that this scaling results in a separation between the dilaton mass and the infrared scale that can not be arbitrary large. Therefore a small dilaton mass necessarily is associated to a secluded conformal sector. We argue that the fact that the dilaton field must have a small displacement from the minimum of its effective potential generated near the infrared scale precludes a cosmologically interesting amount of dilatonic dark matter to be produced by a misalignment mechanism in the early Universe.
1212.6590
Ho-Meoyng Choi
Ho-Meoyng Choi (KNU) and Chueng-Ryong Ji (NCSU)
Relativistic Covariance of Light-Front Few-Body Systems in Hadron Physics
4 pages, contribution to the 20th International IUPAP Conference on Few-Body Problems in Physics, 20 - 25 August, 2012, Fukuoka, Japan
Few Body Syst. 54, 1633 (2013)
10.1007/s00601-012-0535-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the light-front covariance of a vector-meson decay constant using a manifestly covariant fermion field theory model in $(3+1)$ dimensions. The light-front zero-mode issues are analyzed in terms of polarization vectors and method of identifying the zero-mode operator and of obtaining the light-front covariant decay constant is discussed.
[ { "created": "Sat, 29 Dec 2012 05:01:28 GMT", "version": "v1" } ]
2013-08-22
[ [ "Choi", "Ho-Meoyng", "", "KNU" ], [ "Ji", "Chueng-Ryong", "", "NCSU" ] ]
We study the light-front covariance of a vector-meson decay constant using a manifestly covariant fermion field theory model in $(3+1)$ dimensions. The light-front zero-mode issues are analyzed in terms of polarization vectors and method of identifying the zero-mode operator and of obtaining the light-front covariant decay constant is discussed.
1502.04021
Daniel Pitonyak
K. Kanazawa, Y. Koike, A. Metz, D. Pitonyak
Transverse single-spin asymmetries in proton-proton collisions at the AFTER@LHC experiment
10 pages, 4 figures; more details/discussion added to the text, references added/updated, version to appear in Advances in High Energy Physics for the Special Issue "Physics at a Fixed-Target Experiment Using the LHC Beams"
null
null
RBRC-1108
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results for transverse single-spin asymmetries in proton-proton collisions at kinematics relevant for AFTER, a proposed fixed-target experiment at the Large Hadron Collider. These include predictions for pion, jet, and direct photon production from analytical formulas already available in the literature. We also discuss specific measurements that will benefit from the higher luminosity of AFTER, which could help resolve an almost 40-year puzzle of what causes transverse single-spin asymmetries in proton-proton collisions.
[ { "created": "Fri, 13 Feb 2015 15:14:40 GMT", "version": "v1" }, { "created": "Mon, 9 Mar 2015 17:08:21 GMT", "version": "v2" }, { "created": "Wed, 29 Apr 2015 16:06:05 GMT", "version": "v3" } ]
2015-04-30
[ [ "Kanazawa", "K.", "" ], [ "Koike", "Y.", "" ], [ "Metz", "A.", "" ], [ "Pitonyak", "D.", "" ] ]
We present results for transverse single-spin asymmetries in proton-proton collisions at kinematics relevant for AFTER, a proposed fixed-target experiment at the Large Hadron Collider. These include predictions for pion, jet, and direct photon production from analytical formulas already available in the literature. We also discuss specific measurements that will benefit from the higher luminosity of AFTER, which could help resolve an almost 40-year puzzle of what causes transverse single-spin asymmetries in proton-proton collisions.
1810.08080
Alfredo Vega Dr.
Alfredo Vega and Francisca Rojas
Confinement potentials for the study of heavy mesons
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a Coulomb potential plus a confinement potential $ A r^{\nu} $ and we study which of the two terms is dominant in the description of quarkonia. We find that in general the term of confinement is dominant, which allows us to understand why such potentials, like Martin's potential, are successful in describing of heavy mesons.
[ { "created": "Thu, 18 Oct 2018 14:32:36 GMT", "version": "v1" } ]
2018-10-19
[ [ "Vega", "Alfredo", "" ], [ "Rojas", "Francisca", "" ] ]
We consider a Coulomb potential plus a confinement potential $ A r^{\nu} $ and we study which of the two terms is dominant in the description of quarkonia. We find that in general the term of confinement is dominant, which allows us to understand why such potentials, like Martin's potential, are successful in describing of heavy mesons.
2405.03325
Nikolai Krasnikov
N.V.Krasnikov
Dark matter models with suppressed dark matter nuclei elastic cross section
12 pages
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We propose two generalizations of the dark photon model which predict the suppressed elastic dark matter nuclei cross section in comparison with the corresponding prediction of the dark photon model. In the first model the main difference from dark photon model is that the mixing parameter $\epsilon$ is nonlocal formfactor $\epsilon(q^2)= \frac{q^2}{\Lambda^2}V(\frac{q^2}{\Lambda^2}) $ depending on the square of the momentum transfer $q^2$. Here $V(\frac{q^2}{\Lambda^2})$ is an entire function of the growth $\rho \geq \frac{1}{2}$ and $\Lambda$ is nonlocal scale. In this model our world and dark world are described by renormalizable field theories while the communication between them is performed by nonlocal interaction. The second model is renormalizable model where besides dark photon field $A'$ additional vector boson $Z'$ interacts with $B - L$ current. The communication between our world and dark world is performed due to nonzero kinetic mixing between $Z'$ and $A'$ fields. The predictions of the models for the search for dark matter at the accelerators don't contain additional suppression factors.
[ { "created": "Mon, 6 May 2024 10:04:02 GMT", "version": "v1" } ]
2024-05-07
[ [ "Krasnikov", "N. V.", "" ] ]
We propose two generalizations of the dark photon model which predict the suppressed elastic dark matter nuclei cross section in comparison with the corresponding prediction of the dark photon model. In the first model the main difference from dark photon model is that the mixing parameter $\epsilon$ is nonlocal formfactor $\epsilon(q^2)= \frac{q^2}{\Lambda^2}V(\frac{q^2}{\Lambda^2}) $ depending on the square of the momentum transfer $q^2$. Here $V(\frac{q^2}{\Lambda^2})$ is an entire function of the growth $\rho \geq \frac{1}{2}$ and $\Lambda$ is nonlocal scale. In this model our world and dark world are described by renormalizable field theories while the communication between them is performed by nonlocal interaction. The second model is renormalizable model where besides dark photon field $A'$ additional vector boson $Z'$ interacts with $B - L$ current. The communication between our world and dark world is performed due to nonzero kinetic mixing between $Z'$ and $A'$ fields. The predictions of the models for the search for dark matter at the accelerators don't contain additional suppression factors.
1904.05133
Sangho Kim
Sang-Ho Kim and Seung-il Nam
Pomeron, nucleon-resonance, and $(0^+,0^-,1^+)$-meson contributions in $\phi$-meson photoproduction
18 pages, 11 figures
Phys. Rev. C 100, 065208 (2019)
10.1103/PhysRevC.100.065208
PKNU-NuHaTh-2019-03
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the reaction mechanism of the $\phi$-meson photoproduction off the proton target, i.e., $\gamma p\to\phi p$, up to $\sqrt{s}=2.8$ GeV. For this purpose, we employ an effective Lagrangian approach in the tree-level Born approximation, and we employ various experimental and theoretical inputs. As a theoretical setup, the vectorlike Pomeron ($C=+1$) is taken into account as a parameterized two-gluon exchange contribution. We also consider $f_1(1285)$ axial-vector-meson, ($\pi,\eta$) pseudoscalar-meson, and ($a_0,f_0$) scalar-meson exchanges in the $t$ channel, in addition to the experimentally confirmed nucleon resonances, such as $N^*(2000,5/2^+)$ and $N^*(2300,1/2^+)$, for the direct $\phi$-meson radiations in the $s$ and $u$ channels. We provide numerical results for the total and differential cross sections as well as the spin-density matrices in the Gottfried-Jackson, Adair, and helicity frames. We observe that, together with the universally accepted pomeron contribution, the considered meson and nucleon-resonance contributions play significant roles in reproducing the experimental data for the forward and backward $\phi$-meson scattering-angle regions, respectively, indicating the nontrivial interferences between mesonic and baryonic contributions.
[ { "created": "Wed, 10 Apr 2019 12:23:31 GMT", "version": "v1" }, { "created": "Thu, 4 Jul 2019 04:42:43 GMT", "version": "v2" }, { "created": "Tue, 31 Dec 2019 11:09:15 GMT", "version": "v3" } ]
2020-01-01
[ [ "Kim", "Sang-Ho", "" ], [ "Nam", "Seung-il", "" ] ]
We investigate the reaction mechanism of the $\phi$-meson photoproduction off the proton target, i.e., $\gamma p\to\phi p$, up to $\sqrt{s}=2.8$ GeV. For this purpose, we employ an effective Lagrangian approach in the tree-level Born approximation, and we employ various experimental and theoretical inputs. As a theoretical setup, the vectorlike Pomeron ($C=+1$) is taken into account as a parameterized two-gluon exchange contribution. We also consider $f_1(1285)$ axial-vector-meson, ($\pi,\eta$) pseudoscalar-meson, and ($a_0,f_0$) scalar-meson exchanges in the $t$ channel, in addition to the experimentally confirmed nucleon resonances, such as $N^*(2000,5/2^+)$ and $N^*(2300,1/2^+)$, for the direct $\phi$-meson radiations in the $s$ and $u$ channels. We provide numerical results for the total and differential cross sections as well as the spin-density matrices in the Gottfried-Jackson, Adair, and helicity frames. We observe that, together with the universally accepted pomeron contribution, the considered meson and nucleon-resonance contributions play significant roles in reproducing the experimental data for the forward and backward $\phi$-meson scattering-angle regions, respectively, indicating the nontrivial interferences between mesonic and baryonic contributions.
2406.00070
Vincent Cheung
Vincent Cheung, Ramona Vogt
$J/\psi$ photoproduction and polarization in $e+p$ collisions in the improved color evaporation model
arXiv admin note: substantial text overlap with arXiv:2102.09118
null
null
LLNL-JRNL-864888-DRAFT
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the production and polarization of direct $J/\psi$ in the improved color evaporation model in $e+p$ photoproduction. We present the production as functions of transverse momentun, mass of the hadronic final state, and inelasticity. We also present the polarization parameters $\lambda_\vartheta$, $\lambda_{\varphi}$, and $\lambda_{\vartheta \varphi}$ in the helicity and the Collins-Soper frames, as well as the frame-invariant polarization parameter $\tilde{\lambda}$ as a function of transverse momentum and inelasticity. We find agreement with both $J/\psi$ unpolarized cross sections and the invariant polarization parameters as a function of $p_T$.
[ { "created": "Thu, 30 May 2024 18:37:19 GMT", "version": "v1" } ]
2024-06-04
[ [ "Cheung", "Vincent", "" ], [ "Vogt", "Ramona", "" ] ]
We calculate the production and polarization of direct $J/\psi$ in the improved color evaporation model in $e+p$ photoproduction. We present the production as functions of transverse momentun, mass of the hadronic final state, and inelasticity. We also present the polarization parameters $\lambda_\vartheta$, $\lambda_{\varphi}$, and $\lambda_{\vartheta \varphi}$ in the helicity and the Collins-Soper frames, as well as the frame-invariant polarization parameter $\tilde{\lambda}$ as a function of transverse momentum and inelasticity. We find agreement with both $J/\psi$ unpolarized cross sections and the invariant polarization parameters as a function of $p_T$.
hep-ph/0505220
Alex Rivero E
Alejandro Rivero (Universidad de Zaragoza), Andre Gsponer
The strange formula of Dr. Koide
10 pages, 1 figure
null
null
null
hep-ph
null
We present a short historical and bibliographical review of the lepton mass formula of Yoshio Koide, as well as some speculations on its extensions to quark and neutrino masses, and its possible relations to more recent theoretical developments.
[ { "created": "Wed, 25 May 2005 16:54:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rivero", "Alejandro", "", "Universidad de Zaragoza" ], [ "Gsponer", "Andre", "" ] ]
We present a short historical and bibliographical review of the lepton mass formula of Yoshio Koide, as well as some speculations on its extensions to quark and neutrino masses, and its possible relations to more recent theoretical developments.
hep-ph/9803355
Perivolaropoulos Leandros
M. Axenides (N.C.S.R. Democritos), L. Perivolaropoulos (Department of Physics, University of Crete), T. Tomaras (Department of Physics, University of Crete)
Core Phase Structure of Cosmic Strings and Monopoles
6 pages, Use RevTex
Phys.Rev. D58 (1998) 103512
10.1103/PhysRevD.58.103512
CRETE-98-10
hep-ph
null
Global and local symmetries may or may not be restored inside topological defects depending upon the values of the parameters of the model. A detailed study of this parameter dependence of the core structure of strings and monopoles is presented in the context of simple models.
[ { "created": "Sun, 15 Mar 1998 10:09:03 GMT", "version": "v1" } ]
2009-10-31
[ [ "Axenides", "M.", "", "N.C.S.R. Democritos" ], [ "Perivolaropoulos", "L.", "", "Department of\n Physics, University of Crete" ], [ "Tomaras", "T.", "", "Department of Physics, University\n of Crete" ] ]
Global and local symmetries may or may not be restored inside topological defects depending upon the values of the parameters of the model. A detailed study of this parameter dependence of the core structure of strings and monopoles is presented in the context of simple models.
2106.16214
Cheng-Pang Liu
C.-P. Liu, Chih-Pan Wu, Jiunn-Wei Chen, Hsin-Chang Chi, Mukesh K. Pandey, Lakhwinder Singh, Henry T. Wong
Spin-dependent dark matter-electron interactions
Data files and README are provided in the ancillary folder
null
10.1103/PhysRevD.106.063003
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Detectors with low thresholds for electron recoil open a new window to direct searches of sub-GeV dark matter (DM) candidates. In the past decade, many strong limits on DM-electron interactions have been set, but most on the one which is spin-independent (SI) of both dark matter and electron spins. In this work, we study DM-atom scattering through a spin-dependent (SD) interaction at leading order (LO), using well-benchmarked, state-of-the-art atomic many-body calculations. Exclusion limits on the SD DM-electron cross section are derived with data taken from experiments with xenon and germanium detectors at leading sensitivities. In the DM mass range of 0.1 - 10 GeV, the best limits set by the XENON1T experiment: $\sigma_e^{\textrm{(SD)}}<10^{-41}-10^{-40}\,\textrm{cm}^2$ are comparable to the ones drawn on DM-neutron and DM-proton at slightly bigger DM masses. The detector's responses to the LO SD and SI interactions are analyzed. In nonrelativistic limit, a constant ratio between them leads to an indistinguishability of the SD and SI recoil energy spectra. Relativistic calculations however show the scaling starts to break down at a few hundreds of eV, where spin-orbit effects become sizable. We discuss the prospects of disentangling the SI and SD components in DM-electron interactions via spectral shape measurements, as well as having spin-sensitive experimental signatures without SI background.
[ { "created": "Wed, 30 Jun 2021 17:10:18 GMT", "version": "v1" } ]
2022-09-21
[ [ "Liu", "C. -P.", "" ], [ "Wu", "Chih-Pan", "" ], [ "Chen", "Jiunn-Wei", "" ], [ "Chi", "Hsin-Chang", "" ], [ "Pandey", "Mukesh K.", "" ], [ "Singh", "Lakhwinder", "" ], [ "Wong", "Henry T.", "" ] ]
Detectors with low thresholds for electron recoil open a new window to direct searches of sub-GeV dark matter (DM) candidates. In the past decade, many strong limits on DM-electron interactions have been set, but most on the one which is spin-independent (SI) of both dark matter and electron spins. In this work, we study DM-atom scattering through a spin-dependent (SD) interaction at leading order (LO), using well-benchmarked, state-of-the-art atomic many-body calculations. Exclusion limits on the SD DM-electron cross section are derived with data taken from experiments with xenon and germanium detectors at leading sensitivities. In the DM mass range of 0.1 - 10 GeV, the best limits set by the XENON1T experiment: $\sigma_e^{\textrm{(SD)}}<10^{-41}-10^{-40}\,\textrm{cm}^2$ are comparable to the ones drawn on DM-neutron and DM-proton at slightly bigger DM masses. The detector's responses to the LO SD and SI interactions are analyzed. In nonrelativistic limit, a constant ratio between them leads to an indistinguishability of the SD and SI recoil energy spectra. Relativistic calculations however show the scaling starts to break down at a few hundreds of eV, where spin-orbit effects become sizable. We discuss the prospects of disentangling the SI and SD components in DM-electron interactions via spectral shape measurements, as well as having spin-sensitive experimental signatures without SI background.
hep-ph/9709263
Alan Kostelecky
Alan Kostelecky
Testing CPT Symmetry
Presented at the Symposium on Flavor-Changing Neutral Currents, Santa Monica, CA, February 1997
null
null
IUHET 360, March 1997
hep-ph
null
In this talk, I review the possibility that CPT and Lorentz symmetry might be spontaneously broken in nature by effects originating in a theory beyond the standard model, and I discuss some existing and future experimental tests.
[ { "created": "Fri, 5 Sep 1997 18:25:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kostelecky", "Alan", "" ] ]
In this talk, I review the possibility that CPT and Lorentz symmetry might be spontaneously broken in nature by effects originating in a theory beyond the standard model, and I discuss some existing and future experimental tests.
2005.12283
Jacky Kumar
Jason Aebischer and Jacky Kumar
Flavour Violating Effects of Yukawa Running in SMEFT
25 pages and 11 figures
null
10.1007/JHEP09(2020)187
UdeM-GPP-TH-19-278
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study Yukawa Renormalization Group (RG) running effects in the context of the Standard Model Effective Theory (SMEFT).The Yukawa running being flavour dependent leads to RG-induced off-diagonal entries, so that initially diagonal Yukawa matrices at the high scale have to be rediagonalized at the electroweak (EW) scale. Performing such flavour rotations can lead to flavour violating operators which differ from the ones obtained through SMEFT RG evolution. We show, that these flavour rotations can have a large impact on low-energy phenomenology. In order to demonstrate this effect, we compare the two sources of flavour violation numerically as well as analytically and study their influence on several examples of down-type flavour transitions. For this purpose we consider $B_s-\bar B_s$ mixing, $b\to s\gamma$, $b\to s \ell \ell$ as well as electroweak precision observables. We show that the rotation effect can be comparable or even larger than the contribution from pure RGE evolution of the Wilson coefficients.
[ { "created": "Mon, 25 May 2020 18:00:01 GMT", "version": "v1" } ]
2020-10-28
[ [ "Aebischer", "Jason", "" ], [ "Kumar", "Jacky", "" ] ]
We study Yukawa Renormalization Group (RG) running effects in the context of the Standard Model Effective Theory (SMEFT).The Yukawa running being flavour dependent leads to RG-induced off-diagonal entries, so that initially diagonal Yukawa matrices at the high scale have to be rediagonalized at the electroweak (EW) scale. Performing such flavour rotations can lead to flavour violating operators which differ from the ones obtained through SMEFT RG evolution. We show, that these flavour rotations can have a large impact on low-energy phenomenology. In order to demonstrate this effect, we compare the two sources of flavour violation numerically as well as analytically and study their influence on several examples of down-type flavour transitions. For this purpose we consider $B_s-\bar B_s$ mixing, $b\to s\gamma$, $b\to s \ell \ell$ as well as electroweak precision observables. We show that the rotation effect can be comparable or even larger than the contribution from pure RGE evolution of the Wilson coefficients.
hep-ph/0211083
Dimitar Stamenov
E. Leader (Imperial College, London), D.B. Stamenov (Institute for Nuclear Research, Sofia)
Can the polarization of the strange quarks in the proton be positive ?
6 pages, latex, minor changes in the discussion after Eq. (9)
Phys.Rev. D67 (2003) 037503
10.1103/PhysRevD.67.037503
null
hep-ph hep-ex
null
Recently, the HERMES Collaboration at DESY, using a leading order QCD analysis of their data on semi-inclusive deep inelastic production of charged hadrons, reported a marginally positive polarization for the strange quarks in the proton. We argue that a non-negative polarization is almost impossible.
[ { "created": "Wed, 6 Nov 2002 17:07:45 GMT", "version": "v1" }, { "created": "Mon, 11 Nov 2002 20:00:27 GMT", "version": "v2" } ]
2009-11-07
[ [ "Leader", "E.", "", "Imperial College, London" ], [ "Stamenov", "D. B.", "", "Institute for\n Nuclear Research, Sofia" ] ]
Recently, the HERMES Collaboration at DESY, using a leading order QCD analysis of their data on semi-inclusive deep inelastic production of charged hadrons, reported a marginally positive polarization for the strange quarks in the proton. We argue that a non-negative polarization is almost impossible.
hep-ph/0603184
Mikhail Braun
M.A.Braun and C.Pajares
Rapidity and centrality dependence in the percolating colour strings scenario
17 pages, 12 figures
Nucl.Phys.A778:217-232,2006
10.1016/j.nuclphysa.2006.08.009
null
hep-ph
null
In AA collisions fusion and percolation of colour strings is studied at fixed rapidity $y$. Distribution of strings in rapidity is obtained from the observed rapidity spectra in pp collisions. For $y$-dependence of multiplicities in Au-Au collisions good agreement is obtained with the existing experimental data. Predictions for LHC energies coincide with the extrapolation of the data. Agreement with the data of the transverse momentum spectra requires introduction of quenching into the model.
[ { "created": "Thu, 23 Mar 2006 07:17:01 GMT", "version": "v1" } ]
2008-11-26
[ [ "Braun", "M. A.", "" ], [ "Pajares", "C.", "" ] ]
In AA collisions fusion and percolation of colour strings is studied at fixed rapidity $y$. Distribution of strings in rapidity is obtained from the observed rapidity spectra in pp collisions. For $y$-dependence of multiplicities in Au-Au collisions good agreement is obtained with the existing experimental data. Predictions for LHC energies coincide with the extrapolation of the data. Agreement with the data of the transverse momentum spectra requires introduction of quenching into the model.
hep-ph/9510446
Rik Tangerman
R.D. Tangerman and P.J. Mulders
Twist-three distributions and their appearance in the doubly-polarized Drell-Yan process
5 pages, Latex, figures included (uses feynman.tex), talk presented by R.D. Tangerman at 2nd Meeting on Possible Measurements of Singly Polarized pp and pn Collisions at HERA (DESY-IfH Zeuthen, Aug 31- Sep 2, 1995)
null
null
NIKHEF 95-051
hep-ph
null
The twist-three distributions $g_2(x)$ and $h_2(x)$ are defined as quark-field matrix elements between polarized hadron states. They can be written in terms of quark-mass and gluonic operators, after which the Burkhardt-Cottingham sum rule for $g_2$ can be derived and a similar sum rule for $h_2$. Their role in the Drell-Yan double-spin asymmetry $A_{LT}$ is explained.
[ { "created": "Mon, 30 Oct 1995 13:23:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tangerman", "R. D.", "" ], [ "Mulders", "P. J.", "" ] ]
The twist-three distributions $g_2(x)$ and $h_2(x)$ are defined as quark-field matrix elements between polarized hadron states. They can be written in terms of quark-mass and gluonic operators, after which the Burkhardt-Cottingham sum rule for $g_2$ can be derived and a similar sum rule for $h_2$. Their role in the Drell-Yan double-spin asymmetry $A_{LT}$ is explained.
1911.11147
Peter Reimitz
Tilman Plehn, Peter Reimitz, Peter Richardson
Hadronic Footprint of GeV-Mass Dark Matter
33 pages, 8 figures
SciPost Phys. 8, 092 (2020)
10.21468/SciPostPhys.8.6.092
CERN-TH-2019-202, IPPP/19/87
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
GeV-scale dark matter is an increasingly attractive target for direct detection, indirect detection, and collider searches. Its annihilation into hadronic final states produces a challenging zoo of light hadronic resonances. We update Herwig7 to study the photon and positron spectra from annihilation through a vector mediator. It covers dark matter masses between 250 MeV and 5 GeV and includes an error estimate.
[ { "created": "Mon, 25 Nov 2019 19:00:03 GMT", "version": "v1" }, { "created": "Fri, 20 Mar 2020 21:09:06 GMT", "version": "v2" }, { "created": "Fri, 5 Jun 2020 11:02:47 GMT", "version": "v3" } ]
2020-06-24
[ [ "Plehn", "Tilman", "" ], [ "Reimitz", "Peter", "" ], [ "Richardson", "Peter", "" ] ]
GeV-scale dark matter is an increasingly attractive target for direct detection, indirect detection, and collider searches. Its annihilation into hadronic final states produces a challenging zoo of light hadronic resonances. We update Herwig7 to study the photon and positron spectra from annihilation through a vector mediator. It covers dark matter masses between 250 MeV and 5 GeV and includes an error estimate.
hep-ph/9611457
Sirois
Y. Sirois
Searches for SUSY Particles at HERA
Source (LaTeX), Paper 7 pages, 10 figures (postscript) 4th International Conference on Supersymmetries in Physics (SUSY 1996), College Park, Maryland, USA, (May-June 1996)
null
null
H1-10/96-494, X-LPNHE 96-08
hep-ph
null
Searches at the e-p collider HERA for supersymmetric partners of the Standard Model fermions are presented. Assuming R-parity conservation, selectrons and squarks of the Minimal Supersymmetric Standard Model are excluded for masses up to 65 GeV in a new region of the standard parameter space. Admitting in addition a R-parity violating Yukawa coupling $\lambda'$, squarks are sought through direct e-q fusion in a yet unexplored mass-coupling domain, taking into account all possible squark decays. Squark masses up to 240 GeV are excluded for $\lambda' \gtrsim \sqrt{4 \pi \alpha_{em}}$, depending only weakly on the free model parameters.
[ { "created": "Thu, 28 Nov 1996 12:16:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sirois", "Y.", "" ] ]
Searches at the e-p collider HERA for supersymmetric partners of the Standard Model fermions are presented. Assuming R-parity conservation, selectrons and squarks of the Minimal Supersymmetric Standard Model are excluded for masses up to 65 GeV in a new region of the standard parameter space. Admitting in addition a R-parity violating Yukawa coupling $\lambda'$, squarks are sought through direct e-q fusion in a yet unexplored mass-coupling domain, taking into account all possible squark decays. Squark masses up to 240 GeV are excluded for $\lambda' \gtrsim \sqrt{4 \pi \alpha_{em}}$, depending only weakly on the free model parameters.
hep-ph/0407083
Xiao-Gang He
Xiao-Gang He, Xue-Qian Li, and J. P. Ma
Parity, Charge Conjugation and SU(3) Constraints on Threshold Enhancement in $J/\psi$ decays into $\gamma p\bar p$ and $K p \bar\Lambda$
Latex 10 pages, no figures, typos corrected
Phys.Rev. D71 (2005) 014031
10.1103/PhysRevD.71.014031
null
hep-ph hep-ex
null
We study the threshold enhancement effects of baryon-anti-baryon systems in $J/\psi$ decays at BES using parity $P$, charge conjugation $C$, and flavor SU(3) symmetries. The $P$ and $C$ symmetries restrict the $p\bar p$ in $J/\psi \to \gamma p\bar p$ to be in a state with $C=+1$, while the $p\bar p$ in $J/\psi \to \pi^0 p\bar p$ to be with $C=-1$. Combining the $C$ and $P$ symmetries with flavor SU(3) symmetry, i.e. the CPS symmetry, we find that the $\Lambda \bar p$ system cannot be in $0^+$ and $0^-$ states in $J/\psi \to K^+ \Lambda \bar p$. We provide a consistent explanation of observation and non-observation of near threshold enhancements in $J/\psi \to K^+ \Lambda \bar p$ and $J/\psi \to \pi^0 p \bar p$, respectively. We also find that near baryon pair threshold enhancement can happen in several channels for $J/\psi$ decays and can be several times larger than that observed in $J/\psi \to K^+ \Lambda \bar p$ in some channels.
[ { "created": "Wed, 7 Jul 2004 12:38:38 GMT", "version": "v1" }, { "created": "Mon, 12 Jul 2004 03:11:47 GMT", "version": "v2" }, { "created": "Mon, 1 Nov 2004 08:31:34 GMT", "version": "v3" }, { "created": "Mon, 20 Dec 2004 03:53:49 GMT", "version": "v4" } ]
2009-11-10
[ [ "He", "Xiao-Gang", "" ], [ "Li", "Xue-Qian", "" ], [ "Ma", "J. P.", "" ] ]
We study the threshold enhancement effects of baryon-anti-baryon systems in $J/\psi$ decays at BES using parity $P$, charge conjugation $C$, and flavor SU(3) symmetries. The $P$ and $C$ symmetries restrict the $p\bar p$ in $J/\psi \to \gamma p\bar p$ to be in a state with $C=+1$, while the $p\bar p$ in $J/\psi \to \pi^0 p\bar p$ to be with $C=-1$. Combining the $C$ and $P$ symmetries with flavor SU(3) symmetry, i.e. the CPS symmetry, we find that the $\Lambda \bar p$ system cannot be in $0^+$ and $0^-$ states in $J/\psi \to K^+ \Lambda \bar p$. We provide a consistent explanation of observation and non-observation of near threshold enhancements in $J/\psi \to K^+ \Lambda \bar p$ and $J/\psi \to \pi^0 p \bar p$, respectively. We also find that near baryon pair threshold enhancement can happen in several channels for $J/\psi$ decays and can be several times larger than that observed in $J/\psi \to K^+ \Lambda \bar p$ in some channels.
hep-ph/9811320
Alexandre Ignatiev
A.Yu.Ignatiev, G.C.Joshi (University of Melbourne) and Kameshwar C.Wali (Syracuse University)
Black holes with magnetic charge and quantized mass
RevTeX, 11 pages, Invited paper for the first editorial volume of the book series "Contemporary Fundamental Physics" by the Nova Science Publishers
null
null
UM-P-98/46, RCHEP-98/12
hep-ph
null
We examine the issue of magnetic charge quantization in the presence of black holes. It is pointed out that quantization of magnetic charge can lead to the mass quantization for magnetically charged black holes. We also discuss some implications for the experimental searches of magnetically charged black holes.
[ { "created": "Fri, 13 Nov 1998 09:41:31 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ignatiev", "A. Yu.", "", "University of Melbourne" ], [ "Joshi", "G. C.", "", "University of Melbourne" ], [ "Wali", "Kameshwar C.", "", "Syracuse University" ] ]
We examine the issue of magnetic charge quantization in the presence of black holes. It is pointed out that quantization of magnetic charge can lead to the mass quantization for magnetically charged black holes. We also discuss some implications for the experimental searches of magnetically charged black holes.
1710.05536
Shoaib Munir
Waleed Abdallah, Shaaban Khalil, Stefano Moretti, Shoaib Munir
Closing in on the Wino LSP via trilepton searches at the LHC
22 pages, 8 figures, 4 tables. Exclusion limits from Dark Matter Indirect Detection also taken into account. Significant improvements in figures and text. Final results and conclusions unchanged. Version to appear in JHEP
JHEP 1801 (2018) 155
10.1007/JHEP01(2018)155
KIAS-P17074
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutralino dark matter (DM) predicted by the Minimal Supersymmetric Standard Model (MSSM) has been probed in several search modes at the Large Hadron Collider (LHC), one of the leading ones among which is the trilepton plus missing transverse momentum channel. The experimental analysis of this mode has, however, been designed to probe mainly a bino-like DM, originating in the decays of a pair of next-to-lightest neutralino and lightest chargino, both of which are assumed to be wino-like. In this study, we analyse how this trilepton channel can be tuned for probing also the wino-like DM. We note that, while the mentioned standard production mode generally leads to a relatively poor sensitivity for the wino-like DM, there are regions in the MSSM parameter space where the net yield in the trilepton final state can be substantially enhanced at the LHC with $\sqrt{s}=14$ TeV. This is achieved by taking into account also an alternative channel, pair-production of the wino-like DM itself in association with the heavier chargino, and optimisation of the kinematical cuts currently employed by the LHC collaborations. In particular, we find that the cut on the transverse mass of the third lepton highly suppresses both the signal channels and should therefore be discarded in this DM scenario. We perform a detailed detector-level study of some selected parameter space points that are consistent with the most important experimental constraints, including the recent ones from the direct and indirect DM detection facilities. Our analysis demonstrates the high complementarity of the two channels, with their combined significance reaching above 4$\sigma$ for a wino-like DM mass around 100 GeV, with an integrated luminosity as low as 100 fb$^{-1}$.
[ { "created": "Mon, 16 Oct 2017 06:56:08 GMT", "version": "v1" }, { "created": "Sun, 28 Jan 2018 05:02:21 GMT", "version": "v2" } ]
2018-02-01
[ [ "Abdallah", "Waleed", "" ], [ "Khalil", "Shaaban", "" ], [ "Moretti", "Stefano", "" ], [ "Munir", "Shoaib", "" ] ]
The neutralino dark matter (DM) predicted by the Minimal Supersymmetric Standard Model (MSSM) has been probed in several search modes at the Large Hadron Collider (LHC), one of the leading ones among which is the trilepton plus missing transverse momentum channel. The experimental analysis of this mode has, however, been designed to probe mainly a bino-like DM, originating in the decays of a pair of next-to-lightest neutralino and lightest chargino, both of which are assumed to be wino-like. In this study, we analyse how this trilepton channel can be tuned for probing also the wino-like DM. We note that, while the mentioned standard production mode generally leads to a relatively poor sensitivity for the wino-like DM, there are regions in the MSSM parameter space where the net yield in the trilepton final state can be substantially enhanced at the LHC with $\sqrt{s}=14$ TeV. This is achieved by taking into account also an alternative channel, pair-production of the wino-like DM itself in association with the heavier chargino, and optimisation of the kinematical cuts currently employed by the LHC collaborations. In particular, we find that the cut on the transverse mass of the third lepton highly suppresses both the signal channels and should therefore be discarded in this DM scenario. We perform a detailed detector-level study of some selected parameter space points that are consistent with the most important experimental constraints, including the recent ones from the direct and indirect DM detection facilities. Our analysis demonstrates the high complementarity of the two channels, with their combined significance reaching above 4$\sigma$ for a wino-like DM mass around 100 GeV, with an integrated luminosity as low as 100 fb$^{-1}$.
1312.1302
Qin Chang
Qin Chang, Xin-Qiang Li and Ya-Dong Yang
A Comprehensive Analysis of Hadronic b->s Transitions in a Family Non-universal Z' Model
38 pages, 11 figures; To appear in JPG
J. Phys. G 41 (2014) 105002
10.1088/0954-3899/41/10/105002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the latest improved measurements of B-meson decays, we make a comprehensive analysis of the impact of a family non-universal $Z^{\prime}$ boson on $B_s-\bar{B}_s$ mixing and two-body hadronic B-meson decays, all being characterized by the quark-level $b\to s$ transition. Explicitly 22 decay modes and the related 52 observables are considered, and some interesting correlations between them are also carefully examined. Firstly, the allowed oases of $b-s-Z^{\prime}$ coupling parameters $|B^{L,R}_{sb}|$ and $\phi^{L,R}_s$ are extracted from $B_s-\bar{B}_s$ mixing. Then, in the "SM limit"~({\it i.e.,} no new types of $Z^{\prime}$-induced four-quark operators arise compared to the SM case), we study the $Z^{\prime}$ effects on $B\to\pi K$, $\pi K^{\ast}$ and $\rho K$ decays. It is found that a new weak phase $\phi^{L}_s\sim -90^{\circ}$ is crucial for resolving the observed "$\pi K$ CP puzzle" and the allowed oases of the other $Z^{\prime}$ coupling parameters are also strongly restricted. Moreover, the $Z^{\prime}$ effects on $\bar{B}_s\to K K$, $K K^{\ast}$ and $\pi^0 \phi$ decays, being induced by the same quark-level $b\to s q\bar{q}~(q=u,d)$ transitions, are also investigated. Especially, it is found that the decay $\bar{B}_s \to \pi^0 \phi$, once measured, would play a key role in revealing the observed "$\pi K$ CP puzzle" and probing possible new physics hints. Finally, to check the non-universality of $Z^{\prime}$ couplings to light-quark pairs, we have studied the $B\to \phi K$ decays in detail and found that the left-handed $s-s-Z^{\prime}$ coupling is different from the $d-d-Z^{\prime}$ one, which is due to the large $A_{CP}^{dir}(B^-\to\phi K^-)$ reported by the BaBar collaboration.
[ { "created": "Wed, 4 Dec 2013 19:52:27 GMT", "version": "v1" }, { "created": "Wed, 13 Aug 2014 07:33:29 GMT", "version": "v2" } ]
2014-09-16
[ [ "Chang", "Qin", "" ], [ "Li", "Xin-Qiang", "" ], [ "Yang", "Ya-Dong", "" ] ]
Motivated by the latest improved measurements of B-meson decays, we make a comprehensive analysis of the impact of a family non-universal $Z^{\prime}$ boson on $B_s-\bar{B}_s$ mixing and two-body hadronic B-meson decays, all being characterized by the quark-level $b\to s$ transition. Explicitly 22 decay modes and the related 52 observables are considered, and some interesting correlations between them are also carefully examined. Firstly, the allowed oases of $b-s-Z^{\prime}$ coupling parameters $|B^{L,R}_{sb}|$ and $\phi^{L,R}_s$ are extracted from $B_s-\bar{B}_s$ mixing. Then, in the "SM limit"~({\it i.e.,} no new types of $Z^{\prime}$-induced four-quark operators arise compared to the SM case), we study the $Z^{\prime}$ effects on $B\to\pi K$, $\pi K^{\ast}$ and $\rho K$ decays. It is found that a new weak phase $\phi^{L}_s\sim -90^{\circ}$ is crucial for resolving the observed "$\pi K$ CP puzzle" and the allowed oases of the other $Z^{\prime}$ coupling parameters are also strongly restricted. Moreover, the $Z^{\prime}$ effects on $\bar{B}_s\to K K$, $K K^{\ast}$ and $\pi^0 \phi$ decays, being induced by the same quark-level $b\to s q\bar{q}~(q=u,d)$ transitions, are also investigated. Especially, it is found that the decay $\bar{B}_s \to \pi^0 \phi$, once measured, would play a key role in revealing the observed "$\pi K$ CP puzzle" and probing possible new physics hints. Finally, to check the non-universality of $Z^{\prime}$ couplings to light-quark pairs, we have studied the $B\to \phi K$ decays in detail and found that the left-handed $s-s-Z^{\prime}$ coupling is different from the $d-d-Z^{\prime}$ one, which is due to the large $A_{CP}^{dir}(B^-\to\phi K^-)$ reported by the BaBar collaboration.
2307.07013
Mario Fern\'andez Navarro
Marzia Bordone and Mario Fern\'andez Navarro
$\tau_{B_{s}}/\tau_{B_{d}}$ and $\Delta\Gamma_{s}$ confront new physics in $b\to s\tau\tau$
12 pages + Appendix, 4 Figures. v2: Minor discussions added, typos corrected, conclusions unchanged. Version accepted in EPJC
Eur. Phys. J. C 83 (2023) 842
10.1140/epjc/s10052-023-12013-9
CERN-TH-2023-138
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Several new physics scenarios that address anomalies in $B$-physics predict an enhancement of $b \rightarrow s \tau \tau$ with respect to its Standard Model prediction. Such scenarios necessarily imply modifications of the lifetime ratio $\tau_{B_{s}}/\tau_{B_{d}}$ and the lifetime difference $\Delta\Gamma_{s}$. In this work, we explore indirect bounds provided by these observables over new physics scenarios. We also estimate future projections, showing that future experimental and theoretical improvements on both $\tau_{B_{s}}/\tau_{B_{d}}$ and $\Delta\Gamma_{s}$ have the potential to provide bounds competitive with those directly extracted from $b\rightarrow s \tau \tau$ transitions. After performing a model-independent analysis, we apply our results to the particular case of leptoquark mediators proposed to address the $R_{D^{(*)}}$ anomalies.
[ { "created": "Thu, 13 Jul 2023 18:31:02 GMT", "version": "v1" }, { "created": "Fri, 15 Sep 2023 22:40:11 GMT", "version": "v2" } ]
2023-09-26
[ [ "Bordone", "Marzia", "" ], [ "Navarro", "Mario Fernández", "" ] ]
Several new physics scenarios that address anomalies in $B$-physics predict an enhancement of $b \rightarrow s \tau \tau$ with respect to its Standard Model prediction. Such scenarios necessarily imply modifications of the lifetime ratio $\tau_{B_{s}}/\tau_{B_{d}}$ and the lifetime difference $\Delta\Gamma_{s}$. In this work, we explore indirect bounds provided by these observables over new physics scenarios. We also estimate future projections, showing that future experimental and theoretical improvements on both $\tau_{B_{s}}/\tau_{B_{d}}$ and $\Delta\Gamma_{s}$ have the potential to provide bounds competitive with those directly extracted from $b\rightarrow s \tau \tau$ transitions. After performing a model-independent analysis, we apply our results to the particular case of leptoquark mediators proposed to address the $R_{D^{(*)}}$ anomalies.
2202.01434
Hiromasa Takaura
Yuuki Hayashi, Yukinari Sumino, Hiromasa Takaura
Determination of $|V_{cb}|$ using N$^3$LO perturbative corrections to $\Gamma(B \to X_c \ell \nu)$ and 1S masses
14pages, 2 figures, version to appear in PLB
null
10.1016/j.physletb.2022.137068
TU--1144, KEK--TH--2394
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We determine $|V_{cb}|$ using the third-order perturbative series for the inclusive semileptonic $B$ decay width and for the masses of the bottomonium 1S states. We use the masses of $\eta_b(1S)$ and $\Upsilon(1S)$ as short-distance masses and point out that there is a sizable difference of $|V_{cb}|$ between the two 1S mass schemes. This is the dominant error of our determination and stems from insufficiency to describe theoretically the observed mass splitting of the bottomonium 1S states. We also study the significance of the $\mathcal{O}(\Lambda_{\overline{\rm MS}}^2)$ non-perturbative effects in HQET with respect to the current perturbative accuracy. Our result $|V_{cb}|=0.0425 (11)$ is consistent with the PDG value determined from the inclusive decays and has a slightly larger error.
[ { "created": "Thu, 3 Feb 2022 06:38:10 GMT", "version": "v1" }, { "created": "Tue, 5 Apr 2022 10:57:16 GMT", "version": "v2" } ]
2022-04-20
[ [ "Hayashi", "Yuuki", "" ], [ "Sumino", "Yukinari", "" ], [ "Takaura", "Hiromasa", "" ] ]
We determine $|V_{cb}|$ using the third-order perturbative series for the inclusive semileptonic $B$ decay width and for the masses of the bottomonium 1S states. We use the masses of $\eta_b(1S)$ and $\Upsilon(1S)$ as short-distance masses and point out that there is a sizable difference of $|V_{cb}|$ between the two 1S mass schemes. This is the dominant error of our determination and stems from insufficiency to describe theoretically the observed mass splitting of the bottomonium 1S states. We also study the significance of the $\mathcal{O}(\Lambda_{\overline{\rm MS}}^2)$ non-perturbative effects in HQET with respect to the current perturbative accuracy. Our result $|V_{cb}|=0.0425 (11)$ is consistent with the PDG value determined from the inclusive decays and has a slightly larger error.
0803.3725
Shuntaro Nakamura
Shuntaro Nakamura, Ken-ichi Okumura and Masahiro Yamaguchi
Axionic Mirage Mediation
reference added, typo corrected
Phys.Rev.D77:115027,2008
10.1103/PhysRevD.77.115027
TU-809
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although the mirage mediation is one of the most plausible mediation mechanisms of supersymmetry breaking, it suffers from two crucial problems. One is the \mu-/B \mu-problem and the second is the cosmological one. The former stems from the fact that the B parameter tends to be comparable with the gravitino mass, which is two order of magnitude larger than the other soft masses. The latter problem is caused by the decay of the modulus whose branching ratio into the gravitino pair is sizable. In this paper, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this axionic mirage mediation, it is shown that the PQ symmetry breaking scale is dynamically determined around 10^{10-12} GeV due to the supersymmetry breaking effects, and the \mu-problem can be solved naturally. Furthermore, in our model, the lightest supersymmetric particle (LSP) is the axino, that is the superpartner of the axion. The overabundance of the LSPs due to decays of modulus/gravitino, which is the most serious cosmological difficulty in the mirage mediation, can be avoided if the axino is sufficiently light. The next-LSPs (NLSPs) produced by the gravitino decay eventually decay into the axino LSPs, yielding the dominant component of the axinos remaining today. It is shown that the axino with the mass of O(100) MeV is naturally realized, which can constitute the dark matter of the Universe, with the free-streaming length of the order of 0.1 Mpc. The saxion, the real scalar component of the axion supermultiplet, can also be cosmologically harmless due to the dilution of the modulus decay. The lifetime of NLSP is relatively long, but much shorter than 1 sec., when the big-bang nucleosynthesis commences. The decay of NLSP would provide intriguing collider signatures.
[ { "created": "Wed, 26 Mar 2008 13:18:33 GMT", "version": "v1" }, { "created": "Mon, 31 Mar 2008 09:00:10 GMT", "version": "v2" } ]
2008-11-26
[ [ "Nakamura", "Shuntaro", "" ], [ "Okumura", "Ken-ichi", "" ], [ "Yamaguchi", "Masahiro", "" ] ]
Although the mirage mediation is one of the most plausible mediation mechanisms of supersymmetry breaking, it suffers from two crucial problems. One is the \mu-/B \mu-problem and the second is the cosmological one. The former stems from the fact that the B parameter tends to be comparable with the gravitino mass, which is two order of magnitude larger than the other soft masses. The latter problem is caused by the decay of the modulus whose branching ratio into the gravitino pair is sizable. In this paper, we propose a model of mirage mediation, in which Peccei-Quinn symmetry is incorporated. In this axionic mirage mediation, it is shown that the PQ symmetry breaking scale is dynamically determined around 10^{10-12} GeV due to the supersymmetry breaking effects, and the \mu-problem can be solved naturally. Furthermore, in our model, the lightest supersymmetric particle (LSP) is the axino, that is the superpartner of the axion. The overabundance of the LSPs due to decays of modulus/gravitino, which is the most serious cosmological difficulty in the mirage mediation, can be avoided if the axino is sufficiently light. The next-LSPs (NLSPs) produced by the gravitino decay eventually decay into the axino LSPs, yielding the dominant component of the axinos remaining today. It is shown that the axino with the mass of O(100) MeV is naturally realized, which can constitute the dark matter of the Universe, with the free-streaming length of the order of 0.1 Mpc. The saxion, the real scalar component of the axion supermultiplet, can also be cosmologically harmless due to the dilution of the modulus decay. The lifetime of NLSP is relatively long, but much shorter than 1 sec., when the big-bang nucleosynthesis commences. The decay of NLSP would provide intriguing collider signatures.
hep-ph/0701047
Gui-Jun Ding
Gui-Jun Ding, Mu-Lin Yan
Y(2175): Distinguish Hybrid State from Higher Quarkonium
13 pages, 8 figures
Phys.Lett.B657:49-54,2007
10.1016/j.physletb.2007.10.020
null
hep-ph
null
The possibility of Y(2175) as a $2{^3D_1}$ $s\bar{s}$ meson is studied. We study the decay of $2{^3D_1}$ $s\bar{s}$ from both the $^3P_0$ model and the flux tube model, and the results are similar in the two models. We show that the decay patterns of $1^{--}$ strangeonium hybrid and $2{^3D_1}$ $s\bar{s}$ are very different. The experimental search of the decay modes $KK$, $K^{*}K^{*}$, $K(1460)K$, $h_1(1380)\eta$ is suggested to distinguish the two pictures. Measuring the $K^{*}K^{*}$ partial width ratios is crucial to discriminate the $2{^3D_1}$ from the $3{^3S_1}$ $s\bar{s}$ assignment.
[ { "created": "Sun, 7 Jan 2007 03:25:51 GMT", "version": "v1" }, { "created": "Sun, 30 Sep 2007 17:13:49 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ding", "Gui-Jun", "" ], [ "Yan", "Mu-Lin", "" ] ]
The possibility of Y(2175) as a $2{^3D_1}$ $s\bar{s}$ meson is studied. We study the decay of $2{^3D_1}$ $s\bar{s}$ from both the $^3P_0$ model and the flux tube model, and the results are similar in the two models. We show that the decay patterns of $1^{--}$ strangeonium hybrid and $2{^3D_1}$ $s\bar{s}$ are very different. The experimental search of the decay modes $KK$, $K^{*}K^{*}$, $K(1460)K$, $h_1(1380)\eta$ is suggested to distinguish the two pictures. Measuring the $K^{*}K^{*}$ partial width ratios is crucial to discriminate the $2{^3D_1}$ from the $3{^3S_1}$ $s\bar{s}$ assignment.
2312.11965
Yukinari Sumino
Takuya Agemura and Yukinari Sumino
On order $\Lambda_{\rm QCD}^2/m$ renormalons in quarkonium system
13 pages, 9 figures; [Ver.2] Minor modifications; Version to appear in Phys.Lett
null
null
TU--1218
hep-ph
http://creativecommons.org/licenses/by/4.0/
For the heavy quarkonium system we examine ${\cal O}(\Lambda_{\rm QCD}^2/m)$ renormalons, which are expected to be included in the perturbative series of the pole mass and $1/(mr^2)$ interquark potential. We find indications of existence and cancellation of these renormalons, from examinations of stability and convergence properties of the perturbative series and their resummations, as well as by comparison with the known properties of the ${\cal O}(\Lambda_{\rm QCD})$ renormalons.
[ { "created": "Tue, 19 Dec 2023 09:02:32 GMT", "version": "v1" }, { "created": "Tue, 6 Feb 2024 15:33:27 GMT", "version": "v2" } ]
2024-02-07
[ [ "Agemura", "Takuya", "" ], [ "Sumino", "Yukinari", "" ] ]
For the heavy quarkonium system we examine ${\cal O}(\Lambda_{\rm QCD}^2/m)$ renormalons, which are expected to be included in the perturbative series of the pole mass and $1/(mr^2)$ interquark potential. We find indications of existence and cancellation of these renormalons, from examinations of stability and convergence properties of the perturbative series and their resummations, as well as by comparison with the known properties of the ${\cal O}(\Lambda_{\rm QCD})$ renormalons.
2307.11157
Radha Mastandrea
Tobias Golling, Gregor Kasieczka, Claudius Krause, Radha Mastandrea, Benjamin Nachman, John Andrew Raine, Debajyoti Sengupta, David Shih, Manuel Sommerhalder
The Interplay of Machine Learning--based Resonant Anomaly Detection Methods
27 pages, 21 figures. Updated with revisions for journal acceptance
null
10.1140/epjc/s10052-024-12607-x
null
hep-ph hep-ex physics.data-an
http://creativecommons.org/licenses/by/4.0/
Machine learning--based anomaly detection (AD) methods are promising tools for extending the coverage of searches for physics beyond the Standard Model (BSM). One class of AD methods that has received significant attention is resonant anomaly detection, where the BSM is assumed to be localized in at least one known variable. While there have been many methods proposed to identify such a BSM signal that make use of simulated or detected data in different ways, there has not yet been a study of the methods' complementarity. To this end, we address two questions. First, in the absence of any signal, do different methods pick the same events as signal-like? If not, then we can significantly reduce the false-positive rate by comparing different methods on the same dataset. Second, if there is a signal, are different methods fully correlated? Even if their maximum performance is the same, since we do not know how much signal is present, it may be beneficial to combine approaches. Using the Large Hadron Collider (LHC) Olympics dataset, we provide quantitative answers to these questions. We find that there are significant gains possible by combining multiple methods, which will strengthen the search program at the LHC and beyond.
[ { "created": "Thu, 20 Jul 2023 18:00:04 GMT", "version": "v1" }, { "created": "Thu, 14 Mar 2024 09:09:24 GMT", "version": "v2" } ]
2024-03-15
[ [ "Golling", "Tobias", "" ], [ "Kasieczka", "Gregor", "" ], [ "Krause", "Claudius", "" ], [ "Mastandrea", "Radha", "" ], [ "Nachman", "Benjamin", "" ], [ "Raine", "John Andrew", "" ], [ "Sengupta", "Debajyoti", "" ], [ "Shih", "David", "" ], [ "Sommerhalder", "Manuel", "" ] ]
Machine learning--based anomaly detection (AD) methods are promising tools for extending the coverage of searches for physics beyond the Standard Model (BSM). One class of AD methods that has received significant attention is resonant anomaly detection, where the BSM is assumed to be localized in at least one known variable. While there have been many methods proposed to identify such a BSM signal that make use of simulated or detected data in different ways, there has not yet been a study of the methods' complementarity. To this end, we address two questions. First, in the absence of any signal, do different methods pick the same events as signal-like? If not, then we can significantly reduce the false-positive rate by comparing different methods on the same dataset. Second, if there is a signal, are different methods fully correlated? Even if their maximum performance is the same, since we do not know how much signal is present, it may be beneficial to combine approaches. Using the Large Hadron Collider (LHC) Olympics dataset, we provide quantitative answers to these questions. We find that there are significant gains possible by combining multiple methods, which will strengthen the search program at the LHC and beyond.
0802.0161
Alan D. Martin
Alan D. Martin
Proton structure, Partons, QCD, DGLAP and beyond
35 pages, 19 figures, to appear in Proc. of School on QCD, low x physics, saturation and diffraction, Copanello, Calabria, Italy, July 2007, to be published in Acta Physica Polonica
Acta Phys.Polon.B39:2025-2062,2008
null
IPPP/08/03, DCPT/08/06
hep-ph
null
We present an introductory discussion of deep-inelastic lepton-proton scattering as a means to probe the substructure of the proton. A resume of QCD is given, emphasizing the running of the coupling constant and the DGLAP evolution equations for the parton densities. The determination of parton distributions is discussed and their importance for predictions of processes at the LHC is emphasized. Going beyond the pure DGLAP regime, we briefly discuss the behaviour of parton densities at low x, and the evidence for non-linear absorptive contributions.
[ { "created": "Fri, 1 Feb 2008 16:49:50 GMT", "version": "v1" } ]
2010-03-25
[ [ "Martin", "Alan D.", "" ] ]
We present an introductory discussion of deep-inelastic lepton-proton scattering as a means to probe the substructure of the proton. A resume of QCD is given, emphasizing the running of the coupling constant and the DGLAP evolution equations for the parton densities. The determination of parton distributions is discussed and their importance for predictions of processes at the LHC is emphasized. Going beyond the pure DGLAP regime, we briefly discuss the behaviour of parton densities at low x, and the evidence for non-linear absorptive contributions.
hep-ph/9804223
Michael Bordag
M. Bordag, B. Geyer, G.L. Klimchitskaya, V.M. Mostepanenko
Constraints for hypothetical interactions from a recent demonstration of the Casimir force and some possible improvements
15 pages, 3 figures, subm. to Phys. Rev. D
Phys.Rev.D58:075003,1998
10.1103/PhysRevD.58.075003
NTZ 10/98
hep-ph
null
The Casimir force is calculated in the configuration of a spherical lens and a disc of finite radius covered by $Cu$ and $Au$ thin layers which was used in a recent experiment. The correction to the Casimir force due to finiteness of the disc radius is shown to be negligible. Also the corrections are discussed due to the finite conductivity, large-scale and short-scale deviations from the perfect shape of the bounding surfaces and the temperature correction. They were found to be essential when confronting the theoretical results with experimental data. Both Yukawa-type and power-law hypothetical forces are computed which may act in the configuration under consideration due to the exchange of light and/or massless elementary particles between the atoms of the lens and the disc. New constraints on the constants of these forces are determined which follow from the fact that they were not observed within the limits of experimental errors. For Yukawa-type forces the new constraints are up to 30 times stronger than the best ones known up today. A possible improvement of experimental parameters is proposed which gives the possibility to strengthen constraints on Yukawa-type interactions up to $10^4$ times and on power-law interactions up to several hundred times.
[ { "created": "Fri, 3 Apr 1998 11:01:45 GMT", "version": "v1" } ]
2008-11-26
[ [ "Bordag", "M.", "" ], [ "Geyer", "B.", "" ], [ "Klimchitskaya", "G. L.", "" ], [ "Mostepanenko", "V. M.", "" ] ]
The Casimir force is calculated in the configuration of a spherical lens and a disc of finite radius covered by $Cu$ and $Au$ thin layers which was used in a recent experiment. The correction to the Casimir force due to finiteness of the disc radius is shown to be negligible. Also the corrections are discussed due to the finite conductivity, large-scale and short-scale deviations from the perfect shape of the bounding surfaces and the temperature correction. They were found to be essential when confronting the theoretical results with experimental data. Both Yukawa-type and power-law hypothetical forces are computed which may act in the configuration under consideration due to the exchange of light and/or massless elementary particles between the atoms of the lens and the disc. New constraints on the constants of these forces are determined which follow from the fact that they were not observed within the limits of experimental errors. For Yukawa-type forces the new constraints are up to 30 times stronger than the best ones known up today. A possible improvement of experimental parameters is proposed which gives the possibility to strengthen constraints on Yukawa-type interactions up to $10^4$ times and on power-law interactions up to several hundred times.
hep-ph/0701082
Ping Wang 72
P. Wang, D. B. Leinweber, A. W. Thomas, R. D. Young
Chiral extrapolation of nucleon magnetic form factors
19 pages, 10 figures
Phys.Rev.D75:073012,2007
10.1103/PhysRevD.75.073012
null
hep-ph
null
The extrapolation of nucleon magnetic form factors calculated within lattice QCD is investigated within a framework based upon heavy baryon chiral effective-field theory. All one-loop graphs are considered at arbitrary momentum transfer and all octet and decuplet baryons are included in the intermediate states. Finite range regularisation is applied to improve the convergence in the quark-mass expansion. At each value of the momentum transfer ($Q^2$), a separate extrapolation to the physical pion mass is carried out as a function of $m_\pi$ alone. Because of the large values of $Q^2$ involved, the role of the pion form factor in the standard pion-loop integrals is also investigated. The resulting values of the form factors at the physical pion mass are compared with experimental data as a function of $Q^2$ and demonstrate the utility and accuracy of the chiral extrapolation methods presented herein.
[ { "created": "Thu, 11 Jan 2007 01:28:15 GMT", "version": "v1" }, { "created": "Tue, 3 Apr 2007 18:11:21 GMT", "version": "v2" } ]
2008-11-26
[ [ "Wang", "P.", "" ], [ "Leinweber", "D. B.", "" ], [ "Thomas", "A. W.", "" ], [ "Young", "R. D.", "" ] ]
The extrapolation of nucleon magnetic form factors calculated within lattice QCD is investigated within a framework based upon heavy baryon chiral effective-field theory. All one-loop graphs are considered at arbitrary momentum transfer and all octet and decuplet baryons are included in the intermediate states. Finite range regularisation is applied to improve the convergence in the quark-mass expansion. At each value of the momentum transfer ($Q^2$), a separate extrapolation to the physical pion mass is carried out as a function of $m_\pi$ alone. Because of the large values of $Q^2$ involved, the role of the pion form factor in the standard pion-loop integrals is also investigated. The resulting values of the form factors at the physical pion mass are compared with experimental data as a function of $Q^2$ and demonstrate the utility and accuracy of the chiral extrapolation methods presented herein.
0905.2493
Yoshitaka Hatta
Yoshitaka Hatta, Takahiro Ueda and Bo-Wen Xiao
Polarized DIS in N=4 SYM: Where is spin at strong coupling?
24 pages
JHEP 0908:007,2009
10.1088/1126-6708/2009/08/007
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using the AdS/CFT correspondence, we calculate the polarized structure functions in strongly coupled N=4 supersymmetric Yang-Mills theory deformed in the infrared. We find that the flavor singlet contribution to the g_1 structure function is vanishingly small, while the flavor non-singlet contribution shows the Regge behavior at small-x with an intercept slightly less than 1. We explicitly check that the latter satisfies the moment sum rule. We discuss the `spin crisis' problem and suggest that at strong coupling the spin of a hadron entirely comes from the orbital angular momentum.
[ { "created": "Fri, 15 May 2009 14:11:33 GMT", "version": "v1" } ]
2009-08-12
[ [ "Hatta", "Yoshitaka", "" ], [ "Ueda", "Takahiro", "" ], [ "Xiao", "Bo-Wen", "" ] ]
Using the AdS/CFT correspondence, we calculate the polarized structure functions in strongly coupled N=4 supersymmetric Yang-Mills theory deformed in the infrared. We find that the flavor singlet contribution to the g_1 structure function is vanishingly small, while the flavor non-singlet contribution shows the Regge behavior at small-x with an intercept slightly less than 1. We explicitly check that the latter satisfies the moment sum rule. We discuss the `spin crisis' problem and suggest that at strong coupling the spin of a hadron entirely comes from the orbital angular momentum.
0908.2390
Dimiter Stamenov
Elliot Leader, Aleksander V. Sidorov, Dimiter B. Stamenov
Some Remarks on Methods of QCD Analysis of Polarized DIS Data
14 pages, 8 figures
Phys.Rev.D80:054026,2009
10.1103/PhysRevD.80.054026
CERN PH-TH/2009-156
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The results on polarized parton densities (PDFs) obtained using different methods of QCD analysis of the present polarized DIS data are discussed. Their dependence on the method used in the analysis, accounting or not for the kinematic and dynamic 1/Q^2 corrections to spin structure function g_1, is demonstrated. It is pointed out that the precise data in the preasymptotic region require a more careful matching of the QCD predictions to the data in this region in order to determine the polarized PDFs correctly.
[ { "created": "Mon, 17 Aug 2009 16:35:16 GMT", "version": "v1" } ]
2009-11-05
[ [ "Leader", "Elliot", "" ], [ "Sidorov", "Aleksander V.", "" ], [ "Stamenov", "Dimiter B.", "" ] ]
The results on polarized parton densities (PDFs) obtained using different methods of QCD analysis of the present polarized DIS data are discussed. Their dependence on the method used in the analysis, accounting or not for the kinematic and dynamic 1/Q^2 corrections to spin structure function g_1, is demonstrated. It is pointed out that the precise data in the preasymptotic region require a more careful matching of the QCD predictions to the data in this region in order to determine the polarized PDFs correctly.
0704.0001
Pavel Nadolsky
C. Bal\'azs, E. L. Berger, P. M. Nadolsky, C.-P. Yuan
Calculation of prompt diphoton production cross sections at Tevatron and LHC energies
37 pages, 15 figures; published version
Phys.Rev.D76:013009,2007
10.1103/PhysRevD.76.013009
ANL-HEP-PR-07-12
hep-ph
null
A fully differential calculation in perturbative quantum chromodynamics is presented for the production of massive photon pairs at hadron colliders. All next-to-leading order perturbative contributions from quark-antiquark, gluon-(anti)quark, and gluon-gluon subprocesses are included, as well as all-orders resummation of initial-state gluon radiation valid at next-to-next-to-leading logarithmic accuracy. The region of phase space is specified in which the calculation is most reliable. Good agreement is demonstrated with data from the Fermilab Tevatron, and predictions are made for more detailed tests with CDF and DO data. Predictions are shown for distributions of diphoton pairs produced at the energy of the Large Hadron Collider (LHC). Distributions of the diphoton pairs from the decay of a Higgs boson are contrasted with those produced from QCD processes at the LHC, showing that enhanced sensitivity to the signal can be obtained with judicious selection of events.
[ { "created": "Mon, 2 Apr 2007 19:18:42 GMT", "version": "v1" }, { "created": "Tue, 24 Jul 2007 20:10:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Balázs", "C.", "" ], [ "Berger", "E. L.", "" ], [ "Nadolsky", "P. M.", "" ], [ "Yuan", "C. -P.", "" ] ]
A fully differential calculation in perturbative quantum chromodynamics is presented for the production of massive photon pairs at hadron colliders. All next-to-leading order perturbative contributions from quark-antiquark, gluon-(anti)quark, and gluon-gluon subprocesses are included, as well as all-orders resummation of initial-state gluon radiation valid at next-to-next-to-leading logarithmic accuracy. The region of phase space is specified in which the calculation is most reliable. Good agreement is demonstrated with data from the Fermilab Tevatron, and predictions are made for more detailed tests with CDF and DO data. Predictions are shown for distributions of diphoton pairs produced at the energy of the Large Hadron Collider (LHC). Distributions of the diphoton pairs from the decay of a Higgs boson are contrasted with those produced from QCD processes at the LHC, showing that enhanced sensitivity to the signal can be obtained with judicious selection of events.
1504.05238
Andrea Palladino
Andrea Palladino, Francesco Vissani
The natural parametrization of cosmic neutrino oscillations
19 pages, 5 figures. Text and bibliography enhanced, results unchanged. New analysis on flavor triangle included. Accepted for publication in EPJC
null
10.1140/epjc/s10052-015-3664-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The natural parameterization of vacuum oscillations in three neutrino flavors is studied. Compact and exact relations of its three parameters with the ordinary three mixing angles and CP violating phase are obtained. Its usefulness is illustrated by considering various applications: the study of the flavor ratio and of its uncertainties, the comparison of expectations and observations in the flavor triangle, the intensity of the signal due to Glashow resonance. The results in the literature are easily reproduced and in particular the recently obtained agreement of the observations of IceCube with the hypothesis of cosmic neutrino oscillations is confirmed. It is argued that a Gaussian treatment of the errors appropriately describes the effects of the uncertainties on neutrino oscillation parameters.
[ { "created": "Mon, 20 Apr 2015 21:30:33 GMT", "version": "v1" }, { "created": "Thu, 30 Apr 2015 16:39:45 GMT", "version": "v2" }, { "created": "Mon, 7 Sep 2015 13:29:45 GMT", "version": "v3" } ]
2015-10-28
[ [ "Palladino", "Andrea", "" ], [ "Vissani", "Francesco", "" ] ]
The natural parameterization of vacuum oscillations in three neutrino flavors is studied. Compact and exact relations of its three parameters with the ordinary three mixing angles and CP violating phase are obtained. Its usefulness is illustrated by considering various applications: the study of the flavor ratio and of its uncertainties, the comparison of expectations and observations in the flavor triangle, the intensity of the signal due to Glashow resonance. The results in the literature are easily reproduced and in particular the recently obtained agreement of the observations of IceCube with the hypothesis of cosmic neutrino oscillations is confirmed. It is argued that a Gaussian treatment of the errors appropriately describes the effects of the uncertainties on neutrino oscillation parameters.
hep-ph/0212177
Damir Becirevic
D.Becirevic, J.Charles, A.LeYaouanc, L.Oliver, O.Pene and J.C.Raynal
Possible explanation of the discrepancy of the light-cone QCD sum rule calculation of g(D*Dpi) coupling with experiment
9 pages, 1 PostScript figures
JHEP 0301 (2003) 009
10.1088/1126-6708/2003/01/009
CPT-2002/P.4459, LPT Orsay 02-112, Rome-1348/02
hep-ph
null
The introduction of an explicit negative radial excitation contribution in the hadronic side of the light cone QCD sum rule (LCSR) of Belyaev, Braun, Khodjamirian and Ruckl, can explain the large experimental value of g(D*Dpi), recently measured by CLEO. At the same time, it considerably improves the stability of the sum rule when varying the Borel parameter.
[ { "created": "Thu, 12 Dec 2002 17:19:20 GMT", "version": "v1" } ]
2009-11-07
[ [ "Becirevic", "D.", "" ], [ "Charles", "J.", "" ], [ "LeYaouanc", "A.", "" ], [ "Oliver", "L.", "" ], [ "Pene", "O.", "" ], [ "Raynal", "J. C.", "" ] ]
The introduction of an explicit negative radial excitation contribution in the hadronic side of the light cone QCD sum rule (LCSR) of Belyaev, Braun, Khodjamirian and Ruckl, can explain the large experimental value of g(D*Dpi), recently measured by CLEO. At the same time, it considerably improves the stability of the sum rule when varying the Borel parameter.
2104.13827
Ernesto Arganda
Ernesto Arganda, Antonio Delgado, Roberto A. Morales, Mariano Quir\'os
Novel Higgsino Dark Matter Signatures at the LHC
11 pages, 2 tables, 3 figures
Phys. Rev. D 104, 055003 (2021)
10.1103/PhysRevD.104.055003
IFT-UAM/CSIC-21-44
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In the LHC searches for gluinos it is usually assumed that they decay predominantly into the lightest neutralino plus jets. In this work we perform a proof-of-concept collider analysis of a novel supersymmetric signal in which gluinos decay mostly into jets and the bino-like neutralino ($\tilde\chi_3^0$), which in turn decays into the lightest Higgsino-like neutralino ($\tilde\chi_1^0$), considered the dark matter candidate, together with the SM-like Higgs boson ($h$). This new physics signal then consists of an LHC final state made up by four light jets, four $b$-jets, and a large amount of missing transverse energy. We identify $t \bar t$, $V$+jets ($V$= $W$, $Z$), and $t \bar t + X$ ($X$ = $W$, $Z$, $\gamma^*$, $h$) productions as the most problematic backgrounds, and develop a search strategy for the high luminosity phase of the LHC, reaching signal significances at the evidence level for a luminosity of 1000 fb$^{-1}$. The prospects for a luminosity of 3000 fb$^{-1}$ are even more promising, with discovery-level significances.
[ { "created": "Wed, 28 Apr 2021 15:22:01 GMT", "version": "v1" } ]
2021-09-15
[ [ "Arganda", "Ernesto", "" ], [ "Delgado", "Antonio", "" ], [ "Morales", "Roberto A.", "" ], [ "Quirós", "Mariano", "" ] ]
In the LHC searches for gluinos it is usually assumed that they decay predominantly into the lightest neutralino plus jets. In this work we perform a proof-of-concept collider analysis of a novel supersymmetric signal in which gluinos decay mostly into jets and the bino-like neutralino ($\tilde\chi_3^0$), which in turn decays into the lightest Higgsino-like neutralino ($\tilde\chi_1^0$), considered the dark matter candidate, together with the SM-like Higgs boson ($h$). This new physics signal then consists of an LHC final state made up by four light jets, four $b$-jets, and a large amount of missing transverse energy. We identify $t \bar t$, $V$+jets ($V$= $W$, $Z$), and $t \bar t + X$ ($X$ = $W$, $Z$, $\gamma^*$, $h$) productions as the most problematic backgrounds, and develop a search strategy for the high luminosity phase of the LHC, reaching signal significances at the evidence level for a luminosity of 1000 fb$^{-1}$. The prospects for a luminosity of 3000 fb$^{-1}$ are even more promising, with discovery-level significances.
hep-ph/9301251
null
Alan R. White, Ian G. Knowles and Kyungsik Kang
The $\eta_6$ at LEP and TRISTAN
11 pages, ANL-HEP-PR-93-4/BROWN-HET-872
Mod.Phys.Lett.A8:1611-1620,1993
10.1142/S0217732393001355
null
hep-ph
null
The $\eta_6$ is a ``heavy axion'' remnant of dynamical electroweak symmetry breaking by a color sextet quark condensate. Electroweak scale color instanton interactions allow it to be both very massive and yet be responsible for Strong CP conservation in the color triplet quark sector. It may have been seen at LEP via its two-photon decay mode and at TRISTAN via its hadronic decay modes.
[ { "created": "Wed, 20 Jan 1993 14:14:38 GMT", "version": "v1" } ]
2014-11-17
[ [ "White", "Alan R.", "" ], [ "Knowles", "Ian G.", "" ], [ "Kang", "Kyungsik", "" ] ]
The $\eta_6$ is a ``heavy axion'' remnant of dynamical electroweak symmetry breaking by a color sextet quark condensate. Electroweak scale color instanton interactions allow it to be both very massive and yet be responsible for Strong CP conservation in the color triplet quark sector. It may have been seen at LEP via its two-photon decay mode and at TRISTAN via its hadronic decay modes.
hep-ph/0503217
Kim Siyeon
Song-Haeng Lee and Kim Siyeon
The small mixing angle $\theta_{13}$ and the lepton asymmetry
17 pages, 14 figures, information for figures added, version published in PRD
Phys.Rev. D71 (2005) 096006
10.1103/PhysRevD.71.096006
null
hep-ph
null
We present the correlation of low energy CP phases, both Dirac and Majorana, and the lepton asymmetry for the baryon asymmetry in the universe, with a certain class of Yukawa matrices that consist of two right-handed neutrinos and include one texture zero in themselves. For cases in which the amount of the lepton asymmetry $Y_L$ turns out to be proportional to $\theta_{13}^2$, we consider the relation between two types of CP phases and the relation of $Y_L$ versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as $\theta_{13}$ varies.
[ { "created": "Tue, 22 Mar 2005 15:08:16 GMT", "version": "v1" }, { "created": "Fri, 27 May 2005 06:52:43 GMT", "version": "v2" } ]
2009-09-29
[ [ "Lee", "Song-Haeng", "" ], [ "Siyeon", "Kim", "" ] ]
We present the correlation of low energy CP phases, both Dirac and Majorana, and the lepton asymmetry for the baryon asymmetry in the universe, with a certain class of Yukawa matrices that consist of two right-handed neutrinos and include one texture zero in themselves. For cases in which the amount of the lepton asymmetry $Y_L$ turns out to be proportional to $\theta_{13}^2$, we consider the relation between two types of CP phases and the relation of $Y_L$ versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as $\theta_{13}$ varies.
2211.08132
Pengxuan Zhu
Jin Min Yang, Yang Zhang, Pengxuan Zhu and Rui Zhu
Reconstructing masses for semi-invisibly decaying particles pair-produced at lepton colliders
6 pages, 5 figures. W-mass measurement added (accepted by PRD)
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a set of Lorentz invariant kinematic variables for reconstructing mass of semi-invisible decaying particles pair-produced at lepton colliders, $m_{\rm RC}^{\rm min}$, $m_{\rm RC}^{\rm max}$ and $m_{\rm LSP}^{\rm max}$, with analytical formulas. They give the minimal and maximum bounds of the decaying particle mass and upper bound of the invisible particle mass. In the search of new physics, these variables can greatly enhance the statistical significance of signal. For the process of smuon pair production at $\sqrt{s}=240~{\rm GeV}$ lepton collider of 5 ab$^{-1}$, the cross section detection limit is pushed by one order, and the expected exclusion and discovery limits are set above $\sqrt{s}\big/2$ and go into the off-shell region. Moreover, these variables can also be used to improve the precision of $W$-boson mass measurement in full leptonic decayed channel. At future lepton collider, the precision can reach to $2\sim 3$ MeV level.
[ { "created": "Tue, 15 Nov 2022 13:37:08 GMT", "version": "v1" }, { "created": "Tue, 12 Sep 2023 13:29:32 GMT", "version": "v2" } ]
2023-09-13
[ [ "Yang", "Jin Min", "" ], [ "Zhang", "Yang", "" ], [ "Zhu", "Pengxuan", "" ], [ "Zhu", "Rui", "" ] ]
We present a set of Lorentz invariant kinematic variables for reconstructing mass of semi-invisible decaying particles pair-produced at lepton colliders, $m_{\rm RC}^{\rm min}$, $m_{\rm RC}^{\rm max}$ and $m_{\rm LSP}^{\rm max}$, with analytical formulas. They give the minimal and maximum bounds of the decaying particle mass and upper bound of the invisible particle mass. In the search of new physics, these variables can greatly enhance the statistical significance of signal. For the process of smuon pair production at $\sqrt{s}=240~{\rm GeV}$ lepton collider of 5 ab$^{-1}$, the cross section detection limit is pushed by one order, and the expected exclusion and discovery limits are set above $\sqrt{s}\big/2$ and go into the off-shell region. Moreover, these variables can also be used to improve the precision of $W$-boson mass measurement in full leptonic decayed channel. At future lepton collider, the precision can reach to $2\sim 3$ MeV level.
hep-ph/9808425
Sacha Davidson
Sacha Davidson
Basis independent parametrisations of R parity violation in the soft SUSY breaking sector
8 pages, accepted for publication in PLB
Phys.Lett. B439 (1998) 63-70
10.1016/S0370-2693(98)01006-5
CERN-TH-98-161
hep-ph
null
The magnitude of R-parity violating coupling constants depends on which direction in the space of weak doublets with hypercharge = -2 corresponds to the Higgs. To address this ``basis dependence'', one can construct combinations of coupling constants that are invariant under these basis transformations, and which parametrise how much R parity violation is present in the Lagrangian (analogous to Jarlskog invariants for CP violation). This has previously been done for the Higgs vev and the R parity violating couplings constants in the superpotential. In this letter, I build invariants that include soft SUSY breaking interactions, and briefly discuss their relation to invariants involving the Higgs vev. This completes the construction of invariants based on the MSSM with baryon parity.
[ { "created": "Wed, 26 Aug 1998 16:37:26 GMT", "version": "v1" } ]
2009-10-31
[ [ "Davidson", "Sacha", "" ] ]
The magnitude of R-parity violating coupling constants depends on which direction in the space of weak doublets with hypercharge = -2 corresponds to the Higgs. To address this ``basis dependence'', one can construct combinations of coupling constants that are invariant under these basis transformations, and which parametrise how much R parity violation is present in the Lagrangian (analogous to Jarlskog invariants for CP violation). This has previously been done for the Higgs vev and the R parity violating couplings constants in the superpotential. In this letter, I build invariants that include soft SUSY breaking interactions, and briefly discuss their relation to invariants involving the Higgs vev. This completes the construction of invariants based on the MSSM with baryon parity.
hep-ph/0311131
P. Aurenche
F. Arleo, P. Aurenche, F. Bopp, I. Dadic, G. David, H. Delagrange, D. d'Enterria, K.J. Eskola, F. Gelis, J.-Ph. Guillet, S. Jeon, Yu. Kharlov, O. Kodolova, P. Levai, J.H. Liu, I.P. Lokhtin, G.D. Moore, H. Niemi, A. Nikitenko, T. Peitzmann, P. Petreczky, J. Ranft, R. Rapp, P.V. Ruuskanen, K. Redlich, S.S. Rasanen, I. Sarcevic, J. Serreau, D.K. Srivastava, H. Takai, S. Tapprogge, M. Tokarev, I.N. Vardanyan, M. Werlen, P. Yepes
Photon Physics in Heavy Ion Collisions at the LHC
Writeup of the working group "Photon Physics" for the CERN Yellow Report on "Hard Probes in Heavy Ion Collisions at the LHC", 134 pages. One figure added in chapter 5 (comparison with PHENIX data). Some figures and correponding text corrected in chapter 6 (off-chemical equilibrium thermal photon rates). Some figures modified in chapter 7 (off-chemical equilibrium photon rates) and comparison with PHENIX data added
null
null
null
hep-ph nucl-ex nucl-th
null
Various pion and photon production mechanisms in high-energy nuclear collisions at RHIC and LHC are discussed. Comparison with RHIC data is done whenever possible. The prospect of using electromagnetic probes to characterize quark-gluon plasma formation is assessed.
[ { "created": "Mon, 10 Nov 2003 21:36:38 GMT", "version": "v1" }, { "created": "Wed, 19 Nov 2003 17:50:26 GMT", "version": "v2" }, { "created": "Mon, 17 May 2004 12:01:27 GMT", "version": "v3" } ]
2007-05-23
[ [ "Arleo", "F.", "" ], [ "Aurenche", "P.", "" ], [ "Bopp", "F.", "" ], [ "Dadic", "I.", "" ], [ "David", "G.", "" ], [ "Delagrange", "H.", "" ], [ "d'Enterria", "D.", "" ], [ "Eskola", "K. J.", "" ], [ "Gelis", "F.", "" ], [ "Guillet", "J. -Ph.", "" ], [ "Jeon", "S.", "" ], [ "Kharlov", "Yu.", "" ], [ "Kodolova", "O.", "" ], [ "Levai", "P.", "" ], [ "Liu", "J. H.", "" ], [ "Lokhtin", "I. P.", "" ], [ "Moore", "G. D.", "" ], [ "Niemi", "H.", "" ], [ "Nikitenko", "A.", "" ], [ "Peitzmann", "T.", "" ], [ "Petreczky", "P.", "" ], [ "Ranft", "J.", "" ], [ "Rapp", "R.", "" ], [ "Ruuskanen", "P. V.", "" ], [ "Redlich", "K.", "" ], [ "Rasanen", "S. S.", "" ], [ "Sarcevic", "I.", "" ], [ "Serreau", "J.", "" ], [ "Srivastava", "D. K.", "" ], [ "Takai", "H.", "" ], [ "Tapprogge", "S.", "" ], [ "Tokarev", "M.", "" ], [ "Vardanyan", "I. N.", "" ], [ "Werlen", "M.", "" ], [ "Yepes", "P.", "" ] ]
Various pion and photon production mechanisms in high-energy nuclear collisions at RHIC and LHC are discussed. Comparison with RHIC data is done whenever possible. The prospect of using electromagnetic probes to characterize quark-gluon plasma formation is assessed.
hep-ph/9809485
Oleg Tarasov
F. Jegerlehner and O.V. Tarasov
Exact mass dependent two--loop $\bar{\alpha}_s(Q^2)$ in the background MOM renormalization scheme
20 pages, 5 figures, LaTeX, uses axodraw.sty, revised version, Sec. 5 (numerical results) changed (quark masses were not set properly) and enhanced
Nucl.Phys. B549 (1999) 481-498
10.1016/S0550-3213(99)00141-8
DESY 98-093
hep-ph
null
A two-loop calculation of the renormalization group $\beta$--function in a momentum subtraction scheme with massive quarks is presented using the background field formalism. The results have been obtained by using a set of new generalized recurrence relations proposed recently by one of the authors (O.V.T.). The behavior of the mass dependent effective coupling constant is investigated in detail. Compact analytic results are presented.
[ { "created": "Tue, 22 Sep 1998 21:01:21 GMT", "version": "v1" }, { "created": "Thu, 12 Nov 1998 15:13:12 GMT", "version": "v2" } ]
2009-10-31
[ [ "Jegerlehner", "F.", "" ], [ "Tarasov", "O. V.", "" ] ]
A two-loop calculation of the renormalization group $\beta$--function in a momentum subtraction scheme with massive quarks is presented using the background field formalism. The results have been obtained by using a set of new generalized recurrence relations proposed recently by one of the authors (O.V.T.). The behavior of the mass dependent effective coupling constant is investigated in detail. Compact analytic results are presented.
1306.2486
Hannu Paukkunen
Hannu Paukkunen, Kari J. Eskola, N\'estor Armesto (for the LHeC Study Group)
Nuclear PDFs from the LHeC perspective
A transcription of the talk given in XXI International Workshop on Deep-Inelastic Scattering and Related Subjects, Marseilles, France
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the prospects for constraining the nuclear parton distribution functions by small-x deep inelastic scattering. Performing a global fit of nuclear parton distribution functions including a sample of pseudodata representing expected measurements at the planned LHeC collider, we demonstrate that the accuracy of the present nuclear parton distributions could be be improved substantially. We also discuss the impact of flavour-tagged data.
[ { "created": "Tue, 11 Jun 2013 11:05:29 GMT", "version": "v1" } ]
2019-08-14
[ [ "Paukkunen", "Hannu", "", "for the LHeC Study\n Group" ], [ "Eskola", "Kari J.", "", "for the LHeC Study\n Group" ], [ "Armesto", "Néstor", "", "for the LHeC Study\n Group" ] ]
We study the prospects for constraining the nuclear parton distribution functions by small-x deep inelastic scattering. Performing a global fit of nuclear parton distribution functions including a sample of pseudodata representing expected measurements at the planned LHeC collider, we demonstrate that the accuracy of the present nuclear parton distributions could be be improved substantially. We also discuss the impact of flavour-tagged data.
hep-ph/9207214
Arkady Vainshtein
I.I.Bigi, N.G.Uraltsev, A.I.Vainshtein
Nonperturbative Corrections to Inclusive Beauty and Charm Decays: QCD versus Phenomenological Models
11 pages (2 figs are not included), Latex file, FERMILAB-PUB-92/158-T UND-HEP-92-BIG04 TPI-MINN-92/30-T
Phys.Lett.B293:430-436,1992; ERRATUM-ibid.B297:477,1993
10.1016/0370-2693(92)90908-M
null
hep-ph
null
We present a selfconsistent method for treating nonperturbative effects in inclusive nonleptonic and semileptonic decays of heavy flavour hadrons. These effects give rise to powerlike corrections $\propto 1/m_Q^n\,$, $n \ge 2$ with $m_Q$ denoting the heavy quark mass.The leading correction to the semileptonic branching ratio occurs for n=2. It is expressed in terms of the vector-pseudoscalar mass splitting: $\delta BR\ind{sl}/BR\ind{sl} \simeq BR\ind{nl}\, \cdot \,6\,(\,(M_V^2-M_P^2)/m_Q^2)\cdot (c_+^2 - c_-^2)/2N_c$ and yields a {\it reduction} of $BR\ind{sl}$. This nonperturbative correction contributes to the nonleptonic width with a sign opposite to that of the perturbative terms that are non-leading in $1/N_c$. In beauty decays the former reduces the latter by 20 \% whereas in charm decays they more or less cancel. This leads to a {\it reduction} of $BR\ind{sl}$ by no more than 10 \% in beauty decays and by a factor of roughly two in charm decays. We confront these results with those obtained from phenomenological models of heavy flavour decays and find that such models are unable to mimic these leading corrections by a specific choice of quark masses or by invoking Fermi motion.
[ { "created": "Sat, 4 Jul 1992 01:06:35 GMT", "version": "v1" } ]
2011-07-18
[ [ "Bigi", "I. I.", "" ], [ "Uraltsev", "N. G.", "" ], [ "Vainshtein", "A. I.", "" ] ]
We present a selfconsistent method for treating nonperturbative effects in inclusive nonleptonic and semileptonic decays of heavy flavour hadrons. These effects give rise to powerlike corrections $\propto 1/m_Q^n\,$, $n \ge 2$ with $m_Q$ denoting the heavy quark mass.The leading correction to the semileptonic branching ratio occurs for n=2. It is expressed in terms of the vector-pseudoscalar mass splitting: $\delta BR\ind{sl}/BR\ind{sl} \simeq BR\ind{nl}\, \cdot \,6\,(\,(M_V^2-M_P^2)/m_Q^2)\cdot (c_+^2 - c_-^2)/2N_c$ and yields a {\it reduction} of $BR\ind{sl}$. This nonperturbative correction contributes to the nonleptonic width with a sign opposite to that of the perturbative terms that are non-leading in $1/N_c$. In beauty decays the former reduces the latter by 20 \% whereas in charm decays they more or less cancel. This leads to a {\it reduction} of $BR\ind{sl}$ by no more than 10 \% in beauty decays and by a factor of roughly two in charm decays. We confront these results with those obtained from phenomenological models of heavy flavour decays and find that such models are unable to mimic these leading corrections by a specific choice of quark masses or by invoking Fermi motion.
hep-ph/0012264
Yue-Liang Wu
K.C. Chou and Y.L. Wu (ITP)
Predictive SUSY GUT Model for CP Violation, Fermion Masses and Mixings
RevTex, a footnote and references added, contributed paper published in the Proceedings: ``Symposium on Frontiers of Physics at Millennium'', 8-11 Oct. 1999, Beijing, (World Scientific Publishing Company), Editors: Yue-Liang Wu and Jong-Ping Hsu
null
null
null
hep-ph hep-ex
null
CP violation, fermion masses and mixing angles including that of neutrinos are studied in an SUSY SO(10)$\times \Delta (48)\times$ U(1) model. The nonabelian SU(3) discrete family symmetry $\Delta(48)$ associated with a simple scheme of U(1) charge assignment on various fields concerned in superpotential leads to unique Yukawa coupling matrices with zero textures. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully predicted by only four parameters. The masses and mixing angles for the neutrino sector could also be predicted by constructing an appropriate heavy Majorana neutrino mass matrix without involving new parameters. It is found that the atmospheric neutrino deficit, the mass limit put by hot dark matter and the LSND $\bar{\nu}_{\mu} \to \bar{\nu}_{e}$ events may simultaneously be explained, but solar neutrino puzzle can be solved only by introducing a sterile neutrino. An additional parameter is added to obtain the mass and mixing of the sterile neutrino. The hadronic parameters $B_{K}$ and $f_{B}\sqrt{B}$ are extracted from the observed $K^{0}$-$\bar{K}^{0}$ and $B^{0}$-$\bar{B}^{0}$ mixings respectively. The direct CP violation ($\epsilon'/\epsilon$) in kaon decays and the three angles $\alpha$, $\beta$ and $\gamma$ of the unitarity triangle in the CKM matrix are also presented. More precise measurements of $\alpha_{s}(M_{Z})$, $|V_{cb}|$, $|V_{ub}/V_{cb}|$, $m_{t}$, as well as various CP violation and neutrino oscillation experiments will provide an important test for the present model and guide us to a more fundamental theory.
[ { "created": "Wed, 20 Dec 2000 04:23:08 GMT", "version": "v1" }, { "created": "Tue, 2 Jan 2001 02:39:11 GMT", "version": "v2" } ]
2007-05-23
[ [ "Chou", "K. C.", "", "ITP" ], [ "Wu", "Y. L.", "", "ITP" ] ]
CP violation, fermion masses and mixing angles including that of neutrinos are studied in an SUSY SO(10)$\times \Delta (48)\times$ U(1) model. The nonabelian SU(3) discrete family symmetry $\Delta(48)$ associated with a simple scheme of U(1) charge assignment on various fields concerned in superpotential leads to unique Yukawa coupling matrices with zero textures. Thirteen parameters involving masses and mixing angles in the quark and charged lepton sector are successfully predicted by only four parameters. The masses and mixing angles for the neutrino sector could also be predicted by constructing an appropriate heavy Majorana neutrino mass matrix without involving new parameters. It is found that the atmospheric neutrino deficit, the mass limit put by hot dark matter and the LSND $\bar{\nu}_{\mu} \to \bar{\nu}_{e}$ events may simultaneously be explained, but solar neutrino puzzle can be solved only by introducing a sterile neutrino. An additional parameter is added to obtain the mass and mixing of the sterile neutrino. The hadronic parameters $B_{K}$ and $f_{B}\sqrt{B}$ are extracted from the observed $K^{0}$-$\bar{K}^{0}$ and $B^{0}$-$\bar{B}^{0}$ mixings respectively. The direct CP violation ($\epsilon'/\epsilon$) in kaon decays and the three angles $\alpha$, $\beta$ and $\gamma$ of the unitarity triangle in the CKM matrix are also presented. More precise measurements of $\alpha_{s}(M_{Z})$, $|V_{cb}|$, $|V_{ub}/V_{cb}|$, $m_{t}$, as well as various CP violation and neutrino oscillation experiments will provide an important test for the present model and guide us to a more fundamental theory.
hep-ph/0508269
Midori Obara
Midori Obara, Noriyuki Oshimo
Generation Mixing of Sneutrinos in Heavier Chargino Decay
22 pages, Revtex, 7 figures. v2: For the total width of the heavier chargino, the contribution from the decay into a charged slepton and a neutirno has been included. The figures (Figs. 2, 3, 4, 5), the equations and the related descriptions in sections II and III have been revised. Several references and equations added. v3: Several sentences of section I and V have been rewritten, conclusions unchanged
JHEP 0608:054,2006
10.1088/1126-6708/2006/08/054
OCHA-PP-250
hep-ph
null
The heavier chargino decay could yield two charged leptons of different generations, owing to generation mixing of sneutrinos. We discuss the possibility of producing $e$ and $\mu$ through this process in near future collider experiments. The analyses are made systematically in the supersymmetric extension of the standard model without assuming a specific scenario for the mixing. Production of the heavier chargino is evaluated in $e^+e^-$ collisions. In the parameter region consistent with nonobservation of the radiative $\mu$ decay, sizable parts lead to a detectable branching ratio for the generation-changing decay of the heavier chargino.
[ { "created": "Fri, 26 Aug 2005 09:04:41 GMT", "version": "v1" }, { "created": "Fri, 14 Oct 2005 08:06:38 GMT", "version": "v2" }, { "created": "Sat, 24 Jun 2006 06:28:11 GMT", "version": "v3" } ]
2010-02-03
[ [ "Obara", "Midori", "" ], [ "Oshimo", "Noriyuki", "" ] ]
The heavier chargino decay could yield two charged leptons of different generations, owing to generation mixing of sneutrinos. We discuss the possibility of producing $e$ and $\mu$ through this process in near future collider experiments. The analyses are made systematically in the supersymmetric extension of the standard model without assuming a specific scenario for the mixing. Production of the heavier chargino is evaluated in $e^+e^-$ collisions. In the parameter region consistent with nonobservation of the radiative $\mu$ decay, sizable parts lead to a detectable branching ratio for the generation-changing decay of the heavier chargino.
hep-ph/0304226
A. J. Barr
Alan Barr, Christopher Lester, Phil Stephens
m_T2 : the truth behind the glamour
null
J.Phys.G29:2343-2363,2003
10.1088/0954-3899/29/10/304
Cavendish HEP-2002-02/14
hep-ph
null
We present the kinematic variable, m_T2, which is in some ways similar to the more familiar `transverse-mass', but which can be used in events where two or more particles have escaped detection. We define this variable and describe the event topologies to which it applies, then present some of its mathematical properties. We then briefly discuss two case studies which show how m_T2 is vital when reconstructing the masses of supersymmetric particles in mSUGRA-like and AMSB-like scenarios at the Large Hadron Collider.
[ { "created": "Wed, 23 Apr 2003 16:04:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Barr", "Alan", "" ], [ "Lester", "Christopher", "" ], [ "Stephens", "Phil", "" ] ]
We present the kinematic variable, m_T2, which is in some ways similar to the more familiar `transverse-mass', but which can be used in events where two or more particles have escaped detection. We define this variable and describe the event topologies to which it applies, then present some of its mathematical properties. We then briefly discuss two case studies which show how m_T2 is vital when reconstructing the masses of supersymmetric particles in mSUGRA-like and AMSB-like scenarios at the Large Hadron Collider.
1210.6553
Igor Ivanov
I. P. Ivanov, E. Vdovin
Classification of finite reparametrization symmetry groups in the three-Higgs-doublet model
41 pages, 3 figure; v2: additional explanations on group-theoretical issues, matches the published version
Eur. Phys. J. C 73, 2309 (2013)
10.1140/epjc/s10052-013-2309-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Symmetries play a crucial role in electroweak symmetry breaking models with non-minimal Higgs content. Within each class of these models, it is desirable to know which symmetry groups can be implemented via the scalar sector. In N-Higgs-doublet models, this classification problem was solved only for N=2 doublets. Very recently, we suggested a method to classify all realizable finite symmetry groups of Higgs-family transformations in the three-Higgs-doublet model (3HDM). Here, we present this classification in all detail together with an introduction to the theory of solvable groups, which play the key role in our derivation. We also consider generalized-CP symmetries, and discuss the interplay between Higgs-family symmetries and CP-conservation. In particular, we prove that presence of the Z_4 symmetry guarantees the explicit CP-conservation of the potential. This work completes classification of finite reparametrization symmetry groups in 3HDM.
[ { "created": "Wed, 24 Oct 2012 14:50:10 GMT", "version": "v1" }, { "created": "Fri, 15 Feb 2013 01:37:47 GMT", "version": "v2" } ]
2015-06-11
[ [ "Ivanov", "I. P.", "" ], [ "Vdovin", "E.", "" ] ]
Symmetries play a crucial role in electroweak symmetry breaking models with non-minimal Higgs content. Within each class of these models, it is desirable to know which symmetry groups can be implemented via the scalar sector. In N-Higgs-doublet models, this classification problem was solved only for N=2 doublets. Very recently, we suggested a method to classify all realizable finite symmetry groups of Higgs-family transformations in the three-Higgs-doublet model (3HDM). Here, we present this classification in all detail together with an introduction to the theory of solvable groups, which play the key role in our derivation. We also consider generalized-CP symmetries, and discuss the interplay between Higgs-family symmetries and CP-conservation. In particular, we prove that presence of the Z_4 symmetry guarantees the explicit CP-conservation of the potential. This work completes classification of finite reparametrization symmetry groups in 3HDM.
1612.02445
Yong Zhao
Yoshitaka Hatta, Yuya Nakagawa, Bowen Xiao, Feng Yuan, and Yong Zhao
Gluon orbital angular momentum at small-$x$
22 pages. v2 significantly expands the previous version with all the details of derivation as well as a number of new results and discussions. The title and abstract are changed, and an author is added
Phys. Rev. D 95, 114032 (2017)
10.1103/PhysRevD.95.114032
YITP-16-133
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a general analysis of the orbital angular momentum (OAM) distribution of gluons $L_g(x)$ inside the nucleon with particular emphasis on the small-$x$ region. We derive a novel operator representation of $L_g(x)$ in terms of Wilson lines and argue that it is approximately proportional to the gluon helicity distribution $L_g(x) \approx -2\Delta G(x)$ at small-$x$. We also compute longitudinal single spin asymmetry in exclusive diffractive dijet production in lepton-nucleon scattering in the next-to-eikonal approximation and show that the asymmetry is a direct probe of the gluon helicity/OAM distribution as well as the QCD odderon exchange.
[ { "created": "Wed, 7 Dec 2016 21:04:45 GMT", "version": "v1" }, { "created": "Mon, 24 Apr 2017 05:06:32 GMT", "version": "v2" } ]
2017-07-05
[ [ "Hatta", "Yoshitaka", "" ], [ "Nakagawa", "Yuya", "" ], [ "Xiao", "Bowen", "" ], [ "Yuan", "Feng", "" ], [ "Zhao", "Yong", "" ] ]
We present a general analysis of the orbital angular momentum (OAM) distribution of gluons $L_g(x)$ inside the nucleon with particular emphasis on the small-$x$ region. We derive a novel operator representation of $L_g(x)$ in terms of Wilson lines and argue that it is approximately proportional to the gluon helicity distribution $L_g(x) \approx -2\Delta G(x)$ at small-$x$. We also compute longitudinal single spin asymmetry in exclusive diffractive dijet production in lepton-nucleon scattering in the next-to-eikonal approximation and show that the asymmetry is a direct probe of the gluon helicity/OAM distribution as well as the QCD odderon exchange.
0910.4787
Weizhen Deng
Bao-Kai Wang, Xiao-Lin Chen, Wei-Zhen Deng
Dynamical study of the possible molecular state X(3872) with the s-channel one gluon exchange interaction
null
null
10.1088/1674-1137/34/8/003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recently observed X(3872) resonance, which is difficult to be assigned a conventional $c\bar{c}$ charmonium state in the quark model, may be interpreted as a molecular state. Such a molecular state is a hidden flavor four quark state because of its charmonium-like quantum numbers. The s-channel one gluon exchange is an interaction which only acts in the hidden flavor multi-quark system. In this paper, we will study the X(3872) and other similiar hidden flavor molecular states in a quark model by taking into account of the s-channel one gluon exchange interaction.
[ { "created": "Mon, 26 Oct 2009 01:04:18 GMT", "version": "v1" } ]
2015-05-14
[ [ "Wang", "Bao-Kai", "" ], [ "Chen", "Xiao-Lin", "" ], [ "Deng", "Wei-Zhen", "" ] ]
The recently observed X(3872) resonance, which is difficult to be assigned a conventional $c\bar{c}$ charmonium state in the quark model, may be interpreted as a molecular state. Such a molecular state is a hidden flavor four quark state because of its charmonium-like quantum numbers. The s-channel one gluon exchange is an interaction which only acts in the hidden flavor multi-quark system. In this paper, we will study the X(3872) and other similiar hidden flavor molecular states in a quark model by taking into account of the s-channel one gluon exchange interaction.
hep-ph/9710360
Roberto Ugoccioni
R. Ugoccioni and A. Giovannini (Torino Univ. & INFN, Torino)
Oscillations of Moments and Structure of Multiplicity Distributions in e+e- Annihilation
6 pages, LaTeX2e (uses amsmath,epsfig,espcrc2), 4 postscript figures. To be published in the Proceedings of the XXVII International Symposium on Multiparticle Dynamics, Frascati (Italy), September 8--12, 1997
Nucl.Phys.Proc.Suppl.71:211-215,1999
10.1016/S0920-5632(98)00344-2
DFTT 64/97
hep-ph
null
Starting from the recognized fact that oscillations of moments with rank and shoulder structure in the multiplicity distribution have the same origin in the full sample of events in e+e- annihilation, we push our investigation to the 2-jet sample level, and argue in favor of the use of the negative binomial multiplicity distribution as the building block of multiparticle production in e+e- annihilation events. It will be shown that this approach leads to definite predictions for the correlation structure, e.g., that correlations are flavour independent.
[ { "created": "Wed, 15 Oct 1997 07:55:59 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ugoccioni", "R.", "", "Torino Univ. & INFN, Torino" ], [ "Giovannini", "A.", "", "Torino Univ. & INFN, Torino" ] ]
Starting from the recognized fact that oscillations of moments with rank and shoulder structure in the multiplicity distribution have the same origin in the full sample of events in e+e- annihilation, we push our investigation to the 2-jet sample level, and argue in favor of the use of the negative binomial multiplicity distribution as the building block of multiparticle production in e+e- annihilation events. It will be shown that this approach leads to definite predictions for the correlation structure, e.g., that correlations are flavour independent.
1309.5365
Howard Baer
Kyu Jung Bae, Howard Baer and Eung Jin Chun
Mixed axion/neutralino dark matter in the SUSY DFSZ axion model
43 pages incl. 33 .pdf figures; updated figures
null
10.1088/1475-7516/2013/12/028
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine mixed axion/neutralino cold dark matter production in the SUSY DFSZ axion model where an axion superfield couples to Higgs superfields. We calculate a wide array of axino and saxion decay modes along with their decay temperatures, and thermal and non-thermal production rates. For a SUSY benchmark model with a standard underabundance (SUA) of Higgsino-like dark matter (DM), we find for the PQ scale f_a< 10^{12} GeV that the DM abundance is mainly comprised of axions as the saxion/axino decay occurs before the standard neutralino freeze-out and thus its abundance remains suppressed. For 10^{12}<~ f_a<~ 10^{14} GeV, the saxion/axino decays occur after neutralino freeze-out so that the neutralino abundance is enhanced by the production via decay and subsequent re-annihilation. For f_a>~ 10^{14} GeV, both neutralino dark matter and dark radiation are typically overproduced. For judicious parameter choices, these can be suppressed and the combined neutralino/axion abundance brought into accord with measured values. A SUSY benchmark model with a standard overabundance (SOA) of bino DM is also examined and typically remains excluded due at least to too great a neutralino DM abundance for f_a<~ 10^{15} GeV. For f_a>~ 10^{15} GeV and lower saxion masses, large entropy production from saxion decay can dilute all relics and the SOA model can be allowed by all constraints.
[ { "created": "Fri, 20 Sep 2013 20:00:55 GMT", "version": "v1" }, { "created": "Fri, 13 Mar 2015 22:00:31 GMT", "version": "v2" } ]
2015-06-17
[ [ "Bae", "Kyu Jung", "" ], [ "Baer", "Howard", "" ], [ "Chun", "Eung Jin", "" ] ]
We examine mixed axion/neutralino cold dark matter production in the SUSY DFSZ axion model where an axion superfield couples to Higgs superfields. We calculate a wide array of axino and saxion decay modes along with their decay temperatures, and thermal and non-thermal production rates. For a SUSY benchmark model with a standard underabundance (SUA) of Higgsino-like dark matter (DM), we find for the PQ scale f_a< 10^{12} GeV that the DM abundance is mainly comprised of axions as the saxion/axino decay occurs before the standard neutralino freeze-out and thus its abundance remains suppressed. For 10^{12}<~ f_a<~ 10^{14} GeV, the saxion/axino decays occur after neutralino freeze-out so that the neutralino abundance is enhanced by the production via decay and subsequent re-annihilation. For f_a>~ 10^{14} GeV, both neutralino dark matter and dark radiation are typically overproduced. For judicious parameter choices, these can be suppressed and the combined neutralino/axion abundance brought into accord with measured values. A SUSY benchmark model with a standard overabundance (SOA) of bino DM is also examined and typically remains excluded due at least to too great a neutralino DM abundance for f_a<~ 10^{15} GeV. For f_a>~ 10^{15} GeV and lower saxion masses, large entropy production from saxion decay can dilute all relics and the SOA model can be allowed by all constraints.
hep-ph/0405078
Jonathan Engel
S.R. Elliott and J. Engel
Double Beta Decay
Some typos corrected, references corrected and added. A less blurry version of figure 3 is available from authors. 41 pages, 5 figures, submitted to J. Phys. G
J.Phys. G30 (2004) R183
10.1088/0954-3899/30/9/R01
LAUR04-3076
hep-ph nucl-ex nucl-th
null
We review recent developments in double-beta decay, focusing on what can be learned about the three light neutrinos in future experiments. We examine the effects of uncertainties in already measured neutrino parameters and in calculated nuclear matrix elements on the interpretation of upcoming double-beta decay measurements. We then review a number of proposed experiments.
[ { "created": "Mon, 10 May 2004 15:44:44 GMT", "version": "v1" }, { "created": "Mon, 24 May 2004 19:29:51 GMT", "version": "v2" } ]
2009-11-10
[ [ "Elliott", "S. R.", "" ], [ "Engel", "J.", "" ] ]
We review recent developments in double-beta decay, focusing on what can be learned about the three light neutrinos in future experiments. We examine the effects of uncertainties in already measured neutrino parameters and in calculated nuclear matrix elements on the interpretation of upcoming double-beta decay measurements. We then review a number of proposed experiments.
1111.5984
Felix Karbstein
Felix Karbstein, Lars Roessler, Babette D\"obrich, Holger Gies
Optical probes of the quantum vacuum: The photon polarization tensor in external fields
13 pages, 4 figures; typo in Eq. (5) corrected (matches journal version)
Int. J. Mod. Phys. Conf. Ser. 14, 403 (2012)
10.1142/S2010194512007520
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The photon polarization tensor is the central building block of an effective theory description of photon propagation in the quantum vacuum. It accounts for the vacuum fluctuations of the underlying theory, and in the presence of external electromagnetic fields, gives rise to such striking phenomena as vacuum birefringence and dichroism. Standard approximations of the polarization tensor are often restricted to on-the-light-cone dynamics in homogeneous electromagnetic fields, and are limited to certain momentum regimes only. We devise two different strategies to go beyond these limitations: First, we aim at obtaining novel analytical insights into the photon polarization tensor for homogeneous fields, while retaining its full momentum dependence. Second, we employ wordline numerical methods to surpass the constant-field limit.
[ { "created": "Fri, 25 Nov 2011 13:41:42 GMT", "version": "v1" }, { "created": "Mon, 27 Aug 2012 15:38:40 GMT", "version": "v2" } ]
2012-08-28
[ [ "Karbstein", "Felix", "" ], [ "Roessler", "Lars", "" ], [ "Döbrich", "Babette", "" ], [ "Gies", "Holger", "" ] ]
The photon polarization tensor is the central building block of an effective theory description of photon propagation in the quantum vacuum. It accounts for the vacuum fluctuations of the underlying theory, and in the presence of external electromagnetic fields, gives rise to such striking phenomena as vacuum birefringence and dichroism. Standard approximations of the polarization tensor are often restricted to on-the-light-cone dynamics in homogeneous electromagnetic fields, and are limited to certain momentum regimes only. We devise two different strategies to go beyond these limitations: First, we aim at obtaining novel analytical insights into the photon polarization tensor for homogeneous fields, while retaining its full momentum dependence. Second, we employ wordline numerical methods to surpass the constant-field limit.
1307.4226
Mikhail Kalmykov
Fred Jegerlehner, Mikhail Yu. Kalmykov, Bernd A. Kniehl
About the EW contribution to the relation between pole and MS-masses of the top-quark in the Standard Model
6 pages, XXI International Workshop on Deep-Inelastic Scattering and Related Subject -DIS2013, 22-26 April 2013 Marseilles,France; Version 2 adds references
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Results of our recent re-analysis of the electroweak contribution to the relation between pole and running masses of top-quark within the Standard Model is reviewed. We argue, that if vacuum of SM is stable, then there exists an optimal value of renormalization group scale (IR-point), at which the radiative corrections to the matching condition between parameters of Higgs sector and pole masses is minimal or equal to zero. Within the available accuracy, we find the IR-point to lie in an interval between value of Z-boson mass and twice the value of W-boson mass. The value of scale is relevant for extraction of Higgs self-coupling from cross-section as well as for construction of effective Lagrangian.
[ { "created": "Tue, 16 Jul 2013 09:50:17 GMT", "version": "v1" }, { "created": "Mon, 30 Sep 2013 18:54:28 GMT", "version": "v2" } ]
2013-10-01
[ [ "Jegerlehner", "Fred", "" ], [ "Kalmykov", "Mikhail Yu.", "" ], [ "Kniehl", "Bernd A.", "" ] ]
Results of our recent re-analysis of the electroweak contribution to the relation between pole and running masses of top-quark within the Standard Model is reviewed. We argue, that if vacuum of SM is stable, then there exists an optimal value of renormalization group scale (IR-point), at which the radiative corrections to the matching condition between parameters of Higgs sector and pole masses is minimal or equal to zero. Within the available accuracy, we find the IR-point to lie in an interval between value of Z-boson mass and twice the value of W-boson mass. The value of scale is relevant for extraction of Higgs self-coupling from cross-section as well as for construction of effective Lagrangian.
1704.01854
Zhi-Gang Wang
Zhi-Gang Wang
Analysis of the $\Omega_c(3000)$, $\Omega_c(3050)$, $\Omega_c(3066)$, $\Omega_c(3090)$ and $\Omega_c(3119)$ with QCD sum rules
12 pages, 8 figures
Eur. Phys. J. C77 (2017) 325
10.1140/epjc/s10052-017-4895-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we assign the $\Omega_c(3000)$, $\Omega_c(3050)$, $\Omega_c(3066)$, $\Omega_c(3090)$ and $\Omega_c(3119)$ to be the P-wave baryon states with $J^P={\frac{1}{2}}^-$, ${\frac{1}{2}}^-$, ${\frac{3}{2}}^-$, ${\frac{3}{2}}^-$ and ${\frac{5}{2}}^-$, respectively, and study them with the QCD sum rules by introducing an explicit relative P-wave between the two $s$ quarks. The predictions support assigning the $\Omega_c(3050)$, $\Omega_c(3066)$, $\Omega_c(3090)$ and $\Omega_c(3119)$ to be the P-wave baryon states with $J^P={\frac{1}{2}}^-$, ${\frac{3}{2}}^-$, ${\frac{3}{2}}^-$ and ${\frac{5}{2}}^-$, respectively, where the two $s$ quarks are in relative P-wave; while the $\Omega_c(3000)$ can be assigned to the P-wave baryon state with $J^{P}={\frac{1}{2}}^-$, where the two $s$ quarks are in relative S-wave.
[ { "created": "Thu, 6 Apr 2017 14:22:18 GMT", "version": "v1" }, { "created": "Thu, 4 May 2017 09:54:08 GMT", "version": "v2" } ]
2017-05-23
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we assign the $\Omega_c(3000)$, $\Omega_c(3050)$, $\Omega_c(3066)$, $\Omega_c(3090)$ and $\Omega_c(3119)$ to be the P-wave baryon states with $J^P={\frac{1}{2}}^-$, ${\frac{1}{2}}^-$, ${\frac{3}{2}}^-$, ${\frac{3}{2}}^-$ and ${\frac{5}{2}}^-$, respectively, and study them with the QCD sum rules by introducing an explicit relative P-wave between the two $s$ quarks. The predictions support assigning the $\Omega_c(3050)$, $\Omega_c(3066)$, $\Omega_c(3090)$ and $\Omega_c(3119)$ to be the P-wave baryon states with $J^P={\frac{1}{2}}^-$, ${\frac{3}{2}}^-$, ${\frac{3}{2}}^-$ and ${\frac{5}{2}}^-$, respectively, where the two $s$ quarks are in relative P-wave; while the $\Omega_c(3000)$ can be assigned to the P-wave baryon state with $J^{P}={\frac{1}{2}}^-$, where the two $s$ quarks are in relative S-wave.
hep-ph/9608261
Alexander Makhlin
A.Makhlin
The Wedge Form of relativistic Dynamics. II. The Gluons
21 pages, REVTeX
null
null
WSU-NP-96-13
hep-ph
null
I derive expressions for various correlators of the gauge field and find propagators in a new gauge A^\tau=0. This gauge is a part of the wedge form of relativistic dynamics suggested earlier as the tool for the study of quantum dynamics in collisions of hadrons at extremely high energies and in ultrarelativistic heavy ion collisions. The new gauge puts the quark and gluon fields of the colliding hadrons in one Hilbert space and thus allows one to avoid factorization.
[ { "created": "Wed, 7 Aug 1996 23:21:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Makhlin", "A.", "" ] ]
I derive expressions for various correlators of the gauge field and find propagators in a new gauge A^\tau=0. This gauge is a part of the wedge form of relativistic dynamics suggested earlier as the tool for the study of quantum dynamics in collisions of hadrons at extremely high energies and in ultrarelativistic heavy ion collisions. The new gauge puts the quark and gluon fields of the colliding hadrons in one Hilbert space and thus allows one to avoid factorization.
2011.09087
Joshua Eby
Joshua Eby, Lauren Street, Peter Suranyi, and L.C.R. Wijewardhana
Global View of Axion Stars with (Nearly) Planck-Scale Decay Constants
15 pages, 8 figures, 2 appendices. References added; updated to match published PRD version
Phys. Rev. D 103, 063043 (2021)
10.1103/PhysRevD.103.063043
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We show that axion stars formed from axions with nearly Planck-scale decay constants $f$ are unstable to decay, and are unlikely to have phenomenological consequences. More generally, we show how results at smaller $f$ cannot be naively extrapolated to $f=\mathcal{O}(M_P)$ as, contrary to conventional wisdom, gravity and special relativity can both become relevant in the same regime. We clarify the rate of decay by reviewing and extending previous work on oscillons and axion stars, which imply a fast decay rate even for so-called dilute states at large $f$.
[ { "created": "Wed, 18 Nov 2020 05:01:29 GMT", "version": "v1" }, { "created": "Tue, 22 Jun 2021 08:16:04 GMT", "version": "v2" } ]
2021-06-23
[ [ "Eby", "Joshua", "" ], [ "Street", "Lauren", "" ], [ "Suranyi", "Peter", "" ], [ "Wijewardhana", "L. C. R.", "" ] ]
We show that axion stars formed from axions with nearly Planck-scale decay constants $f$ are unstable to decay, and are unlikely to have phenomenological consequences. More generally, we show how results at smaller $f$ cannot be naively extrapolated to $f=\mathcal{O}(M_P)$ as, contrary to conventional wisdom, gravity and special relativity can both become relevant in the same regime. We clarify the rate of decay by reviewing and extending previous work on oscillons and axion stars, which imply a fast decay rate even for so-called dilute states at large $f$.
1902.01232
A. Tureanu
Anca Tureanu
Can Oscillating Neutrino States Be Formulated Universally?
17 pages
null
10.1140/epjc/s10052-020-7628-0
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A standing problem in neutrino physics is the consistent and universal definition of oscillating neutrino states as coherent superpositions of massive neutrino states. This problem is solved in a quantum field theoretical framework of neutrino mixing developed in analogy with the Nambu--Jona-Lasinio model for the dynamical generation of nucleon masses. The massive neutrino states are Bogoliubov quasiparticles and their vacuum is a condensate of "Cooper pairs" of massless flavour neutrinos. Their superpositions as oscillating neutrino states have intrinsic quantum coherence by construction. In this quantization framework, the standard phenomenological flavour neutrino states and oscillation probability formula are validated in the ultrarelativistic approximation.
[ { "created": "Fri, 1 Feb 2019 18:58:25 GMT", "version": "v1" }, { "created": "Fri, 22 Nov 2019 20:00:10 GMT", "version": "v2" }, { "created": "Thu, 23 Jan 2020 19:27:25 GMT", "version": "v3" } ]
2020-01-27
[ [ "Tureanu", "Anca", "" ] ]
A standing problem in neutrino physics is the consistent and universal definition of oscillating neutrino states as coherent superpositions of massive neutrino states. This problem is solved in a quantum field theoretical framework of neutrino mixing developed in analogy with the Nambu--Jona-Lasinio model for the dynamical generation of nucleon masses. The massive neutrino states are Bogoliubov quasiparticles and their vacuum is a condensate of "Cooper pairs" of massless flavour neutrinos. Their superpositions as oscillating neutrino states have intrinsic quantum coherence by construction. In this quantization framework, the standard phenomenological flavour neutrino states and oscillation probability formula are validated in the ultrarelativistic approximation.
0809.1202
Pavel Fileviez Perez
Pavel Fileviez Perez (University of Wisconsin-Madison)
Type III Seesaw and Left-Right Symmetry
5 pages, references added, to appear in JHEP
JHEP 0903:142,2009
10.1088/1126-6708/2009/03/142
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The implementation of the Type III seesaw mechanism for neutrino masses in the context of left-right theories where parity is broken spontaneously is investigated. We propose a simple left-right symmetric theory where the neutrinos masses are generated through a double seesaw mechanism which is a combination of Type I and Type III seesaw. In this context we find a possible candidate for the cold dark matter in the Universe and discuss the Baryogenesis via Leptogenesis mechanisms. The spectrum of the theory, the phenomenological constraints and the possibility to test the theory at the Large Hadron Collider are investigated.
[ { "created": "Sun, 7 Sep 2008 01:08:08 GMT", "version": "v1" }, { "created": "Mon, 9 Mar 2009 15:47:22 GMT", "version": "v2" } ]
2009-04-02
[ [ "Perez", "Pavel Fileviez", "", "University of Wisconsin-Madison" ] ]
The implementation of the Type III seesaw mechanism for neutrino masses in the context of left-right theories where parity is broken spontaneously is investigated. We propose a simple left-right symmetric theory where the neutrinos masses are generated through a double seesaw mechanism which is a combination of Type I and Type III seesaw. In this context we find a possible candidate for the cold dark matter in the Universe and discuss the Baryogenesis via Leptogenesis mechanisms. The spectrum of the theory, the phenomenological constraints and the possibility to test the theory at the Large Hadron Collider are investigated.
hep-ph/9612260
Denner Ansgar
W. Beenakker, A. Denner, S. Dittmaier, J. Hoogland, R. Kleiss, G.J. van Oldenborgh, C.G. Papadopoulos, G. Passarino
The fermion-loop scheme for finite-width effects in e^+ e^- annihilation into four fermions
49 pages, LaTeX, 2 figures, uses amssymb, axodraw
Nucl.Phys. B500 (1997) 255-298
10.1016/S0550-3213(97)00316-7
NIKHEF 96-031, PSI-PR-96-41
hep-ph
null
We describe the gauge-invariant treatment of the finite-width effects of W and Z bosons in the fermion-loop scheme and its application to the six-fermion (LEP2) processes e^- e^+ -> four fermions, with massless external fermions. The fermion-loop scheme consists in including all fermionic one-loop corrections in tree-level amplitudes and resumming the self-energies. We give explicit results for the unrenormalized fermionic one-loop contributions to the gauge-boson self-energies and the triple gauge-boson vertices, and perform the renormalization in a gauge-invariant way by introducing complex pole positions and running couplings. A simple effective Born prescription is presented, which allows for a relatively straightforward implementation of the fermion-loop scheme in LEP1 and LEP2 processes. We apply this prescription to typical LEP2 processes, i.e., e^- e^+ -> \mu^- \bar{\nu}_\mu u \bar{d}, e^- e^+ -> s \bar{c} u \bar{d}, and e^- e^+ -> e^- \bar{\nu}_e u \bar{d}, and give numerical comparisons with other gauge-invariance-preserving schemes in the energy range of LEP2, NLC and beyond.
[ { "created": "Thu, 5 Dec 1996 09:30:59 GMT", "version": "v1" } ]
2009-10-30
[ [ "Beenakker", "W.", "" ], [ "Denner", "A.", "" ], [ "Dittmaier", "S.", "" ], [ "Hoogland", "J.", "" ], [ "Kleiss", "R.", "" ], [ "van Oldenborgh", "G. J.", "" ], [ "Papadopoulos", "C. G.", "" ], [ "Passarino", "G.", "" ] ]
We describe the gauge-invariant treatment of the finite-width effects of W and Z bosons in the fermion-loop scheme and its application to the six-fermion (LEP2) processes e^- e^+ -> four fermions, with massless external fermions. The fermion-loop scheme consists in including all fermionic one-loop corrections in tree-level amplitudes and resumming the self-energies. We give explicit results for the unrenormalized fermionic one-loop contributions to the gauge-boson self-energies and the triple gauge-boson vertices, and perform the renormalization in a gauge-invariant way by introducing complex pole positions and running couplings. A simple effective Born prescription is presented, which allows for a relatively straightforward implementation of the fermion-loop scheme in LEP1 and LEP2 processes. We apply this prescription to typical LEP2 processes, i.e., e^- e^+ -> \mu^- \bar{\nu}_\mu u \bar{d}, e^- e^+ -> s \bar{c} u \bar{d}, and e^- e^+ -> e^- \bar{\nu}_e u \bar{d}, and give numerical comparisons with other gauge-invariance-preserving schemes in the energy range of LEP2, NLC and beyond.
2106.12483
Qiang Zhao
Yin Cheng and Qiang Zhao
Hadronic loop effects on the radiative decays of the first radial excitations of $\eta$ and $\eta'$
Revtex, 6 eps figures, 21 pages
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
Based on the one state assumption of $\eta(1405)$ and $\eta(1475)$, thus, $\eta(1295)$ and $\eta(1405/1475)$ are organized as the first radial excitations of $\eta$ and $\eta'$, respectively, we investigate the productions and radiative decays of these two states in $J/\psi\to \gamma\eta_X\to \gamma\gamma V$, where $\eta_X$ stands for $\eta(1295)$ and $\eta(1405/1475)$ and $V$ for vector mesons $\rho^0, \ \omega, \ \phi$. As we have learned from previous studies that the hadronic decays of these two states receive important contributions from the intermediate $\bar{K}K^*+c.c.$ meson loops due to the triangle singularity mechanism, we show that some measurable effects can also arise from the $\bar{K}K^*+c.c.$ meson loops in their radiative decays. Our calculation shows that the impact of the $\bar{K}K^*+c.c.$ meson loops on the $\eta(1405/1475)$ radiative decays is relatively smaller than on $\eta(1295)$ since the latter has a much larger coupling to $\bar{K}K^*+c.c.$ However, the production of $\eta(1295)$ in the $J/\psi$ radiative decays will be strongly suppressed. As a consequence of the $\bar{K}K^*+c.c.$ meson loop contributions, we find that the mixing angle extracted in the radiative decays of $\eta(1295)$ and $\eta(1405/1475)$ will be different from each other, and both are different from the one determined in other processes.
[ { "created": "Wed, 23 Jun 2021 15:55:36 GMT", "version": "v1" } ]
2021-06-24
[ [ "Cheng", "Yin", "" ], [ "Zhao", "Qiang", "" ] ]
Based on the one state assumption of $\eta(1405)$ and $\eta(1475)$, thus, $\eta(1295)$ and $\eta(1405/1475)$ are organized as the first radial excitations of $\eta$ and $\eta'$, respectively, we investigate the productions and radiative decays of these two states in $J/\psi\to \gamma\eta_X\to \gamma\gamma V$, where $\eta_X$ stands for $\eta(1295)$ and $\eta(1405/1475)$ and $V$ for vector mesons $\rho^0, \ \omega, \ \phi$. As we have learned from previous studies that the hadronic decays of these two states receive important contributions from the intermediate $\bar{K}K^*+c.c.$ meson loops due to the triangle singularity mechanism, we show that some measurable effects can also arise from the $\bar{K}K^*+c.c.$ meson loops in their radiative decays. Our calculation shows that the impact of the $\bar{K}K^*+c.c.$ meson loops on the $\eta(1405/1475)$ radiative decays is relatively smaller than on $\eta(1295)$ since the latter has a much larger coupling to $\bar{K}K^*+c.c.$ However, the production of $\eta(1295)$ in the $J/\psi$ radiative decays will be strongly suppressed. As a consequence of the $\bar{K}K^*+c.c.$ meson loop contributions, we find that the mixing angle extracted in the radiative decays of $\eta(1295)$ and $\eta(1405/1475)$ will be different from each other, and both are different from the one determined in other processes.
hep-ph/9307340
null
A.C.Bawa, K.Charchula and W.J.Stirling
Photoproduction of large-mass lepton pairs at HERA as a probe of the small $x$ structure of the proton
Latex, 7 pages + 5 figures (not included), DTP/93/44 and UDWPHYS-93-02 preprint
Phys.Lett.B313:461-468,1993
10.1016/0370-2693(93)90020-I
null
hep-ph
null
The photoproduction of Drell-Yan lepton pairs at HERA is studied. We show that in the backward rapidity region the cross section is strongly sensitive to the small-$x$ behaviour of the quark distributions in the proton, and that with sufficient luminosity it should be possible to distinguish singular $xq \sim x^{-1/2}$ behaviour from standard Regge $xq \sim x^0$ behaviour. The effect on the event rate of experimental acceptance cuts is studied with the help of a Monte Carlo event generator.
[ { "created": "Tue, 27 Jul 1993 11:32:36 GMT", "version": "v1" } ]
2011-07-19
[ [ "Bawa", "A. C.", "" ], [ "Charchula", "K.", "" ], [ "Stirling", "W. J.", "" ] ]
The photoproduction of Drell-Yan lepton pairs at HERA is studied. We show that in the backward rapidity region the cross section is strongly sensitive to the small-$x$ behaviour of the quark distributions in the proton, and that with sufficient luminosity it should be possible to distinguish singular $xq \sim x^{-1/2}$ behaviour from standard Regge $xq \sim x^0$ behaviour. The effect on the event rate of experimental acceptance cuts is studied with the help of a Monte Carlo event generator.
hep-ph/0306199
Keh-Fei Liu
N. Mathur, Y. Chen, S.J. Dong, T. Draper, I. Horv\'ath, F.X. Lee, K.F. Liu, and J.B. Zhang
Roper Resonance and S_{11}(1535) from Lattice QCD
10 pages, 5 figures, revised version to appear in PLB
Phys.Lett.B605:137-143,2005
10.1016/j.physletb.2004.11.010
UK/03-08
hep-ph hep-lat nucl-ex nucl-th
null
Using the constrained curve fitting method and overlap fermions with the lowest pion mass at $180 {\rm MeV}$, we observe that the masses of the first positive and negative parity excited states of the nucleon tend to cross over as the quark masses are taken to the chiral limit. Both results at the physical pion mass agree with the experimental values of the Roper resonance ($N^{1/2+}(1440)$) and $S_{11}$ ($N^{1/2-}(1535)$). This is seen for the first time in a lattice QCD calculation. These results are obtained on a quenched Iwasaki $16^3 \times 28$ lattice with $a = 0.2 {\rm fm}$. We also extract the ghost $\eta' N$ states (a quenched artifact) which are shown to decouple from the nucleon interpolation field above $m_{\pi} \sim 300 {\rm MeV}$. From the quark mass dependence of these states in the chiral region, we conclude that spontaneously broken chiral symmetry dictates the dynamics of light quarks in the nucleon.
[ { "created": "Sun, 22 Jun 2003 05:59:49 GMT", "version": "v1" }, { "created": "Thu, 6 May 2004 20:45:14 GMT", "version": "v2" }, { "created": "Wed, 1 Dec 2004 20:07:08 GMT", "version": "v3" } ]
2016-08-16
[ [ "Mathur", "N.", "" ], [ "Chen", "Y.", "" ], [ "Dong", "S. J.", "" ], [ "Draper", "T.", "" ], [ "Horváth", "I.", "" ], [ "Lee", "F. X.", "" ], [ "Liu", "K. F.", "" ], [ "Zhang", "J. B.", "" ] ]
Using the constrained curve fitting method and overlap fermions with the lowest pion mass at $180 {\rm MeV}$, we observe that the masses of the first positive and negative parity excited states of the nucleon tend to cross over as the quark masses are taken to the chiral limit. Both results at the physical pion mass agree with the experimental values of the Roper resonance ($N^{1/2+}(1440)$) and $S_{11}$ ($N^{1/2-}(1535)$). This is seen for the first time in a lattice QCD calculation. These results are obtained on a quenched Iwasaki $16^3 \times 28$ lattice with $a = 0.2 {\rm fm}$. We also extract the ghost $\eta' N$ states (a quenched artifact) which are shown to decouple from the nucleon interpolation field above $m_{\pi} \sim 300 {\rm MeV}$. From the quark mass dependence of these states in the chiral region, we conclude that spontaneously broken chiral symmetry dictates the dynamics of light quarks in the nucleon.
1906.11850
Davide Napoletano
Matteo Cacciari, Stefano Forte, Davide Napoletano, Gregory Soyez, Giovanni Stagnitto
The single-jet inclusive cross-section and its definition
19 pages, 6 figures, accepted for publication on PRD
Phys. Rev. D 100, 114015 (2019)
10.1103/PhysRevD.100.114015
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate some well-known problematic aspects of the single-jet inclusive cross-section, specifically its non-unitarity and the possibly related issue of apparent perturbative instability at low orders. We study and clarify their origin by introducing possible alternative weighted definitions of the observable which restore unitarity. We show that the perturbative instability of the standard definition is an accidental artefact of the smallness of the NLO $K$ factor which only manifests itself for values of the jet radius in the range $R\sim 0.3-0.6$, and that its non-unitarity is necessary in order to ensure cancellation of logs of the momentum cutoff used in the jet definition. We also show that alternative unitary definitions do not have better perturbative properties compared to the conventional non-unitary definition, while suffering from lack of cancellation of large logs.
[ { "created": "Thu, 27 Jun 2019 18:00:05 GMT", "version": "v1" }, { "created": "Mon, 2 Dec 2019 09:15:04 GMT", "version": "v2" } ]
2019-12-18
[ [ "Cacciari", "Matteo", "" ], [ "Forte", "Stefano", "" ], [ "Napoletano", "Davide", "" ], [ "Soyez", "Gregory", "" ], [ "Stagnitto", "Giovanni", "" ] ]
We investigate some well-known problematic aspects of the single-jet inclusive cross-section, specifically its non-unitarity and the possibly related issue of apparent perturbative instability at low orders. We study and clarify their origin by introducing possible alternative weighted definitions of the observable which restore unitarity. We show that the perturbative instability of the standard definition is an accidental artefact of the smallness of the NLO $K$ factor which only manifests itself for values of the jet radius in the range $R\sim 0.3-0.6$, and that its non-unitarity is necessary in order to ensure cancellation of logs of the momentum cutoff used in the jet definition. We also show that alternative unitary definitions do not have better perturbative properties compared to the conventional non-unitary definition, while suffering from lack of cancellation of large logs.
hep-ph/0510293
Ross Young
A. W. Thomas, R. D. Young
Baryon Spectroscopy and the Constituent Quark Model
8 pages, 2 figures; Invited talk presented by A. W. Thomas at the Asia-Pacific Few Body Conference, Suranaree University of Technology (Thailand), July 2005
null
null
JLAB-THY-05-416
hep-ph
null
We explore further the idea that the lattice QCD data for hadron properties in the region m_\pi^2 > 0.2 GeV^2 can be described by the constituent quark model. This leads to a natural explanation of the fact that nucleon excited states are generally stable for pion masses greater than their physical excitation energies. Finally we apply these same ideas to the problem of how pentaquarks might behave in lattice QCD, with interesting conclusions.
[ { "created": "Fri, 21 Oct 2005 19:43:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Thomas", "A. W.", "" ], [ "Young", "R. D.", "" ] ]
We explore further the idea that the lattice QCD data for hadron properties in the region m_\pi^2 > 0.2 GeV^2 can be described by the constituent quark model. This leads to a natural explanation of the fact that nucleon excited states are generally stable for pion masses greater than their physical excitation energies. Finally we apply these same ideas to the problem of how pentaquarks might behave in lattice QCD, with interesting conclusions.
hep-ph/0512220
Jamal Jalilian-Marian
Ernest M. Henley and Jamal Jalilian-Marian
Ultra-High Energy Neutrino-Nucleon Scattering and Parton Distributions at Small $x$
10 pages, 4 figures, INT-PUB-05-32
Phys.Rev.D73:094004,2006; AIP Conf.Proc.870:666-668,2006
10.1103/PhysRevD.73.094004
INT-PUB-05-32
hep-ph
null
The cross section for ultra-high energy neutrino-nucleon scattering is very sensitive to the parton distributions at very small values of Bjorken x ($x \leq 10^{-4})$. We numerically investigate the effects of modifying the behavior of the gluon distribution function at very small $x$ in the DGLAP evolution equation. We then use the Color Glass Condensate formalism to calculate the neutrino-nucleon cross section at ultra-high energies and compare the result with those based on modification of DGLAP evolution equation.
[ { "created": "Fri, 16 Dec 2005 23:31:12 GMT", "version": "v1" } ]
2014-11-18
[ [ "Henley", "Ernest M.", "" ], [ "Jalilian-Marian", "Jamal", "" ] ]
The cross section for ultra-high energy neutrino-nucleon scattering is very sensitive to the parton distributions at very small values of Bjorken x ($x \leq 10^{-4})$. We numerically investigate the effects of modifying the behavior of the gluon distribution function at very small $x$ in the DGLAP evolution equation. We then use the Color Glass Condensate formalism to calculate the neutrino-nucleon cross section at ultra-high energies and compare the result with those based on modification of DGLAP evolution equation.
hep-ph/9308267
null
Sun Myong Kim and Thomas F. Walsh
Moments of the Virtual Photon Structure Function
LaTeX, 16 pages + 14 compressed and uuencoded postscript figures, UMN-TH-1111/92
Z.Phys.C72:123-132,1996
10.1007/s002880050230
null
hep-ph
null
The photon structure function is a useful testing ground for QCD. It is perturbatively computable apart from a contribution from what is usually called the hadronic component of the photon. There have been many proposals for this nonperturbative part of the real photon structure function. By studying moments of the virtual photon structure function, we explore the extent to which these proposed nonperturbative contributions can be identified experimentally.
[ { "created": "Thu, 12 Aug 1993 18:02:15 GMT", "version": "v1" } ]
2010-11-01
[ [ "Kim", "Sun Myong", "" ], [ "Walsh", "Thomas F.", "" ] ]
The photon structure function is a useful testing ground for QCD. It is perturbatively computable apart from a contribution from what is usually called the hadronic component of the photon. There have been many proposals for this nonperturbative part of the real photon structure function. By studying moments of the virtual photon structure function, we explore the extent to which these proposed nonperturbative contributions can be identified experimentally.
1909.02619
Nikolaos Kidonakis
Matthew Forslund and Nikolaos Kidonakis
Soft-gluon corrections for single top quark production in association with electroweak bosons
6 pages, 6 figures; Talk presented at the 2019 Meeting of the Division of Particles and Fields of the American Physical Society (DPF2019), July 29 - August 2, 2019, Northeastern University, Boston, C1907293
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results for higher-order soft-gluon radiative corrections for single top-quark production in association with electroweak bosons, including $t\gamma$ and $tZ$ production via anomalous FCNC couplings. We provide results for the total cross sections and differential distributions at LHC energies. We use $K$-factors to show the significance of the corrections compared to leading order, and we discuss uncertainties and the importance of the results.
[ { "created": "Thu, 5 Sep 2019 20:18:33 GMT", "version": "v1" } ]
2019-09-09
[ [ "Forslund", "Matthew", "" ], [ "Kidonakis", "Nikolaos", "" ] ]
We present results for higher-order soft-gluon radiative corrections for single top-quark production in association with electroweak bosons, including $t\gamma$ and $tZ$ production via anomalous FCNC couplings. We provide results for the total cross sections and differential distributions at LHC energies. We use $K$-factors to show the significance of the corrections compared to leading order, and we discuss uncertainties and the importance of the results.
hep-ph/0601114
Alexander E. Dorokhov
A.E. Dorokhov
Nonlocal Condensates and Current-Current Correlators within the Instanton Liquid Model
10 pages, 4 figures, In honour of Professor A. Di Giacomo for his 70th birthday (Adrianofest 26-27th January 2006, Pisa, Italy). To appear in the Proceedings
null
null
null
hep-ph
null
The quark and gluon nonlocal condensates and current-current correlators are discussed within the instanton liquid model.
[ { "created": "Sat, 14 Jan 2006 07:23:50 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dorokhov", "A. E.", "" ] ]
The quark and gluon nonlocal condensates and current-current correlators are discussed within the instanton liquid model.
1712.06599
Ulrich Haisch
Ulrich Haisch and Augustinas Malinauskas
Let there be light from a second light Higgs doublet
21 pages, 14 figures; v3: matches version published in JHEP
null
10.1007/JHEP03(2018)135
CERN-TH-2017-276
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we demonstrate that the unexpected peak at around $95 \, {\rm GeV}$ as seen recently by CMS in the di-photon final state can be explained within the type-I~two-Higgs-doublet model by means of a moderately-to-strongly fermiophobic CP-even Higgs $H$. Depending on the Higgs mass spectrum, the production of such~a~$H$ arises dominantly from vector boson fusion or through a cascade in either $pp \to t \bar t$ with $\overset{(-)}{t} \to H^{\pm} \overset{(-)}{b} \to W^{\pm \, \ast} H \overset{(-)}{b}$ or $pp \to A$ with $A \to W^{\mp} H^{\pm} \to W^{\mp} W^{\pm} H$ or via $pp \to W^{\pm \, \ast} \to H^\pm H$. In this context, we also discuss other Higgs anomalies such as the LEP excess in Higgsstrahlung and the observation of enhanced rates in $t \bar t h$ at both the Tevatron and the LHC, showing that parameters capable of explaining the CMS di-photon signal can address the latter deviations as well. The Higgs spectra that we explore comprise masses between $80 \, {\rm GeV}$ and $350\, {\rm GeV}$. While at present all constraints from direct and indirect searches for spin-0 resonances can be shown to be satisfied for such light Higgses, future LHC data will be able to probe the parameter space that leads to a simultaneous explanation of the discussed anomalies.
[ { "created": "Mon, 18 Dec 2017 19:00:01 GMT", "version": "v1" }, { "created": "Sun, 24 Dec 2017 14:24:54 GMT", "version": "v2" }, { "created": "Wed, 21 Mar 2018 09:25:28 GMT", "version": "v3" } ]
2018-04-18
[ [ "Haisch", "Ulrich", "" ], [ "Malinauskas", "Augustinas", "" ] ]
In this article, we demonstrate that the unexpected peak at around $95 \, {\rm GeV}$ as seen recently by CMS in the di-photon final state can be explained within the type-I~two-Higgs-doublet model by means of a moderately-to-strongly fermiophobic CP-even Higgs $H$. Depending on the Higgs mass spectrum, the production of such~a~$H$ arises dominantly from vector boson fusion or through a cascade in either $pp \to t \bar t$ with $\overset{(-)}{t} \to H^{\pm} \overset{(-)}{b} \to W^{\pm \, \ast} H \overset{(-)}{b}$ or $pp \to A$ with $A \to W^{\mp} H^{\pm} \to W^{\mp} W^{\pm} H$ or via $pp \to W^{\pm \, \ast} \to H^\pm H$. In this context, we also discuss other Higgs anomalies such as the LEP excess in Higgsstrahlung and the observation of enhanced rates in $t \bar t h$ at both the Tevatron and the LHC, showing that parameters capable of explaining the CMS di-photon signal can address the latter deviations as well. The Higgs spectra that we explore comprise masses between $80 \, {\rm GeV}$ and $350\, {\rm GeV}$. While at present all constraints from direct and indirect searches for spin-0 resonances can be shown to be satisfied for such light Higgses, future LHC data will be able to probe the parameter space that leads to a simultaneous explanation of the discussed anomalies.
1210.1006
J. P. Ma
J. P. Ma, Q. Wang and G. P. Zhang
QCD Evolutions of Twist-3 Chirality-Odd Operators
9 pages, 2 figures
null
10.1016/j.physletb.2012.12.007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the scale dependence of twist-3 distributions defined with chirality-odd quark-gluon operators. To derive the scale dependence we explicitly calculate these distributions of multi-parton states instead of a hadron. Taking one-loop corrections into account we obtain the leading evolution kernel in the most general case. In some special cases the evolutions are simplified. We observe that the obtained kernel in general does not get simplified in the large-$N_c$ limit in contrast to the case of those twist-3 distributions defined only with chirality-odd quark operators. In the later, the simplification is significant.
[ { "created": "Wed, 3 Oct 2012 06:49:56 GMT", "version": "v1" } ]
2015-06-11
[ [ "Ma", "J. P.", "" ], [ "Wang", "Q.", "" ], [ "Zhang", "G. P.", "" ] ]
We study the scale dependence of twist-3 distributions defined with chirality-odd quark-gluon operators. To derive the scale dependence we explicitly calculate these distributions of multi-parton states instead of a hadron. Taking one-loop corrections into account we obtain the leading evolution kernel in the most general case. In some special cases the evolutions are simplified. We observe that the obtained kernel in general does not get simplified in the large-$N_c$ limit in contrast to the case of those twist-3 distributions defined only with chirality-odd quark operators. In the later, the simplification is significant.
hep-ph/9511457
Jacek Wosiek
Wolfgang Ochs (Max-Planck-Institute, Werner Heisenberg Institute) and Jacek Wosiek (Jagellonian University)
Critical Angle in the Parton Cascade
21 pages, prepared with RevTeX , 6 uufiled postscript figures
Z.Phys. C72 (1996) 263-269
10.1007/BF02909153
MPI-Ph/95-85, TPJU-17/95
hep-ph
null
The angular correlation function of partons in a jet, as derived from perturbative QCD, is nonanalytic at a critical angle which separates a multiparticle regime with scaling properties from a regime with few particles near the hadronisation scale. Some phenomenological consequences are discussed.
[ { "created": "Wed, 29 Nov 1995 16:44:09 GMT", "version": "v1" } ]
2009-10-28
[ [ "Ochs", "Wolfgang", "", "Max-Planck-Institute, Werner Heisenberg Institute" ], [ "Wosiek", "Jacek", "", "Jagellonian University" ] ]
The angular correlation function of partons in a jet, as derived from perturbative QCD, is nonanalytic at a critical angle which separates a multiparticle regime with scaling properties from a regime with few particles near the hadronisation scale. Some phenomenological consequences are discussed.
hep-ph/0112178
Daniel Magestro
Daniel Magestro (GSI-Darmstadt)
Evidence for chemical equilibration at RHIC
Talk presented at Strange Quarks in Matter 2001, Frankfurt, September 24-29, 2001. Proceedings to be published by J. Phys. G. 8 pages with 4 figures
J.Phys.G28:1745-1752,2002
10.1088/0954-3899/28/7/328
null
hep-ph
null
This contribution focuses on the results of statistical model calculations at RHIC energies, including recently available experimental data. Previous calculations of particle yield ratios showed good agreement with measurements at SPS and lower energies, suggesting that the composite system possesses a high degree of chemical equilibrium at freeze-out. The effect of feeddown contamination on the model parameters is discussed, and the sensitivity of individual ratios to the model parameters ($T$, $\mu_B$) is illustrated.
[ { "created": "Thu, 13 Dec 2001 12:54:05 GMT", "version": "v1" } ]
2008-11-26
[ [ "Magestro", "Daniel", "", "GSI-Darmstadt" ] ]
This contribution focuses on the results of statistical model calculations at RHIC energies, including recently available experimental data. Previous calculations of particle yield ratios showed good agreement with measurements at SPS and lower energies, suggesting that the composite system possesses a high degree of chemical equilibrium at freeze-out. The effect of feeddown contamination on the model parameters is discussed, and the sensitivity of individual ratios to the model parameters ($T$, $\mu_B$) is illustrated.
1610.05382
Jean-Philippe Lansberg
Jean-Philippe Lansberg, Hua-Sheng Shao
Towards an automated tool to evaluate the impact of the nuclear modification of the gluon density on quarkonium, D and B meson production in proton-nucleus collisions
18 pages, 56 figures, 4 tables. Latex
null
10.1140/epjc/s10052-016-4575-x
CERN-TH-2016-206
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple and model-independent procedure to account for the impact of the nuclear modification of the gluon density as encoded in nuclear collinear PDF sets on two-to-two partonic hard processes in proton-nucleus collisions. This applies to a good approximation to quarkonium, D and B meson production, generically referred to H. Our procedure consists in parametrising the square of the parton scattering amplitude, A_{gg -> H X} and constraining it from the proton-proton data. Doing so, we have been able to compute the corresponding nuclear modification factors for J/psi, Upsilon and D^0 as a function of y and P_T at sqrt(s_NN)=5 and 8 TeV in the kinematics of the various LHC experiments in a model independent way. It is of course justified since the most important ingredient in such evaluations is the probability of each kinematical configuration. Our computations for D mesons can also be extended to B meson production. To further illustrate the potentiality of the tool, we provide --for the first time-- predictions for the nuclear modification factor for eta_c production in pPb collisions at the LHC.
[ { "created": "Mon, 17 Oct 2016 23:40:03 GMT", "version": "v1" } ]
2016-12-30
[ [ "Lansberg", "Jean-Philippe", "" ], [ "Shao", "Hua-Sheng", "" ] ]
We propose a simple and model-independent procedure to account for the impact of the nuclear modification of the gluon density as encoded in nuclear collinear PDF sets on two-to-two partonic hard processes in proton-nucleus collisions. This applies to a good approximation to quarkonium, D and B meson production, generically referred to H. Our procedure consists in parametrising the square of the parton scattering amplitude, A_{gg -> H X} and constraining it from the proton-proton data. Doing so, we have been able to compute the corresponding nuclear modification factors for J/psi, Upsilon and D^0 as a function of y and P_T at sqrt(s_NN)=5 and 8 TeV in the kinematics of the various LHC experiments in a model independent way. It is of course justified since the most important ingredient in such evaluations is the probability of each kinematical configuration. Our computations for D mesons can also be extended to B meson production. To further illustrate the potentiality of the tool, we provide --for the first time-- predictions for the nuclear modification factor for eta_c production in pPb collisions at the LHC.
0710.0525
Luis Anchordoqui
Luis A. Anchordoqui, Antonio Delgado, Carlos A. Garcia Canal, Sergio J. Sciutto
Hunting long-lived gluinos at the Pierre Auger Observatory
13 pages revtex, 9 eps figures. A ps version with high resolution figures is available at http://www.hep.physics.neu.edu/staff/doqui/rhadron_highres.ps
Phys.Rev.D77:023009,2008
10.1103/PhysRevD.77.023009
CERN-PH-TH/2007-120
hep-ph
null
Eventual signals of split sypersymmetry in cosmic ray physics are analyzed in detail. The study focusses particularly on quasi-stable colorless R-hadrons originating through confinement of long-lived gluinos (with quarks, anti-quarks, and gluons) produced in pp collisions at astrophysical sources. Because of parton density requirements, the gluino has a momentum which is considerable smaller than the energy of the primary proton, and so production of heavy (mass ~ 500 GeV) R-hadrons requires powerful cosmic ray engines able to accelerate particles up to extreme energies, somewhat above 10^{13.6} GeV. Using a realistic Monte Carlo simulation with the AIRES engine, we study the main characteristics of the air showers triggered when one of these exotic hadrons impinges on a stationary nucleon of the Earth atmosphere. We show that R-hadron air showers present clear differences with respect to those initiated by standard particles. We use this shower characteristics to construct observables which may be used to distinguish long-lived gluinos at the Pierre Auger Observatory.
[ { "created": "Tue, 2 Oct 2007 13:24:40 GMT", "version": "v1" } ]
2008-11-26
[ [ "Anchordoqui", "Luis A.", "" ], [ "Delgado", "Antonio", "" ], [ "Canal", "Carlos A. Garcia", "" ], [ "Sciutto", "Sergio J.", "" ] ]
Eventual signals of split sypersymmetry in cosmic ray physics are analyzed in detail. The study focusses particularly on quasi-stable colorless R-hadrons originating through confinement of long-lived gluinos (with quarks, anti-quarks, and gluons) produced in pp collisions at astrophysical sources. Because of parton density requirements, the gluino has a momentum which is considerable smaller than the energy of the primary proton, and so production of heavy (mass ~ 500 GeV) R-hadrons requires powerful cosmic ray engines able to accelerate particles up to extreme energies, somewhat above 10^{13.6} GeV. Using a realistic Monte Carlo simulation with the AIRES engine, we study the main characteristics of the air showers triggered when one of these exotic hadrons impinges on a stationary nucleon of the Earth atmosphere. We show that R-hadron air showers present clear differences with respect to those initiated by standard particles. We use this shower characteristics to construct observables which may be used to distinguish long-lived gluinos at the Pierre Auger Observatory.
1309.6332
Samuel Wallon
A. Besse, L. Szymanowski and S. Wallon
High energy rho meson leptoproduction
6 pages, 3 figures, proceedings of the International Workshop on Low X Physics, May 30 - June 4 2013, Rehovot and Eilat, Israel
null
null
LPT-ORSAY-13-63
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the longitudinal and transverse polarized cross-sections of the leptoproduction of the rho meson in the high energy limit. Our model is based on the computation of the impact factor gamma*(lambda_gamma) -> rho(lambda_rho) using the twist expansion in the forward limit and expressed in the impact parameter space. This treatment involves in the final stage the twist 2 and twist 3 distribution amplitudes (DAs) of the rho meson and the dipole scattering amplitude. Taking models that exist for the DAs and for the dipole cross-section, we get a phenomenological model for the helicity amplitudes, we compare our predictions with HERA data and get a fairly good description for large enough virtualities of the photon.
[ { "created": "Tue, 24 Sep 2013 20:08:21 GMT", "version": "v1" } ]
2013-09-26
[ [ "Besse", "A.", "" ], [ "Szymanowski", "L.", "" ], [ "Wallon", "S.", "" ] ]
We investigate the longitudinal and transverse polarized cross-sections of the leptoproduction of the rho meson in the high energy limit. Our model is based on the computation of the impact factor gamma*(lambda_gamma) -> rho(lambda_rho) using the twist expansion in the forward limit and expressed in the impact parameter space. This treatment involves in the final stage the twist 2 and twist 3 distribution amplitudes (DAs) of the rho meson and the dipole scattering amplitude. Taking models that exist for the DAs and for the dipole cross-section, we get a phenomenological model for the helicity amplitudes, we compare our predictions with HERA data and get a fairly good description for large enough virtualities of the photon.
1408.6648
Vladimir Braun M
V.M. Braun and A. N. Manashov
QCD evolution equations from conformal symmetry
8 pages, contribution to the proceedings of the conferences "Loops and Legs in Quantum Field Theory", April 27 - May 02, 2014, Weimar, Germany, and "QCD Evolution Workshop", May 12-16, 2014, Santa Fe, USA
null
10.1142/S2010194515600484
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
QCD evolution equations in $\text{MS}$-like schemes can be recovered from the same equations in a modified theory, QCD in non-integer $d=4-2\epsilon$ dimensions, which enjoys exact scale and conformal invariance at the critical point. Restrictions imposed by the conformal symmetry of the modified theory allow one to obtain complete evolution kernels in integer (physical) dimensions at the given order of perturbation theory from the spectrum of anomalous dimensions added by the calculation of the special conformal anomaly at one order less. We use this technique to derive two-loop evolution equations for flavor-nonsinglet quark-antiquark light-ray operators that encode the scale dependence of generalized hadron parton distributions.
[ { "created": "Thu, 28 Aug 2014 08:36:12 GMT", "version": "v1" } ]
2015-06-22
[ [ "Braun", "V. M.", "" ], [ "Manashov", "A. N.", "" ] ]
QCD evolution equations in $\text{MS}$-like schemes can be recovered from the same equations in a modified theory, QCD in non-integer $d=4-2\epsilon$ dimensions, which enjoys exact scale and conformal invariance at the critical point. Restrictions imposed by the conformal symmetry of the modified theory allow one to obtain complete evolution kernels in integer (physical) dimensions at the given order of perturbation theory from the spectrum of anomalous dimensions added by the calculation of the special conformal anomaly at one order less. We use this technique to derive two-loop evolution equations for flavor-nonsinglet quark-antiquark light-ray operators that encode the scale dependence of generalized hadron parton distributions.
hep-ph/9501301
null
M. H. Friedman
ANOTHER LOOK AT THE EINSTEIN-MAXWELL EQUATIONS
6 pages, Latex
null
null
null
hep-ph
null
An electric monopole solution to the equations of Maxwell and Einstein's general relativity is displayed. It differs from the usual one in that all components of the metric vanish at large spatial distances from the charge rather than approaching the Minkowski metric. This enables us to find an approximate solution to that for many charges.
[ { "created": "Sun, 15 Jan 1995 05:22:07 GMT", "version": "v1" } ]
2016-09-01
[ [ "Friedman", "M. H.", "" ] ]
An electric monopole solution to the equations of Maxwell and Einstein's general relativity is displayed. It differs from the usual one in that all components of the metric vanish at large spatial distances from the charge rather than approaching the Minkowski metric. This enables us to find an approximate solution to that for many charges.
hep-ph/9508329
Chun Eung Jin
E.J. Chun, A.S. Yoshipura, A.Yu. Smirnov
Light Singlet Fermions and Neutrino Physics
12 pages, Latex, 1 figure included (Talk presented at the workshop Valencia 95)
null
null
IC/95/240
hep-ph
null
The existence of a light singlet fermion mixed with the electron neutrino is hinted by the simultaneous explanation of various neutrino anomalies. We show that supersymmetry can provide a natural framework for the existence and the desired properties of such a fermion. Quasi Goldstone fermions (QGF) of spontaneously broken global symmetries like the Peccei-Quinn symmetry or lepton number can mix properly with the neutrinos provided the presence of the R-parity breaking term $\e LH_2$. The lightness of QGF can be a consequence of non-minimal K\"ahler potentials like that of no-scale supergravity. In order to keep R-parity, such a sterile component has to be placed in a new singlet superfield with no vacuum expectation value. In the context of the standard seesaw mechanism the lightness of such a singlet can be understood by imposing a $R$-symmetry.
[ { "created": "Fri, 18 Aug 1995 10:21:10 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chun", "E. J.", "" ], [ "Yoshipura", "A. S.", "" ], [ "Smirnov", "A. Yu.", "" ] ]
The existence of a light singlet fermion mixed with the electron neutrino is hinted by the simultaneous explanation of various neutrino anomalies. We show that supersymmetry can provide a natural framework for the existence and the desired properties of such a fermion. Quasi Goldstone fermions (QGF) of spontaneously broken global symmetries like the Peccei-Quinn symmetry or lepton number can mix properly with the neutrinos provided the presence of the R-parity breaking term $\e LH_2$. The lightness of QGF can be a consequence of non-minimal K\"ahler potentials like that of no-scale supergravity. In order to keep R-parity, such a sterile component has to be placed in a new singlet superfield with no vacuum expectation value. In the context of the standard seesaw mechanism the lightness of such a singlet can be understood by imposing a $R$-symmetry.
1709.03148
Kazem Azizi
S. S. Agaev, K. Azizi, H. Sundu
Spectroscopic parameters and decays of the resonance $Z_b(10610)$
12 Pages, 5 Figures and 2 Tables
null
10.1140/epjc/s10052-017-5421-5
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The resonance $Z_b(10610)$ is investigated as the diquark-antidiquark $ Z_b=[bu][\overline b \overline d]$ state with spin-parities $J^{PC}=1^{+-}$. The mass and current coupling of the resonance $Z_b(10610)$ are evaluated using QCD two-point sum rule and taking into account the vacuum condensates up to ten dimensions. We study the vertices $ Z_b\Upsilon(nS)\pi\ (n=1,2,3)$ by applying the QCD light-cone sum rule to compute the corresponding strong couplings $g_{Z_b\Upsilon(nS)\pi}$ and widths of the decays $Z_b \to \Upsilon(nS)\pi$. We explore also the vertices $Z_b h_{b}(mP)\pi\ (m=1,2)$ and calculate the couplings $g_{Z_b h_{b}(mP)\pi}$ and width of the decay channels $Z_b \to h_{b}(mP)\pi$. To this end, we calculate the mass and decay constants of the $h_b(1P)$ and $h_b(2P) $ mesons. The results obtained are compared with experimental data of the Belle Collaboration.
[ { "created": "Sun, 10 Sep 2017 17:59:31 GMT", "version": "v1" }, { "created": "Sun, 26 Nov 2017 11:10:08 GMT", "version": "v2" } ]
2018-01-17
[ [ "Agaev", "S. S.", "" ], [ "Azizi", "K.", "" ], [ "Sundu", "H.", "" ] ]
The resonance $Z_b(10610)$ is investigated as the diquark-antidiquark $ Z_b=[bu][\overline b \overline d]$ state with spin-parities $J^{PC}=1^{+-}$. The mass and current coupling of the resonance $Z_b(10610)$ are evaluated using QCD two-point sum rule and taking into account the vacuum condensates up to ten dimensions. We study the vertices $ Z_b\Upsilon(nS)\pi\ (n=1,2,3)$ by applying the QCD light-cone sum rule to compute the corresponding strong couplings $g_{Z_b\Upsilon(nS)\pi}$ and widths of the decays $Z_b \to \Upsilon(nS)\pi$. We explore also the vertices $Z_b h_{b}(mP)\pi\ (m=1,2)$ and calculate the couplings $g_{Z_b h_{b}(mP)\pi}$ and width of the decay channels $Z_b \to h_{b}(mP)\pi$. To this end, we calculate the mass and decay constants of the $h_b(1P)$ and $h_b(2P) $ mesons. The results obtained are compared with experimental data of the Belle Collaboration.
2009.13667
Jo\~ao Barata
Joao Barata, Yacine Mehtar-Tani, Alba Soto-Ontoso, Konrad Tywoniuk
Revisiting transverse momentum broadening in dense QCD media
Fixed typos from previous version. Main results unchanged; figures were updated. Matches published version
Phys. Rev. D 104, 054047 (2021)
10.1103/PhysRevD.104.054047
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We reconsider the problem of transverse momentum broadening of a highly-energetic parton suffering multiple scatterings in dense colored media, such as the thermal Quark-Gluon plasma or large nuclei. In the framework of Moli\`ere's theory of multiple scattering we re-derive a simple analytic formula, to be used in jet quenching phenomenology, that accounts for both the multiple soft and hard Rutherford scattering regimes. Further, we discuss the sensitivity of momentum broadening to modeling of the non-perturbative infrared sector by presenting a detailed analytic and numerical comparison between the two widely used models in phenomenology: the Hard Thermal Loop and the Gyulassy-Wang potentials. We show that for the relevant values of the parameters the non-universal, model dependent contributions are negligible, at LHC, RHIC and EIC energies thus consolidating the predictive power of jet quenching theory.
[ { "created": "Mon, 28 Sep 2020 22:36:34 GMT", "version": "v1" }, { "created": "Sun, 12 Sep 2021 22:23:52 GMT", "version": "v2" } ]
2021-10-04
[ [ "Barata", "Joao", "" ], [ "Mehtar-Tani", "Yacine", "" ], [ "Soto-Ontoso", "Alba", "" ], [ "Tywoniuk", "Konrad", "" ] ]
We reconsider the problem of transverse momentum broadening of a highly-energetic parton suffering multiple scatterings in dense colored media, such as the thermal Quark-Gluon plasma or large nuclei. In the framework of Moli\`ere's theory of multiple scattering we re-derive a simple analytic formula, to be used in jet quenching phenomenology, that accounts for both the multiple soft and hard Rutherford scattering regimes. Further, we discuss the sensitivity of momentum broadening to modeling of the non-perturbative infrared sector by presenting a detailed analytic and numerical comparison between the two widely used models in phenomenology: the Hard Thermal Loop and the Gyulassy-Wang potentials. We show that for the relevant values of the parameters the non-universal, model dependent contributions are negligible, at LHC, RHIC and EIC energies thus consolidating the predictive power of jet quenching theory.
2302.01718
Zhi-Gang Wang
Xiao-Song Yang, Qi Xin, Zhi-Gang Wang
Analysis of the $T_{c\bar{s}}(2900)$ and related tetraquark states with the QCD sum rules
20 pages, 7 figures
Int. J. Mod. Phys. A38 (2023) 2350056
10.1142/S0217751X23500562
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this research, we tentatively assign the $T_{c\bar{s}}(2900)$ as the $A\bar{A}$-type tetraquark state, and study the mass spectrum of the tetraquark states with strange and doubly strange, which have the spin-parity $J^P = 0^+$, $1^+$ and $2^+$, in the framework of the QCD sum rules in details, where the $A$ denotes the axialvector diquark state. The predicted mass $M=2.92\pm0.12\,\rm{GeV}$ is in consistent with the experimental values $M=2.892\pm0.014\pm0.015\,\rm{GeV}$ and $2.921\pm0.017\pm0.020\,\rm{GeV}$ from the LHCb collaboration and supports assigning the $T_{c\bar{s}}(2900)$ to be the $A\bar{A}$-type scalar $c\bar{s}q\bar{q}$ tetraquark state. The predictions for other tetraquark states can be confronted to the experimental data in the future to diagnose the nature of the fully open flavor exotic states.
[ { "created": "Fri, 3 Feb 2023 13:14:43 GMT", "version": "v1" }, { "created": "Mon, 17 Apr 2023 13:45:41 GMT", "version": "v2" } ]
2023-06-16
[ [ "Yang", "Xiao-Song", "" ], [ "Xin", "Qi", "" ], [ "Wang", "Zhi-Gang", "" ] ]
In this research, we tentatively assign the $T_{c\bar{s}}(2900)$ as the $A\bar{A}$-type tetraquark state, and study the mass spectrum of the tetraquark states with strange and doubly strange, which have the spin-parity $J^P = 0^+$, $1^+$ and $2^+$, in the framework of the QCD sum rules in details, where the $A$ denotes the axialvector diquark state. The predicted mass $M=2.92\pm0.12\,\rm{GeV}$ is in consistent with the experimental values $M=2.892\pm0.014\pm0.015\,\rm{GeV}$ and $2.921\pm0.017\pm0.020\,\rm{GeV}$ from the LHCb collaboration and supports assigning the $T_{c\bar{s}}(2900)$ to be the $A\bar{A}$-type scalar $c\bar{s}q\bar{q}$ tetraquark state. The predictions for other tetraquark states can be confronted to the experimental data in the future to diagnose the nature of the fully open flavor exotic states.
hep-ph/0512267
Graciela B. Gelmini
Graciela B. Gelmini
GZK photons as UHECR above 10$^{19}$ eV
Talk given at TAUP2005, Sept. 10-14 2005, Zaragoza (Spain); 3 pages, 2 figures
J.Phys.Conf.Ser. 39 (2006) 419-421
10.1088/1742-6596/39/1/108
UCLA/05/TEP/32
hep-ph
null
"GZK photons" are produced by extragalactic nucleons through the resonant photoproduction of pions. We present the expected range of the GZK photon fraction of UHECR, assuming a particular UHECR spectrum and primary nucleons, and compare it with the minimal photon fraction predicted by Top-Down models.
[ { "created": "Tue, 20 Dec 2005 23:25:02 GMT", "version": "v1" } ]
2009-11-11
[ [ "Gelmini", "Graciela B.", "" ] ]
"GZK photons" are produced by extragalactic nucleons through the resonant photoproduction of pions. We present the expected range of the GZK photon fraction of UHECR, assuming a particular UHECR spectrum and primary nucleons, and compare it with the minimal photon fraction predicted by Top-Down models.
0710.4463
Sascha Vogel
S.Vogel, H. Petersen, K. Schmidt, E. Santini, C. Sturm, J. Aichelin and M. Bleicher
How Sensitive are Di-Leptons from Rho Mesons to the High Baryon Density Region?
8 pages, 6 figures, expanded version
Phys.Rev.C78:044909,2008
10.1103/PhysRevC.78.044909
null
hep-ph
null
We show that the measurement of di-leptons might provide only a restricted view into the most dense stages of heavy ion reactions. Thus, possible studies of meson and baryon properties at high baryon densities, as e.g. done at GSI-HADES and envisioned for FAIR-CBM, might observe weaker effects than currently expected in certain approaches. We argue that the strong absorption of resonances in the high baryon density region of the heavy ion collision masks information from the early hot and dense phase due to a strong increase of the total decay width because of collisional broadening. To obtain additional information, we also compare the currently used approaches to extract di-leptons from transport simulations - i.e. shining, only vector mesons from final baryon resonance decays and instant emission of di-leptons and find a strong sensitivity on the method employed in particular at FAIR and SPS energies. It is shown explicitly that a restriction to rho meson (and therefore di-lepton) production only in final state baryon resonance decays provide a strong bias towards rather low baryon densities. The results presented are obtained from UrQMD v2.3 calculations using the standard set-up.
[ { "created": "Wed, 24 Oct 2007 13:16:22 GMT", "version": "v1" }, { "created": "Tue, 20 May 2008 14:12:28 GMT", "version": "v2" } ]
2008-11-26
[ [ "Vogel", "S.", "" ], [ "Petersen", "H.", "" ], [ "Schmidt", "K.", "" ], [ "Santini", "E.", "" ], [ "Sturm", "C.", "" ], [ "Aichelin", "J.", "" ], [ "Bleicher", "M.", "" ] ]
We show that the measurement of di-leptons might provide only a restricted view into the most dense stages of heavy ion reactions. Thus, possible studies of meson and baryon properties at high baryon densities, as e.g. done at GSI-HADES and envisioned for FAIR-CBM, might observe weaker effects than currently expected in certain approaches. We argue that the strong absorption of resonances in the high baryon density region of the heavy ion collision masks information from the early hot and dense phase due to a strong increase of the total decay width because of collisional broadening. To obtain additional information, we also compare the currently used approaches to extract di-leptons from transport simulations - i.e. shining, only vector mesons from final baryon resonance decays and instant emission of di-leptons and find a strong sensitivity on the method employed in particular at FAIR and SPS energies. It is shown explicitly that a restriction to rho meson (and therefore di-lepton) production only in final state baryon resonance decays provide a strong bias towards rather low baryon densities. The results presented are obtained from UrQMD v2.3 calculations using the standard set-up.
2203.02758
Wasif Husain
Wasif Husain, Theo F. Motta and Anthony W. Thomas
Consequences of neutron decay inside neutron stars
6 figures
null
10.1088/1475-7516/2022/10/028
null
hep-ph nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
The hypothesis that neutrons might decay into dark matter is explored using neutron stars as a testing ground. It is found that in order to obtain stars with masses at the upper end of those observed, the dark matter must experience a relatively strong self-interaction. Conservation of baryon number and energy then require that the star must undergo some heating, with a decrease in radius, leading to an increase in speed of rotation over a period of days.
[ { "created": "Sat, 5 Mar 2022 14:24:48 GMT", "version": "v1" }, { "created": "Mon, 14 Mar 2022 02:10:23 GMT", "version": "v2" }, { "created": "Thu, 11 Aug 2022 05:13:30 GMT", "version": "v3" } ]
2022-10-26
[ [ "Husain", "Wasif", "" ], [ "Motta", "Theo F.", "" ], [ "Thomas", "Anthony W.", "" ] ]
The hypothesis that neutrons might decay into dark matter is explored using neutron stars as a testing ground. It is found that in order to obtain stars with masses at the upper end of those observed, the dark matter must experience a relatively strong self-interaction. Conservation of baryon number and energy then require that the star must undergo some heating, with a decrease in radius, leading to an increase in speed of rotation over a period of days.
1910.13482
Antonio Costantini
Antonio Costantini
BSM Physics from Enlarged Gauge Symmetry: the 331 Model, a case of study
6 pages, 2 figures, 1 table. Contribution for the European Physical Society Conference on High Energy Physics - EPS-HEP2019
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the most relevant features of a BSM model with extra gauge symmetry, the so called 331 model. The gauge group is $SU(3)_c\times SU(3)_L \times U(1)_X$ impling the presence of extra gauge bosons, both charged and neutral, as well as extra/exotic fermions and an enlarged scalar sector. We present the relevant phenomenology of doubly-charged gauge bosons, which are a distinctive feature of a version of the 331 model, and discuss the role of BSM phenomenology as a tool for testing GUT (inspired) theories.
[ { "created": "Tue, 29 Oct 2019 19:11:04 GMT", "version": "v1" } ]
2019-10-31
[ [ "Costantini", "Antonio", "" ] ]
We discuss the most relevant features of a BSM model with extra gauge symmetry, the so called 331 model. The gauge group is $SU(3)_c\times SU(3)_L \times U(1)_X$ impling the presence of extra gauge bosons, both charged and neutral, as well as extra/exotic fermions and an enlarged scalar sector. We present the relevant phenomenology of doubly-charged gauge bosons, which are a distinctive feature of a version of the 331 model, and discuss the role of BSM phenomenology as a tool for testing GUT (inspired) theories.
2002.04553
Kazem Azizi
S. S. Agaev, K. Azizi, B. Barsbay, H. Sundu
A family of double-beauty tetraquarks: Axial-vector state $T_{bb;\bar{u}\bar{s}}^{-}$
14 Pages, 5 Figures and 3 Tables. To be published in Chinese Physics C
null
10.1088/1674-1137/abc16d
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The spectroscopic parameters and decay channels of the axial-vector tetraquark $T_{bb;\overline{u}\overline{s}}^{-}$ (in what follows, $T_{b: \overline{s}}^{\mathrm{AV}}$) are explored using the quantum chromodynamics (QCD) sum rule method. The mass and coupling of this state are calculated using two-point sum rules by taking into account various vacuum condensates, up to 10 dimensions. Our prediction for the mass of this state $m=(10215\pm 250)~ \mathrm{MeV}$ confirms that it is stable with respect to strong and electromagnetic decays and can dissociate to conventional mesons only via weak transformations. We investigate the dominant semileptonic $T_{b:\overline{s} }^{\mathrm{AV}} \to \mathcal{Z}_{b:\overline{s}}^{0}l\overline{\nu}_l$ and nonleptonic $T_{b:\overline{s}}^{\mathrm{AV}} \to \mathcal{Z}_{b:\overline{s} }^{0}M$ decays of $T_{b:\overline{s}}^{\mathrm{AV}}$. In these processes, $ \mathcal{Z}_{b:\overline{s}}^{0}$ is a scalar tetraquark $[bc][\overline{u} \overline{s}]$ built of a color-triplet diquark and an antidiquark, whereas $M$ is one of the vector mesons $\rho ^{-}$, $K^{\ast}(892)$, $D^{\ast }(2010)^{-}$, and $D_{s}^{\ast -}$. To calculate the partial widths of these decays, we use the QCD three-point sum rule approach and evaluate the weak transition form factors $G_{i}$ $(i=0,1,2,3)$, which govern these processes. The full width $\Gamma _{\mathrm{full}} =(12.9\pm 2.1)\times 10^{-8}~\mathrm{MeV}$ and the mean lifetime $ \tau=5.1_{-0.71}^{+0.99}~\mathrm{fs}$ of the tetraquark $T_{b:\overline{s}}^{ \mathrm{AV}}$ are computed using the aforementioned weak decays. The obtained information about the parameters of $T_{b:\overline{s}}^{\mathrm{AV}}$ and $ \mathcal{Z}_{b:\overline{s}}^{0}$ is useful for experimental investigations of these double-heavy exotic mesons.
[ { "created": "Tue, 11 Feb 2020 17:18:28 GMT", "version": "v1" }, { "created": "Mon, 2 Mar 2020 08:56:22 GMT", "version": "v2" }, { "created": "Tue, 1 Sep 2020 04:10:16 GMT", "version": "v3" }, { "created": "Fri, 23 Oct 2020 16:25:22 GMT", "version": "v4" } ]
2021-02-03
[ [ "Agaev", "S. S.", "" ], [ "Azizi", "K.", "" ], [ "Barsbay", "B.", "" ], [ "Sundu", "H.", "" ] ]
The spectroscopic parameters and decay channels of the axial-vector tetraquark $T_{bb;\overline{u}\overline{s}}^{-}$ (in what follows, $T_{b: \overline{s}}^{\mathrm{AV}}$) are explored using the quantum chromodynamics (QCD) sum rule method. The mass and coupling of this state are calculated using two-point sum rules by taking into account various vacuum condensates, up to 10 dimensions. Our prediction for the mass of this state $m=(10215\pm 250)~ \mathrm{MeV}$ confirms that it is stable with respect to strong and electromagnetic decays and can dissociate to conventional mesons only via weak transformations. We investigate the dominant semileptonic $T_{b:\overline{s} }^{\mathrm{AV}} \to \mathcal{Z}_{b:\overline{s}}^{0}l\overline{\nu}_l$ and nonleptonic $T_{b:\overline{s}}^{\mathrm{AV}} \to \mathcal{Z}_{b:\overline{s} }^{0}M$ decays of $T_{b:\overline{s}}^{\mathrm{AV}}$. In these processes, $ \mathcal{Z}_{b:\overline{s}}^{0}$ is a scalar tetraquark $[bc][\overline{u} \overline{s}]$ built of a color-triplet diquark and an antidiquark, whereas $M$ is one of the vector mesons $\rho ^{-}$, $K^{\ast}(892)$, $D^{\ast }(2010)^{-}$, and $D_{s}^{\ast -}$. To calculate the partial widths of these decays, we use the QCD three-point sum rule approach and evaluate the weak transition form factors $G_{i}$ $(i=0,1,2,3)$, which govern these processes. The full width $\Gamma _{\mathrm{full}} =(12.9\pm 2.1)\times 10^{-8}~\mathrm{MeV}$ and the mean lifetime $ \tau=5.1_{-0.71}^{+0.99}~\mathrm{fs}$ of the tetraquark $T_{b:\overline{s}}^{ \mathrm{AV}}$ are computed using the aforementioned weak decays. The obtained information about the parameters of $T_{b:\overline{s}}^{\mathrm{AV}}$ and $ \mathcal{Z}_{b:\overline{s}}^{0}$ is useful for experimental investigations of these double-heavy exotic mesons.