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0811.2839
Yoshio Koide
Yoshio Koide and Hiroyuki Nishiura
Maximal CP Violation Hypothesis and a Lepton Mixing Matrix
10 pages, 4 figure, version in Phys.Rev.D
Phys.Rev.D79:093005,2009
10.1103/PhysRevD.79.093005
OU-HET 629/2009
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Maximal CP violation hypothesis is applied to a simple lepton mixing matrix form U=V_{CKM}^\dagger U_{TB}, which has recently been speculated under an ansatz that U becomes an exact tribimaximal mixing U_{TB} in a limit of the quark mixing matrix V_{CKM} \to {\bf 1}. The prediction \tan^2 \theta_{12} =1/2 in the case of the exact tribimaximal mixing U=U_{TB} is onsiderably spoiled in the speculated mixing U=V_{CKM}^\dagger U_{TB}. However, the application of the hypothesis to the lepton sector can again recover the spoiled value to \tan^2 \theta_{12} \simeq 1/2 if the original Kobayashi-Maskawa phase convention for V_{CKM} is adopted.
[ { "created": "Tue, 18 Nov 2008 05:41:59 GMT", "version": "v1" }, { "created": "Tue, 25 Nov 2008 05:59:44 GMT", "version": "v2" }, { "created": "Thu, 30 Apr 2009 09:30:35 GMT", "version": "v3" } ]
2010-04-28
[ [ "Koide", "Yoshio", "" ], [ "Nishiura", "Hiroyuki", "" ] ]
Maximal CP violation hypothesis is applied to a simple lepton mixing matrix form U=V_{CKM}^\dagger U_{TB}, which has recently been speculated under an ansatz that U becomes an exact tribimaximal mixing U_{TB} in a limit of the quark mixing matrix V_{CKM} \to {\bf 1}. The prediction \tan^2 \theta_{12} =1/2 in the case of the exact tribimaximal mixing U=U_{TB} is onsiderably spoiled in the speculated mixing U=V_{CKM}^\dagger U_{TB}. However, the application of the hypothesis to the lepton sector can again recover the spoiled value to \tan^2 \theta_{12} \simeq 1/2 if the original Kobayashi-Maskawa phase convention for V_{CKM} is adopted.
hep-ph/9507337
V. Belyaev
V. M. Belyaev and A. V. Radyushkin
Quark-Hadron Duality and $\gamma^* p \to \Delta$ Form Factors
15 pages, LaTeX + 4 PS-figures enclosed in one uuencoded, compressed file
Phys.Lett.B359:194-200,1995
10.1016/0370-2693(95)01048-U
CEBAF-TH-95-11
hep-ph
null
We use local quark-hadron duality to estimate the purely nonperturbative soft contribution to the $\gamma^*p\to \Delta$ form factors. Our results are in agreement with existing experimental data. We predict that the ratio $G_E^*(Q^2)/G_M^*(Q^2)$ is small for all accessible $Q^2$, in contrast to the pQCD expectations that $G_E^*(Q^2)\to -G_M^*(Q^2)$.
[ { "created": "Tue, 18 Jul 1995 23:42:40 GMT", "version": "v1" } ]
2014-11-17
[ [ "Belyaev", "V. M.", "" ], [ "Radyushkin", "A. V.", "" ] ]
We use local quark-hadron duality to estimate the purely nonperturbative soft contribution to the $\gamma^*p\to \Delta$ form factors. Our results are in agreement with existing experimental data. We predict that the ratio $G_E^*(Q^2)/G_M^*(Q^2)$ is small for all accessible $Q^2$, in contrast to the pQCD expectations that $G_E^*(Q^2)\to -G_M^*(Q^2)$.
1008.4345
Ian Clo\"et
Ian C. Cloet and Gerald A. Miller
Third Zemach Moment of the Proton
3 pages, three figures
Phys.Rev.C83:012201,2011
10.1103/PhysRevC.83.012201
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Modern electron scattering experiments have determined the proton electric form factor, G_{Ep}(Q^2), to high precision. We utilize this data, represented by the different form factor parametrizations, to compute the third Zemach moment of the proton charge distribution. We find that existing data rule out a value of the third Zemach moment large enough to explain the current puzzle with the proton charge radius determined from the Lamb shift in muonic hydrogen. This is in contrast with the recent claim of De Rujula [arXiv:1008.3861].
[ { "created": "Wed, 25 Aug 2010 19:29:22 GMT", "version": "v1" }, { "created": "Tue, 31 Aug 2010 16:30:23 GMT", "version": "v2" }, { "created": "Thu, 9 Sep 2010 00:06:55 GMT", "version": "v3" } ]
2011-02-28
[ [ "Cloet", "Ian C.", "" ], [ "Miller", "Gerald A.", "" ] ]
Modern electron scattering experiments have determined the proton electric form factor, G_{Ep}(Q^2), to high precision. We utilize this data, represented by the different form factor parametrizations, to compute the third Zemach moment of the proton charge distribution. We find that existing data rule out a value of the third Zemach moment large enough to explain the current puzzle with the proton charge radius determined from the Lamb shift in muonic hydrogen. This is in contrast with the recent claim of De Rujula [arXiv:1008.3861].
1611.04297
Bernard Pire
B. Pire, K. Semenov-Tian-Shansky, L. Szymanowski
Baryon-to-meson transition distribution amplitudes: formalism and models
8 pages, to be published in the proceedings of the the Light Cone 2016 Conference, Lisbon, Portugal, September 5 - 8, 2016
null
10.1007/s00601-017-1244-z
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In specific kinematics, hard exclusive amplitudes may be factorized into a short distance dominated part computable in a perturbative way on the one hand, and universal, confinement related hadronic matrix elements on the other hand. The extension of this description to processes such as backward meson electroproduction and forward meson production in antiproton-nucleon scattering leads to define new hadronic matrix elements of three quark operators on the light cone, the nucleon-to-meson transition distribution amplitudes, which shed a new light on the nucleon structure.
[ { "created": "Mon, 14 Nov 2016 09:39:17 GMT", "version": "v1" } ]
2017-03-08
[ [ "Pire", "B.", "" ], [ "Semenov-Tian-Shansky", "K.", "" ], [ "Szymanowski", "L.", "" ] ]
In specific kinematics, hard exclusive amplitudes may be factorized into a short distance dominated part computable in a perturbative way on the one hand, and universal, confinement related hadronic matrix elements on the other hand. The extension of this description to processes such as backward meson electroproduction and forward meson production in antiproton-nucleon scattering leads to define new hadronic matrix elements of three quark operators on the light cone, the nucleon-to-meson transition distribution amplitudes, which shed a new light on the nucleon structure.
0712.0780
Arlene Cristina Aguilar
A. C. Aguilar, J. Papavassiliou
Infrared finite ghost propagator in the Feynman gauge
22 pages, 9 figures
Phys.Rev.D77:125022,2008
10.1103/PhysRevD.77.125022
null
hep-ph
null
We demonstrate how to obtain from the Schwinger-Dyson equations of QCD an infrared finite ghost propagator in the Feynman gauge. The key ingredient in this construction is the longitudinal form factor of the non-perturbative gluon-ghost vertex, which, contrary to what happens in the Landau gauge, contributes non-trivially to the gap equation of the ghost. The detailed study of the corresponding vertex equation reveals that in the presence of a dynamical infrared cutoff this form factor remains finite in the limit of vanishing ghost momentum. This, in turn, allows the ghost self-energy to reach a finite value in the infrared, without having to assume any additional properties for the gluon-ghost vertex, such as the presence of massless poles. The implications of this result and possible future directions are briefly outlined.
[ { "created": "Wed, 5 Dec 2007 17:02:19 GMT", "version": "v1" } ]
2008-11-26
[ [ "Aguilar", "A. C.", "" ], [ "Papavassiliou", "J.", "" ] ]
We demonstrate how to obtain from the Schwinger-Dyson equations of QCD an infrared finite ghost propagator in the Feynman gauge. The key ingredient in this construction is the longitudinal form factor of the non-perturbative gluon-ghost vertex, which, contrary to what happens in the Landau gauge, contributes non-trivially to the gap equation of the ghost. The detailed study of the corresponding vertex equation reveals that in the presence of a dynamical infrared cutoff this form factor remains finite in the limit of vanishing ghost momentum. This, in turn, allows the ghost self-energy to reach a finite value in the infrared, without having to assume any additional properties for the gluon-ghost vertex, such as the presence of massless poles. The implications of this result and possible future directions are briefly outlined.
hep-ph/0205297
Dr Rukmani Mohanta
R. Mohanta
Searching for New Physics in the rare decay B^+ \to D_s^+ \phi
LaTex, 12 pages
Phys.Lett.B540:241-246,2002
10.1016/S0370-2693(02)02173-1
null
hep-ph
null
The rare decay $B^+ \to D_s^+ \phi $ can occur only via annihilation type diagram in the standard model. The small branching ratio predicted in the standard model makes this channel sensitive to new physics contributions. We analyze this decay mode, both in the standard model and in several extensions of it. The models considered are minimal supersymmetric model with R-parity violation and two Higgs doublet model. The experimental verification of our findings of large branching ratio and/or nonzero CP asymmetry may signal the presence of new physics.
[ { "created": "Mon, 27 May 2002 03:01:56 GMT", "version": "v1" } ]
2011-03-23
[ [ "Mohanta", "R.", "" ] ]
The rare decay $B^+ \to D_s^+ \phi $ can occur only via annihilation type diagram in the standard model. The small branching ratio predicted in the standard model makes this channel sensitive to new physics contributions. We analyze this decay mode, both in the standard model and in several extensions of it. The models considered are minimal supersymmetric model with R-parity violation and two Higgs doublet model. The experimental verification of our findings of large branching ratio and/or nonzero CP asymmetry may signal the presence of new physics.
hep-ph/0005200
Berezhnoy Alexander V.
A.V. Berezhnoy, A.K. Likhoded
The contribution of the hadronic component of the photon into the $D^*$-meson photoproduction at HERA
12 pages, LATEX file, 5 ps-figures; changed LATEX style; estimated the model uncertainty
null
null
null
hep-ph
null
In the framework of the vector dominance model (VDM) new contribution into the cross-section of $D^*$-meson photoproduction at HERA has been estimated. This contribution is due to the interaction of the virtual vector $c\bar c$-mesons from photon with the proton. It has been shown that the mechanism under discussion plays the essential role for all values of transverse momentum of $D^*$-mesons at HERA. Taking into account for the contribution of this mechanism improves the description of the experimental cross section distribution.
[ { "created": "Fri, 19 May 2000 11:43:58 GMT", "version": "v1" }, { "created": "Mon, 22 May 2000 14:02:34 GMT", "version": "v2" }, { "created": "Wed, 28 Jun 2000 12:15:34 GMT", "version": "v3" } ]
2007-05-23
[ [ "Berezhnoy", "A. V.", "" ], [ "Likhoded", "A. K.", "" ] ]
In the framework of the vector dominance model (VDM) new contribution into the cross-section of $D^*$-meson photoproduction at HERA has been estimated. This contribution is due to the interaction of the virtual vector $c\bar c$-mesons from photon with the proton. It has been shown that the mechanism under discussion plays the essential role for all values of transverse momentum of $D^*$-mesons at HERA. Taking into account for the contribution of this mechanism improves the description of the experimental cross section distribution.
2312.13125
Joon-Bin Lee
Joon-Bin Lee, M.R. Masouminia, Michael H. Seymour, Un-ki Yang
Generalized angular-order parton showers in Herwig 7
null
J. High Energ. Phys. 08 (2024) 064
null
IPPP/23/73, MCnet-23-21
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
This paper presents the inaugural investigation of beyond the Standard Model (BSM) radiation processes, framed as a generalized, process- and model-independent parton shower algorithm within Herwig 7, based on direct translations of Universal FeynRules Output (UFO) constructed via Herwig's ufo2herwig module. Leveraging the fact that shower kinematics are dictated by the spins of involved particles, we calculate comprehensive helicity-dependent branching kernels for all feasible splittings of scalars, fermions, and vector bosons, tailored to Herwig 7's angular-ordering (AO) parton shower algorithm. Utilizing these kernels, we derive BSM splitting functions in the quasi-collinear limit, ensuring compatibility with the Standard Model (SM) and supersymmetry (SUSY) splitting functions when analogous parameter conditions are applied. These newly derived functions have been integrated into the Herwig 7 event generator framework. Comparative analyses with fixed-order matrix element calculations show good agreement for single radiation events. Moreover, the results showcase the influence of BSM radiation at the Large Hadron Collider (LHC) and envisage its implications for future collider endeavours. This research augments our comprehension of BSM radiation effects, with significant bearings on present and prospective collider-based inquiries.
[ { "created": "Wed, 20 Dec 2023 15:44:45 GMT", "version": "v1" }, { "created": "Fri, 9 Aug 2024 22:38:38 GMT", "version": "v2" } ]
2024-08-14
[ [ "Lee", "Joon-Bin", "" ], [ "Masouminia", "M. R.", "" ], [ "Seymour", "Michael H.", "" ], [ "Yang", "Un-ki", "" ] ]
This paper presents the inaugural investigation of beyond the Standard Model (BSM) radiation processes, framed as a generalized, process- and model-independent parton shower algorithm within Herwig 7, based on direct translations of Universal FeynRules Output (UFO) constructed via Herwig's ufo2herwig module. Leveraging the fact that shower kinematics are dictated by the spins of involved particles, we calculate comprehensive helicity-dependent branching kernels for all feasible splittings of scalars, fermions, and vector bosons, tailored to Herwig 7's angular-ordering (AO) parton shower algorithm. Utilizing these kernels, we derive BSM splitting functions in the quasi-collinear limit, ensuring compatibility with the Standard Model (SM) and supersymmetry (SUSY) splitting functions when analogous parameter conditions are applied. These newly derived functions have been integrated into the Herwig 7 event generator framework. Comparative analyses with fixed-order matrix element calculations show good agreement for single radiation events. Moreover, the results showcase the influence of BSM radiation at the Large Hadron Collider (LHC) and envisage its implications for future collider endeavours. This research augments our comprehension of BSM radiation effects, with significant bearings on present and prospective collider-based inquiries.
1401.0276
Sabine Hossenfelder
Sabine Hossenfelder
Theory and Phenomenology of Spacetime Defects
Summary of arXiv:1309.0311 and arXiv:1309.0314. Prepared for the AHEP Special Issue on "Experimental Tests of Quantum Gravity and Exotic Quantum Field Theory Effects"
null
10.1155/2014/950672
null
hep-ph gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Whether or not space-time is fundamentally discrete is of central importance for the development of the theory of quantum gravity. If the fundamental description of space-time is discrete, typically represented in terms of a graph or network, then the apparent smoothness of geometry on large scales should be imperfect -- it should have defects. Here, we review a model for space-time defects and summarize the constraints on the prevalence of these defects that can be derived from observation.
[ { "created": "Wed, 1 Jan 2014 11:41:19 GMT", "version": "v1" } ]
2014-03-24
[ [ "Hossenfelder", "Sabine", "" ] ]
Whether or not space-time is fundamentally discrete is of central importance for the development of the theory of quantum gravity. If the fundamental description of space-time is discrete, typically represented in terms of a graph or network, then the apparent smoothness of geometry on large scales should be imperfect -- it should have defects. Here, we review a model for space-time defects and summarize the constraints on the prevalence of these defects that can be derived from observation.
1107.0715
Marco Farina
Marco Farina, Duccio Pappadopulo, Alessandro Strumia, Tomer Volansky
Can CoGeNT and DAMA Modulations Be Due to Dark Matter?
30 pages, 14 figures. v2: error corrected, some figures changed, references added. Final version, to appear on JCAP
null
10.1088/1475-7516/2011/11/010
null
hep-ph astro-ph.CO astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the dark matter interpretation of the anomalies claimed by the DAMA and CoGeNT experiments, in conjunction with the various null direct-detection experiments. An independent analysis of the CoGeNT data is employed and several experimental and astrophysical uncertainties are considered. Various phenomenological models are studied, including isospin violating interactions, momentum-dependent form factors, velocity-dependent form factors, inelastic scatterings (endothermic and exothermic) and channeling. We find that the severe tension between the anomalies and the null results can be ameliorated but not eliminated, unless extreme assumptions are made.
[ { "created": "Mon, 4 Jul 2011 19:55:34 GMT", "version": "v1" }, { "created": "Thu, 27 Oct 2011 14:10:00 GMT", "version": "v2" } ]
2015-05-28
[ [ "Farina", "Marco", "" ], [ "Pappadopulo", "Duccio", "" ], [ "Strumia", "Alessandro", "" ], [ "Volansky", "Tomer", "" ] ]
We explore the dark matter interpretation of the anomalies claimed by the DAMA and CoGeNT experiments, in conjunction with the various null direct-detection experiments. An independent analysis of the CoGeNT data is employed and several experimental and astrophysical uncertainties are considered. Various phenomenological models are studied, including isospin violating interactions, momentum-dependent form factors, velocity-dependent form factors, inelastic scatterings (endothermic and exothermic) and channeling. We find that the severe tension between the anomalies and the null results can be ameliorated but not eliminated, unless extreme assumptions are made.
1311.2072
Juan Gonzalez-Fraile
C\'edric Delaunay, Thomas Flacke, J. Gonzalez-Fraile, Seung J. Lee, Giuliano Panico, Gilad Perez
Light Non-degenerate Composite Partners at the LHC
49 pages, 18 figures
null
10.1007/JHEP02(2014)055
CERN-PH-TH/2013-259, LAPTh-064/13
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the implications of a large degree of compositeness for the light generation quarks in composite pseudo-Nambu-Goldstone-boson Higgs models. We focus in particular on viable scenarios where the right-handed up-type quarks have a sizable mixing with the strong dynamics. For concreteness we assume the latter to be characterized by an SO(5)/SO(4) symmetry with fermionic resonances in the SO(4) singlet and fourplet representations. Singlet partners dominantly decay to a Higgs boson and jets. As no dedicated searches are currently looking for these final states, singlet partners can still be rather light. Conversely, some fourplet partners dominantly decay to an electroweak gauge boson and a jet, a signature which has been analyzed at the LHC. To constrain the parameter space of this scenario we have reinterpreted various LHC analyses. In the limit of first two generation degeneracy, as in minimal flavor violation or U(2)-symmetric flavor models, fourplet partners need to be relatively heavy, with masses above 1.8 TeV, or the level of compositeness needs to be rather small. The situation is rather different in models that deviate from the first two generation degeneracy paradigm, as the charm parton distribution functions are suppressed relative to the up quark ones. The right-handed charm quark can be composite and its partners being as light as 600 GeV, while the right-handed up quark needs either to be mostly elementary or to have its partners as heavy as 2 TeV. Models with fully composite singlet fermions are also analyzed, leading to similar conclusions. Finally, we consider the case where both the fourplet and the singlet states are present. In this case the bounds could be significantly weaken due to a combination of smaller production rates and the opening of new channels including cascade processes.
[ { "created": "Fri, 8 Nov 2013 21:00:01 GMT", "version": "v1" } ]
2015-06-17
[ [ "Delaunay", "Cédric", "" ], [ "Flacke", "Thomas", "" ], [ "Gonzalez-Fraile", "J.", "" ], [ "Lee", "Seung J.", "" ], [ "Panico", "Giuliano", "" ], [ "Perez", "Gilad", "" ] ]
We study the implications of a large degree of compositeness for the light generation quarks in composite pseudo-Nambu-Goldstone-boson Higgs models. We focus in particular on viable scenarios where the right-handed up-type quarks have a sizable mixing with the strong dynamics. For concreteness we assume the latter to be characterized by an SO(5)/SO(4) symmetry with fermionic resonances in the SO(4) singlet and fourplet representations. Singlet partners dominantly decay to a Higgs boson and jets. As no dedicated searches are currently looking for these final states, singlet partners can still be rather light. Conversely, some fourplet partners dominantly decay to an electroweak gauge boson and a jet, a signature which has been analyzed at the LHC. To constrain the parameter space of this scenario we have reinterpreted various LHC analyses. In the limit of first two generation degeneracy, as in minimal flavor violation or U(2)-symmetric flavor models, fourplet partners need to be relatively heavy, with masses above 1.8 TeV, or the level of compositeness needs to be rather small. The situation is rather different in models that deviate from the first two generation degeneracy paradigm, as the charm parton distribution functions are suppressed relative to the up quark ones. The right-handed charm quark can be composite and its partners being as light as 600 GeV, while the right-handed up quark needs either to be mostly elementary or to have its partners as heavy as 2 TeV. Models with fully composite singlet fermions are also analyzed, leading to similar conclusions. Finally, we consider the case where both the fourplet and the singlet states are present. In this case the bounds could be significantly weaken due to a combination of smaller production rates and the opening of new channels including cascade processes.
2001.02961
Zhi-Gang Wang
Zhi-Gang Wang
Analysis of the $\Omega_b(6316)$, $\Omega_b(6330)$, $\Omega_b(6340)$ and $\Omega_b(6350)$ with QCD sum rules
9 pages, 4 figures
Int. J. Mod. Phys. A35 (2020) 2050043
10.1142/S0217751X20500438
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we introduce an explicit P-wave to construct three-quark currents to study the P-wave $\Omega_b$ states with the full QCD sum rules. The predicted masses have a hierarchy if the same parameters are chosen and favor assigning the $\Omega_b(6316)$, $\Omega_b(6330)$, $\Omega_b(6340)$ and $\Omega_b(6350)$ to be the P-wave $\Omega_b$ states with the $J^P={\frac{3}{2}}^-$, ${\frac{1}{2}}^-$, ${\frac{5}{2}}^-$ and ${\frac{3}{2}}^-$, respectively.
[ { "created": "Thu, 9 Jan 2020 13:15:34 GMT", "version": "v1" }, { "created": "Mon, 9 Mar 2020 07:24:27 GMT", "version": "v2" } ]
2020-04-15
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we introduce an explicit P-wave to construct three-quark currents to study the P-wave $\Omega_b$ states with the full QCD sum rules. The predicted masses have a hierarchy if the same parameters are chosen and favor assigning the $\Omega_b(6316)$, $\Omega_b(6330)$, $\Omega_b(6340)$ and $\Omega_b(6350)$ to be the P-wave $\Omega_b$ states with the $J^P={\frac{3}{2}}^-$, ${\frac{1}{2}}^-$, ${\frac{5}{2}}^-$ and ${\frac{3}{2}}^-$, respectively.
1108.2694
Ricardo Gonzalez Felipe
R. Gonzalez Felipe
Neutrinos and the matter-antimatter asymmetry in the Universe
8 pages, 1 table, 1 figure; Based on talk given at the Symposium STARS2011, 1 - 4 May 2011, Havana, Cuba; to be published in the Proceedings
null
10.1142/S0218301311040074
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discovery of neutrino oscillations provides a solid evidence for nonzero neutrino masses and leptonic mixing. The fact that neutrino masses are so tiny constitutes a puzzling problem in particle physics. From the theoretical viewpoint, the smallness of neutrino masses can be elegantly explained through the seesaw mechanism. Another challenging issue for particle physics and cosmology is the explanation of the matter-antimatter asymmetry observed in Nature. Among the viable mechanisms, leptogenesis is a simple and well-motivated framework. In this talk we briefly review these aspects, making emphasis on the possibility of linking neutrino physics to the cosmological baryon asymmetry originated from leptogenesis.
[ { "created": "Fri, 12 Aug 2011 19:38:17 GMT", "version": "v1" } ]
2015-05-30
[ [ "Felipe", "R. Gonzalez", "" ] ]
The discovery of neutrino oscillations provides a solid evidence for nonzero neutrino masses and leptonic mixing. The fact that neutrino masses are so tiny constitutes a puzzling problem in particle physics. From the theoretical viewpoint, the smallness of neutrino masses can be elegantly explained through the seesaw mechanism. Another challenging issue for particle physics and cosmology is the explanation of the matter-antimatter asymmetry observed in Nature. Among the viable mechanisms, leptogenesis is a simple and well-motivated framework. In this talk we briefly review these aspects, making emphasis on the possibility of linking neutrino physics to the cosmological baryon asymmetry originated from leptogenesis.
hep-ph/9806525
Tetsuya Shiromizu
Tetsuya Shiromizu
Generation of Magnetic Field due to Excited Q-Balls
6 pages, LaTex, to appear in Phys.Rev.D
Phys.Rev. D58 (1998) 107301
10.1103/PhysRevD.58.107301
DAMTP/R/98/25, UTAP-192
hep-ph astro-ph
null
We investigate phase transitions due to excited Q-balls. As excited Q-balls have angular momentum, a magnetic field can be generated if one considers gauged Q-balls. Based on the course of the phase transition we estimate the strength of the magnetic field and then we find that it might be the origin of observed magnetic fields of astrophysical objects such as galaxies and clusters of galaxies.
[ { "created": "Tue, 30 Jun 1998 09:48:57 GMT", "version": "v1" } ]
2009-10-31
[ [ "Shiromizu", "Tetsuya", "" ] ]
We investigate phase transitions due to excited Q-balls. As excited Q-balls have angular momentum, a magnetic field can be generated if one considers gauged Q-balls. Based on the course of the phase transition we estimate the strength of the magnetic field and then we find that it might be the origin of observed magnetic fields of astrophysical objects such as galaxies and clusters of galaxies.
hep-ph/9805412
null
Hongying Jin and X.M. Zhang
Scalar Glueball Decay Into Pions In Effective Theory
10 pages, latex, 3 ps figures
null
null
null
hep-ph
null
We examine the mixing between the sigma meson $\sigma$ and the "pure" glueball field $H$ and study the decays of the scalar glueball candidate $f_0(1500)$ (a linear combination of $\sigma$ and $H$) into two and four pions in effective linear sigma model. From recent experimental data on $f_0(1500)$ decay to pions we point out that the mixing angle is of order of 0.1.
[ { "created": "Thu, 21 May 1998 14:44:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Jin", "Hongying", "" ], [ "Zhang", "X. M.", "" ] ]
We examine the mixing between the sigma meson $\sigma$ and the "pure" glueball field $H$ and study the decays of the scalar glueball candidate $f_0(1500)$ (a linear combination of $\sigma$ and $H$) into two and four pions in effective linear sigma model. From recent experimental data on $f_0(1500)$ decay to pions we point out that the mixing angle is of order of 0.1.
1206.5701
K. S. Babu
K. S. Babu and R. N. Mohapatra
Coupling Unification, GUT-Scale Baryogenesis and Neutron-Antineutron Oscillation in SO(10)
15 pages, 4 eps figures, references added, to appear in Phys. Lett. B
null
10.1016/j.physletb.2012.08.006
OSU-HEP-12-06; UMD-PP-012-009
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that unification of the three gauge couplings can be realized consistently in a class of non-supersymmetric SO(10) models with a one-step breaking to the Standard Model if a color-sextet scalar field survives down to the TeV scale. Such scalars, which should be accessible to the LHC for direct detection, arise naturally in SO(10) as remnants of the seesaw mechanism for neutrino masses. The diquark couplings of these scalars lead to \Delta B = 2 baryon number violating processes such as neutron-antineutron oscillation. We estimate the free neutron-antineutron transition time to be \tau_{n-\bar{n}} \approx (10^9-10^{12}) sec., which is in the interesting range for next generation n-\bar{n} oscillation experiments. These models also realize naturally the recently proposed (B-L)-violating GUT scale baryogenesis which survives to low temperatures unaffected by the electroweak sphaleron interactions.
[ { "created": "Mon, 25 Jun 2012 15:07:21 GMT", "version": "v1" }, { "created": "Mon, 20 Aug 2012 18:32:46 GMT", "version": "v2" } ]
2015-06-05
[ [ "Babu", "K. S.", "" ], [ "Mohapatra", "R. N.", "" ] ]
We show that unification of the three gauge couplings can be realized consistently in a class of non-supersymmetric SO(10) models with a one-step breaking to the Standard Model if a color-sextet scalar field survives down to the TeV scale. Such scalars, which should be accessible to the LHC for direct detection, arise naturally in SO(10) as remnants of the seesaw mechanism for neutrino masses. The diquark couplings of these scalars lead to \Delta B = 2 baryon number violating processes such as neutron-antineutron oscillation. We estimate the free neutron-antineutron transition time to be \tau_{n-\bar{n}} \approx (10^9-10^{12}) sec., which is in the interesting range for next generation n-\bar{n} oscillation experiments. These models also realize naturally the recently proposed (B-L)-violating GUT scale baryogenesis which survives to low temperatures unaffected by the electroweak sphaleron interactions.
1808.09014
Nikolaos Kidonakis
Matthew Forslund and Nikolaos Kidonakis
Associated production of a top quark with a photon via anomalous couplings
11 pages, 6 figures; published version
Phys. Rev. D 98, 074017 (2018)
10.1103/PhysRevD.98.074017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the associated production of a top quark with a photon via anomalous $t$-$q$-$\gamma$ couplings, and present higher-order corrections from soft-gluon emission for the processes $gq \rightarrow t\gamma$ at LHC energies. We perform soft-gluon resummation at next-to-leading-logarithm accuracy and derive approximate next-to-next-to-leading order (aNNLO) double-differential cross sections. We calculate at aNNLO the total $t\gamma$ production cross sections and the top-quark transverse-momentum and rapidity distributions for various LHC energies, and show that the soft-gluon corrections are large and dominant in these processes.
[ { "created": "Mon, 27 Aug 2018 19:48:49 GMT", "version": "v1" }, { "created": "Thu, 18 Oct 2018 19:39:55 GMT", "version": "v2" } ]
2018-10-24
[ [ "Forslund", "Matthew", "" ], [ "Kidonakis", "Nikolaos", "" ] ]
We discuss the associated production of a top quark with a photon via anomalous $t$-$q$-$\gamma$ couplings, and present higher-order corrections from soft-gluon emission for the processes $gq \rightarrow t\gamma$ at LHC energies. We perform soft-gluon resummation at next-to-leading-logarithm accuracy and derive approximate next-to-next-to-leading order (aNNLO) double-differential cross sections. We calculate at aNNLO the total $t\gamma$ production cross sections and the top-quark transverse-momentum and rapidity distributions for various LHC energies, and show that the soft-gluon corrections are large and dominant in these processes.
1512.05731
Tuhin Subhra Mukherjee
Shrihari Gopalakrishna, Tuhin Subhra Mukherjee, Soumya Sadhukhan
Status and Prospects of the Two-Higgs-Doublet SU(6)/Sp(6) little-Higgs Model and the Alignment Limit
21 pages, 11 figures, Comments added
Phys. Rev. D 94, 015034 (2016)
10.1103/PhysRevD.94.015034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study in detail the little-Higgs model proposed by Low, Skiba and Smith with an SU(6)/Sp(6) group structure. The effective theory at the TeV scale is a two-Higgs doublet model (2HDM) with additional heavy vector-like fermions and vector-bosons. We identify a set of independent input parameters and develop expressions for masses and couplings in terms of these. We perform a random scan of the parameter space and find points that satisfy constraints, including the recent 8 TeV LHC Higgs measurements, namely, the Higgs mass, Higgs couplings to the top, bottom, $\tau$, $W^\pm$ and $Z$, top-quark mass, and collider bounds on colored vector-like fermions ($t'$ and $b'$), and also precision electroweak constraints. The LHC constraints on the $hWW$ and $hZZ$ couplings are satisfied by being close to the "alignment limit". We find how fine-tuned the model is after including these constraints. For the points that satisfy the constraints, we present the 1-loop effective couplings of the CP-even and CP-odd neutral scalars to two gluons including contributions of standard model and heavy vector-like quarks. We also present the branching ratios of the heavy neutral scalars into the $\gamma\gamma,\, \tau\bar\tau,\, b\bar b,\, t\bar t, WW, ZZ, Zh, hh$ modes, and the heavy charged scalar into $tb,\, \tau\nu, cs, W h$ modes. These will aid searches of the heavy scalars at the LHC and other future colliders.
[ { "created": "Thu, 17 Dec 2015 19:29:49 GMT", "version": "v1" }, { "created": "Mon, 1 Aug 2016 21:41:41 GMT", "version": "v2" } ]
2016-08-03
[ [ "Gopalakrishna", "Shrihari", "" ], [ "Mukherjee", "Tuhin Subhra", "" ], [ "Sadhukhan", "Soumya", "" ] ]
We study in detail the little-Higgs model proposed by Low, Skiba and Smith with an SU(6)/Sp(6) group structure. The effective theory at the TeV scale is a two-Higgs doublet model (2HDM) with additional heavy vector-like fermions and vector-bosons. We identify a set of independent input parameters and develop expressions for masses and couplings in terms of these. We perform a random scan of the parameter space and find points that satisfy constraints, including the recent 8 TeV LHC Higgs measurements, namely, the Higgs mass, Higgs couplings to the top, bottom, $\tau$, $W^\pm$ and $Z$, top-quark mass, and collider bounds on colored vector-like fermions ($t'$ and $b'$), and also precision electroweak constraints. The LHC constraints on the $hWW$ and $hZZ$ couplings are satisfied by being close to the "alignment limit". We find how fine-tuned the model is after including these constraints. For the points that satisfy the constraints, we present the 1-loop effective couplings of the CP-even and CP-odd neutral scalars to two gluons including contributions of standard model and heavy vector-like quarks. We also present the branching ratios of the heavy neutral scalars into the $\gamma\gamma,\, \tau\bar\tau,\, b\bar b,\, t\bar t, WW, ZZ, Zh, hh$ modes, and the heavy charged scalar into $tb,\, \tau\nu, cs, W h$ modes. These will aid searches of the heavy scalars at the LHC and other future colliders.
1611.05270
Cem Salih Un
Ali Cici, Zerrin Kirca and Cem Salih Un
Light Stops and Fine-Tuning in MSSM
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the fine-tuning issue within the MSSM framework. Following the idea that the fine-tuning can measure effects of some missing mechanism, we impose non-universal gaugino masses at the GUT scalem and explore the low scale implications. We realize that the fine-tuning parametrized with Delta_EW can be as low as zero. We consider the stop mass with a special importance and focus on the mass scales as m_stop <=700 GeV, which are excluded by current experiments when the stop decays into a neutralino along with a top quark or a chargino along with a b quark. We find that the stop mass can be as low as about 200 GeV with Delta_EW ~ 50. We find that the solutions in this region can be exluded only up to 60% when stop decays into a neutralino-top quark, and 50% when it decays into a chargino-b quark pair. Setting 65% CL to be potential exclusion and 95% to be pure exclusion limit such solutions will be tested in near future experiments, which are conducted with higher luminosity. In addition to stop, the region with low fine-tuning and light stops predicts masses for the other supersymmetric particles such as m_sbottom >~ 600 GeV, m_stau >~ 1 TeV, m_chargino >~ 120 GeV. The details for the mass scales and decay rates are also provided by tables of benchmark points.
[ { "created": "Wed, 16 Nov 2016 13:33:10 GMT", "version": "v1" }, { "created": "Thu, 17 Nov 2016 13:22:18 GMT", "version": "v2" }, { "created": "Mon, 31 Jul 2017 19:05:55 GMT", "version": "v3" } ]
2017-08-02
[ [ "Cici", "Ali", "" ], [ "Kirca", "Zerrin", "" ], [ "Un", "Cem Salih", "" ] ]
We discuss the fine-tuning issue within the MSSM framework. Following the idea that the fine-tuning can measure effects of some missing mechanism, we impose non-universal gaugino masses at the GUT scalem and explore the low scale implications. We realize that the fine-tuning parametrized with Delta_EW can be as low as zero. We consider the stop mass with a special importance and focus on the mass scales as m_stop <=700 GeV, which are excluded by current experiments when the stop decays into a neutralino along with a top quark or a chargino along with a b quark. We find that the stop mass can be as low as about 200 GeV with Delta_EW ~ 50. We find that the solutions in this region can be exluded only up to 60% when stop decays into a neutralino-top quark, and 50% when it decays into a chargino-b quark pair. Setting 65% CL to be potential exclusion and 95% to be pure exclusion limit such solutions will be tested in near future experiments, which are conducted with higher luminosity. In addition to stop, the region with low fine-tuning and light stops predicts masses for the other supersymmetric particles such as m_sbottom >~ 600 GeV, m_stau >~ 1 TeV, m_chargino >~ 120 GeV. The details for the mass scales and decay rates are also provided by tables of benchmark points.
hep-ph/0109275
Francesco Villante
G. Fiorentini, F.L. Villante and B. Ricci
A few comments after the charged current measurement at the Sudbury Neutrino Observatory
13 pages, 2 figures. Based on the talks given by G.Fiorentini and F.L.Villante at the NO-VE Workshop, Venice, Italy, 24-26 July 2001. To be published in the proceedings
null
null
null
hep-ph astro-ph
null
The comparison of the SNO charged current result with the solar neutrino signal measured by Super-Kamiokande has provided, for the first time, the evidence of a non electron flavour active neutrino component in the solar flux. We remark here that this evidence can be obtained in a model independent way, i.e. without any assumpion about solar models, about the energy dependence of the neutrino oscillation probability and about the presence of sterile neutrinos. Furthermore, from the 8B neutrino flux obtained by combining SNO and Super-Kamiokande, one can determine the central solar temperature, T = 1.57 (1 \pm 1%) 10^7 K, and provide an estimate of the beryllium neutrino flux, Phi_Be = 4.9 (1 \pm 11%) 10^9 cm^{-2} s^{-1}.
[ { "created": "Fri, 28 Sep 2001 18:33:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fiorentini", "G.", "" ], [ "Villante", "F. L.", "" ], [ "Ricci", "B.", "" ] ]
The comparison of the SNO charged current result with the solar neutrino signal measured by Super-Kamiokande has provided, for the first time, the evidence of a non electron flavour active neutrino component in the solar flux. We remark here that this evidence can be obtained in a model independent way, i.e. without any assumpion about solar models, about the energy dependence of the neutrino oscillation probability and about the presence of sterile neutrinos. Furthermore, from the 8B neutrino flux obtained by combining SNO and Super-Kamiokande, one can determine the central solar temperature, T = 1.57 (1 \pm 1%) 10^7 K, and provide an estimate of the beryllium neutrino flux, Phi_Be = 4.9 (1 \pm 11%) 10^9 cm^{-2} s^{-1}.
1511.09461
Giuseppe Ruoso
Giuseppe Ruoso, Augusto Lombardi, Antonello Ortolan, Ruggero Pengo, Caterina Braggio, Giovanni Carugno, Carmelo Sebastiano Gallo, Clive C. Speake
The QUAX proposal: a search of galactic axion with magnetic materials
5 pages, Contribution for the proceedings of the TAUP2015, International Conference on Topics in Astroparticle and Underground Physics, 7-11 September 2015, Torino, Italy
null
10.1088/1742-6596/718/4/042051
null
hep-ph physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Aim of the QUAX (QUaerere AXion) proposal is to exploit the interaction of cosmological axions with the spin of electrons in a magnetized sample. Their effect is equivalent to the application of an oscillating rf field with frequency and amplitude which are fixed by axion mass and coupling constant, respectively. The rf receiver module of the QUAX detector consists of magnetized samples with the Larmor resonance frequency tuned to the axion mass by a polarizing static magnetic field. The interaction of electrons with the axion-equivalent rf field produces oscillations in the total magnetization of the samples. To amplify such a tiny field, a pump field at the same frequency is applied in a direction orthogonal to the polarizing field. The induced oscillatory magnetization along the polarizing field is measured by a SQUID amplifier operated at its quantum noise level.
[ { "created": "Mon, 30 Nov 2015 20:38:55 GMT", "version": "v1" } ]
2016-06-22
[ [ "Ruoso", "Giuseppe", "" ], [ "Lombardi", "Augusto", "" ], [ "Ortolan", "Antonello", "" ], [ "Pengo", "Ruggero", "" ], [ "Braggio", "Caterina", "" ], [ "Carugno", "Giovanni", "" ], [ "Gallo", "Carmelo Sebastiano...
Aim of the QUAX (QUaerere AXion) proposal is to exploit the interaction of cosmological axions with the spin of electrons in a magnetized sample. Their effect is equivalent to the application of an oscillating rf field with frequency and amplitude which are fixed by axion mass and coupling constant, respectively. The rf receiver module of the QUAX detector consists of magnetized samples with the Larmor resonance frequency tuned to the axion mass by a polarizing static magnetic field. The interaction of electrons with the axion-equivalent rf field produces oscillations in the total magnetization of the samples. To amplify such a tiny field, a pump field at the same frequency is applied in a direction orthogonal to the polarizing field. The induced oscillatory magnetization along the polarizing field is measured by a SQUID amplifier operated at its quantum noise level.
hep-ph/0408301
Chris Korthals Altes
C.P. Korthals Altes
Dilute monopole gas, magnetic screening and k-tensions in hot gluodynamics
13 pages, talk given at Workshop on Continuous Advances in QCD 2004, Minneapolis, Minnesota, 13-16 May 2004
null
10.1142/9789812702326_0036
null
hep-ph
null
An adjoint multiplet of screened monopoles forming a dilute gas fits very well lattice data at high $T$. There are now seven ratios for k-strings available, checking within a few percent with the prediction $k(N-k)$. The diluteness turns out to be a small parameter for SU(N) gluodynamics, to a good approximation ($1\over N^2$) independent of the value of $N$, and also independent of $T$. This suggests a dilute Bose-Einstein gas, with a BE transition at the deconfinement temperature $T_c$.
[ { "created": "Thu, 26 Aug 2004 13:02:58 GMT", "version": "v1" } ]
2017-08-23
[ [ "Altes", "C. P. Korthals", "" ] ]
An adjoint multiplet of screened monopoles forming a dilute gas fits very well lattice data at high $T$. There are now seven ratios for k-strings available, checking within a few percent with the prediction $k(N-k)$. The diluteness turns out to be a small parameter for SU(N) gluodynamics, to a good approximation ($1\over N^2$) independent of the value of $N$, and also independent of $T$. This suggests a dilute Bose-Einstein gas, with a BE transition at the deconfinement temperature $T_c$.
1510.08738
Miguel Sanchis
Miguel-Angel Sanchis-Lozano, Edward K. Sarkisyan-Grinbaum and Salvador Moreno-Picot
Searching for hidden sector in multiparticle production at the LHC
13 pages, 7 figures
null
10.1016/j.physletb.2016.01.038
IFIC/15-83, FTUV-15-1028
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the impact of a hidden sector beyond the Standard Model, e.g. a Hidden Valley model, on factorial moments and cumulants of multiplicity distributions in multiparticle production with a special emphasis on the prospects for LHC results.
[ { "created": "Thu, 29 Oct 2015 15:27:54 GMT", "version": "v1" }, { "created": "Thu, 14 Jan 2016 16:14:01 GMT", "version": "v2" } ]
2016-01-27
[ [ "Sanchis-Lozano", "Miguel-Angel", "" ], [ "Sarkisyan-Grinbaum", "Edward K.", "" ], [ "Moreno-Picot", "Salvador", "" ] ]
We study the impact of a hidden sector beyond the Standard Model, e.g. a Hidden Valley model, on factorial moments and cumulants of multiplicity distributions in multiparticle production with a special emphasis on the prospects for LHC results.
hep-ph/9605352
Thomas G. Rizzo
Thomas G. Rizzo
The Polarization Asymmetry and Triple Gauge Boson Couplings in $\gamma e$ Collisions at the NLC
8 pages plus figures, gzipped compressed postscript file
null
null
SLAC-PUB-7155
hep-ph
null
We examine the capability of the NLC in the $\gamma e$ collider mode to probe the CP-conserving $\gamma WW$ and $\gamma ZZ$ anomalous couplings through the use of the polarization asymmetry. When combined with other measurements, very strong constraints on both varieties of anomalous couplings can be obtained. [To appear in {\it Physics and Technology of the Next Linear Collider}, eds. D.\ Burke and M.\ Peskin, reports submitted to Snowmass 1996.]
[ { "created": "Mon, 20 May 1996 02:29:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rizzo", "Thomas G.", "" ] ]
We examine the capability of the NLC in the $\gamma e$ collider mode to probe the CP-conserving $\gamma WW$ and $\gamma ZZ$ anomalous couplings through the use of the polarization asymmetry. When combined with other measurements, very strong constraints on both varieties of anomalous couplings can be obtained. [To appear in {\it Physics and Technology of the Next Linear Collider}, eds. D.\ Burke and M.\ Peskin, reports submitted to Snowmass 1996.]
2403.02147
Selcuk Bilmis
T.M.Aliev, S.Bilmis, M.Savci
QCD Sum Rule study of $J^P = 1^\pm$ exotic states with two heavy quarks in the molecular picture
To be published in Chinese Physics C
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this study, the spectroscopic parameters of the exotic molecular states composed of mesons containing two heavy quarks (scalar-axial and pseudoscalar-axial meson combinations) are investigated within QCD sum rules. Our findings reveal that the molecular states containing charm quarks do not form bound states, whereas the states with b-quarks can form the exotic molecular states. This observation has significant implications for understanding the structure of these exotic states.
[ { "created": "Mon, 4 Mar 2024 15:57:05 GMT", "version": "v1" } ]
2024-03-05
[ [ "Aliev", "T. M.", "" ], [ "Bilmis", "S.", "" ], [ "Savci", "M.", "" ] ]
In this study, the spectroscopic parameters of the exotic molecular states composed of mesons containing two heavy quarks (scalar-axial and pseudoscalar-axial meson combinations) are investigated within QCD sum rules. Our findings reveal that the molecular states containing charm quarks do not form bound states, whereas the states with b-quarks can form the exotic molecular states. This observation has significant implications for understanding the structure of these exotic states.
1910.06025
Ajay Kumar Rai
Raghav Chaturvedi and Ajay Kumar Rai
Charmonium spectroscopy motivated by general features of pNRQCD
17 pages, 4 figures (Suggestions and comments are invited)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Mass spectrum of charmonium is computed in the framework of potential non-relativistic quantum chromodynamics. \textit{O}$(1/m)$ and \textit{O}$(1/m^2)$ relativistic corrections to the Cornell potential and spin-dependent potential have been added, and is solved numerically. New experimentally observed and modified positive and negative parity states like ${{\boldsymbol \psi}{(4230)}}$, ${{\boldsymbol \psi}{(4260)}}$, ${{\boldsymbol \psi}{(4360)}}$, ${{\boldsymbol \psi}{(4390)}}$, ${{\boldsymbol \psi}{(4660)}}$, ${{\boldsymbol \chi}_{{c1}}{(4140)}}$ and ${{\boldsymbol \chi}_{{c1}}{(4274)}}$ near open-flavor threshold have also been studied. We explain them as admixtures of S-D wave states and P-wave states. Apart from these states, some other states like ${{\mathit X}{(3915)}}$, ${{\boldsymbol \chi}_{{c1}}{(3872)}}$, ${{\boldsymbol \psi}{(3770)}}$ and ${{\boldsymbol \psi}{(4160)}}$ have been identified as $2^3P_0$, $2^3P_1$, $1^3D_1$ and $2^3D_1$ states. Subsequently, the electromagnetic transition widths and $\gamma\gamma$, $e^+e^-$, light hadron and $\gamma\gamma\gamma$ decay widths of several states are calculated at various leading orders. All the calculated results are compared with experimental and results from various theoretical models.
[ { "created": "Mon, 14 Oct 2019 10:23:55 GMT", "version": "v1" } ]
2020-10-29
[ [ "Chaturvedi", "Raghav", "" ], [ "Rai", "Ajay Kumar", "" ] ]
Mass spectrum of charmonium is computed in the framework of potential non-relativistic quantum chromodynamics. \textit{O}$(1/m)$ and \textit{O}$(1/m^2)$ relativistic corrections to the Cornell potential and spin-dependent potential have been added, and is solved numerically. New experimentally observed and modified positive and negative parity states like ${{\boldsymbol \psi}{(4230)}}$, ${{\boldsymbol \psi}{(4260)}}$, ${{\boldsymbol \psi}{(4360)}}$, ${{\boldsymbol \psi}{(4390)}}$, ${{\boldsymbol \psi}{(4660)}}$, ${{\boldsymbol \chi}_{{c1}}{(4140)}}$ and ${{\boldsymbol \chi}_{{c1}}{(4274)}}$ near open-flavor threshold have also been studied. We explain them as admixtures of S-D wave states and P-wave states. Apart from these states, some other states like ${{\mathit X}{(3915)}}$, ${{\boldsymbol \chi}_{{c1}}{(3872)}}$, ${{\boldsymbol \psi}{(3770)}}$ and ${{\boldsymbol \psi}{(4160)}}$ have been identified as $2^3P_0$, $2^3P_1$, $1^3D_1$ and $2^3D_1$ states. Subsequently, the electromagnetic transition widths and $\gamma\gamma$, $e^+e^-$, light hadron and $\gamma\gamma\gamma$ decay widths of several states are calculated at various leading orders. All the calculated results are compared with experimental and results from various theoretical models.
2312.10236
Jo\~ao Barata
Jo\~ao Barata, Jean-Paul Blaizot, Yacine Mehtar-Tani
Quantum to classical parton evolution in the QGP
4 pages, Proceedings of Quark Matter 2023
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study the time evolution of the density matrix of a high energy quark in the presence of a dense QCD background that is modeled as a stochastic Gaussian color field. At late times, we find that only the color singlet component of the quark's reduced density matrix survives the in-medium evolution and that the density matrix becomes asymptotically diagonal in both transverse position and momentum spaces. In addition, we observe an accelerated entropy growth due to the larger phase space being explored by the quark and that the quantum and classical quark entropies converge at late times. We further observe that the quark state loses all memory of the initial condition. Combined with the fact that the reduced density matrix satisfies Boltzmann-diffusion transport, we conclude that the quark reduced density matrix can be interpreted as a classical phase space distribution.
[ { "created": "Fri, 15 Dec 2023 22:08:44 GMT", "version": "v1" } ]
2023-12-19
[ [ "Barata", "João", "" ], [ "Blaizot", "Jean-Paul", "" ], [ "Mehtar-Tani", "Yacine", "" ] ]
We study the time evolution of the density matrix of a high energy quark in the presence of a dense QCD background that is modeled as a stochastic Gaussian color field. At late times, we find that only the color singlet component of the quark's reduced density matrix survives the in-medium evolution and that the density matrix becomes asymptotically diagonal in both transverse position and momentum spaces. In addition, we observe an accelerated entropy growth due to the larger phase space being explored by the quark and that the quantum and classical quark entropies converge at late times. We further observe that the quark state loses all memory of the initial condition. Combined with the fact that the reduced density matrix satisfies Boltzmann-diffusion transport, we conclude that the quark reduced density matrix can be interpreted as a classical phase space distribution.
1901.04126
Yun-Hua Chen
Yun-Hua Chen
Chromopolarizability of charmonium and $\pi\pi$ final state interaction revisited
8 pages, 1 figure
Advances in High Energy Physics, Volume 2019, Article ID 7650678
10.1155/2019/7650678
null
hep-ph hep-ex hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The chromopolarizability of a quarknonium describes the quarknonium's interaction with soft gluonic fields and can be measured in the heavy quarkonium decays. Within the framework of dispersion theory which consider the $\pi\pi$ final state interaction (FSI) model-independently, we analyze the transition $\psi^\prime\to J/\psi\pi^+\pi^-$ and obtain the chromopolarizability $\alpha_{\psi^\prime \psi}$ and the parameter $\kappa$. It is found that the $\pi\pi$ FSI plays an important role in extracting the chromopolarizability from the experimental data. The obtained chromopolarizability with the FSI is reduced to about 1/2 of that without the FSI. With the FSI, we determine the chromopolarizability $|\alpha_{\psi^\prime\psi}|=(1.44\pm 0.02)$ GeV$^{-3}$ and the parameter $\kappa=0.139\pm 0.005.$ Our results could be useful in studying the interactions of charmonium with light hadrons.
[ { "created": "Mon, 14 Jan 2019 04:38:34 GMT", "version": "v1" }, { "created": "Thu, 17 Jan 2019 14:24:01 GMT", "version": "v2" }, { "created": "Thu, 7 Mar 2019 13:42:28 GMT", "version": "v3" }, { "created": "Thu, 2 May 2019 16:11:32 GMT", "version": "v4" } ]
2019-05-03
[ [ "Chen", "Yun-Hua", "" ] ]
The chromopolarizability of a quarknonium describes the quarknonium's interaction with soft gluonic fields and can be measured in the heavy quarkonium decays. Within the framework of dispersion theory which consider the $\pi\pi$ final state interaction (FSI) model-independently, we analyze the transition $\psi^\prime\to J/\psi\pi^+\pi^-$ and obtain the chromopolarizability $\alpha_{\psi^\prime \psi}$ and the parameter $\kappa$. It is found that the $\pi\pi$ FSI plays an important role in extracting the chromopolarizability from the experimental data. The obtained chromopolarizability with the FSI is reduced to about 1/2 of that without the FSI. With the FSI, we determine the chromopolarizability $|\alpha_{\psi^\prime\psi}|=(1.44\pm 0.02)$ GeV$^{-3}$ and the parameter $\kappa=0.139\pm 0.005.$ Our results could be useful in studying the interactions of charmonium with light hadrons.
hep-ph/9610223
Paul Mackenzie
Brian J. Gough, George M. Hockney, Aida X. El-Khadra, Andreas S. Kronfeld, Paul B. Mackenzie, Bart P. Mertens, Tetsuya Onogi, and James N. Simone
The Light Quark Masses from Lattice Gauge Theory
4 pages, two embedded figures
Phys.Rev.Lett.79:1622-1625,1997
10.1103/PhysRevLett.79.1622
Fermilab Pub-96-283, Illinois ILL-TH-96-07, Hiroshima HUPD-961
hep-ph
null
We investigate the masses of the light quarks with lattice QCD. We show that most of the large dependence on the lattice spacing, a, observed in previous determinations using Wilson fermions is removed with the use of an O(a) corrected action. In the quenched approximation, we obtain for the strange quark MS bar mass m_s(2 GeV) = 95 (16) MeV, and for the average of the up and down quark masses m_l(2 GeV) = 3.6 (6) MeV. Short distance arguments and existing staggered fermion calculations make it likely that the answers including the effects of quark loops lie 20 % to 40 % below this: m_s(2 GeV) in the range 54-92 MeV, and m_l(2 GeV) in the range 2.1-3.5 MeV. We argue that almost all lattice determinations of the light quark masses are consistent with these values. These low values are outside the range usually given by conventional phenomenology.
[ { "created": "Wed, 2 Oct 1996 22:01:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Gough", "Brian J.", "" ], [ "Hockney", "George M.", "" ], [ "El-Khadra", "Aida X.", "" ], [ "Kronfeld", "Andreas S.", "" ], [ "Mackenzie", "Paul B.", "" ], [ "Mertens", "Bart P.", "" ], [ "Onogi", "Tetsuya", ...
We investigate the masses of the light quarks with lattice QCD. We show that most of the large dependence on the lattice spacing, a, observed in previous determinations using Wilson fermions is removed with the use of an O(a) corrected action. In the quenched approximation, we obtain for the strange quark MS bar mass m_s(2 GeV) = 95 (16) MeV, and for the average of the up and down quark masses m_l(2 GeV) = 3.6 (6) MeV. Short distance arguments and existing staggered fermion calculations make it likely that the answers including the effects of quark loops lie 20 % to 40 % below this: m_s(2 GeV) in the range 54-92 MeV, and m_l(2 GeV) in the range 2.1-3.5 MeV. We argue that almost all lattice determinations of the light quark masses are consistent with these values. These low values are outside the range usually given by conventional phenomenology.
hep-ph/0509371
Stefano Forte
Stefano Forte
Progress in Small x Resummation
8 pages, 6 figures, LaTeX with IJMPA document class, invited plenary talk at the conference on QCD and hadronic physics, Beijing 2005
Int.J.Mod.Phys. A21 (2006) 769-776
10.1142/S0217751X06032010
IFUM-847/FT
hep-ph
null
I review recent theoretical progress in the resummation of small x contributions to the evolution of parton distributions, in view of its potential significance for accurate phenomenology at future colliders. I show that a consistent perturbative resummation of collinear and energy logs is now possible, and necessary if one wishes to use recent NNLO results in the HERA kinematic region.
[ { "created": "Fri, 30 Sep 2005 16:38:59 GMT", "version": "v1" } ]
2016-09-06
[ [ "Forte", "Stefano", "" ] ]
I review recent theoretical progress in the resummation of small x contributions to the evolution of parton distributions, in view of its potential significance for accurate phenomenology at future colliders. I show that a consistent perturbative resummation of collinear and energy logs is now possible, and necessary if one wishes to use recent NNLO results in the HERA kinematic region.
0911.4091
Dmitry Borisyuk
Dmitry Borisyuk
Proton charge and magnetic rms radii from the elastic $ep$ scattering data
6 pages, 4 figures. Numbers slightly changed due to discovered error in minimization program. Sec.III revised, discussion of G_E behaviour added.
Nucl.Phys.A843:59-67,2010
10.1016/j.nuclphysa.2010.05.054
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The elastic electron-proton scattering data are analysed in order to determine proton charge and magnetic rms radii, r_E and r_M. Along with the usual statistical error, we try to estimate a systematic error in the radii, caused by the inadequacy of particular form factor parameterization employed. The range of data to use in the analysis is chosen so as to minimize the total (statistical + systematic) error. We obtain r_E = 0.912 +- 0.009 (stat) +- 0.007 (syst) fm, and r_M = 0.876 +- 0.010 (stat) +- 0.016 (syst) fm. The cross-section data were corrected for two-photon exchange. We found that without such corrections obtained r_E and r_M are somewhat smaller while the quality of fit is worse.
[ { "created": "Fri, 20 Nov 2009 20:26:03 GMT", "version": "v1" }, { "created": "Mon, 26 Apr 2010 20:39:43 GMT", "version": "v2" } ]
2014-11-20
[ [ "Borisyuk", "Dmitry", "" ] ]
The elastic electron-proton scattering data are analysed in order to determine proton charge and magnetic rms radii, r_E and r_M. Along with the usual statistical error, we try to estimate a systematic error in the radii, caused by the inadequacy of particular form factor parameterization employed. The range of data to use in the analysis is chosen so as to minimize the total (statistical + systematic) error. We obtain r_E = 0.912 +- 0.009 (stat) +- 0.007 (syst) fm, and r_M = 0.876 +- 0.010 (stat) +- 0.016 (syst) fm. The cross-section data were corrected for two-photon exchange. We found that without such corrections obtained r_E and r_M are somewhat smaller while the quality of fit is worse.
2405.18017
Di Zhang
Di Zhang
Threshold Effects on the Massless Neutrino in the Canonical Seesaw Mechanism
8 pages, 3 figures
null
null
TUM-HEP 1512/24
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we revisit the one-loop renormalization group equations (RGEs) among non-degenerate seesaw scales, i.e., threshold effects in the canonical seesaw mechanism, which have been obtained for more than two decades. We find some contributions from the Weinberg operator to its Wilson coefficient, the neutrino Yukawa coupling matrix, and the Higgs quartic coupling absent in the previous calculations. Based on the updated one-loop RGEs, we derive the RGE of the effective neutrino mass matrix's determinant without any approximation. Then, for the first time, we provide a strict proof that the one-loop RG running effects among non-degenerate seesaw scales can not generate a non-zero mass for the initial massless neutrino in the minimal type-I seesaw mechanism or in the canonical one with a rank-degenerate neutrino Yukawa coupling matrix. One has to include two- or higher-loop corrections to achieve a non-zero mass for the massless neutrino.
[ { "created": "Tue, 28 May 2024 09:59:08 GMT", "version": "v1" } ]
2024-05-29
[ [ "Zhang", "Di", "" ] ]
In this work, we revisit the one-loop renormalization group equations (RGEs) among non-degenerate seesaw scales, i.e., threshold effects in the canonical seesaw mechanism, which have been obtained for more than two decades. We find some contributions from the Weinberg operator to its Wilson coefficient, the neutrino Yukawa coupling matrix, and the Higgs quartic coupling absent in the previous calculations. Based on the updated one-loop RGEs, we derive the RGE of the effective neutrino mass matrix's determinant without any approximation. Then, for the first time, we provide a strict proof that the one-loop RG running effects among non-degenerate seesaw scales can not generate a non-zero mass for the initial massless neutrino in the minimal type-I seesaw mechanism or in the canonical one with a rank-degenerate neutrino Yukawa coupling matrix. One has to include two- or higher-loop corrections to achieve a non-zero mass for the massless neutrino.
2210.05703
Xabier Marcano
Fabiola Fortuna, Alejandro Ibarra, Xabier Marcano, Marcela Mar\'in, Pablo Roig
Indirect upper limits on $\ell_i\to\ell_j\gamma\gamma$ from $\ell_i\to\ell_j\gamma$
5 pages, 3 figures
Phys. Rev. D 107, 2023, 015027
10.1103/PhysRevD.107.015027
TUM-HEP 1422/22, IFT-UAM/CSIC-22-124
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We perform an effective field theory analysis to correlate the charged lepton flavor violating processes $\ell_i\to\ell_j\gamma\gamma$ and $\ell_i\to\ell_j\gamma$. Using the current upper bounds on the rate for $\ell_i\to\ell_j\gamma$, we derive model-independent upper limits on the rates for $\ell_i\to\ell_j\gamma\gamma$. Our indirect limits are about three orders of magnitude stronger than the direct bounds from current searches for $\mu\to e\gamma\gamma$, and four orders of magnitude better than current bounds for $\tau\to\ell\gamma\gamma$. We also stress the relevance of Belle II or a Super Tau Charm Facility to discover the rare decay $\tau\to\ell\gamma\gamma$.
[ { "created": "Tue, 11 Oct 2022 18:05:55 GMT", "version": "v1" } ]
2023-01-31
[ [ "Fortuna", "Fabiola", "" ], [ "Ibarra", "Alejandro", "" ], [ "Marcano", "Xabier", "" ], [ "Marín", "Marcela", "" ], [ "Roig", "Pablo", "" ] ]
We perform an effective field theory analysis to correlate the charged lepton flavor violating processes $\ell_i\to\ell_j\gamma\gamma$ and $\ell_i\to\ell_j\gamma$. Using the current upper bounds on the rate for $\ell_i\to\ell_j\gamma$, we derive model-independent upper limits on the rates for $\ell_i\to\ell_j\gamma\gamma$. Our indirect limits are about three orders of magnitude stronger than the direct bounds from current searches for $\mu\to e\gamma\gamma$, and four orders of magnitude better than current bounds for $\tau\to\ell\gamma\gamma$. We also stress the relevance of Belle II or a Super Tau Charm Facility to discover the rare decay $\tau\to\ell\gamma\gamma$.
1712.02202
J\'er\^ome Charles
J\'er\^ome Charles, David Greynat, Eduardo de Rafael
The Mellin-Barnes Approach to Hadronic Vacuum Polarization and $g_{\mu}-2$
37 pages, many figures. V2: Numerical results updated according to arXiv:1802.02995v1. V3: Published version with improvements suggested by the referee, conclusions unchanged
Phys. Rev. D 97, 076014 (2018)
10.1103/PhysRevD.97.076014
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that with a precise determination of a few derivatives of the hadronic vacuum polarization (HVP) self-energy function $\Pi(Q^2)$ at $Q^2=0$, from lattice QCD (LQCD) or from a dedicated low-energy experiment, one can obtain an evaluation of the lowest order HVP contribution to the anomalous magnetic moment of the muon $a_{\mu}^{\rm HVP}$ with an accuracy comparable to the one reached using the $e^+ e^-$ annihilation cross-section into hadrons. The technique of Mellin-Barnes approximants (MBa) that we propose is illustrated in detail with the example of the two loop vacuum polarization function in QED. We then apply it to the first few moments of the hadronic spectral function obtained from experiment and show that the resulting MBa evaluations of $a_{\mu}^{\rm HVP}$ converge very quickly to the full experimental determination.
[ { "created": "Wed, 6 Dec 2017 14:38:21 GMT", "version": "v1" }, { "created": "Tue, 20 Feb 2018 14:51:29 GMT", "version": "v2" }, { "created": "Wed, 9 May 2018 10:10:02 GMT", "version": "v3" } ]
2018-05-16
[ [ "Charles", "Jérôme", "" ], [ "Greynat", "David", "" ], [ "de Rafael", "Eduardo", "" ] ]
It is shown that with a precise determination of a few derivatives of the hadronic vacuum polarization (HVP) self-energy function $\Pi(Q^2)$ at $Q^2=0$, from lattice QCD (LQCD) or from a dedicated low-energy experiment, one can obtain an evaluation of the lowest order HVP contribution to the anomalous magnetic moment of the muon $a_{\mu}^{\rm HVP}$ with an accuracy comparable to the one reached using the $e^+ e^-$ annihilation cross-section into hadrons. The technique of Mellin-Barnes approximants (MBa) that we propose is illustrated in detail with the example of the two loop vacuum polarization function in QED. We then apply it to the first few moments of the hadronic spectral function obtained from experiment and show that the resulting MBa evaluations of $a_{\mu}^{\rm HVP}$ converge very quickly to the full experimental determination.
hep-ph/0305072
Ulrich Jentschura
Ulrich D. Jentschura
Extrapolation of the Zalpha-Expansion and Two--Loop Bound--State Energy Shifts
10 pages, LaTeX, Phys. Lett. B, in press
Phys.Lett. B564 (2003) 225-230
10.1016/S0370-2693(03)00562-8
null
hep-ph
null
Quantum electrodynamic (QED) effects that shift the binding energies of hydrogenic energy levels have been expressed in terms of a semi-analytic expansion in powers of Zalpha and ln[(Zalpha)^{-2}], where Z is the nuclear charge number and alpha is the fine-structure constant. For many QED effects, numerical data are available in the domain of high Z where the Zalpha expansion fails. In this Letter, we demonstrate that it is possible, within certain limits of accuracy, to extrapolate the Zalpha-expansion from the low-Z to the high-Z domain. We also review two-loop self-energy effects and provide an estimate for the problematic nonlogarithmic coefficient B_60.
[ { "created": "Wed, 7 May 2003 13:29:10 GMT", "version": "v1" } ]
2009-11-10
[ [ "Jentschura", "Ulrich D.", "" ] ]
Quantum electrodynamic (QED) effects that shift the binding energies of hydrogenic energy levels have been expressed in terms of a semi-analytic expansion in powers of Zalpha and ln[(Zalpha)^{-2}], where Z is the nuclear charge number and alpha is the fine-structure constant. For many QED effects, numerical data are available in the domain of high Z where the Zalpha expansion fails. In this Letter, we demonstrate that it is possible, within certain limits of accuracy, to extrapolate the Zalpha-expansion from the low-Z to the high-Z domain. We also review two-loop self-energy effects and provide an estimate for the problematic nonlogarithmic coefficient B_60.
0804.2858
Federico Urban
Federico R. Urban
On the Brane Cosmology of KK Gravitinos
To appear in the Proceedings of the XXXVI ITEP Winter School 2008, Session ``Particle Physics'', held in Otradnoe, Moscow Region, Russia, February 8--16, 2008
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this report I consider the cosmology of KK gravitinos in models with extra dimensions, in particular in connection with the known non--standard high energy regime of expansion which is associated with them. The main result is that the production of such KK modes, once one considers BBN constraints on the allowed entropy released in their decays, is not compatible with non--standard expansion after inflation: there is no five--dimensional Planck mass for which the produced KK gravitinos are safe with respect to BBN. This conclusion holds for both flat and warped models in which only gravity propagates in the full spacetime. This report is based on the work arXiv:0705.4227 [hep-ph].
[ { "created": "Thu, 17 Apr 2008 17:17:37 GMT", "version": "v1" } ]
2008-04-18
[ [ "Urban", "Federico R.", "" ] ]
In this report I consider the cosmology of KK gravitinos in models with extra dimensions, in particular in connection with the known non--standard high energy regime of expansion which is associated with them. The main result is that the production of such KK modes, once one considers BBN constraints on the allowed entropy released in their decays, is not compatible with non--standard expansion after inflation: there is no five--dimensional Planck mass for which the produced KK gravitinos are safe with respect to BBN. This conclusion holds for both flat and warped models in which only gravity propagates in the full spacetime. This report is based on the work arXiv:0705.4227 [hep-ph].
1807.07823
Salvatore Marco Giampaolo
A. Capolupo, S. M. Giampaolo, G. Lambiase
Decoherence in neutrino oscillations, neutrino nature and CPT violation
7 pages, 3 figures
null
10.1016/j.physletb.2019.03.062
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze many aspects of the phenomenon of the decoherence for neutrinos propagating in long baseline experiments. We show that, in the presence of an off-diagonal term in the dissipative matrix, the Majorana neutrino can violate the CP T symmetry, which, on the contrary, is preserved for Dirac neutrinos. We show that oscillation formulas for Majorana neutrinos depend on the choice of the mixing matrix U. Indeed, different choices of U lead to different oscillation formulas. Moreover, we study the possibility to reveal the differences between Dirac and Majorana neutrinos in the oscillations. We use the present values of the experimental parameters in order to relate our theoretical proposal with experiments.
[ { "created": "Fri, 20 Jul 2018 13:03:59 GMT", "version": "v1" }, { "created": "Tue, 11 Sep 2018 11:35:27 GMT", "version": "v2" } ]
2019-05-22
[ [ "Capolupo", "A.", "" ], [ "Giampaolo", "S. M.", "" ], [ "Lambiase", "G.", "" ] ]
We analyze many aspects of the phenomenon of the decoherence for neutrinos propagating in long baseline experiments. We show that, in the presence of an off-diagonal term in the dissipative matrix, the Majorana neutrino can violate the CP T symmetry, which, on the contrary, is preserved for Dirac neutrinos. We show that oscillation formulas for Majorana neutrinos depend on the choice of the mixing matrix U. Indeed, different choices of U lead to different oscillation formulas. Moreover, we study the possibility to reveal the differences between Dirac and Majorana neutrinos in the oscillations. We use the present values of the experimental parameters in order to relate our theoretical proposal with experiments.
hep-ph/9312225
Noriaki Kitazawa
N.Kitazawa and T.Kurimoto
Heavy meson effective thoery with 1/M_Q correction
14pages, revtex
Phys.Lett. B323 (1994) 65-70
10.1016/0370-2693(94)00047-6
DPNU-93-37, OS-GE 38-93
hep-ph
null
We construct an effective Lagrangian of heavy and light mesons with $1/M_Q$ correction. The Lagrangian is constructed model independent way by using only the information of the symmetry of QCD. Reparameterisation invariance at the meson level is taken into account for the consistency of the theory. The partial decay width of the process $D^{*+} \rightarrow D^0 \pi^+$ and the form factors of the process ${\bar B}^0 \rightarrow \pi^+ l {\bar \nu}$ are calculated with the $1/M_Q$ correction. We also introduce the light vector mesons based on the approach of the hidden local symmetry. The form factors of the process ${\bar B}^0 \rightarrow \rho^+ l {\bar \nu}$ are calculated with thus introduced $\rho$-meson. These results are easily translated to the $D$-meson semileptonic decays.
[ { "created": "Mon, 6 Dec 1993 09:23:03 GMT", "version": "v1" } ]
2009-10-22
[ [ "Kitazawa", "N.", "" ], [ "Kurimoto", "T.", "" ] ]
We construct an effective Lagrangian of heavy and light mesons with $1/M_Q$ correction. The Lagrangian is constructed model independent way by using only the information of the symmetry of QCD. Reparameterisation invariance at the meson level is taken into account for the consistency of the theory. The partial decay width of the process $D^{*+} \rightarrow D^0 \pi^+$ and the form factors of the process ${\bar B}^0 \rightarrow \pi^+ l {\bar \nu}$ are calculated with the $1/M_Q$ correction. We also introduce the light vector mesons based on the approach of the hidden local symmetry. The form factors of the process ${\bar B}^0 \rightarrow \rho^+ l {\bar \nu}$ are calculated with thus introduced $\rho$-meson. These results are easily translated to the $D$-meson semileptonic decays.
hep-ph/0508009
Debajyoti Choudhury
Debajyoti Choudhury (Univ of Delhi, India), Madhumita Datta and Manas Maity (Visva-Bharati, India)
Looking for the Top-squark at the Tevatron with four jets
4 pages, 4 embedded figures, RevTeX
Phys.Rev. D73 (2006) 055013
10.1103/PhysRevD.73.055013
null
hep-ph
null
The scalar partner of the top quark is relatively light in many models of supersymmetry breaking. We study the production of top squarks (stops) at the Tevatron collider and their subsequent decay through baryon-number violating couplings such that the final state contains no leptons. Performing a detector-level analysis, we demonstrate that, even in the absence of leptons or missing energy, stop masses upto 210 \gev/c^2 can be accessible at the Tevatron.
[ { "created": "Sun, 31 Jul 2005 05:27:17 GMT", "version": "v1" } ]
2009-11-11
[ [ "Choudhury", "Debajyoti", "", "Univ of Delhi, India" ], [ "Datta", "Madhumita", "", "Visva-Bharati, India" ], [ "Maity", "Manas", "", "Visva-Bharati, India" ] ]
The scalar partner of the top quark is relatively light in many models of supersymmetry breaking. We study the production of top squarks (stops) at the Tevatron collider and their subsequent decay through baryon-number violating couplings such that the final state contains no leptons. Performing a detector-level analysis, we demonstrate that, even in the absence of leptons or missing energy, stop masses upto 210 \gev/c^2 can be accessible at the Tevatron.
hep-ph/9703211
Stephen P. Martin
S. Ambrosanio, Graham D. Kribs and Stephen P. Martin
Signals for gauge-mediated supersymmetry breaking models at the CERN LEP2 collider
36 pages, LaTeX, 10 figures embedded using epsf.sty (published version; minor changes in wording)
Phys.Rev.D56:1761-1777,1997
10.1103/PhysRevD.56.1761
null
hep-ph hep-ex
null
We consider a general class of models with gauge-mediated supersymmetry breaking in which the gravitino is the lightest supersymmetric particle. Several qualitatively different scenarios arise for the phenomenology of such models, depending on which superpartner(s) decay dominantly to the gravitino. At LEP2, neutralino pair production and slepton pair production can lead to a variety of promising discovery signals, which we systematically study. We investigate the impact of backgrounds for these signals and show how they can be reduced, and outline the effects of model parameter variations on the discovery potential.
[ { "created": "Sun, 2 Mar 1997 22:29:30 GMT", "version": "v1" }, { "created": "Wed, 25 Jun 1997 15:22:42 GMT", "version": "v2" } ]
2010-04-06
[ [ "Ambrosanio", "S.", "" ], [ "Kribs", "Graham D.", "" ], [ "Martin", "Stephen P.", "" ] ]
We consider a general class of models with gauge-mediated supersymmetry breaking in which the gravitino is the lightest supersymmetric particle. Several qualitatively different scenarios arise for the phenomenology of such models, depending on which superpartner(s) decay dominantly to the gravitino. At LEP2, neutralino pair production and slepton pair production can lead to a variety of promising discovery signals, which we systematically study. We investigate the impact of backgrounds for these signals and show how they can be reduced, and outline the effects of model parameter variations on the discovery potential.
0710.2846
Tri-Nang Pham
T. N. Pham
Two-photon decay of heavy quarkonium from heavy-quark spin symmetry
9 pages, Talk given at the QCD@Work 2007 International Workshop on QCD: Theory and Experiment}, Martina Franca, Italy, 16--20 June 2007
AIPConf.Proc.964:124-131,2007
10.1063/1.2823837
null
hep-ph
null
With the recent measurements on $\eta_{c}$ and $\eta_{c}^{\prime}$ at CLEO, Babar and Belle, and with the prospect of finding the $\eta_{b}$ at the Tevatron, it seems appropriate to have another look at the two-photon decay of heavy quarkonium from the standpoint of an effective Lagrangian based on local operator expansion and heavy-quark spin symmetry. In this talk, I would like to discuss a recent work on the two-photon decay rates of ground states and excited states of $\eta_c$ and $\eta_b$ using the local operator expansion approach and heavy-quark spin symmetry and taking into account the binding-energy. We find that the predicted two-photon width for $\eta_c$ agrees well with experiment, but the predicted value for $\eta_c(2S)$ is twice larger than the CLEO estimation. We point out that the essentially model-independent ratio of $\eta_b$ two-photon width to the $\Upsilon$ leptonic width and the $\eta_b $ two-photon width could be used to extract the strong coupling constant $\alpha_s$ .
[ { "created": "Mon, 15 Oct 2007 15:31:56 GMT", "version": "v1" } ]
2008-11-26
[ [ "Pham", "T. N.", "" ] ]
With the recent measurements on $\eta_{c}$ and $\eta_{c}^{\prime}$ at CLEO, Babar and Belle, and with the prospect of finding the $\eta_{b}$ at the Tevatron, it seems appropriate to have another look at the two-photon decay of heavy quarkonium from the standpoint of an effective Lagrangian based on local operator expansion and heavy-quark spin symmetry. In this talk, I would like to discuss a recent work on the two-photon decay rates of ground states and excited states of $\eta_c$ and $\eta_b$ using the local operator expansion approach and heavy-quark spin symmetry and taking into account the binding-energy. We find that the predicted two-photon width for $\eta_c$ agrees well with experiment, but the predicted value for $\eta_c(2S)$ is twice larger than the CLEO estimation. We point out that the essentially model-independent ratio of $\eta_b$ two-photon width to the $\Upsilon$ leptonic width and the $\eta_b $ two-photon width could be used to extract the strong coupling constant $\alpha_s$ .
hep-ph/9612247
L. B. Okun
L. B. Okun
Tests of CPT
Latex, 5 pages,Talk at the Workshop on $K$-physics, ORSAY, France, 30 May - 4 June, 1996
null
null
ITEP-TH-55/96
hep-ph
null
A few remarks concerning theoretical suggestions and experimental tests of CPT during 1980's - 1990's. Is it worth to search for the particle-antiparticle mass differences in sectors other than $K^0\bar{K}^0$?
[ { "created": "Wed, 4 Dec 1996 13:20:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Okun", "L. B.", "" ] ]
A few remarks concerning theoretical suggestions and experimental tests of CPT during 1980's - 1990's. Is it worth to search for the particle-antiparticle mass differences in sectors other than $K^0\bar{K}^0$?
hep-ph/0301022
Prasanta Kumar Das
Uma Mahanta and Prasanta Das
The effect of a light radion on the triviality bound on higgs mass
9 pages, latex, 2 eps figures
Int.J.Mod.Phys.A20:1089-1093,2005
10.1142/S0217751X05020719
null
hep-ph
null
In this paper we study how the triviality bound on higgs mass in the context of the SM is modified by a light stabilized radion of the Goldberger-Wise variety. Our approach is inherently perturbative. Including the radion contribution to $\bt(\l)$ and $\bt(g_t)$ to one loop we evolve the higgs self coupling $\l$ from the cut off $\L(=\vphi)$ down to the EW scale $\mu_0 = v$. The triviality bound is obtained by requiring that $\l(\L) = \sqrt{4 \pi}$ which is the perturbative limit. We also study the effect of small changes in the UVBC on the triviality bound both in the presence and absence of a light radion.
[ { "created": "Sun, 5 Jan 2003 18:13:30 GMT", "version": "v1" } ]
2010-11-05
[ [ "Mahanta", "Uma", "" ], [ "Das", "Prasanta", "" ] ]
In this paper we study how the triviality bound on higgs mass in the context of the SM is modified by a light stabilized radion of the Goldberger-Wise variety. Our approach is inherently perturbative. Including the radion contribution to $\bt(\l)$ and $\bt(g_t)$ to one loop we evolve the higgs self coupling $\l$ from the cut off $\L(=\vphi)$ down to the EW scale $\mu_0 = v$. The triviality bound is obtained by requiring that $\l(\L) = \sqrt{4 \pi}$ which is the perturbative limit. We also study the effect of small changes in the UVBC on the triviality bound both in the presence and absence of a light radion.
1605.02496
Kazem Azizi
S. S. Agaev, K. Azizi, H. Sundu
Application of the QCD light cone sum rule to tetraquarks: the strong vertices $X_bX_b\rho$ and $X_cX_c\rho$
10 Pages, 5 Figures and 1 Table
Phys. Rev. D 93, 114036 (2016)
10.1103/PhysRevD.93.114036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The full version of QCD light-cone sum rule method is applied to tetraquarks containing a single heavy $b$ or $c$ quark. To this end, investigations of the strong vertices $X_{b}X_{b}\rho$ and $X_{c}X_{c}\rho$ are performed, where $X_b=[su][\bar b\bar d]$ and $X_c=[su][\bar c\bar d]$ are the exotic states built of four quarks of different flavors. The strong coupling constants $G_{X_{b}X_{b}\rho}$ and $G_{X_{c}X_{c}\rho}$ corresponding to these vertices are found using the $\rho$-meson leading and higher-twist distribution amplitudes. In the calculations $X_{b}$ and $X_{c}$ are treated as scalar bound states of a diquark and antidiquark.
[ { "created": "Mon, 9 May 2016 09:51:43 GMT", "version": "v1" }, { "created": "Mon, 27 Jun 2016 18:31:26 GMT", "version": "v2" }, { "created": "Fri, 24 Feb 2017 11:46:35 GMT", "version": "v3" } ]
2017-02-27
[ [ "Agaev", "S. S.", "" ], [ "Azizi", "K.", "" ], [ "Sundu", "H.", "" ] ]
The full version of QCD light-cone sum rule method is applied to tetraquarks containing a single heavy $b$ or $c$ quark. To this end, investigations of the strong vertices $X_{b}X_{b}\rho$ and $X_{c}X_{c}\rho$ are performed, where $X_b=[su][\bar b\bar d]$ and $X_c=[su][\bar c\bar d]$ are the exotic states built of four quarks of different flavors. The strong coupling constants $G_{X_{b}X_{b}\rho}$ and $G_{X_{c}X_{c}\rho}$ corresponding to these vertices are found using the $\rho$-meson leading and higher-twist distribution amplitudes. In the calculations $X_{b}$ and $X_{c}$ are treated as scalar bound states of a diquark and antidiquark.
2101.00142
Xingchen Xu
Xingchen Xu, Glennys R. Farrar
Resonant Scattering between Dark Matter and Baryons: Revised Direct Detection and CMB Limits
31+10 pages,15+3 figures. v2 adds some citations and additional analyses: (1) repulsive as well as attractive interaction, (2) separate analysis of CMB and CMB+Ly-alpha limits & non-trivial role of DM-He scattering relative to Born case, (3) Milky Way gas clouds and Milky Way satellites, (4) velocity dependence near resonances (& approximate analytic expression), (4) dependence on mediator mass
null
null
null
hep-ph astro-ph.CO astro-ph.HE hep-ex
http://creativecommons.org/licenses/by-nc-nd/4.0/
Traditional dark matter models, eg. WIMPs, assume dark matter is weakly coupled to the standard model so that elastic scattering between dark matter and baryons can be described perturbatively by Born approximation. Most direct detection experiments are analyzed according to that assumption. We show that when the fundamental DM-baryon interaction is attractive, dark matter-nucleus scattering is non-perturbative in much of the relevant parameter range. The cross section exhibits rich resonant behavior with a highly non-trivial dependence on atomic mass; furthermore, the extended rather than point-like nature of nuclei significantly impacts the cross sections. The repulsive case also requires full numerical calculation. These non-perturbative effects change existing constraints. Near a resonance value of the parameters, the cross section has non-trivial velocity dependence rather than the usual $\sigma \sim v^0$; we take the velocity dependence into account. (However doing so has little impact on current constraints.) We report the corrected exclusion regions superseding previous limits from XQC, CRESST Surface Run, CMB power spectrum and extensions with Lyman-$\alpha$ and Milky Way satellites, and Milky Way gas clouds. Some limits become weaker than previous bounds in the literature, while others become stronger. Gaps which open by correct treatment of some particular constraint can sometimes be closed using a different constraint. We also discuss the dependence on mediator mass and give approximate expressions for the velocity dependence near a resonance. Sexaquark ($uuddss$) DM with mass around 2 GeV, which exchanges QCD mesons with baryons, remains unconstrained for most of the parameter space of interest. A statement in the literature that a DM-nucleus cross section larger than $10^{-25}\,{\rm cm}^2$ implies dark matter is composite, is corrected.
[ { "created": "Fri, 1 Jan 2021 02:41:08 GMT", "version": "v1" }, { "created": "Thu, 2 Dec 2021 12:52:26 GMT", "version": "v2" } ]
2021-12-03
[ [ "Xu", "Xingchen", "" ], [ "Farrar", "Glennys R.", "" ] ]
Traditional dark matter models, eg. WIMPs, assume dark matter is weakly coupled to the standard model so that elastic scattering between dark matter and baryons can be described perturbatively by Born approximation. Most direct detection experiments are analyzed according to that assumption. We show that when the fundamental DM-baryon interaction is attractive, dark matter-nucleus scattering is non-perturbative in much of the relevant parameter range. The cross section exhibits rich resonant behavior with a highly non-trivial dependence on atomic mass; furthermore, the extended rather than point-like nature of nuclei significantly impacts the cross sections. The repulsive case also requires full numerical calculation. These non-perturbative effects change existing constraints. Near a resonance value of the parameters, the cross section has non-trivial velocity dependence rather than the usual $\sigma \sim v^0$; we take the velocity dependence into account. (However doing so has little impact on current constraints.) We report the corrected exclusion regions superseding previous limits from XQC, CRESST Surface Run, CMB power spectrum and extensions with Lyman-$\alpha$ and Milky Way satellites, and Milky Way gas clouds. Some limits become weaker than previous bounds in the literature, while others become stronger. Gaps which open by correct treatment of some particular constraint can sometimes be closed using a different constraint. We also discuss the dependence on mediator mass and give approximate expressions for the velocity dependence near a resonance. Sexaquark ($uuddss$) DM with mass around 2 GeV, which exchanges QCD mesons with baryons, remains unconstrained for most of the parameter space of interest. A statement in the literature that a DM-nucleus cross section larger than $10^{-25}\,{\rm cm}^2$ implies dark matter is composite, is corrected.
2102.12237
Johannes Bl\"umlein
J. Bl\"umlein, A. De Freitas, and K. Sch\"onwald
The QED Initial State Corrections to the Forward-Backward Asymmetry of $e^+e^- \to \gamma^*/Z^{0*}$ to Higher Orders
Dedicated to the Memory of Tini Veltman, who made it possible to probe the Standard Model at high precision
null
10.1016/j.physletb.2021.136250
DESY 21--013, DO--TH 21/04, TTP21--004, SAGEX--21--03
hep-ph hep-ex
http://creativecommons.org/licenses/by-sa/4.0/
The QED initial state corrections are calculated to the forward-backward asymmetry for $e^+e^- \rightarrow \gamma^*/{Z^{0}}^*$ in the leading logarithmic approximation to $O(\alpha^6 L^6)$ extending the known corrections up to $O(\alpha^2 L^2)$ in analytic form. We use the method of massive on-shell operator matrix elements and present the radiators both in Mellin-$N$ and momentum fraction $z$-space. Numerical results are presented for various energies around the $Z$-peak by also including energy cuts. These corrections are of relevance for the precision measurements at the FCC$\_$ee.
[ { "created": "Wed, 24 Feb 2021 11:59:59 GMT", "version": "v1" } ]
2021-04-28
[ [ "Blümlein", "J.", "" ], [ "De Freitas", "A.", "" ], [ "Schönwald", "K.", "" ] ]
The QED initial state corrections are calculated to the forward-backward asymmetry for $e^+e^- \rightarrow \gamma^*/{Z^{0}}^*$ in the leading logarithmic approximation to $O(\alpha^6 L^6)$ extending the known corrections up to $O(\alpha^2 L^2)$ in analytic form. We use the method of massive on-shell operator matrix elements and present the radiators both in Mellin-$N$ and momentum fraction $z$-space. Numerical results are presented for various energies around the $Z$-peak by also including energy cuts. These corrections are of relevance for the precision measurements at the FCC$\_$ee.
hep-ph/9311294
Gregory Korchemsky
G.P.Korchemsky
On near forward high energy scattering in QCD
LaTeX style, 13 pages, 4 figures (included)
Phys.Lett. B325 (1994) 459-466
10.1016/0370-2693(94)90040-X
ITP-SB-93-73
hep-ph hep-th
null
We consider elastic quark-quark scattering at high energy and fixed transferred momentum. Performing factorization of soft gluon exchanges into Wilson lines vacuum expectation values and studying their properties, we find that the asymptotics of the scattering amplitude is controlled by the renormalization properties of the so called cross singularities of Wilson loops. Using this fact, we evaluate the scattering amplitude and show that its asymptotics is determined by the properties of the $2\times 2$ matrix of anomalous dimensions which appears after one renormalizes the cross singularities of Wilson loops. A generalization to the case of quark-antiquark and gluon-gluon elastic scattering is discussed.
[ { "created": "Mon, 15 Nov 1993 17:25:07 GMT", "version": "v1" }, { "created": "Tue, 23 Nov 1993 18:39:12 GMT", "version": "v2" } ]
2009-10-22
[ [ "Korchemsky", "G. P.", "" ] ]
We consider elastic quark-quark scattering at high energy and fixed transferred momentum. Performing factorization of soft gluon exchanges into Wilson lines vacuum expectation values and studying their properties, we find that the asymptotics of the scattering amplitude is controlled by the renormalization properties of the so called cross singularities of Wilson loops. Using this fact, we evaluate the scattering amplitude and show that its asymptotics is determined by the properties of the $2\times 2$ matrix of anomalous dimensions which appears after one renormalizes the cross singularities of Wilson loops. A generalization to the case of quark-antiquark and gluon-gluon elastic scattering is discussed.
1903.00698
Aleksey Pivovarov
M. K. Volkov, Aleksey A. Pivovarov and K. Nurlan
The tetraquark $K_{1}(1400)$ in the decays $\tau \to [\omega(782), \phi(1020)] K^{-} \nu_{\tau}$
Another explanation of the nature of the physical state $K_{1}(1400)$ was found
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the extended Nambu--Jona-Lasinio model, the decay widths of the processes $\tau \to [\omega(782), \phi(1020)] K^{-} \nu_{\tau}$ were calculated. The intermediate strange quark-antiquark mesons in both the ground and the first radially excited states were taken into account. The meson $K_{1}(1400)$, being a possible candidate for the role of the tetraquark meson, was also taken into account as an intermediate state. The result for the process $\tau \to \omega(782) K^{-} \nu_{\tau}$ is in satisfactory agreement with the experimental data. Simultaneously, the result for the decay $\tau \to \phi(1020) K^{-} \nu_{\tau}$ is in agreement with the experimental data with precision $1.3 \sigma$.
[ { "created": "Sat, 2 Mar 2019 13:21:42 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2019 09:22:59 GMT", "version": "v2" } ]
2019-06-26
[ [ "Volkov", "M. K.", "" ], [ "Pivovarov", "Aleksey A.", "" ], [ "Nurlan", "K.", "" ] ]
In the extended Nambu--Jona-Lasinio model, the decay widths of the processes $\tau \to [\omega(782), \phi(1020)] K^{-} \nu_{\tau}$ were calculated. The intermediate strange quark-antiquark mesons in both the ground and the first radially excited states were taken into account. The meson $K_{1}(1400)$, being a possible candidate for the role of the tetraquark meson, was also taken into account as an intermediate state. The result for the process $\tau \to \omega(782) K^{-} \nu_{\tau}$ is in satisfactory agreement with the experimental data. Simultaneously, the result for the decay $\tau \to \phi(1020) K^{-} \nu_{\tau}$ is in agreement with the experimental data with precision $1.3 \sigma$.
1610.08196
Ilya F. Ginzburg
I.F. Ginzburg
What tell us LHC data about Higgs boson parity
4 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently CMS and ATLAS announced that they had measured the Higgs boson parity. Here we note that their approach can determine this parity only under the additional assumption that this particle has a definite parity. If parity conservation is violated in the Higgs sector, the parity of observed "Higgs" boson does not exist. The approach used in the mentioned experiments does not allow to observe such opportunity. In this sense titles of mentioned CMS and ATLAS publications are misleading.
[ { "created": "Wed, 26 Oct 2016 06:42:31 GMT", "version": "v1" } ]
2016-10-27
[ [ "Ginzburg", "I. F.", "" ] ]
Recently CMS and ATLAS announced that they had measured the Higgs boson parity. Here we note that their approach can determine this parity only under the additional assumption that this particle has a definite parity. If parity conservation is violated in the Higgs sector, the parity of observed "Higgs" boson does not exist. The approach used in the mentioned experiments does not allow to observe such opportunity. In this sense titles of mentioned CMS and ATLAS publications are misleading.
1006.2379
Charles Gale
Simon Caron-Huot and Charles Gale
Finite-size effects on the radiative energy loss of a fast parton in hot and dense strongly interacting matter
15 pages, 7 figures, typos and references corrected. Clearer figures. Harmonized with published version
Phys.Rev.C82:064902,2010
10.1103/PhysRevC.82.064902
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider finite-size effects on the radiative energy loss of a fast parton moving in a finite temperature strongly interacting medium, using the light cone path integral formalism put forward by Zakharov. We present a convenient reformulation of the problem which makes possible its exact numerical analysis. This is done by introducing the concept of a radiation rate in the presence of finite-size effects. This effectively extends the finite-temperature approach of AMY (Arnold, Moore, and Yaffe) to include interference between vacuum and medium radiation. We compare results with those obtained in the regime considered by AMY, with those obtained at leading order in an opacity expansion, and with those obtained deep in the LPM (Landau-Pomeranchuk-Migdal) regime.
[ { "created": "Fri, 11 Jun 2010 19:55:54 GMT", "version": "v1" }, { "created": "Mon, 6 Dec 2010 16:12:03 GMT", "version": "v2" } ]
2010-12-24
[ [ "Caron-Huot", "Simon", "" ], [ "Gale", "Charles", "" ] ]
We consider finite-size effects on the radiative energy loss of a fast parton moving in a finite temperature strongly interacting medium, using the light cone path integral formalism put forward by Zakharov. We present a convenient reformulation of the problem which makes possible its exact numerical analysis. This is done by introducing the concept of a radiation rate in the presence of finite-size effects. This effectively extends the finite-temperature approach of AMY (Arnold, Moore, and Yaffe) to include interference between vacuum and medium radiation. We compare results with those obtained in the regime considered by AMY, with those obtained at leading order in an opacity expansion, and with those obtained deep in the LPM (Landau-Pomeranchuk-Migdal) regime.
1605.08442
Sebastian Macaluso
Aria Basirnia, Sebastian Macaluso and David Shih
Dark Matter and the Higgs in Natural SUSY
37 pages, 15 figures, updated LUX limits
null
10.1007/JHEP03(2017)073
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Null results from dark matter (DM) direct detection experiments and the 125 GeV Higgs both pose serious challenges to minimal supersymmetry. In this paper, we propose a simple extension of the MSSM that economically solves both problems: a "dark sector" consisting of a singlet and a pair of $SU(2)$ doublets. Loops of the dark sector fields help lift the Higgs mass to 125 GeV consistent with naturalness, while the lightest fermion in the dark sector can be viable thermal relic DM, provided that it is mostly singlet. The DM relic abundance is controlled by s-wave annihilation to tops and Higgsinos, leading to a tight relation between the relic abundance and the spin-dependent direct detection cross section. As a result, the model will be fully probed by the next generation of direct detection experiments. Finally we discuss the discovery potential at LHC Run II.
[ { "created": "Thu, 26 May 2016 20:02:20 GMT", "version": "v1" }, { "created": "Tue, 22 Nov 2016 19:22:32 GMT", "version": "v2" } ]
2017-04-05
[ [ "Basirnia", "Aria", "" ], [ "Macaluso", "Sebastian", "" ], [ "Shih", "David", "" ] ]
Null results from dark matter (DM) direct detection experiments and the 125 GeV Higgs both pose serious challenges to minimal supersymmetry. In this paper, we propose a simple extension of the MSSM that economically solves both problems: a "dark sector" consisting of a singlet and a pair of $SU(2)$ doublets. Loops of the dark sector fields help lift the Higgs mass to 125 GeV consistent with naturalness, while the lightest fermion in the dark sector can be viable thermal relic DM, provided that it is mostly singlet. The DM relic abundance is controlled by s-wave annihilation to tops and Higgsinos, leading to a tight relation between the relic abundance and the spin-dependent direct detection cross section. As a result, the model will be fully probed by the next generation of direct detection experiments. Finally we discuss the discovery potential at LHC Run II.
hep-ph/0701253
Kevin Dusling
Kevin Dusling and Ismail Zahed
Transverse momentum spectra of dileptons at NA60
10 pages, 5 figures
Phys.Rev.C80:014902,2009
10.1103/PhysRevC.80.014902
null
hep-ph
null
Recently the NA60 collaboration has reported the transverse mass spectra of dimuons coming from In-In collisions at 158 GeV/A. The measured yields display a strong invariant mass dependence not typical of radial flow, suggesting that different sources contribute in different mass regions. We interpret the dimuon transverse mass spectra from an early thermalized partonic phase and hadronic phase constrained by the strictures of broken chiral symmetry. Each phase develops a specific transverse momentum dependence by hydrodynamical expansion. We show that a measurement of the momentum anisotropy at NA60 could provide information on the dominant emission source (hadronic or partonic) in the intermediate mass region 1.5 <= M <= 3.0 GeV.
[ { "created": "Tue, 30 Jan 2007 18:45:18 GMT", "version": "v1" } ]
2009-08-18
[ [ "Dusling", "Kevin", "" ], [ "Zahed", "Ismail", "" ] ]
Recently the NA60 collaboration has reported the transverse mass spectra of dimuons coming from In-In collisions at 158 GeV/A. The measured yields display a strong invariant mass dependence not typical of radial flow, suggesting that different sources contribute in different mass regions. We interpret the dimuon transverse mass spectra from an early thermalized partonic phase and hadronic phase constrained by the strictures of broken chiral symmetry. Each phase develops a specific transverse momentum dependence by hydrodynamical expansion. We show that a measurement of the momentum anisotropy at NA60 could provide information on the dominant emission source (hadronic or partonic) in the intermediate mass region 1.5 <= M <= 3.0 GeV.
2012.06911
Luigi Delle Rose
Luigi Delle Rose, Shaaban Khalil, Stefano Moretti
Explaining electron and muon $g-2$ anomalies in an Aligned 2-Higgs Doublet Model with Right-Handed Neutrinos
9 pages, 4 figures
null
10.1016/j.physletb.2021.136216
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explain anomalies currently present in various data samples used for the measurement of the anomalous magnetic moment of electron ($a_e$) and muon ($a_\mu$) in terms of an Aligned 2-Higgs Doublet Model with right-handed neutrinos. The explanation is driven by one and two-loop topologies wherein a very light CP-odd neutral Higgs state ($A$) contributes significantly to $a_\mu$ but negligibly to $a_e$, so as to revert the sign of the new physics corrections in the former case with respect to the latter, wherein the dominant contribution is due to a charged Higgs boson ($H^\pm$) and heavy neutrinos with mass at the electroweak scale. For the region of parameter space of our new physics model which explains the aforementioned anomalies we also predict an almost background-free smoking-gun signature of it, consisting of $H^\pm A$ production followed by Higgs boson decays yielding multi-$\tau$ final states, which can be pursued at the Large Hadron Collider.
[ { "created": "Sat, 12 Dec 2020 22:19:47 GMT", "version": "v1" } ]
2021-03-24
[ [ "Rose", "Luigi Delle", "" ], [ "Khalil", "Shaaban", "" ], [ "Moretti", "Stefano", "" ] ]
We explain anomalies currently present in various data samples used for the measurement of the anomalous magnetic moment of electron ($a_e$) and muon ($a_\mu$) in terms of an Aligned 2-Higgs Doublet Model with right-handed neutrinos. The explanation is driven by one and two-loop topologies wherein a very light CP-odd neutral Higgs state ($A$) contributes significantly to $a_\mu$ but negligibly to $a_e$, so as to revert the sign of the new physics corrections in the former case with respect to the latter, wherein the dominant contribution is due to a charged Higgs boson ($H^\pm$) and heavy neutrinos with mass at the electroweak scale. For the region of parameter space of our new physics model which explains the aforementioned anomalies we also predict an almost background-free smoking-gun signature of it, consisting of $H^\pm A$ production followed by Higgs boson decays yielding multi-$\tau$ final states, which can be pursued at the Large Hadron Collider.
1909.09527
Bj\"orn Herrmann
J. Branahl, J. Harz, B. Herrmann, M. Klasen, K. Kova\v{r}\'ik, S. Schmiemann
SUSY-QCD corrected and Sommerfeld enhanced stau annihilation into heavy quarks with scheme and scale uncertainties
12 pages, 11 figures. Minor changes, matches published version
Phys. Rev. D 100, 115003 (2019)
10.1103/PhysRevD.100.115003
LAPTH-045/19, MS-TP-19-28, TUM-HEP-1226-19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate stau-antistau annihilation into heavy quarks in the phenomenological Minimal Supersymmetric Standard Model within the DM@NLO project. We present the calculation of the corresponding cross section including corrections up to $\mathcal{O}(\alpha_s)$ and QED Sommerfeld enhancement. The numerical impact of these corrections is discussed for the cross section and the dark matter relic density, where we focus on top-quark final states and consider either neutralino or gravitino dark matter. Similarly to previous work, we find that the presented corrections should be included when calculating the relic density or extracting parameters from cosmological observations. Considering scheme and scale variations, we estimate the theoretical uncertainty that affects the prediction of the annihilation cross section and thus the prediction of the relic density.
[ { "created": "Fri, 20 Sep 2019 14:29:06 GMT", "version": "v1" }, { "created": "Tue, 26 Nov 2019 17:15:53 GMT", "version": "v2" } ]
2019-12-11
[ [ "Branahl", "J.", "" ], [ "Harz", "J.", "" ], [ "Herrmann", "B.", "" ], [ "Klasen", "M.", "" ], [ "Kovařík", "K.", "" ], [ "Schmiemann", "S.", "" ] ]
We investigate stau-antistau annihilation into heavy quarks in the phenomenological Minimal Supersymmetric Standard Model within the DM@NLO project. We present the calculation of the corresponding cross section including corrections up to $\mathcal{O}(\alpha_s)$ and QED Sommerfeld enhancement. The numerical impact of these corrections is discussed for the cross section and the dark matter relic density, where we focus on top-quark final states and consider either neutralino or gravitino dark matter. Similarly to previous work, we find that the presented corrections should be included when calculating the relic density or extracting parameters from cosmological observations. Considering scheme and scale variations, we estimate the theoretical uncertainty that affects the prediction of the annihilation cross section and thus the prediction of the relic density.
hep-ph/0411096
Giacomo Sguazzoni
Giacomo Sguazzoni
Higgs and Beyond Standard Model Searches at LEP
10 pages, 7 figures, talk presented at Hadron Structure 2004, Smolenice Castle, Slovakia
Acta Phys.Slov. 55 (2005) 93-102
null
null
hep-ph
null
Extensive searches for Higgs bosons and other new phenomena predicted by extensions of the Standard Model have been performed at LEP. A summary is given reviewing the principal aspects and presenting a selection of results.
[ { "created": "Sat, 6 Nov 2004 00:37:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sguazzoni", "Giacomo", "" ] ]
Extensive searches for Higgs bosons and other new phenomena predicted by extensions of the Standard Model have been performed at LEP. A summary is given reviewing the principal aspects and presenting a selection of results.
1603.05808
Samoil Bilenky M.
S. M. Bilenky
Comments on the determination of the neutrino mass ordering in reactor neutrino experiments
null
null
10.1134/S1547477117030050
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of determination of the neutrino mass ordering via precise study of the vacuum neutrino oscillations in the JUNO and other future medium baseline reactor neutrino experiments. We are proposing to resolve neutrino mass ordering by determination of the neutrino oscillation parameters from analysis of the data of the reactor experiments and comparison them with the oscillation parameters obtained from analysis of the solar and KamLAND experiments.
[ { "created": "Fri, 18 Mar 2016 09:54:17 GMT", "version": "v1" } ]
2017-06-07
[ [ "Bilenky", "S. M.", "" ] ]
We consider the problem of determination of the neutrino mass ordering via precise study of the vacuum neutrino oscillations in the JUNO and other future medium baseline reactor neutrino experiments. We are proposing to resolve neutrino mass ordering by determination of the neutrino oscillation parameters from analysis of the data of the reactor experiments and comparison them with the oscillation parameters obtained from analysis of the solar and KamLAND experiments.
0706.1729
Bruno Machet
Quentin Duret (LPTHE), Bruno Machet (LPTHE)
Mixing angles of quarks and leptons as an outcome of SU(2) horizontal symmetries
While calculations are unchanged w.r.t. arXiv:0705.1237, the horizontal symmetries controlling the mixing angles have been uncovered, motivating a change of title and a new entry in the arXiv. A new point of view about which angles are measured has also been adopted
null
null
null
hep-ph
null
We show that all mixing angles are determined, within experimental uncertainty, by a product of SU(2) horizontal symmetries intimately linked to the algebra of weak neutral currents. This concerns: on one hand, the three quark mixing angles; on the other hand, a neutrino-like pattern in which theta_{23} is maximal and tan (2 theta_{12}) = 2. The latter turns out to exactly satisfy the ``quark-lepton complementarity condition'' theta_c + theta_{12} = pi/4. Moreover, among all solutions, two values for the third neutrino mixing angle arise, which satisfy the bound sin^2(theta_{13}) \leq 0.1: theta_{13} = +/- 5.7 10^{-3} and theta_{13} = +/- 0.2717.
[ { "created": "Tue, 12 Jun 2007 15:30:46 GMT", "version": "v1" } ]
2007-06-13
[ [ "Duret", "Quentin", "", "LPTHE" ], [ "Machet", "Bruno", "", "LPTHE" ] ]
We show that all mixing angles are determined, within experimental uncertainty, by a product of SU(2) horizontal symmetries intimately linked to the algebra of weak neutral currents. This concerns: on one hand, the three quark mixing angles; on the other hand, a neutrino-like pattern in which theta_{23} is maximal and tan (2 theta_{12}) = 2. The latter turns out to exactly satisfy the ``quark-lepton complementarity condition'' theta_c + theta_{12} = pi/4. Moreover, among all solutions, two values for the third neutrino mixing angle arise, which satisfy the bound sin^2(theta_{13}) \leq 0.1: theta_{13} = +/- 5.7 10^{-3} and theta_{13} = +/- 0.2717.
1209.0817
Soeren Schlichting
J. Berges, S. Schlichting
The non-linear Glasma
16 pages, 7 figures, to appear in Phys. Rev. D
null
10.1103/PhysRevD.87.014026
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the evolution of quantum fluctuations in the Glasma created immediately after the collision of heavy nuclei. It is shown how the presence of instabilities leads to an enhancement of non-linear interactions among initially small fluctuations. The non-linear dynamics leads to an enhanced growth of fluctuations in a large momentum region exceeding by far the originally unstable band. We investigate the dependence on the coupling constant at weak coupling using classical statistical lattice simulations for SU(2) gauge theory and show how these non-linearities can be analytically understood within the framework of two-particle irreducible (2PI) effective action techniques. The dependence on the coupling constant is only logarithmic in accordance with analytic expectations. Concerning the isotropization of bulk quantities, our results indicate that the system exhibits an order-one anisotropy on parametrically large time scales. Despite this fact, we find that gauge invariant pressure correlation functions seem to exhibit a power law behavior characteristic for wave turbulence.
[ { "created": "Tue, 4 Sep 2012 22:15:59 GMT", "version": "v1" }, { "created": "Tue, 8 Jan 2013 15:26:51 GMT", "version": "v2" } ]
2013-05-30
[ [ "Berges", "J.", "" ], [ "Schlichting", "S.", "" ] ]
We study the evolution of quantum fluctuations in the Glasma created immediately after the collision of heavy nuclei. It is shown how the presence of instabilities leads to an enhancement of non-linear interactions among initially small fluctuations. The non-linear dynamics leads to an enhanced growth of fluctuations in a large momentum region exceeding by far the originally unstable band. We investigate the dependence on the coupling constant at weak coupling using classical statistical lattice simulations for SU(2) gauge theory and show how these non-linearities can be analytically understood within the framework of two-particle irreducible (2PI) effective action techniques. The dependence on the coupling constant is only logarithmic in accordance with analytic expectations. Concerning the isotropization of bulk quantities, our results indicate that the system exhibits an order-one anisotropy on parametrically large time scales. Despite this fact, we find that gauge invariant pressure correlation functions seem to exhibit a power law behavior characteristic for wave turbulence.
hep-ph/0512025
Massimiliano Grazzini
M. Grazzini
The transverse-momentum distribution of the Higgs boson at the LHC
4 pages, 2 figures, to appear in the Proceedings of the International Europhysics Conference on High Energy Physics, July 21st - 27th 2005, Lisboa, Portugal
null
null
DFF 430/12/05
hep-ph
null
We present QCD predictions for the transverse momentum (q_T) distribution of the Higgs boson at the LHC. At small q_T the logarithmically-enhanced terms are resummed to all orders up to next-to-next-to-leading logarithmic accuracy. The resummed component is consistently matched to the next-to-leading order calculation valid at large q_T. The results, which implement the most advanced perturbative predictions available at present for this observable, show a good stability with respect to theoretical uncertainties. The numerical program HqT, used to perform the calculation, is briefly discussed.
[ { "created": "Fri, 2 Dec 2005 09:48:01 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grazzini", "M.", "" ] ]
We present QCD predictions for the transverse momentum (q_T) distribution of the Higgs boson at the LHC. At small q_T the logarithmically-enhanced terms are resummed to all orders up to next-to-next-to-leading logarithmic accuracy. The resummed component is consistently matched to the next-to-leading order calculation valid at large q_T. The results, which implement the most advanced perturbative predictions available at present for this observable, show a good stability with respect to theoretical uncertainties. The numerical program HqT, used to perform the calculation, is briefly discussed.
hep-ph/0408024
Shunzo Kumano
M. Hirai, S. Kumano, and N. Saito (Asymmetry Analysis Collaboration)
AAC analysis of polarized parton distributions with uncertainties
4 pages, LaTeX, 4 eps files, dis04.cls, to be published in the proceedings of the 12th International Workshop on Deep Inelastic Scattering (DIS04), Strbske-Pleso, Slovakia, April 14-18, 2004. Polarized PDF library is available at http://spin.riken.bnl.gov/aac/
null
null
SAGA-HE-210-04
hep-ph hep-ex nucl-ex nucl-th
null
We report recent studies of the Asymmetry Analysis Collaboration (AAC) on polarized parton distribution functions (PDFs). Using the data on the spin symmetry A_1 in deep inelastic lepton scattering, we investigate optimum polarized PDFs. Their uncertainties are estimated by the Hessian method. The uncertainties are large for the polarized antiquark and gluon distributions. We discuss the role of accurate SLAC-E155 proton data on the determination of the PDFs. The obtained distributions are compared with other parametrization results.
[ { "created": "Tue, 3 Aug 2004 01:33:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Hirai", "M.", "", "Asymmetry Analysis Collaboration" ], [ "Kumano", "S.", "", "Asymmetry Analysis Collaboration" ], [ "Saito", "N.", "", "Asymmetry Analysis Collaboration" ] ]
We report recent studies of the Asymmetry Analysis Collaboration (AAC) on polarized parton distribution functions (PDFs). Using the data on the spin symmetry A_1 in deep inelastic lepton scattering, we investigate optimum polarized PDFs. Their uncertainties are estimated by the Hessian method. The uncertainties are large for the polarized antiquark and gluon distributions. We discuss the role of accurate SLAC-E155 proton data on the determination of the PDFs. The obtained distributions are compared with other parametrization results.
hep-ph/0307318
Sancho Moura Oliveira
S. M. Oliveira and R. Santos (CFTC, Univ. de Lisboa)
Bounds on the mass of the b' quark, revisited
9 pages and 7 figures. REVTEX4
Phys.Rev.D68:093012,2003
10.1103/PhysRevD.68.093012
null
hep-ph
null
Recent results from the DELPHI collaboration led us to review the present bounds on the b' quark mass. We use all available experimental data for m_b' > 96 GeV to constrain the b' quark mass as a function of the Cabibbo-Kobayashi-Maskawa elements in a sequential four generations model. We find that there is still room for a b' with a mass larger than 96 GeV.
[ { "created": "Fri, 25 Jul 2003 15:03:34 GMT", "version": "v1" }, { "created": "Thu, 31 Jul 2003 12:43:02 GMT", "version": "v2" } ]
2011-03-23
[ [ "Oliveira", "S. M.", "", "CFTC, Univ. de Lisboa" ], [ "Santos", "R.", "", "CFTC, Univ. de Lisboa" ] ]
Recent results from the DELPHI collaboration led us to review the present bounds on the b' quark mass. We use all available experimental data for m_b' > 96 GeV to constrain the b' quark mass as a function of the Cabibbo-Kobayashi-Maskawa elements in a sequential four generations model. We find that there is still room for a b' with a mass larger than 96 GeV.
hep-ph/0002104
Adam Lewandowski
Adam Lewandowski
Constraints on a Model with Pure Right-Handed Third Generation Couplings
14 pages
Phys.Rev. D62 (2000) 055007
10.1103/PhysRevD.62.055007
JHU-TIPAC-200001
hep-ph
null
We examine constraints on a model with pure right-handed third generation charged couplings. The parameters of the right-handed mixing matrix and the right-handed coupling strength are constrained from semi-leptonic B decays, the mass difference of neutral mesons, the CP violating observables epsilon and epsilon', and the electric dipole moment of the neutron. We find the model to be tightly constrained by these parameters with several fine tuning conditions on the phases in the right-handed mixing matrix. There is also a necessarily non-zero value of the left and right W mixing parameter. CP asymmetry phases in neutral B decays are discussed.
[ { "created": "Wed, 9 Feb 2000 18:50:33 GMT", "version": "v1" } ]
2009-10-31
[ [ "Lewandowski", "Adam", "" ] ]
We examine constraints on a model with pure right-handed third generation charged couplings. The parameters of the right-handed mixing matrix and the right-handed coupling strength are constrained from semi-leptonic B decays, the mass difference of neutral mesons, the CP violating observables epsilon and epsilon', and the electric dipole moment of the neutron. We find the model to be tightly constrained by these parameters with several fine tuning conditions on the phases in the right-handed mixing matrix. There is also a necessarily non-zero value of the left and right W mixing parameter. CP asymmetry phases in neutral B decays are discussed.
0805.3015
Wei Khim Ng
Wei Khim Ng and Rajesh R. Parwani
Probing Quantum Nonlinearities through Neutrino Oscillations
null
Mod.Phys.Lett.A25:793-804,2010
10.1142/S0217732310032792
null
hep-ph hep-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate potential quantum nonlinear corrections to Dirac's equation through its sub-leading effect on neutrino oscillation probabilities. Working in the plane-wave approximation and in the $\mu-\tau$ sector, we explore various classes of nonlinearities, with or without an accompanying Lorentz violation. The parameters in our models are first delimited by current experimental data before they are used to estimate corrections to oscillation probabilities. We find that only a small subset of the considered nonlinearities have the potential to be relevant at higher energies and thus possibly detectable in future experiments. A falsifiable prediction of our models is an energy dependent effective mass-squared, generically involving fractional powers of the energy.
[ { "created": "Tue, 20 May 2008 07:01:26 GMT", "version": "v1" }, { "created": "Sat, 5 Feb 2011 06:37:27 GMT", "version": "v2" } ]
2011-02-08
[ [ "Ng", "Wei Khim", "" ], [ "Parwani", "Rajesh R.", "" ] ]
We investigate potential quantum nonlinear corrections to Dirac's equation through its sub-leading effect on neutrino oscillation probabilities. Working in the plane-wave approximation and in the $\mu-\tau$ sector, we explore various classes of nonlinearities, with or without an accompanying Lorentz violation. The parameters in our models are first delimited by current experimental data before they are used to estimate corrections to oscillation probabilities. We find that only a small subset of the considered nonlinearities have the potential to be relevant at higher energies and thus possibly detectable in future experiments. A falsifiable prediction of our models is an energy dependent effective mass-squared, generically involving fractional powers of the energy.
1908.11816
Matthias Lutz F.M.
Yonggoo Heo, C. Kobdaj and M.F.M. Lutz
Constraints from a large-N_c analysis on meson-baryon interactions at chiral order Q^3
24 pages
Phys. Rev. D 100, 094035 (2019)
10.1103/PhysRevD.100.094035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the chiral Lagrangian for baryon fields with J^P =\frac{1}{2}^+ or J^P =\frac{3}{2}^+ quantum numbers as constructed from QCD with up, down and strange quarks. The specific class of counter terms that are of chiral order Q^3 and contribute to meson-baryon interactions at the two-body level is constructed. Altogether we find 24 terms. In order to pave the way for realistic applications we establish a set of 22 sum rules for the low-energy constants as they are implied by QCD in the large-N_c limit. Given such a constraint there remain only 2 independent unknown parameters that need to be determined by either Lattice QCD simulations or directly from experimental cross section measurements. At subleading order we arrive at 5 parameters.
[ { "created": "Fri, 30 Aug 2019 16:14:40 GMT", "version": "v1" } ]
2019-12-04
[ [ "Heo", "Yonggoo", "" ], [ "Kobdaj", "C.", "" ], [ "Lutz", "M. F. M.", "" ] ]
We consider the chiral Lagrangian for baryon fields with J^P =\frac{1}{2}^+ or J^P =\frac{3}{2}^+ quantum numbers as constructed from QCD with up, down and strange quarks. The specific class of counter terms that are of chiral order Q^3 and contribute to meson-baryon interactions at the two-body level is constructed. Altogether we find 24 terms. In order to pave the way for realistic applications we establish a set of 22 sum rules for the low-energy constants as they are implied by QCD in the large-N_c limit. Given such a constraint there remain only 2 independent unknown parameters that need to be determined by either Lattice QCD simulations or directly from experimental cross section measurements. At subleading order we arrive at 5 parameters.
hep-ph/0006295
Andrey Onishenko
A.I.Onishchenko (ITEP, Moscow)
Inclusive and exclusive decays of doubly heavy baryons
8 pages, JHEP-class, 7 eps-figures, 5 tables, Talk given at Vth International Workshop "HEAVY QUARK PHYSICS" April 6-8, 2000, Dubna, Russia
null
null
null
hep-ph
null
In this paper we give a short review of the recently obtained results on inclusive and exclusive decays of doubly heavy baryons.
[ { "created": "Mon, 26 Jun 2000 18:01:36 GMT", "version": "v1" } ]
2007-05-23
[ [ "Onishchenko", "A. I.", "", "ITEP, Moscow" ] ]
In this paper we give a short review of the recently obtained results on inclusive and exclusive decays of doubly heavy baryons.
0912.5278
Alexander E. Dorokhov
A.E. Dorokhov
How the recent BABAR data for P to \gamma\gamma* affect the Standard Model predictions for the rare decays P to l+l-
11 pages, 3 figures
JETP Lett.91:163-169,2010
10.1134/S0021364010040016
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Measuring the lepton anomalous magnetic moments $(g-2)$ and the rare decays of light pseudoscalar mesons into lepton pairs $P\to l^{+}l^{-} $, serve as important tests of the Standard Model. To reduce the theoretical uncertainty in the standard model predictions, the data on the charge and transition form factors of the light pseudoscalar mesons play a significant role. Recently, new data on the behavior of the transition form factors $P\to\gamma\gamma* $ at large momentum transfer were supplied by the BABAR collaboration. There are several problems with the theoretical interpretation of these data: 1) An unexpectedly slow decrease of the pion transition form factor at high momenta, 2) the qualitative difference in the behavior of the pion form factor and the $\eta$ and $\eta^\prime$ form factors at high momenta, 3) the inconsistency of the measured ratio of the $\eta$ and $\eta^\prime$ form factors with the predicted one. We comment on the influence of the new BABAR data on the rare decay branchings.
[ { "created": "Wed, 30 Dec 2009 14:06:14 GMT", "version": "v1" }, { "created": "Thu, 14 Jan 2010 08:40:48 GMT", "version": "v2" } ]
2014-11-20
[ [ "Dorokhov", "A. E.", "" ] ]
Measuring the lepton anomalous magnetic moments $(g-2)$ and the rare decays of light pseudoscalar mesons into lepton pairs $P\to l^{+}l^{-} $, serve as important tests of the Standard Model. To reduce the theoretical uncertainty in the standard model predictions, the data on the charge and transition form factors of the light pseudoscalar mesons play a significant role. Recently, new data on the behavior of the transition form factors $P\to\gamma\gamma* $ at large momentum transfer were supplied by the BABAR collaboration. There are several problems with the theoretical interpretation of these data: 1) An unexpectedly slow decrease of the pion transition form factor at high momenta, 2) the qualitative difference in the behavior of the pion form factor and the $\eta$ and $\eta^\prime$ form factors at high momenta, 3) the inconsistency of the measured ratio of the $\eta$ and $\eta^\prime$ form factors with the predicted one. We comment on the influence of the new BABAR data on the rare decay branchings.
1211.1186
Ilya Gorbunov N
Gennady Kozlov
Dilaton vs Higgs: Nearly Conformal theory with confinement-like pattern
8 pages, 1 fig., Talk at the Conference "Quark Confinement and the Hadron Spectrum X" (8-12 October, 2012, TUM Campus Garching, Munich, Germany) to appear in the Proceedings
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the model containing a dilaton vs Higgs boson in the nearly conformal sector (NCS). The potential of a dilaton in NCS is linearly rising with distances. The light scalar dilaton would be one of the best candidates to explain the LHC data in recent discovery of a Higgs-like resonance at 125 GeV.
[ { "created": "Tue, 6 Nov 2012 11:31:32 GMT", "version": "v1" } ]
2012-11-07
[ [ "Kozlov", "Gennady", "" ] ]
We consider the model containing a dilaton vs Higgs boson in the nearly conformal sector (NCS). The potential of a dilaton in NCS is linearly rising with distances. The light scalar dilaton would be one of the best candidates to explain the LHC data in recent discovery of a Higgs-like resonance at 125 GeV.
hep-ph/9706439
Graciela Gelmini
J. A. Casas (CSIC, Spain) and G. B. Gelmini (UCLA, Usa)
Conditions for Viable Affleck-Dine Baryogenesis -- Implications for String Theories
13 pp., LaTex file
Phys.Lett. B410 (1997) 36-44
10.1016/S0370-2693(97)00971-4
IEM-FT-157/97 and UCLA/97/TEP/15
hep-ph
null
We examine the conditions for a viable Affleck-Dine baryogenesis in supergravity (SUGRA) scenarios, finding surprisingly strong constraints on the type of SUGRA theory. These constraints are beautifully fulfilled by string-based SUGRA models provided that inflation is driven by a modulus (T) field.
[ { "created": "Sat, 21 Jun 1997 00:44:35 GMT", "version": "v1" } ]
2009-10-30
[ [ "Casas", "J. A.", "", "CSIC, Spain" ], [ "Gelmini", "G. B.", "", "UCLA, Usa" ] ]
We examine the conditions for a viable Affleck-Dine baryogenesis in supergravity (SUGRA) scenarios, finding surprisingly strong constraints on the type of SUGRA theory. These constraints are beautifully fulfilled by string-based SUGRA models provided that inflation is driven by a modulus (T) field.
2301.07456
Vinod Mamale
Shreyansh S. Dave, Sanatan Digal, Vinod Mamale
Parametric resonance in abelian and non-abelian gauge fields via space-time oscillations
22 pages, 21 figures
Phys. Rev. D 109, 076023 (2024)
10.1103/PhysRevD.109.076023
null
hep-ph astro-ph.HE gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We study the evolution of abelian $U(1)$ electromagnetic as well as non-abelian $SU(2)$ gauge fields, in the presence of space-time oscillations. Analysis of the time evolution of abelian gauge fields shows the presence of parametric resonance in spatial modes. A similar analysis in the case of non-abelian gauge fields, in the linear approximation, shows the presence of the same resonant spatial modes. The resonant modes induce large fluctuations in physical observables including those that break the $CP-$symmetry. We also carry out time evolution of small random fluctuations of the gauge fields, using numerical simulations in $2+1$ and $3+1$ dimensions. These simulations help to study non-linear effects in the case of non-abelian gauge theories. Our results show that there is an increase in energy density with the coupling, at late times. These results suggest that gravitational waves may excite non-abelian gauge fields more efficiently than electromagnetic fields. Also, gravitational waves in the early Universe and from the merger of neutron stars, black holes etc. may enhance $CP-$violation and generate an imbalance in chiral charge distributions, magnetic fields etc.
[ { "created": "Wed, 18 Jan 2023 12:01:04 GMT", "version": "v1" }, { "created": "Wed, 27 Mar 2024 16:03:35 GMT", "version": "v2" } ]
2024-04-26
[ [ "Dave", "Shreyansh S.", "" ], [ "Digal", "Sanatan", "" ], [ "Mamale", "Vinod", "" ] ]
We study the evolution of abelian $U(1)$ electromagnetic as well as non-abelian $SU(2)$ gauge fields, in the presence of space-time oscillations. Analysis of the time evolution of abelian gauge fields shows the presence of parametric resonance in spatial modes. A similar analysis in the case of non-abelian gauge fields, in the linear approximation, shows the presence of the same resonant spatial modes. The resonant modes induce large fluctuations in physical observables including those that break the $CP-$symmetry. We also carry out time evolution of small random fluctuations of the gauge fields, using numerical simulations in $2+1$ and $3+1$ dimensions. These simulations help to study non-linear effects in the case of non-abelian gauge theories. Our results show that there is an increase in energy density with the coupling, at late times. These results suggest that gravitational waves may excite non-abelian gauge fields more efficiently than electromagnetic fields. Also, gravitational waves in the early Universe and from the merger of neutron stars, black holes etc. may enhance $CP-$violation and generate an imbalance in chiral charge distributions, magnetic fields etc.
hep-ph/9911337
Oscar Vives
D.A. Demir (1), A. Masiero (2) and O. Vives (2), ((1) ICTP, Trieste, (2) SISSA-ISAS and INFN, Trieste)
CP violation as a probe of flavor origin in Supersymmetry
Reference added. 7 pages, no figures
Phys.Lett. B479 (2000) 230-234
10.1016/S0370-2693(00)00321-X
SISSA/134/99/EP, IC/99/165
hep-ph
null
We address the question of the relation between supersymmetry breaking and the origin of flavor in the context of CP violating phenomena. We prove that, in the absence of the Cabibbo-Kobayashi-Maskawa phase, a general Minimal Supersymmetric Standard Model with all possible phases in the soft-breaking terms, but no new flavor structure beyond the usual Yukawa matrices, can never give a sizeable contribution to $\epsilon_K$, $\epsilon^\prime/\epsilon$ or hadronic $B^0$ CP asymmetries. Observation of supersymmetric contributions to CP asymmetries in B decays would hint at a non-flavor blind mechanism of supersymmetry breaking.
[ { "created": "Fri, 12 Nov 1999 18:32:56 GMT", "version": "v1" }, { "created": "Mon, 7 Feb 2000 17:48:42 GMT", "version": "v2" } ]
2009-10-31
[ [ "Demir", "D. A.", "" ], [ "Masiero", "A.", "" ], [ "Vives", "O.", "" ] ]
We address the question of the relation between supersymmetry breaking and the origin of flavor in the context of CP violating phenomena. We prove that, in the absence of the Cabibbo-Kobayashi-Maskawa phase, a general Minimal Supersymmetric Standard Model with all possible phases in the soft-breaking terms, but no new flavor structure beyond the usual Yukawa matrices, can never give a sizeable contribution to $\epsilon_K$, $\epsilon^\prime/\epsilon$ or hadronic $B^0$ CP asymmetries. Observation of supersymmetric contributions to CP asymmetries in B decays would hint at a non-flavor blind mechanism of supersymmetry breaking.
2003.14293
Giuseppe Bevilacqua
Giuseppe Bevilacqua
Effects of top-quark decay modeling in $t\bar{t}\gamma$ production at the LHC
13 pages, 1 table, 3 figures. To appear in the Proceedings of the XXVI Cracow Epiphany Conference on LHC Physics: Standard Model and Beyond, 7-10 January 2020, Cracow, Poland
null
10.5506/APhysPolB.51.1267
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a systematic comparison of different approaches for the modeling of $t\bar{t}\gamma$ final states with leptonic decays at the LHC. On the one hand, we consider a complete calculation at NLO QCD accuracy which includes all resonant and non-resonant diagrams. On the other hand, we consider predictions in the narrow-width approximation with top quark decays modeled at various accuracies. In this way we quantify the impact of the off-shell effects in $t\bar{t}\gamma$ production. We also discuss the relative importance of double-, single- and non-resonant contributions in the complete calculation. Finally we investigate the fraction of isolated photons from decays of top quarks, which represent a background for measurements of anomalous $t\gamma$ couplings.
[ { "created": "Tue, 31 Mar 2020 15:29:39 GMT", "version": "v1" } ]
2020-08-26
[ [ "Bevilacqua", "Giuseppe", "" ] ]
We present a systematic comparison of different approaches for the modeling of $t\bar{t}\gamma$ final states with leptonic decays at the LHC. On the one hand, we consider a complete calculation at NLO QCD accuracy which includes all resonant and non-resonant diagrams. On the other hand, we consider predictions in the narrow-width approximation with top quark decays modeled at various accuracies. In this way we quantify the impact of the off-shell effects in $t\bar{t}\gamma$ production. We also discuss the relative importance of double-, single- and non-resonant contributions in the complete calculation. Finally we investigate the fraction of isolated photons from decays of top quarks, which represent a background for measurements of anomalous $t\gamma$ couplings.
1502.06767
Carlos Merino
G.H. Arakelyan, C. Merino, and Yu.M. Shabelski
Midrapidity Hyperon Production in pp and pA Collisions
Proceedings of Initial Stages 2014 Conference (6 pages, 2 figures, and 2 tables)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we present the description of the production of strange and mulistrange baryons in a wide energy region, from CERN SpS up to LHC, in the framework of the Quark-Gluon String model.
[ { "created": "Tue, 24 Feb 2015 11:24:21 GMT", "version": "v1" } ]
2015-02-25
[ [ "Arakelyan", "G. H.", "" ], [ "Merino", "C.", "" ], [ "Shabelski", "Yu. M.", "" ] ]
In this paper we present the description of the production of strange and mulistrange baryons in a wide energy region, from CERN SpS up to LHC, in the framework of the Quark-Gluon String model.
2211.00022
Jonas Frerick
Jonas Frerick, Felix Kahlhoefer, Kai Schmidt-Hoberg
$A'$ view of the sunrise: Boosting helioscopes with angular information
29 pages, 14 figures
null
10.1088/1475-7516/2023/03/001
DESY-22-165, TTP22-065
hep-ph astro-ph.SR
http://creativecommons.org/licenses/by/4.0/
The Sun may copiously produce hypothetical light particles such as axions or dark photons, a scenario which can be experimentally probed with so-called helioscopes. Here we investigate the impact of the angular and spectral distribution of solar dark photons on the sensitivity of such instruments. For the first time we evaluate this spectral and angular dependence of the dark photon flux over the whole mass range and apply this information to existing data from the Hinode Solar X-Ray Telescope. Specifically we use calibration images for a classical helioscope analysis as well as data from a solar eclipse providing sensitivity to exceptionally large oscillation lengths. We demonstrate that exploiting the signal features can boost the constraints by more than one order of magnitude in terms of the mixing parameter compared to a naive counting experiment.
[ { "created": "Mon, 31 Oct 2022 18:00:02 GMT", "version": "v1" } ]
2023-03-08
[ [ "Frerick", "Jonas", "" ], [ "Kahlhoefer", "Felix", "" ], [ "Schmidt-Hoberg", "Kai", "" ] ]
The Sun may copiously produce hypothetical light particles such as axions or dark photons, a scenario which can be experimentally probed with so-called helioscopes. Here we investigate the impact of the angular and spectral distribution of solar dark photons on the sensitivity of such instruments. For the first time we evaluate this spectral and angular dependence of the dark photon flux over the whole mass range and apply this information to existing data from the Hinode Solar X-Ray Telescope. Specifically we use calibration images for a classical helioscope analysis as well as data from a solar eclipse providing sensitivity to exceptionally large oscillation lengths. We demonstrate that exploiting the signal features can boost the constraints by more than one order of magnitude in terms of the mixing parameter compared to a naive counting experiment.
0904.4025
Kuang-Ta Chao
Ying Fan, Yan-Qing Ma, Kuang-Ta Chao
Relativistic Correction to J/\psi Production at Hadron Colliders
9 pages, 5 figures
Phys.Rev.D79:114009,2009
10.1103/PhysRevD.79.114009
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Relativistic corrections to the color-singlet J/\psi hadroproduction at the Tevatron and LHC are calculated up to O(v^2) in nonrelativistic QCD (NRQCD). The short distance coefficients are obtained by matching full QCD with NRQCD results for the subprocess g+g\to J/\psi+g. The long distance matrix elements are extracted from observed J/\psi hadronic and leptonic decay widths up to O}(v^2). Using the CTEQ6 parton distribution functions, we calculate the LO production cross sections and relativistic corrections for the process p+\bar{p}(p)\to J/\psi+X at the Tevatron and LHC. We find that the enhancement of O(v^2) relativistic corrections to the cross sections over a wide range of large transverse momentum p_t is negligible, only at a level of about 1 %. This tiny effect is due to the smallness of the correction to short distance coefficients and the suppression from long distance matrix elements. These results indicate that relativistic corrections can not help to resolve the large discrepancy between leading order prediction and experimental data for J/\psi production at the Tevatron.
[ { "created": "Sun, 26 Apr 2009 13:44:24 GMT", "version": "v1" } ]
2009-11-19
[ [ "Fan", "Ying", "" ], [ "Ma", "Yan-Qing", "" ], [ "Chao", "Kuang-Ta", "" ] ]
Relativistic corrections to the color-singlet J/\psi hadroproduction at the Tevatron and LHC are calculated up to O(v^2) in nonrelativistic QCD (NRQCD). The short distance coefficients are obtained by matching full QCD with NRQCD results for the subprocess g+g\to J/\psi+g. The long distance matrix elements are extracted from observed J/\psi hadronic and leptonic decay widths up to O}(v^2). Using the CTEQ6 parton distribution functions, we calculate the LO production cross sections and relativistic corrections for the process p+\bar{p}(p)\to J/\psi+X at the Tevatron and LHC. We find that the enhancement of O(v^2) relativistic corrections to the cross sections over a wide range of large transverse momentum p_t is negligible, only at a level of about 1 %. This tiny effect is due to the smallness of the correction to short distance coefficients and the suppression from long distance matrix elements. These results indicate that relativistic corrections can not help to resolve the large discrepancy between leading order prediction and experimental data for J/\psi production at the Tevatron.
hep-ph/0110077
Misha Stephanov
M. Stephanov
Thermal fluctuations in the interacting pion gas
12 pages, 4 figures, RevTeX
Phys.Rev. D65 (2002) 096008
10.1103/PhysRevD.65.096008
null
hep-ph nucl-th
null
We derive the two-particle fluctuation correlator in a thermal gas of pi-mesons to the lowest order in an interaction due to a resonance exchange. A diagrammatic technique is used. We discuss how this result can be applied to event-by-event fluctuations in heavy-ion collisions, in particular, to search for the critical point of QCD. As a practical example, we determine the shape of the rapidity correlator.
[ { "created": "Fri, 5 Oct 2001 17:58:39 GMT", "version": "v1" } ]
2009-11-07
[ [ "Stephanov", "M.", "" ] ]
We derive the two-particle fluctuation correlator in a thermal gas of pi-mesons to the lowest order in an interaction due to a resonance exchange. A diagrammatic technique is used. We discuss how this result can be applied to event-by-event fluctuations in heavy-ion collisions, in particular, to search for the critical point of QCD. As a practical example, we determine the shape of the rapidity correlator.
hep-ph/0512067
Tobias Huber
T. Huber, S. Schilling
B -> X_s l+ l- in the Standard Model and in Two-Higgs-Doublet Models
9 pages, 2 Figures, uses moriond.sty. Presented at 40th Rencontres de Moriond on QCD and High Energy Hadronic Interactions, La Thuile, Aosta Valley, Italy, 12-19 Mar 2005
null
null
null
hep-ph
null
We present recent results of the rare semileptonic decay B -> X_s l+ l-. We particularly focus on higher order electroweak corrections in the Standard Model (SM) as well as O(alpha_s) corrections in Two-Higgs-doublet models (THDM), both of which are computed within an effective field theory approach. The calculation of higher order electroweak corrections reveals the presence of enhanced electromagnetic logarithms log(m_b^2/m_l^2) in the differential branching ratio. The inclusion of O(alpha_s) in the THDM reduces the scale dependence of the corresponding Wilson coefficients significantly.
[ { "created": "Mon, 5 Dec 2005 18:45:17 GMT", "version": "v1" } ]
2016-09-06
[ [ "Huber", "T.", "" ], [ "Schilling", "S.", "" ] ]
We present recent results of the rare semileptonic decay B -> X_s l+ l-. We particularly focus on higher order electroweak corrections in the Standard Model (SM) as well as O(alpha_s) corrections in Two-Higgs-doublet models (THDM), both of which are computed within an effective field theory approach. The calculation of higher order electroweak corrections reveals the presence of enhanced electromagnetic logarithms log(m_b^2/m_l^2) in the differential branching ratio. The inclusion of O(alpha_s) in the THDM reduces the scale dependence of the corresponding Wilson coefficients significantly.
hep-ph/0310296
Tetsuo Nishikawa
Tetsuo Nishikawa, Yoshimasa Hidaka, Munehisa Ohtani and Osamu Morimatsu
Effect of pion thermal width on the sigma spectrum
Contribution to the International Workshop on QCD: QCD@Work 2003 - Conversano (Italy) 14-18 June 2003 (eConf C030614)
null
null
null
hep-ph
null
We study the effect of the thermal width of $\pi$ on the spectral function of $\sigma$. In order to take into account a finite thermal width of $\pi$, we replace the internal pion mass in the self-energy of $\sigma$ with that of the complex pole found in a previous paper. The obtained spectral function for $T\aplg 100 {\rm MeV}$ turns out to possess two broad peaks. Although a sharp peak at $\sigma\to\pi\pi$ threshold was observed in the one-loop calculation without the pion thermal width, the peak is shown to be smeared out. We also search for the poles of the $\sigma$ propagator and analyze the behavior of the spectral function with these poles.
[ { "created": "Mon, 27 Oct 2003 09:22:53 GMT", "version": "v1" } ]
2007-05-23
[ [ "Nishikawa", "Tetsuo", "" ], [ "Hidaka", "Yoshimasa", "" ], [ "Ohtani", "Munehisa", "" ], [ "Morimatsu", "Osamu", "" ] ]
We study the effect of the thermal width of $\pi$ on the spectral function of $\sigma$. In order to take into account a finite thermal width of $\pi$, we replace the internal pion mass in the self-energy of $\sigma$ with that of the complex pole found in a previous paper. The obtained spectral function for $T\aplg 100 {\rm MeV}$ turns out to possess two broad peaks. Although a sharp peak at $\sigma\to\pi\pi$ threshold was observed in the one-loop calculation without the pion thermal width, the peak is shown to be smeared out. We also search for the poles of the $\sigma$ propagator and analyze the behavior of the spectral function with these poles.
2007.09897
C. Q. Geng
Chao-Qiang Geng, Chia-Wei Liu, Tien-Hsueh Tsai
Nonleptonic two-body weak decays of $\Lambda_b$ in modified MIT bag model
16 pages, no figure, revised version accepted by PRD
Phys. Rev. D 102, 034033 (2020)
10.1103/PhysRevD.102.034033
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the nonleptonic two-body weak decays of $\Lambda_b$ by modifying the MIT bag model without introducing new parameters to construct the momentum eigenstates of the baryons. We find that the branching ratios of $\Lambda_b^0 \to \Lambda_c^+ \pi^-$, $\Lambda_c^+ K^-$, $p \pi^-$ and $pK^-$ are $(4.5\pm0.2)\times 10^{-3}$, $(3.4\pm 0.1)\times 10^{-4}$, $(5.0\pm 0.5)\times 10^{-6}$ and $(6.0\pm 0.7) \times 10^{-6}$, which are all well consistent with the current experimental data, respectively. We also explore P and CP asymmetries for the decays of $\Lambda_b^0 \to p (\pi^-,K^-)$. In particular, we obtain that the direct CP-violating rate asymmetries in $\Lambda_b^0 \to p \pi^-$ and $\Lambda_b^0 \to p K^-$ are around $-4.4\%$ and $6.7\%$, in comparison with $(-2.5\pm2.9)\%$ and $(-2.5\pm2.2)\%$ from the Particle Data Group in 2020, respectively.
[ { "created": "Mon, 20 Jul 2020 05:53:39 GMT", "version": "v1" }, { "created": "Thu, 13 Aug 2020 04:58:35 GMT", "version": "v2" } ]
2020-09-02
[ [ "Geng", "Chao-Qiang", "" ], [ "Liu", "Chia-Wei", "" ], [ "Tsai", "Tien-Hsueh", "" ] ]
We study the nonleptonic two-body weak decays of $\Lambda_b$ by modifying the MIT bag model without introducing new parameters to construct the momentum eigenstates of the baryons. We find that the branching ratios of $\Lambda_b^0 \to \Lambda_c^+ \pi^-$, $\Lambda_c^+ K^-$, $p \pi^-$ and $pK^-$ are $(4.5\pm0.2)\times 10^{-3}$, $(3.4\pm 0.1)\times 10^{-4}$, $(5.0\pm 0.5)\times 10^{-6}$ and $(6.0\pm 0.7) \times 10^{-6}$, which are all well consistent with the current experimental data, respectively. We also explore P and CP asymmetries for the decays of $\Lambda_b^0 \to p (\pi^-,K^-)$. In particular, we obtain that the direct CP-violating rate asymmetries in $\Lambda_b^0 \to p \pi^-$ and $\Lambda_b^0 \to p K^-$ are around $-4.4\%$ and $6.7\%$, in comparison with $(-2.5\pm2.9)\%$ and $(-2.5\pm2.2)\%$ from the Particle Data Group in 2020, respectively.
hep-ph/9710374
Basim Kamal
B. Kamal (Brookhaven)
Drell-Yan forward-backward and spin asymmetries for arbitrary vector boson production at next-to-leading order
34 pages, figures included, revtex. Some discussions and references added/modified. In more compact form. To appear in Phys. Rev. D
Phys.Rev. D57 (1998) 6663-6691
10.1103/PhysRevD.57.6663
BNL-64853
hep-ph
null
Longitudinally polarized, unpolarized and forward-backward mass differential cross sections for Drell-Yan lepton-pair production by arbitrary vector bosons are calculated in next-to-leading order (NLO) QCD. Analytical results are presented in a form valid for all consistent $n$-dimensional regularization schemes, with the mass factorization scheme kept general. NLO predictions for all Drell-Yan type processes ($W^\pm$, $Z$ and $\gamma^*$) at BNL's relativistic heavy ion collider (RHIC) are made using polarized parton distributions which fit the recent deep-inelastic scattering data. These are examined as tools in the determination of the polarized parton distributions and the unpolarized $\bar{u}/\bar{d}$ ratio. NLO predictions for the forward-backward lepton asymmetry at Fermilab are made and the precision determination of $\sin^2 \theta_W$ from future runs is studied. In all the above, the QCD corrections are found to be significant. An introductory discussion is given of various theoretical issues, such as allowable factorization and regularization schemes, and scale dependences.
[ { "created": "Thu, 16 Oct 1997 07:12:56 GMT", "version": "v1" }, { "created": "Wed, 11 Mar 1998 01:26:46 GMT", "version": "v2" } ]
2009-10-30
[ [ "Kamal", "B.", "", "Brookhaven" ] ]
Longitudinally polarized, unpolarized and forward-backward mass differential cross sections for Drell-Yan lepton-pair production by arbitrary vector bosons are calculated in next-to-leading order (NLO) QCD. Analytical results are presented in a form valid for all consistent $n$-dimensional regularization schemes, with the mass factorization scheme kept general. NLO predictions for all Drell-Yan type processes ($W^\pm$, $Z$ and $\gamma^*$) at BNL's relativistic heavy ion collider (RHIC) are made using polarized parton distributions which fit the recent deep-inelastic scattering data. These are examined as tools in the determination of the polarized parton distributions and the unpolarized $\bar{u}/\bar{d}$ ratio. NLO predictions for the forward-backward lepton asymmetry at Fermilab are made and the precision determination of $\sin^2 \theta_W$ from future runs is studied. In all the above, the QCD corrections are found to be significant. An introductory discussion is given of various theoretical issues, such as allowable factorization and regularization schemes, and scale dependences.
hep-ph/9304239
null
U. Baur, S. Errede, and J. Ohnemus
Ratios of $W^\pm\gamma$ and $Z\gamma$ Cross Sections: New Tools in Probing the Weak Boson Sector at the Tevatron
TeX, 39 pages, FSU-HEP-930322, UIUC-HEP-93-01, DTP/93/14, 15 Figures (uuencoded tar file, postscript) appended
Phys.Rev. D48 (1993) 4103-4120
10.1103/PhysRevD.48.4103
null
hep-ph
null
The ratios ${\cal R}_{\gamma ,\ell}=B(Z\to\ell^+\ell^-)\cdot\sigma(Z\gamma) /\allowbreak B(W\to\ell\nu)\cdot\sigma(W^\pm\gamma)$, ${\cal R}_{\gamma , \nu}= B(Z\to\bar\nu\nu)\cdot\sigma(Z\gamma)/\allowbreak B(W\to\ell\nu)\cdot\sigma(W^ \pm\gamma)$, ${\cal R}_{W\gamma}=\sigma(W^\pm\gamma)/\allowbreak\sigma(W^\pm)$, and ${\cal R}_{Z\gamma}=\sigma(Z\gamma)/\allowbreak\sigma(Z)$ are studied as tools to probe the electroweak boson self-interactions. As a function of the minimum photon transverse momentum, ${\cal R}_{\gamma ,\ell}$ and ${\cal R}_{ \gamma ,\nu}$ are found to directly reflect the radiation zero present in $W^ \pm\gamma$ production in the Standard Model. All four ratios are sensitive to anomalous $WW\gamma$ and/or $ZZ\gamma/Z\gamma\gamma$ couplings. The sensitivity of the cross section ratios to the cuts imposed on the final state particles, as well as the systematic uncertainties resulting from different parametrizations of parton distribution functions, the choice of the factorization scale $Q^2$, and from higher order QCD corrections are explored. Taking into account these uncertainties, sensitivity limits for anomalous three gauge boson couplings, based on a measurement of the cross section ratios with an integrated luminosity of 25~pb$^{-1}$ at the Tevatron, are estimated.
[ { "created": "Thu, 8 Apr 1993 20:57:31 GMT", "version": "v1" } ]
2009-10-22
[ [ "Baur", "U.", "" ], [ "Errede", "S.", "" ], [ "Ohnemus", "J.", "" ] ]
The ratios ${\cal R}_{\gamma ,\ell}=B(Z\to\ell^+\ell^-)\cdot\sigma(Z\gamma) /\allowbreak B(W\to\ell\nu)\cdot\sigma(W^\pm\gamma)$, ${\cal R}_{\gamma , \nu}= B(Z\to\bar\nu\nu)\cdot\sigma(Z\gamma)/\allowbreak B(W\to\ell\nu)\cdot\sigma(W^ \pm\gamma)$, ${\cal R}_{W\gamma}=\sigma(W^\pm\gamma)/\allowbreak\sigma(W^\pm)$, and ${\cal R}_{Z\gamma}=\sigma(Z\gamma)/\allowbreak\sigma(Z)$ are studied as tools to probe the electroweak boson self-interactions. As a function of the minimum photon transverse momentum, ${\cal R}_{\gamma ,\ell}$ and ${\cal R}_{ \gamma ,\nu}$ are found to directly reflect the radiation zero present in $W^ \pm\gamma$ production in the Standard Model. All four ratios are sensitive to anomalous $WW\gamma$ and/or $ZZ\gamma/Z\gamma\gamma$ couplings. The sensitivity of the cross section ratios to the cuts imposed on the final state particles, as well as the systematic uncertainties resulting from different parametrizations of parton distribution functions, the choice of the factorization scale $Q^2$, and from higher order QCD corrections are explored. Taking into account these uncertainties, sensitivity limits for anomalous three gauge boson couplings, based on a measurement of the cross section ratios with an integrated luminosity of 25~pb$^{-1}$ at the Tevatron, are estimated.
0901.2208
Dmitri Kazakov
D.I.Kazakov
Radiative Corrections, Divergences, Regularization, Renormalization, Renormalization Group and All That in Examples in Quantum Field Theory
Lectures, 91 pages, 46 figures, Russian version can be found at http://theor.jinr.ru/~kazakovd
null
null
JINR, UC-2008-34
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The present lectures are a practical guide to the calculation of radiative corrections to the Green functions in quantum field theory. The appearance of ultraviolet divergences is explained, their classification is given, the renormalization procedure which allows one to get the finite results is described, and the basis of the renormalization group in QFT is presented. Numerous examples of calculations in scalar and gauge theories are given. Quantum anomalies are discussed. In conclusion the procedure which allows one to get rid of infrared divergences in S-matrix elements is described. The lectures are based on the standard quantum field theory textbooks, the list of which is given at the end of the text. These lectures were given to the 4-th year students of the Department of General and Applied Physics of the Moscow Institute of Physics and Technology (Technical University).
[ { "created": "Thu, 15 Jan 2009 09:49:15 GMT", "version": "v1" } ]
2009-01-16
[ [ "Kazakov", "D. I.", "" ] ]
The present lectures are a practical guide to the calculation of radiative corrections to the Green functions in quantum field theory. The appearance of ultraviolet divergences is explained, their classification is given, the renormalization procedure which allows one to get the finite results is described, and the basis of the renormalization group in QFT is presented. Numerous examples of calculations in scalar and gauge theories are given. Quantum anomalies are discussed. In conclusion the procedure which allows one to get rid of infrared divergences in S-matrix elements is described. The lectures are based on the standard quantum field theory textbooks, the list of which is given at the end of the text. These lectures were given to the 4-th year students of the Department of General and Applied Physics of the Moscow Institute of Physics and Technology (Technical University).
1111.5813
Elliot Leader
Elliot Leader
Reply to the comment of Huey-Wen Lin and Keh-Fei Liu on "Controversy concerning the definition of quark and gluon angular momentum" by E. Leader (arXiv:1111.0678, PRD 83, 096012 (2011))
2 pages, no figures
null
10.1103/PhysRevD.85.058902
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Lin and Liu evaluate the nucleon expectation value of the non gauge-invariant canonical quark momentum operator on a lattice, and obtain zero. They conclude that my argument that, despite the non gauge-invariance of the operator, its physical matrix elements \emph{are} gauge-invariant, cannot be correct. I show that their result has no bearing on the question of gauge-invariance, and also point to an amusing lattice paradox.
[ { "created": "Thu, 24 Nov 2011 16:33:54 GMT", "version": "v1" } ]
2013-05-30
[ [ "Leader", "Elliot", "" ] ]
Lin and Liu evaluate the nucleon expectation value of the non gauge-invariant canonical quark momentum operator on a lattice, and obtain zero. They conclude that my argument that, despite the non gauge-invariance of the operator, its physical matrix elements \emph{are} gauge-invariant, cannot be correct. I show that their result has no bearing on the question of gauge-invariance, and also point to an amusing lattice paradox.
hep-ph/9912314
Gayane A. Amatuni
N.A. Korkhmazyan (Armenian Pedagogical Institute), N.N. Korkhmazyan (Armenian Pedagogical Institute)
On Quark-Lepton Symmetry
5 pages, 1 figure
null
null
null
hep-ph
null
The new quantum number is introduced. It is shown that the conservation of -number results in the conservation of difference between baryon and lepton numbers. The problem of quark-lepton symmetry is discussed. It is shown that the nature of quark-lepton symmetry stems from the fact that the particles of one generation are subject to the symmetry transformation represented by 4-group of diedr.
[ { "created": "Sun, 12 Dec 1999 21:41:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Korkhmazyan", "N. A.", "", "Armenian Pedagogical Institute" ], [ "Korkhmazyan", "N. N.", "", "Armenian Pedagogical Institute" ] ]
The new quantum number is introduced. It is shown that the conservation of -number results in the conservation of difference between baryon and lepton numbers. The problem of quark-lepton symmetry is discussed. It is shown that the nature of quark-lepton symmetry stems from the fact that the particles of one generation are subject to the symmetry transformation represented by 4-group of diedr.
hep-ph/0010160
Alessandro Papa
R. Fiore, L.L. Jenkovszky, E.A. Kuraev, A.I. Lengyel, F. Paccanoni, A. Papa
Finite sum of gluon ladders and high energy cross sections
18 pages, LaTeX, 2 EPS figures, uses axodraw.sty
Phys.Rev. D63 (2001) 056010
10.1103/PhysRevD.63.056010
DFPD 00/TH/48, UNICAL-TH 00/7
hep-ph
null
A model for the Pomeron at $t=0$ is suggested. It is based on the idea of a finite sum of ladder diagrams in QCD. Accordingly, the number of $s$-channel gluon rungs and correspondingly the powers of logarithms in the forward scattering amplitude depends on the phase space (energy) available, i.e. as energy increases, progressively new prongs with additional gluon rungs in the $s$-channel open. Explicit expressions for the total cross section involving two and three rungs or, alternatively, three and four prongs (with $\ln^2(s)$ and $\ln^3(s)$ as highest terms, respectively) are fitted to the proton-proton and proton-antiproton total cross section data in the accelerator region. Both QCD calculation and fits to the data indicate fast convergence of the series. In the fit, two terms (a constant and a logarithmically rising one) almost saturate the whole series, the $\ln^2(s)$ term being small and the next one, $\ln^3(s)$, negligible. Theoretical predictions for the photon-photon total cross section are also given.
[ { "created": "Mon, 16 Oct 2000 09:59:21 GMT", "version": "v1" } ]
2009-10-31
[ [ "Fiore", "R.", "" ], [ "Jenkovszky", "L. L.", "" ], [ "Kuraev", "E. A.", "" ], [ "Lengyel", "A. I.", "" ], [ "Paccanoni", "F.", "" ], [ "Papa", "A.", "" ] ]
A model for the Pomeron at $t=0$ is suggested. It is based on the idea of a finite sum of ladder diagrams in QCD. Accordingly, the number of $s$-channel gluon rungs and correspondingly the powers of logarithms in the forward scattering amplitude depends on the phase space (energy) available, i.e. as energy increases, progressively new prongs with additional gluon rungs in the $s$-channel open. Explicit expressions for the total cross section involving two and three rungs or, alternatively, three and four prongs (with $\ln^2(s)$ and $\ln^3(s)$ as highest terms, respectively) are fitted to the proton-proton and proton-antiproton total cross section data in the accelerator region. Both QCD calculation and fits to the data indicate fast convergence of the series. In the fit, two terms (a constant and a logarithmically rising one) almost saturate the whole series, the $\ln^2(s)$ term being small and the next one, $\ln^3(s)$, negligible. Theoretical predictions for the photon-photon total cross section are also given.
hep-ph/0111187
Marcus Bleicher
M. Bleicher, F. M. Liu, A. Ker\"anen, J. Aichelin, S.A. Bass, F. Becattini, K. Redlich, K. Werner
Overpopulation of $\bar \Omega$ in pp collisions: a way to distinguish statistical hadronization from string dynamics
4 pages, 4 figures
Phys.Rev.Lett. 88 (2002) 202501
10.1103/PhysRevLett.88.202501
CERN-TH/2001-316
hep-ph
null
The $\bar{\Omega}/\Omega$ ratio originating from string decays is predicted to be larger than unity in proton proton interactions at SPS energies ($E_{\rm lab}$=160 GeV). The anti-omega dominance increases with decreasing beam energy. This surprising behavior is caused by the combinatorics of quark-antiquark production in small and low-mass strings. Since this behavior is not found in a statistical description of hadron production in proton proton collisions, it may serve as a key observable to probe the hadronization mechanism in such collisions.
[ { "created": "Thu, 15 Nov 2001 12:24:06 GMT", "version": "v1" } ]
2009-11-07
[ [ "Bleicher", "M.", "" ], [ "Liu", "F. M.", "" ], [ "Keränen", "A.", "" ], [ "Aichelin", "J.", "" ], [ "Bass", "S. A.", "" ], [ "Becattini", "F.", "" ], [ "Redlich", "K.", "" ], [ "Werner", "K.", ...
The $\bar{\Omega}/\Omega$ ratio originating from string decays is predicted to be larger than unity in proton proton interactions at SPS energies ($E_{\rm lab}$=160 GeV). The anti-omega dominance increases with decreasing beam energy. This surprising behavior is caused by the combinatorics of quark-antiquark production in small and low-mass strings. Since this behavior is not found in a statistical description of hadron production in proton proton collisions, it may serve as a key observable to probe the hadronization mechanism in such collisions.
1606.02558
Jonathan Davis
Jonathan H. Davis
Projections for measuring the size of the solar core with neutrino-electron scattering
5 pages, 2 figures. Matches version accepted to PRL. Improved 2D analysis and results discussion
Phys. Rev. Lett. 117, 211101 (2016)
10.1103/PhysRevLett.117.211101
KCL-PH-TH/2016-36
hep-ph astro-ph.SR hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We quantify the amount of data needed in order to measure the size and position of the $^8$B neutrino production region within the solar core, for experiments looking at elastic scattering between electrons and solar neutrinos. The directions of the electrons immediately after scattering are strongly correlated with the incident directions of the neutrinos, however this is degraded significantly by the subsequent scattering of these electrons in the detector medium. We generate distributions of such electrons for different neutrino production profiles, and use a maximum likelihood analysis to make projections for future experimental sensitivity. We find that with approximately 20 years worth of data the Super Kamiokande experiment could constrain the central radius of the shell in which $^8$B neutrinos are produced to be less than 0.22 of the total solar radius at 95% confidence.
[ { "created": "Wed, 8 Jun 2016 14:00:40 GMT", "version": "v1" }, { "created": "Mon, 20 Jun 2016 15:43:54 GMT", "version": "v2" }, { "created": "Mon, 31 Oct 2016 08:34:10 GMT", "version": "v3" } ]
2016-11-16
[ [ "Davis", "Jonathan H.", "" ] ]
We quantify the amount of data needed in order to measure the size and position of the $^8$B neutrino production region within the solar core, for experiments looking at elastic scattering between electrons and solar neutrinos. The directions of the electrons immediately after scattering are strongly correlated with the incident directions of the neutrinos, however this is degraded significantly by the subsequent scattering of these electrons in the detector medium. We generate distributions of such electrons for different neutrino production profiles, and use a maximum likelihood analysis to make projections for future experimental sensitivity. We find that with approximately 20 years worth of data the Super Kamiokande experiment could constrain the central radius of the shell in which $^8$B neutrinos are produced to be less than 0.22 of the total solar radius at 95% confidence.
hep-ph/9909418
Stefano Moretti
A. Dedes (RAL) and S. Moretti (RAL and Uppsala University)
Effects of CP-violating phases on Higgs boson production at hadron colliders in the Minimal Supersymmetric Standard Model
31 pages, latex (uses axodraw.sty), 14 figures - typos corrected in Tab. I, eqs. (A.6) and (A.15): version to appear in Nucl. Phys. B
Nucl.Phys. B576 (2000) 29-55
10.1016/S0550-3213(00)00144-9
RAL-TR-1999-042, TSL/ISV-99-0218
hep-ph
null
If the soft Supersymmetry (SUSY) breaking masses and couplings are complex, then the associated CP-violating phases can in principle modify the known phenomenological pattern of the Minimal Supersymmetric Standard Model (MSSM). We investigate here their effects on Higgs boson production in the gluon-gluon fusion mode at the Tevatron and the Large Hadron Collider (LHC), by taking into account all experimental bounds available at present. The by far most stringent ones are those derived from the measurements of the Electric Dipole Moments (EDMs) of fermions. However, it has recently been suggested that, over a sizable portion of the MSSM parameter space, cancellations among the SUSY contributions to the EDMs can take place, so that the CP-violating phases can evade those limits. We find a strong dependence of the production rates of any neutral Higgs state upon the complex masses and couplings over such parts of the MSSM parameter space. We show these effects relatively to the ordinary MSSM rates as well as illustrate them at absolute cross section level at both colliders
[ { "created": "Fri, 17 Sep 1999 13:02:14 GMT", "version": "v1" }, { "created": "Fri, 3 Mar 2000 16:47:54 GMT", "version": "v2" } ]
2009-10-31
[ [ "Dedes", "A.", "", "RAL" ], [ "Moretti", "S.", "", "RAL and Uppsala University" ] ]
If the soft Supersymmetry (SUSY) breaking masses and couplings are complex, then the associated CP-violating phases can in principle modify the known phenomenological pattern of the Minimal Supersymmetric Standard Model (MSSM). We investigate here their effects on Higgs boson production in the gluon-gluon fusion mode at the Tevatron and the Large Hadron Collider (LHC), by taking into account all experimental bounds available at present. The by far most stringent ones are those derived from the measurements of the Electric Dipole Moments (EDMs) of fermions. However, it has recently been suggested that, over a sizable portion of the MSSM parameter space, cancellations among the SUSY contributions to the EDMs can take place, so that the CP-violating phases can evade those limits. We find a strong dependence of the production rates of any neutral Higgs state upon the complex masses and couplings over such parts of the MSSM parameter space. We show these effects relatively to the ordinary MSSM rates as well as illustrate them at absolute cross section level at both colliders
1008.3785
Majid Hashemi
Majid Hashemi
Possibility of observing MSSM charged Higgs in association with a W boson at LHC
20 pages, 19 figures
Phys.Rev.D83:055004,2011
10.1103/PhysRevD.83.055004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Possibility of observing associated production of charged Higgs and W boson in the framework of MSSM at LHC is studied. Both leptonic and hadronic decays of W boson are studied while the charged Higgs boson is considered to decay to a $\tau$ lepton and a neutrino. Therefore two search categories are defined based on the leptonic and hadronic final states, i.e. $\ell \tau+E^{miss}_{T}$ and $jj \tau+E^{miss}_{T}$ where $\ell=e$ or $\mu$ and $j$ is a light jet from $W$ decay. The discovery chance of the two categories is evaluated at an integrated luminosity of 300 \invfb at LHC. It is shown that both leptonic and hadronic final states have the chance of discovery at high \tanb. Finally $5\sigma$ and $3\sigma$ contours are provided for both search categories.
[ { "created": "Mon, 23 Aug 2010 09:59:08 GMT", "version": "v1" }, { "created": "Wed, 25 Aug 2010 05:30:17 GMT", "version": "v2" }, { "created": "Tue, 11 Jan 2011 13:11:35 GMT", "version": "v3" } ]
2011-03-21
[ [ "Hashemi", "Majid", "" ] ]
Possibility of observing associated production of charged Higgs and W boson in the framework of MSSM at LHC is studied. Both leptonic and hadronic decays of W boson are studied while the charged Higgs boson is considered to decay to a $\tau$ lepton and a neutrino. Therefore two search categories are defined based on the leptonic and hadronic final states, i.e. $\ell \tau+E^{miss}_{T}$ and $jj \tau+E^{miss}_{T}$ where $\ell=e$ or $\mu$ and $j$ is a light jet from $W$ decay. The discovery chance of the two categories is evaluated at an integrated luminosity of 300 \invfb at LHC. It is shown that both leptonic and hadronic final states have the chance of discovery at high \tanb. Finally $5\sigma$ and $3\sigma$ contours are provided for both search categories.
1501.03151
Dietrich Bodeker
D. Bodeker and M. Sangel
Order g^2 susceptibilities in the symmetric phase of the Standard Model
18 pages, 2 figures
null
10.1088/1475-7516/2015/04/040
BI-TP 2014/25
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Susceptibilities of conserved charges such as baryon minus lepton number enter baryogenesis computations, since they provide the relationship between conserved charges and chemical potentials. Their next-to-leading order corrections are of order g, where g is a generic Standard Model coupling. They are due to soft Higgs boson exchange, and have been calculated recently, together with some order g^2 corrections. Here we compute the complete g^2 contributions. Close to the electroweak crossover the soft Higgs contribution is of order g^2, and is determined by the non-perturbative physics at the magnetic screening scale.
[ { "created": "Tue, 13 Jan 2015 21:00:01 GMT", "version": "v1" } ]
2015-06-23
[ [ "Bodeker", "D.", "" ], [ "Sangel", "M.", "" ] ]
Susceptibilities of conserved charges such as baryon minus lepton number enter baryogenesis computations, since they provide the relationship between conserved charges and chemical potentials. Their next-to-leading order corrections are of order g, where g is a generic Standard Model coupling. They are due to soft Higgs boson exchange, and have been calculated recently, together with some order g^2 corrections. Here we compute the complete g^2 contributions. Close to the electroweak crossover the soft Higgs contribution is of order g^2, and is determined by the non-perturbative physics at the magnetic screening scale.
1504.04604
Yu-Feng Zhou
Hong-Bo Jin, Yue-Liang Wu, Yu-Feng Zhou
Upper limits on DM annihilation cross sections from the first AMS-02 antiproton data
15 pages, 6 figures. More discussions on DM contributions added, to appear in PRD. arXiv admin note: text overlap with arXiv:1410.0171
Phys. Rev. D 92, 055027 (2015)
10.1103/PhysRevD.92.055027
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The first measurement on the antiproton to proton ratio made by the AMS-02 collaboration agrees with the expection from conventional cosmic-ray secondaries in the kinetic energy range $\sim 10-100$ GeV, which can be turned into stringent upper limits on the dark matter (DM) annihilation cross sections above $\sim 300$ GeV. Using the GALPROP code, we derive the upper limits in various propagation models and DM profiles. We show that in the "conventional" propagation model, for the $q\bar q$, $b\bar b$, and $WW$ final states, the constraints can be more stringent than that derived from the recent Ferm-LAT gamma-ray data on the dwarf spheroidal satellite galaxies. Making use of the typical minimal, median and maximal models obtained from a previous global fit, we show that the variation of the upper limits is around a factor of five. The possibility of DM contribution to the high energy $\bar p/p$ data is discussed.
[ { "created": "Fri, 17 Apr 2015 18:59:15 GMT", "version": "v1" }, { "created": "Wed, 29 Apr 2015 15:57:16 GMT", "version": "v2" }, { "created": "Thu, 27 Aug 2015 12:29:17 GMT", "version": "v3" } ]
2015-09-30
[ [ "Jin", "Hong-Bo", "" ], [ "Wu", "Yue-Liang", "" ], [ "Zhou", "Yu-Feng", "" ] ]
The first measurement on the antiproton to proton ratio made by the AMS-02 collaboration agrees with the expection from conventional cosmic-ray secondaries in the kinetic energy range $\sim 10-100$ GeV, which can be turned into stringent upper limits on the dark matter (DM) annihilation cross sections above $\sim 300$ GeV. Using the GALPROP code, we derive the upper limits in various propagation models and DM profiles. We show that in the "conventional" propagation model, for the $q\bar q$, $b\bar b$, and $WW$ final states, the constraints can be more stringent than that derived from the recent Ferm-LAT gamma-ray data on the dwarf spheroidal satellite galaxies. Making use of the typical minimal, median and maximal models obtained from a previous global fit, we show that the variation of the upper limits is around a factor of five. The possibility of DM contribution to the high energy $\bar p/p$ data is discussed.
2102.13175
Ulugbek Yakhshiev
Ulugbek Yakhshiev
Test of the nonrelativistic $c\bar{c}$ potential
5 pages
null
10.1007/s40042-021-00234-8
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
We analyze the charmonium states by testing a phenomenological nonrelativistic potential and propose a new set of parameters. This new set of parameters are fixed using only the lowest lying S-wave states of charmonia where the spin-orbit and tensor interactions will not contribute. After fitting the parameters we analyze the whole fine structure of charmonium states taking into account the spin-orbit and tensor interactions too. Calculations showed that the nonrelativistic potential model with the phenomenologically defined parameters is indeed well approximation for describing the charmonium states.
[ { "created": "Thu, 25 Feb 2021 21:05:11 GMT", "version": "v1" } ]
2021-07-14
[ [ "Yakhshiev", "Ulugbek", "" ] ]
We analyze the charmonium states by testing a phenomenological nonrelativistic potential and propose a new set of parameters. This new set of parameters are fixed using only the lowest lying S-wave states of charmonia where the spin-orbit and tensor interactions will not contribute. After fitting the parameters we analyze the whole fine structure of charmonium states taking into account the spin-orbit and tensor interactions too. Calculations showed that the nonrelativistic potential model with the phenomenologically defined parameters is indeed well approximation for describing the charmonium states.
1710.02463
Nelia Mann
Ziyi Hu, Brian Maddock, Nelia Mann
A Second Look at String-Inspired Models for Proton-Proton Scattering via Pomeron Exchange
16 pages, 7 figures, 2 tables
null
10.1007/JHEP08(2018)093
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We re-examine a string dual model for elastic proton-proton scattering via Pomeron exchange. We argue that the method of "Reggeizing" a propagator to take into account an entire trajectory of exchanged particles can be generalized, in particular by modifying the value of the mass-shell parameter in the model. We then fit the generalized model to scattering data at large s and small t. The fitting results are inconclusive, but suggest that a better fit might be obtained by allowing the mass-shell to vary. The model fits the data equally well (roughly) for a wide range of values of the mass-shell parameter, but the other fitting parameters (the slope and intercept of the Regge trajectory, and the coupling constant and dipole mass from the proton-proton-glueball coupling) are then inconsistent with what we expect. On the other hand, using the traditional method of Reggeization generates a weaker fit, but the other parameters obtain more physically reasonable values. In analyzing the fitting results, we also found that our model is more consistent with the sqrt(s) = 1800 GeV coming from the E710 experiment than that coming from the CDF experiment, and that our model has the greatest discrepancy with the data in the range 0.5 GeV^2 < |t| < 0.6 GeV^2, suggesting that the transition from soft Pomeron to hard Pomeron may occur closer to t = -0.5 GeV^2 rather than t = -0.6 GeV^2 as previously thought.
[ { "created": "Fri, 6 Oct 2017 15:51:30 GMT", "version": "v1" } ]
2018-09-26
[ [ "Hu", "Ziyi", "" ], [ "Maddock", "Brian", "" ], [ "Mann", "Nelia", "" ] ]
We re-examine a string dual model for elastic proton-proton scattering via Pomeron exchange. We argue that the method of "Reggeizing" a propagator to take into account an entire trajectory of exchanged particles can be generalized, in particular by modifying the value of the mass-shell parameter in the model. We then fit the generalized model to scattering data at large s and small t. The fitting results are inconclusive, but suggest that a better fit might be obtained by allowing the mass-shell to vary. The model fits the data equally well (roughly) for a wide range of values of the mass-shell parameter, but the other fitting parameters (the slope and intercept of the Regge trajectory, and the coupling constant and dipole mass from the proton-proton-glueball coupling) are then inconsistent with what we expect. On the other hand, using the traditional method of Reggeization generates a weaker fit, but the other parameters obtain more physically reasonable values. In analyzing the fitting results, we also found that our model is more consistent with the sqrt(s) = 1800 GeV coming from the E710 experiment than that coming from the CDF experiment, and that our model has the greatest discrepancy with the data in the range 0.5 GeV^2 < |t| < 0.6 GeV^2, suggesting that the transition from soft Pomeron to hard Pomeron may occur closer to t = -0.5 GeV^2 rather than t = -0.6 GeV^2 as previously thought.
2212.01794
Michael Fucilla
Michael Fucilla
The Higgs impact factor at next-to-leading order
6 pages, 2 Figures. Presented by Michael Fucilla at Diffraction and Low-x 2022, Corigliano Calabro (Italy), September 24-30, 2022
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compute at next-to-leading order level the impact factor for the production of a forward Higgs boson from a colliding proton. Combined with other forward impact factors, it can be used to describe, at next-to-leading logarithmic accuracy, processes in which two objects featuring large separation in rapidity are detected at the Large Hadron Collider (LHC). As well, combined with a proper definition of the \textit{unintegrated gluon distribution} (UGD), it can be used to compute small-$x$ corrections to the forward Higgs production.
[ { "created": "Sun, 4 Dec 2022 10:45:53 GMT", "version": "v1" } ]
2022-12-06
[ [ "Fucilla", "Michael", "" ] ]
We compute at next-to-leading order level the impact factor for the production of a forward Higgs boson from a colliding proton. Combined with other forward impact factors, it can be used to describe, at next-to-leading logarithmic accuracy, processes in which two objects featuring large separation in rapidity are detected at the Large Hadron Collider (LHC). As well, combined with a proper definition of the \textit{unintegrated gluon distribution} (UGD), it can be used to compute small-$x$ corrections to the forward Higgs production.
hep-ph/9605225
null
Stefano Moretti (Cavendish Laboratory, Cambridge, UK)
The process $e^+e^-\to b\bar bW^+W^-$ at the Next Linear Collider in the Minimal Supersymmetric Standard Model
43 pages, latex, 20 PostScript figures included, complete file and full resolution figures available at ftp://axpa.hep.phy.cam.ac.uk/moretti or at http://www.hep.phy.cam.ac.uk/theory/papers/
Z.Phys. C73 (1997) 653-668
null
Cavendish-HEP-96/03, DFTT 19/96
hep-ph
null
The complete matrix element for $e^+e^-\rightarrow b\bar b W^+W^-$ is computed at tree-level within the Minimal Supersymmetric Standard Model. Rates of interest to phenomenological analyses at the Next Linear Collider are given. In particular, we study: - $t\bar t$ production and decay $t\bar t\ar (bW^+)(\bar bW^-)$; - $ZH$ production followed by $Z\ar b\bar b$ and $H\ar W^+W^-$; - $AH$ production followed by $A\ar b\bar b$ and $H\ar W^+W^-$; - $hW^+W^-$ production followed by $h\ar b\bar b$. Top and Higgs finite width effects are included, as well as all those of the irreducible backgrounds.
[ { "created": "Sun, 5 May 1996 16:38:38 GMT", "version": "v1" } ]
2007-05-23
[ [ "Moretti", "Stefano", "", "Cavendish Laboratory, Cambridge, UK" ] ]
The complete matrix element for $e^+e^-\rightarrow b\bar b W^+W^-$ is computed at tree-level within the Minimal Supersymmetric Standard Model. Rates of interest to phenomenological analyses at the Next Linear Collider are given. In particular, we study: - $t\bar t$ production and decay $t\bar t\ar (bW^+)(\bar bW^-)$; - $ZH$ production followed by $Z\ar b\bar b$ and $H\ar W^+W^-$; - $AH$ production followed by $A\ar b\bar b$ and $H\ar W^+W^-$; - $hW^+W^-$ production followed by $h\ar b\bar b$. Top and Higgs finite width effects are included, as well as all those of the irreducible backgrounds.
1610.00009
Matthias Neubert
Martin Bauer (U. Heidelberg), Matthias Neubert (MITP and JGU Mainz, Cornell U.) and Andrea Thamm (JGU Mainz)
Analyzing the CP Nature of a New Scalar Particle via S->Zh Decay
This letter is a significantly rewritten descendent of our previous work arXiv:1607.01016, which was motivated by the 750 GeV diphoton resonance. The current version contains relevant new material and is independent of the existence of such a resonance (6 pages, 4 figures; accepted for publication in Phys. Rev. Lett.)
Phys. Rev. Lett. 117, 181801 (2016)
10.1103/PhysRevLett.117.181801
MITP/16-105
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Scalar particles $S$ which are singlets under the Standard Model gauge group are generic features of many models of fundamental physics, in particular as possible mediators to a hidden sector. We show that the decay $S\to Zh$ provides a powerful probe of the CP nature of the scalar, because it is allowed only if $S$ has CP-odd interactions. We perform a model-independent analysis of this decay using an effective Lagrangian and compute the relevant Wilson coefficients arising from integrating out heavy fermions to one-loop order.
[ { "created": "Fri, 30 Sep 2016 20:00:02 GMT", "version": "v1" } ]
2016-11-02
[ [ "Bauer", "Martin", "", "U. Heidelberg" ], [ "Neubert", "Matthias", "", "MITP and JGU Mainz,\n Cornell U." ], [ "Thamm", "Andrea", "", "JGU Mainz" ] ]
Scalar particles $S$ which are singlets under the Standard Model gauge group are generic features of many models of fundamental physics, in particular as possible mediators to a hidden sector. We show that the decay $S\to Zh$ provides a powerful probe of the CP nature of the scalar, because it is allowed only if $S$ has CP-odd interactions. We perform a model-independent analysis of this decay using an effective Lagrangian and compute the relevant Wilson coefficients arising from integrating out heavy fermions to one-loop order.
2005.03016
Rhorry Gauld
R. Gauld, A. Gehrmann-De Ridder, E. W. N. Glover, A. Huss, I. Majer
Predictions for $\mathrm{Z}$-boson production in association with a $\mathrm{b}$-jet at $\mathcal{O}(\alpha_s^3)$
7 pages including references, 3 figures. v2 matches PRL version
null
10.1103/PhysRevLett.125.222002
NIKHEF 2020-012, ZU-TH 12/20, IPPP/20/13, CERN-TH-2020-071
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Precise predictions are provided for the production of a $\mathrm{Z}$-boson and a $\mathrm{b}$-jet in hadron-hadron collisions within the framework of perturbative QCD, at $\mathcal{O}(\alpha_s^3)$. To obtain these predictions we perform the first calculation of a hadronic scattering process involving the direct production of a flavoured-jet at next-to-next-to-leading order accuracy in massless QCD, and extend techniques to also account for the impact of finite heavy-quark mass effects. The predictions are compared to CMS data obtained in $\mathrm{pp}$ collisions at a centre-of-mass energy of $8~\mathrm{TeV}$, which are the most precise data from Run I of the LHC for this process, where a good description of the data is achieved. To allow this comparison we have performed an unfolding of the data, which overcomes the long-standing issue that the experimental and theoretical definitions of jet flavour are incompatible.
[ { "created": "Wed, 6 May 2020 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 11 Jan 2021 11:51:45 GMT", "version": "v2" } ]
2021-01-12
[ [ "Gauld", "R.", "" ], [ "Ridder", "A. Gehrmann-De", "" ], [ "Glover", "E. W. N.", "" ], [ "Huss", "A.", "" ], [ "Majer", "I.", "" ] ]
Precise predictions are provided for the production of a $\mathrm{Z}$-boson and a $\mathrm{b}$-jet in hadron-hadron collisions within the framework of perturbative QCD, at $\mathcal{O}(\alpha_s^3)$. To obtain these predictions we perform the first calculation of a hadronic scattering process involving the direct production of a flavoured-jet at next-to-next-to-leading order accuracy in massless QCD, and extend techniques to also account for the impact of finite heavy-quark mass effects. The predictions are compared to CMS data obtained in $\mathrm{pp}$ collisions at a centre-of-mass energy of $8~\mathrm{TeV}$, which are the most precise data from Run I of the LHC for this process, where a good description of the data is achieved. To allow this comparison we have performed an unfolding of the data, which overcomes the long-standing issue that the experimental and theoretical definitions of jet flavour are incompatible.
1512.00913
Teruyuki Kitabayashi
Teruyuki Kitabayashi and Masaki Yasu\`e
Formulae for flavour neutrino masses and its application to texture two zeros
8 pages, 2 figures, version accepted for publication in Physical Review D
Phys. Rev. D 93, 053012 (2016)
10.1103/PhysRevD.93.053012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate the usefulness of flavour neutrino masses expressed in terms of $M_{ee},M_{e\mu}$ and $M_{e\tau}$. The analytical expressions for the flavour neutrino masses, mass eigenstates and physical CP-violating Majorana phases for texture two zeros are obtained exactly.
[ { "created": "Thu, 3 Dec 2015 00:41:06 GMT", "version": "v1" }, { "created": "Wed, 24 Feb 2016 02:11:13 GMT", "version": "v2" } ]
2016-03-30
[ [ "Kitabayashi", "Teruyuki", "" ], [ "Yasuè", "Masaki", "" ] ]
We demonstrate the usefulness of flavour neutrino masses expressed in terms of $M_{ee},M_{e\mu}$ and $M_{e\tau}$. The analytical expressions for the flavour neutrino masses, mass eigenstates and physical CP-violating Majorana phases for texture two zeros are obtained exactly.
hep-ph/0311307
Ilya Lvovich Shapiro
Ilya L. Shapiro
An Overview of the Anomaly-Induced Inflation
Talk presented at IRGA2003 (Renormalization Group and Anomalies in Gravitation and Cosmology, Ouro Preto, Brazil, 16-23 March, 2003)
null
10.1016/S0920-5632(03)02431-9
null
hep-ph
null
The anomaly-induced inflation (modified Starobinsky model) is based on the application of the effective quantum field theory approach to the Early Universe. We present a brief general review of this model with a special attention to the existing difficulties and unsolved problems.
[ { "created": "Mon, 24 Nov 2003 17:50:39 GMT", "version": "v1" } ]
2009-11-10
[ [ "Shapiro", "Ilya L.", "" ] ]
The anomaly-induced inflation (modified Starobinsky model) is based on the application of the effective quantum field theory approach to the Early Universe. We present a brief general review of this model with a special attention to the existing difficulties and unsolved problems.
hep-ph/9902377
A. N. Mitra
A.N.Mitra
Soft-QCD Effects In B to gamma gamma Decay: Quark Level Form Factors
11 pages, 1 figure, LaTex
null
10.1016/S0370-2693(99)01504-X
null
hep-ph
null
Soft-QCD effects of quark-level form factors in $\gamma\gamma$ decay of $B_s$-mesons via $D{\bar D}$ intermediate states, suggested by Ellis et al, are examined in the "Salpeter" model [reinterpreted in terms of the Markov-Yukawa Transversality Principle (MYTP)] when formulated on a covariant light front (null-plane). The gluonic kernel in the infrared regime which generates the constituent mass via standard $DB{\chi}S$, is calibrated to both $q{\bar q}$ and qqq spectra, meson mass splittings, pion form factor,and other parameters. With this check, an exact evaluation of the $D{\bar D}\gamma$ vertex form factor $F(\alpha)$ (normalized to F(0)=1), gives a multiplicative effect of $F^2(\alpha)$ on the $B_s \Rightarrow \gamma\gamma$ amplitude via D-meson triangle loop, where $\alpha$ = $(p^2+M^2)/M^2$ is the off-shellness parameter of the exchanged D-meson of mass M and 4-momentum $p_\mu$, and is a variables of the (internal)loop integration. Unfortunately, the $F^2(\alpha)$ effect decreases the loop amplitude by a factor of 30 w.r.t. the point hadron value, resulting in a reduction of 3 orders of magnitude in long distance (hadronic) contributions to the $B_s \Rightarrow \gamma\gamma$ decay rate, thus greatly impairing the visibility of such modes. PACS: 11.10.St ; 12.38.Lg ; 13.20.Gd ; 13.40.Hq Keywords: $B_s$ radiative decay; Soft-QCD; Vertex-Fn; Form-factor; Markov-Yukawa-Transversality Principle; Salpeter eq; Cov. light front
[ { "created": "Wed, 17 Feb 1999 16:49:13 GMT", "version": "v1" }, { "created": "Tue, 8 Jun 1999 12:53:04 GMT", "version": "v2" }, { "created": "Sun, 17 Oct 1999 15:17:28 GMT", "version": "v3" } ]
2009-10-31
[ [ "Mitra", "A. N.", "" ] ]
Soft-QCD effects of quark-level form factors in $\gamma\gamma$ decay of $B_s$-mesons via $D{\bar D}$ intermediate states, suggested by Ellis et al, are examined in the "Salpeter" model [reinterpreted in terms of the Markov-Yukawa Transversality Principle (MYTP)] when formulated on a covariant light front (null-plane). The gluonic kernel in the infrared regime which generates the constituent mass via standard $DB{\chi}S$, is calibrated to both $q{\bar q}$ and qqq spectra, meson mass splittings, pion form factor,and other parameters. With this check, an exact evaluation of the $D{\bar D}\gamma$ vertex form factor $F(\alpha)$ (normalized to F(0)=1), gives a multiplicative effect of $F^2(\alpha)$ on the $B_s \Rightarrow \gamma\gamma$ amplitude via D-meson triangle loop, where $\alpha$ = $(p^2+M^2)/M^2$ is the off-shellness parameter of the exchanged D-meson of mass M and 4-momentum $p_\mu$, and is a variables of the (internal)loop integration. Unfortunately, the $F^2(\alpha)$ effect decreases the loop amplitude by a factor of 30 w.r.t. the point hadron value, resulting in a reduction of 3 orders of magnitude in long distance (hadronic) contributions to the $B_s \Rightarrow \gamma\gamma$ decay rate, thus greatly impairing the visibility of such modes. PACS: 11.10.St ; 12.38.Lg ; 13.20.Gd ; 13.40.Hq Keywords: $B_s$ radiative decay; Soft-QCD; Vertex-Fn; Form-factor; Markov-Yukawa-Transversality Principle; Salpeter eq; Cov. light front
hep-ph/9703435
David Bowser-Chao
David Bowser-Chao, Darwin Chang, Wai-Yee Keung
Electron Electric Dipole Moment from CP Violation in the Charged Higgs Sector
resubmission now matches published version in PRL, plus adds reference to AGS proposal to measure the muon edm to 10^-24 e-cm; complete uncompressed postscript at http://hepster.phy.uic.edu/~davechao/work/default.html
Phys.Rev.Lett.79:1988-1991,1997
10.1103/PhysRevLett.79.1988
NHCU-HEP-97-5, UICHEP-TH/97-3
hep-ph
null
The leading contributions to the electron (or muon) electric dipole moment due to CP violation in the charged Higgs sector are at the two-loop level. A careful analysis of the model-independent contribution is provided. We also consider specific scenarios to demonstrate how charged Higgs sector CP violation can naturally give rise to large electric dipole moments. Numerical results show that the electron electric dipole moment in such models can lie at the experimentally accessible level.
[ { "created": "Wed, 26 Mar 1997 22:34:12 GMT", "version": "v1" }, { "created": "Tue, 2 Dec 1997 23:15:08 GMT", "version": "v2" } ]
2009-09-01
[ [ "Bowser-Chao", "David", "" ], [ "Chang", "Darwin", "" ], [ "Keung", "Wai-Yee", "" ] ]
The leading contributions to the electron (or muon) electric dipole moment due to CP violation in the charged Higgs sector are at the two-loop level. A careful analysis of the model-independent contribution is provided. We also consider specific scenarios to demonstrate how charged Higgs sector CP violation can naturally give rise to large electric dipole moments. Numerical results show that the electron electric dipole moment in such models can lie at the experimentally accessible level.