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1312.0705
Hyeong-Chan Kim
Hyeong-Chan Kim
Physics at the surface of a star in Eddington-inspired Born-Infeld gravity
7 pages, Comments are added for negative curvatures
Phys. Rev. D 89, 064001 (2014)
10.1103/PhysRevD.89.064001
null
gr-qc astro-ph.SR hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study phenomena happening at the surface of a star in Eddington-inspired Born-Infeld (EiBI) gravity. The star is made of particles, which are effectively described by a polytropic fluid. The EiBI theory was known to have a pathology that singularities happen at a star surface. We suggest that the gravitational back-reaction on the particles cures the problem. Strong tidal forces near the (surface) singularity modify the effective equation of state of the particles or make the surface be unstable depending on its matter contents. The geodesic deviation equations take after the Hooke's law, where its frequency-squared is proportional to the scalar curvature at the surface. For a positive curvature, a particle collides with a probing wall more often and increases the pressure. With the increased pressure, the surface is no longer singular. For a negative curvature, the matters around the surface experience repulsions with infinite accelerations. Therefore, the EiBI gravity is saved from the pathology of surface singularity.
[ { "created": "Tue, 3 Dec 2013 05:55:02 GMT", "version": "v1" }, { "created": "Sat, 4 Jan 2014 03:00:55 GMT", "version": "v2" } ]
2014-06-17
[ [ "Kim", "Hyeong-Chan", "" ] ]
We study phenomena happening at the surface of a star in Eddington-inspired Born-Infeld (EiBI) gravity. The star is made of particles, which are effectively described by a polytropic fluid. The EiBI theory was known to have a pathology that singularities happen at a star surface. We suggest that the gravitational back-reaction on the particles cures the problem. Strong tidal forces near the (surface) singularity modify the effective equation of state of the particles or make the surface be unstable depending on its matter contents. The geodesic deviation equations take after the Hooke's law, where its frequency-squared is proportional to the scalar curvature at the surface. For a positive curvature, a particle collides with a probing wall more often and increases the pressure. With the increased pressure, the surface is no longer singular. For a negative curvature, the matters around the surface experience repulsions with infinite accelerations. Therefore, the EiBI gravity is saved from the pathology of surface singularity.
2001.07580
Salvatore Marco Giampaolo
Luca Buoninfante, Antonio Capolupo, Salvatore M. Giampaolo, Gaetano Lambiase
Revealing neutrino nature and $CPT$ violation with decoherence effects
13 pages, 2 figures
null
10.1140/epjc/s10052-020-08549-9
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study decoherence effects on mixing among three generations of neutrinos. We show that in presence of a non--diagonal dissipation matrix, both Dirac and Majorana neutrinos can violate the $CPT$ symmetry and the oscillation formulae depend on the parametrization of the mixing matrix. We reveal the $CP$ violation in the transitions preserving the flavor, for a certain form of the dissipator. In particular, the $CP$ violation affects all the transitions in the case of Majorana neutrinos, unlike Dirac neutrinos which still preserve the $CP$ symmetry in one of the transitions flavor preserving. This theoretical result shows that decoherence effects, if exist for neutrinos, could allow to determine the neutrino nature and to test fundamental symmetries of physics. Next long baseline experiments could allow such an analysis. We relate our study with experiments by using the characteristic parameters and the constraints on the elements of the dissipation matrix of current experiments.
[ { "created": "Tue, 21 Jan 2020 14:46:16 GMT", "version": "v1" }, { "created": "Wed, 29 Jan 2020 14:15:21 GMT", "version": "v2" } ]
2020-12-02
[ [ "Buoninfante", "Luca", "" ], [ "Capolupo", "Antonio", "" ], [ "Giampaolo", "Salvatore M.", "" ], [ "Lambiase", "Gaetano", "" ] ]
We study decoherence effects on mixing among three generations of neutrinos. We show that in presence of a non--diagonal dissipation matrix, both Dirac and Majorana neutrinos can violate the $CPT$ symmetry and the oscillation formulae depend on the parametrization of the mixing matrix. We reveal the $CP$ violation in the transitions preserving the flavor, for a certain form of the dissipator. In particular, the $CP$ violation affects all the transitions in the case of Majorana neutrinos, unlike Dirac neutrinos which still preserve the $CP$ symmetry in one of the transitions flavor preserving. This theoretical result shows that decoherence effects, if exist for neutrinos, could allow to determine the neutrino nature and to test fundamental symmetries of physics. Next long baseline experiments could allow such an analysis. We relate our study with experiments by using the characteristic parameters and the constraints on the elements of the dissipation matrix of current experiments.
1006.2596
Kenji Fukushima
Kenji Fukushima
Phase diagram of hot and dense QCD constrained by the Statistical Model
5 pages, 3 figures; all figures updated, results and conclusions not modified
Phys.Lett.B695:387-391,2011
10.1016/j.physletb.2010.11.040
YITP-10-46
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a prescription to constrain the chiral effective model approach to the QCD phase diagram using the thermal Statistical Model, which is a description consistent with the experimental data at the freeze-out. In the transition region where thermal quantities of hadrons blow up, deconfined quarks and gluons should smoothly take over the degrees of freedom from hadrons in the Statistical Model. We use the Polyakov-loop coupled Nambu--Jona-Lasinio (PNJL) model as an effective description in the quark side. We require that the validity regions of these descriptions should have an overlap on the phase diagram, which constrains model uncertainty. Our results favor a phase diagram with the chiral phase transition located at slightly higher temperature than deconfinement.
[ { "created": "Mon, 14 Jun 2010 04:27:17 GMT", "version": "v1" }, { "created": "Wed, 30 Jun 2010 10:24:55 GMT", "version": "v2" } ]
2011-06-27
[ [ "Fukushima", "Kenji", "" ] ]
We propose a prescription to constrain the chiral effective model approach to the QCD phase diagram using the thermal Statistical Model, which is a description consistent with the experimental data at the freeze-out. In the transition region where thermal quantities of hadrons blow up, deconfined quarks and gluons should smoothly take over the degrees of freedom from hadrons in the Statistical Model. We use the Polyakov-loop coupled Nambu--Jona-Lasinio (PNJL) model as an effective description in the quark side. We require that the validity regions of these descriptions should have an overlap on the phase diagram, which constrains model uncertainty. Our results favor a phase diagram with the chiral phase transition located at slightly higher temperature than deconfinement.
1001.2726
Josep M. Pons
J. M. Pons, D. C. Salisbury, K. A. Sundermeyer
Observables in classical canonical gravity: folklore demystified
15 pages, To appear in Proceedings of 1st Mediterranean Conference on Classical and Quantum Gravity. Corrected minor typos
null
10.1088/1742-6596/222/1/012018
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give an overview of some conceptual difficulties, sometimes called paradoxes, that have puzzled for years the physical interpetation of classical canonical gravity and, by extension, the canonical formulation of generally covariant theories. We identify these difficulties as stemming form some terminological misunderstandings as to what is meant by "gauge invariance", or what is understood classically by a "physical state". We make a thorough analysis of the issue and show that all purported paradoxes disappear when the right terminology is in place. Since this issue is connected with the search of observables - gauge invariant quantities - for these theories, we formally show that time evolving observables can be constructed for every observer. This construction relies on the fixation of the gauge freedom of diffeomorphism invariance by means of a scalar coordinatization. We stress the condition that the coordinatization must be made with scalars. As an example of our method for obtaining observables we discuss the case of the massive particle in AdS spacetime.
[ { "created": "Fri, 15 Jan 2010 16:21:25 GMT", "version": "v1" }, { "created": "Wed, 12 May 2010 10:43:14 GMT", "version": "v2" } ]
2015-05-18
[ [ "Pons", "J. M.", "" ], [ "Salisbury", "D. C.", "" ], [ "Sundermeyer", "K. A.", "" ] ]
We give an overview of some conceptual difficulties, sometimes called paradoxes, that have puzzled for years the physical interpetation of classical canonical gravity and, by extension, the canonical formulation of generally covariant theories. We identify these difficulties as stemming form some terminological misunderstandings as to what is meant by "gauge invariance", or what is understood classically by a "physical state". We make a thorough analysis of the issue and show that all purported paradoxes disappear when the right terminology is in place. Since this issue is connected with the search of observables - gauge invariant quantities - for these theories, we formally show that time evolving observables can be constructed for every observer. This construction relies on the fixation of the gauge freedom of diffeomorphism invariance by means of a scalar coordinatization. We stress the condition that the coordinatization must be made with scalars. As an example of our method for obtaining observables we discuss the case of the massive particle in AdS spacetime.
1501.07128
Matthias Steinhauser
Luminita N. Mihaila and Matthias Steinhauser
Selected topics on multi-loop calculations to Higgs boson properties and renormalization group functions
28 pages, Contribution to the Proceedings of the Final Meeting of the Collaborative Research Centre / Transregio 9 "Computational Particle Physics", Durbach, Germany, September 2014, to appear in Nucl. Phys. (Proc. Suppl.)
null
null
TTP14-036, SFB/CPP-14-99
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review some results obtained in the context of the Collaborative Research Center/Transregio~9. In particular we discuss three-loop corrections to the Higgs boson mass in the Minimal Supersymmetric Standard Model, higher order corrections to Higgs boson production, and the calculations of renormalization group functions and decoupling constants.
[ { "created": "Wed, 28 Jan 2015 15:03:55 GMT", "version": "v1" } ]
2015-01-29
[ [ "Mihaila", "Luminita N.", "" ], [ "Steinhauser", "Matthias", "" ] ]
We review some results obtained in the context of the Collaborative Research Center/Transregio~9. In particular we discuss three-loop corrections to the Higgs boson mass in the Minimal Supersymmetric Standard Model, higher order corrections to Higgs boson production, and the calculations of renormalization group functions and decoupling constants.
hep-ph/9911286
null
R.S. Bhalerao (Indiana U., USA and TIFR, India), N.G. Kelkar (BARC, India), B. Ram (NMSU, USA)
Model for Polarized and Unpolarized Parton Density Functions in the Nucleon
version to appear in Phys. Lett. B; a note added at the end of the paper; no other change; latex, 10 pages, 4 ps figures
Phys.Lett. B476 (2000) 285-290
10.1016/S0370-2693(00)00158-1
null
hep-ph hep-ex nucl-th
null
We present a physical model for polarized and unpolarized structure functions and parton density functions (PDFs) of the proton and the neutron. It reproduces the data on F_2^p(x,Q^2) for 0.00001<x<1 and 2.5<Q^2<5000 GeV^2, F_2^p(x)-F_2^n(x), F_2^n(x)/F_2^p(x), xg(x), dbar(x)-ubar(x), d(x)/u(x), the Gottfried sum, the fractional momentum of charged partons and the polarized structure functions g_1^{p,n}(x), at various Q^2. We present for the first time, proton and neutron PDFs which do not assume charge symmetry. Contrary to the common practice, we explain polarized and unpolarized data with a single model.
[ { "created": "Tue, 9 Nov 1999 15:19:10 GMT", "version": "v1" }, { "created": "Tue, 8 Feb 2000 10:12:44 GMT", "version": "v2" } ]
2009-10-31
[ [ "Bhalerao", "R. S.", "", "Indiana U., USA and TIFR, India" ], [ "Kelkar", "N. G.", "", "BARC,\n India" ], [ "Ram", "B.", "", "NMSU, USA" ] ]
We present a physical model for polarized and unpolarized structure functions and parton density functions (PDFs) of the proton and the neutron. It reproduces the data on F_2^p(x,Q^2) for 0.00001<x<1 and 2.5<Q^2<5000 GeV^2, F_2^p(x)-F_2^n(x), F_2^n(x)/F_2^p(x), xg(x), dbar(x)-ubar(x), d(x)/u(x), the Gottfried sum, the fractional momentum of charged partons and the polarized structure functions g_1^{p,n}(x), at various Q^2. We present for the first time, proton and neutron PDFs which do not assume charge symmetry. Contrary to the common practice, we explain polarized and unpolarized data with a single model.
2109.07479
Ke-Pan Xie
Katsuya Hashino, Jia Liu, Xiao-Ping Wang, Ke-Pan Xie
Dark matter transient annihilations in the early Universe
7 pages+appendix and references, 4 figures. Match the published version
null
10.1103/PhysRevD.105.055009
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The cosmological evolution can modify the dark matter (DM) properties in the early Universe to be vastly different from the properties today. Therefore, the relation between the relic abundance and the DM constraints today needs to be revisited. We propose novel \textit{transient} annihilations of DM which helps to alleviate the pressure from DM null detection results. As a concrete example, we consider the vector portal DM and focus on the mass evolution of the dark photon. When the Universe cools down, the gauge boson mass can increase monotonically and go across several important thresholds; opening new transient annihilation channels in the early Universe. Those channels are either forbidden or weakened at the late Universe which helps to evade the indirect searches. In particular, the transient resonant channel can survive direct detection (DD) without tuning the DM to be half of the dark photon mass and can be soon tested by future DD or collider experiments. A feature of the scenario is the existence of a light dark scalar.
[ { "created": "Wed, 15 Sep 2021 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 1 Mar 2022 03:52:03 GMT", "version": "v2" } ]
2022-03-15
[ [ "Hashino", "Katsuya", "" ], [ "Liu", "Jia", "" ], [ "Wang", "Xiao-Ping", "" ], [ "Xie", "Ke-Pan", "" ] ]
The cosmological evolution can modify the dark matter (DM) properties in the early Universe to be vastly different from the properties today. Therefore, the relation between the relic abundance and the DM constraints today needs to be revisited. We propose novel \textit{transient} annihilations of DM which helps to alleviate the pressure from DM null detection results. As a concrete example, we consider the vector portal DM and focus on the mass evolution of the dark photon. When the Universe cools down, the gauge boson mass can increase monotonically and go across several important thresholds; opening new transient annihilation channels in the early Universe. Those channels are either forbidden or weakened at the late Universe which helps to evade the indirect searches. In particular, the transient resonant channel can survive direct detection (DD) without tuning the DM to be half of the dark photon mass and can be soon tested by future DD or collider experiments. A feature of the scenario is the existence of a light dark scalar.
1310.7223
Jurgen Riedel
Yves Brihaye and J\"urgen Riedel
Rotating Boson Stars in Einstein-Gauss-Bonnet gravity
Discussion enlarged and references added. 15 pages, 9 figures
Phys. Rev. D 89, 104060 (2014)
10.1103/PhysRevD.89.104060
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A self-interacting SU(2)-doublet of complex scalar fields, minimally coupled to Einstein-Gauss-Bonnet gravity is considered in five space-time dimensions. The classical equations admit two families of solitons corresponding to spinning and non-spinning bosons stars. The generic solutions are constructed numerically and agree with exact results that are available in special limits of the parameters. The pattern of the boson stars is shown to be qualitatively affected by the Gauss-Bonnet coupling constant.
[ { "created": "Sun, 27 Oct 2013 18:00:05 GMT", "version": "v1" }, { "created": "Tue, 26 Nov 2013 14:45:44 GMT", "version": "v2" } ]
2014-06-11
[ [ "Brihaye", "Yves", "" ], [ "Riedel", "Jürgen", "" ] ]
A self-interacting SU(2)-doublet of complex scalar fields, minimally coupled to Einstein-Gauss-Bonnet gravity is considered in five space-time dimensions. The classical equations admit two families of solitons corresponding to spinning and non-spinning bosons stars. The generic solutions are constructed numerically and agree with exact results that are available in special limits of the parameters. The pattern of the boson stars is shown to be qualitatively affected by the Gauss-Bonnet coupling constant.
1110.6223
Oscar Loaiza-Brito
Celia Escamilla-Rivera, Gerardo Garcia-Jimenez, Oscar Loaiza-Brito, Octavio Obregon
Closed String Tachyon: Inflation and Cosmological Collapse
12 pages, 6 figures
null
10.1088/0264-9381/30/3/035005
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By compactifying a critical bosonic string theory on an internal non-flat space with a constant volume, we study the role played by the closed string tachyon in the cosmology of the effective four-dimensional space-time. The effective tachyon potential consists on a negative constant related to the internal curvature space and a polynomial with only quadratic and quartic terms of the tachyon field. Based on it, we present a solution for the tachyon field and the scale factor, which describes an accelerated universe which expands to a maximum value before collapsing. At early times, the closed string tachyon potential behaves as a cosmological constant driving the Universe to an expansion. The value of the cosmological constant is determined by the curvature of the internal space which also fixes the value of the vacuum energy. As time evolves, inflation is present in our models, and it finishes long before the collapsing. At late times, we show that the collapse of the Universe starts as soon as the tachyon field condensates. We also comment on the consistency of our solution at early times at which quantum aspects become important under the perspective of quantum cosmology. Finally we briefly mention the relation among the curvature of the internal space and the value of the energy vacuum in a non-constant internal volume scenario.
[ { "created": "Fri, 28 Oct 2011 00:15:09 GMT", "version": "v1" } ]
2015-06-03
[ [ "Escamilla-Rivera", "Celia", "" ], [ "Garcia-Jimenez", "Gerardo", "" ], [ "Loaiza-Brito", "Oscar", "" ], [ "Obregon", "Octavio", "" ] ]
By compactifying a critical bosonic string theory on an internal non-flat space with a constant volume, we study the role played by the closed string tachyon in the cosmology of the effective four-dimensional space-time. The effective tachyon potential consists on a negative constant related to the internal curvature space and a polynomial with only quadratic and quartic terms of the tachyon field. Based on it, we present a solution for the tachyon field and the scale factor, which describes an accelerated universe which expands to a maximum value before collapsing. At early times, the closed string tachyon potential behaves as a cosmological constant driving the Universe to an expansion. The value of the cosmological constant is determined by the curvature of the internal space which also fixes the value of the vacuum energy. As time evolves, inflation is present in our models, and it finishes long before the collapsing. At late times, we show that the collapse of the Universe starts as soon as the tachyon field condensates. We also comment on the consistency of our solution at early times at which quantum aspects become important under the perspective of quantum cosmology. Finally we briefly mention the relation among the curvature of the internal space and the value of the energy vacuum in a non-constant internal volume scenario.
1001.2561
Joao Silva
P.M. Ferreira, L. Lavoura, and Joao P. Silva
Renormalization-group constraints on Yukawa alignment in multi-Higgs-doublet models
7 pages, Latex, no figures
Phys.Lett.B688:341-344,2010
10.1016/j.physletb.2010.04.033
CFTP/10-001
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We write down the renormalization-group equations for the Yukawa-coupling matrices in a general multi-Higgs-doublet model. We then assume that the matrices of the Yukawa couplings of the various Higgs doublets to right-handed fermions of fixed quantum numbers are all proportional to each other. We demonstrate that, in the case of the two-Higgs-doublet model, this proportionality is preserved by the renormalization-group running only in the cases of the standard type-I, II, X, and Y models. We furthermore show that a similar result holds even when there are more than two Higgs doublets: the Yukawa-coupling matrices to fermions of a given electric charge remain proportional under the renormalization-group running if and only if there is a basis for the Higgs doublets in which all the fermions of a given electric charge couple to only one Higgs doublet.
[ { "created": "Thu, 14 Jan 2010 21:04:42 GMT", "version": "v1" } ]
2014-11-20
[ [ "Ferreira", "P. M.", "" ], [ "Lavoura", "L.", "" ], [ "Silva", "Joao P.", "" ] ]
We write down the renormalization-group equations for the Yukawa-coupling matrices in a general multi-Higgs-doublet model. We then assume that the matrices of the Yukawa couplings of the various Higgs doublets to right-handed fermions of fixed quantum numbers are all proportional to each other. We demonstrate that, in the case of the two-Higgs-doublet model, this proportionality is preserved by the renormalization-group running only in the cases of the standard type-I, II, X, and Y models. We furthermore show that a similar result holds even when there are more than two Higgs doublets: the Yukawa-coupling matrices to fermions of a given electric charge remain proportional under the renormalization-group running if and only if there is a basis for the Higgs doublets in which all the fermions of a given electric charge couple to only one Higgs doublet.
gr-qc/0009104
A. Heidmann
M. Cerdonio, L. Conti, A. Heidmann and M. Pinard
Thermoelastic effects at low temperatures and quantum limits in displacement measurements
9 pages, 2 figures
Phys.Rev. D63 (2001) 082003
10.1103/PhysRevD.63.082003
null
gr-qc quant-ph
null
The displacement fluctuations of mirrors in optomechanical devices, induced via thermal expansion by temperature fluctuations due either to thermodynamic fluctuations or to fluctuations in the photon absorption, can be made smaller than quantum fluctuations, at the low temperatures, high reflectivities and high light powers needed to readout displacements at the standard quantum limit. The result is relevant for the design of quantum limited gravitational-wave detectors, both "interferometers" and "bars", and for experiments to study directly mechanical motion in the quantum regime.
[ { "created": "Fri, 29 Sep 2000 17:02:49 GMT", "version": "v1" }, { "created": "Wed, 10 Jan 2001 17:40:08 GMT", "version": "v2" } ]
2009-10-31
[ [ "Cerdonio", "M.", "" ], [ "Conti", "L.", "" ], [ "Heidmann", "A.", "" ], [ "Pinard", "M.", "" ] ]
The displacement fluctuations of mirrors in optomechanical devices, induced via thermal expansion by temperature fluctuations due either to thermodynamic fluctuations or to fluctuations in the photon absorption, can be made smaller than quantum fluctuations, at the low temperatures, high reflectivities and high light powers needed to readout displacements at the standard quantum limit. The result is relevant for the design of quantum limited gravitational-wave detectors, both "interferometers" and "bars", and for experiments to study directly mechanical motion in the quantum regime.
2211.01888
Andrea Antonelli
Andrea Antonelli
Accurate waveform models for gravitational-wave astrophysics: synergetic approaches from analytical relativity
PhD Thesis. Contains novel results in Section 1.3.2 regarding the derivation of the N3LO SO dynamics. Sections 2 to 6 are arXiv1901.07102, arXiv:1907.11597, arXiv:2003.11391, arXiv:2010.02018, arXiv:2104.01897, respectively
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Gravitational-wave (GW) astrophysics is a field in full blossom. Since the landmark detection of GWs from a binary black hole on September 14th 2015, several compact-object binaries have been reported by the LIGO-Virgo collaboration. Such events carry astrophysical and cosmological information ranging from an understanding of how black holes and neutron stars are formed, what neutron stars are composed of, how the Universe expands, and allow testing general relativity in the highly-dynamical strong-field regime. It is the goal of GW astrophysics to extract such information as accurately as possible. Yet, this is only possible if the tools and technology used to detect and analyze GWs are advanced enough. A key aspect of GW searches are waveform models, which encapsulate our best predictions for the gravitational radiation under a certain set of parameters, and that need to be cross-correlated with data to extract GW signals. Waveforms must be very accurate to avoid missing important physics in the data, which might be the key to answer the fundamental questions of GW astrophysics. The continuous improvements of the current LIGO-Virgo detectors, the development of next-generation ground-based detectors such as the Einstein Telescope or the Cosmic Explorer, as well as the development of the Laser Interferometer Space Antenna (LISA), demand accurate waveform models. [Abridged.]
[ { "created": "Thu, 3 Nov 2022 15:20:53 GMT", "version": "v1" } ]
2022-11-04
[ [ "Antonelli", "Andrea", "" ] ]
Gravitational-wave (GW) astrophysics is a field in full blossom. Since the landmark detection of GWs from a binary black hole on September 14th 2015, several compact-object binaries have been reported by the LIGO-Virgo collaboration. Such events carry astrophysical and cosmological information ranging from an understanding of how black holes and neutron stars are formed, what neutron stars are composed of, how the Universe expands, and allow testing general relativity in the highly-dynamical strong-field regime. It is the goal of GW astrophysics to extract such information as accurately as possible. Yet, this is only possible if the tools and technology used to detect and analyze GWs are advanced enough. A key aspect of GW searches are waveform models, which encapsulate our best predictions for the gravitational radiation under a certain set of parameters, and that need to be cross-correlated with data to extract GW signals. Waveforms must be very accurate to avoid missing important physics in the data, which might be the key to answer the fundamental questions of GW astrophysics. The continuous improvements of the current LIGO-Virgo detectors, the development of next-generation ground-based detectors such as the Einstein Telescope or the Cosmic Explorer, as well as the development of the Laser Interferometer Space Antenna (LISA), demand accurate waveform models. [Abridged.]
0812.4417
Maria Amparo T\'ortola
A. Bola\~nos, O. G. Miranda, A. Palazzo, M. A. T\'ortola and J. W. F. Valle
Probing non-standard neutrino-electron interactions with solar and reactor neutrinos
18 pages, 3 figures, matches version published in Phys. Rev. D
Phys.Rev.D79:113012,2009
10.1103/PhysRevD.79.113012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Most neutrino mass extensions of the standard electroweak model entail non-standard interactions which, in the low energy limit, can be parametrized in term of effective four-fermion operators $\nu_\alpha \nu_\beta \bar f f $. Typically of sub-weak strength, $\epsilon_{\alpha \beta} G_F$, these are characterized by dimensionless coupling parameters, $\epsilon_{\alpha \beta}$, which may be relatively sizeable in a wide class of schemes. Here we focus on non-universal (NU) flavor conserving couplings ($\alpha = \beta$) with electrons ($f = e$) and analyse their impact on the phenomenology of solar neutrinos. We consistently take into account their effect both at the level of propagation where they modify the standard MSW behavior, and at the level of detection, where they affect the cross section of neutrino elastic scattering on electrons. We find limits which are comparable to other existing model-independent constraints.
[ { "created": "Tue, 23 Dec 2008 16:14:41 GMT", "version": "v1" }, { "created": "Fri, 19 Jun 2009 16:14:01 GMT", "version": "v2" } ]
2010-04-15
[ [ "Bolaños", "A.", "" ], [ "Miranda", "O. G.", "" ], [ "Palazzo", "A.", "" ], [ "Tórtola", "M. A.", "" ], [ "Valle", "J. W. F.", "" ] ]
Most neutrino mass extensions of the standard electroweak model entail non-standard interactions which, in the low energy limit, can be parametrized in term of effective four-fermion operators $\nu_\alpha \nu_\beta \bar f f $. Typically of sub-weak strength, $\epsilon_{\alpha \beta} G_F$, these are characterized by dimensionless coupling parameters, $\epsilon_{\alpha \beta}$, which may be relatively sizeable in a wide class of schemes. Here we focus on non-universal (NU) flavor conserving couplings ($\alpha = \beta$) with electrons ($f = e$) and analyse their impact on the phenomenology of solar neutrinos. We consistently take into account their effect both at the level of propagation where they modify the standard MSW behavior, and at the level of detection, where they affect the cross section of neutrino elastic scattering on electrons. We find limits which are comparable to other existing model-independent constraints.
1502.02195
Jose Edgar Madriz Aguilar
Jose Edgar Madriz Aguilar
New effective coupled $F(^{(4)}\!R,\varphi)$ modified gravity from $f(^{(5)}\!R)$ gravity in five dimensions
6 pages, no figures
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We obtain a new kind of $F(^{(4)}\!R,\varphi)$ modified gravity theory as an effective four-dimensional (4D) theory derived from $f(^{(5)}\!R)$ gravity in five dimensions (5D). This new theory exhibits a different matter coupling than the one in BBHL theory. We show that the field equations of the Wesson's induced matter theory and of some braneworld scenarios can be obtained as maximally symmetric solutions of the $f(^{(5)}\!R)$ theory. We found criteria for the Goldov-Kawasaki instabilities for both the $f(^{(5)}\!R)$ and the $F(^{(4)}\!R,\varphi)$ theories. We demonstrate that under certain conditions imposed on the 5D geometry it is possible to interpret the $F(^{(4)}\!R,\varphi)$ theory as a modified gravity theory with dynamical coefficients, making this new theory a viable candidate to address the present accelerating cosmic expansion issue.
[ { "created": "Sat, 7 Feb 2015 23:40:48 GMT", "version": "v1" }, { "created": "Thu, 23 Apr 2015 22:37:31 GMT", "version": "v2" } ]
2015-04-27
[ [ "Aguilar", "Jose Edgar Madriz", "" ] ]
We obtain a new kind of $F(^{(4)}\!R,\varphi)$ modified gravity theory as an effective four-dimensional (4D) theory derived from $f(^{(5)}\!R)$ gravity in five dimensions (5D). This new theory exhibits a different matter coupling than the one in BBHL theory. We show that the field equations of the Wesson's induced matter theory and of some braneworld scenarios can be obtained as maximally symmetric solutions of the $f(^{(5)}\!R)$ theory. We found criteria for the Goldov-Kawasaki instabilities for both the $f(^{(5)}\!R)$ and the $F(^{(4)}\!R,\varphi)$ theories. We demonstrate that under certain conditions imposed on the 5D geometry it is possible to interpret the $F(^{(4)}\!R,\varphi)$ theory as a modified gravity theory with dynamical coefficients, making this new theory a viable candidate to address the present accelerating cosmic expansion issue.
1402.3841
Ernest Ma
Ernest Ma (UC Riverside)
The Higgs Connection -- Flavor and Dark Matter
10 pages, 5 figures (Fig.5 revised), Talk at International Conference on Flavor Physics and Mass Generation (Singapore, February 2014)
null
10.1142/S0217751X14300348
UCRHEP-T540 (February 2014)
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Three families of quarks and leptons, one Higgs to rule them all, and in the darkness bind them.
[ { "created": "Sun, 16 Feb 2014 21:07:52 GMT", "version": "v1" }, { "created": "Mon, 28 Apr 2014 19:54:28 GMT", "version": "v2" } ]
2015-06-18
[ [ "Ma", "Ernest", "", "UC Riverside" ] ]
Three families of quarks and leptons, one Higgs to rule them all, and in the darkness bind them.
0804.3195
Roberto Contino
Roberto Contino
Z', Z_KK, Z* and all that: current bounds and theoretical prejudices on heavy neutral vector bosons
Talk given at: V Workshop Italiano sulla fisica p-p ad LHC, Perugia, Italy, 30 Jan. - 2 Feb. 2008
Nuovo Cim.B123:511-515,2008
10.1393/ncb/i2008-10553-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review the current experimental bounds and theoretical predictions for different kinds of heavy neutral vector bosons.
[ { "created": "Sun, 20 Apr 2008 14:40:28 GMT", "version": "v1" } ]
2010-11-11
[ [ "Contino", "Roberto", "" ] ]
I review the current experimental bounds and theoretical predictions for different kinds of heavy neutral vector bosons.
2111.02137
Claus Kiefer
Claus Kiefer
On a Quantum Weyl Curvature Hypothesis
13 pages, Invited contribution for a special topical collection celebrating Sir Roger Penrose's Nobel Prize, ed. by I. Fuentes and H. Ulbricht, final version
AVS Quantum Sci. 4, 015607 (2022)
10.1116/5.0076811
null
gr-qc quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Roger Penrose's Weyl curvature hypothesis states that the Weyl curvature is small at past singularities, but not at future singularities. We review the motivations for this conjecture and present estimates for the entropy of our Universe. We then extend this hypothesis to the quantum regime by demanding that the initial state of primordial quantum fluctuations be the adiabatic vacuum in a (quasi-) de~Sitter space. We finally attempt a justification of this quantum version from a fundamental theory of quantum gravity and speculate on its consequences in the case of a classically recollapsing universe.
[ { "created": "Wed, 3 Nov 2021 11:11:05 GMT", "version": "v1" }, { "created": "Fri, 1 Apr 2022 08:30:37 GMT", "version": "v2" } ]
2022-04-04
[ [ "Kiefer", "Claus", "" ] ]
Roger Penrose's Weyl curvature hypothesis states that the Weyl curvature is small at past singularities, but not at future singularities. We review the motivations for this conjecture and present estimates for the entropy of our Universe. We then extend this hypothesis to the quantum regime by demanding that the initial state of primordial quantum fluctuations be the adiabatic vacuum in a (quasi-) de~Sitter space. We finally attempt a justification of this quantum version from a fundamental theory of quantum gravity and speculate on its consequences in the case of a classically recollapsing universe.
1005.2985
Matteo Smerlak
Carlo Rovelli, Matteo Smerlak
Thermal time and the Tolman-Ehrenfest effect: temperature as the "speed of time"
4 pages; sharpened discussion of the underlying physical assumptions
Class.Quant.Grav.28:075007,2011
10.1088/0264-9381/28/7/075007
null
gr-qc physics.class-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The notion of thermal time has been introduced as a possible basis for a fully general-relativistic thermodynamics. Here we study this notion in the restricted context of stationary spacetimes. We show that the Tolman-Ehrenfest effect (in a stationary gravitational field, temperature is not constant in space at thermal equilibrium) can be derived very simply by applying the equivalence principle to a key property of thermal time: at equilibrium, temperature is the rate of thermal time with respect to proper time - the `speed of (thermal) time'. Unlike other published derivations of the Tolman-Ehrenfest relation, this one is free from any further dynamical assumption, thereby illustrating the physical import of the notion of thermal time.
[ { "created": "Mon, 17 May 2010 17:37:32 GMT", "version": "v1" }, { "created": "Thu, 20 May 2010 09:04:41 GMT", "version": "v2" }, { "created": "Tue, 25 May 2010 14:52:25 GMT", "version": "v3" }, { "created": "Mon, 17 Jan 2011 15:42:28 GMT", "version": "v4" }, { "created": "Tue, 18 Jan 2011 16:50:55 GMT", "version": "v5" } ]
2011-03-14
[ [ "Rovelli", "Carlo", "" ], [ "Smerlak", "Matteo", "" ] ]
The notion of thermal time has been introduced as a possible basis for a fully general-relativistic thermodynamics. Here we study this notion in the restricted context of stationary spacetimes. We show that the Tolman-Ehrenfest effect (in a stationary gravitational field, temperature is not constant in space at thermal equilibrium) can be derived very simply by applying the equivalence principle to a key property of thermal time: at equilibrium, temperature is the rate of thermal time with respect to proper time - the `speed of (thermal) time'. Unlike other published derivations of the Tolman-Ehrenfest relation, this one is free from any further dynamical assumption, thereby illustrating the physical import of the notion of thermal time.
2203.02930
Di Wang
Di Wang
From topological amplitude to rescattering dynamics in doubly charmed baryon decays
14 pages, 10 figures
Phys. Rev. D 105, 073002 (2022)
10.1103/PhysRevD.105.073002
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The doubly charmed baryon $\Xi^{++}_{cc}$ was observed by LHCb cooperation in 2017. The branching fractions of two-body doubly charmed baryon decays were predicted in the framework of rescattering mechanism, and some $SU(3)_F$ relations were investigated in the topological amplitudes. In this work, we study the correlation between topological diagram at quark level and rescattering triangle diagram at hadron level in the doubly charmed baryon decay. The completeness of our framework is confirmed from the fact that all the twelve possible structures of meson-baryon scattering appear once each in the the intermediate form between topological diagram and triangle diagram, topological-scattering diagram. It is found the triangle diagrams derived from the topological diagrams are consistent with the ones derived directly from the chiral Lagrangian. The relative magnitudes of rescattering contributions in the $C$, $C^\prime$, $E$, $E^\prime$, $P$ and $P^\prime$ diagrams extracted from $SU(3)_F$ symmetry are consistent with the numerical analysis in literature. Taking $\Xi^{++}_{cc}\to \Xi^+_c\pi^+$, $\Xi^{+}_{cc}\to \Xi^0_c\pi^+$ and $\Xi^{+}_{cc}\to \Xi^+_c\pi^0$ modes as examples, we show the isospin relation is satisfied in terms of triangle diagrams.
[ { "created": "Sun, 6 Mar 2022 10:27:38 GMT", "version": "v1" } ]
2022-04-12
[ [ "Wang", "Di", "" ] ]
The doubly charmed baryon $\Xi^{++}_{cc}$ was observed by LHCb cooperation in 2017. The branching fractions of two-body doubly charmed baryon decays were predicted in the framework of rescattering mechanism, and some $SU(3)_F$ relations were investigated in the topological amplitudes. In this work, we study the correlation between topological diagram at quark level and rescattering triangle diagram at hadron level in the doubly charmed baryon decay. The completeness of our framework is confirmed from the fact that all the twelve possible structures of meson-baryon scattering appear once each in the the intermediate form between topological diagram and triangle diagram, topological-scattering diagram. It is found the triangle diagrams derived from the topological diagrams are consistent with the ones derived directly from the chiral Lagrangian. The relative magnitudes of rescattering contributions in the $C$, $C^\prime$, $E$, $E^\prime$, $P$ and $P^\prime$ diagrams extracted from $SU(3)_F$ symmetry are consistent with the numerical analysis in literature. Taking $\Xi^{++}_{cc}\to \Xi^+_c\pi^+$, $\Xi^{+}_{cc}\to \Xi^0_c\pi^+$ and $\Xi^{+}_{cc}\to \Xi^+_c\pi^0$ modes as examples, we show the isospin relation is satisfied in terms of triangle diagrams.
hep-ph/9505297
null
M. Drees and R.M. Godbole
Inclusive Charm Production at HERA and the Charm Content of the Photon
Talk given by RMG at `Photon 95', Sheffield, April 1995; LaTeX with equation.sty; 7 pages and 4 figures (not included). A compressed PS file of the entire paper, including figures, can be obtained via anonymous ftp from ftp://phenom.physics.wisc.edu/pub/preprints/1995/madph-95-889.ps.Z
null
null
MAD-PH-889, LNF-95/029 (P)
hep-ph
null
We calculate the contribution to inclusive high tranverse momentum ($p_T$) charm production at HERA from the excitation of charm in the photon. At large values of \pt\ the results of such a calculation, in the structure function language, will be more reliable as it sums the large logs, $\log(p_T^2/m_c^2)$, as opposed to calculating the contribution of the $2 \to 3 $ subprocess in fixed order of perturbation theory. We find that this contribution is large and comparable to the contribution from $\gamma g$ fusion production of charm. Suitable cuts on the rapidity of the `away-side' large \pt\ jet allow a very neat separation between the contributions from the excitation process and from pair-production. We further find that including this excitation contribution we can reproduce the measured inclusive $D^*$ and $\mu$ cross--sections measured by the ZEUS and H1 collaborations respectively, in a LO calculation.
[ { "created": "Fri, 12 May 1995 18:50:00 GMT", "version": "v1" } ]
2007-05-23
[ [ "Drees", "M.", "" ], [ "Godbole", "R. M.", "" ] ]
We calculate the contribution to inclusive high tranverse momentum ($p_T$) charm production at HERA from the excitation of charm in the photon. At large values of \pt\ the results of such a calculation, in the structure function language, will be more reliable as it sums the large logs, $\log(p_T^2/m_c^2)$, as opposed to calculating the contribution of the $2 \to 3 $ subprocess in fixed order of perturbation theory. We find that this contribution is large and comparable to the contribution from $\gamma g$ fusion production of charm. Suitable cuts on the rapidity of the `away-side' large \pt\ jet allow a very neat separation between the contributions from the excitation process and from pair-production. We further find that including this excitation contribution we can reproduce the measured inclusive $D^*$ and $\mu$ cross--sections measured by the ZEUS and H1 collaborations respectively, in a LO calculation.
hep-ph/9909526
Athenasios Dedes
A. Dedes and S. Moretti (Rutherford Appleton Lab.)
Higgs boson production in association with squark pairs in the MSSM at the LHC
4 pages, Talk given by A. Dedes at the XIth Recontres de Blois, ``Frontiers of Matter'', June 27-July 3, 1999, France
null
null
RAL-TR-1999-067
hep-ph
null
We study neutral and charged Higgs boson production in association with stop and sbottom squarks at the Large Hadron Collider (LHC), within the so-called M-SUGRA scenario, i.e., the Supergravity (SUGRA) inspired Minimal Supersymmetric Standard Model (MSSM). For low values of \tan\beta only the cases \tilde{t}_1\tilde{t}_1^* H, \tilde{t}_1\tilde{t}_1^* h and \tilde{t}_1\tilde{t}_2^* h give detectable rates while for \tan\beta greater than 30 a variety of signals involving all Higgs bosons can be accessed, at high collider luminosity. The dependence of these reactions on the M-SUGRA parameters might further allow one to pin down the actual structure of the underlying Supersymmetric (SUSY) model.
[ { "created": "Tue, 28 Sep 1999 10:07:48 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dedes", "A.", "", "Rutherford Appleton Lab." ], [ "Moretti", "S.", "", "Rutherford Appleton Lab." ] ]
We study neutral and charged Higgs boson production in association with stop and sbottom squarks at the Large Hadron Collider (LHC), within the so-called M-SUGRA scenario, i.e., the Supergravity (SUGRA) inspired Minimal Supersymmetric Standard Model (MSSM). For low values of \tan\beta only the cases \tilde{t}_1\tilde{t}_1^* H, \tilde{t}_1\tilde{t}_1^* h and \tilde{t}_1\tilde{t}_2^* h give detectable rates while for \tan\beta greater than 30 a variety of signals involving all Higgs bosons can be accessed, at high collider luminosity. The dependence of these reactions on the M-SUGRA parameters might further allow one to pin down the actual structure of the underlying Supersymmetric (SUSY) model.
gr-qc/0610037
Francesco Cianfrani dr
Francesco Cianfrani, Giovanni Montani
The electro-weak model as a phenomenological issue of multidimensions
3 pages, proceedings of the XI Marcel Grossmann meeting on Relativistic Astrophysics, July 23-29, 2006, Berlin
null
null
null
gr-qc
null
We consider Kaluza-Klein theories as candidates for the unification of gravity and the electro-weak model. In particular, we fix how to reproduce geometrically the interaction between fermions and gauge bosons, in the low energy limit.
[ { "created": "Mon, 9 Oct 2006 15:57:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cianfrani", "Francesco", "" ], [ "Montani", "Giovanni", "" ] ]
We consider Kaluza-Klein theories as candidates for the unification of gravity and the electro-weak model. In particular, we fix how to reproduce geometrically the interaction between fermions and gauge bosons, in the low energy limit.
2106.08664
Simon Badger
Simon Badger, Christian Br{\o}nnum-Hansen, Dmitry Chicherin, Thomas Gehrmann, Heribertus Bayu Hartanto, Johannes Henn, Matteo Marcoli, Ryan Moodie, Tiziano Peraro, Simone Zoia
Virtual QCD corrections to gluon-initiated diphoton plus jet production at hadron colliders
27 pages, 3 figures, 3 tables
null
10.1007/JHEP11(2021)083
null
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We present an analytic computation of the gluon-initiated contribution to diphoton plus jet production at hadron colliders up to two loops in QCD. We reconstruct the analytic form of the finite remainders from numerical evaluations over finite fields including all colour contributions. Compact expressions are found using the pentagon function basis. We provide a fast and stable implementation for the colour- and helicity-summed interference between the one-loop and two-loop finite remainders in C++ as part of the NJet library.
[ { "created": "Wed, 16 Jun 2021 10:05:25 GMT", "version": "v1" } ]
2021-12-01
[ [ "Badger", "Simon", "" ], [ "Brønnum-Hansen", "Christian", "" ], [ "Chicherin", "Dmitry", "" ], [ "Gehrmann", "Thomas", "" ], [ "Hartanto", "Heribertus Bayu", "" ], [ "Henn", "Johannes", "" ], [ "Marcoli", "Matteo", "" ], [ "Moodie", "Ryan", "" ], [ "Peraro", "Tiziano", "" ], [ "Zoia", "Simone", "" ] ]
We present an analytic computation of the gluon-initiated contribution to diphoton plus jet production at hadron colliders up to two loops in QCD. We reconstruct the analytic form of the finite remainders from numerical evaluations over finite fields including all colour contributions. Compact expressions are found using the pentagon function basis. We provide a fast and stable implementation for the colour- and helicity-summed interference between the one-loop and two-loop finite remainders in C++ as part of the NJet library.
1906.05555
Le Duc Ninh
Stefan M\"olbitz, Le Duc Ninh, Peter Uwer
Next-to-leading order QCD corrections for single top-quark production in association with two jets
29 pages, 16 figures, 5 Tables
Phys. Rev. D 101, 016013 (2020)
10.1103/PhysRevD.101.016013
HU-EP-19/16, IFIRSE-TH-2019-3
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we calculate the next-to-leading order (NLO) QCD corrections for single on-shell top-quark production in association with two jets at proton-proton colliders. The tW channel is assumed to be measured independently. The QCD corrections to the inclusive cross section are about 28 (22)\% for top (anti-top) quark production at the 13 TeV LHC. Theoretical errors are dominated by scale uncertainties, which are found to be around 5\% at NLO. Results for various kinematical distributions are also provided using a well-motivated dynamical scale. The QCD corrections are found to have a non-trivial dependence on the phase-space.
[ { "created": "Thu, 13 Jun 2019 09:07:05 GMT", "version": "v1" } ]
2020-01-29
[ [ "Mölbitz", "Stefan", "" ], [ "Ninh", "Le Duc", "" ], [ "Uwer", "Peter", "" ] ]
In this article we calculate the next-to-leading order (NLO) QCD corrections for single on-shell top-quark production in association with two jets at proton-proton colliders. The tW channel is assumed to be measured independently. The QCD corrections to the inclusive cross section are about 28 (22)\% for top (anti-top) quark production at the 13 TeV LHC. Theoretical errors are dominated by scale uncertainties, which are found to be around 5\% at NLO. Results for various kinematical distributions are also provided using a well-motivated dynamical scale. The QCD corrections are found to have a non-trivial dependence on the phase-space.
2210.12898
Martin Reiris
Javier Peraza and Mart\'in Reiris and Omar E. Ortiz
Periodic analogues of the Kerr solutions: a numerical study
25 pages
null
10.1088/1361-6382/ace7a7
null
gr-qc
http://creativecommons.org/licenses/by/4.0/
In recent years black hole configurations with non standard topology or with non-standard asymptotic have gained considerable attention. In this article we carry out numerical investigations aimed to find periodic coaxial configurations of co-rotating 3+1 vacuum black holes, for which existence and uniqueness has not yet been theoretically proven. The aimed configurations would extend Myers/Korotkin-Nicolai's family of non-rotating (static) coaxial arrays of black holes. We find that numerical solutions with a given value for the area A and for the angular momentum J of the horizons appear to exist only when the separation between consecutive horizons is larger than a certain critical value that depends only on A and |J|. We also establish that the solutions have the same Lewis's cylindrical asymptotic as Stockum's infinite rotating cylinders. Below the mentioned critical value the rotational energy appears to be too big to sustain a global equilibrium and a singularity shows up at a finite distance from the bulk. This phenomenon is a relative of Stockum's asymptotic's collapse, manifesting when the angular momentum (per unit of axial length) reaches a critical value compared to the mass (per unit of axial length), and that results from a transition in the Lewis's class of the cylindrical exterior solution. This remarkable phenomenon seems to be unexplored in the context of coaxial arrays of black holes. Ergospheres and other global properties are also presented in detail.
[ { "created": "Mon, 24 Oct 2022 00:57:05 GMT", "version": "v1" } ]
2023-08-16
[ [ "Peraza", "Javier", "" ], [ "Reiris", "Martín", "" ], [ "Ortiz", "Omar E.", "" ] ]
In recent years black hole configurations with non standard topology or with non-standard asymptotic have gained considerable attention. In this article we carry out numerical investigations aimed to find periodic coaxial configurations of co-rotating 3+1 vacuum black holes, for which existence and uniqueness has not yet been theoretically proven. The aimed configurations would extend Myers/Korotkin-Nicolai's family of non-rotating (static) coaxial arrays of black holes. We find that numerical solutions with a given value for the area A and for the angular momentum J of the horizons appear to exist only when the separation between consecutive horizons is larger than a certain critical value that depends only on A and |J|. We also establish that the solutions have the same Lewis's cylindrical asymptotic as Stockum's infinite rotating cylinders. Below the mentioned critical value the rotational energy appears to be too big to sustain a global equilibrium and a singularity shows up at a finite distance from the bulk. This phenomenon is a relative of Stockum's asymptotic's collapse, manifesting when the angular momentum (per unit of axial length) reaches a critical value compared to the mass (per unit of axial length), and that results from a transition in the Lewis's class of the cylindrical exterior solution. This remarkable phenomenon seems to be unexplored in the context of coaxial arrays of black holes. Ergospheres and other global properties are also presented in detail.
2302.09148
Ernesto Contreras
Roberto Avalos, Ernesto Contreras
Quasi Normal Modes of hairy black holes at higher--order WKB approach
null
Eur. Phys. J. C 83, 155 (2023)
10.1140/epjc/s10052-023-11288-2
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we implement the $13^{th}$ order semi-analytical WKB method to explore the stability of hairy black holes obtained in the framework of Gravitational Decoupling. In particular, we perform a detailed analysis of the frequencies of the quasi-normal modes as a function of the primary hair of the solutions with the aim to bound their values. We explore a broad interval in a step of 0.1 of the hair parameters. We find that except for some cases where the method is expected to have poor accuracy, all the solutions seem to be stable and the role played by the primary hair is twofold: to modulate the damping factor of the perturbation and to decrease the frequency of its oscillation.
[ { "created": "Fri, 17 Feb 2023 21:18:37 GMT", "version": "v1" } ]
2023-02-21
[ [ "Avalos", "Roberto", "" ], [ "Contreras", "Ernesto", "" ] ]
In this work, we implement the $13^{th}$ order semi-analytical WKB method to explore the stability of hairy black holes obtained in the framework of Gravitational Decoupling. In particular, we perform a detailed analysis of the frequencies of the quasi-normal modes as a function of the primary hair of the solutions with the aim to bound their values. We explore a broad interval in a step of 0.1 of the hair parameters. We find that except for some cases where the method is expected to have poor accuracy, all the solutions seem to be stable and the role played by the primary hair is twofold: to modulate the damping factor of the perturbation and to decrease the frequency of its oscillation.
hep-ph/0007024
Mitja Rosina
D. Janc and M. Rosina (University of Ljubljana and J.Stefan Institute)
A Phenomenological Estimate of the Binding Energy of Heavy Dimesons
14 pages, 2 figures, LaTeX; errors in the text corrected and comments added
Few Body Syst.31:1-11,2001
10.1007/s006010170001
null
hep-ph
null
A phenomenological estimate is derived such that the binding energies of dimesons are expressed as combinations of masses of different mesons and baryons. The estimate is almost model-independent, the only major assumptions being that the wave functions of the two light quarks in $\Lambda_c$, $\Lambda_b$ and in the $\bar{c}\bar{c}qq$ and $\bar{b}\bar{b}qq$ dimesons are very similar, and that for heavy quarks the $QQ$ interaction is half as strong as the $Q\bar{Q}$ interaction. We get $\bar{b}\bar{b}qq$ (I=0, J=1) bound by about 100 MeV and $\bar{c}\bar{c}qq$ unbound.
[ { "created": "Tue, 4 Jul 2000 09:40:50 GMT", "version": "v1" }, { "created": "Wed, 5 Jul 2000 08:46:13 GMT", "version": "v2" }, { "created": "Thu, 14 Dec 2000 14:26:02 GMT", "version": "v3" } ]
2011-01-27
[ [ "Janc", "D.", "", "University of Ljubljana and J.Stefan Institute" ], [ "Rosina", "M.", "", "University of Ljubljana and J.Stefan Institute" ] ]
A phenomenological estimate is derived such that the binding energies of dimesons are expressed as combinations of masses of different mesons and baryons. The estimate is almost model-independent, the only major assumptions being that the wave functions of the two light quarks in $\Lambda_c$, $\Lambda_b$ and in the $\bar{c}\bar{c}qq$ and $\bar{b}\bar{b}qq$ dimesons are very similar, and that for heavy quarks the $QQ$ interaction is half as strong as the $Q\bar{Q}$ interaction. We get $\bar{b}\bar{b}qq$ (I=0, J=1) bound by about 100 MeV and $\bar{c}\bar{c}qq$ unbound.
2311.14330
Konstantin Osetrin
V.V. Obukhov and K.E. Osetrin and A.V. Shapovalov
Comments on the article "M.O. Katanaev, Complete separation of variables in the geodesic Hamilton-Jacobi equation in four dimensions, Physica Scripta (2023), 98, 104001"
6 pages
null
null
null
gr-qc math-ph math.MP
http://creativecommons.org/licenses/by-nc-nd/4.0/
The present note is a feedback on the article by M.O. Katanaev in "Physica Scripta" (2023, 98, 104001), where, in our opinion, a distorted view of the classical theory of separation of variables in the Hamilton-Jacobi equation is given. We show that the metrics given in this paper, addmiting separation of variables, are special cases of V.N. Shapovalov metrics ("Siberian Mathematical Journal", 1979, 20, 790), finally obtained in the 70s of the last century. The results of the article in question, unlike the original ones, do not have scientific novelty and contain omissions and incorrect statements.
[ { "created": "Fri, 24 Nov 2023 08:08:44 GMT", "version": "v1" } ]
2023-11-27
[ [ "Obukhov", "V. V.", "" ], [ "Osetrin", "K. E.", "" ], [ "Shapovalov", "A. V.", "" ] ]
The present note is a feedback on the article by M.O. Katanaev in "Physica Scripta" (2023, 98, 104001), where, in our opinion, a distorted view of the classical theory of separation of variables in the Hamilton-Jacobi equation is given. We show that the metrics given in this paper, addmiting separation of variables, are special cases of V.N. Shapovalov metrics ("Siberian Mathematical Journal", 1979, 20, 790), finally obtained in the 70s of the last century. The results of the article in question, unlike the original ones, do not have scientific novelty and contain omissions and incorrect statements.
1106.0459
Chuwen Xiao
C. W. Xiao, M. Bayar, E. Oset
$NDK$, $\bar{K} DN$ and $ND\bar{D}$ molecules
9 figures
Phys.Rev.D84:034037,2011
10.1103/PhysRevD.84.034037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one D meson, and in addition another meson, $\bar{D}, K$ or $\bar{K}$. The systems are studied using the Fixed Center Approximation to the Faddeev equations. The study is made assuming scattering of a $K$ or a $\bar{K}$ on a $DN$ cluster, which is known to generate the $\Lambda_c(2595)$, or the scattering of a nucleon on the $D\bar{D}$ cluster, which has been shown to generate a hidden charm resonance named X(3700). We also investigate the configuration of scattering of $N$ on the $KD$ cluster, which is known to generate the $D_{s0}^*(2317)$. In all cases we find bound states, with the $NDK$ system, of exotic nature, more bound than the $\bar{K} DN$.
[ { "created": "Thu, 2 Jun 2011 16:09:07 GMT", "version": "v1" }, { "created": "Tue, 9 Aug 2011 15:03:20 GMT", "version": "v2" }, { "created": "Thu, 1 Sep 2011 10:19:01 GMT", "version": "v3" } ]
2012-10-29
[ [ "Xiao", "C. W.", "" ], [ "Bayar", "M.", "" ], [ "Oset", "E.", "" ] ]
We investigate theoretically baryon systems made of three hadrons which contain one nucleon and one D meson, and in addition another meson, $\bar{D}, K$ or $\bar{K}$. The systems are studied using the Fixed Center Approximation to the Faddeev equations. The study is made assuming scattering of a $K$ or a $\bar{K}$ on a $DN$ cluster, which is known to generate the $\Lambda_c(2595)$, or the scattering of a nucleon on the $D\bar{D}$ cluster, which has been shown to generate a hidden charm resonance named X(3700). We also investigate the configuration of scattering of $N$ on the $KD$ cluster, which is known to generate the $D_{s0}^*(2317)$. In all cases we find bound states, with the $NDK$ system, of exotic nature, more bound than the $\bar{K} DN$.
0810.4928
Nikolai Zotov
S.P. Baranov (Lebedev Institute of Physics), N.P. Zotov (SINP, Moscow State University)
Production and polarization of Upsilon mesons in the k_T-factorization approach in more detail
4 pges, 4 figures
JETP Lett.88:711-715,2008
10.1134/S0021364008230021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of the k_T-factorization approach, the production and polarization of Upsilon mesons at the Fermilab Tevatron is considered, and a comparision of the calculated double differential distributions and spin alignment parameter $\alpha$ with the D0 experimental data is shown. We argue that measuring the double differential cross section and the polarization of upsilonium states can serve as a crucial test discriminating two competing theoretical approaches to the parton dynamics in QCD.
[ { "created": "Mon, 27 Oct 2008 20:30:32 GMT", "version": "v1" } ]
2009-07-30
[ [ "Baranov", "S. P.", "", "Lebedev Institute of Physics" ], [ "Zotov", "N. P.", "", "SINP, Moscow\n State University" ] ]
In the framework of the k_T-factorization approach, the production and polarization of Upsilon mesons at the Fermilab Tevatron is considered, and a comparision of the calculated double differential distributions and spin alignment parameter $\alpha$ with the D0 experimental data is shown. We argue that measuring the double differential cross section and the polarization of upsilonium states can serve as a crucial test discriminating two competing theoretical approaches to the parton dynamics in QCD.
hep-ph/0208264
Katherine Freese
Katherine Freese
Generalized Cardassian Expansion: Models in Which the Universe is Flat, Matter Dominated, and Accelerating
5 pages, Conference Proceeding, Meeting on Sources and Detection of Dark Matter and Dark Energy in the Universe, Marina del Rey, CA, February 2002
Nucl.Phys.Proc.Suppl.124:50-54,2003
10.1016/S0920-5632(03)02076-0
null
hep-ph astro-ph
null
The Cardassian universe is a proposed modification to the Friedmann Robertson Walker (FRW) equation in which the universe is flat, matter dominated, and accelerating. Here we generalize the original Cardassian proposal to include additional variants on the FRW equation. Specific examples are presented. In the ordinary FRW equation, the right hand side is a linear function of the energy density, $H^2 \sim \rho$. Here, instead, the right hand side of the FRW equation is a different function of the energy density, $H^2 \sim g(\rho)$. This function returns to ordinary FRW at early times, but modifies the expansion at a late epoch of the universe. The only ingredients in this universe are matter and radiation: in particular, there is {\it no} vacuum contribution. Currently the modification of the FRW equation is such that the universe accelerates. The universe can be flat and yet consist of only matter and radiation, and still be compatible with observations. The energy density required to close the universe is much smaller than in a standard cosmology, so that matter can be sufficient to provide a flat geometry. The modifications may arise, e.g., as a consequence of our observable universe living as a 3-dimensional brane in a higher dimensional universe. The Cardassian model survives several observational tests, including the cosmic background radiation, the age of the universe, the cluster baryon fraction, and structure formation. As will be shown in future work, the predictions for observational tests of the generalized Cardassian models can be very different from generic quintessence models, whether the equation of state is constant or time dependent.
[ { "created": "Thu, 29 Aug 2002 07:13:26 GMT", "version": "v1" }, { "created": "Thu, 5 Sep 2002 21:29:22 GMT", "version": "v2" }, { "created": "Wed, 30 Jul 2003 21:01:13 GMT", "version": "v3" } ]
2010-12-09
[ [ "Freese", "Katherine", "" ] ]
The Cardassian universe is a proposed modification to the Friedmann Robertson Walker (FRW) equation in which the universe is flat, matter dominated, and accelerating. Here we generalize the original Cardassian proposal to include additional variants on the FRW equation. Specific examples are presented. In the ordinary FRW equation, the right hand side is a linear function of the energy density, $H^2 \sim \rho$. Here, instead, the right hand side of the FRW equation is a different function of the energy density, $H^2 \sim g(\rho)$. This function returns to ordinary FRW at early times, but modifies the expansion at a late epoch of the universe. The only ingredients in this universe are matter and radiation: in particular, there is {\it no} vacuum contribution. Currently the modification of the FRW equation is such that the universe accelerates. The universe can be flat and yet consist of only matter and radiation, and still be compatible with observations. The energy density required to close the universe is much smaller than in a standard cosmology, so that matter can be sufficient to provide a flat geometry. The modifications may arise, e.g., as a consequence of our observable universe living as a 3-dimensional brane in a higher dimensional universe. The Cardassian model survives several observational tests, including the cosmic background radiation, the age of the universe, the cluster baryon fraction, and structure formation. As will be shown in future work, the predictions for observational tests of the generalized Cardassian models can be very different from generic quintessence models, whether the equation of state is constant or time dependent.
1106.4709
Guohuai Zhu
Guohuai Zhu
Implications of the recent measurement of pure annihilation $B_s \to \pi^+ \pi^-$ decays in QCD factorization
11 pages, 3 figures, accepted for publication in Phys. Lett. B
null
10.1016/j.physletb.2011.07.045
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The CDF 3.7 sigma evidence of pure annihilation $B_s \to \pi^+ \pi^-$ decays, if confirmed, would imply a large annihilation scenario in the QCD factorization approach. This is somewhat unexpected as the large annihilation scenario was disfavored in previous studies. In this paper we reinvestigate the role of annihilation topology in QCD factorization. We find that it is not easy to reach the CDF central value of $B_s \to \pi^+ \pi^-$ decays when other decay channels are considered. Our analysis also reveals that, for well-measured charmless B decays into two final pseudoscalar mesons, the QCD factorization predictions with large annihilation parameters show good agreement with the experimental data except $B_s \to K^+ K^-$ and $B_d \to K^0 \bar{K}^0$ decays. Though other possibilities can not be excluded, this may indicate that the SU(3) flavor symmetry breaking should be taken into account for the annihilation topology. In addition, there are different annihilation topologies, so that somewhat different annihilation parameters may be chosen for different final states and different annihilation topologies. If so, the predictive power of the QCD factorization method may be rather limited for many decay channels.
[ { "created": "Thu, 23 Jun 2011 13:12:42 GMT", "version": "v1" }, { "created": "Wed, 20 Jul 2011 01:52:09 GMT", "version": "v2" } ]
2015-05-28
[ [ "Zhu", "Guohuai", "" ] ]
The CDF 3.7 sigma evidence of pure annihilation $B_s \to \pi^+ \pi^-$ decays, if confirmed, would imply a large annihilation scenario in the QCD factorization approach. This is somewhat unexpected as the large annihilation scenario was disfavored in previous studies. In this paper we reinvestigate the role of annihilation topology in QCD factorization. We find that it is not easy to reach the CDF central value of $B_s \to \pi^+ \pi^-$ decays when other decay channels are considered. Our analysis also reveals that, for well-measured charmless B decays into two final pseudoscalar mesons, the QCD factorization predictions with large annihilation parameters show good agreement with the experimental data except $B_s \to K^+ K^-$ and $B_d \to K^0 \bar{K}^0$ decays. Though other possibilities can not be excluded, this may indicate that the SU(3) flavor symmetry breaking should be taken into account for the annihilation topology. In addition, there are different annihilation topologies, so that somewhat different annihilation parameters may be chosen for different final states and different annihilation topologies. If so, the predictive power of the QCD factorization method may be rather limited for many decay channels.
1905.02777
Mauro Anselmino
Mauro Anselmino, Raj Kishore and Asmita Mukherjee
The Polarising Fragmentation Function and the Lambda polarisation in e+ e- processes
8 pages, 4 figures. Version accepted for publication in PRD; minor changes, ackowledgements and references added
Phys. Rev. D 100, 014029 (2019)
10.1103/PhysRevD.100.014029
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The surprising polarisation of Lambdas and other hyperons measured in many unpolarised hadronic processes, p N --> Lambda X, has been a long standing challenge for QCD phenomenology. One possible explanation was suggested, related to non perturbative properties of the quark hadronisation process, and encoded in the so-called Polarising Fragmentation Function (PFF). Recent Belle data have shown a non zero Lambda polarisation also in unpolarised e+ e- processes, e+ e- --> Lambda X and e+ e- --> Lambda h X. We consider the single inclusive case and the role of the PFFs. Adopting a simplified kinematics it is shown how they can originate a polarisation P_Lambda different from 0 and give explicit expressions for it in terms of the PFFs. Although the Belle data do not allow yet, in our approach, an extraction of the PFFs, some clear predictions are given, suggesting crucial measurements, and estimates of P_Lambda are computed, in qualitative agreement with the Belle data.
[ { "created": "Tue, 7 May 2019 19:19:19 GMT", "version": "v1" }, { "created": "Wed, 17 Jul 2019 07:57:05 GMT", "version": "v2" } ]
2019-08-07
[ [ "Anselmino", "Mauro", "" ], [ "Kishore", "Raj", "" ], [ "Mukherjee", "Asmita", "" ] ]
The surprising polarisation of Lambdas and other hyperons measured in many unpolarised hadronic processes, p N --> Lambda X, has been a long standing challenge for QCD phenomenology. One possible explanation was suggested, related to non perturbative properties of the quark hadronisation process, and encoded in the so-called Polarising Fragmentation Function (PFF). Recent Belle data have shown a non zero Lambda polarisation also in unpolarised e+ e- processes, e+ e- --> Lambda X and e+ e- --> Lambda h X. We consider the single inclusive case and the role of the PFFs. Adopting a simplified kinematics it is shown how they can originate a polarisation P_Lambda different from 0 and give explicit expressions for it in terms of the PFFs. Although the Belle data do not allow yet, in our approach, an extraction of the PFFs, some clear predictions are given, suggesting crucial measurements, and estimates of P_Lambda are computed, in qualitative agreement with the Belle data.
hep-ph/9805237
Nikolaos Irges
Nikolaos Irges
Dynamical supersymmetry breaking in a superstring inspired model
13 pages
Phys.Rev. D58 (1998) 115011
10.1103/PhysRevD.58.115011
UFIFT-HEP-98-10
hep-ph
null
We present a dilaton dominated scenario for supersymmetry breaking in a recently constructed realistic superstring inspired model with an anomalous U(1) symmetry. Supersymmetry is broken via gaugino condensation due to a confining SU(Nc) gauge group in the hidden sector. In particular, we find that by imposing on the model the phenomenological constraint of the absence of observed flavor changing neutral currents, there is a range of parameters related to the hidden sector and the Kahler potential for which we obtain a low energy spectrum consistent with present experimental bounds. As an illustrative example, we derive the low energy spectrum of a specific model. We find that the LSP is the lightest neutralino with a mass of 53 GeV and the lightest Higgs has a mass of 104 GeV.
[ { "created": "Wed, 6 May 1998 15:42:29 GMT", "version": "v1" }, { "created": "Mon, 11 May 1998 16:02:09 GMT", "version": "v2" }, { "created": "Wed, 20 May 1998 14:14:30 GMT", "version": "v3" } ]
2009-10-31
[ [ "Irges", "Nikolaos", "" ] ]
We present a dilaton dominated scenario for supersymmetry breaking in a recently constructed realistic superstring inspired model with an anomalous U(1) symmetry. Supersymmetry is broken via gaugino condensation due to a confining SU(Nc) gauge group in the hidden sector. In particular, we find that by imposing on the model the phenomenological constraint of the absence of observed flavor changing neutral currents, there is a range of parameters related to the hidden sector and the Kahler potential for which we obtain a low energy spectrum consistent with present experimental bounds. As an illustrative example, we derive the low energy spectrum of a specific model. We find that the LSP is the lightest neutralino with a mass of 53 GeV and the lightest Higgs has a mass of 104 GeV.
1909.10585
Mihai Horoi
Adam Zettel and Mihai Horoi
Novel matter effects on neutrino oscillations observables
Talk presented at the 2019 Meeting of the Division of Particles and Fields of the American Physical Society (DPF2019), July 29 - August 2, 2019, Northeastern University, Boston, C1907293
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent article (arxiv:1803.06332) we noticed that the electron density in condensed matter exhibits large spikes close to the atomic nuclei. We showed that these spikes in the electron densities, 3-4 orders of magnitude larger than those inside the Sun's core, have no effect on the neutrino emission and absorption probabilities or on the neutrinoless double beta decay probability. However, it was not clear if the effect of these spikes is equivalent to that of an average constant electron density in matter. We investigated these effects by a direct integration of the coupled Dirac equations describing the propagation of flavor neutrinos into, through, and out of the matter. We found little evidence that these spikes affect the standard oscillations probabilities, but found a new fast and efficient algorithm of calculating these probabilities for neutrinos propagating through varying electron densities.
[ { "created": "Mon, 23 Sep 2019 19:34:07 GMT", "version": "v1" } ]
2019-09-25
[ [ "Zettel", "Adam", "" ], [ "Horoi", "Mihai", "" ] ]
In a recent article (arxiv:1803.06332) we noticed that the electron density in condensed matter exhibits large spikes close to the atomic nuclei. We showed that these spikes in the electron densities, 3-4 orders of magnitude larger than those inside the Sun's core, have no effect on the neutrino emission and absorption probabilities or on the neutrinoless double beta decay probability. However, it was not clear if the effect of these spikes is equivalent to that of an average constant electron density in matter. We investigated these effects by a direct integration of the coupled Dirac equations describing the propagation of flavor neutrinos into, through, and out of the matter. We found little evidence that these spikes affect the standard oscillations probabilities, but found a new fast and efficient algorithm of calculating these probabilities for neutrinos propagating through varying electron densities.
2305.00989
Samuel Alipour-Fard
Samuel Alipour-Fard, Patrick T. Komiske, Eric M. Metodiev, Jesse Thaler
Pileup and Infrared Radiation Annihilation (PIRANHA): A Paradigm for Continuous Jet Grooming
38+35 pages, 20 figures. PIRANHA algorithm code available at http://github.com/pkomiske/Piranha; v2: Citations to linearized optimal transport literature, discussion of frozen QCD coupling, other minor changes; v3: Modified introduction of P-RSF algorithm for clarity, perturbative discussion of discontinuity in Sec. 3, added appendix on groomed energy fraction, other minor changes
J. High Energ. Phys. 2023, 157 (2023)
10.1007/JHEP09(2023)157
MIT-CTP 5540
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Jet grooming is an important strategy for analyzing relativistic particle collisions in the presence of contaminating radiation. Most jet grooming techniques introduce hard cutoffs to remove soft radiation, leading to discontinuous behavior and associated experimental and theoretical challenges. In this paper, we introduce Pileup and Infrared Radiation Annihilation (PIRANHA), a paradigm for continuous jet grooming that overcomes the discontinuity and infrared sensitivity of hard-cutoff grooming procedures. We motivate PIRANHA from the perspective of optimal transport and the Energy Mover's Distance and review Apollonius Subtraction and Iterated Voronoi Subtraction as examples of PIRANHA-style grooming. We then introduce a new tree-based implementation of PIRANHA, Recursive Subtraction, with reduced computational costs. Finally, we demonstrate the performance of Recursive Subtraction in mitigating sensitivity to soft distortions from hadronization and detector effects, and additive contamination from pileup and the underlying event.
[ { "created": "Mon, 1 May 2023 18:00:00 GMT", "version": "v1" }, { "created": "Wed, 21 Jun 2023 18:00:00 GMT", "version": "v2" }, { "created": "Mon, 2 Oct 2023 16:28:55 GMT", "version": "v3" } ]
2023-10-03
[ [ "Alipour-Fard", "Samuel", "" ], [ "Komiske", "Patrick T.", "" ], [ "Metodiev", "Eric M.", "" ], [ "Thaler", "Jesse", "" ] ]
Jet grooming is an important strategy for analyzing relativistic particle collisions in the presence of contaminating radiation. Most jet grooming techniques introduce hard cutoffs to remove soft radiation, leading to discontinuous behavior and associated experimental and theoretical challenges. In this paper, we introduce Pileup and Infrared Radiation Annihilation (PIRANHA), a paradigm for continuous jet grooming that overcomes the discontinuity and infrared sensitivity of hard-cutoff grooming procedures. We motivate PIRANHA from the perspective of optimal transport and the Energy Mover's Distance and review Apollonius Subtraction and Iterated Voronoi Subtraction as examples of PIRANHA-style grooming. We then introduce a new tree-based implementation of PIRANHA, Recursive Subtraction, with reduced computational costs. Finally, we demonstrate the performance of Recursive Subtraction in mitigating sensitivity to soft distortions from hadronization and detector effects, and additive contamination from pileup and the underlying event.
2108.05283
Harikrishnan Ramani
Dmitry Budker, Peter W. Graham, Harikrishnan Ramani, Ferdinand Schmidt-Kaler, Christian Smorra and Stefan Ulmer
Millicharged dark matter detection with ion traps
17 pages, 4 figures
null
null
null
hep-ph astro-ph.CO physics.atom-ph quant-ph
http://creativecommons.org/licenses/by/4.0/
We propose the use of trapped ions for detection of millicharged dark matter. Millicharged particles will scatter off the ions, giving a signal either in individual events or in the overall heating rate of the ions. Ion traps have several properties which make them ideal detectors for such a signal. First, ion traps have demonstrated significant isolation of the ions from the environment, greatly reducing the background heating and event rates. Second, ion traps can have low thresholds for detection of energy deposition, down to $\sim \text{neV}$. Third, since the ions are charged, they naturally have large cross sections for scattering with the millicharged particles, further enhanced by the low velocities of the thermalized millicharges. Despite ion-trap setups being optimized for other goals, we find that existing measurements put new constraints on millicharged dark matter which are many orders of magnitude beyond previous bounds. For example, for a millicharge dark matter mass $m_Q=10~\textrm{GeV}$ and charge $10^{-3}$ of the electron charge, ion traps limit the local density to be $n_Q \lesssim 1 \, \textrm{cm}^{-3}$, a factor $\sim 10^8$ better than current constraints. Future dedicated ion trap experiments could reach even further into unexplored parameter space.
[ { "created": "Wed, 11 Aug 2021 15:29:36 GMT", "version": "v1" } ]
2021-08-12
[ [ "Budker", "Dmitry", "" ], [ "Graham", "Peter W.", "" ], [ "Ramani", "Harikrishnan", "" ], [ "Schmidt-Kaler", "Ferdinand", "" ], [ "Smorra", "Christian", "" ], [ "Ulmer", "Stefan", "" ] ]
We propose the use of trapped ions for detection of millicharged dark matter. Millicharged particles will scatter off the ions, giving a signal either in individual events or in the overall heating rate of the ions. Ion traps have several properties which make them ideal detectors for such a signal. First, ion traps have demonstrated significant isolation of the ions from the environment, greatly reducing the background heating and event rates. Second, ion traps can have low thresholds for detection of energy deposition, down to $\sim \text{neV}$. Third, since the ions are charged, they naturally have large cross sections for scattering with the millicharged particles, further enhanced by the low velocities of the thermalized millicharges. Despite ion-trap setups being optimized for other goals, we find that existing measurements put new constraints on millicharged dark matter which are many orders of magnitude beyond previous bounds. For example, for a millicharge dark matter mass $m_Q=10~\textrm{GeV}$ and charge $10^{-3}$ of the electron charge, ion traps limit the local density to be $n_Q \lesssim 1 \, \textrm{cm}^{-3}$, a factor $\sim 10^8$ better than current constraints. Future dedicated ion trap experiments could reach even further into unexplored parameter space.
1612.08495
Jay Tasson
Natasha A. Flowers, Casey Goodge, and Jay D. Tasson
Superconducting-Gravimeter Tests of Local Lorentz Invariance
5 pages, 1 figure, published version
Phys. Rev. Lett. 119, 201101 (2017)
10.1103/PhysRevLett.119.201101
null
gr-qc hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Superconducting-gravimeter measurements are used to test the local Lorentz invariance of the gravitational interaction and of matter-gravity couplings. The best laboratory sensitivities to date are achieved via a maximum-reach analysis for 13 Lorentz-violating operators, with some improvements exceeding an order of magnitude.
[ { "created": "Tue, 27 Dec 2016 04:05:21 GMT", "version": "v1" }, { "created": "Tue, 19 Dec 2017 16:16:10 GMT", "version": "v2" } ]
2017-12-20
[ [ "Flowers", "Natasha A.", "" ], [ "Goodge", "Casey", "" ], [ "Tasson", "Jay D.", "" ] ]
Superconducting-gravimeter measurements are used to test the local Lorentz invariance of the gravitational interaction and of matter-gravity couplings. The best laboratory sensitivities to date are achieved via a maximum-reach analysis for 13 Lorentz-violating operators, with some improvements exceeding an order of magnitude.
2012.01249
Javier Duarte
Javier Duarte and Jean-Roch Vlimant
Graph Neural Networks for Particle Tracking and Reconstruction
44 pages, 20 figures. Submitted for review. To appear in "Artificial Intelligence for Particle Physics", World Scientific Publishing
Artificial Intelligence for High Energy Physics, Chapter 12, pp. 387-436 (2022)
10.1142/9789811234033_0012
null
hep-ph hep-ex physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Machine learning methods have a long history of applications in high energy physics (HEP). Recently, there is a growing interest in exploiting these methods to reconstruct particle signatures from raw detector data. In order to benefit from modern deep learning algorithms that were initially designed for computer vision or natural language processing tasks, it is common practice to transform HEP data into images or sequences. Conversely, graph neural networks (GNNs), which operate on graph data composed of elements with a set of features and their pairwise connections, provide an alternative way of incorporating weight sharing, local connectivity, and specialized domain knowledge. Particle physics data, such as the hits in a tracking detector, can generally be represented as graphs, making the use of GNNs natural. In this chapter, we recapitulate the mathematical formalism of GNNs and highlight aspects to consider when designing these networks for HEP data, including graph construction, model architectures, learning objectives, and graph pooling. We also review promising applications of GNNs for particle tracking and reconstruction in HEP and summarize the outlook for their deployment in current and future experiments.
[ { "created": "Wed, 2 Dec 2020 14:53:59 GMT", "version": "v1" }, { "created": "Mon, 7 Dec 2020 16:10:57 GMT", "version": "v2" } ]
2022-03-17
[ [ "Duarte", "Javier", "" ], [ "Vlimant", "Jean-Roch", "" ] ]
Machine learning methods have a long history of applications in high energy physics (HEP). Recently, there is a growing interest in exploiting these methods to reconstruct particle signatures from raw detector data. In order to benefit from modern deep learning algorithms that were initially designed for computer vision or natural language processing tasks, it is common practice to transform HEP data into images or sequences. Conversely, graph neural networks (GNNs), which operate on graph data composed of elements with a set of features and their pairwise connections, provide an alternative way of incorporating weight sharing, local connectivity, and specialized domain knowledge. Particle physics data, such as the hits in a tracking detector, can generally be represented as graphs, making the use of GNNs natural. In this chapter, we recapitulate the mathematical formalism of GNNs and highlight aspects to consider when designing these networks for HEP data, including graph construction, model architectures, learning objectives, and graph pooling. We also review promising applications of GNNs for particle tracking and reconstruction in HEP and summarize the outlook for their deployment in current and future experiments.
1711.08796
Gazal Sharma
Gazal Sharma, Shankita Bhardwaj, B. C. Chauhan and Surender Verma
Quark-lepton complementarity model based predictions for $\theta_{23}^{PMNS}$ with neutrino mass hierarchy
3 pages, 3 figures
XXII DAE High Energy Physics Symposium, Springer Proc.Phys. 203 (2018) 251-256
10.1007/978-3-319-73171-1_57
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
After the successful investigation and confirmation of non zero $\theta_{13}^{PMNS}$ by various experiments, we are standing at a square where we still encounter a number of issues, which are to be settled. In this paper, we have extended our recent work towards a precise prediction of the $\theta_{23}^{PMNS}$ mixing angle, taking into account the neutrino mass hierarchy. We parameterize the non-trivial correlation between quark (CKM) and lepton (PMNS) mixing matrices in quark-lepton complementarity (QLC) model as $V_{c}= U_{CKM}. \psi. U_{PMNS}$, where $\psi$ is a diagonal phase matrix. Monte Carlo simulations are used to estimate the texture of $V_{c}$ and compare the results with the standard Tri-Bi-Maximal (TBM) and Bi-Maximal(BM) structures of neutrino mixing matrix. We have predicted the value of $\theta_{23}^{PMNS} $ for normal and inverted neutrino mass hierarchies. The value of $\theta_{23}^{PMNS}$ obtained for two cases are about $1.3\sigma$ away from each other, implying the better precision can give us a strong hint for the type of neutrino mass hierarchy.
[ { "created": "Thu, 23 Nov 2017 18:19:59 GMT", "version": "v1" }, { "created": "Tue, 26 Jun 2018 10:38:47 GMT", "version": "v2" } ]
2018-06-27
[ [ "Sharma", "Gazal", "" ], [ "Bhardwaj", "Shankita", "" ], [ "Chauhan", "B. C.", "" ], [ "Verma", "Surender", "" ] ]
After the successful investigation and confirmation of non zero $\theta_{13}^{PMNS}$ by various experiments, we are standing at a square where we still encounter a number of issues, which are to be settled. In this paper, we have extended our recent work towards a precise prediction of the $\theta_{23}^{PMNS}$ mixing angle, taking into account the neutrino mass hierarchy. We parameterize the non-trivial correlation between quark (CKM) and lepton (PMNS) mixing matrices in quark-lepton complementarity (QLC) model as $V_{c}= U_{CKM}. \psi. U_{PMNS}$, where $\psi$ is a diagonal phase matrix. Monte Carlo simulations are used to estimate the texture of $V_{c}$ and compare the results with the standard Tri-Bi-Maximal (TBM) and Bi-Maximal(BM) structures of neutrino mixing matrix. We have predicted the value of $\theta_{23}^{PMNS} $ for normal and inverted neutrino mass hierarchies. The value of $\theta_{23}^{PMNS}$ obtained for two cases are about $1.3\sigma$ away from each other, implying the better precision can give us a strong hint for the type of neutrino mass hierarchy.
1712.05722
Weijian Wang
Zhi-Long Han, Weijian Wang and Ran Ding
Radiative Seesaw Model and DAMPE Excess from Leptophilic Gauge Symmetry
17 pages, 5 figures, references added
Eur.Phys.J. C78 (2018) no.3, 216
10.1140/epjc/s10052-018-5714-3
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In the light of the $e^{+}+e^{-}$ excess observed by DAMPE experiment, we propose an anomaly-free radiative seesaw model with an alternative leptophilic $U(1)_X$ gauge symmetry. In the model, only right-handed leptons are charged under $U(1)_X$ symmetry. The tiny Dirac neutrino masses are generated at one-loop level and charged leptons acquire masses though the type-I seesaw-like mechanism with heavy intermediate fermions. In order to cancel the anomaly, irrational $U(1)_{X}$ charge numbers are assigned to some new particles. After the spontaneous breaking of $U(1)_{X}$ symmetry, the dark $Z_{2}$ symmetry could appear as a residual symmetry such that the stability of inert particles with irrational charge numbers are guaranteed, naturally leading to stable DM candidates. We show that the Dirac fermion DM contained in the model can explain the DAMPE excess. Meanwhile, experimental constraints from DM relic density, direct detection, LEP and anomalous magnetic moments are satisfied.
[ { "created": "Fri, 15 Dec 2017 15:54:35 GMT", "version": "v1" }, { "created": "Sat, 17 Mar 2018 07:39:36 GMT", "version": "v2" } ]
2018-03-20
[ [ "Han", "Zhi-Long", "" ], [ "Wang", "Weijian", "" ], [ "Ding", "Ran", "" ] ]
In the light of the $e^{+}+e^{-}$ excess observed by DAMPE experiment, we propose an anomaly-free radiative seesaw model with an alternative leptophilic $U(1)_X$ gauge symmetry. In the model, only right-handed leptons are charged under $U(1)_X$ symmetry. The tiny Dirac neutrino masses are generated at one-loop level and charged leptons acquire masses though the type-I seesaw-like mechanism with heavy intermediate fermions. In order to cancel the anomaly, irrational $U(1)_{X}$ charge numbers are assigned to some new particles. After the spontaneous breaking of $U(1)_{X}$ symmetry, the dark $Z_{2}$ symmetry could appear as a residual symmetry such that the stability of inert particles with irrational charge numbers are guaranteed, naturally leading to stable DM candidates. We show that the Dirac fermion DM contained in the model can explain the DAMPE excess. Meanwhile, experimental constraints from DM relic density, direct detection, LEP and anomalous magnetic moments are satisfied.
gr-qc/0005025
Sergiu Vacaru
Sergiu I. Vacaru
Anholonomic Soliton-Dilaton and Black Hole Solutions in General Relativity
revtex, twocolumns, 24 pages, version 3 with minor corrections
JHEP 0104:009,2001
10.1088/1126-6708/2001/04/009
null
gr-qc hep-th math-ph math.MP nlin.SI
null
A new method of construction of integral varieties of Einstein equations in three dimensional (3D) and 4D gravity is presented whereby, under corresponding redefinition of physical values with respect to anholonomic frames of reference with associated nonlinear connections, the structure of gravity field equations is substantially simplified. It is shown that there are 4D solutions of Einstein equations which are constructed as nonlinear superpositions of soliton solutions of 2D (pseudo) Euclidean sine-Gordon equations (or of Lorentzian black holes in Jackiw-Teitelboim dilaton gravity). The Belinski-Zakharov-Meison solitons for vacuum gravitational field equations are generalized to various cases of two and three coordinate dependencies, local anisotropy and matter sources. The general framework of this study is based on investigation of anholonomic soliton-dilaton black hole structures in general relativity. We prove that there are possible static and dynamical black hole, black torus and disk/cylinder like solutions (of non-vacuum gravitational field equations) with horizons being parametrized by hypersurface equations of rotation ellipsoid, torus, cylinder and another type configurations. Solutions describing locally anisotropic variants of the Schwarzschild-- Kerr (black hole), Weyl (cylindrical symmetry) and Neugebauer--Meinel (disk) solutions with anisotropic variable masses, distributions of matter and interaction constants are shown to be contained in Einstein's gravity. It is demonstrated in which manner locally anisotropic multi-soliton-- dilaton-black hole type solutions can be generated.
[ { "created": "Tue, 9 May 2000 09:43:10 GMT", "version": "v1" }, { "created": "Fri, 12 May 2000 13:38:55 GMT", "version": "v2" }, { "created": "Tue, 13 Jun 2000 08:02:11 GMT", "version": "v3" } ]
2010-02-03
[ [ "Vacaru", "Sergiu I.", "" ] ]
A new method of construction of integral varieties of Einstein equations in three dimensional (3D) and 4D gravity is presented whereby, under corresponding redefinition of physical values with respect to anholonomic frames of reference with associated nonlinear connections, the structure of gravity field equations is substantially simplified. It is shown that there are 4D solutions of Einstein equations which are constructed as nonlinear superpositions of soliton solutions of 2D (pseudo) Euclidean sine-Gordon equations (or of Lorentzian black holes in Jackiw-Teitelboim dilaton gravity). The Belinski-Zakharov-Meison solitons for vacuum gravitational field equations are generalized to various cases of two and three coordinate dependencies, local anisotropy and matter sources. The general framework of this study is based on investigation of anholonomic soliton-dilaton black hole structures in general relativity. We prove that there are possible static and dynamical black hole, black torus and disk/cylinder like solutions (of non-vacuum gravitational field equations) with horizons being parametrized by hypersurface equations of rotation ellipsoid, torus, cylinder and another type configurations. Solutions describing locally anisotropic variants of the Schwarzschild-- Kerr (black hole), Weyl (cylindrical symmetry) and Neugebauer--Meinel (disk) solutions with anisotropic variable masses, distributions of matter and interaction constants are shown to be contained in Einstein's gravity. It is demonstrated in which manner locally anisotropic multi-soliton-- dilaton-black hole type solutions can be generated.
hep-ph/0308188
Athar Husain
H. Athar (NCTS)
Mixed high energy neutrinos from cosmos
18 pages, 3 figs, a mainly pedagogical review (to appear in Chin. J. Phys.)
Chin.J.Phys. 42 (2004) 1-20
null
null
hep-ph astro-ph
null
Production of the expected high energy neutrino flux with energy greater than tens of thousands of GeV in some astrophysical sites such as the galactic plane as well as the centers of some distant galaxies is reviewed. The expected changes in these neutrino fluxes because of neutrino oscillations during their propagation to us are described. Observational signatures for these neutrino fluxes with and without neutrino oscillations are discussed.
[ { "created": "Tue, 19 Aug 2003 08:33:59 GMT", "version": "v1" } ]
2007-05-23
[ [ "Athar", "H.", "", "NCTS" ] ]
Production of the expected high energy neutrino flux with energy greater than tens of thousands of GeV in some astrophysical sites such as the galactic plane as well as the centers of some distant galaxies is reviewed. The expected changes in these neutrino fluxes because of neutrino oscillations during their propagation to us are described. Observational signatures for these neutrino fluxes with and without neutrino oscillations are discussed.
1906.09470
Jilberto Zamora-Sa\'a
Sebastian Tapia, Jilberto Zamora-Sa\'a
Exploring CP-Violating heavy neutrino oscillations in rare tau decays at Belle II
null
Nucl.Phys. B952 (2020) 114936
10.1016/j.nuclphysb.2020.114936
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we study the lepton number violating tau decays via two intermediate on-shell Majorana neutrinos $N_j$ into two charged pions, and a charged lepton $\tau^{\pm} \to \pi^{\pm} N_j \to \pi^{\pm} \pi^{\pm} \ell^{\mp}$. We consider the scenario where the heavy neutrino masses are within $0.5$ GeV $\leq M_N \leq 1.5$ GeV. We evaluated the possibility to measure the modulation of the decay width along the detector length for these processes at taus factories, such as Belle II. We study some realistic conditions which could lead to the observation of this phenomenon at futures $\tau$'s factories.
[ { "created": "Sat, 22 Jun 2019 17:00:07 GMT", "version": "v1" }, { "created": "Tue, 25 Jun 2019 14:43:05 GMT", "version": "v2" }, { "created": "Sat, 25 Jan 2020 11:22:23 GMT", "version": "v3" } ]
2020-03-18
[ [ "Tapia", "Sebastian", "" ], [ "Zamora-Saá", "Jilberto", "" ] ]
In this work, we study the lepton number violating tau decays via two intermediate on-shell Majorana neutrinos $N_j$ into two charged pions, and a charged lepton $\tau^{\pm} \to \pi^{\pm} N_j \to \pi^{\pm} \pi^{\pm} \ell^{\mp}$. We consider the scenario where the heavy neutrino masses are within $0.5$ GeV $\leq M_N \leq 1.5$ GeV. We evaluated the possibility to measure the modulation of the decay width along the detector length for these processes at taus factories, such as Belle II. We study some realistic conditions which could lead to the observation of this phenomenon at futures $\tau$'s factories.
2407.15606
Yigal Shamir
Maarten Golterman and Yigal Shamir
Power counting of the pion-dilaton effective field theory
RevTeX, 17 pages
null
null
null
hep-ph hep-lat
http://creativecommons.org/licenses/by/4.0/
Confining QCD-like theories close to the conformal window have a ``walking'' coupling. This is believed to lead to a light singlet scalar meson in the low-energy spectrum, a dilaton, which is the pseudo Nambu--Goldstone boson for the approximate scale symmetry. Extending chiral perturbation theory to include the dilaton requires a new small parameter to control the dilaton mass and its interactions. In our previous work we derived a systematic power counting for the dilaton couplings by matching the effective low-energy theory to the underlying theory using mild assumptions. In this paper we examine two alternative power countings which were proposed in the literature based on a phenomenological picture for the conformal transition. We find that one of these power countings fails, in fact, to generate a systematic expansion; the other coincides with the power counting we derived. We also point out that the so-called $\Delta$-potential coincides with the tree-level potential of the former, invalid, power counting.
[ { "created": "Mon, 22 Jul 2024 13:03:35 GMT", "version": "v1" } ]
2024-07-23
[ [ "Golterman", "Maarten", "" ], [ "Shamir", "Yigal", "" ] ]
Confining QCD-like theories close to the conformal window have a ``walking'' coupling. This is believed to lead to a light singlet scalar meson in the low-energy spectrum, a dilaton, which is the pseudo Nambu--Goldstone boson for the approximate scale symmetry. Extending chiral perturbation theory to include the dilaton requires a new small parameter to control the dilaton mass and its interactions. In our previous work we derived a systematic power counting for the dilaton couplings by matching the effective low-energy theory to the underlying theory using mild assumptions. In this paper we examine two alternative power countings which were proposed in the literature based on a phenomenological picture for the conformal transition. We find that one of these power countings fails, in fact, to generate a systematic expansion; the other coincides with the power counting we derived. We also point out that the so-called $\Delta$-potential coincides with the tree-level potential of the former, invalid, power counting.
gr-qc/9504016
Giuseppe Pollifrone-.+39-6-49914350-
G. Esposito, A. Yu. Kamenshchik, I. V. Mishakov, and G. Pollifrone
One-Loop Amplitudes in Euclidean Quantum Gravity
26 pages, plain TeX, no figures
Phys.Rev. D52 (1995) 3457-3465
10.1103/PhysRevD.52.3457
Rome1-1101/95, DSF 95/16
gr-qc hep-th
null
This paper studies the linearized gravitational field in the presence of boundaries. For this purpose, $\zeta$-function regularization is used to perform the mode-by-mode evaluation of BRST-invariant Faddeev-Popov amplitudes in the case of flat Euclidean four-space bounded by a three-sphere. On choosing the de Donder gauge-averaging term, the resulting $\zeta(0)$ value is found to agree with the space-time covariant calculation of the same amplitudes, which relies on the recently corrected geometric formulas for the asymptotic heat kernel in the case of mixed boundary conditions. Two sets of mixed boundary conditions for Euclidean quantum gravity are then compared in detail. The analysis proves that one cannot restrict the path-integral measure to transverse-traceless perturbations. By contrast, gauge-invariant amplitudes are only obtained on considering from the beginning all perturbative modes of the gravitational field, jointly with ghost modes.
[ { "created": "Wed, 12 Apr 1995 09:06:26 GMT", "version": "v1" } ]
2009-10-28
[ [ "Esposito", "G.", "" ], [ "Kamenshchik", "A. Yu.", "" ], [ "Mishakov", "I. V.", "" ], [ "Pollifrone", "G.", "" ] ]
This paper studies the linearized gravitational field in the presence of boundaries. For this purpose, $\zeta$-function regularization is used to perform the mode-by-mode evaluation of BRST-invariant Faddeev-Popov amplitudes in the case of flat Euclidean four-space bounded by a three-sphere. On choosing the de Donder gauge-averaging term, the resulting $\zeta(0)$ value is found to agree with the space-time covariant calculation of the same amplitudes, which relies on the recently corrected geometric formulas for the asymptotic heat kernel in the case of mixed boundary conditions. Two sets of mixed boundary conditions for Euclidean quantum gravity are then compared in detail. The analysis proves that one cannot restrict the path-integral measure to transverse-traceless perturbations. By contrast, gauge-invariant amplitudes are only obtained on considering from the beginning all perturbative modes of the gravitational field, jointly with ghost modes.
hep-ph/9801409
Alon Faraggi
Alon E. Faraggi
Family Universal Anomalous U(1) in Realistic Superstring Derived Models
16 pages. Standard Latex
Phys.Lett.B426:315-322,1998
10.1016/S0370-2693(98)00286-X
UFIFT-HEP-98-5
hep-ph hep-th
null
An important issue in supersymmetry phenomenology is the suppression of squarks contributions to Flavor Changing Neutral Currents (FCNC). Recently it was noted that in some free fermionic three generation models the anomalous U(1) is family universal. It was further shown that if the $D$--term of the $U(1)_A$ is the dominant source of supersymmetry breaking, the squark masses are indeed approximately degenerate. In this paper I discuss the properties of the superstring models that give rise to the flavor universal anomalous U(1). The root cause for the universal $U(1)_A$ is the cyclic permutation symmetry, the characteristic property of the $Z_2\times Z_2$ orbifold compactification, realized in the free fermionic models by the NAHE set of boundary condition basis vectors. The properties of the three generation models that preserve this cyclic permutation symmetry in the flavor charges are discussed. The cyclic permutation symmetry of the $Z_2\times Z_2$ orbifold compactification is proposed to be the characteristic property, of phenomenological interest, that distinguishes it from other classes of superstring compactifications.
[ { "created": "Sun, 25 Jan 1998 18:03:46 GMT", "version": "v1" } ]
2014-11-17
[ [ "Faraggi", "Alon E.", "" ] ]
An important issue in supersymmetry phenomenology is the suppression of squarks contributions to Flavor Changing Neutral Currents (FCNC). Recently it was noted that in some free fermionic three generation models the anomalous U(1) is family universal. It was further shown that if the $D$--term of the $U(1)_A$ is the dominant source of supersymmetry breaking, the squark masses are indeed approximately degenerate. In this paper I discuss the properties of the superstring models that give rise to the flavor universal anomalous U(1). The root cause for the universal $U(1)_A$ is the cyclic permutation symmetry, the characteristic property of the $Z_2\times Z_2$ orbifold compactification, realized in the free fermionic models by the NAHE set of boundary condition basis vectors. The properties of the three generation models that preserve this cyclic permutation symmetry in the flavor charges are discussed. The cyclic permutation symmetry of the $Z_2\times Z_2$ orbifold compactification is proposed to be the characteristic property, of phenomenological interest, that distinguishes it from other classes of superstring compactifications.
1312.7027
Beranger Dumont
Beranger Dumont, John F. Gunion, Sabine Kraml
The phenomenological MSSM in view of the 125 GeV Higgs data
28 pages, 13 figures; v2: matches version accepted for publication in PRD
Phys. Rev. D 89, 055018 (2014)
10.1103/PhysRevD.89.055018
LPSC14011, UCD-2014-001
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The parameter space of the phenomenological MSSM (pMSSM) is explored by means of Markov Chain Monte Charlo (MCMC) methods, taking into account the latest LHC results on the Higgs signal at 125 GeV in addition to relevant low-energy observables and LEP constraints. We use a Bayesian approach to derive posterior densities for the parameters and observables of interests. We find in particular that the Higgs measurements have a significant impact on the parameters mu and tan beta due to radiative corrections to the bottom Yukawa coupling. We show moreover the impact of the most recent dark matter measurements on the probability distributions, and we discuss prospects for the next run of the LHC at 13-14 TeV.
[ { "created": "Wed, 25 Dec 2013 22:05:21 GMT", "version": "v1" }, { "created": "Tue, 4 Mar 2014 00:03:58 GMT", "version": "v2" } ]
2014-03-26
[ [ "Dumont", "Beranger", "" ], [ "Gunion", "John F.", "" ], [ "Kraml", "Sabine", "" ] ]
The parameter space of the phenomenological MSSM (pMSSM) is explored by means of Markov Chain Monte Charlo (MCMC) methods, taking into account the latest LHC results on the Higgs signal at 125 GeV in addition to relevant low-energy observables and LEP constraints. We use a Bayesian approach to derive posterior densities for the parameters and observables of interests. We find in particular that the Higgs measurements have a significant impact on the parameters mu and tan beta due to radiative corrections to the bottom Yukawa coupling. We show moreover the impact of the most recent dark matter measurements on the probability distributions, and we discuss prospects for the next run of the LHC at 13-14 TeV.
hep-ph/0509026
Bj\"orn Schenke
B. Schenke, C. Greiner
Dilepton production from hot hadronic matter in nonequilibrium
25 pages, 20 figures, accepted version for publication in Phys.Rev.C
Phys.Rev.C73:034909,2006
10.1103/PhysRevC.73.034909
null
hep-ph nucl-th
null
The influence of time dependent medium modifications of low mass vector mesons on dilepton yields is investigated within a nonequilibrium quantum field theoretical description on the basis of the Kadanoff-Baym equations. Time scales for the adaption of the spectral properties to changing self energies are given and, under use of a model for the fireball evolution, nonequilibrium dilepton yields from the decay of rho- and omega-mesons are calculated. In a comparison of these yields with those from calculations that assume instantaneous (Markovian) adaption to the changing medium, quantum mechanical memory effects turn out to be important.
[ { "created": "Sat, 3 Sep 2005 10:29:22 GMT", "version": "v1" }, { "created": "Wed, 11 Jan 2006 10:35:22 GMT", "version": "v2" } ]
2008-11-26
[ [ "Schenke", "B.", "" ], [ "Greiner", "C.", "" ] ]
The influence of time dependent medium modifications of low mass vector mesons on dilepton yields is investigated within a nonequilibrium quantum field theoretical description on the basis of the Kadanoff-Baym equations. Time scales for the adaption of the spectral properties to changing self energies are given and, under use of a model for the fireball evolution, nonequilibrium dilepton yields from the decay of rho- and omega-mesons are calculated. In a comparison of these yields with those from calculations that assume instantaneous (Markovian) adaption to the changing medium, quantum mechanical memory effects turn out to be important.
hep-ph/0405027
Egle Tomasi-Gustafsson
Michail P. Rekalo and Egle Tomasi-Gustafsson
$P$-parity of charm and strange particles in electroproduction processes, in collinear regime
4 pages
Phys.Lett. B599 (2004) 247-252
10.1016/j.physletb.2004.08.037
null
hep-ph
null
We show that definite polarization observables for the simplest electroproduction processes, $\ell+N\to \ell+B(1/2^\pm)+M(0^\pm)$, $B=Y(\Lambda, \Sigma$ or $Y_c$-hyperon, $\Theta^+$-pentaquark) and $M=K$, $\bar{K}$ or $D$, are sensitive to the relative P-parity $\pi(B)$ of the NBM-system. The interference of the longitudinal and transversal amplitudes for the collinear regime of the processes $\gamma^*+N\to B+M $($\gamma^*$ is the virtual photon) - at any value of momentum transfer squared and excitation energy of the $BM$-system - generates model independent relations between analyzing powers (in unpolarized lepton scattering by polarized target), from one side, and the components of the produced baryon $B$ polarization. It is important to stress that these relations depend on the above mentioned P-parity, and constitute a model independent method for the determination of unknown parities of strange and charm particles.
[ { "created": "Tue, 4 May 2004 13:19:27 GMT", "version": "v1" } ]
2009-11-10
[ [ "Rekalo", "Michail P.", "" ], [ "Tomasi-Gustafsson", "Egle", "" ] ]
We show that definite polarization observables for the simplest electroproduction processes, $\ell+N\to \ell+B(1/2^\pm)+M(0^\pm)$, $B=Y(\Lambda, \Sigma$ or $Y_c$-hyperon, $\Theta^+$-pentaquark) and $M=K$, $\bar{K}$ or $D$, are sensitive to the relative P-parity $\pi(B)$ of the NBM-system. The interference of the longitudinal and transversal amplitudes for the collinear regime of the processes $\gamma^*+N\to B+M $($\gamma^*$ is the virtual photon) - at any value of momentum transfer squared and excitation energy of the $BM$-system - generates model independent relations between analyzing powers (in unpolarized lepton scattering by polarized target), from one side, and the components of the produced baryon $B$ polarization. It is important to stress that these relations depend on the above mentioned P-parity, and constitute a model independent method for the determination of unknown parities of strange and charm particles.
hep-ph/0402141
Hyun-Chul Kim
Hyun-Chul Kim, Chang-Hwan Lee, Hee-Jung Lee
Pentaquark $\Theta^+$ mass and width in dense matter
7 pages, 3 figures. Final version published in J. of. Kor. Phys. Soc
J.Korean Phys.Soc. 46 (2005) 393-396
null
PNU-NTG-03/2004,PNU-NURI-02/2004
hep-ph
null
We investigate medium modifications of the pentaquark $\Theta^+$ in dense medium, taking into account different parities of the exotic $\Theta^+$ baryon. We find that the chemical potential of the $\Theta^+$ is shifted in a density-dependent way to one-loop order. We also investigated the effect of the scaled nucleon mass in dense medium on the $\Theta^+$ propagator. The results turn out to depend sensitively on the scaled nucleon mass and on the parity of the $\Theta^+$.
[ { "created": "Fri, 13 Feb 2004 09:59:05 GMT", "version": "v1" }, { "created": "Sun, 15 Feb 2004 07:03:10 GMT", "version": "v2" }, { "created": "Fri, 5 Mar 2004 11:55:48 GMT", "version": "v3" }, { "created": "Fri, 11 Mar 2005 04:50:57 GMT", "version": "v4" } ]
2007-05-23
[ [ "Kim", "Hyun-Chul", "" ], [ "Lee", "Chang-Hwan", "" ], [ "Lee", "Hee-Jung", "" ] ]
We investigate medium modifications of the pentaquark $\Theta^+$ in dense medium, taking into account different parities of the exotic $\Theta^+$ baryon. We find that the chemical potential of the $\Theta^+$ is shifted in a density-dependent way to one-loop order. We also investigated the effect of the scaled nucleon mass in dense medium on the $\Theta^+$ propagator. The results turn out to depend sensitively on the scaled nucleon mass and on the parity of the $\Theta^+$.
2405.15807
Milena Skvortsova
Milena Skvortsova
Ringing of the Extreme Regular Black Holes
9 pages, 8 figures, RevTex
null
null
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate quasinormal ringing in both time and frequency domains for scalar and neutrino perturbations around black hole solutions that simultaneously describe regular and extreme configurations within a non-linear electrodynamics framework. Two types of solutions are considered: those with de Sitter and Minkowski cores. The quasinormal frequencies obtained from two independent methods exhibit excellent agreement. Furthermore, we derive an analytical expression in the eikonal limit and discuss the validity of the correspondence between eikonal quasinormal modes and null geodesics.
[ { "created": "Mon, 20 May 2024 14:41:36 GMT", "version": "v1" } ]
2024-05-28
[ [ "Skvortsova", "Milena", "" ] ]
We investigate quasinormal ringing in both time and frequency domains for scalar and neutrino perturbations around black hole solutions that simultaneously describe regular and extreme configurations within a non-linear electrodynamics framework. Two types of solutions are considered: those with de Sitter and Minkowski cores. The quasinormal frequencies obtained from two independent methods exhibit excellent agreement. Furthermore, we derive an analytical expression in the eikonal limit and discuss the validity of the correspondence between eikonal quasinormal modes and null geodesics.
hep-ph/0603161
R. Rosenfelder
R. Rosenfelder
On the Numerical Evaluation of a Class of Oscillatory Integrals in Worldline Variational Calculations
18 pages, 6 figures, Latex; v2: 21 pages, 6 figures, 2 tables, misprints corrected, new chapter on double exponential method; v3: misprint in eq. (5.19) corrected, numerical results unchanged as stepsize was calculated correctly in program
null
null
PSI-PR-06-07
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Filon-Simpson quadrature rules are derived for integrals of the type \int_a^b dx f(x) sin(xy)/(xy) and \int_a^b dx f(x) 4 sin^2(xy/2)/(xy)^2 which are needed in applications of the worldline variational approach to Quantum Field Theory. These new integration rules reduce to the standard Simpson rule for y = 0 and are exact for y \to \infty when a = 0 and f(0) \ne 0.The subleading term in the asymptotic expansion is also reproduced more and more precisely when the number of integration points is increased. Tests show that the numerical results are indeed stable over a wide range of y-values whereas usual Gauss-Legendre quadrature rules are more precise at low y but fail completely for large values of y. The associated Filon-Simpson weights are given in terms of sine and cosine integrals and have to be evaluated for each value of y. A Fortran program to calculate them in a fast and accurate manner is available. A detailed comparison with the double exponential method of Ooura and Mori is made.
[ { "created": "Tue, 21 Mar 2006 15:53:26 GMT", "version": "v1" }, { "created": "Thu, 22 Nov 2018 12:07:48 GMT", "version": "v2" }, { "created": "Sat, 25 Apr 2020 10:14:31 GMT", "version": "v3" } ]
2020-04-28
[ [ "Rosenfelder", "R.", "" ] ]
Filon-Simpson quadrature rules are derived for integrals of the type \int_a^b dx f(x) sin(xy)/(xy) and \int_a^b dx f(x) 4 sin^2(xy/2)/(xy)^2 which are needed in applications of the worldline variational approach to Quantum Field Theory. These new integration rules reduce to the standard Simpson rule for y = 0 and are exact for y \to \infty when a = 0 and f(0) \ne 0.The subleading term in the asymptotic expansion is also reproduced more and more precisely when the number of integration points is increased. Tests show that the numerical results are indeed stable over a wide range of y-values whereas usual Gauss-Legendre quadrature rules are more precise at low y but fail completely for large values of y. The associated Filon-Simpson weights are given in terms of sine and cosine integrals and have to be evaluated for each value of y. A Fortran program to calculate them in a fast and accurate manner is available. A detailed comparison with the double exponential method of Ooura and Mori is made.
2404.04333
Yong Tang
Jiang-Chuan Yu, Yan Cao, Yong Tang, Yue-Liang Wu
Detecting Ultralight Dark Matter Gravitationally with Laser Interferometers in Space
7 pages + supplementary material, 3 figures
null
null
null
hep-ph astro-ph.CO gr-qc
http://creativecommons.org/licenses/by/4.0/
Ultralight dark matter (ULDM) is one of the leading well-motivated dark matter candidates, predicted in many theories beyond the standard model of particle physics and cosmology. There have been increasing interests in searching for ULDM in physical and astronomical experiments, mostly assuming there are additional interactions other than gravity between ULDM and normal matter. Here we demonstrate that even if ULDM has only gravitational interaction, it shall induce gravitational perturbations in solar system that may be large enough to cause detectable signals in future gravitational-wave (GW) laser interferometers in space. We investigate the sensitivities of Michelson time-delay interferometer to ULDM of various spins, and show vector ULDM with mass $m\lesssim 10^{-18}~$eV can be probed by space-based GW detectors aiming at $\mu$Hz frequencies. Our findings exhibit that GW detectors may directly probe ULDM in some mass ranges that otherwise are challenging to examine.
[ { "created": "Fri, 5 Apr 2024 18:03:57 GMT", "version": "v1" } ]
2024-04-09
[ [ "Yu", "Jiang-Chuan", "" ], [ "Cao", "Yan", "" ], [ "Tang", "Yong", "" ], [ "Wu", "Yue-Liang", "" ] ]
Ultralight dark matter (ULDM) is one of the leading well-motivated dark matter candidates, predicted in many theories beyond the standard model of particle physics and cosmology. There have been increasing interests in searching for ULDM in physical and astronomical experiments, mostly assuming there are additional interactions other than gravity between ULDM and normal matter. Here we demonstrate that even if ULDM has only gravitational interaction, it shall induce gravitational perturbations in solar system that may be large enough to cause detectable signals in future gravitational-wave (GW) laser interferometers in space. We investigate the sensitivities of Michelson time-delay interferometer to ULDM of various spins, and show vector ULDM with mass $m\lesssim 10^{-18}~$eV can be probed by space-based GW detectors aiming at $\mu$Hz frequencies. Our findings exhibit that GW detectors may directly probe ULDM in some mass ranges that otherwise are challenging to examine.
hep-ph/0508144
Ramazan Sever
Sameer M. Ikhdair and Ramazan Sever
A Systematic Study on Nonrelativistic Quarkonium Interaction
24 pages
Int.J.Mod.Phys. A21 (2006) 3989-4002
10.1142/S0217751X06030953
null
hep-ph
null
recently proposed strictly phenomenological static quark-antiquark potential belonging to the generality $V(r)=-Ar^{-\alpha}+\kappa r^{\beta}+V_{0}$ is tested with heavy quarkonia in the context of the shifted large N-expansion method. This nonrelativistic potential model fits the spin-averaged mass spectra of the $c\bar{c},$ $b\bar{b}$ and $c% \bar{b}$ quarkonia within a few ${\rm MeV}$ and also the five experimentally known leptonic decay widths of the $c\bar{c}$ and $b% \bar{b}$ vector states. Further, we compute the hyperfine splittings of the bottomonium spectrum as well as the fine and hyperfine splittings of the charmonium spectrum. We give predictions for not yet observed $B_{c}$ splittings. The model is then used to predict the masses of the remaining quarkonia and the leptonic decay widths of the two pseudoscalar $c\bar{b%}$ states. Our results are compared with other models to gauge the reliability of the predictions and point out differences.
[ { "created": "Fri, 12 Aug 2005 06:00:48 GMT", "version": "v1" } ]
2009-11-11
[ [ "Ikhdair", "Sameer M.", "" ], [ "Sever", "Ramazan", "" ] ]
recently proposed strictly phenomenological static quark-antiquark potential belonging to the generality $V(r)=-Ar^{-\alpha}+\kappa r^{\beta}+V_{0}$ is tested with heavy quarkonia in the context of the shifted large N-expansion method. This nonrelativistic potential model fits the spin-averaged mass spectra of the $c\bar{c},$ $b\bar{b}$ and $c% \bar{b}$ quarkonia within a few ${\rm MeV}$ and also the five experimentally known leptonic decay widths of the $c\bar{c}$ and $b% \bar{b}$ vector states. Further, we compute the hyperfine splittings of the bottomonium spectrum as well as the fine and hyperfine splittings of the charmonium spectrum. We give predictions for not yet observed $B_{c}$ splittings. The model is then used to predict the masses of the remaining quarkonia and the leptonic decay widths of the two pseudoscalar $c\bar{b%}$ states. Our results are compared with other models to gauge the reliability of the predictions and point out differences.
1510.05722
Aqeel Ahmed
Aqeel Ahmed, Bohdan Grzadkowski, John F. Gunion and Yun Jiang
Higgs dark matter from a warped extra dimension
11 pages, 5 figues. Contribution to the proceedings of the 18th International Conference From the Planck Scale to the Electroweak Scale, May 2015, Ioannina, Greece. Based on arXiv:1504.03706
PoS (PLANCK 2015) 002
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a 5D $\mathbb{Z}_2$-symmetric IR-UV-IR model with a {\it warped KK-parity} under which the bulk fields have towers of either even or odd KK-modes. We show that this $\mathbb{Z}_2$-symmetric geometry is equivalent to two times the UV-IR geometry (Randall-Sundrum model) provided each bulk field is subject to Neumann (or mixed) and Dirichlet boundary conditions at the UV-brane for even and odd fields, respectively. The 5D Standard Model (SM) bosonic sector is considered, such that in the 4D low-energy effective theory the $\mathbb{Z}_2$-even zero-modes correspond to the SM degrees of freedom, whereas the $\mathbb{Z}_2$-odd zero modes serve as a dark sector. In the zero-mode scalar sector, the even scalar mimics the SM Higgs boson, while the odd scalar (dark-Higgs) is stable and serves as a dark matter candidate. Implications for this dark matter are discussed; it is found that the dark-Higgs can provide only a small fraction of the observed dark matter abundance.
[ { "created": "Mon, 19 Oct 2015 23:53:17 GMT", "version": "v1" } ]
2015-10-21
[ [ "Ahmed", "Aqeel", "" ], [ "Grzadkowski", "Bohdan", "" ], [ "Gunion", "John F.", "" ], [ "Jiang", "Yun", "" ] ]
We present a 5D $\mathbb{Z}_2$-symmetric IR-UV-IR model with a {\it warped KK-parity} under which the bulk fields have towers of either even or odd KK-modes. We show that this $\mathbb{Z}_2$-symmetric geometry is equivalent to two times the UV-IR geometry (Randall-Sundrum model) provided each bulk field is subject to Neumann (or mixed) and Dirichlet boundary conditions at the UV-brane for even and odd fields, respectively. The 5D Standard Model (SM) bosonic sector is considered, such that in the 4D low-energy effective theory the $\mathbb{Z}_2$-even zero-modes correspond to the SM degrees of freedom, whereas the $\mathbb{Z}_2$-odd zero modes serve as a dark sector. In the zero-mode scalar sector, the even scalar mimics the SM Higgs boson, while the odd scalar (dark-Higgs) is stable and serves as a dark matter candidate. Implications for this dark matter are discussed; it is found that the dark-Higgs can provide only a small fraction of the observed dark matter abundance.
2108.02711
Kyrill Bugaev
O. V. Vitiuk, V. M. Pugatch, K.A. Bugaev, P. P. Panasiuk, N. S. Yakovenko, B. E. Grinyuk, E. S. Zherebtsova, M. Bleicher, L.V. Bravina, A.V. Taranenko and E.E. Zabrodin
Triple nuclear collisions - a new method to explore the matter properties under new extreme conditions
Summary of the talk given at the Online Conference "Strangeness in Quark Matter 2021"
null
10.1051/epjconf/202225913012
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest to explore an entirely new method to experimentally and theoretically study the phase diagram of strongly interacting matter based on the triple nuclear collisions (TNC). We simulated the TNC using the UrQMD 3.4 model at the beam center-of-mass collision energies $\sqrt{s_{NN}} = 200$ GeV and $\sqrt{s_{NN}} = 2.76$ TeV. It is found that in the most central and simultaneous TNC the initial baryonic charge density is about 3 times higher than the one achieved in the usual binary nuclear collisions at the same energies. As a consequence, the production of protons and $\Lambda$-hyperons is increased by a factor of 2 and 1.5, respectively. Using the MIT Bag model equation we study the evolution of the central cell in TNC and demonstrate that for the top RHIC energy of collision the baryonic chemical potential is 2-2.5 times larger than the one achieved in the binary nuclear collision at the same type of reaction. Based on these estimates, we show that TNC offers an entirely new possibility to study the QCD phase diagram at very high baryonic charge densities.
[ { "created": "Thu, 5 Aug 2021 16:23:38 GMT", "version": "v1" } ]
2022-02-16
[ [ "Vitiuk", "O. V.", "" ], [ "Pugatch", "V. M.", "" ], [ "Bugaev", "K. A.", "" ], [ "Panasiuk", "P. P.", "" ], [ "Yakovenko", "N. S.", "" ], [ "Grinyuk", "B. E.", "" ], [ "Zherebtsova", "E. S.", "" ], [ "Bleicher", "M.", "" ], [ "Bravina", "L. V.", "" ], [ "Taranenko", "A. V.", "" ], [ "Zabrodin", "E. E.", "" ] ]
We suggest to explore an entirely new method to experimentally and theoretically study the phase diagram of strongly interacting matter based on the triple nuclear collisions (TNC). We simulated the TNC using the UrQMD 3.4 model at the beam center-of-mass collision energies $\sqrt{s_{NN}} = 200$ GeV and $\sqrt{s_{NN}} = 2.76$ TeV. It is found that in the most central and simultaneous TNC the initial baryonic charge density is about 3 times higher than the one achieved in the usual binary nuclear collisions at the same energies. As a consequence, the production of protons and $\Lambda$-hyperons is increased by a factor of 2 and 1.5, respectively. Using the MIT Bag model equation we study the evolution of the central cell in TNC and demonstrate that for the top RHIC energy of collision the baryonic chemical potential is 2-2.5 times larger than the one achieved in the binary nuclear collision at the same type of reaction. Based on these estimates, we show that TNC offers an entirely new possibility to study the QCD phase diagram at very high baryonic charge densities.
hep-ph/0301245
Ralf Rapp
R. Rapp and E.V. Shuryak
D-Meson Production from Recombination in Hadronic Collisions
14 pages RevTeX including 10 ps-figures
Phys.Rev. D67 (2003) 074036
10.1103/PhysRevD.67.074036
null
hep-ph hep-ex nucl-th
null
Nonperturbative effects in $D$-meson production in pion-nucleon and proton-nucleon collisions are investigated within the recombination model. The coalescence of perturbatively created charm quarks with sea- and valence-quarks from projectile and target fragments is shown to be competitive in magnitude with standard fragmentation calculations at both central (small $x_F$) and forward rapidities. Corresponding flavor asymmetries for inclusive $D$-meson production are thus mostly generated on the (light-) parton distribution level, and turn out to be in reasonable overall agreement with available fixed-target data. Predictions for upcoming measurements at RHIC are given.
[ { "created": "Tue, 28 Jan 2003 14:26:09 GMT", "version": "v1" } ]
2009-11-10
[ [ "Rapp", "R.", "" ], [ "Shuryak", "E. V.", "" ] ]
Nonperturbative effects in $D$-meson production in pion-nucleon and proton-nucleon collisions are investigated within the recombination model. The coalescence of perturbatively created charm quarks with sea- and valence-quarks from projectile and target fragments is shown to be competitive in magnitude with standard fragmentation calculations at both central (small $x_F$) and forward rapidities. Corresponding flavor asymmetries for inclusive $D$-meson production are thus mostly generated on the (light-) parton distribution level, and turn out to be in reasonable overall agreement with available fixed-target data. Predictions for upcoming measurements at RHIC are given.
2310.07505
Roberto Casadio
R. Casadio, R. da Rocha, A. Giusti, P. Meert
Thermodynamic and configurational entropy of quantum Schwarzschild geometries
LaTeX, 14 pages, 6 graphs in 3 figures
null
null
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study different entropies for coherent states representing the geometry of spherically symmetric compact systems. We show that the thermodynamic entropy reproduces the Bekenstein-Hawking result in the presence of thermal modes at the Hawking temperature if the object is a black hole and saturates the Bekenstein bound for more general compact objects. We also analyse the information entropy of the quantum coherent state without radiation and find further support against the singular Schwarzschild geometry.
[ { "created": "Wed, 11 Oct 2023 14:02:09 GMT", "version": "v1" } ]
2023-10-12
[ [ "Casadio", "R.", "" ], [ "da Rocha", "R.", "" ], [ "Giusti", "A.", "" ], [ "Meert", "P.", "" ] ]
We study different entropies for coherent states representing the geometry of spherically symmetric compact systems. We show that the thermodynamic entropy reproduces the Bekenstein-Hawking result in the presence of thermal modes at the Hawking temperature if the object is a black hole and saturates the Bekenstein bound for more general compact objects. We also analyse the information entropy of the quantum coherent state without radiation and find further support against the singular Schwarzschild geometry.
0712.3193
Ivanov Dmitry
D.Yu. Ivanov
Exclusive vector meson electroproduction
7 pages; Talk given at 12th International Conference on Elastic and Diffractive Scattering: Forward Physics and QCD, Hamburg, DESY, Germany, 21-25 May 2007
null
null
null
hep-ph
null
We discuss exclusive vector meson electroproduction within the QCD collinear factorization framework. In Bjorken kinematics the amplitude factorizes in a convolution of the nonperturbative meson distribution amplitude and the generalized parton densities with the perturbatively calculable hard-scattering amplitudes, which are presently known to next-to-leading order (NLO). At small $x_{\rm B}$ NLO corrections are very large. It is related to appearance of BFKL type logarithms in the hard-scattering amplitudes, that calls for a resummation of these effects at higher orders. Here we report the first results of such resummation.
[ { "created": "Wed, 19 Dec 2007 14:29:32 GMT", "version": "v1" } ]
2007-12-20
[ [ "Ivanov", "D. Yu.", "" ] ]
We discuss exclusive vector meson electroproduction within the QCD collinear factorization framework. In Bjorken kinematics the amplitude factorizes in a convolution of the nonperturbative meson distribution amplitude and the generalized parton densities with the perturbatively calculable hard-scattering amplitudes, which are presently known to next-to-leading order (NLO). At small $x_{\rm B}$ NLO corrections are very large. It is related to appearance of BFKL type logarithms in the hard-scattering amplitudes, that calls for a resummation of these effects at higher orders. Here we report the first results of such resummation.
1602.00923
Treleani Daniele
Daniele Treleani and Giorgio Calucci
A Brief Comment on Multi-Gluon Amplitudes and Double Parton Interactions
5 pages, 5 figures. Prepared for the MPI@LHC2015, ICTP Trieste, Italy
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A typical contribution to a color ordered multi-gluon amplitude, which can split into two weakly correlated two-body gluon scattering amplitudes and may thus contribute to a Double Parton Interaction, is briefly discussed. We find that the color ordered amplitude is not enhanced in the typical configuration generated by a DPI, where the transverse momenta of final state gluons are compensated pairwise, while a dominant contribution to the multi-gluon amplitude is due to terms proportional to the fusion amplitude of two initial state gluons. Which corresponds to an amplitude effectively describing a two rather than a three-body partonic interaction.
[ { "created": "Tue, 2 Feb 2016 13:52:14 GMT", "version": "v1" } ]
2016-02-03
[ [ "Treleani", "Daniele", "" ], [ "Calucci", "Giorgio", "" ] ]
A typical contribution to a color ordered multi-gluon amplitude, which can split into two weakly correlated two-body gluon scattering amplitudes and may thus contribute to a Double Parton Interaction, is briefly discussed. We find that the color ordered amplitude is not enhanced in the typical configuration generated by a DPI, where the transverse momenta of final state gluons are compensated pairwise, while a dominant contribution to the multi-gluon amplitude is due to terms proportional to the fusion amplitude of two initial state gluons. Which corresponds to an amplitude effectively describing a two rather than a three-body partonic interaction.
gr-qc/0210109
Valerio Bozza
V. Bozza
Quasi-Equatorial Gravitational Lensing by Spinning Black Holes in the Strong Field Limit
13 pages, 9 figures. Improved version with detailed physical discussion
Phys.Rev.D67:103006,2003
10.1103/PhysRevD.67.103006
null
gr-qc astro-ph
null
Spherically symmetric black holes produce, by strong field lensing, two infinite series of relativistic images, formed by light rays winding around the black hole at distances comparable to the gravitational radius. In this paper, we address the relevance of the black hole spin for the strong field lensing phenomenology, focusing on trajectories close to the equatorial plane for simplicity. In this approximation, we derive a two-dimensional lens equation and formulae for the position and the magnification of the relativistic images in the strong field limit. The most outstanding effect is the generation of a non trivial caustic structure. Caustics drift away from the optical axis and acquire finite extension. For a high enough black hole spin, depending on the source extension, we can practically observe only one image rather than two infinite series of relativistic images. In this regime, additional non equatorial images may play an important role in the phenomenology.
[ { "created": "Thu, 31 Oct 2002 17:35:55 GMT", "version": "v1" }, { "created": "Mon, 17 Feb 2003 10:28:30 GMT", "version": "v2" } ]
2010-02-23
[ [ "Bozza", "V.", "" ] ]
Spherically symmetric black holes produce, by strong field lensing, two infinite series of relativistic images, formed by light rays winding around the black hole at distances comparable to the gravitational radius. In this paper, we address the relevance of the black hole spin for the strong field lensing phenomenology, focusing on trajectories close to the equatorial plane for simplicity. In this approximation, we derive a two-dimensional lens equation and formulae for the position and the magnification of the relativistic images in the strong field limit. The most outstanding effect is the generation of a non trivial caustic structure. Caustics drift away from the optical axis and acquire finite extension. For a high enough black hole spin, depending on the source extension, we can practically observe only one image rather than two infinite series of relativistic images. In this regime, additional non equatorial images may play an important role in the phenomenology.
1309.4191
Zuo-Tang Liang
Shu-yi Wei, Yu-kun Song, Zuo-tang Liang
Higher twist contribution to fragmentation function in inclusive hadron production in e^+e^- annihilation
version to appear in PRD, 36 pages, 2 figures
Phys. Rev. D 89, 014024 (2014)
10.1103/PhysRevD.89.014024
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply collinear expansion to inclusive hadron production in $e^+e^-$ annihilation and derive a formalism suitable for systematic study of leading as well as higher twist contributions to fragmentation functions at the tree level. We make the calculations for hadrons with spin-0, spin-1/2 as well as spin-1 and obtain the results in terms of different components of fragmentation functions for the hadronic tensors, the differential cross section as well as hadron polarizations in different cases. The results show a number of interesting features such as the existence of transverse polarization for spin-1/2 hadrons at the twist-3 level, the quark polarization independence of the spin alignment of vector mesons.
[ { "created": "Tue, 17 Sep 2013 06:07:01 GMT", "version": "v1" }, { "created": "Sat, 14 Dec 2013 03:54:22 GMT", "version": "v2" } ]
2014-02-05
[ [ "Wei", "Shu-yi", "" ], [ "Song", "Yu-kun", "" ], [ "Liang", "Zuo-tang", "" ] ]
We apply collinear expansion to inclusive hadron production in $e^+e^-$ annihilation and derive a formalism suitable for systematic study of leading as well as higher twist contributions to fragmentation functions at the tree level. We make the calculations for hadrons with spin-0, spin-1/2 as well as spin-1 and obtain the results in terms of different components of fragmentation functions for the hadronic tensors, the differential cross section as well as hadron polarizations in different cases. The results show a number of interesting features such as the existence of transverse polarization for spin-1/2 hadrons at the twist-3 level, the quark polarization independence of the spin alignment of vector mesons.
2003.02523
Minyong Guo
Minyong Guo and Peng-Cheng Li
The innermost stable circular orbit and shadow in the novel $4D$ Einstein-Gauss-Bonnet gravity
14 pages, 4 figures; v2: new reference and some modifications added, accepted in EPJC
null
10.1140/epjc/s10052-020-8164-7
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, a novel $4D$ Einstein-Gauss-Bonnet (EGB) gravity was formulated and a spherically symmetric black hole solution in this theory was derived by D. Glavan and C. Lin \cite{Glavan:2019inb}. In this paper, we study the geodesic motions in the background of the spherically symmetric black hole, by focusing on the innermost stable circular orbits (ISCO) for massive particle and photon sphere and shadow. Also, we find that a negative GB coupling constant is allowable in this theory, as in which case the singular behavior of the black hole can be hidden inside the event horizon. Moreover, we find that due to this extension a recently proposed universal bound on black hole size in \cite{Lu:2019zxb} can be broken.
[ { "created": "Thu, 5 Mar 2020 10:27:47 GMT", "version": "v1" }, { "created": "Tue, 10 Mar 2020 13:44:02 GMT", "version": "v2" }, { "created": "Tue, 16 Jun 2020 03:15:59 GMT", "version": "v3" } ]
2020-07-15
[ [ "Guo", "Minyong", "" ], [ "Li", "Peng-Cheng", "" ] ]
Recently, a novel $4D$ Einstein-Gauss-Bonnet (EGB) gravity was formulated and a spherically symmetric black hole solution in this theory was derived by D. Glavan and C. Lin \cite{Glavan:2019inb}. In this paper, we study the geodesic motions in the background of the spherically symmetric black hole, by focusing on the innermost stable circular orbits (ISCO) for massive particle and photon sphere and shadow. Also, we find that a negative GB coupling constant is allowable in this theory, as in which case the singular behavior of the black hole can be hidden inside the event horizon. Moreover, we find that due to this extension a recently proposed universal bound on black hole size in \cite{Lu:2019zxb} can be broken.
hep-ph/9409452
Wojtek Zakrzewski
W.J. Zakrzewski
A modified discrete sine-Gordon Model
23pages, NI-94014
null
10.1088/0951-7715/8/4/004
null
hep-ph
null
We modify the recently proposed model of Speight and Ward to make it possess time dependent solutions. We find that for each lattice spacing and for each velocity of the sine Gordon kink we can find a modification of the model for which this kink is a solution. We find that this model has really 3 ``kink-like" solutions; the original kink, the static kink and a further kink moving with velocity $v\sim0.97$. We discuss various properties of the model, from the point of view of its usefulness for numerical simulations.
[ { "created": "Fri, 30 Sep 1994 09:52:31 GMT", "version": "v1" } ]
2009-10-28
[ [ "Zakrzewski", "W. J.", "" ] ]
We modify the recently proposed model of Speight and Ward to make it possess time dependent solutions. We find that for each lattice spacing and for each velocity of the sine Gordon kink we can find a modification of the model for which this kink is a solution. We find that this model has really 3 ``kink-like" solutions; the original kink, the static kink and a further kink moving with velocity $v\sim0.97$. We discuss various properties of the model, from the point of view of its usefulness for numerical simulations.
hep-ph/0109062
Stefan Dittmaier
Stefan Dittmaier and Michael Kramer
Electroweak radiative corrections to W-boson production at hadron colliders
29 pages, latex, 17 postscript files, revised version that is to appear in Phys.Rev.D, some explanations added and results extended by a discussion of the QED factorization scale dependence
Phys.Rev.D65:073007,2002
10.1103/PhysRevD.65.073007
BI-TP 2000/04, DESY 01-121, Edinburgh 2001/11
hep-ph
null
The complete set of electroweak O(alpha) corrections to the Drell--Yan-like production of W bosons is calculated and compared to an approximation provided by the leading term of an expansion about the W-resonance pole. All relevant formulae are listed explicitly, and particular attention is paid to issues of gauge invariance and the instability of the W bosons. A detailed discussion of numerical results underlines the phenomenological importance of the electroweak corrections to W-boson production at the Tevatron and at the LHC. While the pole expansion yields a good description of resonance observables, it is not sufficient for the high-energy tail of transverse-momentum distributions, relevant for new-physics searches.
[ { "created": "Fri, 7 Sep 2001 15:48:47 GMT", "version": "v1" }, { "created": "Wed, 14 Nov 2001 10:00:57 GMT", "version": "v2" } ]
2009-09-25
[ [ "Dittmaier", "Stefan", "" ], [ "Kramer", "Michael", "" ] ]
The complete set of electroweak O(alpha) corrections to the Drell--Yan-like production of W bosons is calculated and compared to an approximation provided by the leading term of an expansion about the W-resonance pole. All relevant formulae are listed explicitly, and particular attention is paid to issues of gauge invariance and the instability of the W bosons. A detailed discussion of numerical results underlines the phenomenological importance of the electroweak corrections to W-boson production at the Tevatron and at the LHC. While the pole expansion yields a good description of resonance observables, it is not sufficient for the high-energy tail of transverse-momentum distributions, relevant for new-physics searches.
hep-ph/0511075
Noriyuki Oshimo
Noriyuki Oshimo
Generation mixing phenomena for leptons in $e^+e^-$ collisions
2 pages, to be published in the Proceedings of the 3rd International Symposium on New Developments of Integrated Sciences, Tokyo, Japan, 10, 11, March, 2005
null
null
OCHA-PP-254
hep-ph
null
We discuss the possibility of measuring the generation mixing for the leptons in $e^+e^-$ collision experiments within the framework of the supersymmetric standard model.
[ { "created": "Mon, 7 Nov 2005 14:46:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Oshimo", "Noriyuki", "" ] ]
We discuss the possibility of measuring the generation mixing for the leptons in $e^+e^-$ collision experiments within the framework of the supersymmetric standard model.
1503.02968
Jacopo Ferretti
E. Santopinto, J. Ferretti
The unquenched quark model
Talk given at the conference "Dark Matter, Hadron Physics and Fusion Physics", Messina (Italy), September 24-26, 2014
EPJ Web Conf. 96 (2015) 01026
10.1051/epjconf/20159601026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this contribution, we briefly discuss the results for charmonium and bottomonium spectra with self-energy corrections in the unquenched quark model, due to the coupling to the meson-meson continuum. The UQM formalism can be extended to include also the effects of hybrid mesons, i.e. hybrid loops. Finally, we discuss the results of a calculation of hybrid mesons spectrum in Coulomb Gauge QCD.
[ { "created": "Tue, 10 Mar 2015 16:14:42 GMT", "version": "v1" } ]
2015-10-05
[ [ "Santopinto", "E.", "" ], [ "Ferretti", "J.", "" ] ]
In this contribution, we briefly discuss the results for charmonium and bottomonium spectra with self-energy corrections in the unquenched quark model, due to the coupling to the meson-meson continuum. The UQM formalism can be extended to include also the effects of hybrid mesons, i.e. hybrid loops. Finally, we discuss the results of a calculation of hybrid mesons spectrum in Coulomb Gauge QCD.
1307.6133
A. J. Buchmann
Michael L. Schmid and Alfons J. Buchmann
Hyperquarks and bosonic preon bound states
19 pages, 6 figures
Phys. Rev. D80, 095020 (2009)
10.1103/PhysRevD.80.095020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a model in which leptons, quarks, and the recently introduced hyperquarks are built up from two fundamental spin 1/2 preons, the standard model weak gauge bosons emerge as preon bound states. In addition, the model predicts a host of new composite gauge bosons, in particular those responsible for hyperquark and proton decay. Their presence entails a left-right symmetric extension of the standard model weak interactions and a scheme for a partial and grand unification of nongravitational interactions based on respectively the effective gauge groups SU(6)_P and SU(9)_G. This leads to a prediction of the Weinberg angle at low energies in good agreement with experiment. Furthermore, using evolution equations for the effective coupling strengths, we calculate the partial and grand unification scales, the hyperquark mass scale, as well as the mass and decay rate of the lightest hyperhadron.
[ { "created": "Tue, 23 Jul 2013 16:04:37 GMT", "version": "v1" } ]
2013-07-24
[ [ "Schmid", "Michael L.", "" ], [ "Buchmann", "Alfons J.", "" ] ]
In a model in which leptons, quarks, and the recently introduced hyperquarks are built up from two fundamental spin 1/2 preons, the standard model weak gauge bosons emerge as preon bound states. In addition, the model predicts a host of new composite gauge bosons, in particular those responsible for hyperquark and proton decay. Their presence entails a left-right symmetric extension of the standard model weak interactions and a scheme for a partial and grand unification of nongravitational interactions based on respectively the effective gauge groups SU(6)_P and SU(9)_G. This leads to a prediction of the Weinberg angle at low energies in good agreement with experiment. Furthermore, using evolution equations for the effective coupling strengths, we calculate the partial and grand unification scales, the hyperquark mass scale, as well as the mass and decay rate of the lightest hyperhadron.
hep-ph/9608316
Kurt Langfeld
Kurt Langfeld
On the possibility of the dual Meissner effect induced by instantons
discussion of the random instanton orientation added
Eur.Phys.J.C4:533-541,1998
10.1007/s100520050226
UNITU-THEP-14/1996
hep-ph hep-th
null
The classical Yang-Mills equation of motion is numerically investigated in the Lorentz gauge for a SU(2) gauge group. The color-electric field of two point-like charges is studied in the ''empty'' vacuum and in a state with an instanton present. The major effect for a fixed orientation of the instanton is that the color-electric field lines are expelled or attracted from the instanton region depending on the orientation of the instanton. If over the orientations of the instanton is averaged, this effect drops out. In this case of a random instanton orientation, we find that the external color-electric field is expelled from the instanton core. The origin of this effect is discussed.
[ { "created": "Wed, 14 Aug 1996 08:25:13 GMT", "version": "v1" }, { "created": "Wed, 20 Aug 1997 12:57:22 GMT", "version": "v2" } ]
2011-09-13
[ [ "Langfeld", "Kurt", "" ] ]
The classical Yang-Mills equation of motion is numerically investigated in the Lorentz gauge for a SU(2) gauge group. The color-electric field of two point-like charges is studied in the ''empty'' vacuum and in a state with an instanton present. The major effect for a fixed orientation of the instanton is that the color-electric field lines are expelled or attracted from the instanton region depending on the orientation of the instanton. If over the orientations of the instanton is averaged, this effect drops out. In this case of a random instanton orientation, we find that the external color-electric field is expelled from the instanton core. The origin of this effect is discussed.
2012.10756
Marcos A. Garcia Garcia
Marcos A. G. Garcia, Kunio Kaneta, Yann Mambrini, Keith A. Olive
Inflaton Oscillations and Post-Inflationary Reheating
40 pages, 17 figures
null
10.1088/1475-7516/2021/04/012
UMN-TH-4006/20, FTPI-MINN-20/37, IFT-UAM/CSIC-20-185, KIAS-P20071
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze in detail the perturbative decay of the inflaton oscillating about a generic form of its potential $V(\phi) = \phi^k$, taking into account the effects of non-instantaneous reheating. We show that evolution of the temperature as a function of the cosmological scale factor depends on the spin statistics of the final state decay products when $k > 2$. We also include the inflaton-induced mass of the final states leading to either kinematic suppression or enhancement if the final states are fermionic or bosonic respectively. We compute the maximum temperature reached after inflation, the subsequent evolution of the temperature and the final reheat temperature. We apply our results to the computation of the dark matter abundance through thermal scattering during reheating. We also provide an example based on supersymmetry for the coupling of the inflaton to matter.
[ { "created": "Sat, 19 Dec 2020 18:43:43 GMT", "version": "v1" }, { "created": "Wed, 7 Apr 2021 10:08:46 GMT", "version": "v2" } ]
2021-04-14
[ [ "Garcia", "Marcos A. G.", "" ], [ "Kaneta", "Kunio", "" ], [ "Mambrini", "Yann", "" ], [ "Olive", "Keith A.", "" ] ]
We analyze in detail the perturbative decay of the inflaton oscillating about a generic form of its potential $V(\phi) = \phi^k$, taking into account the effects of non-instantaneous reheating. We show that evolution of the temperature as a function of the cosmological scale factor depends on the spin statistics of the final state decay products when $k > 2$. We also include the inflaton-induced mass of the final states leading to either kinematic suppression or enhancement if the final states are fermionic or bosonic respectively. We compute the maximum temperature reached after inflation, the subsequent evolution of the temperature and the final reheat temperature. We apply our results to the computation of the dark matter abundance through thermal scattering during reheating. We also provide an example based on supersymmetry for the coupling of the inflaton to matter.
hep-ph/9603383
null
D. Apostolakis, P. Ditsas, and S. Katsanevas (Department of Physics, University of Crete and University of Athens)
The Standard Model process $e^+e^-\to \nu\bar{\nu}b\bar{b}$ and its Higgs signal at LEPI
18 pages + 12 compressed figures (use gunzip to decompress them)
Z.Phys. C76 (1997) 201-211
null
Crete 96-12
hep-ph
null
We present and study the results for the standard model process $e^+e^-\to \nu\bar{\nu}b\bar{b}$ at c.m energies 150$\leq \sqrt{s} (GeV) \leq $ 240 and for Higgs boson masses $80 GeV \leq m_H \leq 120 GeV$, obtained from all tree-level diagrams and including the most important radiative corrections. The $\sqrt{s}$ dependence and the interference properties of the Higgs boson contribution and of various coherent background contributions to the total cross section are examined. The effect of the QED initial state radiative corrections is estimated. The important differential distributions for the Higgs boson and the background components are studied, providing information usefull for choosing cuts in Higgs searches. We also examine the effect of a minimal set of cuts and evaluate the importance of the WW fusion for detecting a higher mass Higgs boson at LEPII.
[ { "created": "Fri, 22 Mar 1996 17:09:59 GMT", "version": "v1" }, { "created": "Mon, 25 Mar 1996 11:46:11 GMT", "version": "v2" } ]
2008-02-03
[ [ "Apostolakis", "D.", "", "Department of Physics,\n University of Crete and University of Athens" ], [ "Ditsas", "P.", "", "Department of Physics,\n University of Crete and University of Athens" ], [ "Katsanevas", "S.", "", "Department of Physics,\n University of Crete and University of Athens" ] ]
We present and study the results for the standard model process $e^+e^-\to \nu\bar{\nu}b\bar{b}$ at c.m energies 150$\leq \sqrt{s} (GeV) \leq $ 240 and for Higgs boson masses $80 GeV \leq m_H \leq 120 GeV$, obtained from all tree-level diagrams and including the most important radiative corrections. The $\sqrt{s}$ dependence and the interference properties of the Higgs boson contribution and of various coherent background contributions to the total cross section are examined. The effect of the QED initial state radiative corrections is estimated. The important differential distributions for the Higgs boson and the background components are studied, providing information usefull for choosing cuts in Higgs searches. We also examine the effect of a minimal set of cuts and evaluate the importance of the WW fusion for detecting a higher mass Higgs boson at LEPII.
0805.0152
Kresimir Kumericki
Kresimir Kumericki, Dieter Mueller, Kornelija Passek-Kumericki
Sum rules and dualities for generalized parton distributions: is there a holographic principle?
45 pages, 4 figures, Sect. 2 reorganized for clarity. Typos in Eq. (20) corrected. 4 new refs. Matches published version
Eur.Phys.J.C58:193-215,2008
10.1140/epjc/s10052-008-0741-0
null
hep-ph hep-ex hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
To leading order approximation, the physical content of generalized parton distributions (GPDs) that is accessible in deep virtual electroproduction of photons or mesons is contained in their value on the cross-over trajectory. This trajectory separates the t-channel and s-channel dominated GPD regions. The underlying Lorentz covariance implies correspondence between these two regions through their relation to GPDs on the cross-over trajectory. This point of view leads to a family of GPD sum rules which are a quark analogue of finite energy sum rules and it guides us to a new phenomenological GPD concept. As an example, we discuss the constraints from the JLab/Hall A data on the dominant u-quark GPD H. The question arises whether GPDs are governed by some kind of holographic principle.
[ { "created": "Thu, 1 May 2008 21:09:14 GMT", "version": "v1" }, { "created": "Mon, 5 May 2008 00:09:46 GMT", "version": "v2" }, { "created": "Fri, 17 Oct 2008 13:29:40 GMT", "version": "v3" } ]
2008-12-18
[ [ "Kumericki", "Kresimir", "" ], [ "Mueller", "Dieter", "" ], [ "Passek-Kumericki", "Kornelija", "" ] ]
To leading order approximation, the physical content of generalized parton distributions (GPDs) that is accessible in deep virtual electroproduction of photons or mesons is contained in their value on the cross-over trajectory. This trajectory separates the t-channel and s-channel dominated GPD regions. The underlying Lorentz covariance implies correspondence between these two regions through their relation to GPDs on the cross-over trajectory. This point of view leads to a family of GPD sum rules which are a quark analogue of finite energy sum rules and it guides us to a new phenomenological GPD concept. As an example, we discuss the constraints from the JLab/Hall A data on the dominant u-quark GPD H. The question arises whether GPDs are governed by some kind of holographic principle.
1110.6637
Aleksandrs Aleksejevs
A. Aleksejevs, S. Barkanova, Y. Kolomensky, E. Kuraev, V. Zykunov
High precision calculations of electroweak radiative corrections for polarized Moller scattering at one loop and beyond
PAVI11 Workshop Proceedings (September 5-9, 2011, Rome)
Nuovo Cimento C, 2012
10.1393/ncc/i2012-11261-2
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Parity-violating Moller scattering measurements are a powerful probe of new physics effects, and the upcoming high-precision experiments will require a new level of accuracy for electroweak radiative corrections (EWC). First, we perform the updated calculations of one-loop EWC for Moller scattering asymmetry using two different approaches: semi-automatic, precise, with FeynArts and FormCalc as base languages, and "by hand", with reasonable approximations. In addition, we provide a tuned comparison between the one-loop results obtained in two different renormalization schemes: on-shell and constrained differential renormalization. As the last step, we discuss the two-loop EWC induced by squaring one-loop diagrams, and show that the significant size of this partial correction indicates a need for a complete study of the two-loop EWC in order to meet the precision goals of future experiments.
[ { "created": "Sun, 30 Oct 2011 19:20:02 GMT", "version": "v1" } ]
2012-08-31
[ [ "Aleksejevs", "A.", "" ], [ "Barkanova", "S.", "" ], [ "Kolomensky", "Y.", "" ], [ "Kuraev", "E.", "" ], [ "Zykunov", "V.", "" ] ]
Parity-violating Moller scattering measurements are a powerful probe of new physics effects, and the upcoming high-precision experiments will require a new level of accuracy for electroweak radiative corrections (EWC). First, we perform the updated calculations of one-loop EWC for Moller scattering asymmetry using two different approaches: semi-automatic, precise, with FeynArts and FormCalc as base languages, and "by hand", with reasonable approximations. In addition, we provide a tuned comparison between the one-loop results obtained in two different renormalization schemes: on-shell and constrained differential renormalization. As the last step, we discuss the two-loop EWC induced by squaring one-loop diagrams, and show that the significant size of this partial correction indicates a need for a complete study of the two-loop EWC in order to meet the precision goals of future experiments.
hep-ph/9911436
Jungil Lee
Eric Braaten (Ohio State), Bernd A. Kniehl and Jungil Lee (Hamburg)
Polarization of Prompt J/psi at the Tevatron
4 pages, 2 figures, one reference added, accepted for publication in Phys. Rev. D
Phys.Rev.D62:094005,2000
10.1103/PhysRevD.62.094005
DESY 99-175
hep-ph
null
The polarization of prompt J/psi at the Fermilab Tevatron is calculated within the nonrelativistic QCD factorization framework. The contribution from radiative decays of P-wave charmonium states decreases, but does not eliminate, the transverse polarization at large transverse momentum. The angular distribution parameter alpha for leptonic decays of the J/\psi is predicted to increase from near 0 at p_T = 5 GeV to about 0.5 at p_T = 20 GeV. The prediction is consistent with measurements by the CDF Collaboration at intermediate values of p_T, but disagrees by about 3 standard deviations at the largest values of p_T measured.
[ { "created": "Mon, 22 Nov 1999 16:19:46 GMT", "version": "v1" }, { "created": "Wed, 17 May 2000 23:45:15 GMT", "version": "v2" }, { "created": "Wed, 26 Jul 2000 17:24:36 GMT", "version": "v3" } ]
2011-03-23
[ [ "Braaten", "Eric", "", "Ohio State" ], [ "Kniehl", "Bernd A.", "", "Hamburg" ], [ "Lee", "Jungil", "", "Hamburg" ] ]
The polarization of prompt J/psi at the Fermilab Tevatron is calculated within the nonrelativistic QCD factorization framework. The contribution from radiative decays of P-wave charmonium states decreases, but does not eliminate, the transverse polarization at large transverse momentum. The angular distribution parameter alpha for leptonic decays of the J/\psi is predicted to increase from near 0 at p_T = 5 GeV to about 0.5 at p_T = 20 GeV. The prediction is consistent with measurements by the CDF Collaboration at intermediate values of p_T, but disagrees by about 3 standard deviations at the largest values of p_T measured.
0705.3086
Takeo Moroi
Shoji Asai, Takeo Moroi, Kazuyuki Nishihara, T.T. Yanagida
Testing the Anomaly Mediation at the LHC
12 pages, 6 figures
Phys.Lett.B653:81-87,2007
10.1016/j.physletb.2007.06.080
UT-ICEPP-07-02, TU-792
hep-ph hep-ex
null
We consider a supersymmetric model in which gaugino masses are generated by the anomaly-mediation mechanism while scalar masses are from tree-level supergravity interaction. In such a model, scalar fermions as well as Higgsinos become as heavy as O(10-100TeV) and hence only the gauginos are superparticles kinematically accessible to the LHC. We study how and how well the properties of gauginos can be studied. We also discuss the strategy to test the anomaly-mediation model at the LHC.
[ { "created": "Tue, 22 May 2007 03:16:22 GMT", "version": "v1" }, { "created": "Wed, 13 Jun 2007 09:41:12 GMT", "version": "v2" }, { "created": "Tue, 26 Jun 2007 09:16:19 GMT", "version": "v3" } ]
2008-11-26
[ [ "Asai", "Shoji", "" ], [ "Moroi", "Takeo", "" ], [ "Nishihara", "Kazuyuki", "" ], [ "Yanagida", "T. T.", "" ] ]
We consider a supersymmetric model in which gaugino masses are generated by the anomaly-mediation mechanism while scalar masses are from tree-level supergravity interaction. In such a model, scalar fermions as well as Higgsinos become as heavy as O(10-100TeV) and hence only the gauginos are superparticles kinematically accessible to the LHC. We study how and how well the properties of gauginos can be studied. We also discuss the strategy to test the anomaly-mediation model at the LHC.
1012.4643
Scientific Information Service Cern
C. Grojean and M. Spiropulu
Proceedings of the 2009 European School of High-Energy Physics, Bautzen, Germany, 14 - 27 June 2009
7 lectures, 234 pages, published as CERN Yellow Report http://cdsweb.cern.ch/record/1119304
null
null
CERN-2010-002
hep-ph
http://creativecommons.org/licenses/by/3.0/
The European School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lecture notes on quantum field theory, quantum chromodynamics, physics beyond the Standard Model, flavour physics, effective field theory, cosmology, as well as statistical data analysis.
[ { "created": "Tue, 21 Dec 2010 13:09:41 GMT", "version": "v1" } ]
2010-12-22
[ [ "Grojean", "C.", "" ], [ "Spiropulu", "M.", "" ] ]
The European School of High-Energy Physics is intended to give young physicists an introduction to the theoretical aspects of recent advances in elementary particle physics. These proceedings contain lecture notes on quantum field theory, quantum chromodynamics, physics beyond the Standard Model, flavour physics, effective field theory, cosmology, as well as statistical data analysis.
2401.16890
Gerard Hooft 't
Gerard t Hooft
Black Hole Firewalls and Quantum Mechanics
7 pages, no figures
null
null
null
gr-qc math-ph math.MP quant-ph
http://creativecommons.org/licenses/by/4.0/
Firewalls in black holes are easiest to understand by imposing time reversal invariance, together with a unitary evolution law. The best approach seems to be to split up the time span of a black hole into short periods, during which no firewalls can be detected by any observer. Then, gluing together subsequent time periods, firewalls seem to appear, but they can always be transformed away. At all times we need a Hilbert space of a finite dimension, as long as particles far separated from the black hole are ignored. Our conclusion contradicts other findings, particularly a recent paper by Strauss and Whiting. Indeed, the firewall transformation removes the entanglement between very early and very late in- and out-particles, in a far-from-trivial way.
[ { "created": "Tue, 30 Jan 2024 10:50:56 GMT", "version": "v1" } ]
2024-01-31
[ [ "Hooft", "Gerard t", "" ] ]
Firewalls in black holes are easiest to understand by imposing time reversal invariance, together with a unitary evolution law. The best approach seems to be to split up the time span of a black hole into short periods, during which no firewalls can be detected by any observer. Then, gluing together subsequent time periods, firewalls seem to appear, but they can always be transformed away. At all times we need a Hilbert space of a finite dimension, as long as particles far separated from the black hole are ignored. Our conclusion contradicts other findings, particularly a recent paper by Strauss and Whiting. Indeed, the firewall transformation removes the entanglement between very early and very late in- and out-particles, in a far-from-trivial way.
2005.00390
Jianlong Lu
Jianlong Lu
Why Neutrino Masses Cannot Arise from Nonzero VEV of Charged Higgs Field in the Only Higgs Doublet
3 pages, 0 figure. Comment on arXiv:2003.12069
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A scheme of neutrino mass generation is proposed by [arXiv:2003.12069], in which the small nonzero neutrino masses come from nonzero vacuum expectation value (VEV) of the charged Higgs field in the Higgs doublet in the Standard Model of particle physics (SM). However, the introduction of nonzero VEV for the charged Higgs field implies broken ${\rm U}(1)$ symmetry in the electroweak theory, which leads to non-conservation of electric charge and nonzero mass of photon. By comparing the predicted ratio of VEVs of charged Higgs field and neutral Higgs field in [1] with the ratio constrained by the present experimental upper bound of photon mass, we show that this scheme does not work.
[ { "created": "Thu, 30 Apr 2020 08:47:51 GMT", "version": "v1" } ]
2020-05-04
[ [ "Lu", "Jianlong", "" ] ]
A scheme of neutrino mass generation is proposed by [arXiv:2003.12069], in which the small nonzero neutrino masses come from nonzero vacuum expectation value (VEV) of the charged Higgs field in the Higgs doublet in the Standard Model of particle physics (SM). However, the introduction of nonzero VEV for the charged Higgs field implies broken ${\rm U}(1)$ symmetry in the electroweak theory, which leads to non-conservation of electric charge and nonzero mass of photon. By comparing the predicted ratio of VEVs of charged Higgs field and neutral Higgs field in [1] with the ratio constrained by the present experimental upper bound of photon mass, we show that this scheme does not work.
1109.2122
Victor Shchigolev Konstantinovich
V.K. Shchigolev
Cosmological Model of Interacting Phantom and Yang-Mills Fields
7 pages, 2 figures
PRAMANA - Journal of Physics, Vol. 78, No. 5, 2012, pp. 819-825
10.1007/s12043-012-0272-y
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we consider a model of interacting phantom and Yang-Mills (YM) fields supposing the dilaton-type coupling. Making use of specific solution for YM equation previously found by the author, we obtain simple exact solutions for the accelerated expansion of FRW cosmological model. Besides, we derive the induced potentials of phantom field corresponding to some given regimes of expansion.The effective equation of state (EoS) have been reconstructed for all types of the models considered here.
[ { "created": "Fri, 9 Sep 2011 20:08:55 GMT", "version": "v1" }, { "created": "Wed, 14 Sep 2011 16:21:11 GMT", "version": "v2" }, { "created": "Thu, 15 Sep 2011 18:51:13 GMT", "version": "v3" } ]
2012-09-13
[ [ "Shchigolev", "V. K.", "" ] ]
In this paper, we consider a model of interacting phantom and Yang-Mills (YM) fields supposing the dilaton-type coupling. Making use of specific solution for YM equation previously found by the author, we obtain simple exact solutions for the accelerated expansion of FRW cosmological model. Besides, we derive the induced potentials of phantom field corresponding to some given regimes of expansion.The effective equation of state (EoS) have been reconstructed for all types of the models considered here.
2209.12552
Jan Tristram Acu\~na
Jan Tristram Acu\~na, Patrick Stengel, Piero Ullio
Neutron Star Heating in Dark Matter Models for Muon g-2 with Scalar Lepton Partners up to the TeV Scale
7 pages, 4 figures, 1 supplementary material
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the kinetic heating of neutron stars due to dark matter scattering in minimal models with scalar lepton partners mediating interactions which can account for the anomalous magnetic moment of the muon. In particular, such models in which the dark matter is a thermally produced Majorana fermion can be extremely difficult to detect at conventional searches. We demonstrate that future infrared observations of an old neutron star population could definitively probe the entire parameter space of this scenario.
[ { "created": "Mon, 26 Sep 2022 10:13:16 GMT", "version": "v1" } ]
2022-09-27
[ [ "Acuña", "Jan Tristram", "" ], [ "Stengel", "Patrick", "" ], [ "Ullio", "Piero", "" ] ]
We investigate the kinetic heating of neutron stars due to dark matter scattering in minimal models with scalar lepton partners mediating interactions which can account for the anomalous magnetic moment of the muon. In particular, such models in which the dark matter is a thermally produced Majorana fermion can be extremely difficult to detect at conventional searches. We demonstrate that future infrared observations of an old neutron star population could definitively probe the entire parameter space of this scenario.
hep-ph/9608325
Wolfgang Hollik
W. Hollik
Higgs mass prediction
10 pages, LaTex + 2 figures. Invited talk at the XI Topical Workshop on Proton-Antiproton Collider Physics, Abano Terme, May 26 - June 1, 1996. A few references have been added
null
null
KA-TP-19-1996
hep-ph
null
In this talk the Higgs boson effects in electroweak precision observables are reviewed and the possibility of indirect information on the Higgs mass from electroweak radiative corrections and precision data is discussed.
[ { "created": "Wed, 14 Aug 1996 18:30:45 GMT", "version": "v1" }, { "created": "Fri, 6 Sep 1996 16:31:00 GMT", "version": "v2" } ]
2008-02-03
[ [ "Hollik", "W.", "" ] ]
In this talk the Higgs boson effects in electroweak precision observables are reviewed and the possibility of indirect information on the Higgs mass from electroweak radiative corrections and precision data is discussed.
1508.04552
T. Lappi
T. Lappi and H. M\"antysaari
Solving the NLO BK equation in coordinate space
6 pages, 4 figures. Talk by T.L. at DIS 2015, Dallas, TX, April 2015
PoS(DIS2015)080
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present results from a numerical solution of the next-to-leading order (NLO) Balitsky-Kovchegov (BK) equation in coordinate space in the large Nc limit. We show that the solution is not stable for initial conditions that are close to those used in phenomenological applications of the leading order equation. We identify the problematic terms in the NLO kernel as being related to large logarithms of a small parent dipole size, and also show that rewriting the equation in terms of the "conformal dipole" does not remove the problem. Our results qualitatively agree with expectations based on the behavior of the linear NLO BFKL equation.
[ { "created": "Wed, 19 Aug 2015 07:44:53 GMT", "version": "v1" } ]
2016-01-19
[ [ "Lappi", "T.", "" ], [ "Mäntysaari", "H.", "" ] ]
We present results from a numerical solution of the next-to-leading order (NLO) Balitsky-Kovchegov (BK) equation in coordinate space in the large Nc limit. We show that the solution is not stable for initial conditions that are close to those used in phenomenological applications of the leading order equation. We identify the problematic terms in the NLO kernel as being related to large logarithms of a small parent dipole size, and also show that rewriting the equation in terms of the "conformal dipole" does not remove the problem. Our results qualitatively agree with expectations based on the behavior of the linear NLO BFKL equation.
2209.01233
Herzallah Alharazin
H. Alharazin, E. Epelbaum, J. Gegelia, U.-G. Mei{\ss}ner, B.-D. Sun
Gravitational form factors of the delta resonance in chiral EFT
arXiv admin note: text overlap with arXiv:2006.05890
null
null
null
hep-ph hep-ex hep-lat
http://creativecommons.org/licenses/by/4.0/
The leading one-loop corrections to the gravitational form factors of the delta resonance are calculated in the framework of chiral effective field theory. Various contributions to the energy-momentum tensor and the renormalization of the low-energy constants are worked out. Using the small scale expansion, expressions for static quantities are obtained and the real and imaginary parts of the gravitational form factors are calculated numerically.
[ { "created": "Fri, 2 Sep 2022 18:40:53 GMT", "version": "v1" }, { "created": "Mon, 3 Oct 2022 11:48:08 GMT", "version": "v2" } ]
2022-10-04
[ [ "Alharazin", "H.", "" ], [ "Epelbaum", "E.", "" ], [ "Gegelia", "J.", "" ], [ "Meißner", "U. -G.", "" ], [ "Sun", "B. -D.", "" ] ]
The leading one-loop corrections to the gravitational form factors of the delta resonance are calculated in the framework of chiral effective field theory. Various contributions to the energy-momentum tensor and the renormalization of the low-energy constants are worked out. Using the small scale expansion, expressions for static quantities are obtained and the real and imaginary parts of the gravitational form factors are calculated numerically.
1503.03931
Sangyong Jeon
Sangyong Jeon and Ulrich Heinz
Introduction to Hydrodynamics
Typos are corrected and some references are added. To be included in QGP 5 edited by Xin-Nian Wang
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We give a pedagogical review of relativistic hydrodynamics relevant to relativistic heavy ion collisions. Topics discussed include linear response theory derivation of 2nd order viscous hydrodynamics including the Kubo formulas, kinetic theory derivation of 2nd order viscous hydrodynamics, anisotropic hydrodynamics and a brief review of numerical algorithms. Emphasis is given to the theory of hydrodynamics rather than phenomenology.
[ { "created": "Fri, 13 Mar 2015 02:07:00 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 2015 18:10:43 GMT", "version": "v2" } ]
2015-07-22
[ [ "Jeon", "Sangyong", "" ], [ "Heinz", "Ulrich", "" ] ]
We give a pedagogical review of relativistic hydrodynamics relevant to relativistic heavy ion collisions. Topics discussed include linear response theory derivation of 2nd order viscous hydrodynamics including the Kubo formulas, kinetic theory derivation of 2nd order viscous hydrodynamics, anisotropic hydrodynamics and a brief review of numerical algorithms. Emphasis is given to the theory of hydrodynamics rather than phenomenology.
1603.04251
Jorge C. Romao
Jorge C. Rom\~ao
The need for the Higgs boson in the Standard Model
31 pages, 15 Figures in Postscript. Based on lectures given at IDPASC Schools in Udine (2012) and Braga (2014). The plots in Fig 9 were replaced with the indication of the cuts in the scattering angle
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the role of the Higgs boson in preserving unitarity of the scattering amplitudes in the Standard Model (SM). We will look at the processes $\nu_e + \bar{\nu}_e \rightarrow W^-_L +W^+_L $, $ W^-_L + W^+_L \rightarrow W^-_L +W^+_L $ and $e^- + e^+ \rightarrow W^-_L +W^+_L $ for longitudinally polarized gauge bosons. Special emphasis will be put in using algebraic methods to evaluate the amplitudes and cross sections. This note is based on Lectures given at the IDPASC Schools in Udine (2012) and Braga (2014).
[ { "created": "Mon, 14 Mar 2016 13:12:04 GMT", "version": "v1" }, { "created": "Thu, 26 Sep 2019 10:55:43 GMT", "version": "v2" } ]
2019-09-27
[ [ "Romão", "Jorge C.", "" ] ]
We review the role of the Higgs boson in preserving unitarity of the scattering amplitudes in the Standard Model (SM). We will look at the processes $\nu_e + \bar{\nu}_e \rightarrow W^-_L +W^+_L $, $ W^-_L + W^+_L \rightarrow W^-_L +W^+_L $ and $e^- + e^+ \rightarrow W^-_L +W^+_L $ for longitudinally polarized gauge bosons. Special emphasis will be put in using algebraic methods to evaluate the amplitudes and cross sections. This note is based on Lectures given at the IDPASC Schools in Udine (2012) and Braga (2014).
1802.04294
Alexander Fieguth
A.Fieguth, M.Hoferichter, P.Klos, J.Men\'endez, A.Schwenk, C.Weinheimer
Discriminating WIMP-nucleus response functions in present and future XENON-like direct detection experiments
10 pages, 7 figures
Phys. Rev. D 97, 103532 (2018)
10.1103/PhysRevD.97.103532
INT-PUB-18-006
hep-ph astro-ph.CO hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The standard interpretation of direct-detection limits on dark matter involves particular assumptions of the underlying WIMP-nucleus interaction, such as, in the simplest case, the choice of a Helm form factor that phenomenologically describes an isoscalar spin-independent interaction. In general, the interaction of dark matter with the target nuclei may well proceed via different mechanisms, which would lead to a different shape of the corresponding nuclear structure factors as a function of the momentum transfer $q$. We study to what extent different WIMP-nucleus responses can be differentiated based on the $q$-dependence of their structure factors (or "form factors"). We assume an overall strength of the interaction consistent with present spin-independent limits and consider an exposure corresponding to XENON1T-like, XENONnT-like, and DARWIN-like direct detection experiments. We find that, as long as the interaction strength does not lie too much below current limits, the DARWIN settings allow a conclusive discrimination of many different response functions based on their $q$-dependence, with immediate consequences for elucidating the nature of dark matter.
[ { "created": "Mon, 12 Feb 2018 19:00:28 GMT", "version": "v1" }, { "created": "Thu, 31 May 2018 17:27:14 GMT", "version": "v2" } ]
2018-06-06
[ [ "Fieguth", "A.", "" ], [ "Hoferichter", "M.", "" ], [ "Klos", "P.", "" ], [ "Menéndez", "J.", "" ], [ "Schwenk", "A.", "" ], [ "Weinheimer", "C.", "" ] ]
The standard interpretation of direct-detection limits on dark matter involves particular assumptions of the underlying WIMP-nucleus interaction, such as, in the simplest case, the choice of a Helm form factor that phenomenologically describes an isoscalar spin-independent interaction. In general, the interaction of dark matter with the target nuclei may well proceed via different mechanisms, which would lead to a different shape of the corresponding nuclear structure factors as a function of the momentum transfer $q$. We study to what extent different WIMP-nucleus responses can be differentiated based on the $q$-dependence of their structure factors (or "form factors"). We assume an overall strength of the interaction consistent with present spin-independent limits and consider an exposure corresponding to XENON1T-like, XENONnT-like, and DARWIN-like direct detection experiments. We find that, as long as the interaction strength does not lie too much below current limits, the DARWIN settings allow a conclusive discrimination of many different response functions based on their $q$-dependence, with immediate consequences for elucidating the nature of dark matter.
1304.6860
Malgorzata Worek
G. Bevilacqua, M. Czakon, M. Kr\"amer, M. Kubocz and M. Worek
Quantifying quark mass effects at the LHC: A study of pp -> b anti-b b anti-b + X at next-to-leading order
13 pages, 6 tables, 4 figures
JHEP 1307 (2013) 095
10.1007/JHEP07(2013)095
TTK-13-11
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of four bottom quarks is an important benchmark channel for Higgs analyses and searches for new physics at the LHC. We report on the calculation of the next-to-leading order QCD corrections to the process pp -> b anti-b b anti-b + X with the HELAC-NLO automated framework, and present results for inclusive cross sections and differential distributions. We discuss the impact of the higher-order corrections and, in particular, the effect of the bottom quark mass. In addition, we provide an estimate of the theoretical uncertainty from the variation of the renormalisation and factorisation scales and the parton distribution functions. The results are obtained with a new subtraction formalism for real radiation at next-to-leading order, implemented in the HELAC-DIPOLES package.
[ { "created": "Thu, 25 Apr 2013 10:19:58 GMT", "version": "v1" } ]
2013-07-23
[ [ "Bevilacqua", "G.", "" ], [ "Czakon", "M.", "" ], [ "Krämer", "M.", "" ], [ "Kubocz", "M.", "" ], [ "Worek", "M.", "" ] ]
The production of four bottom quarks is an important benchmark channel for Higgs analyses and searches for new physics at the LHC. We report on the calculation of the next-to-leading order QCD corrections to the process pp -> b anti-b b anti-b + X with the HELAC-NLO automated framework, and present results for inclusive cross sections and differential distributions. We discuss the impact of the higher-order corrections and, in particular, the effect of the bottom quark mass. In addition, we provide an estimate of the theoretical uncertainty from the variation of the renormalisation and factorisation scales and the parton distribution functions. The results are obtained with a new subtraction formalism for real radiation at next-to-leading order, implemented in the HELAC-DIPOLES package.
1209.6080
Peter Taylor
Adrian C. Ottewill and Peter Taylor
Quantum field theory on the Bertotti-Robinson space-time
15 pages, to be published in PRD
null
10.1103/PhysRevD.86.104067
null
gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of quantum field theory on the Bertotti-Robinson space-time, which arises naturally as the near horizon geometry of an extremal Reissner-Nordstrom black hole but can also arise in certain near-horizon limits of non-extremal Reissner Nordstrom space-time. The various vacuum states have been considered in the context of $AdS_{2}$ black holes by Spradlin and Strominger who showed that the Poincare vacuum, the Global vacuum and the Hartle-Hawking vacuum are all equivalent, while the Boulware vacuum and the Schwarzschild vacuum are equivalent. We verify this by explicitly computing the Green's functions in closed form for a massless scalar field corresponding to each of these vacua. Obtaining a closed form for the Green's function corresponding to the Boulware vacuum is non-trivial, we present it here for the first time by deriving a new summation formula for associated Legendre functions that allows us to perform the mode-sum. Having obtained the propagator for the Boulware vacuum, which is a zero-temperature Green's function, we can then consider the case of a scalar field at an arbitrary temperature by an infinite image imaginary-time sum, which yields the Hartle-Hawking propagator upon setting the temperature to the Hawking temperature. Finally, we compute the renormalized stress-energy tensor for a massless scalar field in the various quantum vacua.
[ { "created": "Wed, 26 Sep 2012 21:19:48 GMT", "version": "v1" } ]
2015-06-11
[ [ "Ottewill", "Adrian C.", "" ], [ "Taylor", "Peter", "" ] ]
We consider the problem of quantum field theory on the Bertotti-Robinson space-time, which arises naturally as the near horizon geometry of an extremal Reissner-Nordstrom black hole but can also arise in certain near-horizon limits of non-extremal Reissner Nordstrom space-time. The various vacuum states have been considered in the context of $AdS_{2}$ black holes by Spradlin and Strominger who showed that the Poincare vacuum, the Global vacuum and the Hartle-Hawking vacuum are all equivalent, while the Boulware vacuum and the Schwarzschild vacuum are equivalent. We verify this by explicitly computing the Green's functions in closed form for a massless scalar field corresponding to each of these vacua. Obtaining a closed form for the Green's function corresponding to the Boulware vacuum is non-trivial, we present it here for the first time by deriving a new summation formula for associated Legendre functions that allows us to perform the mode-sum. Having obtained the propagator for the Boulware vacuum, which is a zero-temperature Green's function, we can then consider the case of a scalar field at an arbitrary temperature by an infinite image imaginary-time sum, which yields the Hartle-Hawking propagator upon setting the temperature to the Hawking temperature. Finally, we compute the renormalized stress-energy tensor for a massless scalar field in the various quantum vacua.
2110.10126
Ayan Paul
Marco Ciuchini, Marco Fedele, Enrico Franco, Ayan Paul, Luca Silvestrini and Mauro Valli
Charming Penguins and Lepton Universality Violation in $b \to s \ell^+ \ell^-$ decays
21 pages, 7 figures, 3 tables, updated plots and tables
null
null
DESY 21-168, HU-EP-21/42, TTP21-040, P3H-21-077, YITP-SB-2021-20
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHCb experiment has very recently presented new results on Lepton Universality Violation (LUV) in $B \to K^{(*)} \ell^+ \ell^-$ decays involving $K_S$ in the final state, which strengthens the recent evidence of LUV obtained in $B^+ \to K^{+} \ell^+ \ell^-$ decays and the previous measurements of $B \to K^{*0} \ell^+ \ell^-$. While LUV observables in the Standard Model are theoretically clean, their predictions in New Physics scenarios are sensitive to the details of the hadronic dynamics, and in particular of the charming penguin contribution. In this work, we show how a conservative treatment of hadronic uncertainties is crucial not only to assess the significance of deviations from the Standard Model but also to obtain a conservative picture of the New Physics responsible for LUV. Adopting a very general parameterization of charming penguins, we find that: $i)$ current data hint at a sizable $q^2$ and helicity dependence of charm loop amplitudes; $ii)$ conservative NP solutions to $B$ anomalies favour a left-handed or an axial lepton coupling rather than a vector one.
[ { "created": "Tue, 19 Oct 2021 17:39:56 GMT", "version": "v1" }, { "created": "Thu, 9 Dec 2021 19:23:31 GMT", "version": "v2" }, { "created": "Mon, 19 Dec 2022 19:10:02 GMT", "version": "v3" } ]
2022-12-21
[ [ "Ciuchini", "Marco", "" ], [ "Fedele", "Marco", "" ], [ "Franco", "Enrico", "" ], [ "Paul", "Ayan", "" ], [ "Silvestrini", "Luca", "" ], [ "Valli", "Mauro", "" ] ]
The LHCb experiment has very recently presented new results on Lepton Universality Violation (LUV) in $B \to K^{(*)} \ell^+ \ell^-$ decays involving $K_S$ in the final state, which strengthens the recent evidence of LUV obtained in $B^+ \to K^{+} \ell^+ \ell^-$ decays and the previous measurements of $B \to K^{*0} \ell^+ \ell^-$. While LUV observables in the Standard Model are theoretically clean, their predictions in New Physics scenarios are sensitive to the details of the hadronic dynamics, and in particular of the charming penguin contribution. In this work, we show how a conservative treatment of hadronic uncertainties is crucial not only to assess the significance of deviations from the Standard Model but also to obtain a conservative picture of the New Physics responsible for LUV. Adopting a very general parameterization of charming penguins, we find that: $i)$ current data hint at a sizable $q^2$ and helicity dependence of charm loop amplitudes; $ii)$ conservative NP solutions to $B$ anomalies favour a left-handed or an axial lepton coupling rather than a vector one.
1803.07045
Thomas Becher
Marcel Balsiger, Thomas Becher, Ding Yu Shao
Non-global logarithms in jet and isolation cone cross sections
39 pages, 13 figures. v2: journal version with new result (4.18) for narrow isolation cones
null
10.1007/JHEP08(2018)104
CERN-TH-2018-187
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Starting from a factorization theorem in effective field theory, we derive a parton-shower equation for the resummation of non-global logarithms. We have implemented this shower and interfaced it with a tree-level event generator to obtain an automated framework to resum the leading logarithm of non-global observables in the large-$N_c$ limit. Using this setup, we compute gap fractions for dijet processes and isolation cone cross sections relevant for photon production. We compare our results with fixed-order computations and LHC measurements. We find that naive exponentiation is often not adequate, especially when the vetoed region is small, since non-global contributions are enhanced due to their dependence on the veto-region size. Since our parton shower is derived from first principles and based on renormalization-group evolution, it is clear what ingredients will have to be included to perform resummations at subleading logarithmic accuracy in the future.
[ { "created": "Mon, 19 Mar 2018 17:18:24 GMT", "version": "v1" }, { "created": "Wed, 15 Aug 2018 12:02:17 GMT", "version": "v2" } ]
2018-09-26
[ [ "Balsiger", "Marcel", "" ], [ "Becher", "Thomas", "" ], [ "Shao", "Ding Yu", "" ] ]
Starting from a factorization theorem in effective field theory, we derive a parton-shower equation for the resummation of non-global logarithms. We have implemented this shower and interfaced it with a tree-level event generator to obtain an automated framework to resum the leading logarithm of non-global observables in the large-$N_c$ limit. Using this setup, we compute gap fractions for dijet processes and isolation cone cross sections relevant for photon production. We compare our results with fixed-order computations and LHC measurements. We find that naive exponentiation is often not adequate, especially when the vetoed region is small, since non-global contributions are enhanced due to their dependence on the veto-region size. Since our parton shower is derived from first principles and based on renormalization-group evolution, it is clear what ingredients will have to be included to perform resummations at subleading logarithmic accuracy in the future.
2203.12289
Vadim Guzey
L. Frankfurt (Tel Aviv U. and Penn State U.), V. Guzey (St. Petersburg, INP), A. Stasto (Penn State U.), M. Strikman (Penn State U.)
Selected topics in diffraction with protons and nuclei: past, present, and future
128 pages, 55 figures. Review prepared for and submitted to Reports on Progress in Physics
null
10.1088/1361-6633/ac8228
null
hep-ph hep-ex nucl-ex
http://creativecommons.org/licenses/by/4.0/
We review a broad range of phenomena in diffraction in the context of hadron-hadron, hadron-nucleus collisions and deep inelastic lepton-proton/nucleus scattering focusing on the interplay between the perturbative QCD and non-perturbative models. We discuss inclusive diffraction in DIS, phenomenology of dipole models, resummation and parton saturation at low $x$, hard diffractive production of vector mesons, inelastic diffraction in hadron-hadron scattering, formalism of color fluctuations, inclusive coherent and incoherent diffraction as well as soft and hard diffraction phenomena in hadron-hadron/nucleus and photon-nucleus collisions. For each topic we review key results from the past and present experiments including HERA and the LHC. Finally, we identify the remaining open questions, which could be addressed in the continuing experiments, in particular in photon-induced reactions at the LHC and the future Electron-Ion Collider (EIC) in the US, Large Hadron electron Collider (LHeC) and Future Circular Collider (FCC) at CERN.
[ { "created": "Wed, 23 Mar 2022 09:19:20 GMT", "version": "v1" } ]
2022-11-23
[ [ "Frankfurt", "L.", "", "Tel Aviv U. and Penn State U." ], [ "Guzey", "V.", "", "St.\n Petersburg, INP" ], [ "Stasto", "A.", "", "Penn State U." ], [ "Strikman", "M.", "", "Penn State U." ] ]
We review a broad range of phenomena in diffraction in the context of hadron-hadron, hadron-nucleus collisions and deep inelastic lepton-proton/nucleus scattering focusing on the interplay between the perturbative QCD and non-perturbative models. We discuss inclusive diffraction in DIS, phenomenology of dipole models, resummation and parton saturation at low $x$, hard diffractive production of vector mesons, inelastic diffraction in hadron-hadron scattering, formalism of color fluctuations, inclusive coherent and incoherent diffraction as well as soft and hard diffraction phenomena in hadron-hadron/nucleus and photon-nucleus collisions. For each topic we review key results from the past and present experiments including HERA and the LHC. Finally, we identify the remaining open questions, which could be addressed in the continuing experiments, in particular in photon-induced reactions at the LHC and the future Electron-Ion Collider (EIC) in the US, Large Hadron electron Collider (LHeC) and Future Circular Collider (FCC) at CERN.
1006.1710
Dharam Vir Ahluwalia
D. V. Ahluwalia, S. P. Horvath
Muon lifetime dependent effects in MiniBooNE and LSND
MiniBoone's arXiv:1805.12028 has created a situation that requires an ab initio analysis of all the relevant data. In this eight year old e-print, precisely such a situation was anticipated. It was argued that incorporating quantum entanglement in the neutrino oscillation phenomenology has the potential to re-interpret the relevant data without invoking a fourth mass eigenstate
null
null
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that because the source-detector distance of 1.8 microseconds (in natural units) for the MiniBooNE is comparable to the muon lifetime of 2.2 microseconds, and because time dilation effects are wiped out in the beam stop, the Goldman entanglement of the neutrinos leads to hitherto unsuspected interpretational consequences. We show that a distinct possibility exists in which a LSND-like experiment sees no CP violation, whereas a MiniBooNE-like setup reproduces the LSND results for the $\bar\nu_\mu$ to $\bar\nu_e$ oscillations while seeing only a significantly suppressed signal for the $\nu_\mu$ to $\nu_e$ oscillations. We also discuss an alternate scenario. This also suggests that the LSND experiment and the MiniBooNE should not be compared without taking into account the Goldman entanglement.
[ { "created": "Wed, 9 Jun 2010 06:28:35 GMT", "version": "v1" }, { "created": "Sat, 12 Jun 2010 09:00:12 GMT", "version": "v2" }, { "created": "Fri, 1 Jun 2018 01:57:04 GMT", "version": "v3" } ]
2018-06-04
[ [ "Ahluwalia", "D. V.", "" ], [ "Horvath", "S. P.", "" ] ]
We argue that because the source-detector distance of 1.8 microseconds (in natural units) for the MiniBooNE is comparable to the muon lifetime of 2.2 microseconds, and because time dilation effects are wiped out in the beam stop, the Goldman entanglement of the neutrinos leads to hitherto unsuspected interpretational consequences. We show that a distinct possibility exists in which a LSND-like experiment sees no CP violation, whereas a MiniBooNE-like setup reproduces the LSND results for the $\bar\nu_\mu$ to $\bar\nu_e$ oscillations while seeing only a significantly suppressed signal for the $\nu_\mu$ to $\nu_e$ oscillations. We also discuss an alternate scenario. This also suggests that the LSND experiment and the MiniBooNE should not be compared without taking into account the Goldman entanglement.
hep-ph/9410322
Dr F. Caravaglios
F.Caravaglios and G.G.Ross
Reconciling the LEP and Slac Measurements of Sin^2(\Theta_W)
8 pages , CERN-TH.7474/94, OUTP9424P
Phys.Lett. B346 (1995) 159-164
10.1016/0370-2693(94)01628-P
null
hep-ph
null
We consider whether a discrepancy between the SLAC and LEP measurements of $\Sw$ can be explained by new physics. We find that only the contribution of a new neutral gauge boson, $Z^\prime$, nearly degenerate with the Z can affect the SLAC measurement while leaving the LEP observables almost unaffected. We briefly discuss possible signals for this new gauge boson, including changes in the $Z$ lineshape when measured with polarised electrons, small changes in $R_b$, $A^e_{FB}$, and larger changes in two jet and $t\bar{t}$ production at hadron colliders.
[ { "created": "Wed, 19 Oct 1994 17:50:46 GMT", "version": "v1" } ]
2009-10-28
[ [ "Caravaglios", "F.", "" ], [ "Ross", "G. G.", "" ] ]
We consider whether a discrepancy between the SLAC and LEP measurements of $\Sw$ can be explained by new physics. We find that only the contribution of a new neutral gauge boson, $Z^\prime$, nearly degenerate with the Z can affect the SLAC measurement while leaving the LEP observables almost unaffected. We briefly discuss possible signals for this new gauge boson, including changes in the $Z$ lineshape when measured with polarised electrons, small changes in $R_b$, $A^e_{FB}$, and larger changes in two jet and $t\bar{t}$ production at hadron colliders.
0709.1603
Jose Geraldo Pereira
R. Aldrovandi, J. G. Pereira, K. H. Vu
The Nonlinear Essence of Gravitational Waves
Plain Latex, 13 pages, no figures. Accepted for publication in Foundations of Physiscs
Found.Phys.37:1503-1517,2007
10.1007/s10701-007-9180-2
null
gr-qc hep-th
null
A critical review of gravitational wave theory is made. It is pointed out that the usual linear approach to the gravitational wave theory is neither conceptually consistent nor mathematically justified. Relying upon that analysis it is then argued that -- analogously to a Yang-Mills propagating field, which must be nonlinear to carry its gauge charge -- a gravitational wave must necessarily be nonlinear to transport its own charge -- that is, energy-momentum.
[ { "created": "Tue, 11 Sep 2007 12:33:40 GMT", "version": "v1" } ]
2008-11-26
[ [ "Aldrovandi", "R.", "" ], [ "Pereira", "J. G.", "" ], [ "Vu", "K. H.", "" ] ]
A critical review of gravitational wave theory is made. It is pointed out that the usual linear approach to the gravitational wave theory is neither conceptually consistent nor mathematically justified. Relying upon that analysis it is then argued that -- analogously to a Yang-Mills propagating field, which must be nonlinear to carry its gauge charge -- a gravitational wave must necessarily be nonlinear to transport its own charge -- that is, energy-momentum.
1802.07048
Jielei Zhang
Jielei Zhang, Rumin Wang
Search for vector charmonium(-like) states in the $e^+e^- \rightarrow \eta J/\psi$ line shape
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The cross section of $e^+e^- \rightarrow \eta J/\psi$ has been measured by BESIII and Belle experiments. Fit to the $e^+e^- \rightarrow \eta J/\psi$ line shape, three resonant structures are evident. The parameters for the three resonant structures are $M_{1}=(3980\pm17\pm7)$ MeV/$c^{2}$, $\Gamma_{1}=(104\pm32\pm13)$ MeV; $M_{2}=(4219\pm5\pm4)$ MeV/$c^{2}$, $\Gamma_{2}=(63\pm9\pm3)$ MeV; $M_{3}=(4401\pm12\pm4)$ MeV/$c^{2}$, $\Gamma_{3}=(49\pm19\pm4)$ MeV, where the first uncertainties are statistical and the second systematic. We attribute the three structures to $\psi(4040)$, $Y(4220)$ and $\psi(4415)$ states. The branching fractions $\mathcal{B}(\psi(4040) \rightarrow \eta J/\psi)$ and $\mathcal{B}(\psi(4415) \rightarrow \eta J/\psi)$ are given. If $Y(4220)$ is taken as $\psi(4S)$ state, the branching fraction $\mathcal{B}(\psi(4S) \rightarrow \eta J/\psi)$ is also given. Combining all $Y(4220)$ parameters obtained from different decays, we give average parameters for $Y(4220)$, which are $M_{Y(4220)}=(4220.8\pm2.4)$ MeV/$c^{2}$, $\Gamma_{Y(4220)}=(54.8\pm3.3)$ MeV.
[ { "created": "Tue, 20 Feb 2018 10:30:46 GMT", "version": "v1" }, { "created": "Wed, 2 May 2018 11:37:09 GMT", "version": "v2" } ]
2018-05-03
[ [ "Zhang", "Jielei", "" ], [ "Wang", "Rumin", "" ] ]
The cross section of $e^+e^- \rightarrow \eta J/\psi$ has been measured by BESIII and Belle experiments. Fit to the $e^+e^- \rightarrow \eta J/\psi$ line shape, three resonant structures are evident. The parameters for the three resonant structures are $M_{1}=(3980\pm17\pm7)$ MeV/$c^{2}$, $\Gamma_{1}=(104\pm32\pm13)$ MeV; $M_{2}=(4219\pm5\pm4)$ MeV/$c^{2}$, $\Gamma_{2}=(63\pm9\pm3)$ MeV; $M_{3}=(4401\pm12\pm4)$ MeV/$c^{2}$, $\Gamma_{3}=(49\pm19\pm4)$ MeV, where the first uncertainties are statistical and the second systematic. We attribute the three structures to $\psi(4040)$, $Y(4220)$ and $\psi(4415)$ states. The branching fractions $\mathcal{B}(\psi(4040) \rightarrow \eta J/\psi)$ and $\mathcal{B}(\psi(4415) \rightarrow \eta J/\psi)$ are given. If $Y(4220)$ is taken as $\psi(4S)$ state, the branching fraction $\mathcal{B}(\psi(4S) \rightarrow \eta J/\psi)$ is also given. Combining all $Y(4220)$ parameters obtained from different decays, we give average parameters for $Y(4220)$, which are $M_{Y(4220)}=(4220.8\pm2.4)$ MeV/$c^{2}$, $\Gamma_{Y(4220)}=(54.8\pm3.3)$ MeV.
1001.2395
Otakar Svitek
Otakar Svitek
Existence of horizons in Robinson-Trautman spacetimes of arbitrary dimension
to appear in proceedings of MGM12 Paris, France
null
10.1142/9789814374552_0136
null
gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive the higher dimensional generalization of Penrose-Tod equation describing past horizon in Robinson-Trautman spacetimes with a cosmological constant and pure radiation. Results for D=4 dimensions are summarized. Existence of its solutions in D>4 dimensions is proved using tools for nonlinear elliptic partial differential equations.
[ { "created": "Thu, 14 Jan 2010 10:11:49 GMT", "version": "v1" } ]
2016-11-15
[ [ "Svitek", "Otakar", "" ] ]
We derive the higher dimensional generalization of Penrose-Tod equation describing past horizon in Robinson-Trautman spacetimes with a cosmological constant and pure radiation. Results for D=4 dimensions are summarized. Existence of its solutions in D>4 dimensions is proved using tools for nonlinear elliptic partial differential equations.
1707.09749
Bartosz Fornal
Bartosz Fornal
Is There a Sign of New Physics in Beryllium Transitions?
19 pages + references, 10 figures; Invited talk given at the American Physical Society April Meeting 2017, Washington, DC, January 28, 2017; based mainly on arXiv:1604.07411 [hep-ph] and arXiv:1608.03591 [hep-ph]
Int. J. Mod. Phys. A 32 (2017) 1730020
10.1142/S0217751X17300204
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the current status of the anomaly in beryllium-8 nuclear transitions recently reported in the angular distribution of internal conversion electron-positron pairs. We present a phenomenological analysis of the signal and review the models proposed to explain it, focusing on those involving a new light protophobic vector gauge boson. We also elaborate on the prospects of verifying the anomaly in present and future experiments.
[ { "created": "Mon, 31 Jul 2017 08:02:35 GMT", "version": "v1" } ]
2017-08-28
[ [ "Fornal", "Bartosz", "" ] ]
We discuss the current status of the anomaly in beryllium-8 nuclear transitions recently reported in the angular distribution of internal conversion electron-positron pairs. We present a phenomenological analysis of the signal and review the models proposed to explain it, focusing on those involving a new light protophobic vector gauge boson. We also elaborate on the prospects of verifying the anomaly in present and future experiments.
2111.13099
Katsuya Hashino
Katsuya Hashino, Shinya Kanemura and Tomo Takahashi
Primordial black holes as a probe of strongly first-order electroweak phase transition
14 pages, 2 figures. Version accepted by Physics Letters B
null
10.1016/j.physletb.2022.137261
OU-HET-1123
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Primordial black holes can be produced by density fluctuations generated from delayed vacuum decays of first-order phase transition. The primordial black holes generated at the electroweak phase transition have masses of about $10^{-5}$ solar mass. Such primordial black holes in the mass range can be tested by current and future microlensing observations, such as Subaru HSC, OGLE, PRIME and Roman telescope. Therefore, we may be able to explore new physics models with strongly first-order electroweak phase transition via primordial black holes. We examine this possibility by using models with first-order electroweak phase transition in the standard model effective field theory with dimension 6 and 8 operators. We find that depending on parameters of the phase transition a sufficient number of primordial black holes can be produced to be observed by above mentioned experiments. Our results would suggest that primordial black holes can be used as a new probe of models with strongly first-order electroweak phase transition, which has complementarity with measurements of the triple Higgs boson coupling at future collider experiments and observations of gravitational waves at future space-based interferometers.
[ { "created": "Thu, 25 Nov 2021 14:27:21 GMT", "version": "v1" }, { "created": "Wed, 22 Jun 2022 07:03:03 GMT", "version": "v2" } ]
2022-07-27
[ [ "Hashino", "Katsuya", "" ], [ "Kanemura", "Shinya", "" ], [ "Takahashi", "Tomo", "" ] ]
Primordial black holes can be produced by density fluctuations generated from delayed vacuum decays of first-order phase transition. The primordial black holes generated at the electroweak phase transition have masses of about $10^{-5}$ solar mass. Such primordial black holes in the mass range can be tested by current and future microlensing observations, such as Subaru HSC, OGLE, PRIME and Roman telescope. Therefore, we may be able to explore new physics models with strongly first-order electroweak phase transition via primordial black holes. We examine this possibility by using models with first-order electroweak phase transition in the standard model effective field theory with dimension 6 and 8 operators. We find that depending on parameters of the phase transition a sufficient number of primordial black holes can be produced to be observed by above mentioned experiments. Our results would suggest that primordial black holes can be used as a new probe of models with strongly first-order electroweak phase transition, which has complementarity with measurements of the triple Higgs boson coupling at future collider experiments and observations of gravitational waves at future space-based interferometers.
hep-ph/9905338
Benjamin Tseng
B. Tseng, Cheng-Wei Chiang
Charmless Hardronic Decays $B_u \to V V $: Angular Distributions, Direct CP Violation and Determination of the Unitary Triangle
14 pages, Latex
null
null
null
hep-ph
null
Two-body charmless nonleptonic decays of $B_u \to V V$ are studied within the generalized factorization approach using a recent calculation of the effective Wilson coefficients $c^{eff}_i$, which are not only renormalization-scale and -scheme independent but also gauge invariant and infrared finite. After making a universal ansatz for the nonfactorizable contributions, we parametrize these effects in terms of $N_c^{eff}(LL)$ and $N_c^{eff}(LR)$, the effective numbers of colors arising from $(V-A)(V-A)$ and $(V-A)(V+A)$ four-quark operators, respectively. Three different schemes for these contributions are considered: (i) the naive factorization, (ii) the large-N_c improved factorization, and (iii) our preferred choice: $(N_c^{eff}(LL), N_c^{eff}(RR))=(2,5)$. We present the full angular distribution of all charmless $B_u \to V V$ decays in both transversity and helicity frames.Direct CP violation in these normalized angular correlation coefficients is not negligible in $B^-_u \to K^{*-} \rho^0, K^{*-} \omega$, and direct CP violation in the partial rate difference for $B^-_u \to K^{*-} \omega, K^{*-} \rho$ and $\rho^- \omega$ can be as large as 45%, 25%, -10%, respectively. Due to the sizable QCD penguin contributions in $\rho^- \omega$, the determination of the unitary triangle $\alpha$ via this decay mode is more promising than via $\rho^- \rho^0$. It is also encouraging to determine the unitary triangle $\gamma$ through $B^-_u \to K^{*-} \rho$ because of $N_c$-insensitivity and the not-so-small tree contribution. The impacts of a negative $\rho$ on the branching ratios and CP violation are studied. We also comment on the theoretical uncertainties and their possible impacts.
[ { "created": "Fri, 14 May 1999 05:56:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tseng", "B.", "" ], [ "Chiang", "Cheng-Wei", "" ] ]
Two-body charmless nonleptonic decays of $B_u \to V V$ are studied within the generalized factorization approach using a recent calculation of the effective Wilson coefficients $c^{eff}_i$, which are not only renormalization-scale and -scheme independent but also gauge invariant and infrared finite. After making a universal ansatz for the nonfactorizable contributions, we parametrize these effects in terms of $N_c^{eff}(LL)$ and $N_c^{eff}(LR)$, the effective numbers of colors arising from $(V-A)(V-A)$ and $(V-A)(V+A)$ four-quark operators, respectively. Three different schemes for these contributions are considered: (i) the naive factorization, (ii) the large-N_c improved factorization, and (iii) our preferred choice: $(N_c^{eff}(LL), N_c^{eff}(RR))=(2,5)$. We present the full angular distribution of all charmless $B_u \to V V$ decays in both transversity and helicity frames.Direct CP violation in these normalized angular correlation coefficients is not negligible in $B^-_u \to K^{*-} \rho^0, K^{*-} \omega$, and direct CP violation in the partial rate difference for $B^-_u \to K^{*-} \omega, K^{*-} \rho$ and $\rho^- \omega$ can be as large as 45%, 25%, -10%, respectively. Due to the sizable QCD penguin contributions in $\rho^- \omega$, the determination of the unitary triangle $\alpha$ via this decay mode is more promising than via $\rho^- \rho^0$. It is also encouraging to determine the unitary triangle $\gamma$ through $B^-_u \to K^{*-} \rho$ because of $N_c$-insensitivity and the not-so-small tree contribution. The impacts of a negative $\rho$ on the branching ratios and CP violation are studied. We also comment on the theoretical uncertainties and their possible impacts.