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1012.4642
Julio Marny Hoff da Silva
M. Dias, F. de Campos, and J. M. Hoff da Silva
Exploring Elko typical signature
17 pages, 10 figures, final (and extended) version. Accepted for publication in PLB
Physics Letters B, 706 (2012) 352
10.1016/j.physletb.2011.11.030
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the prospects of observing the presence of a relatively light Elko particle as a possible dark matter candidate, by pointing out a typical signature for the process encompassing the Elko non-locality, exploring some consequences of the unusual Elko propagator behavior when analyzed outside the Elko axis of propagation. We also consider the production of a light Elko associated to missing energy and isolated leptons at the LHC, with center of mass energy of 7 and 14 TeV and total luminosity from $1 fb^{-1}$ to $10 fb^{-1}$. Basically, the Elko non locality engenders a peculiar signal in the missing energy turning it sensible to the angle of detection.
[ { "created": "Tue, 21 Dec 2010 13:07:16 GMT", "version": "v1" }, { "created": "Mon, 11 Apr 2011 14:25:48 GMT", "version": "v2" }, { "created": "Thu, 17 Nov 2011 17:26:54 GMT", "version": "v3" } ]
2015-03-17
[ [ "Dias", "M.", "" ], [ "de Campos", "F.", "" ], [ "da Silva", "J. M. Hoff", "" ] ]
We study the prospects of observing the presence of a relatively light Elko particle as a possible dark matter candidate, by pointing out a typical signature for the process encompassing the Elko non-locality, exploring some consequences of the unusual Elko propagator behavior when analyzed outside the Elko axis of propagation. We also consider the production of a light Elko associated to missing energy and isolated leptons at the LHC, with center of mass energy of 7 and 14 TeV and total luminosity from $1 fb^{-1}$ to $10 fb^{-1}$. Basically, the Elko non locality engenders a peculiar signal in the missing energy turning it sensible to the angle of detection.
hep-ph/9505380
null
Michael Kr\"amer
Photoproduction of Heavy Quarks
7 pages, latex, 2 figures appended as uuencoded file (hardcopy can be obtained upon request from mkraemer@desy.de). Talk presented at the Conference "Photon '95", Sheffield, UK, April 8-13, 1995; to appear in the proceedings
null
null
null
hep-ph
null
Heavy quarks are copiously produced in two-photon collisions at $e^+e^-$ colliders. The theoretical predictions including QCD radiative corrections are compared to recent experimental data on $\gamma\gamma$ production of charm quarks at PETRA, PEP, TRISTAN and LEP. Photoproduction of heavy quarks at HERA is an important tool to measure the gluon distribution in the proton. New theoretical results on heavy quark photoproduction at large transverse momenta are discussed and NLO predictions for inelastic $J/\psi$ photoproduction in the HERA energy range are given. The sensitivity of the results to the parametrization of the gluon distribution in the small-$x$ region is demonstrated.
[ { "created": "Thu, 25 May 1995 10:48:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Krämer", "Michael", "" ] ]
Heavy quarks are copiously produced in two-photon collisions at $e^+e^-$ colliders. The theoretical predictions including QCD radiative corrections are compared to recent experimental data on $\gamma\gamma$ production of charm quarks at PETRA, PEP, TRISTAN and LEP. Photoproduction of heavy quarks at HERA is an important tool to measure the gluon distribution in the proton. New theoretical results on heavy quark photoproduction at large transverse momenta are discussed and NLO predictions for inelastic $J/\psi$ photoproduction in the HERA energy range are given. The sensitivity of the results to the parametrization of the gluon distribution in the small-$x$ region is demonstrated.
1204.2929
Liliana Apolin\'ario
Liliana Apolin\'ario, N\'estor Armesto, Carlos A. Salgado
Medium-induced emissions of hard gluons
17 pages, 6 figures. Minor corrections, references updated. Accepted by Phys. Lett. B
Phys. Lett. B718 (2012), 160-168
10.1016/j.physletb.2012.10.040
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a derivation of the medium-induced gluon radiation spectrum beyond the current limitation of soft gluon emission. Making use of the path integral approach to describe the propagation of high-energy particles inside a medium, we study the limiting case of a hard gluon emission. Analytical and numerical results are presented and discussed within the multiple soft scattering approximation. An ansatz interpolating between soft and hard gluon emissions is provided. The Landau-Pomeranchuk-Migdal effect is observed in the expected kinematic region.
[ { "created": "Fri, 13 Apr 2012 09:19:32 GMT", "version": "v1" }, { "created": "Thu, 18 Oct 2012 17:35:00 GMT", "version": "v2" } ]
2012-11-08
[ [ "Apolinário", "Liliana", "" ], [ "Armesto", "Néstor", "" ], [ "Salgado", "Carlos A.", "" ] ]
We present a derivation of the medium-induced gluon radiation spectrum beyond the current limitation of soft gluon emission. Making use of the path integral approach to describe the propagation of high-energy particles inside a medium, we study the limiting case of a hard gluon emission. Analytical and numerical results are presented and discussed within the multiple soft scattering approximation. An ansatz interpolating between soft and hard gluon emissions is provided. The Landau-Pomeranchuk-Migdal effect is observed in the expected kinematic region.
hep-ph/0612126
Thomas Flacke
Thomas Flacke and David Maybury
Aspects of Axion Phenomenology in a slice of AdS_5
25 pages, 9 figures
JHEP 0703:007,2007
10.1088/1126-6708/2007/03/007
OUTP-06 17 P
hep-ph
null
Motivated by multi-throat considerations, we study the phenomenological implications of a bulk axion in a slice of AdS_5 with a large extra dimension: k~0.01 eV, kR > 1. In particular, we compare axion physics with a warped geometry to axions in flat compactifications. As in flat compactification scenarios, we find that the mass of the axion can become independent from the underlying Peccei-Quinn scale. Surprisingly, we find that in warped extra dimensions the axion's invisibility, cosmological viability, and basic phenomenology remain essentially unaltered in comparison to axions in flat compactifications.
[ { "created": "Mon, 11 Dec 2006 15:19:16 GMT", "version": "v1" } ]
2010-10-27
[ [ "Flacke", "Thomas", "" ], [ "Maybury", "David", "" ] ]
Motivated by multi-throat considerations, we study the phenomenological implications of a bulk axion in a slice of AdS_5 with a large extra dimension: k~0.01 eV, kR > 1. In particular, we compare axion physics with a warped geometry to axions in flat compactifications. As in flat compactification scenarios, we find that the mass of the axion can become independent from the underlying Peccei-Quinn scale. Surprisingly, we find that in warped extra dimensions the axion's invisibility, cosmological viability, and basic phenomenology remain essentially unaltered in comparison to axions in flat compactifications.
2210.03247
Merna Ibrahim Ms.
Merna Ibrahim, Mustafa Ashry, Esraa Elkhateeb, Adel M.Awad and Ahmad Moursy
Modified hybrid inflation, reheating and stabilization of the electroweak vacuum
24 pages, 5 figures, 3 tables
Phys. Rev. D 107, 035023 (2023)
10.1103/PhysRevD.107.035023
null
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We propose a modification to the standard hybrid inflation model \cite{Linde:1993cn}, that connects a successful hybrid inflation scenario to the standard model Higgs sector, via the electroweak vacuum stability. The proposed model results in an effective inflation potential of a hilltop-type, with both the trans-Planckian and sub-Planckian inflation regimes consistent with the recent Planck/BICEP combined results. Reheating via the inflation sector decays to right-handed neutrinos is considered. An upper bound on the reheating temperature $T_{\rm R} \lsim 2\times 10^{11}~(1\times 10^{13})$ GeV, for large~(small) field inflation, will suppress contributions from one-loop quantum corrections to the inflation potential. This may push the neutrino Yukawa couplings to be ${\cal O}(1)$ and affect the vacuum stability. We show that the couplings of the SM Higgs to the inflation sector can guarantee the electroweak vacuum stability up to the Planck scale. The so-called hybrid Higgs-inflaton model leads to a positive correction for the Higgs quartic coupling at a threshold scale, which is shown to have a very significant effect in stabilizing the electroweak vacuum. We find that even with ${\cal O}(1)$ neutrino Yukawa couplings, threshold corrections leave the SM vacuum stability intact.
[ { "created": "Thu, 6 Oct 2022 23:19:34 GMT", "version": "v1" }, { "created": "Tue, 7 Feb 2023 15:40:40 GMT", "version": "v2" }, { "created": "Wed, 22 Feb 2023 13:31:31 GMT", "version": "v3" } ]
2023-02-23
[ [ "Ibrahim", "Merna", "" ], [ "Ashry", "Mustafa", "" ], [ "Elkhateeb", "Esraa", "" ], [ "Awad", "Adel M.", "" ], [ "Moursy", "Ahmad", "" ] ]
We propose a modification to the standard hybrid inflation model \cite{Linde:1993cn}, that connects a successful hybrid inflation scenario to the standard model Higgs sector, via the electroweak vacuum stability. The proposed model results in an effective inflation potential of a hilltop-type, with both the trans-Planckian and sub-Planckian inflation regimes consistent with the recent Planck/BICEP combined results. Reheating via the inflation sector decays to right-handed neutrinos is considered. An upper bound on the reheating temperature $T_{\rm R} \lsim 2\times 10^{11}~(1\times 10^{13})$ GeV, for large~(small) field inflation, will suppress contributions from one-loop quantum corrections to the inflation potential. This may push the neutrino Yukawa couplings to be ${\cal O}(1)$ and affect the vacuum stability. We show that the couplings of the SM Higgs to the inflation sector can guarantee the electroweak vacuum stability up to the Planck scale. The so-called hybrid Higgs-inflaton model leads to a positive correction for the Higgs quartic coupling at a threshold scale, which is shown to have a very significant effect in stabilizing the electroweak vacuum. We find that even with ${\cal O}(1)$ neutrino Yukawa couplings, threshold corrections leave the SM vacuum stability intact.
hep-ph/0503292
Kai Hencken
Kai Hencken (1), Gerhard Baur (2), Ute Dreyer (1), Dirk Trautmann (1) ((1) Universitaet Basel, (2) Forschungszentrum Juelich)
Ultraperipheral Collisions
12 pages, Talk presented at "Physics at LHC", Vienna, Austria, July 13-17, 2004. To be published in Czechoslovak Journal of Physics
Czech.J.Phys.55:B693-B704,2005
null
null
hep-ph
null
Ultraperipheral collisions at heavy ion colliders use the strong Coulomb fields surrounding the ions to study photon-photon and photon-hadron processes at high energy. A number of processes of interest are discussed here.
[ { "created": "Thu, 31 Mar 2005 09:23:15 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hencken", "Kai", "", "Universitaet Basel" ], [ "Baur", "Gerhard", "", "Forschungszentrum Juelich" ], [ "Dreyer", "Ute", "", "Universitaet Basel" ], [ "Trautmann", "Dirk", "", "Universitaet Basel" ] ]
Ultraperipheral collisions at heavy ion colliders use the strong Coulomb fields surrounding the ions to study photon-photon and photon-hadron processes at high energy. A number of processes of interest are discussed here.
1809.08181
Kirill Tuchin
Kirill Tuchin
Chiral Cherenkov and chiral transition radiation in anisotropic matter
13 pages, 6 figures
Phys. Rev. D 98, 114026 (2018)
10.1103/PhysRevD.98.114026
null
hep-ph cond-mat.mes-hall nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A significant contribution to the electromagnetic radiation by a fast electric charge moving in anisotropic chiral matter arises from spontaneous photon radiation due to the chiral anomaly. While such a process, also known as the "vacuum Cherenkov radiation", is forbidden in the QED vacuum, it can occur in chiral matter, where it is more appropriate to call it the "chiral Cherenkov radiation". Its contribution to the radiation spectrum is of order $\alpha^2$ compared to $\alpha^3$ of the bremsstrahlung. I derive the frequency spectrum and the angular distribution of this radiation in the high energy limit. The quantum effects due to the hard photon emission and the fermion mass are taken into account. The obtained spectra are analyzed in the case the quark-gluon plasma and a Weyl semimetal.
[ { "created": "Fri, 21 Sep 2018 16:01:35 GMT", "version": "v1" } ]
2018-12-26
[ [ "Tuchin", "Kirill", "" ] ]
A significant contribution to the electromagnetic radiation by a fast electric charge moving in anisotropic chiral matter arises from spontaneous photon radiation due to the chiral anomaly. While such a process, also known as the "vacuum Cherenkov radiation", is forbidden in the QED vacuum, it can occur in chiral matter, where it is more appropriate to call it the "chiral Cherenkov radiation". Its contribution to the radiation spectrum is of order $\alpha^2$ compared to $\alpha^3$ of the bremsstrahlung. I derive the frequency spectrum and the angular distribution of this radiation in the high energy limit. The quantum effects due to the hard photon emission and the fermion mass are taken into account. The obtained spectra are analyzed in the case the quark-gluon plasma and a Weyl semimetal.
2111.13620
Shuai Liu
Shuai Y. F. Liu and Ralf Rapp
Heavy-Light Susceptibilities in a Strongly Coupled Quark-Gluon Plasma
6 pages, 4 figures
null
10.1103/PhysRevC.106.055201
null
hep-ph hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quark number susceptibilities as computed in lattice QCD are commonly believed to provide insights into the microscopic structure of QCD matter, in particular its degrees of freedom. We generalize a previously constructed partonic $T$-matrix approach to finite chemical potential to calculate various susceptibilities, in particular for configurations containing a heavy charm quark. At vanishing chemical potential and moderate temperatures, this approach predicts large collisional widths of partons generated by dynamically formed hadronic resonance states which lead to transport parameters characteristic for a strongly coupled system. The quark chemical potential dependence is implemented into the propagators and the in-medium color potential, where two newly introduced parameters for the thermal and screening masses are fixed through a fit to the baryon number susceptibility, $\chi^B_2$. With this setup, we calculate heavy-light susceptibilities without further tuning; the results qualitatively agree with the lattice-QCD (lQCD) data for both $\chi^{uc}_{11}$ and $\chi^{uc}_{22}$. This implies that the lQCD results are compatible with a significant content of broad $D$-meson and charm-light diquark bound states in a moderately hot QGP.
[ { "created": "Fri, 26 Nov 2021 17:31:48 GMT", "version": "v1" } ]
2022-11-30
[ [ "Liu", "Shuai Y. F.", "" ], [ "Rapp", "Ralf", "" ] ]
Quark number susceptibilities as computed in lattice QCD are commonly believed to provide insights into the microscopic structure of QCD matter, in particular its degrees of freedom. We generalize a previously constructed partonic $T$-matrix approach to finite chemical potential to calculate various susceptibilities, in particular for configurations containing a heavy charm quark. At vanishing chemical potential and moderate temperatures, this approach predicts large collisional widths of partons generated by dynamically formed hadronic resonance states which lead to transport parameters characteristic for a strongly coupled system. The quark chemical potential dependence is implemented into the propagators and the in-medium color potential, where two newly introduced parameters for the thermal and screening masses are fixed through a fit to the baryon number susceptibility, $\chi^B_2$. With this setup, we calculate heavy-light susceptibilities without further tuning; the results qualitatively agree with the lattice-QCD (lQCD) data for both $\chi^{uc}_{11}$ and $\chi^{uc}_{22}$. This implies that the lQCD results are compatible with a significant content of broad $D$-meson and charm-light diquark bound states in a moderately hot QGP.
2009.07730
Timo Fleig
Timo Fleig, Martin Jung
P,T-Odd Interactions in Atomic ${}^{129}$Xe and Phenomenological Applications
25 pages, 0 figures
Phys. Rev. A 103, 012807 (2021)
10.1103/PhysRevA.103.012807
null
hep-ph physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate interaction constants for the contributions from \PT-odd scalar-pseudoscalar and tensor-pseudotensor operators to the electric dipole moment of ${}^{129}$Xe, for the first time in case of the former, using relativistic many-body theory including the effects of dynamical electron correlations. These interaction constants are necessary ingredients to relating the corresponding measurements to fundamental parameters in models of physics beyond the Standard Model. We obtain $\alpha_{C_S} = \left( 0.71 \pm 0.18 \right) [10^{-23}\, e~\text{cm}]$ and $\alpha_{C_T}= \left( 0.520 \pm 0.049 \right) [10^{-20}\, \left<\Sigma\right>_{\text{Xe}}\, e~\text{cm}]$, respectively. We apply our results to test a phenomenological relation between the two quantities, commonly used in the literature, and discuss their present and future phenomenological impact.
[ { "created": "Wed, 16 Sep 2020 15:01:45 GMT", "version": "v1" }, { "created": "Wed, 16 Dec 2020 12:10:44 GMT", "version": "v2" } ]
2021-01-27
[ [ "Fleig", "Timo", "" ], [ "Jung", "Martin", "" ] ]
We calculate interaction constants for the contributions from \PT-odd scalar-pseudoscalar and tensor-pseudotensor operators to the electric dipole moment of ${}^{129}$Xe, for the first time in case of the former, using relativistic many-body theory including the effects of dynamical electron correlations. These interaction constants are necessary ingredients to relating the corresponding measurements to fundamental parameters in models of physics beyond the Standard Model. We obtain $\alpha_{C_S} = \left( 0.71 \pm 0.18 \right) [10^{-23}\, e~\text{cm}]$ and $\alpha_{C_T}= \left( 0.520 \pm 0.049 \right) [10^{-20}\, \left<\Sigma\right>_{\text{Xe}}\, e~\text{cm}]$, respectively. We apply our results to test a phenomenological relation between the two quantities, commonly used in the literature, and discuss their present and future phenomenological impact.
hep-ph/9811462
Aharon Levy
Aharon Levy
The structure of the Troika: Proton, Photon and Pomeron, as seen at HERA
52 pages, including 52 figures. Talk presented at the XXI International Workshop on the Fundamental Problems of High Energy Physics and Field Theory, 23-25 June 1998, Protvino, Russia
null
null
TAUP 2531-98
hep-ph
null
HERA, the electron-proton collider, enables to probe the proton with a high resolving power due to the deep inelastic scattering reactions at high $Q^2$ values. In the low $Q^2$ region, one can study the properties of the photon. The large fraction of diffractive events found both in the low and high $Q^2$ region allows the study of the Pomeron. A review of what we have learned from HERA so far about the structure of these three objects is presented.
[ { "created": "Tue, 24 Nov 1998 17:57:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Levy", "Aharon", "" ] ]
HERA, the electron-proton collider, enables to probe the proton with a high resolving power due to the deep inelastic scattering reactions at high $Q^2$ values. In the low $Q^2$ region, one can study the properties of the photon. The large fraction of diffractive events found both in the low and high $Q^2$ region allows the study of the Pomeron. A review of what we have learned from HERA so far about the structure of these three objects is presented.
1905.09257
Bin Wang
Bin Wang
Layers of quark-gluon plasma induced by chiral magnetic effect and the separation of $u,d$ quarks' critical end points
arXiv admin note: text overlap with arXiv:1703.07744
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we show that the chiral magnetic effect (CME) could cause the quark-gluon plasma (QGP) approximately forming three layers along the strong magnetic field characterised by different compositions of quark chemical potentials. This phenomenon may bring new observable outcomes, for example different layers would have different CEPs and the $u,d$ quarks would have different critical end points (CEPs). Since the $s$ quark would make the up and the down layers have some 'asymmetry' on chemical potentials, there is the possibility that at some special conditions one flavor of $u,d$ quarks lies at CEP in one layer but another flavor dose not in any layer. These results may be helpful in testing the existence of CME.
[ { "created": "Wed, 22 May 2019 17:33:03 GMT", "version": "v1" }, { "created": "Fri, 29 Oct 2021 13:33:23 GMT", "version": "v2" } ]
2021-11-01
[ [ "Wang", "Bin", "" ] ]
In this work we show that the chiral magnetic effect (CME) could cause the quark-gluon plasma (QGP) approximately forming three layers along the strong magnetic field characterised by different compositions of quark chemical potentials. This phenomenon may bring new observable outcomes, for example different layers would have different CEPs and the $u,d$ quarks would have different critical end points (CEPs). Since the $s$ quark would make the up and the down layers have some 'asymmetry' on chemical potentials, there is the possibility that at some special conditions one flavor of $u,d$ quarks lies at CEP in one layer but another flavor dose not in any layer. These results may be helpful in testing the existence of CME.
1805.11948
German F. R. Sborlini
Leandro Cieri, Giancarlo Ferrera, German F. R. Sborlini
Combining QED and QCD transverse-momentum resummation for Z boson production at hadron colliders
13 pages, 3 figures
null
10.1007/JHEP08(2018)165
TIF-UNIMI-2018-4
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the transverse-momentum ($q_T$) distribution of $Z$ bosons produced in hadronic collisions. At small values of $q_T$, we perform the analytic resummation of the logarithmically enhanced QED contributions up to next-to-leading logarithmic accuracy, including the mixed QCD-QED contributions at leading logarithmic accuracy. Resummed results are consistently matched with the next-to-leading fixed-order results (i.e. $\mathcal{O}(\alpha^2)$) at small, intermediate and large values of $q_T$. We combine the QED corrections with the known QCD results at next-to-next-to-leading order ($\mathcal{O}(\alpha_S^2)$) and next-to-next-to-leading logarithmic accuracy. We show numerical results at LHC and Tevatron energies, studying the impact of the QED corrections and providing an estimate of the corresponding perturbative uncertainty. Our analytic results for the combined QED and QCD resummation, obtained through an extension of the $q_T$ resummation formalism in QCD, are valid for the production of generic neutral and colourless high-mass systems in hadronic collision.
[ { "created": "Wed, 30 May 2018 13:39:48 GMT", "version": "v1" } ]
2018-09-26
[ [ "Cieri", "Leandro", "" ], [ "Ferrera", "Giancarlo", "" ], [ "Sborlini", "German F. R.", "" ] ]
We consider the transverse-momentum ($q_T$) distribution of $Z$ bosons produced in hadronic collisions. At small values of $q_T$, we perform the analytic resummation of the logarithmically enhanced QED contributions up to next-to-leading logarithmic accuracy, including the mixed QCD-QED contributions at leading logarithmic accuracy. Resummed results are consistently matched with the next-to-leading fixed-order results (i.e. $\mathcal{O}(\alpha^2)$) at small, intermediate and large values of $q_T$. We combine the QED corrections with the known QCD results at next-to-next-to-leading order ($\mathcal{O}(\alpha_S^2)$) and next-to-next-to-leading logarithmic accuracy. We show numerical results at LHC and Tevatron energies, studying the impact of the QED corrections and providing an estimate of the corresponding perturbative uncertainty. Our analytic results for the combined QED and QCD resummation, obtained through an extension of the $q_T$ resummation formalism in QCD, are valid for the production of generic neutral and colourless high-mass systems in hadronic collision.
hep-ph/0101124
Thomas Gehrmann
T.Gehrmann, E. Remiddi
Two-Loop Master Integrals for $\gamma^* \to 3$ Jets: The non-planar topologies
22 pages, LaTeX, version to be published, Note added on numerical checks of the results, typos corrected
Nucl.Phys.B601:287-317,2001
10.1016/S0550-3213(01)00074-8
CERN-TH/2001-005
hep-ph
null
The calculation of the two-loop corrections to the three-jet production rate and to event shapes in electron--positron annihilation requires the computation of a number of two-loop four-point master integrals with one off-shell and three on-shell legs. Up to now, only those master integrals corresponding to planar topologies were known. In this paper, we compute the yet outstanding non-planar master integrals by solving differential equations in the external invariants which are fulfilled by these master integrals. We obtain the master integrals as expansions in $\e=(4-d)/2$, where $d$ is the space-time dimension. The fully analytic results are expressed in terms of the two-dimensional harmonic polylogarithms already introduced in the evaluation of the planar topologies.
[ { "created": "Fri, 12 Jan 2001 11:27:08 GMT", "version": "v1" }, { "created": "Fri, 20 Apr 2001 07:48:06 GMT", "version": "v2" } ]
2011-09-29
[ [ "Gehrmann", "T.", "" ], [ "Remiddi", "E.", "" ] ]
The calculation of the two-loop corrections to the three-jet production rate and to event shapes in electron--positron annihilation requires the computation of a number of two-loop four-point master integrals with one off-shell and three on-shell legs. Up to now, only those master integrals corresponding to planar topologies were known. In this paper, we compute the yet outstanding non-planar master integrals by solving differential equations in the external invariants which are fulfilled by these master integrals. We obtain the master integrals as expansions in $\e=(4-d)/2$, where $d$ is the space-time dimension. The fully analytic results are expressed in terms of the two-dimensional harmonic polylogarithms already introduced in the evaluation of the planar topologies.
1107.1990
Boris Kerbikov
B. Kerbikov, M. Andreichikov
Electrical conductivity of quark matter in magnetic field
3 pages, 0 figures
null
null
INT-PUB-11-032
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fermion currents in dense quark matter embedded into magnetic field are under intense discussions motivated by Chiral Magnetic Effect. We argue that conductivity of quark matter may be independent of the magnetic field direction and not proportional to the magnetic field strength.
[ { "created": "Mon, 11 Jul 2011 10:33:30 GMT", "version": "v1" }, { "created": "Mon, 18 Jul 2011 14:45:07 GMT", "version": "v2" }, { "created": "Mon, 5 Dec 2011 06:49:48 GMT", "version": "v3" } ]
2011-12-06
[ [ "Kerbikov", "B.", "" ], [ "Andreichikov", "M.", "" ] ]
Fermion currents in dense quark matter embedded into magnetic field are under intense discussions motivated by Chiral Magnetic Effect. We argue that conductivity of quark matter may be independent of the magnetic field direction and not proportional to the magnetic field strength.
1601.00782
G\'abor Andr\'as Alm\'asi
G\'abor Andr\'as Alm\'asi, Bengt Friman, Krzysztof Redlich
Modeling chiral criticality and its consequences for heavy-ion collisions
4 pages, 4 figures, contribution to the Quark Matter 2015 proceedings
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the critical fluctuations near the chiral critical endpoint (CEP) in a chiral effective model and discuss possible signals of the CEP, recently explored experimentally in nuclear collision. Particular attention is paid to the dependence of such signals on the location of the phase boundary and the CEP relative to the chemical freeze-out conditions in nuclear collisions. We argue that in effective models, standard freeze-out fits to heavy-ion data should not be used directly. Instead, the relevant quantities should be examined on lines in the phase diagram that are defined self-consistently, within the framework of the model. We discuss possible choices for such an approach.
[ { "created": "Tue, 5 Jan 2016 10:23:29 GMT", "version": "v1" }, { "created": "Mon, 25 Jan 2016 15:59:28 GMT", "version": "v2" }, { "created": "Tue, 26 Jan 2016 09:16:08 GMT", "version": "v3" } ]
2016-01-27
[ [ "Almási", "Gábor András", "" ], [ "Friman", "Bengt", "" ], [ "Redlich", "Krzysztof", "" ] ]
We explore the critical fluctuations near the chiral critical endpoint (CEP) in a chiral effective model and discuss possible signals of the CEP, recently explored experimentally in nuclear collision. Particular attention is paid to the dependence of such signals on the location of the phase boundary and the CEP relative to the chemical freeze-out conditions in nuclear collisions. We argue that in effective models, standard freeze-out fits to heavy-ion data should not be used directly. Instead, the relevant quantities should be examined on lines in the phase diagram that are defined self-consistently, within the framework of the model. We discuss possible choices for such an approach.
hep-ph/9807302
null
Michael C. Birse, Judith A. McGovern and Keith G. Richardson (University of Manchester)
A renormalisation-group treatment of two-body scattering
6 pages (RevTeX), 1 figure (epsf); picture of RG flow and more discussion of momentum dependence added
Phys.Lett. B464 (1999) 169-176
10.1016/S0370-2693(99)00991-0
MC/TH 98/11
hep-ph cond-mat hep-th nucl-th
null
Nonrelativistic two-body scattering by a short-ranged potential is studied using the renormalisation group. Two fixed points are identified: a trivial one and one describing systems with a bound state at zero energy. The eigenvalues of the linearised renormalisation group are used to assign a systematic power-counting to terms in the potential near each of these fixed points. The expansion around the nontrivial fixed point is shown to be equivalent to the effective-range expansion.
[ { "created": "Thu, 9 Jul 1998 11:18:24 GMT", "version": "v1" }, { "created": "Thu, 11 Feb 1999 09:12:07 GMT", "version": "v2" }, { "created": "Wed, 14 Jul 1999 15:00:22 GMT", "version": "v3" } ]
2009-10-31
[ [ "Birse", "Michael C.", "", "University of Manchester" ], [ "McGovern", "Judith A.", "", "University of Manchester" ], [ "Richardson", "Keith G.", "", "University of Manchester" ] ]
Nonrelativistic two-body scattering by a short-ranged potential is studied using the renormalisation group. Two fixed points are identified: a trivial one and one describing systems with a bound state at zero energy. The eigenvalues of the linearised renormalisation group are used to assign a systematic power-counting to terms in the potential near each of these fixed points. The expansion around the nontrivial fixed point is shown to be equivalent to the effective-range expansion.
1611.03670
Rong Wang
Rong Wang, Xurong Chen, Qiang Fu
Global study of nuclear modifications on parton distribution functions
12 pages, 9 figures, minor modifications
Nucl. Phys. B 920 (2017) 1
10.1016/j.nuclphysb.2017.04.008
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A global analysis of nuclear medium modifications of parton distributions is presented using deeply inelastic scattering data of various nuclear targets. Two obtained data sets are provided for quark and gluon nuclear modification factors, referred as nIMParton16. One is from the global fit only to the experimental data of isospin-scalar nuclei (Set A), and the other is from the fit to all the measured nuclear data (Set B). The scale-dependence is described by DGLAP equations with nonlinear corrections in this work. The Fermi motion and off-shell effect, nucleon swelling, and parton-parton recombination are taken into account together for modeling the complicated $x$-dependence of nuclear modification. The nuclear gluon shadowing in this paper is dynamically generated by the QCD evolution of parton splitting and recombination processes with zero gluon density at the input scale. Sophisticated nuclear dependence of nuclear medium effects is studied with only two free parameters. With the obtained free parameters from the global analysis, the nuclear modifications of parton distribution functions of unmeasured nuclei can be predicted in our model. Nuclear modification of deuteron is also predicted and shown with recent measurement at JLab.
[ { "created": "Fri, 11 Nov 2016 12:01:38 GMT", "version": "v1" }, { "created": "Sun, 27 Nov 2016 13:25:04 GMT", "version": "v2" }, { "created": "Mon, 6 Feb 2017 02:07:21 GMT", "version": "v3" }, { "created": "Thu, 20 Apr 2017 03:45:28 GMT", "version": "v4" } ]
2017-04-21
[ [ "Wang", "Rong", "" ], [ "Chen", "Xurong", "" ], [ "Fu", "Qiang", "" ] ]
A global analysis of nuclear medium modifications of parton distributions is presented using deeply inelastic scattering data of various nuclear targets. Two obtained data sets are provided for quark and gluon nuclear modification factors, referred as nIMParton16. One is from the global fit only to the experimental data of isospin-scalar nuclei (Set A), and the other is from the fit to all the measured nuclear data (Set B). The scale-dependence is described by DGLAP equations with nonlinear corrections in this work. The Fermi motion and off-shell effect, nucleon swelling, and parton-parton recombination are taken into account together for modeling the complicated $x$-dependence of nuclear modification. The nuclear gluon shadowing in this paper is dynamically generated by the QCD evolution of parton splitting and recombination processes with zero gluon density at the input scale. Sophisticated nuclear dependence of nuclear medium effects is studied with only two free parameters. With the obtained free parameters from the global analysis, the nuclear modifications of parton distribution functions of unmeasured nuclei can be predicted in our model. Nuclear modification of deuteron is also predicted and shown with recent measurement at JLab.
1805.11590
Mingyang Cui
Ming-Yang Cui, Wei-Chih Huang, Yue-Lin Sming Tsai, Qiang Yuan
Consistency test of the AMS-02 antiproton excess with direct detection data based on the effective field theory approach
null
null
10.1088/1475-7516/2018/11/039
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The potential antiproton excess in the AMS-02 data is of much interest and can probably come from dark matter annihilations. Based on the effective field theory approach, in this work we investigate the compatibility of the DM interpretation of the AMS-02 antiproton excess and the null results from direct detection experiments, LUX, PandaX-II, and XENON1T. We focus on dimension-five and -six operators with fermion DM. Only one of dimension-five and one of dimension-six operators can successfully account for the antiproton excess, while the rest either are excluded by direct detection or require very small cut-off scales which invalidate the effective field theory approach.
[ { "created": "Tue, 29 May 2018 17:17:42 GMT", "version": "v1" }, { "created": "Sat, 9 Jun 2018 05:59:39 GMT", "version": "v2" } ]
2018-12-05
[ [ "Cui", "Ming-Yang", "" ], [ "Huang", "Wei-Chih", "" ], [ "Tsai", "Yue-Lin Sming", "" ], [ "Yuan", "Qiang", "" ] ]
The potential antiproton excess in the AMS-02 data is of much interest and can probably come from dark matter annihilations. Based on the effective field theory approach, in this work we investigate the compatibility of the DM interpretation of the AMS-02 antiproton excess and the null results from direct detection experiments, LUX, PandaX-II, and XENON1T. We focus on dimension-five and -six operators with fermion DM. Only one of dimension-five and one of dimension-six operators can successfully account for the antiproton excess, while the rest either are excluded by direct detection or require very small cut-off scales which invalidate the effective field theory approach.
1709.06354
Raghunath Sahoo
Sushanta Tripathy, Swatantra Kumar Tiwari, Mohammed Younus, and Raghunath Sahoo
Elliptic Flow in Pb+Pb Collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV at the LHC Using Boltzmann Transport Equation with Non-extensive Statistics
9 pages and 12 Figures, Published version in EPJA
Eur. Phys. J. A (2018) 54: 38
10.1140/epja/i2018-12461-2
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Elliptic flow in heavy-ion collisions is an important signature of a possible de-confinement transition from hadronic phase to partonic phase. In the present work, we use non-extensive statistics, which has been used for transverse momentum ($p_{\rm T}$) distribution in proton+proton ($p+p$) collisions, as the initial particle distribution function in Boltzmann Transport Equation (BTE). A Boltzmann-Gibbs Blast Wave (BGBW) function is taken as an equilibrium function to get the final distribution to describe the particle production in heavy-ion collisions. In this formalism, we try to estimate the elliptic flow in Pb+Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV at the LHC for different centralities. The elliptic flow ($v_2$) of identified particles seems to be described quite well in the available $p_{\rm T}$ range. An approach, which combines the non-extensive nature of particle production in $p+p$ collisions through an evolution in kinetic theory using BTE, with BGBW equilibrium distribution is successful in describing the spectra and elliptic flow in heavy-ion collisions.
[ { "created": "Tue, 19 Sep 2017 11:34:20 GMT", "version": "v1" }, { "created": "Mon, 5 Mar 2018 11:55:17 GMT", "version": "v2" } ]
2018-03-06
[ [ "Tripathy", "Sushanta", "" ], [ "Tiwari", "Swatantra Kumar", "" ], [ "Younus", "Mohammed", "" ], [ "Sahoo", "Raghunath", "" ] ]
Elliptic flow in heavy-ion collisions is an important signature of a possible de-confinement transition from hadronic phase to partonic phase. In the present work, we use non-extensive statistics, which has been used for transverse momentum ($p_{\rm T}$) distribution in proton+proton ($p+p$) collisions, as the initial particle distribution function in Boltzmann Transport Equation (BTE). A Boltzmann-Gibbs Blast Wave (BGBW) function is taken as an equilibrium function to get the final distribution to describe the particle production in heavy-ion collisions. In this formalism, we try to estimate the elliptic flow in Pb+Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV at the LHC for different centralities. The elliptic flow ($v_2$) of identified particles seems to be described quite well in the available $p_{\rm T}$ range. An approach, which combines the non-extensive nature of particle production in $p+p$ collisions through an evolution in kinetic theory using BTE, with BGBW equilibrium distribution is successful in describing the spectra and elliptic flow in heavy-ion collisions.
hep-ph/0308114
Michal Praszalowicz
Michal Praszalowicz
Pentaquark in the Skyrme Model
12 pages, 4 figures. In v2 Numerical error in Eq.(19) corrected. The resulting mass of N* is now smaller by 2%. This can be seen in the replaced Fig.1b. Minor typos corrected. All conclusions and discussion remains unchanged. In v3 reference added
Phys.Lett.B575:234-241,2003
10.1016/j.physletb.2003.09.049
TPJU-5/2003
hep-ph
null
The mass of the newly discovered pentaquark is calculated within the framework of the SU(3) Skyrme Model. Various estimates based on the \emph{model independent} approach are compared with the model results and with the Chiral Quark Model. Our discussion shows that $\Theta^{+}$ is light with the mass of the order 1.5 GeV.
[ { "created": "Mon, 11 Aug 2003 09:51:57 GMT", "version": "v1" }, { "created": "Fri, 29 Aug 2003 10:52:42 GMT", "version": "v2" }, { "created": "Fri, 26 Sep 2003 13:54:04 GMT", "version": "v3" } ]
2011-07-19
[ [ "Praszalowicz", "Michal", "" ] ]
The mass of the newly discovered pentaquark is calculated within the framework of the SU(3) Skyrme Model. Various estimates based on the \emph{model independent} approach are compared with the model results and with the Chiral Quark Model. Our discussion shows that $\Theta^{+}$ is light with the mass of the order 1.5 GeV.
2008.04385
Ka\u{g}an \c{S}im\c{s}ek
T. M. Aliev, T. Barakat, K. \c{S}im\c{s}ek
Gravitational formfactors of the $ \rho $ meson in QCD sum rules
Edit 1: Added Ref. [12] Edit 2: Added new references
Phys. Rev. D 103, 054001 (2021)
10.1103/PhysRevD.103.054001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
By using the quark part of the energy-momentum tensor current, the gravitational formfactors of the $ \rho $ meson are calculated within the light-cone sum rules method. In the considered version, the energy-momentum tensor current is not conserved and as a result, there appear nine formfactors, six (three) of which correspond to the conservation (nonconservation) of the energy-momentum tensor current. We also compare our results with the one existing in the literature.
[ { "created": "Mon, 10 Aug 2020 19:48:04 GMT", "version": "v1" }, { "created": "Wed, 12 Aug 2020 08:43:26 GMT", "version": "v2" }, { "created": "Thu, 13 Aug 2020 02:09:27 GMT", "version": "v3" } ]
2021-03-10
[ [ "Aliev", "T. M.", "" ], [ "Barakat", "T.", "" ], [ "Şimşek", "K.", "" ] ]
By using the quark part of the energy-momentum tensor current, the gravitational formfactors of the $ \rho $ meson are calculated within the light-cone sum rules method. In the considered version, the energy-momentum tensor current is not conserved and as a result, there appear nine formfactors, six (three) of which correspond to the conservation (nonconservation) of the energy-momentum tensor current. We also compare our results with the one existing in the literature.
2107.05421
Roman Pasechnik
Alfredo Aranda, Francisco J. de Anda, Ant\'onio P. Morais and Roman Pasechnik
Can $E_8$ unification at low energies be consistent with proton decay?
13 pages, 5 figures; descriptions of RG evolution and proton decay have been added, conclusions unchanged
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model is presented that achieves unification of the full Standard Model (SM) field content into a single superfield. It has $E_8$ as a gauge group and simple SUSY in ten spacetime dimensions. The extra dimensions are orbifolded such that they reduce the gauge symmetry directly to the SM one. At low energies, only the SM field content remains with viable unified Yukawa couplings. Full unification can be achieved at energies as low as $10^6\ \rm{GeV}$ with controlled proton decay.
[ { "created": "Mon, 12 Jul 2021 13:40:33 GMT", "version": "v1" }, { "created": "Sun, 5 Feb 2023 16:42:12 GMT", "version": "v2" }, { "created": "Fri, 27 Oct 2023 11:57:09 GMT", "version": "v3" } ]
2023-10-30
[ [ "Aranda", "Alfredo", "" ], [ "de Anda", "Francisco J.", "" ], [ "Morais", "António P.", "" ], [ "Pasechnik", "Roman", "" ] ]
A model is presented that achieves unification of the full Standard Model (SM) field content into a single superfield. It has $E_8$ as a gauge group and simple SUSY in ten spacetime dimensions. The extra dimensions are orbifolded such that they reduce the gauge symmetry directly to the SM one. At low energies, only the SM field content remains with viable unified Yukawa couplings. Full unification can be achieved at energies as low as $10^6\ \rm{GeV}$ with controlled proton decay.
hep-ph/9407312
W. S. Hou
Wei-Shu Hou, Ern-Bin Tsai, Chao-Qiang Geng and Paul Turcotte
Possibility of $m_t < M_W + m_b$ for SUSY-type of Two Higgs Doublet Model
11 pages + 3 Figures (not included), ReVTeX, NTUTH-94-15 and NHCU-HEP-94-16
Prog.Theor.Phys.94:1089-1096,1995
10.1143/PTP.94.1089
null
hep-ph
null
Allowing for realistic uncertainties in input parameters, we demonstrate that the present CLEO limit of $5.4\times 10^{-4}$ for inclusive $b\to s\gamma$ decay does not yet fully exclude the $t\to bH^+$ decay possibility in supersymmetric type of two Higgs doublet models. Combined with direct search for $t\to bH^+$ via $H^+\to \tau^+\nu$ at the Tevatron, we conclude that $\tan\beta \sim 1$ is the ``allowed" window for $m_{H^+} < m_t < M_W$. The possibility becomes excluded, however, {\it if} the CLEO limit is pushed below $4\times 10^{-4}$.
[ { "created": "Mon, 18 Jul 1994 11:12:09 GMT", "version": "v1" } ]
2009-09-25
[ [ "Hou", "Wei-Shu", "" ], [ "Tsai", "Ern-Bin", "" ], [ "Geng", "Chao-Qiang", "" ], [ "Turcotte", "Paul", "" ] ]
Allowing for realistic uncertainties in input parameters, we demonstrate that the present CLEO limit of $5.4\times 10^{-4}$ for inclusive $b\to s\gamma$ decay does not yet fully exclude the $t\to bH^+$ decay possibility in supersymmetric type of two Higgs doublet models. Combined with direct search for $t\to bH^+$ via $H^+\to \tau^+\nu$ at the Tevatron, we conclude that $\tan\beta \sim 1$ is the ``allowed" window for $m_{H^+} < m_t < M_W$. The possibility becomes excluded, however, {\it if} the CLEO limit is pushed below $4\times 10^{-4}$.
1205.6479
Brian Henning
Brian Henning and Hitoshi Murayama
Constraints on Light Dark Matter from Big Bang Nucleosynthesis
13 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the effects of relic dark matter annihilations on big bang nucleosynthesis (BBN). The magnitude of these effects have scale simply with the dark matter mass and annihilation cross-section, which we derive. Estimates based on these scaling behaviors indicate that BBN severely constrains hadronic and radiative dark matter annihilation channels in the previously unconsidered dark matter mass region MeV $\lesssim m_{\chi} \lesssim 10$ GeV. Interestingly, we find that BBN constraints on hadronic annihilation channels are competitive with similar bounds derived from the cosmic microwave background.
[ { "created": "Tue, 29 May 2012 20:00:44 GMT", "version": "v1" } ]
2012-05-31
[ [ "Henning", "Brian", "" ], [ "Murayama", "Hitoshi", "" ] ]
We examine the effects of relic dark matter annihilations on big bang nucleosynthesis (BBN). The magnitude of these effects have scale simply with the dark matter mass and annihilation cross-section, which we derive. Estimates based on these scaling behaviors indicate that BBN severely constrains hadronic and radiative dark matter annihilation channels in the previously unconsidered dark matter mass region MeV $\lesssim m_{\chi} \lesssim 10$ GeV. Interestingly, we find that BBN constraints on hadronic annihilation channels are competitive with similar bounds derived from the cosmic microwave background.
1809.01505
Ilknur Hos
I. Hos, H. Saygin, S. Kuday
Azimuthal Angular Decorrelation of Jets at Future High Energy Colliders
10 pages, 6 figures
null
10.5506/APhysPolB.50.149
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The azimuthal angular decorrelation that is relevant to small-x QCD physics is studied in this paper to show the BFKL effect with a recent event generator. Events are generated at \sqrt{s} = 100 TeV with proton-proton collisions and jets, that are reconstructed by the Anti-k_{T} algorithm (R=0.7), with p_{T}>35GeV and in the rapidity range of |y|<6 are selected for the study. The azimuthal-angle difference between Mueller-Navelet Jets (\Delta\text{{\Phi}} ) in the rapidity seperation (\Delta y) up to 12 is analysed. The distributions of <cosn(\pi-\Delta\Phi)> for n=1,2,3 and their ratio are also presented as a function of \Delta y.
[ { "created": "Wed, 5 Sep 2018 13:42:28 GMT", "version": "v1" } ]
2019-03-27
[ [ "Hos", "I.", "" ], [ "Saygin", "H.", "" ], [ "Kuday", "S.", "" ] ]
The azimuthal angular decorrelation that is relevant to small-x QCD physics is studied in this paper to show the BFKL effect with a recent event generator. Events are generated at \sqrt{s} = 100 TeV with proton-proton collisions and jets, that are reconstructed by the Anti-k_{T} algorithm (R=0.7), with p_{T}>35GeV and in the rapidity range of |y|<6 are selected for the study. The azimuthal-angle difference between Mueller-Navelet Jets (\Delta\text{{\Phi}} ) in the rapidity seperation (\Delta y) up to 12 is analysed. The distributions of <cosn(\pi-\Delta\Phi)> for n=1,2,3 and their ratio are also presented as a function of \Delta y.
1307.0799
Ikaros Bigi
I.I. Bigi
Memorial Contribution about Kolya Uraltsev's Talk at 2012 Workshop $B\to D**$
5 pages; Proceedings of 2012 Workshop $B\to D**$; comments of Kolya Uraltsev's broad horizons
null
null
UND-HEP-13-BIG02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Uraltev has given us a deeper understanding of the forces underlying the data from beauty and charm hadrons for the last 35 years and neutron EDM in the future -- in particular about non-perturbative QCD. At the Workshop in the November 2012 before his death he has focused mostly on the data about semi-leptonic B decays beyond $B \to l \nu D/D^*$. Here is a very short review of his talk at this Workshop. Next year colleagues will produce a `Memorial Book' about Kolya Uraltsev's excellent contributions to fundamental dynamics.
[ { "created": "Tue, 2 Jul 2013 19:23:59 GMT", "version": "v1" }, { "created": "Sun, 14 Jul 2013 17:25:07 GMT", "version": "v2" } ]
2013-07-16
[ [ "Bigi", "I. I.", "" ] ]
Uraltev has given us a deeper understanding of the forces underlying the data from beauty and charm hadrons for the last 35 years and neutron EDM in the future -- in particular about non-perturbative QCD. At the Workshop in the November 2012 before his death he has focused mostly on the data about semi-leptonic B decays beyond $B \to l \nu D/D^*$. Here is a very short review of his talk at this Workshop. Next year colleagues will produce a `Memorial Book' about Kolya Uraltsev's excellent contributions to fundamental dynamics.
hep-ph/0610091
Haijhun Wanng
Hai-Jhun Wanng, Jun-Chen Su
Strange meson-nucleon states in the quark potential model
15 pages, 4 figures
J.Phys.G32:713-734,2006
10.1088/0954-3899/32/5/008
null
hep-ph
null
The quark potential model and resonating group method are used to investigate the $\bar{K}N$ bound states and/or resonances. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the confining potential with incorporating the QCD renormalization correction and the spin-orbital suppression effect in it. It was shown in our previous work that by considering the color octet contribution, use of this model to investigate the $KN$ low energy elastic scattering leads to the results which are in pretty good agreement with the experimental data. In this paper, the same model and method are employed to calculate the masses of the $\bar{K}N$ bound systems. For this purpose, the resonating group equation is transformed into a standard Schr\"odinger equation in which a nonlocal effective $\bar{K}N$ interaction potential is included. Solving the Schr\"odinger equation by the variational method, we are able to reproduce the masses of some currently concerned $\bar{K}N$ states and get a view that these states possibly exist as $\bar{K}N$ molecular states. For the $KN$ system, the same calculation gives no support to the existence of the resonance $\Theta ^{+}(1540)$ which was announced recently.
[ { "created": "Mon, 9 Oct 2006 01:36:36 GMT", "version": "v1" } ]
2009-11-11
[ [ "Wanng", "Hai-Jhun", "" ], [ "Su", "Jun-Chen", "" ] ]
The quark potential model and resonating group method are used to investigate the $\bar{K}N$ bound states and/or resonances. The model potential consists of the t-channel and s-channel one-gluon exchange potentials and the confining potential with incorporating the QCD renormalization correction and the spin-orbital suppression effect in it. It was shown in our previous work that by considering the color octet contribution, use of this model to investigate the $KN$ low energy elastic scattering leads to the results which are in pretty good agreement with the experimental data. In this paper, the same model and method are employed to calculate the masses of the $\bar{K}N$ bound systems. For this purpose, the resonating group equation is transformed into a standard Schr\"odinger equation in which a nonlocal effective $\bar{K}N$ interaction potential is included. Solving the Schr\"odinger equation by the variational method, we are able to reproduce the masses of some currently concerned $\bar{K}N$ states and get a view that these states possibly exist as $\bar{K}N$ molecular states. For the $KN$ system, the same calculation gives no support to the existence of the resonance $\Theta ^{+}(1540)$ which was announced recently.
1902.04900
Marcel Alguer\'o
Marcel Alguer\'o, Bernat Capdevila, S\'ebastien Descotes-Genon, Pere Masjuan and Joaquim Matias
What $R_K$ and $Q_5$ can tell us about New Physics in $b\to s\ell\ell$ transitions?
37 pages, 16 figures
null
10.1007/JHEP07(2019)096
LPT-Orsay-19-04
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The deviations with respect to the Standard Model that are currently observed in $b \to s \ell\ell$ transitions, or $B$ anomalies, can be interpreted in terms of different New Physics (NP) scenarios within a model-independent effective approach. We identify a set of internal tensions of the fit that require further attention and whose theoretical or experimental nature could be determined with more data. In this landscape of NP, we discuss possible ways to discriminate among favoured NP hypotheses in the short term thanks to current and forthcoming observables. While an update of $R_K$ should help to disentangle the type of NP we may be observing (Lepton-Flavour Universality Violating and/or Lepton Flavour Universal), additional observables, in particular $Q_5$, turn out to be central to determine which NP hypothesis should be preferred. We also analyse the preferences shown by the current global fit concerning various NP hypotheses, using two different tools: the behaviour of the pulls of individual observables under NP scenarios and the directions favoured by approximate quadratic parametrisations of the observables in terms of Wilson coefficients.
[ { "created": "Wed, 13 Feb 2019 13:32:46 GMT", "version": "v1" }, { "created": "Wed, 10 Jul 2019 15:13:26 GMT", "version": "v2" } ]
2019-09-04
[ [ "Algueró", "Marcel", "" ], [ "Capdevila", "Bernat", "" ], [ "Descotes-Genon", "Sébastien", "" ], [ "Masjuan", "Pere", "" ], [ "Matias", "Joaquim", "" ] ]
The deviations with respect to the Standard Model that are currently observed in $b \to s \ell\ell$ transitions, or $B$ anomalies, can be interpreted in terms of different New Physics (NP) scenarios within a model-independent effective approach. We identify a set of internal tensions of the fit that require further attention and whose theoretical or experimental nature could be determined with more data. In this landscape of NP, we discuss possible ways to discriminate among favoured NP hypotheses in the short term thanks to current and forthcoming observables. While an update of $R_K$ should help to disentangle the type of NP we may be observing (Lepton-Flavour Universality Violating and/or Lepton Flavour Universal), additional observables, in particular $Q_5$, turn out to be central to determine which NP hypothesis should be preferred. We also analyse the preferences shown by the current global fit concerning various NP hypotheses, using two different tools: the behaviour of the pulls of individual observables under NP scenarios and the directions favoured by approximate quadratic parametrisations of the observables in terms of Wilson coefficients.
1108.0350
Chaehyun Yu
P. Ko, Yuji Omura, Chaehyun Yu (KIAS)
Top forward-backward asymmetry and the CDF Wjj excess in leptophobic U(1)' flavor models
5 pages, 2 figures, version published in Phys. Rev. D
Phys. Rev. D 85, 115010 (2012)
10.1103/PhysRevD.85.115010
KIAS-PREPRINT-P11042
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct anomaly-free leptophobic U(1)' flavor models with light Z'(~ 145 GeV). In order to allow renormalizable Yukawa interactions for the standard model chiral fermions, new Higgs doublets with nonzero U(1)' charges are introduced. Then the neutral (pseudo)scalar Higgs bosons as well as Z' contribute to the t\bar{t} and the same sign top pair productions [\sigma(t\bar{t}]) and \sigma(tt)], and one can evade the strong constraint from \sigma(tt). The top forward-backward asymmetry (A_{FB}) and Wjj excess at CDF could be accommodated by A_{FB}^{New} = 0.084 ~ 0.12 and \sigma(W j j) \lesssim O(10) pb \times \sin^2 2 \beta.
[ { "created": "Mon, 1 Aug 2011 16:06:00 GMT", "version": "v1" }, { "created": "Wed, 18 Jul 2012 08:21:43 GMT", "version": "v2" } ]
2013-05-30
[ [ "Ko", "P.", "", "KIAS" ], [ "Omura", "Yuji", "", "KIAS" ], [ "Yu", "Chaehyun", "", "KIAS" ] ]
We construct anomaly-free leptophobic U(1)' flavor models with light Z'(~ 145 GeV). In order to allow renormalizable Yukawa interactions for the standard model chiral fermions, new Higgs doublets with nonzero U(1)' charges are introduced. Then the neutral (pseudo)scalar Higgs bosons as well as Z' contribute to the t\bar{t} and the same sign top pair productions [\sigma(t\bar{t}]) and \sigma(tt)], and one can evade the strong constraint from \sigma(tt). The top forward-backward asymmetry (A_{FB}) and Wjj excess at CDF could be accommodated by A_{FB}^{New} = 0.084 ~ 0.12 and \sigma(W j j) \lesssim O(10) pb \times \sin^2 2 \beta.
hep-ph/0607206
Hai-Yang Cheng
Hai-Yang Cheng, Chun-Khiang Chua, Keh-Fei Liu
Scalar Glueball, Scalar Quarkonia, and their Mixing
16 pages; add discussions on the justification of the lattice results as input for this work, to appear in Phys. Rev. D
Phys.Rev.D74:094005,2006
10.1103/PhysRevD.74.094005
null
hep-ph
null
The isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$ and their mixing are studied. We employ two recent lattice results as the starting point; one is the isovector scalar meson $a_0(1450)$ which displays an unusual property of being nearly independent of quark mass for quark masses smaller than that of the strange, and the other is the scalar glueball mass at 1710 MeV in the quenched approximation. In the SU(3) symmetry limit, $f_0(1500)$ turns out to be a pure SU(3) octet and is degenerate with $a_0(1450)$, while $f_0(1370)$ is mainly an SU(3) singlet with a slight mixing with the scalar glueball which is the primary component of $f_0(1710)$. These features remain essentially unchanged even when SU(3) breaking is taken into account. We discuss the sources of SU(3) breaking and their consequences on flavor-dependent decays of these mesons. The observed enhancement of $\omega f_0(1710)$ production over $\phi f_0(1710)$ in hadronic $J/\psi$ decays and the copious $f_0(1710)$ production in radiative $J/\psi$ decays lend further support to the prominent glueball nature of $f_0(1710)$.
[ { "created": "Wed, 19 Jul 2006 07:10:55 GMT", "version": "v1" }, { "created": "Fri, 20 Oct 2006 02:14:54 GMT", "version": "v2" } ]
2008-11-26
[ [ "Cheng", "Hai-Yang", "" ], [ "Chua", "Chun-Khiang", "" ], [ "Liu", "Keh-Fei", "" ] ]
The isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$ and their mixing are studied. We employ two recent lattice results as the starting point; one is the isovector scalar meson $a_0(1450)$ which displays an unusual property of being nearly independent of quark mass for quark masses smaller than that of the strange, and the other is the scalar glueball mass at 1710 MeV in the quenched approximation. In the SU(3) symmetry limit, $f_0(1500)$ turns out to be a pure SU(3) octet and is degenerate with $a_0(1450)$, while $f_0(1370)$ is mainly an SU(3) singlet with a slight mixing with the scalar glueball which is the primary component of $f_0(1710)$. These features remain essentially unchanged even when SU(3) breaking is taken into account. We discuss the sources of SU(3) breaking and their consequences on flavor-dependent decays of these mesons. The observed enhancement of $\omega f_0(1710)$ production over $\phi f_0(1710)$ in hadronic $J/\psi$ decays and the copious $f_0(1710)$ production in radiative $J/\psi$ decays lend further support to the prominent glueball nature of $f_0(1710)$.
1007.3909
Gregory Adkins
Gregory S. Adkins
Search for CP and CPT violation in positronium decay
Presented at the Fifth Meeting on CPT and Lorentz Symmetry, Bloomington, Indiana, June 28-July 2, 2010
null
10.1142/9789814327688_0050
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Positronium, the electron-positron bound state, is described to a good approximation by pure QED. The states of positronium have definite values of C and P. Consequently, positronium is an attractive system for the investigation of possible violations of the discrete symmetries in the leptonic sector. We discuss signals for CP and CPT violation in the decay of spin-polarized orthopositronium and show where such correlations might arise in the context of the Standard-Model Extension.
[ { "created": "Thu, 22 Jul 2010 15:13:18 GMT", "version": "v1" } ]
2017-08-23
[ [ "Adkins", "Gregory S.", "" ] ]
Positronium, the electron-positron bound state, is described to a good approximation by pure QED. The states of positronium have definite values of C and P. Consequently, positronium is an attractive system for the investigation of possible violations of the discrete symmetries in the leptonic sector. We discuss signals for CP and CPT violation in the decay of spin-polarized orthopositronium and show where such correlations might arise in the context of the Standard-Model Extension.
0812.3331
Gilad Perez
Cedric Delaunay, Patrick J. Fox and Gilad Perez
Probing Dark Matter Dynamics via Earthborn Neutrinos at IceCube
5 pages and 3 figures
JHEP 0905:099,2009
10.1088/1126-6708/2009/05/099
FERMILAB-PUB-08-568-T, WIS/23/08-DEC-DPP
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent results from PAMELA and ATIC hint that O(TeV) dark matter (DM) is annihilating, in our galactic neighborhood, predominantly to leptons. The annihilation rate is much larger now than during freeze-out, one possible explanation of this is a low-velocity enhancement of the annihilation cross section. In a model independent fashion, we show that in this case the rate of neutrino emission from the Earth, due to DM annihilation, may be greatly enhanced while the rate from the Sun is unaltered. There is potential for IceCube to see these earthborn neutrinos while the same parameter space will be soon covered by direct detection experiments. Combining these near-future data will allow extraction of valuable information about the DM sector dynamics.
[ { "created": "Wed, 17 Dec 2008 20:29:03 GMT", "version": "v1" }, { "created": "Mon, 12 Jan 2009 09:39:44 GMT", "version": "v2" } ]
2009-05-29
[ [ "Delaunay", "Cedric", "" ], [ "Fox", "Patrick J.", "" ], [ "Perez", "Gilad", "" ] ]
Recent results from PAMELA and ATIC hint that O(TeV) dark matter (DM) is annihilating, in our galactic neighborhood, predominantly to leptons. The annihilation rate is much larger now than during freeze-out, one possible explanation of this is a low-velocity enhancement of the annihilation cross section. In a model independent fashion, we show that in this case the rate of neutrino emission from the Earth, due to DM annihilation, may be greatly enhanced while the rate from the Sun is unaltered. There is potential for IceCube to see these earthborn neutrinos while the same parameter space will be soon covered by direct detection experiments. Combining these near-future data will allow extraction of valuable information about the DM sector dynamics.
0906.2675
Zhe Xu
I. Bouras, A. El, O. Fochler, J. Uphoff, Z. Xu, and C. Greiner
Dissipation, Collective Flow and Mach Cones at RHIC
4 pages, 4 figes. Invited talk by C. Greiner at the XLIVth Rencontres de Moriond (QCD and High Energy Interactions), La Thuile, Italy, March 2009
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fast thermalization and a strong buildup of elliptic flow of QCD matter as found at RHIC are understood as the consequence of perturbative QCD (pQCD) interactions within the 3+1 dimensional parton cascade BAMPS. The main contributions stem from pQCD bremsstrahlung $2 \leftrightarrow 3 $ processes. By comparing to Au+Au data of the flow parameter $v_2$ the shear viscosity to entropy ratio $\eta/s$ has been extracted dynamically and lies in the range of 0.08 and 0.2. Also jet-quenching has been investigated consistently within a full dynamical picture of the heavy ion collision. The results for gluonic jets indicate a slightly too large suppression, but are encouraging to understand the two major phenomena, strong flow and jet-quenching, within a unified microscopic treatment of kinetic processes. In addition, simulations on the temporal propagation of dissipative shock waves lead to the observation that an $\eta/s$ ratio larger than 0.2 prevents the development of well-defined shock waves on timescales typical for ultrarelativistic heavy-ion collisions.
[ { "created": "Mon, 15 Jun 2009 12:49:13 GMT", "version": "v1" } ]
2009-06-16
[ [ "Bouras", "I.", "" ], [ "El", "A.", "" ], [ "Fochler", "O.", "" ], [ "Uphoff", "J.", "" ], [ "Xu", "Z.", "" ], [ "Greiner", "C.", "" ] ]
Fast thermalization and a strong buildup of elliptic flow of QCD matter as found at RHIC are understood as the consequence of perturbative QCD (pQCD) interactions within the 3+1 dimensional parton cascade BAMPS. The main contributions stem from pQCD bremsstrahlung $2 \leftrightarrow 3 $ processes. By comparing to Au+Au data of the flow parameter $v_2$ the shear viscosity to entropy ratio $\eta/s$ has been extracted dynamically and lies in the range of 0.08 and 0.2. Also jet-quenching has been investigated consistently within a full dynamical picture of the heavy ion collision. The results for gluonic jets indicate a slightly too large suppression, but are encouraging to understand the two major phenomena, strong flow and jet-quenching, within a unified microscopic treatment of kinetic processes. In addition, simulations on the temporal propagation of dissipative shock waves lead to the observation that an $\eta/s$ ratio larger than 0.2 prevents the development of well-defined shock waves on timescales typical for ultrarelativistic heavy-ion collisions.
1404.0280
Hiroshi Okada
Hiroshi Okada
Two loop Induced Dirac Neutrino Model and Dark Matters with Global $U(1)'$ Symmetry
13 pages, 2 figures, 2 tables. arXiv admin note: text overlap with arXiv:1401.6921, arXiv:1312.3761
null
null
KIAS-P14024
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a two loop induced Dirac type neutrino model at TeV scale. Subsequently, three types of dark matter particles; fermion and two bosons, are naturally introduced. Here we discuss to analyze two possibilities; two component dark matter scenario (Dirac fermion and complex boson) and single dark matter one (another real boson), comparing to current experimental data such as Planck/WMAP and LUX. We briefly mention the possibility to explain the discrepancy of the effective number of neutrino species reported by several experiments.
[ { "created": "Tue, 1 Apr 2014 15:38:38 GMT", "version": "v1" } ]
2014-04-02
[ [ "Okada", "Hiroshi", "" ] ]
We propose a two loop induced Dirac type neutrino model at TeV scale. Subsequently, three types of dark matter particles; fermion and two bosons, are naturally introduced. Here we discuss to analyze two possibilities; two component dark matter scenario (Dirac fermion and complex boson) and single dark matter one (another real boson), comparing to current experimental data such as Planck/WMAP and LUX. We briefly mention the possibility to explain the discrepancy of the effective number of neutrino species reported by several experiments.
0812.0866
Guohuai Zhu
Mingxing Luo, Liucheng Wang, Guohuai Zhu
Dielectron and Diphoton channels in 2HDM
Minor changes, version to appera in Phys. Lett. B
Phys.Lett.B672:65-70,2009
10.1016/j.physletb.2008.12.055
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was observed recently by Randall and Wise that, any particle in the Standard Model cannot decay to $e^+e^-$ and $\gamma \gamma$ final states with comparably measurable branching ratios. This is also true for most extensions of the Standard Model, with the Randall-Sundrum model as an outstanding exception. In this paper, we show that two-Higgs-Doublet-Models (2HDM) yield another possible exception if certain parameters are properly chosen. In addition, we have checked that this model survives the tests of low energy processes, including the anomalous magnetic moment and electric dipole moment of leptons, lepton-flavor-violating decays $\mu^- \to e^- \gamma$ and $e^- e^+ e^-$.
[ { "created": "Thu, 4 Dec 2008 06:14:08 GMT", "version": "v1" }, { "created": "Fri, 19 Dec 2008 04:11:56 GMT", "version": "v2" } ]
2009-02-18
[ [ "Luo", "Mingxing", "" ], [ "Wang", "Liucheng", "" ], [ "Zhu", "Guohuai", "" ] ]
It was observed recently by Randall and Wise that, any particle in the Standard Model cannot decay to $e^+e^-$ and $\gamma \gamma$ final states with comparably measurable branching ratios. This is also true for most extensions of the Standard Model, with the Randall-Sundrum model as an outstanding exception. In this paper, we show that two-Higgs-Doublet-Models (2HDM) yield another possible exception if certain parameters are properly chosen. In addition, we have checked that this model survives the tests of low energy processes, including the anomalous magnetic moment and electric dipole moment of leptons, lepton-flavor-violating decays $\mu^- \to e^- \gamma$ and $e^- e^+ e^-$.
hep-ph/0007043
Gordon Moorhouse
A. B. Henriques and R. G. Moorhouse
Inflaton Particles in Reheating
14 pages, 4 figures;code corrected,figures and some conclusions changed
Phys.Lett. B492 (2000) 331-338; Erratum-ibid. B528 (2002) 306-307
10.1016/S0370-2693(02)01236-4
null
hep-ph
null
In many theories of reheating starting from the classical spatially homogeneous inflaton field, its accompanying inhomogeneous part (which arises from primordial quantum fluctuations) is treated as a first order perturbation. We examine some consequences of treating it non-perturbatively in a model where a first order treatment is invalid. In particular we consider effects on the long-wavelength curvature parameter relevant to the cosmic microwave background fluctuations.
[ { "created": "Wed, 5 Jul 2000 14:14:26 GMT", "version": "v1" }, { "created": "Tue, 22 Aug 2000 15:35:54 GMT", "version": "v2" }, { "created": "Fri, 25 Aug 2000 11:52:48 GMT", "version": "v3" }, { "created": "Fri, 18 Jan 2002 15:28:13 GMT", "version": "v4" } ]
2009-10-31
[ [ "Henriques", "A. B.", "" ], [ "Moorhouse", "R. G.", "" ] ]
In many theories of reheating starting from the classical spatially homogeneous inflaton field, its accompanying inhomogeneous part (which arises from primordial quantum fluctuations) is treated as a first order perturbation. We examine some consequences of treating it non-perturbatively in a model where a first order treatment is invalid. In particular we consider effects on the long-wavelength curvature parameter relevant to the cosmic microwave background fluctuations.
hep-ph/0406065
Narendra Sahu
Narendra Sahu and S. Uma Sankar
Bounds on neutrino masses from leptogenesis in type-II see-saw models
minor typos corrected, references added, match with published version
Phys.Rev.D71:013006,2005
10.1103/PhysRevD.71.013006
null
hep-ph
null
The presence of the triplet $\Delta_{L}$ in left-right symmetric theories leads to type-II see-saw mechanism for the neutrino masses. In these models, assuming a normal mass hierarchy for the heavy Majorana neutrinos, we derive a lower bound on the mass of the lightest of heavy Majorana neutrino from the leptogenesis constraint. From this bound we establish a consistent picture for the hierarchy of heavy Majorana neutrinos in a class of left right symmetric models in which we identify the neutrino Dirac mass matrix with that of Fritzsch type charged lepton mass matrix. It is shown that these values are compatible with the current neutrino oscillation data.
[ { "created": "Sat, 5 Jun 2004 11:14:47 GMT", "version": "v1" }, { "created": "Wed, 3 Nov 2004 16:59:10 GMT", "version": "v2" }, { "created": "Mon, 17 Jan 2005 15:44:38 GMT", "version": "v3" } ]
2014-11-17
[ [ "Sahu", "Narendra", "" ], [ "Sankar", "S. Uma", "" ] ]
The presence of the triplet $\Delta_{L}$ in left-right symmetric theories leads to type-II see-saw mechanism for the neutrino masses. In these models, assuming a normal mass hierarchy for the heavy Majorana neutrinos, we derive a lower bound on the mass of the lightest of heavy Majorana neutrino from the leptogenesis constraint. From this bound we establish a consistent picture for the hierarchy of heavy Majorana neutrinos in a class of left right symmetric models in which we identify the neutrino Dirac mass matrix with that of Fritzsch type charged lepton mass matrix. It is shown that these values are compatible with the current neutrino oscillation data.
2312.16306
Zhengliang Liang
Zheng-Liang Liang and Lin Zhang
Dynamic solar Primakoff process
matches the published version
Phys. Rev. D 109, 083005-Published 4 April 2024
10.1103/PhysRevD.109.083005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Primakoff mechanism is one of the primary channels for the production of solar axion. In canonical estimation of the Primakoff photon-axion conversion rate, the recoil effect is neglected and a static structure factor is adopted. By use of the linear response theory, we provide a dynamic description of the solar Primakoff process. It is found that the collective electrons overtake ions as the dominant factor, in contrast to the static screening picture where ions contribute more to the photon-axion conversion. Nonetheless, the resulting axion flux is only 1-2% lower than the standard estimate based on the static structure factor.
[ { "created": "Tue, 26 Dec 2023 19:25:09 GMT", "version": "v1" }, { "created": "Fri, 5 Apr 2024 15:17:12 GMT", "version": "v2" } ]
2024-04-08
[ [ "Liang", "Zheng-Liang", "" ], [ "Zhang", "Lin", "" ] ]
The Primakoff mechanism is one of the primary channels for the production of solar axion. In canonical estimation of the Primakoff photon-axion conversion rate, the recoil effect is neglected and a static structure factor is adopted. By use of the linear response theory, we provide a dynamic description of the solar Primakoff process. It is found that the collective electrons overtake ions as the dominant factor, in contrast to the static screening picture where ions contribute more to the photon-axion conversion. Nonetheless, the resulting axion flux is only 1-2% lower than the standard estimate based on the static structure factor.
0907.1374
Alan D. Martin
M.G. Ryskin, A.D. Martin, V.A. Khoze and A.G. Shuvaev
Soft physics at the LHC
28 pages, 11 figures, Topical Review to be published in J.Phys.G, based on two lectures by Misha Ryskin at the St. Petersburg Winter School, Gatchina, February 2009
J.Phys.G36:093001,2009
10.1088/0954-3899/36/9/093001
IPPP/09/24, DCPT/09/48
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We recall the main features of the Regge approach used to understand soft interactions at LHC and higher energies. Unitarity tames the power growth of the elastic proton-proton scattering amplitude with energy, and leads to the migration of the secondary particles produced in high-energy proton-proton collisions to larger transverse momenta. We discuss, in qualitative terms, the role of processes containing large rapidity gaps (LRG), and the probability that the gaps survive population by secondaries produced in additional soft interactions. We explain how the Regge diagram corresponding to a LRG event simultaneously describes events with different (single, double, etc.) particle density in the same rapidity interval. We show that the role of these, enhanced, multi-Pomeron diagrams can be studied by measuring multiplicity fluctuations and long-range rapidity correlations between secondaries produced at the Tevatron and the LHC. Finally, we make a list of the characteristic features of the multi-Pomeron description of soft interactions that may be observed at the high energies accessible at the Tevatron and the LHC.
[ { "created": "Wed, 8 Jul 2009 10:43:38 GMT", "version": "v1" } ]
2009-10-09
[ [ "Ryskin", "M. G.", "" ], [ "Martin", "A. D.", "" ], [ "Khoze", "V. A.", "" ], [ "Shuvaev", "A. G.", "" ] ]
We recall the main features of the Regge approach used to understand soft interactions at LHC and higher energies. Unitarity tames the power growth of the elastic proton-proton scattering amplitude with energy, and leads to the migration of the secondary particles produced in high-energy proton-proton collisions to larger transverse momenta. We discuss, in qualitative terms, the role of processes containing large rapidity gaps (LRG), and the probability that the gaps survive population by secondaries produced in additional soft interactions. We explain how the Regge diagram corresponding to a LRG event simultaneously describes events with different (single, double, etc.) particle density in the same rapidity interval. We show that the role of these, enhanced, multi-Pomeron diagrams can be studied by measuring multiplicity fluctuations and long-range rapidity correlations between secondaries produced at the Tevatron and the LHC. Finally, we make a list of the characteristic features of the multi-Pomeron description of soft interactions that may be observed at the high energies accessible at the Tevatron and the LHC.
hep-ph/0309301
Valentin Zakharov
V.I. Zakharov
Hints on dual variables from the lattice SU(2) gluodynamics
12 pages. Talk at the Conference ``Confinement 2003'', RIKEN (Japan), July 21-24,(2003)
null
null
MPP-2003-91
hep-ph hep-lat hep-th
null
In many cases, topological excitations become fundamental variables in a dual formulation of the theory. Assuming this is true in case of SU(2) gluodynamics, we look for hints on the dual variables from the lattice simulations. Two-dimensional vortices, or branes with recently established properties seem to be most natural candidates. The total area of the branes scales in the physical units while the non-Abelian action is ultraviolet divergent. The branes are populated with magnetic monopoles, or tachyonic mode.
[ { "created": "Fri, 26 Sep 2003 02:42:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Zakharov", "V. I.", "" ] ]
In many cases, topological excitations become fundamental variables in a dual formulation of the theory. Assuming this is true in case of SU(2) gluodynamics, we look for hints on the dual variables from the lattice simulations. Two-dimensional vortices, or branes with recently established properties seem to be most natural candidates. The total area of the branes scales in the physical units while the non-Abelian action is ultraviolet divergent. The branes are populated with magnetic monopoles, or tachyonic mode.
1202.4745
Marco Martini
M. Martini, M. Ericson and G. Chanfray
Neutrino energy reconstruction problems and neutrino oscillations
null
null
10.1103/PhysRevD.85.093012
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the accuracy of the usual procedure for neutrino energy reconstruction which is based on the quasielastic kinematics. Our results are described in terms of a probability distribution for a real neutrino energy value. Several factors are responsible of the deviations from the reconstructed value. The main one is the multinucleon component of the neutrino interaction which in the case of Cherenkov detectors enters as a quasielastic cross section, increasing the mean neutrino energy which can differ appreciably from the reconstructed value. As an application we derive, for excess electron events attributed to the conversion of muon neutrinos, the true neutrino energy distribution based on the experimental one which is given in terms of the reconstructed value. The result is a reshaping effect. For MiniBooNE the low energy peak is suppressed and shifted at higher energies, which may influence the interpretation in terms of oscillation. For T2K at the Super Kamiokande far detector the reshaping translates into a narrowing of the energy distribution.
[ { "created": "Tue, 21 Feb 2012 20:47:59 GMT", "version": "v1" }, { "created": "Mon, 14 May 2012 06:28:46 GMT", "version": "v2" } ]
2013-05-30
[ [ "Martini", "M.", "" ], [ "Ericson", "M.", "" ], [ "Chanfray", "G.", "" ] ]
We discuss the accuracy of the usual procedure for neutrino energy reconstruction which is based on the quasielastic kinematics. Our results are described in terms of a probability distribution for a real neutrino energy value. Several factors are responsible of the deviations from the reconstructed value. The main one is the multinucleon component of the neutrino interaction which in the case of Cherenkov detectors enters as a quasielastic cross section, increasing the mean neutrino energy which can differ appreciably from the reconstructed value. As an application we derive, for excess electron events attributed to the conversion of muon neutrinos, the true neutrino energy distribution based on the experimental one which is given in terms of the reconstructed value. The result is a reshaping effect. For MiniBooNE the low energy peak is suppressed and shifted at higher energies, which may influence the interpretation in terms of oscillation. For T2K at the Super Kamiokande far detector the reshaping translates into a narrowing of the energy distribution.
1109.2164
Matthew Buckley
Matthew R. Buckley, Stefano Profumo
Regenerating a Symmetry in Asymmetric Dark Matter
5 pages, 2 figures
null
10.1103/PhysRevLett.108.011301
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Asymmetric dark matter theories generically allow for mass terms that lead to particle-antiparticle mixing. Over the age of the Universe, dark matter can thus oscillate from a purely asymmetric configuration into a symmetric mix of particles and antiparticles, allowing for pair-annihilation processes. Additionally, requiring efficient depletion of the primordial thermal (symmetric) component generically entails large annihilation rates. We show that unless some symmetry completely forbids dark matter particle-antiparticle mixing, asymmetric dark matter is effectively ruled out for a large range of masses, for almost any oscillation time-scale shorter than the age of the Universe.
[ { "created": "Fri, 9 Sep 2011 21:47:49 GMT", "version": "v1" } ]
2013-05-30
[ [ "Buckley", "Matthew R.", "" ], [ "Profumo", "Stefano", "" ] ]
Asymmetric dark matter theories generically allow for mass terms that lead to particle-antiparticle mixing. Over the age of the Universe, dark matter can thus oscillate from a purely asymmetric configuration into a symmetric mix of particles and antiparticles, allowing for pair-annihilation processes. Additionally, requiring efficient depletion of the primordial thermal (symmetric) component generically entails large annihilation rates. We show that unless some symmetry completely forbids dark matter particle-antiparticle mixing, asymmetric dark matter is effectively ruled out for a large range of masses, for almost any oscillation time-scale shorter than the age of the Universe.
hep-ph/0108026
Michael Ogilvie
Peter N. Meisinger and Michael C. Ogilvie
Complete High Temperature Expansions for One-Loop Finite Temperature Effects
9 pages, RevTeX, no figures. To be published in Phys. Rev D. v2 has revised introduction and conclusions, plus a few typographical errors are corrected; v3 corrects one typo
Phys.Rev. D65 (2002) 056013
10.1103/PhysRevD.65.056013
null
hep-ph hep-th
null
We develop exact, simple closed form expressions for partition functions associated with relativistic bosons and fermions in odd spatial dimensions. These expressions, valid at high temperature, include the effects of a non-trivial Polyakov loop and generalize well-known high temperature expansions. The key technical point is the proof of a set of Bessel function identities which resum low temperature expansions into high temperature expansions. The complete expressions for these partition functions can be used to obtain one-loop finite temperature contributions to effective potentials, and thus free energies and pressures.
[ { "created": "Thu, 2 Aug 2001 23:08:35 GMT", "version": "v1" }, { "created": "Tue, 16 Oct 2001 22:12:37 GMT", "version": "v2" }, { "created": "Wed, 31 Oct 2001 20:48:10 GMT", "version": "v3" } ]
2009-11-07
[ [ "Meisinger", "Peter N.", "" ], [ "Ogilvie", "Michael C.", "" ] ]
We develop exact, simple closed form expressions for partition functions associated with relativistic bosons and fermions in odd spatial dimensions. These expressions, valid at high temperature, include the effects of a non-trivial Polyakov loop and generalize well-known high temperature expansions. The key technical point is the proof of a set of Bessel function identities which resum low temperature expansions into high temperature expansions. The complete expressions for these partition functions can be used to obtain one-loop finite temperature contributions to effective potentials, and thus free energies and pressures.
hep-ph/0009334
Robert Shrock
S. Nussinov and R. Shrock
Weak and Electromagnetic Nuclear Decay Signatures for Neutrino Reactions in SuperKamiokande
7 pages, latex, to appear in Phys. Rev. Lett
Phys.Rev.Lett. 86 (2001) 2223-2226
10.1103/PhysRevLett.86.2223
null
hep-ph hep-ex
null
We suggest the study of events in the SuperKamiokande neutrino data due to charged- and neutral-current neutrino reactions followed by weak and/or electromagnetic decays of struck nuclei and fragments thereof. This study could improve the prospects of obtaining evidence for $\tau$ production from $\nu_\mu \to \nu_\tau$ oscillations and could augment the data sample used to disfavor $\nu_\mu \to \nu_{sterile}$ oscillations.
[ { "created": "Thu, 28 Sep 2000 20:05:32 GMT", "version": "v1" }, { "created": "Sat, 6 Jan 2001 02:17:45 GMT", "version": "v2" } ]
2009-10-31
[ [ "Nussinov", "S.", "" ], [ "Shrock", "R.", "" ] ]
We suggest the study of events in the SuperKamiokande neutrino data due to charged- and neutral-current neutrino reactions followed by weak and/or electromagnetic decays of struck nuclei and fragments thereof. This study could improve the prospects of obtaining evidence for $\tau$ production from $\nu_\mu \to \nu_\tau$ oscillations and could augment the data sample used to disfavor $\nu_\mu \to \nu_{sterile}$ oscillations.
hep-ph/0302275
Michael Faisst
M. Faisst, J. Kuhn, T. Seidensticker, and O. Veretin
Three Loop Top Quark Contributions to the rho Parameter
15 pages, 8 figures; Eqs. 8, 9, 11, 12, 20, and 21, relevant for the limit of large M_H, are modified. Numerical results, figures, and conclusion remain unaffected
Nucl.Phys.B665:649-662,2003
10.1016/S0550-3213(03)00450-4
null
hep-ph
null
We present results for the three-loop top quark contributions to the rho parameter in the limit of large top quark mass. The simultaneous dependence on the mass of the Higgs boson M_H and the mass of the top quark m_t is obtained from expansions in the range of M_H around m_t and in the limit M_H >> m_t. In combination with the previous result for M_H = 0 the dependence of the rho parameter on the leading Yukawa contributions, i.e. on m_t and M_H, is well under control for all mass values of practical importance. The effects lead to a shift in the W mass in the order of 5 MeV and are relevant for precision measurements at TESLA.
[ { "created": "Fri, 28 Feb 2003 14:24:01 GMT", "version": "v1" }, { "created": "Thu, 3 Apr 2003 16:39:49 GMT", "version": "v2" } ]
2009-03-16
[ [ "Faisst", "M.", "" ], [ "Kuhn", "J.", "" ], [ "Seidensticker", "T.", "" ], [ "Veretin", "O.", "" ] ]
We present results for the three-loop top quark contributions to the rho parameter in the limit of large top quark mass. The simultaneous dependence on the mass of the Higgs boson M_H and the mass of the top quark m_t is obtained from expansions in the range of M_H around m_t and in the limit M_H >> m_t. In combination with the previous result for M_H = 0 the dependence of the rho parameter on the leading Yukawa contributions, i.e. on m_t and M_H, is well under control for all mass values of practical importance. The effects lead to a shift in the W mass in the order of 5 MeV and are relevant for precision measurements at TESLA.
1201.5572
Thomas Becher
Thomas Becher, Guido Bell and Stefanie Marti
NNLO soft function for electroweak boson production at large transverse momentum
16 pages, 3 figures
null
10.1007/JHEP04(2012)034
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The soft function relevant for the production of an electroweak boson (photon, W, Z or H) with large transverse momentum at a hadron collider is computed at next-to-next-to-leading order. This is the first two-loop computation of a soft function involving three light-cone directions. With the result, the threshold resummation for these processes can now be performed at next-to-next-to-next-to-leading logarithmic accuracy.
[ { "created": "Thu, 26 Jan 2012 16:35:14 GMT", "version": "v1" } ]
2015-06-03
[ [ "Becher", "Thomas", "" ], [ "Bell", "Guido", "" ], [ "Marti", "Stefanie", "" ] ]
The soft function relevant for the production of an electroweak boson (photon, W, Z or H) with large transverse momentum at a hadron collider is computed at next-to-next-to-leading order. This is the first two-loop computation of a soft function involving three light-cone directions. With the result, the threshold resummation for these processes can now be performed at next-to-next-to-next-to-leading logarithmic accuracy.
1311.1127
Susanne Westhoff
Susanne Westhoff
Top Charge Asymmetry -- Theory Status Fall 2013
prepared for the proceedings of "Top 2013 -- 6th International Workshop on Top Quark Physics", Sep 14-19 2013, Durbach, Germany
null
null
PITT-PACC-1310
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review the current status of the charge asymmetry in hadronic top-quark pair production from a theory perspective. The standard-model predictions for the observables at the Tevatron and LHC are being discussed, as well as possible explanations of the Tevatron excess in terms of new physics. I give an outlook for future investigations of the top-quark charge asymmetry, focussing on novel observables at the LHC.
[ { "created": "Tue, 5 Nov 2013 17:16:43 GMT", "version": "v1" } ]
2013-11-06
[ [ "Westhoff", "Susanne", "" ] ]
I review the current status of the charge asymmetry in hadronic top-quark pair production from a theory perspective. The standard-model predictions for the observables at the Tevatron and LHC are being discussed, as well as possible explanations of the Tevatron excess in terms of new physics. I give an outlook for future investigations of the top-quark charge asymmetry, focussing on novel observables at the LHC.
1605.08055
Michele Maltoni
M.C. Gonzalez-Garcia, Michele Maltoni, Ivan Martinez-Soler, Ningqiang Song
Non-standard neutrino interactions in the Earth and the flavor of astrophysical neutrinos
12 pages, 6 figures
Astroparticle Physics 84 (2016) 15-22
10.1016/j.astropartphys.2016.07.001
IFT-UAM/CSIC-16-048, YITP-SB-16-23
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the modification of the detected flavor content of ultra high-energy astrophysical neutrinos in the presence of non-standard interactions of neutrinos with the Earth matter. Unlike the case of new physics affecting the propagation from the source to the Earth, non-standard Earth matter effects induce a dependence of the flavor content on the arrival direction of the neutrino. We find that, within the current limits on non-standard neutrino interaction parameters, large deviations from the standard 3-nu oscillation predictions can be expected, in particular for fluxes dominated by one flavor at the source. Conversely they do not give sizable corrections to the expectation of equalized flavors in the Earth for sources dominated by production via pion-muon decay-chain.
[ { "created": "Wed, 25 May 2016 20:00:07 GMT", "version": "v1" } ]
2017-02-28
[ [ "Gonzalez-Garcia", "M. C.", "" ], [ "Maltoni", "Michele", "" ], [ "Martinez-Soler", "Ivan", "" ], [ "Song", "Ningqiang", "" ] ]
We study the modification of the detected flavor content of ultra high-energy astrophysical neutrinos in the presence of non-standard interactions of neutrinos with the Earth matter. Unlike the case of new physics affecting the propagation from the source to the Earth, non-standard Earth matter effects induce a dependence of the flavor content on the arrival direction of the neutrino. We find that, within the current limits on non-standard neutrino interaction parameters, large deviations from the standard 3-nu oscillation predictions can be expected, in particular for fluxes dominated by one flavor at the source. Conversely they do not give sizable corrections to the expectation of equalized flavors in the Earth for sources dominated by production via pion-muon decay-chain.
1304.2309
Ralf Rapp
Ralf Rapp
Dilepton Spectroscopy of QCD Matter at Collider Energies
25 pages, 21 figures, contribution to Special Issue of Advances in High-Energy Physics on "Physics of Quark Gluon Plasma: An Update and Status Report"; v2: improved discussion of QGP rate and updated figures
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Low-mass dilepton spectra as measured in high-energy heavy-ion collisions are a unique tool to obtain spectroscopic information about the strongly interacting medium produced in these reactions. Specifically, in-medium modifications of the vector spectral function, which is well known in the vacuum, can be deduced from the thermal radiation off the expanding QCD fireball. This, in particular, allows to investigate the fate of the $\rho$ resonance in the dense medium, and possibly infer from it signatures of the (partial) restoration of chiral symmetry, which is spontaneously broken in the QCD vacuum. After briefly reviewing calculations of thermal dilepton emission rates from hot QCD matter, utilizing effective hadronic theory, lattice QCD or resummed perturbative QCD, we focus on applications to dilepton spectra at heavy-ion collider experiments at RHIC and LHC. This includes invariant-mass spectra at full RHIC energy with transverse-momentum dependencies and azimuthal asymmetries, as well as a systematic investigation of the excitation function down to fixed-target energies, thus making contact to previous precision measurements at the SPS. Furthermore, predictions for the energy frontier at the LHC are presented in both dielectron and dimuon channels.
[ { "created": "Mon, 8 Apr 2013 18:55:27 GMT", "version": "v1" }, { "created": "Thu, 11 Jul 2013 16:26:13 GMT", "version": "v2" } ]
2013-07-12
[ [ "Rapp", "Ralf", "" ] ]
Low-mass dilepton spectra as measured in high-energy heavy-ion collisions are a unique tool to obtain spectroscopic information about the strongly interacting medium produced in these reactions. Specifically, in-medium modifications of the vector spectral function, which is well known in the vacuum, can be deduced from the thermal radiation off the expanding QCD fireball. This, in particular, allows to investigate the fate of the $\rho$ resonance in the dense medium, and possibly infer from it signatures of the (partial) restoration of chiral symmetry, which is spontaneously broken in the QCD vacuum. After briefly reviewing calculations of thermal dilepton emission rates from hot QCD matter, utilizing effective hadronic theory, lattice QCD or resummed perturbative QCD, we focus on applications to dilepton spectra at heavy-ion collider experiments at RHIC and LHC. This includes invariant-mass spectra at full RHIC energy with transverse-momentum dependencies and azimuthal asymmetries, as well as a systematic investigation of the excitation function down to fixed-target energies, thus making contact to previous precision measurements at the SPS. Furthermore, predictions for the energy frontier at the LHC are presented in both dielectron and dimuon channels.
hep-ph/0304099
Roberto Casadio
Roberto Casadio
On brane-world black holes and short scale physics
14 pages, 5 figures
Annals Phys. 307 (2003) 195-208
10.1016/S0003-4916(03)00117-9
null
hep-ph astro-ph gr-qc hep-th
null
There is evidence that trans-Planckian physics does not affect the Hawking radiation in four dimensions and, consequently, deviations from the linear dispersion relation (for massless particles) at very high energies cannot be revealed using four-dimensional black holes. We study this issue in the context of models with extra spatial dimensions and show that small black holes that could be produced in accelerators might also provide a chance of testing the high energy regime where non-linear dispersion relations are generally expected.
[ { "created": "Thu, 10 Apr 2003 12:17:15 GMT", "version": "v1" } ]
2009-11-10
[ [ "Casadio", "Roberto", "" ] ]
There is evidence that trans-Planckian physics does not affect the Hawking radiation in four dimensions and, consequently, deviations from the linear dispersion relation (for massless particles) at very high energies cannot be revealed using four-dimensional black holes. We study this issue in the context of models with extra spatial dimensions and show that small black holes that could be produced in accelerators might also provide a chance of testing the high energy regime where non-linear dispersion relations are generally expected.
2109.04981
Sabine Kraml
Kyle Cranmer, Sabine Kraml, Harrison B. Prosper (editors), Philip Bechtle, Florian U. Bernlochner, Itay M. Bloch, Enzo Canonero, Marcin Chrzaszcz, Andrea Coccaro, Jan Conrad, Glen Cowan, Matthew Feickert, Nahuel Ferreiro Iachellini, Andrew Fowlie, Lukas Heinrich, Alexander Held, Thomas Kuhr, Anders Kvellestad, Maeve Madigan, Farvah Mahmoudi, Knut Dundas Mor{\aa}, Mark S. Neubauer, Maurizio Pierini, Juan Rojo, Sezen Sekmen, Luca Silvestrini, Veronica Sanz, Giordon Stark, Riccardo Torre, Robert Thorne, Wolfgang Waltenberger, Nicholas Wardle, Jonas Wittbrodt
Publishing statistical models: Getting the most out of particle physics experiments
60 pages, 15 figures
SciPost Phys. 12, 037 (2022)
10.21468/SciPostPhys.12.1.037
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The statistical models used to derive the results of experimental analyses are of incredible scientific value and are essential information for analysis preservation and reuse. In this paper, we make the scientific case for systematically publishing the full statistical models and discuss the technical developments that make this practical. By means of a variety of physics cases -- including parton distribution functions, Higgs boson measurements, effective field theory interpretations, direct searches for new physics, heavy flavor physics, direct dark matter detection, world averages, and beyond the Standard Model global fits -- we illustrate how detailed information on the statistical modelling can enhance the short- and long-term impact of experimental results.
[ { "created": "Fri, 10 Sep 2021 16:42:11 GMT", "version": "v1" } ]
2022-01-26
[ [ "Cranmer", "Kyle", "", "editors" ], [ "Kraml", "Sabine", "", "editors" ], [ "Prosper", "Harrison B.", "", "editors" ], [ "Bechtle", "Philip", "" ], [ "Bernlochner", "Florian U.", "" ], [ "Bloch", "Itay M.", "" ], [ "Canonero", "Enzo", "" ], [ "Chrzaszcz", "Marcin", "" ], [ "Coccaro", "Andrea", "" ], [ "Conrad", "Jan", "" ], [ "Cowan", "Glen", "" ], [ "Feickert", "Matthew", "" ], [ "Iachellini", "Nahuel Ferreiro", "" ], [ "Fowlie", "Andrew", "" ], [ "Heinrich", "Lukas", "" ], [ "Held", "Alexander", "" ], [ "Kuhr", "Thomas", "" ], [ "Kvellestad", "Anders", "" ], [ "Madigan", "Maeve", "" ], [ "Mahmoudi", "Farvah", "" ], [ "Morå", "Knut Dundas", "" ], [ "Neubauer", "Mark S.", "" ], [ "Pierini", "Maurizio", "" ], [ "Rojo", "Juan", "" ], [ "Sekmen", "Sezen", "" ], [ "Silvestrini", "Luca", "" ], [ "Sanz", "Veronica", "" ], [ "Stark", "Giordon", "" ], [ "Torre", "Riccardo", "" ], [ "Thorne", "Robert", "" ], [ "Waltenberger", "Wolfgang", "" ], [ "Wardle", "Nicholas", "" ], [ "Wittbrodt", "Jonas", "" ] ]
The statistical models used to derive the results of experimental analyses are of incredible scientific value and are essential information for analysis preservation and reuse. In this paper, we make the scientific case for systematically publishing the full statistical models and discuss the technical developments that make this practical. By means of a variety of physics cases -- including parton distribution functions, Higgs boson measurements, effective field theory interpretations, direct searches for new physics, heavy flavor physics, direct dark matter detection, world averages, and beyond the Standard Model global fits -- we illustrate how detailed information on the statistical modelling can enhance the short- and long-term impact of experimental results.
1210.6337
Yu Jia
Feng Feng, Yu Jia, and Wen-Long Sang
Reconciling the nonrelativistic QCD prediction and the $J/\psi\to 3\gamma$ data
7 pages, 1 figure, version accepted for publication in PRD RC
null
10.1103/PhysRevD.87.051501
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been a long-standing problem that the rare electromagnetic decay process $J/\psi\to 3\gamma$ is plagued with both large and negative radiative and relativistic corrections. To date it remains futile to make a definite prediction to confront with the branching fraction of $J/\psi\to 3\gamma$ recently measured by the \textsf{CLEO-c} and \textsf{BESIII} Collaborations. In this work, we investigate the joint perturbative and relativistic correction (i.e. the ${\mathcal O}(\alpha_s v^2)$ correction, where $v$ denotes the characteristic velocity of the charm quark inside the $J/\psi$) for this decay process, which turns out to be very significant. After incorporating the contribution from this new ingredient, with the reasonable choice of the input parameters, we are able to account for the measured decay rates in a satisfactory degree.
[ { "created": "Tue, 23 Oct 2012 19:44:04 GMT", "version": "v1" }, { "created": "Fri, 15 Feb 2013 15:50:55 GMT", "version": "v2" } ]
2013-03-14
[ [ "Feng", "Feng", "" ], [ "Jia", "Yu", "" ], [ "Sang", "Wen-Long", "" ] ]
It has been a long-standing problem that the rare electromagnetic decay process $J/\psi\to 3\gamma$ is plagued with both large and negative radiative and relativistic corrections. To date it remains futile to make a definite prediction to confront with the branching fraction of $J/\psi\to 3\gamma$ recently measured by the \textsf{CLEO-c} and \textsf{BESIII} Collaborations. In this work, we investigate the joint perturbative and relativistic correction (i.e. the ${\mathcal O}(\alpha_s v^2)$ correction, where $v$ denotes the characteristic velocity of the charm quark inside the $J/\psi$) for this decay process, which turns out to be very significant. After incorporating the contribution from this new ingredient, with the reasonable choice of the input parameters, we are able to account for the measured decay rates in a satisfactory degree.
1709.02067
Toshiaki Kaneko
T. Kaneko
Counting the number of Feynman Graphs in QCD
23 pages, 1 figure
null
10.1016/j.cpc.2017.12.020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Information about the number of Feynman graphs for a given physical process in a given field theory is especially useful for confirming the result of a Feynman graph generator used in an automatic system of perturbative calculations. A method of counting the number of Feynman graphs with weight of symmetry factor was established based on zero-dimensional field theory, and was used in scalar theories and QED. In this article this method is generalized to more complicated models by direct calculation of generating functions on a symbolic calculating system. This method is applied to QCD with and without counter terms, where many higher order are being calculated automatically.
[ { "created": "Thu, 7 Sep 2017 04:55:22 GMT", "version": "v1" }, { "created": "Fri, 8 Sep 2017 02:52:51 GMT", "version": "v2" }, { "created": "Mon, 12 Nov 2018 06:31:54 GMT", "version": "v3" } ]
2018-11-13
[ [ "Kaneko", "T.", "" ] ]
Information about the number of Feynman graphs for a given physical process in a given field theory is especially useful for confirming the result of a Feynman graph generator used in an automatic system of perturbative calculations. A method of counting the number of Feynman graphs with weight of symmetry factor was established based on zero-dimensional field theory, and was used in scalar theories and QED. In this article this method is generalized to more complicated models by direct calculation of generating functions on a symbolic calculating system. This method is applied to QCD with and without counter terms, where many higher order are being calculated automatically.
2002.00977
Himanshu Swami
Himanshu Swami, Kinjalk Lochan, Ketan M. Patel
Signature of neutrino mass hierarchy in gravitational lensing
21 pages, 5 figures. Minor edits in Eqs. 19 and 20. Results remain unchanged
Phys. Rev. D 102, 024043 (2020)
10.1103/PhysRevD.102.024043
null
hep-ph astro-ph.SR gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In flat spacetime, the vacuum neutrino flavour oscillations are known to be sensitive only to the difference between the squared masses, and not to the individual masses, of neutrinos. In this work, we show that the lensing of neutrinos induced by a gravitational source substantially modifies this standard picture and it gives rise to a novel contribution through which the oscillation probabilities also depend on the individual neutrino masses. A gravitating mass located between a source and a detector deflects the neutrinos in their journey, and at a detection point, neutrinos arriving through different paths can lead to the phenomenon of interference. The flavour transition probabilities computed in the presence of such interference depend on the individual masses of neutrinos whenever there is a non-zero path difference between the interfering neutrinos. We demonstrate this explicitly by considering an example of weak lensing induced by a Schwarzschild mass. Through the simplest two flavour case, we show that the oscillation probability in the presence of lensing is sensitive to the sign of $\Delta m^2 = m_2^2 -m_1^2$, for non-maximal mixing between two neutrinos, unlike in the case of standard vacuum oscillation in flat spacetime. Further, the probability itself oscillates with respect to the path difference and the frequency of such oscillations depends on the absolute mass scale $m_1$ or $m_2$. We also give results for realistic three flavour case and discuss various implications of gravitationally modified neutrino oscillations and means of observing them.
[ { "created": "Mon, 3 Feb 2020 19:00:15 GMT", "version": "v1" }, { "created": "Thu, 16 Jul 2020 12:14:36 GMT", "version": "v2" }, { "created": "Tue, 20 Jul 2021 09:34:04 GMT", "version": "v3" } ]
2021-07-21
[ [ "Swami", "Himanshu", "" ], [ "Lochan", "Kinjalk", "" ], [ "Patel", "Ketan M.", "" ] ]
In flat spacetime, the vacuum neutrino flavour oscillations are known to be sensitive only to the difference between the squared masses, and not to the individual masses, of neutrinos. In this work, we show that the lensing of neutrinos induced by a gravitational source substantially modifies this standard picture and it gives rise to a novel contribution through which the oscillation probabilities also depend on the individual neutrino masses. A gravitating mass located between a source and a detector deflects the neutrinos in their journey, and at a detection point, neutrinos arriving through different paths can lead to the phenomenon of interference. The flavour transition probabilities computed in the presence of such interference depend on the individual masses of neutrinos whenever there is a non-zero path difference between the interfering neutrinos. We demonstrate this explicitly by considering an example of weak lensing induced by a Schwarzschild mass. Through the simplest two flavour case, we show that the oscillation probability in the presence of lensing is sensitive to the sign of $\Delta m^2 = m_2^2 -m_1^2$, for non-maximal mixing between two neutrinos, unlike in the case of standard vacuum oscillation in flat spacetime. Further, the probability itself oscillates with respect to the path difference and the frequency of such oscillations depends on the absolute mass scale $m_1$ or $m_2$. We also give results for realistic three flavour case and discuss various implications of gravitationally modified neutrino oscillations and means of observing them.
hep-ph/9410383
null
G.M. Shore
Target independence of the `proton spin' effect
6 pages, SWAT 94-48
Nucl.Phys.Proc.Suppl. 39BC (1995) 101-105
10.1016/0920-5632(95)00051-A
null
hep-ph
null
Recent work by the author in collaboration with S. Narison and G. Veneziano on the EMC-SMC-SLAC `proton spin' effect is reviewed. This uses a novel approach to deep inelastic scattering in which the matrix elements arising from the OPE are factorised into composite operator propagators and proper vertices. For polarised $\mu p$ scattering, the composite operator propagator is equated to the square root of the first moment of the QCD topological susceptibility, $\sqrt{\chi^\prime(0)}$. We evaluate $\chi^\prime(0)$ using QCD spectral sum rules and find a significant suppression relative to its OZI expectation. This is identified as the source of the violation of the Ellis-Jaffe sum rule for the first moment of the polarised proton structure function $g_1^p$. Our predictions, $\int_0^1 dx g_1^p(x;Q^2=10GeV^2) = 0.143\pm 0.005$ and $\Delta\Sigma =0.353\pm 0.052$, are in excellent agreement with the new SMC data. This supports our earlier conjecture that the suppression in the flavour singlet component of the first moment of $g_1^p$ is a target-independent feature of QCD related to the $U(1)$ anomaly and is not a special property of the proton structure.
[ { "created": "Wed, 26 Oct 1994 21:02:33 GMT", "version": "v1" } ]
2009-10-28
[ [ "Shore", "G. M.", "" ] ]
Recent work by the author in collaboration with S. Narison and G. Veneziano on the EMC-SMC-SLAC `proton spin' effect is reviewed. This uses a novel approach to deep inelastic scattering in which the matrix elements arising from the OPE are factorised into composite operator propagators and proper vertices. For polarised $\mu p$ scattering, the composite operator propagator is equated to the square root of the first moment of the QCD topological susceptibility, $\sqrt{\chi^\prime(0)}$. We evaluate $\chi^\prime(0)$ using QCD spectral sum rules and find a significant suppression relative to its OZI expectation. This is identified as the source of the violation of the Ellis-Jaffe sum rule for the first moment of the polarised proton structure function $g_1^p$. Our predictions, $\int_0^1 dx g_1^p(x;Q^2=10GeV^2) = 0.143\pm 0.005$ and $\Delta\Sigma =0.353\pm 0.052$, are in excellent agreement with the new SMC data. This supports our earlier conjecture that the suppression in the flavour singlet component of the first moment of $g_1^p$ is a target-independent feature of QCD related to the $U(1)$ anomaly and is not a special property of the proton structure.
1107.1500
Eduardo Pont\'on
Adrian Carmona, Eduardo Ponton and Jose Santiago
Phenomenology of Non-Custodial Warped Models
Most relevant one-loop contributions to EWP observables included, physics results partially changed. References added. 29 pages, 14 Figures
null
10.1007/JHEP10(2011)137
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effect of bulk fermions on electroweak precision observables in a recently proposed model with warped extra dimensions and no custodial symmetry. We find that the top-quark mass, together with the corrections to the Zbb vertex and the one-loop contribution to the T parameter, which is finite, impose important constraints that single out a well defined region of parameter space. New massive vector bosons can be as light as 1.5 TeV and have large couplings to the t_R quark, and suppressed couplings to the t_L, b_L and lighter quarks. We discuss the implications for searches of models with warped extra dimensions at the LHC.
[ { "created": "Thu, 7 Jul 2011 20:00:10 GMT", "version": "v1" }, { "created": "Tue, 16 Aug 2011 19:48:48 GMT", "version": "v2" } ]
2015-05-28
[ [ "Carmona", "Adrian", "" ], [ "Ponton", "Eduardo", "" ], [ "Santiago", "Jose", "" ] ]
We study the effect of bulk fermions on electroweak precision observables in a recently proposed model with warped extra dimensions and no custodial symmetry. We find that the top-quark mass, together with the corrections to the Zbb vertex and the one-loop contribution to the T parameter, which is finite, impose important constraints that single out a well defined region of parameter space. New massive vector bosons can be as light as 1.5 TeV and have large couplings to the t_R quark, and suppressed couplings to the t_L, b_L and lighter quarks. We discuss the implications for searches of models with warped extra dimensions at the LHC.
hep-ph/0702106
Boris Kopeliovich
B.Z. Kopeliovich, I.K. Potashnikova, I. Schmidt, A.V. Tarasov
Diffractive Excitation of Heavy Flavors: Leading Twist Mechanisms
Latex, 19 pages, 12 figures. A short commenting on previously done computations is added
Phys.Rev.D76:034019,2007
10.1103/PhysRevD.76.034019
USM-TH-205
hep-ph
null
Diffractive production of heavy flavors is calculated within the light-cone dipole approach. Novel leading twist mechanisms are proposed, which involve both short and long transverse distances inside the incoming hadron. Nevertheless, the diffractive cross section turns out to be sensitive to the primordial transverse momenta of projectile gluons, rather than to the hadronic size. Our calculations agree with the available data for diffractive production of charm and beauty, and with the observed weak variation of the diffraction-to-inclusive cross section ratios as function of the hard scale.
[ { "created": "Sat, 10 Feb 2007 02:45:47 GMT", "version": "v1" }, { "created": "Sat, 24 Mar 2007 16:36:19 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kopeliovich", "B. Z.", "" ], [ "Potashnikova", "I. K.", "" ], [ "Schmidt", "I.", "" ], [ "Tarasov", "A. V.", "" ] ]
Diffractive production of heavy flavors is calculated within the light-cone dipole approach. Novel leading twist mechanisms are proposed, which involve both short and long transverse distances inside the incoming hadron. Nevertheless, the diffractive cross section turns out to be sensitive to the primordial transverse momenta of projectile gluons, rather than to the hadronic size. Our calculations agree with the available data for diffractive production of charm and beauty, and with the observed weak variation of the diffraction-to-inclusive cross section ratios as function of the hard scale.
2110.05924
Tomas Gonzalo
Tom\'as E. Gonzalo
BSM Developments and Tools
11 pages
null
null
TTK-21-40
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this conference paper I introduce a selection of BSM tools and describe their most recent developments. I choose to focus on tools for the reinterpretation of LHC searches, tools that compute dark matter constraints, beyond-the-Standard-Model (BSM) inference tools, and tools that calculate amplitudes and cross sections directly from the Lagrangian.
[ { "created": "Tue, 12 Oct 2021 12:15:39 GMT", "version": "v1" } ]
2021-10-13
[ [ "Gonzalo", "Tomás E.", "" ] ]
In this conference paper I introduce a selection of BSM tools and describe their most recent developments. I choose to focus on tools for the reinterpretation of LHC searches, tools that compute dark matter constraints, beyond-the-Standard-Model (BSM) inference tools, and tools that calculate amplitudes and cross sections directly from the Lagrangian.
1111.6221
Fu Yong-Ping
Fu Yong-Ping, Li Yun-De
Intermediate mass dileptons from the passage of jets and high energy photons through quark-gluon plasma
2 figures
Chinese Physics Letters, 27 (2010) 101202
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of the intermediate mass dileptons originating from the annihilation and Compton scattering of the jets and high energy photons (resolved photons) passing through the quark-gluon plasma is calculated. The contribution of the dilepton yield due to the jet-plasma and high energy photon-plasma interaction is pronounced compared to the thermal and Drell-Yan dilepton spectrum at intermediate mass. The ordinary spectrum of thermal and Drell-Yan processes is enhanced by the jet and photon-plasma mechanism. The numerical results match to the PHENIX data accurately in the intermediate mass region for Au-Au 200 GeV/A collisions at RHIC.
[ { "created": "Sun, 27 Nov 2011 03:14:36 GMT", "version": "v1" } ]
2011-11-29
[ [ "Yong-Ping", "Fu", "" ], [ "Yun-De", "Li", "" ] ]
The production of the intermediate mass dileptons originating from the annihilation and Compton scattering of the jets and high energy photons (resolved photons) passing through the quark-gluon plasma is calculated. The contribution of the dilepton yield due to the jet-plasma and high energy photon-plasma interaction is pronounced compared to the thermal and Drell-Yan dilepton spectrum at intermediate mass. The ordinary spectrum of thermal and Drell-Yan processes is enhanced by the jet and photon-plasma mechanism. The numerical results match to the PHENIX data accurately in the intermediate mass region for Au-Au 200 GeV/A collisions at RHIC.
hep-ph/0507007
Konstantin Klimenko
D. Ebert, K.G. Klimenko
Pion condensation in quark matter with finite baryon density
7 pages, 6 figures; two references added
J.Phys. G32 (2006) 599-608
10.1088/0954-3899/32/5/001
HU-EP-05/27
hep-ph
null
The phase structure of the Nambu -- Jona-Lasinio model at zero temperature and in the presence of baryon- and isospin chemical potentials is investigated. It is shown that in the chiral limit and for a wide range of model parameters there exist two different phases with pion condensation. In the first, ordinary phase, quarks are gapped particles. In the second, gapless pion condensation phase, there is no energy cost for creating only $u$- or both $u$ and $d$ quarks, and the density of baryons is nonzero.
[ { "created": "Fri, 1 Jul 2005 08:40:09 GMT", "version": "v1" }, { "created": "Fri, 12 Aug 2005 15:39:35 GMT", "version": "v2" }, { "created": "Mon, 26 Sep 2005 12:30:11 GMT", "version": "v3" }, { "created": "Sat, 1 Apr 2006 10:02:53 GMT", "version": "v4" } ]
2009-11-11
[ [ "Ebert", "D.", "" ], [ "Klimenko", "K. G.", "" ] ]
The phase structure of the Nambu -- Jona-Lasinio model at zero temperature and in the presence of baryon- and isospin chemical potentials is investigated. It is shown that in the chiral limit and for a wide range of model parameters there exist two different phases with pion condensation. In the first, ordinary phase, quarks are gapped particles. In the second, gapless pion condensation phase, there is no energy cost for creating only $u$- or both $u$ and $d$ quarks, and the density of baryons is nonzero.
hep-ph/9903388
Sharon Jensen
Stanley J. Brodsky, John R. Hiller, and Gary McCartor
Application of Pauli-Villars Regularization and Discretized Light-Cone Quantization to a (3+1)-Dimensional Model
RevTex, 27 pages
Phys.Rev.D60:054506,1999
10.1103/PhysRevD.60.054506
SLAC-PUB-8078, UMN-D-99-1, SMUHEP/99-04
hep-ph
null
We apply Pauli-Villars regularization and discrete light-cone quantization to the nonperturbative solution of a (3+1)-dimensional model field theory. The matrix eigenvalue problem is solved for the lowest-mass state with use of the complex symmetric Lanczos algorithm. This permits the calculation of each Fock-sector wave function, and from these we obtain values for various quantities, such as average multiplicities and average momenta of constituents, structure functions, and a form factor slope.
[ { "created": "Wed, 17 Mar 1999 17:41:34 GMT", "version": "v1" } ]
2009-09-11
[ [ "Brodsky", "Stanley J.", "" ], [ "Hiller", "John R.", "" ], [ "McCartor", "Gary", "" ] ]
We apply Pauli-Villars regularization and discrete light-cone quantization to the nonperturbative solution of a (3+1)-dimensional model field theory. The matrix eigenvalue problem is solved for the lowest-mass state with use of the complex symmetric Lanczos algorithm. This permits the calculation of each Fock-sector wave function, and from these we obtain values for various quantities, such as average multiplicities and average momenta of constituents, structure functions, and a form factor slope.
hep-ph/0503021
Pilar Hernandez
J.Burguet-Castell, D.Casper, E.Couce, J.J.Gomez-Cadenas, P.Hernandez
Optimal $\beta$-beam at the CERN-SPS
22 pages
Nucl.Phys.B725:306-326,2005
10.1016/j.nuclphysb.2005.06.037
IFIC/05-16, FTUV-05-0303
hep-ph
null
A $\beta$-beam with maximum $\gamma=150$ (for $\helio$ ions) or $\gamma=250$ (for $\neon$) could be achieved at the CERN-SPS. We study the sensitivity to $\theta_{13}$ and $\delta$ of such a beam as function of $\gamma$, optimizing with the baseline constrained to CERN-Frejus (130 km), and also with simultaneous variation of the baseline. These results are compared to the {\it standard} scenario previously considered, with lower $\gamma=60/100$, and also with a higher $\gamma\sim 350$ option that requires a more powerful accelerator. Although higher $\gamma$ is better, loss of sensitivity to $\theta _{13}$ and $\delta$ is most pronounced for $\gamma$ below 100.
[ { "created": "Wed, 2 Mar 2005 11:41:13 GMT", "version": "v1" } ]
2010-04-06
[ [ "Burguet-Castell", "J.", "" ], [ "Casper", "D.", "" ], [ "Couce", "E.", "" ], [ "Gomez-Cadenas", "J. J.", "" ], [ "Hernandez", "P.", "" ] ]
A $\beta$-beam with maximum $\gamma=150$ (for $\helio$ ions) or $\gamma=250$ (for $\neon$) could be achieved at the CERN-SPS. We study the sensitivity to $\theta_{13}$ and $\delta$ of such a beam as function of $\gamma$, optimizing with the baseline constrained to CERN-Frejus (130 km), and also with simultaneous variation of the baseline. These results are compared to the {\it standard} scenario previously considered, with lower $\gamma=60/100$, and also with a higher $\gamma\sim 350$ option that requires a more powerful accelerator. Although higher $\gamma$ is better, loss of sensitivity to $\theta _{13}$ and $\delta$ is most pronounced for $\gamma$ below 100.
hep-ph/0402284
Gilberto Tavares-Velasco
J. Hernandez-Sanchez, M. A. Perez, G. Tavares-Velasco and J. J. Toscano
Decay H^+ -> W^+ gamma in a nonlinear R_xi-gauge
12 pages, 9 figures
Phys.Rev.D69:095008,2004
10.1103/PhysRevD.69.095008
null
hep-ph
null
A new evaluation of the charged Higgs boson decay $H^+ -> W^+\gamma$ is presented in the context of the general two-Higgs doublet model. A nonlinear $R_\xi$-gauge which considerably simplifies the calculation is introduced and simple expressions are obtained for the fermionic and bosonic contributions. The $H^+ -> W^+\gamma$ branching ratio is analyzed for several values of the parameters of the model. Although this decay can have a branching fraction as large as $10^{-4}$ in a certain region of the parameter space, it is found that such a region is disfavored by the most recent constraints on $b -> s\gamma$, $g-2$ of the muon, $Z -> b \bar b$, and the $\rho$ parameter, along with the exclusions from direct searches at the CERN $e^-e^+$ LEP collider. The possibility of detecting this decay at future colliders is discussed.
[ { "created": "Fri, 27 Feb 2004 05:48:54 GMT", "version": "v1" } ]
2011-07-19
[ [ "Hernandez-Sanchez", "J.", "" ], [ "Perez", "M. A.", "" ], [ "Tavares-Velasco", "G.", "" ], [ "Toscano", "J. J.", "" ] ]
A new evaluation of the charged Higgs boson decay $H^+ -> W^+\gamma$ is presented in the context of the general two-Higgs doublet model. A nonlinear $R_\xi$-gauge which considerably simplifies the calculation is introduced and simple expressions are obtained for the fermionic and bosonic contributions. The $H^+ -> W^+\gamma$ branching ratio is analyzed for several values of the parameters of the model. Although this decay can have a branching fraction as large as $10^{-4}$ in a certain region of the parameter space, it is found that such a region is disfavored by the most recent constraints on $b -> s\gamma$, $g-2$ of the muon, $Z -> b \bar b$, and the $\rho$ parameter, along with the exclusions from direct searches at the CERN $e^-e^+$ LEP collider. The possibility of detecting this decay at future colliders is discussed.
hep-ph/0412167
Zvi Bern
Zvi Bern, Darren Forde, David A. Kosower and Pierpaolo Mastrolia
Twistor-Inspired Construction of Electroweak Vector Boson Currents
22 pages, 4 figures, v2 minor corrections and added commentary on multiple vector bosons
Phys.Rev.D72:025006,2005
10.1103/PhysRevD.72.025006
UCLA/04/TEP/49, Saclay/SPhT-T04/16
hep-ph hep-th
null
We present an extension of the twistor-motivated MHV vertices and accompanying rules presented by Cachazo, Svrvcek and Witten to the construction of vector-boson currents coupling to an arbitrary source. In particular, we give rules for constructing off-shell vector-boson currents with one fermion pair and n gluons of arbitrary helicity. These currents may be employed directly in the computation of electroweak amplitudes. The rules yield expressions in agreement with previously-obtained results for Z,W,\gamma^* --> qbar q + n gluons (analytically up to n=3, beyond via the Berends--Giele recursion relations). We also confirm that the contribution to a seven-point amplitude containing the non-abelian triple vector-boson coupling obtained using the next-to-MHV currents matches the previous result in the literature.
[ { "created": "Tue, 14 Dec 2004 20:08:14 GMT", "version": "v1" }, { "created": "Tue, 22 Feb 2005 19:37:32 GMT", "version": "v2" } ]
2011-07-19
[ [ "Bern", "Zvi", "" ], [ "Forde", "Darren", "" ], [ "Kosower", "David A.", "" ], [ "Mastrolia", "Pierpaolo", "" ] ]
We present an extension of the twistor-motivated MHV vertices and accompanying rules presented by Cachazo, Svrvcek and Witten to the construction of vector-boson currents coupling to an arbitrary source. In particular, we give rules for constructing off-shell vector-boson currents with one fermion pair and n gluons of arbitrary helicity. These currents may be employed directly in the computation of electroweak amplitudes. The rules yield expressions in agreement with previously-obtained results for Z,W,\gamma^* --> qbar q + n gluons (analytically up to n=3, beyond via the Berends--Giele recursion relations). We also confirm that the contribution to a seven-point amplitude containing the non-abelian triple vector-boson coupling obtained using the next-to-MHV currents matches the previous result in the literature.
1311.4200
Mikhail Krivoruchenko
S. Kovalenko, M. I. Krivoruchenko, F. Simkovic
Neutrino propagation in nuclear medium and neutrinoless double-beta decay
5 pages REVTeX, accepted for publication in PRL
Phys. Rev. Lett. 112, 142503 (2014)
10.1103/PhysRevLett.112.142503
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a novel effect in neutrinoless double beta (0{\nu}{\beta}{\beta}) decay related with the fact that its underlying mechanisms take place in the nuclear matter environment. We study the neutrino exchange mechanism and demonstrate the possible impact of nuclear medium via Lepton Number Violating (LNV) 4-fermion interactions of neutrino with quarks from decaying nucleus. The net effect of these interactions is generation of an effective in-medium Majorana neutrino mass matrix. The enhanced rate of the 0{\nu}{\beta}{\beta}-decay can lead to the apparent incompatibility of observations of the 0{\nu}{\beta}{\beta}-decay with the value of the neutrino mass determined or restricted by the {\beta}-decay and cosmological data. The effective neutrino masses and mixing are calculated for the complete set of the relevant 4-fermion neutrino-quark operators. Using experimental data on the 0{\nu}{\beta}{\beta}-decay in combination with the {\beta}-decay and cosmological data we evaluate the characteristic scales of the LNV operators: {\Lambda} > 2.4 TeV.
[ { "created": "Sun, 17 Nov 2013 19:07:30 GMT", "version": "v1" }, { "created": "Fri, 21 Mar 2014 06:53:21 GMT", "version": "v2" } ]
2014-04-23
[ [ "Kovalenko", "S.", "" ], [ "Krivoruchenko", "M. I.", "" ], [ "Simkovic", "F.", "" ] ]
We discuss a novel effect in neutrinoless double beta (0{\nu}{\beta}{\beta}) decay related with the fact that its underlying mechanisms take place in the nuclear matter environment. We study the neutrino exchange mechanism and demonstrate the possible impact of nuclear medium via Lepton Number Violating (LNV) 4-fermion interactions of neutrino with quarks from decaying nucleus. The net effect of these interactions is generation of an effective in-medium Majorana neutrino mass matrix. The enhanced rate of the 0{\nu}{\beta}{\beta}-decay can lead to the apparent incompatibility of observations of the 0{\nu}{\beta}{\beta}-decay with the value of the neutrino mass determined or restricted by the {\beta}-decay and cosmological data. The effective neutrino masses and mixing are calculated for the complete set of the relevant 4-fermion neutrino-quark operators. Using experimental data on the 0{\nu}{\beta}{\beta}-decay in combination with the {\beta}-decay and cosmological data we evaluate the characteristic scales of the LNV operators: {\Lambda} > 2.4 TeV.
hep-ph/9610323
James Wells
JoAnne L. Hewett and James D. Wells (SLAC)
Searching for supersymmetry in rare B decays
26 pages
Phys.Rev. D55 (1997) 5549-5560
10.1103/PhysRevD.55.5549
SLAC-PUB-7290
hep-ph
null
We quantify the ability of B-Factories to observe supersymmetric contributions to the rare decays B -> X_s \gamma and B -> X_s l+ l-. A global fit to the Wilson coefficients which contribute to these decays is performed from Monte Carlo generated data on B(B -> X_s \gamma) and the kinematic distributions associated with the final state lepton pair in B -> X_s l+ l-. This fit is then compared to supersymmetric predictions. Evaluation of the Wilson coefficients is carried out with several different patterns of the superpartner spectrum. We find that the B-Factories will be able to probe regions of the SUSY parameter space not accessible to LEPII, the Tevatron, and perhaps the LHC. We also employ the recent NLO calculation of the matrix elements for B -> X_s \gamma and find the bound mH+ > 300 GeV in two-Higgs-doublet models using present data.
[ { "created": "Thu, 10 Oct 1996 23:49:58 GMT", "version": "v1" } ]
2009-10-28
[ [ "Hewett", "JoAnne L.", "", "SLAC" ], [ "Wells", "James D.", "", "SLAC" ] ]
We quantify the ability of B-Factories to observe supersymmetric contributions to the rare decays B -> X_s \gamma and B -> X_s l+ l-. A global fit to the Wilson coefficients which contribute to these decays is performed from Monte Carlo generated data on B(B -> X_s \gamma) and the kinematic distributions associated with the final state lepton pair in B -> X_s l+ l-. This fit is then compared to supersymmetric predictions. Evaluation of the Wilson coefficients is carried out with several different patterns of the superpartner spectrum. We find that the B-Factories will be able to probe regions of the SUSY parameter space not accessible to LEPII, the Tevatron, and perhaps the LHC. We also employ the recent NLO calculation of the matrix elements for B -> X_s \gamma and find the bound mH+ > 300 GeV in two-Higgs-doublet models using present data.
hep-ph/9805360
Luis M. Bettencourt
Luis M.A. Bettencourt (Los Alamos) and C. Wetterich (U. of Heidelberg)
Time evolution of correlation functions for classical and quantum anharmonic oscillators
4 pages, 4 figures, RevTex, revised version
null
null
LAUR-98-1914, HD-THEP-98-19
hep-ph astro-ph cond-mat hep-th quant-ph
null
The time evolution of the correlation functions of an ensemble of anharmonic N-component oscillators with O(N) symmetry is described by a flow equation, exact up to corrections of order $1/N^2$. We find effective irreversibility. Nevertheless, analytical and numerical investigation reveals that the system does not reach thermal equilibrium for large times, even when $N\to \infty$. Depending on the initial distribution, the dynamics is asymptotically stable or it exhibits growing modes which break the conditions for the validity of the 1/N expansion for large time. We investigate both classical and quantum systems, the latter being the limit of an O(N) symmetric scalar quantum field theory in zero spatial dimensions.
[ { "created": "Mon, 18 May 1998 17:15:19 GMT", "version": "v1" }, { "created": "Fri, 29 May 1998 20:45:40 GMT", "version": "v2" } ]
2007-05-23
[ [ "Bettencourt", "Luis M. A.", "", "Los Alamos" ], [ "Wetterich", "C.", "", "U. of Heidelberg" ] ]
The time evolution of the correlation functions of an ensemble of anharmonic N-component oscillators with O(N) symmetry is described by a flow equation, exact up to corrections of order $1/N^2$. We find effective irreversibility. Nevertheless, analytical and numerical investigation reveals that the system does not reach thermal equilibrium for large times, even when $N\to \infty$. Depending on the initial distribution, the dynamics is asymptotically stable or it exhibits growing modes which break the conditions for the validity of the 1/N expansion for large time. We investigate both classical and quantum systems, the latter being the limit of an O(N) symmetric scalar quantum field theory in zero spatial dimensions.
0907.2414
Jonathan Rosner
Jonathan L. Rosner
Flavor Questions for the LHC
12 pages, 8 figures, presented at Flavor Physics and CP Violation 2009, Lake Placid, NY, May 27 - June 1, 2009, to be published by Proceedings of Science. Misprints corrected; reference added
PoS FPCP2009:051,2009
null
EFI 09-20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The physics underlying quark and lepton masses and mixings (the "flavor problem") is the least well understood aspect of the Standard Model. Some questions of flavor physics, and ways in which the LHC can help shed light on this problem, are described.
[ { "created": "Tue, 14 Jul 2009 19:40:51 GMT", "version": "v1" }, { "created": "Tue, 21 Jul 2009 16:06:34 GMT", "version": "v2" } ]
2014-11-20
[ [ "Rosner", "Jonathan L.", "" ] ]
The physics underlying quark and lepton masses and mixings (the "flavor problem") is the least well understood aspect of the Standard Model. Some questions of flavor physics, and ways in which the LHC can help shed light on this problem, are described.
2403.07984
Bei Zhou
Ryan Plestid, Bei Zhou
Final state radiation from high and ultrahigh energy neutrino interactions
10 pages and 5 figures. Comments are welcome
null
null
null
hep-ph astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charged leptons produced by high-energy and ultrahigh-energy neutrinos have a substantial probability of emitting prompt internal bremsstrahlung $\nu_\ell + N \rightarrow \ell + X + \gamma$. This can have important consequences for neutrino detection. We discuss observable consequences at high- and ultrahigh-energy neutrino telescopes and LHC's Forward Physics Facility. Logarithmic enhancements can be substantial (e.g.\ $\sim 20\%$) when either the charged lepton's energy, or the rest of the cascade, is measured. We comment on applications involving the inelasticity distribution including measurements of the $\nu/\bar{\nu}$ flux ratio, throughgoing muons, and double-bang signatures for high-energy neutrino observation. Furthermore, for ultrahigh-energy neutrino observation, we find that final state radiation affects flavor measurements and decreases the energy of both Earth-emergent tau leptons and regenerated tau neutrinos. Finally, for LHC's Forward Physics Facility, we find that final state radiation will impact future extractions of strange quark parton distribution functions. Final state radiation should be included in future analyses at neutrino telescopes and the Forward Physics Facility.
[ { "created": "Tue, 12 Mar 2024 18:00:13 GMT", "version": "v1" } ]
2024-03-14
[ [ "Plestid", "Ryan", "" ], [ "Zhou", "Bei", "" ] ]
Charged leptons produced by high-energy and ultrahigh-energy neutrinos have a substantial probability of emitting prompt internal bremsstrahlung $\nu_\ell + N \rightarrow \ell + X + \gamma$. This can have important consequences for neutrino detection. We discuss observable consequences at high- and ultrahigh-energy neutrino telescopes and LHC's Forward Physics Facility. Logarithmic enhancements can be substantial (e.g.\ $\sim 20\%$) when either the charged lepton's energy, or the rest of the cascade, is measured. We comment on applications involving the inelasticity distribution including measurements of the $\nu/\bar{\nu}$ flux ratio, throughgoing muons, and double-bang signatures for high-energy neutrino observation. Furthermore, for ultrahigh-energy neutrino observation, we find that final state radiation affects flavor measurements and decreases the energy of both Earth-emergent tau leptons and regenerated tau neutrinos. Finally, for LHC's Forward Physics Facility, we find that final state radiation will impact future extractions of strange quark parton distribution functions. Final state radiation should be included in future analyses at neutrino telescopes and the Forward Physics Facility.
hep-ph/9603425
Anna Jadczyk
S. Ciechanowicz, Z. Oziewicz, N. Popov
Relativistic and Neutrino Mass Effects in Partial Muon Capture
10 pages, LaTex file Corrected conclusions on neutrino mass effects to multipole amplitudes: Only bilinear neutrino mass terms are possible now in eq. (29)
J.Phys.G22:1601-1610,1996
10.1088/0954-3899/22/11/008
IFT UWr 906/96
hep-ph
null
The characteristics of the partial nuclear muon capture with massive left-handed Dirac neutrino and relativistic component of the muon wave function have been derived. The multipole amplitudes are given as a function of neutrino mass parameter and reduced nuclear matrix elements which are modified by the small component of the muon wave function. As an example, the capture rate, asymmetry and polarization of recoil nuclei are investigated in terms of these multipole amplitudes.
[ { "created": "Thu, 28 Mar 1996 10:23:44 GMT", "version": "v1" }, { "created": "Mon, 15 Apr 1996 15:19:06 GMT", "version": "v2" } ]
2008-11-26
[ [ "Ciechanowicz", "S.", "" ], [ "Oziewicz", "Z.", "" ], [ "Popov", "N.", "" ] ]
The characteristics of the partial nuclear muon capture with massive left-handed Dirac neutrino and relativistic component of the muon wave function have been derived. The multipole amplitudes are given as a function of neutrino mass parameter and reduced nuclear matrix elements which are modified by the small component of the muon wave function. As an example, the capture rate, asymmetry and polarization of recoil nuclei are investigated in terms of these multipole amplitudes.
1908.07011
Robert Szafron
Martin Beneke, Christoph Bobeth, Robert Szafron
Power-enhanced leading-logarithmic QED corrections to $B_q \to \mu^+\mu^-$
49 pages + appendices, 6 figures v2: added erratum concerning the QED part of the soft anomalous dimension. Numerical results are unchanged
JHEP10(2019)232
10.1007/JHEP10(2019)232
TUM-HEP-1212/19
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a systematic treatment of the previously discovered power-enhanced QED corrections to the leptonic decay $B_q\to \mu^+\mu^-$ ($q = d, s$) in the framework of soft-collinear effective theory (SCET). Employing two-step matching on SCET$_\text{I}$ and SCET$_\text{II}$, and the respective renormalization group equations, we sum the leading-logarithmic QED corrections and the mixed QED-QCD corrections to all orders in the couplings for the matrix element of the semileptonic weak effective operator $\sim Q_9$. We propose a treatment of the $B$-meson decay constant and light-cone distribution amplitude in the presence of process-specific QED corrections. Finally we include ultrasoft photon radiation and provide updated values of the non-radiative and radiative branching fractions of $B_q \to \mu^+\mu^-$ decay that include the double-logarithmic QED and QCD corrections.
[ { "created": "Mon, 19 Aug 2019 18:21:40 GMT", "version": "v1" }, { "created": "Mon, 21 Nov 2022 13:18:30 GMT", "version": "v2" } ]
2022-11-22
[ [ "Beneke", "Martin", "" ], [ "Bobeth", "Christoph", "" ], [ "Szafron", "Robert", "" ] ]
We provide a systematic treatment of the previously discovered power-enhanced QED corrections to the leptonic decay $B_q\to \mu^+\mu^-$ ($q = d, s$) in the framework of soft-collinear effective theory (SCET). Employing two-step matching on SCET$_\text{I}$ and SCET$_\text{II}$, and the respective renormalization group equations, we sum the leading-logarithmic QED corrections and the mixed QED-QCD corrections to all orders in the couplings for the matrix element of the semileptonic weak effective operator $\sim Q_9$. We propose a treatment of the $B$-meson decay constant and light-cone distribution amplitude in the presence of process-specific QED corrections. Finally we include ultrasoft photon radiation and provide updated values of the non-radiative and radiative branching fractions of $B_q \to \mu^+\mu^-$ decay that include the double-logarithmic QED and QCD corrections.
2206.04715
Andres Daniel Perez
Jong Soo Kim, Daniel E. Lopez-Fogliani, Andres D. Perez, Roberto Ruiz de Austri
Right-handed sneutrino and gravitino multicomponent dark matter in light of neutrino detectors
Discussions improved and expanded, version published in JCAP, 35 pages, 7 figures, 3 tables
JCAP04(2023)050
10.1088/1475-7516/2023/04/050
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the possibility that right-handed (RH) sneutrinos and gravitinos can coexist and explain the dark matter (DM) problem. We compare extensions of the minimal supersymmetric standard model (MSSM) and the next-to-MSSM (NMSSM) adding RH neutrinos superfields, with special emphasis on the latter. If the gravitino is the lightest supersymmetric particle (LSP) and the RH sneutrino the next-to-LSP (NLSP), the heavier particle decays to the former plus left-handed (LH) neutrinos through the mixing between the scalar partners of the LH and RH neutrinos. However, the interaction is suppressed by the Planck mass, and if the LH-RH sneutrino mixing parameter is small, $\ll O(10^{-2})$, a long-lived RH sneutrino NLSP is possible even surpassing the age of the Universe. As a byproduct, the NLSP to LSP decay produces monochromatic neutrinos in the ballpark of current and planned neutrino telescopes like Super-Kamiokande, IceCube and Antares that we use to set constraints and show prospects of detection. In the NMSSM+RHN, assuming a gluino mass parameter $M_3 = 3$ TeV we found the following lower limits for the gravitino mass $m_{3/2} \gtrsim 1-600$ GeV and the reheating temperature $T_R \gtrsim 10^5 - 3 \times 10^7$ GeV, for $m_{\tilde{\nu}_R} \sim 10-800$ GeV. If we take $M_3=10$ TeV, then the limits on $T_R$ are relaxed by one order of magnitude.
[ { "created": "Thu, 9 Jun 2022 18:11:50 GMT", "version": "v1" }, { "created": "Thu, 27 Apr 2023 10:21:36 GMT", "version": "v2" } ]
2023-04-28
[ [ "Kim", "Jong Soo", "" ], [ "Lopez-Fogliani", "Daniel E.", "" ], [ "Perez", "Andres D.", "" ], [ "de Austri", "Roberto Ruiz", "" ] ]
We investigate the possibility that right-handed (RH) sneutrinos and gravitinos can coexist and explain the dark matter (DM) problem. We compare extensions of the minimal supersymmetric standard model (MSSM) and the next-to-MSSM (NMSSM) adding RH neutrinos superfields, with special emphasis on the latter. If the gravitino is the lightest supersymmetric particle (LSP) and the RH sneutrino the next-to-LSP (NLSP), the heavier particle decays to the former plus left-handed (LH) neutrinos through the mixing between the scalar partners of the LH and RH neutrinos. However, the interaction is suppressed by the Planck mass, and if the LH-RH sneutrino mixing parameter is small, $\ll O(10^{-2})$, a long-lived RH sneutrino NLSP is possible even surpassing the age of the Universe. As a byproduct, the NLSP to LSP decay produces monochromatic neutrinos in the ballpark of current and planned neutrino telescopes like Super-Kamiokande, IceCube and Antares that we use to set constraints and show prospects of detection. In the NMSSM+RHN, assuming a gluino mass parameter $M_3 = 3$ TeV we found the following lower limits for the gravitino mass $m_{3/2} \gtrsim 1-600$ GeV and the reheating temperature $T_R \gtrsim 10^5 - 3 \times 10^7$ GeV, for $m_{\tilde{\nu}_R} \sim 10-800$ GeV. If we take $M_3=10$ TeV, then the limits on $T_R$ are relaxed by one order of magnitude.
1611.04332
Wolfgang Lucha
Wolfgang Lucha, Dmitri Melikhov
On the description of exotic hadron states within QCD sum rules
8 pages, 3 figures, talk presented at "Quark Confinement and the Hadron Spectrum XII" (28 August - 3 September 2016, Thessaloniki, Greece)
EPJ Web of Conferences 137 (2017) 05014
10.1051/epjconf/201713705014
HEPHY-PUB 977/16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Revisiting the QCD sum-rule description of exotic hadron states, we argue that, in order to arrive at trustable analyses of, for instance, strong decay widths of multiquarks, it is inevitable to adopt the QCD sum-rule approach beyond the leading perturbative level.
[ { "created": "Mon, 14 Nov 2016 10:50:40 GMT", "version": "v1" } ]
2017-03-27
[ [ "Lucha", "Wolfgang", "" ], [ "Melikhov", "Dmitri", "" ] ]
Revisiting the QCD sum-rule description of exotic hadron states, we argue that, in order to arrive at trustable analyses of, for instance, strong decay widths of multiquarks, it is inevitable to adopt the QCD sum-rule approach beyond the leading perturbative level.
hep-ph/0311089
Zurab Silagadze
Z.K. Silagadze
Vector-Meson-Dominance model contribution to $\pi^0 \to 4\gamma$
6 pages, LaTeX, references added, to be published in Physica Scripta
Phys.Scripta70:280-282,2004
10.1088/0031-8949/70/5/003
null
hep-ph
null
Vector-Meson-Dominance model contribution to $\pi^0 \to 4\gamma$ is calculated. The result confirms old estimates that this contribution is much smaller than the purely electromagnetic photon spliting graph contribution calculated earlier.
[ { "created": "Fri, 7 Nov 2003 09:37:06 GMT", "version": "v1" }, { "created": "Fri, 9 Apr 2004 04:31:54 GMT", "version": "v2" } ]
2008-11-26
[ [ "Silagadze", "Z. K.", "" ] ]
Vector-Meson-Dominance model contribution to $\pi^0 \to 4\gamma$ is calculated. The result confirms old estimates that this contribution is much smaller than the purely electromagnetic photon spliting graph contribution calculated earlier.
2309.12369
Jacob Scott
Prasanth Shyamsundar, Jacob L. Scott, Stephen Mrenna, Konstantin T. Matchev, Kyoungchul Kong
Variance Reduction via Simultaneous Importance Sampling and Control Variates Techniques Using Vegas
20 pages, 2 figures, 3 tables
null
null
null
hep-ph physics.data-an
http://creativecommons.org/licenses/by/4.0/
Monte Carlo (MC) integration is an important calculational technique in the physical sciences. Practical considerations require that the calculations are performed as accurately as possible for a given set of computational resources. To improve the accuracy of MC integration, a number of useful variance reduction algorithms have been developed, including importance sampling and control variates. In this work, we demonstrate how these two methods can be applied simultaneously, thus combining their benefits. We provide a python wrapper, named CoVVVR, which implements our approach in the Vegas program. The improvements are quantified with several benchmark examples from the literature.
[ { "created": "Tue, 19 Sep 2023 22:21:18 GMT", "version": "v1" }, { "created": "Wed, 24 Jan 2024 15:34:19 GMT", "version": "v2" } ]
2024-01-25
[ [ "Shyamsundar", "Prasanth", "" ], [ "Scott", "Jacob L.", "" ], [ "Mrenna", "Stephen", "" ], [ "Matchev", "Konstantin T.", "" ], [ "Kong", "Kyoungchul", "" ] ]
Monte Carlo (MC) integration is an important calculational technique in the physical sciences. Practical considerations require that the calculations are performed as accurately as possible for a given set of computational resources. To improve the accuracy of MC integration, a number of useful variance reduction algorithms have been developed, including importance sampling and control variates. In this work, we demonstrate how these two methods can be applied simultaneously, thus combining their benefits. We provide a python wrapper, named CoVVVR, which implements our approach in the Vegas program. The improvements are quantified with several benchmark examples from the literature.
hep-ph/0301127
Bodenm\"uller
H. Fritzsch, M. Gell-Mann
Light Cone Current Algebra
49 pages The paper was originally issued as a preprint in 1972 and published in a book edited by E. Gotsman, Dept. of Physics and Astronomy, Tel Aviv University. The reference reads "Licht Cone Current Algebra" by Harald Fritzsch and Murray Gell-Mann. After receicing many requests for reprints of this article describing some ideas which led to QCD, we decided to place the article in the e-Print archive
null
null
LMU 23/02
hep-ph
null
This talk follows by a few months a talk by the same authors on nearly the same subject at the Coral Gables Conference. The ideas presented here are basically the same, but with some amplification, some change of viewpoint, and a number of new questions for the future. For our own convenience, we have transcribed the Coral Gables paper, but with an added ninth section, entitled "Problems of light cone current algebra", dealing with our present views and emphasizing research topics that require study.
[ { "created": "Fri, 17 Jan 2003 09:31:20 GMT", "version": "v1" } ]
2007-05-23
[ [ "Fritzsch", "H.", "" ], [ "Gell-Mann", "M.", "" ] ]
This talk follows by a few months a talk by the same authors on nearly the same subject at the Coral Gables Conference. The ideas presented here are basically the same, but with some amplification, some change of viewpoint, and a number of new questions for the future. For our own convenience, we have transcribed the Coral Gables paper, but with an added ninth section, entitled "Problems of light cone current algebra", dealing with our present views and emphasizing research topics that require study.
hep-ph/0402170
Carlos Javier Solano Salinas
Virendra Gupta, C. J. Solano, and H. S. Mani
Predictions for hadron polarizations and left-right asymmetry in inclusive reactions involving photons
17 pages, 4 figures, article
null
null
null
hep-ph
null
A phenomenological model which has had some success in explaining polarization phenomena and left-right asymmetry in inclusive proton-proton scattering is considered for reactions involving photons. In particular, the reactions (a) $ \gamma + p \to H + X;$ (b) $\gamma + p (\uparrow) \to \pi^{\pm} + X $ and (c) $p(\uparrow) + p \to \gamma + X$ are considered where $\gamma =$ resolved photon and hyperon $ H = \Lambda^0, \Sigma^{\pm}$ etc. Predictions for hyperon polarization in (a) and the asymmetry (in (b) and (c)) provide further tests of this particular model. Feasibility of observing (b) at HERA and the effect of the polarization of the sea in the proton in $p (\uparrow) + p \to \pi^{\pm} + X$ is briefly discussed.
[ { "created": "Tue, 17 Feb 2004 15:52:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gupta", "Virendra", "" ], [ "Solano", "C. J.", "" ], [ "Mani", "H. S.", "" ] ]
A phenomenological model which has had some success in explaining polarization phenomena and left-right asymmetry in inclusive proton-proton scattering is considered for reactions involving photons. In particular, the reactions (a) $ \gamma + p \to H + X;$ (b) $\gamma + p (\uparrow) \to \pi^{\pm} + X $ and (c) $p(\uparrow) + p \to \gamma + X$ are considered where $\gamma =$ resolved photon and hyperon $ H = \Lambda^0, \Sigma^{\pm}$ etc. Predictions for hyperon polarization in (a) and the asymmetry (in (b) and (c)) provide further tests of this particular model. Feasibility of observing (b) at HERA and the effect of the polarization of the sea in the proton in $p (\uparrow) + p \to \pi^{\pm} + X$ is briefly discussed.
2304.06747
Jos\'e Filipe Bastos
Francisco Albergaria, G.C. Branco, Jos\'e Filipe Bastos, J.I. Silva-Marcos
Does Quark Mixing play a role in the Lepton Sector?
9 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a simple relation between the quark and the lepton mixing within the framework of type-I seesaw mechanism. We show that within our ansatz the empirical King-Mohapatra-Smirnov relation, which suggests a connection between the CKM and PMNS mixing where $|V^\text{PMNS}_{13}|\approx \frac{1}{\sqrt{2}}\sin(\theta_C) $, can be derived. This is possible within a restricted region of the Dirac and Majorana mass parameters.
[ { "created": "Thu, 13 Apr 2023 18:00:02 GMT", "version": "v1" } ]
2023-04-17
[ [ "Albergaria", "Francisco", "" ], [ "Branco", "G. C.", "" ], [ "Bastos", "José Filipe", "" ], [ "Silva-Marcos", "J. I.", "" ] ]
We suggest a simple relation between the quark and the lepton mixing within the framework of type-I seesaw mechanism. We show that within our ansatz the empirical King-Mohapatra-Smirnov relation, which suggests a connection between the CKM and PMNS mixing where $|V^\text{PMNS}_{13}|\approx \frac{1}{\sqrt{2}}\sin(\theta_C) $, can be derived. This is possible within a restricted region of the Dirac and Majorana mass parameters.
hep-ph/0508220
Valery Zhdanov
V.I.Zhdanov, M.S.Borshch
Ultra-Relativistic Expansion of Ideal Fluid with Linear Equation of State
10 pages
J.Phys.Stud. 9 (2005) 233-237
null
null
hep-ph
null
We study solutions of the relativistic hydrodynamical equations, which describe spherical or cylindrical expansion of ideal fluid. We derived approximate solutions involving two arbitrary functions, which describe asymptotic behavior of expanding fireballs in ultra-relativistic limit. In case of a sufficiently stiff linear equation of state the solution may be represented in form of an asymptotic series.
[ { "created": "Mon, 22 Aug 2005 11:55:47 GMT", "version": "v1" } ]
2016-09-06
[ [ "Zhdanov", "V. I.", "" ], [ "Borshch", "M. S.", "" ] ]
We study solutions of the relativistic hydrodynamical equations, which describe spherical or cylindrical expansion of ideal fluid. We derived approximate solutions involving two arbitrary functions, which describe asymptotic behavior of expanding fireballs in ultra-relativistic limit. In case of a sufficiently stiff linear equation of state the solution may be represented in form of an asymptotic series.
1005.5441
Claudio Coriano
Claudio Coriano, Marco Guzzi, George Lazarides, Antonio Mariano
Cosmological Properties of a Gauged Axion
29 pages, 5 figures. Revised version, accepted by Phys. Rev. D
Phys.Rev.D82:065013,2010
10.1103/PhysRevD.82.065013
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the most salient cosmological features of axions in extensions of the Standard Model with a gauged anomalous extra U(1) symmetry. The model is built by imposing the constraint of gauge invariance in the anomalous effective action, which is extended with Wess-Zumino counterterms. These generate axion-like interactions of the axions to the gauge fields and a gauged shift symmetry. The scalar sector is assumed to acquire a non-perturbative potential after inflation, at the electroweak phase transition, which induces a mixing of the Stuckelberg field of the model with the scalars of the electroweak sector, and at the QCD phase transition. We discuss the possible mechanisms of sequential misalignments which could affect the axions of these models, and generated, in this case, at both transitions. We compute the contribution of these particles to dark matter, quantifying their relic densities as a function of the Stuckelberg mass. We also show that models with a single anomalous U(1) in general do not account for the dark energy, due to the presence of mixed U(1)-SU(3) anomalies.
[ { "created": "Sat, 29 May 2010 08:53:17 GMT", "version": "v1" }, { "created": "Thu, 3 Jun 2010 21:39:56 GMT", "version": "v2" }, { "created": "Mon, 26 Jul 2010 13:16:18 GMT", "version": "v3" } ]
2015-03-17
[ [ "Coriano", "Claudio", "" ], [ "Guzzi", "Marco", "" ], [ "Lazarides", "George", "" ], [ "Mariano", "Antonio", "" ] ]
We analyze the most salient cosmological features of axions in extensions of the Standard Model with a gauged anomalous extra U(1) symmetry. The model is built by imposing the constraint of gauge invariance in the anomalous effective action, which is extended with Wess-Zumino counterterms. These generate axion-like interactions of the axions to the gauge fields and a gauged shift symmetry. The scalar sector is assumed to acquire a non-perturbative potential after inflation, at the electroweak phase transition, which induces a mixing of the Stuckelberg field of the model with the scalars of the electroweak sector, and at the QCD phase transition. We discuss the possible mechanisms of sequential misalignments which could affect the axions of these models, and generated, in this case, at both transitions. We compute the contribution of these particles to dark matter, quantifying their relic densities as a function of the Stuckelberg mass. We also show that models with a single anomalous U(1) in general do not account for the dark energy, due to the presence of mixed U(1)-SU(3) anomalies.
hep-ph/0702042
Peter Boyle
D. J. Antonio, P. A. Boyle, T. Blum, N. H. Christ, S. D. Cohen, C. Dawson, T. Izubuchi, R. D. Kenway, C. Jung, S. Li, M. F. Lin, R. D. Mawhinney, J. Noaki, S. Ohta, B. J. Pendleton, E. E. Scholz, A. Soni, R. J. Tweedie, A. Yamaguchi (RBC and UKQCD Collaborations)
Neutral kaon mixing from 2+1 flavor Domain Wall QCD
4 pages, 4 figures. RBC and UKQCD collaborations
Phys.Rev.Lett.100:032001,2008
10.1103/PhysRevLett.100.032001
Edinburgh 2007/2, RBRC-638,CU-TP-1174,KEK-TH-1131
hep-ph hep-lat
null
We present the first results for neutral kaon mixing using 2+1 flavors of domain wall fermions. A new approach is used to extrapolate to the physical up and down quark masses from our numerical studies with pion masses in the range 240 -- 420 MeV; only $SU(2)_L \times SU(2)_R$ chiral symmetry is assumed and the kaon is not assumed to be light. Our main result is $B_K^{\bar{\rm MS}}(2 \mathrm{GeV}) = 0.524(10)(28)$ where the first error is statistical and the second incorporates estimates for all systematic errors.
[ { "created": "Mon, 5 Feb 2007 16:52:22 GMT", "version": "v1" }, { "created": "Fri, 9 Feb 2007 00:29:03 GMT", "version": "v2" }, { "created": "Thu, 6 Sep 2007 10:51:22 GMT", "version": "v3" }, { "created": "Mon, 22 Oct 2007 12:29:12 GMT", "version": "v4" } ]
2008-11-26
[ [ "Antonio", "D. J.", "", "RBC and UKQCD Collaborations" ], [ "Boyle", "P. A.", "", "RBC and UKQCD Collaborations" ], [ "Blum", "T.", "", "RBC and UKQCD Collaborations" ], [ "Christ", "N. H.", "", "RBC and UKQCD Collaborations" ], [ "Cohen", "S. D.", "", "RBC and UKQCD Collaborations" ], [ "Dawson", "C.", "", "RBC and UKQCD Collaborations" ], [ "Izubuchi", "T.", "", "RBC and UKQCD Collaborations" ], [ "Kenway", "R. D.", "", "RBC and UKQCD Collaborations" ], [ "Jung", "C.", "", "RBC and UKQCD Collaborations" ], [ "Li", "S.", "", "RBC and UKQCD Collaborations" ], [ "Lin", "M. F.", "", "RBC and UKQCD Collaborations" ], [ "Mawhinney", "R. D.", "", "RBC and UKQCD Collaborations" ], [ "Noaki", "J.", "", "RBC and UKQCD Collaborations" ], [ "Ohta", "S.", "", "RBC and UKQCD Collaborations" ], [ "Pendleton", "B. J.", "", "RBC and UKQCD Collaborations" ], [ "Scholz", "E. E.", "", "RBC and UKQCD Collaborations" ], [ "Soni", "A.", "", "RBC and UKQCD Collaborations" ], [ "Tweedie", "R. J.", "", "RBC and UKQCD Collaborations" ], [ "Yamaguchi", "A.", "", "RBC and UKQCD Collaborations" ] ]
We present the first results for neutral kaon mixing using 2+1 flavors of domain wall fermions. A new approach is used to extrapolate to the physical up and down quark masses from our numerical studies with pion masses in the range 240 -- 420 MeV; only $SU(2)_L \times SU(2)_R$ chiral symmetry is assumed and the kaon is not assumed to be light. Our main result is $B_K^{\bar{\rm MS}}(2 \mathrm{GeV}) = 0.524(10)(28)$ where the first error is statistical and the second incorporates estimates for all systematic errors.
1410.0508
Alan D. Martin
V.A. Khoze, A.D. Martin, M.G. Ryskin
t dependence of the slope of the high energy elastic pp cross section
16 pages, 11 figures; IPPP/14/86, DCPT/14/172, version to be published in J.Phys.G
null
10.1088/0954-3899/42/2/025003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the main factors which cause the variation of the value of the local slope of the elastic pp cross section B(t)=d[\ln(d\sigma_el(pp)/dt]/dt with t. Namely, we discuss the role of the pion-loop insertion in the pomeron trajectory, the t-dependence of the pomeron-nucleon coupling and the role of the eikonalization of the proton-proton amplitude in both the one- and two-channel eikonal models.
[ { "created": "Thu, 2 Oct 2014 10:55:16 GMT", "version": "v1" }, { "created": "Wed, 26 Nov 2014 14:25:01 GMT", "version": "v2" } ]
2015-06-23
[ [ "Khoze", "V. A.", "" ], [ "Martin", "A. D.", "" ], [ "Ryskin", "M. G.", "" ] ]
We consider the main factors which cause the variation of the value of the local slope of the elastic pp cross section B(t)=d[\ln(d\sigma_el(pp)/dt]/dt with t. Namely, we discuss the role of the pion-loop insertion in the pomeron trajectory, the t-dependence of the pomeron-nucleon coupling and the role of the eikonalization of the proton-proton amplitude in both the one- and two-channel eikonal models.
0908.0730
Joerg Jaeckel
Joerg Jaeckel
Strong fields and recycled accelerator parts as a laboratory for fundamental physics
14 pages, 6 figures. Contributed to the proceedings of the workshop "Advanced QED Methods for Future Accelerators"
J.Phys.Conf.Ser.198:012008,2009
10.1088/1742-6596/198/1/012008
IPPP/09/60; DCPT/09/120
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Over the last few years it has become increasingly clear that low energy, but high precision experiments provide a powerful and complementary window to physics beyond the Standard Model. In this note we illuminate this by using minicharged particles as an example. We argue that minicharged particles arise naturally in extensions of the Standard Model. Compatibility with charge quantization arguments suggests that minicharged particles typically arise together with a massless hidden sector U(1) gauge field. We present several low energy experiments employing strong lasers, electric and magnetic fields that can be used to search for (light) minicharged particles and their accompanying U(1) gauge boson.
[ { "created": "Wed, 5 Aug 2009 20:37:51 GMT", "version": "v1" } ]
2010-01-06
[ [ "Jaeckel", "Joerg", "" ] ]
Over the last few years it has become increasingly clear that low energy, but high precision experiments provide a powerful and complementary window to physics beyond the Standard Model. In this note we illuminate this by using minicharged particles as an example. We argue that minicharged particles arise naturally in extensions of the Standard Model. Compatibility with charge quantization arguments suggests that minicharged particles typically arise together with a massless hidden sector U(1) gauge field. We present several low energy experiments employing strong lasers, electric and magnetic fields that can be used to search for (light) minicharged particles and their accompanying U(1) gauge boson.
hep-ph/9611390
Andrew Gentles
A. J. Gentles and D. A. Ross
Chiral Symmetry Breaking in Axial Gauge QCD from the Dyson Schwinger Equations
18 pages + 7 epsf figures (included). Uses Revtex 3.0 and epsf.sty
null
null
SHEP-96-32, November 1996
hep-ph
null
We investigate the nonperturbative behaviour of the quark propagator in axial gauge using a truncation of the Dyson-Schwinger equations which respects the Ward-Takahashi identity and multiplicative renormalisability. We demonstrate that above a critical coupling $\alpha_c$, which depends on the form of the gluon propagator, one can obtain massive solutions for both explicit and dynamically generated quark masses. The stability of these is discussed in the context of the Cornwall-Jackiw-Tomboulis effective action.
[ { "created": "Thu, 21 Nov 1996 20:20:24 GMT", "version": "v1" } ]
2007-05-23
[ [ "Gentles", "A. J.", "" ], [ "Ross", "D. A.", "" ] ]
We investigate the nonperturbative behaviour of the quark propagator in axial gauge using a truncation of the Dyson-Schwinger equations which respects the Ward-Takahashi identity and multiplicative renormalisability. We demonstrate that above a critical coupling $\alpha_c$, which depends on the form of the gluon propagator, one can obtain massive solutions for both explicit and dynamically generated quark masses. The stability of these is discussed in the context of the Cornwall-Jackiw-Tomboulis effective action.
0805.3887
Diego Guadagnoli
Andrzej J. Buras, Diego Guadagnoli
Correlations among new CP violating effects in Delta F = 2 observables
8 pages, 5 figures, 2 tables. v2: additional negative correction to epsilon_K included, other input updated, numerics slightly changed. Conclusions unchanged. References added
Phys.Rev.D78:033005,2008
10.1103/PhysRevD.78.033005
TUM-HEP-688/08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We point out that the observed CP violation in Bd - bar{Bd} mixing, taking into account the measured ratio Delta Md / Delta Ms, the recently improved lattice value of the non-perturbative parameter BK and an additional effective suppression factor kappa_epsilon ~= 0.92 in epsilon_K neglected sofar in most analyses, may be insufficient to describe the measured value of epsilon_K within the Standard Model (SM), thus hinting at new CP violating contributions to the K - bar{K} and/or Bd - bar{Bd} systems. Furthermore, assuming that Delta Md / Delta Ms is SM-like, the signs and the magnitudes of new physics effects in epsilon_K and in the CP asymmetries S_{psi Ks} and S_{psi phi} may turn out to be correlated. For example, in a scenario with new CP-phases in Bd and Bs mixings being approximately equal and negative, a common new phase ~= - 5 degrees could remove the tension between epsilon_K and S_{psi Ks} present in the SM and simultaneously accommodate, at least partly, the recent claim of S_{psi phi} being much larger than the SM expectation. We emphasize the importance of precise determinations of Vcb, BK, FK and xi_s, to which the parameter epsilon_K and its correlation with the CP violation in the Bd - bar{Bd} system are very sensitive.
[ { "created": "Mon, 26 May 2008 16:28:01 GMT", "version": "v1" }, { "created": "Fri, 6 Jun 2008 18:52:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Buras", "Andrzej J.", "" ], [ "Guadagnoli", "Diego", "" ] ]
We point out that the observed CP violation in Bd - bar{Bd} mixing, taking into account the measured ratio Delta Md / Delta Ms, the recently improved lattice value of the non-perturbative parameter BK and an additional effective suppression factor kappa_epsilon ~= 0.92 in epsilon_K neglected sofar in most analyses, may be insufficient to describe the measured value of epsilon_K within the Standard Model (SM), thus hinting at new CP violating contributions to the K - bar{K} and/or Bd - bar{Bd} systems. Furthermore, assuming that Delta Md / Delta Ms is SM-like, the signs and the magnitudes of new physics effects in epsilon_K and in the CP asymmetries S_{psi Ks} and S_{psi phi} may turn out to be correlated. For example, in a scenario with new CP-phases in Bd and Bs mixings being approximately equal and negative, a common new phase ~= - 5 degrees could remove the tension between epsilon_K and S_{psi Ks} present in the SM and simultaneously accommodate, at least partly, the recent claim of S_{psi phi} being much larger than the SM expectation. We emphasize the importance of precise determinations of Vcb, BK, FK and xi_s, to which the parameter epsilon_K and its correlation with the CP violation in the Bd - bar{Bd} system are very sensitive.
1201.2543
Ye-Ling Zhou
Zhi-zhong Xing and Ye-Ling Zhou
Enhanced Electromagnetic Transition Dipole Moments and Radiative Decays of Massive Neutrinos due to the Seesaw-induced Non-unitary Effects
10 pages, 4 figures, more discussions and references added, accepted for publication in PLB
null
10.1016/j.physletb.2012.07.043
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a simple extension of the standard electroweak theory where the phenomenon of lepton flavor mixing is described by a 3x3 unitary matrix V, the electric and magnetic dipole moments of three active neutrinos are suppressed not only by their tiny masses but also by the Glashow-Iliopoulos-Maiani (GIM) mechanism. We show that it is possible to lift the GIM suppression if the canonical seesaw mechanism of neutrino mass generation, which allows V to be slightly non-unitary, is taken into account. In view of current experimental constraints on the non-unitarity of V, we find that the effective electromagnetic transition dipole moments of three light Majorana neutrinos and the rates of their radiative decays can be maximally enhanced by a factor of O(10^2) and a factor of O(10^4), respectively. This important observation reveals an intrinsic and presumably significant correlation between the electromagnetic properties of massive neutrinos and the origin of their small masses.
[ { "created": "Thu, 12 Jan 2012 12:26:53 GMT", "version": "v1" }, { "created": "Tue, 24 Apr 2012 14:18:22 GMT", "version": "v2" }, { "created": "Tue, 7 Aug 2012 12:48:35 GMT", "version": "v3" } ]
2012-08-08
[ [ "Xing", "Zhi-zhong", "" ], [ "Zhou", "Ye-Ling", "" ] ]
In a simple extension of the standard electroweak theory where the phenomenon of lepton flavor mixing is described by a 3x3 unitary matrix V, the electric and magnetic dipole moments of three active neutrinos are suppressed not only by their tiny masses but also by the Glashow-Iliopoulos-Maiani (GIM) mechanism. We show that it is possible to lift the GIM suppression if the canonical seesaw mechanism of neutrino mass generation, which allows V to be slightly non-unitary, is taken into account. In view of current experimental constraints on the non-unitarity of V, we find that the effective electromagnetic transition dipole moments of three light Majorana neutrinos and the rates of their radiative decays can be maximally enhanced by a factor of O(10^2) and a factor of O(10^4), respectively. This important observation reveals an intrinsic and presumably significant correlation between the electromagnetic properties of massive neutrinos and the origin of their small masses.
0811.0368
Mark Strikman
L.Frankfurt (TAU), M.Strikman (PSU), M.Zhalov (PNPI)
Tracking fast small color dipoles through strong gluon fields at the LHC
4 pages, final version published in PRL
null
10.1103/PhysRevLett.102.232001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the process gamma +A \to J/psi + gap + X at large momentum transfer provides a quick and effective way to test onset of a novel perturbative QCD regime of strong absorption for the interaction of small dipoles at the collider energies. We find that already the first heavy ion run at the LHC will allow to study this reaction with sufficient statistics via ultraperipheral collisions hence probing the interaction of q\bar q dipoles of sizes ~ 0.2 fm with nuclear media down to x ~ 10^{-5}.
[ { "created": "Mon, 3 Nov 2008 19:00:34 GMT", "version": "v1" }, { "created": "Tue, 18 Nov 2008 17:08:06 GMT", "version": "v2" }, { "created": "Sat, 22 Nov 2008 14:49:21 GMT", "version": "v3" }, { "created": "Sat, 27 Jun 2009 10:44:30 GMT", "version": "v4" } ]
2013-05-29
[ [ "Frankfurt", "L.", "", "TAU" ], [ "Strikman", "M.", "", "PSU" ], [ "Zhalov", "M.", "", "PNPI" ] ]
We argue that the process gamma +A \to J/psi + gap + X at large momentum transfer provides a quick and effective way to test onset of a novel perturbative QCD regime of strong absorption for the interaction of small dipoles at the collider energies. We find that already the first heavy ion run at the LHC will allow to study this reaction with sufficient statistics via ultraperipheral collisions hence probing the interaction of q\bar q dipoles of sizes ~ 0.2 fm with nuclear media down to x ~ 10^{-5}.
1712.09986
Yu Jia
Feng Feng, Saadi Ishaq, Yu Jia, Jia-Yue Zhang
Fragmentation function of gluon into spin-singlet $P$-wave quarkonium
10 pages, 2 figures
Phys. Rev. D 102, 014038 (2020)
10.1103/PhysRevD.102.014038
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Following the operator definition of the fragmentation function developed by Collins and Soper, we compute the gluon-to-$h_c$ fragmentation function at the lowest order in the velocity expansion in NRQCD factorization approach. Utilizing some modern technique developed in the area of multi-loop calculation, we are able to analytically deduce the infrared-finite color-singlet short-distance coefficient associated with the fragmentation function. The fragmentation probability for gluon into $h_c$ is estimated to be order $10^{-6}$.
[ { "created": "Thu, 28 Dec 2017 18:48:24 GMT", "version": "v1" } ]
2020-07-29
[ [ "Feng", "Feng", "" ], [ "Ishaq", "Saadi", "" ], [ "Jia", "Yu", "" ], [ "Zhang", "Jia-Yue", "" ] ]
Following the operator definition of the fragmentation function developed by Collins and Soper, we compute the gluon-to-$h_c$ fragmentation function at the lowest order in the velocity expansion in NRQCD factorization approach. Utilizing some modern technique developed in the area of multi-loop calculation, we are able to analytically deduce the infrared-finite color-singlet short-distance coefficient associated with the fragmentation function. The fragmentation probability for gluon into $h_c$ is estimated to be order $10^{-6}$.
2307.14449
Federica Capellino
Federica Capellino, Andrea Dubla, Stefan Floerchinger, Eduardo Grossi, Andreas Kirchner, Silvia Masciocchi
Fluid dynamics of charm quarks in the quark--gluon plasma
11 pages, 6 figures
Phys. Rev. D 108, 116011 (2023)
10.1103/PhysRevD.108.116011
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A fluid-dynamic approach to charm-quark diffusion in the quark-gluon plasma (QGP) is developed for the first time. Results for integrated yields and momentum distributions of charmed hadrons obtained with a fluid-dynamic description for the dynamics of the QGP coupled to an additional heavy-quark-antiquark current are shown. In addition to the thermodynamic Equation of State (EoS), this description uses a heavy-quark diffusion constant which we take from Lattice QCD calculations. The results describe quantitatively experimental data measured at the LHC at the center-of-mass energy of $\sqrt{s_{\rm NN}}$ = 5.02 TeV up to $p_{\rm T}\sim$ 4-5 GeV/$c$, showing that charm quarks undergo a very fast hydrodynamization in the medium created by ultrarelativistic heavy-ion collisions.
[ { "created": "Wed, 26 Jul 2023 18:41:21 GMT", "version": "v1" }, { "created": "Mon, 15 Jan 2024 10:30:17 GMT", "version": "v2" } ]
2024-01-17
[ [ "Capellino", "Federica", "" ], [ "Dubla", "Andrea", "" ], [ "Floerchinger", "Stefan", "" ], [ "Grossi", "Eduardo", "" ], [ "Kirchner", "Andreas", "" ], [ "Masciocchi", "Silvia", "" ] ]
A fluid-dynamic approach to charm-quark diffusion in the quark-gluon plasma (QGP) is developed for the first time. Results for integrated yields and momentum distributions of charmed hadrons obtained with a fluid-dynamic description for the dynamics of the QGP coupled to an additional heavy-quark-antiquark current are shown. In addition to the thermodynamic Equation of State (EoS), this description uses a heavy-quark diffusion constant which we take from Lattice QCD calculations. The results describe quantitatively experimental data measured at the LHC at the center-of-mass energy of $\sqrt{s_{\rm NN}}$ = 5.02 TeV up to $p_{\rm T}\sim$ 4-5 GeV/$c$, showing that charm quarks undergo a very fast hydrodynamization in the medium created by ultrarelativistic heavy-ion collisions.
0907.0951
Vitaly Okorokov A
V.A. Okorokov (Moscow Engineering Physics Institute)
Slope analysis for elastic nucleon-nucleon scattering
12 pages, 8 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on the all available experimental data at low and intermediate momentum transfer values. Energy dependence of the elastic diffraction slopes is approximated by various analytic functions. The expanded "standard" logarithmic approximations with minimum number of free parameters allow to describe experimental slopes in all available energy range reasonably. The estimations of asymptotic shrinkage parameter $\alpha'_{\cal{P}}$ were obtained for various $|t|$ domains based on the all available experimental data. Various approximations differ from each other both in the low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering at NICA, RHIC and LHC energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions.
[ { "created": "Mon, 6 Jul 2009 09:53:32 GMT", "version": "v1" }, { "created": "Wed, 31 Dec 2014 10:17:43 GMT", "version": "v2" } ]
2015-01-05
[ [ "Okorokov", "V. A.", "", "Moscow Engineering Physics Institute" ] ]
The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on the all available experimental data at low and intermediate momentum transfer values. Energy dependence of the elastic diffraction slopes is approximated by various analytic functions. The expanded "standard" logarithmic approximations with minimum number of free parameters allow to describe experimental slopes in all available energy range reasonably. The estimations of asymptotic shrinkage parameter $\alpha'_{\cal{P}}$ were obtained for various $|t|$ domains based on the all available experimental data. Various approximations differ from each other both in the low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering at NICA, RHIC and LHC energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions.
1605.09404
John W. Moffat
J. W. Moffat
Quarks and Bosons as Composite Particles
5 pages. No figures. Revised text. arXiv admin note: substantial text overlap with arXiv:1401.3029
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A composite model of quarks and bosons is proposed in which a spin $1/2$ isospin doublet $\psi$ is the basic building block of quarks, $W^\pm$, $Z^0$ and Higgs boson $H^0$ in the standard model. The $\psi$ has two components $\alpha$ and $\beta$ with charges $Q_\alpha=\frac{2}{3}e$ and $Q_\beta=-\frac{1}{3}e$, respectively. The two constituent flavors $\alpha$ and $\beta$ combine to form the three generations of colored standard model quark flavors. A triplet of massless hypergluons binds the constituents called geminis. The strong confining non-Abelian $SU(2)_C$ constituent color dynamics has a confining energy scale $\Lambda_{CD}$. The leptons, the massless photon, gluons and triplet of hypergluons are treated as point particles. The non-Abelian $SU(2)_C$ color dynamics satisfies asymptotic freedom, and, together with the compositeness of the Higgs boson $H^0$, resolve the Higgs mass and gauge hierarchy fine-tuning problems.
[ { "created": "Mon, 30 May 2016 20:26:59 GMT", "version": "v1" }, { "created": "Mon, 2 Jan 2017 19:07:27 GMT", "version": "v2" } ]
2017-01-04
[ [ "Moffat", "J. W.", "" ] ]
A composite model of quarks and bosons is proposed in which a spin $1/2$ isospin doublet $\psi$ is the basic building block of quarks, $W^\pm$, $Z^0$ and Higgs boson $H^0$ in the standard model. The $\psi$ has two components $\alpha$ and $\beta$ with charges $Q_\alpha=\frac{2}{3}e$ and $Q_\beta=-\frac{1}{3}e$, respectively. The two constituent flavors $\alpha$ and $\beta$ combine to form the three generations of colored standard model quark flavors. A triplet of massless hypergluons binds the constituents called geminis. The strong confining non-Abelian $SU(2)_C$ constituent color dynamics has a confining energy scale $\Lambda_{CD}$. The leptons, the massless photon, gluons and triplet of hypergluons are treated as point particles. The non-Abelian $SU(2)_C$ color dynamics satisfies asymptotic freedom, and, together with the compositeness of the Higgs boson $H^0$, resolve the Higgs mass and gauge hierarchy fine-tuning problems.
1010.3982
Jenifer Nebreda
J. Nebreda and J. R. Pelaez (U. Complutense de Madrid)
Dependence on the quark masses of elastic phase shifts and light resonances within standard and unitarized Chiral Perturbation Theory
To appear in the proceedings of the 12th International Conference on Meson-Nucleon Physics and the Structure of the Nucleon, College of William and Mary Williamsburg, Virginia, May 31-June 4, 2010
null
10.1063/1.3647220
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the dependence of the pion-pion scattering phase shifts on the light quark mass in both standard and unitarized SU(2) Chiral Perturbation Theory (ChPT) to one and two loops. We then use unitarized SU(3) ChPT to study the elastic f_0(600), kappa(800), rho(770) and K*(892) resonances. The quark masses are varied up to values of interest for lattice studies. We find a very soft dependence on the light quark mass of the pion-pion phase shifts at one loop and slightly stronger at two loops and a good agreement with lattice results. The SU(3) analysis shows that the properties of the rho(770) and K*(892) depend smoothly on the quark mass whereas the scalar resonances present a non-analyticity at high quark masses. We also confirm the lattice assumption of quark mass independence of the vector two-meson coupling that, however, is violated for scalars.
[ { "created": "Tue, 19 Oct 2010 17:21:50 GMT", "version": "v1" } ]
2015-05-20
[ [ "Nebreda", "J.", "", "U. Complutense de Madrid" ], [ "Pelaez", "J. R.", "", "U. Complutense de Madrid" ] ]
We study the dependence of the pion-pion scattering phase shifts on the light quark mass in both standard and unitarized SU(2) Chiral Perturbation Theory (ChPT) to one and two loops. We then use unitarized SU(3) ChPT to study the elastic f_0(600), kappa(800), rho(770) and K*(892) resonances. The quark masses are varied up to values of interest for lattice studies. We find a very soft dependence on the light quark mass of the pion-pion phase shifts at one loop and slightly stronger at two loops and a good agreement with lattice results. The SU(3) analysis shows that the properties of the rho(770) and K*(892) depend smoothly on the quark mass whereas the scalar resonances present a non-analyticity at high quark masses. We also confirm the lattice assumption of quark mass independence of the vector two-meson coupling that, however, is violated for scalars.
hep-ph/0104314
V. Kartvelishvili
V. Kartvelishvili (University of Manchester, UK) and R. Kvatadze (High Energy Physics Institute, Tbilisi State University, Georgia)
Event weights for simulating Bose-Einstein correlations
16 pages, 8 .eps figures, 5 tables
Phys.Lett. B514 (2001) 7-18
10.1016/S0370-2693(01)00769-9
MAN/HEP/2001/2
hep-ph
null
An event weighting method for simulating Bose-Einstein effects in hadronic final states is presented. The weight for an event depends on the momentum distribution of identical bosons in the event. By using a theoretically motivated parametrisation allowing weights below as well as above unity, the necessity of a weight-rescaling procedure is eliminated. A single parameter is used to adjust the average event weight to unity. Once adjusted, the same value of the parameter gives average event weights that are essentially independent of energy, initial quark flavour, multiplicity and jet topology. The influence of Bose-Estein correlations on various measurable quantities in W pair production is found to be small. In particular, none of the scenarios considered resulted in a W mass shift larger than 20 MeV.
[ { "created": "Mon, 30 Apr 2001 20:58:32 GMT", "version": "v1" } ]
2009-11-07
[ [ "Kartvelishvili", "V.", "", "University of Manchester, UK" ], [ "Kvatadze", "R.", "", "High\n Energy Physics Institute, Tbilisi State University, Georgia" ] ]
An event weighting method for simulating Bose-Einstein effects in hadronic final states is presented. The weight for an event depends on the momentum distribution of identical bosons in the event. By using a theoretically motivated parametrisation allowing weights below as well as above unity, the necessity of a weight-rescaling procedure is eliminated. A single parameter is used to adjust the average event weight to unity. Once adjusted, the same value of the parameter gives average event weights that are essentially independent of energy, initial quark flavour, multiplicity and jet topology. The influence of Bose-Estein correlations on various measurable quantities in W pair production is found to be small. In particular, none of the scenarios considered resulted in a W mass shift larger than 20 MeV.
hep-ph/0703224
RongGang Ping
Hong Chen, Rong-Gang Ping
Study of X(1812) as a $(K^*\bar K^*)$ Molecular State
4 figures, 10 pages
J.Phys.G34:2679-2690,2007
10.1088/0954-3899/34/12/012
null
hep-ph
null
We investigate the decay and the production mechanism of the resonance X(1812) recently observed in the $\jp\to\gamma X(1812), X(1812)\to\omega\phi$ at BESII. The decay widths of $X(1812)\to\eta\eta'$,$ \eta\eta$,$ \omega\phi$,$ K^+K^-$,$ \rho^+\rho^-$, $ \omega\omega$,$ K^{*+}K^{*-}$ and $\pi^+\pi^-$ are evaluated based on the scenario of the X(1812) as a candidate of $(\ksks)$ molecule. It turns out that the quark exchange mechanism plays an important role in the understanding of the large decay width for the $X(1812)\to\omega\phi$. It is also found that the decay widths for $X(1812)\to\eta\eta'$ and $\eta\eta$ are enhanced by the quark exchange mechanism. These channels are suggested to be the tools to test the molecular scenario in experiment. The branching fraction of $Br(X\to\omega\phi)$ is evaluated to be about 4.60%. Searches for additional evidence about the X(1812) in $\jp$ radiative decays are reviewed. In the molecular scenario, the X(1812) production rate is also evaluated to be $\Gamma(\jp\to\gamma X)/\Gamma(\jp\to\gamma K^{*+}K^{*-})=2.13^{+7.41}_{-1.85}$, which is close to the measured value $2.83\pm0.92$.
[ { "created": "Wed, 21 Mar 2007 02:35:38 GMT", "version": "v1" }, { "created": "Fri, 9 Nov 2007 02:58:24 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chen", "Hong", "" ], [ "Ping", "Rong-Gang", "" ] ]
We investigate the decay and the production mechanism of the resonance X(1812) recently observed in the $\jp\to\gamma X(1812), X(1812)\to\omega\phi$ at BESII. The decay widths of $X(1812)\to\eta\eta'$,$ \eta\eta$,$ \omega\phi$,$ K^+K^-$,$ \rho^+\rho^-$, $ \omega\omega$,$ K^{*+}K^{*-}$ and $\pi^+\pi^-$ are evaluated based on the scenario of the X(1812) as a candidate of $(\ksks)$ molecule. It turns out that the quark exchange mechanism plays an important role in the understanding of the large decay width for the $X(1812)\to\omega\phi$. It is also found that the decay widths for $X(1812)\to\eta\eta'$ and $\eta\eta$ are enhanced by the quark exchange mechanism. These channels are suggested to be the tools to test the molecular scenario in experiment. The branching fraction of $Br(X\to\omega\phi)$ is evaluated to be about 4.60%. Searches for additional evidence about the X(1812) in $\jp$ radiative decays are reviewed. In the molecular scenario, the X(1812) production rate is also evaluated to be $\Gamma(\jp\to\gamma X)/\Gamma(\jp\to\gamma K^{*+}K^{*-})=2.13^{+7.41}_{-1.85}$, which is close to the measured value $2.83\pm0.92$.
hep-ph/9504280
null
M. Chaichian, P. Chiappetta, J.-M. Gerard, R. Gonzalez Felipe and J. Weyers
TOP-INDUCED ELECTROWEAK BREAKING IN THE MINIMAL SUPERSYMMETRIC STANDARD MODEL
10 pages, Latex, 6 Postcript Figures
Phys.Lett. B365 (1996) 141-148
10.1016/0370-2693(95)01238-9
HU-SEFT R 1995-08, UCL-IPT-95-07, CPT-95/PE.3185
hep-ph
null
Severe constraints on parameters of the minimal supersymmetric standard model follow from a dynamical electroweak symmetry breaking mechanism dominated by top and stop loops. In particular, the lightest Higgs boson mass is expected to be smaller than 100 GeV.
[ { "created": "Tue, 11 Apr 1995 13:40:30 GMT", "version": "v1" } ]
2009-10-28
[ [ "Chaichian", "M.", "" ], [ "Chiappetta", "P.", "" ], [ "Gerard", "J. -M.", "" ], [ "Felipe", "R. Gonzalez", "" ], [ "Weyers", "J.", "" ] ]
Severe constraints on parameters of the minimal supersymmetric standard model follow from a dynamical electroweak symmetry breaking mechanism dominated by top and stop loops. In particular, the lightest Higgs boson mass is expected to be smaller than 100 GeV.
hep-ph/0601035
Branimir Zauner
B. Zauner, A. Svarc and S. Ceci
The importance of piN &#8594; K Lambda process for the pole structure of the P11 partial wave T-matrix in the coupled channel pion-nucleon partial wave analysis
4 pages, 5 figures; talk held at NSTAR 2005 in Tallahassee, FL
null
10.1142/9789812773333_0055
null
hep-ph
null
The pole structure of the P11 pion-nucleon partial wave is examined with the emphasis on the 1700 MeV energy domain. The mechanism of eliminating continuum ambiguities in pion-nucleon partial wave analyses by using the coupled channel formalism, presented elsewhere for the piN -> etaN channel, is applied for the piN -> K Lambda channel, with the aim to clarify the issue whether physical reality requires none (VPI/GWU), one (KH80, CMB, Kent, Pittsburgh/ANL, Giessen), or possibly two (Zagreb) poles of the partial wave T-matrix in the 1700 MeV range. The role of second inelastic channel for resolving the dilemma is demonstrated. It is pointed out that the experiments for the piN -> K Lambda and piN -> K Sigma channel, extremely important for the 1700 MeV range, are old and inconclusive so an urgent need for remeasuring that channel is stressed.
[ { "created": "Thu, 5 Jan 2006 12:24:58 GMT", "version": "v1" } ]
2017-08-23
[ [ "Zauner", "B.", "" ], [ "Svarc", "A.", "" ], [ "Ceci", "S.", "" ] ]
The pole structure of the P11 pion-nucleon partial wave is examined with the emphasis on the 1700 MeV energy domain. The mechanism of eliminating continuum ambiguities in pion-nucleon partial wave analyses by using the coupled channel formalism, presented elsewhere for the piN -> etaN channel, is applied for the piN -> K Lambda channel, with the aim to clarify the issue whether physical reality requires none (VPI/GWU), one (KH80, CMB, Kent, Pittsburgh/ANL, Giessen), or possibly two (Zagreb) poles of the partial wave T-matrix in the 1700 MeV range. The role of second inelastic channel for resolving the dilemma is demonstrated. It is pointed out that the experiments for the piN -> K Lambda and piN -> K Sigma channel, extremely important for the 1700 MeV range, are old and inconclusive so an urgent need for remeasuring that channel is stressed.
hep-ph/0510377
Dremin
I.M. Dremin, V.I. Yakovlev
Charm in cosmic rays (The long-flying component of EAS cores)
12 pages, 8 figures, LATEX
Astropart.Phys.26:1-9,2006
10.1016/j.astropartphys.2006.04.005
null
hep-ph astro-ph hep-ex nucl-ex
null
Experimental data on cosmic ray cascades with enlarged attenuation lengths (Tien-Shan effect) are presented and analyzed in terms of charm hadroproduction. The very first estimates of charm hadroproduction cross sections from experimental data at high energies are confirmed and compared with recent accelerator results.
[ { "created": "Fri, 28 Oct 2005 12:18:21 GMT", "version": "v1" } ]
2011-05-23
[ [ "Dremin", "I. M.", "" ], [ "Yakovlev", "V. I.", "" ] ]
Experimental data on cosmic ray cascades with enlarged attenuation lengths (Tien-Shan effect) are presented and analyzed in terms of charm hadroproduction. The very first estimates of charm hadroproduction cross sections from experimental data at high energies are confirmed and compared with recent accelerator results.
1012.3186
Giacomo Morpurgo
G.Morpurgo
Some remarks on a paper by G.-S. Yang and H.-C.Kim: Mass splitting of SU(3) baryons within a chiral soliton model
Several typos corrected, one reference added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a recent paper Yang and Kim discuss the lowest baryon mass formulas using a chiral soliton model. However, contrary to their assertion, their result is not equivalent to a generalized Gell Mann-Okubo mass formula derived (G.Morpurgo 1992) using only general properties of QCD (The General parameterization method). The reason for the non equivalence is that the generalized mass formula include all the main terms that break flavor at second order, whereas the Authors above do not go beyond first order flavor breaking (and should therefore find the usual Gell Mann Okubo formula). That is is not so, due to some inconsistencies. Below we confine to the part of the Yang-Kim paper dealing with the mass formula. We will not consider the other items of their paper.
[ { "created": "Tue, 14 Dec 2010 22:16:22 GMT", "version": "v1" }, { "created": "Tue, 4 Jan 2011 12:50:08 GMT", "version": "v2" } ]
2011-01-05
[ [ "Morpurgo", "G.", "" ] ]
In a recent paper Yang and Kim discuss the lowest baryon mass formulas using a chiral soliton model. However, contrary to their assertion, their result is not equivalent to a generalized Gell Mann-Okubo mass formula derived (G.Morpurgo 1992) using only general properties of QCD (The General parameterization method). The reason for the non equivalence is that the generalized mass formula include all the main terms that break flavor at second order, whereas the Authors above do not go beyond first order flavor breaking (and should therefore find the usual Gell Mann Okubo formula). That is is not so, due to some inconsistencies. Below we confine to the part of the Yang-Kim paper dealing with the mass formula. We will not consider the other items of their paper.
0712.2947
Wolfgang Lucha
Z.-F. Li, Wolfgang Lucha, F. Schoberl
Stability in the instantaneous Bethe-Salpeter formalism: reduced exact-propagator bound-state equation with harmonic interaction
13 pages
J.Phys.G35:115002,2008
10.1088/0954-3899/35/11/115002
HEPHY-PUB 855/07
hep-ph nucl-th
null
Several numerical investigations of the Salpeter equation with static confining interactions of Lorentz-scalar type revealed that its solutions are plagued by instabilities of presumably Klein-paradox nature. By proving rigorously that the energies of all predicted bound states are part of real, entirely discrete spectra bounded from below, these instabilities are shown, for confining interactions of harmonic-oscillator shape, to be absent for a reduced version of an instantaneous Bethe-Salpeter formalism designed to generalize the Salpeter equation towards an approximate inclusion of the exact propagators of all bound-state constituents.
[ { "created": "Tue, 18 Dec 2007 12:55:57 GMT", "version": "v1" } ]
2008-11-26
[ [ "Li", "Z. -F.", "" ], [ "Lucha", "Wolfgang", "" ], [ "Schoberl", "F.", "" ] ]
Several numerical investigations of the Salpeter equation with static confining interactions of Lorentz-scalar type revealed that its solutions are plagued by instabilities of presumably Klein-paradox nature. By proving rigorously that the energies of all predicted bound states are part of real, entirely discrete spectra bounded from below, these instabilities are shown, for confining interactions of harmonic-oscillator shape, to be absent for a reduced version of an instantaneous Bethe-Salpeter formalism designed to generalize the Salpeter equation towards an approximate inclusion of the exact propagators of all bound-state constituents.
1705.03913
Matthew Buckley
Matthew R. Buckley, David Feld
Hiding Thermal Dark Matter with Leptons
14 pages 5 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Any form of dark matter which was in thermal equilibrium with the Standard Model in the early Universe must have some annihilation mechanism in order to avoid overclosure. In general, such models are now constrained by the negative experimental results from colliders, direct detection, and indirect detection, all of which are capable of probing interactions at the approximate strength suggested by a thermal cross section. It is timely to consider what scenarios of thermal dark matter which are still viable. In this paper we consider a class of dark matter models which is designed to avoid many of the current constraints: Majorana dark matter coupling to the Standard Model through leptophilic singlet scalars and pseudoscalars. We show that requiring realistic electroweak symmetry breaking generically forces the mediators to couple with quarks, allowing these models to be constrained by the current experimental data. We find that -- barring fine-tuning -- this type of thermal dark matter is excluded by a combination of direct and indirect detection for masses below $\sim 100$ GeV. Heavier dark matter is still viable, but in principle visible via its indirect detection signature.
[ { "created": "Wed, 10 May 2017 18:24:02 GMT", "version": "v1" } ]
2017-05-12
[ [ "Buckley", "Matthew R.", "" ], [ "Feld", "David", "" ] ]
Any form of dark matter which was in thermal equilibrium with the Standard Model in the early Universe must have some annihilation mechanism in order to avoid overclosure. In general, such models are now constrained by the negative experimental results from colliders, direct detection, and indirect detection, all of which are capable of probing interactions at the approximate strength suggested by a thermal cross section. It is timely to consider what scenarios of thermal dark matter which are still viable. In this paper we consider a class of dark matter models which is designed to avoid many of the current constraints: Majorana dark matter coupling to the Standard Model through leptophilic singlet scalars and pseudoscalars. We show that requiring realistic electroweak symmetry breaking generically forces the mediators to couple with quarks, allowing these models to be constrained by the current experimental data. We find that -- barring fine-tuning -- this type of thermal dark matter is excluded by a combination of direct and indirect detection for masses below $\sim 100$ GeV. Heavier dark matter is still viable, but in principle visible via its indirect detection signature.