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hep-ph/0602188
Yuji Koike
Yuji Koike, Junji Nagashima (Niigata Univ.) and Werner Vogelsang (BNL and RBRC)
Resummation for Polarized Semi-Inclusive Deep-Inelastic Scattering at Small Transverse Momentum
LateX 26 pages. Final version which appeared in Nucl. Phys. B. Figure labels have been changed
Nucl.Phys.B744:59-79,2006
10.1016/j.nuclphysb.2006.03.009
BNL-NT-06/9, RBRC-586
hep-ph
null
We study the transverse-momentum distribution of hadrons produced in semi-inclusive deep-inelastic scattering (SIDIS). We consider cross sections for various combinations of polarizations of the initial lepton and nucleon or the produced hadron, for which we perform the resummation of large double-logarithmic perturbative corrections arising at small transverse momentum. We present phenomenological results for the processes $lp\to l\pi X$ with longitudinally polarized leptons and protons. We discuss the impact of the perturbative resummation and of estimated non-perturbative contributions on the corresponding cross sections and their spin asymmetry. Our results should be relevant for ongoing studies in the COMPASS experiment at CERN, and for future experiments at the proposed eRHIC collider at BNL.
[ { "created": "Tue, 21 Feb 2006 06:56:32 GMT", "version": "v1" }, { "created": "Wed, 17 May 2006 08:43:19 GMT", "version": "v2" } ]
2008-11-26
[ [ "Koike", "Yuji", "", "Niigata Univ." ], [ "Nagashima", "Junji", "", "Niigata Univ." ], [ "Vogelsang", "Werner", "", "BNL\n and RBRC" ] ]
We study the transverse-momentum distribution of hadrons produced in semi-inclusive deep-inelastic scattering (SIDIS). We consider cross sections for various combinations of polarizations of the initial lepton and nucleon or the produced hadron, for which we perform the resummation of large double-logarithmic perturbative corrections arising at small transverse momentum. We present phenomenological results for the processes $lp\to l\pi X$ with longitudinally polarized leptons and protons. We discuss the impact of the perturbative resummation and of estimated non-perturbative contributions on the corresponding cross sections and their spin asymmetry. Our results should be relevant for ongoing studies in the COMPASS experiment at CERN, and for future experiments at the proposed eRHIC collider at BNL.
2308.00650
Prashant Thakur
Prashant Thakur, Tuhin Malik, Arpan Das, T. K. Jha, Constan\c{c}a Provid\^encia
Exploring robust correlations between fermionic dark matter model parameters and neutron star properties: A two-fluid perspective
15 Pages, 12 figures, 4 tables
null
null
null
hep-ph astro-ph.HE nucl-th
http://creativecommons.org/licenses/by/4.0/
The current observational properties of neutron stars have not definitively ruled out the possibility of dark matter. In this study, we primarily focus on exploring correlations between the dark matter model parameters and different neutron star properties using a rich set of EOSs. We adopt a two-fluid approach to calculate the properties of neutron stars. For the nuclear matter EOS, we employ several realistic EOS derived from the relativistic mean field model (RMF), each exhibiting varying stiffness and composition. In parallel, we look into the dark matter EOS, considering fermionic matter with repulsive interaction described by a relativistic mean field Lagrangian. A reasonable range of parameters is sampled meticulously. Interestingly, our results reveal a promising correlation between the dark matter model parameters and stellar properties, particularly when we ignore the uncertainties in the nuclear matter EOS. However, when introducing uncertainties in the nuclear sector, the correlation weakens, suggesting that the task of conclusively constraining any particular dark matter model might be challenging using global properties alone, such as mass, radius, and tidal deformability. Notably, we find that dark-matter admixed stars tend to have higher central baryonic density, potentially allowing for non-nucleonic degrees of freedom or direct Urca processes in stars with lower masses. There is also a tantalizing hint regarding the detection of stars with the same mass but different surface temperatures, which may indicate the presence of dark matter. With our robust and extensive dataset, we delve deeper and demonstrate that even in the presence of dark matter, the semi-universal C-Love relation remains intact.
[ { "created": "Tue, 1 Aug 2023 16:32:33 GMT", "version": "v1" } ]
2023-08-02
[ [ "Thakur", "Prashant", "" ], [ "Malik", "Tuhin", "" ], [ "Das", "Arpan", "" ], [ "Jha", "T. K.", "" ], [ "Providência", "Constança", "" ] ]
The current observational properties of neutron stars have not definitively ruled out the possibility of dark matter. In this study, we primarily focus on exploring correlations between the dark matter model parameters and different neutron star properties using a rich set of EOSs. We adopt a two-fluid approach to calculate the properties of neutron stars. For the nuclear matter EOS, we employ several realistic EOS derived from the relativistic mean field model (RMF), each exhibiting varying stiffness and composition. In parallel, we look into the dark matter EOS, considering fermionic matter with repulsive interaction described by a relativistic mean field Lagrangian. A reasonable range of parameters is sampled meticulously. Interestingly, our results reveal a promising correlation between the dark matter model parameters and stellar properties, particularly when we ignore the uncertainties in the nuclear matter EOS. However, when introducing uncertainties in the nuclear sector, the correlation weakens, suggesting that the task of conclusively constraining any particular dark matter model might be challenging using global properties alone, such as mass, radius, and tidal deformability. Notably, we find that dark-matter admixed stars tend to have higher central baryonic density, potentially allowing for non-nucleonic degrees of freedom or direct Urca processes in stars with lower masses. There is also a tantalizing hint regarding the detection of stars with the same mass but different surface temperatures, which may indicate the presence of dark matter. With our robust and extensive dataset, we delve deeper and demonstrate that even in the presence of dark matter, the semi-universal C-Love relation remains intact.
0901.0771
Seung-il Nam
Seung-il Nam and Hyun-Chul Kim
Photoproduction of Theta^+(1540,1/2^+) reexamined with new theoretical information
16 pages, 16 figures
Phys.Rev.D79:034031,2009
10.1103/PhysRevD.79.034031
YITP-09-01, INHA-NTG-01/09
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We reinvestigate the photoproduction of the exotic pentaquark baryon Theta^+(1540,1/2^+) from the gamma N -> Kbar Theta^+ reaction process within the effective Lagrangian approach, taking into account new theoretical information on the K-N-Theta and K*-N-Theta coupling strengths from the chiral quark-soliton model (chiQSM). We also consider the crossing-symmetric hadronic form factor, satisfying the on-shell condition as well. Due to the sizable vector and tensor couplings for the vector kaon, g_{K* N Theta} and f_{K* N Theta}, which are almost the same with the vector coupling g_{K N Theta} ~ 0.8 for the pseudoscalar kaon, the K*-exchange contribution plays a critical role in the photon beam asymmetries.
[ { "created": "Wed, 7 Jan 2009 08:26:00 GMT", "version": "v1" } ]
2009-03-12
[ [ "Nam", "Seung-il", "" ], [ "Kim", "Hyun-Chul", "" ] ]
We reinvestigate the photoproduction of the exotic pentaquark baryon Theta^+(1540,1/2^+) from the gamma N -> Kbar Theta^+ reaction process within the effective Lagrangian approach, taking into account new theoretical information on the K-N-Theta and K*-N-Theta coupling strengths from the chiral quark-soliton model (chiQSM). We also consider the crossing-symmetric hadronic form factor, satisfying the on-shell condition as well. Due to the sizable vector and tensor couplings for the vector kaon, g_{K* N Theta} and f_{K* N Theta}, which are almost the same with the vector coupling g_{K N Theta} ~ 0.8 for the pseudoscalar kaon, the K*-exchange contribution plays a critical role in the photon beam asymmetries.
1011.3528
Nikolaos Mavromatos
Nick E. Mavromatos
Quantum-Gravity Induced Lorentz Violation and Dynamical Mass Generation
34 pages latex, uses special macros (axodraw), three eps figures incorporated
Phys.Rev.D83:025018,2011
10.1103/PhysRevD.83.025018
CERN-PH-TH/2010-263, KCL-PH-TH/2010-32
hep-ph gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In Ref. [1] (by J. Alexandre) a minimal extension of (3+1)-dimensional Quantum Electrodynamics has been proposed, which includes Lorentz-Violation (LV) in the form of higher-(spatial)-derivative isotropic terms in the gauge sector, suppressed by a mass scale $M$. The model can lead to dynamical mass generation for charged fermions. In this article I elaborate further on this idea and I attempt to connect it to specific quantum-gravity models, inspired from string/brane theory. Specifically, in the first part of the article, I comment briefly on the gauge dependence of the dynamical mass generation in the approximations of [1], and I propose a possible avenue for obtaining the true gauge-parameter-independent value of the mass by means of Pinch Technique argumentations. In the second part of the work I embed the LV QED model into multibrane world scenarios with a view to provide a geometrical way of enhancing the dynamical mass to phenomenologically realistic values by means of bulk warp metric factors, in an (inverse) Randall-Sundrum hierarchy. Finally in the third part of this note, I demonstrate that such Lorentz Violating QED models may represent parts of a low-energy effective action (of Finsler-Born-Infeld type) of open strings propagating in quantum D0-particle stochastic space-time foam backgrounds, which are viewed as consistent quantum gravity configurations.
[ { "created": "Mon, 15 Nov 2010 21:23:45 GMT", "version": "v1" } ]
2011-02-25
[ [ "Mavromatos", "Nick E.", "" ] ]
In Ref. [1] (by J. Alexandre) a minimal extension of (3+1)-dimensional Quantum Electrodynamics has been proposed, which includes Lorentz-Violation (LV) in the form of higher-(spatial)-derivative isotropic terms in the gauge sector, suppressed by a mass scale $M$. The model can lead to dynamical mass generation for charged fermions. In this article I elaborate further on this idea and I attempt to connect it to specific quantum-gravity models, inspired from string/brane theory. Specifically, in the first part of the article, I comment briefly on the gauge dependence of the dynamical mass generation in the approximations of [1], and I propose a possible avenue for obtaining the true gauge-parameter-independent value of the mass by means of Pinch Technique argumentations. In the second part of the work I embed the LV QED model into multibrane world scenarios with a view to provide a geometrical way of enhancing the dynamical mass to phenomenologically realistic values by means of bulk warp metric factors, in an (inverse) Randall-Sundrum hierarchy. Finally in the third part of this note, I demonstrate that such Lorentz Violating QED models may represent parts of a low-energy effective action (of Finsler-Born-Infeld type) of open strings propagating in quantum D0-particle stochastic space-time foam backgrounds, which are viewed as consistent quantum gravity configurations.
1903.05365
Apurba Tiwari
Apurba Tiwari and Sudhir Kumar Gupta
T-odd anomalous interactions of the top-quark at the Large Hadron Collider
13 Pages and 10 figures
Advances in High Energy Physics-Volume 2021-Article ID 6676930
10.1155/2021/6676930
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effects of T-odd interactions of top-quark via the pair production of top-quark in the semileptonic detection modes at the Large Hadron Collider by means of the T-odd observables constructed through the momenta of the observed decay products of the top (and anti-top)-quark for a wide range of CP-violating scale $\Lambda$. Estimates on the sensitivities of the coupling strength of such interactions for 13 TeV LHC energy with $\int \mathcal L dt$ = 36.1 fb$^{-1}$, 140 fb$^{-1}$ and for HL-LHC with 14 TeV energy with integrated luminosities of 0.3 ab$^{-1}$, 1 ab$^{-1}$, 2 ab$^{-1}$ and 3 ab$^{-1}$ are also presented for $\Lambda$ ranging between $M_W$ and 2 TeV.
[ { "created": "Wed, 13 Mar 2019 08:54:19 GMT", "version": "v1" }, { "created": "Wed, 14 Oct 2020 08:39:24 GMT", "version": "v2" }, { "created": "Mon, 19 Apr 2021 14:51:15 GMT", "version": "v3" } ]
2021-04-20
[ [ "Tiwari", "Apurba", "" ], [ "Gupta", "Sudhir Kumar", "" ] ]
We study the effects of T-odd interactions of top-quark via the pair production of top-quark in the semileptonic detection modes at the Large Hadron Collider by means of the T-odd observables constructed through the momenta of the observed decay products of the top (and anti-top)-quark for a wide range of CP-violating scale $\Lambda$. Estimates on the sensitivities of the coupling strength of such interactions for 13 TeV LHC energy with $\int \mathcal L dt$ = 36.1 fb$^{-1}$, 140 fb$^{-1}$ and for HL-LHC with 14 TeV energy with integrated luminosities of 0.3 ab$^{-1}$, 1 ab$^{-1}$, 2 ab$^{-1}$ and 3 ab$^{-1}$ are also presented for $\Lambda$ ranging between $M_W$ and 2 TeV.
1911.06279
Olcyr Sumensari
Claudia Cornella, Paride Paradisi and Olcyr Sumensari
Hunting for ALPs with Lepton Flavor Violation
40 pages, 13 figures, published version. Numerical mistake corrected in Figs. 4 and 8, conclusions unchanged
null
10.1007/JHEP01(2020)158
ZU-TH 46/19
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the low-energy signatures of axion-like particles (ALPs) in lepton flavor violating (LFV) processes. By using a dimension-5 effective Lagrangian, we compute the most general ALP contributions to LFV decays of leptons and mesons. The provided expressions are valid for any choice of ALP mass and couplings. We explore the complementarity of different processes, identifying specific patterns to be experimentally tested. Constraints on LFV couplings are derived from existing data and prospects for forthcoming experiments are also discussed. As a by-product, we revisit the possibility of a simultaneous explanation of the observed discrepancies in the muon and electron $g-2$ through ALP interactions.
[ { "created": "Thu, 14 Nov 2019 18:02:25 GMT", "version": "v1" }, { "created": "Mon, 20 Jan 2020 15:01:06 GMT", "version": "v2" }, { "created": "Wed, 20 Jan 2021 21:29:58 GMT", "version": "v3" } ]
2021-01-22
[ [ "Cornella", "Claudia", "" ], [ "Paradisi", "Paride", "" ], [ "Sumensari", "Olcyr", "" ] ]
We examine the low-energy signatures of axion-like particles (ALPs) in lepton flavor violating (LFV) processes. By using a dimension-5 effective Lagrangian, we compute the most general ALP contributions to LFV decays of leptons and mesons. The provided expressions are valid for any choice of ALP mass and couplings. We explore the complementarity of different processes, identifying specific patterns to be experimentally tested. Constraints on LFV couplings are derived from existing data and prospects for forthcoming experiments are also discussed. As a by-product, we revisit the possibility of a simultaneous explanation of the observed discrepancies in the muon and electron $g-2$ through ALP interactions.
hep-ph/0409121
Marek Karliner
Marek Karliner and Bryan R. Webber
Coalescence model for Theta_c pentaquark formation
Expanded general discussion of the coalescence model. Revised sec. 2.4, following correction of an error in HERWIG in the programming of the space-time structure of the underlying event in hadron-hadron collisions. Quantitative changes are small
JHEP0412:045,2004
10.1088/1126-6708/2004/12/045
Cavendish-HEP-04/09, TAUP-2774-04
hep-ph hep-ex
null
We present a model for the formation of the charmed pentaquark Theta_c in hard scattering processes such as deep inelastic scattering, e^+e^- annihilation, and high-energy p pbar collisions. The model assumes that the cross section for Theta_c formation is proportional to the rate of production of p D^{*-} (or pbar D^{*+}) pairs in close proximity both in momentum space and in coordinate space. The constant of proportionality is determined from the Theta_c cross section in deep inelastic scattering as reported by the H1 experiment. The HERWIG Monte Carlo is used to generate simulated DIS events and also to model the space-time structure of the final state. Requiring the proton and the D^* be within a 100 MeV mass window and separated by a spacelike distance of no more than 2 fm, we find that a large "coalescence enhancement factor" F_co \sim 10 is required to account for the H1 signal. The same approach is then applied in order to estimate the number and characteristics of Theta_c events produced at LEP and the Tevatron.
[ { "created": "Fri, 10 Sep 2004 14:57:37 GMT", "version": "v1" }, { "created": "Mon, 20 Sep 2004 17:00:36 GMT", "version": "v2" }, { "created": "Fri, 14 Jan 2005 12:36:06 GMT", "version": "v3" } ]
2008-11-26
[ [ "Karliner", "Marek", "" ], [ "Webber", "Bryan R.", "" ] ]
We present a model for the formation of the charmed pentaquark Theta_c in hard scattering processes such as deep inelastic scattering, e^+e^- annihilation, and high-energy p pbar collisions. The model assumes that the cross section for Theta_c formation is proportional to the rate of production of p D^{*-} (or pbar D^{*+}) pairs in close proximity both in momentum space and in coordinate space. The constant of proportionality is determined from the Theta_c cross section in deep inelastic scattering as reported by the H1 experiment. The HERWIG Monte Carlo is used to generate simulated DIS events and also to model the space-time structure of the final state. Requiring the proton and the D^* be within a 100 MeV mass window and separated by a spacelike distance of no more than 2 fm, we find that a large "coalescence enhancement factor" F_co \sim 10 is required to account for the H1 signal. The same approach is then applied in order to estimate the number and characteristics of Theta_c events produced at LEP and the Tevatron.
1210.1976
John F. Gunion
Genevi\`eve B\'elanger, Ulrich Ellwanger, John F. Gunion, Yun Jiang, Sabine Kraml, John H. Schwarz
Higgs Bosons at 98 and 125 GeV at LEP and the LHC
24 pages, 15 figures, minor corrections, figure improvements, final version as it will appear in the journal
null
10.1007/JHEP01(2013)069
UCD 2012-1
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss NMSSM scenarios in which the lightest Higgs boson $h_1$ is consistent with the small LEP excess at about 98 GeV in $e^+e^- \to Zh$ with $h\to b\anti b$ and the heavier Higgs boson $h_2$ has the primary features of the LHC Higgs-like signals at 125 GeV, including an enhanced $\gamma\gamma$ rate. Verification or falsification of the 98 GeV $h_1$ may be possible at the LHC during the 14 TeV run. The detection of the other NMSSM Higgs bosons at the LHC and future colliders is also discussed, as well as dark matter properties of the scenario under consideration.
[ { "created": "Sat, 6 Oct 2012 16:58:38 GMT", "version": "v1" }, { "created": "Fri, 19 Oct 2012 12:04:04 GMT", "version": "v2" }, { "created": "Wed, 9 Jan 2013 02:16:19 GMT", "version": "v3" } ]
2015-06-11
[ [ "Bélanger", "Geneviève", "" ], [ "Ellwanger", "Ulrich", "" ], [ "Gunion", "John F.", "" ], [ "Jiang", "Yun", "" ], [ "Kraml", "Sabine", "" ], [ "Schwarz", "John H.", "" ] ]
We discuss NMSSM scenarios in which the lightest Higgs boson $h_1$ is consistent with the small LEP excess at about 98 GeV in $e^+e^- \to Zh$ with $h\to b\anti b$ and the heavier Higgs boson $h_2$ has the primary features of the LHC Higgs-like signals at 125 GeV, including an enhanced $\gamma\gamma$ rate. Verification or falsification of the 98 GeV $h_1$ may be possible at the LHC during the 14 TeV run. The detection of the other NMSSM Higgs bosons at the LHC and future colliders is also discussed, as well as dark matter properties of the scenario under consideration.
1904.11706
Jun He Prof.
Xiao-Yun Wang, Xu-Rong Chen, Jun He
Possibility to study pentaquark states $P_{c}(4312), P_{c}(4440)$, and $P_{c}(4457)$ in $\gamma p\rightarrow J/\psi p$ reaction
7 pages, 7 figures, version to be published in PRD
Phys. Rev. D 99, 114007 (2019)
10.1103/PhysRevD.99.114007
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the observation of the pentaquark states $P_{c}(4312),P_{c}(4440)$ and $P_{c}(4457)$ at LHCb, photoproduction of these three $P_{c}$ states via the interaction $\gamma p\rightarrow J/\psi p$ is investigated in an effective Lagrangian approach. The $t$-channel Pomeron exchange diffractive process is considered as the main background for the $J/\psi $ photoproduction. The numerical results show that the theoretical cross section, which is calculated by assuming a branching ratio $Br[P_{c}\rightarrow J/\psi p]\simeq 3\%$, is consistent with the existing experimental data of the $ \gamma p\rightarrow J/\psi p$ process. With such a branching ratio, if experimental precision reaches 0.1 nb within a bin of 100 MeV for photon energy, two peaks are expected to be obviously observed in the $J/\psi $ photoproduction. To observe the two-peak structure from $P_{c}(4440)$ and $ P_{c}(4457)$, higher precision, about 0.1nb/10 MeV, is required to distinguish two close pentaquarks. If the physical branching ratio is larger, the requirement of experimental precision will be reduced. The differential cross sections for reaction $\gamma p\rightarrow J/\psi p$ are also present. It is found that the $t$-channel Pomeron exchange provides a sharp increase at extreme forward angles and gives a sizable contribution at most energy points, while the contributions from the $s$-channel $P_{c}$ exchanges play important roles at threshold energies. The experimental measurement of the $\gamma p\rightarrow J/\psi p$ process in the near-threshold energy region around $E_{\gamma }\simeq 9.4-10.5$ GeV is suggested, and is accessible at CEBAF@JLab and COMPASS.
[ { "created": "Fri, 26 Apr 2019 08:04:40 GMT", "version": "v1" }, { "created": "Fri, 31 May 2019 01:38:08 GMT", "version": "v2" } ]
2019-06-13
[ [ "Wang", "Xiao-Yun", "" ], [ "Chen", "Xu-Rong", "" ], [ "He", "Jun", "" ] ]
Inspired by the observation of the pentaquark states $P_{c}(4312),P_{c}(4440)$ and $P_{c}(4457)$ at LHCb, photoproduction of these three $P_{c}$ states via the interaction $\gamma p\rightarrow J/\psi p$ is investigated in an effective Lagrangian approach. The $t$-channel Pomeron exchange diffractive process is considered as the main background for the $J/\psi $ photoproduction. The numerical results show that the theoretical cross section, which is calculated by assuming a branching ratio $Br[P_{c}\rightarrow J/\psi p]\simeq 3\%$, is consistent with the existing experimental data of the $ \gamma p\rightarrow J/\psi p$ process. With such a branching ratio, if experimental precision reaches 0.1 nb within a bin of 100 MeV for photon energy, two peaks are expected to be obviously observed in the $J/\psi $ photoproduction. To observe the two-peak structure from $P_{c}(4440)$ and $ P_{c}(4457)$, higher precision, about 0.1nb/10 MeV, is required to distinguish two close pentaquarks. If the physical branching ratio is larger, the requirement of experimental precision will be reduced. The differential cross sections for reaction $\gamma p\rightarrow J/\psi p$ are also present. It is found that the $t$-channel Pomeron exchange provides a sharp increase at extreme forward angles and gives a sizable contribution at most energy points, while the contributions from the $s$-channel $P_{c}$ exchanges play important roles at threshold energies. The experimental measurement of the $\gamma p\rightarrow J/\psi p$ process in the near-threshold energy region around $E_{\gamma }\simeq 9.4-10.5$ GeV is suggested, and is accessible at CEBAF@JLab and COMPASS.
2111.00469
Alexander Studenikin
Alexander Studenikin
Electromagnetic neutrino: The basic processes and astrophysical probes
5 pages, 2 figures, based on the oral presentation at the 17th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2021), 26 August - 3 September 2021, hosted by IFIC Valencia and held online
null
10.1088/1742-6596/2156/1/012120
null
hep-ph astro-ph.HE
http://creativecommons.org/licenses/by/4.0/
After a brief reminder on the electromagnetic properties of neutrinos, the main processes of the electromagnetic interactions of neutrinos in astrophysics and the corresponding limitations on millicharges and effective magnetic moments of the particle are discussed.
[ { "created": "Sun, 31 Oct 2021 11:21:05 GMT", "version": "v1" } ]
2022-03-02
[ [ "Studenikin", "Alexander", "" ] ]
After a brief reminder on the electromagnetic properties of neutrinos, the main processes of the electromagnetic interactions of neutrinos in astrophysics and the corresponding limitations on millicharges and effective magnetic moments of the particle are discussed.
hep-ph/9704451
Edward Shuryak
E.V. Shuryak (Stony Brook)
The QCD Phase Transition: From the Microscopic Mechanism to Signals Talk at Renconres de Moriond - 97
null
null
null
null
hep-ph
null
This talk consists of two very different parts: the first one deals with non-perturbative QCD and physics of the chiral restoration, the second with rather low-key (and still unfinished) work aiming at obtaining EOS and other properties of hot/dense hadronic matter from data on heavy ion collisions. The microscopic mechanism for chiral restoration phase transition is a transition from randomly placed tunneling events (instantons) at low T to a set of strongly correlated tunneling-anti-tunneling events (known as instanton - anti-instanton molecules) at high T. Many features of the transition can be explained in this simple picture, especially the critical line and its dependence on quark masses. This scenario predicts qualitative change of the basic quark-quark interactions around the phase transition line, with some states (such as pion-sigma ones) probably surviving even at $T>T_c$. In the second half of the talk we discuss experimental data on collective flow in heavy ion collision, its hydro-based description and relation to equation of state (EOS). A distinct feature of the QCD phase transition region is high degree of ``softness'', (small ratio pressure/energy density). We present some preliminary results indicated that it is indeed needed to explain the radial flow at SPS energies.
[ { "created": "Wed, 30 Apr 1997 17:11:47 GMT", "version": "v1" } ]
2016-09-06
[ [ "Shuryak", "E. V.", "", "Stony Brook" ] ]
This talk consists of two very different parts: the first one deals with non-perturbative QCD and physics of the chiral restoration, the second with rather low-key (and still unfinished) work aiming at obtaining EOS and other properties of hot/dense hadronic matter from data on heavy ion collisions. The microscopic mechanism for chiral restoration phase transition is a transition from randomly placed tunneling events (instantons) at low T to a set of strongly correlated tunneling-anti-tunneling events (known as instanton - anti-instanton molecules) at high T. Many features of the transition can be explained in this simple picture, especially the critical line and its dependence on quark masses. This scenario predicts qualitative change of the basic quark-quark interactions around the phase transition line, with some states (such as pion-sigma ones) probably surviving even at $T>T_c$. In the second half of the talk we discuss experimental data on collective flow in heavy ion collision, its hydro-based description and relation to equation of state (EOS). A distinct feature of the QCD phase transition region is high degree of ``softness'', (small ratio pressure/energy density). We present some preliminary results indicated that it is indeed needed to explain the radial flow at SPS energies.
1706.03073
Yuber Ferney Perez Gonzalez
Enrico Bertuzzo, Pedro A. N. Machado, Yuber F. Perez-Gonzalez, Renata Zukanovich Funchal
Constraints from Triple Gauge Couplings on Vectorlike Leptons
Matches version published in PRD. Some references added and LHC limits included
Phys. Rev. D 96, 035035 (2017)
10.1103/PhysRevD.96.035035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the contributions of colorless vectorlike fermions to the triple gauge couplings $W^+ W^- \gamma$ and $W^+ W^- Z^0$. We consider models in which their coupling to the Standard Model Higgs boson is allowed or forbidden by quantum numbers. We assess the sensitivity of the future accelerators FCC-ee, ILC and CLIC to the parameters of these models, assuming they will be able to constrain the anomalous triple gauge couplings with a precision $\delta \kappa_V \sim \mathcal{O}(10^{-4})$, $V=\gamma,Z^0$. We show that the combination of measurements at different center-of-mass energies helps to improve the sensitivity to the contribution of vectorlike fermions, in particular when they couple to the Higgs. In fact, the measurements at the FCC-ee and, especially, the ILC and the CLIC, may turn the triple gauge couplings into a new set of precision parameters able to constrain the models better than the oblique parameters or the $H \to \gamma \gamma$ decay, even assuming the considerable improvement of the latter measurements achievable at the new machines.
[ { "created": "Fri, 9 Jun 2017 18:00:02 GMT", "version": "v1" }, { "created": "Wed, 30 Aug 2017 18:48:57 GMT", "version": "v2" } ]
2017-09-06
[ [ "Bertuzzo", "Enrico", "" ], [ "Machado", "Pedro A. N.", "" ], [ "Perez-Gonzalez", "Yuber F.", "" ], [ "Funchal", "Renata Zukanovich", "" ] ]
We study the contributions of colorless vectorlike fermions to the triple gauge couplings $W^+ W^- \gamma$ and $W^+ W^- Z^0$. We consider models in which their coupling to the Standard Model Higgs boson is allowed or forbidden by quantum numbers. We assess the sensitivity of the future accelerators FCC-ee, ILC and CLIC to the parameters of these models, assuming they will be able to constrain the anomalous triple gauge couplings with a precision $\delta \kappa_V \sim \mathcal{O}(10^{-4})$, $V=\gamma,Z^0$. We show that the combination of measurements at different center-of-mass energies helps to improve the sensitivity to the contribution of vectorlike fermions, in particular when they couple to the Higgs. In fact, the measurements at the FCC-ee and, especially, the ILC and the CLIC, may turn the triple gauge couplings into a new set of precision parameters able to constrain the models better than the oblique parameters or the $H \to \gamma \gamma$ decay, even assuming the considerable improvement of the latter measurements achievable at the new machines.
hep-ph/0310005
Stepan Olean
S.S. Olean
Effective Lagrangian for Baryons and Baryon-Meson Interaction
4 pages
null
null
null
hep-ph
null
Expansion of model Nambu-Jona-Lasinio is considered and on its basis an effective lagrangian for mesons, baryons and baryon - meson interaction has been obtained.
[ { "created": "Wed, 1 Oct 2003 12:28:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Olean", "S. S.", "" ] ]
Expansion of model Nambu-Jona-Lasinio is considered and on its basis an effective lagrangian for mesons, baryons and baryon - meson interaction has been obtained.
0802.1534
Darren Forde
Darren Forde
Constructing QCD one-loop amplitudes
5 Pages. To appear in the proceedings of the 8th International Symposium on Radiative Corrections (RADCOR 2007): Application of Quantum Field Theory to Phenomenology, Florence, Italy, 1-6 Oct 2007
PoS RADCOR2007:017,2007
null
SLAC-PUB-13124, UCLA/08/TEP/4
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of constructing one-loop amplitudes using a unitarity bootstrap approach we discuss a general systematic procedure for obtaining the coefficients of the scalar bubble and triangle integral functions of one-loop amplitudes. Coefficients are extracted after examining the behaviour of the cut integrand as the unconstrained parameters of a specifically chosen parametersiation of the cut loop momentum approach infinity.
[ { "created": "Mon, 11 Feb 2008 21:18:39 GMT", "version": "v1" } ]
2009-08-07
[ [ "Forde", "Darren", "" ] ]
In the context of constructing one-loop amplitudes using a unitarity bootstrap approach we discuss a general systematic procedure for obtaining the coefficients of the scalar bubble and triangle integral functions of one-loop amplitudes. Coefficients are extracted after examining the behaviour of the cut integrand as the unconstrained parameters of a specifically chosen parametersiation of the cut loop momentum approach infinity.
1809.04805
Rui Santos
Abdesslam Arhrib, Rachid Benbrik, Jaouad El Falaki, Marco Sampaio, Rui Santos
Pseudoscalar decays to gauge bosons at the LHC and at a future 100 TeV collider
null
Phys. Rev. D 99, 035043 (2019)
10.1103/PhysRevD.99.035043
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the search for a CP-odd scalar decaying into gauge bosons in the framework of a CP-conserving two-Higgs doublet model (2HDM) and of a 2HDM extended with a vector-like quark (VLQ) at the Large Hadron Collider and at a future 100 TeV collider. The rate of decay of a pseudoscalar to $Z$-bosons could be important to ascertain the CP-nature of the scalars in the model. In the 2HDM $A \to ZZ$ will be extremely hard to detect even at a future 100 TeV $pp$ collider while in the 2HDM+VLQ this decay can be probed even during the present LHC run. We further discuss all decays of the pseudoscalar into gauge bosons at the LHC and at a future 100 TeV collider in the alignment limit where the lightest scalar is the 125 GeV Higgs with SM-like couplings to the fermions and gauge bosons.
[ { "created": "Thu, 13 Sep 2018 07:23:22 GMT", "version": "v1" }, { "created": "Tue, 18 Dec 2018 14:24:25 GMT", "version": "v2" } ]
2019-03-06
[ [ "Arhrib", "Abdesslam", "" ], [ "Benbrik", "Rachid", "" ], [ "Falaki", "Jaouad El", "" ], [ "Sampaio", "Marco", "" ], [ "Santos", "Rui", "" ] ]
We discuss the search for a CP-odd scalar decaying into gauge bosons in the framework of a CP-conserving two-Higgs doublet model (2HDM) and of a 2HDM extended with a vector-like quark (VLQ) at the Large Hadron Collider and at a future 100 TeV collider. The rate of decay of a pseudoscalar to $Z$-bosons could be important to ascertain the CP-nature of the scalars in the model. In the 2HDM $A \to ZZ$ will be extremely hard to detect even at a future 100 TeV $pp$ collider while in the 2HDM+VLQ this decay can be probed even during the present LHC run. We further discuss all decays of the pseudoscalar into gauge bosons at the LHC and at a future 100 TeV collider in the alignment limit where the lightest scalar is the 125 GeV Higgs with SM-like couplings to the fermions and gauge bosons.
2009.14212
Nico Adolph
Nico Adolph, Joachim Brod, Gudrun Hiller
Radiative three-body D-meson decays in and beyond the standard model
40 pages, 20 figures; clarifications and minor improvements; published version
null
10.1140/epjc/s10052-021-08832-3
DO-TH 20/11
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study radiative charm decays $D \to P_1 P_2 \gamma$, $P_{1,2}=\pi,K$ in QCD factorization at leading order and within heavy hadron chiral perturbation theory. Branching ratios including resonance contributions are around $\sim 10^{-3}$ for the Cabibbo-favored modes into $K \pi \gamma$ and $\sim 10^{-5}$ for the singly Cabibbo-suppressed modes into $\pi^+ \pi^- \gamma, K^+ K^- \gamma$, and thus in reach of the flavor factories BES III and Belle II. Dalitz plots and forward-backward asymmetries reveal significant differences between the two QCD frameworks; such observables are therefore ideally suited for a data-driven identification of relevant decay mechanisms in the standard-model dominated $D \to K \pi \gamma$ decays. This increases the potential to probe new physics with the $D \to \pi^+ \pi^- \gamma$ and $D \to K^+ K^- \gamma$ decays, which are sensitive to enhanced dipole operators. CP asymmetries are useful to test the SM and look for new physics in neutral $|\Delta C|=1$ transitions. Cuts in the Dalitz plot enhance the sensitivity to new physics due to the presence of both $s$- and $t,u$-channel intermediate resonances.
[ { "created": "Tue, 29 Sep 2020 18:00:02 GMT", "version": "v1" }, { "created": "Wed, 24 Feb 2021 13:43:08 GMT", "version": "v2" } ]
2021-02-25
[ [ "Adolph", "Nico", "" ], [ "Brod", "Joachim", "" ], [ "Hiller", "Gudrun", "" ] ]
We study radiative charm decays $D \to P_1 P_2 \gamma$, $P_{1,2}=\pi,K$ in QCD factorization at leading order and within heavy hadron chiral perturbation theory. Branching ratios including resonance contributions are around $\sim 10^{-3}$ for the Cabibbo-favored modes into $K \pi \gamma$ and $\sim 10^{-5}$ for the singly Cabibbo-suppressed modes into $\pi^+ \pi^- \gamma, K^+ K^- \gamma$, and thus in reach of the flavor factories BES III and Belle II. Dalitz plots and forward-backward asymmetries reveal significant differences between the two QCD frameworks; such observables are therefore ideally suited for a data-driven identification of relevant decay mechanisms in the standard-model dominated $D \to K \pi \gamma$ decays. This increases the potential to probe new physics with the $D \to \pi^+ \pi^- \gamma$ and $D \to K^+ K^- \gamma$ decays, which are sensitive to enhanced dipole operators. CP asymmetries are useful to test the SM and look for new physics in neutral $|\Delta C|=1$ transitions. Cuts in the Dalitz plot enhance the sensitivity to new physics due to the presence of both $s$- and $t,u$-channel intermediate resonances.
0710.5352
Farida Iddir
F.Iddir and L.Semlala
Hybrid States from Constituent Glue Model
19 pages, 11 Tables
Int.J.Mod.Phys.A23:5229-5250,2008
10.1142/S0217751X08042687
null
hep-ph
null
The hybrid meson is one of the most interesting new hadron specie beyond the naive quark model. It acquire a great attention both from the theoretical and experimental efforts. Many good candidates have been claimed to be observed, but there is no absolute confirmation about existence of hybrid mesons. In the present work we propose new calculations of the masses and decay widths of the hybrid mesons in the context of constituent gluon model.
[ { "created": "Mon, 29 Oct 2007 08:11:57 GMT", "version": "v1" }, { "created": "Tue, 11 Dec 2007 07:49:09 GMT", "version": "v2" } ]
2009-02-11
[ [ "Iddir", "F.", "" ], [ "Semlala", "L.", "" ] ]
The hybrid meson is one of the most interesting new hadron specie beyond the naive quark model. It acquire a great attention both from the theoretical and experimental efforts. Many good candidates have been claimed to be observed, but there is no absolute confirmation about existence of hybrid mesons. In the present work we propose new calculations of the masses and decay widths of the hybrid mesons in the context of constituent gluon model.
1405.3445
Sang-Ho Kim
Sang-Ho Kim, Atsushi Hosaka, Hyun-Chul Kim, Hiroyuki Noumi, and Kotaro Shirotori
Pion induced Reactions for Charmed Baryons
14 pages, 3 figures
null
10.1093/ptep/ptu131
INHA-NTG-04/2014
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study pion induced reactions for charmed baryons $B$, $\pi$ + N $\rightarrow$ $D^*$ + $B$. First we estimate charm production rates in comparison with strangeness production using a Regge model which is dominated by vector ($D^*$ or $K^*$ ) Reggeon exchange. Then we examine the production rates of various charmed baryons $B$ in a quark-diquark model. We find that the production of excited states are not necessarily suppressed, a sharp contrast to strangeness production, which is a unique feature of the charm production with a large momentum transfer.
[ { "created": "Wed, 14 May 2014 10:44:08 GMT", "version": "v1" } ]
2014-11-11
[ [ "Kim", "Sang-Ho", "" ], [ "Hosaka", "Atsushi", "" ], [ "Kim", "Hyun-Chul", "" ], [ "Noumi", "Hiroyuki", "" ], [ "Shirotori", "Kotaro", "" ] ]
We study pion induced reactions for charmed baryons $B$, $\pi$ + N $\rightarrow$ $D^*$ + $B$. First we estimate charm production rates in comparison with strangeness production using a Regge model which is dominated by vector ($D^*$ or $K^*$ ) Reggeon exchange. Then we examine the production rates of various charmed baryons $B$ in a quark-diquark model. We find that the production of excited states are not necessarily suppressed, a sharp contrast to strangeness production, which is a unique feature of the charm production with a large momentum transfer.
hep-ph/0011379
Misha Stephanov
D.H. Rischke, D.T. Son, and M.A. Stephanov
Asymptotic deconfinement in high-density QCD
4 pages; restructured, published version
Phys.Rev.Lett. 87 (2001) 062001
10.1103/PhysRevLett.87.062001
null
hep-ph nucl-th
null
We discuss QCD with two light flavors at large baryon chemical potential mu. Color superconductivity leads to partial breaking of the color SU(3) group. We show that the infrared physics is governed by the gluodynamics of the remaining SU(2) group with an exponentially soft confinement scale Lambda_QCD' Delta*exp[-a*mu/(g*Delta)], where Delta<<mu is the superconducting gap, g is the strong coupling, and a=0.81... We estimate that at moderate baryon densities Lambda_QCD' is O(10 MeV) or smaller. The confinement radius increases exponentially with density, leading to "asymptotic deconfinement." The velocity of the SU(2) gluons is small due to the large dielectric constant of the medium.
[ { "created": "Wed, 29 Nov 2000 20:08:32 GMT", "version": "v1" }, { "created": "Sat, 28 Jul 2001 01:19:49 GMT", "version": "v2" } ]
2007-05-23
[ [ "Rischke", "D. H.", "" ], [ "Son", "D. T.", "" ], [ "Stephanov", "M. A.", "" ] ]
We discuss QCD with two light flavors at large baryon chemical potential mu. Color superconductivity leads to partial breaking of the color SU(3) group. We show that the infrared physics is governed by the gluodynamics of the remaining SU(2) group with an exponentially soft confinement scale Lambda_QCD' Delta*exp[-a*mu/(g*Delta)], where Delta<<mu is the superconducting gap, g is the strong coupling, and a=0.81... We estimate that at moderate baryon densities Lambda_QCD' is O(10 MeV) or smaller. The confinement radius increases exponentially with density, leading to "asymptotic deconfinement." The velocity of the SU(2) gluons is small due to the large dielectric constant of the medium.
hep-ph/0310122
Piotr Kielanowski
P. Kielanowski and S.R. Juarez W
Precise bounds on the Higgs boson mass
14 pages, 7 figures. Expanded the discussion of the Higgs mass relation between the parameters of the Standard Model. Included the method of the Higgs effective potential
Phys.Rev.D72:096003,2005
10.1103/PhysRevD.72.096003
null
hep-ph
null
We study the renormalization group evolution of the Higgs quartic coupling $\lambda_{H}$ and the Higgs mass $m_{H}$ in the Standard Model. The one loop equation for $\lambda_{H}$ is non linear and it is of the Riccati type which we numerically and analytically solve in the energy range $[m_{t},E_{GU}]$ where $m_{t}$ is the mass of the top quark and $E_{GU}=10^{14}$ GeV. We find that depending on the value of $\lambda_{H}(m_{t})$ the solution for $\lambda_{H}(E)$ may have singularities or zeros and become negative in the former energy range so the ultra violet cut off of the standard model should be below the energy where the zero or singularity of $\lambda_{H}$ occurs. We find that for $0.369\leq\lambda_{H}(m_{t})\leq0.613$ the Standard Model is valid in the whole range $[m_{t},E_{GU}]$. We consider two cases of the Higgs mass relation to the parameters of the standard model: (a) the effective potential method and (b) the tree level mass relations. The limits for $\lambda_{H}(m_{t})$ correspond to the following Higgs mass relation $150\leq m_{H}\lessapprox 193$ GeV. We also plot the dependence of the ultra violet cut off on the value of the Higgs mass. We analyze the evolution of the vacuum expectation value of the Higgs field and show that it depends on the value of the Higgs mass. The pattern of the energy behavior of the VEV is different for the cases (a) and (b). The behavior of $\lambda_{H}(E)$, $m_{H}(E)$ and $v(E)$ indicates the existence of a phase transition in the standard model. For the effective potential this phase transition occurs at the mass range $m_{H}\approx 180$ GeV and for the tree level mass relations at $m_{H}\approx 168$ GeV.
[ { "created": "Fri, 10 Oct 2003 00:48:39 GMT", "version": "v1" }, { "created": "Mon, 29 Dec 2003 21:02:14 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kielanowski", "P.", "" ], [ "W", "S. R. Juarez", "" ] ]
We study the renormalization group evolution of the Higgs quartic coupling $\lambda_{H}$ and the Higgs mass $m_{H}$ in the Standard Model. The one loop equation for $\lambda_{H}$ is non linear and it is of the Riccati type which we numerically and analytically solve in the energy range $[m_{t},E_{GU}]$ where $m_{t}$ is the mass of the top quark and $E_{GU}=10^{14}$ GeV. We find that depending on the value of $\lambda_{H}(m_{t})$ the solution for $\lambda_{H}(E)$ may have singularities or zeros and become negative in the former energy range so the ultra violet cut off of the standard model should be below the energy where the zero or singularity of $\lambda_{H}$ occurs. We find that for $0.369\leq\lambda_{H}(m_{t})\leq0.613$ the Standard Model is valid in the whole range $[m_{t},E_{GU}]$. We consider two cases of the Higgs mass relation to the parameters of the standard model: (a) the effective potential method and (b) the tree level mass relations. The limits for $\lambda_{H}(m_{t})$ correspond to the following Higgs mass relation $150\leq m_{H}\lessapprox 193$ GeV. We also plot the dependence of the ultra violet cut off on the value of the Higgs mass. We analyze the evolution of the vacuum expectation value of the Higgs field and show that it depends on the value of the Higgs mass. The pattern of the energy behavior of the VEV is different for the cases (a) and (b). The behavior of $\lambda_{H}(E)$, $m_{H}(E)$ and $v(E)$ indicates the existence of a phase transition in the standard model. For the effective potential this phase transition occurs at the mass range $m_{H}\approx 180$ GeV and for the tree level mass relations at $m_{H}\approx 168$ GeV.
1409.6553
Mojtaba Mohammadi Najafabadi
Sara Khatibi and Mojtaba Mohammadi Najafabadi
Exploring the Anomalous Higgs-top Couplings
15 pages, 8 figures
Phys. Rev. D 90,074014 (2014)
10.1103/PhysRevD.90.074014
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Top quark with its large Yukawa coupling is crucially important to explore TeV scale physics. Therefore, the study of Higgs-top sector is highly motivated to look for any deviations from the standard model predictions. The most general lowest order Lagrangian for the Higgs-top Yukawa coupling has scalar ($\kappa$) and pseudoscalar ($\tilde{\kappa}$) components. Currently, these couplings are constrained indirectly using the present experimental limits on the Higgs-$\gamma$-$\gamma$ and Higgs-gluon-gluon couplings. Furthermore, stronger bounds on $\kappa$ and $\tilde{\kappa}$ are obtained using the limits on the electric dipole moments (EDM). In this work, we propose an asymmetry-like observable $O_{\phi}$ in $t\bar{t}H$ production at the LHC to probe the Higgs-top coupling and to distinguish between the scalar and pseudoscalar components. We also show that the presence of the pseudoscalar component in the Higgs-top Yukawa coupling leads to a sizeable value for the top quark EDM. It is shown that a limit of $10^{-19}$ e.cm, which is achievable by the future $e^{-}e^{+}$ collider, allows us to exclude a significant region in the $(\kappa,\tilde{\kappa})$ plane.
[ { "created": "Tue, 23 Sep 2014 14:22:07 GMT", "version": "v1" }, { "created": "Tue, 14 Oct 2014 08:13:17 GMT", "version": "v2" } ]
2014-10-15
[ [ "Khatibi", "Sara", "" ], [ "Najafabadi", "Mojtaba Mohammadi", "" ] ]
Top quark with its large Yukawa coupling is crucially important to explore TeV scale physics. Therefore, the study of Higgs-top sector is highly motivated to look for any deviations from the standard model predictions. The most general lowest order Lagrangian for the Higgs-top Yukawa coupling has scalar ($\kappa$) and pseudoscalar ($\tilde{\kappa}$) components. Currently, these couplings are constrained indirectly using the present experimental limits on the Higgs-$\gamma$-$\gamma$ and Higgs-gluon-gluon couplings. Furthermore, stronger bounds on $\kappa$ and $\tilde{\kappa}$ are obtained using the limits on the electric dipole moments (EDM). In this work, we propose an asymmetry-like observable $O_{\phi}$ in $t\bar{t}H$ production at the LHC to probe the Higgs-top coupling and to distinguish between the scalar and pseudoscalar components. We also show that the presence of the pseudoscalar component in the Higgs-top Yukawa coupling leads to a sizeable value for the top quark EDM. It is shown that a limit of $10^{-19}$ e.cm, which is achievable by the future $e^{-}e^{+}$ collider, allows us to exclude a significant region in the $(\kappa,\tilde{\kappa})$ plane.
hep-ph/0411259
Marieke Postma
Rachel Jeannerot and Marieke Postma
Majorana zero modes
37 pages, no figures
JHEP0412:032,2004
10.1088/1126-6708/2004/12/032
null
hep-ph astro-ph hep-th
null
We derive the zero mode solutions for a Majorana fermion in the background of a cosmic string and contrast it with the zero mode solution for a (neutral) Dirac fermion. A Majorana zero mode carries no vector or axial charge, and it cannot be bosonised. We study the implications for vorton formation and stability. In the massless limit stability of the zero mode is guaranteed by energy-momentum conservation. However, zero modes obtain an effective mass on string loops. It is found that the conditions under which current formation can be effective are exactly those for which zero mode decay is most likely to occur.
[ { "created": "Fri, 19 Nov 2004 16:20:43 GMT", "version": "v1" }, { "created": "Tue, 11 Jan 2005 15:24:00 GMT", "version": "v2" } ]
2008-11-26
[ [ "Jeannerot", "Rachel", "" ], [ "Postma", "Marieke", "" ] ]
We derive the zero mode solutions for a Majorana fermion in the background of a cosmic string and contrast it with the zero mode solution for a (neutral) Dirac fermion. A Majorana zero mode carries no vector or axial charge, and it cannot be bosonised. We study the implications for vorton formation and stability. In the massless limit stability of the zero mode is guaranteed by energy-momentum conservation. However, zero modes obtain an effective mass on string loops. It is found that the conditions under which current formation can be effective are exactly those for which zero mode decay is most likely to occur.
hep-ph/0112135
Gino Isidori
Giancarlo D'Ambrosio and Gino Isidori
$K^+\to \pi^+\nu\bar\nu$: a rising star on the stage of flavour physics
13 pages, 3 figures; minor modifications, version to appear in Phys.Lett.B
Phys.Lett.B530:108-116,2002
10.1016/S0370-2693(02)01328-X
CERN-TH/2001-355
hep-ph
null
Motivated by the new experimental information reported by the BNL--E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of $\br(K^+\to\pi^+\nu\bar\nu)$. Although still affected by a large error, the BNL--E787 result favours values of $\br(K^+\to \pi^+\nu\bar\nu)$ substantially larger than what expected within the Standard Model. As a result, this data already provide non-trivial constraints on the unitarity triangle, when interpreted within the Standard Model framework. We stress the importance of the clean relation between $\br(K^+\to \pi^+\nu\bar\nu)$, $\sin2\beta$ and $\Delta M_{B_d}/\Delta M_{B_s}$ that in the next few years could provide one of the deepest probes of the Standard Model in the sector of quark-flavour dynamics. A speculative discussion about possible non-standard interpretations of a large $\br(K^+\to \pi^+\nu\bar\nu)$ is also presented. Two main scenarios naturally emerge: those with direct new-physics contributions to the $s \to d \nu\bar\nu$ amplitude and those with direct new-physics effects only in $B_d$--$\bar B_d$ mixing. Realistic models originating these two scenarios and possible future strategies to clearly identify them are briefly discussed.
[ { "created": "Mon, 10 Dec 2001 14:32:36 GMT", "version": "v1" }, { "created": "Tue, 15 Jan 2002 17:06:53 GMT", "version": "v2" } ]
2010-11-23
[ [ "D'Ambrosio", "Giancarlo", "" ], [ "Isidori", "Gino", "" ] ]
Motivated by the new experimental information reported by the BNL--E787 Collaboration, we analyse the present impact and the future prospects opened by the measurement of $\br(K^+\to\pi^+\nu\bar\nu)$. Although still affected by a large error, the BNL--E787 result favours values of $\br(K^+\to \pi^+\nu\bar\nu)$ substantially larger than what expected within the Standard Model. As a result, this data already provide non-trivial constraints on the unitarity triangle, when interpreted within the Standard Model framework. We stress the importance of the clean relation between $\br(K^+\to \pi^+\nu\bar\nu)$, $\sin2\beta$ and $\Delta M_{B_d}/\Delta M_{B_s}$ that in the next few years could provide one of the deepest probes of the Standard Model in the sector of quark-flavour dynamics. A speculative discussion about possible non-standard interpretations of a large $\br(K^+\to \pi^+\nu\bar\nu)$ is also presented. Two main scenarios naturally emerge: those with direct new-physics contributions to the $s \to d \nu\bar\nu$ amplitude and those with direct new-physics effects only in $B_d$--$\bar B_d$ mixing. Realistic models originating these two scenarios and possible future strategies to clearly identify them are briefly discussed.
0807.4937
Matthias Neubert
S. Casagrande, F. Goertz, U. Haisch, M. Neubert and T. Pfoh (Johannes Gutenberg University, Mainz)
Flavor Physics in the Randall-Sundrum Model: I. Theoretical Setup and Electroweak Precision Tests
70 pages, 12 figures. v2: Incorrect treatment of phases in zero-mode approximation corrected, and discussion of electroweak precision tests modified. v3: Additional minor modifications and typos corrected; version published in JHEP
JHEP 0810:094,2008
10.1088/1126-6708/2008/10/094
MZ-TH/08-18
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A complete discussion of tree-level flavor-changing effects in the Randall-Sundrum (RS) model with brane-localized Higgs sector and bulk gauge and matter fields is presented. The bulk equations of motion for the gauge and fermion fields, supplemented by boundary conditions taking into account the couplings to the Higgs sector, are solved exactly. For gauge fields the Kaluza-Klein (KK) decomposition is performed in a covariant R_xi gauge. For fermions the mixing between different generations is included in a completely general way. The hierarchies observed in the fermion spectrum and the quark mixing matrix are explained naturally in terms of anarchic five-dimensional Yukawa matrices and wave-function overlap integrals. Detailed studies of the flavor-changing couplings of the Higgs boson and of gauge bosons and their KK excitations are performed, including in particular the couplings of the standard W and Z bosons. A careful analysis of electroweak precision observables including the S and T parameters and the Zbb couplings shows that the simplest RS model containing only Standard Model particles and their KK excitations is consistent with all experimental bounds for a KK scale as low as a few TeV, if one allows for a heavy Higgs boson and/or for an ultra-violet cutoff below the Planck scale. The study of flavor-changing effects includes analyses of the non-unitarity of the quark mixing matrix, anomalous right-handed couplings of the W bosons, tree-level flavor-changing neutral current couplings of the Z and Higgs bosons, the rare decays t-->c(u)+Z and t-->c(u)+h, and the flavor mixing among KK fermions. The results obtained in this work form the basis for general calculations of flavor-changing processes in the RS model and its extensions.
[ { "created": "Thu, 31 Jul 2008 17:46:23 GMT", "version": "v1" }, { "created": "Wed, 3 Sep 2008 14:49:12 GMT", "version": "v2" }, { "created": "Mon, 20 Oct 2008 15:56:56 GMT", "version": "v3" } ]
2009-01-06
[ [ "Casagrande", "S.", "", "Johannes\n Gutenberg University, Mainz" ], [ "Goertz", "F.", "", "Johannes\n Gutenberg University, Mainz" ], [ "Haisch", "U.", "", "Johannes\n Gutenberg University, Mainz" ], [ "Neubert", "M.", "", "Johannes\n ...
A complete discussion of tree-level flavor-changing effects in the Randall-Sundrum (RS) model with brane-localized Higgs sector and bulk gauge and matter fields is presented. The bulk equations of motion for the gauge and fermion fields, supplemented by boundary conditions taking into account the couplings to the Higgs sector, are solved exactly. For gauge fields the Kaluza-Klein (KK) decomposition is performed in a covariant R_xi gauge. For fermions the mixing between different generations is included in a completely general way. The hierarchies observed in the fermion spectrum and the quark mixing matrix are explained naturally in terms of anarchic five-dimensional Yukawa matrices and wave-function overlap integrals. Detailed studies of the flavor-changing couplings of the Higgs boson and of gauge bosons and their KK excitations are performed, including in particular the couplings of the standard W and Z bosons. A careful analysis of electroweak precision observables including the S and T parameters and the Zbb couplings shows that the simplest RS model containing only Standard Model particles and their KK excitations is consistent with all experimental bounds for a KK scale as low as a few TeV, if one allows for a heavy Higgs boson and/or for an ultra-violet cutoff below the Planck scale. The study of flavor-changing effects includes analyses of the non-unitarity of the quark mixing matrix, anomalous right-handed couplings of the W bosons, tree-level flavor-changing neutral current couplings of the Z and Higgs bosons, the rare decays t-->c(u)+Z and t-->c(u)+h, and the flavor mixing among KK fermions. The results obtained in this work form the basis for general calculations of flavor-changing processes in the RS model and its extensions.
hep-ph/9205202
David Kaplan
Kiwoon Choi, David B. Kaplan, Ann E. Nelson
Is CP a Gauge Symmetry?
22
Nucl.Phys.B391:515-530,1993
10.1016/0550-3213(93)90082-Z
null
hep-ph
null
We suggest here that CP is a discrete {\it gauge} symmetry, and is therefore not violated by quantum gravity. We show that four dimensional CP can arise as a discrete gauge symmetry in theories with dimensional compactification, if the original number of Minkowski dimensions equals $8k+1$, $8k+2$ or $8k+3$, and if there are certain restrictions on the gauge group; these conditions are met by superstrings. CP may then be broken spontaneously below $10^9$ GeV, explaining the observed CP violation in the kaon system without inducing a large EDMN. We discuss the phenomenology of such models, as well as the peculiar nature of cosmic ``CP strings'' which could be produced at the compactification scale. Such strings have the curious property that a particle carried around the string is turned into its CP conjugate. A single CP string renders four dimensional spacetime nonorientable.
[ { "created": "Mon, 4 May 1992 22:01:53 GMT", "version": "v1" } ]
2010-11-01
[ [ "Choi", "Kiwoon", "" ], [ "Kaplan", "David B.", "" ], [ "Nelson", "Ann E.", "" ] ]
We suggest here that CP is a discrete {\it gauge} symmetry, and is therefore not violated by quantum gravity. We show that four dimensional CP can arise as a discrete gauge symmetry in theories with dimensional compactification, if the original number of Minkowski dimensions equals $8k+1$, $8k+2$ or $8k+3$, and if there are certain restrictions on the gauge group; these conditions are met by superstrings. CP may then be broken spontaneously below $10^9$ GeV, explaining the observed CP violation in the kaon system without inducing a large EDMN. We discuss the phenomenology of such models, as well as the peculiar nature of cosmic ``CP strings'' which could be produced at the compactification scale. Such strings have the curious property that a particle carried around the string is turned into its CP conjugate. A single CP string renders four dimensional spacetime nonorientable.
2305.08627
Vedran Brdar
Vedran Brdar
Short Baseline Oscillations and the Gallium Mystery
7 pages, 3 figures, contribution to the 2023 Electroweak session of the 57th Rencontres de Moriond
null
null
CERN-TH-2023-082
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Data from several neutrino experiments suggest an anomalous neutrino flavor transition across relatively short baselines which is in conflict with the three-flavor neutrino oscillation paradigm. In particular, MiniBooNE and BEST collaborations have reported anomalous findings at $\sim 5\sigma$. In this contribution, such measurements and their possible explanations within and beyond the Standard Model are discussed.
[ { "created": "Mon, 15 May 2023 13:20:44 GMT", "version": "v1" } ]
2023-05-16
[ [ "Brdar", "Vedran", "" ] ]
Data from several neutrino experiments suggest an anomalous neutrino flavor transition across relatively short baselines which is in conflict with the three-flavor neutrino oscillation paradigm. In particular, MiniBooNE and BEST collaborations have reported anomalous findings at $\sim 5\sigma$. In this contribution, such measurements and their possible explanations within and beyond the Standard Model are discussed.
hep-ph/9809513
Kimball A. Milton
K. A. Milton, I. L. Solovtsov, and O. P. Solovtsova
The Gross--Llewellyn Smith Sum Rule in the Analytic Approach to Perturbative QCD
17 pages, 9 eps figures, REVTeX
Phys. Rev. D 60, 016001 (1999)
10.1103/PhysRevD.60.016001
OKHEP-98-07
hep-ph
null
We apply analytic perturbation theory to the Gross--Llewellyn Smith sum rule. We study the $Q^2$ evolution and the renormalization scheme dependence of the analytic three-loop QCD correction to this sum rule, and demonstrate that the results are practically renormalization scheme independent and lead to rather different $Q^2$ evolution than the standard perturbative correction possesses.
[ { "created": "Wed, 23 Sep 1998 20:55:23 GMT", "version": "v1" } ]
2016-08-25
[ [ "Milton", "K. A.", "" ], [ "Solovtsov", "I. L.", "" ], [ "Solovtsova", "O. P.", "" ] ]
We apply analytic perturbation theory to the Gross--Llewellyn Smith sum rule. We study the $Q^2$ evolution and the renormalization scheme dependence of the analytic three-loop QCD correction to this sum rule, and demonstrate that the results are practically renormalization scheme independent and lead to rather different $Q^2$ evolution than the standard perturbative correction possesses.
0705.2176
Federico Urban
C. Bambi, F.R. Urban
Gravitational particle production in braneworld cosmology
4 pages, 1 figure, v3 with new definition of $\Lambda$ and minor text modifications
Phys.Rev.Lett.99:191302,2007
10.1103/PhysRevLett.99.191302
null
hep-ph astro-ph.CO gr-qc
null
Gravitational particle production in time variable metric of an expanding universe is efficient only when the Hubble parameter $H$ is not too small in comparison with the particle mass. In standard cosmology, the huge value of the Planck mass $M_{Pl}$ makes the mechanism phenomenologically irrelevant. On the other hand, in braneworld cosmology the expansion rate of the early universe can be much faster and many weakly interacting particles can be abundantly created. Cosmological implications are discussed.
[ { "created": "Tue, 15 May 2007 15:47:05 GMT", "version": "v1" }, { "created": "Mon, 21 May 2007 08:34:51 GMT", "version": "v2" }, { "created": "Mon, 19 Nov 2007 08:13:49 GMT", "version": "v3" } ]
2009-06-12
[ [ "Bambi", "C.", "" ], [ "Urban", "F. R.", "" ] ]
Gravitational particle production in time variable metric of an expanding universe is efficient only when the Hubble parameter $H$ is not too small in comparison with the particle mass. In standard cosmology, the huge value of the Planck mass $M_{Pl}$ makes the mechanism phenomenologically irrelevant. On the other hand, in braneworld cosmology the expansion rate of the early universe can be much faster and many weakly interacting particles can be abundantly created. Cosmological implications are discussed.
hep-ph/0412235
Ivanov Dmitri
D.Yu. Ivanov, G. Krasnikov and L. Szymanowski
Hard exclusive production of a vector meson
3 pages, prepared for Diffraction 2004, International Workshop on Diffraction in High-Energy Physics, Cala Gonone, Sardinia, Italy, September 18 - 23, 2004
null
10.1016/j.nuclphysbps.2005.02.078
null
hep-ph
null
The processes of a light neutral vector meson, V=\rho^0, \omega, \phi, electroproduction and a heavy quarkonium, V=J/\Psi, \Upsilon, photoproduction are studied in the framework of QCD factorization. We derive a complete set of hard-scattering amplitudes which describe these processes at next-to-leading order (NLO).
[ { "created": "Thu, 16 Dec 2004 14:02:52 GMT", "version": "v1" } ]
2009-11-10
[ [ "Ivanov", "D. Yu.", "" ], [ "Krasnikov", "G.", "" ], [ "Szymanowski", "L.", "" ] ]
The processes of a light neutral vector meson, V=\rho^0, \omega, \phi, electroproduction and a heavy quarkonium, V=J/\Psi, \Upsilon, photoproduction are studied in the framework of QCD factorization. We derive a complete set of hard-scattering amplitudes which describe these processes at next-to-leading order (NLO).
hep-ph/9303256
Stevenson
M. Consoli and P.M. Stevenson
Resolution of the lambda Phi^4 Puzzle and a 2 Tev Higgs Boson
(Revised and expanded version) 18 pages, LaTeX, DE-FG05-92ER40717-5
null
null
null
hep-ph hep-lat
null
We argue that massless (lambda Phi^4)_4 is "trivial" without being entirely trivial. It has a non-trivial effective potential which leads to spontaneous symmetry breaking, but the particle excitations above the broken vacuum are non-interacting. The key to this picture is the realization that the constant background field (the mode with zero 4-momentum) renormalizes differently from the fluctuation field (the finite-momentum modes). This picture reconciles rigorous results and lattice calculations with one-loop and Gaussian-approximation analyses. Because of "triviality", these latter two methods should be effectively exact. Indeed, they yield the same renormalized effective potential and the same relation m_h^2 = 8 pi^2 v^2 between the particle mass and the physical vacuum expectation value. This relation predicts a Higgs mass m_h about 2 TeV in the standard model. The non-interacting nature of the scalar sector implies, by the equivalence theorem, that Higgs and gauge bosons interact only weakly, through their gauge and Yukawa couplings.
[ { "created": "Sun, 14 Mar 1993 23:33:00 GMT", "version": "v1" }, { "created": "Tue, 3 Aug 1993 15:19:00 GMT", "version": "v2" } ]
2008-02-03
[ [ "Consoli", "M.", "" ], [ "Stevenson", "P. M.", "" ] ]
We argue that massless (lambda Phi^4)_4 is "trivial" without being entirely trivial. It has a non-trivial effective potential which leads to spontaneous symmetry breaking, but the particle excitations above the broken vacuum are non-interacting. The key to this picture is the realization that the constant background field (the mode with zero 4-momentum) renormalizes differently from the fluctuation field (the finite-momentum modes). This picture reconciles rigorous results and lattice calculations with one-loop and Gaussian-approximation analyses. Because of "triviality", these latter two methods should be effectively exact. Indeed, they yield the same renormalized effective potential and the same relation m_h^2 = 8 pi^2 v^2 between the particle mass and the physical vacuum expectation value. This relation predicts a Higgs mass m_h about 2 TeV in the standard model. The non-interacting nature of the scalar sector implies, by the equivalence theorem, that Higgs and gauge bosons interact only weakly, through their gauge and Yukawa couplings.
hep-ph/0509349
Donini Andrea
A. Donini, E. Fernandez-Martinez and S. Rigolin
$\nu_\mu$ disappearance at the SPL, T2K-I and the Neutrino Factory
2 pages, 3 epsfig; NUFACT'05, 21-26 June 2005, Frascati
Nucl.Phys.Proc.Suppl.155:176-177,2006
10.1016/j.nuclphysbps.2006.02.037
null
hep-ph
null
We study the $\nu_\mu$ disappearance channel at T2K-phase I and the SPL and analyse the achievable reduction of present uncertainties in $\theta_{23}$ and $\Delta m^2_{23}$. We analyse the impact of discrete ambiguities in sign($\Delta m^2{23}$) and sign($2 \tan \theta_{23}$). We show how the disappearance channel at the Neutrino Factory is complementary to the ``golden'' and ``silver'' appearance channels and can be used to reduce the eightfold-ambiguity problem in ($\theta_{13}-\delta$).
[ { "created": "Thu, 29 Sep 2005 15:30:06 GMT", "version": "v1" } ]
2009-07-29
[ [ "Donini", "A.", "" ], [ "Fernandez-Martinez", "E.", "" ], [ "Rigolin", "S.", "" ] ]
We study the $\nu_\mu$ disappearance channel at T2K-phase I and the SPL and analyse the achievable reduction of present uncertainties in $\theta_{23}$ and $\Delta m^2_{23}$. We analyse the impact of discrete ambiguities in sign($\Delta m^2{23}$) and sign($2 \tan \theta_{23}$). We show how the disappearance channel at the Neutrino Factory is complementary to the ``golden'' and ``silver'' appearance channels and can be used to reduce the eightfold-ambiguity problem in ($\theta_{13}-\delta$).
hep-ph/0405241
David London
David London
CP Violation in the B System: Measuring New-Physics Parameters
13 pages, 6 figures (included), plain latex. Talk given at MRST 2004: From Quarks to Cosmology, Concordia University, Montreal, May 2004
Int.J.Mod.Phys. A19 (2004) 5463-5476
10.1142/S0217751X04022712
UdeM-GPP-TH-04-122, McGill 04/30
hep-ph
null
I review CP violation in the standard model (SM). I also describe the predictions for CP violation in the B system, along with signals for physics beyond the SM. I stress the numerous contributions of Pat O'Donnell to this subject. Finally, I discuss a new method for measuring new-physics parameters in B decays. This knowledge will allow us to partially identify any new physics which is found, before its direct production at high-energy colliders.
[ { "created": "Mon, 24 May 2004 19:16:28 GMT", "version": "v1" } ]
2009-11-10
[ [ "London", "David", "" ] ]
I review CP violation in the standard model (SM). I also describe the predictions for CP violation in the B system, along with signals for physics beyond the SM. I stress the numerous contributions of Pat O'Donnell to this subject. Finally, I discuss a new method for measuring new-physics parameters in B decays. This knowledge will allow us to partially identify any new physics which is found, before its direct production at high-energy colliders.
2311.09012
Sergei Chekanov V.
S. V. Chekanov
Estimation of the chances to find new phenomena at the LHC in a model-agnostic combinatorial analysis
13 pages,1 figure, submitted to a journal
null
null
HEP-ANL-186383
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we estimate the number of event topologies that have the potential to be produced in $pp$ collisions at the Large Hadron Collider (LHC) without violating kinematic and other constraints. We use numerical calculations and combinatorics, guided by large-scale Monte Carlo simulations of Standard Model (SM) processes. Then, we set the upper limit on the probability that new physics may escape detection, assuming a model-agnostic approach. The calculated probability is unexpectedly large, and the fact that the LHC has not found new physics until now is not entirely surprising. We argue that the optimal direction for maximizing the chances of finding new physics is to use unsupervised machine learning for anomaly detection or algorithms designed for event classification.
[ { "created": "Wed, 15 Nov 2023 14:55:41 GMT", "version": "v1" }, { "created": "Thu, 16 May 2024 16:17:12 GMT", "version": "v2" } ]
2024-05-17
[ [ "Chekanov", "S. V.", "" ] ]
In this paper, we estimate the number of event topologies that have the potential to be produced in $pp$ collisions at the Large Hadron Collider (LHC) without violating kinematic and other constraints. We use numerical calculations and combinatorics, guided by large-scale Monte Carlo simulations of Standard Model (SM) processes. Then, we set the upper limit on the probability that new physics may escape detection, assuming a model-agnostic approach. The calculated probability is unexpectedly large, and the fact that the LHC has not found new physics until now is not entirely surprising. We argue that the optimal direction for maximizing the chances of finding new physics is to use unsupervised machine learning for anomaly detection or algorithms designed for event classification.
0903.5464
Martin Hentschinski
J.Bartels and M.Hentschinski
The triple Pomeron vertex in large-N QCD and the pair-of-pants topology
32 pages, 140 figures
JHEP 0908:103,2009
10.1088/1126-6708/2009/08/103
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the high energy behavior of QCD for different surface topologies of color graphs. After a brief review of the planar limit (bootstrap and gluon reggeization) and of the cylinder topology (BFKL) we investigate the 3 -> 3 scattering in the triple Regge limit which belongs to the pair-of-pants topology. We re-derive the triple Pomeron vertex function and show that it belongs to a specific set of graphs in color space which we identify as the analogue of the Mandelstam diagram.
[ { "created": "Tue, 31 Mar 2009 13:50:59 GMT", "version": "v1" } ]
2009-09-28
[ [ "Bartels", "J.", "" ], [ "Hentschinski", "M.", "" ] ]
We investigate the high energy behavior of QCD for different surface topologies of color graphs. After a brief review of the planar limit (bootstrap and gluon reggeization) and of the cylinder topology (BFKL) we investigate the 3 -> 3 scattering in the triple Regge limit which belongs to the pair-of-pants topology. We re-derive the triple Pomeron vertex function and show that it belongs to a specific set of graphs in color space which we identify as the analogue of the Mandelstam diagram.
hep-ph/9903210
Alexander V. Kuznetsov
A.V. Kuznetsov, N.V. Mikheev
Comment on the paper: ``Neutrino pair production by a virtual photon in an external magnetic field'' by Zhukovskii et al
4 pages, LATEX
null
null
YARU-HE-99/01
hep-ph
null
We point out some serious mistakes in the investigation of Zhukovskii et al. Both the amplitude and the probability of the process were calculated wrongly, that is, the problem of the neutrino pair production by a virtual photon in an external magnetic field is still unsolved.
[ { "created": "Mon, 1 Mar 1999 16:22:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kuznetsov", "A. V.", "" ], [ "Mikheev", "N. V.", "" ] ]
We point out some serious mistakes in the investigation of Zhukovskii et al. Both the amplitude and the probability of the process were calculated wrongly, that is, the problem of the neutrino pair production by a virtual photon in an external magnetic field is still unsolved.
hep-ph/9503479
null
H. Baer, A. Bartl, C.H. Chen, H. Eberl, J. Feng, K. Fujii, J. Gunion, T. Kamon, C. Kao, J.~L.~Lopez, W. Majerotto, P. McIntyre, R. Munroe, H. Murayama, F. Paige, W. Porod, J. Sender, A. Sopczak, X. Tata, T. Tsukamoto and J. White
LOW ENERGY SUPERSYMMETRY PHENOMENOLOGY
74 page (Latex) file; a PS or uuencoded manuscript with embedded figures is available via anonymous ftp at ftp://hep.fsu.edu/preprints/baer/FSUHEP950401.ps or .uu . Contributed chapter to DPF study group on Electroweak Symmetry Breaking and Beyond the Standard Model.
null
null
FSU-HEP-950401, LBL-37016 and UH-511-822-95
hep-ph
null
We summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, we evaluate the capabilities of various $e^+e^-$, $p\bar p$ and $pp$ colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, we discuss capabilities of future facilities to dis-entangle the anticipated spectrum of super-particles, and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. We comment upon the complementarity of proposed hadron and $e^+e^-$ machines for a comprehensive study of low energy supersymmetry.
[ { "created": "Fri, 31 Mar 1995 01:19:17 GMT", "version": "v1" } ]
2009-09-25
[ [ "Baer", "H.", "" ], [ "Bartl", "A.", "" ], [ "Chen", "C. H.", "" ], [ "Eberl", "H.", "" ], [ "Feng", "J.", "" ], [ "Fujii", "K.", "" ], [ "Gunion", "J.", "" ], [ "Kamon", "T.", "" ], [ ...
We summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, we evaluate the capabilities of various $e^+e^-$, $p\bar p$ and $pp$ colliders to discover evidence for supersymmetric particles. Furthermore, assuming supersymmetry is discovered, we discuss capabilities of future facilities to dis-entangle the anticipated spectrum of super-particles, and, via precision measurements, to test mass and coupling parameters for comparison with various theoretical expectations. We comment upon the complementarity of proposed hadron and $e^+e^-$ machines for a comprehensive study of low energy supersymmetry.
hep-ph/9702210
Ralf Rapp
R. Rapp, G. Chanfray and J. Wambach
Rho Meson Propagation and Dilepton Enhancement in Hot Hadronic Matter
27 pages RevTeX, 9 eps-figures, submitted to Nucl. Phys. A
Nucl.Phys. A617 (1997) 472-495
10.1016/S0375-9474(97)00137-1
SUNY-NTG-97-04
hep-ph
null
A realistic model for the free rho meson with coupling to two-pion states is employed to calculate the rho propagator in a hot and dense hadron gas. The medium modifications are based on hadronic rescattering processes: intermediate two-pion states are renormalized through interactions with surrounding nucleons and deltas, and rho meson scattering is considered off nucleons, deltas, pions and kaons. Constraints from gauge invariance as well as the full off-shell dynamics of the interactions are accounted for. Within the vector dominance model we apply the resulting in-medium rho spectral function to compute $e^+e^-$ production rates from $\pi^+\pi^-$ annihilation. The calculation of corresponding $e^+e^-$ spectra as recently measured in central collisions of heavy-ions at CERN/SpS energies gives reasonable agreement with the experimental data.
[ { "created": "Fri, 31 Jan 1997 16:42:17 GMT", "version": "v1" } ]
2009-10-30
[ [ "Rapp", "R.", "" ], [ "Chanfray", "G.", "" ], [ "Wambach", "J.", "" ] ]
A realistic model for the free rho meson with coupling to two-pion states is employed to calculate the rho propagator in a hot and dense hadron gas. The medium modifications are based on hadronic rescattering processes: intermediate two-pion states are renormalized through interactions with surrounding nucleons and deltas, and rho meson scattering is considered off nucleons, deltas, pions and kaons. Constraints from gauge invariance as well as the full off-shell dynamics of the interactions are accounted for. Within the vector dominance model we apply the resulting in-medium rho spectral function to compute $e^+e^-$ production rates from $\pi^+\pi^-$ annihilation. The calculation of corresponding $e^+e^-$ spectra as recently measured in central collisions of heavy-ions at CERN/SpS energies gives reasonable agreement with the experimental data.
0909.4144
Zhi-Gang Wang
Zhi-Gang Wang
Analysis of the vertexes $\Omega_Q^*\Omega_Q \phi$ and radiative decays $\Omega_Q^*\to \Omega_Q \gamma$
17 pages, 12 figures, revised version
Phys. Rev. D81: 036002, 2010
10.1103/PhysRevD.81.036002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we study the vertexes $\Omega_Q^*\Omega_Q \phi$ with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate $\phi(1020)$, and calculate the radiative decays $\Omega_Q^*\to \Omega_Q \gamma$.
[ { "created": "Wed, 23 Sep 2009 07:55:43 GMT", "version": "v1" }, { "created": "Sat, 28 Nov 2009 08:59:56 GMT", "version": "v2" }, { "created": "Fri, 15 Jan 2010 00:53:33 GMT", "version": "v3" } ]
2010-02-20
[ [ "Wang", "Zhi-Gang", "" ] ]
In this article, we study the vertexes $\Omega_Q^*\Omega_Q \phi$ with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate $\phi(1020)$, and calculate the radiative decays $\Omega_Q^*\to \Omega_Q \gamma$.
1311.6468
James Cline
James M. Cline, Zuowei Liu, Guy D. Moore, Wei Xue
Scattering properties of dark atoms and molecules
13 pages, 14 figures; v2: new section added with analytic fits for momentum transfer cross section; published version
Phys. Rev. D 89, 043514 (2014)
10.1103/PhysRevD.89.043514
null
hep-ph astro-ph.CO physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
There has been renewed interest in the possibility that dark matter exists in the form of atoms, analogous to those of the visible world. An important input for understanding the cosmological consequences of dark atoms is their self-scattering. Making use of results from atomic physics for the potentials between hydrogen atoms, we compute the low-energy elastic scattering cross sections for dark atoms. We find an intricate dependence upon the ratio of the dark proton to electron mass, allowing for the possibility to "design" low-energy features in the cross section. Dependences upon other parameters, namely the gauge coupling and reduced mass, scale out of the problem by using atomic units. We derive constraints on the parameter space of dark atoms by demanding that their scattering cross section does not exceed bounds from dark matter halo shapes. We discuss the formation of molecular dark hydrogen in the universe, and determine the analogous constraints on the model when the dark matter is predominantly in molecular form.
[ { "created": "Mon, 25 Nov 2013 21:00:04 GMT", "version": "v1" }, { "created": "Wed, 15 Jan 2014 00:12:26 GMT", "version": "v2" } ]
2014-02-26
[ [ "Cline", "James M.", "" ], [ "Liu", "Zuowei", "" ], [ "Moore", "Guy D.", "" ], [ "Xue", "Wei", "" ] ]
There has been renewed interest in the possibility that dark matter exists in the form of atoms, analogous to those of the visible world. An important input for understanding the cosmological consequences of dark atoms is their self-scattering. Making use of results from atomic physics for the potentials between hydrogen atoms, we compute the low-energy elastic scattering cross sections for dark atoms. We find an intricate dependence upon the ratio of the dark proton to electron mass, allowing for the possibility to "design" low-energy features in the cross section. Dependences upon other parameters, namely the gauge coupling and reduced mass, scale out of the problem by using atomic units. We derive constraints on the parameter space of dark atoms by demanding that their scattering cross section does not exceed bounds from dark matter halo shapes. We discuss the formation of molecular dark hydrogen in the universe, and determine the analogous constraints on the model when the dark matter is predominantly in molecular form.
1111.1263
Gerald Cleaver
Timothy Renner, Jared Greenwald, Douglas Moore, Gerald Cleaver
Initial Systematic Investigations of the Landscape of Low Layer NAHE Extensions
65 Pages, 31 Tables, 31 Figures
null
10.1140/epjc/s10052-012-2167-y
BU-HEPP-11-06
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discovery that the number of physically consistent string vacua is on the order of 10^500 has prompted several statistical studies of string phenomenology. Contained here is one such study that focuses on the Weakly Coupled Free Fermionic Heterotic String (WCFFHS) formalism. Presented are systematic extensions of the well-known NAHE (Nanopoulos, Antoniadis, Hagelin, Ellis) set of basis vectors, which have been shown to produce phenomenologically realistic models. Statistics related to the number of U(1)'s, gauge group factors, non-Abelian singlets, ST SUSYs, as well as the gauge groups themselve are discussed for the full range of models produced as well as models containing GUT groups only. Prior results of other large-scale investigations are compared with these regarding the aforementioned quantities. Statistical coupling between the gauge groups and the number of ST SUSYs is also discussed, and it was found that for order-3 extensions there are more models with enhanced ST SUSY when there is an exceptional group present. Also discussed are some three-generation GUT models found in the data sets. These models are unique because they come from basis vectors which still have a geometric interpretation -- there are no "rank-cuts" in these models.
[ { "created": "Fri, 4 Nov 2011 22:09:53 GMT", "version": "v1" }, { "created": "Thu, 5 Jul 2012 19:56:07 GMT", "version": "v2" } ]
2012-11-20
[ [ "Renner", "Timothy", "" ], [ "Greenwald", "Jared", "" ], [ "Moore", "Douglas", "" ], [ "Cleaver", "Gerald", "" ] ]
The discovery that the number of physically consistent string vacua is on the order of 10^500 has prompted several statistical studies of string phenomenology. Contained here is one such study that focuses on the Weakly Coupled Free Fermionic Heterotic String (WCFFHS) formalism. Presented are systematic extensions of the well-known NAHE (Nanopoulos, Antoniadis, Hagelin, Ellis) set of basis vectors, which have been shown to produce phenomenologically realistic models. Statistics related to the number of U(1)'s, gauge group factors, non-Abelian singlets, ST SUSYs, as well as the gauge groups themselve are discussed for the full range of models produced as well as models containing GUT groups only. Prior results of other large-scale investigations are compared with these regarding the aforementioned quantities. Statistical coupling between the gauge groups and the number of ST SUSYs is also discussed, and it was found that for order-3 extensions there are more models with enhanced ST SUSY when there is an exceptional group present. Also discussed are some three-generation GUT models found in the data sets. These models are unique because they come from basis vectors which still have a geometric interpretation -- there are no "rank-cuts" in these models.
1801.03007
Desmond Villalba
Nobuchika Okada, Digesh Raut, Desmond Villalba
Aspects of Domain-Wall Standard Model
22 pages, 3 figures. arXiv admin note: text overlap with arXiv:1712.09323 We had left this paper for some time and we wanted to submit it to a journal, therefore we made some minor updates. We have only updated figure 2 on page 14 and the subtext, figure 3 on page 16 and the subtext, and updated the references to reflect modern ATLAS/CMS constraints
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have recently proposed a setup of the "Domain-Wall Standard Model" in a non-compact 5-dimensional space-time, where all the Standard Model (SM) fields are localized in certain domains of the 5th dimension. While the SM is realized as a 4-dimensional effective theory at low energies, the model involves Kaluza-Klein (KK) modes of the SM particles. In this paper we introduce two simple solvable examples which lead to domain-wall configurations for the SM particles and their KK-modes. Based on the examples, we address a variety of phenomenologies of the Domain-Wall SM, such as the KK-mode gauge boson phenomenology at the Large Hadron Collider (LHC), the effect of the KK-mode SM fermions on Higgs boson phenomenology, and the KK-mode fermion search at the LHC with its decay into a corresponding SM fermion and a Nambu-Goldstone boson associated with a spontaneous breaking of the translational invariance in the 5th dimension. We also propose a simple unified picture of localizing all the SM fields.
[ { "created": "Mon, 8 Jan 2018 18:28:40 GMT", "version": "v1" }, { "created": "Wed, 9 Aug 2023 14:04:42 GMT", "version": "v2" } ]
2023-08-10
[ [ "Okada", "Nobuchika", "" ], [ "Raut", "Digesh", "" ], [ "Villalba", "Desmond", "" ] ]
We have recently proposed a setup of the "Domain-Wall Standard Model" in a non-compact 5-dimensional space-time, where all the Standard Model (SM) fields are localized in certain domains of the 5th dimension. While the SM is realized as a 4-dimensional effective theory at low energies, the model involves Kaluza-Klein (KK) modes of the SM particles. In this paper we introduce two simple solvable examples which lead to domain-wall configurations for the SM particles and their KK-modes. Based on the examples, we address a variety of phenomenologies of the Domain-Wall SM, such as the KK-mode gauge boson phenomenology at the Large Hadron Collider (LHC), the effect of the KK-mode SM fermions on Higgs boson phenomenology, and the KK-mode fermion search at the LHC with its decay into a corresponding SM fermion and a Nambu-Goldstone boson associated with a spontaneous breaking of the translational invariance in the 5th dimension. We also propose a simple unified picture of localizing all the SM fields.
0804.3007
Sandhya Choubey
Sanjib Kumar Agarwalla, Sandhya Choubey, Amitava Raychaudhuri
Exceptional Sensitivity to Neutrino Parameters with a Two Baseline Beta-Beam Set-up
24 pages, 5 figures, version to appear in Nucl.Phys.B
Nucl.Phys.B805:305-325,2008
10.1016/j.nuclphysb.2008.07.026
HRI-P-08-04-001, CU-PHYSICS/08-2008
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and (b) a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We choose 8B/8Li source ions with a boost factor \gamma of 650 for the magic baseline while for the closer detector we consider 18Ne/6He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With \gamma=650 for 8B/8Li and \gamma=575 for 18Ne/6He and total luminosity corresponding to 5\times (1.1 \times 10^{18}) and 5\times (2.9\times 10^{18}) useful ion decays in neutrino and antineutrino modes respectively, we find that our two detector set-up can probe maximal CP violation and establish the neutrino mass ordering if \sin^22\theta_{13} is 1.4\times 10^{-4} and 2.7\times 10^{-4}, respectively, or more. The sensitivity reach for \sin^22\theta_{13} itself is 5.5 \times 10^{-4}. With a factor of 10 higher luminosity, the corresponding \sin^22\theta_{13} reach of this set-up would be 1.8\times 10^{-5}, 4.6\times 10^{-5} and 5.3\times 10^{-5} respectively for the above three performance indicators. CP violation can be discovered for 64% of the possible \delta_{CP} values for \sin^22\theta_{13} \geq 10^{-3} (\geq 8\times 10^{-5}), for the standard luminosity (10 times enhanced luminosity). Comparable physics performance can be achieved in a set-up where data from CERN to INO@ICAL is combined with that from CERN to the Boulby mine in United Kingdom, a baseline of 1050 km.
[ { "created": "Fri, 18 Apr 2008 13:04:46 GMT", "version": "v1" }, { "created": "Mon, 28 Jul 2008 17:20:38 GMT", "version": "v2" } ]
2008-11-26
[ [ "Agarwalla", "Sanjib Kumar", "" ], [ "Choubey", "Sandhya", "" ], [ "Raychaudhuri", "Amitava", "" ] ]
We examine the reach of a Beta-beam experiment with two detectors at carefully chosen baselines for exploring neutrino mass parameters. Locating the source at CERN, the two detectors and baselines are: (a) a 50 kton iron calorimeter (ICAL) at a baseline of around 7150 km which is roughly the magic baseline, e.g., ICAL@INO, and (b) a 50 kton Totally Active Scintillator Detector at a distance of 730 km, e.g., at Gran Sasso. We choose 8B/8Li source ions with a boost factor \gamma of 650 for the magic baseline while for the closer detector we consider 18Ne/6He ions with a range of Lorentz boosts. We find that the locations of the two detectors complement each other leading to an exceptional high sensitivity. With \gamma=650 for 8B/8Li and \gamma=575 for 18Ne/6He and total luminosity corresponding to 5\times (1.1 \times 10^{18}) and 5\times (2.9\times 10^{18}) useful ion decays in neutrino and antineutrino modes respectively, we find that our two detector set-up can probe maximal CP violation and establish the neutrino mass ordering if \sin^22\theta_{13} is 1.4\times 10^{-4} and 2.7\times 10^{-4}, respectively, or more. The sensitivity reach for \sin^22\theta_{13} itself is 5.5 \times 10^{-4}. With a factor of 10 higher luminosity, the corresponding \sin^22\theta_{13} reach of this set-up would be 1.8\times 10^{-5}, 4.6\times 10^{-5} and 5.3\times 10^{-5} respectively for the above three performance indicators. CP violation can be discovered for 64% of the possible \delta_{CP} values for \sin^22\theta_{13} \geq 10^{-3} (\geq 8\times 10^{-5}), for the standard luminosity (10 times enhanced luminosity). Comparable physics performance can be achieved in a set-up where data from CERN to INO@ICAL is combined with that from CERN to the Boulby mine in United Kingdom, a baseline of 1050 km.
1509.00673
Qiaoli Yang
Qiaoli Yang
Axions and Dark Matter
10 pages, a contribution to the special issue of the Modern Physics Letters A "Dark Matter Particle Candidates"
Mod. Phys. Lett. A, 32, 1740003 (2017)
10.1142/S021773231740003X
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter constitutes about $23\%$ of the total energy density of the universe but its properties are still little known besides that it should be composed by cold and weakly interacting particles. Many beyond standard model theories can provide proper candidates to serve as dark matter and the axion introduced to solve the strong CP problem turns out to be an attractive one. In this paper, we briefly review several important features of the axion and the axion dark matter.
[ { "created": "Wed, 2 Sep 2015 12:58:16 GMT", "version": "v1" }, { "created": "Thu, 10 Sep 2015 03:55:30 GMT", "version": "v2" }, { "created": "Sun, 26 Feb 2017 17:09:32 GMT", "version": "v3" } ]
2017-05-18
[ [ "Yang", "Qiaoli", "" ] ]
Dark matter constitutes about $23\%$ of the total energy density of the universe but its properties are still little known besides that it should be composed by cold and weakly interacting particles. Many beyond standard model theories can provide proper candidates to serve as dark matter and the axion introduced to solve the strong CP problem turns out to be an attractive one. In this paper, we briefly review several important features of the axion and the axion dark matter.
2208.08137
Rinku Maji
Rinku Maji, Qaisar Shafi
Monopoles, Strings and Gravitational Waves in Non-minimal Inflation
21 pages, 10 figures, matches version published in JCAP
JCAP03(2023)007
10.1088/1475-7516/2023/03/007
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss how in $SO(10)$ grand unification an observable number density of topologically stable intermediate mass ( $\sim 10^{14}$ GeV) monopoles survive inflation driven by a Coleman-Weinberg potential and non-minimal coupling of the inflaton field to gravity. The scalar spectral index $n_s$ is in excellent agreement with the current observations, and the tensor to scalar ratio $r\gtrsim 0.003$. The model also predicts the presence of intermediate scale topologically stable cosmic strings, and their gravitational wave spectrum reflects the amount of cosmic inflation experienced by the associated symmetry breaking. The discovery of these primordial monopoles and the stochastic gravitational wave background from the strings would provide important new insights regarding the symmetry breaking patterns in the early universe.
[ { "created": "Wed, 17 Aug 2022 08:13:22 GMT", "version": "v1" }, { "created": "Sat, 4 Mar 2023 06:18:00 GMT", "version": "v2" } ]
2023-03-07
[ [ "Maji", "Rinku", "" ], [ "Shafi", "Qaisar", "" ] ]
We discuss how in $SO(10)$ grand unification an observable number density of topologically stable intermediate mass ( $\sim 10^{14}$ GeV) monopoles survive inflation driven by a Coleman-Weinberg potential and non-minimal coupling of the inflaton field to gravity. The scalar spectral index $n_s$ is in excellent agreement with the current observations, and the tensor to scalar ratio $r\gtrsim 0.003$. The model also predicts the presence of intermediate scale topologically stable cosmic strings, and their gravitational wave spectrum reflects the amount of cosmic inflation experienced by the associated symmetry breaking. The discovery of these primordial monopoles and the stochastic gravitational wave background from the strings would provide important new insights regarding the symmetry breaking patterns in the early universe.
hep-ph/0111394
Ismd31
Sonja Kabana
A new interpretation of the QCD phase transition and of strangeness as QGP signature
5 pages, 3 figures in eps, talk given at XXXI International Symposium on Multiparticle Dynamics, Sept 1-7, 2001, Datong China. URL http://ismd31.ccnu.edu.cn/ This paper is the "University of Bern preprint BUHE-01-03"
null
10.1142/9789812778048_0032
null
hep-ph
null
We address the question of how to identify the QCD phase transition using measured light (u,d,s-structured) hadrons, without invoking comparison to the QCD $\epsilon_c$ predictions, and extract $\epsilon_c$ from the data. We analyse several particle and nuclear collisions and extract their chemical freeze-out temperature $T$ at zero baryochemical potential ($\mu_B$). We find at $\mu_B=0$ a universal rise and saturation of both the $T$ and of the strangeness suppression factor $\lambda_s$ (=$\frac {2\bar{s}} {\bar{u} + \bar{d}} $) with increasing initial energy density ($\epsilon_i$). The onset of saturation of both $T$ and $\lambda_s$, is interpreted as due to the event of the QCD phase transition. The critical energy density is estimated to be $\epsilon_c$ $\sim$ 1 +0.3 -0.5 GeV/fm$^3$, corresponding approximately to a $\sqrt{s}$ of $\sim$ 8.8 GeV for central Pb+Pb collisions. Concerning the role of strangeness, we identify trivial and non-trivial sources of strangeness enhancement: The peak of $\lambda_s$ in Pb+Pb collisions at $\sqrt{s}$=8.8 GeV and other phenomena of 'strangeness enhancement' defined with respect to p+p data, are trivially traced back to the different baryochemical potentials and $\epsilon_i$ of the compared systems. A non trivial redefined '$\lambda_s$ enhancement' is however also present. The netbaryonfree $\lambda_s$ limit is estimated to be approximately reached in Au+Au collisions at the LHC.
[ { "created": "Thu, 29 Nov 2001 09:27:00 GMT", "version": "v1" } ]
2017-08-23
[ [ "Kabana", "Sonja", "" ] ]
We address the question of how to identify the QCD phase transition using measured light (u,d,s-structured) hadrons, without invoking comparison to the QCD $\epsilon_c$ predictions, and extract $\epsilon_c$ from the data. We analyse several particle and nuclear collisions and extract their chemical freeze-out temperature $T$ at zero baryochemical potential ($\mu_B$). We find at $\mu_B=0$ a universal rise and saturation of both the $T$ and of the strangeness suppression factor $\lambda_s$ (=$\frac {2\bar{s}} {\bar{u} + \bar{d}} $) with increasing initial energy density ($\epsilon_i$). The onset of saturation of both $T$ and $\lambda_s$, is interpreted as due to the event of the QCD phase transition. The critical energy density is estimated to be $\epsilon_c$ $\sim$ 1 +0.3 -0.5 GeV/fm$^3$, corresponding approximately to a $\sqrt{s}$ of $\sim$ 8.8 GeV for central Pb+Pb collisions. Concerning the role of strangeness, we identify trivial and non-trivial sources of strangeness enhancement: The peak of $\lambda_s$ in Pb+Pb collisions at $\sqrt{s}$=8.8 GeV and other phenomena of 'strangeness enhancement' defined with respect to p+p data, are trivially traced back to the different baryochemical potentials and $\epsilon_i$ of the compared systems. A non trivial redefined '$\lambda_s$ enhancement' is however also present. The netbaryonfree $\lambda_s$ limit is estimated to be approximately reached in Au+Au collisions at the LHC.
2401.11638
Tae-Sun Park
Tae-Sun Park
Chiral perturbation theory with vector mesons and the pion form factors
null
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
The chiral perturbation theory (ChPT) of pions is extended to include vector mesons as well as pertinent degrees of freedom. By counting the typical momentum scale of vector mesons as order of $Q$ and vector meson masses as of the order of $\Lambda_\chi$, a consistent theory could be obtained. The explicit renormalization procedure of the theory is presented for the form factors of the pion up to one-loop accuracy. The resulting theory prediction for the form factors is in good agreement with the experimental data for a wide range of momentum transfers. The vector-meson dominance mechanism is also discussed in the systematic framework of ChPT.
[ { "created": "Mon, 22 Jan 2024 00:32:36 GMT", "version": "v1" } ]
2024-01-23
[ [ "Park", "Tae-Sun", "" ] ]
The chiral perturbation theory (ChPT) of pions is extended to include vector mesons as well as pertinent degrees of freedom. By counting the typical momentum scale of vector mesons as order of $Q$ and vector meson masses as of the order of $\Lambda_\chi$, a consistent theory could be obtained. The explicit renormalization procedure of the theory is presented for the form factors of the pion up to one-loop accuracy. The resulting theory prediction for the form factors is in good agreement with the experimental data for a wide range of momentum transfers. The vector-meson dominance mechanism is also discussed in the systematic framework of ChPT.
2209.04221
Jorge Segovia
M.C. Gordillo, F. De Soto and J. Segovia
The $\mathbf{X(3872)}$'s excitation and its connection with production at hadron colliders
5 pages, 1 figure. arXiv admin note: text overlap with arXiv:2105.11976
null
10.1103/PhysRevD.106.094004
null
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHCb collaboration has found that the production rate of $X(3872)$ in proton-proton collisions decreases as final state particle multiplicity increases. Moreover, the ALICE experiment at CERN has observed that the number of deuterons produced increases with multiplicity, a behavior that is qualitatively different from that of the $X(3872)$. These experimental findings may point to a compact structure for the $X(3872)$ or, at least, that its hadronization could proceed through a charm-anticharm core. We have recently used a diffusion Monte Carlo method to solve the many-body Schr\"odinger equation that describes the $X(3872)$ as a $c \bar c q \bar q$ tetraquark system with quantum numbers $I^G(J^{PC})=0^+(1^{++})$ and $1^-(1^{++})$. According to our structural analysis, the quark--(anti-)quark correlations resemble light-meson--heavy-meson molecules of type $\omega J/\psi$ and $\rho J/\psi$, rather than the most extended $D\bar D^{\ast}$ interpretation. It was argued that this fact may be the key to make compatible the molecular features of the $X(3872)$ with its production observables. The same formalism allows us to compute the first color excited $c \bar c q \bar q$ tetraquark state with either $I^G(J^{PC})=0^+(1^{++})$ or $1^-(1^{++})$. A bound-state is found in each channel, their masses are around 4.0 GeV which is an energy region where many new exotic candidates have been collected by the Particle Data Group. Concerning their structural properties, these states cluster in a compact diquark-antidiquark arrangement which matches perfectly with a so-called Born-Oppenheimer tetraquark configuration. The promptly production rates of these states in proton-proton, proton-nucleus and nucleus-nucleus collisions should fall off equal to or even faster than those of the $X(3872)$.
[ { "created": "Fri, 9 Sep 2022 10:14:48 GMT", "version": "v1" } ]
2022-11-23
[ [ "Gordillo", "M. C.", "" ], [ "De Soto", "F.", "" ], [ "Segovia", "J.", "" ] ]
The LHCb collaboration has found that the production rate of $X(3872)$ in proton-proton collisions decreases as final state particle multiplicity increases. Moreover, the ALICE experiment at CERN has observed that the number of deuterons produced increases with multiplicity, a behavior that is qualitatively different from that of the $X(3872)$. These experimental findings may point to a compact structure for the $X(3872)$ or, at least, that its hadronization could proceed through a charm-anticharm core. We have recently used a diffusion Monte Carlo method to solve the many-body Schr\"odinger equation that describes the $X(3872)$ as a $c \bar c q \bar q$ tetraquark system with quantum numbers $I^G(J^{PC})=0^+(1^{++})$ and $1^-(1^{++})$. According to our structural analysis, the quark--(anti-)quark correlations resemble light-meson--heavy-meson molecules of type $\omega J/\psi$ and $\rho J/\psi$, rather than the most extended $D\bar D^{\ast}$ interpretation. It was argued that this fact may be the key to make compatible the molecular features of the $X(3872)$ with its production observables. The same formalism allows us to compute the first color excited $c \bar c q \bar q$ tetraquark state with either $I^G(J^{PC})=0^+(1^{++})$ or $1^-(1^{++})$. A bound-state is found in each channel, their masses are around 4.0 GeV which is an energy region where many new exotic candidates have been collected by the Particle Data Group. Concerning their structural properties, these states cluster in a compact diquark-antidiquark arrangement which matches perfectly with a so-called Born-Oppenheimer tetraquark configuration. The promptly production rates of these states in proton-proton, proton-nucleus and nucleus-nucleus collisions should fall off equal to or even faster than those of the $X(3872)$.
2001.09563
Hua-Xing Chen
Hua-Xing Chen
Decay properties of $P_c$ states through the Fierz rearrangement
18 pages, 3 figures, 1 table, to be published in EPJC
null
10.1140/epjc/s10052-020-08519-1
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We systematically study hidden-charm pentaquark currents with the quark configurations $[\bar c u][u d c]$, $[\bar c d][u u c]$, and $[\bar c c][u u d]$. Some of their relations are derived using the Fierz rearrangement of the Dirac and color indices, and the obtained results are used to study strong decay properties of $P_c$ states as $\bar D^{(*)} \Sigma_c$ hadronic molecules. We calculate their relative branching ratios for the $J/\psi p$, $\eta_c p$, $\chi_{c0} p$, $\chi_{c1} p$, $\bar D^{(*)0} \Lambda_c^+$, $\bar D^{0} \Sigma_c^{+}$, and $\bar D^{-} \Sigma_c^{++}$ decay channels. We propose to search for the $P_c(4312)$ in the $\eta_c p$ channel and the $P_c(4440)/P_c(4457)$ in the $\bar D^{0} \Lambda_c^+$ channel.
[ { "created": "Mon, 27 Jan 2020 02:16:44 GMT", "version": "v1" }, { "created": "Fri, 9 Oct 2020 06:31:56 GMT", "version": "v2" } ]
2020-10-28
[ [ "Chen", "Hua-Xing", "" ] ]
We systematically study hidden-charm pentaquark currents with the quark configurations $[\bar c u][u d c]$, $[\bar c d][u u c]$, and $[\bar c c][u u d]$. Some of their relations are derived using the Fierz rearrangement of the Dirac and color indices, and the obtained results are used to study strong decay properties of $P_c$ states as $\bar D^{(*)} \Sigma_c$ hadronic molecules. We calculate their relative branching ratios for the $J/\psi p$, $\eta_c p$, $\chi_{c0} p$, $\chi_{c1} p$, $\bar D^{(*)0} \Lambda_c^+$, $\bar D^{0} \Sigma_c^{+}$, and $\bar D^{-} \Sigma_c^{++}$ decay channels. We propose to search for the $P_c(4312)$ in the $\eta_c p$ channel and the $P_c(4440)/P_c(4457)$ in the $\bar D^{0} \Lambda_c^+$ channel.
hep-ph/0305196
Capella
A.Capella (LPT, Orsay)
Microscopic Models of Heavy Ion Interactions
39 pages, 18 figures. Lectures at VIII Hispalensis International Summer School, Seville (Spain), to be published by Springer Verlag
null
10.1007/978-3-540-44504-3_1
LPT-Orsay-03-36
hep-ph
null
An introduction to dynamical microscopic models of hadronic and nuclear interactions is presented. Special emphasis is put in the relation between multiparticle production and total cross-section contributions. In heavy ion collisions, some observables, considered as signals of the production of a Quark Gluon Plasma (QGP), are studied. It is shown that they can only be described if final state interactions are introduced. It is argued that the cross-sections required are too small to drive the system to thermal equilibrium within the duration time of the final state interaction.
[ { "created": "Sat, 17 May 2003 20:29:53 GMT", "version": "v1" } ]
2015-06-25
[ [ "Capella", "A.", "", "LPT, Orsay" ] ]
An introduction to dynamical microscopic models of hadronic and nuclear interactions is presented. Special emphasis is put in the relation between multiparticle production and total cross-section contributions. In heavy ion collisions, some observables, considered as signals of the production of a Quark Gluon Plasma (QGP), are studied. It is shown that they can only be described if final state interactions are introduced. It is argued that the cross-sections required are too small to drive the system to thermal equilibrium within the duration time of the final state interaction.
1112.0696
Igor O. Cherednikov
Igor O. Cherednikov
Geometry of gauge links in operator definitions of transverse-momentum dependent PDFs: A comparative view
9 pages, 4 figures. Presented at the International Conference "Photon-2011", 22-27 May 2011 Spa, Belgium
null
null
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Different approaches to the problem of a gauge-invariant operator definition of transverse-momentum dependent parton densities (TMDs) are reviewed and compared from the point of view of their compatibility with the operator definition of collinear (integrated) parton distribution functions. In particular, geometry of the longitudinal and transverse gauge links (Wilson lines) both in unsubtracted quark TMDs and in the associate soft factors is addressed. A possible connection between different operator definitions is also discussed.
[ { "created": "Sat, 3 Dec 2011 22:19:37 GMT", "version": "v1" } ]
2011-12-06
[ [ "Cherednikov", "Igor O.", "" ] ]
Different approaches to the problem of a gauge-invariant operator definition of transverse-momentum dependent parton densities (TMDs) are reviewed and compared from the point of view of their compatibility with the operator definition of collinear (integrated) parton distribution functions. In particular, geometry of the longitudinal and transverse gauge links (Wilson lines) both in unsubtracted quark TMDs and in the associate soft factors is addressed. A possible connection between different operator definitions is also discussed.
hep-ph/0009034
Karsten Tabelow
Fu Jinghua, Meng Ta-chung, R. Rittel, and K. Tabelow
Criticality in quark-gluon systems far beyond thermal and chemical equilibrium
13 pages, including 1 figure and 1 table
Phys.Rev.Lett. 86 (2001) 1961-1964
10.1103/PhysRevLett.86.1961
null
hep-ph
null
Experimental evidence and theoretical arguments for the existence of self-organized criticality in systems of gluons and quarks are presented. It is observed that the existing data for high-transverse-momentum jet-production exhibit striking regularities; and it is shown that, together with first-principle considerations, such regularities can be used, not only to probe the possible compositness of quarks, but also to obtain {\em direct evidence} for, or against, the existence of critical temperature and/or critical chemical potential in quark-gluon systems when hadrons are squeezed together.
[ { "created": "Mon, 4 Sep 2000 14:02:58 GMT", "version": "v1" } ]
2009-10-31
[ [ "Jinghua", "Fu", "" ], [ "Ta-chung", "Meng", "" ], [ "Rittel", "R.", "" ], [ "Tabelow", "K.", "" ] ]
Experimental evidence and theoretical arguments for the existence of self-organized criticality in systems of gluons and quarks are presented. It is observed that the existing data for high-transverse-momentum jet-production exhibit striking regularities; and it is shown that, together with first-principle considerations, such regularities can be used, not only to probe the possible compositness of quarks, but also to obtain {\em direct evidence} for, or against, the existence of critical temperature and/or critical chemical potential in quark-gluon systems when hadrons are squeezed together.
hep-ph/0609299
Cyrille Marquet
O. Kepka, C. Marquet, R. Peschanski and C. Royon
Next-leading BFKL effects in forward-jet production at HERA
5 pages, 4 figures, NLL-BFKL saddle-point approximation now compared with exact integration, version to appear in PLB
Phys.Lett.B655:236-240,2007
10.1016/j.physletb.2007.08.088
null
hep-ph
null
We show that next-leading logarithmic (NLL) Balitsky-Fadin-Kuraev-Lipatov (BFKL) effects can be tested by the forward-jet cross sections recently measured at HERA. For d\sigma/dx, the NLL corrections are small which confirms the stability of the BFKL description. The triple differential cross section d\sigma/dxdk_T^2dQ^2 is sensitive to NLL effects and opens the way for an experimental test of the full BFKL theoretical framework at NLL accuracy.
[ { "created": "Thu, 28 Sep 2006 17:00:51 GMT", "version": "v1" }, { "created": "Mon, 1 Oct 2007 15:43:47 GMT", "version": "v2" } ]
2008-11-26
[ [ "Kepka", "O.", "" ], [ "Marquet", "C.", "" ], [ "Peschanski", "R.", "" ], [ "Royon", "C.", "" ] ]
We show that next-leading logarithmic (NLL) Balitsky-Fadin-Kuraev-Lipatov (BFKL) effects can be tested by the forward-jet cross sections recently measured at HERA. For d\sigma/dx, the NLL corrections are small which confirms the stability of the BFKL description. The triple differential cross section d\sigma/dxdk_T^2dQ^2 is sensitive to NLL effects and opens the way for an experimental test of the full BFKL theoretical framework at NLL accuracy.
hep-ph/0502013
Andrei Afanasev
Andrei V. Afanasev, Stanley J. Brodsky, Carl E. Carlson, Yu-Chun Chen, Marc Vanderhaeghen
The two-photon exchange contribution to elastic electron-nucleon scattering at large momentum transfer
38 pages, 22 figures
Phys.Rev.D72:013008,2005
10.1103/PhysRevD.72.013008
SLAC-PUB-10990, WM-05-102, JLAB-PHY-05-297
hep-ph nucl-th
null
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer by using a quark-parton representation of virtual Compton scattering. We thus can relate the two-photon exchange amplitude to the generalized parton distributions which also enter in other wide angle scattering processes. We find that the interference of one- and two-photon exchange contribution is able to substantially resolve the difference between electric form factor measurements from Rosenbluth and polarization transfer experiments. Two-photon exchange has additional consequences which could be experimentally observed, including nonzero polarization effects and a positron-proton/electron-proton scattering asymmetry. The predicted Rosenbluth plot is no longer precisely linear; it acquires a measurable curvature, particularly at large laboratory angle.
[ { "created": "Tue, 1 Feb 2005 20:57:59 GMT", "version": "v1" } ]
2008-11-26
[ [ "Afanasev", "Andrei V.", "" ], [ "Brodsky", "Stanley J.", "" ], [ "Carlson", "Carl E.", "" ], [ "Chen", "Yu-Chun", "" ], [ "Vanderhaeghen", "Marc", "" ] ]
We estimate the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer by using a quark-parton representation of virtual Compton scattering. We thus can relate the two-photon exchange amplitude to the generalized parton distributions which also enter in other wide angle scattering processes. We find that the interference of one- and two-photon exchange contribution is able to substantially resolve the difference between electric form factor measurements from Rosenbluth and polarization transfer experiments. Two-photon exchange has additional consequences which could be experimentally observed, including nonzero polarization effects and a positron-proton/electron-proton scattering asymmetry. The predicted Rosenbluth plot is no longer precisely linear; it acquires a measurable curvature, particularly at large laboratory angle.
hep-ph/0306057
Vladimir Braun
V.M. Braun, G.P. Korchemsky and D. Mueller
The Uses of Conformal Symmetry in QCD
110 pages, invited review for "Prog. Part. Nucl. Phys"
Prog.Part.Nucl.Phys.51:311-398,2003
10.1016/S0146-6410(03)90004-4
null
hep-ph hep-th
null
The Lagrangian of Quantum Chromodynamics is invariant under conformal transformations. Although this symmetry is broken by quantum corrections, it has important consequences for strong interactions at short distances and provides one with powerful tools in practical calculations. In this review we give a short exposition of the relevant ideas, techniques and applications of conformal symmetry to various problems of interest.
[ { "created": "Fri, 6 Jun 2003 10:00:14 GMT", "version": "v1" } ]
2009-07-09
[ [ "Braun", "V. M.", "" ], [ "Korchemsky", "G. P.", "" ], [ "Mueller", "D.", "" ] ]
The Lagrangian of Quantum Chromodynamics is invariant under conformal transformations. Although this symmetry is broken by quantum corrections, it has important consequences for strong interactions at short distances and provides one with powerful tools in practical calculations. In this review we give a short exposition of the relevant ideas, techniques and applications of conformal symmetry to various problems of interest.
hep-ph/0306284
Jonathan L. Rosner
Jonathan L. Rosner
$B$ Physics (Theory)
23 pages, LaTeX, 12 figures, invited talk presented at Fourth Tropical Workshop, Cairns, Australia, 9--13 June 2003. Proceedings to be published by AIP. Some updated figures
AIP Conf.Proc.689:150-174,2003
10.1063/1.1627734
EFI 03-32
hep-ph
null
Some theoretical aspects of $B$ physics are reviewed. These include a brief recapitulation of information on weak quark transitions as described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix, a description of CP asymmetries in $B$ decays to CP eigenstates and self-tagging modes, a discussion of final-state phases in $B$ and charm decays, some topics on $B_s$ properties and decays, the prospects for unusual excited $B$ states opened by discovery of some narrow $c \bar s$ resonances, and the prospects for seeing the heavier $Q=1/3$ quarks predicted in some extended grand unified theories.
[ { "created": "Sat, 28 Jun 2003 20:52:26 GMT", "version": "v1" }, { "created": "Wed, 30 Jul 2003 15:49:06 GMT", "version": "v2" } ]
2014-11-17
[ [ "Rosner", "Jonathan L.", "" ] ]
Some theoretical aspects of $B$ physics are reviewed. These include a brief recapitulation of information on weak quark transitions as described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix, a description of CP asymmetries in $B$ decays to CP eigenstates and self-tagging modes, a discussion of final-state phases in $B$ and charm decays, some topics on $B_s$ properties and decays, the prospects for unusual excited $B$ states opened by discovery of some narrow $c \bar s$ resonances, and the prospects for seeing the heavier $Q=1/3$ quarks predicted in some extended grand unified theories.
1210.2703
Joachim Kopp
Joachim Kopp
New signals in dark matter detectors
6 pages, 3 figures, contribution to the proceedings of the PASCOS 2012 conference in Merida, Mexico; based on work done in collaboration with Roni Harnik and Pedro Machado, see arXiv:1202.6073
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the scattering of solar neutrinos on electrons and nuclei in dark matter direct detection experiments. The rates of these processes are small in the Standard Model, but can be enhanced by several orders of magnitude if the neutrino sector is slightly non-minimal. This makes even the current generation of dark matter detectors very sensitive to non-standard neutrino physics. Examples discussed here are neutrino magnetic moments and toy models with a simple hidden sector containing a sterile neutrino and a light new gauge boson ("dark photon"). We discuss the expected event spectra and temporal modulation effects, as well as constraints from a variety of astrophysical, cosmological, and laboratory experiments.
[ { "created": "Tue, 9 Oct 2012 19:46:02 GMT", "version": "v1" } ]
2012-10-10
[ [ "Kopp", "Joachim", "" ] ]
We investigate the scattering of solar neutrinos on electrons and nuclei in dark matter direct detection experiments. The rates of these processes are small in the Standard Model, but can be enhanced by several orders of magnitude if the neutrino sector is slightly non-minimal. This makes even the current generation of dark matter detectors very sensitive to non-standard neutrino physics. Examples discussed here are neutrino magnetic moments and toy models with a simple hidden sector containing a sterile neutrino and a light new gauge boson ("dark photon"). We discuss the expected event spectra and temporal modulation effects, as well as constraints from a variety of astrophysical, cosmological, and laboratory experiments.
2311.07684
Rajesh Mondal
Md Riajul Haque, Debaprasad Maity, Rajesh Mondal
Gravitational neutrino reheating
7 pages, 4 figures, title modified, updated plots, version accepted by PRD
null
null
null
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Despite having important cosmological implications, the reheating phase is believed to play a crucial role in cosmology and particle physics model building. Conventionally, the model of reheating with an arbitrary coupling of inflaton to massless fields naturally lacks precise prediction and hence difficult to verify through observation. In this paper, we propose a simple and natural reheating mechanism where the particle physics model, namely the Type-I seesaw is shown to play a major role in the entire reheating process where inflaton is coupled with all the fields only gravitationally. Besides successfully resolving the well-known neutrino mass and baryon asymmetry problems, this scenario offers successful reheating, predicts distinct primordial gravitational wave spectrum and non-vanishing lowest active neutrino mass. Our novel mechanism opens up a new avenue of integrating particle physics and cosmology in the context of reheating.
[ { "created": "Mon, 13 Nov 2023 19:05:27 GMT", "version": "v1" }, { "created": "Tue, 21 Nov 2023 05:19:26 GMT", "version": "v2" }, { "created": "Tue, 12 Mar 2024 06:20:12 GMT", "version": "v3" } ]
2024-03-13
[ [ "Haque", "Md Riajul", "" ], [ "Maity", "Debaprasad", "" ], [ "Mondal", "Rajesh", "" ] ]
Despite having important cosmological implications, the reheating phase is believed to play a crucial role in cosmology and particle physics model building. Conventionally, the model of reheating with an arbitrary coupling of inflaton to massless fields naturally lacks precise prediction and hence difficult to verify through observation. In this paper, we propose a simple and natural reheating mechanism where the particle physics model, namely the Type-I seesaw is shown to play a major role in the entire reheating process where inflaton is coupled with all the fields only gravitationally. Besides successfully resolving the well-known neutrino mass and baryon asymmetry problems, this scenario offers successful reheating, predicts distinct primordial gravitational wave spectrum and non-vanishing lowest active neutrino mass. Our novel mechanism opens up a new avenue of integrating particle physics and cosmology in the context of reheating.
hep-ph/0608288
Alexander Bakulev
A. P. Bakulev, A. V. Pimikov
Self-consistent Gaussian model of nonperturbative QCD vacuum
15 pages, 7 figures, english version
ActaPhys.Polon.B37:3627-3634,2006
null
null
hep-ph
null
We show that the minimal Gaussian model of nonlocal vacuum quark and quark-gluon condensates in QCD generates the non-transversity of vector current correlators. We suggest the improved Gaussian model of the nonperturbative QCD vacuum, which respects QCD equations of motion and minimizes the revealed gauge-invariance breakdown. We obtain the refined values of pion distribution amplitude (DA) conformal moments using the improved QCD vacuum model and construct the allowed region for Gegenbauer coefficients a_2 and a_4 of the pion DA.
[ { "created": "Sat, 26 Aug 2006 21:23:56 GMT", "version": "v1" }, { "created": "Thu, 5 Oct 2006 15:38:59 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bakulev", "A. P.", "" ], [ "Pimikov", "A. V.", "" ] ]
We show that the minimal Gaussian model of nonlocal vacuum quark and quark-gluon condensates in QCD generates the non-transversity of vector current correlators. We suggest the improved Gaussian model of the nonperturbative QCD vacuum, which respects QCD equations of motion and minimizes the revealed gauge-invariance breakdown. We obtain the refined values of pion distribution amplitude (DA) conformal moments using the improved QCD vacuum model and construct the allowed region for Gegenbauer coefficients a_2 and a_4 of the pion DA.
hep-ph/0311007
J. D. Vergados
Giomataris (CEA, Saclay, France) and J.D. Vergados (University of Ioannina, Greece)
Neutrinos in a spherical box
16 Pages, LaTex, 7 figures, talk given at NANP 2003, Dubna, Russia, June 23, 2003
null
10.1134/1.1772443
null
hep-ph
null
In the present paper we study some neutrino properties as they may appear in the low energy neutrinos emitted in triton decay with maximum neutrino energy of 18.6 keV. The technical challenges to this end can be achieved by building a very large TPC capable of detecting low energy recoils, down to a a few tenths of a keV, within the required low background constraints. More specifically We propose the development of a spherical gaseous TPC of about 10-m in radius and a 200 Mcurie triton source in the center of curvature. One can list a number of exciting studies, concerning fundamental physics issues, that could be made using a large volume TPC and low energy antineutrinos: 1) The oscillation length involving the small angle of the neutrino mixing matrix, directly measured in this disappearance experiment, is fully contained inside the detector. Measuring the counting rate of neutrino-electron elastic scattering as a function of the distance of the source will give a precise and unambiguous measurement of the oscillation parameters free of systematic errors. In fact first estimates show that even with a year's data taking a sensitivity of a few percent for the measurement of the above angle will be achieved. 2) The low energy detection threshold offers a unique sensitivity for the neutrino magnetic moment which is about two orders of magnitude beyond the current experimental limit. 3) Scattering at such low neutrino energies has never been studied and any departure from the expected behavior may be an indication of new physics beyond the standard model. In this work we mainly focus on the various theoretical issues involved including a precise determination of the Weinberg angle at very low momentum transfer.
[ { "created": "Sat, 1 Nov 2003 16:52:04 GMT", "version": "v1" } ]
2015-06-25
[ [ "Giomataris", "", "", "CEA, Saclay, France" ], [ "Vergados", "J. D.", "", "University of\n Ioannina, Greece" ] ]
In the present paper we study some neutrino properties as they may appear in the low energy neutrinos emitted in triton decay with maximum neutrino energy of 18.6 keV. The technical challenges to this end can be achieved by building a very large TPC capable of detecting low energy recoils, down to a a few tenths of a keV, within the required low background constraints. More specifically We propose the development of a spherical gaseous TPC of about 10-m in radius and a 200 Mcurie triton source in the center of curvature. One can list a number of exciting studies, concerning fundamental physics issues, that could be made using a large volume TPC and low energy antineutrinos: 1) The oscillation length involving the small angle of the neutrino mixing matrix, directly measured in this disappearance experiment, is fully contained inside the detector. Measuring the counting rate of neutrino-electron elastic scattering as a function of the distance of the source will give a precise and unambiguous measurement of the oscillation parameters free of systematic errors. In fact first estimates show that even with a year's data taking a sensitivity of a few percent for the measurement of the above angle will be achieved. 2) The low energy detection threshold offers a unique sensitivity for the neutrino magnetic moment which is about two orders of magnitude beyond the current experimental limit. 3) Scattering at such low neutrino energies has never been studied and any departure from the expected behavior may be an indication of new physics beyond the standard model. In this work we mainly focus on the various theoretical issues involved including a precise determination of the Weinberg angle at very low momentum transfer.
1106.2187
Toru Kojo
Toru Kojo
A (1+1) dimensional example of Quarkyonic matter
32 pages, 9 figures, published version
null
10.1016/j.nuclphysa.2011.12.002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the (1+1) dimensional QCD (QCD_2) at finite density to consider a number of qualitative issues: confinement in dense quark matter, the chiral symmetry breaking near the Fermi surface, the relation between chiral spirals and quark number density, and a possibility of the spontaneous flavor symmetry breaking. We argue that while the free energy is dominated by perturbative quarks, confined excitations at zero density can persist up to high density. So quark matter in QCD$_2$ is an example of Quarkyonic matter. The non-Abelian bosonization and associated charge-flavor-color separation are mainly used in order to clarify basic structures of QCD_2 at finite density.
[ { "created": "Sat, 11 Jun 2011 00:03:29 GMT", "version": "v1" }, { "created": "Tue, 28 Aug 2012 21:57:23 GMT", "version": "v2" } ]
2015-05-28
[ [ "Kojo", "Toru", "" ] ]
We analyze the (1+1) dimensional QCD (QCD_2) at finite density to consider a number of qualitative issues: confinement in dense quark matter, the chiral symmetry breaking near the Fermi surface, the relation between chiral spirals and quark number density, and a possibility of the spontaneous flavor symmetry breaking. We argue that while the free energy is dominated by perturbative quarks, confined excitations at zero density can persist up to high density. So quark matter in QCD$_2$ is an example of Quarkyonic matter. The non-Abelian bosonization and associated charge-flavor-color separation are mainly used in order to clarify basic structures of QCD_2 at finite density.
1307.4711
Mauro Napsuciale
Selim G\'omez-\'Avila and M. Napsuciale
Covariant basis induced by parity for the $(j,0)\oplus (0,j)$ representation
15 pages, ytableau.sty file added to the submission to display correctly Young diagrams
Phys. Rev. D 88, 096012 (2013)
10.1103/PhysRevD.88.096012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we build a covariant basis for operators acting on the $(j,0)\oplus(0,j)$ Lorentz group representations. The construction is based on an analysis of the covariant properties of the parity operator, which for these representations transforms as the completely temporal component of a symmetrical tensor of rank $2j$. The covariant properties of parity involve the Jordan algebra of anti commutators of the Lorentz group generators which unlike the Lie algebra is not universal. We make the construction explicit for $j=1/2,1$ and $3/2$, reproducing well-known results for the $j=1/2$ case. We provide an algorithm for the corresponding calculations for arbitrary $j$. This covariant basis provides an inventory of all the possible interaction terms for gauge and non-gauge theories of fields for these representations. In particular, it supplies a single second rank antisymmetric structure, which in the Poincar\'e projector formalism implies a single Pauli term arising from gauge interactions and a single (free) parameter $g$, the gyromagnetic factor. This simple structure predicts that for an elementary particle in this formalism all multipole moments, $Q^{l}_{E}$ and $Q^{l}_{M}$, are dictated by the complete algebraic structure of the Lorentz generators and the value of $g$. We explicitly calculate the multipole moments, for arbitrary $j$ up to $l=8$. Comparing with results in the literature we find that only the electric charge and magnetic moment of a spin $j$ particle are independent of the Lorentz representation under which it transforms, all higher multipoles being representation dependent. Finally we show that the propagation of the corresponding spin $j$ waves in a electromagnetic background is causal.
[ { "created": "Wed, 17 Jul 2013 18:02:03 GMT", "version": "v1" }, { "created": "Tue, 12 Nov 2013 13:57:41 GMT", "version": "v2" }, { "created": "Fri, 15 Nov 2013 10:52:17 GMT", "version": "v3" } ]
2013-12-04
[ [ "Gómez-Ávila", "Selim", "" ], [ "Napsuciale", "M.", "" ] ]
In this work, we build a covariant basis for operators acting on the $(j,0)\oplus(0,j)$ Lorentz group representations. The construction is based on an analysis of the covariant properties of the parity operator, which for these representations transforms as the completely temporal component of a symmetrical tensor of rank $2j$. The covariant properties of parity involve the Jordan algebra of anti commutators of the Lorentz group generators which unlike the Lie algebra is not universal. We make the construction explicit for $j=1/2,1$ and $3/2$, reproducing well-known results for the $j=1/2$ case. We provide an algorithm for the corresponding calculations for arbitrary $j$. This covariant basis provides an inventory of all the possible interaction terms for gauge and non-gauge theories of fields for these representations. In particular, it supplies a single second rank antisymmetric structure, which in the Poincar\'e projector formalism implies a single Pauli term arising from gauge interactions and a single (free) parameter $g$, the gyromagnetic factor. This simple structure predicts that for an elementary particle in this formalism all multipole moments, $Q^{l}_{E}$ and $Q^{l}_{M}$, are dictated by the complete algebraic structure of the Lorentz generators and the value of $g$. We explicitly calculate the multipole moments, for arbitrary $j$ up to $l=8$. Comparing with results in the literature we find that only the electric charge and magnetic moment of a spin $j$ particle are independent of the Lorentz representation under which it transforms, all higher multipoles being representation dependent. Finally we show that the propagation of the corresponding spin $j$ waves in a electromagnetic background is causal.
2406.19445
Tran Quang Thong Nguyen
Tim Linden, Thong T. Q. Nguyen, and Tim M. P. Tait
X-Ray Constraints on Dark Photon Tridents
4+3 pages, 4 figures. Comments are welcome!
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark photons that are sufficiently light and/or weakly-interacting represent a compelling vision of dark matter. Dark photon decay into three photons, which we call the dark photon trident, can be the dominant channel when the dark photon mass falls below the electron pair threshold and can produce a significant flux of x-rays. We use 16 years of data from INTEGRAL/SPI to constrain sub-MeV dark photon decay, producing new worlds-best constraints on the kinetic mixing parameter for dark photon masses between 61 keV and 1022 keV, and comment on the potential for future x-ray observatories to discover the trident decay process.
[ { "created": "Thu, 27 Jun 2024 18:00:01 GMT", "version": "v1" } ]
2024-07-01
[ [ "Linden", "Tim", "" ], [ "Nguyen", "Thong T. Q.", "" ], [ "Tait", "Tim M. P.", "" ] ]
Dark photons that are sufficiently light and/or weakly-interacting represent a compelling vision of dark matter. Dark photon decay into three photons, which we call the dark photon trident, can be the dominant channel when the dark photon mass falls below the electron pair threshold and can produce a significant flux of x-rays. We use 16 years of data from INTEGRAL/SPI to constrain sub-MeV dark photon decay, producing new worlds-best constraints on the kinetic mixing parameter for dark photon masses between 61 keV and 1022 keV, and comment on the potential for future x-ray observatories to discover the trident decay process.
hep-ph/9312211
null
S.M. Bilenky and C. Giunti
Future Solar Neutrino Experiments and Neutrino Spin-Flavour Precession
DFTT 75/93. 11 pages, 1 figure (included). Compressed Postscript file. If you prefer the uncompressed postscript file or a hardcopy of the paper, please write to GIUNTI@TO.INFN.IT
null
null
null
hep-ph astro-ph
null
The main features of the observables in the SNO and Super-Kamiokande solar neutrino experiments in the case of neutrino spin and/or spin-flavour precession in the magnetic field of the sun are discussed. It is shown without any model dependent assumption that in the case of Majorana transition magnetic moments the NC event rate $N^{\mathrm{NC}}$ does not depend on time and a measurement of $N^{\mathrm{NC}}$ will allow to determine the initial flux of $^8\mathrm{B}$ neutrinos with a theoretical uncertainty of a few \%. In the case of Dirac magnetic moments the NC event rate will depend on time and we obtain a model independent lower bound for the transition probability of initial $\nu_e$'s into right-handed sterile neutrinos.
[ { "created": "Thu, 2 Dec 1993 17:48:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bilenky", "S. M.", "" ], [ "Giunti", "C.", "" ] ]
The main features of the observables in the SNO and Super-Kamiokande solar neutrino experiments in the case of neutrino spin and/or spin-flavour precession in the magnetic field of the sun are discussed. It is shown without any model dependent assumption that in the case of Majorana transition magnetic moments the NC event rate $N^{\mathrm{NC}}$ does not depend on time and a measurement of $N^{\mathrm{NC}}$ will allow to determine the initial flux of $^8\mathrm{B}$ neutrinos with a theoretical uncertainty of a few \%. In the case of Dirac magnetic moments the NC event rate will depend on time and we obtain a model independent lower bound for the transition probability of initial $\nu_e$'s into right-handed sterile neutrinos.
1812.03908
Dario J Blandon Uribe
Dario J. Blandon, Diego A. Restrepo, William A. Ponce, Eduardo Rojas
Non-universal electroweak extensions of the standard model and the scotogenic models
PIC2018: XXXVIII International Symposium on Physics in Collision, Bogot\'a, Colombia, 2018. 6 pages, LaTeX, 1 pdf figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In order to analyze some low energy experimental anomalies, we charge with a non-universal $U(1)'$ gauge symmetry the standard model fermions, taking as a starting point the well-known scotogenic model. In order to have non-trivial solutions to the anomalies and the Yukawa constraints, we add three neutral singlet Dirac fermions. We have found two possible non-universal solutions which, as a matter of principle, are suitable to analyze family-dependent experimental anomalies.
[ { "created": "Mon, 10 Dec 2018 16:42:17 GMT", "version": "v1" } ]
2018-12-11
[ [ "Blandon", "Dario J.", "" ], [ "Restrepo", "Diego A.", "" ], [ "Ponce", "William A.", "" ], [ "Rojas", "Eduardo", "" ] ]
In order to analyze some low energy experimental anomalies, we charge with a non-universal $U(1)'$ gauge symmetry the standard model fermions, taking as a starting point the well-known scotogenic model. In order to have non-trivial solutions to the anomalies and the Yukawa constraints, we add three neutral singlet Dirac fermions. We have found two possible non-universal solutions which, as a matter of principle, are suitable to analyze family-dependent experimental anomalies.
1911.07862
Akshay Ghalsasi
Nicolas Fernandez, Akshay Ghalsasi, Stefano Profumo
Superradiance and the Spins of Black Holes from LIGO and X-ray binaries
10 pages, 5 Figures, comments welcome
null
null
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Measurements of the spin of stellar mass black holes (BHs) are now possible both through LIGO observations of binary BH mergers and for BHs in X-ray binary systems. The spins of BHs as inferred from LIGO observations suggest that BH spins are on the lower end of what is expected for a ``flat'' distribution of spins, while those from BHs in X-ray binaries tend to be large. Superradiance, a process that can effectively reduce the spin of BHs before they merge, could explain the lower observed spins in binary BH mergers for a non self-interacting light boson. In this paper, we use Bayesian analysis to infer the posterior probability distribution for the mass of a light boson that could fit LIGO data. We also analyze spins of BHs from X-ray binaries, and find that the X-ray binary data can be explained by superradiance due to a light boson with large self-interactions. We infer the mass range for such a boson that is consistent with the X-ray binary data.
[ { "created": "Mon, 18 Nov 2019 19:00:02 GMT", "version": "v1" } ]
2019-11-20
[ [ "Fernandez", "Nicolas", "" ], [ "Ghalsasi", "Akshay", "" ], [ "Profumo", "Stefano", "" ] ]
Measurements of the spin of stellar mass black holes (BHs) are now possible both through LIGO observations of binary BH mergers and for BHs in X-ray binary systems. The spins of BHs as inferred from LIGO observations suggest that BH spins are on the lower end of what is expected for a ``flat'' distribution of spins, while those from BHs in X-ray binaries tend to be large. Superradiance, a process that can effectively reduce the spin of BHs before they merge, could explain the lower observed spins in binary BH mergers for a non self-interacting light boson. In this paper, we use Bayesian analysis to infer the posterior probability distribution for the mass of a light boson that could fit LIGO data. We also analyze spins of BHs from X-ray binaries, and find that the X-ray binary data can be explained by superradiance due to a light boson with large self-interactions. We infer the mass range for such a boson that is consistent with the X-ray binary data.
1108.3609
Sonny Mantry
Sonny Mantry and Frank Petriello
Transverse Momentum Distributions from Effective Field Theory
9 pages, 3 figures, Invited Talk presented at the workshop on "QCD Evolution of Parton Distributions: from Collinear to Non-collinear Case", April 8th-9th, 2011, Thomas Jefferson National Accelerator Facility
null
10.1142/S2010194511001619
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review a new approach to calculating transverse momentum distributions of the Higgs and electroweak gauge bosons using the Soft-Collinear Effective Theory. We derive a factorization theorem for transverse momentum distributions in terms of newly-defined impact-parameter beam functions (iBFs) and an inverse soft function (iSF). The iBFs correspond to completely unintegrated parton distribution functions and provide interesting probes of momentum distributions within nucleons. The numerical matching between the low and high transverse momentum regions is improved in this approach with respect to standard techniques. We present results for next-to-leading logarithmic resummation for the Higgs and Z-boson distributions and give a comparison with Tevatron data.
[ { "created": "Thu, 18 Aug 2011 02:34:28 GMT", "version": "v1" } ]
2015-05-30
[ [ "Mantry", "Sonny", "" ], [ "Petriello", "Frank", "" ] ]
We review a new approach to calculating transverse momentum distributions of the Higgs and electroweak gauge bosons using the Soft-Collinear Effective Theory. We derive a factorization theorem for transverse momentum distributions in terms of newly-defined impact-parameter beam functions (iBFs) and an inverse soft function (iSF). The iBFs correspond to completely unintegrated parton distribution functions and provide interesting probes of momentum distributions within nucleons. The numerical matching between the low and high transverse momentum regions is improved in this approach with respect to standard techniques. We present results for next-to-leading logarithmic resummation for the Higgs and Z-boson distributions and give a comparison with Tevatron data.
2001.11059
Alberto Mart\'in-Ruiz
C. A. Escobar, E. Chan-L\'opez, and A. Mart\'in-Ruiz
Casimir effect in polymer scalar field theory
Accepted for publication in Physical Review D
null
10.1103/PhysRevD.101.046023
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the Casimir effect in the classical geometry of two parallel conducting plates, separated by a distance $L$, due to the presence of a minimal length $\lambda$ arising from a background independent (polymer) quantization scheme. To this end, we polymer-quantize the classical Klein-Gordon Hamiltonian for a massive scalar field confined between the plates and obtain the energy spectrum. The minimal length scale of the theory introduces a natural cutoff for the momenta in the plane parallel to the plates and a maximum number of discrete modes between the plates. The zero-point energy is calculated by summing over the modes, and by assuming $\lambda \ll L$, we expressed it as an expansion in powers of $1/N$, being $N=L/ \lambda$ the number of points between the plates. Closed analytical expressions are obtained for the Casimir energy in the cases of small and large scalar mass limits.
[ { "created": "Wed, 29 Jan 2020 19:26:06 GMT", "version": "v1" } ]
2020-02-26
[ [ "Escobar", "C. A.", "" ], [ "Chan-López", "E.", "" ], [ "Martín-Ruiz", "A.", "" ] ]
In this paper, we study the Casimir effect in the classical geometry of two parallel conducting plates, separated by a distance $L$, due to the presence of a minimal length $\lambda$ arising from a background independent (polymer) quantization scheme. To this end, we polymer-quantize the classical Klein-Gordon Hamiltonian for a massive scalar field confined between the plates and obtain the energy spectrum. The minimal length scale of the theory introduces a natural cutoff for the momenta in the plane parallel to the plates and a maximum number of discrete modes between the plates. The zero-point energy is calculated by summing over the modes, and by assuming $\lambda \ll L$, we expressed it as an expansion in powers of $1/N$, being $N=L/ \lambda$ the number of points between the plates. Closed analytical expressions are obtained for the Casimir energy in the cases of small and large scalar mass limits.
hep-ph/0610026
Christoph Luhn
Herbi K. Dreiner, Christoph Luhn, Hitoshi Murayama, Marc Thormeier
Baryon Triality and Neutrino Masses from an Anomalous Flavor U(1)
matches published version, typos corrected, references added, 54 pages, 3 figures, 5 tables
Nucl.Phys.B774:127-167,2007
10.1016/j.nuclphysb.2007.03.028
UFIFT-HEP-07-4
hep-ph hep-th
null
We construct a concise U(1)_X Froggatt-Nielsen model in which baryon triality, a discrete gauge Z_3 symmetry, arises from U(1)_X breaking. The proton is thus stable, however, R-parity is violated. With the proper choice of U(1)_X charges we can obtain neutrino masses and mixings consistent with an explanation of the atmospheric and solar neutrino anomalies in terms of neutrino oscillations, with no right-handed neutrinos required. The only mass scale apart from M_grav is m_3/2 ~ m_soft.
[ { "created": "Mon, 2 Oct 2006 22:13:45 GMT", "version": "v1" }, { "created": "Wed, 15 Aug 2007 23:53:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Dreiner", "Herbi K.", "" ], [ "Luhn", "Christoph", "" ], [ "Murayama", "Hitoshi", "" ], [ "Thormeier", "Marc", "" ] ]
We construct a concise U(1)_X Froggatt-Nielsen model in which baryon triality, a discrete gauge Z_3 symmetry, arises from U(1)_X breaking. The proton is thus stable, however, R-parity is violated. With the proper choice of U(1)_X charges we can obtain neutrino masses and mixings consistent with an explanation of the atmospheric and solar neutrino anomalies in terms of neutrino oscillations, with no right-handed neutrinos required. The only mass scale apart from M_grav is m_3/2 ~ m_soft.
hep-ph/9208250
null
M. A. Doncheski, R. W. Robinett and L. Weinkauf
Spin-Spin Asymmetries in Large Transverse Momentum Higgs Boson Production
10 pages, 4 figures (not included), LaTeX; PSU/TH/113, MAD/PH/709
Phys.Rev. D47 (1993) 1243-1246
10.1103/PhysRevD.47.1243
null
hep-ph
null
We examine the spin-dependence of standard model Higgs boson production at large transverse momentum via the processes $gg \rightarrow gH^0$, $qg \rightarrow qH^0$, and $q\overline{q} \rightarrow gH^0$. The partonic level spin-spin asymmetries ($\hat{a}_{LL}$) for these processes are large at SSC/LHC energies.
[ { "created": "Wed, 26 Aug 1992 14:55:16 GMT", "version": "v1" } ]
2016-09-01
[ [ "Doncheski", "M. A.", "" ], [ "Robinett", "R. W.", "" ], [ "Weinkauf", "L.", "" ] ]
We examine the spin-dependence of standard model Higgs boson production at large transverse momentum via the processes $gg \rightarrow gH^0$, $qg \rightarrow qH^0$, and $q\overline{q} \rightarrow gH^0$. The partonic level spin-spin asymmetries ($\hat{a}_{LL}$) for these processes are large at SSC/LHC energies.
0707.1998
Alessandro Mirizzi
G.L.Fogli, E.Lisi, A.Marrone (Bari U. & INFN, Bari), A.Mirizzi (Munich, Max Planck Institut & Bari U. & INFN, Bari)
Collective neutrino flavor transitions in supernovae and the role of trajectory averaging
v2 (27 pages, including 9 eps figures). Typos removed, references updated. Minor comments added. Corrected numerical errors in Eq.(6). Matches the published version
JCAP 0712:010,2007
10.1088/1475-7516/2007/12/010
MPP-2007-54
hep-ph astro-ph
null
Non-linear effects on supernova neutrino oscillations, associated with neutrino self-interactions, are known to induce collective flavor transitions near the supernova core for theta_13 \neq 0. In scenarios with very shallow electron density profiles, these transformations have been shown to couple with ordinary matter effects, jointly producing spectral distortions both in normal and inverted hierarchy. In this work we consider a complementary scenario, characterized by higher electron density, as indicated by post-bounce shock-wave simulations. In this case, early collective flavor transitions are decoupled from later, ordinary matter effects. Moreover, such transitions become more amenable to both numerical computations and analytical interpretations in inverted hierarchy, while they basically vanish in normal hierarchy. We numerically evolve the neutrino density matrix in the region relevant for self-interaction effects. In the approximation of averaged intersection angle between neutrino trajectories, our simulations neatly show the collective phenomena of synchronization, bipolar oscillations, and spectral split, recently discussed in the literature. In the more realistic (but computationally demanding) case of non-averaged neutrino trajectories, our simulations do not show new significant features, apart from the smearing of ``fine structures'' such as bipolar nutations. Our results seem to suggest that, at least for non-shallow matter density profiles, averaging over neutrino trajectories plays a minor role in the final outcome. In this case, the swap of nu_e and nu_{\mu,\tau} spectra above a critical energy may represent an unmistakable signature of the inverted hierarchy, especially for theta_{13} small enough to render further matter effects irrelevant.
[ { "created": "Fri, 13 Jul 2007 13:17:21 GMT", "version": "v1" }, { "created": "Mon, 17 Dec 2007 13:36:08 GMT", "version": "v2" } ]
2009-10-07
[ [ "Fogli", "G. L.", "", "Bari U. & INFN, Bari" ], [ "Lisi", "E.", "", "Bari U. & INFN, Bari" ], [ "Marrone", "A.", "", "Bari U. & INFN, Bari" ], [ "Mirizzi", "A.", "", "Munich, Max Planck Institut & Bari U. & INFN, Bari" ] ]
Non-linear effects on supernova neutrino oscillations, associated with neutrino self-interactions, are known to induce collective flavor transitions near the supernova core for theta_13 \neq 0. In scenarios with very shallow electron density profiles, these transformations have been shown to couple with ordinary matter effects, jointly producing spectral distortions both in normal and inverted hierarchy. In this work we consider a complementary scenario, characterized by higher electron density, as indicated by post-bounce shock-wave simulations. In this case, early collective flavor transitions are decoupled from later, ordinary matter effects. Moreover, such transitions become more amenable to both numerical computations and analytical interpretations in inverted hierarchy, while they basically vanish in normal hierarchy. We numerically evolve the neutrino density matrix in the region relevant for self-interaction effects. In the approximation of averaged intersection angle between neutrino trajectories, our simulations neatly show the collective phenomena of synchronization, bipolar oscillations, and spectral split, recently discussed in the literature. In the more realistic (but computationally demanding) case of non-averaged neutrino trajectories, our simulations do not show new significant features, apart from the smearing of ``fine structures'' such as bipolar nutations. Our results seem to suggest that, at least for non-shallow matter density profiles, averaging over neutrino trajectories plays a minor role in the final outcome. In this case, the swap of nu_e and nu_{\mu,\tau} spectra above a critical energy may represent an unmistakable signature of the inverted hierarchy, especially for theta_{13} small enough to render further matter effects irrelevant.
1904.04483
Byung-Yoon Park
Byung-Yoon Park, Won-Gi Paeng, Vicente Vento
The Inhomogeneous Phase of Dense Skyrmion Matter
8 figures, 14 pages
null
10.1016/j.nuclphysa.2019.06.010
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It was predicted qualitatively in ref.[1] that skyrmion matter at low density is stable in an inhomogeneous phase where skyrmions condensate into lumps while the remaining space is mostly empty. The aim of this paper is to proof quantitatively this prediction. In order to construct an inhomogeneous medium we distort the original FCC crystal to produce a phase of planar structures made of skyrmions. We implement mathematically these planar structures by means of the 't Hooft instanton solution using the Atiyah-Manton ansatz. The results of our calculation of the average density and energy confirm the prediction suggesting that the phase diagram of the dense skyrmion matter is a lot more complex than a simple phase transition from the skyrmion FCC crystal lattice to the half-skyrmion CC one. Our results show that skyrmion matter shares common properties with standard nuclear matter developing a skin and leading to a binding energy equation which resembles the Weiszaecker mass formula.
[ { "created": "Tue, 9 Apr 2019 06:22:41 GMT", "version": "v1" } ]
2019-07-24
[ [ "Park", "Byung-Yoon", "" ], [ "Paeng", "Won-Gi", "" ], [ "Vento", "Vicente", "" ] ]
It was predicted qualitatively in ref.[1] that skyrmion matter at low density is stable in an inhomogeneous phase where skyrmions condensate into lumps while the remaining space is mostly empty. The aim of this paper is to proof quantitatively this prediction. In order to construct an inhomogeneous medium we distort the original FCC crystal to produce a phase of planar structures made of skyrmions. We implement mathematically these planar structures by means of the 't Hooft instanton solution using the Atiyah-Manton ansatz. The results of our calculation of the average density and energy confirm the prediction suggesting that the phase diagram of the dense skyrmion matter is a lot more complex than a simple phase transition from the skyrmion FCC crystal lattice to the half-skyrmion CC one. Our results show that skyrmion matter shares common properties with standard nuclear matter developing a skin and leading to a binding energy equation which resembles the Weiszaecker mass formula.
2310.07691
Shao-Jiang Wang
Jun-Chen Wang, Zi-Yan Yuwen, Yu-Shi Hao, Shao-Jiang Wang
General backreaction force of cosmological bubble expansion
18 pages, 1 figure, two columns, to match the published version in Physical Review D
Phys. Rev. D 110 (2024) 016031
10.1103/PhysRevD.110.016031
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The gravitational-wave energy-density spectra from cosmological first-order phase transitions crucially depend on the terminal wall velocity of asymptotic bubble expansion when the driving force from the effective potential difference is gradually balanced by the backreaction force from the thermal plasma. Much attention has previously focused on the backreaction force acting on the bubble wall alone but overlooked the backreaction forces on the sound shell and shock-wave front, if any, which have been both numerically and analytically accomplished in our previous studies but only for a bag equation of state. In this paper, we will generalize the backreaction force on bubble expansion beyond the simple bag model.
[ { "created": "Wed, 11 Oct 2023 17:37:24 GMT", "version": "v1" }, { "created": "Mon, 5 Feb 2024 10:02:58 GMT", "version": "v2" }, { "created": "Fri, 28 Jun 2024 06:25:21 GMT", "version": "v3" }, { "created": "Wed, 31 Jul 2024 14:28:27 GMT", "version": "v4" } ]
2024-08-01
[ [ "Wang", "Jun-Chen", "" ], [ "Yuwen", "Zi-Yan", "" ], [ "Hao", "Yu-Shi", "" ], [ "Wang", "Shao-Jiang", "" ] ]
The gravitational-wave energy-density spectra from cosmological first-order phase transitions crucially depend on the terminal wall velocity of asymptotic bubble expansion when the driving force from the effective potential difference is gradually balanced by the backreaction force from the thermal plasma. Much attention has previously focused on the backreaction force acting on the bubble wall alone but overlooked the backreaction forces on the sound shell and shock-wave front, if any, which have been both numerically and analytically accomplished in our previous studies but only for a bag equation of state. In this paper, we will generalize the backreaction force on bubble expansion beyond the simple bag model.
2106.12436
Stephen Parke
Peter B. Denton and Stephen J. Parke
Parameter symmetries of neutrino oscillations in vacuum, matter, and approximation schemes
18 pages, 1 figure. Minor changes to addressee referees' comments
null
10.1103/PhysRevD.105.013002
FERMILAB-PUB-21-279-T
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Expressions for neutrino oscillations contain a high degree of symmetry, but typical forms for the oscillation probabilities mask these symmetries of the oscillation parameters. We elucidate the $2^7$ parameter symmetries of the vacuum parameters and draw connections to the choice of definitions of the parameters as well as interesting degeneracies. We also show that in the presence of matter an \emph{additional} set of $2^7$ parameter symmetries exist of the matter parameters. Due to the complexity of the exact expressions for neutrino oscillations in matter, numerous approximations have been developed; we show that under certain assumptions, approximate expressions have at most $2^6$ additional parameter symmetries of the matter parameters. We also include one parameter symmetry related to the LMA-Dark degeneracy that holds under the assumption of CPT invariance; this adds one additional factor of two to all of the above cases. Explicit, non-trivial examples are given of how physical observables in neutrino oscillations, such as the probabilities, CP violation, the position of the solar and atmospheric resonance, and the effective $\Delta m^2$'s for disappearance probabilities, are invariant under all of the above symmetries. We investigate which of these parameter symmetries apply to numerous approximate expressions in the literature and show that a more careful consideration of symmetries improves the precision of approximations.
[ { "created": "Wed, 23 Jun 2021 14:40:22 GMT", "version": "v1" }, { "created": "Sat, 11 Dec 2021 01:03:38 GMT", "version": "v2" } ]
2022-01-19
[ [ "Denton", "Peter B.", "" ], [ "Parke", "Stephen J.", "" ] ]
Expressions for neutrino oscillations contain a high degree of symmetry, but typical forms for the oscillation probabilities mask these symmetries of the oscillation parameters. We elucidate the $2^7$ parameter symmetries of the vacuum parameters and draw connections to the choice of definitions of the parameters as well as interesting degeneracies. We also show that in the presence of matter an \emph{additional} set of $2^7$ parameter symmetries exist of the matter parameters. Due to the complexity of the exact expressions for neutrino oscillations in matter, numerous approximations have been developed; we show that under certain assumptions, approximate expressions have at most $2^6$ additional parameter symmetries of the matter parameters. We also include one parameter symmetry related to the LMA-Dark degeneracy that holds under the assumption of CPT invariance; this adds one additional factor of two to all of the above cases. Explicit, non-trivial examples are given of how physical observables in neutrino oscillations, such as the probabilities, CP violation, the position of the solar and atmospheric resonance, and the effective $\Delta m^2$'s for disappearance probabilities, are invariant under all of the above symmetries. We investigate which of these parameter symmetries apply to numerous approximate expressions in the literature and show that a more careful consideration of symmetries improves the precision of approximations.
hep-ph/0201006
Eef van Beveren
Eef van Beveren (Univ.Coimbra, Portugal) and George Rupp (IST, Lisboa, Portugal)
Scalar Mesons within a model for all non-exotic mesons
16 pages, plain LaTeX
Proceedings Workshop on Recent Developments in Particle and Nuclear Physics, April 30, 2001, Coimbra (Portugal) ISBN 972-95630-3-9, pages 1-16
null
null
hep-ph
null
We describe a four-parameter model for non-exotic meson-meson scattering, which accommodates all non-exotic mesons, hence also the light scalar mesons, as resonances and bound states characterised by complex singularities of the scattering amplitude as a function of the total invariant mass. The majority of the full $S$-matrix mesonic poles stem from an underlying confinement spectrum. However, the light scalar mesons K0*(830), a0(980), f0(400-1200), and f0(980) do not, but instead originate in 3P0-barrier semi-bound states. In the case of bound states, wave functions can be determined. For ccbar and bbbar, radiative transitions have been calculated. Here we compare the results to the data.
[ { "created": "Wed, 2 Jan 2002 18:02:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "van Beveren", "Eef", "", "Univ.Coimbra, Portugal" ], [ "Rupp", "George", "", "IST, Lisboa,\n Portugal" ] ]
We describe a four-parameter model for non-exotic meson-meson scattering, which accommodates all non-exotic mesons, hence also the light scalar mesons, as resonances and bound states characterised by complex singularities of the scattering amplitude as a function of the total invariant mass. The majority of the full $S$-matrix mesonic poles stem from an underlying confinement spectrum. However, the light scalar mesons K0*(830), a0(980), f0(400-1200), and f0(980) do not, but instead originate in 3P0-barrier semi-bound states. In the case of bound states, wave functions can be determined. For ccbar and bbbar, radiative transitions have been calculated. Here we compare the results to the data.
hep-ph/0405192
Tai-Fu Feng
Tai-Fu Feng
Two-loop gluino corrections to the inclusive $B\to X_{_s}\gamma$ decay in CP violating MSSM with large $\tan\beta$
revtex, 21 pages, including 7 ps figures
Phys.Rev. D70 (2004) 096012
10.1103/PhysRevD.70.096012
null
hep-ph
null
We investigate two-loop gluino corrections to the effective Lagrangian for $b\to s+\gamma(g)$ in the minimal supersymmetric extension of the standard model (MSSM) at large $\tan\beta$, including the contributions in which quark flavor change is mediated by charginos. Using the translation invariant of loop momenta and the Ward-Takahashi identities (WTIs) that are required by the $SU(3)_c\times U(1)_{_{em}}$ gauge invariance, we simplify our expressions to concise forms. As an example, we discuss two-loop gluino corrections to the CP asymmetry of inclusive $B\to X_{_s}\gamma$ decay in CP violating MSSM.
[ { "created": "Thu, 20 May 2004 07:41:31 GMT", "version": "v1" }, { "created": "Fri, 30 Jul 2004 12:01:33 GMT", "version": "v2" } ]
2009-11-10
[ [ "Feng", "Tai-Fu", "" ] ]
We investigate two-loop gluino corrections to the effective Lagrangian for $b\to s+\gamma(g)$ in the minimal supersymmetric extension of the standard model (MSSM) at large $\tan\beta$, including the contributions in which quark flavor change is mediated by charginos. Using the translation invariant of loop momenta and the Ward-Takahashi identities (WTIs) that are required by the $SU(3)_c\times U(1)_{_{em}}$ gauge invariance, we simplify our expressions to concise forms. As an example, we discuss two-loop gluino corrections to the CP asymmetry of inclusive $B\to X_{_s}\gamma$ decay in CP violating MSSM.
1107.4060
Yannis Burnier
Yannis Burnier, Edward Shuryak
Can the Standard Model CP violation near the W-bags explain the cosmological baryonic asymmetry?
7 pages, 2 figures
null
10.1103/PhysRevD.84.073003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the scenario of cold electroweak baryogenesis, oscillations of the Higgs field lead to metastable domains of unbroken phase where the Higgs field nearly vanishes. Those domains have also been identified with the $W-t-\bar{t}$ bags, a non-topological soliton made of large number ($\sim 1000$) of gauge quanta and heavy (top and anti-top) quarks. As real-time numerical studies had shown, sphalerons (topological transition events violating the baryon number) occur only inside those bags. In this work we estimate the amount of CP violation in this scenario coming from the Standard Model, via the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix, resulting in top-minus-antitop difference of the population in the bags. Since these tops/anti-tops are "recycled" by sphalerons, this population difference leads directly to the baryonic asymmetry of the Universe. We look at the effect appearing in the 4th order in weak $W$ diagrams describing interference of different quark flavor contributions. We found that there are multiple cancellations of diagrams and clearly sign-definite effect appears only in the 6th order expansion over flavor-dependent phases. We then estimate contributions to these diagrams in which weak interaction occurs (i) inside, (ii) near and (iii) far from the $W-t-\bar{t}$ b-bags, optimizing the contributions in each of them. We conclude that the second ("near") scenario is the dominant one, producing CP violation of the order of $10^{-10}$, in our crude estimates. Together with the baryon violation rate of about $10^{-2}$, previously demonstrated for this scenario, it puts the resulting asymmetry close to what is needed to explain the observed baryonic asymmetry in the Universe. Our answer also has a definite sign, which apparently seems to be the correct one.
[ { "created": "Wed, 20 Jul 2011 18:42:23 GMT", "version": "v1" } ]
2013-05-29
[ [ "Burnier", "Yannis", "" ], [ "Shuryak", "Edward", "" ] ]
In the scenario of cold electroweak baryogenesis, oscillations of the Higgs field lead to metastable domains of unbroken phase where the Higgs field nearly vanishes. Those domains have also been identified with the $W-t-\bar{t}$ bags, a non-topological soliton made of large number ($\sim 1000$) of gauge quanta and heavy (top and anti-top) quarks. As real-time numerical studies had shown, sphalerons (topological transition events violating the baryon number) occur only inside those bags. In this work we estimate the amount of CP violation in this scenario coming from the Standard Model, via the Cabibbo-Kobayashi-Maskawa (CKM) quark mixing matrix, resulting in top-minus-antitop difference of the population in the bags. Since these tops/anti-tops are "recycled" by sphalerons, this population difference leads directly to the baryonic asymmetry of the Universe. We look at the effect appearing in the 4th order in weak $W$ diagrams describing interference of different quark flavor contributions. We found that there are multiple cancellations of diagrams and clearly sign-definite effect appears only in the 6th order expansion over flavor-dependent phases. We then estimate contributions to these diagrams in which weak interaction occurs (i) inside, (ii) near and (iii) far from the $W-t-\bar{t}$ b-bags, optimizing the contributions in each of them. We conclude that the second ("near") scenario is the dominant one, producing CP violation of the order of $10^{-10}$, in our crude estimates. Together with the baryon violation rate of about $10^{-2}$, previously demonstrated for this scenario, it puts the resulting asymmetry close to what is needed to explain the observed baryonic asymmetry in the Universe. Our answer also has a definite sign, which apparently seems to be the correct one.
hep-ph/0212063
Kingman Cheung
Kingman Cheung (NCTS), Gi-Chol Cho (Ochanomizu Univ.)
Hadronic production of light color-triplet Higgs bosons: an alternative signature for GUT
We added the description of a model by Goldberger et al.-- a 5D SU(5) SUSY model in a slice of AdS space with special boundary conditions to suppress proton decay. The color-triplet also has a TeV mass
Phys.Rev. D67 (2003) 075003
10.1103/PhysRevD.67.075003
NSC-NCTS-021205, OCHA-PP-196
hep-ph hep-ex hep-th
null
The conventional signature for grand unified theories (GUT) is the proton decay. Recently, some models in extra dimensions or with specific discrete symmetries, which aim at solving the doublet-triplet problem, allow the color-triplet in the TeV mass region by suppressing the Yukawa couplings of the triplets to matter fermions. We study the hadronic production and detection of these TeV colored Higgs bosons as an alternative signature for GUT, which would behave like massive stable charged particles in particle detectors producing a striking signature of a charged track in the central tracking system and being ionized in the outer muon chamber. We found that the LHC is sensitive to a colored Higgs boson up to about 1.5 TeV. If the color-triplets are stable in cosmological time scale, they may constitute an interesting fraction of the dark matter.
[ { "created": "Wed, 4 Dec 2002 13:32:31 GMT", "version": "v1" }, { "created": "Fri, 10 Jan 2003 15:46:51 GMT", "version": "v2" } ]
2009-11-07
[ [ "Cheung", "Kingman", "", "NCTS" ], [ "Cho", "Gi-Chol", "", "Ochanomizu Univ." ] ]
The conventional signature for grand unified theories (GUT) is the proton decay. Recently, some models in extra dimensions or with specific discrete symmetries, which aim at solving the doublet-triplet problem, allow the color-triplet in the TeV mass region by suppressing the Yukawa couplings of the triplets to matter fermions. We study the hadronic production and detection of these TeV colored Higgs bosons as an alternative signature for GUT, which would behave like massive stable charged particles in particle detectors producing a striking signature of a charged track in the central tracking system and being ionized in the outer muon chamber. We found that the LHC is sensitive to a colored Higgs boson up to about 1.5 TeV. If the color-triplets are stable in cosmological time scale, they may constitute an interesting fraction of the dark matter.
1304.1867
Michal Praszalowicz
Michal Praszalowicz
Geometrical scaling in high energy collisions and its breaking
6 pages, 4 figures, presented at the Conference Excited QCD, Bjelasnica, Sarajevo, Feb. 3 - 9, 2013
null
null
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
We analyze geometrical scaling (GS) in Deep Inelstic Scattering at HERA and in pp collisions at the LHC energies and in NA61/SHINE experiment. We argue that GS is working up to relatively large Bjorken $x \sim 0.1$. This allows to study GS in negative pion multiplicity $p_{\rm T}$ distributions at NA61/SHINE energies where clear sign of scaling violations is seen with growing rapidity when one of the colliding partons has Bjorekn $x \ge 0.1$.
[ { "created": "Sat, 6 Apr 2013 09:03:58 GMT", "version": "v1" } ]
2013-04-09
[ [ "Praszalowicz", "Michal", "" ] ]
We analyze geometrical scaling (GS) in Deep Inelstic Scattering at HERA and in pp collisions at the LHC energies and in NA61/SHINE experiment. We argue that GS is working up to relatively large Bjorken $x \sim 0.1$. This allows to study GS in negative pion multiplicity $p_{\rm T}$ distributions at NA61/SHINE energies where clear sign of scaling violations is seen with growing rapidity when one of the colliding partons has Bjorekn $x \ge 0.1$.
hep-ph/0203069
Bhaskar Dutta
R. Arnowitt, B. Dutta, T. Kamon, M. Tanaka
Detection of B_s->mu mu at the Tevatron Run II and Constraints on the SUSY Parameter Space
12 pages, latex, 7 figures, references added, comments added on RunIIb trigger, to appear in Phys. Lett.B
Phys.Lett.B538:121-129,2002
10.1016/S0370-2693(02)01972-X
CTP-TAMU-02-02
hep-ph
null
A measurement of the branching ratio for the rare decay mode B_s->mu mu at the Tevatron is an opportunity to test various supersymmetric scenarios. We investigate the prospects for studying this mode in Run II and estimate that CDF would be sensitive to this decay for a branching ratio > 1.2 \times 10^{-8} with 15 \invfb (or, if a similar analysis holds for D0, >6.5\times 10^{-9} for the combined data). We calculate the branching ratio in minimal supergravity (mSUGRA) parameter space, and find that tan\beta > 30 can be probed. (This mSUGRA parameter space cannot be probed by direct production of SUSY particles at Run II.) Including other experimental constraints on the mSUGRA parameter space, one finds that CDF \bsmumu measurements would be able to cover the full mSUGRA parameter space for tan\beta = 50 if the muon g_{\mu} - 2 anomaly exceeds \sim 11 \times 10^{-10}, and about half the allowed parameter space for tan\beta = 40. A large branching ratio > 7(14) \times 10^{-8} (feasible with only 2 \invfb) would be sufficient to exclude the mSUGRA model for tan\beta\leq 50(55). Dark matter neutralino-proton detection cross sections are examined in the allowed region, and should be large enough to be accessible to future planned experiments. Combined measurements of \bsmumu the Higgs mass m_h and the muon g_{\mu}-2 anomaly would be sufficient to determine the \mu>0 mSUGRA parameters (or show the model is inconsistent with the data). We also briefly discuss the \bsmumu decay in R parity violating models. There, for some models, the branching ratio can be large enough to be detected even for small tan\beta and large \mhalf.
[ { "created": "Thu, 7 Mar 2002 01:11:28 GMT", "version": "v1" }, { "created": "Tue, 28 May 2002 14:45:14 GMT", "version": "v2" } ]
2008-11-26
[ [ "Arnowitt", "R.", "" ], [ "Dutta", "B.", "" ], [ "Kamon", "T.", "" ], [ "Tanaka", "M.", "" ] ]
A measurement of the branching ratio for the rare decay mode B_s->mu mu at the Tevatron is an opportunity to test various supersymmetric scenarios. We investigate the prospects for studying this mode in Run II and estimate that CDF would be sensitive to this decay for a branching ratio > 1.2 \times 10^{-8} with 15 \invfb (or, if a similar analysis holds for D0, >6.5\times 10^{-9} for the combined data). We calculate the branching ratio in minimal supergravity (mSUGRA) parameter space, and find that tan\beta > 30 can be probed. (This mSUGRA parameter space cannot be probed by direct production of SUSY particles at Run II.) Including other experimental constraints on the mSUGRA parameter space, one finds that CDF \bsmumu measurements would be able to cover the full mSUGRA parameter space for tan\beta = 50 if the muon g_{\mu} - 2 anomaly exceeds \sim 11 \times 10^{-10}, and about half the allowed parameter space for tan\beta = 40. A large branching ratio > 7(14) \times 10^{-8} (feasible with only 2 \invfb) would be sufficient to exclude the mSUGRA model for tan\beta\leq 50(55). Dark matter neutralino-proton detection cross sections are examined in the allowed region, and should be large enough to be accessible to future planned experiments. Combined measurements of \bsmumu the Higgs mass m_h and the muon g_{\mu}-2 anomaly would be sufficient to determine the \mu>0 mSUGRA parameters (or show the model is inconsistent with the data). We also briefly discuss the \bsmumu decay in R parity violating models. There, for some models, the branching ratio can be large enough to be detected even for small tan\beta and large \mhalf.
1808.06639
Lopamudra Mukherjee
Basabendu Barman, Debasish Borah, Lopamudra Mukherjee, Soumitra Nandi
Correlating the anomalous results in $b \to s$ decays with inert Higgs doublet dark matter and muon $(g-2)$
Version to be published in PRD
Phys. Rev. D 100, 115010 (2019)
10.1103/PhysRevD.100.115010
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article, we have considered an extension of the inert Higgs doublet model with $SU(2)_L$ singlet vector like fermions. Our model is capable of addressing some interesting anomalous results in $b\to s\ell^+\ell^-$ decays (like $R(K^{(*)})$) and in muon $(g-2)$. Apart from explaining these anomalies, and being consistent with other flavour data, the model satisfies relevant constraints in the dark matter sector, while remaining within the reach of ongoing direct detection experiments. The model also produces signatures at the large hadron collider (LHC) with final states comprised of dilepton, dijet and missing energy, providing signals to be probed at higher luminosity.
[ { "created": "Mon, 20 Aug 2018 18:19:00 GMT", "version": "v1" }, { "created": "Thu, 16 May 2019 10:42:27 GMT", "version": "v2" }, { "created": "Thu, 14 Nov 2019 11:43:59 GMT", "version": "v3" } ]
2019-12-11
[ [ "Barman", "Basabendu", "" ], [ "Borah", "Debasish", "" ], [ "Mukherjee", "Lopamudra", "" ], [ "Nandi", "Soumitra", "" ] ]
In this article, we have considered an extension of the inert Higgs doublet model with $SU(2)_L$ singlet vector like fermions. Our model is capable of addressing some interesting anomalous results in $b\to s\ell^+\ell^-$ decays (like $R(K^{(*)})$) and in muon $(g-2)$. Apart from explaining these anomalies, and being consistent with other flavour data, the model satisfies relevant constraints in the dark matter sector, while remaining within the reach of ongoing direct detection experiments. The model also produces signatures at the large hadron collider (LHC) with final states comprised of dilepton, dijet and missing energy, providing signals to be probed at higher luminosity.
2404.07912
Wenyang Qian
Wenyang Qian and Bin Wu
Quantum computation in fermionic thermal field theories
30 pages, 6 figures
null
10.1007/JHEP07(2024)166
null
hep-ph hep-lat hep-th nucl-th quant-ph
http://creativecommons.org/licenses/by-nc-nd/4.0/
Thermal properties of quantum fields at finite temperature are crucial to understanding strongly interacting matter and recent development in quantum computing has provided an alternative and promising avenue of study. In this work, we study thermal field theories involving only fermions using quantum algorithms. We first delve into the presentations of fermion fields via qubits on digital quantum computers alongside the quantum algorithms such as quantum imaginary time evolutions employed to evaluate thermal properties of generic quantum field theories. Specifically, we show numerical results such as the thermal distribution and the energy density of thermal field theories for Majorana fermions in 1+1 dimensions using quantum simulators. In addition to free field theory, we also study the effects of interactions resulting from coupling with a spatially homogeneous Majorana field. In both cases, we show analytically that thermal properties of the system can be described using phase-space distributions, and the quantum simulation results agree with analytical and semiclassical expectations. Our work is an important step to understand thermal fixed points, preparing for quantum simulation of thermalization in real time.
[ { "created": "Thu, 11 Apr 2024 16:57:15 GMT", "version": "v1" }, { "created": "Tue, 16 Jul 2024 12:18:54 GMT", "version": "v2" } ]
2024-07-23
[ [ "Qian", "Wenyang", "" ], [ "Wu", "Bin", "" ] ]
Thermal properties of quantum fields at finite temperature are crucial to understanding strongly interacting matter and recent development in quantum computing has provided an alternative and promising avenue of study. In this work, we study thermal field theories involving only fermions using quantum algorithms. We first delve into the presentations of fermion fields via qubits on digital quantum computers alongside the quantum algorithms such as quantum imaginary time evolutions employed to evaluate thermal properties of generic quantum field theories. Specifically, we show numerical results such as the thermal distribution and the energy density of thermal field theories for Majorana fermions in 1+1 dimensions using quantum simulators. In addition to free field theory, we also study the effects of interactions resulting from coupling with a spatially homogeneous Majorana field. In both cases, we show analytically that thermal properties of the system can be described using phase-space distributions, and the quantum simulation results agree with analytical and semiclassical expectations. Our work is an important step to understand thermal fixed points, preparing for quantum simulation of thermalization in real time.
hep-ph/9402241
null
R. Foot
Neutrino oscillations and the exact parity model
14, McGill/93-46
Mod.Phys.Lett. A9 (1994) 169-180
10.1142/S0217732394000186
null
hep-ph
null
We re-examine neutrino oscillations in exact parity models. Previously it was shown in a specific model that large neutrino mixing angles result. We show here that this is a general result of neutrino mixing in exact parity models provided that the neutrino mass matrix is real. In this case, the effects of neutrino mixing in exact parity models is such that the probability of a given weak eigenstate remaining in that eigenstate averages to {\it less} than a half when averaged over many oscillations. This result is interesting in view of the accumulating evidence for a significant deficit in the number of solar neutrinos. It may also be of relevance to the atmospheric neutrino anomaly.
[ { "created": "Mon, 7 Feb 1994 22:59:50 GMT", "version": "v1" } ]
2015-06-25
[ [ "Foot", "R.", "" ] ]
We re-examine neutrino oscillations in exact parity models. Previously it was shown in a specific model that large neutrino mixing angles result. We show here that this is a general result of neutrino mixing in exact parity models provided that the neutrino mass matrix is real. In this case, the effects of neutrino mixing in exact parity models is such that the probability of a given weak eigenstate remaining in that eigenstate averages to {\it less} than a half when averaged over many oscillations. This result is interesting in view of the accumulating evidence for a significant deficit in the number of solar neutrinos. It may also be of relevance to the atmospheric neutrino anomaly.
2405.05305
Patrick Hager
Philipp B\"oer, Patrick Hager, Matthias Neubert, Michel Stillger, Xiaofeng Xu
Renormalization-Group Improved Resummation of Super-Leading Logarithms
v2: 37 pages, 5 figures, matches published version
null
null
MITP-24-012
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new strategy is presented for systematically treating super-leading logarithmic contributions including higher-order Glauber exchanges for non-global LHC observables in renormalization-group (RG) improved perturbation theory. This represents an important improvement over previous approaches, as it allows for the consistent inclusion of the scale dependence of the strong coupling, thereby providing more reliable estimates of the scale uncertainties in theoretical predictions. The key idea is to rearrange the relevant RG evolution operator in such a way that all double-logarithmic corrections are exponentiated from the outset. This forms the starting point for the first resummation of super-leading logarithms at leading order in RG-improved perturbation theory for arbitrary $2\to M$ scattering processes. Moreover, the asymptotic scaling of subleading logarithmic corrections from higher-order Glauber exchanges is determined, demonstrating their parametric suppression.
[ { "created": "Wed, 8 May 2024 18:00:00 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2024 14:00:01 GMT", "version": "v2" } ]
2024-08-09
[ [ "Böer", "Philipp", "" ], [ "Hager", "Patrick", "" ], [ "Neubert", "Matthias", "" ], [ "Stillger", "Michel", "" ], [ "Xu", "Xiaofeng", "" ] ]
A new strategy is presented for systematically treating super-leading logarithmic contributions including higher-order Glauber exchanges for non-global LHC observables in renormalization-group (RG) improved perturbation theory. This represents an important improvement over previous approaches, as it allows for the consistent inclusion of the scale dependence of the strong coupling, thereby providing more reliable estimates of the scale uncertainties in theoretical predictions. The key idea is to rearrange the relevant RG evolution operator in such a way that all double-logarithmic corrections are exponentiated from the outset. This forms the starting point for the first resummation of super-leading logarithms at leading order in RG-improved perturbation theory for arbitrary $2\to M$ scattering processes. Moreover, the asymptotic scaling of subleading logarithmic corrections from higher-order Glauber exchanges is determined, demonstrating their parametric suppression.
2404.14579
Joerg Aichelin
Iurii Karpenko, Alexander Lind, Martin Rohrmoser, Joerg Aichelin, Pol-Bernard Gossiaux
SUBA-Jet: a new Model for Jets in Heavy Ion Collisions
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new model for jet quenching in a quark gluon plasma (QGP). The jet energy loss has two steps. The initial jet parton with a high virtuality loses energy by a perturbative vacuum parton shower modified by medium interactions until it becomes on shell. Subsequent energy loss originates from elastic and radiative collisions with the medium constituents. Coherency of the radiative collisions is achieved by starting with virtual gluons that act as field dressing of the initial jet parton. These are formed according to a Gunion-Bertsch seed. The QCD version of the LPM effect is obtained by increasing the phase of the virtual gluons through elastic scatterings with the medium. Above a phase threshold, the virtual gluons will be formed and can produce coherent radiation themselves. The model has been implemented in a Monte Carlo code and is validated by successfully reproducing the BDMPS-Z prediction for the energy spectrum of radiated gluons in a static medium. Results for the more realistic case, in which the assumptions of the BDMPS-Z approach are released, are also shown. We investigate the influence of various parameters on the energy spectrum and the transverse momentum distribution, such as the in-medium quark masses, the energy transfer in the recoil process, and the phase accumulation criteria, especially for low and intermediate energy gluons.
[ { "created": "Mon, 22 Apr 2024 20:58:27 GMT", "version": "v1" } ]
2024-04-24
[ [ "Karpenko", "Iurii", "" ], [ "Lind", "Alexander", "" ], [ "Rohrmoser", "Martin", "" ], [ "Aichelin", "Joerg", "" ], [ "Gossiaux", "Pol-Bernard", "" ] ]
We present a new model for jet quenching in a quark gluon plasma (QGP). The jet energy loss has two steps. The initial jet parton with a high virtuality loses energy by a perturbative vacuum parton shower modified by medium interactions until it becomes on shell. Subsequent energy loss originates from elastic and radiative collisions with the medium constituents. Coherency of the radiative collisions is achieved by starting with virtual gluons that act as field dressing of the initial jet parton. These are formed according to a Gunion-Bertsch seed. The QCD version of the LPM effect is obtained by increasing the phase of the virtual gluons through elastic scatterings with the medium. Above a phase threshold, the virtual gluons will be formed and can produce coherent radiation themselves. The model has been implemented in a Monte Carlo code and is validated by successfully reproducing the BDMPS-Z prediction for the energy spectrum of radiated gluons in a static medium. Results for the more realistic case, in which the assumptions of the BDMPS-Z approach are released, are also shown. We investigate the influence of various parameters on the energy spectrum and the transverse momentum distribution, such as the in-medium quark masses, the energy transfer in the recoil process, and the phase accumulation criteria, especially for low and intermediate energy gluons.
1902.01791
A. F. W. van Hameren
A. van Hameren
A note on QED gauge invariance of off-shell amplitudes
5 pages
null
null
IFJPAN-IV-2019-2
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The consistent construction of scattering amplitudes for processes with off-shell initial partons and involving electro-weak interactions is addressed.
[ { "created": "Tue, 5 Feb 2019 17:02:09 GMT", "version": "v1" } ]
2019-02-06
[ [ "van Hameren", "A.", "" ] ]
The consistent construction of scattering amplitudes for processes with off-shell initial partons and involving electro-weak interactions is addressed.
2312.08970
Zuowei Liu
Jinhan Liang, Zuowei Liu, Lan Yang
Search for strongly interacting dark matter at Belle II
17 pages, 16 figures. v2: version accepted for publication in PRD
null
null
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A small component of dark matter (DM) that is strongly interacting with the standard model sector is consistent with various experimental observations. Despite the small abundance, strongly-interacting DM can lead to pronounced signals in DM direct detection experiments. We study Belle II sensitivity on strongly-interacting DM that has a MeV-GeV mass and couples with electrons. By taking into account the substantial interactions between DM and electrons within detectors, we compute the ``ceiling'' of the mono-photon signature at Belle II, beyond which the mono-photon channel loses its sensitivity, and visible ECL clusters due to DM scatterings assume significance. We study two ECL signatures for strongly-interacting DM: the mono-cluster and the di-cluster channels. To carry out detailed calculations and to compare with other constraints, we consider DM models with light mediators, as they naturally lead to sizable interaction cross sections. We compute exclusion regions for the di-cluster, mono-cluster, and mono-photon channels. We find that Belle II (with currently accumulated data of 362 fb$^{-1}$) can rule out a significant portion of the parameter space above the ceilings of the constraints from various DM direct detection and neutrino experiments, for the vector mediator case with mass $\gtrsim 10$ MeV. Belle II also offers superior constraints on new light particles compared to PBH for the scalar mediator with mass $\gtrsim 10$ MeV.
[ { "created": "Thu, 14 Dec 2023 14:20:01 GMT", "version": "v1" }, { "created": "Sun, 19 May 2024 06:48:20 GMT", "version": "v2" } ]
2024-05-21
[ [ "Liang", "Jinhan", "" ], [ "Liu", "Zuowei", "" ], [ "Yang", "Lan", "" ] ]
A small component of dark matter (DM) that is strongly interacting with the standard model sector is consistent with various experimental observations. Despite the small abundance, strongly-interacting DM can lead to pronounced signals in DM direct detection experiments. We study Belle II sensitivity on strongly-interacting DM that has a MeV-GeV mass and couples with electrons. By taking into account the substantial interactions between DM and electrons within detectors, we compute the ``ceiling'' of the mono-photon signature at Belle II, beyond which the mono-photon channel loses its sensitivity, and visible ECL clusters due to DM scatterings assume significance. We study two ECL signatures for strongly-interacting DM: the mono-cluster and the di-cluster channels. To carry out detailed calculations and to compare with other constraints, we consider DM models with light mediators, as they naturally lead to sizable interaction cross sections. We compute exclusion regions for the di-cluster, mono-cluster, and mono-photon channels. We find that Belle II (with currently accumulated data of 362 fb$^{-1}$) can rule out a significant portion of the parameter space above the ceilings of the constraints from various DM direct detection and neutrino experiments, for the vector mediator case with mass $\gtrsim 10$ MeV. Belle II also offers superior constraints on new light particles compared to PBH for the scalar mediator with mass $\gtrsim 10$ MeV.
1710.05736
Petja Paakkinen
Petja Paakkinen, Kari J. Eskola, Hannu Paukkunen
Pion-nucleus Drell-Yan data as a novel constraint for nuclear PDFs
5 pages, 4 figures. To appear in the proceedings of the XXV International Workshop on Deep-Inelastic Scattering and Related Subjects
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have studied the prospects of using the Drell-Yan dilepton process in pion-nucleus collisions as a novel input in the global analysis of nuclear parton distribution functions (nPDFs). In a NLO QCD framework, we find the measured nuclear cross-section ratios from the NA3, NA10 and E615 experiments to be largely insensitive to the pion parton distributions and also compatible with the EPS09 and nCTEQ15 nPDFs. These data sets can thus be, and in EPPS16 have been, included in global nPDF analyses without introducing significant new theoretical uncertainties or tension with the other data. In particular, we explore the constraining power of these data sets on the possible flavour asymmetry in the valence-quark nuclear modifications. Moreover, using the COMPASS kinematics we present predictions for pion charge-difference ratio, a new measurable which could help to further constrain this asymmetry.
[ { "created": "Mon, 16 Oct 2017 14:33:19 GMT", "version": "v1" } ]
2017-10-17
[ [ "Paakkinen", "Petja", "" ], [ "Eskola", "Kari J.", "" ], [ "Paukkunen", "Hannu", "" ] ]
We have studied the prospects of using the Drell-Yan dilepton process in pion-nucleus collisions as a novel input in the global analysis of nuclear parton distribution functions (nPDFs). In a NLO QCD framework, we find the measured nuclear cross-section ratios from the NA3, NA10 and E615 experiments to be largely insensitive to the pion parton distributions and also compatible with the EPS09 and nCTEQ15 nPDFs. These data sets can thus be, and in EPPS16 have been, included in global nPDF analyses without introducing significant new theoretical uncertainties or tension with the other data. In particular, we explore the constraining power of these data sets on the possible flavour asymmetry in the valence-quark nuclear modifications. Moreover, using the COMPASS kinematics we present predictions for pion charge-difference ratio, a new measurable which could help to further constrain this asymmetry.
2003.01987
Francois Arleo
Fran\c{c}ois Arleo, St\'ephane Peign\'e
Quenching of light hadron spectra in pA collisions from fully coherent energy loss
5 pages, 4 figures
Phys. Rev. Lett. 125, 032301 (2020)
10.1103/PhysRevLett.125.032301
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We single out the role of fully coherent induced gluon radiation on light hadron production in pA collisions. The effect has an interesting color structure, as the induced radiation depends on the global color charge of the partonic subprocess final state. Baseline predictions for light hadron nuclear suppression in pPb collisions at the LHC are provided, taking into account only the effect of fully coherent energy loss, which proves of the same order of magnitude as gluon shadowing or saturation. This underlines the need to include fully coherent energy loss in phenomenological studies of hadron production in pA collisions.
[ { "created": "Wed, 4 Mar 2020 10:44:31 GMT", "version": "v1" } ]
2020-07-22
[ [ "Arleo", "François", "" ], [ "Peigné", "Stéphane", "" ] ]
We single out the role of fully coherent induced gluon radiation on light hadron production in pA collisions. The effect has an interesting color structure, as the induced radiation depends on the global color charge of the partonic subprocess final state. Baseline predictions for light hadron nuclear suppression in pPb collisions at the LHC are provided, taking into account only the effect of fully coherent energy loss, which proves of the same order of magnitude as gluon shadowing or saturation. This underlines the need to include fully coherent energy loss in phenomenological studies of hadron production in pA collisions.
1503.00647
Victor Goncalves
V. P. Goncalves, D. S. Pires
Deeply virtual Compton scattering at small-$x$ in future Electron - Ion Colliders
11 pages, 10 figures. Improved version to be published in Physical Review C
null
10.1103/PhysRevC.91.055207
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The study of exclusive processes in the future electron-ion ($eA$) colliders will be an important tool to investigate the QCD dynamics at high energies as they are in general driven by the gluon content of the target which is strongly subject to parton saturation effects. In this paper we compute the coherent and incoherent cross sections for the deeply virtual Compton scattering (DVCS) process relying on the color dipole approach and considering different models for the dipole - proton scattering amplitude. The dependencies of the cross sections with the energy, photon virtuality, nuclear mass number and squared momentum transfer are analysed in detail. We demonstrate that the ratio between the incoherent and coherent cross sections decreases at smaller values of $Q^2$ and increases at smaller values of $A$. We show that the coherent cross section dominates at small $t$ and exhibits the typical diffractive pattern, with the number of dips in the range $|t| \le 0.3$ GeV$^2$ increasing with the mass atomic number. Our results indicate that the position of the dips are independent of the model used to treat the dipole - proton interaction as well as of the center-of-mass energy.
[ { "created": "Mon, 2 Mar 2015 18:08:16 GMT", "version": "v1" }, { "created": "Mon, 11 May 2015 19:01:26 GMT", "version": "v2" } ]
2015-06-11
[ [ "Goncalves", "V. P.", "" ], [ "Pires", "D. S.", "" ] ]
The study of exclusive processes in the future electron-ion ($eA$) colliders will be an important tool to investigate the QCD dynamics at high energies as they are in general driven by the gluon content of the target which is strongly subject to parton saturation effects. In this paper we compute the coherent and incoherent cross sections for the deeply virtual Compton scattering (DVCS) process relying on the color dipole approach and considering different models for the dipole - proton scattering amplitude. The dependencies of the cross sections with the energy, photon virtuality, nuclear mass number and squared momentum transfer are analysed in detail. We demonstrate that the ratio between the incoherent and coherent cross sections decreases at smaller values of $Q^2$ and increases at smaller values of $A$. We show that the coherent cross section dominates at small $t$ and exhibits the typical diffractive pattern, with the number of dips in the range $|t| \le 0.3$ GeV$^2$ increasing with the mass atomic number. Our results indicate that the position of the dips are independent of the model used to treat the dipole - proton interaction as well as of the center-of-mass energy.
2307.15445
Per Grafstrom
Per Grafstr\"om
About AKM scaling and oscillations in elastic scattering at very small momentum transfer at the LHC
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The ATLAS and TOTEM collaborations have measured the differential elastic cross section at centre-of mass energy $\sqrt{s}$=13 TeV and at small four-moment squared $|t|$. The data at very small $|t|$ i.e. $|t|<0.01GeV^{2}$ have been analysed in terms of so called AKM (Auberson, Kinoshita and Martin) oscillations. An indication of a possible oscillation of this type had previously been reported at $\sqrt{s}$=541 GeV using data from the UA4/2 experiment. There are no such indications in the data at 13 TeV examined here.
[ { "created": "Fri, 28 Jul 2023 09:54:20 GMT", "version": "v1" } ]
2023-07-31
[ [ "Grafström", "Per", "" ] ]
The ATLAS and TOTEM collaborations have measured the differential elastic cross section at centre-of mass energy $\sqrt{s}$=13 TeV and at small four-moment squared $|t|$. The data at very small $|t|$ i.e. $|t|<0.01GeV^{2}$ have been analysed in terms of so called AKM (Auberson, Kinoshita and Martin) oscillations. An indication of a possible oscillation of this type had previously been reported at $\sqrt{s}$=541 GeV using data from the UA4/2 experiment. There are no such indications in the data at 13 TeV examined here.
2109.12536
Chandini Dash
Chandini Dash, Snigdha Mishra, Sudhanwa Patra, Purushottam Sahu
Gauge coupling unification in a minimal non-supersymmetric $E_6$ GUT
5 pages, 4 tables, 2 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider a minimal renormalizable non-supersymmetric $E_6$ Grand Unified Theory using fundamental representation $27$ for fermions and scalars. The scalar with adjoint representation ${78}$ is also taken for direct breaking of $E_{6}$ to SM. The proposed model, guided by TeV-scale vector-like fermions and scalar leptoquark offer successful gauge unification even in the absence of any intermediate symmetry. Embedded with threshold corrections, it is shown to be compatible with the present experimental limit on proton decay lifetime. The unique feature of the model shows that, the GUT threshold corrections to the unification mass, is controlled by superheavy gauge bosons only, thereby minimising the uncertainty of the GUT predictions. The scalar leptoquark and vector-like fermions residing in $27$ representation can explain flavor physics anomalies like $R_{D^{(\ast)}}$ as reported by the LHCb collaboration and the muon anomalous magnetic moment reported by the recent muon $g-2$ experiment at Fermilab. The model can also predict a sub-eV scale neutrino at one-loop level via exchange of $W$ and $Z$ gauge bosons through MRIS mechanism.
[ { "created": "Sun, 26 Sep 2021 09:09:25 GMT", "version": "v1" }, { "created": "Tue, 6 Feb 2024 15:46:26 GMT", "version": "v2" } ]
2024-02-07
[ [ "Dash", "Chandini", "" ], [ "Mishra", "Snigdha", "" ], [ "Patra", "Sudhanwa", "" ], [ "Sahu", "Purushottam", "" ] ]
We consider a minimal renormalizable non-supersymmetric $E_6$ Grand Unified Theory using fundamental representation $27$ for fermions and scalars. The scalar with adjoint representation ${78}$ is also taken for direct breaking of $E_{6}$ to SM. The proposed model, guided by TeV-scale vector-like fermions and scalar leptoquark offer successful gauge unification even in the absence of any intermediate symmetry. Embedded with threshold corrections, it is shown to be compatible with the present experimental limit on proton decay lifetime. The unique feature of the model shows that, the GUT threshold corrections to the unification mass, is controlled by superheavy gauge bosons only, thereby minimising the uncertainty of the GUT predictions. The scalar leptoquark and vector-like fermions residing in $27$ representation can explain flavor physics anomalies like $R_{D^{(\ast)}}$ as reported by the LHCb collaboration and the muon anomalous magnetic moment reported by the recent muon $g-2$ experiment at Fermilab. The model can also predict a sub-eV scale neutrino at one-loop level via exchange of $W$ and $Z$ gauge bosons through MRIS mechanism.
hep-ph/0504180
Matthias Buchler
Matthias Buchler
The leading two loop counterterm in the nonleptonic weak sector of CHPT
28 pages, 3 figures, uses axodraw
Eur.Phys.J.C44:111-126,2005
10.1140/epjc/s2005-02315-9
UW-PT-05-10
hep-ph
null
We calculate the leading divergences at NNLO for the octet part of the nonleptonic weak sector of chiral perturbation theory, using renormalization group methods. The role of counterterms which vanish at the equation of motion and their use to simplify the calculation is shown explicitly. The obtained countertem Lagrangian can be employed to calculate the chiral double log contributions of quantities in this sector, most notably the K --> pi pi amplitude. The double log contribution of the latter is discussed in a separate paper.
[ { "created": "Wed, 20 Apr 2005 18:44:31 GMT", "version": "v1" }, { "created": "Wed, 20 Apr 2005 20:48:51 GMT", "version": "v2" }, { "created": "Mon, 7 Nov 2005 14:53:55 GMT", "version": "v3" } ]
2009-01-07
[ [ "Buchler", "Matthias", "" ] ]
We calculate the leading divergences at NNLO for the octet part of the nonleptonic weak sector of chiral perturbation theory, using renormalization group methods. The role of counterterms which vanish at the equation of motion and their use to simplify the calculation is shown explicitly. The obtained countertem Lagrangian can be employed to calculate the chiral double log contributions of quantities in this sector, most notably the K --> pi pi amplitude. The double log contribution of the latter is discussed in a separate paper.
hep-ph/0401174
Alexander E. Dorokhov
A.E. Dorokhov
QCD vacuum topological susceptibility in a non-local chiral quark model
Talk at SPIN-03 Workshop, Dubna, September 16-20, 2003, to appear in Proceedings; 6 pages, 1 figure
Phys.Part.Nucl.Lett. 1 (2004) 240-243
null
null
hep-ph
null
The topological susceptibility of QCD vacuum is studied in the framework of a covariant chiral quark model with non-local quark-quark interaction. The relation of the first moment of topological susceptibility \chi'(0) and the 'spin crisis' problem is briefly discussed. It is shown, in particular, that one always gets the inequality \chi'(0)>\chi'_{OZI}.
[ { "created": "Fri, 23 Jan 2004 10:46:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Dorokhov", "A. E.", "" ] ]
The topological susceptibility of QCD vacuum is studied in the framework of a covariant chiral quark model with non-local quark-quark interaction. The relation of the first moment of topological susceptibility \chi'(0) and the 'spin crisis' problem is briefly discussed. It is shown, in particular, that one always gets the inequality \chi'(0)>\chi'_{OZI}.
hep-ph/9606359
null
Utpal Sarkar
Electroweak Baryogenesis and Constraints on Left-handed Majorana Neutrino Masses
10 pages, LATEX file with a postscript file attached at the end with instructions to print
Phys.Lett.B390:97-100,1997
10.1016/S0370-2693(96)01388-3
null
hep-ph
null
The lepton number violating interactions generated by the light Majorana neutrinos can erase the primordial baryon asymmetry of the universe during the electroweak phase transition. The Majorana masses of the left-handed neutrinos are constrained to avoid this problem. These constraints do not depend on the $(B-L)$ symmetry breaking mechanism.
[ { "created": "Tue, 18 Jun 1996 15:09:23 GMT", "version": "v1" } ]
2014-11-17
[ [ "Sarkar", "Utpal", "" ] ]
The lepton number violating interactions generated by the light Majorana neutrinos can erase the primordial baryon asymmetry of the universe during the electroweak phase transition. The Majorana masses of the left-handed neutrinos are constrained to avoid this problem. These constraints do not depend on the $(B-L)$ symmetry breaking mechanism.
1210.7567
Takahiro Sasaki
Masanobu Yahiro, Hiroaki Kouno, Yuji Sakai, Takahiro Sasaki, Takahiro Makiyama
A simple model with Z_N symmetry
7 pages, 7 figures, Presented at The XXXth International Symposium on Lattice Field Theory, Lattice2012
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple model with the Z_N symmetry in order to answer whether the symmetry is a good concept in QCD with light quark mass. The model is constructed by imposing the flavor-dependent twisted boundary condition (TBC) on the three-flavor Polyakov-loop extended Nambu-Jona-Lasinio model. In the model, the Z_N symmetry is preserved below some temperature T_c, but spontaneously broken above T_c. Dynamics of the simple model is similar to that of the original PNJL model without the TBC, indicating that the Z_N symmetry is a good concept. We also investigate the interplay between the Z_N symmetry and the emergence of the quarkyonic phase.
[ { "created": "Mon, 29 Oct 2012 05:31:05 GMT", "version": "v1" } ]
2012-10-30
[ [ "Yahiro", "Masanobu", "" ], [ "Kouno", "Hiroaki", "" ], [ "Sakai", "Yuji", "" ], [ "Sasaki", "Takahiro", "" ], [ "Makiyama", "Takahiro", "" ] ]
We propose a simple model with the Z_N symmetry in order to answer whether the symmetry is a good concept in QCD with light quark mass. The model is constructed by imposing the flavor-dependent twisted boundary condition (TBC) on the three-flavor Polyakov-loop extended Nambu-Jona-Lasinio model. In the model, the Z_N symmetry is preserved below some temperature T_c, but spontaneously broken above T_c. Dynamics of the simple model is similar to that of the original PNJL model without the TBC, indicating that the Z_N symmetry is a good concept. We also investigate the interplay between the Z_N symmetry and the emergence of the quarkyonic phase.
hep-ph/9710506
Gerhard Schuler
Gerhard A. Schuler (CERN)
Two-photon physics with GALUGA 2.0
Latex, 32 pages, 7 figures, uses 12pt.sty, epsfig.sty, amsbsy.sty
Comput.Phys.Commun. 108 (1998) 279-303
10.1016/S0010-4655(97)00127-6
CERN-TH/97-265
hep-ph
null
An extended version of the Monte Carlo program GALUGA is presented for the computation of two-photon production in $\e^+\e^-$ collisions. Functions implemented for the five $\gamma^\star\gamma^\star$ structure functions now include several ans\"atze of the total hadronic cross section based on the BFKL--Pomeron and various Regge-like models. In addition, structure functions for resonance formation are included with full dependence on the two photon virtualities $Q_1^2$ and $Q_2^2$ as given in the constituent-quark model. The six lowest-lying resonances of each of the C-even mesons with $J^{P}= 0^-$, $0^+$, $1^+$, $2^+$ and $2^-$ are provided. The program can also be used to calculate with exact kinematics the effective two-photon luminosity function. Special emphasis is put on a numerically stable evaluation of all variables over the full $Q_i^2$ range while keeping all dependences on the electron mass and $Q_i^2$.
[ { "created": "Tue, 28 Oct 1997 14:51:41 GMT", "version": "v1" } ]
2009-10-30
[ [ "Schuler", "Gerhard A.", "", "CERN" ] ]
An extended version of the Monte Carlo program GALUGA is presented for the computation of two-photon production in $\e^+\e^-$ collisions. Functions implemented for the five $\gamma^\star\gamma^\star$ structure functions now include several ans\"atze of the total hadronic cross section based on the BFKL--Pomeron and various Regge-like models. In addition, structure functions for resonance formation are included with full dependence on the two photon virtualities $Q_1^2$ and $Q_2^2$ as given in the constituent-quark model. The six lowest-lying resonances of each of the C-even mesons with $J^{P}= 0^-$, $0^+$, $1^+$, $2^+$ and $2^-$ are provided. The program can also be used to calculate with exact kinematics the effective two-photon luminosity function. Special emphasis is put on a numerically stable evaluation of all variables over the full $Q_i^2$ range while keeping all dependences on the electron mass and $Q_i^2$.
hep-ph/0210033
Vladimir Shevchenko
V.Shevchenko
On the pattern of Casimir scaling violation in gluodynamics
LaTeX, 12 pages, no figures
Phys.Lett. B550 (2002) 85-92
10.1016/S0370-2693(02)02968-4
ITP-UU-02/48
hep-ph hep-th
null
Results of lattice analysis indicate that the static potential in SU(3) gauge theory is proportional to eigenvalue of quadratic Casimir operator for the corresponding representation with a good accuracy. We discuss the mechanism of possible deviations from the Casimir scaling in gluodynamics in terms of correlators of path-ordered gauge-invariant operators defined on the worldsheet of the confining string.
[ { "created": "Wed, 2 Oct 2002 11:16:07 GMT", "version": "v1" } ]
2009-11-07
[ [ "Shevchenko", "V.", "" ] ]
Results of lattice analysis indicate that the static potential in SU(3) gauge theory is proportional to eigenvalue of quadratic Casimir operator for the corresponding representation with a good accuracy. We discuss the mechanism of possible deviations from the Casimir scaling in gluodynamics in terms of correlators of path-ordered gauge-invariant operators defined on the worldsheet of the confining string.
1106.3299
Oleg Kuprash Evgenovych
Laszlo Jenkovszky, Oleg Kuprash, Jerry L\"ams\"a, Risto Orava
Low-Mass Diffraction at the LHC
8 pages, 9 figures. Minor changes. To be published in the Modern Physics Letters A
null
10.1142/S0217732311036346
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The expected resonance structure for the low-mass single diffractive states from a Regge-dual model elaborated paper by the present authors in a previous is predicted. Estimates for the observable low-mass single diffraction dissociation (SDD) cross sections and efficiencies for single diffractive events simulated by PYTHIA 6.2 as a function of the diffractive mass are given.
[ { "created": "Thu, 16 Jun 2011 18:29:32 GMT", "version": "v1" }, { "created": "Wed, 6 Jul 2011 15:15:15 GMT", "version": "v2" } ]
2015-05-28
[ [ "Jenkovszky", "Laszlo", "" ], [ "Kuprash", "Oleg", "" ], [ "Lämsä", "Jerry", "" ], [ "Orava", "Risto", "" ] ]
The expected resonance structure for the low-mass single diffractive states from a Regge-dual model elaborated paper by the present authors in a previous is predicted. Estimates for the observable low-mass single diffraction dissociation (SDD) cross sections and efficiencies for single diffractive events simulated by PYTHIA 6.2 as a function of the diffractive mass are given.
hep-ph/0511167
Xavier Garcia i Tormo
Xavier Garcia i Tormo, Joan Soto
Radiative decays and the nature of heavy quarkonia
5 pages, 3 figures. Clarifications introduced, including extra curve in plots. Journal version
Phys.Rev.Lett.96:111801,2006
10.1103/PhysRevLett.96.111801
UB-ECM-PF 05/28
hep-ph
null
We argue that the photon spectra in radiative decays of various heavy quarkonium states provide important information on their nature. If two of these states are in the strong coupling regime, we are able to produce a parameter-free model independent formula, which holds at next-to-leading order and includes both direct and fragmentation contributions. When the formula is checked against recent CLEO data it favors Upsilon (2S) and Upsilon (3S) in the strong coupling regime and disfavors Upsilon (1S) in it.
[ { "created": "Mon, 14 Nov 2005 15:23:21 GMT", "version": "v1" }, { "created": "Tue, 21 Mar 2006 18:10:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Tormo", "Xavier Garcia i", "" ], [ "Soto", "Joan", "" ] ]
We argue that the photon spectra in radiative decays of various heavy quarkonium states provide important information on their nature. If two of these states are in the strong coupling regime, we are able to produce a parameter-free model independent formula, which holds at next-to-leading order and includes both direct and fragmentation contributions. When the formula is checked against recent CLEO data it favors Upsilon (2S) and Upsilon (3S) in the strong coupling regime and disfavors Upsilon (1S) in it.
1112.1104
D.N. Triantafyllopoulos
E. Iancu, D. N. Triantafyllopoulos
JIMWLK evolution in the Gaussian approximation
v2: 45 pages, 4 figures, various corrections, section 4.4 updated, to appear in JHEP
null
10.1007/JHEP04(2012)025
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate that the Balitsky-JIMWLK equations describing the high-energy evolution of the n-point functions of the Wilson lines (the QCD scattering amplitudes in the eikonal approximation) admit a controlled mean field approximation of the Gaussian type, for any value of the number of colors Nc. This approximation is strictly correct in the weak scattering regime at relatively large transverse momenta, where it reproduces the BFKL dynamics, and in the strong scattering regime deeply at saturation, where it properly describes the evolution of the scattering amplitudes towards the respective black disk limits. The approximation scheme is fully specified by giving the 2-point function (the S-matrix for a color dipole), which in turn can be related to the solution to the Balitsky-Kovchegov equation, including at finite Nc. Any higher n-point function with n greater than or equal to 4 can be computed in terms of the dipole S-matrix by solving a closed system of evolution equations (a simplified version of the respective Balitsky-JIMWLK equations) which are local in the transverse coordinates. For simple configurations of the projectile in the transverse plane, our new results for the 4-point and the 6-point functions coincide with the high-energy extrapolations of the respective results in the McLerran-Venugopalan model. One cornerstone of our construction is a symmetry property of the JIMWLK evolution, that we notice here for the first time: the fact that, with increasing energy, a hadron is expanding its longitudinal support symmetrically around the light-cone. This corresponds to invariance under time reversal for the scattering amplitudes.
[ { "created": "Mon, 5 Dec 2011 21:41:45 GMT", "version": "v1" }, { "created": "Fri, 23 Mar 2012 23:10:06 GMT", "version": "v2" } ]
2015-06-03
[ [ "Iancu", "E.", "" ], [ "Triantafyllopoulos", "D. N.", "" ] ]
We demonstrate that the Balitsky-JIMWLK equations describing the high-energy evolution of the n-point functions of the Wilson lines (the QCD scattering amplitudes in the eikonal approximation) admit a controlled mean field approximation of the Gaussian type, for any value of the number of colors Nc. This approximation is strictly correct in the weak scattering regime at relatively large transverse momenta, where it reproduces the BFKL dynamics, and in the strong scattering regime deeply at saturation, where it properly describes the evolution of the scattering amplitudes towards the respective black disk limits. The approximation scheme is fully specified by giving the 2-point function (the S-matrix for a color dipole), which in turn can be related to the solution to the Balitsky-Kovchegov equation, including at finite Nc. Any higher n-point function with n greater than or equal to 4 can be computed in terms of the dipole S-matrix by solving a closed system of evolution equations (a simplified version of the respective Balitsky-JIMWLK equations) which are local in the transverse coordinates. For simple configurations of the projectile in the transverse plane, our new results for the 4-point and the 6-point functions coincide with the high-energy extrapolations of the respective results in the McLerran-Venugopalan model. One cornerstone of our construction is a symmetry property of the JIMWLK evolution, that we notice here for the first time: the fact that, with increasing energy, a hadron is expanding its longitudinal support symmetrically around the light-cone. This corresponds to invariance under time reversal for the scattering amplitudes.