id
stringlengths
9
14
submitter
stringlengths
1
56
authors
stringlengths
5
7.68k
title
stringlengths
3
299
comments
stringlengths
1
1.15k
journal-ref
stringlengths
9
298
doi
stringlengths
12
97
report-no
stringlengths
3
341
categories
stringclasses
869 values
license
stringclasses
9 values
orig_abstract
stringlengths
16
2.44k
versions
listlengths
1
39
update_date
stringlengths
10
10
authors_parsed
listlengths
1
565
abstract
stringlengths
13
2.44k
1212.5995
P C Vinodkumar
Arpit Parmar, Bhavin Patel and P. C. Vinodkumar
Medium effects on the quarkonia states above critical temperature
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the quarkonia correlators for charmonium and bottomonium systems in the pseudoscalar, vector and scalar channels. For the description of quark-antiquark interaction we adopt the temperature dependant colour screening potential of the power law form. The spectroscopic parameters defined from the model are employed in the spectral functions to compute the quarkonia correlators. We find considerable medium modifications to the effective masses of the quarkonia as well as in the behaviour of the respective radial wave functions. These modifications are then reflected in the computed correlators. The general behaviour of correlators in the vector and scalar channel are in accordance with the latest lattice results while their behaviour in the pseudoscalar channels are found to be different.
[ { "created": "Tue, 25 Dec 2012 05:53:14 GMT", "version": "v1" } ]
2012-12-27
[ [ "Parmar", "Arpit", "" ], [ "Patel", "Bhavin", "" ], [ "Vinodkumar", "P. C.", "" ] ]
We present the quarkonia correlators for charmonium and bottomonium systems in the pseudoscalar, vector and scalar channels. For the description of quark-antiquark interaction we adopt the temperature dependant colour screening potential of the power law form. The spectroscopic parameters defined from the model are employed in the spectral functions to compute the quarkonia correlators. We find considerable medium modifications to the effective masses of the quarkonia as well as in the behaviour of the respective radial wave functions. These modifications are then reflected in the computed correlators. The general behaviour of correlators in the vector and scalar channel are in accordance with the latest lattice results while their behaviour in the pseudoscalar channels are found to be different.
hep-ph/0110179
Agnes Mocsy
A. Mocsy (University of Minnesota)
Non-Equilibrium Aspects of Chiral Field Theories
147 pages, 31 figures, Ph. D. Thesis (advisor J. Kapusta)
null
null
NUC-MINN-01/13-T
hep-ph
null
First, the chiral phase transition at nonzero temperature and baryon chemical potential is studied at mean field level in the sigma model that includes quark degrees of freedom explicitly. For small bare quark masses the critical point separating the first order phase transition line and the smooth crossover region is determined, and the spinodal lines are drawn. Adiabatic lines are computed showing that the critical point does not serve as focusing point in the adiabatic expansion. Second, coarse-grained evolution equations for inhomogeneous chiral condensate fields coupled to a heat bath are derived in the linear sigma model. Multiple effects of the thermal background on the Disoriented Chiral Condensate (DCC) are studied within linear response theory. In-medium modification of the pion dispersion relation is examined. The deviation from the speed of light of the velocity of soft Goldstone modes is calculated. Decay widths of pions and sigma mesons are computed at nonzero temperature at one- and two-loop order in perturbation theory. We show that elastic scattering processes are significant for the dissipation of DCCs in the phase transition region. Throughout this work we made sure that Goldstone's Theorem is fulfilled when chiral symmetry is spontaneously broken.
[ { "created": "Sun, 14 Oct 2001 19:22:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Mocsy", "A.", "", "University of Minnesota" ] ]
First, the chiral phase transition at nonzero temperature and baryon chemical potential is studied at mean field level in the sigma model that includes quark degrees of freedom explicitly. For small bare quark masses the critical point separating the first order phase transition line and the smooth crossover region is determined, and the spinodal lines are drawn. Adiabatic lines are computed showing that the critical point does not serve as focusing point in the adiabatic expansion. Second, coarse-grained evolution equations for inhomogeneous chiral condensate fields coupled to a heat bath are derived in the linear sigma model. Multiple effects of the thermal background on the Disoriented Chiral Condensate (DCC) are studied within linear response theory. In-medium modification of the pion dispersion relation is examined. The deviation from the speed of light of the velocity of soft Goldstone modes is calculated. Decay widths of pions and sigma mesons are computed at nonzero temperature at one- and two-loop order in perturbation theory. We show that elastic scattering processes are significant for the dissipation of DCCs in the phase transition region. Throughout this work we made sure that Goldstone's Theorem is fulfilled when chiral symmetry is spontaneously broken.
hep-ph/9908361
Andrej Arbuzov
A.B. Arbuzov
Non-singlet splitting functions in QED
8 pages, LaTeX2e
Phys.Lett.B470:252-258,1999
10.1016/S0370-2693(99)01290-3
null
hep-ph
null
Iterative solution of QED evolution equations for non-singlet electron structure functions is considered. Analytical expressions in the fourth and fifth orders are presented in terms of splitting functions. Relation to the existing exponentiated solution is discussed.
[ { "created": "Mon, 16 Aug 1999 07:39:36 GMT", "version": "v1" } ]
2014-11-17
[ [ "Arbuzov", "A. B.", "" ] ]
Iterative solution of QED evolution equations for non-singlet electron structure functions is considered. Analytical expressions in the fourth and fifth orders are presented in terms of splitting functions. Relation to the existing exponentiated solution is discussed.
1904.02339
Juan-Juan Niu
Juan-Juan Niu, Lei Guo, Hong-Hao Ma, and Xing-Gang Wu
Production of doubly heavy baryons via Higgs boson decays
15 pages, 3 figures, 7 tables
Eur. Phys. J. C79 (2019) 339
10.1140/epjc/s10052-019-6842-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We systematically analyzed the production of semi-inclusive doubly heavy baryons ($\Xi_{cc}$, $\Xi_{bc}$ and $\Xi_{bb}$) for the process $H^0 \rightarrow \Xi_{QQ'}+ \bar {Q'} + \bar {Q}$ through four main Higgs decay channels within the framework of non-relativistic QCD. The contributions from the intermediate diquark states, $\langle cc\rangle[^{1}S_{0}]_{\mathbf{6}}$, $\langle cc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}$, $\langle bc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}/ \mathbf{6}}$, $\langle bc\rangle[^{1}S_{0}]_{\mathbf{\bar 3}/ \mathbf{6}}$, $\langle bb\rangle[^{1}S_{0}]_{\mathbf{6}}$ and $\langle bb\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}$, have been taken into consideration. The differential distributions and three main sources of the theoretical uncertainties have been discussed. At the High Luminosity Large Hadron Collider, there will be about 0.43$\times10^4$ events of $\Xi_{cc}$, 6.32$\times10^4$ events of $\Xi_{bc}$ and 0.28$\times10^4$ events of $\Xi_{bb}$ produced per year. There are fewer events produced at the Circular Electron Positron Collider and the International Linear Collider, about $0.26\times 10^{2}$ events of $\Xi_{cc}$, $3.83\times 10^{2}$ events of $\Xi_{bc}$ and $0.17\times 10^{2}$ events of $\Xi_{bb}$ in operation.
[ { "created": "Thu, 4 Apr 2019 04:02:31 GMT", "version": "v1" }, { "created": "Tue, 16 Apr 2019 14:29:30 GMT", "version": "v2" } ]
2019-04-17
[ [ "Niu", "Juan-Juan", "" ], [ "Guo", "Lei", "" ], [ "Ma", "Hong-Hao", "" ], [ "Wu", "Xing-Gang", "" ] ]
We systematically analyzed the production of semi-inclusive doubly heavy baryons ($\Xi_{cc}$, $\Xi_{bc}$ and $\Xi_{bb}$) for the process $H^0 \rightarrow \Xi_{QQ'}+ \bar {Q'} + \bar {Q}$ through four main Higgs decay channels within the framework of non-relativistic QCD. The contributions from the intermediate diquark states, $\langle cc\rangle[^{1}S_{0}]_{\mathbf{6}}$, $\langle cc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}$, $\langle bc\rangle[^{3}S_{1}]_{\mathbf{\bar 3}/ \mathbf{6}}$, $\langle bc\rangle[^{1}S_{0}]_{\mathbf{\bar 3}/ \mathbf{6}}$, $\langle bb\rangle[^{1}S_{0}]_{\mathbf{6}}$ and $\langle bb\rangle[^{3}S_{1}]_{\mathbf{\bar 3}}$, have been taken into consideration. The differential distributions and three main sources of the theoretical uncertainties have been discussed. At the High Luminosity Large Hadron Collider, there will be about 0.43$\times10^4$ events of $\Xi_{cc}$, 6.32$\times10^4$ events of $\Xi_{bc}$ and 0.28$\times10^4$ events of $\Xi_{bb}$ produced per year. There are fewer events produced at the Circular Electron Positron Collider and the International Linear Collider, about $0.26\times 10^{2}$ events of $\Xi_{cc}$, $3.83\times 10^{2}$ events of $\Xi_{bc}$ and $0.17\times 10^{2}$ events of $\Xi_{bb}$ in operation.
1309.0017
Keith Hamilton
Keith Hamilton, Paolo Nason, Emanuele Re, Giulia Zanderighi
NNLOPS simulation of Higgs boson production
25 pages, 10 figures. Very minor clarifications in the text for v2
null
10.1007/JHEP10(2013)222
MCnet-13-11, CERN-PH-TH/2013-205, OUTP-13-18P
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We detail a simulation of Higgs boson production via gluon fusion, accurate at next-to-next-to-leading order in the strong coupling, including matching to a parton shower, yielding a fully exclusive, hadron-level description of the final-state. The approach relies on the POWHEG method for merging the NLO Higgs plus jet cross-section with the parton shower, and on the MINLO method to simultaneously achieve NLO accuracy for inclusive Higgs boson production. The NNLO accuracy is reached by a reweighting procedure making use of the HNNLO program.
[ { "created": "Fri, 30 Aug 2013 20:11:46 GMT", "version": "v1" }, { "created": "Tue, 8 Oct 2013 15:47:06 GMT", "version": "v2" } ]
2015-06-17
[ [ "Hamilton", "Keith", "" ], [ "Nason", "Paolo", "" ], [ "Re", "Emanuele", "" ], [ "Zanderighi", "Giulia", "" ] ]
We detail a simulation of Higgs boson production via gluon fusion, accurate at next-to-next-to-leading order in the strong coupling, including matching to a parton shower, yielding a fully exclusive, hadron-level description of the final-state. The approach relies on the POWHEG method for merging the NLO Higgs plus jet cross-section with the parton shower, and on the MINLO method to simultaneously achieve NLO accuracy for inclusive Higgs boson production. The NNLO accuracy is reached by a reweighting procedure making use of the HNNLO program.
hep-ph/0501099
Magno Machado
V.P. Goncalves, M.V.T. Machado
The QCD Pomeron in Ultraperipheral Heavy Ion Collisions: IV. Photonuclear Production of Vector Mesons
19 pages, 6 figures and 2 tables. Version to be published in Eur. Phys. J. C
Eur.Phys.J.C40:519-529,2005
10.1140/epjc/s2005-02175-3
null
hep-ph hep-ex nucl-th
null
The photonuclear production of vector mesons in ultraperipheral heavy ion collisions is investigated within the QCD color dipole picture, with particular emphasis on the saturation model. The integrated cross section and the rapidity distribution for the A + A --> V + A + A (V = rho, omega, phi, J/Psi) process are computed and theoretical estimates for scattering on both light and heavy nuclei are given for energies of RHIC and LHC. A comparison with the recent STAR data on coherent production of rho mesons is also presented. Furthermore, we calculate the photoproduction of vector mesons in proton-proton collisions at RHIC, Tevatron and LHC energies.
[ { "created": "Wed, 12 Jan 2005 16:50:41 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2005 15:45:55 GMT", "version": "v2" } ]
2011-09-13
[ [ "Goncalves", "V. P.", "" ], [ "Machado", "M. V. T.", "" ] ]
The photonuclear production of vector mesons in ultraperipheral heavy ion collisions is investigated within the QCD color dipole picture, with particular emphasis on the saturation model. The integrated cross section and the rapidity distribution for the A + A --> V + A + A (V = rho, omega, phi, J/Psi) process are computed and theoretical estimates for scattering on both light and heavy nuclei are given for energies of RHIC and LHC. A comparison with the recent STAR data on coherent production of rho mesons is also presented. Furthermore, we calculate the photoproduction of vector mesons in proton-proton collisions at RHIC, Tevatron and LHC energies.
hep-ph/0507149
Charles Suggs
R. Jaffe
Color Non-Singlet Spectroscopy
References added and typos corrected
Phys.Rev. D72 (2005) 074508
10.1103/PhysRevD.72.074508
MIT-CTP-3663
hep-ph hep-lat nucl-th
null
Study of the spectrum and structure of color non-singlet combinations of quarks and antiquarks, neutralized by a non-dynamical compensating color source, may provide an interesting way to address questions about QCD that cannot be addressed by experiment at the present time. These states can be simulated in lattice QCD and the results can be used to improve phenomenological models of hadrons. Here these ideas are applied to color triplet states of qqqq and qq bar q.
[ { "created": "Tue, 12 Jul 2005 16:34:09 GMT", "version": "v1" }, { "created": "Mon, 8 Aug 2005 18:18:28 GMT", "version": "v2" } ]
2009-11-11
[ [ "Jaffe", "R.", "" ] ]
Study of the spectrum and structure of color non-singlet combinations of quarks and antiquarks, neutralized by a non-dynamical compensating color source, may provide an interesting way to address questions about QCD that cannot be addressed by experiment at the present time. These states can be simulated in lattice QCD and the results can be used to improve phenomenological models of hadrons. Here these ideas are applied to color triplet states of qqqq and qq bar q.
hep-ph/0612029
Borut Bajc
Borut Bajc and Goran Senjanovic
Seesaw at LHC
4 pages; the possibility of lepton violating signatures at LHC stressed, relevant cross sections and branching ratios estimated, few references added, main conclusions unchanged
JHEP 0708:014,2007
10.1088/1126-6708/2007/08/014
null
hep-ph
null
We study the implementation of the type III seesaw in the ordinary nonsupersymmetric SU(5) grand unified theory. This allows for an alternative definition of the minimal SU(5) model, with the inclusion of the adjoint fermionic multiplet. The main prediction of the theory is the light fermionic SU(2) triplet with mass at the electroweak scale. Due to their gauge couplings, these triplets can be produced pair-wise via Drell-Yan, and due to the Majorana nature of the neutral component their decays leave a clear signature of same sign di-leptons and four jets. This allows for their possible discovery at LHC and provides an example of directly measurable seesaw parameters.
[ { "created": "Mon, 4 Dec 2006 18:50:15 GMT", "version": "v1" }, { "created": "Mon, 2 Jul 2007 13:28:05 GMT", "version": "v2" } ]
2011-09-30
[ [ "Bajc", "Borut", "" ], [ "Senjanovic", "Goran", "" ] ]
We study the implementation of the type III seesaw in the ordinary nonsupersymmetric SU(5) grand unified theory. This allows for an alternative definition of the minimal SU(5) model, with the inclusion of the adjoint fermionic multiplet. The main prediction of the theory is the light fermionic SU(2) triplet with mass at the electroweak scale. Due to their gauge couplings, these triplets can be produced pair-wise via Drell-Yan, and due to the Majorana nature of the neutral component their decays leave a clear signature of same sign di-leptons and four jets. This allows for their possible discovery at LHC and provides an example of directly measurable seesaw parameters.
1311.0446
Tarek Hussein
Wedad AL-Harbi and Tarek Hussein
Thermodynamic Treatment of High Energy Heavy Ion Collision
15 pages, 6 figures, 2 tables. arXiv admin note: text overlap with arXiv:hep-lat/0608013 by other authors
Acta Physica Polonica B, Vol. 44 (2013), 1905
10.5506/APhysPolB.44.1905
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/3.0/
The hadron production in heavy ion collision is treated in the framework of thermodynamic vision. Thermodynamic system formed during central collision of Pb-Pb at high energies is considered, through which binary collision is assumed among the valance quarks. The partition function of the system is calculated; accordingly the free available energy, the entropy and the chemical potential are calculated. The concept of string fragmentation and defragmentation are used to form the newly produced particles. The average multiplicity of the newly produced particles are calculated and compared with the recent experimental results.
[ { "created": "Sun, 3 Nov 2013 09:47:55 GMT", "version": "v1" } ]
2017-08-23
[ [ "AL-Harbi", "Wedad", "" ], [ "Hussein", "Tarek", "" ] ]
The hadron production in heavy ion collision is treated in the framework of thermodynamic vision. Thermodynamic system formed during central collision of Pb-Pb at high energies is considered, through which binary collision is assumed among the valance quarks. The partition function of the system is calculated; accordingly the free available energy, the entropy and the chemical potential are calculated. The concept of string fragmentation and defragmentation are used to form the newly produced particles. The average multiplicity of the newly produced particles are calculated and compared with the recent experimental results.
1405.3592
Yasuhara Daiki
Yuta Hamada, Tatsuo Kobayashi, Atsushi Ogasahara, Yuji Omura, Fumihiro Takayama, Daiki Yasuhara
Revisiting Discrete Dark Matter Model:\theta_{13}\neq0 and \nu_{R} Dark Matter
The wrong estimations in Eq(4.9) and Fig.14 in the published version of this paper are corrected. As the result, the prefered mass range for $\eta$ bosons are lowered. Some comments on constraints from rare lepton decays and SM precision test added
JHEP10(2014)183
10.1007/JHEP10(2014)183
KUNS-2497, EPHOU-14011, YITP-14-40
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the discrete dark matter model with $A_4$ flavor symmetry originally introduced by M.Hirsch {\it et.al}. We show that radiative corrections can lead to non-zero $\theta_{13}$ and non-zero mass for the lightest neutrino. We find an interesting relation among neutrino mixing parameters and it indicates the sizable deviation of $s_{23}$ from the maximal angle $s_{23}^2=1/2$ and the degenerate mass spectrum for neutrinos. Also we study the possibilities that the right-handed neutrino is a dark matter candidate. Assuming the thermal freeze-out explains observed dark matter abundance, TeV-scale right-handed neutrino and flavored scalar bosons are required. In such a case, flavor symmetry plays an important role for the suppression of lepton flavor violating processes as well as for the stability of dark matter. We show that this scenario can be viable against currently existing constraints from collider, low energy experiments and cosmological observations.
[ { "created": "Wed, 14 May 2014 17:45:01 GMT", "version": "v1" }, { "created": "Tue, 10 Jun 2014 04:59:59 GMT", "version": "v2" }, { "created": "Mon, 29 Sep 2014 05:54:39 GMT", "version": "v3" }, { "created": "Tue, 30 Dec 2014 03:37:01 GMT", "version": "v4" } ]
2015-06-19
[ [ "Hamada", "Yuta", "" ], [ "Kobayashi", "Tatsuo", "" ], [ "Ogasahara", "Atsushi", "" ], [ "Omura", "Yuji", "" ], [ "Takayama", "Fumihiro", "" ], [ "Yasuhara", "Daiki", "" ] ]
We revisit the discrete dark matter model with $A_4$ flavor symmetry originally introduced by M.Hirsch {\it et.al}. We show that radiative corrections can lead to non-zero $\theta_{13}$ and non-zero mass for the lightest neutrino. We find an interesting relation among neutrino mixing parameters and it indicates the sizable deviation of $s_{23}$ from the maximal angle $s_{23}^2=1/2$ and the degenerate mass spectrum for neutrinos. Also we study the possibilities that the right-handed neutrino is a dark matter candidate. Assuming the thermal freeze-out explains observed dark matter abundance, TeV-scale right-handed neutrino and flavored scalar bosons are required. In such a case, flavor symmetry plays an important role for the suppression of lepton flavor violating processes as well as for the stability of dark matter. We show that this scenario can be viable against currently existing constraints from collider, low energy experiments and cosmological observations.
1806.08414
Vincent Mathieu
V. Mathieu, J. Nys, C. Fernandez-Ramirez, A. N. Hiller Blin, A. Jackura, A. Pilloni, A. P. Szczepaniak and G. Fox (JPAC Collaboration)
Structure of Pion Photoproduction Amplitudes
19 pages, 15 figures and 4 tables
Phys. Rev. D 98, 014041 (2018)
10.1103/PhysRevD.98.014041
JLAB-THY-18-2755
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We derive and apply the finite energy sum rules to pion photoproduction. We evaluate the low energy part of the sum rules using several state-of-the-art models. We show how the differences in the low energy side of the sum rules might originate from different quantum number assignments of baryon resonances. We interpret the observed features in the low energy side of the sum rules with the expectation from Regge theory. Finally, we present a model, in terms of a Regge-pole expansion, that matches the sum rules and the high-energy observables.
[ { "created": "Thu, 21 Jun 2018 20:08:15 GMT", "version": "v1" } ]
2018-08-08
[ [ "Mathieu", "V.", "", "JPAC Collaboration" ], [ "Nys", "J.", "", "JPAC Collaboration" ], [ "Fernandez-Ramirez", "C.", "", "JPAC Collaboration" ], [ "Blin", "A. N. Hiller", "", "JPAC Collaboration" ], [ "Jackura", "A.", "", "JPAC Collaboration" ], [ "Pilloni", "A.", "", "JPAC Collaboration" ], [ "Szczepaniak", "A. P.", "", "JPAC Collaboration" ], [ "Fox", "G.", "", "JPAC Collaboration" ] ]
We derive and apply the finite energy sum rules to pion photoproduction. We evaluate the low energy part of the sum rules using several state-of-the-art models. We show how the differences in the low energy side of the sum rules might originate from different quantum number assignments of baryon resonances. We interpret the observed features in the low energy side of the sum rules with the expectation from Regge theory. Finally, we present a model, in terms of a Regge-pole expansion, that matches the sum rules and the high-energy observables.
2109.14538
Florian Goertz
Andrei Angelescu, Andreas Bally, Simone Blasi, Florian Goertz
Unification of Gauge Symmetries... including their breaking
Contribution to Proceedings of EPS-HEP2021, 26-30 July 2021, Univ. Hamburg and DESY, 9 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, we present a minimal viable scenario that unifies the gauge symmetries of the Standard Model (SM) and their breaking sector. Our Gauge-Higgs Grand Unification setup employs 5D warped space with a $SU(6)$ bulk gauge field that includes both a $SU(5)$ grand unified theory (GUT) and a Higgs sector as a scalar component of the 5D vector field, solving the hierarchy problem. By appropriately breaking the gauge symmetry on the boundaries of the extra dimension the issue of light exotic new states, appearing generically in such models, is eliminated and the SM fermion spectrum is naturally reproduced. The Higgs potential is computed at one-loop, finding straightforward solutions with a realistic $m_h = 125$ GeV. The problem of proton decay is addressed by showing that baryon number is a hidden symmetry of the model. The presence of a scalar leptoquark and a scalar singlet is highlighted, which might play a role in solving further problems of the SM, allowing for example for electroweak baryogenesis. Finally, the $X$ and $Y$ gauge bosons from $SU(5)$ GUTs are found at collider accessible masses, opening a window to the unification structure at low energies.
[ { "created": "Wed, 29 Sep 2021 16:36:59 GMT", "version": "v1" } ]
2021-09-30
[ [ "Angelescu", "Andrei", "" ], [ "Bally", "Andreas", "" ], [ "Blasi", "Simone", "" ], [ "Goertz", "Florian", "" ] ]
In this talk, we present a minimal viable scenario that unifies the gauge symmetries of the Standard Model (SM) and their breaking sector. Our Gauge-Higgs Grand Unification setup employs 5D warped space with a $SU(6)$ bulk gauge field that includes both a $SU(5)$ grand unified theory (GUT) and a Higgs sector as a scalar component of the 5D vector field, solving the hierarchy problem. By appropriately breaking the gauge symmetry on the boundaries of the extra dimension the issue of light exotic new states, appearing generically in such models, is eliminated and the SM fermion spectrum is naturally reproduced. The Higgs potential is computed at one-loop, finding straightforward solutions with a realistic $m_h = 125$ GeV. The problem of proton decay is addressed by showing that baryon number is a hidden symmetry of the model. The presence of a scalar leptoquark and a scalar singlet is highlighted, which might play a role in solving further problems of the SM, allowing for example for electroweak baryogenesis. Finally, the $X$ and $Y$ gauge bosons from $SU(5)$ GUTs are found at collider accessible masses, opening a window to the unification structure at low energies.
1703.09492
Koichi Murase
Kenji Fukushima, Koichi Murase, Shi Pu
Fixed points and flow analysis on off-equilibrium dynamics in the boson Boltzmann equation
14 pages, 9 figures
null
10.1016/j.aop.2017.08.032
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider fixed points of steady solutions and flow directions using the boson Boltzmann equation that is a one-dimensionally reduced kinetic equation after the angular integration. With an elastic collision integral of the two-to-two scattering process, in the dense (dilute) regime where the distribution function is large (small), the boson Boltzmann equation has approximate fixed points with a power-law spectrum in addition to the thermal distribution function. We argue that the power-law fixed point can be exact in special cases. We elaborate a graphical presentation to display evolving flow directions similarly to the renormalization group flow, which explicitly exhibits how fixed points are connected and parameter space is separated by critical lines. We discuss that such a flow diagram contains useful information on thermalization processes out of equilibrium.
[ { "created": "Tue, 28 Mar 2017 10:12:31 GMT", "version": "v1" } ]
2017-10-11
[ [ "Fukushima", "Kenji", "" ], [ "Murase", "Koichi", "" ], [ "Pu", "Shi", "" ] ]
We consider fixed points of steady solutions and flow directions using the boson Boltzmann equation that is a one-dimensionally reduced kinetic equation after the angular integration. With an elastic collision integral of the two-to-two scattering process, in the dense (dilute) regime where the distribution function is large (small), the boson Boltzmann equation has approximate fixed points with a power-law spectrum in addition to the thermal distribution function. We argue that the power-law fixed point can be exact in special cases. We elaborate a graphical presentation to display evolving flow directions similarly to the renormalization group flow, which explicitly exhibits how fixed points are connected and parameter space is separated by critical lines. We discuss that such a flow diagram contains useful information on thermalization processes out of equilibrium.
2004.14556
Ya-Peng Zhao
Ya-Peng Zhao
Thermodynamic properties and transport coefficients of QCD matter within the non-extensive Polyakov-Nambu-Jona-Lasinio model
null
Phys. Rev. D 101, 096006 (2020)
10.1103/PhysRevD.101.096006
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a non-extensive version of the Polyakov-Nambu-Jona-Lasinio model which is based on the non-extentive statistical mechanics. This new statistics is characterized by a dimensionless non-extensivity parameter $q$ that accounts for all possible effects violating the assumptions of the Boltzmann-Gibbs statistics (when $q\rightarrow1$, it returns to the Boltzmann-Gibbs case). Using this q-Polyakov-Nambu-Jona-Lasinio model and including two different Polyakov-loop potentials, we discussed the influence of the parameter $q$ on chiral and deconfinement phase transition, various thermodynamic quantities and transport coefficients at finite temperature and zero quark chemical potential. We found that the Stefan-Boltzmann limit is actually related to the choice of statistics. For example, in the Tsallis statistics, the thermodynamic quantities $\frac{\epsilon}{T^{4}}$, $\frac{p}{T^{4}}$ and $\frac{s}{T^{3}}$ all increase with $q$, exceed their usual Stefan-Boltzmann limits and tend to a new $q$-related Tsallis limit at temperature high enough. Interestingly, however, due to a surprising cancellation, the high temperature limit of $c_{s}^{2}$ is still its SB limit $1/3$. In addition, we found some similarities between the non-extensive effect and the finite-size effect. For example, as $q$ increases (size decreases), the criticality of $\frac{c_{v}}{T^{3}}$ and $c_{s}^{2}$ gradually disappears. Besides, in order to better study the non-extensive effect, we defined a new susceptibility and calculated the response of thermodynamic quantities and transport coefficients to $q$. And found that their response patterns are different.
[ { "created": "Thu, 30 Apr 2020 03:20:29 GMT", "version": "v1" } ]
2020-05-20
[ [ "Zhao", "Ya-Peng", "" ] ]
We present a non-extensive version of the Polyakov-Nambu-Jona-Lasinio model which is based on the non-extentive statistical mechanics. This new statistics is characterized by a dimensionless non-extensivity parameter $q$ that accounts for all possible effects violating the assumptions of the Boltzmann-Gibbs statistics (when $q\rightarrow1$, it returns to the Boltzmann-Gibbs case). Using this q-Polyakov-Nambu-Jona-Lasinio model and including two different Polyakov-loop potentials, we discussed the influence of the parameter $q$ on chiral and deconfinement phase transition, various thermodynamic quantities and transport coefficients at finite temperature and zero quark chemical potential. We found that the Stefan-Boltzmann limit is actually related to the choice of statistics. For example, in the Tsallis statistics, the thermodynamic quantities $\frac{\epsilon}{T^{4}}$, $\frac{p}{T^{4}}$ and $\frac{s}{T^{3}}$ all increase with $q$, exceed their usual Stefan-Boltzmann limits and tend to a new $q$-related Tsallis limit at temperature high enough. Interestingly, however, due to a surprising cancellation, the high temperature limit of $c_{s}^{2}$ is still its SB limit $1/3$. In addition, we found some similarities between the non-extensive effect and the finite-size effect. For example, as $q$ increases (size decreases), the criticality of $\frac{c_{v}}{T^{3}}$ and $c_{s}^{2}$ gradually disappears. Besides, in order to better study the non-extensive effect, we defined a new susceptibility and calculated the response of thermodynamic quantities and transport coefficients to $q$. And found that their response patterns are different.
1811.07879
Kazuhiro Tanaka
Kazuhiro Tanaka (Juntendo Univ.)
Three-loop formula for quark and gluon contributions to the QCD trace anomaly
26 pages, text improved and references added
null
10.1007/JHEP01(2019)120
J-PARC TH-0140
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the QCD energy-momentum tensor $T^{\mu\nu}$, the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions among quarks and gluons, although the total tensor $T^{\mu\nu}$ is not renormalized thanks to the conservation of energy and momentum. Recently it has been shown that, through the renormalization, each of the quark and gluon parts of $T^{\mu\nu}$ receives a definite amount of anomalous trace contribution, such that their sum reproduces the well-known QCD trace anomaly, $T^\mu_\mu= (\beta/2g)F^{\mu\nu}F_{\mu\nu}+ m (1+\gamma_m)\bar{\psi}\psi$, and the corresponding formulas have been derived up to two-loop order. We extend this result to the three-loop order, working out all the relevant three-loop renormalization structure for the quark and gluon energy-momentum tensors in the (modified) minimal subtraction scheme in the dimensional regularization. We apply our three-loop formula of the quark/gluon decomposition of the trace anomaly to calculate the anomaly-induced mass structure of nucleons as well as pions.
[ { "created": "Mon, 19 Nov 2018 18:52:57 GMT", "version": "v1" }, { "created": "Wed, 21 Nov 2018 18:22:17 GMT", "version": "v2" } ]
2019-02-20
[ [ "Tanaka", "Kazuhiro", "", "Juntendo Univ." ] ]
In the QCD energy-momentum tensor $T^{\mu\nu}$, the terms that contribute to physical matrix elements are expressed as the sum of the gauge-invariant quark part and gluon part. Each part undergoes the renormalization due to the interactions among quarks and gluons, although the total tensor $T^{\mu\nu}$ is not renormalized thanks to the conservation of energy and momentum. Recently it has been shown that, through the renormalization, each of the quark and gluon parts of $T^{\mu\nu}$ receives a definite amount of anomalous trace contribution, such that their sum reproduces the well-known QCD trace anomaly, $T^\mu_\mu= (\beta/2g)F^{\mu\nu}F_{\mu\nu}+ m (1+\gamma_m)\bar{\psi}\psi$, and the corresponding formulas have been derived up to two-loop order. We extend this result to the three-loop order, working out all the relevant three-loop renormalization structure for the quark and gluon energy-momentum tensors in the (modified) minimal subtraction scheme in the dimensional regularization. We apply our three-loop formula of the quark/gluon decomposition of the trace anomaly to calculate the anomaly-induced mass structure of nucleons as well as pions.
hep-ph/9604356
Indranil
Indranil Dasgupta
Baryogenesis from Cosmic Strings at the Electroweak Scale
28 pages, Latex, two postscript figures, the model is simplified slightly, experimental signatures are detailed, some typographical errors corrected, no major change in conclusions
Phys.Rev. D55 (1997) 3318-3329
10.1103/PhysRevD.55.3318
BUHEP-96-7
hep-ph
null
We explore the viability of baryogenesis from light scalar decays after the electroweak phase transition. A minimal model of this kind is constructed with new CP violating interactions involving a heavy fourth family. The departure from thermal equilbrium must come from topological defects like cosmic strings, and we show that almost any mechanism for producing the cosmic strings at the electroweak scale results in a viable theory. Baryogenesis occurs in the fourth generation but the baryon number is later transported to the visible generations. This mechanism of indirect baryogenesis allows us to satisfy experimental limits on the proton lifetime while still having perturbative baryon number violation at low energies. The fourth family has very small mixing angles which opens the possibility of distinct observable signatures in collider experiments.
[ { "created": "Fri, 19 Apr 1996 01:28:44 GMT", "version": "v1" }, { "created": "Tue, 1 Oct 1996 23:31:12 GMT", "version": "v2" } ]
2016-09-01
[ [ "Dasgupta", "Indranil", "" ] ]
We explore the viability of baryogenesis from light scalar decays after the electroweak phase transition. A minimal model of this kind is constructed with new CP violating interactions involving a heavy fourth family. The departure from thermal equilbrium must come from topological defects like cosmic strings, and we show that almost any mechanism for producing the cosmic strings at the electroweak scale results in a viable theory. Baryogenesis occurs in the fourth generation but the baryon number is later transported to the visible generations. This mechanism of indirect baryogenesis allows us to satisfy experimental limits on the proton lifetime while still having perturbative baryon number violation at low energies. The fourth family has very small mixing angles which opens the possibility of distinct observable signatures in collider experiments.
hep-ph/9812417
Matthias Jamin
H.G. Dosch, M. Eidemueller, M. Jamin
QCD sum rule analysis of the field strength correlator
16 pages, 1 figure
Phys.Lett.B452:379-386,1999
10.1016/S0370-2693(99)00224-5
HD-THEP-98-51
hep-ph
null
The gauge invariant two-point correlator for the gluon field strength tensor is analysed by means of the QCD sum rule method. To this end, we make use of a relation of this correlator to a two-point function for a quark-gluon hybrid in the limit of the quark mass going to infinity. From the sum rules a relation between the gluon correlation length and the gluon condensate is obtained. We briefly compare our results to recent determinations of the field strength correlator on the lattice.
[ { "created": "Thu, 17 Dec 1998 17:49:39 GMT", "version": "v1" } ]
2008-11-26
[ [ "Dosch", "H. G.", "" ], [ "Eidemueller", "M.", "" ], [ "Jamin", "M.", "" ] ]
The gauge invariant two-point correlator for the gluon field strength tensor is analysed by means of the QCD sum rule method. To this end, we make use of a relation of this correlator to a two-point function for a quark-gluon hybrid in the limit of the quark mass going to infinity. From the sum rules a relation between the gluon correlation length and the gluon condensate is obtained. We briefly compare our results to recent determinations of the field strength correlator on the lattice.
2307.02207
Taylor Gray
Riccardo Catena and Taylor R. Gray
Spin-1 Thermal Targets for Dark Matter Searches at Beam Dump and Fixed Target Experiments
null
null
null
null
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
The current framework for dark matter searches at beam dump and fixed target experiments relies on four benchmark models, the complex scalar, inelastic scalar, pseudo-Dirac and finally, Majorana DM models. While this approach has so far been successful in the interpretation of the available data, it a priori excludes the possibility that DM is made of spin-1 particles -- a restriction which is neither theoretically nor experimentally justified. In this work we extend the current landscape of sub-GeV DM models to a set of models for spin-1 DM, including a family of simplified models (involving one DM candidate and one mediator -- the dark photon) and an ultraviolet complete model based on a non-abelian gauge group where DM is a spin-1 Strongly Interacting Massive Particle. For each of these models, we calculate the DM relic density, the expected number of signal events at beam dump experiments, the rate of energy injection in the early universe thermal bath and in the Intergalactic Medium, as well as the helicity amplitudes for forward processes subject to the unitary bound. We then compare these predictions with experimental results from Planck, CMB surveys, IGM temperature observations, LSND, MiniBooNE, NA64, and BaBar and with available projections from LDMX and Belle II. Through this comparison, we identify the regions in the parameter space of the models considered in this work where DM is simultaneously thermally produced, compatible with present observations, and within reach at Belle II and LDMX. We find that the simplified models are strongly constrained by current beam dump experiments and the unitarity bound, and will thus be conclusively probed in the first stage of LDMX data taking. We also find that the SIMP model explored in this work predicts the observed DM abundance, is compatible with current observations and within reach at LDMX in a wide region of the parameter space.
[ { "created": "Wed, 5 Jul 2023 11:14:10 GMT", "version": "v1" }, { "created": "Thu, 19 Oct 2023 09:51:15 GMT", "version": "v2" } ]
2023-10-20
[ [ "Catena", "Riccardo", "" ], [ "Gray", "Taylor R.", "" ] ]
The current framework for dark matter searches at beam dump and fixed target experiments relies on four benchmark models, the complex scalar, inelastic scalar, pseudo-Dirac and finally, Majorana DM models. While this approach has so far been successful in the interpretation of the available data, it a priori excludes the possibility that DM is made of spin-1 particles -- a restriction which is neither theoretically nor experimentally justified. In this work we extend the current landscape of sub-GeV DM models to a set of models for spin-1 DM, including a family of simplified models (involving one DM candidate and one mediator -- the dark photon) and an ultraviolet complete model based on a non-abelian gauge group where DM is a spin-1 Strongly Interacting Massive Particle. For each of these models, we calculate the DM relic density, the expected number of signal events at beam dump experiments, the rate of energy injection in the early universe thermal bath and in the Intergalactic Medium, as well as the helicity amplitudes for forward processes subject to the unitary bound. We then compare these predictions with experimental results from Planck, CMB surveys, IGM temperature observations, LSND, MiniBooNE, NA64, and BaBar and with available projections from LDMX and Belle II. Through this comparison, we identify the regions in the parameter space of the models considered in this work where DM is simultaneously thermally produced, compatible with present observations, and within reach at Belle II and LDMX. We find that the simplified models are strongly constrained by current beam dump experiments and the unitarity bound, and will thus be conclusively probed in the first stage of LDMX data taking. We also find that the SIMP model explored in this work predicts the observed DM abundance, is compatible with current observations and within reach at LDMX in a wide region of the parameter space.
1605.01149
Baishali Saikia
D.K. Choudhury and Baishali Saikia
Transverse Momentum Dependent Parton Distributions with self-similarity at small $x$ and models of proton structure function
28 pages, 10 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we make re-analysis of a self-similarity based model of the proton structure function at small $x$ pursued in recent years. The additional assumption is that it should be singularity free in the entire kinematic range $0\leq \textit{x}\leq 1$. Our analysis indicates that the singularity free version of the model is valid in a more restrictive range of $Q^{2}$. We then analyse the defining Transverse Momentum Dependent Parton Distributions (TMD) occurred in the models and show that the proper generalizations and initial conditions on them not only remove the undesired singularity but also results in a QCD compatible structure function with logarithmic growth in $Q^2$. The phenomenological range of validity is then found to be much larger than the earlier versions. We also extrapolate the models to large $x$ in a parameter free way.
[ { "created": "Wed, 4 May 2016 05:42:24 GMT", "version": "v1" } ]
2016-05-05
[ [ "Choudhury", "D. K.", "" ], [ "Saikia", "Baishali", "" ] ]
In this paper we make re-analysis of a self-similarity based model of the proton structure function at small $x$ pursued in recent years. The additional assumption is that it should be singularity free in the entire kinematic range $0\leq \textit{x}\leq 1$. Our analysis indicates that the singularity free version of the model is valid in a more restrictive range of $Q^{2}$. We then analyse the defining Transverse Momentum Dependent Parton Distributions (TMD) occurred in the models and show that the proper generalizations and initial conditions on them not only remove the undesired singularity but also results in a QCD compatible structure function with logarithmic growth in $Q^2$. The phenomenological range of validity is then found to be much larger than the earlier versions. We also extrapolate the models to large $x$ in a parameter free way.
1809.09114
Wouter Dekens
W. Dekens, J. de Vries, M. Jung, and K.K. Vos
The phenomenology of electric dipole moments in models of scalar leptoquarks
Published version
JHEP 01 (2019) 069
10.1007/JHEP01(2019)069
SI-HEP-2018-29, QFET-2018-18, ACFI-T18-14
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the phenomenology of electric dipole moments (EDMs) induced in various scalar leptoquark models. We consider generic leptoquark couplings to quarks and leptons and match to Standard Model effective field theory. After evolving the resulting operators to low energies, we connect to EDM experiments by using up-to-date hadronic, nuclear, and atomic matrix elements. We show that current experimental limits set strong constraints on the possible CP-violating phases in leptoquark models. Depending on the quarks and leptons involved in the interaction, the existing searches for EDMs of leptons, nucleons, atoms, and molecules all play a role in constraining the CP-violating couplings. We discuss the impact of hadronic and nuclear uncertainties as well as the sensitivities that can be achieved with future EDM experiments. Finally, we study the impact of EDM constraints on a specific leptoquark model that can explain the recent $B$-physics anomalies.
[ { "created": "Mon, 24 Sep 2018 18:00:02 GMT", "version": "v1" }, { "created": "Tue, 22 Jan 2019 23:16:46 GMT", "version": "v2" } ]
2019-01-24
[ [ "Dekens", "W.", "" ], [ "de Vries", "J.", "" ], [ "Jung", "M.", "" ], [ "Vos", "K. K.", "" ] ]
We study the phenomenology of electric dipole moments (EDMs) induced in various scalar leptoquark models. We consider generic leptoquark couplings to quarks and leptons and match to Standard Model effective field theory. After evolving the resulting operators to low energies, we connect to EDM experiments by using up-to-date hadronic, nuclear, and atomic matrix elements. We show that current experimental limits set strong constraints on the possible CP-violating phases in leptoquark models. Depending on the quarks and leptons involved in the interaction, the existing searches for EDMs of leptons, nucleons, atoms, and molecules all play a role in constraining the CP-violating couplings. We discuss the impact of hadronic and nuclear uncertainties as well as the sensitivities that can be achieved with future EDM experiments. Finally, we study the impact of EDM constraints on a specific leptoquark model that can explain the recent $B$-physics anomalies.
1003.5989
Juan M. Torres-Rincon
Juan M. Torres-Rincon and Felipe J. Llanes-Estrada
Heavy Quark Fluorescence
4 pages, 4 figures, Figure 2 updated and some typos corrected. To be published in Physical Review Letters
Phys.Rev.Lett.105:022003,2010
10.1103/PhysRevLett.105.022003
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy hadrons containing heavy quarks (for example, Upsilon-mesons) feature a scale separation between the heavy quark mass (about 4.5 GeV for the b-quark) and the QCD scale (about 0.3 GeV}) that controls effective masses of lighter constituents. Therefore, as in ordinary molecules, the de-excitation of the lighter, faster degrees of freedom leaves the velocity distribution of the heavy quarks unchanged, populating the available decay channels in qualitatively predictable ways. Automatically an application of the Franck-Condon principle of molecular physics explains several puzzling results of Upsilon(5S) decays as measured by the Belle collaboration, such as the high rate of Bs*-anti Bs* versus Bs*-anti Bs production, the strength of three-body B-anti B + pion decays, or the dip in B momentum shown in these decays. We argue that the data is showing the first Sturm-Liouville zero of the Upsilon(5S) quantum mechanical squared wavefunction, and providing evidence for a largely b-anti b composition of this meson.
[ { "created": "Wed, 31 Mar 2010 08:28:06 GMT", "version": "v1" }, { "created": "Tue, 8 Jun 2010 13:35:17 GMT", "version": "v2" } ]
2014-11-20
[ [ "Torres-Rincon", "Juan M.", "" ], [ "Llanes-Estrada", "Felipe J.", "" ] ]
Heavy hadrons containing heavy quarks (for example, Upsilon-mesons) feature a scale separation between the heavy quark mass (about 4.5 GeV for the b-quark) and the QCD scale (about 0.3 GeV}) that controls effective masses of lighter constituents. Therefore, as in ordinary molecules, the de-excitation of the lighter, faster degrees of freedom leaves the velocity distribution of the heavy quarks unchanged, populating the available decay channels in qualitatively predictable ways. Automatically an application of the Franck-Condon principle of molecular physics explains several puzzling results of Upsilon(5S) decays as measured by the Belle collaboration, such as the high rate of Bs*-anti Bs* versus Bs*-anti Bs production, the strength of three-body B-anti B + pion decays, or the dip in B momentum shown in these decays. We argue that the data is showing the first Sturm-Liouville zero of the Upsilon(5S) quantum mechanical squared wavefunction, and providing evidence for a largely b-anti b composition of this meson.
1407.0174
Tong Li
Csaba Bal\'azs and Tong Li
Simplified Dark Matter Models Confront the Gamma Ray Excess
23 pages, 7 figures, 2 tables. Version to appear in Physical Review D
Phys. Rev. D 90, 055026 (2014)
10.1103/PhysRevD.90.055026
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the excess of gamma rays from the Galactic Center, we confront a number of simplified dark matter models with experimental data. Assuming a single dark matter particle coupled to standard matter via a spin-0 mediator, we compare model evidences for Majorana fermion, real scalar and real vector dark matter candidates. We consider dark matter annihilation into various fermionic final states contributing to the observed differential gamma ray flux. Our likelihood function also includes the dark matter relic density, its elastic scattering cross section with nuclei, and collider limits. Using Bayesian inference we confine the mass and couplings strengths of the dark matter and mediator particle. Our results show that, if the gamma ray excess is due to dark matter the above parameters are well constrained by the observations. We find that the Majorana fermion dark matter model is supported the most by the data.
[ { "created": "Tue, 1 Jul 2014 10:35:38 GMT", "version": "v1" }, { "created": "Mon, 22 Sep 2014 00:41:09 GMT", "version": "v2" } ]
2014-10-01
[ [ "Balázs", "Csaba", "" ], [ "Li", "Tong", "" ] ]
Inspired by the excess of gamma rays from the Galactic Center, we confront a number of simplified dark matter models with experimental data. Assuming a single dark matter particle coupled to standard matter via a spin-0 mediator, we compare model evidences for Majorana fermion, real scalar and real vector dark matter candidates. We consider dark matter annihilation into various fermionic final states contributing to the observed differential gamma ray flux. Our likelihood function also includes the dark matter relic density, its elastic scattering cross section with nuclei, and collider limits. Using Bayesian inference we confine the mass and couplings strengths of the dark matter and mediator particle. Our results show that, if the gamma ray excess is due to dark matter the above parameters are well constrained by the observations. We find that the Majorana fermion dark matter model is supported the most by the data.
1306.6060
Markus Diehl
Markus Diehl
From form factors to generalized parton distributions
7 pages, 3 figures. To appear in the proceedings of DIS 2013
null
null
DESY-13-113
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I present an extraction of generalized parton distributions from selected data on the electromagnetic nucleon form factors. The extracted distributions can in particular be used to quantify the contribution to the proton spin from the total angular momentum carried by valence quarks, as well as their transverse spatial distribution inside the proton.
[ { "created": "Tue, 25 Jun 2013 18:52:12 GMT", "version": "v1" } ]
2013-06-26
[ [ "Diehl", "Markus", "" ] ]
I present an extraction of generalized parton distributions from selected data on the electromagnetic nucleon form factors. The extracted distributions can in particular be used to quantify the contribution to the proton spin from the total angular momentum carried by valence quarks, as well as their transverse spatial distribution inside the proton.
hep-ph/0111206
Stefan Groote
S. Groote, J.G. K\"orner and A.A. Pivovarov
An interpolation of the vacuum polarization function for the evaluation of hadronic contributions to the muon anomalous magnetic moment
23 pages in LaTeX, 11 PostScript figures included in the text
Eur.Phys.J.C24:393-405,2002
10.1007/s10052-002-0958-2
MZ-TH/01-31
hep-ph
null
We propose a simple parameterization of the two-point correlator of hadronic electromagnetic currents for the evaluation of the hadronic contributions to the muon anomalous magnetic moment. The parameterization is explicitly done in the Euclidean domain. The model function contains a phenomenological parameter which provides an infrared cutoff to guarantee the smooth behavior of the correlator at the origin in accordance with experimental data in e+ e- annihilation. After fixing a numerical value for this parameter from the leading order hadronic contribution to the muon anomalous magnetic moment the next-to-leading order results related to the vacuum polarization function are accurately reproduced. The properties of the four-point correlator of hadronic electromagnetic currents as for instance the so-called light-by-light scattering amplitude relevant for the calculation of the muon anomalous magnetic moment are briefly discussed.
[ { "created": "Fri, 16 Nov 2001 13:19:27 GMT", "version": "v1" }, { "created": "Tue, 16 Jul 2002 11:18:26 GMT", "version": "v2" } ]
2011-09-13
[ [ "Groote", "S.", "" ], [ "Körner", "J. G.", "" ], [ "Pivovarov", "A. A.", "" ] ]
We propose a simple parameterization of the two-point correlator of hadronic electromagnetic currents for the evaluation of the hadronic contributions to the muon anomalous magnetic moment. The parameterization is explicitly done in the Euclidean domain. The model function contains a phenomenological parameter which provides an infrared cutoff to guarantee the smooth behavior of the correlator at the origin in accordance with experimental data in e+ e- annihilation. After fixing a numerical value for this parameter from the leading order hadronic contribution to the muon anomalous magnetic moment the next-to-leading order results related to the vacuum polarization function are accurately reproduced. The properties of the four-point correlator of hadronic electromagnetic currents as for instance the so-called light-by-light scattering amplitude relevant for the calculation of the muon anomalous magnetic moment are briefly discussed.
hep-ph/0406331
Altug Ozpineci
T.M. Aliev and A. Ozpineci
Radiative Decays of Decuplet to Octet Baryons in Light Cone QCD
43 pages, 30 figures, uses graphicx and amssymb, included a more general analysis, Conclusions changed
Nucl.Phys. B732 (2006) 291-320
10.1016/j.nuclphysb.2005.07.038
null
hep-ph
null
The radiative decays of decuplet to octet baryons are analyzed within the light cone QCD sum rules framework.The electromagnetic transition form factors for these decays are calculated up to twist four accuracy for photon wave functions as well as including first order strange quark mass corrections. A comparison of our results with predictions of lattice theory and existing experimental data is presented.
[ { "created": "Wed, 30 Jun 2004 08:41:25 GMT", "version": "v1" }, { "created": "Tue, 14 Jun 2005 08:49:58 GMT", "version": "v2" } ]
2015-06-25
[ [ "Aliev", "T. M.", "" ], [ "Ozpineci", "A.", "" ] ]
The radiative decays of decuplet to octet baryons are analyzed within the light cone QCD sum rules framework.The electromagnetic transition form factors for these decays are calculated up to twist four accuracy for photon wave functions as well as including first order strange quark mass corrections. A comparison of our results with predictions of lattice theory and existing experimental data is presented.
hep-ph/0612166
Enrico Lunghi
E. Lunghi and J. Matias
Huge right-handed current effects in B->K*(K pi)l+l- in supersymmetry
12 pages, 4 figures, version to appear on JHEP
JHEP 0704:058,2007
10.1088/1126-6708/2007/04/058
null
hep-ph
null
Transverse asymmetries in the decay B->K*(K pi)l+l- are an extremely sensitive probe of right-handed flavour-changing neutral currents. We show how to include the contribution from the chiral partner of the electromagnetic operator on the transverse asymmetries at NLO in QCD factorization. We then consider supersymmetric models with non-minimal flavour violation in the down-squark sector. We include all the relevant experimental constraints and present a numerical formula for B->Xs gamma that takes into account the most recent NNLO calculations. We show that the flavour-changing parameters of these models are poorly constrained by present data and allow for large effects on the transverse asymmetries that we consider.
[ { "created": "Wed, 13 Dec 2006 19:40:01 GMT", "version": "v1" }, { "created": "Wed, 11 Apr 2007 19:35:46 GMT", "version": "v2" } ]
2010-02-03
[ [ "Lunghi", "E.", "" ], [ "Matias", "J.", "" ] ]
Transverse asymmetries in the decay B->K*(K pi)l+l- are an extremely sensitive probe of right-handed flavour-changing neutral currents. We show how to include the contribution from the chiral partner of the electromagnetic operator on the transverse asymmetries at NLO in QCD factorization. We then consider supersymmetric models with non-minimal flavour violation in the down-squark sector. We include all the relevant experimental constraints and present a numerical formula for B->Xs gamma that takes into account the most recent NNLO calculations. We show that the flavour-changing parameters of these models are poorly constrained by present data and allow for large effects on the transverse asymmetries that we consider.
hep-ph/9708227
Masashi Hayakawa
M. Hayakawa (KEK) and T. Kinoshita (Cornell University)
Pseudoscalar pole terms in the hadronic light-by-light scattering contribution to muon $ g - 2 $
43 pages, Revtex, four figures, cited values of hadronic vacuum polarization contributions and the references are up-dated, to appear in Phys. Rev. D
Phys.Rev.D57:465-477,1998; Erratum-ibid.D66:019902,2002
10.1103/PhysRevD.57.465 10.1103/PhysRevD.66.019902
KEK-TH-530
hep-ph
null
The pseudoscalar pole contribution is the dominant source of the $ {\cal O}(\alpha^3) $ hadronic light-by-light scattering effect in muon $g - 2$. We have examined this contribution taking account of the off-shell structure of the pseudoscalar-photon-photon anomaly vertex deduced from available experimental data. Our work leads to an improved estimate, $ -79.2 (15.4) \times 10^{-11}$, for the total hadronic light-by-light scattering contribution to the muon $g - 2$.
[ { "created": "Mon, 4 Aug 1997 07:25:18 GMT", "version": "v1" }, { "created": "Mon, 25 Aug 1997 02:08:41 GMT", "version": "v2" }, { "created": "Thu, 23 Oct 1997 07:41:03 GMT", "version": "v3" } ]
2014-11-17
[ [ "Hayakawa", "M.", "", "KEK" ], [ "Kinoshita", "T.", "", "Cornell University" ] ]
The pseudoscalar pole contribution is the dominant source of the $ {\cal O}(\alpha^3) $ hadronic light-by-light scattering effect in muon $g - 2$. We have examined this contribution taking account of the off-shell structure of the pseudoscalar-photon-photon anomaly vertex deduced from available experimental data. Our work leads to an improved estimate, $ -79.2 (15.4) \times 10^{-11}$, for the total hadronic light-by-light scattering contribution to the muon $g - 2$.
1707.09367
Alexander Quintero Velez
Rafael Herrera and Alexander Quintero Velez
A $\mathrm{U}(2) \times \mathrm{U}(3)$ gauge theory extension of the standard model
26 pages, final version
J. Geom. Phys., 141:45-64, 2019
10.1016/j.geomphys.2019.03.004
null
hep-ph hep-th math.RT
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider an extension of the standard model based on the group $\mathrm{U}(2) \times \mathrm{U}(3)$, which is naturally compatible with the standard model interacting-particle representations and the spontaneous symmetry breaking of $\mathrm{U}(2) \times \mathrm{U}(3)$ to an electrostrong $\mathrm{U}(3)$. In its minimal version, the model only adds one extra $\mathrm{U}(1)$ gauge boson and it implies that the hypercharge is distributed between the factors of the hyperweak and hyperstrong forces. We show that the anomaly cancellation condition can be solved by adding exotic fermions associated with a $16$-dimensional representation of $\mathrm{U}(2) \times \mathrm{U}(3)$. A brief discussion of the mechanism of the spontaneous breakdown of $\mathrm{U}(2) \times \mathrm{U}(3)$ in the gauge boson sector is given.
[ { "created": "Sun, 30 Jul 2017 14:29:37 GMT", "version": "v1" }, { "created": "Mon, 30 Jul 2018 15:36:58 GMT", "version": "v2" }, { "created": "Thu, 5 Dec 2019 11:41:43 GMT", "version": "v3" } ]
2019-12-06
[ [ "Herrera", "Rafael", "" ], [ "Velez", "Alexander Quintero", "" ] ]
We consider an extension of the standard model based on the group $\mathrm{U}(2) \times \mathrm{U}(3)$, which is naturally compatible with the standard model interacting-particle representations and the spontaneous symmetry breaking of $\mathrm{U}(2) \times \mathrm{U}(3)$ to an electrostrong $\mathrm{U}(3)$. In its minimal version, the model only adds one extra $\mathrm{U}(1)$ gauge boson and it implies that the hypercharge is distributed between the factors of the hyperweak and hyperstrong forces. We show that the anomaly cancellation condition can be solved by adding exotic fermions associated with a $16$-dimensional representation of $\mathrm{U}(2) \times \mathrm{U}(3)$. A brief discussion of the mechanism of the spontaneous breakdown of $\mathrm{U}(2) \times \mathrm{U}(3)$ in the gauge boson sector is given.
1011.0400
Andrea Beraudo
W.M. Alberico, A. Beraudo, A. De Pace, A. Molinari, M. Monteno, M. Nardi and F. Prino
Heavy quark dynamics in the QGP: R_AA and v_2 from RHIC to LHC
Talk given at the conference "Hard Probes 2010"
Nucl.Phys.A855:404-407,2011
10.1016/j.nuclphysa.2011.02.091
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the stochastic dynamics of c and b quarks in the hot plasma produced in nucleus-nucleus collisions at RHIC and LHC, providing results for the nuclear modification factor R_AA and the elliptic flow coefficient v_2 of the single-electron spectra arising from their semi-leptonic decays. The initial QQbar pairs are generated using the POWHEG code, implementing pQCD at NLO. For the propagation in the plasma we develop a relativistic Langevin equation (solved in a medium described by hydrodynamics) whose transport coefficients are evaluated through a first-principle calculation. Finally, at T_c, the heavy quarks are made hadronize and decay into electrons: the resulting spectra are then compared with RHIC results. Predictions for LHC are also attempted.
[ { "created": "Mon, 1 Nov 2010 18:10:02 GMT", "version": "v1" } ]
2011-04-07
[ [ "Alberico", "W. M.", "" ], [ "Beraudo", "A.", "" ], [ "De Pace", "A.", "" ], [ "Molinari", "A.", "" ], [ "Monteno", "M.", "" ], [ "Nardi", "M.", "" ], [ "Prino", "F.", "" ] ]
We study the stochastic dynamics of c and b quarks in the hot plasma produced in nucleus-nucleus collisions at RHIC and LHC, providing results for the nuclear modification factor R_AA and the elliptic flow coefficient v_2 of the single-electron spectra arising from their semi-leptonic decays. The initial QQbar pairs are generated using the POWHEG code, implementing pQCD at NLO. For the propagation in the plasma we develop a relativistic Langevin equation (solved in a medium described by hydrodynamics) whose transport coefficients are evaluated through a first-principle calculation. Finally, at T_c, the heavy quarks are made hadronize and decay into electrons: the resulting spectra are then compared with RHIC results. Predictions for LHC are also attempted.
hep-ph/0610328
Taekoon Lee
Taekoon Lee
Borel resummation with low order perturbations in QCD
Talk given at QCD06, Montpellier, France
Nucl.Phys.Proc.Suppl.174:79-82,2007
10.1016/j.nuclphysbps.2007.08.094
null
hep-ph
null
The bilocal expansion of Borel transform provides an efficient way of Borel resummation with low order perturbations in QCD. Its applications to the heavy quark pole mass, static potential, and lattice calculation are reviewed.
[ { "created": "Wed, 25 Oct 2006 07:48:00 GMT", "version": "v1" } ]
2008-11-26
[ [ "Lee", "Taekoon", "" ] ]
The bilocal expansion of Borel transform provides an efficient way of Borel resummation with low order perturbations in QCD. Its applications to the heavy quark pole mass, static potential, and lattice calculation are reviewed.
hep-ph/0609309
Grunberg
Georges Grunberg
Infrared finite coupling in Sudakov resummation: the precise set-up
5 pages, improved version of hep-ph/0606033, new result on universality of power corrections; version 2: added material, comments and references (to appear in Physical Review D (Rapid Communication)); version 3: a few misprints corrected, one reference added (journal version)
Phys.Rev.D74:111901,2006
10.1103/PhysRevD.74.111901
null
hep-ph
null
I show that Sudakov resummation takes a transparent form if one deals with the second logarithmic derivative of the short distance coefficient functions for deep inelastic scattering and the Drell-Yan process. A uniquely defined Sudakov exponent emerges, and the constant terms not included in the exponent are conjectured to be given by the second logarithmic derivative of the massless quark form factor. The precise framework for the implementation of the dispersive approach to power corrections is set-up, yielding results in agreement with infrared renormalon expectations, but which are not tied to the single (dressed) gluon exchange approximation. Indications for a Banks-Zaks type of perturbative fixed point in the Sudakov effective coupling at low N_f are pointed out. Existence of a fixed point in the Sudakov coupling is argued to imply its universality.
[ { "created": "Fri, 29 Sep 2006 16:17:12 GMT", "version": "v1" }, { "created": "Wed, 15 Nov 2006 16:47:46 GMT", "version": "v2" }, { "created": "Thu, 14 Dec 2006 14:20:57 GMT", "version": "v3" } ]
2008-11-26
[ [ "Grunberg", "Georges", "" ] ]
I show that Sudakov resummation takes a transparent form if one deals with the second logarithmic derivative of the short distance coefficient functions for deep inelastic scattering and the Drell-Yan process. A uniquely defined Sudakov exponent emerges, and the constant terms not included in the exponent are conjectured to be given by the second logarithmic derivative of the massless quark form factor. The precise framework for the implementation of the dispersive approach to power corrections is set-up, yielding results in agreement with infrared renormalon expectations, but which are not tied to the single (dressed) gluon exchange approximation. Indications for a Banks-Zaks type of perturbative fixed point in the Sudakov effective coupling at low N_f are pointed out. Existence of a fixed point in the Sudakov coupling is argued to imply its universality.
hep-ph/9401296
null
H.J. Lu
Rapidity Gap in Jet Events at Lep200
24 pages, (18 Figures, not included, available by anonymous ftp) RevTeX, U. of MD PP #94-073
Nucl.Phys. B427 (1994) 455-474
null
null
hep-ph
null
We analyze various perturbative mechanisms for the production of jet events containing rapidity gaps in $e^+e^-$ annihilation at LEP200 energies. We found that the processes $e^+e^- \to \gamma^* \gamma^*, \gamma^* Z, Z Z, WW \to 4~ jets$ generate gap events at an observable rate. We point out that LEP200 offers a unique opportunity for the study of gap events due to a smaller background of ``fake-gaps".
[ { "created": "Thu, 20 Jan 1994 19:44:24 GMT", "version": "v1" } ]
2009-09-25
[ [ "Lu", "H. J.", "" ] ]
We analyze various perturbative mechanisms for the production of jet events containing rapidity gaps in $e^+e^-$ annihilation at LEP200 energies. We found that the processes $e^+e^- \to \gamma^* \gamma^*, \gamma^* Z, Z Z, WW \to 4~ jets$ generate gap events at an observable rate. We point out that LEP200 offers a unique opportunity for the study of gap events due to a smaller background of ``fake-gaps".
hep-ph/0503066
Sourav Sarkar
Sourav Sarkar, E. Oset and M. J. Vicente Vacas
Chiral coupled channel dynamics of the Lambda(1520) and the K-P -> pi0 pi0 Lambda reaction
null
Phys.Rev.C72:015206,2005
10.1103/PhysRevC.72.015206
FTUV-05-0307, IFIC-05-0307
hep-ph
null
We study the $\Lambda(1520)D_{03}$ in a chiral coupled channel approach. This resonance appears as dynamically generated from the interaction of the decuplet of baryons and the octet of mesons in s-wave, and its treatment is improved here with the phenomenological inclusion of the $\bar{K} N$ and $\pi \Sigma$ channels in d-wave. Since the most important building block in the $\Lambda(1520)$ is the $\pi \Sgs(1385)P_{13}$ channel, we study the $K^- p \to \pi \Sgs(1385) (\pi^0 \Lambda)$ reaction in the region of the $\Lambda(1520)$ and above, and compare the results with recent experimental data. With the coupling of the $\Lambda(1520)$ to the $\pi \Sgs$ channel predicted by the theory we find a cross section in good agreement with the data and there is as well agreement for the invariant mass distributions which show a neat peak for the $\Sgs(1385)$ in the $(\pi^0 \Lambda)$ spectrum. Predictions are made of a strong $\Lambda(1520)$ resonant peak of the cross section, as a function of the $K^-$ momentum, in the region below the measured data which, if confirmed experimentally, would give a stronger support to the idea of the $\Lambda(1520)$ as a dynamically generated resonance.
[ { "created": "Mon, 7 Mar 2005 18:40:46 GMT", "version": "v1" }, { "created": "Wed, 9 Mar 2005 14:46:29 GMT", "version": "v2" }, { "created": "Mon, 23 May 2005 16:57:06 GMT", "version": "v3" } ]
2011-02-09
[ [ "Sarkar", "Sourav", "" ], [ "Oset", "E.", "" ], [ "Vacas", "M. J. Vicente", "" ] ]
We study the $\Lambda(1520)D_{03}$ in a chiral coupled channel approach. This resonance appears as dynamically generated from the interaction of the decuplet of baryons and the octet of mesons in s-wave, and its treatment is improved here with the phenomenological inclusion of the $\bar{K} N$ and $\pi \Sigma$ channels in d-wave. Since the most important building block in the $\Lambda(1520)$ is the $\pi \Sgs(1385)P_{13}$ channel, we study the $K^- p \to \pi \Sgs(1385) (\pi^0 \Lambda)$ reaction in the region of the $\Lambda(1520)$ and above, and compare the results with recent experimental data. With the coupling of the $\Lambda(1520)$ to the $\pi \Sgs$ channel predicted by the theory we find a cross section in good agreement with the data and there is as well agreement for the invariant mass distributions which show a neat peak for the $\Sgs(1385)$ in the $(\pi^0 \Lambda)$ spectrum. Predictions are made of a strong $\Lambda(1520)$ resonant peak of the cross section, as a function of the $K^-$ momentum, in the region below the measured data which, if confirmed experimentally, would give a stronger support to the idea of the $\Lambda(1520)$ as a dynamically generated resonance.
hep-ph/9303203
null
J.P. Ma and B.H.J. McKellar
CP Test in the W Pair Production via Photon Fusion at NLC
11 pages, Tex, UM-P-93/16, OZ-93/6 One figure not included
Phys.Lett.B319:533-538,1993
10.1016/0370-2693(93)91762-C
null
hep-ph
null
We study the possibility to test CP invariance in the $W^+W^-$ production via photon fusion at NLC. The predictions of the CP violation effects are made within two Higgs doublet extensions of the minimal standard model, where CP violation is introduced by a neutral Higgs exchange in s channel in our case. The width effect in the Higgs propagator on the CP violation effects is studied in detail. The CP violation effects can be measured in some parameter region of the extensions.
[ { "created": "Tue, 2 Mar 1993 02:14:42 GMT", "version": "v1" } ]
2010-11-01
[ [ "Ma", "J. P.", "" ], [ "McKellar", "B. H. J.", "" ] ]
We study the possibility to test CP invariance in the $W^+W^-$ production via photon fusion at NLC. The predictions of the CP violation effects are made within two Higgs doublet extensions of the minimal standard model, where CP violation is introduced by a neutral Higgs exchange in s channel in our case. The width effect in the Higgs propagator on the CP violation effects is studied in detail. The CP violation effects can be measured in some parameter region of the extensions.
hep-ph/0701153
Juan Jose Sanz-Cillero
J.J. Sanz-Cillero
1/NC Expansion of QCD Amplitudes
6 pages, 1 figure, appolb.cls style. Talk given at Effective theories of colours and flavours: from Eurodaphne to Euridice, 24-27 August 2006, Kazimierz (Poland)
null
null
null
hep-ph
null
This talk comments the main features of a hadronic description of QCD in the limit of large number of colours. We derive a quantum field theory for mesons based on chiral symmetry and a perturbative expansion in 1/NC. Some large-NC and next-to-leading order results are reviewed.
[ { "created": "Fri, 19 Jan 2007 09:53:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Sanz-Cillero", "J. J.", "" ] ]
This talk comments the main features of a hadronic description of QCD in the limit of large number of colours. We derive a quantum field theory for mesons based on chiral symmetry and a perturbative expansion in 1/NC. Some large-NC and next-to-leading order results are reviewed.
hep-ph/9707218
null
B. Blok
How quark hadron duality in QCD may work
Talk at QCD-97 Euroconference, Montpellier,France, July 1997. Technion preprint, 18 pp
Nucl.Phys.Proc.Suppl. 64 (1998) 481-486
10.1016/S0920-5632(97)01111-0
null
hep-ph
null
We pursue the issue of the local quark-hadron duality at high energies in two- and four-dimensional QCD. A mechanism of the dynamical realization of the quark-hadron duality in two-dimensional QCD in the limit of large number of colors, $N_c \to \infty$, (the ' t Hooft model) is investigated. We argue that a similar mechanism of dynamical smearing may be relevant in four-dimensional QCD. Although particular details of our results are model-dependent (especially in the latter case), the general features of the duality implementation conjectured previously get further support.
[ { "created": "Wed, 2 Jul 1997 08:04:43 GMT", "version": "v1" } ]
2009-10-30
[ [ "Blok", "B.", "" ] ]
We pursue the issue of the local quark-hadron duality at high energies in two- and four-dimensional QCD. A mechanism of the dynamical realization of the quark-hadron duality in two-dimensional QCD in the limit of large number of colors, $N_c \to \infty$, (the ' t Hooft model) is investigated. We argue that a similar mechanism of dynamical smearing may be relevant in four-dimensional QCD. Although particular details of our results are model-dependent (especially in the latter case), the general features of the duality implementation conjectured previously get further support.
hep-ph/0102241
William Kilgore
Robert V. Harlander, William B. Kilgore
Soft and virtual corrections to pp -> H + X at NNLO
16 pages, 7 figures, 16 ps files embedded with epsf. Minor modifications: references and note added, results unchanged
Phys.Rev. D64 (2001) 013015
10.1103/PhysRevD.64.013015
BNL-HET-01/6
hep-ph
null
The contributions of virtual corrections and soft gluon emission to the inclusive Higgs production cross section pp -> H + X are computed at next-to-next-to-leading order in the heavy top quark limit. We show that this part of the total cross section is well behaved in the sense of perturbative convergence, with the NNLO corrections amounting to an enhancement of the NLO cross section by \sim 5% for LHC and 10-20% for the Tevatron. We compare our results with an existing estimate of the full NNLO effects and argue that an analytic evaluation of the hard scattering contributions is needed.
[ { "created": "Mon, 19 Feb 2001 21:33:39 GMT", "version": "v1" }, { "created": "Thu, 7 Jun 2001 18:50:05 GMT", "version": "v2" } ]
2009-11-07
[ [ "Harlander", "Robert V.", "" ], [ "Kilgore", "William B.", "" ] ]
The contributions of virtual corrections and soft gluon emission to the inclusive Higgs production cross section pp -> H + X are computed at next-to-next-to-leading order in the heavy top quark limit. We show that this part of the total cross section is well behaved in the sense of perturbative convergence, with the NNLO corrections amounting to an enhancement of the NLO cross section by \sim 5% for LHC and 10-20% for the Tevatron. We compare our results with an existing estimate of the full NNLO effects and argue that an analytic evaluation of the hard scattering contributions is needed.
hep-ph/9307250
null
S. M. Troshin and N. E. Tyurin
Beyond the black disk limit
Latex, 5 pages, no figures, IHEP 93-53
Phys.Lett. B316 (1993) 175-177
10.1016/0370-2693(93)90675-8
null
hep-ph
null
We consider consequences of violation of the black disk limit possibly revealed by the new CDF measurements of the total, elastic and diffractive cross--sections.
[ { "created": "Mon, 12 Jul 1993 12:51:58 GMT", "version": "v1" } ]
2009-10-22
[ [ "Troshin", "S. M.", "" ], [ "Tyurin", "N. E.", "" ] ]
We consider consequences of violation of the black disk limit possibly revealed by the new CDF measurements of the total, elastic and diffractive cross--sections.
hep-ph/9807224
Carlo Ewerz
Vladimir Gribov
QCD at large and short distances (annotated version)
38 pages, Latex, 108 figures included using epsfig.sty. Annotated version of hep-ph/9708424, misprints eliminated, equations checked and some corrected, comments added (see abstract for further details)
Eur.Phys.J.C10:71-90,1999
10.1007/s100529900051
Bonn TK 97-08
hep-ph
null
The formulation of QCD which contains no divergences and no renormalization procedure is presented. It contains both perturbative and non-perturbative phenomena. It is shown that, due to its asymptotically free nature, the theory is not defined uniquely. The chiral symmetry breaking and the nature of the octet of pseudo-scalar particles as quasi-Goldstone states are analysed in the theory with massless and massive quarks. The U(1) problem is discussed. ======================================================================= Note: The original version of the paper completed by the author in April 1997 was submitted to the hep-ph archive (hep-ph/9708424) a few days after Prof. V.N. Gribov passed away on August 13, 1997. This is the first of the two papers concluding his 20 year long study of the problem of quark confinement in QCD. In an attempt to understand the paper by a group of his colleagues, started in November 1997 in Orsay, this annotated version appeared. A number of misprints were eliminated, most of the equations were checked, and some corrected. Comments have been added in order to make the text easier to read. These comments are displayed in square brackets. Many theorists participated in the process; the comments were assembled and the final version prepared by Yu. Dokshitzer, C. Ewerz, A. Kaidalov, A. Mueller, J. Nyiri and A. Vainshtein. The second paper ``The theory of quark confinement'' will soon be published.
[ { "created": "Thu, 2 Jul 1998 16:02:29 GMT", "version": "v1" } ]
2011-09-13
[ [ "Gribov", "Vladimir", "" ] ]
The formulation of QCD which contains no divergences and no renormalization procedure is presented. It contains both perturbative and non-perturbative phenomena. It is shown that, due to its asymptotically free nature, the theory is not defined uniquely. The chiral symmetry breaking and the nature of the octet of pseudo-scalar particles as quasi-Goldstone states are analysed in the theory with massless and massive quarks. The U(1) problem is discussed. ======================================================================= Note: The original version of the paper completed by the author in April 1997 was submitted to the hep-ph archive (hep-ph/9708424) a few days after Prof. V.N. Gribov passed away on August 13, 1997. This is the first of the two papers concluding his 20 year long study of the problem of quark confinement in QCD. In an attempt to understand the paper by a group of his colleagues, started in November 1997 in Orsay, this annotated version appeared. A number of misprints were eliminated, most of the equations were checked, and some corrected. Comments have been added in order to make the text easier to read. These comments are displayed in square brackets. Many theorists participated in the process; the comments were assembled and the final version prepared by Yu. Dokshitzer, C. Ewerz, A. Kaidalov, A. Mueller, J. Nyiri and A. Vainshtein. The second paper ``The theory of quark confinement'' will soon be published.
hep-ph/0112128
Jisheng Chen
Ji-sheng Chen, Jia-rong Li and Peng-fei Zhuang
Non-Abelian Medium Effects in Quark-Gluon Plasma
12 pages(Revtex), no figures
Int.J.Mod.Phys. A17 (2002) 1435-1448
10.1142/S0217751X02009849
null
hep-ph
null
Based on the kinetic theory, the non-Abelian medium property of hot Quark-Gluon Plasma is investigated. The nonlinearity of the plasma comes from two aspects: The nonlinear wave-wave interaction and self-interaction of color field. The non-Abelian color permittivity is obtained by expanding the kinetic equations to third order. As an application, the nonlinear Landau damping rate and the nonlinear eigenfrequency shift are calculated in the longwave length limit.
[ { "created": "Mon, 10 Dec 2001 02:44:11 GMT", "version": "v1" } ]
2009-11-07
[ [ "Chen", "Ji-sheng", "" ], [ "Li", "Jia-rong", "" ], [ "Zhuang", "Peng-fei", "" ] ]
Based on the kinetic theory, the non-Abelian medium property of hot Quark-Gluon Plasma is investigated. The nonlinearity of the plasma comes from two aspects: The nonlinear wave-wave interaction and self-interaction of color field. The non-Abelian color permittivity is obtained by expanding the kinetic equations to third order. As an application, the nonlinear Landau damping rate and the nonlinear eigenfrequency shift are calculated in the longwave length limit.
1108.5259
Timothy Burns
T. J. Burns
P-wave spin-spin splitting and meson loops
4 pages, typo corrected. Contribution to the Proceedings of the XIV International Conference on Hadron Spectroscopy (Hadron 2011), 13-17 June 2011, Munich, Germany
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In quark potential models the hyperfine splitting of P-wave mesons is zero in the nonrelativistic limit, a prediction strikingly confirmed by experiment in both charmonia and bottomonia. The result, however, ignores the coupling of bare quarkonia to meson-meson pairs. This coupling causes mass shifts among the states and so could potentially spoil the quark model prediction. This turns out not to be the case: in a variety of models the hyperfine splitting remains small despite large mass shifts. This is shown to be a generic feature of models in which the coupling involves the creation of a light quark pair with spin-one and the quark spin wavefunctions are conserved. This talk reports on the results of Phys. Rev. D84, 034021 (2011).
[ { "created": "Fri, 26 Aug 2011 08:44:58 GMT", "version": "v1" }, { "created": "Mon, 29 Aug 2011 16:27:40 GMT", "version": "v2" } ]
2011-08-30
[ [ "Burns", "T. J.", "" ] ]
In quark potential models the hyperfine splitting of P-wave mesons is zero in the nonrelativistic limit, a prediction strikingly confirmed by experiment in both charmonia and bottomonia. The result, however, ignores the coupling of bare quarkonia to meson-meson pairs. This coupling causes mass shifts among the states and so could potentially spoil the quark model prediction. This turns out not to be the case: in a variety of models the hyperfine splitting remains small despite large mass shifts. This is shown to be a generic feature of models in which the coupling involves the creation of a light quark pair with spin-one and the quark spin wavefunctions are conserved. This talk reports on the results of Phys. Rev. D84, 034021 (2011).
2303.02900
Partha Pratim Bhaduri
Deekshit Kumar, Nachiketa Sarkar, Partha Pratim Bhaduri, Amaresh Jaiswal
Examination of thermalization of quarkonia at energies available at the CERN Large Hadron Collider
10 pages, 5 figures. Some typos corrected
Published in Phys. Rev. C 107, 064906 (2023)
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We analyze the relative yields of different bottomonia and charmonia states produced in Pb-Pb, p-Pb and high multiplicity p-p collisions at LHC, within a semi-classical grand canonical ensemble approach. The underlying assumption is the early thermalization and subsequent freezeout of these heavy hadrons resulting in their chemical freezeout at a temperature of approximately $230$~MeV, significantly higher than that of light and strange hadrons. The systematic dependence of the freezeout temperature on the collision centrality is also investigated in details.
[ { "created": "Mon, 6 Mar 2023 05:30:45 GMT", "version": "v1" }, { "created": "Fri, 24 Mar 2023 06:34:23 GMT", "version": "v2" }, { "created": "Tue, 27 Jun 2023 09:14:17 GMT", "version": "v3" } ]
2023-06-28
[ [ "Kumar", "Deekshit", "" ], [ "Sarkar", "Nachiketa", "" ], [ "Bhaduri", "Partha Pratim", "" ], [ "Jaiswal", "Amaresh", "" ] ]
We analyze the relative yields of different bottomonia and charmonia states produced in Pb-Pb, p-Pb and high multiplicity p-p collisions at LHC, within a semi-classical grand canonical ensemble approach. The underlying assumption is the early thermalization and subsequent freezeout of these heavy hadrons resulting in their chemical freezeout at a temperature of approximately $230$~MeV, significantly higher than that of light and strange hadrons. The systematic dependence of the freezeout temperature on the collision centrality is also investigated in details.
hep-ph/9209218
Errol Gotsman
E. Gotsman, E.M. Levin and U. Maor
A Quantitative Investigation of the Pomeron
pages 15, Latex
Z.Phys. C57 (1993) 677-684
10.1007/BF01561488
DESY 92-040
hep-ph
null
A comparative investigation of various Pomeron models is carried out through the study of their predicted values of $ \sigma_{tot}$, B, and $\frac{\sigma_{el}}{\sigma_{tot}}$ in high energy pp and p$\bar{p}$ scattering. Our results strongly support a picture of the Pomeron in which we have both moderate blackening and expansion of the p($\bar{p}$) - p amplitude in impact parameter space as a function of energy in the ISR-SSC domain. In particular, we obtain an excellent reproduction of the data with a hybrid eikonal model which combines the hard Lipatov-like QCD Pomeron with the old fashioned soft Pomeron and Regge terms. Our analysis shows that the additive quark model, at least in the naive form, is not compatible with the data.
[ { "created": "Mon, 7 Sep 1992 06:59:53 GMT", "version": "v1" } ]
2009-10-22
[ [ "Gotsman", "E.", "" ], [ "Levin", "E. M.", "" ], [ "Maor", "U.", "" ] ]
A comparative investigation of various Pomeron models is carried out through the study of their predicted values of $ \sigma_{tot}$, B, and $\frac{\sigma_{el}}{\sigma_{tot}}$ in high energy pp and p$\bar{p}$ scattering. Our results strongly support a picture of the Pomeron in which we have both moderate blackening and expansion of the p($\bar{p}$) - p amplitude in impact parameter space as a function of energy in the ISR-SSC domain. In particular, we obtain an excellent reproduction of the data with a hybrid eikonal model which combines the hard Lipatov-like QCD Pomeron with the old fashioned soft Pomeron and Regge terms. Our analysis shows that the additive quark model, at least in the naive form, is not compatible with the data.
0808.3619
Jun-Feng Sun
Jun-Feng Sun, Dong-Sheng Du, Yue-Ling Yang
Study of Bc --> J/psi pi, etac pi decays with perturbative QCD approach
21 pages, revtex4
Eur.Phys.J.C60:107-117,2009
10.1140/epjc/s10052-009-0872-y
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Bc --> J/psi pi, etac pi decays are studied with the perturbative QCD approach. It is found that form factors and branching ratios are sensitive to the parameters w, v, f_J/psi and f_etac, where w and v are the parameters of the charmonium wave functions for Coulomb potential and harmonic oscillator potential, respectively, f_J/psi and f_etac are the decay constants of the J/psi and etac mesons, respectively. The large branching ratios and the clear signals of the final states make the Bc --> J/psi pi, etac pi decays to be the prospective channels for measurements at the hadron colliders
[ { "created": "Wed, 27 Aug 2008 02:31:07 GMT", "version": "v1" }, { "created": "Thu, 28 Aug 2008 09:28:39 GMT", "version": "v2" }, { "created": "Sat, 28 Feb 2009 07:47:40 GMT", "version": "v3" } ]
2009-03-12
[ [ "Sun", "Jun-Feng", "" ], [ "Du", "Dong-Sheng", "" ], [ "Yang", "Yue-Ling", "" ] ]
The Bc --> J/psi pi, etac pi decays are studied with the perturbative QCD approach. It is found that form factors and branching ratios are sensitive to the parameters w, v, f_J/psi and f_etac, where w and v are the parameters of the charmonium wave functions for Coulomb potential and harmonic oscillator potential, respectively, f_J/psi and f_etac are the decay constants of the J/psi and etac mesons, respectively. The large branching ratios and the clear signals of the final states make the Bc --> J/psi pi, etac pi decays to be the prospective channels for measurements at the hadron colliders
hep-ph/9806263
Alex Pomarol
A. Pomarol and M. Quiros
The Standard Model from extra dimensions
8 pages, LaTex
Phys.Lett.B438:255-260,1998
10.1016/S0370-2693(98)00979-4
IEM-FT-175/98 and UAB-FT-449
hep-ph hep-th
null
We present a simple N=1 five-dimensional model where the fifth dimension is compactified on the orbifold $S^1/Z_2$. Non-chiral matter lives in the bulk of the fifth dimension (five dimensions) while chiral matter lives on the fixed points of the orbifold (four-dimensional boundaries). The massless sector constitutes the Minimal Supersymmetric Standard Model while the massive modes rearrange in N=2 supermultiplets. After supersymmetry breaking by the Scherk-Schwarz mechanism the zero modes can be reduced to the non-supersymmetric Standard Model.
[ { "created": "Thu, 4 Jun 1998 18:11:37 GMT", "version": "v1" } ]
2009-07-09
[ [ "Pomarol", "A.", "" ], [ "Quiros", "M.", "" ] ]
We present a simple N=1 five-dimensional model where the fifth dimension is compactified on the orbifold $S^1/Z_2$. Non-chiral matter lives in the bulk of the fifth dimension (five dimensions) while chiral matter lives on the fixed points of the orbifold (four-dimensional boundaries). The massless sector constitutes the Minimal Supersymmetric Standard Model while the massive modes rearrange in N=2 supermultiplets. After supersymmetry breaking by the Scherk-Schwarz mechanism the zero modes can be reduced to the non-supersymmetric Standard Model.
hep-ph/0202161
Ariel Zhitnitsky
Ariel R. Zhitnitsky (University of British Columbia, Vancouver, Canada)
"Nonbaryonic" Dark Matter as Baryonic Color Superconductor
Title changed. Two figures and Appendix added. Part on baryogenesis is removed and posted as a separate paper hep-ph/0309086
JCAP 0310:010,2003
10.1088/1475-7516/2003/10/010
null
hep-ph astro-ph nucl-th
null
We discuss a novel cold dark matter candidate which is formed from the ordinary quarks during the QCD phase transition when the axion domain wall undergoes an unchecked collapse due to the tension in the wall. If a large number of quarks is trapped inside the bulk of a closed axion domain wall, the collapse stops due to the internal Fermi pressure. In this case the system in the bulk, may reach the critical density when it undergoes a phase transition to a color superconducting phase with the ground state being the quark condensate, similar to the Cooper pairs in BCS theory. If this happens, the new state of matter representing the diquark condensate with a large baryon number $B \sim 10^{32}$ becomes a stable soliton-like configuration. Consequently, it may serve as a novel cold dark matter candidate.
[ { "created": "Fri, 15 Feb 2002 23:21:47 GMT", "version": "v1" }, { "created": "Fri, 21 Jun 2002 18:47:55 GMT", "version": "v2" }, { "created": "Wed, 13 Nov 2002 21:53:17 GMT", "version": "v3" }, { "created": "Wed, 10 Sep 2003 18:38:34 GMT", "version": "v4" } ]
2010-12-17
[ [ "Zhitnitsky", "Ariel R.", "", "University of British Columbia, Vancouver,\n Canada" ] ]
We discuss a novel cold dark matter candidate which is formed from the ordinary quarks during the QCD phase transition when the axion domain wall undergoes an unchecked collapse due to the tension in the wall. If a large number of quarks is trapped inside the bulk of a closed axion domain wall, the collapse stops due to the internal Fermi pressure. In this case the system in the bulk, may reach the critical density when it undergoes a phase transition to a color superconducting phase with the ground state being the quark condensate, similar to the Cooper pairs in BCS theory. If this happens, the new state of matter representing the diquark condensate with a large baryon number $B \sim 10^{32}$ becomes a stable soliton-like configuration. Consequently, it may serve as a novel cold dark matter candidate.
hep-ph/9404311
Kim Jihn E.
Kiwoon Choi, Jihn E. Kim and Hans Peter Nilles
Cosmological Constant and Soft Terms in Supergravity
Latex file, 11 pages plus 1 figure (the figure not included), SNUTP 94--19
Phys.Rev.Lett. 73 (1994) 1758-1761
10.1103/PhysRevLett.73.1758
null
hep-ph hep-th
null
Some of the soft SUSY breaking parameters in hidden sector supergravity model depend on the expectation value of the hidden sector scalar potential, $<V_h>$, whose tree level value is equal to the tree level cosmological constant. The current practice of calculating soft parameters assumes that $<V_h>=0$. Quantum correction to the cosmological constant can differ from the correction to $<V_h>$ by an amount of order $m^2_{3/2}M_{Pl}^2/8\pi$. This implies that, for the vanishing cosmological constant, the $<V_h>$--dependent parts of soft terms can be sizable, and hence the supergravity phenomenology should be accordingly modified.
[ { "created": "Thu, 21 Apr 1994 02:18:56 GMT", "version": "v1" } ]
2009-10-28
[ [ "Choi", "Kiwoon", "" ], [ "Kim", "Jihn E.", "" ], [ "Nilles", "Hans Peter", "" ] ]
Some of the soft SUSY breaking parameters in hidden sector supergravity model depend on the expectation value of the hidden sector scalar potential, $<V_h>$, whose tree level value is equal to the tree level cosmological constant. The current practice of calculating soft parameters assumes that $<V_h>=0$. Quantum correction to the cosmological constant can differ from the correction to $<V_h>$ by an amount of order $m^2_{3/2}M_{Pl}^2/8\pi$. This implies that, for the vanishing cosmological constant, the $<V_h>$--dependent parts of soft terms can be sizable, and hence the supergravity phenomenology should be accordingly modified.
2012.00863
Dubravko Klabu\v{c}ar
Ivan Dadi\'c, Dubravko Klabu\v{c}ar and Domagoj Kui\'c
Direct Photons from Hot Quark Matter in Renormalized Finite-Time-Path QED
17 pages, 1 figure
Particles 3 (2020) 676-692
10.3390/particles3040044
ZTF-EP-20-09
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
Within the finite-time-path out-of-equilibrium quantum field theory (QFT), we calculate direct photon emission from early stages of heavy ion collisions, from a narrow window, in which uncertainty relations are still important and they provide a new mechanism for production of photons. The basic difference with respect to earlier calculations, leading to diverging results, is that we use renormalized QED of quarks and photons. Our result is a finite contribution that is consistent with uncertainty relations.
[ { "created": "Tue, 1 Dec 2020 22:04:54 GMT", "version": "v1" } ]
2020-12-03
[ [ "Dadić", "Ivan", "" ], [ "Klabučar", "Dubravko", "" ], [ "Kuić", "Domagoj", "" ] ]
Within the finite-time-path out-of-equilibrium quantum field theory (QFT), we calculate direct photon emission from early stages of heavy ion collisions, from a narrow window, in which uncertainty relations are still important and they provide a new mechanism for production of photons. The basic difference with respect to earlier calculations, leading to diverging results, is that we use renormalized QED of quarks and photons. Our result is a finite contribution that is consistent with uncertainty relations.
1506.05204
Ila Garg
Ila Garg
New minimal supersymmetric SO(10) GUT phenomenology and its cosmological implications
Ph.D Thesis (Defended on 1 April, 2015), 187 Pages, 16 Figures, References added
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Supersymmetric GUTs based on SO(10) gauge group are leading contenders to describe particle physics beyond the Standard Model. Among these the "New minimal supersymmetric SO(10) grand unified theory" (NMSGUT) based on Higgs system 10+120+210+126+$\overline{126}$ has been developing since 1982. It now successfully fits the whole standard Model gauge coupling, symmetry breaking and fermion mass-mixing data as well as the neutrino mass and mixing data in terms of NMSGUT parameters and just 6 soft supersymmetry breaking parameters defined at the GUT scale. In this thesis we study the phenomenology of NMSGUT, its implications for inflationary and Cold Dark matter cosmology and develop Renormalization group(RG) equations for the flow of NMSGUT couplings in the extreme ultraviolet. In the first part we show that superheavy threshold effects can drastically lower the SO(10) yukawa couplings required for realistic unification and this cures the long standing problem of fast proton decay in Susy GUT. Then we propose a novel Supersymmetric Seesaw inflection(SSI) scenario based upon a SU(2)_L x U(1)_R x U(1)_{B-L} invariant model, where the inflation mass is controlled by the large conjugate sneutrino mass. We show that it is much less fine-tuned and more stable than Dirac sneutrino based MSSM inflation. NMSGUT can embed SSI, and even provide a large tensor scalar ratio, but obstacles in achieving enough inflation remain. The NMSGUT Bino LSP is a good dark matter candidate when it can co-annihilate with a nearly degenerate sfermion as in fits with a light smuon. We also calculate two loop NMSGUT gauge-Yukawa Renormalization Group(RG) beta functions and show that GUT scale negative Higgs mass squared parameters required by NMSGUT fits can arise by RG flows from positive values at the Planck scale.
[ { "created": "Wed, 17 Jun 2015 04:55:00 GMT", "version": "v1" }, { "created": "Fri, 4 Sep 2015 11:51:23 GMT", "version": "v2" } ]
2015-09-07
[ [ "Garg", "Ila", "" ] ]
Supersymmetric GUTs based on SO(10) gauge group are leading contenders to describe particle physics beyond the Standard Model. Among these the "New minimal supersymmetric SO(10) grand unified theory" (NMSGUT) based on Higgs system 10+120+210+126+$\overline{126}$ has been developing since 1982. It now successfully fits the whole standard Model gauge coupling, symmetry breaking and fermion mass-mixing data as well as the neutrino mass and mixing data in terms of NMSGUT parameters and just 6 soft supersymmetry breaking parameters defined at the GUT scale. In this thesis we study the phenomenology of NMSGUT, its implications for inflationary and Cold Dark matter cosmology and develop Renormalization group(RG) equations for the flow of NMSGUT couplings in the extreme ultraviolet. In the first part we show that superheavy threshold effects can drastically lower the SO(10) yukawa couplings required for realistic unification and this cures the long standing problem of fast proton decay in Susy GUT. Then we propose a novel Supersymmetric Seesaw inflection(SSI) scenario based upon a SU(2)_L x U(1)_R x U(1)_{B-L} invariant model, where the inflation mass is controlled by the large conjugate sneutrino mass. We show that it is much less fine-tuned and more stable than Dirac sneutrino based MSSM inflation. NMSGUT can embed SSI, and even provide a large tensor scalar ratio, but obstacles in achieving enough inflation remain. The NMSGUT Bino LSP is a good dark matter candidate when it can co-annihilate with a nearly degenerate sfermion as in fits with a light smuon. We also calculate two loop NMSGUT gauge-Yukawa Renormalization Group(RG) beta functions and show that GUT scale negative Higgs mass squared parameters required by NMSGUT fits can arise by RG flows from positive values at the Planck scale.
hep-ph/9810538
null
Y. S. Kim
Lorentz Covariance and Internal Space-time Symmetry of Relativistic Extended Particles
RevTex 25 pages, 3 psfigs, Contribution to the Nova Collection of papers on the Lorentz group (edited by Valeri Dvoeglazov)
null
null
null
hep-ph hep-th nucl-th quant-ph
null
The difference between Lorentz invariance and Lorentz covariance is discussed in detail. A covariant formalism is developed for the internal space-time symmetry of extended particles, especially in connection with the insightful observations Feynman made during the period 1969-72. A Lorentz-group formalism is presented for the harmonic oscillator model of Feynman, Kislinger and Ravndal, which was originally based on hadronic mass spectra. This covariant version allows us to construct a parton distribution function by Lorentz-boosting the oscillator wave function of a hadron at rest. The role of the time-separation variable is discussed in detail. It is shown that, due to our inability to make measurements on this variable, it belongs to Feynman's rest of the universe. Our failure to observe the rest of the universe leads to an increase in entropy.
[ { "created": "Fri, 30 Oct 1998 20:59:23 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kim", "Y. S.", "" ] ]
The difference between Lorentz invariance and Lorentz covariance is discussed in detail. A covariant formalism is developed for the internal space-time symmetry of extended particles, especially in connection with the insightful observations Feynman made during the period 1969-72. A Lorentz-group formalism is presented for the harmonic oscillator model of Feynman, Kislinger and Ravndal, which was originally based on hadronic mass spectra. This covariant version allows us to construct a parton distribution function by Lorentz-boosting the oscillator wave function of a hadron at rest. The role of the time-separation variable is discussed in detail. It is shown that, due to our inability to make measurements on this variable, it belongs to Feynman's rest of the universe. Our failure to observe the rest of the universe leads to an increase in entropy.
hep-ph/0506039
Ivan Vitev
Ivan Vitev
Coherent power corrections to structure functions
Proceedings of the XIII international workshop in Deep Inelastic Scattering DIS 2005. 5 pages 6 figures
null
10.1063/1.2122035
null
hep-ph
null
We calculate and resum a perturbative expansion of nuclear enhanced power corrections to the structure functions measured in deeply inelastic scattering of leptons on a nuclear target. Our results for the Bjorken x-, Q**2- and A-dependence of nuclear shadowing in F2(x,Q**2;A) and the nuclear modifications to FL(x,Q**2;A), obtained in terms of the QCD factorization approach, are consistent with the existing data. We predict the dynamical shadowing from final state interactions in neutrino-nucleus reactions for sea and valence quarks in the structure functions F2(x,Q**2;A) and xF3(x,Q**2;A), respectively. In p+A collisions we calculate the centrality and rapidity dependent nuclear suppression of single and double inclusive hadron production at moderate transverse momenta.
[ { "created": "Sat, 4 Jun 2005 22:53:51 GMT", "version": "v1" } ]
2015-06-25
[ [ "Vitev", "Ivan", "" ] ]
We calculate and resum a perturbative expansion of nuclear enhanced power corrections to the structure functions measured in deeply inelastic scattering of leptons on a nuclear target. Our results for the Bjorken x-, Q**2- and A-dependence of nuclear shadowing in F2(x,Q**2;A) and the nuclear modifications to FL(x,Q**2;A), obtained in terms of the QCD factorization approach, are consistent with the existing data. We predict the dynamical shadowing from final state interactions in neutrino-nucleus reactions for sea and valence quarks in the structure functions F2(x,Q**2;A) and xF3(x,Q**2;A), respectively. In p+A collisions we calculate the centrality and rapidity dependent nuclear suppression of single and double inclusive hadron production at moderate transverse momenta.
0811.3086
Tim Ledwig
Tim Ledwig, Antonio Silva, Marc Vanderhaeghen
Electromagnetic properties of the Delta(1232) and decuplet baryons in the self-consistent SU(3) chiral quark-soliton model
24 pages, 8 figures
Phys.Rev.D79:094025,2009
10.1103/PhysRevD.79.094025
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the electromagnetic properties of the Delta(1232) resonance within the self-consistent chiral quark-soliton model. In particular we present the Delta form factors of the vector-current GE0, GE2 and GM1 for a momentum-transfer range of $Q^{2} \leq 1GeV^{2}$. We apply the symmetry-conserving quantization of the soliton and take 1/N_c rotational corrections into account. Values for the magnetic moments of all decuplet baryons as well as for the N-Delta transition are given. Special interest is also given to the electric quadrupole moment of the Delta.
[ { "created": "Wed, 19 Nov 2008 12:55:03 GMT", "version": "v1" } ]
2009-07-30
[ [ "Ledwig", "Tim", "" ], [ "Silva", "Antonio", "" ], [ "Vanderhaeghen", "Marc", "" ] ]
We examine the electromagnetic properties of the Delta(1232) resonance within the self-consistent chiral quark-soliton model. In particular we present the Delta form factors of the vector-current GE0, GE2 and GM1 for a momentum-transfer range of $Q^{2} \leq 1GeV^{2}$. We apply the symmetry-conserving quantization of the soliton and take 1/N_c rotational corrections into account. Values for the magnetic moments of all decuplet baryons as well as for the N-Delta transition are given. Special interest is also given to the electric quadrupole moment of the Delta.
2009.13449
Francesco Becattini
F. Becattini (Univeristy of Florence), M. Buzzegoli (Iowa State U.), A. Palermo (University of Florence), G. Prokhorov (JINR, Dubna)
Polarization as a signature of local parity violation in hot QCD matter
13 pages, 3 figures; final version to appear in Physics Letters B
null
10.1016/j.physletb.2021.136706
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that local parity violation due to chirality imbalance in relativistic nuclear collisions can be revealed by measuring the projection of the polarization vector onto the momentum, i.e. the helicity, of final state baryons. The proposed method does not require a coupling to the electromagnetic field, like in the Chiral Magnetic Effect. By using linear response theory, we show that, in the presence of a chiral imbalance, the spin 1/2 baryons and anti-baryons receive an additional contribution to the polarization along their momentum and proportional to the axial chemical potential. The additional, parity-breaking, contribution to helicity can be detected by studying helicity-helicity azimuthal angular correlation.
[ { "created": "Mon, 28 Sep 2020 16:18:15 GMT", "version": "v1" }, { "created": "Thu, 29 Oct 2020 11:30:22 GMT", "version": "v2" }, { "created": "Fri, 6 Aug 2021 16:00:54 GMT", "version": "v3" }, { "created": "Thu, 7 Oct 2021 10:11:12 GMT", "version": "v4" } ]
2021-10-08
[ [ "Becattini", "F.", "", "Univeristy of Florence" ], [ "Buzzegoli", "M.", "", "Iowa State U." ], [ "Palermo", "A.", "", "University of Florence" ], [ "Prokhorov", "G.", "", "JINR, Dubna" ] ]
We show that local parity violation due to chirality imbalance in relativistic nuclear collisions can be revealed by measuring the projection of the polarization vector onto the momentum, i.e. the helicity, of final state baryons. The proposed method does not require a coupling to the electromagnetic field, like in the Chiral Magnetic Effect. By using linear response theory, we show that, in the presence of a chiral imbalance, the spin 1/2 baryons and anti-baryons receive an additional contribution to the polarization along their momentum and proportional to the axial chemical potential. The additional, parity-breaking, contribution to helicity can be detected by studying helicity-helicity azimuthal angular correlation.
1205.0007
Miguel Pato
Alejandro Ibarra, Sergio L\'opez Gehler, Miguel Pato
Dark matter constraints from box-shaped gamma-ray features
17 pages, 5 figures
JCAP07(2012)043
10.1088/1475-7516/2012/07/043
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The observation of a sharp spectral feature in the gamma-ray sky would be one of the cleanest ways to identify dark matter and pinpoint its properties. Over the years a lot of attention has been paid to two specific features, namely gamma-ray lines and internal bremsstrahlung. Here, we explore a third class of spectral signatures, box-shaped gamma-ray spectra, that naturally arise in dark matter cascade annihilations or decays into intermediate particles that in turn decay into photons. Using Fermi-LAT data, we derive constraints on the dark matter parameter space for both annihilating and decaying dark matter, and show explicitly that our limits are competitive to strategies employing standard spectral features. More importantly, we find robust limits even in the case of non-degenerate dark matter and intermediate particle masses. This result is particularly relevant in constraining dark matter frameworks with gamma-ray data. We conclude by illustrating the power of box-shaped gamma-ray constraints on concrete particle physics scenarios.
[ { "created": "Mon, 30 Apr 2012 20:00:02 GMT", "version": "v1" }, { "created": "Tue, 24 Jul 2012 00:19:22 GMT", "version": "v2" } ]
2012-07-25
[ [ "Ibarra", "Alejandro", "" ], [ "Gehler", "Sergio López", "" ], [ "Pato", "Miguel", "" ] ]
The observation of a sharp spectral feature in the gamma-ray sky would be one of the cleanest ways to identify dark matter and pinpoint its properties. Over the years a lot of attention has been paid to two specific features, namely gamma-ray lines and internal bremsstrahlung. Here, we explore a third class of spectral signatures, box-shaped gamma-ray spectra, that naturally arise in dark matter cascade annihilations or decays into intermediate particles that in turn decay into photons. Using Fermi-LAT data, we derive constraints on the dark matter parameter space for both annihilating and decaying dark matter, and show explicitly that our limits are competitive to strategies employing standard spectral features. More importantly, we find robust limits even in the case of non-degenerate dark matter and intermediate particle masses. This result is particularly relevant in constraining dark matter frameworks with gamma-ray data. We conclude by illustrating the power of box-shaped gamma-ray constraints on concrete particle physics scenarios.
2111.03571
Jin Hu
Jin Hu
Relativistic first-order spin hydrodynamics via the Chapman-Enskog expansion
null
null
10.1103/PhysRevD.105.076009
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
In this paper, we present a detailed derivation of relativistic first-order spin hydrodynamics using the Chapman-Enskog method to linearize the nonlocal collision term for massive fermions proposed in \cite{Weickgenannt:2021cuo}, which well describes spin-orbit coupling in the collision process and is relevant for the research on local spin polarization. Based on this collisional term, we provide a formal discussion about first-order spin hydrodynamics and determine the motion equations of fluid variables and nonequilibrium corrections to the energy-momentum and spin tensors. The results indicate that the motion equations show no differences compared to spinless first-order hydrodynamics and the energy-momentum tensor receives no corrections from spin as far as first-order theory is concerned, which calls for the construction of second-order theory of fluids naturally incorporating the effect of spin-orbit coupling.
[ { "created": "Fri, 5 Nov 2021 15:48:42 GMT", "version": "v1" }, { "created": "Fri, 25 Feb 2022 16:17:27 GMT", "version": "v2" } ]
2022-04-27
[ [ "Hu", "Jin", "" ] ]
In this paper, we present a detailed derivation of relativistic first-order spin hydrodynamics using the Chapman-Enskog method to linearize the nonlocal collision term for massive fermions proposed in \cite{Weickgenannt:2021cuo}, which well describes spin-orbit coupling in the collision process and is relevant for the research on local spin polarization. Based on this collisional term, we provide a formal discussion about first-order spin hydrodynamics and determine the motion equations of fluid variables and nonequilibrium corrections to the energy-momentum and spin tensors. The results indicate that the motion equations show no differences compared to spinless first-order hydrodynamics and the energy-momentum tensor receives no corrections from spin as far as first-order theory is concerned, which calls for the construction of second-order theory of fluids naturally incorporating the effect of spin-orbit coupling.
hep-ph/0304098
Peter Williams
P. H. Williams
A Z-Monitor to Calibrate Higgs Production via Vector Boson Fusion with Rapidity Gaps at the LHC
4 pages, 7 figures. Presented at 38th Rencontres de Moriond on QCD and Hadronic Interactions, Les Arcs, France, 22-29 Mar 2003
null
null
IPPP/03/17, DCPT/03/34
hep-ph
null
We study central Z-boson production accompanied by rapidity gaps on either side as a way to gauge Higgs weak boson fusion production at the LHC. We analyse the backgrounds for the bb-decay mode and show that these can be substantially reduced. Special attention is paid to the evaluation of the gap survival factor, which is the major source of theoretical uncertainty in the rate of H and Z central production events with rapidity gaps.
[ { "created": "Thu, 10 Apr 2003 10:15:40 GMT", "version": "v1" } ]
2007-05-23
[ [ "Williams", "P. H.", "" ] ]
We study central Z-boson production accompanied by rapidity gaps on either side as a way to gauge Higgs weak boson fusion production at the LHC. We analyse the backgrounds for the bb-decay mode and show that these can be substantially reduced. Special attention is paid to the evaluation of the gap survival factor, which is the major source of theoretical uncertainty in the rate of H and Z central production events with rapidity gaps.
2406.01729
Oscar Rodr\'iguez
Mar\'ia J. Dom\'inguez, Oscar Rodr\'iguez, \'Oscar Zapata
Reopening the Z portal with semi-annihilations
27 pages, 9 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In one-component dark matter (DM) scenarios is commonly assumed that a scalar WIMP must either be part of an $SU(2)_L$ multiplet with zero hypercharge or have suppressed vector interactions with the $Z$ gauge boson to circumvent stringent direct detection (DD) bounds. In this work, we demonstrate that multi-component scenarios with a dark scalar doublet exhibiting vector-like interactions with the $Z$ boson are also compatible with bounds arising from DD searches. Specifically, we consider a simple extension of the Standard Model wherein the dark sector comprises a doublet and a complex singlet $\phi$, both charged under a $Z_6$ symmetry. We find that semi-annihilation processes drastically reduce the relic abundance of the neutral component of the doublet, $H^0$, sufficiently attenuating the effects of its large $Z$-mediated elastic scattering cross-section with nucleons to satisfy the DD constraints. Although the contribution of $H^0$ to the total relic abundance is nearly negligible, with $\phi$ dominating, both dark matter components are expected to be detectable in ongoing and future DD experiments. The viability of the model is tested against several theoretical and experimental constraints, resulting in a parameter space featuring a non-degenerate mass spectrum at the electroweak scale.
[ { "created": "Mon, 3 Jun 2024 18:42:38 GMT", "version": "v1" }, { "created": "Tue, 13 Aug 2024 14:42:13 GMT", "version": "v2" } ]
2024-08-14
[ [ "Domínguez", "María J.", "" ], [ "Rodríguez", "Oscar", "" ], [ "Zapata", "Óscar", "" ] ]
In one-component dark matter (DM) scenarios is commonly assumed that a scalar WIMP must either be part of an $SU(2)_L$ multiplet with zero hypercharge or have suppressed vector interactions with the $Z$ gauge boson to circumvent stringent direct detection (DD) bounds. In this work, we demonstrate that multi-component scenarios with a dark scalar doublet exhibiting vector-like interactions with the $Z$ boson are also compatible with bounds arising from DD searches. Specifically, we consider a simple extension of the Standard Model wherein the dark sector comprises a doublet and a complex singlet $\phi$, both charged under a $Z_6$ symmetry. We find that semi-annihilation processes drastically reduce the relic abundance of the neutral component of the doublet, $H^0$, sufficiently attenuating the effects of its large $Z$-mediated elastic scattering cross-section with nucleons to satisfy the DD constraints. Although the contribution of $H^0$ to the total relic abundance is nearly negligible, with $\phi$ dominating, both dark matter components are expected to be detectable in ongoing and future DD experiments. The viability of the model is tested against several theoretical and experimental constraints, resulting in a parameter space featuring a non-degenerate mass spectrum at the electroweak scale.
hep-ph/9909473
Eugene Golowich
V. Cirigliano, J.F. Donoghue and E. Golowich
Electromagnetic Corrections to K->pi pi II - Dispersive Matching
26 pages, 10 figures, 1 table, Comments added in Conclusion
Phys.Rev. D61 (2000) 093002
10.1103/PhysRevD.61.093002
null
hep-ph
null
We express the leading electromagnetic corrections in K-> pi pi amplitudes as integrals over the virtual photon squared-momentum Q^2. The high Q^2 behavior is obtained via the operator product expansion. The low Q^2 behavior is calculated using chiral perturbation theory. We model the intermediate Q^2 region using resonance contributions in order to enforce the matching of these two regimes. The results confirm our previous estimates that the electromagnetic corrections provide a reasonably small shift in the delta I - 3/2 amplitude.
[ { "created": "Wed, 22 Sep 1999 15:28:40 GMT", "version": "v1" }, { "created": "Mon, 29 Nov 1999 15:40:23 GMT", "version": "v2" } ]
2009-10-31
[ [ "Cirigliano", "V.", "" ], [ "Donoghue", "J. F.", "" ], [ "Golowich", "E.", "" ] ]
We express the leading electromagnetic corrections in K-> pi pi amplitudes as integrals over the virtual photon squared-momentum Q^2. The high Q^2 behavior is obtained via the operator product expansion. The low Q^2 behavior is calculated using chiral perturbation theory. We model the intermediate Q^2 region using resonance contributions in order to enforce the matching of these two regimes. The results confirm our previous estimates that the electromagnetic corrections provide a reasonably small shift in the delta I - 3/2 amplitude.
hep-ph/0007083
A. D. Martin
V.A. Khoze (Durham), A.D. Martin (Durham) M.G. Ryskin (Durham & St.Petersburg)
The compatibility of diffractive hard scattering in p pbar and ep collisions
8 pages, 1 figure, LaTeX, version to be published in PLB
Phys.Lett.B502:87-91,2001
10.1016/S0370-2693(01)00170-8
DTP/00/40
hep-ph
null
We show that the data for diffractive dijet production at the Tevatron p pbar collider are consistent with diffractive deep inelastic e p data collected at HERA. The breakdown of factorization between the two data sets is naturally explained by a strong tendency to populate the rapidity gap in the p pbar diffractive process by secondaries from soft underlying interactions and by bremsstrahlung associated with the presence of the hard dijet subprocess.
[ { "created": "Mon, 10 Jul 2000 14:17:11 GMT", "version": "v1" }, { "created": "Tue, 13 Feb 2001 17:26:26 GMT", "version": "v2" } ]
2011-03-23
[ [ "Khoze", "V. A.", "", "Durham" ], [ "Martin", "A. D.", "", "Durham" ], [ "Ryskin", "M. G.", "", "Durham &\n St.Petersburg" ] ]
We show that the data for diffractive dijet production at the Tevatron p pbar collider are consistent with diffractive deep inelastic e p data collected at HERA. The breakdown of factorization between the two data sets is naturally explained by a strong tendency to populate the rapidity gap in the p pbar diffractive process by secondaries from soft underlying interactions and by bremsstrahlung associated with the presence of the hard dijet subprocess.
2012.04991
Philipp Isserstedt
Philipp Isserstedt, Christian S. Fischer, Thorsten Steinert
Thermodynamics from the quark condensate
9 pages, 7 figures; v2: minor changes, version published in PRD
Phys. Rev. D 103, 054012 (2021)
10.1103/PhysRevD.103.054012
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a method to compute thermodynamic quantities within functional continuum frameworks that is independent of the employed truncation. As a proof of principle, we first apply it to a Nambu-Jona-Lasinio model in mean-field approximation. Then, we use the method with solutions obtained from a coupled set of truncated Dyson-Schwinger equations for the quark and gluon propagators of (2+1)-flavor quantum chromodynamics in Landau gauge to obtain the pressure, entropy density, energy density, and interaction measure across the phase diagram of strong-interaction matter. We also discuss the limitation of the proposed method.
[ { "created": "Wed, 9 Dec 2020 11:50:20 GMT", "version": "v1" }, { "created": "Thu, 11 Mar 2021 20:49:46 GMT", "version": "v2" } ]
2021-03-15
[ [ "Isserstedt", "Philipp", "" ], [ "Fischer", "Christian S.", "" ], [ "Steinert", "Thorsten", "" ] ]
We present a method to compute thermodynamic quantities within functional continuum frameworks that is independent of the employed truncation. As a proof of principle, we first apply it to a Nambu-Jona-Lasinio model in mean-field approximation. Then, we use the method with solutions obtained from a coupled set of truncated Dyson-Schwinger equations for the quark and gluon propagators of (2+1)-flavor quantum chromodynamics in Landau gauge to obtain the pressure, entropy density, energy density, and interaction measure across the phase diagram of strong-interaction matter. We also discuss the limitation of the proposed method.
2305.13379
Isabel Mira Oldengott
Emil Brinch Holm, Isabel M. Oldengott, Stefan Zentarra
Local clustering of relic neutrinos with kinetic field theory
7 pages, 1 figure; list of references updated
null
10.1016/j.physletb.2023.138073
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The density of relic neutrinos is expected to be enhanced due to clustering in our local neighbourhood at Earth. We introduce a novel analytical technique to calculate the neutrino overdensity, based on kinetic field theory. Kinetic field theory is a particle-based theory for cosmic structure formation and in this work we apply it for the first time to massive neutrinos. The gravitational interaction is expanded in a perturbation series and we take into account the first-order contribution to the local density of relic neutrinos. For neutrino masses that are consistent with cosmological neutrino mass bounds, our results are in excellent agreement with state-of-the-art calculations.
[ { "created": "Mon, 22 May 2023 18:00:12 GMT", "version": "v1" }, { "created": "Wed, 2 Aug 2023 08:35:39 GMT", "version": "v2" } ]
2023-08-09
[ [ "Holm", "Emil Brinch", "" ], [ "Oldengott", "Isabel M.", "" ], [ "Zentarra", "Stefan", "" ] ]
The density of relic neutrinos is expected to be enhanced due to clustering in our local neighbourhood at Earth. We introduce a novel analytical technique to calculate the neutrino overdensity, based on kinetic field theory. Kinetic field theory is a particle-based theory for cosmic structure formation and in this work we apply it for the first time to massive neutrinos. The gravitational interaction is expanded in a perturbation series and we take into account the first-order contribution to the local density of relic neutrinos. For neutrino masses that are consistent with cosmological neutrino mass bounds, our results are in excellent agreement with state-of-the-art calculations.
1905.02360
Bo-Qiang Ma
Xiaonan Liu, Bo-Qiang Ma
Nucleon strangeness polarization from $\Lambda/\bar\Lambda$ hyperon production in polarized proton-proton collision at RHIC
10 latex pages, 6 figures, final version for publication
null
10.1140/epjc/s10052-019-6916-z
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the inclusive production of a polarized $\Lambda$ or $\bar{\Lambda}$ hyperon from the single longitudinally polarized proton and proton ($pp$) collision at RHIC. By comparing the data reported by the STAR Collaboration, we find that this process is sensitive to the polarization of strange and antistrange quarks of the proton in the experimental range. By introducing asymmetric coefficients with the minimization of $\chi^2$, we further identify the asymmetry of the polarized strange-antistrange quarks in the proton sea and find that the first moment is $\Delta s \approx -0.025\pm 0.019$ for strange quark and $\Delta\bar s \approx -0.001\pm 0.012$ for antistrange quark, with central values agreeing with the light-cone meson-baryon fluctuation model prediction, the recent lattice QCD determination of strangeness polarization and results from a global QCD analysis given by the Jefferson Lab Angular Momentum (JAM) Collaboration.
[ { "created": "Tue, 7 May 2019 05:30:53 GMT", "version": "v1" }, { "created": "Tue, 14 May 2019 03:22:25 GMT", "version": "v2" } ]
2019-06-05
[ [ "Liu", "Xiaonan", "" ], [ "Ma", "Bo-Qiang", "" ] ]
We calculate the inclusive production of a polarized $\Lambda$ or $\bar{\Lambda}$ hyperon from the single longitudinally polarized proton and proton ($pp$) collision at RHIC. By comparing the data reported by the STAR Collaboration, we find that this process is sensitive to the polarization of strange and antistrange quarks of the proton in the experimental range. By introducing asymmetric coefficients with the minimization of $\chi^2$, we further identify the asymmetry of the polarized strange-antistrange quarks in the proton sea and find that the first moment is $\Delta s \approx -0.025\pm 0.019$ for strange quark and $\Delta\bar s \approx -0.001\pm 0.012$ for antistrange quark, with central values agreeing with the light-cone meson-baryon fluctuation model prediction, the recent lattice QCD determination of strangeness polarization and results from a global QCD analysis given by the Jefferson Lab Angular Momentum (JAM) Collaboration.
hep-ph/9901216
Anatoli Efremov
A.V.Efremov, Yu.I.Ivanshin, O.G.Smirnova, L.G.Tkatchev, R.Ya.Zulkarneev
On the T-Odd Quark Fragmentation Function and on Transversal Handedness
10 pp, 5 epsfig, Latex 2e, szjp.cls, epsfig.sty, wrapfig.sty included. Talk in "Spin and Symmetry - Praha98". To be published in Czechoslovak Journal of Physics, Suppl
Czech.J.Phys. 49S2 (1999) 75-84
10.1007/s10582-999-0088-2
null
hep-ph
null
The first probe of the correlation of the T-odd one-particle fragmentation function responsible for the left--right asymmetry of fragmentation of a transversely polarized quark is done by using the 1991-95 DELPHI data for $Z\to 2$-jet decay. Integrated over the fraction of longitudinal and transversal momenta, this correlation is of 1.5% order, which means order of 13% for the analyzing power. A rather large ($\approx 10%$) handedness transversal to the production plane was observed in the diffractive production of ($\pi^-\pi^+\pi^-$) triples from nuclei by the $40 GeV/c \pi^-$--beam. It was shown that the phenomenon has a clear dynamic origin and resembles the single spin asymmetry behavior. All this makes us hope to use this effects in polarized DIS experiments for transversity measurement.
[ { "created": "Mon, 4 Jan 1999 17:43:02 GMT", "version": "v1" } ]
2009-10-31
[ [ "Efremov", "A. V.", "" ], [ "Ivanshin", "Yu. I.", "" ], [ "Smirnova", "O. G.", "" ], [ "Tkatchev", "L. G.", "" ], [ "Zulkarneev", "R. Ya.", "" ] ]
The first probe of the correlation of the T-odd one-particle fragmentation function responsible for the left--right asymmetry of fragmentation of a transversely polarized quark is done by using the 1991-95 DELPHI data for $Z\to 2$-jet decay. Integrated over the fraction of longitudinal and transversal momenta, this correlation is of 1.5% order, which means order of 13% for the analyzing power. A rather large ($\approx 10%$) handedness transversal to the production plane was observed in the diffractive production of ($\pi^-\pi^+\pi^-$) triples from nuclei by the $40 GeV/c \pi^-$--beam. It was shown that the phenomenon has a clear dynamic origin and resembles the single spin asymmetry behavior. All this makes us hope to use this effects in polarized DIS experiments for transversity measurement.
1512.04651
Boris Mangazeev
Edgar V. Bugaev and Boris V. Mangazeev
Nuclear shadowing in deep inelastic scattering on nuclei at low and medium Q^2
6 pages, 2 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Nuclear shadowing corrections to the structure functions of deep inelastic scattering of intermediate-mass nuclei are calculated at very low values of Bjorken x and small values of Q^2 (Q^2<5 GeV^2). The two-component approach (generalized VMD plus hard pomeron) is used for a description of the underlying virtual photon - nucleon interaction. The hard component of the nucleon structure function is calculated in a framework of the colour dipole model with dipole cross section having Regge-type energy dependence. Numerical results for nuclear shadowing corrections are compared with available data of E665 and NMC collaborations.
[ { "created": "Tue, 15 Dec 2015 05:04:45 GMT", "version": "v1" } ]
2015-12-16
[ [ "Bugaev", "Edgar V.", "" ], [ "Mangazeev", "Boris V.", "" ] ]
Nuclear shadowing corrections to the structure functions of deep inelastic scattering of intermediate-mass nuclei are calculated at very low values of Bjorken x and small values of Q^2 (Q^2<5 GeV^2). The two-component approach (generalized VMD plus hard pomeron) is used for a description of the underlying virtual photon - nucleon interaction. The hard component of the nucleon structure function is calculated in a framework of the colour dipole model with dipole cross section having Regge-type energy dependence. Numerical results for nuclear shadowing corrections are compared with available data of E665 and NMC collaborations.
1905.11750
Takhmasib Aliev
T.M.Aliev, T.Barakat, and S.Bilmis
Properties of excited $B_c$ states in QCD
11 pages, 4 figures Misprints are corrected and reference list has been updated
Nuclear Physics B, Volume 947, 2019, 114726
10.1016/j.nuclphysb.2019.114726
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The mass and leptonic decay constants of recently observed two new excited $B_c$ states at LHC are studied within the QCD sum rules. Considering the contributions of the ground and radially excited states, the mass and residues of the excited states of pseudoscalar and vector mesons are calculated in the framework of two different approaches of the QCD sum rules, namely, linear combinations of the corresponding sum rules and its derivatives as well as QCD sum rules with the incorporation of the least square fitting method. The obtained results on mass $m_{B_c^+}(2S) = 6.88 \pm 0.03~\rm{GeV} $ and $m_{B_c^{*+}}(2S) = 6.94 \pm 0.03~\rm{GeV} $ are in good agreement with the experimental data. Our predictions for the decay constants of these states are: $f_{B_c^+}(2S) = 0.42 \pm 0.02~\rm{GeV} $ and $f_{B_c^{*+}}(2S) = 0.46 \pm 0.01~\rm{GeV}$, which can be checked at future experiments to be conducted at the LHC. Comparison of our results with the predictions of the other approaches on mass and residues is also presented.
[ { "created": "Tue, 28 May 2019 11:30:26 GMT", "version": "v1" }, { "created": "Tue, 27 Aug 2019 07:30:26 GMT", "version": "v2" } ]
2019-08-28
[ [ "Aliev", "T. M.", "" ], [ "Barakat", "T.", "" ], [ "Bilmis", "S.", "" ] ]
The mass and leptonic decay constants of recently observed two new excited $B_c$ states at LHC are studied within the QCD sum rules. Considering the contributions of the ground and radially excited states, the mass and residues of the excited states of pseudoscalar and vector mesons are calculated in the framework of two different approaches of the QCD sum rules, namely, linear combinations of the corresponding sum rules and its derivatives as well as QCD sum rules with the incorporation of the least square fitting method. The obtained results on mass $m_{B_c^+}(2S) = 6.88 \pm 0.03~\rm{GeV} $ and $m_{B_c^{*+}}(2S) = 6.94 \pm 0.03~\rm{GeV} $ are in good agreement with the experimental data. Our predictions for the decay constants of these states are: $f_{B_c^+}(2S) = 0.42 \pm 0.02~\rm{GeV} $ and $f_{B_c^{*+}}(2S) = 0.46 \pm 0.01~\rm{GeV}$, which can be checked at future experiments to be conducted at the LHC. Comparison of our results with the predictions of the other approaches on mass and residues is also presented.
hep-ph/0206291
Mahiko Suzuki
M. Suzuki
Helicity conservation in inclusive nonleptonic decay B to VX: Test of long-distance final state interaction
15 pages in Revtex with 3 figures embedded
Phys.Rev.D66:054018,2002
10.1103/PhysRevD.66.054018
LBNL-50942
hep-ph
null
The polarization measurement in the inclusive B decay provides us with a simple test of how much the long-distance final-state interaction takes place as the energy of the observed meson varies in the final state. We give the expectation of the perturbative QCD for the energy dependence of the helicity fractions in a semiquantitative form. Experiment will tell us for which decay processes the perturbative calculation should be applicable.
[ { "created": "Thu, 27 Jun 2002 17:27:23 GMT", "version": "v1" } ]
2014-11-17
[ [ "Suzuki", "M.", "" ] ]
The polarization measurement in the inclusive B decay provides us with a simple test of how much the long-distance final-state interaction takes place as the energy of the observed meson varies in the final state. We give the expectation of the perturbative QCD for the energy dependence of the helicity fractions in a semiquantitative form. Experiment will tell us for which decay processes the perturbative calculation should be applicable.
hep-ph/9609295
Ramon Munoz Tapia
S. Moretti, R. Munoz-Tapia and K. Odagiri
Gluino signals in 4jet events and vertex tagging at LEP1
28 pages, 9 figures embedded with epsfig, Latex. Major revision taking into account latest bounds. Version to appear in Zeit. f. Phys. C
Eur.Phys.J.C4:351-362,1998
10.1007/s100520050213
null
hep-ph
null
Heavy flavour tagging provides a broad range of possibilities in testing QCD features at LEP. We present here a study of 4jets events at LEP I where the so-called light gluinos could be directly produced. We show that microvertex techniques offer a unique chance to exploit simple kinematical distributions in order to optimise the signal coming from gluino production with respect to the background of ordinary QCD events. Our results indicate that experimental analyses along the lines suggested here can exclude or reveal the presence of a gluino for masses up to 10 GeV and lifetimes below 10$^{-9}$ sec. We also point out that a large fraction of gluino events could decay in configurations carrying large missing energy, so to escape the usual selection criteria of 4jet samples. In our study, mass effects of quarks and gluinos have been taken into account exactly. Our results are independent from both the jet algorithm and its resolution parameter.}
[ { "created": "Mon, 9 Sep 1996 17:09:48 GMT", "version": "v1" }, { "created": "Wed, 17 Sep 1997 11:06:31 GMT", "version": "v2" } ]
2011-09-13
[ [ "Moretti", "S.", "" ], [ "Munoz-Tapia", "R.", "" ], [ "Odagiri", "K.", "" ] ]
Heavy flavour tagging provides a broad range of possibilities in testing QCD features at LEP. We present here a study of 4jets events at LEP I where the so-called light gluinos could be directly produced. We show that microvertex techniques offer a unique chance to exploit simple kinematical distributions in order to optimise the signal coming from gluino production with respect to the background of ordinary QCD events. Our results indicate that experimental analyses along the lines suggested here can exclude or reveal the presence of a gluino for masses up to 10 GeV and lifetimes below 10$^{-9}$ sec. We also point out that a large fraction of gluino events could decay in configurations carrying large missing energy, so to escape the usual selection criteria of 4jet samples. In our study, mass effects of quarks and gluinos have been taken into account exactly. Our results are independent from both the jet algorithm and its resolution parameter.}
hep-ph/9602333
Plamen Krastev
P.I. Krastev, S.T. Petcov and L. Qiuyu
On the MSW $\nu_e \to \nu_s$ transition solution of the solar neutrino problem
23 pages, revtex; texfile and figures available also as one tar-compressed, uuencoded file from ftp://ftp.sns.ias.edu/pub/krastev/STER (first three figures, when unpacked, are 6.9 Mb each !!!)
Phys.Rev.D54:7057-7066,1996
10.1103/PhysRevD.54.7057
Preprint IASSNS-AST 96/11 and Ref. SISSA 89/95/EP
hep-ph astro-ph
null
We study the stability of the two--neutrino MSW solution of the solar neutrino problem, corresponding to solar $\nu_e$ transitions into sterile neutrino, $\nu_e \rightarrow \nu_s$, with respect to changes of the total fluxes of $^{8}$B and $^{7}$Be neutrinos, $\Phi_{{\rm B}}$ and $\Phi_{{\rm Be}}$. For any value of $\Phi_{{\rm Be}}$ from the interval $0.7\Phi^{{\rm BP}}_{{\rm Be}}\leq \Phi_{{\rm Be}} \leq 1.3\Phi^{{\rm BP}}_{{\rm Be}}$ (for $\Phi_{{\rm Be}} = 0.7\Phi^{{\rm BP}}_{{\rm Be}}$) the $\nu_e \rightarrow \nu_{s}$ MSW transitions provide at 95\% C.L. a description of the existing solar neutrino data for $0.40~(0.39)~\Phi^{{\rm BP}}_{{\rm B}} \ltap \Phi_{{\rm B}} \ltap 36~(40)\Phi^{{\rm BP}}_{{\rm B}}$, $\Phi^{{\rm BP}}_{{\rm B}}$ and $\Phi^{{\rm BP}}_{{\rm Be}}$ being the fluxes in the solar model of Bahcall--Pinsonneault from 1992. The corresponding allowed regions of values of the parameters \dm2 and \sn2, characterizing the solar neutrino transitions, are derived. The physical implications of the found MSW $\nu_e \rightarrow \nu_s$ solutions for the future solar neutrino experiments are considered as well.
[ { "created": "Fri, 16 Feb 1996 21:58:02 GMT", "version": "v1" } ]
2008-11-26
[ [ "Krastev", "P. I.", "" ], [ "Petcov", "S. T.", "" ], [ "Qiuyu", "L.", "" ] ]
We study the stability of the two--neutrino MSW solution of the solar neutrino problem, corresponding to solar $\nu_e$ transitions into sterile neutrino, $\nu_e \rightarrow \nu_s$, with respect to changes of the total fluxes of $^{8}$B and $^{7}$Be neutrinos, $\Phi_{{\rm B}}$ and $\Phi_{{\rm Be}}$. For any value of $\Phi_{{\rm Be}}$ from the interval $0.7\Phi^{{\rm BP}}_{{\rm Be}}\leq \Phi_{{\rm Be}} \leq 1.3\Phi^{{\rm BP}}_{{\rm Be}}$ (for $\Phi_{{\rm Be}} = 0.7\Phi^{{\rm BP}}_{{\rm Be}}$) the $\nu_e \rightarrow \nu_{s}$ MSW transitions provide at 95\% C.L. a description of the existing solar neutrino data for $0.40~(0.39)~\Phi^{{\rm BP}}_{{\rm B}} \ltap \Phi_{{\rm B}} \ltap 36~(40)\Phi^{{\rm BP}}_{{\rm B}}$, $\Phi^{{\rm BP}}_{{\rm B}}$ and $\Phi^{{\rm BP}}_{{\rm Be}}$ being the fluxes in the solar model of Bahcall--Pinsonneault from 1992. The corresponding allowed regions of values of the parameters \dm2 and \sn2, characterizing the solar neutrino transitions, are derived. The physical implications of the found MSW $\nu_e \rightarrow \nu_s$ solutions for the future solar neutrino experiments are considered as well.
1904.08569
De-Min Li
Chen-Guang Zhao, Guan-Ying Wang, Guan-Nan Li, En Wang, and De-Min Li
The $\phi(2170)$ production in the process $\gamma p\to \eta \phi p$
6 pages, 4 Figures, version accepted for publication in Physical Review D
Phys. Rev. D 99, 114014 (2019)
10.1103/PhysRevD.99.114014
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have studied the $\gamma p\to \eta \phi p$ reaction within the effective Lagrangian approach, by considering the contribution of the intermediate state $\phi(2170)$ production, and the background contributions of $t$-channel $\pi^0$ and $\eta$ mesons exchanges with the intermediate states $N$ and $N(1535)$. Our calculations show that there may be a peak, at least a bump structure around 2180 MeV associated to the resonance $\phi(2170)$ in the $\eta\phi$ mass distribution. We suggest to search for the resonance $\phi(2170)$ in this reaction, which would be helpful to shed light on its nature.
[ { "created": "Thu, 18 Apr 2019 02:21:32 GMT", "version": "v1" }, { "created": "Sun, 19 May 2019 10:52:33 GMT", "version": "v2" }, { "created": "Tue, 4 Jun 2019 03:11:55 GMT", "version": "v3" } ]
2019-06-26
[ [ "Zhao", "Chen-Guang", "" ], [ "Wang", "Guan-Ying", "" ], [ "Li", "Guan-Nan", "" ], [ "Wang", "En", "" ], [ "Li", "De-Min", "" ] ]
We have studied the $\gamma p\to \eta \phi p$ reaction within the effective Lagrangian approach, by considering the contribution of the intermediate state $\phi(2170)$ production, and the background contributions of $t$-channel $\pi^0$ and $\eta$ mesons exchanges with the intermediate states $N$ and $N(1535)$. Our calculations show that there may be a peak, at least a bump structure around 2180 MeV associated to the resonance $\phi(2170)$ in the $\eta\phi$ mass distribution. We suggest to search for the resonance $\phi(2170)$ in this reaction, which would be helpful to shed light on its nature.
1211.1808
Nodoka Yamanaka
Nodoka Yamanaka
Two-loop level rainbowlike supersymmetric contribution to the fermion electric dipole moment
5 pages, 5 figures
Phys.Rev. D87 (2013) 011701
10.1103/PhysRevD.87.011701
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the two-loop level electric and chromo-electric dipole moments of the fermion involving fermion-sfermion inner loop, gaugino, and higgsino in the minimal supersymmetric standard model, and analyze the chromo-electric dipole moment with the top-stop inner loop. It is found that this contribution is comparable with, and even dominates in some situation over the Barr-Zee type diagram generated from the CP-violation of the top squark sector in TeV scale supersymmetry breaking.
[ { "created": "Thu, 8 Nov 2012 09:55:36 GMT", "version": "v1" }, { "created": "Sun, 30 Dec 2012 05:47:01 GMT", "version": "v2" } ]
2013-01-07
[ [ "Yamanaka", "Nodoka", "" ] ]
We calculate the two-loop level electric and chromo-electric dipole moments of the fermion involving fermion-sfermion inner loop, gaugino, and higgsino in the minimal supersymmetric standard model, and analyze the chromo-electric dipole moment with the top-stop inner loop. It is found that this contribution is comparable with, and even dominates in some situation over the Barr-Zee type diagram generated from the CP-violation of the top squark sector in TeV scale supersymmetry breaking.
0709.4202
Jurgen Reuter
Jurgen Reuter
SUSY Multi-Step Unification without Doublet-Triplet Splitting
Submitted for the SUSY07 proceedings, 4 pages, 3 eps figures
null
null
FR-THEP-07-09
hep-ph
null
Matter-Higgs unification in string-inspired supersymmetric Grand Unified Theories predicts the existence of colored states in the Higgs multiplets and calls for two extra generations of Higgs-like fields ('unhiggses'). If these states are present near the TeV scale, gauge-coupling unification points to the existence of two distinct scales, 10^15 GeV where right-handed neutrinos and a Pati-Salam symmetry appear, and 10^18 GeV where complete unification is achieved. Baryon-number conservation, while not guaranteed, can naturally emerge from an underlying flavor symmetry. Collider signatures and dark-matter physics may be drastically different from the conventional MSSM.
[ { "created": "Wed, 26 Sep 2007 16:07:30 GMT", "version": "v1" } ]
2007-09-27
[ [ "Reuter", "Jurgen", "" ] ]
Matter-Higgs unification in string-inspired supersymmetric Grand Unified Theories predicts the existence of colored states in the Higgs multiplets and calls for two extra generations of Higgs-like fields ('unhiggses'). If these states are present near the TeV scale, gauge-coupling unification points to the existence of two distinct scales, 10^15 GeV where right-handed neutrinos and a Pati-Salam symmetry appear, and 10^18 GeV where complete unification is achieved. Baryon-number conservation, while not guaranteed, can naturally emerge from an underlying flavor symmetry. Collider signatures and dark-matter physics may be drastically different from the conventional MSSM.
1906.04080
Edward Shuryak
Dmitri Kharzeev, Edward Shuryak and Ismail Zahed
Baryogenesis and helical magnetogenesis from the electroweak transition of the minimal Standard Model
The paper is significantly changed:. New concept is "topological stability" of sphaleron zero mode, which we claim survives all plasma corrections and still has zero eigenvalue. Novel discussion of CP violation at sphaleron explosion lead to asymmetry of about 10^-9, which set the resulting baryon asymmetry of Universe in the ballpark of observed value
Phys. Rev. D 102, 073003 (2020)
10.1103/PhysRevD.102.073003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We start by considering the production rates of sphalerons with different size $\rho$ in the symmetric phase, $T>T_{EW}$. At small $\rho$, the distribution is cut off by the growing mass $M\sim 1/\rho$, and at large $\rho$ by the magnetic screening mass. In the broken phase, $T<T_{EW}$ the scale is set by the Higgs VEV $v(T)$. We introduce the concept of "Sphaleron freezeout" whereby the sphaleron production rate matches the Hubble Universe expansion rate. At freezeout the sphalerons are out of equilibrium. Sphaleron explosions generate sound and even gravity waves, when nonzero Weinberg angle make them non-spherical. We revisit CP violation during the sphaleron explosions. We assess its magnitude using the Standard Model CKM quark matrix, first for nonzero and then zero Dirac eigenstates. We find that its magnitude is maximal at the sphaleron freezeout condition with $T\approx 130\, GeV$. We proceed to estimate the amount of CP violation needed to generate the observed magnitude of baryon asymmetry of Universe. The result is about an order of magnitude below our CKM-based estimates. We also relate the baryon asymmetry to the generation of $U(1)$ magnetic chirality, which is expected to be conserved and perhaps visible in polarized intergalactic magnetic fields.
[ { "created": "Mon, 10 Jun 2019 15:52:11 GMT", "version": "v1" }, { "created": "Thu, 2 Jan 2020 15:39:38 GMT", "version": "v2" } ]
2020-10-21
[ [ "Kharzeev", "Dmitri", "" ], [ "Shuryak", "Edward", "" ], [ "Zahed", "Ismail", "" ] ]
We start by considering the production rates of sphalerons with different size $\rho$ in the symmetric phase, $T>T_{EW}$. At small $\rho$, the distribution is cut off by the growing mass $M\sim 1/\rho$, and at large $\rho$ by the magnetic screening mass. In the broken phase, $T<T_{EW}$ the scale is set by the Higgs VEV $v(T)$. We introduce the concept of "Sphaleron freezeout" whereby the sphaleron production rate matches the Hubble Universe expansion rate. At freezeout the sphalerons are out of equilibrium. Sphaleron explosions generate sound and even gravity waves, when nonzero Weinberg angle make them non-spherical. We revisit CP violation during the sphaleron explosions. We assess its magnitude using the Standard Model CKM quark matrix, first for nonzero and then zero Dirac eigenstates. We find that its magnitude is maximal at the sphaleron freezeout condition with $T\approx 130\, GeV$. We proceed to estimate the amount of CP violation needed to generate the observed magnitude of baryon asymmetry of Universe. The result is about an order of magnitude below our CKM-based estimates. We also relate the baryon asymmetry to the generation of $U(1)$ magnetic chirality, which is expected to be conserved and perhaps visible in polarized intergalactic magnetic fields.
hep-ph/9807413
Tatsu Takeuchi
Aaron K. Grant (UCLA) and Tatsu Takeuchi (Virginia Tech)
An analysis of Precision Electroweak Measurements: Summer 98 Update
LaTeX2e, 23 pages, 18 postscript figures, uses epsf.sty
null
null
VPI-IPPAP-98-1, UCLA/98/TEP/20
hep-ph
null
We update our analysis of precision electroweak measurements using the latest data announced at Moriond, March 1998. Possible oblique corrections from new physics are parametrized using the STU formalism of Ref.[1], and non-oblique corrections to the Zbb vertex are parametrized using the xi_b zeta_b formalism of Ref.[2]. The implications of the analysis on minimal SU(5) grand unification is discussed.
[ { "created": "Sat, 18 Jul 1998 20:20:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grant", "Aaron K.", "", "UCLA" ], [ "Takeuchi", "Tatsu", "", "Virginia Tech" ] ]
We update our analysis of precision electroweak measurements using the latest data announced at Moriond, March 1998. Possible oblique corrections from new physics are parametrized using the STU formalism of Ref.[1], and non-oblique corrections to the Zbb vertex are parametrized using the xi_b zeta_b formalism of Ref.[2]. The implications of the analysis on minimal SU(5) grand unification is discussed.
1301.6973
Pablo Roig
D. G\'omez Dumm and P. Roig
Dispersive representation of the pion vector form factor in $\tau\to\pi\pi\nu_\tau$ decays
22 pages, 4 figures. Determination of rho(770) pole parameters substantially improved using a new method, based on rational approximants. Other results unchanged. Version to be published in EPJC
Eur. Phys. J. C (2013) 73: 2528
10.1140/epjc/s10052-013-2528-1
UAB-FT-725
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a dispersive representation of the charged pion vector form factor that is consistent with chiral symmetry and fulfills the constraints imposed by analyticity and unitarity. Unknown parameters are fitted to the very precise data on $\tau^-\to\pi^-\pi^0\nu_\tau$ decays obtained by Belle, leading to a good description of the corresponding spectral function up to a $\pi\pi$ squared invariant mass $s\simeq 1.5$ GeV$^2$. We discuss the effect of isospin corrections, and obtain the values of low energy observables. For larger values of $s$, this representation is complemented with a phenomenological description to allow its implementation in the new TAUOLA hadronic currents.
[ { "created": "Tue, 29 Jan 2013 16:34:39 GMT", "version": "v1" }, { "created": "Tue, 6 Aug 2013 07:46:49 GMT", "version": "v2" } ]
2013-09-10
[ [ "Dumm", "D. Gómez", "" ], [ "Roig", "P.", "" ] ]
We propose a dispersive representation of the charged pion vector form factor that is consistent with chiral symmetry and fulfills the constraints imposed by analyticity and unitarity. Unknown parameters are fitted to the very precise data on $\tau^-\to\pi^-\pi^0\nu_\tau$ decays obtained by Belle, leading to a good description of the corresponding spectral function up to a $\pi\pi$ squared invariant mass $s\simeq 1.5$ GeV$^2$. We discuss the effect of isospin corrections, and obtain the values of low energy observables. For larger values of $s$, this representation is complemented with a phenomenological description to allow its implementation in the new TAUOLA hadronic currents.
0812.0942
Tanja Branz
Tanja Branz, Thomas Gutsche, Valery E. Lyubovitskij
Weak decays of heavy hadron molecules involving the f0(980)
11 pages, 5 figures, accepted for publication in Phys. Rev. D
Phys.Rev.D79:014035,2009
10.1103/PhysRevD.79.014035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study weak decays of the charm- and bottom-strange mesons Ds0*(2317), Ds1(2460), Bs0*(5725) and Bs1(5778) with f0(980) in the final state by assuming a hadronic molecule interpretation for their structures. Since in the proposed framework the initial and final states are occupied by hadronic molecules, the predictions for observables can provide a sensitive tool to further test the hadronic molecule structure in future experiments.
[ { "created": "Thu, 4 Dec 2008 15:55:58 GMT", "version": "v1" }, { "created": "Mon, 2 Feb 2009 10:09:24 GMT", "version": "v2" } ]
2009-02-23
[ [ "Branz", "Tanja", "" ], [ "Gutsche", "Thomas", "" ], [ "Lyubovitskij", "Valery E.", "" ] ]
We study weak decays of the charm- and bottom-strange mesons Ds0*(2317), Ds1(2460), Bs0*(5725) and Bs1(5778) with f0(980) in the final state by assuming a hadronic molecule interpretation for their structures. Since in the proposed framework the initial and final states are occupied by hadronic molecules, the predictions for observables can provide a sensitive tool to further test the hadronic molecule structure in future experiments.
1312.5718
Dennis D. Dietrich
Dennis D. Dietrich
Hadrons on the worldline, holography, and Wilson flow
6 pages, 1 figure. v2 corresponds to published version
Phys. Rev. D 89, 086005 (2014)
10.1103/PhysRevD.89.086005
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Holographic principles have impacted the way we look at strong coupling phenomena in quantum chromodynamics, strongly interacting extensions of the standard model, and {condensed-matter} physics. In real world settings, however, we still lack understanding of why and when such an approach is justified. Therefore, here, without invoking any such principle a priori, we demonstrate how such a picture arises in the worldline formulation of quantum field theory. Among other connections to holographic models, a warped AdS5 geometry, a quantum mechanical picture, and hidden local symmetry emerge, as well as a Wilson flow (gradient flow), which extends the four-dimensional sources to five-dimensional fields and a link to the Gutzwiller trace formula. The worldline formulation also reproduces the non-relativistic case, which is important for condensed-matter physics.
[ { "created": "Thu, 19 Dec 2013 20:05:55 GMT", "version": "v1" }, { "created": "Wed, 9 Apr 2014 02:30:36 GMT", "version": "v2" } ]
2014-04-23
[ [ "Dietrich", "Dennis D.", "" ] ]
Holographic principles have impacted the way we look at strong coupling phenomena in quantum chromodynamics, strongly interacting extensions of the standard model, and {condensed-matter} physics. In real world settings, however, we still lack understanding of why and when such an approach is justified. Therefore, here, without invoking any such principle a priori, we demonstrate how such a picture arises in the worldline formulation of quantum field theory. Among other connections to holographic models, a warped AdS5 geometry, a quantum mechanical picture, and hidden local symmetry emerge, as well as a Wilson flow (gradient flow), which extends the four-dimensional sources to five-dimensional fields and a link to the Gutzwiller trace formula. The worldline formulation also reproduces the non-relativistic case, which is important for condensed-matter physics.
hep-ph/9911485
Pierre van Baal
M. Garcia Perez, T.G. Kovacs and P. van Baal
Comments on the Instanton Size Distribution
LaTeX, 15 pages, 3 figures
Phys.Lett. B472 (2000) 295-301
10.1016/S0370-2693(99)01451-3
FTUAM-99-39; INLO-PUB-20/99
hep-ph hep-lat hep-th
null
By studying the non-linear effects of overlapping instanton pairs we address difficulties in the identification of instanton distributions when the average instanton size is comparable to the average distance. For the exact charge two solution, we study how its parametrisation relates to a description in terms of individual instantons. There exist two dual sets of parameters describing the same charge two instanton solution. This duality implies the existence of a minimal separation between two instantons. Conventionally used lattice instanton finder algorithms based on the assumption of diluteness tend to underestimate instanton sizes. Finally we numerically confirm this for realistic parameters of the instanton liquid. The effect is enhanced by parallel orientation in group space.
[ { "created": "Thu, 25 Nov 1999 13:29:39 GMT", "version": "v1" } ]
2009-10-31
[ [ "Perez", "M. Garcia", "" ], [ "Kovacs", "T. G.", "" ], [ "van Baal", "P.", "" ] ]
By studying the non-linear effects of overlapping instanton pairs we address difficulties in the identification of instanton distributions when the average instanton size is comparable to the average distance. For the exact charge two solution, we study how its parametrisation relates to a description in terms of individual instantons. There exist two dual sets of parameters describing the same charge two instanton solution. This duality implies the existence of a minimal separation between two instantons. Conventionally used lattice instanton finder algorithms based on the assumption of diluteness tend to underestimate instanton sizes. Finally we numerically confirm this for realistic parameters of the instanton liquid. The effect is enhanced by parallel orientation in group space.
hep-ph/9504337
Herbert Dreiner
A. H. Chamseddine and Herbi Dreiner (ETH-Zurich)
Anomaly-Free Gauged R-Symmetry in Local Supersymmetry
29 pages, latex, including 3 tables. Final version accepted for publication in NPB. Slight revision of supersymmetry breaking and dropped sub-section on mu problem, which will appear expaned elsewhere
Nucl.Phys. B458 (1996) 65-89
10.1016/0550-3213(95)00583-8
ETH-TH/95-04
hep-ph hep-th
null
We discuss local \R-symmetry as a potentially powerful new model building tool. We first review and clarify that a $U(1)$ \R-symmetry can only be gauged in local and not in global supersymmetry. We determine the anomaly-cancellation conditions for the gauged \R-symmetry. For the standard superpotential these equations have {\it no} solution, independently of how many Standard Model singlets are added to the model. There is also no solution when we increase the number of families and the number of pairs of Higgs doublets. When the Green-Schwarz mechanism is employed to cancel the anomalies, solutions only exist for a large number of singlets. We find many anomaly-free family-independent models with an extra $SU(3)_c$ octet chiral superfield. We consider in detail the conditions for an anomaly-free {\it family dependent} $ U(1)_R$ and find solutions with one, two, three and four extra singlets. Only with three and four extra singlets do we naturally obtain sfermion masses of order the weak-scale. For these solutions we consider the spontaneous breaking of supersymmetry and the $R$-symmetry in the context of local supersymmetry. In general the $U(1)_R$ gauge group is broken at or close to the Planck scale. We consider the effects of the \R-symmetry on baryon- and lepton-number violation in supersymmetry. There is no logical connection between a conserved \R-symmetry and conserved \R-parity. For conserved \R-symmetry we have models for all possibilities of conserved or broken \R-parity. Most models predict dominant effects which could be observed at HERA.
[ { "created": "Wed, 19 Apr 1995 14:25:39 GMT", "version": "v1" }, { "created": "Mon, 26 Jun 1995 12:42:07 GMT", "version": "v2" }, { "created": "Sat, 2 Dec 1995 03:51:16 GMT", "version": "v3" } ]
2011-02-19
[ [ "Chamseddine", "A. H.", "", "ETH-Zurich" ], [ "Dreiner", "Herbi", "", "ETH-Zurich" ] ]
We discuss local \R-symmetry as a potentially powerful new model building tool. We first review and clarify that a $U(1)$ \R-symmetry can only be gauged in local and not in global supersymmetry. We determine the anomaly-cancellation conditions for the gauged \R-symmetry. For the standard superpotential these equations have {\it no} solution, independently of how many Standard Model singlets are added to the model. There is also no solution when we increase the number of families and the number of pairs of Higgs doublets. When the Green-Schwarz mechanism is employed to cancel the anomalies, solutions only exist for a large number of singlets. We find many anomaly-free family-independent models with an extra $SU(3)_c$ octet chiral superfield. We consider in detail the conditions for an anomaly-free {\it family dependent} $ U(1)_R$ and find solutions with one, two, three and four extra singlets. Only with three and four extra singlets do we naturally obtain sfermion masses of order the weak-scale. For these solutions we consider the spontaneous breaking of supersymmetry and the $R$-symmetry in the context of local supersymmetry. In general the $U(1)_R$ gauge group is broken at or close to the Planck scale. We consider the effects of the \R-symmetry on baryon- and lepton-number violation in supersymmetry. There is no logical connection between a conserved \R-symmetry and conserved \R-parity. For conserved \R-symmetry we have models for all possibilities of conserved or broken \R-parity. Most models predict dominant effects which could be observed at HERA.
2307.11734
Martin Formanek
Martin Formanek, John P. Palastro, Dillon Ramsey, Stefan Weber, Antonino Di Piazza
Signatures of vacuum birefringence in low-power flying focus pulses
14 pages, 5 figures
Phys. Rev. D 109 (2024), 056009
10.1103/PhysRevD.109.056009
null
hep-ph physics.optics
http://creativecommons.org/licenses/by/4.0/
Vacuum birefringence produces a differential phase between orthogonally polarized components of a weak electromagnetic probe in the presence of a strong electromagnetic field. Despite representing a hallmark prediction of quantum electrodynamics, vacuum birefringence remains untested in pure light configurations due to the extremely large electromagnetic fields required for a detectable phase difference. Here, we exploit the programmable focal velocity and extended focal range of a flying focus laser pulse to substantially lower the laser power required for detection of vacuum birefringence. In the proposed scheme, a linearly polarized x-ray probe pulse counter-propagates with respect to a flying focus pulse, whose focus moves at the speed of light in the same direction as the x-ray probe. The peak intensity of the flying focus pulse overlaps the probe over millimeter-scale distances and induces a polarization ellipticity on the order of $10^{-10}$, which lies within the detection sensitivity of existing x-ray polarimeters.
[ { "created": "Fri, 21 Jul 2023 17:46:40 GMT", "version": "v1" }, { "created": "Fri, 8 Mar 2024 15:36:53 GMT", "version": "v2" } ]
2024-03-11
[ [ "Formanek", "Martin", "" ], [ "Palastro", "John P.", "" ], [ "Ramsey", "Dillon", "" ], [ "Weber", "Stefan", "" ], [ "Di Piazza", "Antonino", "" ] ]
Vacuum birefringence produces a differential phase between orthogonally polarized components of a weak electromagnetic probe in the presence of a strong electromagnetic field. Despite representing a hallmark prediction of quantum electrodynamics, vacuum birefringence remains untested in pure light configurations due to the extremely large electromagnetic fields required for a detectable phase difference. Here, we exploit the programmable focal velocity and extended focal range of a flying focus laser pulse to substantially lower the laser power required for detection of vacuum birefringence. In the proposed scheme, a linearly polarized x-ray probe pulse counter-propagates with respect to a flying focus pulse, whose focus moves at the speed of light in the same direction as the x-ray probe. The peak intensity of the flying focus pulse overlaps the probe over millimeter-scale distances and induces a polarization ellipticity on the order of $10^{-10}$, which lies within the detection sensitivity of existing x-ray polarimeters.
hep-ph/0608316
Alfredo Valcarce
J. Vijande, A. Valcarce, K. Tsushima
Dynamical study of ${\bf QQ-\bar u \bar d}$ mesons
10 pages, 5 tables. Accepted for publication in Phys. Rev. D
Phys.Rev.D74:054018,2006
10.1103/PhysRevD.74.054018
null
hep-ph hep-ex nucl-th
null
It has been recently conjectured by Selem and Wilczek \cite{Sel06} the existence of a $ss-[\bar u \bar d]$ meson due to strong correlations between the two light antiquarks. We make a detailed study of this system within a dynamical quark model which has proven to be successful in reproducing the most important features of low-energy hadron phenomenology. Our results, obtained within a parameter-free calculation, show that the antidiquark component of the $ss \bar u \bar d$ system indeed entails the stronger attraction, and drives its energy much lower than the $\bar{N}\Xi$ threshold, but still above the $\bar{K^0} {K^*}^-$ or $\bar{{K^*}^0} K^-$ thresholds. We have also studied the $cc \bar u \bar d$ and $bb \bar u \bar d$ systems. Exotic mesons are only expected to exist in the limit of large mass for the two-quark subsystem, $bb\bar u \bar d$, since the calculated mass is below the $\bar{B^0} {B^*}^-$ or $\bar{{B^*}^0} B^-$ thresholds.
[ { "created": "Wed, 30 Aug 2006 10:24:29 GMT", "version": "v1" } ]
2008-11-26
[ [ "Vijande", "J.", "" ], [ "Valcarce", "A.", "" ], [ "Tsushima", "K.", "" ] ]
It has been recently conjectured by Selem and Wilczek \cite{Sel06} the existence of a $ss-[\bar u \bar d]$ meson due to strong correlations between the two light antiquarks. We make a detailed study of this system within a dynamical quark model which has proven to be successful in reproducing the most important features of low-energy hadron phenomenology. Our results, obtained within a parameter-free calculation, show that the antidiquark component of the $ss \bar u \bar d$ system indeed entails the stronger attraction, and drives its energy much lower than the $\bar{N}\Xi$ threshold, but still above the $\bar{K^0} {K^*}^-$ or $\bar{{K^*}^0} K^-$ thresholds. We have also studied the $cc \bar u \bar d$ and $bb \bar u \bar d$ systems. Exotic mesons are only expected to exist in the limit of large mass for the two-quark subsystem, $bb\bar u \bar d$, since the calculated mass is below the $\bar{B^0} {B^*}^-$ or $\bar{{B^*}^0} B^-$ thresholds.
hep-ph/9503257
Mikhail Bilenky
Mikhail Bilenky and Arcadi Santamaria
BEYOND THE STANDARD MODEL WITH EFFECTIVE LAGRANGIANS
LaTeX file, 9 pages, Dec. 1994. Contribution to the Proceedings of the 28th Symposium on the Theory of Elementary Particles, Wendisch-Rietz, August 30 - September 3, 1994.
null
null
DESY 95-027
hep-ph
null
We discuss some applications of the effective quantum field theory to the description of the physics beyond the Standard Model. We consider two different examples. In the first one we derive, at the one-loop level, an effective lagrangian for an extension of the Standard Model with a charged scalar singlet by ``integrating out'' the heavy scalar. In the second example we illustrate the use of general effective theories at the loop level.
[ { "created": "Tue, 7 Mar 1995 16:35:31 GMT", "version": "v1" } ]
2016-09-01
[ [ "Bilenky", "Mikhail", "" ], [ "Santamaria", "Arcadi", "" ] ]
We discuss some applications of the effective quantum field theory to the description of the physics beyond the Standard Model. We consider two different examples. In the first one we derive, at the one-loop level, an effective lagrangian for an extension of the Standard Model with a charged scalar singlet by ``integrating out'' the heavy scalar. In the second example we illustrate the use of general effective theories at the loop level.
1704.05457
Hongxi Xing
Radja Boughezal, Frank Petriello, Ulrich Schubert, Hongxi Xing
The spin-dependent quark beam function at NNLO
18 pages, 3 figures, references added, corrections made in some equations
Phys. Rev. D 96, 034001 (2017)
10.1103/PhysRevD.96.034001
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the beam function for longitudinally-polarized quarks through next-to-next-to-leading order (NNLO) in QCD perturbation theory. This is the last missing ingredient needed to apply the factorization theorem for the $N$-jettiness event-shape variable in polarized collisions through the NNLO level. We present all technical details of our derivation. As a by-product of our calculation we provide the first independent check of the previously-obtained unpolarized quark beam function. We anticipate that our result will have phenomenological applications in describing data from polarized collisions.
[ { "created": "Tue, 18 Apr 2017 18:00:00 GMT", "version": "v1" }, { "created": "Wed, 10 May 2017 01:33:09 GMT", "version": "v2" } ]
2017-08-09
[ [ "Boughezal", "Radja", "" ], [ "Petriello", "Frank", "" ], [ "Schubert", "Ulrich", "" ], [ "Xing", "Hongxi", "" ] ]
We calculate the beam function for longitudinally-polarized quarks through next-to-next-to-leading order (NNLO) in QCD perturbation theory. This is the last missing ingredient needed to apply the factorization theorem for the $N$-jettiness event-shape variable in polarized collisions through the NNLO level. We present all technical details of our derivation. As a by-product of our calculation we provide the first independent check of the previously-obtained unpolarized quark beam function. We anticipate that our result will have phenomenological applications in describing data from polarized collisions.
2004.12174
Ziyue Wang
Ziyue Wang, Xingyu Guo, Shuzhe Shi and Pengfei Zhuang
Mass Correction to Chiral Kinetic Equations
4 pages, Quark Matter 2019 conference proceeding. Drawn from arXiv:1903.03461
null
10.1016/j.nuclphysa.2020.121976
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study fermion mass correction to chiral kinetic equations in electromagnetic fields. Different from the chiral limit where fermion number density is the only independent distribution, the number and spin densities are coupled to each other for massive fermion systems. To the first order in $\hbar$, we derived the quantum correction to the classical on-shell condition and the Boltzmann-type transport equations. To the linear order in the fermion mass, the mass correction does not change the structure of the chiral kinetic equations and behaves like additional collision terms. While the mass correction exists already at classical level in general electromagnetic fields, it is only a first order quantum correction in the study of chiral magnetic effect.
[ { "created": "Sat, 25 Apr 2020 15:49:48 GMT", "version": "v1" } ]
2021-02-03
[ [ "Wang", "Ziyue", "" ], [ "Guo", "Xingyu", "" ], [ "Shi", "Shuzhe", "" ], [ "Zhuang", "Pengfei", "" ] ]
We study fermion mass correction to chiral kinetic equations in electromagnetic fields. Different from the chiral limit where fermion number density is the only independent distribution, the number and spin densities are coupled to each other for massive fermion systems. To the first order in $\hbar$, we derived the quantum correction to the classical on-shell condition and the Boltzmann-type transport equations. To the linear order in the fermion mass, the mass correction does not change the structure of the chiral kinetic equations and behaves like additional collision terms. While the mass correction exists already at classical level in general electromagnetic fields, it is only a first order quantum correction in the study of chiral magnetic effect.
0704.0235
Thomas G. Rizzo
Thomas G. Rizzo
The Determination of the Helicity of $W'$ Boson Couplings at the LHC
29 pages, 11 figures; discussion and reference added, typos corrected
JHEP 0705:037,2007
10.1088/1126-6708/2007/05/037
SLAC-PUB-12392
hep-ph hep-ex
null
Apart from its mass and width, the most important property of a new charged gauge boson, $W'$, is the helicity of its couplings to the SM fermions. Such particles are expected to exist in many extensions of the Standard Model. In this paper we explore the capability of the LHC to determine the $W'$ coupling helicity at low integrated luminosities in the $\ell +E_T^{miss}$ discovery channel. We find that measurements of the transverse mass distribution, reconstructed from this final state in the $W-W'$ interference region, provides the best determination of this quantity. To make such measurements requires integrated luminosities of $\sim 10(60) fb^{-1}$ assuming $M_{W'}=1.5(2.5)$ TeV and provided that the $W'$ couplings have Standard Model magnitude. This helicity determination can be further strengthened by the use of various discovery channel leptonic asymmetries, also measured in the same interference regime, but with higher integrated luminosities.
[ { "created": "Mon, 2 Apr 2007 16:55:32 GMT", "version": "v1" }, { "created": "Mon, 9 Apr 2007 16:54:09 GMT", "version": "v2" }, { "created": "Thu, 3 May 2007 16:39:43 GMT", "version": "v3" }, { "created": "Mon, 7 May 2007 14:49:56 GMT", "version": "v4" } ]
2009-11-13
[ [ "Rizzo", "Thomas G.", "" ] ]
Apart from its mass and width, the most important property of a new charged gauge boson, $W'$, is the helicity of its couplings to the SM fermions. Such particles are expected to exist in many extensions of the Standard Model. In this paper we explore the capability of the LHC to determine the $W'$ coupling helicity at low integrated luminosities in the $\ell +E_T^{miss}$ discovery channel. We find that measurements of the transverse mass distribution, reconstructed from this final state in the $W-W'$ interference region, provides the best determination of this quantity. To make such measurements requires integrated luminosities of $\sim 10(60) fb^{-1}$ assuming $M_{W'}=1.5(2.5)$ TeV and provided that the $W'$ couplings have Standard Model magnitude. This helicity determination can be further strengthened by the use of various discovery channel leptonic asymmetries, also measured in the same interference regime, but with higher integrated luminosities.
2308.16608
Wei Liu
Daniele Barducci, Wei Liu, Arsenii Titov, Zeren Simon Wang, Yu Zhang
Probing the dipole portal to heavy neutral leptons via meson decays at the high-luminosity LHC
16 pages+refs, 5 figures, 2 tables, to match the PRD version
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We consider the dipole portal to sterile neutrinos, also called heavy neutral leptons (HNLs). The dipole interaction with the photon leads to HNL production in meson decays, as well as triggers the HNL decay into an active neutrino and a photon. HNLs with masses of order of 0.01-1 GeV are naturally long-lived if the dipole coupling is sufficiently small. We perform Monte-Carlo simulations and derive the sensitivities of the proposed FASER2 and FACET long-lived particle experiments to HNLs produced via the dipole operator in meson decays at the high-luminosity LHC. Our findings show that these future detectors will be complementary to each other, as well as to existing experiments, and will be able to probe new parts of the parameter space, especially in the case of the dipole operator coupled to the tau neutrino.
[ { "created": "Thu, 31 Aug 2023 10:08:53 GMT", "version": "v1" }, { "created": "Mon, 4 Dec 2023 11:45:39 GMT", "version": "v2" } ]
2023-12-05
[ [ "Barducci", "Daniele", "" ], [ "Liu", "Wei", "" ], [ "Titov", "Arsenii", "" ], [ "Wang", "Zeren Simon", "" ], [ "Zhang", "Yu", "" ] ]
We consider the dipole portal to sterile neutrinos, also called heavy neutral leptons (HNLs). The dipole interaction with the photon leads to HNL production in meson decays, as well as triggers the HNL decay into an active neutrino and a photon. HNLs with masses of order of 0.01-1 GeV are naturally long-lived if the dipole coupling is sufficiently small. We perform Monte-Carlo simulations and derive the sensitivities of the proposed FASER2 and FACET long-lived particle experiments to HNLs produced via the dipole operator in meson decays at the high-luminosity LHC. Our findings show that these future detectors will be complementary to each other, as well as to existing experiments, and will be able to probe new parts of the parameter space, especially in the case of the dipole operator coupled to the tau neutrino.
hep-ph/9612395
Matthias Steinhauser
Matthias Steinhauser
Corrections of O(\alpha_s^2) to the Decay of an Intermediate-Mass Higgs Boson into Two Photons
9 pages, LaTeX, 13 postscript figures. Contribution to the proceedings of the Ringberg Workshop, Tegernsee, Germany, 8-13 December 1996
null
null
MPI/PhT/96-130
hep-ph
null
The QCD correction of $O(\alpha_s^2)$ to the decay of the Standard Model Higgs boson into two photons is presented. We consider the contribution coming from diagrams with a heavy top quark as virtual particle. The first three terms of the expansion in the inverse top mass is calculated. Expressing the result through the on-shell top mass M_t, we find large coefficients for the power-suppressed terms whereas in the $\overline{MS}$ scheme the coefficients are tiny.
[ { "created": "Wed, 18 Dec 1996 11:28:32 GMT", "version": "v1" } ]
2007-05-23
[ [ "Steinhauser", "Matthias", "" ] ]
The QCD correction of $O(\alpha_s^2)$ to the decay of the Standard Model Higgs boson into two photons is presented. We consider the contribution coming from diagrams with a heavy top quark as virtual particle. The first three terms of the expansion in the inverse top mass is calculated. Expressing the result through the on-shell top mass M_t, we find large coefficients for the power-suppressed terms whereas in the $\overline{MS}$ scheme the coefficients are tiny.
2206.08940
Mathias Pierre
Marcos A. G. Garcia, Mathias Pierre, and Sarunas Verner
Scalar Dark Matter Production from Preheating and Structure Formation Constraints
42 pages, 18 figures; v2: minor changes to match published version
null
10.1103/PhysRevD.107.043530
DESY-22-104
hep-ph astro-ph.CO gr-qc hep-th
http://creativecommons.org/licenses/by/4.0/
We investigate the out-of-equilibrium production of scalar dark matter (DM) from the inflaton condensate during inflation and reheating. We assume that this scalar couples only to the inflaton via a direct quartic coupling and is minimally coupled to gravity. We consider all possible production regimes: purely gravitational, weak direct coupling (perturbative), and strong direct coupling (non-perturbative). For each regime, we use different approaches to determine the dark matter phase space distribution and the corresponding relic abundance. For the purely gravitational regime, scalar dark matter quanta are copiously excited during inflation resulting in an infrared (IR) dominated distribution function and a relic abundance which overcloses the universe for a reheating temperature $T_\text{reh}>34 ~\text{GeV}$. A non-vanishing direct coupling induces an effective DM mass and suppresses the large IR modes in favor of ultraviolet (UV) modes and a minimal scalar abundance is generated when the interference between the direct and gravitational couplings is maximal. For large direct couplings, backreaction on the inflaton condensate is accounted for by using the Hartree approximation and lattice simulation techniques. Since scalar DM candidates can behave as non-cold dark matter, we estimate the impact of such species on the matter power spectrum and derive the corresponding constraints from the Lyman-$\alpha$ measurements. We find that they correspond to a lower bound on the DM mass of $\gtrsim 3\times 10^{-4} \, \rm{eV}$ for purely gravitational production, and $\gtrsim 20 \, \rm {eV}$ for direct coupling production. We discuss the implications of these results.
[ { "created": "Fri, 17 Jun 2022 18:00:00 GMT", "version": "v1" }, { "created": "Thu, 15 Jun 2023 07:08:05 GMT", "version": "v2" } ]
2023-06-16
[ [ "Garcia", "Marcos A. G.", "" ], [ "Pierre", "Mathias", "" ], [ "Verner", "Sarunas", "" ] ]
We investigate the out-of-equilibrium production of scalar dark matter (DM) from the inflaton condensate during inflation and reheating. We assume that this scalar couples only to the inflaton via a direct quartic coupling and is minimally coupled to gravity. We consider all possible production regimes: purely gravitational, weak direct coupling (perturbative), and strong direct coupling (non-perturbative). For each regime, we use different approaches to determine the dark matter phase space distribution and the corresponding relic abundance. For the purely gravitational regime, scalar dark matter quanta are copiously excited during inflation resulting in an infrared (IR) dominated distribution function and a relic abundance which overcloses the universe for a reheating temperature $T_\text{reh}>34 ~\text{GeV}$. A non-vanishing direct coupling induces an effective DM mass and suppresses the large IR modes in favor of ultraviolet (UV) modes and a minimal scalar abundance is generated when the interference between the direct and gravitational couplings is maximal. For large direct couplings, backreaction on the inflaton condensate is accounted for by using the Hartree approximation and lattice simulation techniques. Since scalar DM candidates can behave as non-cold dark matter, we estimate the impact of such species on the matter power spectrum and derive the corresponding constraints from the Lyman-$\alpha$ measurements. We find that they correspond to a lower bound on the DM mass of $\gtrsim 3\times 10^{-4} \, \rm{eV}$ for purely gravitational production, and $\gtrsim 20 \, \rm {eV}$ for direct coupling production. We discuss the implications of these results.
1612.07125
Shabbar Raza
Waqas Ahmed, Lorenzo Calibbi, Tianjun Li, Azar Mustafayev, Shabbar Raza
Low Fine Tuning in Yukawa-deflected Gauge Mediation
19 pages, 6 figures, 1 table. v2: version accepted for publication in PRD
Phys. Rev. D 95, 095031 (2017)
10.1103/PhysRevD.95.095031
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss a class of models with gauge-mediated supersymmetry breaking characterized by a non-unified messenger sector inducing non-standard gaugino mass ratios, as well as by additional contributions to the soft mass terms from a matter-messenger coupling. The well-known effect of this coupling is to generate A-terms at one-loop level, hence raising the Higgs mass without relying on super-heavy stops. At the same time, a hierarchy between Wino and gluino masses, as induced by the non-unified messenger fields, can greatly lower the radiative corrections to the Higgs soft mass term driven by the high-energy parameters, thus reducing the fine tuning. We search for models with low fine tuning within this scenario, and we discuss the spectrum, collider phenomenology, constraints, and prospects of the found solutions. We find that some setups are accessible or already excluded by searches at the Large Hadron Collider, and all our scenarios with a tuning better than about 2\% can be tested at the International Linear Collider.
[ { "created": "Wed, 21 Dec 2016 14:09:09 GMT", "version": "v1" }, { "created": "Sat, 13 May 2017 12:54:18 GMT", "version": "v2" } ]
2017-06-07
[ [ "Ahmed", "Waqas", "" ], [ "Calibbi", "Lorenzo", "" ], [ "Li", "Tianjun", "" ], [ "Mustafayev", "Azar", "" ], [ "Raza", "Shabbar", "" ] ]
We discuss a class of models with gauge-mediated supersymmetry breaking characterized by a non-unified messenger sector inducing non-standard gaugino mass ratios, as well as by additional contributions to the soft mass terms from a matter-messenger coupling. The well-known effect of this coupling is to generate A-terms at one-loop level, hence raising the Higgs mass without relying on super-heavy stops. At the same time, a hierarchy between Wino and gluino masses, as induced by the non-unified messenger fields, can greatly lower the radiative corrections to the Higgs soft mass term driven by the high-energy parameters, thus reducing the fine tuning. We search for models with low fine tuning within this scenario, and we discuss the spectrum, collider phenomenology, constraints, and prospects of the found solutions. We find that some setups are accessible or already excluded by searches at the Large Hadron Collider, and all our scenarios with a tuning better than about 2\% can be tested at the International Linear Collider.
hep-ph/0407222
Alexander Kup\v{c}o
Alexander Kupco, Robert Peschanski, Christophe Royon
Decisive test for the Pomeron at Tevatron
5 pages, 3 figures, 1 tabel revtex format
Phys.Lett.B606:139-144,2005
10.1016/j.physletb.2004.11.072
null
hep-ph
null
We propose a new measurement to be performed at the Tevatron which can be decisive to distinguish between Pomeron-based and soft color interaction models of hard diffractive scattering.
[ { "created": "Tue, 20 Jul 2004 07:14:46 GMT", "version": "v1" } ]
2008-11-26
[ [ "Kupco", "Alexander", "" ], [ "Peschanski", "Robert", "" ], [ "Royon", "Christophe", "" ] ]
We propose a new measurement to be performed at the Tevatron which can be decisive to distinguish between Pomeron-based and soft color interaction models of hard diffractive scattering.
hep-ph/9812305
Alan Chodos
Alan Chodos, Hisakazu Minakata, and Fred Cooper
Cooper pairing at large N in a 2-dimensional model
11 pages, plain TeX, no figures
Phys.Lett. B449 (1999) 260-266
10.1016/S0370-2693(99)00084-2
YCTP-P24-98; TMUP-HEL-9813
hep-ph
null
We study a 2-dimensional model of Fermi fields that is closely related to the Gross-Neveu model, and show that to leading order in 1/N a <psi-psi> condensate forms. This effect is independent of the chemical potential, a peculiarity that we expect to be specific to 2 dimensions. We also expect the condensate to be unstable against corrections at higher orders in 1/N. We compute the Green's functions associated with the composite psi-psi, and show that the Fermion acquires a Majorana mass proportional to the gap, and that a massless Goldstone pole appears.
[ { "created": "Wed, 9 Dec 1998 18:33:29 GMT", "version": "v1" } ]
2009-10-31
[ [ "Chodos", "Alan", "" ], [ "Minakata", "Hisakazu", "" ], [ "Cooper", "Fred", "" ] ]
We study a 2-dimensional model of Fermi fields that is closely related to the Gross-Neveu model, and show that to leading order in 1/N a <psi-psi> condensate forms. This effect is independent of the chemical potential, a peculiarity that we expect to be specific to 2 dimensions. We also expect the condensate to be unstable against corrections at higher orders in 1/N. We compute the Green's functions associated with the composite psi-psi, and show that the Fermion acquires a Majorana mass proportional to the gap, and that a massless Goldstone pole appears.
hep-ph/0508292
Prasanta Das Kumar
Prasanta Kumar Das
Determination of $\gamma$ from the $\eta - \eta'$ mixing within QCD Factorization
16 pages, 12 eps figures
null
null
null
hep-ph
null
The charmless nonleptonic $B\to \eta K$ decay is an useful probe to test the strong interaction dynamics part of the Standard Model. Within the QCD factorization framework, we analyse this particular decay by using the most recent data of $BR(B^+ \to \eta K^+)$ and $A_{cp}(B^+ \to \eta K^+)$ available in the Heavy Flavour Averaging Group (HFAG) webcite. Using these data we constraint the unitarity angle $\gamma$ and $\eta-\eta'$ mixing angle $\theta$. We find that such constraint is scale dependent, e.g. for $\gamma = 70^o$, the data for $BR(B^+ \to \eta K^+)$ (= $(2.6 \pm 0.5)\times 10^{-6}$) suggests that $\theta$ should lie in between $-46^o$ and $-44^o$, $-30^o$ and $-26^o$ for $\mu = m_b/2$. For $\mu = m_b$, the same $BR$ data (with the same $\gamma$) suggests that $\theta$ should lie in between $-54^o$ and $-50^o$, $-30^o$ and $-26^o$. The allowed region followed from $A_{cp}=-0.25\pm 0.14$, is found to be rather wider than that obtained from the $BR(B^+ \to \eta K^+)$ data. For $\gamma=70^o$ and $\theta = -21.3^o$, we find $BR(B^-(+) \to \eta K^-(+))= 2.93(4.91) \times 10^{-6}$ and $A_{cp}=-0.252$ at $\mu=m_b$, and about $ 2.98(5.72) \times 10^{-6}$ and -0.315 corresponding to $\mu=m_b/2$. We investigate the role of the power corrections in such constraints.
[ { "created": "Mon, 29 Aug 2005 12:31:29 GMT", "version": "v1" } ]
2007-05-23
[ [ "Das", "Prasanta Kumar", "" ] ]
The charmless nonleptonic $B\to \eta K$ decay is an useful probe to test the strong interaction dynamics part of the Standard Model. Within the QCD factorization framework, we analyse this particular decay by using the most recent data of $BR(B^+ \to \eta K^+)$ and $A_{cp}(B^+ \to \eta K^+)$ available in the Heavy Flavour Averaging Group (HFAG) webcite. Using these data we constraint the unitarity angle $\gamma$ and $\eta-\eta'$ mixing angle $\theta$. We find that such constraint is scale dependent, e.g. for $\gamma = 70^o$, the data for $BR(B^+ \to \eta K^+)$ (= $(2.6 \pm 0.5)\times 10^{-6}$) suggests that $\theta$ should lie in between $-46^o$ and $-44^o$, $-30^o$ and $-26^o$ for $\mu = m_b/2$. For $\mu = m_b$, the same $BR$ data (with the same $\gamma$) suggests that $\theta$ should lie in between $-54^o$ and $-50^o$, $-30^o$ and $-26^o$. The allowed region followed from $A_{cp}=-0.25\pm 0.14$, is found to be rather wider than that obtained from the $BR(B^+ \to \eta K^+)$ data. For $\gamma=70^o$ and $\theta = -21.3^o$, we find $BR(B^-(+) \to \eta K^-(+))= 2.93(4.91) \times 10^{-6}$ and $A_{cp}=-0.252$ at $\mu=m_b$, and about $ 2.98(5.72) \times 10^{-6}$ and -0.315 corresponding to $\mu=m_b/2$. We investigate the role of the power corrections in such constraints.
1105.3934
Bedangadas Mohanty
Sourendu Gupta, Xiaofeng Luo, Bedangadas Mohanty, Hans Georg Ritter and Nu Xu
Scale for the Phase Diagram of Quantum Chromodynamics
16 pages and 4 figures. Accepted for publication in Science
Science 332:1525-1528,2011
10.1126/science.1204621
null
hep-ph hep-lat hep-th nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Matter described by Quantum Chromodynamics (QCD), the theory of strong interactions, may undergo phase transitions when its temperature and the chemical potentials are varied. QCD at finite temperature is studied in the laboratory by colliding heavy-ions at varying beam energies. We present a test of QCD in the non-perturbative domain through a comparison of thermodynamic fluctuations predicted in lattice computations with the experimental data of baryon number distributions in high-energy heavy-ion collisions. This study provides evidence for thermalization in these collisions, and allows us to find the crossover temperature between normal nuclear matter and a deconfined phase called the quark gluon plasma. This value allows us to set a scale for the phase diagram of QCD.
[ { "created": "Thu, 19 May 2011 17:22:20 GMT", "version": "v1" } ]
2011-06-24
[ [ "Gupta", "Sourendu", "" ], [ "Luo", "Xiaofeng", "" ], [ "Mohanty", "Bedangadas", "" ], [ "Ritter", "Hans Georg", "" ], [ "Xu", "Nu", "" ] ]
Matter described by Quantum Chromodynamics (QCD), the theory of strong interactions, may undergo phase transitions when its temperature and the chemical potentials are varied. QCD at finite temperature is studied in the laboratory by colliding heavy-ions at varying beam energies. We present a test of QCD in the non-perturbative domain through a comparison of thermodynamic fluctuations predicted in lattice computations with the experimental data of baryon number distributions in high-energy heavy-ion collisions. This study provides evidence for thermalization in these collisions, and allows us to find the crossover temperature between normal nuclear matter and a deconfined phase called the quark gluon plasma. This value allows us to set a scale for the phase diagram of QCD.
2206.13524
Grant Remmen
Grant N. Remmen, Nicholas L. Rodd
Spinning Sum Rules for the Dimension-Six SMEFT
51 pages, 1 figure
JHEP 2209:030,2022
10.1007/JHEP09(2022)030
CERN-TH-2022-105
hep-ph hep-th
http://creativecommons.org/licenses/by/4.0/
We construct new dispersive sum rules for the effective field theory of the standard model at mass dimension six. These spinning sum rules encode information about the spin of UV states: the sign of the IR Wilson coefficients carries a memory of the dominant spin in the UV completion. The sum rules are constructed for operators containing scalars and fermions, although we consider the dimension-six SMEFT exhaustively, outlining why equivalent relations do not hold for the remaining operators. As with any dimension-six dispersive argument, our conclusions are contingent on the absence of potential poles at infinity, so-called boundary terms, and we discuss in detail where these are expected to appear. There are a number of phenomenological applications of spinning sum rules, and as an example we explore the connection to the Peskin-Takeuchi parameters and, more generally, the set of oblique parameters in universal theories.
[ { "created": "Mon, 27 Jun 2022 18:00:00 GMT", "version": "v1" }, { "created": "Tue, 6 Sep 2022 19:25:16 GMT", "version": "v2" } ]
2022-09-08
[ [ "Remmen", "Grant N.", "" ], [ "Rodd", "Nicholas L.", "" ] ]
We construct new dispersive sum rules for the effective field theory of the standard model at mass dimension six. These spinning sum rules encode information about the spin of UV states: the sign of the IR Wilson coefficients carries a memory of the dominant spin in the UV completion. The sum rules are constructed for operators containing scalars and fermions, although we consider the dimension-six SMEFT exhaustively, outlining why equivalent relations do not hold for the remaining operators. As with any dimension-six dispersive argument, our conclusions are contingent on the absence of potential poles at infinity, so-called boundary terms, and we discuss in detail where these are expected to appear. There are a number of phenomenological applications of spinning sum rules, and as an example we explore the connection to the Peskin-Takeuchi parameters and, more generally, the set of oblique parameters in universal theories.
2007.07739
Hyungjin Kim
Hyungjin Kim
A constraint on light primordial black holes from the interstellar medium temperature
10 pages, 5 figures; discussion extended, minor typos/numerical error corrected, conclusion unchanged, matches the version accepted for publication in MNRAS
null
10.1093/mnras/stab1222
null
hep-ph astro-ph.CO astro-ph.GA
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Primordial black holes are a viable dark matter candidate. They decay via Hawking evaporation. Energetic particles from the Hawking radiation interact with interstellar gas, depositing their energy as heat and ionization. For a sufficiently high Hawking temperature, fast electrons produced by black holes deposit a substantial fraction of energy as heat through the Coulomb interaction. Using the dwarf galaxy Leo T, we place an upper bound on the fraction of primordial black hole dark matter. For $M < 5 \times 10^{-17} M_\odot$, our bound is competitive with or stronger than other bounds.
[ { "created": "Wed, 15 Jul 2020 15:10:59 GMT", "version": "v1" }, { "created": "Thu, 6 May 2021 18:18:07 GMT", "version": "v2" } ]
2021-05-12
[ [ "Kim", "Hyungjin", "" ] ]
Primordial black holes are a viable dark matter candidate. They decay via Hawking evaporation. Energetic particles from the Hawking radiation interact with interstellar gas, depositing their energy as heat and ionization. For a sufficiently high Hawking temperature, fast electrons produced by black holes deposit a substantial fraction of energy as heat through the Coulomb interaction. Using the dwarf galaxy Leo T, we place an upper bound on the fraction of primordial black hole dark matter. For $M < 5 \times 10^{-17} M_\odot$, our bound is competitive with or stronger than other bounds.
2102.02185
Namit Mahajan
Namit Mahajan
$\rho$ exchange contribution to neutrinoless double beta decay
null
null
10.1140/epjc/s10052-023-11716-3
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider $\rho$ meson contributions to neutrinoless double beta decay amplitude stemming from the hadronization of the short distance quark-electron currents. These contributions are evaluated within vacuum dominance approximation. The one and two $\rho$ exchange contributions affect the Fermi transition nuclear matrix element in a way that lead to near cancellations in the same chirality, left-left and right-right, short range amplitudes when these new contributions are combined with the conventional short range amplitudes, while the left-right amplitude almost triples. This then necessitates the inclusion of $\rho$ exchange amplitudes in any phenomenological study, like in left-right theories.
[ { "created": "Wed, 3 Feb 2021 18:24:50 GMT", "version": "v1" } ]
2023-07-12
[ [ "Mahajan", "Namit", "" ] ]
We consider $\rho$ meson contributions to neutrinoless double beta decay amplitude stemming from the hadronization of the short distance quark-electron currents. These contributions are evaluated within vacuum dominance approximation. The one and two $\rho$ exchange contributions affect the Fermi transition nuclear matrix element in a way that lead to near cancellations in the same chirality, left-left and right-right, short range amplitudes when these new contributions are combined with the conventional short range amplitudes, while the left-right amplitude almost triples. This then necessitates the inclusion of $\rho$ exchange amplitudes in any phenomenological study, like in left-right theories.
hep-ph/9708272
Jan Kalinowski
J. Kalinowski, R. Rueckl, H. Spiesberger and P.M. Zerwas
R-Parity Violating SUSY Signals in Lepton-Pair Production at the Tevatron
LaTeX file, 12 pages, 4 figures, uses epsfig, axodraw
Phys.Lett.B414:297-304,1997
10.1016/S0370-2693(97)01184-2
BI-TP 97/29, DESY 97-062, WUE-ITP-97-024
hep-ph
null
In supersymmetric theories with R-parity breaking, sleptons can be produced in quark-antiquark annihilation at the Tevatron through interactions in which two quark fields are coupled to a slepton field. If at the same time trilinear slepton-lepton-lepton couplings are present, the sleptons can be searched for as resonances in $p\bar{p}\to \tilde{\nu} \to l^+l^-$ and $\tilde{\tau}\to l\nu $ final states. Existing Tevatron data can be exploited to derive bounds on the Yukawa couplings of sleptons to quark and lepton pairs. Similar bounds can also be obtained from $e^+e^-$ annihilation to hadrons at LEP2.
[ { "created": "Thu, 7 Aug 1997 11:24:32 GMT", "version": "v1" } ]
2016-09-06
[ [ "Kalinowski", "J.", "" ], [ "Rueckl", "R.", "" ], [ "Spiesberger", "H.", "" ], [ "Zerwas", "P. M.", "" ] ]
In supersymmetric theories with R-parity breaking, sleptons can be produced in quark-antiquark annihilation at the Tevatron through interactions in which two quark fields are coupled to a slepton field. If at the same time trilinear slepton-lepton-lepton couplings are present, the sleptons can be searched for as resonances in $p\bar{p}\to \tilde{\nu} \to l^+l^-$ and $\tilde{\tau}\to l\nu $ final states. Existing Tevatron data can be exploited to derive bounds on the Yukawa couplings of sleptons to quark and lepton pairs. Similar bounds can also be obtained from $e^+e^-$ annihilation to hadrons at LEP2.
1412.5660
Sonia El Hedri
Sonia El Hedri, William Shepherd, Devin G.E. Walker
Perturbative Unitarity Constraints on Gauge Portals
10 pages, 12 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dark matter that was once in thermal equilibrium with the Standard Model is generally prohibited from obtaining all of its mass from the electroweak phase transition. This implies a new scale of physics and mediator particles to facilitate dark matter annihilation. In this work, we focus on dark matter that annihilates through a generic gauge boson portal. We show how partial wave unitarity places upper bounds on the dark gauge boson, dark Higgs and dark matter masses. Outside of well-defined fine-tuned regions, we find an upper bound of 9 TeV for the dark matter mass when the dark Higgs and dark gauge bosons both facilitate the dark matter annihilations. In this scenario, the upper bound on the dark Higgs and dark gauge boson masses are 10 TeV and 16 TeV, respectively. When only the dark gauge boson facilitates dark matter annihilations, we find an upper bound of 3 TeV and 6 TeV for the dark matter and dark gauge boson, respectively. Overall, using the gauge portal as a template, we describe a method to not only place upper bounds on the dark matter mass but also on the new particles with Standard Model quantum numbers. We briefly discuss the reach of future accelerator, direct and indirect detection experiments for this class of models.
[ { "created": "Wed, 17 Dec 2014 22:41:27 GMT", "version": "v1" } ]
2014-12-19
[ [ "Hedri", "Sonia El", "" ], [ "Shepherd", "William", "" ], [ "Walker", "Devin G. E.", "" ] ]
Dark matter that was once in thermal equilibrium with the Standard Model is generally prohibited from obtaining all of its mass from the electroweak phase transition. This implies a new scale of physics and mediator particles to facilitate dark matter annihilation. In this work, we focus on dark matter that annihilates through a generic gauge boson portal. We show how partial wave unitarity places upper bounds on the dark gauge boson, dark Higgs and dark matter masses. Outside of well-defined fine-tuned regions, we find an upper bound of 9 TeV for the dark matter mass when the dark Higgs and dark gauge bosons both facilitate the dark matter annihilations. In this scenario, the upper bound on the dark Higgs and dark gauge boson masses are 10 TeV and 16 TeV, respectively. When only the dark gauge boson facilitates dark matter annihilations, we find an upper bound of 3 TeV and 6 TeV for the dark matter and dark gauge boson, respectively. Overall, using the gauge portal as a template, we describe a method to not only place upper bounds on the dark matter mass but also on the new particles with Standard Model quantum numbers. We briefly discuss the reach of future accelerator, direct and indirect detection experiments for this class of models.
1805.10173
Michel Tytgat
Stefano Colucci, Federica Giacchino, Michel H.G. Tytgat and J\'er\^ome Vandecasteele
Radiative corrections to vectorlike portal dark matter
25 pages, 12 figures. One extra figure. Conclusions unchanged. Version published in PRD
Phys. Rev. D 98, 115029 (2018)
10.1103/PhysRevD.98.115029
ULB-TH/18-08; BONN-TH-2018-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A massive real scalar dark matter particle $S$ can couple to Standard Model leptons or quarks through a vector-like fermionic mediator $\psi$, a scenario known as the Vector-like portal. Due to helicity suppression of the annihilation cross section into a pair of SM fermions, it has been shown in previous works that radiative corrections, either at one-loop or through radiation of gauge bosons, may play a significant role both in determining the relic abundance and for indirect detection. All previous works considered the limit of massless final state quarks or leptons. In this work, we focus on a technical issue, which is to reliably determine the annihilation cross sections taking into account finite fermion masses. Following previous works in the framework of simplified supersymmetric dark matter scenarios, and building on an analogy with Higgs decay into fermions, we address the issue of infrared and collinear divergences that plagues the cross section by adopting an effective operator description, which captures most of the relevant physics and give explicit expressions for the annihilation cross sections. We then develop several approximations for the differential and total cross sections, which simplify greatly their expressions, and which can then be used in various phenomenological studies of similar models. Finally, we describe our method to compute the final gamma-ray spectrum, including hadronisation of the heavy fermions, and provide some illustrative spectra for specific dark matter candidates.
[ { "created": "Fri, 25 May 2018 14:21:45 GMT", "version": "v1" }, { "created": "Wed, 6 Feb 2019 14:49:40 GMT", "version": "v2" } ]
2019-02-07
[ [ "Colucci", "Stefano", "" ], [ "Giacchino", "Federica", "" ], [ "Tytgat", "Michel H. G.", "" ], [ "Vandecasteele", "Jérôme", "" ] ]
A massive real scalar dark matter particle $S$ can couple to Standard Model leptons or quarks through a vector-like fermionic mediator $\psi$, a scenario known as the Vector-like portal. Due to helicity suppression of the annihilation cross section into a pair of SM fermions, it has been shown in previous works that radiative corrections, either at one-loop or through radiation of gauge bosons, may play a significant role both in determining the relic abundance and for indirect detection. All previous works considered the limit of massless final state quarks or leptons. In this work, we focus on a technical issue, which is to reliably determine the annihilation cross sections taking into account finite fermion masses. Following previous works in the framework of simplified supersymmetric dark matter scenarios, and building on an analogy with Higgs decay into fermions, we address the issue of infrared and collinear divergences that plagues the cross section by adopting an effective operator description, which captures most of the relevant physics and give explicit expressions for the annihilation cross sections. We then develop several approximations for the differential and total cross sections, which simplify greatly their expressions, and which can then be used in various phenomenological studies of similar models. Finally, we describe our method to compute the final gamma-ray spectrum, including hadronisation of the heavy fermions, and provide some illustrative spectra for specific dark matter candidates.
2404.12409
Boris Blankleider
B. Blankleider and A. N. Kvinikhidze
Exact unified tetraquark equations
22 pages, 7 figures, to be published in Few-Body Systems. arXiv admin note: substantial text overlap with arXiv:2302.11542
null
null
null
hep-ph nucl-th
http://creativecommons.org/licenses/by/4.0/
Recently we formulated covariant equations describing the tetraquark in terms of an admixture of two-body states $D\bar D$ (diquark-antidiquark), $MM$ (meson-meson), and three-body-like states where two of the quarks are spectators while the other two are interacting [Phys. Rev. D 107, 094014 (2023)]. A feature of these equations is that they unify descriptions of seemingly unrelated models of the tetraquark, like, for example, the $D\bar D$ model of the Moscow group [Faustov et al., Universe 7, 94 (2021)] and the coupled channel $D \bar D-MM$ model of the Giessen group [Heupel et al., Phys. Lett. B718, 545 (2012)]. Here we extend these equations to the exact case where $q\bar{q}$ annihilation is incorporated explicitly, and all previously neglected terms (three-body forces, non-pole contributions to two-quark t matrices, etc.) are taken into account through the inclusion of a single $q\bar{q}$ potential $\Delta$.
[ { "created": "Wed, 17 Apr 2024 10:15:59 GMT", "version": "v1" } ]
2024-04-22
[ [ "Blankleider", "B.", "" ], [ "Kvinikhidze", "A. N.", "" ] ]
Recently we formulated covariant equations describing the tetraquark in terms of an admixture of two-body states $D\bar D$ (diquark-antidiquark), $MM$ (meson-meson), and three-body-like states where two of the quarks are spectators while the other two are interacting [Phys. Rev. D 107, 094014 (2023)]. A feature of these equations is that they unify descriptions of seemingly unrelated models of the tetraquark, like, for example, the $D\bar D$ model of the Moscow group [Faustov et al., Universe 7, 94 (2021)] and the coupled channel $D \bar D-MM$ model of the Giessen group [Heupel et al., Phys. Lett. B718, 545 (2012)]. Here we extend these equations to the exact case where $q\bar{q}$ annihilation is incorporated explicitly, and all previously neglected terms (three-body forces, non-pole contributions to two-quark t matrices, etc.) are taken into account through the inclusion of a single $q\bar{q}$ potential $\Delta$.
2210.14094
Shao-Jiang Wang
Song He, Li Li, Zhibin Li, Shao-Jiang Wang
Gravitational Waves and Primordial Black Hole Productions from Gluodynamics by Holography
v1, 5 pages + appendix, 5 figures; v2, title slightly changed, version accepted for publication in Sci. China Phys. Mech. Astron
Sci. China Phys. Mech. Astron. 67 (2024) 240411
10.1007/s11433-023-2293-2
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Understanding the nature of quantum chromodynamics (QCD) matter is important but challenging due to the presence of non-perturbative dynamics under extreme conditions. We construct a holographic model describing the gluon sector of QCD at finite temperatures in the non-perturbative regime. The equation of state as a function of temperature is in good accordance with the lattice QCD data. Moreover, the Polyakov loop and the gluon condensation, which are proper order parameters to capture the deconfinement phase transition, also agree quantitatively well with the lattice QCD data. We obtain a strong first-order confinement/deconfinement phase transition at $T_c=276.5\,\text{MeV}$ that is consistent with the lattice QCD prediction. Based on our model for a pure gluon hidden sector, we compute the stochastic gravitational waves and primordial black hole (PBH) productions from this confinement/deconfinement phase transition in the early Universe. The resulting stochastic gravitational-wave backgrounds are found to be within detectability in the International Pulsar Timing Array and Square Kilometre Array in the near future when the associated productions of PBHs saturate the current observational bounds on the PBH abundances from the LIGO-Virgo-Collaboration O3 data.
[ { "created": "Tue, 25 Oct 2022 15:23:32 GMT", "version": "v1" }, { "created": "Tue, 9 Jan 2024 15:24:11 GMT", "version": "v2" } ]
2024-02-23
[ [ "He", "Song", "" ], [ "Li", "Li", "" ], [ "Li", "Zhibin", "" ], [ "Wang", "Shao-Jiang", "" ] ]
Understanding the nature of quantum chromodynamics (QCD) matter is important but challenging due to the presence of non-perturbative dynamics under extreme conditions. We construct a holographic model describing the gluon sector of QCD at finite temperatures in the non-perturbative regime. The equation of state as a function of temperature is in good accordance with the lattice QCD data. Moreover, the Polyakov loop and the gluon condensation, which are proper order parameters to capture the deconfinement phase transition, also agree quantitatively well with the lattice QCD data. We obtain a strong first-order confinement/deconfinement phase transition at $T_c=276.5\,\text{MeV}$ that is consistent with the lattice QCD prediction. Based on our model for a pure gluon hidden sector, we compute the stochastic gravitational waves and primordial black hole (PBH) productions from this confinement/deconfinement phase transition in the early Universe. The resulting stochastic gravitational-wave backgrounds are found to be within detectability in the International Pulsar Timing Array and Square Kilometre Array in the near future when the associated productions of PBHs saturate the current observational bounds on the PBH abundances from the LIGO-Virgo-Collaboration O3 data.