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1401.0250
Hao Sun
Hao Sun and Chong-Xing Yue
Precise photoproduction of the charged top-pions at the LHC with forward detector acceptances
21pages, 7figures. arXiv admin note: text overlap with arXiv:1201.4364 by other authors
Eur.Phys.J. C74 (2014) 2823
10.1140/epjc/s10052-014-2823-5
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the photoproduction of the charged top-pion predicted by the top triangle moose ($TTM$) model (a deconstructed version of the topcolor-assisted technicolor $TC2$ model) via the processes $pp\rightarrow p \gamma p \rightarrow \pi^\pm_t t +X$ at the 14 $TeV$ Large Hadron Collider ($LHC$) including next-to-leading order ($NLO$) $QCD$ corrections. Our results show that the production cross sections and distributions are sensitive to the free parameters $\sin\omega$ and $M_{\pi_t}$. Typical $QCD$ correction value is $7\% \sim 11\%$ and does not depend much on $\sin\omega$ as well as the forward detector acceptances.
[ { "created": "Wed, 1 Jan 2014 04:51:00 GMT", "version": "v1" } ]
2014-06-17
[ [ "Sun", "Hao", "" ], [ "Yue", "Chong-Xing", "" ] ]
We study the photoproduction of the charged top-pion predicted by the top triangle moose ($TTM$) model (a deconstructed version of the topcolor-assisted technicolor $TC2$ model) via the processes $pp\rightarrow p \gamma p \rightarrow \pi^\pm_t t +X$ at the 14 $TeV$ Large Hadron Collider ($LHC$) including next-to-leading order ($NLO$) $QCD$ corrections. Our results show that the production cross sections and distributions are sensitive to the free parameters $\sin\omega$ and $M_{\pi_t}$. Typical $QCD$ correction value is $7\% \sim 11\%$ and does not depend much on $\sin\omega$ as well as the forward detector acceptances.
hep-ph/0606203
Dmitri Melikhov
Dmitri Melikhov and Berthold Stech
Fall-apart decays of polyquark hadrons
19 pages, discussion of the parameters used is added on page 5, version published in Phys. Rev. D
Phys.Rev.D74:034022,2006
10.1103/PhysRevD.74.034022
null
hep-ph
null
We analyse fall-apart decays of poliquark (tetra, penta and molecule type) hadrons within the constituent quark picture. For processes in which a poliquark hadron goes to final states containing a light pseudoscalar meson the constraints given by chiral symmetry are implemented. As an application of the approach developed, fall-apart decays of $a(980)$ and X(3872) are studied, assuming these mesons are poliquark hadrons. Two extreme options - confined diquark-diquark states and molecular states - are considered. For $a^0(980)$, the observed width can be obtained assuming that this meson is a diquark-diquark composite with a relatively large size of around $1\div 1.5$ fm. The pure $K \bar K $ molecular-type state, however, can be excluded. For the X(3872), a sufficiently small width can be obtained if it is a dominantly isospin-0 diquark-diquark composite with a very large size of $\ge 2.5$ fm. The pure molecular option appears possible if the binding energy is tiny, $E_b\lesssim 0.2$ MeV, corresponding to a huge size.
[ { "created": "Mon, 19 Jun 2006 17:20:01 GMT", "version": "v1" }, { "created": "Wed, 30 Aug 2006 09:06:00 GMT", "version": "v2" } ]
2008-11-26
[ [ "Melikhov", "Dmitri", "" ], [ "Stech", "Berthold", "" ] ]
We analyse fall-apart decays of poliquark (tetra, penta and molecule type) hadrons within the constituent quark picture. For processes in which a poliquark hadron goes to final states containing a light pseudoscalar meson the constraints given by chiral symmetry are implemented. As an application of the approach developed, fall-apart decays of $a(980)$ and X(3872) are studied, assuming these mesons are poliquark hadrons. Two extreme options - confined diquark-diquark states and molecular states - are considered. For $a^0(980)$, the observed width can be obtained assuming that this meson is a diquark-diquark composite with a relatively large size of around $1\div 1.5$ fm. The pure $K \bar K $ molecular-type state, however, can be excluded. For the X(3872), a sufficiently small width can be obtained if it is a dominantly isospin-0 diquark-diquark composite with a very large size of $\ge 2.5$ fm. The pure molecular option appears possible if the binding energy is tiny, $E_b\lesssim 0.2$ MeV, corresponding to a huge size.
0905.1649
Zakaria Merebashvili
B.A. Kniehl, A.V. Kotikov, Z.V. Merebashvili, O.L. Veretin
Heavy-quark pair production in polarized photon-photon collisions at next-to-leading order: Fully integrated total cross sections
Revtex, 8 pages, 1 MATHEMATICA file, trivial typo for F_{16} in Eq. (4.6) corrected, one reference added, matches the published version
Phys.Rev.D79:114032,2009
10.1103/PhysRevD.79.114032
DESY 09-070
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the production of heavy-quark pairs in the collisions of polarized and unpolarized on-shell photons and present, in analytic form, the fully integrated total cross sections for total photon spins $J_z=0, \pm 2$ at next-to-leading-order in QCD. Phenomenological applications include $b\bar b$ production, which represents an irreducible background to standard-model intermediate-mass Higgs-boson production, as well as $t\bar t$ production.
[ { "created": "Mon, 11 May 2009 16:22:21 GMT", "version": "v1" }, { "created": "Mon, 29 Jun 2009 23:05:22 GMT", "version": "v2" } ]
2009-07-09
[ [ "Kniehl", "B. A.", "" ], [ "Kotikov", "A. V.", "" ], [ "Merebashvili", "Z. V.", "" ], [ "Veretin", "O. L.", "" ] ]
We consider the production of heavy-quark pairs in the collisions of polarized and unpolarized on-shell photons and present, in analytic form, the fully integrated total cross sections for total photon spins $J_z=0, \pm 2$ at next-to-leading-order in QCD. Phenomenological applications include $b\bar b$ production, which represents an irreducible background to standard-model intermediate-mass Higgs-boson production, as well as $t\bar t$ production.
1611.08615
Diego Redigolo
Andrey Katz, Alberto Mariotti, Stefan Pokorski, Diego Redigolo, Robert Ziegler
SUSY Meets Her Twin
37 pages plus appendices, 15 figures
null
10.1007/JHEP01(2017)142
CERN-TH-2016-240, TTP16-054
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.
[ { "created": "Fri, 25 Nov 2016 21:14:29 GMT", "version": "v1" } ]
2017-03-08
[ [ "Katz", "Andrey", "" ], [ "Mariotti", "Alberto", "" ], [ "Pokorski", "Stefan", "" ], [ "Redigolo", "Diego", "" ], [ "Ziegler", "Robert", "" ] ]
We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.
hep-ph/0403274
Dmitri Peressounko
D. Peressounko, for WA98 collaboration
Interferometry of direct photons in Pb+Pb collisions at 158 AGeV
4 pages, 3 figures, proceedings for Quark Matter 2004
null
10.1088/0954-3899/30/8/059
null
hep-ph
null
We present final results from the WA98 experiment which provide first measurements of Bose-Einstein correlations of direct photons in ultrarelativistic heavy ion collisions. Invariant interferometric radii were extracted in the range $100<K_T<300$ MeV/c and compared to interferometric radii of charged pions. The yield of direct photons for $100<p_T<300$ MeV/c was extracted from the correlation strength parameter and compared to the yield of direct photons measured in WA98 at higher $p_T$ with the statistical subtraction method, and to predictions of a fireball model.
[ { "created": "Sat, 27 Mar 2004 16:11:45 GMT", "version": "v1" } ]
2009-11-10
[ [ "Peressounko", "D.", "" ], [ "collaboration", "for WA98", "" ] ]
We present final results from the WA98 experiment which provide first measurements of Bose-Einstein correlations of direct photons in ultrarelativistic heavy ion collisions. Invariant interferometric radii were extracted in the range $100<K_T<300$ MeV/c and compared to interferometric radii of charged pions. The yield of direct photons for $100<p_T<300$ MeV/c was extracted from the correlation strength parameter and compared to the yield of direct photons measured in WA98 at higher $p_T$ with the statistical subtraction method, and to predictions of a fireball model.
hep-ph/9503458
null
Michael S. Chanowitz
Probing for Ultraheavy Quanta at LHC
12 pages plain LATEX plus 2 postscript figures in separate uuencoded file or by request. Complete manuscript available as a postscript file at http://theor1.lbl.gov/www/theorygroup/papers/36949.ps
Phys.Lett.B352:376-381,1995
10.1016/0370-2693(95)00477-3
LBL-36949
hep-ph
null
Experiments at the LHC are sensitive to the presence or absence of matter quanta at mass scales far beyond the scales they can probe directly. The production of $Z$ boson pairs by gluon-gluon fusion is greatly enhanced if there are ultraheavy quanta that carry $SU(3)_{\rm Color}$ and get their mass from electroweak symmetry breaking. For example, a fourth generation quark doublet with an arbitrarily heavy mass would induce a large excess in the $ZZ$ yield that could be detected at the LHC with only $\simeq 10\%$ of the design luminosity.
[ { "created": "Tue, 28 Mar 1995 22:00:49 GMT", "version": "v1" } ]
2010-11-01
[ [ "Chanowitz", "Michael S.", "" ] ]
Experiments at the LHC are sensitive to the presence or absence of matter quanta at mass scales far beyond the scales they can probe directly. The production of $Z$ boson pairs by gluon-gluon fusion is greatly enhanced if there are ultraheavy quanta that carry $SU(3)_{\rm Color}$ and get their mass from electroweak symmetry breaking. For example, a fourth generation quark doublet with an arbitrarily heavy mass would induce a large excess in the $ZZ$ yield that could be detected at the LHC with only $\simeq 10\%$ of the design luminosity.
1112.4963
Sedigheh Deldar
Sedigheh Deldar, Hadi Lookzadeh, Seyed Mohsen Hosseini Nejad (University of Tehran)
Confinement in G(2) Gauge Theories Using Thick Center Vortex Model and domain structures
15 pages, 9 figures, Version accepted for publication in PRD
Phys.Rev. D85 (2012) 054501
10.1103/PhysRevD.85.054501
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The thick center vortex model with the idea of using domain structures is used to calculate the potentials between two G(2) heavy sources in the fundamental, the adjoint and the 27 dimensional representations. The potentials are screened at large distances. This behavior is expected from the thick center vortex model since G(2) has only a trivial center element which makes no contribution to the average Wilson loop at the large distance regime. A linear potential is obtained at intermediate distances for all representations. This behavior can be explained by the thickness of the vortices (domains) and by defining a flux for the trivial center element of G(2). The role of the SU(3) subgroup of G(2) in the linear regime is also discussed. The string tensions are in rough agreement with the Casimir operators of the corresponding representations.
[ { "created": "Wed, 21 Dec 2011 09:51:04 GMT", "version": "v1" }, { "created": "Sun, 12 Aug 2012 08:24:49 GMT", "version": "v2" } ]
2012-08-14
[ [ "Deldar", "Sedigheh", "", "University of Tehran" ], [ "Lookzadeh", "Hadi", "", "University of Tehran" ], [ "Nejad", "Seyed Mohsen Hosseini", "", "University of Tehran" ] ]
The thick center vortex model with the idea of using domain structures is used to calculate the potentials between two G(2) heavy sources in the fundamental, the adjoint and the 27 dimensional representations. The potentials are screened at large distances. This behavior is expected from the thick center vortex model since G(2) has only a trivial center element which makes no contribution to the average Wilson loop at the large distance regime. A linear potential is obtained at intermediate distances for all representations. This behavior can be explained by the thickness of the vortices (domains) and by defining a flux for the trivial center element of G(2). The role of the SU(3) subgroup of G(2) in the linear regime is also discussed. The string tensions are in rough agreement with the Casimir operators of the corresponding representations.
hep-ph/9810358
Andrey Grozin
A.G.Grozin
Decoupling of heavy-quark loops in light-light and heavy-light quark currents
LaTeX2e, 4 pages, 1 inline figure, requires axodraw.sty
Phys.Lett. B445 (1998) 165-167
10.1016/S0370-2693(98)01439-7
TTP98-36
hep-ph
null
Matching of light-light quark currents in QCD with a heavy flavour and in the low-energy effective QCD is calculated in MSbar at two loops. Heavy-light HQET currents are similarly considered.
[ { "created": "Wed, 14 Oct 1998 15:28:09 GMT", "version": "v1" } ]
2009-10-31
[ [ "Grozin", "A. G.", "" ] ]
Matching of light-light quark currents in QCD with a heavy flavour and in the low-energy effective QCD is calculated in MSbar at two loops. Heavy-light HQET currents are similarly considered.
2405.10662
Mojtaba Hosseini
Mojtaba Hosseini, Seyed Yaser Ayazi, Ahmad Mohamadnejad
Gravitational wave in a filtered vector dark matter model
15 pages, 5 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider a first order phase transition (FOPT) for a Vector Dark Matter (VDM) in the early universe in which its mass may partially arise from such mechanism in the hidden sector. We calculate the ratio of VDM that may enter the bubble for various bubble wall velocities as well as various nucleation temperatures that produce the measured dark matter relic abundance via bubble filtering. In the following, we focus on gravitational wave (GW) signals which produced by FOPT and show that it can be detectable at the DECIGO, TianQin, LISA and Ultimate-DECIGO (UDECIGO) experiments.
[ { "created": "Fri, 17 May 2024 09:45:13 GMT", "version": "v1" }, { "created": "Mon, 8 Jul 2024 22:20:14 GMT", "version": "v2" } ]
2024-07-10
[ [ "Hosseini", "Mojtaba", "" ], [ "Ayazi", "Seyed Yaser", "" ], [ "Mohamadnejad", "Ahmad", "" ] ]
We consider a first order phase transition (FOPT) for a Vector Dark Matter (VDM) in the early universe in which its mass may partially arise from such mechanism in the hidden sector. We calculate the ratio of VDM that may enter the bubble for various bubble wall velocities as well as various nucleation temperatures that produce the measured dark matter relic abundance via bubble filtering. In the following, we focus on gravitational wave (GW) signals which produced by FOPT and show that it can be detectable at the DECIGO, TianQin, LISA and Ultimate-DECIGO (UDECIGO) experiments.
1008.3355
Aleksandrs Aleksejevs
Aleksandrs Aleksejevs, Svetlana Barkanova, Alexander Ilyichev, Vladimir Zykunov
Electroweak radiative corrections for polarized Moller scattering at future 11 GeV JLab experiment
15 pages, 5 tables and 5 figures
Phys.Rev.D82:093013,2010
10.1103/PhysRevD.82.093013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform updated and detailed calculations of the complete NLO set of electroweak radiative corrections to parity violating e- e- --> e- e- (gamma) scattering asymmetries at energies relevant for the ultra-precise Moller experiment coming soon at JLab. Our numerical results are presented for a range of experimental cuts and relative importance of various contributions is analyzed. We also provide very compact expressions analytically free from non-physical parameters and show them to be valid for fast yet accurate estimations.
[ { "created": "Thu, 19 Aug 2010 17:13:31 GMT", "version": "v1" }, { "created": "Sat, 23 Oct 2010 23:25:30 GMT", "version": "v2" } ]
2010-12-23
[ [ "Aleksejevs", "Aleksandrs", "" ], [ "Barkanova", "Svetlana", "" ], [ "Ilyichev", "Alexander", "" ], [ "Zykunov", "Vladimir", "" ] ]
We perform updated and detailed calculations of the complete NLO set of electroweak radiative corrections to parity violating e- e- --> e- e- (gamma) scattering asymmetries at energies relevant for the ultra-precise Moller experiment coming soon at JLab. Our numerical results are presented for a range of experimental cuts and relative importance of various contributions is analyzed. We also provide very compact expressions analytically free from non-physical parameters and show them to be valid for fast yet accurate estimations.
hep-ph/9503457
Michael Goodband
M.Goodband and M.Hindmarsh
Bound States and Instabilities of Vortices
Latex, 20 pages, 6 uuencoded figures
Phys.Rev. D52 (1995) 4621-4632
10.1103/PhysRevD.52.4621
SUSX-TH-95/71
hep-ph
null
We examine the spectrum of small perturbations around global and local (gauge) abelian vortices, using simple numerical matrix techniques. The results are of interest for both cosmic strings and for their condensed matter analogues, superfluid and superconducting vortices. We tabulate the instabilities of higher winding number vortices, and find several bound states. These localised oscillations of the order parameter can be thought of as particle states trapped in the core of the string.
[ { "created": "Tue, 28 Mar 1995 17:10:54 GMT", "version": "v1" } ]
2009-10-28
[ [ "Goodband", "M.", "" ], [ "Hindmarsh", "M.", "" ] ]
We examine the spectrum of small perturbations around global and local (gauge) abelian vortices, using simple numerical matrix techniques. The results are of interest for both cosmic strings and for their condensed matter analogues, superfluid and superconducting vortices. We tabulate the instabilities of higher winding number vortices, and find several bound states. These localised oscillations of the order parameter can be thought of as particle states trapped in the core of the string.
0812.4234
Subhendu Rakshit
E. A. Paschos and Subhendu Rakshit
Pion Spectra in the Production of Resonances by Neutrinos
18 pages, 10 figures
null
null
TIFR/DHEP/INO-1201
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A method is presented using helicity cross sections for calculating neutrino-nucleon interactions. The formalism is applied in the calculation of the pion spectra produced by nu_mu and nu_tau beams. The masses of the charged leptons are kept throughout the calculations. Cross sections are presented in numerous figures where the contributions of the significant form factors are also shown. The article describes the steps of the calculation and gives details so that it can be reproduced and adapted to the kinematic conditions of the experiments.
[ { "created": "Mon, 22 Dec 2008 16:29:24 GMT", "version": "v1" } ]
2008-12-23
[ [ "Paschos", "E. A.", "" ], [ "Rakshit", "Subhendu", "" ] ]
A method is presented using helicity cross sections for calculating neutrino-nucleon interactions. The formalism is applied in the calculation of the pion spectra produced by nu_mu and nu_tau beams. The masses of the charged leptons are kept throughout the calculations. Cross sections are presented in numerous figures where the contributions of the significant form factors are also shown. The article describes the steps of the calculation and gives details so that it can be reproduced and adapted to the kinematic conditions of the experiments.
hep-ph/0202269
Lisi Eligio
G.L. Fogli, E. Lisi, A. Mirizzi (U. of Bari & INFN, Bari), D. Montanino (U. of Lecce and INFN, Lecce)
Reexamining nonstandard interaction effects on supernova neutrino flavor oscillations
Text clarified, one figure added. To appear in PRD
Phys.Rev.D66:013009,2002
10.1103/PhysRevD.66.013009
null
hep-ph
null
Several extensions of the standard electroweak model allow new four-fermion interactions (nu_a nu_b * ff) with strength eps_ab*G_F, where (a,b) are flavor indices. We revisit their effects on flavor oscillations of massive (anti)neutrinos in supernovae, in order to achieve, in the region above the protoneutron star, an analytical treatment valid for generic values of the neutrino mixing angles (omega,phi,psi)=(theta_12,theta_13,theta_23). Assuming that eps_ab<<1, we find that the leading effects on the flavor transitions occurring at high (H) and low (L) density along the supernova matter profile can be simply embedded through the replacements phi-->phi+eps_H and omega-->omega+eps_L, respectively, where eps_H and eps_L are specific linear combinations of the eps_ab's. Similar replacements hold for eventual oscillations in the Earth matter. From a phenomenological point of view, the most relevant consequence is a possible uncontrolled bias (phi-->phi+eps_H) in the value of the mixing angle phi inferred by inversion of supernova neutrino data. Such a drawback, however, does not preclude the discrimination of the neutrino mass spectrum hierarchy (direct or inverse) through supernova neutrino oscillations.
[ { "created": "Wed, 27 Feb 2002 18:41:50 GMT", "version": "v1" }, { "created": "Wed, 20 Mar 2002 09:10:54 GMT", "version": "v2" }, { "created": "Fri, 21 Jun 2002 09:07:13 GMT", "version": "v3" } ]
2009-10-07
[ [ "Fogli", "G. L.", "", "U. of Bari & INFN, Bari" ], [ "Lisi", "E.", "", "U. of Bari & INFN, Bari" ], [ "Mirizzi", "A.", "", "U. of Bari & INFN, Bari" ], [ "Montanino", "D.", "", "U. of Lecce and INFN, Lecce" ] ]
Several extensions of the standard electroweak model allow new four-fermion interactions (nu_a nu_b * ff) with strength eps_ab*G_F, where (a,b) are flavor indices. We revisit their effects on flavor oscillations of massive (anti)neutrinos in supernovae, in order to achieve, in the region above the protoneutron star, an analytical treatment valid for generic values of the neutrino mixing angles (omega,phi,psi)=(theta_12,theta_13,theta_23). Assuming that eps_ab<<1, we find that the leading effects on the flavor transitions occurring at high (H) and low (L) density along the supernova matter profile can be simply embedded through the replacements phi-->phi+eps_H and omega-->omega+eps_L, respectively, where eps_H and eps_L are specific linear combinations of the eps_ab's. Similar replacements hold for eventual oscillations in the Earth matter. From a phenomenological point of view, the most relevant consequence is a possible uncontrolled bias (phi-->phi+eps_H) in the value of the mixing angle phi inferred by inversion of supernova neutrino data. Such a drawback, however, does not preclude the discrimination of the neutrino mass spectrum hierarchy (direct or inverse) through supernova neutrino oscillations.
1009.3355
Roman Pasechnik
Roman Pasechnik, Jacques Soffer, and Oleg Teryaev
Nucleon spin structure at low momentum transfers
12 pages, 6 figures
Phys.Rev.D82:076007,2010
10.1103/PhysRevD.82.076007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The generalized Gerasimov-Drell-Hearn (GDH) sum rule is known to be very sensitive to QCD radiative and power corrections. We improve the previously developed QCD-inspired model for the $Q^2$-dependence of the GDH sum rule. We take into account higher order radiative and higher twist power corrections extracted from precise Jefferson Lab data on the lowest moment of the spin-dependent proton structure function $\Gamma_1^{p}(Q^2)$ and on the Bjorken sum rule $\Gamma_1^{p-n}(Q^2)$. By using the singularity-free analytic perturbation theory we demonstrate that the matching point between chiral-like positive-$Q^2$ expansion and QCD operator product $1/Q^2$-expansion for the nucleon spin sum rules can be shifted down to rather low $Q\simeq\Lambda_{QCD}$ leading to a good description of recent proton, neutron, deuteron and Bjorken sum rule data at all accessible $Q^2$.
[ { "created": "Fri, 17 Sep 2010 07:49:47 GMT", "version": "v1" } ]
2010-10-27
[ [ "Pasechnik", "Roman", "" ], [ "Soffer", "Jacques", "" ], [ "Teryaev", "Oleg", "" ] ]
The generalized Gerasimov-Drell-Hearn (GDH) sum rule is known to be very sensitive to QCD radiative and power corrections. We improve the previously developed QCD-inspired model for the $Q^2$-dependence of the GDH sum rule. We take into account higher order radiative and higher twist power corrections extracted from precise Jefferson Lab data on the lowest moment of the spin-dependent proton structure function $\Gamma_1^{p}(Q^2)$ and on the Bjorken sum rule $\Gamma_1^{p-n}(Q^2)$. By using the singularity-free analytic perturbation theory we demonstrate that the matching point between chiral-like positive-$Q^2$ expansion and QCD operator product $1/Q^2$-expansion for the nucleon spin sum rules can be shifted down to rather low $Q\simeq\Lambda_{QCD}$ leading to a good description of recent proton, neutron, deuteron and Bjorken sum rule data at all accessible $Q^2$.
hep-ph/0605276
Fabio Siringo
Fabio Siringo, Luca Marotta
Self-consistent variational approach to the minimal left-right symmetric model of electroweak interactions
5 pages, 3 figures. New comments added and typing errors in eq. 8 and 11 corrected
Phys.Rev.D74:115001,2006
10.1103/PhysRevD.74.115001
null
hep-ph
null
The problem of mass generation is addressed by a Gaussian variational method for the minimal left-right symmetric model of electroweak interactions. Without any scalar bidoublet, the Gaussian effective potential is shown to have a minimum for a broken symmetry vacuum with a finite expectation value for both the scalar Higgs doublets. The symmetry is broken by the fermionic coupling that destabilizes the symmetric vacuum, yielding a self consistent fermionic mass. In this framework a light Higgs is only compatible with the existence of a new high energy mass scale below 2 TeV.
[ { "created": "Thu, 25 May 2006 16:48:19 GMT", "version": "v1" }, { "created": "Thu, 14 Dec 2006 19:22:39 GMT", "version": "v2" } ]
2008-11-26
[ [ "Siringo", "Fabio", "" ], [ "Marotta", "Luca", "" ] ]
The problem of mass generation is addressed by a Gaussian variational method for the minimal left-right symmetric model of electroweak interactions. Without any scalar bidoublet, the Gaussian effective potential is shown to have a minimum for a broken symmetry vacuum with a finite expectation value for both the scalar Higgs doublets. The symmetry is broken by the fermionic coupling that destabilizes the symmetric vacuum, yielding a self consistent fermionic mass. In this framework a light Higgs is only compatible with the existence of a new high energy mass scale below 2 TeV.
hep-ph/9609476
Elisabetta Sassaroli
Elisabetta Sassaroli (MIT)
Flavor Oscillations in Field Theory
15 pages, no figures, RevTex. The theoretical discussion has been improved to take into account the neutrino chirality. Agreement with the standard treatment of neutrino flavor oscillations is obtained. Some parts of the paper have been revised
null
null
MIT-CTP-2571
hep-ph
null
Neutrino flavor oscillations are discussed in terms of two coupled Dirac fields. The interacting Lagrangian is diagonalized to obtain the exact eigenvalues and eigenfunctions. Flavor wave functions are then derived directly from the quantized neutrino fields. Probability density obtained by squaring these wave functions upon taking into account the neutrino chirality are in agreement with the standard neutrino oscillation probabilities.
[ { "created": "Wed, 25 Sep 1996 17:47:24 GMT", "version": "v1" }, { "created": "Wed, 4 Dec 1996 23:58:40 GMT", "version": "v2" } ]
2008-02-03
[ [ "Sassaroli", "Elisabetta", "", "MIT" ] ]
Neutrino flavor oscillations are discussed in terms of two coupled Dirac fields. The interacting Lagrangian is diagonalized to obtain the exact eigenvalues and eigenfunctions. Flavor wave functions are then derived directly from the quantized neutrino fields. Probability density obtained by squaring these wave functions upon taking into account the neutrino chirality are in agreement with the standard neutrino oscillation probabilities.
hep-ph/9605406
Brian Hendee Smith
Ming Lu, Michael Luke, Martin J. Savage, and Brian H. Smith
Higher Order QCD Corrections to $b\to c\overline{c}s$
LaTex, 14 pages, 2 eps figures. Added one reference, changed some comments
Phys.Rev.D55:2827-2832,1997
10.1103/PhysRevD.55.2827
UTPT--96-07, CMU--HEP96--07, DOE--ER/40682--118
hep-ph
null
We calculate the ${\cal O}(\alpha_s^2 \beta_0 )$ corrections to the decay rate $b\rightarrow c\bar c s$. For reasonable values of $m_c/m_b$ this term is of the same order as both the one-loop and $\CO(\alpha_s^2 \log^2 m_W/m_b)$ corrections to the decay rate. For $m_c/m_b=0.3$ the $\CO(\alpha_s^2\beta_0)$ corrections enhance the rate by $\sim 18\%$ . We also discuss the $\CO(\alpha_s^2\beta_0)$ corrections to $R_\tau$, the $B$ semileptonic branching fraction and the charm multiplicity.
[ { "created": "Sun, 26 May 1996 20:41:39 GMT", "version": "v1" }, { "created": "Mon, 27 May 1996 22:33:29 GMT", "version": "v2" } ]
2014-11-17
[ [ "Lu", "Ming", "" ], [ "Luke", "Michael", "" ], [ "Savage", "Martin J.", "" ], [ "Smith", "Brian H.", "" ] ]
We calculate the ${\cal O}(\alpha_s^2 \beta_0 )$ corrections to the decay rate $b\rightarrow c\bar c s$. For reasonable values of $m_c/m_b$ this term is of the same order as both the one-loop and $\CO(\alpha_s^2 \log^2 m_W/m_b)$ corrections to the decay rate. For $m_c/m_b=0.3$ the $\CO(\alpha_s^2\beta_0)$ corrections enhance the rate by $\sim 18\%$ . We also discuss the $\CO(\alpha_s^2\beta_0)$ corrections to $R_\tau$, the $B$ semileptonic branching fraction and the charm multiplicity.
1012.0890
Ilya Narodetskii
I.M.Narodetskiy, Yu.A.Simonov, A.I.Veselov
Binding Energies and Melting Temperatures of Heavy Hadrons in Quark-Gluon Plasma
a slightly extended version of the talk delivered at "Quark Confinement and the Hadron Spectrum IX - QCHS IX" International Conference (30 August - 3 September 2010, Madrid, Spain), a reference added, minor comments added
null
10.1063/1.3575070
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the static potential of a quark-antiquark pair at $T\,\geq\,T_c$, where $T_c$ is a temperature of a deconfinement phase transition in QCD. We discuss the possibility that the non-perturbative part of this potential can be studied through the modification of the correlation functions, which define the quadratic field correlators of the nonperturbative vaccuum fields. We use the non-perturbative quark-antiquark potential derived in this way and the screened one-gluon-exchange potential with $T$-dependent Debye screening mass to calculate $J/\psi$, $\Upsilon$ and $\Omega_{bbb}$ binding energies and melting temperatures in the deconfined phase of the full 2-flavors QCD.
[ { "created": "Sat, 4 Dec 2010 07:53:11 GMT", "version": "v1" }, { "created": "Sun, 16 Jan 2011 16:09:31 GMT", "version": "v2" } ]
2015-05-20
[ [ "Narodetskiy", "I. M.", "" ], [ "Simonov", "Yu. A.", "" ], [ "Veselov", "A. I.", "" ] ]
We analyze the static potential of a quark-antiquark pair at $T\,\geq\,T_c$, where $T_c$ is a temperature of a deconfinement phase transition in QCD. We discuss the possibility that the non-perturbative part of this potential can be studied through the modification of the correlation functions, which define the quadratic field correlators of the nonperturbative vaccuum fields. We use the non-perturbative quark-antiquark potential derived in this way and the screened one-gluon-exchange potential with $T$-dependent Debye screening mass to calculate $J/\psi$, $\Upsilon$ and $\Omega_{bbb}$ binding energies and melting temperatures in the deconfined phase of the full 2-flavors QCD.
hep-ph/9911245
Christoph Greub
F. Borzumati (CERN, SISSA), C. Greub (Bern), T. Hurth (CERN), D. Wyler (Zurich)
Gluino Contribution to Radiative B Decays: Organization of QCD Corrections and Leading Order Results
36 pages including 16 postscript figures; uses epsf; journal version: one ref. added; rephrasing of a couple of paragraphs
Phys.Rev.D62:075005,2000
10.1103/PhysRevD.62.075005
CERN-TH/99-205, SISSA 121/99/EP, BUTP-99/14, MPI/PhT-99-37, CALT-68-2239, ZH-TH 24/99
hep-ph
null
The gluino-induced contributions to the decay b-> s gamma are investigated in supersymmetric frameworks with generic sources of flavour violation. It is shown that, when QCD corrections are taken into account, the relevant operator basis of the Standard Model effective Hamiltonian gets enlarged to contain: i) magnetic and chromomagnetic operators with a factor of alpha_s and weighted by a quark mass m_b or m_c; ii) magnetic and chromomagnetic operators of lower dimensionality, also containing alpha_s; iii) four-quark operators weighted by a factor alpha_s^2. Numerical results are given, showing the effects of the leading order QCD corrections on the inclusive branching ratio for b-> s gamma. Constraints on supersymmetric sources of flavour violation are derived.
[ { "created": "Thu, 4 Nov 1999 21:21:17 GMT", "version": "v1" }, { "created": "Sat, 8 Jul 2000 17:08:59 GMT", "version": "v2" } ]
2011-01-05
[ [ "Borzumati", "F.", "", "CERN, SISSA" ], [ "Greub", "C.", "", "Bern" ], [ "Hurth", "T.", "", "CERN" ], [ "Wyler", "D.", "", "Zurich" ] ]
The gluino-induced contributions to the decay b-> s gamma are investigated in supersymmetric frameworks with generic sources of flavour violation. It is shown that, when QCD corrections are taken into account, the relevant operator basis of the Standard Model effective Hamiltonian gets enlarged to contain: i) magnetic and chromomagnetic operators with a factor of alpha_s and weighted by a quark mass m_b or m_c; ii) magnetic and chromomagnetic operators of lower dimensionality, also containing alpha_s; iii) four-quark operators weighted by a factor alpha_s^2. Numerical results are given, showing the effects of the leading order QCD corrections on the inclusive branching ratio for b-> s gamma. Constraints on supersymmetric sources of flavour violation are derived.
hep-ph/9907305
Zoltan Kunszt
L. Dixon, Z. Kunszt, A. Signer
Vector Boson Pair Production in Hadronic Collisions at Order $\alpha_s$: Lepton Correlations and Anomalous Couplings
23 pages, 8 figures, 3 tables
Phys.Rev.D60:114037,1999
10.1103/PhysRevD.60.114037
SLAC-PUB-8188, ETHZ-TH/99-10, DTP/99/72
hep-ph
null
We present cross sections for production of electroweak vector boson pairs, $WW$, $WZ$ and $ZZ$, in $p\bar{p}$ and $pp$ collisions, at next-to-leading order in $\alpha_s$. We treat the leptonic decays of the bosons in the narrow-width approximation, but retain all spin information via decay angle correlations. We also include the effects of $WWZ$ and $WW\gamma$ anomalous couplings.
[ { "created": "Mon, 12 Jul 1999 15:34:05 GMT", "version": "v1" } ]
2010-11-15
[ [ "Dixon", "L.", "" ], [ "Kunszt", "Z.", "" ], [ "Signer", "A.", "" ] ]
We present cross sections for production of electroweak vector boson pairs, $WW$, $WZ$ and $ZZ$, in $p\bar{p}$ and $pp$ collisions, at next-to-leading order in $\alpha_s$. We treat the leptonic decays of the bosons in the narrow-width approximation, but retain all spin information via decay angle correlations. We also include the effects of $WWZ$ and $WW\gamma$ anomalous couplings.
hep-ph/9408256
null
Ulf-G. Mei{\ss}ner
Aspects of Nucleon Chiral Perturbation Theory
plain TeX (macro included), 12pp, lecture delivered at the workshop on "Chiral Dynamics: Theory and Experiments", MIT, July 25-29, 1994
null
10.1007/3-540-59279-2_63
CRN 94-44
hep-ph nucl-th
null
I review recent progress made in the calculation of nucleon properties in the framework of heavy baryon CHPT. Topics include: Compton scattering, $\pi N$ scattering, the anatomy of a low-energy constant and the induced pseudoscalar form factor.
[ { "created": "Tue, 9 Aug 1994 12:26:52 GMT", "version": "v1" } ]
2009-10-28
[ [ "Meißner", "Ulf-G.", "" ] ]
I review recent progress made in the calculation of nucleon properties in the framework of heavy baryon CHPT. Topics include: Compton scattering, $\pi N$ scattering, the anatomy of a low-energy constant and the induced pseudoscalar form factor.
1101.0134
Jure Zupan
Jure Zupan
The case for measuring gamma precisely
6 pages, 2 figures, 1 table, talk presented at The 6th International Workshop on the CKM Unitarity Triangle, University of Warwick, UK, 6-10 September 2010
null
null
UCHEP-11-10
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We first review the methods for determining gamma from B->D K decays that appeared after CKM 2008. We then discuss the theoretical errors in gamma extraction. The errors due to neglected D-Dbar and B_{d,s}-Bbar_{d,s} mixing can be avoided by including their effects in the fits. The ultimate theoretical error is then given by electroweak corrections that we estimate to give a shift delta gamma/gamma O(10^-6).
[ { "created": "Thu, 30 Dec 2010 19:05:00 GMT", "version": "v1" } ]
2012-06-26
[ [ "Zupan", "Jure", "" ] ]
We first review the methods for determining gamma from B->D K decays that appeared after CKM 2008. We then discuss the theoretical errors in gamma extraction. The errors due to neglected D-Dbar and B_{d,s}-Bbar_{d,s} mixing can be avoided by including their effects in the fits. The ultimate theoretical error is then given by electroweak corrections that we estimate to give a shift delta gamma/gamma O(10^-6).
1107.3006
Masahiro Ibe
Jason L. Evans, Masahiro Ibe, Tsutomu T. Yanagida
Relatively Heavy Higgs Boson in More Generic Gauge Mediation
17pages, 5 figures, revised version
null
10.1016/j.physletb.2011.10.031
ICRR-590-2011-7, IPMU11-0116
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss gauge mediation models where the doublet messengers and Higgs doublets are allowed to mix through a "charged" coupling. The charged coupling replaces messenger parity as a means of suppressing flavor changing neutral currents without introducing any unwanted CP violation. As a result of this mixing between the Higgs doublets and the messengers, relatively large A-terms are generated at the messenger scale. These large A-terms produce a distinct weak scale mass spectrum. Particularly, we show that the lightest Higgs boson mass is enhanced and can be as heavy as 125GeV for a gluino mass as light as 2TeV. We also show that the stops are heavier than that predicted by conventional gauge mediation models. It is also shown that these models have a peculiar slepton mass spectrum.
[ { "created": "Fri, 15 Jul 2011 08:14:07 GMT", "version": "v1" }, { "created": "Fri, 29 Jul 2011 18:03:25 GMT", "version": "v2" } ]
2015-05-28
[ [ "Evans", "Jason L.", "" ], [ "Ibe", "Masahiro", "" ], [ "Yanagida", "Tsutomu T.", "" ] ]
We discuss gauge mediation models where the doublet messengers and Higgs doublets are allowed to mix through a "charged" coupling. The charged coupling replaces messenger parity as a means of suppressing flavor changing neutral currents without introducing any unwanted CP violation. As a result of this mixing between the Higgs doublets and the messengers, relatively large A-terms are generated at the messenger scale. These large A-terms produce a distinct weak scale mass spectrum. Particularly, we show that the lightest Higgs boson mass is enhanced and can be as heavy as 125GeV for a gluino mass as light as 2TeV. We also show that the stops are heavier than that predicted by conventional gauge mediation models. It is also shown that these models have a peculiar slepton mass spectrum.
0912.3495
Tobias Kleinschmidt
Wolfgang Kilian and Tobias Kleinschmidt
Numerical Evaluation of Feynman Loop Integrals by Reduction to Tree Graphs
33 pages, 9 figures
null
null
IPPP/09/97, DCTP/09/194, Edinburgh 2009/17, SI-HEP-2009-16
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a new method for the numerical evaluation of loop integrals which is based on the Feynman Tree Theorem. The loop integrals are replaced by phase-space integration over fictitious extra on-shell particles. This integration can be performed alongside with the Monte-Carlo integration of ordinary phase space, avoiding the time-consuming nesting of loop evaluation inside the integrand, and directly leading to NLO event generation. We systematically construct subtractions, necessary to cancel both ultraviolet divergences and the extra threshold singularities in phase-space which arise in the numerical evaluation. Infrared singularities can be dealt with by standard methods. As a proof of concept, we apply the method to NLO Bhabha scattering in QED and construct the corresponding NLO Monte Carlo event generator.
[ { "created": "Thu, 17 Dec 2009 19:20:30 GMT", "version": "v1" } ]
2009-12-18
[ [ "Kilian", "Wolfgang", "" ], [ "Kleinschmidt", "Tobias", "" ] ]
We present a new method for the numerical evaluation of loop integrals which is based on the Feynman Tree Theorem. The loop integrals are replaced by phase-space integration over fictitious extra on-shell particles. This integration can be performed alongside with the Monte-Carlo integration of ordinary phase space, avoiding the time-consuming nesting of loop evaluation inside the integrand, and directly leading to NLO event generation. We systematically construct subtractions, necessary to cancel both ultraviolet divergences and the extra threshold singularities in phase-space which arise in the numerical evaluation. Infrared singularities can be dealt with by standard methods. As a proof of concept, we apply the method to NLO Bhabha scattering in QED and construct the corresponding NLO Monte Carlo event generator.
2204.11551
Utkarsh Patel
Utkarsh Patel, Sudhanwa Patra (IIT Bhilai)
Numerically analyzing self-interacting dark matter
Regular Article, 19 two-column pages, 9 figures, 4 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We consider the scenario of self-interacting dark matter(SIDM) with a light mediator in a model-independent way, which can alleviate two long-standing issues of the small scale cosmology namely cusp vs. core and too-big-to-fail. A Yukawa potential is chosen to achieve mediator exchange between DM particles as part of their self-interactions. The dynamics of self-interacting transfer cross-section are studied for a range of mediator mass($m_Z'$). Also, a relationship is established between the cross-section and DM particles' relative velocity, which ensures the solution to the DM crisis at small scales. Our obtained numerical results are efficient compared to the earlier works in the context that a lesser number of $\ell$ modes have been used by us to achieve the same level of accuracy in the cross-section calculations. For a better understanding of the SIDM parameter space, we perform an analytical analysis on the dependence of transfer cross-section over the other important SIDM parameters using a Hulth\'{e}n potential which is similar in its behavior to Yukawa potential. A detailed evolution of particle dynamics using the Boltzmann equation and the effect of Sommerfeld enhancement on such calculations has also been studied here. We also provide a minimal anomaly-free leptophilic extension of the standard model, that can incorporate SIDM and its mediator candidate in the framework.
[ { "created": "Mon, 25 Apr 2022 10:52:33 GMT", "version": "v1" }, { "created": "Fri, 30 Dec 2022 09:46:11 GMT", "version": "v2" } ]
2023-01-02
[ [ "Patel", "Utkarsh", "", "IIT Bhilai" ], [ "Patra", "Sudhanwa", "", "IIT Bhilai" ] ]
We consider the scenario of self-interacting dark matter(SIDM) with a light mediator in a model-independent way, which can alleviate two long-standing issues of the small scale cosmology namely cusp vs. core and too-big-to-fail. A Yukawa potential is chosen to achieve mediator exchange between DM particles as part of their self-interactions. The dynamics of self-interacting transfer cross-section are studied for a range of mediator mass($m_Z'$). Also, a relationship is established between the cross-section and DM particles' relative velocity, which ensures the solution to the DM crisis at small scales. Our obtained numerical results are efficient compared to the earlier works in the context that a lesser number of $\ell$ modes have been used by us to achieve the same level of accuracy in the cross-section calculations. For a better understanding of the SIDM parameter space, we perform an analytical analysis on the dependence of transfer cross-section over the other important SIDM parameters using a Hulth\'{e}n potential which is similar in its behavior to Yukawa potential. A detailed evolution of particle dynamics using the Boltzmann equation and the effect of Sommerfeld enhancement on such calculations has also been studied here. We also provide a minimal anomaly-free leptophilic extension of the standard model, that can incorporate SIDM and its mediator candidate in the framework.
hep-ph/9712391
Robert Delbourgo
R Delbourgo and Dongsheng Liu (University of Tasmania)
Amplitude analysis of hadron decays
31 pages, RevTeX
Phys.Rev.D57:5732-5745,1998
10.1103/PhysRevD.57.5732
UTAS-PHYS-97-32
hep-ph
null
We provide succinct covariant amplitude decompositions of 2-body weak hadronic decays, with which to compare data, including exclusive rates, helicity amplitudes and polarizations. For weak decays, the systematic dependence of these amplitudes on masses and quantum numbers of participating particles are determined within a factor of about two by the CKM angles and the Fermi constant so theoretical models need to be much more accurate if they are to be convincing.
[ { "created": "Tue, 16 Dec 1997 00:18:33 GMT", "version": "v1" }, { "created": "Tue, 16 Dec 1997 05:50:41 GMT", "version": "v2" } ]
2008-11-26
[ [ "Delbourgo", "R", "", "University of Tasmania" ], [ "Liu", "Dongsheng", "", "University of Tasmania" ] ]
We provide succinct covariant amplitude decompositions of 2-body weak hadronic decays, with which to compare data, including exclusive rates, helicity amplitudes and polarizations. For weak decays, the systematic dependence of these amplitudes on masses and quantum numbers of participating particles are determined within a factor of about two by the CKM angles and the Fermi constant so theoretical models need to be much more accurate if they are to be convincing.
0812.0637
A. D. Polosa
B Grinstein, R Jora and AD Polosa
A note on large N scalar QCD_2
9 pages, 1 figure
Phys.Lett.B671:440-444,2009
10.1016/j.physletb.2008.12.046
UCSD/PTH 08-09
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We review the features of the bound state equation in large N scalar QCD in two dimensions, the 't Hooft model, and compute the discrete hadron mass spectrum in this theory. We make the Ansatz that the scalar fields of this model represent spin zero diquarks and we estimate the minimum allowed mass for the first radial excitation of the lowest diquark-antidiquark scalar meson. The discussion is extended to the case of spin one diquarks.
[ { "created": "Wed, 3 Dec 2008 02:48:27 GMT", "version": "v1" } ]
2009-04-24
[ [ "Grinstein", "B", "" ], [ "Jora", "R", "" ], [ "Polosa", "AD", "" ] ]
We review the features of the bound state equation in large N scalar QCD in two dimensions, the 't Hooft model, and compute the discrete hadron mass spectrum in this theory. We make the Ansatz that the scalar fields of this model represent spin zero diquarks and we estimate the minimum allowed mass for the first radial excitation of the lowest diquark-antidiquark scalar meson. The discussion is extended to the case of spin one diquarks.
1012.2627
Asmita Mukherjee
R. Manohar, A. Mukherjee, D. Chakrabarti
Generalized Parton Distributions for the Proton in Position Space : Non-Zero Skewness
18 pages, Latex, 7 figs
Phys.Rev.D83:014004,2011
10.1103/PhysRevD.83.014004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the generalized parton distributions (GPDs) for u and d quarks in a proton in transverse and longitudinal position space using a recent phenomenological parametrization. We take nonzero skewness \zeta and consider the region x> \zeta. Impact parameter space representation of the GPD E is found to depend sharply on the parameters used within the model, in particular in the low x region. In longitudinal position space a diffraction pattern is observed, as seen before in several other model
[ { "created": "Mon, 13 Dec 2010 04:09:06 GMT", "version": "v1" } ]
2011-02-02
[ [ "Manohar", "R.", "" ], [ "Mukherjee", "A.", "" ], [ "Chakrabarti", "D.", "" ] ]
We investigate the generalized parton distributions (GPDs) for u and d quarks in a proton in transverse and longitudinal position space using a recent phenomenological parametrization. We take nonzero skewness \zeta and consider the region x> \zeta. Impact parameter space representation of the GPD E is found to depend sharply on the parameters used within the model, in particular in the low x region. In longitudinal position space a diffraction pattern is observed, as seen before in several other model
2008.13594
Peter Kroll
S.V. Goloskokov, P. Kroll, O. Teryaev
Lepton-pair production in hard exclusive hadron-hadron collisions
18 pages , 10 figures using Latex
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate lepton-pair production in hard exclusive hadron-hadron collisions. We consider a double handbag (DH) mechanism in which the process amplitude factorizes in hard subprocesses, qq -> qq gamma* and qg -> qg gamma*, and in soft hadron matrix elements parameterized as generalized parton distributions (GPDs). Employing GPDs extracted from exclusive meson electroproduction, we present predictions for the lepton-pair cross section at kinematics typical for the LHC, NICA and FAIR. It turns out from our numerical studies that the quark-gluon subprocess dominates by far, the quark-quark (antiquark) subprocesses are almost negligible.
[ { "created": "Mon, 31 Aug 2020 13:32:22 GMT", "version": "v1" } ]
2020-09-01
[ [ "Goloskokov", "S. V.", "" ], [ "Kroll", "P.", "" ], [ "Teryaev", "O.", "" ] ]
We investigate lepton-pair production in hard exclusive hadron-hadron collisions. We consider a double handbag (DH) mechanism in which the process amplitude factorizes in hard subprocesses, qq -> qq gamma* and qg -> qg gamma*, and in soft hadron matrix elements parameterized as generalized parton distributions (GPDs). Employing GPDs extracted from exclusive meson electroproduction, we present predictions for the lepton-pair cross section at kinematics typical for the LHC, NICA and FAIR. It turns out from our numerical studies that the quark-gluon subprocess dominates by far, the quark-quark (antiquark) subprocesses are almost negligible.
1108.3297
Koji Tsumura
Shinya Kanemura, Yasuhiro Okada, Hiroyuki Taniguchi, Koji Tsumura
Indirect bounds on heavy scalar masses of the two-Higgs-doublet model in light of recent Higgs boson searches
11 pages, 5 eps files
null
10.1016/j.physletb.2011.09.035
KEK-TH-1480, UT-HET 057
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an upper bound on masses of additional scalar bosons from the electroweak precision data and theoretical constraints such as perturbative unitarity and vacuum stability in the two Higgs doublet model taking account of recent Higgs boson search results. If the mass of the Standard-Model-like Higgs boson is rather heavy and is outside the allowed region by the electroweak precision data, such a discrepancy should be compensated by contributions from the additional scalar bosons. We show the upper bound on masses of the additional scalar bosons to be about 2 $(1)$ TeV for the mass of the Standard-Model-like Higgs boson to be 240 $(500)$ GeV.
[ { "created": "Tue, 16 Aug 2011 18:02:01 GMT", "version": "v1" } ]
2015-05-30
[ [ "Kanemura", "Shinya", "" ], [ "Okada", "Yasuhiro", "" ], [ "Taniguchi", "Hiroyuki", "" ], [ "Tsumura", "Koji", "" ] ]
We study an upper bound on masses of additional scalar bosons from the electroweak precision data and theoretical constraints such as perturbative unitarity and vacuum stability in the two Higgs doublet model taking account of recent Higgs boson search results. If the mass of the Standard-Model-like Higgs boson is rather heavy and is outside the allowed region by the electroweak precision data, such a discrepancy should be compensated by contributions from the additional scalar bosons. We show the upper bound on masses of the additional scalar bosons to be about 2 $(1)$ TeV for the mass of the Standard-Model-like Higgs boson to be 240 $(500)$ GeV.
1209.4016
S. Descotes-Genon
S\'ebastien Descotes-Genon (LPT Orsay)
Combined constraints on CP-violation in the Standard Model and beyond
6 pages, 3 figures. To appear in the proceedings of Flavour Physics and CP Violation (May 2012, Hefei, China) and 4th Workshop on Theory, Phenomenology and Experiments in Flavour Physics (June 2012, Capri, Italy)
null
10.1016/j.nuclphysbps.2013.06.016
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I review the status of CP violation in the Standard Model from the combination of flavour constraints within the CKMfitter frequentist approach and I describe studies of New Physics restricted to the Delta F=2 sector to explain recent results on neutral-meson mixing. All results have been obtained using data available for the Winter 2012 conferences.
[ { "created": "Tue, 18 Sep 2012 16:24:51 GMT", "version": "v1" } ]
2015-06-11
[ [ "Descotes-Genon", "Sébastien", "", "LPT Orsay" ] ]
I review the status of CP violation in the Standard Model from the combination of flavour constraints within the CKMfitter frequentist approach and I describe studies of New Physics restricted to the Delta F=2 sector to explain recent results on neutral-meson mixing. All results have been obtained using data available for the Winter 2012 conferences.
2210.16337
Vassilis C. Spanos
John Ellis, Keith A. Olive, Vassilis C. Spanos, Ioanna D. Stamou
The CMSSM Survives Planck, the LHC, LUX-ZEPLIN, Fermi-LAT, H.E.S.S. and IceCube
44 pages, 20 figures, journal version to appear in EPJ-C
null
10.1140/epjc/s10052-023-11405-1
KCL-PH-TH/2022-52, CERN-TH-2022-172, UMN-TH-4204/22, FTPI-MINN-22/29
hep-ph astro-ph.CO hep-ex hep-th
http://creativecommons.org/licenses/by/4.0/
We revisit the viability of the CMSSM, searching for regions of parameter space that yield a neutralino dark matter density compatible with Planck measurements, as well as LHC constraints including sparticle searches and the mass of the Higgs boson, recent direct limits on spin-independent and -dependent dark matter scattering from the LUX-ZEPLIN (LZ) experiment, the indirect constraints from Fermi-LAT and H.E.S.S. on dark matter annihilations to photons in dwarf spheroidal galaxies and the Galactic Centre, and the IceCube limits on muons from annihilations to neutrinos in the Sun. For representative values of $\tan \beta$ and $A_0$ we map in detail the Planck-compatible strips in CMSSM parameter planes, which exhibit multiple distinctive features for large $\tan \beta$, $A_0 = 0$ and $\mu > 0$, and identify portions of the strips that survive all the phenomenological constraints. We find that the most powerful constraint is that from $m_h$, followed by the LZ limit on spin-independent scattering, whereas sparticle searches at the LHC and indirect dark matter searches are less restrictive. Most of the surviving CMSSM parameter space features a Higgsino-like dark matter particle with a mass $\sim 1000-1100$ GeV, which could best be probed with future direct searches for dark matter scattering.
[ { "created": "Fri, 28 Oct 2022 18:00:12 GMT", "version": "v1" }, { "created": "Sat, 25 Mar 2023 08:07:26 GMT", "version": "v2" } ]
2023-04-12
[ [ "Ellis", "John", "" ], [ "Olive", "Keith A.", "" ], [ "Spanos", "Vassilis C.", "" ], [ "Stamou", "Ioanna D.", "" ] ]
We revisit the viability of the CMSSM, searching for regions of parameter space that yield a neutralino dark matter density compatible with Planck measurements, as well as LHC constraints including sparticle searches and the mass of the Higgs boson, recent direct limits on spin-independent and -dependent dark matter scattering from the LUX-ZEPLIN (LZ) experiment, the indirect constraints from Fermi-LAT and H.E.S.S. on dark matter annihilations to photons in dwarf spheroidal galaxies and the Galactic Centre, and the IceCube limits on muons from annihilations to neutrinos in the Sun. For representative values of $\tan \beta$ and $A_0$ we map in detail the Planck-compatible strips in CMSSM parameter planes, which exhibit multiple distinctive features for large $\tan \beta$, $A_0 = 0$ and $\mu > 0$, and identify portions of the strips that survive all the phenomenological constraints. We find that the most powerful constraint is that from $m_h$, followed by the LZ limit on spin-independent scattering, whereas sparticle searches at the LHC and indirect dark matter searches are less restrictive. Most of the surviving CMSSM parameter space features a Higgsino-like dark matter particle with a mass $\sim 1000-1100$ GeV, which could best be probed with future direct searches for dark matter scattering.
hep-ph/0410225
Terunuma Sachiko
M. Bando, T. Kugo, A. Sugamoto, S. Terunuma
Pentaquark Baryons in String Theory -- Talk at Pentaquark 04
talk given by A. Sugamoto at International Workshop PENTAQUARK04, July 20-23 (2004) at SPring-8; to appear in the proceedings
null
null
null
hep-ph
null
Pentaquark baryons $\Theta^{+}$ and $\Xi^{--}$ are studied in the dual gravity theory of QCD in which simple mass formulae of pentaquarks are derived in the Maldacena prototype model for supersymmetric QCD and a more realistic model for ordinary QCD. In this approach it is possible to explain the extremely narrow decay widths of pentaquarks. With the aim of constructing more reliable mass formulae, a sketch is given on spin and the hyperfine interaction in the string picture.
[ { "created": "Fri, 15 Oct 2004 09:32:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Bando", "M.", "" ], [ "Kugo", "T.", "" ], [ "Sugamoto", "A.", "" ], [ "Terunuma", "S.", "" ] ]
Pentaquark baryons $\Theta^{+}$ and $\Xi^{--}$ are studied in the dual gravity theory of QCD in which simple mass formulae of pentaquarks are derived in the Maldacena prototype model for supersymmetric QCD and a more realistic model for ordinary QCD. In this approach it is possible to explain the extremely narrow decay widths of pentaquarks. With the aim of constructing more reliable mass formulae, a sketch is given on spin and the hyperfine interaction in the string picture.
1110.6151
J. Patrick Harding
Kevork N. Abazajian and J. Patrick Harding
Constraints on WIMP and Sommerfeld-Enhanced Dark Matter Annihilation from HESS Observations of the Galactic Center
19 pages, 5 figures; v3: Matches JCAP version; includes discussion of numerical studies of the density profile of MW-type halos, updated references and comparisons
JCAP 1201:041,2012
10.1088/1475-7516/2012/01/041
null
hep-ph astro-ph.CO astro-ph.GA astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine the constraints on models of weakly interacting massive particle (WIMP) dark matter from the recent observations of the Galactic center by the High Energy Spectroscopic System (HESS) telescope. We analyze canonical WIMP annihilation into Standard Model particle final states, including b/b-bar, t/t-bar and W^+ W^-. The constraints on annihilation into b/b-bar is within an order of magnitude of the thermal cross section at ~3 TeV, while the tau^+/tau^- channel is within a factor of ~2 of thermal. We also study constraints on Sommerfeld-enhanced dark matter annihilation models, and find that the gamma-ray observational constraints here rule out all of the parameter space consistent with dark matter annihilation interpretations of PAMELA and the Fermi-LAT e^+/e^- spectrum, in specific classes of models, and strongly constrains these interpretations in other classes. The gamma-ray constraints we find are more constraining on these models, in many cases, than current relic density, cosmic microwave background, halo shape and naturalness constraints.
[ { "created": "Thu, 27 Oct 2011 18:20:51 GMT", "version": "v1" }, { "created": "Tue, 1 Nov 2011 21:23:01 GMT", "version": "v2" }, { "created": "Tue, 3 Jan 2012 18:39:31 GMT", "version": "v3" } ]
2012-02-09
[ [ "Abazajian", "Kevork N.", "" ], [ "Harding", "J. Patrick", "" ] ]
We examine the constraints on models of weakly interacting massive particle (WIMP) dark matter from the recent observations of the Galactic center by the High Energy Spectroscopic System (HESS) telescope. We analyze canonical WIMP annihilation into Standard Model particle final states, including b/b-bar, t/t-bar and W^+ W^-. The constraints on annihilation into b/b-bar is within an order of magnitude of the thermal cross section at ~3 TeV, while the tau^+/tau^- channel is within a factor of ~2 of thermal. We also study constraints on Sommerfeld-enhanced dark matter annihilation models, and find that the gamma-ray observational constraints here rule out all of the parameter space consistent with dark matter annihilation interpretations of PAMELA and the Fermi-LAT e^+/e^- spectrum, in specific classes of models, and strongly constrains these interpretations in other classes. The gamma-ray constraints we find are more constraining on these models, in many cases, than current relic density, cosmic microwave background, halo shape and naturalness constraints.
1305.4245
Andrey Grozin
A. G. Grozin
Introduction to effective field theories. 3. Bloch--Nordsieck effective theory, HQET
64 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This is a continuation of the lectures [1,2]. In this part we discuss interaction of electrons with soft photons in QED and Heavy Quark Effective Theory (HQET).
[ { "created": "Sat, 18 May 2013 09:47:45 GMT", "version": "v1" } ]
2013-05-21
[ [ "Grozin", "A. G.", "" ] ]
This is a continuation of the lectures [1,2]. In this part we discuss interaction of electrons with soft photons in QED and Heavy Quark Effective Theory (HQET).
1903.11255
Leon Friedrich
Nicole F. Bell, Matthew J. Dolan, Leon S. Friedrich, Michael J. Ramsey-Musolf and Raymond R. Volkas
Electroweak Baryogenesis with Vector-like Leptons and Scalar Singlets
38 pages, 8 figures. Citations added. Benchmarks, figures and tables updated, error fixed in calculations. Matches version published in JHEP
J. High Energ. Phys. (2019) 2019: 12
10.1007/JHEP09(2019)012
ACFI-T19-02
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the viability of electroweak baryogenesis in a model with a first order electroweak phase transition induced by the addition of two gauge singlet scalars. A vector-like lepton doublet is introduced in order to provide CP violating interactions with the singlets and Standard Model leptons, and the asymmetry generation dynamics are examined using the vacuum expectation value insertion approximation. We find that such a model is readily capable of generating sufficient baryon asymmetry while satisfying electron electric dipole moment and collider phenomenology constraints.
[ { "created": "Wed, 27 Mar 2019 05:39:56 GMT", "version": "v1" }, { "created": "Mon, 7 Oct 2019 05:22:24 GMT", "version": "v2" } ]
2019-10-08
[ [ "Bell", "Nicole F.", "" ], [ "Dolan", "Matthew J.", "" ], [ "Friedrich", "Leon S.", "" ], [ "Ramsey-Musolf", "Michael J.", "" ], [ "Volkas", "Raymond R.", "" ] ]
We investigate the viability of electroweak baryogenesis in a model with a first order electroweak phase transition induced by the addition of two gauge singlet scalars. A vector-like lepton doublet is introduced in order to provide CP violating interactions with the singlets and Standard Model leptons, and the asymmetry generation dynamics are examined using the vacuum expectation value insertion approximation. We find that such a model is readily capable of generating sufficient baryon asymmetry while satisfying electron electric dipole moment and collider phenomenology constraints.
1105.1626
Lucian Harland-Lang
L.A. Harland-Lang, V.A. Khoze, M.G. Ryskin, W.J. Stirling
Central exclusive meson pair production in the perturbative regime at hadron colliders
37 pages, 14 figures. Some discussion added and clarified, version published in EPJC
null
10.1140/epjc/s10052-011-1714-2
IPPP/11/19, DCPT/11/38, Cavendish-HEP-11/06
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The central exclusive production (CEP) of heavy resonance states that subsequently decay into meson pairs, MMbar, is an important signature for such processes at hadron colliders. However there is a potentially important background from the direct QCD production of meson pairs, as mediated for example by the exclusive gg --> MMbar hard scattering subprocess. This is in fact an interesting process in its own right, testing novel aspects of perturbative QCD technology. We explicitly calculate the gg --> MMbar helicity amplitudes for different meson states within the hard exclusive formalism, and comment on the application of MHV techniques to the calculation. Using these results, we describe how meson pair CEP can be calculated in the perturbative regime, and present some sample numerical predictions for a variety of final states. We also briefly consider the dominant non-perturbative contributions, which are expected to be important when the meson transverse momentum is small.
[ { "created": "Mon, 9 May 2011 10:49:05 GMT", "version": "v1" }, { "created": "Thu, 22 Sep 2011 12:37:54 GMT", "version": "v2" } ]
2011-09-23
[ [ "Harland-Lang", "L. A.", "" ], [ "Khoze", "V. A.", "" ], [ "Ryskin", "M. G.", "" ], [ "Stirling", "W. J.", "" ] ]
The central exclusive production (CEP) of heavy resonance states that subsequently decay into meson pairs, MMbar, is an important signature for such processes at hadron colliders. However there is a potentially important background from the direct QCD production of meson pairs, as mediated for example by the exclusive gg --> MMbar hard scattering subprocess. This is in fact an interesting process in its own right, testing novel aspects of perturbative QCD technology. We explicitly calculate the gg --> MMbar helicity amplitudes for different meson states within the hard exclusive formalism, and comment on the application of MHV techniques to the calculation. Using these results, we describe how meson pair CEP can be calculated in the perturbative regime, and present some sample numerical predictions for a variety of final states. We also briefly consider the dominant non-perturbative contributions, which are expected to be important when the meson transverse momentum is small.
2012.09474
Ki-Young Choi
Ki-Young Choi, Eung Jin Chun, Jongkuk Kim
Dispersion of neutrinos in a medium
7 pages, 3 figures
null
null
KIAS-P20072
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the dispersion relations of Weyl or Majorana, and Dirac neutrinos in a complex scalar medium which interacts with the neutrinos through Yukawa couplings. They are solved by perturbative calculation in various limits representing different physical situations, some of which allow the medium-induced neutrino oscillation to occur. Remarkably, peculiar dispersion relations arise differently for Majorana or Dirac neutrinos in the non-relativistic limit. This provides an unpleasant restriction on the cosmological scenario of a scalar dark matter coupling to neutrinos. At present, the model parameter space is constrained by the neutrino scattering with dark matter through astrophysical neutrino observations.
[ { "created": "Thu, 17 Dec 2020 09:54:19 GMT", "version": "v1" }, { "created": "Wed, 23 Dec 2020 13:55:31 GMT", "version": "v2" } ]
2020-12-24
[ [ "Choi", "Ki-Young", "" ], [ "Chun", "Eung Jin", "" ], [ "Kim", "Jongkuk", "" ] ]
We analyze the dispersion relations of Weyl or Majorana, and Dirac neutrinos in a complex scalar medium which interacts with the neutrinos through Yukawa couplings. They are solved by perturbative calculation in various limits representing different physical situations, some of which allow the medium-induced neutrino oscillation to occur. Remarkably, peculiar dispersion relations arise differently for Majorana or Dirac neutrinos in the non-relativistic limit. This provides an unpleasant restriction on the cosmological scenario of a scalar dark matter coupling to neutrinos. At present, the model parameter space is constrained by the neutrino scattering with dark matter through astrophysical neutrino observations.
2210.06078
Terry Generet
Micha{\l} Czakon, Terry Generet, Alexander Mitov, Rene Poncelet
NNLO B-fragmentation fits and their application to $t\bar t$ production and decay at the LHC
46 pages, 59 figures, matches published version
JHEP03(2023)251
10.1007/JHEP03(2023)251
Cavendish-HEP-22/08, P3H-22-100, TTK-22-31
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In this work we derive three sets of non-perturbative fragmentation functions, with uncertainties, for $B$-hadrons, $J/\psi$'s and muons resulting from semileptonic $B$ decays. All three sets are with next-to-next-to leading order accuracy and include next-to-next-to leading logarithmic soft gluon resummation. The novel feature of these new sets is that they are fully consistent with our formalism for next-to-next-to leading order (NNLO) calculations for final states with identified $B$, $J/\psi$ or a $\mu$. We employ the fragmentation functions derived in this work to make state of the art predictions for such final states in $t\bar t$ events at the LHC. A special emphasis is placed on observables sensitive to the top quark mass. The present work opens the door for many LHC applications, like, open $B$ production or $B$ production in association with bosons.
[ { "created": "Wed, 12 Oct 2022 10:44:06 GMT", "version": "v1" }, { "created": "Mon, 3 Apr 2023 10:27:43 GMT", "version": "v2" } ]
2023-04-04
[ [ "Czakon", "Michał", "" ], [ "Generet", "Terry", "" ], [ "Mitov", "Alexander", "" ], [ "Poncelet", "Rene", "" ] ]
In this work we derive three sets of non-perturbative fragmentation functions, with uncertainties, for $B$-hadrons, $J/\psi$'s and muons resulting from semileptonic $B$ decays. All three sets are with next-to-next-to leading order accuracy and include next-to-next-to leading logarithmic soft gluon resummation. The novel feature of these new sets is that they are fully consistent with our formalism for next-to-next-to leading order (NNLO) calculations for final states with identified $B$, $J/\psi$ or a $\mu$. We employ the fragmentation functions derived in this work to make state of the art predictions for such final states in $t\bar t$ events at the LHC. A special emphasis is placed on observables sensitive to the top quark mass. The present work opens the door for many LHC applications, like, open $B$ production or $B$ production in association with bosons.
2307.01871
Jilberto Zamora-Saa
G. A. Vasquez (1) and Jilberto Zamora-Saa (2) ((1) University of Victoria, (2) Universidad Andres Bello)
Unveiling the Heavy Neutrino Nature at LHCb
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, we study the lepton number violating Bc meson decays via one intermediate on-shell heavy neutrino. The specific studied process is $B_{c}^{+} \to \mu^{+} \ N \to \mu^{+} \mu^{+} \tau^{-} \nu$ which could allow distinguishing the nature of the heavy neutrino nature (Dirac or Majorana) by studying the tau lepton energy spectrum in the LHCb experiment. The result suggests that this signature could be observed in the collected data during the HL-LHCb lifetime.
[ { "created": "Tue, 4 Jul 2023 18:31:40 GMT", "version": "v1" } ]
2023-07-06
[ [ "Vasquez", "G. A.", "" ], [ "Zamora-Saa", "Jilberto", "" ] ]
In this work, we study the lepton number violating Bc meson decays via one intermediate on-shell heavy neutrino. The specific studied process is $B_{c}^{+} \to \mu^{+} \ N \to \mu^{+} \mu^{+} \tau^{-} \nu$ which could allow distinguishing the nature of the heavy neutrino nature (Dirac or Majorana) by studying the tau lepton energy spectrum in the LHCb experiment. The result suggests that this signature could be observed in the collected data during the HL-LHCb lifetime.
1308.3986
Daniel Ma\^itre
Z. Bern, L. J. Dixon, F. Febres Cordero, S. H\"oche, H. Ita, D. A. Kosower, K. J. Ozeren, D. Ma\^itre
High multiplicity W+jets predictions at NLO
5 pages, Proceedings for the DIS2013 conference
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings we present results from a recent calculation for the production of a W boson in conjunction with five jets at next-to-leading order in perturbative QCD. We also use results at lower multiplicities to extrapolate the cross section to the same process with six jets.
[ { "created": "Mon, 19 Aug 2013 11:32:08 GMT", "version": "v1" } ]
2013-08-20
[ [ "Bern", "Z.", "" ], [ "Dixon", "L. J.", "" ], [ "Cordero", "F. Febres", "" ], [ "Höche", "S.", "" ], [ "Ita", "H.", "" ], [ "Kosower", "D. A.", "" ], [ "Ozeren", "K. J.", "" ], [ "Maître", "D.", "" ] ]
In these proceedings we present results from a recent calculation for the production of a W boson in conjunction with five jets at next-to-leading order in perturbative QCD. We also use results at lower multiplicities to extrapolate the cross section to the same process with six jets.
hep-ph/0407344
L. Wolfenstein
Lincoln Wolfenstein
Regge Amplitudes and Final State Phases in the Decays B to D Pi
3 pages including References
null
null
CMU-HEP-04-05
hep-ph
null
The scattering amplitude of D Pi at the energy of the B mass can be calculated using Regge theory. Recent papers have used this to calculate the final state strong phases in the decays B to D Pi. It is argued that while the Regge amplitude can yield an absorption correction to the decay rate, it is not useful for determining the strong phase.
[ { "created": "Thu, 29 Jul 2004 14:26:41 GMT", "version": "v1" } ]
2007-05-23
[ [ "Wolfenstein", "Lincoln", "" ] ]
The scattering amplitude of D Pi at the energy of the B mass can be calculated using Regge theory. Recent papers have used this to calculate the final state strong phases in the decays B to D Pi. It is argued that while the Regge amplitude can yield an absorption correction to the decay rate, it is not useful for determining the strong phase.
0712.0429
Zuo-Hong Li
Zuo-Hong Li, Wei Liu, Hai-Yan Liu
Systematic Study on QCD Interactions of Heavy Mesons with $\rho$ Meson
16 pages, 1 eps figure, version to appear in PLB
Phys.Lett.B659:598-606,2008
10.1016/j.physletb.2007.11.074
null
hep-ph
null
The strong interactions of the negative-parity heavy mesons with $\rho$ meson may be described consistently in the context of an effective lagrangian, which is invariant under isospin SU(2) transformation. Four coupling constants $g_{HH\rho}$, $f_{H^*H\rho}$, $g_{H^*H^*\rho}$ and $f_{H^*H^*\rho}$ enter the effective lagrangian, where $H$ $(H^*)$ denotes a pseudoscalar bottom or charm meson (the corresponding vector meson). Using QCD light cone sum rule (LCSR) method and, as inputs, the hadronic parameters updated recently, we give an estimate of $g_{H^*H^*\rho}$ and $f_{H^*H^*\rho}$, about which little was known before, and present an improved result for $g_{HH\rho}$ and $f_{H^*H\rho}$. Also, we examine the heavy quark asymptotic behavior of these nonperturbative quantities and assess the two low energy parameters $\beta$ and $\lambda$ of the corresponding effective chiral lagrangian.
[ { "created": "Tue, 4 Dec 2007 03:51:25 GMT", "version": "v1" } ]
2008-11-26
[ [ "Li", "Zuo-Hong", "" ], [ "Liu", "Wei", "" ], [ "Liu", "Hai-Yan", "" ] ]
The strong interactions of the negative-parity heavy mesons with $\rho$ meson may be described consistently in the context of an effective lagrangian, which is invariant under isospin SU(2) transformation. Four coupling constants $g_{HH\rho}$, $f_{H^*H\rho}$, $g_{H^*H^*\rho}$ and $f_{H^*H^*\rho}$ enter the effective lagrangian, where $H$ $(H^*)$ denotes a pseudoscalar bottom or charm meson (the corresponding vector meson). Using QCD light cone sum rule (LCSR) method and, as inputs, the hadronic parameters updated recently, we give an estimate of $g_{H^*H^*\rho}$ and $f_{H^*H^*\rho}$, about which little was known before, and present an improved result for $g_{HH\rho}$ and $f_{H^*H\rho}$. Also, we examine the heavy quark asymptotic behavior of these nonperturbative quantities and assess the two low energy parameters $\beta$ and $\lambda$ of the corresponding effective chiral lagrangian.
2303.04287
Naoya Kitajima
Naoya Kitajima, Kazunori Nakayama
Viable Vector Coherent Oscillation Dark Matter
28 pages, 3 figures
null
10.1088/1475-7516/2023/07/014
TU-1181, KEK-QUP-2023-0004
hep-ph astro-ph.CO
http://creativecommons.org/licenses/by/4.0/
We construct a viable model of the vector coherent oscillation dark matter. The vector boson is coupled to the inflaton through the kinetic function so that the effective Hubble mass term is cancelled out. In order to avoid strong constraints from isocurvature perturbation and statistically anisotropic curvature perturbation, the inflaton is arranged so that it does not contribute to the observed large scale curvature perturbation and we introduce a curvaton. We found viable vector coherent oscillation dark matter scenario for the wide vector mass range from $10^{-21}\,{\rm eV}$ to $1\,{\rm eV}$.
[ { "created": "Tue, 7 Mar 2023 23:22:50 GMT", "version": "v1" } ]
2023-07-12
[ [ "Kitajima", "Naoya", "" ], [ "Nakayama", "Kazunori", "" ] ]
We construct a viable model of the vector coherent oscillation dark matter. The vector boson is coupled to the inflaton through the kinetic function so that the effective Hubble mass term is cancelled out. In order to avoid strong constraints from isocurvature perturbation and statistically anisotropic curvature perturbation, the inflaton is arranged so that it does not contribute to the observed large scale curvature perturbation and we introduce a curvaton. We found viable vector coherent oscillation dark matter scenario for the wide vector mass range from $10^{-21}\,{\rm eV}$ to $1\,{\rm eV}$.
hep-ph/9801251
Stefan Pokorski
M. Carena, S. Pokorski and C.E.M. Wagner
Photon Signatures for Low Energy Supersymmetry Breaking and Broken R-parity
12 pages, LateX
Phys.Lett.B430:281-289,1998
10.1016/S0370-2693(98)00389-X
CERN-TH/97-373; FNAL-PUB/97-
hep-ph
null
The possible phenomenological consequences of R-parity violating interactions in the framework of low energy supersymmetry breaking are studied. It is pointed out that even very weak R-parity violation would completely overshadow one of the basic signatures of low energy supersymmetry breaking models, that is, the decay of the next to lightest supersymmetric particle into a photon (lepton) and missing energy. Thus, the observation of these decays would put very strong limits on R-parity violating couplings. Vice-versa, if R-parity violation is established experimentally, before a detailed knowledge of the spectrum is obtained, it will be very difficult to distinguish gravity mediated from low energy gauge mediated supersymmetry breaking. Those conclusions are very model independent. We also comment on the possibility of mixing between charged and neutral leptons with charginos and neutralinos, respectively, and its phenomenological consequences for the photon (lepton) signatures, in scenarios where this mixing is generated by the presence of bilinear or trilinear R-parity violating terms in the superpotential.
[ { "created": "Fri, 9 Jan 1998 16:03:05 GMT", "version": "v1" } ]
2008-11-26
[ [ "Carena", "M.", "" ], [ "Pokorski", "S.", "" ], [ "Wagner", "C. E. M.", "" ] ]
The possible phenomenological consequences of R-parity violating interactions in the framework of low energy supersymmetry breaking are studied. It is pointed out that even very weak R-parity violation would completely overshadow one of the basic signatures of low energy supersymmetry breaking models, that is, the decay of the next to lightest supersymmetric particle into a photon (lepton) and missing energy. Thus, the observation of these decays would put very strong limits on R-parity violating couplings. Vice-versa, if R-parity violation is established experimentally, before a detailed knowledge of the spectrum is obtained, it will be very difficult to distinguish gravity mediated from low energy gauge mediated supersymmetry breaking. Those conclusions are very model independent. We also comment on the possibility of mixing between charged and neutral leptons with charginos and neutralinos, respectively, and its phenomenological consequences for the photon (lepton) signatures, in scenarios where this mixing is generated by the presence of bilinear or trilinear R-parity violating terms in the superpotential.
hep-ph/9508366
Charles A. Nelson
Charles A. Nelson
Tests for Tau's Charged-Current Structure
Contributed paper to LP95, Beijing. Revision of SUNY BING [10/1/94] which will appear in Phys. Let. [ tau ---> pi nu channel added; appendix deleted] Before LaTeXing, cut off "by-line" at bottom
Phys. Lett. B355 (1995) 561
10.1016/0370-2693(95)00779-K
SUNY BING 5/15/95
hep-ph
null
The Lorentz structure of the tau lepton's charged-current can almost be completely determined by use of stage-two spin-correlation functions for the $\{\rho ^{-},\rho ^{+}\}$and $\{a_1^{-},a_1^{+}\}$ decay modes. It is possible to test for a ``$(V-A)$ $ + $ something'' structure in the ${J^{Charged}}_{Lepton}$ current, so as to bound the scales $\Lambda$ for ``new physics" such as arising from tau weak magnetism, weak electricity, and/or 2nd-class currents. In practice, only limited information can be obtained from the $\tau \rightarrow \pi \nu$ modes.
[ { "created": "Thu, 24 Aug 1995 13:13:10 GMT", "version": "v1" } ]
2009-10-28
[ [ "Nelson", "Charles A.", "" ] ]
The Lorentz structure of the tau lepton's charged-current can almost be completely determined by use of stage-two spin-correlation functions for the $\{\rho ^{-},\rho ^{+}\}$and $\{a_1^{-},a_1^{+}\}$ decay modes. It is possible to test for a ``$(V-A)$ $ + $ something'' structure in the ${J^{Charged}}_{Lepton}$ current, so as to bound the scales $\Lambda$ for ``new physics" such as arising from tau weak magnetism, weak electricity, and/or 2nd-class currents. In practice, only limited information can be obtained from the $\tau \rightarrow \pi \nu$ modes.
1208.4053
Stefan Dittmaier
Ansgar Denner, Stefan Dittmaier, Stefan Kallweit, Stefano Pozzorini
NLO QCD corrections to off-shell ttbar production at hadron colliders
7 pages, 4 eps figures, to appear in the Proceedings of the 11th Workshop "Loops and Legs in Quantum Field Theory", Wernigerode, Germany, 2012
null
null
FR-PHENO_2012-021
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of top-antitop-quark pairs at hadron colliders is interesting both in its own right as signal process, but also as background to many searches for new physics. The corresponding predictions aim at the precision level of few per cent, rendering not only the inclusion of radiative corrections of the strong and electroweak interactions relevant, but also of off-shell and finite-width effects originating from the top-quark decays t -> b W -> b l \nu_l / qq'. We report on a calculation for the full process pp -> W^+ W^- b \bar{b} -> \nu_e e^+ \mu^- \nu_\mu b \bar{b} at next-to-leading order QCD and discuss the effects of the finite widths of the top quarks and of the W bosons for selected observables. Generically it turns out that finite-top-width effects are at the per-cent level whenever the top-quark resonances dominate, but those effects can reach tens of per cent in off-shell tails. Finite-W-width effects, on the other hand, are suppressed to less than 0.5% whenever the top quarks can become resonant and only become sizeable in exceptional cases. One such case, however, is the invariant mass of a bottom quark and the corresponding charged lepton, which result from the same top-quark decay - an observable that is relevant for precision measurements of the top-quark mass.
[ { "created": "Mon, 20 Aug 2012 16:52:10 GMT", "version": "v1" } ]
2012-08-21
[ [ "Denner", "Ansgar", "" ], [ "Dittmaier", "Stefan", "" ], [ "Kallweit", "Stefan", "" ], [ "Pozzorini", "Stefano", "" ] ]
The production of top-antitop-quark pairs at hadron colliders is interesting both in its own right as signal process, but also as background to many searches for new physics. The corresponding predictions aim at the precision level of few per cent, rendering not only the inclusion of radiative corrections of the strong and electroweak interactions relevant, but also of off-shell and finite-width effects originating from the top-quark decays t -> b W -> b l \nu_l / qq'. We report on a calculation for the full process pp -> W^+ W^- b \bar{b} -> \nu_e e^+ \mu^- \nu_\mu b \bar{b} at next-to-leading order QCD and discuss the effects of the finite widths of the top quarks and of the W bosons for selected observables. Generically it turns out that finite-top-width effects are at the per-cent level whenever the top-quark resonances dominate, but those effects can reach tens of per cent in off-shell tails. Finite-W-width effects, on the other hand, are suppressed to less than 0.5% whenever the top quarks can become resonant and only become sizeable in exceptional cases. One such case, however, is the invariant mass of a bottom quark and the corresponding charged lepton, which result from the same top-quark decay - an observable that is relevant for precision measurements of the top-quark mass.
hep-ph/9406391
null
D. Atwood and A. Soni
CP Violation in $B^\pm\to \gamma\pi^\pm\pi^+\pi^-$
8, SLAC-PUB-6524
Phys.Rev.Lett.74:220-223,1995
10.1103/PhysRevLett.74.220
null
hep-ph
null
We consider CP violating effects in decays of the type $B^\pm\to \gamma a^\pm_{1,2}$ where $a_{1,2}$ are the $J^P=1^+$ and $2^+$ resonances each decaying to the common final state via $a^\pm_{1,2} \to\pi^\pm\rho^0$. The resonances enhance the CP asymmetries and also knowledge of their masses and widths facilitates calculations of the effects. Several types of CP asymmetries are sizable ($\sim10$--30\%) requiring about (3--10)${}\times10^8$ $B^\pm$ mesons for detection at the $3\sigma$ level thereby providing a method for measuring the angle $\alpha$ in the unitarity triangle. \bigskip
[ { "created": "Fri, 24 Jun 1994 19:01:16 GMT", "version": "v1" } ]
2010-11-01
[ [ "Atwood", "D.", "" ], [ "Soni", "A.", "" ] ]
We consider CP violating effects in decays of the type $B^\pm\to \gamma a^\pm_{1,2}$ where $a_{1,2}$ are the $J^P=1^+$ and $2^+$ resonances each decaying to the common final state via $a^\pm_{1,2} \to\pi^\pm\rho^0$. The resonances enhance the CP asymmetries and also knowledge of their masses and widths facilitates calculations of the effects. Several types of CP asymmetries are sizable ($\sim10$--30\%) requiring about (3--10)${}\times10^8$ $B^\pm$ mesons for detection at the $3\sigma$ level thereby providing a method for measuring the angle $\alpha$ in the unitarity triangle. \bigskip
hep-ph/0103263
T. Becher
T. Becher and H. Leutwyler
Low energy analysis of pi N --> pi N
97 pages (LaTeX), 16 figures. Two references added, correction in table one. Published version
JHEP 0106:017,2001
10.1088/1126-6708/2001/06/017
CLNS-01/1727, BUTP-01/11
hep-ph
null
We derive a representation for the pion nucleon scattering amplitude that is valid to the fourth order of the chiral expansion. To obtain the correct analytic structure of the singularities in the low energy region, we have performed the calculation in a relativistic framework (infrared regularization). The result can be written in terms of functions of a single variable. We study the corresponding dispersion relations and discuss the problems encountered in the straightforward nonrelativistic expansion of the infrared singularities. As an application, we evaluate the corrections to the Goldberger-Treiman relation and to the low energy theorem that relates the value of the amplitude at the Cheng-Dashen point to the \sigma-term. While chiral symmetry does govern the behaviour of the amplitude in the vicinity of this point, the representation for the scattering amplitude is not accurate enough to use it for an extrapolation of the experimental data to the subthreshold region. We propose to perform this extrapolation on the basis of a set of integral equations that interrelate the lowest partial waves and are analogous to the Roy equations for \pi\pi scattering.
[ { "created": "Sat, 24 Mar 2001 02:36:17 GMT", "version": "v1" }, { "created": "Thu, 11 Oct 2001 22:06:39 GMT", "version": "v2" } ]
2010-02-03
[ [ "Becher", "T.", "" ], [ "Leutwyler", "H.", "" ] ]
We derive a representation for the pion nucleon scattering amplitude that is valid to the fourth order of the chiral expansion. To obtain the correct analytic structure of the singularities in the low energy region, we have performed the calculation in a relativistic framework (infrared regularization). The result can be written in terms of functions of a single variable. We study the corresponding dispersion relations and discuss the problems encountered in the straightforward nonrelativistic expansion of the infrared singularities. As an application, we evaluate the corrections to the Goldberger-Treiman relation and to the low energy theorem that relates the value of the amplitude at the Cheng-Dashen point to the \sigma-term. While chiral symmetry does govern the behaviour of the amplitude in the vicinity of this point, the representation for the scattering amplitude is not accurate enough to use it for an extrapolation of the experimental data to the subthreshold region. We propose to perform this extrapolation on the basis of a set of integral equations that interrelate the lowest partial waves and are analogous to the Roy equations for \pi\pi scattering.
1811.04939
Kim V. Berghaus
Kim V. Berghaus, Melissa D. Diamond, D. E. Kaplan
Decays of Long-Lived Relics and Their Signatures at IceCube
19 pages, 6 figures. v2: Small corrections/additional references added. v3: matches published JHEP version. Figure 3 added to show projected $\gamma$-ray spectra. Figure 6 updated to include spectrum without EW shower
J. High Energ. Phys. (2019) 2019: 145
10.1007/JHEP05(2019)145
null
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider long-lived relic particles as the source of the PeV-scale neutrinos detected at the IceCube observatory over the last six years. We derive the present day neutrino flux, including primary neutrinos from direct decays, secondary neutrinos from electroweak showering, and tertiary neutrinos from re-scatters off the relic neutrino background. We compare the high-energy neutrino flux prediction to the most recently available datasets and find qualitative differences to expected spectra from other astrophysical processes. We utilize electroweak corrections to constrain heavy decaying relic abundances, using measurements impacted by electromagnetic energy injection, such as light element abundances during Big Bang nucleosynthesis, cosmic microwave background anisotropies, and diffuse $\gamma$-ray spectra. We compare these abundances to those necessary to source the IceCube neutrinos and find two viable regions in parameter space, ultimately testable by future neutrino, $\gamma$-ray, and cosmic microwave background observatories.
[ { "created": "Mon, 12 Nov 2018 19:00:01 GMT", "version": "v1" }, { "created": "Sat, 22 Dec 2018 09:27:20 GMT", "version": "v2" }, { "created": "Sat, 13 Jul 2019 18:08:14 GMT", "version": "v3" } ]
2019-07-16
[ [ "Berghaus", "Kim V.", "" ], [ "Diamond", "Melissa D.", "" ], [ "Kaplan", "D. E.", "" ] ]
We consider long-lived relic particles as the source of the PeV-scale neutrinos detected at the IceCube observatory over the last six years. We derive the present day neutrino flux, including primary neutrinos from direct decays, secondary neutrinos from electroweak showering, and tertiary neutrinos from re-scatters off the relic neutrino background. We compare the high-energy neutrino flux prediction to the most recently available datasets and find qualitative differences to expected spectra from other astrophysical processes. We utilize electroweak corrections to constrain heavy decaying relic abundances, using measurements impacted by electromagnetic energy injection, such as light element abundances during Big Bang nucleosynthesis, cosmic microwave background anisotropies, and diffuse $\gamma$-ray spectra. We compare these abundances to those necessary to source the IceCube neutrinos and find two viable regions in parameter space, ultimately testable by future neutrino, $\gamma$-ray, and cosmic microwave background observatories.
hep-ph/0211322
Jonathan R. Ellis
John Ellis (CERN)
What Next in Flavour Physics and CP Violation?
25 pages LateX, 12 eps figures, Invited Talk at the 1st International Workshop On Frontier Science: Charm, Beauty, And CP Frascati, Rome, Italy
Frascati Phys.Ser.31:381-405,2003
null
CERN-TH/2002-339
hep-ph
null
The future of flavour physics and CP violation in the quark, lepton and Higgs sectors are discussed, particularly from the viewpoint of physics beyond the Standard Model, such as supersymmetry. Current issues in B to pi^+ pi^-, phi K_s and D^*+ D^*-, B_s physics and rare B decays are reviewed. The prospects for seeing flavour and CP violation in the charged-lepton sector are discussed, using the minimal supersymmetric seesaw model as a guide. Finally, the possible consequences of CP violation in the Higgs sector are mentioned.
[ { "created": "Wed, 20 Nov 2002 18:25:37 GMT", "version": "v1" } ]
2009-09-11
[ [ "Ellis", "John", "", "CERN" ] ]
The future of flavour physics and CP violation in the quark, lepton and Higgs sectors are discussed, particularly from the viewpoint of physics beyond the Standard Model, such as supersymmetry. Current issues in B to pi^+ pi^-, phi K_s and D^*+ D^*-, B_s physics and rare B decays are reviewed. The prospects for seeing flavour and CP violation in the charged-lepton sector are discussed, using the minimal supersymmetric seesaw model as a guide. Finally, the possible consequences of CP violation in the Higgs sector are mentioned.
hep-ph/0608205
Leonard Lesniak
B. El-Bennich, A. Furman, R. Kaminski, L. Lesniak, B. Loiseau
Interference between f0(980) and rho(770) resonances in B --> pion-pion-kaon decays
12 pages, 7 figures, subsection VD, Appendix A and one reference added
Phys.Rev.D74:114009,2006
10.1103/PhysRevD.74.114009
LPNHE 2006-12
hep-ph hep-ex nucl-th
null
We study the contribution of the strong interaction between the two pions in S- and P-waves to the weak B --> pion pion kaon decay amplitudes. The interference between these two waves is analyzed in the pion-pion effective mass range of the rho(770) and f0(980) resonances. We use a unitary pion-pion and antikaon-kaon coupled-channel model to describe the S-wave interactions and a Breit-Wigner function for the P-wave amplitude. The weak B-decay amplitudes, obtained from QCD factorization, are supplemented with charming penguin contributions in both waves. The four complex parameters of these long distance terms are determined by fitting the model to the BaBar and Belle data on B^{+,-,0} --> pi+ pi- K^{+,-,0} branching fractions, CP asymmetries, pion-pion effective mass and helicity-angle distributions. This set of data, and in particular the large direct CP-asymmetry for B^{+,-} --> rho0(770) K^{+,-} decays, is well reproduced. The interplay of charming penguin amplitudes and the interference of S- and P-waves describes rather successfully the experimental S and A values of the CP-violating asymmetry for both B0 --> f0(980) K0S and B0 --> rho0(770) K0S decays.
[ { "created": "Fri, 18 Aug 2006 11:06:19 GMT", "version": "v1" }, { "created": "Wed, 22 Nov 2006 16:35:51 GMT", "version": "v2" } ]
2008-11-26
[ [ "El-Bennich", "B.", "" ], [ "Furman", "A.", "" ], [ "Kaminski", "R.", "" ], [ "Lesniak", "L.", "" ], [ "Loiseau", "B.", "" ] ]
We study the contribution of the strong interaction between the two pions in S- and P-waves to the weak B --> pion pion kaon decay amplitudes. The interference between these two waves is analyzed in the pion-pion effective mass range of the rho(770) and f0(980) resonances. We use a unitary pion-pion and antikaon-kaon coupled-channel model to describe the S-wave interactions and a Breit-Wigner function for the P-wave amplitude. The weak B-decay amplitudes, obtained from QCD factorization, are supplemented with charming penguin contributions in both waves. The four complex parameters of these long distance terms are determined by fitting the model to the BaBar and Belle data on B^{+,-,0} --> pi+ pi- K^{+,-,0} branching fractions, CP asymmetries, pion-pion effective mass and helicity-angle distributions. This set of data, and in particular the large direct CP-asymmetry for B^{+,-} --> rho0(770) K^{+,-} decays, is well reproduced. The interplay of charming penguin amplitudes and the interference of S- and P-waves describes rather successfully the experimental S and A values of the CP-violating asymmetry for both B0 --> f0(980) K0S and B0 --> rho0(770) K0S decays.
1903.12627
Yu Jia
Saadi Ishaq, Yu Jia, Xiaonu Xiong, De-Shan Yang
$W$ radiative decay to heavy-light mesons in HQET factorization through ${\cal O}(\alpha_s)$
22 pages, 8 figures, 1 table. Text expanded and improved, two more figures and one table added, references added
Phys. Rev. D 100, 054027 (2019)
10.1103/PhysRevD.100.054027
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Analogous to NRQCD factorization for heavy quarkonium exclusive production, in this work we propose to employ the heavy-quark-effective-theory (HQET) factorization, which has been predominantly applied to account for exclusive $B$ decays, to study the exclusive production of the heavy-flavored mesons. We take $W\to B(D_s)+\gamma$ as a prototype process. The validity of the HQET factorization rests upon the presumed scale hierarchy: $m_W\sim m_b\gg \Lambda_{\rm QCD}$. Through an explicit analysis at next-to-leading order in $\alpha_s$ yet at leading order in $1/m_b$, we verify that the decay form factors can indeed be expressed as the convolution between perturbatively calculable hard-scattering kernel and the $B$ meson light-cone distribution amplitude (LCDA) defined in HQET. It is observed that the factorization scale dependence becomes reduced after incorporating the NLO perturbative correction. An interesting future investigation is to identify and resum large collinear logarithms of $m_W/m_b$ that arise ubiquitously in the fixed-order expressions of the hard-scattering kernel in HQET factorization.
[ { "created": "Fri, 29 Mar 2019 17:23:20 GMT", "version": "v1" }, { "created": "Mon, 3 Jun 2019 15:09:42 GMT", "version": "v2" } ]
2019-10-02
[ [ "Ishaq", "Saadi", "" ], [ "Jia", "Yu", "" ], [ "Xiong", "Xiaonu", "" ], [ "Yang", "De-Shan", "" ] ]
Analogous to NRQCD factorization for heavy quarkonium exclusive production, in this work we propose to employ the heavy-quark-effective-theory (HQET) factorization, which has been predominantly applied to account for exclusive $B$ decays, to study the exclusive production of the heavy-flavored mesons. We take $W\to B(D_s)+\gamma$ as a prototype process. The validity of the HQET factorization rests upon the presumed scale hierarchy: $m_W\sim m_b\gg \Lambda_{\rm QCD}$. Through an explicit analysis at next-to-leading order in $\alpha_s$ yet at leading order in $1/m_b$, we verify that the decay form factors can indeed be expressed as the convolution between perturbatively calculable hard-scattering kernel and the $B$ meson light-cone distribution amplitude (LCDA) defined in HQET. It is observed that the factorization scale dependence becomes reduced after incorporating the NLO perturbative correction. An interesting future investigation is to identify and resum large collinear logarithms of $m_W/m_b$ that arise ubiquitously in the fixed-order expressions of the hard-scattering kernel in HQET factorization.
hep-ph/0104075
Francois Gelis
F. Gelis (BNL), D. Schiff, J. Serreau (LPT, Orsay)
A simple out-of-equilibrium field theory formalism ?
Latex, 5 pages, no figures
Phys.Rev. D64 (2001) 056006
10.1103/PhysRevD.64.056006
LPT-ORSAY 01/31, BNL-NT-01/7
hep-ph
null
In this paper, we determine a condition of applicability of a very simple formalism for the calculation of a fast process taking place in a non-equilibrium medium, in which the particle distribution functions are frozen in time. Indeed, a well known obstacle for the use of such a naive formalism is the appearance of the so-called ``pinch singularities''. We argue that these potentially dangerous terms can be regularized, and that they are negligible if the characteristic time-scale of the process under study is small compared to the relaxation time of the system.
[ { "created": "Fri, 6 Apr 2001 21:37:49 GMT", "version": "v1" } ]
2009-11-07
[ [ "Gelis", "F.", "", "BNL" ], [ "Schiff", "D.", "", "LPT, Orsay" ], [ "Serreau", "J.", "", "LPT, Orsay" ] ]
In this paper, we determine a condition of applicability of a very simple formalism for the calculation of a fast process taking place in a non-equilibrium medium, in which the particle distribution functions are frozen in time. Indeed, a well known obstacle for the use of such a naive formalism is the appearance of the so-called ``pinch singularities''. We argue that these potentially dangerous terms can be regularized, and that they are negligible if the characteristic time-scale of the process under study is small compared to the relaxation time of the system.
1902.05109
Ahmed Ismail
Tao Han, Ahmed Ismail, Barmak Shams Es Haghi
SUSY Signals from QCD Production at the Upgraded LHC
17 pages, 4 figures, 2 tables. v2: typos corrected, minor changes, conclusions unaffected, version published in PLB
Phys. Lett. B 793, 354 (2019)
10.1016/j.physletb.2019.05.004
PITT-PACC-1820
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Weak-scale supersymmetry remains to be one of the best-motivated theories of physics beyond the Standard Model. We evaluate the sensitivities of the High Luminosity (HL) and High Energy (HE) upgrades of the LHC to gluinos and stops, decaying through the simplified topologies $\tilde{g} \to q \bar{q} \chi^0$, $\tilde{g} \to t \bar{t} \chi^0$ and $\tilde{t} \to t \tilde{\chi}^0$. Our HL-LHC analyses improve on existing experimental projections by optimizing the acceptance of kinematic variables. The HE-LHC studies represent the first 27 TeV analyses. We find that the HL-(HE-)LHC with 3 ab$^{-1}$ (15 ab$^{-1}$) of integrated luminosity will be sensitive to the masses of gluinos and stops at 3.2 (5.7) TeV and 1.5 (2.7) TeV, respectively, decaying to massless neutralinos.
[ { "created": "Wed, 13 Feb 2019 20:13:53 GMT", "version": "v1" }, { "created": "Mon, 13 May 2019 14:57:06 GMT", "version": "v2" } ]
2019-05-14
[ [ "Han", "Tao", "" ], [ "Ismail", "Ahmed", "" ], [ "Haghi", "Barmak Shams Es", "" ] ]
Weak-scale supersymmetry remains to be one of the best-motivated theories of physics beyond the Standard Model. We evaluate the sensitivities of the High Luminosity (HL) and High Energy (HE) upgrades of the LHC to gluinos and stops, decaying through the simplified topologies $\tilde{g} \to q \bar{q} \chi^0$, $\tilde{g} \to t \bar{t} \chi^0$ and $\tilde{t} \to t \tilde{\chi}^0$. Our HL-LHC analyses improve on existing experimental projections by optimizing the acceptance of kinematic variables. The HE-LHC studies represent the first 27 TeV analyses. We find that the HL-(HE-)LHC with 3 ab$^{-1}$ (15 ab$^{-1}$) of integrated luminosity will be sensitive to the masses of gluinos and stops at 3.2 (5.7) TeV and 1.5 (2.7) TeV, respectively, decaying to massless neutralinos.
2207.13709
JiJi Fan
Lingfeng Li, JiJi Fan
Jupiter missions as probes of dark matter
34 pages, 10 figures; minor modifications and references added; major conclusion unchanged
null
10.1007/JHEP10(2022)186
null
hep-ph astro-ph.CO astro-ph.EP astro-ph.HE astro-ph.IM
http://creativecommons.org/licenses/by/4.0/
Jupiter, the fascinating largest planet in the solar system, has been visited by nine spacecraft, which have collected a significant amount of data about Jovian properties. In this paper, we show that one type of the in situ measurements on the relativistic electron fluxes could be used to probe dark matter (DM) and dark mediator between the dark sector and our visible world. Jupiter, with its immense weight and cool core, could be an ideal capturer for DM with masses around the GeV scale. The captured DM particles could annihilate into long-lived dark mediators such as dark photons, which subsequently decay into electrons and positrons outside Jupiter. The charged particles, trapped by the Jovian magnetic field, have been measured in Jupiter missions such as the Galileo probe and the Juno orbiter. We use the data available to set upper bounds on the cross section of DM scattering off nucleons, $\sigma_{\chi n}$, for dark mediators with lifetime of order ${\cal O}(0.1-1)$s. The results show that data from Jupiter missions already probe regions in the parameter space un- or under-explored by existing DM searches, e.g., constrain $\sigma_{\chi n}$ of order $(10^{-40} - 10^{-38})$ cm$^2$ for 1 GeV DM dominantly annihilating into $e^+e^-$ through dark mediators. This study serves as an example and an initial step to explore the full physics potential of the large planetary datasets from Jupiter missions. We also outline several other potential directions related to secondary products of electrons, positron signals and solar axions.
[ { "created": "Wed, 27 Jul 2022 18:00:01 GMT", "version": "v1" }, { "created": "Mon, 8 Aug 2022 20:35:10 GMT", "version": "v2" } ]
2022-11-23
[ [ "Li", "Lingfeng", "" ], [ "Fan", "JiJi", "" ] ]
Jupiter, the fascinating largest planet in the solar system, has been visited by nine spacecraft, which have collected a significant amount of data about Jovian properties. In this paper, we show that one type of the in situ measurements on the relativistic electron fluxes could be used to probe dark matter (DM) and dark mediator between the dark sector and our visible world. Jupiter, with its immense weight and cool core, could be an ideal capturer for DM with masses around the GeV scale. The captured DM particles could annihilate into long-lived dark mediators such as dark photons, which subsequently decay into electrons and positrons outside Jupiter. The charged particles, trapped by the Jovian magnetic field, have been measured in Jupiter missions such as the Galileo probe and the Juno orbiter. We use the data available to set upper bounds on the cross section of DM scattering off nucleons, $\sigma_{\chi n}$, for dark mediators with lifetime of order ${\cal O}(0.1-1)$s. The results show that data from Jupiter missions already probe regions in the parameter space un- or under-explored by existing DM searches, e.g., constrain $\sigma_{\chi n}$ of order $(10^{-40} - 10^{-38})$ cm$^2$ for 1 GeV DM dominantly annihilating into $e^+e^-$ through dark mediators. This study serves as an example and an initial step to explore the full physics potential of the large planetary datasets from Jupiter missions. We also outline several other potential directions related to secondary products of electrons, positron signals and solar axions.
2202.04384
Maria Gomez-Rocha
Mar\'ia G\'omez-Rocha, Oliver Heger, Wolfgang Schweiger
An estimation of non-valence contributions to form factors of heavy-light mesons
Presented by Maria Gomez-Rocha at the 19th International Conference on Hadron Spectroscopy and Structure in memoriam Simon Eidelman (HADRON 2021); 5 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the influence of non-valence quark-pair contributions in weak transition form factors of heavy-light mesons. Form factors are first calculated for spacelike momentum transfers in a reference frame where such contributions are suppressed. Analytic continuation to the timelike region and a comparison with the direct decay calculation, done with pure valence degrees of freedom, provides an estimate of the role that quark-pair contributions may play. We use the point form of relativistic quantum mechanics, which is particularly useful when treating heavy-light systems.
[ { "created": "Wed, 9 Feb 2022 10:52:40 GMT", "version": "v1" } ]
2022-02-10
[ [ "Gómez-Rocha", "María", "" ], [ "Heger", "Oliver", "" ], [ "Schweiger", "Wolfgang", "" ] ]
We study the influence of non-valence quark-pair contributions in weak transition form factors of heavy-light mesons. Form factors are first calculated for spacelike momentum transfers in a reference frame where such contributions are suppressed. Analytic continuation to the timelike region and a comparison with the direct decay calculation, done with pure valence degrees of freedom, provides an estimate of the role that quark-pair contributions may play. We use the point form of relativistic quantum mechanics, which is particularly useful when treating heavy-light systems.
2007.08733
Davi Costa
Davi B. Costa
Anomaly-free $U(1)^m$ extensions of the Standard Model
6 pages
null
10.1103/PhysRevD.102.115006
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We construct anomaly-free $U(1)_1\times U(1)_2\times...\times U(1)_m$ gauge extensions of the Standard Model. To perform this construction we put together anomaly-free $U(1)$ extensions of one and two families of fermions. The availability of free parameters that enter linearly in the equations for the fermion charges and the large number of different classes of extensions may help other model builders interested in their use to solve problems of particle physics.
[ { "created": "Fri, 17 Jul 2020 03:05:56 GMT", "version": "v1" }, { "created": "Thu, 23 Jul 2020 16:16:08 GMT", "version": "v2" }, { "created": "Thu, 6 Aug 2020 13:38:34 GMT", "version": "v3" }, { "created": "Wed, 12 Aug 2020 16:16:34 GMT", "version": "v4" }, { "created": "Sun, 8 Nov 2020 15:34:33 GMT", "version": "v5" } ]
2020-12-30
[ [ "Costa", "Davi B.", "" ] ]
We construct anomaly-free $U(1)_1\times U(1)_2\times...\times U(1)_m$ gauge extensions of the Standard Model. To perform this construction we put together anomaly-free $U(1)$ extensions of one and two families of fermions. The availability of free parameters that enter linearly in the equations for the fermion charges and the large number of different classes of extensions may help other model builders interested in their use to solve problems of particle physics.
1902.03781
Hyun Min Lee
Soo-Min Choi, Yoo-Jin Kang, Hyun Min Lee, Kimiko Yamashita
Unitary inflaton as decaying dark matter
36 pages, 7 figures, v2: minor corrections made and references added, v3: discussion on preheating added, accepted for Journal of High Energy Physics, v4: Lyman-alpha bound included and inflationary predictions refined for perturbative reheating
null
10.1007/JHEP05(2019)060
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the inflation model of a singlet scalar field (sigma field) with both quadratic and linear non-minimal couplings where unitarity is ensured up to the Planck scale. We assume that a $Z_2$ symmetry for the sigma field is respected by the scalar potential in Jordan frame but it is broken explicitly by the linear non-minimal coupling due to quantum gravity. We discuss the impacts of the linear non-minimal coupling on various dynamics from inflation to low energy, such as a sizable tensor-to-scalar ratio, a novel reheating process with quartic potential dominance, and suppressed physical parameters in the low energy, etc. In particular, the linear non-minimal coupling leads to the linear couplings of the sigma field to the Standard Model through the trace of the energy-momentum tensor in Einstein frame. Thus, regarding the sigma field as a decaying dark matter, we consider the non-thermal production mechanisms for dark matter from the decays of Higgs and inflaton condensate and show the parameter space that is compatible with the correct relic density and cosmological constraints.
[ { "created": "Mon, 11 Feb 2019 09:05:16 GMT", "version": "v1" }, { "created": "Sat, 16 Feb 2019 11:02:57 GMT", "version": "v2" }, { "created": "Mon, 29 Apr 2019 01:28:19 GMT", "version": "v3" }, { "created": "Tue, 29 Oct 2019 22:27:09 GMT", "version": "v4" } ]
2019-10-31
[ [ "Choi", "Soo-Min", "" ], [ "Kang", "Yoo-Jin", "" ], [ "Lee", "Hyun Min", "" ], [ "Yamashita", "Kimiko", "" ] ]
We consider the inflation model of a singlet scalar field (sigma field) with both quadratic and linear non-minimal couplings where unitarity is ensured up to the Planck scale. We assume that a $Z_2$ symmetry for the sigma field is respected by the scalar potential in Jordan frame but it is broken explicitly by the linear non-minimal coupling due to quantum gravity. We discuss the impacts of the linear non-minimal coupling on various dynamics from inflation to low energy, such as a sizable tensor-to-scalar ratio, a novel reheating process with quartic potential dominance, and suppressed physical parameters in the low energy, etc. In particular, the linear non-minimal coupling leads to the linear couplings of the sigma field to the Standard Model through the trace of the energy-momentum tensor in Einstein frame. Thus, regarding the sigma field as a decaying dark matter, we consider the non-thermal production mechanisms for dark matter from the decays of Higgs and inflaton condensate and show the parameter space that is compatible with the correct relic density and cosmological constraints.
1104.5371
Hannu Holopainen
Hannu Holopainen, Sami R\"as\"anen, Kari J. Eskola
Elliptic flow of thermal photons in heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider
11 pages, 13 figures
null
10.1103/PhysRevC.84.064903
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the thermal photon transverse momentum spectra and elliptic flow in $\sqrt{s_{NN}} = 200$ GeV Au+Au collisions at RHIC and in $\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb collisions at the LHC, using an ideal-hydrodynamical framework which is constrained by the measured hadron spectra at RHIC and LHC. The sensitivity of the results to the QCD-matter equation of state and to the photon emission rates is studied, and the photon $v_2$ is discussed in the light of the photonic $p_T$ spectrum measured by the PHENIX Collaboration. In particular, we make a prediction for the thermal photon $p_T$ spectra and elliptic flow for the current LHC Pb+Pb collisions.
[ { "created": "Thu, 28 Apr 2011 12:29:46 GMT", "version": "v1" } ]
2013-05-29
[ [ "Holopainen", "Hannu", "" ], [ "Räsänen", "Sami", "" ], [ "Eskola", "Kari J.", "" ] ]
We calculate the thermal photon transverse momentum spectra and elliptic flow in $\sqrt{s_{NN}} = 200$ GeV Au+Au collisions at RHIC and in $\sqrt{s_{NN}} = 2.76$ TeV Pb+Pb collisions at the LHC, using an ideal-hydrodynamical framework which is constrained by the measured hadron spectra at RHIC and LHC. The sensitivity of the results to the QCD-matter equation of state and to the photon emission rates is studied, and the photon $v_2$ is discussed in the light of the photonic $p_T$ spectrum measured by the PHENIX Collaboration. In particular, we make a prediction for the thermal photon $p_T$ spectra and elliptic flow for the current LHC Pb+Pb collisions.
hep-ph/9809258
Silvano Simula
F. Cardarelli and S. Simula
The light baryon spectrum and the exchange of pseudoscalar and vector mesons among constituent quarks
to appear in the Proc. of the 3rd Int. Conf. on Quark Confinement and the Hadron Spectrum (CONFIII), JLab (Newport News, USA), June 7-12, 1998
null
null
preprint INFN-RM3 98/3, September 1998
hep-ph nucl-th
null
The effects of the exchanges of both pseudoscalar and vector mesons among constituent quarks on the mass spectra of light baryons are investigated, paying particular attention to the contribution of tensor and spin-orbit terms. It is shown that the latter ones heavily affect the calculated spectra at variance with the empirical observation of the weakness of the baryon spin-orbit splittings. The relativistic suppression of the strength of the interaction among light quarks is argued to be a possible way to reproduce the light-baryon mass spectra.
[ { "created": "Fri, 4 Sep 1998 08:50:18 GMT", "version": "v1" } ]
2007-05-23
[ [ "Cardarelli", "F.", "" ], [ "Simula", "S.", "" ] ]
The effects of the exchanges of both pseudoscalar and vector mesons among constituent quarks on the mass spectra of light baryons are investigated, paying particular attention to the contribution of tensor and spin-orbit terms. It is shown that the latter ones heavily affect the calculated spectra at variance with the empirical observation of the weakness of the baryon spin-orbit splittings. The relativistic suppression of the strength of the interaction among light quarks is argued to be a possible way to reproduce the light-baryon mass spectra.
hep-ph/0602097
Ralf Lehnert
Ralf Lehnert
Lorentz and CPT tests involving antiprotons
20 pages, 6 figures; Invited talk at Workshop for Physics with Ultra Slow Antiproton Beams, Wako, Japan, 14-16 Mar 2005
null
null
null
hep-ph
null
Lorentz and CPT tests involving matter-antimatter comparisons at low temperatures are discussed. SME predictions for transition frequencies in such systems include both matter-antimatter differences and sidereal variations. In hydrogen-antihydrogen spectroscopy, leading-order effects in a 1S-2S transition as well as in a 1S Zeeman transition could exist that can be employed to obtain clean constraints. Similarly, tight bounds can be determined from Penning-trap experiments involving antiprotons.
[ { "created": "Sat, 11 Feb 2006 00:05:54 GMT", "version": "v1" } ]
2007-05-23
[ [ "Lehnert", "Ralf", "" ] ]
Lorentz and CPT tests involving matter-antimatter comparisons at low temperatures are discussed. SME predictions for transition frequencies in such systems include both matter-antimatter differences and sidereal variations. In hydrogen-antihydrogen spectroscopy, leading-order effects in a 1S-2S transition as well as in a 1S Zeeman transition could exist that can be employed to obtain clean constraints. Similarly, tight bounds can be determined from Penning-trap experiments involving antiprotons.
hep-ph/0011133
Simon Albino
Simon Albino and Richard D. Ball
Soft Resummation of Quark Anomalous Dimensions and Coefficient Functions in MS-bar Factorization
12 pages
Phys.Lett.B513:93-102,2001
10.1016/S0370-2693(01)00742-0
null
hep-ph hep-th
null
The asymptotic behaviour at large N of the MS-bar quark anomalous dimensions is derived to all orders assuming only MS-bar factorization and standard results for the exponentiation of soft logarithms in the quark initiated bare cross sections for deep inelastic scattering and Drell-Yan. The result is then used to write the MS-bar quark coefficient functions in a form in which all terms of $O(\ln^m N)$ are resummed.
[ { "created": "Thu, 9 Nov 2000 17:20:37 GMT", "version": "v1" } ]
2014-11-17
[ [ "Albino", "Simon", "" ], [ "Ball", "Richard D.", "" ] ]
The asymptotic behaviour at large N of the MS-bar quark anomalous dimensions is derived to all orders assuming only MS-bar factorization and standard results for the exponentiation of soft logarithms in the quark initiated bare cross sections for deep inelastic scattering and Drell-Yan. The result is then used to write the MS-bar quark coefficient functions in a form in which all terms of $O(\ln^m N)$ are resummed.
hep-ph/0006177
Ariel Megevand
Ariel Megevand
Development of the electroweak phase transition and baryogenesis
26 pages, 7 figures; typos corrected, reference added
Int.J.Mod.Phys. D9 (2000) 733-756
10.1142/S0218271800000724
null
hep-ph astro-ph
null
We investigate the evolution of the electroweak phase transition, using a one-Higgs effective potential that can be regarded as an approximation for the Minimal Supersymmetric Standard Model. The phase transition occurs in a small interval around a temperature T_t below the critical one. We calculate this temperature as a function of the parameters of the potential and of a damping coefficient related to the viscosity of the plasma. The parameters that are relevant for baryogenesis, such as the velocity and thickness of the walls of bubbles and the value of the Higgs field inside them, change significantly in the range of temperatures where the first-order phase transition can occur. However, we find that in the likely interval for T_t there is no significant variation of these parameters. Furthermore, the temperature T_t is in general not far below the temperature at which bubbles begin to nucleate.
[ { "created": "Thu, 15 Jun 2000 19:19:21 GMT", "version": "v1" }, { "created": "Fri, 23 Jun 2000 18:24:24 GMT", "version": "v2" } ]
2009-10-31
[ [ "Megevand", "Ariel", "" ] ]
We investigate the evolution of the electroweak phase transition, using a one-Higgs effective potential that can be regarded as an approximation for the Minimal Supersymmetric Standard Model. The phase transition occurs in a small interval around a temperature T_t below the critical one. We calculate this temperature as a function of the parameters of the potential and of a damping coefficient related to the viscosity of the plasma. The parameters that are relevant for baryogenesis, such as the velocity and thickness of the walls of bubbles and the value of the Higgs field inside them, change significantly in the range of temperatures where the first-order phase transition can occur. However, we find that in the likely interval for T_t there is no significant variation of these parameters. Furthermore, the temperature T_t is in general not far below the temperature at which bubbles begin to nucleate.
0808.0136
Ayres Freitas
A. Freitas
Status of Constraints on Supersymmetry
Invited talk at the Hadron Collider Physics Symposium (HCP2008), Galena, Illinois, USA, May 27-31, 2008; 10 pages, LaTeX; v2: recent updates for some results
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A short summary of constraints on the parameter space of supersymmetric models is given. Experimental limits from high energy colliders, electroweak precision data, flavor and Higgs physics, and cosmology are considered. The main focus is on the MSSM with conserved R- and CP-parity and minimal flavor violation, but more general scenarios and extended models will also be discussed briefly.
[ { "created": "Fri, 1 Aug 2008 15:10:18 GMT", "version": "v1" }, { "created": "Sun, 17 Aug 2008 18:04:31 GMT", "version": "v2" } ]
2008-08-17
[ [ "Freitas", "A.", "" ] ]
A short summary of constraints on the parameter space of supersymmetric models is given. Experimental limits from high energy colliders, electroweak precision data, flavor and Higgs physics, and cosmology are considered. The main focus is on the MSSM with conserved R- and CP-parity and minimal flavor violation, but more general scenarios and extended models will also be discussed briefly.
1305.3820
Feng Feng
Hai-Rong Dong, Feng Feng and Hai-Bo Li
Lepton number violation in D meson decay
17 pages, 3 figures, 5 tables, references added and numerical results updated
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The lepton number violating process can be induced by introducing a fourth generation heavy Majorana neutrino, which is coupled to the charged leptons of Standard Model. There have been many previous studies on the leptonic number violating decay processes with this mechanism, we follow the trend to study the process: $D \to K \ell \ell \pi$ with the same-sign dilepton final states. We restrict ourself to certain neutrino mass regions, in which the heavy neutrino could be on shell and the dominant contribution to the branching fraction comes from the resonance enhanced effect. Applying the Narrow Width Approximation, we found that upper limit for the branching fractions for $D^0 \to K^-\ell^+\ell^+\pi^-$ are generally at the order of $10^{-10}$ to $10^{-9}$, if we take the most stringent upper limit bound currently available in the literature for the mixing matrix elements. We also provide the constrains, which is competitive compared to the LNV B decays, on the mixing matrix element $|V_{eN}|^2$ based on the upper limit of $D^0 \to K^- e^+ e^+ \pi^-$ estimated from Monte-Carlo study at BESIII.
[ { "created": "Thu, 16 May 2013 14:22:32 GMT", "version": "v1" }, { "created": "Mon, 22 Jul 2013 14:15:59 GMT", "version": "v2" } ]
2013-07-23
[ [ "Dong", "Hai-Rong", "" ], [ "Feng", "Feng", "" ], [ "Li", "Hai-Bo", "" ] ]
The lepton number violating process can be induced by introducing a fourth generation heavy Majorana neutrino, which is coupled to the charged leptons of Standard Model. There have been many previous studies on the leptonic number violating decay processes with this mechanism, we follow the trend to study the process: $D \to K \ell \ell \pi$ with the same-sign dilepton final states. We restrict ourself to certain neutrino mass regions, in which the heavy neutrino could be on shell and the dominant contribution to the branching fraction comes from the resonance enhanced effect. Applying the Narrow Width Approximation, we found that upper limit for the branching fractions for $D^0 \to K^-\ell^+\ell^+\pi^-$ are generally at the order of $10^{-10}$ to $10^{-9}$, if we take the most stringent upper limit bound currently available in the literature for the mixing matrix elements. We also provide the constrains, which is competitive compared to the LNV B decays, on the mixing matrix element $|V_{eN}|^2$ based on the upper limit of $D^0 \to K^- e^+ e^+ \pi^-$ estimated from Monte-Carlo study at BESIII.
hep-ph/0308018
Xiangdong Ji
Ahmad Idilbi, Xiangdong Ji, and Jian-Ping Ma
Delta-to-N-gamma Coulomb Quadrupole Amplitude in PQCD
9 pages, two figures
Phys.Rev. D69 (2004) 014006
10.1103/PhysRevD.69.014006
null
hep-ph
null
We present a leading-order pQCD calculation of the helicity-flip $\Delta\to N\gamma^*$ matrix element $G_0$ (Coulomb quadrupole amplitude $C2$), taking into account the transverse momenta of the quarks and the contribution from the gluons. In the large $Q^2$ limit, its scaling behavior acquires a double-logarithmic correction $\log^2{(Q^2/\Lambda^2)}$ compared with the standard scaling analysis, due to the contribution from the orbital motion of the small-$x$ partons. Based on this and on the latest JLab experimental results of the $C2-M1$ ratio $R_{SM}$ at $Q^2$ = 3 $\sim$ 4 GeV$^2$, we make a phenomenological prediction for the latter at higher values of $Q^2$.
[ { "created": "Fri, 1 Aug 2003 22:20:55 GMT", "version": "v1" } ]
2009-11-10
[ [ "Idilbi", "Ahmad", "" ], [ "Ji", "Xiangdong", "" ], [ "Ma", "Jian-Ping", "" ] ]
We present a leading-order pQCD calculation of the helicity-flip $\Delta\to N\gamma^*$ matrix element $G_0$ (Coulomb quadrupole amplitude $C2$), taking into account the transverse momenta of the quarks and the contribution from the gluons. In the large $Q^2$ limit, its scaling behavior acquires a double-logarithmic correction $\log^2{(Q^2/\Lambda^2)}$ compared with the standard scaling analysis, due to the contribution from the orbital motion of the small-$x$ partons. Based on this and on the latest JLab experimental results of the $C2-M1$ ratio $R_{SM}$ at $Q^2$ = 3 $\sim$ 4 GeV$^2$, we make a phenomenological prediction for the latter at higher values of $Q^2$.
1511.05349
Kapil Saraswat
Kapil Saraswat, Prashant Shukla, Venktesh Singh
Energy loss of $B$ and $D$ mesons in PbPb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV
arXiv admin note: substantial text overlap with arXiv:1507.06742
PoS (ICPAQGP2015) 082
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the calculations of collisional and radiative energy loss of $B$ and $D$ mesons in the medium produced in PbPb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV. The nuclear modification factor $R_{AA}$ of $B$ and $D$ mesons including shadowing and energy loss are calculated and compared with the measured data. While the $D$ meson $R_{AA}$ can be described in terms of the radiative energy loss alone, both the collisional as well as radiative energy loss are required to explain the $B$ meson measurements.
[ { "created": "Tue, 17 Nov 2015 11:21:55 GMT", "version": "v1" } ]
2017-09-11
[ [ "Saraswat", "Kapil", "" ], [ "Shukla", "Prashant", "" ], [ "Singh", "Venktesh", "" ] ]
We present the calculations of collisional and radiative energy loss of $B$ and $D$ mesons in the medium produced in PbPb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV. The nuclear modification factor $R_{AA}$ of $B$ and $D$ mesons including shadowing and energy loss are calculated and compared with the measured data. While the $D$ meson $R_{AA}$ can be described in terms of the radiative energy loss alone, both the collisional as well as radiative energy loss are required to explain the $B$ meson measurements.
1805.07282
Marco Merchand
Marco Merchand, Marc Sher and Keith Thrasher
Radion-Higgs Mixing in 2HDMs
31 pages, 27 figures. Version to be published in JHEP
null
10.1007/JHEP09(2018)029
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the custodial Randall-Sundrum model with two Higgs doublets localized in the $\TeV $ brane. The scalar potential is CP- conserving and has a softly broken $Z_2$ symmetry. In the presence of a curvature-scalar mixing term $ \xi_{ab} \mathcal{R} \Phi_a^\dagger \Phi_b$ the radion that stabilizes the extra dimension now mixes with the two CP-even neutral scalars $h$ and $H$. A goodness of fit of the LHC data on the properties of the light Higgs is performed on the parameter space of the type-I and type-II models. LHC direct searches for heavy scalars in different decay channels can help distinguish between the radion and a heavy Higgs. The most important signatures involve the ratio of heavy scalar decays into $b$ quark pairs to those into $Z$ pairs, as well as the decay of the scalar (pseudoscalar) into a $Z$ plus a pseudoscalar (scalar).
[ { "created": "Fri, 18 May 2018 15:23:19 GMT", "version": "v1" }, { "created": "Tue, 4 Sep 2018 05:25:40 GMT", "version": "v2" } ]
2018-09-26
[ [ "Merchand", "Marco", "" ], [ "Sher", "Marc", "" ], [ "Thrasher", "Keith", "" ] ]
We study the custodial Randall-Sundrum model with two Higgs doublets localized in the $\TeV $ brane. The scalar potential is CP- conserving and has a softly broken $Z_2$ symmetry. In the presence of a curvature-scalar mixing term $ \xi_{ab} \mathcal{R} \Phi_a^\dagger \Phi_b$ the radion that stabilizes the extra dimension now mixes with the two CP-even neutral scalars $h$ and $H$. A goodness of fit of the LHC data on the properties of the light Higgs is performed on the parameter space of the type-I and type-II models. LHC direct searches for heavy scalars in different decay channels can help distinguish between the radion and a heavy Higgs. The most important signatures involve the ratio of heavy scalar decays into $b$ quark pairs to those into $Z$ pairs, as well as the decay of the scalar (pseudoscalar) into a $Z$ plus a pseudoscalar (scalar).
1009.0093
Francois Gelis
Francois Gelis
Color Glass Condensate and Glasma
11 pages, 14 figures, to appear in the proceedings of the RIKEN BNL Research Center Workshop on "Saturation, the Color Glass Condensate and Glasma: What Have we Learned from RHIC?", May 10-12, 2010
Nucl.Phys.A854:10-17,2011
10.1016/j.nuclphysa.2010.09.001
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, I review the Color Glass Condensate theory of gluon saturation, and its application to the early stages of heavy ion collisions.
[ { "created": "Wed, 1 Sep 2010 05:38:34 GMT", "version": "v1" }, { "created": "Mon, 6 Sep 2010 14:49:52 GMT", "version": "v2" } ]
2011-03-17
[ [ "Gelis", "Francois", "" ] ]
In this talk, I review the Color Glass Condensate theory of gluon saturation, and its application to the early stages of heavy ion collisions.
hep-ph/0508194
Tord Riemann
J. Fleischer (Univ. Bielefeld), T. Riemann (DESY), O.V. Tarasov (DESY)
Analytic epsilon-Expansion of the Scalar One-loop Bhabha Box Function
12 pages, latex, uses appolb.cls; presented by J.F. at 27th International Conference of Theoretical Physics: Matter to the Deepest: Recent Developments in Physics of Fundamental Interactions (Ustron 03), Ustron, Poland, 15-21 Sep 2003
Acta Phys.Polon.B34:5345-5356,2003
null
null
hep-ph
null
We derive the first three terms of the epsilon-expansion of the scalar one-loop Bhabha box function from a representation in terms of three generalized hypergeometric functions, which is valid in arbitrary dimensions.
[ { "created": "Thu, 18 Aug 2005 13:45:08 GMT", "version": "v1" } ]
2010-01-05
[ [ "Fleischer", "J.", "", "Univ. Bielefeld" ], [ "Riemann", "T.", "", "DESY" ], [ "Tarasov", "O. V.", "", "DESY" ] ]
We derive the first three terms of the epsilon-expansion of the scalar one-loop Bhabha box function from a representation in terms of three generalized hypergeometric functions, which is valid in arbitrary dimensions.
hep-ph/0111055
Sergei V. Semenov
V. V. Khruschev (1 and 3), V. I. Savrin (2) and S. V. Semenov (3) ((1) Center for Gravitation and Fundamental Metrology, VNIIMS, Moscow, (2) Institute of Nuclear Physics, Moscow State University, (3) Russian Research Center "Kurchatov Institute", Moscow)
On the Parameters of the QCD-Motivated Potential in the Relativistic Independent Quark Model
10 pages, LaTex; added references for the beginning, changed the last paragraph at the end, made a few stylistic corrections
Phys.Lett. B525 (2002) 283-288
10.1016/S0370-2693(01)01456-3
null
hep-ph
null
In the framework of the relativistic independent quark model the parameters of the QCD-motivated static potential and the quark masses are calculated on the basis of the $1^{--}$ meson mass spectra. The value of the confining potential coefficient is found to be ($0.197\pm 0.005) GeV${}^2$. for quark- antiquark interaction independently on their flavours. The dependence of the quasi-Coulombic potential strength on the interaction distance are consistent with the QCD-motivated behaviour. The $q\bar q$-separations are evaluated and the $e^+e^-$ decay widths are estimated with the help of relativistic modification of the Van Royen-Weisskopf formula.
[ { "created": "Tue, 6 Nov 2001 14:29:01 GMT", "version": "v1" }, { "created": "Fri, 30 Nov 2001 16:11:54 GMT", "version": "v2" } ]
2009-11-07
[ [ "Khruschev", "V. V.", "", "1 and 3" ], [ "Savrin", "V. I.", "" ], [ "Semenov", "S. V.", "" ] ]
In the framework of the relativistic independent quark model the parameters of the QCD-motivated static potential and the quark masses are calculated on the basis of the $1^{--}$ meson mass spectra. The value of the confining potential coefficient is found to be ($0.197\pm 0.005) GeV${}^2$. for quark- antiquark interaction independently on their flavours. The dependence of the quasi-Coulombic potential strength on the interaction distance are consistent with the QCD-motivated behaviour. The $q\bar q$-separations are evaluated and the $e^+e^-$ decay widths are estimated with the help of relativistic modification of the Van Royen-Weisskopf formula.
1012.1975
Grzegorz Wilk
Grzegorz Wilk, Zbigniew Wlodarczyk and Wojciech Wolak
Composition of fluctuations of different observables
8 pages, 3 figures, to be published in Acta Phys. Polon. B (2011)
Acta Phys. Polon. B42 (2011) 1277-1285
10.5506/APhysPolB.42.1277
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We demonstrate that description of fluctuations observed in multiparticle production processes using Tsallis statistics approach (in which fluctuations are described by the nonextensivity parameter q) leads to a specific sum rule for parameters q seen in different observables which can be verified experimentally.
[ { "created": "Thu, 9 Dec 2010 11:04:59 GMT", "version": "v1" }, { "created": "Tue, 22 Feb 2011 14:55:54 GMT", "version": "v2" } ]
2011-06-09
[ [ "Wilk", "Grzegorz", "" ], [ "Wlodarczyk", "Zbigniew", "" ], [ "Wolak", "Wojciech", "" ] ]
We demonstrate that description of fluctuations observed in multiparticle production processes using Tsallis statistics approach (in which fluctuations are described by the nonextensivity parameter q) leads to a specific sum rule for parameters q seen in different observables which can be verified experimentally.
1612.06316
Jaime Hern\'andez-S\'anchez Dr.
J. Hern\'andez-S\'anchez, O. Flores-S\'anchez, C. G. Honorato, S. Moretti, S. Rosado
Prospect for observing a light charged Higgs through the decay $H^+ \to c \bar{b} + c.c.$ at the LHeC
5 pages, 2 figures, contribution to Prospects for Charged Higgs Discovery at Colliders (Charged 2016)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the production and decay of a light charged Higgs boson at the future Large Hadron electron Collider (LHeC) in the framework of the Two Higgs Doublet Type III, assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We analyze the charge current production processes $e^- p \to \nu_e q H^+ $ considering the signature $H^+ \to c \bar{b} + c.c.$ of the final state. We take this signature and we compare it to the irreducible background from Standard Model (SM) interactions. We consider scenarios of the model which are consistent with current experimental data from Higgs and flavor physics.
[ { "created": "Mon, 19 Dec 2016 19:16:51 GMT", "version": "v1" } ]
2016-12-20
[ [ "Hernández-Sánchez", "J.", "" ], [ "Flores-Sánchez", "O.", "" ], [ "Honorato", "C. G.", "" ], [ "Moretti", "S.", "" ], [ "Rosado", "S.", "" ] ]
We study the production and decay of a light charged Higgs boson at the future Large Hadron electron Collider (LHeC) in the framework of the Two Higgs Doublet Type III, assuming a four-zero texture in the Yukawa matrices and a general Higgs potential. We analyze the charge current production processes $e^- p \to \nu_e q H^+ $ considering the signature $H^+ \to c \bar{b} + c.c.$ of the final state. We take this signature and we compare it to the irreducible background from Standard Model (SM) interactions. We consider scenarios of the model which are consistent with current experimental data from Higgs and flavor physics.
1608.05207
Ryoutaro Watanabe
Minoru Tanaka and Ryoutaro Watanabe
New physics contributions in $B\to\pi\tau\bar\nu$ and $B\to\tau\bar\nu$
17 pages, 4 figures, 1 table; revised version accepted by journal
Prog Theor Exp Phys (2017)
10.1093/ptep/ptw175
OU-HET-902, CTPU-16-20
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study possible new physics contributions in $B\to\pi\tau\bar\nu $ and $B\to\tau\bar\nu$ employing the model-independent effective Lagrangian that describes the quark-level transition $b \to u \tau\nu$ at low energies. The decay rate of $B\to\pi\tau\bar\nu$ and its theoretical uncertainty are evaluated using the $B\to\pi$ form factors given by recent lattice QCD studies. Comparing theoretical results with the current experimental data, $\mathcal{B}(B\to\pi\tau\bar\nu)<2.5\times 10^{-4}$ and $\mathcal{B}(B\to\tau\bar\nu)=(1.14\pm 0.22)\times 10^{-4}$, we obtain constraints on the Wilson coefficients that quantify potential new physics. We also present the expected sensitivity of the SuperKEKB/Belle~II experiment.
[ { "created": "Thu, 18 Aug 2016 08:45:01 GMT", "version": "v1" }, { "created": "Thu, 10 Nov 2016 02:20:45 GMT", "version": "v2" } ]
2019-12-06
[ [ "Tanaka", "Minoru", "" ], [ "Watanabe", "Ryoutaro", "" ] ]
We study possible new physics contributions in $B\to\pi\tau\bar\nu $ and $B\to\tau\bar\nu$ employing the model-independent effective Lagrangian that describes the quark-level transition $b \to u \tau\nu$ at low energies. The decay rate of $B\to\pi\tau\bar\nu$ and its theoretical uncertainty are evaluated using the $B\to\pi$ form factors given by recent lattice QCD studies. Comparing theoretical results with the current experimental data, $\mathcal{B}(B\to\pi\tau\bar\nu)<2.5\times 10^{-4}$ and $\mathcal{B}(B\to\tau\bar\nu)=(1.14\pm 0.22)\times 10^{-4}$, we obtain constraints on the Wilson coefficients that quantify potential new physics. We also present the expected sensitivity of the SuperKEKB/Belle~II experiment.
1903.00506
Yacine Mehtar-Tani
Yacine Mehtar-Tani
Gluon bremsstrahlung in finite media beyond multiple soft scattering approximation
22 pages, 5 figures, minor corrections, to appear in JHEP
null
10.1007/JHEP07(2019)057
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit the calculation of the medium-induced gluon spectrum in a finite QCD and develop a new approach that goes beyond multiple soft scattering approximation. We show by expanding around the harmonic oscillator that the first two orders encompass the two known analytic limits: single hard and multiple soft scattering regimes, valid at high and low frequencies, respectively. Finally, we investigate the sensitivity of our results to the infrared and observe that for large media the spectrum is weakly dependent on the infrared medium scale.
[ { "created": "Fri, 1 Mar 2019 19:34:37 GMT", "version": "v1" }, { "created": "Tue, 11 Jun 2019 14:29:44 GMT", "version": "v2" } ]
2019-09-04
[ [ "Mehtar-Tani", "Yacine", "" ] ]
We revisit the calculation of the medium-induced gluon spectrum in a finite QCD and develop a new approach that goes beyond multiple soft scattering approximation. We show by expanding around the harmonic oscillator that the first two orders encompass the two known analytic limits: single hard and multiple soft scattering regimes, valid at high and low frequencies, respectively. Finally, we investigate the sensitivity of our results to the infrared and observe that for large media the spectrum is weakly dependent on the infrared medium scale.
hep-ph/0008332
Shmatov Sergei
M.Savina, S.Shmatov, P.Zarubin
Estimation of Collision Impact Parameter
6 pages, 3 figures
J.Phys.G27:2267-2274,2001
10.1088/0954-3899/27/11/307
null
hep-ph
null
We demonstrate that the nuclear collision geometry (i.e. impact parameter) can be determined with 1.5 fm accuracy in an event-by-event analysis by measuring the transverse energy flow in the pseudorapidity region $3 \le |\eta| \le 5$ with a minimal dependence on collision dynamics details at the LHC energy scale. Using the HIJING model we have illustrated our calculation by a simulation of events of nucleus-nucleus interactions at the c.m.s energy from 1 up to 5.5 TeV per nucleon and various type of nuclei.
[ { "created": "Thu, 31 Aug 2000 14:29:42 GMT", "version": "v1" } ]
2008-11-26
[ [ "Savina", "M.", "" ], [ "Shmatov", "S.", "" ], [ "Zarubin", "P.", "" ] ]
We demonstrate that the nuclear collision geometry (i.e. impact parameter) can be determined with 1.5 fm accuracy in an event-by-event analysis by measuring the transverse energy flow in the pseudorapidity region $3 \le |\eta| \le 5$ with a minimal dependence on collision dynamics details at the LHC energy scale. Using the HIJING model we have illustrated our calculation by a simulation of events of nucleus-nucleus interactions at the c.m.s energy from 1 up to 5.5 TeV per nucleon and various type of nuclei.
2112.14261
Aqeel Ahmed
Aqeel Ahmed and Saereh Najjari
Ultraviolet freeze-in dark matter through the dilaton portal
v2: 13 pages and 7 figures, matches the published version in PRD
null
null
MITP-21-043
hep-ph
http://creativecommons.org/licenses/by/4.0/
We study a class of models in which the Standard Model (SM) and dark matter (DM) belong to a conformal/scale-invariant theory at high energies. Scale invariance is spontaneously broken at scale $f$, giving rise to a dilaton as the corresponding Goldstone boson. In the low energy theory, we assume that DM interacts with the SM solely through the dilaton portal, which is suppressed by the conformal breaking scale $f$. For $f\gg{\rm TeV}$, the portal interactions are extremely weak, resulting in DM not being in thermal equilibrium with the SM. Thus, ultraviolet freeze-in production of DM occurs through the dilaton portal, being most effective at the maximum temperature of the SM bath. The temperature evolution is greatly impacted by the reheating dynamics, which we parametrize using a general equation of state $w$ and temperature at the end of reheating $T_{\rm rh}$. We analyze the implications of the reheating dynamics for DM production in this framework and identify regions of parameter space that result in the observed DM relic abundance for a wide range of DM masses and reheating temperatures for scalar, vector, or fermion DM.
[ { "created": "Tue, 28 Dec 2021 19:00:01 GMT", "version": "v1" }, { "created": "Thu, 9 Mar 2023 13:29:08 GMT", "version": "v2" } ]
2023-03-10
[ [ "Ahmed", "Aqeel", "" ], [ "Najjari", "Saereh", "" ] ]
We study a class of models in which the Standard Model (SM) and dark matter (DM) belong to a conformal/scale-invariant theory at high energies. Scale invariance is spontaneously broken at scale $f$, giving rise to a dilaton as the corresponding Goldstone boson. In the low energy theory, we assume that DM interacts with the SM solely through the dilaton portal, which is suppressed by the conformal breaking scale $f$. For $f\gg{\rm TeV}$, the portal interactions are extremely weak, resulting in DM not being in thermal equilibrium with the SM. Thus, ultraviolet freeze-in production of DM occurs through the dilaton portal, being most effective at the maximum temperature of the SM bath. The temperature evolution is greatly impacted by the reheating dynamics, which we parametrize using a general equation of state $w$ and temperature at the end of reheating $T_{\rm rh}$. We analyze the implications of the reheating dynamics for DM production in this framework and identify regions of parameter space that result in the observed DM relic abundance for a wide range of DM masses and reheating temperatures for scalar, vector, or fermion DM.
hep-ph/0611323
Zhang He
Wei Chao and He Zhang
One-loop renormalization group equations of the neutrino mass matrix in the triplet seesaw model
null
Phys.Rev.D75:033003,2007
10.1103/PhysRevD.75.033003
null
hep-ph
null
Within the framework of the standard model plus one heavy Higgs triplet, we derive a full set of one-loop renormalization group equations of the neutrino mass matrix and Higgs couplings in both full and effective theories. The explicit RGEs of neutrino masses, flavor mixing angles and CP-violating phases are also obtained, and their non-trivial running behaviors around the Higgs triplet mass threshold are numerically illustrated.
[ { "created": "Mon, 27 Nov 2006 02:24:26 GMT", "version": "v1" }, { "created": "Thu, 25 Jan 2007 02:16:25 GMT", "version": "v2" } ]
2008-11-26
[ [ "Chao", "Wei", "" ], [ "Zhang", "He", "" ] ]
Within the framework of the standard model plus one heavy Higgs triplet, we derive a full set of one-loop renormalization group equations of the neutrino mass matrix and Higgs couplings in both full and effective theories. The explicit RGEs of neutrino masses, flavor mixing angles and CP-violating phases are also obtained, and their non-trivial running behaviors around the Higgs triplet mass threshold are numerically illustrated.
hep-ph/0207038
Geng
Chuan-Hung Chen and C.Q. Geng
Long distance contributions in $B\toK^*\ell^+\ell^-$ decays with polarized $K^*$
LaTex, 13 pages, 4 figures, accepted for publication in PRD
Phys.Rev. D66 (2002) 034006
10.1103/PhysRevD.66.034006
null
hep-ph
null
We use momentum correlations as physical observables in $B\to K^{*}l^{+}l^{-}$ decays with $K^{*}$ polarized to study the long distance contributions. We show that these observables are sensitive to the scenarios of the long distance parametrizations. We find that the T-odd observable is directly related to the nonfactorizable effect in the standard model.
[ { "created": "Tue, 2 Jul 2002 23:52:21 GMT", "version": "v1" }, { "created": "Thu, 4 Jul 2002 07:41:34 GMT", "version": "v2" } ]
2009-11-07
[ [ "Chen", "Chuan-Hung", "" ], [ "Geng", "C. Q.", "" ] ]
We use momentum correlations as physical observables in $B\to K^{*}l^{+}l^{-}$ decays with $K^{*}$ polarized to study the long distance contributions. We show that these observables are sensitive to the scenarios of the long distance parametrizations. We find that the T-odd observable is directly related to the nonfactorizable effect in the standard model.
1607.04496
Rainer Schicker M
R.Schicker, R.Fiore, L.Jenkovszky
Resonance production in Pomeron-Pomeron collisions at the LHC
Proceedings XXIV Int. Workshop on Deep-Inelastic Scattering and Related Subjects (DIS16), DESY, 11-15 April 2016, 5 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A model for Pomeron-Pomeron total cross section in the resonance region $\sqrt{M^{2}} \le$ 5 GeV is presented. This model is based on Regge poles from the Pomeron and two different $f$ trajectories, and includes the isolated f$_{0}(500)$ resonance in the region $\sqrt{M^{2}}\lesssim 1$ GeV. A slowly varying background is included. The presented Pomeron-Pomeron cross section is not directly measurable, but is an essential ingredient for calculating exclusive resonance production at the LHC.
[ { "created": "Thu, 14 Jul 2016 16:52:15 GMT", "version": "v1" } ]
2016-07-18
[ [ "Schicker", "R.", "" ], [ "Fiore", "R.", "" ], [ "Jenkovszky", "L.", "" ] ]
A model for Pomeron-Pomeron total cross section in the resonance region $\sqrt{M^{2}} \le$ 5 GeV is presented. This model is based on Regge poles from the Pomeron and two different $f$ trajectories, and includes the isolated f$_{0}(500)$ resonance in the region $\sqrt{M^{2}}\lesssim 1$ GeV. A slowly varying background is included. The presented Pomeron-Pomeron cross section is not directly measurable, but is an essential ingredient for calculating exclusive resonance production at the LHC.
1005.0337
Willibald Plessas
Ki-Seok Choi, W. Plessas, and R.F. Wagenbrunn
Axial charges of octet and decuplet baryons
null
Phys.Rev.D82:014007,2010
10.1103/PhysRevD.82.014007
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a study of axial charges of baryon ground and resonant states with relativistic constituent quark models. In particular, the axial charges of octet and decuplet $N$, $\Sigma$, $\Xi$, $\Delta$, $\Sigma^*$, and $\Xi^*$ baryons are considered. The theoretical predictions are compared to existing experimental data and results from other approaches, notably from lattice quantum chromodynamics and chiral perturbation theory. The relevance of axial charges with regard to $\pi$-dressing and spontaneous chiral-symmetry breaking is discussed.
[ { "created": "Mon, 3 May 2010 16:25:57 GMT", "version": "v1" } ]
2010-11-02
[ [ "Choi", "Ki-Seok", "" ], [ "Plessas", "W.", "" ], [ "Wagenbrunn", "R. F.", "" ] ]
We present a study of axial charges of baryon ground and resonant states with relativistic constituent quark models. In particular, the axial charges of octet and decuplet $N$, $\Sigma$, $\Xi$, $\Delta$, $\Sigma^*$, and $\Xi^*$ baryons are considered. The theoretical predictions are compared to existing experimental data and results from other approaches, notably from lattice quantum chromodynamics and chiral perturbation theory. The relevance of axial charges with regard to $\pi$-dressing and spontaneous chiral-symmetry breaking is discussed.
1607.03223
Jun He Prof.
Jun He
Understanding spin parity of $P_c(4450)$ and $Y(4274)$ in a hadronic molecular state picture
7 pages, 5 figures. published version
Phys. Rev. D 95, 074004 (2017)
10.1103/PhysRevD.95.074004
null
hep-ph hep-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hidden-charmed pentaquark $P_c(4450)$ and the charmonium-like state $Y(4274)$ are investigated as a $\bar{D}^*\Sigma_c$ and a $D_s\bar{D}_{s0}(2317)$ molecular state, respectively. The spin parities of these two states cannot be well understood if only S-wave $\bar{D}^*\Sigma_c$ and $D_s\bar{D}_{s0}(2317)$ interactions are considered. In this work, the interactions are studied in a quasipotential Bethe-Salpeter equation approach with a partial wave decomposition on spin parity $J^P$, and the contributions of different partial waves are studied in a two-channel scattering model including a generating channel and an observation channel. Two poles at $4447\pm4i$ and $4392\pm46i$ MeV are produced from the $\bar{D}^*\Sigma_c$ interaction coupled with the $J/\psi p$ channel in $3/2^-$ wave and $5/2^+$ wave, respectively. The peak for the $5/2^+$ state has a comparable height as that of the $3/2^-$ state in the $J/\psi p$ invariant mass spectrum. The $D_s\bar{D}_{s0}(2317)$ interaction coupled with the $J/\psi\phi$ channel is studied and a pole at $4275\pm11i$ MeV is produced in $J^{P}=1^{+}$ wave, which corresponds to P-wave $D_s\bar{D}_{s0}(2317)$ interaction. The pole from S-wave $D_s\bar{D}_{s0}(2317)$ interaction is far below that from P-wave interaction even the $J/\psi\phi$ threshold, so cannot be observed in the $J/\psi\phi$ channel. The result suggests that in these cases a state carrying a spin parity corresponding to P-wave interaction should be taken as seriously as these carrying a spin parity corresponding to S-wave interaction in the hadronic molecular state picture.
[ { "created": "Tue, 12 Jul 2016 03:10:04 GMT", "version": "v1" }, { "created": "Mon, 5 Sep 2016 14:16:37 GMT", "version": "v2" }, { "created": "Tue, 11 Apr 2017 01:23:28 GMT", "version": "v3" } ]
2017-04-12
[ [ "He", "Jun", "" ] ]
The hidden-charmed pentaquark $P_c(4450)$ and the charmonium-like state $Y(4274)$ are investigated as a $\bar{D}^*\Sigma_c$ and a $D_s\bar{D}_{s0}(2317)$ molecular state, respectively. The spin parities of these two states cannot be well understood if only S-wave $\bar{D}^*\Sigma_c$ and $D_s\bar{D}_{s0}(2317)$ interactions are considered. In this work, the interactions are studied in a quasipotential Bethe-Salpeter equation approach with a partial wave decomposition on spin parity $J^P$, and the contributions of different partial waves are studied in a two-channel scattering model including a generating channel and an observation channel. Two poles at $4447\pm4i$ and $4392\pm46i$ MeV are produced from the $\bar{D}^*\Sigma_c$ interaction coupled with the $J/\psi p$ channel in $3/2^-$ wave and $5/2^+$ wave, respectively. The peak for the $5/2^+$ state has a comparable height as that of the $3/2^-$ state in the $J/\psi p$ invariant mass spectrum. The $D_s\bar{D}_{s0}(2317)$ interaction coupled with the $J/\psi\phi$ channel is studied and a pole at $4275\pm11i$ MeV is produced in $J^{P}=1^{+}$ wave, which corresponds to P-wave $D_s\bar{D}_{s0}(2317)$ interaction. The pole from S-wave $D_s\bar{D}_{s0}(2317)$ interaction is far below that from P-wave interaction even the $J/\psi\phi$ threshold, so cannot be observed in the $J/\psi\phi$ channel. The result suggests that in these cases a state carrying a spin parity corresponding to P-wave interaction should be taken as seriously as these carrying a spin parity corresponding to S-wave interaction in the hadronic molecular state picture.
2312.17733
P. S. Bhupal Dev
P. S. Bhupal Dev, Rabindra N. Mohapatra, Yongchao Zhang
Explanation of the 95 GeV $\gamma\gamma$ and $b\bar{b}$ excesses in the Minimal Left-Right Symmetric Model
9 pages + references, 6 figures; minor changes, version published in Phys. Lett. B
Phys. Lett. B 849 (2024) 138481
10.1016/j.physletb.2024.138481
CETUP-2023-021
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
We propose a simple interpretation of the $\gamma\gamma$ excesses reported by both CMS and ATLAS groups at 95 GeV together with the LEP excess in the $Zb\bar{b}$ channel around the same mass in terms of a neutral scalar field in the minimal left-right symmetric model (LRSM). We point out that the scalar field which implements the seesaw mechanism for neutrino masses has all the right properties to explain these observations, without introducing any extra scalar fields. The key point is that this scalar particle is hardly constrained because it couples only to heavy right-handed particles. As a result, the diphoton decay mode receives contributions from both mixing with the Standard Model (SM) Higgs and the heavy charged bosons in the LRSM, depending on the $SU(2)_R\times U(1)_{B-L}$ symmetry breaking scale $v_R$. The complete allowed parameter space for explaining the 95 GeV excesses in this model can be probed with the high-precision measurements of the SM Higgs mixing with other scalars at the high-luminosity LHC and future Higgs factories.
[ { "created": "Fri, 29 Dec 2023 18:41:36 GMT", "version": "v1" }, { "created": "Tue, 30 Jan 2024 00:19:48 GMT", "version": "v2" } ]
2024-02-14
[ [ "Dev", "P. S. Bhupal", "" ], [ "Mohapatra", "Rabindra N.", "" ], [ "Zhang", "Yongchao", "" ] ]
We propose a simple interpretation of the $\gamma\gamma$ excesses reported by both CMS and ATLAS groups at 95 GeV together with the LEP excess in the $Zb\bar{b}$ channel around the same mass in terms of a neutral scalar field in the minimal left-right symmetric model (LRSM). We point out that the scalar field which implements the seesaw mechanism for neutrino masses has all the right properties to explain these observations, without introducing any extra scalar fields. The key point is that this scalar particle is hardly constrained because it couples only to heavy right-handed particles. As a result, the diphoton decay mode receives contributions from both mixing with the Standard Model (SM) Higgs and the heavy charged bosons in the LRSM, depending on the $SU(2)_R\times U(1)_{B-L}$ symmetry breaking scale $v_R$. The complete allowed parameter space for explaining the 95 GeV excesses in this model can be probed with the high-precision measurements of the SM Higgs mixing with other scalars at the high-luminosity LHC and future Higgs factories.
2212.04730
Alexander Ilyichev Dr.
A. Afanasev, I. Akushevich, A. Ilyichev, N. Merenkov
ESFRAD. FORTRAN code for calculation of QED corrections to polarized ep-scattering by the electron structure function method
Contribution to: 17th International Workshop on High-Energy Physics and Quantum Field Theory (QFTHEP 2003), 154-161
null
null
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
The main features of the electron structure function method for calculations of the higher order QED radiative effects to polarized deep-inelastic ep-scattering are presented. A new FORTRAN code ESFRAD based on this method was developed. A detailed quantitative comparison between the results of ESFRAD and other methods implemented in the codes POLRAD and RADGEN for calculation of the higher order radiative corrections is performed.
[ { "created": "Fri, 9 Dec 2022 08:58:34 GMT", "version": "v1" } ]
2022-12-12
[ [ "Afanasev", "A.", "" ], [ "Akushevich", "I.", "" ], [ "Ilyichev", "A.", "" ], [ "Merenkov", "N.", "" ] ]
The main features of the electron structure function method for calculations of the higher order QED radiative effects to polarized deep-inelastic ep-scattering are presented. A new FORTRAN code ESFRAD based on this method was developed. A detailed quantitative comparison between the results of ESFRAD and other methods implemented in the codes POLRAD and RADGEN for calculation of the higher order radiative corrections is performed.
hep-ph/9611243
Andrea Romanino
Gautam Bhattacharyya and Andrea Romanino
Naturalness constraints on gauge-mediated supersymmetry breaking models
Latex, 8 pages, 1 eps figure enclosed. Minor changes, version to be published
Phys.Rev. D55 (1997) 7015-7019
10.1103/PhysRevD.55.7015
IFUP-TH 67/96
hep-ph
null
The question of naturalness is addressed in the context of gauge-mediated supersymmetry breaking models. Requiring that $M_Z$ arises naturally imposes upper limits on the right-handed selectron mass in these models that are stronger than in the Minimal Supersymmetric Standard Model and are interesting from the point of view of searches at the current and future colliders.
[ { "created": "Tue, 5 Nov 1996 21:24:59 GMT", "version": "v1" }, { "created": "Thu, 27 Feb 1997 13:09:41 GMT", "version": "v2" } ]
2009-10-30
[ [ "Bhattacharyya", "Gautam", "" ], [ "Romanino", "Andrea", "" ] ]
The question of naturalness is addressed in the context of gauge-mediated supersymmetry breaking models. Requiring that $M_Z$ arises naturally imposes upper limits on the right-handed selectron mass in these models that are stronger than in the Minimal Supersymmetric Standard Model and are interesting from the point of view of searches at the current and future colliders.
1010.2494
Paul Hohler
Paul M. Hohler
Charmonium sum rules applied to a holographic model
9 pages, 2 figures, Corrected typos to bring inline with PRD version
Phys.Rev.D83:026005,2011
10.1103/PhysRevD.83.026005
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The heavy-quark QCD sum rules are applied to a model of charmonium based upon the gauge/gravity duality. We find that there is strong agreement between the moments of the polarization function calculated from the holographic model and the experimental data suggesting that the model is consistent with the heavy-quark QCD sum rules at zero temperature.
[ { "created": "Tue, 12 Oct 2010 20:00:19 GMT", "version": "v1" }, { "created": "Wed, 9 Feb 2011 22:53:28 GMT", "version": "v2" } ]
2011-02-11
[ [ "Hohler", "Paul M.", "" ] ]
The heavy-quark QCD sum rules are applied to a model of charmonium based upon the gauge/gravity duality. We find that there is strong agreement between the moments of the polarization function calculated from the holographic model and the experimental data suggesting that the model is consistent with the heavy-quark QCD sum rules at zero temperature.
hep-ph/0402193
Arif Shoshi
A.H. Mueller and A.I. Shoshi (Columbia U.)
Small-x physics beyond the Kovchegov equation
38 pages, 8 figures, typos corrected
Nucl.Phys.B692:175-208,2004
10.1016/j.nuclphysb.2004.05.016
CU-TP-1104
hep-ph
null
We note the differences between the Kovchegov equation and the Balitsky-JIMWLK equations as methods of evaluating high energy hard scattering near the unitarity limit. We attempt to simulate some of the correlations absent in the Kovchegov equation by introducing two boundaries rather than the single boundary which effectively approximates the unitarity limit guaranteed in the Kovchegov equation. We solve the problem of BFKL evolution in the presence of two boundaries and note that the resulting T-matrix now is the same in different frames, which was not the case in the single boundary case. The scaling behavior of the solution to the Kovchegov equation is apparently now lost.
[ { "created": "Wed, 18 Feb 2004 18:34:52 GMT", "version": "v1" }, { "created": "Fri, 27 Feb 2004 21:44:48 GMT", "version": "v2" } ]
2008-11-26
[ [ "Mueller", "A. H.", "", "Columbia U." ], [ "Shoshi", "A. I.", "", "Columbia U." ] ]
We note the differences between the Kovchegov equation and the Balitsky-JIMWLK equations as methods of evaluating high energy hard scattering near the unitarity limit. We attempt to simulate some of the correlations absent in the Kovchegov equation by introducing two boundaries rather than the single boundary which effectively approximates the unitarity limit guaranteed in the Kovchegov equation. We solve the problem of BFKL evolution in the presence of two boundaries and note that the resulting T-matrix now is the same in different frames, which was not the case in the single boundary case. The scaling behavior of the solution to the Kovchegov equation is apparently now lost.
1901.04517
Akira Watanabe
Akira Watanabe
Total Hadronic Cross Sections via the Holographic Pomeron Exchange
4 pages, 1 figure, prepared for the proceedings of the 8th International Conference on Quarks and Nuclear Physics (QNP2018), 13 - 17 November 2018, Tsukuba, Japan
null
10.7566/JPSCP.26.021014
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The analysis on the hadron-hadron scattering at high energies in the framework of holographic QCD is presented. Combining the Pomeron exchange kernel and the hadron-Pomeron couplings which are obtained from the bottom-up AdS/QCD models, we calculate the total cross sections. Our calculation for the nucleon-nucleon scattering is consistent with the experimental data including the recent ones measured by the TOTEM collaboration at the LHC. Within the framework, one can consider other processes involving other hadrons. As examples to show this feature of the model, the resulting total cross sections of the pion-nucleon and pion-pion scattering are also presented.
[ { "created": "Mon, 14 Jan 2019 19:03:07 GMT", "version": "v1" } ]
2020-01-08
[ [ "Watanabe", "Akira", "" ] ]
The analysis on the hadron-hadron scattering at high energies in the framework of holographic QCD is presented. Combining the Pomeron exchange kernel and the hadron-Pomeron couplings which are obtained from the bottom-up AdS/QCD models, we calculate the total cross sections. Our calculation for the nucleon-nucleon scattering is consistent with the experimental data including the recent ones measured by the TOTEM collaboration at the LHC. Within the framework, one can consider other processes involving other hadrons. As examples to show this feature of the model, the resulting total cross sections of the pion-nucleon and pion-pion scattering are also presented.
hep-ph/9908257
Venya Berezinsky
V.Berezinsky and A.Vilenkin
Ultra high energy neutrinos from hidden-sector topological defects
Revtex, 31 pages
Phys.Rev. D62 (2000) 083512
10.1103/PhysRevD.62.083512
null
hep-ph
null
We study Topological Defects (TD) in hidden (mirror) matter as possible sources of ultra-high energy neutrinos. The hidden/mirror and ordinary matter are assumed to interact very weakly through gravity or superheavy particles. An inflationary scenario is outlined in which superheavy defects are formed in hidden/mirror matter (and not in ordinary matter), and at the same time the density of mirror matter produced at the end of inflation is much smaller than that of ordinary matter. Superheavy particles produced by hidden-sector TD and the products of their decays are all sterile in our world. Only mirror neutrinos oscillate into ordinary neutrinos. We show that oscillations with maximal mixing of neutrinos from both worlds are possible and that values of $\Delta m^2$, needed for for solution of solar-neutrino and atmospheric-neutrino problems, allow the oscillation of ultra-high energy neutrinos on a timescale of the age of the Universe. A model of mass-degenerate visible and mirror neutrinos with maximal mixing is constructed. Constraints on UHE neutrino fluxes are obtained. The estimated fluxes can be 3 orders of magnitude higher than those from ordinary matter. Detection of these fluxes is briefly discussed.
[ { "created": "Wed, 4 Aug 1999 17:19:51 GMT", "version": "v1" } ]
2009-10-31
[ [ "Berezinsky", "V.", "" ], [ "Vilenkin", "A.", "" ] ]
We study Topological Defects (TD) in hidden (mirror) matter as possible sources of ultra-high energy neutrinos. The hidden/mirror and ordinary matter are assumed to interact very weakly through gravity or superheavy particles. An inflationary scenario is outlined in which superheavy defects are formed in hidden/mirror matter (and not in ordinary matter), and at the same time the density of mirror matter produced at the end of inflation is much smaller than that of ordinary matter. Superheavy particles produced by hidden-sector TD and the products of their decays are all sterile in our world. Only mirror neutrinos oscillate into ordinary neutrinos. We show that oscillations with maximal mixing of neutrinos from both worlds are possible and that values of $\Delta m^2$, needed for for solution of solar-neutrino and atmospheric-neutrino problems, allow the oscillation of ultra-high energy neutrinos on a timescale of the age of the Universe. A model of mass-degenerate visible and mirror neutrinos with maximal mixing is constructed. Constraints on UHE neutrino fluxes are obtained. The estimated fluxes can be 3 orders of magnitude higher than those from ordinary matter. Detection of these fluxes is briefly discussed.
2012.01865
Yoshitaka Hatta
Yoshitaka Hatta
Nucleon electric dipole moment from polarized deep inelastic scattering
8 pages. v2 discussion on uncertainties added, to be published in Phys.Lett.B
null
10.1016/j.physletb.2021.136126
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In a previous paper \cite{Hatta:2020ltd}, we have pointed out the connection between the $CP$-odd three-gluon (Weinberg) operator and certain twist-four corrections in polarized deep inelastic scattering. Based on this observation, we give a numerical estimate of the electric dipole moment of the proton and neutron induced by the Weinberg operator. Our result is smaller than the previous estimates based on QCD sum rules by a factor of about 3 or more.
[ { "created": "Thu, 3 Dec 2020 12:19:20 GMT", "version": "v1" }, { "created": "Wed, 3 Feb 2021 06:08:23 GMT", "version": "v2" } ]
2021-02-10
[ [ "Hatta", "Yoshitaka", "" ] ]
In a previous paper \cite{Hatta:2020ltd}, we have pointed out the connection between the $CP$-odd three-gluon (Weinberg) operator and certain twist-four corrections in polarized deep inelastic scattering. Based on this observation, we give a numerical estimate of the electric dipole moment of the proton and neutron induced by the Weinberg operator. Our result is smaller than the previous estimates based on QCD sum rules by a factor of about 3 or more.
2310.06459
Tejhas Kapoor
Tejhas Kapoor
New physics search via CP observables in $B_s^0 \rightarrow \phi \phi$ decay with Chromomagnetic operators
6 pages, 1 figure, 2 tables. Talk given at EPS-HEP2023, Universit\"at Hamburg, Hamburg, Germany, Aug 21-25, 2023
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
In this work, we investigate the time-dependent angular analysis of $B_s^0 \rightarrow \phi \phi$ decay to search for new physics signals via CP-violating observables. We work with a new physics Hamiltonian containing both left- and right-handed Chromomagnetic dipole operators. The hierarchy of the helicity amplitudes in this model gives us a new scheme of experimental search, which is different from the ones LHCb has used in its analysis. To illustrate this new scheme, we perform a sensitivity study using two pseudo datasets generated using LHCb's measured values. We find the sensitivity of CP-violating observables to be of the order of $5-7\%$ with the current LHCb statistics. In addition, we present a revised version of the table of coefficients of time-dependent terms in the angular decay distribution with precisely defined quantities.
[ { "created": "Tue, 10 Oct 2023 09:32:44 GMT", "version": "v1" } ]
2023-10-11
[ [ "Kapoor", "Tejhas", "" ] ]
In this work, we investigate the time-dependent angular analysis of $B_s^0 \rightarrow \phi \phi$ decay to search for new physics signals via CP-violating observables. We work with a new physics Hamiltonian containing both left- and right-handed Chromomagnetic dipole operators. The hierarchy of the helicity amplitudes in this model gives us a new scheme of experimental search, which is different from the ones LHCb has used in its analysis. To illustrate this new scheme, we perform a sensitivity study using two pseudo datasets generated using LHCb's measured values. We find the sensitivity of CP-violating observables to be of the order of $5-7\%$ with the current LHCb statistics. In addition, we present a revised version of the table of coefficients of time-dependent terms in the angular decay distribution with precisely defined quantities.
0707.0378
Enrico Nardi
Enrico Nardi, Juan Racker and Esteban Roulet
CP violation in scatterings, three body processes and the Boltzmann equations for leptogenesis
24 pages, 6 figures. One appendix added. Some numerical results and corresponding figures (mainly fig. 3) corrected. Final version to be published in JHEP
JHEP0709:090,2007
10.1088/1126-6708/2007/09/090
null
hep-ph
null
We obtain the Boltzmann equations for leptogenesis including decay and scattering processes with two and three body initial or final states. We present an explicit computation of the CP violating scattering asymmetries. We analyze their possible impact in leptogenesis, and we discuss the validity of their approximate expressions in terms of the decay asymmetry. In scenarios in which the initial heavy neutrino density vanishes, the inclusion of CP asymmetries in scatterings can enforce a cancellation between the lepton asymmetry generated at early times and the asymmetry produced at later times. We argue that a sizeable amount of washout is crucial for spoiling this cancellation, and we show that in the regimes in which the washouts are particularly weak, the inclusion of CP violation in scatterings yields a reduction in the final value of the lepton asymmetry. In the strong washout regimes the inclusion of CP violation in scatterings still leads to a significant enhancement of the lepton asymmetry at high temperatures; however, due to the independence from the early conditions that is characteristic of these regimes, the final value of the lepton asymmetry remains approximately unchanged.
[ { "created": "Tue, 3 Jul 2007 10:07:46 GMT", "version": "v1" }, { "created": "Mon, 17 Sep 2007 16:47:44 GMT", "version": "v2" } ]
2008-11-26
[ [ "Nardi", "Enrico", "" ], [ "Racker", "Juan", "" ], [ "Roulet", "Esteban", "" ] ]
We obtain the Boltzmann equations for leptogenesis including decay and scattering processes with two and three body initial or final states. We present an explicit computation of the CP violating scattering asymmetries. We analyze their possible impact in leptogenesis, and we discuss the validity of their approximate expressions in terms of the decay asymmetry. In scenarios in which the initial heavy neutrino density vanishes, the inclusion of CP asymmetries in scatterings can enforce a cancellation between the lepton asymmetry generated at early times and the asymmetry produced at later times. We argue that a sizeable amount of washout is crucial for spoiling this cancellation, and we show that in the regimes in which the washouts are particularly weak, the inclusion of CP violation in scatterings yields a reduction in the final value of the lepton asymmetry. In the strong washout regimes the inclusion of CP violation in scatterings still leads to a significant enhancement of the lepton asymmetry at high temperatures; however, due to the independence from the early conditions that is characteristic of these regimes, the final value of the lepton asymmetry remains approximately unchanged.
1305.6567
Sanjin Beni\'c
Sanjin Beni\'c
Physical interpretation of the dressed Polyakov loop in the Nambu--Jona-Lasinio model
Changes in text, title and abstract. Version accepted by PRD
null
10.1103/PhysRevD.88.077501
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the rapid rise of the dressed Polyakov loop in the Nambu--Jona-Lasinio (NJL) model as a function of temperature. In QCD such a behaviour is interpreted as a confinement- deconfinement phase transition. However, we demonstrate that in the NJL model this is simply a remnant of the chiral transition.
[ { "created": "Tue, 28 May 2013 17:44:47 GMT", "version": "v1" }, { "created": "Mon, 8 Jul 2013 14:15:54 GMT", "version": "v2" }, { "created": "Wed, 2 Oct 2013 11:37:50 GMT", "version": "v3" } ]
2015-06-16
[ [ "Benić", "Sanjin", "" ] ]
We investigate the rapid rise of the dressed Polyakov loop in the Nambu--Jona-Lasinio (NJL) model as a function of temperature. In QCD such a behaviour is interpreted as a confinement- deconfinement phase transition. However, we demonstrate that in the NJL model this is simply a remnant of the chiral transition.
0808.1496
Alexandre Grezzi de Miranda Schmidt
A. T. Suzuki, J. D. Bolzan, A. G. M. Schmidt
Gluing Feynman diagrams in NDIM: Insights into the three-point vertex
13 pages, 3 figures, latex
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Three-point vertex diagram plays a key role in the whole renormalization program of several QFT (quantum field theory) models such as QED, QCD, the Standard Model of eletroweak interactions and so forth. The exact analytic result for the triangle diagram therefore is fundamental. In this work we calculate in two different ways a two-point two-loop massless Feynman diagram using what we call a "gluing" technique in the context of NDIM (Negative Dimensional Integration Method). The two-loop diagram in question can be "glued" in two different ways and we show that both yield the same result and reproduce the one calculated via NDIM for the complete diagram, which, of course, is equivalent to the exact solution obtained by normal positive dimensional calculation. Furthermore, in the process we conclude that the usual massless off-shell triangle diagram result does not hold anymore and present a new solution for it with only three hypergeometric functions $F_{4}$.
[ { "created": "Mon, 11 Aug 2008 11:46:48 GMT", "version": "v1" } ]
2008-08-12
[ [ "Suzuki", "A. T.", "" ], [ "Bolzan", "J. D.", "" ], [ "Schmidt", "A. G. M.", "" ] ]
Three-point vertex diagram plays a key role in the whole renormalization program of several QFT (quantum field theory) models such as QED, QCD, the Standard Model of eletroweak interactions and so forth. The exact analytic result for the triangle diagram therefore is fundamental. In this work we calculate in two different ways a two-point two-loop massless Feynman diagram using what we call a "gluing" technique in the context of NDIM (Negative Dimensional Integration Method). The two-loop diagram in question can be "glued" in two different ways and we show that both yield the same result and reproduce the one calculated via NDIM for the complete diagram, which, of course, is equivalent to the exact solution obtained by normal positive dimensional calculation. Furthermore, in the process we conclude that the usual massless off-shell triangle diagram result does not hold anymore and present a new solution for it with only three hypergeometric functions $F_{4}$.
2004.11092
Balbeer Singh
Balbeer Singh, Manu Kurian, Surasree Mazumder, Hiranmaya Mishra, Vinod Chandra and Santosh K. Das
Momentum broadening of heavy quark in a magnetized thermal QCD medium
16 pages, 4 figures, substantial modifications
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Anisotropic momentum diffusion coefficients of heavy quarks have been computed in a strongly magnetized quark-gluon plasma beyond the static limit within the framework of Langevin dynamics. Depending on the orientation of the motion of the heavy quark with respect to the direction of the magnetic field, five momentum diffusion coefficients of heavy quark have been estimated in the magnetized thermal medium. Specifically, we have focussed our attention to temperature range and strength of magnetic field satisfying the condition, $\it{i.e.}$ $M\gg\sqrt{eB}\gg T$, $M$ being the mass of heavy quark. The light quarks/antiquarks follow $1+1-$dimensional lowest Landau level (LLL) kinematics, and heavy quark dynamics are not directly affected by the magnetic field in the medium. The thermal gluon contribution to the diffusion coefficient is proportions to $T^3$, whereas, the contribution of light quarks in the lowest Landau state to the same is seen to be proportional to $T|eB|$. Furthermore, it is observed that for the case of heavy quark motion parallel to the magnetic field, the component of diffusion coefficient transverse both to the field and the heavy quark velocity $(\kappa^{\parallel}_{TT})$ turns out to be dominant as compared to the component longitudinal to both the field and motion $(\kappa^{\parallel}_{LL})$, $i.e.$, $\kappa^{\parallel}_{TT}\gg \kappa^{\parallel}_{LL}$. Further, for the case of heavy quark moving perpendicular to the magnetic field, it is seen that the diffusion coefficients transverse to the magnetic field are dominant, i.e., $\kappa^{\perp}_{LT}, \kappa^{\perp}_{TT}\gg \kappa^{\perp}_{TL}$.
[ { "created": "Thu, 23 Apr 2020 11:39:00 GMT", "version": "v1" }, { "created": "Mon, 7 Dec 2020 10:16:18 GMT", "version": "v2" } ]
2020-12-08
[ [ "Singh", "Balbeer", "" ], [ "Kurian", "Manu", "" ], [ "Mazumder", "Surasree", "" ], [ "Mishra", "Hiranmaya", "" ], [ "Chandra", "Vinod", "" ], [ "Das", "Santosh K.", "" ] ]
Anisotropic momentum diffusion coefficients of heavy quarks have been computed in a strongly magnetized quark-gluon plasma beyond the static limit within the framework of Langevin dynamics. Depending on the orientation of the motion of the heavy quark with respect to the direction of the magnetic field, five momentum diffusion coefficients of heavy quark have been estimated in the magnetized thermal medium. Specifically, we have focussed our attention to temperature range and strength of magnetic field satisfying the condition, $\it{i.e.}$ $M\gg\sqrt{eB}\gg T$, $M$ being the mass of heavy quark. The light quarks/antiquarks follow $1+1-$dimensional lowest Landau level (LLL) kinematics, and heavy quark dynamics are not directly affected by the magnetic field in the medium. The thermal gluon contribution to the diffusion coefficient is proportions to $T^3$, whereas, the contribution of light quarks in the lowest Landau state to the same is seen to be proportional to $T|eB|$. Furthermore, it is observed that for the case of heavy quark motion parallel to the magnetic field, the component of diffusion coefficient transverse both to the field and the heavy quark velocity $(\kappa^{\parallel}_{TT})$ turns out to be dominant as compared to the component longitudinal to both the field and motion $(\kappa^{\parallel}_{LL})$, $i.e.$, $\kappa^{\parallel}_{TT}\gg \kappa^{\parallel}_{LL}$. Further, for the case of heavy quark moving perpendicular to the magnetic field, it is seen that the diffusion coefficients transverse to the magnetic field are dominant, i.e., $\kappa^{\perp}_{LT}, \kappa^{\perp}_{TT}\gg \kappa^{\perp}_{TL}$.
hep-ph/9302219
Fernando Cornet
Ll. Ametller, J. Bijnens, A. Bramon and F. Cornet
Semileptonic $\pi$ and $K$ Decays and the Chiral Anomaly at One-loop
10 pages of LaTeX (+3 figures available on request)
Phys.Lett. B303 (1993) 140-146
10.1016/0370-2693(93)90058-P
NORDITA-93/13 N,P UAB-FT-299/92 UG-FT-27/92
hep-ph
null
We calculate the $O(p^6)$ corrections to the anomalous form factors appearing in $\pi^+$, $K^+ \to e^+ \nu \gamma,\ \mu^+\nu\gamma$ and $K_{l4}$ decays in Chiral Perturbation Theory. The relevant dimension $6$ terms of the lagrangian are evaluated assuming their saturation by the vector meson contribution.
[ { "created": "Thu, 4 Feb 1993 16:45:43 GMT", "version": "v1" } ]
2009-10-22
[ [ "Ametller", "Ll.", "" ], [ "Bijnens", "J.", "" ], [ "Bramon", "A.", "" ], [ "Cornet", "F.", "" ] ]
We calculate the $O(p^6)$ corrections to the anomalous form factors appearing in $\pi^+$, $K^+ \to e^+ \nu \gamma,\ \mu^+\nu\gamma$ and $K_{l4}$ decays in Chiral Perturbation Theory. The relevant dimension $6$ terms of the lagrangian are evaluated assuming their saturation by the vector meson contribution.
1807.01007
S. Weinzierl
Luise Adams and Stefan Weinzierl
On a class of Feynman integrals evaluating to iterated integrals of modular forms
21 pages, talk given at the KMPB conference "Elliptic Integrals, Elliptic Functions and Modular Forms in Quantum Field Theory"
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk we discuss a class of Feynman integrals, which can be expressed to all orders in the dimensional regularisation parameter as iterated integrals of modular forms. We review the mathematical prerequisites related to elliptic curves and modular forms. Feynman integrals, which evaluate to iterated integrals of modular forms go beyond the class of multiple polylogarithms. Nevertheless, we may bring for all examples considered the associated system of differential equations by a non-algebraic transformation to an $\varepsilon$-form, which makes a solution in terms of iterated integrals immediate.
[ { "created": "Tue, 3 Jul 2018 08:04:56 GMT", "version": "v1" } ]
2018-07-04
[ [ "Adams", "Luise", "" ], [ "Weinzierl", "Stefan", "" ] ]
In this talk we discuss a class of Feynman integrals, which can be expressed to all orders in the dimensional regularisation parameter as iterated integrals of modular forms. We review the mathematical prerequisites related to elliptic curves and modular forms. Feynman integrals, which evaluate to iterated integrals of modular forms go beyond the class of multiple polylogarithms. Nevertheless, we may bring for all examples considered the associated system of differential equations by a non-algebraic transformation to an $\varepsilon$-form, which makes a solution in terms of iterated integrals immediate.
1611.04334
Thomas Hilger
Thomas Hilger, Andreas Krassnigg
Charming quasi-exotic open-flavor mesons
10 pages, 8 figures, 'XII Confinement and the hadron spectrum'-proceedings contribution
null
10.1051/epjconf/201713701010
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss charmed mesons in the covariant Dyson-Schwinger-Bethe-Salpeter-equation approach. In particular we computed masses, leptonic decay constants, and an orbital-angular-momentum decomposition for a basic set of states. We also report an efficient way to treat the two coupled quark propagator dressing functions via a single function.
[ { "created": "Mon, 14 Nov 2016 11:06:23 GMT", "version": "v1" } ]
2017-04-05
[ [ "Hilger", "Thomas", "" ], [ "Krassnigg", "Andreas", "" ] ]
We discuss charmed mesons in the covariant Dyson-Schwinger-Bethe-Salpeter-equation approach. In particular we computed masses, leptonic decay constants, and an orbital-angular-momentum decomposition for a basic set of states. We also report an efficient way to treat the two coupled quark propagator dressing functions via a single function.
1510.03450
Yeo Woong Yoon
Sunghoon Jung, Jeonghyeon Song, Yeo Woong Yoon
Interference effect on heavy Higgs resonance signal in \gamma\gamma and ZZ channels
22 pages, 10 figures; added discussion about real-part interference
Phys. Rev. D 93, 055035 (2016)
10.1103/PhysRevD.93.055035
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The resonance-continuum interference is usually neglected when the width of a resonance is small compared to the resonance mass. We re-examine this standard by studying the interference effects in high-resolution decay channels, $\gamma\gamma$ and $ZZ$, of the heavy Higgs boson $H^0$ in nearly aligned two-Higgs-doublet models. For the $H^0$ with a sub-percent width-to-mass ratio, we find that, in the parameter space where the LHC 14 TeV $ZZ$ resonance search can be sensitive, the interference effects can modify the $ZZ$ signal rate by ${\cal O}(10)\%$ and the exclusion reach by ${\cal O}(10)$ GeV. In other parameter space where the $ZZ$ or $\gamma\gamma$ signal rate is smaller, the LHC 14 TeV reach is absent, but a resonance shape can be much more dramatically changed. In particular, the $\gamma\gamma$ signal rate can change by ${\cal O}(100)\%$. Relevant to such parameter space, we suggest variables that can characterize a general resonance shape. We also illustrate the relevance of the width on the interference by adding non-standard decay modes of the heavy Higgs boson.
[ { "created": "Mon, 12 Oct 2015 20:24:47 GMT", "version": "v1" }, { "created": "Wed, 20 Jan 2016 09:28:03 GMT", "version": "v2" } ]
2016-03-30
[ [ "Jung", "Sunghoon", "" ], [ "Song", "Jeonghyeon", "" ], [ "Yoon", "Yeo Woong", "" ] ]
The resonance-continuum interference is usually neglected when the width of a resonance is small compared to the resonance mass. We re-examine this standard by studying the interference effects in high-resolution decay channels, $\gamma\gamma$ and $ZZ$, of the heavy Higgs boson $H^0$ in nearly aligned two-Higgs-doublet models. For the $H^0$ with a sub-percent width-to-mass ratio, we find that, in the parameter space where the LHC 14 TeV $ZZ$ resonance search can be sensitive, the interference effects can modify the $ZZ$ signal rate by ${\cal O}(10)\%$ and the exclusion reach by ${\cal O}(10)$ GeV. In other parameter space where the $ZZ$ or $\gamma\gamma$ signal rate is smaller, the LHC 14 TeV reach is absent, but a resonance shape can be much more dramatically changed. In particular, the $\gamma\gamma$ signal rate can change by ${\cal O}(100)\%$. Relevant to such parameter space, we suggest variables that can characterize a general resonance shape. We also illustrate the relevance of the width on the interference by adding non-standard decay modes of the heavy Higgs boson.