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hep-ph/9801319
Gao Yanming
Zhou Yufeng, Peng Hongan, Liu Lianshou
The Contribution of Reggeon in Charge Exchange Processes
10 pages 6 figures in 2 separate PS files
null
null
HZPP-9801
hep-ph
null
We discuss in this paper The experimental results on maximum psedo-rapidity $\eta_{max}$ distribution in the charge exchange process $e+p\to e+n+X$ in ZEUS Collaboration at HERA. We calculate the contributions of \regg ($\rho$-Reggeon associated with $\rho$ meson) from regge phenomenology and $\pi^{+}$-exchange from pion cloud model. The results show that neither the \regg-exchange nor the pion cloud model alone can explain the experimental data well, but after considering both these two processes together, by using Monte Carlo simulation, a good agreement between theoretical results and experimental data is found. This means that in discussing the large rapidity gap phenomena in deep inelastic scattering, both of the two processes play substantial role.
[ { "created": "Fri, 16 Jan 1998 01:45:49 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yufeng", "Zhou", "" ], [ "Hongan", "Peng", "" ], [ "Lianshou", "Liu", "" ] ]
We discuss in this paper The experimental results on maximum psedo-rapidity $\eta_{max}$ distribution in the charge exchange process $e+p\to e+n+X$ in ZEUS Collaboration at HERA. We calculate the contributions of \regg ($\rho$-Reggeon associated with $\rho$ meson) from regge phenomenology and $\pi^{+}$-exchange from pion cloud model. The results show that neither the \regg-exchange nor the pion cloud model alone can explain the experimental data well, but after considering both these two processes together, by using Monte Carlo simulation, a good agreement between theoretical results and experimental data is found. This means that in discussing the large rapidity gap phenomena in deep inelastic scattering, both of the two processes play substantial role.
hep-ph/0504070
Gouranga Nayak
Gouranga C. Nayak (SUNY, Stony Brook) and Peter van Nieuwenhuizen (SUNY, Stony Brook)
Soft-Gluon Production Due to a Gluon Loop in a Constant Chromo-Electric Background Field
8 pages latex, Final Version to appear in Phys. Rev. D
Phys.Rev. D71 (2005) 125001
10.1103/PhysRevD.71.125001
YITP-SB-05-09
hep-ph hep-th nucl-th
null
We obtain an exact result for the soft gluon production and its p_T distribution due to a gluon loop in a constant chromo-electric background field E^a with arbitrary color. Unlike Schwinger's result for e^+e^- pair production in QED which depends only on one gauge invariant quantity, the Electric field E, we find that the p_T distribution of the gluons depend on two gauge invariant quantities, E^aE^a and [d_{abc}E^aE^bE^c]^2.
[ { "created": "Sat, 9 Apr 2005 20:20:50 GMT", "version": "v1" }, { "created": "Tue, 24 May 2005 20:04:04 GMT", "version": "v2" } ]
2009-11-11
[ [ "Nayak", "Gouranga C.", "", "SUNY, Stony Brook" ], [ "van Nieuwenhuizen", "Peter", "", "SUNY, Stony Brook" ] ]
We obtain an exact result for the soft gluon production and its p_T distribution due to a gluon loop in a constant chromo-electric background field E^a with arbitrary color. Unlike Schwinger's result for e^+e^- pair production in QED which depends only on one gauge invariant quantity, the Electric field E, we find that the p_T distribution of the gluons depend on two gauge invariant quantities, E^aE^a and [d_{abc}E^aE^bE^c]^2.
1207.4996
Brian C. Tiburzi
B. C. Tiburzi
Isotensor Hadronic Parity Violation
4 pages, 2 figures, brief report, v2. version to be published
null
10.1103/PhysRevD.86.097501
RBRC-962
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Weak interactions between quarks give rise to hadronic parity violation which can be observed in nuclear and few-nucleon systems. We study the QCD renormalization of the isotensor component of parity violation at next-to-leading order accuracy. The renormalization group is employed to evolve the interaction down to hadronic scales. As the results are renormalization scheme dependent, we compare various schemes, including 't Hooft-Veltman dimensional regularization, and several regularization independent-momentum subtraction schemes.
[ { "created": "Fri, 20 Jul 2012 16:54:37 GMT", "version": "v1" }, { "created": "Tue, 16 Oct 2012 15:13:51 GMT", "version": "v2" } ]
2013-05-30
[ [ "Tiburzi", "B. C.", "" ] ]
Weak interactions between quarks give rise to hadronic parity violation which can be observed in nuclear and few-nucleon systems. We study the QCD renormalization of the isotensor component of parity violation at next-to-leading order accuracy. The renormalization group is employed to evolve the interaction down to hadronic scales. As the results are renormalization scheme dependent, we compare various schemes, including 't Hooft-Veltman dimensional regularization, and several regularization independent-momentum subtraction schemes.
hep-ph/0502057
Magdalena Sowa
M. Sowa
Influence of charming penguins on the extraction of gamma in B->PP decays
9 pages, 3 eps figures
Acta Phys.Polon. B36 (2005) 817-826
null
null
hep-ph
null
Charmless B->PP decays are studied using flavor SU(3) symmetry. Amplitude with charming penguin topology is considered for two cases: with zero and with arbitrary strong phase. Two sets of data (an older and the most recent one) are used in the fits, so that the stability of the fits is tested. It is shown that within the present uncertainties in the data the parameters of the fit may be significantly modified, especially the gamma angle. The fits indicate the strong phase of the charming penguin amplitude to be around $\pm 20^{o}$.
[ { "created": "Sun, 6 Feb 2005 16:53:52 GMT", "version": "v1" } ]
2016-09-06
[ [ "Sowa", "M.", "" ] ]
Charmless B->PP decays are studied using flavor SU(3) symmetry. Amplitude with charming penguin topology is considered for two cases: with zero and with arbitrary strong phase. Two sets of data (an older and the most recent one) are used in the fits, so that the stability of the fits is tested. It is shown that within the present uncertainties in the data the parameters of the fit may be significantly modified, especially the gamma angle. The fits indicate the strong phase of the charming penguin amplitude to be around $\pm 20^{o}$.
2005.12323
I. V. Danilkin
Victor Ananyev, Igor Danilkin, Marc Vanderhaeghen
Light-by-light scattering sum rule for radiative transitions of bottomonia
9 pages, 2 figures
Phys. Rev. D 102, 096019 (2020)
10.1103/PhysRevD.102.096019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We generalize a forward light-by-light scattering sum rule to the case of heavy quarkonium radiative transitions. We apply such sum rule to the bottomonium states, and use available data on radiative transitions in its evaluation. For the transitions that are not known experimentally, we provide theoretical estimates within a potential model, and consider the spread between similar approaches in the literature as an estimate for the model error. For the $\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ states we observe that, due to a cancellation between transitions involving $\chi_{b0}, \chi_{b1}$, and $\chi_{b2}$ states, the sum rule is satisfied within experimental and theoretical error estimates. Having tested this sum rule for the low-lying bottomonium states, it may be used as a tool to investigate the nature of exotic states in the charmonium and bottomonium spectrum through the corresponding radiative transitions.
[ { "created": "Mon, 25 May 2020 18:17:50 GMT", "version": "v1" }, { "created": "Wed, 11 Nov 2020 20:47:08 GMT", "version": "v2" } ]
2020-11-25
[ [ "Ananyev", "Victor", "" ], [ "Danilkin", "Igor", "" ], [ "Vanderhaeghen", "Marc", "" ] ]
We generalize a forward light-by-light scattering sum rule to the case of heavy quarkonium radiative transitions. We apply such sum rule to the bottomonium states, and use available data on radiative transitions in its evaluation. For the transitions that are not known experimentally, we provide theoretical estimates within a potential model, and consider the spread between similar approaches in the literature as an estimate for the model error. For the $\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ states we observe that, due to a cancellation between transitions involving $\chi_{b0}, \chi_{b1}$, and $\chi_{b2}$ states, the sum rule is satisfied within experimental and theoretical error estimates. Having tested this sum rule for the low-lying bottomonium states, it may be used as a tool to investigate the nature of exotic states in the charmonium and bottomonium spectrum through the corresponding radiative transitions.
hep-ph/0412170
Fabian Brau
Fabian Brau
Bohr-Sommerfeld quantization and meson spectroscopy
13 pages
Phys.Rev. D62 (2000) 014005
10.1103/PhysRevD.62.014005
null
hep-ph
null
We use the Bohr-Sommerfeld quantization approach in the context of constituent quark models. This method provides, for the Cornell potential, analytical formulae for the energy spectra which closely approximate numerical exact calculations performed with the Schrodinger or the spinless Salpeter equations. The Bohr-Sommerfeld quantization procedure can also be used to calculate other observables such as r.m.s. radius or wave function at the origin. Asymptotic dependence of these observables on quantum numbers are also obtained in the case of potentials which behave asymptotically as a power-law. We discuss the constraints imposed by these formulae on the dynamics of the quark-antiquark interaction.
[ { "created": "Tue, 14 Dec 2004 12:20:13 GMT", "version": "v1" } ]
2007-05-23
[ [ "Brau", "Fabian", "" ] ]
We use the Bohr-Sommerfeld quantization approach in the context of constituent quark models. This method provides, for the Cornell potential, analytical formulae for the energy spectra which closely approximate numerical exact calculations performed with the Schrodinger or the spinless Salpeter equations. The Bohr-Sommerfeld quantization procedure can also be used to calculate other observables such as r.m.s. radius or wave function at the origin. Asymptotic dependence of these observables on quantum numbers are also obtained in the case of potentials which behave asymptotically as a power-law. We discuss the constraints imposed by these formulae on the dynamics of the quark-antiquark interaction.
hep-ph/0402139
Ivanov Dmitri
D.Yu. Ivanov, G.L. Kotkin, V.G. Serbo
Complete description of polarization effects in emission of a photon by an electron in the field of a strong laser wave
18 pages, minor changes, published version
Eur.Phys.J.C36:127-145,2004
10.1140/epjc/s2004-01892-3
null
hep-ph nucl-ex physics.atom-ph
null
We consider emission of a photon by an electron in the field of a strong laser wave. Polarization effects in this process are important for a number of physical problems. A probability of this process for circularly or linearly polarized laser photons and for arbitrary polarization of all other particles is calculated. We obtain the complete set of functions which describe such a probability in a compact invariant form. Besides, we discuss in some detail the polarization effects in the kinematics relevant to the problem of electron to photon conversion at photon-photon and photon-electron colliders.
[ { "created": "Fri, 13 Feb 2004 09:25:55 GMT", "version": "v1" }, { "created": "Fri, 2 Jul 2004 11:59:39 GMT", "version": "v2" }, { "created": "Thu, 8 Jul 2004 04:52:53 GMT", "version": "v3" }, { "created": "Wed, 10 Nov 2004 19:44:52 GMT", "version": "v4" } ]
2008-11-26
[ [ "Ivanov", "D. Yu.", "" ], [ "Kotkin", "G. L.", "" ], [ "Serbo", "V. G.", "" ] ]
We consider emission of a photon by an electron in the field of a strong laser wave. Polarization effects in this process are important for a number of physical problems. A probability of this process for circularly or linearly polarized laser photons and for arbitrary polarization of all other particles is calculated. We obtain the complete set of functions which describe such a probability in a compact invariant form. Besides, we discuss in some detail the polarization effects in the kinematics relevant to the problem of electron to photon conversion at photon-photon and photon-electron colliders.
2102.07984
Sheng-Tao Li
Sheng-Tao Li, Gang L\"u
Hunting for direct CP violation in $\bar{B}_s^0 \to {\pi^+}{\pi^-}K^{*0}$
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In perturbative QCD approach, based on the first order of isospin symmetry breaking, we study the direct $CP$ violation in the decay of $\bar{B}_s^0\to\rho(\omega )K^{*0}\to {\pi^+}{\pi^-}K^{*0}$. An interesting mechanism is applied to enlarge the $CP$ violating asymmetry involving the charge symmetry breaking between $\rho$ and $\omega$. We find that the $CP$ violation is large by the $\rho-\omega$ mixing mechanism when the invariant masses of the $\pi^+\pi^-$ pairs is in the vicinity of the $\omega$ resonance. For the decay process of $\bar{B}^0_{s}\to\rho(\omega )K^{*0}\to{\pi^+}{\pi^-}K^{*0}$, the maximum $CP$ violation can reach $-59.12\%$. Furthermore, taking $\rho-\omega$ mixing into account, we calculate the branching ratio for $\bar{B}_s^0 \rightarrow \rho(\omega) K^{*0}$. We also discuss the possibility of observing the predicted $CP$ violation asymmetry at the LHC.
[ { "created": "Tue, 16 Feb 2021 07:14:50 GMT", "version": "v1" }, { "created": "Sat, 23 Oct 2021 11:47:39 GMT", "version": "v2" } ]
2021-10-26
[ [ "Li", "Sheng-Tao", "" ], [ "Lü", "Gang", "" ] ]
In perturbative QCD approach, based on the first order of isospin symmetry breaking, we study the direct $CP$ violation in the decay of $\bar{B}_s^0\to\rho(\omega )K^{*0}\to {\pi^+}{\pi^-}K^{*0}$. An interesting mechanism is applied to enlarge the $CP$ violating asymmetry involving the charge symmetry breaking between $\rho$ and $\omega$. We find that the $CP$ violation is large by the $\rho-\omega$ mixing mechanism when the invariant masses of the $\pi^+\pi^-$ pairs is in the vicinity of the $\omega$ resonance. For the decay process of $\bar{B}^0_{s}\to\rho(\omega )K^{*0}\to{\pi^+}{\pi^-}K^{*0}$, the maximum $CP$ violation can reach $-59.12\%$. Furthermore, taking $\rho-\omega$ mixing into account, we calculate the branching ratio for $\bar{B}_s^0 \rightarrow \rho(\omega) K^{*0}$. We also discuss the possibility of observing the predicted $CP$ violation asymmetry at the LHC.
hep-ph/0308216
Kalmykov Mikhail
F.Jegerlehner, M.Yu.Kalmykov
O(\alpha \alpha_s) correction to the pole mass of the t-quark within the Standard Model
23 pages, LaTeX, 5-eps figures; In v.2 the typos in Eqs.(4.41), (5.54), (5.56), (5.57) and Fifure 4 corrected. New references are added
Nucl.Phys.B676:365-389,2004
10.1016/j.nuclphysb.2003.10.012
DESY 03-11; SFB/CPP-03-1
hep-ph
null
We have calculated the O(\alpha \alpha_s) contributions to the relationship between the MS-mass and the pole of the t-quark propagator in the Standard Model in the limit of a diagonal CKM matrix and for a massless b-quark. Analytical results for the so far unknown master-integrals appearing in the calculation are also given.
[ { "created": "Thu, 21 Aug 2003 08:16:24 GMT", "version": "v1" }, { "created": "Mon, 20 Oct 2003 15:54:18 GMT", "version": "v2" } ]
2014-11-17
[ [ "Jegerlehner", "F.", "" ], [ "Kalmykov", "M. Yu.", "" ] ]
We have calculated the O(\alpha \alpha_s) contributions to the relationship between the MS-mass and the pole of the t-quark propagator in the Standard Model in the limit of a diagonal CKM matrix and for a massless b-quark. Analytical results for the so far unknown master-integrals appearing in the calculation are also given.
1504.07841
Gennady Lykasov I
D.A. Artemenkov, G.I. Lykasov, A.I. Malakhov
Self-similarity of hadron production in p-p and A-A collisions at high energies
13 pages, 7 figures
null
10.1142/S0217751X15501274
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the self-similarity approach applied to study the hadron production in p-p and A-A collisions. This approach allows us to describe rather well the ratio of the proton to anti-proton yields in A-A collisions as a function of the energy at a wide range from a few GeV to a few TeV. We suggest a modification of this approach to describe rather well the inclusive spectra of hadrons produced in $pp$ collisions at different initial energies from the AGS to LHC.
[ { "created": "Wed, 29 Apr 2015 12:56:08 GMT", "version": "v1" } ]
2015-10-28
[ [ "Artemenkov", "D. A.", "" ], [ "Lykasov", "G. I.", "" ], [ "Malakhov", "A. I.", "" ] ]
We analyze the self-similarity approach applied to study the hadron production in p-p and A-A collisions. This approach allows us to describe rather well the ratio of the proton to anti-proton yields in A-A collisions as a function of the energy at a wide range from a few GeV to a few TeV. We suggest a modification of this approach to describe rather well the inclusive spectra of hadrons produced in $pp$ collisions at different initial energies from the AGS to LHC.
0812.3078
Viktor Begun
V. V. Begun, M. Ga\'zdzicki, M. I. Gorenstein
Semi-Inclusive Distributions in Statistical Models
Two subsections are added: "Average multiplicities, fluctuations and correlations" and "Quantum statistics"
Phys.Rev.C80:064903,2009
10.1103/PhysRevC.80.064903
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The semi-inclusive properties of the system of neutral and charged particles with net charge equal to zero are considered in the grand canonical, canonical and micro-canonical ensembles as well as in micro-canonical ensemble with scaling volume fluctuations. Distributions of neutral particle multiplicity and charged particle momentum are calculated as a function of the number of charged particles. Different statistical ensembles lead to qualitatively different dependencies. They are being compared with the corresponding experimental data on multi-hadron production in $p+p$ interactions at high energies.
[ { "created": "Tue, 16 Dec 2008 14:46:31 GMT", "version": "v1" }, { "created": "Wed, 21 Oct 2009 20:06:56 GMT", "version": "v2" } ]
2010-04-15
[ [ "Begun", "V. V.", "" ], [ "Gaździcki", "M.", "" ], [ "Gorenstein", "M. I.", "" ] ]
The semi-inclusive properties of the system of neutral and charged particles with net charge equal to zero are considered in the grand canonical, canonical and micro-canonical ensembles as well as in micro-canonical ensemble with scaling volume fluctuations. Distributions of neutral particle multiplicity and charged particle momentum are calculated as a function of the number of charged particles. Different statistical ensembles lead to qualitatively different dependencies. They are being compared with the corresponding experimental data on multi-hadron production in $p+p$ interactions at high energies.
2203.05939
David d'Enterria
David d'Enterria, Marco Drewes, Andrea Giammanco, Jan Hajer, Elena Bratkovskaya, Roderik Bruce, Nazar Burmasov, Mateusz Dyndal, Oliver Gould, Iwona Grabowska-Bold, Malgorzata Gumberidze, Taku Gunji, Romain Holzmann, John M. Jowett, Evgeny Kryshen, Vitalii A. Okorokov, Ida Schmidt, Aditya Upreti
Opportunities for new physics searches with heavy ions at colliders
26 pages, 5 figures. White paper of the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021)
J. Phys. G: Nucl. Part. Phys. 50 (2023) 050501
10.1088/1361-6471/acc197
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Opportunities for searches for phenomena beyond the Standard Model (BSM) using heavy-ions beams at high energies are outlined. Different BSM searches proposed in the last years in collisions of heavy ions, mostly at the Large Hadron Collider, are summarized. A few concrete selected cases are reviewed including searches for axion-like particles, anomalous $\tau$ electromagnetic moments, magnetic monopoles, and dark photons. Expectations for the achievable sensitivities of these searches in the coming years are given. Studies of CP violation in hot and dense QCD matter and connections to ultrahigh-energy cosmic rays physics are also mentioned.
[ { "created": "Fri, 11 Mar 2022 14:16:43 GMT", "version": "v1" }, { "created": "Fri, 14 Apr 2023 13:44:31 GMT", "version": "v2" } ]
2023-04-17
[ [ "d'Enterria", "David", "" ], [ "Drewes", "Marco", "" ], [ "Giammanco", "Andrea", "" ], [ "Hajer", "Jan", "" ], [ "Bratkovskaya", "Elena", "" ], [ "Bruce", "Roderik", "" ], [ "Burmasov", "Nazar", "" ], [ "Dyndal", "Mateusz", "" ], [ "Gould", "Oliver", "" ], [ "Grabowska-Bold", "Iwona", "" ], [ "Gumberidze", "Malgorzata", "" ], [ "Gunji", "Taku", "" ], [ "Holzmann", "Romain", "" ], [ "Jowett", "John M.", "" ], [ "Kryshen", "Evgeny", "" ], [ "Okorokov", "Vitalii A.", "" ], [ "Schmidt", "Ida", "" ], [ "Upreti", "Aditya", "" ] ]
Opportunities for searches for phenomena beyond the Standard Model (BSM) using heavy-ions beams at high energies are outlined. Different BSM searches proposed in the last years in collisions of heavy ions, mostly at the Large Hadron Collider, are summarized. A few concrete selected cases are reviewed including searches for axion-like particles, anomalous $\tau$ electromagnetic moments, magnetic monopoles, and dark photons. Expectations for the achievable sensitivities of these searches in the coming years are given. Studies of CP violation in hot and dense QCD matter and connections to ultrahigh-energy cosmic rays physics are also mentioned.
1802.08531
Simon Platzer
Ren\'e \'Angeles Mart\'inez, Matthew De Angelis, Jeffrey R. Forshaw, Simon Pl\"atzer, Michael H. Seymour
Soft gluon evolution and non-global logarithms
34 pages, 6 figures
null
null
MAN/HEP/2018/001, CERN-TH-2018-037, IFJPAN-IV-2018-4, UWTHPH-2018-3, MCnet-18-03
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider soft-gluon evolution at the amplitude level. Our evolution includes Coulomb exchanges and applies to generic hard-scattering processes involving any number of coloured partons. We emphasise the special role played by a Lorentz-invariant evolution variable, which coincides with the transverse momentum of the latest emission in a suitably defined dipole zero-momentum frame. We also relate the evolution algorithm, which was used originally in the derivation of super-leading logarithms, to renormalization group evolution equations that have been encountered recently. Handling large colour matrices presents the most significant challenge to numerical implementations and we present a means to expand systematically about the leading colour approximation.
[ { "created": "Fri, 23 Feb 2018 13:54:37 GMT", "version": "v1" } ]
2018-02-26
[ [ "Martínez", "René Ángeles", "" ], [ "De Angelis", "Matthew", "" ], [ "Forshaw", "Jeffrey R.", "" ], [ "Plätzer", "Simon", "" ], [ "Seymour", "Michael H.", "" ] ]
We consider soft-gluon evolution at the amplitude level. Our evolution includes Coulomb exchanges and applies to generic hard-scattering processes involving any number of coloured partons. We emphasise the special role played by a Lorentz-invariant evolution variable, which coincides with the transverse momentum of the latest emission in a suitably defined dipole zero-momentum frame. We also relate the evolution algorithm, which was used originally in the derivation of super-leading logarithms, to renormalization group evolution equations that have been encountered recently. Handling large colour matrices presents the most significant challenge to numerical implementations and we present a means to expand systematically about the leading colour approximation.
1703.05327
Jos\'e Francisco Zurita
Rakhi Mahbubani, Pedro Schwaller, Jose Zurita
Closing the window for compressed Dark Sectors with disappearing charged tracks
20 pages, 11 figures
null
10.1007/JHEP06(2017)119
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the sensitivity at current and future hadron colliders to a heavy electrically-charged particle with a proper decay length below a centimetre, whose decay products are invisible due to below-threshold energies and/or small couplings to the Standard Model. A cosmologically-motivated example of a framework that contains such a particle is the Minimal Supersymmetric Standard Model in the limit of pure Higgsinos. The current hadron-collider search strategy has no sensitivity to the upper range of pure Higgsino masses that are consistent with the thermal relic density, even at a future collider with 100 TeV centre-of-mass energy. We show that performing a disappearing track search within the inner 10 cm of detector volume would improve the reach in lifetime by a factor of 3 at the 14 TeV LHC and a further factor of 5 at a 100 TeV collider, resulting in around 10 events for 1.1 TeV thermal Higgsinos. In order to include the particles with the largest boost in the analysis, we furthermore propose a purely track-based search in both the central and forward regions, each of which would increase the number of events by another factor of 5, improving our reach at small lifetimes. This would allow us to definitively discover or exclude the experimentally-elusive pure-Higgsino thermal relic at a 100 TeV collider.
[ { "created": "Wed, 15 Mar 2017 18:00:01 GMT", "version": "v1" } ]
2017-08-02
[ [ "Mahbubani", "Rakhi", "" ], [ "Schwaller", "Pedro", "" ], [ "Zurita", "Jose", "" ] ]
We investigate the sensitivity at current and future hadron colliders to a heavy electrically-charged particle with a proper decay length below a centimetre, whose decay products are invisible due to below-threshold energies and/or small couplings to the Standard Model. A cosmologically-motivated example of a framework that contains such a particle is the Minimal Supersymmetric Standard Model in the limit of pure Higgsinos. The current hadron-collider search strategy has no sensitivity to the upper range of pure Higgsino masses that are consistent with the thermal relic density, even at a future collider with 100 TeV centre-of-mass energy. We show that performing a disappearing track search within the inner 10 cm of detector volume would improve the reach in lifetime by a factor of 3 at the 14 TeV LHC and a further factor of 5 at a 100 TeV collider, resulting in around 10 events for 1.1 TeV thermal Higgsinos. In order to include the particles with the largest boost in the analysis, we furthermore propose a purely track-based search in both the central and forward regions, each of which would increase the number of events by another factor of 5, improving our reach at small lifetimes. This would allow us to definitively discover or exclude the experimentally-elusive pure-Higgsino thermal relic at a 100 TeV collider.
1907.03131
Stanislaw Mrowczynski
Margaret E. Carrington and Stanislaw Mrowczynski
Effective Coupling Constant of Plasmons
18 pages, minor corrections, to appear in Phys. Rev. D
Phys. Rev. D 100, 056020 (2019)
10.1103/PhysRevD.100.056020
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study an ultrarelativistic QED plasma in thermal equilibrium. Plasmons - photon collective excitations - are postulated to correspond not to poles of the retarded photon propagator but to poles of the propagator multiplied by the fine structure constant. This product is an invariant of the renormalization group that is independent of an arbitrarily chosen renormalization scale. In addition, our proposal is physically motivated since one needs to scatter a charged particle off a plasma system to probe its spectrum of collective excitations. We present a detailed calculation of the QED running coupling constant at finite temperature using the Keldysh-Schwinger representation of the real-time formalism. We discuss the issue of how to choose the renormalization scale and show that the temperature is a natural choice which prevents the breakdown of perturbation theory through the generation of potentially large logarithmic terms. Our method could be applied to anisotropic systems where the choice of the renormalization scale is less clear, and could have important consequences for the study of collective modes.
[ { "created": "Sat, 6 Jul 2019 14:29:10 GMT", "version": "v1" }, { "created": "Sat, 13 Jul 2019 12:15:12 GMT", "version": "v2" }, { "created": "Thu, 15 Aug 2019 18:53:28 GMT", "version": "v3" } ]
2019-10-02
[ [ "Carrington", "Margaret E.", "" ], [ "Mrowczynski", "Stanislaw", "" ] ]
We study an ultrarelativistic QED plasma in thermal equilibrium. Plasmons - photon collective excitations - are postulated to correspond not to poles of the retarded photon propagator but to poles of the propagator multiplied by the fine structure constant. This product is an invariant of the renormalization group that is independent of an arbitrarily chosen renormalization scale. In addition, our proposal is physically motivated since one needs to scatter a charged particle off a plasma system to probe its spectrum of collective excitations. We present a detailed calculation of the QED running coupling constant at finite temperature using the Keldysh-Schwinger representation of the real-time formalism. We discuss the issue of how to choose the renormalization scale and show that the temperature is a natural choice which prevents the breakdown of perturbation theory through the generation of potentially large logarithmic terms. Our method could be applied to anisotropic systems where the choice of the renormalization scale is less clear, and could have important consequences for the study of collective modes.
hep-ph/0111340
Stanley J. Brodsky
Stanley J. Brodsky
QCD Phenomenology and Light-Front Wavefunctions
Invited lectures, presented at the Cracow School Of Theoretical Physics: 41st Course: Fundamental Interactions, Zakopane, Poland, 2-11 June 2001
Acta Phys.Polon.B32:4013-4068,2001
null
SLAC-PUB-9056
hep-ph
null
A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B-meson decays, two-photon exclusive reactions, diffractive dissociation into jets, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. Light-front quantization can also be used in the Hamiltonian form to construct an event generator for high energy physics reactions at the amplitude level. The light-cone partition function, summed over exponentially-weighted light-cone energies, has simple boost properties which may be useful for studies in heavy ion collisions. I also review recent work which shows that the structure functions measured in deep inelastic lepton scattering are affected by final-state rescattering, thus modifying their connection to light-front probability distributions. In particular, the shadowing of nuclear structure functions is due to destructive interference effects from leading-twist diffraction of the virtual photon, physics not included in the nuclear light-cone wavefunctions.
[ { "created": "Tue, 27 Nov 2001 08:43:52 GMT", "version": "v1" } ]
2009-09-11
[ [ "Brodsky", "Stanley J.", "" ] ]
A natural calculus for describing the bound-state structure of relativistic composite systems in quantum field theory is the light-front Fock expansion which encodes the properties of a hadrons in terms of a set of frame-independent n-particle wavefunctions. Light-front quantization in the doubly-transverse light-cone gauge has a number of remarkable advantages, including explicit unitarity, a physical Fock expansion, the absence of ghost degrees of freedom, and the decoupling properties needed to prove factorization theorems in high momentum transfer inclusive and exclusive reactions. A number of applications are discussed in these lectures, including semileptonic B-meson decays, two-photon exclusive reactions, diffractive dissociation into jets, and deeply virtual Compton scattering. The relation of the intrinsic sea to the light-front wavefunctions is discussed. Light-front quantization can also be used in the Hamiltonian form to construct an event generator for high energy physics reactions at the amplitude level. The light-cone partition function, summed over exponentially-weighted light-cone energies, has simple boost properties which may be useful for studies in heavy ion collisions. I also review recent work which shows that the structure functions measured in deep inelastic lepton scattering are affected by final-state rescattering, thus modifying their connection to light-front probability distributions. In particular, the shadowing of nuclear structure functions is due to destructive interference effects from leading-twist diffraction of the virtual photon, physics not included in the nuclear light-cone wavefunctions.
hep-ph/9701369
Baurov Alexey Yuryevich
Yu.A. Baurov (Central Scientific Research Institute of Machinery, Moscow) and A.V. Kopajev (Sternberg State Astronomical Institute, Moscow)
Experimental Investigations of New Interaction by Use of Stationary High-accuracy Quartz Gravimeter
11 pages, latex, 6 ps figures, Submit to Ph. Rev. D15
null
null
null
hep-ph astro-ph gr-qc
null
Smooth anomalous in time dependence recordings of a high accuracy quartz gravimeter with a constant magnet attached to it, were revealed. These anomalies of minute's duration have amplitudes sometimes by more than an order of magnitude greater than that of the Moon tide, and may not be explained with the aid of current physical concepts. The experimental procedure was based on the hypothesis of a new interaction arising when acting on physical vacuum by magnetic systems through their vectorial potential. The coordinates of physical space magnetic anisotropy due to existence of the cosmological vector potential $A_g$, a new basic vectorial constant, are determined. In particular, the declination coordinate $\delta\approx 34^\circ$ of the vector $A_g$ (second equatorial coordinate system) is determined for the first time by experiment. The hypothesis considered was used for physical justification of the results obtained.
[ { "created": "Fri, 24 Jan 1997 16:27:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baurov", "Yu. A.", "", "Central Scientific Research Institute of Machinery,\n Moscow" ], [ "Kopajev", "A. V.", "", "Sternberg State Astronomical Institute, Moscow" ] ]
Smooth anomalous in time dependence recordings of a high accuracy quartz gravimeter with a constant magnet attached to it, were revealed. These anomalies of minute's duration have amplitudes sometimes by more than an order of magnitude greater than that of the Moon tide, and may not be explained with the aid of current physical concepts. The experimental procedure was based on the hypothesis of a new interaction arising when acting on physical vacuum by magnetic systems through their vectorial potential. The coordinates of physical space magnetic anisotropy due to existence of the cosmological vector potential $A_g$, a new basic vectorial constant, are determined. In particular, the declination coordinate $\delta\approx 34^\circ$ of the vector $A_g$ (second equatorial coordinate system) is determined for the first time by experiment. The hypothesis considered was used for physical justification of the results obtained.
1606.02684
Leonard S. Kisslinger
Leonard S. Kisslinger
Neutrino Oscillations With Two Sterile Neutrinos
8pages,2 figures,uses newly measured sterile-active neutrino mixing angle
null
10.1007/s10773-016-3069-9
IJTP-D-16-00225R1
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This work estimates the probability of $\mu$ to $e$ neutrino oscillation with two sterile neutrinos using a 5x5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4x4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.
[ { "created": "Thu, 19 May 2016 16:33:44 GMT", "version": "v1" } ]
2016-06-29
[ [ "Kisslinger", "Leonard S.", "" ] ]
This work estimates the probability of $\mu$ to $e$ neutrino oscillation with two sterile neutrinos using a 5x5 U-matrix, an extension of the previous estimate with one sterile neutrino and a 4x4 U-matrix. The sterile neutrino-active neutrino mass differences and the mixing angles of the two sterile neutrinos with the three active neutrinos are taken from recent publications, and the oscillation probability for one sterile neutrino is compared to the previous estimate.
2112.13857
Casey Cartwright
Casey Cartwright, Matthias Kaminski, Bjoern Schenke
Energy dependence of the chiral magnetic effect in expanding holographic plasma
18 pages, 6 figures, comments welcome
null
10.1103/PhysRevC.105.034903
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Based on a holographic far-from-equilibrium calculation of the chiral magnetic effect~(CME) in an expanding quark gluon plasma, we study collisions at various energies. We compute the time evolution of the CME current in the presence of a time-dependent axial charge density and subject to a time-dependent magnetic field. The plasma expansion leads to a dilution of the CME current. We study distinct combinations of how the initial magnetic field and initial axial charge behave with changing initial energy as proposed in previous literature. Most scenarios we consider lead to an increasing time-integrated CME current, when increasing the initial energy. This would make it more likely to observe the CME at higher collision energies.
[ { "created": "Mon, 27 Dec 2021 19:00:04 GMT", "version": "v1" } ]
2022-03-23
[ [ "Cartwright", "Casey", "" ], [ "Kaminski", "Matthias", "" ], [ "Schenke", "Bjoern", "" ] ]
Based on a holographic far-from-equilibrium calculation of the chiral magnetic effect~(CME) in an expanding quark gluon plasma, we study collisions at various energies. We compute the time evolution of the CME current in the presence of a time-dependent axial charge density and subject to a time-dependent magnetic field. The plasma expansion leads to a dilution of the CME current. We study distinct combinations of how the initial magnetic field and initial axial charge behave with changing initial energy as proposed in previous literature. Most scenarios we consider lead to an increasing time-integrated CME current, when increasing the initial energy. This would make it more likely to observe the CME at higher collision energies.
1902.02944
Hyun-Chul Kim
Hyun-Chul Kim
Structure of heavy baryons in a pion mean-field approach
4 pages, No figure. Contribution to the proceedings of "8th International Conference on Quarks and Nuclear Physics (QNP2018)", November 13-17, 2018, Tsukuba, Japan
null
10.7566/JPSCP.26.022025
INHA-NTG-05/2019
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this talk, we briefly review a series of recent works on singly heavy baryons, based on a pion mean-field approach. In the limit of the infinitely heavy quark mass, heavy baryons are governed mainly by the light degress of freedom. Taking the number of colors to be infinity, a heavy baryon arises as a state consisting of $N_c-1$ valence quarks bound by the pion mean fields created self-consistently. Within this framework, we present the results of the mass spectra of the charmed and bottom baryons, and their magnetic moments. The behavior of the electromagnetic form factors will be also mentioned.
[ { "created": "Fri, 8 Feb 2019 05:55:48 GMT", "version": "v1" } ]
2020-01-08
[ [ "Kim", "Hyun-Chul", "" ] ]
In this talk, we briefly review a series of recent works on singly heavy baryons, based on a pion mean-field approach. In the limit of the infinitely heavy quark mass, heavy baryons are governed mainly by the light degress of freedom. Taking the number of colors to be infinity, a heavy baryon arises as a state consisting of $N_c-1$ valence quarks bound by the pion mean fields created self-consistently. Within this framework, we present the results of the mass spectra of the charmed and bottom baryons, and their magnetic moments. The behavior of the electromagnetic form factors will be also mentioned.
hep-ph/9404258
Zhangzx
Ma Wen-Gan, Sun La-Zhen, Liu Yao-Yang, Jiang Yi and Chao-Hsi Chang
The forward-backward asymmetry with $Z'$ effects in the process $e^{+}$ $e^{-}$ $\rightarrow$ $\mu^{+}$ $\mu^{-}$
10, AS-ITP-94-11
J.Phys. G20 (1994) 1391-1398
10.1088/0954-3899/20/9/008
null
hep-ph
null
Having taken the QED radiative correction and one-loop weak corrections into account, we have computed the unpolarized forward-backward asymmetry in the process $e^+e^- -> \mu^+\mu^-$ at a very reasonable accuracy. Special attention to the effects around the LEP 200 energy, induced by the possible $Z'$ boson of the left-right symmetric model $SU(2)_{L} \times SU(2)_{R} \times U(1)_{B-L}$, is paid. The numerical results of the directly measurable asymmetry $A_{FB}^{\mu}$ versus the CMS energies are presented in figures. One may be convinced by the results that precise measurements on the asymmetry in future colliders will possibly present some indirectly evidence of the $Z'$ boson.
[ { "created": "Tue, 12 Apr 1994 22:32:08 GMT", "version": "v1" } ]
2009-10-28
[ [ "Wen-Gan", "Ma", "" ], [ "La-Zhen", "Sun", "" ], [ "Yao-Yang", "Liu", "" ], [ "Yi", "Jiang", "" ], [ "Chang", "Chao-Hsi", "" ] ]
Having taken the QED radiative correction and one-loop weak corrections into account, we have computed the unpolarized forward-backward asymmetry in the process $e^+e^- -> \mu^+\mu^-$ at a very reasonable accuracy. Special attention to the effects around the LEP 200 energy, induced by the possible $Z'$ boson of the left-right symmetric model $SU(2)_{L} \times SU(2)_{R} \times U(1)_{B-L}$, is paid. The numerical results of the directly measurable asymmetry $A_{FB}^{\mu}$ versus the CMS energies are presented in figures. One may be convinced by the results that precise measurements on the asymmetry in future colliders will possibly present some indirectly evidence of the $Z'$ boson.
2307.00803
Zhongyu Wang
Zhong-Yu Wang and Zhi-Feng Sun
The hidden strange $B_{c}$-like molecular states
15 pages, 8 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the chiral unitary approach, we evaluate the hidden strange $B_{c}$-like molecular states of $b\bar{c}s\bar{s}$ systems $\bar{B}_{s}\bar{D}_{s}$, $\bar{B}_{s}^{*}\bar{D}_{s}$, $\bar{B}_{s}\bar{D}_{s}^{*}$, and $\bar{B}_{s}^{*}\bar{D}_{s}^{*}$ coupled to the non-strange channels. The $S$-wave scattering amplitudes are calculated based on the vector meson exchange, four pseudoscalar mesons contact interactions, and four vector mesons contact interactions obtained from the extended local hidden gauge approach. We find six states below the threshold of the most relevant channel. The binding energies of these states are around $1-10$ MeV and the widths are around $0.2-0.7$ MeV. Our research is a supplement to the mass spectra of $B_{c}$-like states, which may be useful for the experimental search in the future.
[ { "created": "Mon, 3 Jul 2023 07:38:21 GMT", "version": "v1" }, { "created": "Sun, 9 Jul 2023 08:30:39 GMT", "version": "v2" } ]
2023-07-11
[ [ "Wang", "Zhong-Yu", "" ], [ "Sun", "Zhi-Feng", "" ] ]
With the chiral unitary approach, we evaluate the hidden strange $B_{c}$-like molecular states of $b\bar{c}s\bar{s}$ systems $\bar{B}_{s}\bar{D}_{s}$, $\bar{B}_{s}^{*}\bar{D}_{s}$, $\bar{B}_{s}\bar{D}_{s}^{*}$, and $\bar{B}_{s}^{*}\bar{D}_{s}^{*}$ coupled to the non-strange channels. The $S$-wave scattering amplitudes are calculated based on the vector meson exchange, four pseudoscalar mesons contact interactions, and four vector mesons contact interactions obtained from the extended local hidden gauge approach. We find six states below the threshold of the most relevant channel. The binding energies of these states are around $1-10$ MeV and the widths are around $0.2-0.7$ MeV. Our research is a supplement to the mass spectra of $B_{c}$-like states, which may be useful for the experimental search in the future.
hep-ph/0206207
Tetsuo Shindou
Takahiro Miura, Tetsuo Shindou and Eiichi Takasugi
Exploring the neutrino mass matrix at M_R scale
revtex4, 20 pages, 6 figures
Phys.Rev. D66 (2002) 093002
10.1103/PhysRevD.66.093002
OU-HET 414
hep-ph
null
We discuss the neutrino mass matrix which predicts zero or small values of |V_{13}| in MSSM and found the inequality, sin^2 2theta_{12} <= sin^2 2theta_sol, where sin^2 2theta_{12} is the mixing angle at M_R scale and sin^2 2theta_{sol} is the value determined by the solar neutrino oscillation. This constraint says that the model which predicts a larger value of tan^2 theta_{sol} at M_R than the experimental value is excluded. In particular, the bi-maximal mixing scheme at M_R scale is excluded, from the experimental value tan^2 theta_sol<1. In this model, |V_{13}| and a Dirac phase at m_Z are induced radiatively and turn out to be not small. The effective neutrino mass <m_nu> is expected to be of order 0.05 eV.
[ { "created": "Fri, 21 Jun 2002 12:14:49 GMT", "version": "v1" }, { "created": "Fri, 19 Jul 2002 13:10:30 GMT", "version": "v2" }, { "created": "Sat, 20 Jul 2002 06:11:07 GMT", "version": "v3" }, { "created": "Tue, 10 Sep 2002 08:29:00 GMT", "version": "v4" } ]
2009-11-07
[ [ "Miura", "Takahiro", "" ], [ "Shindou", "Tetsuo", "" ], [ "Takasugi", "Eiichi", "" ] ]
We discuss the neutrino mass matrix which predicts zero or small values of |V_{13}| in MSSM and found the inequality, sin^2 2theta_{12} <= sin^2 2theta_sol, where sin^2 2theta_{12} is the mixing angle at M_R scale and sin^2 2theta_{sol} is the value determined by the solar neutrino oscillation. This constraint says that the model which predicts a larger value of tan^2 theta_{sol} at M_R than the experimental value is excluded. In particular, the bi-maximal mixing scheme at M_R scale is excluded, from the experimental value tan^2 theta_sol<1. In this model, |V_{13}| and a Dirac phase at m_Z are induced radiatively and turn out to be not small. The effective neutrino mass <m_nu> is expected to be of order 0.05 eV.
1405.7177
Vesna Borka Jovanovi\'c
V. Borka Jovanovi\'c, D. Borka, P. Jovanovi\'c, J. Milo\v{s}evi\'c, S. R. Ignjatovi\'c
Masses of constituent quarks confined in open bottom hadrons
15 pages, 6 tables, 1 figure. Accepted for publication in Mod. Phys. Lett. A
null
10.1142/S0217732314502022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We apply color-spin and flavor-spin quark-quark interactions to the meson and baryon constituent quarks, and calculate constituent quark masses, as well as the coupling constants of these interactions. The main goal of this paper was to determine constituent quark masses from light and open bottom hadron masses, using the fitting method we have developed and clustering of hadron groups. We use color-spin Fermi-Breit (FB) and flavor-spin Glozman-Riska (GR) hyperfine interaction (HFI) to determine constituent quark masses (especially $b$ quark mass). Another aim was to discern between the FB and GR HFI because our previous findings had indicated that both interactions were satisfactory. Our improved fitting procedure of constituent quark masses showed that on average color-spin (Fermi-Breit) hyperfine interaction yields better fits. The method also shows the way how the constituent quark masses and the strength of the interaction constants appear in different hadron environments.
[ { "created": "Wed, 28 May 2014 10:02:49 GMT", "version": "v1" }, { "created": "Fri, 10 Oct 2014 08:30:45 GMT", "version": "v2" }, { "created": "Wed, 3 Dec 2014 09:33:43 GMT", "version": "v3" } ]
2014-12-04
[ [ "Jovanović", "V. Borka", "" ], [ "Borka", "D.", "" ], [ "Jovanović", "P.", "" ], [ "Milošević", "J.", "" ], [ "Ignjatović", "S. R.", "" ] ]
We apply color-spin and flavor-spin quark-quark interactions to the meson and baryon constituent quarks, and calculate constituent quark masses, as well as the coupling constants of these interactions. The main goal of this paper was to determine constituent quark masses from light and open bottom hadron masses, using the fitting method we have developed and clustering of hadron groups. We use color-spin Fermi-Breit (FB) and flavor-spin Glozman-Riska (GR) hyperfine interaction (HFI) to determine constituent quark masses (especially $b$ quark mass). Another aim was to discern between the FB and GR HFI because our previous findings had indicated that both interactions were satisfactory. Our improved fitting procedure of constituent quark masses showed that on average color-spin (Fermi-Breit) hyperfine interaction yields better fits. The method also shows the way how the constituent quark masses and the strength of the interaction constants appear in different hadron environments.
hep-ph/9702326
Lubov Vassilevskaya
N.V. Mikheev and L.A. Vassilevskaya
Axion decay $a \to f \tilde f$ in a strong magnetic field
6 pages, latex. Amended version, references added, to be published in Phys.Lett.B
Phys.Lett. B410 (1997) 203-206
10.1016/S0370-2693(97)00876-9
YARU-HE-97/03
hep-ph
null
The axion decay into charged fermion-antifermion pair $a ~\to f ~\tilde f$ is studied in external crossed and magnetic fields. The result we have obtained can be of use to re-examine the lower limit on the axion mass in case of possible existence of strong magnetic fields at the early Universe stage.
[ { "created": "Thu, 13 Feb 1997 14:18:51 GMT", "version": "v1" }, { "created": "Fri, 1 Aug 1997 12:12:30 GMT", "version": "v2" } ]
2009-10-30
[ [ "Mikheev", "N. V.", "" ], [ "Vassilevskaya", "L. A.", "" ] ]
The axion decay into charged fermion-antifermion pair $a ~\to f ~\tilde f$ is studied in external crossed and magnetic fields. The result we have obtained can be of use to re-examine the lower limit on the axion mass in case of possible existence of strong magnetic fields at the early Universe stage.
1011.3694
Davide Cadamuro
Davide Cadamuro, Steen Hannestad, Georg Raffelt and Javier Redondo
Cosmological bounds on sub-MeV mass axions
19 pages, 10 figures
JCAP 1102:003,2011
10.1088/1475-7516/2011/02/003
MPP-2010-148
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Axions with mass greater than 0.7 eV are excluded by cosmological precision data because they provide too much hot dark matter. While for masses above 20 eV the axion lifetime drops below the age of the universe, we show that the cosmological exclusion range can be extended from 0.7 eV till 300 keV, primarily by the cosmic deuterium abundance: axion decays would strongly modify the baryon-to-photon ratio at BBN relative to the one at CMB decoupling. Additional arguments include neutrino dilution relative to photons by axion decays and spectral CMB distortions. Our new cosmological constraints complement stellar-evolution limits and laboratory bounds.
[ { "created": "Tue, 16 Nov 2010 14:00:11 GMT", "version": "v1" }, { "created": "Fri, 21 Jan 2011 13:36:06 GMT", "version": "v2" } ]
2015-03-17
[ [ "Cadamuro", "Davide", "" ], [ "Hannestad", "Steen", "" ], [ "Raffelt", "Georg", "" ], [ "Redondo", "Javier", "" ] ]
Axions with mass greater than 0.7 eV are excluded by cosmological precision data because they provide too much hot dark matter. While for masses above 20 eV the axion lifetime drops below the age of the universe, we show that the cosmological exclusion range can be extended from 0.7 eV till 300 keV, primarily by the cosmic deuterium abundance: axion decays would strongly modify the baryon-to-photon ratio at BBN relative to the one at CMB decoupling. Additional arguments include neutrino dilution relative to photons by axion decays and spectral CMB distortions. Our new cosmological constraints complement stellar-evolution limits and laboratory bounds.
hep-ph/9406399
Yamawaki
Koichi Yamawaki and V.I. Zakharov
Nambu-Jona-Lasinio Model vs QCD
LaTeX, 9 pages, UM-TH-94-20, DPNU-94-23
null
null
null
hep-ph
null
We argue that the extended Nambu-Jona-Lasinio model which introduces four-quark interactions to describe hadron physics at low energies can be confronted with fundamental quantum chromodynamics by means of spectral sum rules. While there arise rather restrictive bounds on the strength of the effective four-quark interaction in the vector channel, introduction of the four-quark interaction in the pseudoscalar channel resolves a long standing puzzle of the sum rules.
[ { "created": "Mon, 27 Jun 1994 05:40:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Yamawaki", "Koichi", "" ], [ "Zakharov", "V. I.", "" ] ]
We argue that the extended Nambu-Jona-Lasinio model which introduces four-quark interactions to describe hadron physics at low energies can be confronted with fundamental quantum chromodynamics by means of spectral sum rules. While there arise rather restrictive bounds on the strength of the effective four-quark interaction in the vector channel, introduction of the four-quark interaction in the pseudoscalar channel resolves a long standing puzzle of the sum rules.
hep-ph/9909413
Csaba Boros
C. Boros, J.T. Londergan and A.W. Thomas
On the $\xi$-Distribution of Inclusively Produced Particles in $e^+e^-$ Annihilation
null
Phys.Lett.B473:305-308,2000
10.1016/S0370-2693(99)01498-7
ADP-99-39/T376 and IU/NTC 99-09
hep-ph
null
We discuss the momentum distributions of inclusively produced particles in $e^+e^-$ annihilation. We show that the dependence of the position of the maxima of the $\xi=\ln(1/z)$ spectra on the mass of the produced particles follows naturally from the general definition of fragmentation functions when energy-momentum conservation is correctly incorporated.
[ { "created": "Fri, 17 Sep 1999 06:21:24 GMT", "version": "v1" } ]
2010-02-17
[ [ "Boros", "C.", "" ], [ "Londergan", "J. T.", "" ], [ "Thomas", "A. W.", "" ] ]
We discuss the momentum distributions of inclusively produced particles in $e^+e^-$ annihilation. We show that the dependence of the position of the maxima of the $\xi=\ln(1/z)$ spectra on the mass of the produced particles follows naturally from the general definition of fragmentation functions when energy-momentum conservation is correctly incorporated.
hep-ph/9501308
Nick Evans
Nick Evans
FERMION MASSES IN EXTENDED TECHNICOLOUR
7 pages, latex, two figures appended
null
null
YCTP-P3-95
hep-ph
null
Talks presented at Beyond The Standard Model IV Conference, Lake Tahoe, Dec 94: NEW FERMION FAMILIES AND PRECISION ELECTROWEAK DATA: We highlight a trend in the precision electroweak data towards light new physics and argue that some spectra of strongly interacting technifamilies are plausibly compatible with the data. FERMION MASSES IN EXTENDED TECHNICOLOUR: An ETC model with a minimal number of operators responsible for fermion masses that break the global symmetries in the observed manner postdicts the light quark masses. The up down mass inversion may be explained by the inclusion of a family symmetric ansatz for the CKM matrix angles.
[ { "created": "Mon, 16 Jan 1995 21:32:39 GMT", "version": "v1" } ]
2016-09-01
[ [ "Evans", "Nick", "" ] ]
Talks presented at Beyond The Standard Model IV Conference, Lake Tahoe, Dec 94: NEW FERMION FAMILIES AND PRECISION ELECTROWEAK DATA: We highlight a trend in the precision electroweak data towards light new physics and argue that some spectra of strongly interacting technifamilies are plausibly compatible with the data. FERMION MASSES IN EXTENDED TECHNICOLOUR: An ETC model with a minimal number of operators responsible for fermion masses that break the global symmetries in the observed manner postdicts the light quark masses. The up down mass inversion may be explained by the inclusion of a family symmetric ansatz for the CKM matrix angles.
0710.1843
Pearl Sandick
Pearl Sandick
Dark Matter Phenomenology of GUT-less SUSY Breaking
4 pages, 3 figures, Submitted for the SUSY07 proceedings
null
null
null
hep-ph
null
We study models in which supersymmetry breaking appears at an intermediate scale, M_in, below the GUT scale. That is, that the soft supersymmetry-breaking parameters of the MSSM are universal at M_in. We demand that the lightest neutralino be the LSP, and that the relic neutralino density not conflict with measurements by WMAP and others, and study the morphology of this constraint as the universality scale is reduced from the GUT scale. At moderate values of M_in, we find that the allowed regions of the (m_1/2,m_0) plane are squeezed by the requirements of electroweak symmetry breaking and that the lightest neutralino be the LSP, whereas the constraint on the relic density is less severe. At very low M_in, the electroweak vacuum conditions become the dominant constraint, and a secondary source of astrophysical cold dark matter would be necessary to explain the measured relic density for nearly all values of the soft SUSY-breaking parameters and tan(beta).
[ { "created": "Tue, 9 Oct 2007 18:07:31 GMT", "version": "v1" } ]
2007-10-10
[ [ "Sandick", "Pearl", "" ] ]
We study models in which supersymmetry breaking appears at an intermediate scale, M_in, below the GUT scale. That is, that the soft supersymmetry-breaking parameters of the MSSM are universal at M_in. We demand that the lightest neutralino be the LSP, and that the relic neutralino density not conflict with measurements by WMAP and others, and study the morphology of this constraint as the universality scale is reduced from the GUT scale. At moderate values of M_in, we find that the allowed regions of the (m_1/2,m_0) plane are squeezed by the requirements of electroweak symmetry breaking and that the lightest neutralino be the LSP, whereas the constraint on the relic density is less severe. At very low M_in, the electroweak vacuum conditions become the dominant constraint, and a secondary source of astrophysical cold dark matter would be necessary to explain the measured relic density for nearly all values of the soft SUSY-breaking parameters and tan(beta).
1608.04746
Athanasios Karozas
Miguel Crispim Rom\~ao, Athanasios Karozas, Stephen F. King, George K. Leontaris, Andrew K. Meadowcroft
R-Parity violation in F-Theory
40 pages, 13 figures, minor corrections
null
10.1007/JHEP11(2016)081
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss R-parity violation (RPV) in semi-local and local F-theory constructions. We first present a detailed analysis of all possible combinations of RPV operators arising from semi-local F-theory spectral cover constructions, assuming an $SU(5)$ GUT. We provide a classification of all possible allowed combinations of RPV operators originating from operators of the form $10\cdot \bar 5\cdot \bar 5$, including the effect of $U(1)$ fluxes with global restrictions. We then relax the global constraints and perform explicit computations of the bottom/tau and RPV Yukawa couplings, at an $SO(12)$ local point of enhancement in the presence of general fluxes subject only to local flux restrictions. We compare our results to the experimental limits on each allowed RPV operator, and show that operators such as $LLe^c$, $LQd^c$ and $u^cd^cd^c$ may be present separately within current bounds, possibly on the edge of observability, suggesting lepton number violation or neutron-antineutron oscillations could constrain F-theory models.
[ { "created": "Tue, 16 Aug 2016 20:00:04 GMT", "version": "v1" }, { "created": "Wed, 23 Nov 2016 17:34:09 GMT", "version": "v2" } ]
2016-11-24
[ [ "Romão", "Miguel Crispim", "" ], [ "Karozas", "Athanasios", "" ], [ "King", "Stephen F.", "" ], [ "Leontaris", "George K.", "" ], [ "Meadowcroft", "Andrew K.", "" ] ]
We discuss R-parity violation (RPV) in semi-local and local F-theory constructions. We first present a detailed analysis of all possible combinations of RPV operators arising from semi-local F-theory spectral cover constructions, assuming an $SU(5)$ GUT. We provide a classification of all possible allowed combinations of RPV operators originating from operators of the form $10\cdot \bar 5\cdot \bar 5$, including the effect of $U(1)$ fluxes with global restrictions. We then relax the global constraints and perform explicit computations of the bottom/tau and RPV Yukawa couplings, at an $SO(12)$ local point of enhancement in the presence of general fluxes subject only to local flux restrictions. We compare our results to the experimental limits on each allowed RPV operator, and show that operators such as $LLe^c$, $LQd^c$ and $u^cd^cd^c$ may be present separately within current bounds, possibly on the edge of observability, suggesting lepton number violation or neutron-antineutron oscillations could constrain F-theory models.
2004.01852
Carlos Andres Escobar Ruiz
C. A. Escobar and R. Potting
Degenerate behavior in nonlinear vacuum electrodynamics
17 pages, 2 figures, Accepted for publication in Physica Scripta
null
10.1088/1402-4896/ab842d
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study nonlinear vacuum electrodynamics in the first-order formulation proposed by Pleba\'nski. We analyze in detail the equations of motion, and identify conditions for which a singularity can occur for the time derivative of one of the field components. The resulting degenerate behavior can give rise to a shock wave with a reduction of the local number of degrees of freedom. We use an example model to illustrate the occurrence of superluminal propagation for field values approaching the singularity.
[ { "created": "Sat, 4 Apr 2020 04:59:12 GMT", "version": "v1" } ]
2020-06-24
[ [ "Escobar", "C. A.", "" ], [ "Potting", "R.", "" ] ]
We study nonlinear vacuum electrodynamics in the first-order formulation proposed by Pleba\'nski. We analyze in detail the equations of motion, and identify conditions for which a singularity can occur for the time derivative of one of the field components. The resulting degenerate behavior can give rise to a shock wave with a reduction of the local number of degrees of freedom. We use an example model to illustrate the occurrence of superluminal propagation for field values approaching the singularity.
1310.1107
Pisin Chen
Pisin Chen
Recent Progress in Cosmology and Particle Astrophysics
10 pages, 2 figures
null
null
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent years have seen dramatic progress in cosmology and particle astrophysics. So much so that anyone who dares to offer an overview would certainly risk him- or herself for being incomplete and biased at best, and even incorrect due to the author's limited expertise. It is with this understanding and excuse that I risk myself in offering this review. After a brief summary of Planck mission's first results, I highlight some selected theoretical and experimental advancement in dark energy, dark matter, and cosmic neutrinos research. It is hoped that with a glance through these exciting development, one would be convinced that we are now a step closer to the ultimate understanding of our universe, while major breakthroughs are still required.
[ { "created": "Thu, 3 Oct 2013 20:24:47 GMT", "version": "v1" } ]
2013-10-07
[ [ "Chen", "Pisin", "" ] ]
Recent years have seen dramatic progress in cosmology and particle astrophysics. So much so that anyone who dares to offer an overview would certainly risk him- or herself for being incomplete and biased at best, and even incorrect due to the author's limited expertise. It is with this understanding and excuse that I risk myself in offering this review. After a brief summary of Planck mission's first results, I highlight some selected theoretical and experimental advancement in dark energy, dark matter, and cosmic neutrinos research. It is hoped that with a glance through these exciting development, one would be convinced that we are now a step closer to the ultimate understanding of our universe, while major breakthroughs are still required.
hep-ph/0612112
Heinrich Leutwyler
H. Leutwyler
pi pi scattering
Contribution to the proceedings of the workshop "Chiral Dynamics, Theory & Experiment", Durham/Chapel Hill, NC, USA, September 2006
null
10.1142/9789812790804_0002
null
hep-ph
null
Recent work in low energy pion physics is reviewed. One of the exciting new developments in this field is that simulations of QCD on a lattice now start providing information about the low energy structure of the continuum theory, for physical values of the quark masses. Although the various sources of systematic error yet need to be explored more thoroughly, the results obtained for the correlation function of the axial current with the quantum numbers of the pion already have important implications for the effective Lagrangian of QCD. The consequences for $\pi\pi$ scattering are discussed in some detail. The second part of the report briefly reviews recent developments in the dispersion theory of the scattering amplitude. One of the important results here is that the position of the lowest resonances of QCD can now be determined in a model independent manner and rather precisely. Beyond any doubt, the partial wave with $I=\ell=0$ contains a pole on the second sheet, not far from the threshold: the lowest resonance of QCD carries the quantum numbers of the vacuum.
[ { "created": "Mon, 11 Dec 2006 09:44:35 GMT", "version": "v1" } ]
2017-08-23
[ [ "Leutwyler", "H.", "" ] ]
Recent work in low energy pion physics is reviewed. One of the exciting new developments in this field is that simulations of QCD on a lattice now start providing information about the low energy structure of the continuum theory, for physical values of the quark masses. Although the various sources of systematic error yet need to be explored more thoroughly, the results obtained for the correlation function of the axial current with the quantum numbers of the pion already have important implications for the effective Lagrangian of QCD. The consequences for $\pi\pi$ scattering are discussed in some detail. The second part of the report briefly reviews recent developments in the dispersion theory of the scattering amplitude. One of the important results here is that the position of the lowest resonances of QCD can now be determined in a model independent manner and rather precisely. Beyond any doubt, the partial wave with $I=\ell=0$ contains a pole on the second sheet, not far from the threshold: the lowest resonance of QCD carries the quantum numbers of the vacuum.
1706.09469
Sarira Sahu
Jose F. Nieves, Yaithd D. Olivas, Sarira Sahu
Neutrino dispersion relation in a magnetized multi-stream matter background
Title changed, 21 pages, 1 figure
Eur.Phys.J. C78 (2018) no.5, 400
10.1140/epjc/s10052-018-5884-z
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the propagation of a neutrino in a medium that consists of two or more thermal backgrounds of electrons and nucleons moving with some relative velocity, in the presence of a static and homogeneous electromagnetic field. We calculate the neutrino self-energy and dispersion relation using the linear thermal Schwinger propagator, we give the formulas for the dispersion relation and discuss general features of the results obtained, in particular the effects of the stream contributions. As a specific example we discuss in some detail the case of a magnetized two-stream electron, i.e., two electron backgrounds with a relative velocity $\vec v$ in the presence of a magnetic field. For a neutrino propagating with momentum $\vec k$, in the presence of the stream the neutrino dispersion relation acquires an anisotropic contribution of the form $\hat k\cdot\vec v$ in addition to the well known term $\hat k\cdot\vec B$, as well as an additional contribution proportional to $\vec B\cdot\vec v$. We consider the contribution from a nucleon stream background as an example of other possible stream backgrounds, and comment on possible generalizations to take into account the effects of inhomogeneous fields. We explain why a term of the form $\hat k\cdot(\vec v\times\vec B)$ does not appear in the dispersion relation in the constant field case, while a term of similar form can appear in the presence of an inhomogeneous field involving its gradient.
[ { "created": "Wed, 28 Jun 2017 20:06:48 GMT", "version": "v1" }, { "created": "Sat, 28 Jul 2018 19:05:39 GMT", "version": "v2" } ]
2018-07-31
[ [ "Nieves", "Jose F.", "" ], [ "Olivas", "Yaithd D.", "" ], [ "Sahu", "Sarira", "" ] ]
We study the propagation of a neutrino in a medium that consists of two or more thermal backgrounds of electrons and nucleons moving with some relative velocity, in the presence of a static and homogeneous electromagnetic field. We calculate the neutrino self-energy and dispersion relation using the linear thermal Schwinger propagator, we give the formulas for the dispersion relation and discuss general features of the results obtained, in particular the effects of the stream contributions. As a specific example we discuss in some detail the case of a magnetized two-stream electron, i.e., two electron backgrounds with a relative velocity $\vec v$ in the presence of a magnetic field. For a neutrino propagating with momentum $\vec k$, in the presence of the stream the neutrino dispersion relation acquires an anisotropic contribution of the form $\hat k\cdot\vec v$ in addition to the well known term $\hat k\cdot\vec B$, as well as an additional contribution proportional to $\vec B\cdot\vec v$. We consider the contribution from a nucleon stream background as an example of other possible stream backgrounds, and comment on possible generalizations to take into account the effects of inhomogeneous fields. We explain why a term of the form $\hat k\cdot(\vec v\times\vec B)$ does not appear in the dispersion relation in the constant field case, while a term of similar form can appear in the presence of an inhomogeneous field involving its gradient.
1503.00859
Ulrich Nierste
Philipp Frings, Ulrich Nierste, and Martin Wiebusch
Penguin contributions to CP phases in $B_{d,s}$ decays to charmonium
typo in Eqs. (2) and (3) corrected, references updated.Matches version published in PRL
Phys. Rev. Lett. 115, 061802 (2015)
10.1103/PhysRevLett.115.061802
TTP15-006
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The precision of the CP phases $2\beta$ and $2\beta_s$ determined from the mixing-induced CP asymmetries in $B_d\to J/\psi K_S$ and $B_s\to J/\psi \phi$, respectively, is limited by the unknown long-distance contribution of a penguin diagram involving up quarks. The penguin contribution is expected to be comparable in size to the precision of the LHCb and Belle II experiments and therefore limits the sensitivity of the measured quantities to new physics. We analyze the infrared QCD structure of this contribution and find that all soft and collinear divergences either cancel between different diagrams or factorize into matrix elements of local four-quark operators up to terms suppressed by $\Lambda_{QCD}/m_{\psi}$, where $m_{\psi}$ denotes the $J/\psi$ mass. Our results, which are based on an operator product expansion, allow us to calculate the penguin-to-tree ratio $P/T$ in terms of the matrix elements of these operators and to constrain the penguin contribution to the phase $2\beta$ as $|\Delta \phi_d|\leq {0.68}^\circ$. The penguin contribution to $2\beta_s$ is bounded as $|\Delta \phi_s^{0}|\leq {0.97}^\circ$, $|\Delta \phi_s^{\parallel}|\leq {1.22}^\circ$, and $|\Delta \phi_s^{\perp}|\leq {0.99}^\circ$ for the case of longitudinal, parallel, and perpendicular $\phi$ and $J/\psi$ polarizations, respectively. We further place bounds on $|\Delta \phi_d|$ for $B_d\to \psi(2S) K_S$ and the polarization amplitudes in $B_d\to J/\psi K^*$. In our approach it is further possible to constrain $P/T$ for decays in which $P/T$ is Cabibbo-unsuppressed and we derive upper limits on the penguin contribution to the mixing-induced CP asymmetries in $B_d\to J/\psi \pi^0$, $B_d\to J/\psi \rho^0$, $B_s\to J/\psi K_S$, and $B_s\to J/\psi K^*$. For all studied decay modes we also constrain the sizes of the direct CP asymmetries.
[ { "created": "Tue, 3 Mar 2015 08:52:19 GMT", "version": "v1" }, { "created": "Mon, 6 Jul 2015 16:54:02 GMT", "version": "v2" }, { "created": "Mon, 3 Aug 2015 15:34:49 GMT", "version": "v3" } ]
2015-08-12
[ [ "Frings", "Philipp", "" ], [ "Nierste", "Ulrich", "" ], [ "Wiebusch", "Martin", "" ] ]
The precision of the CP phases $2\beta$ and $2\beta_s$ determined from the mixing-induced CP asymmetries in $B_d\to J/\psi K_S$ and $B_s\to J/\psi \phi$, respectively, is limited by the unknown long-distance contribution of a penguin diagram involving up quarks. The penguin contribution is expected to be comparable in size to the precision of the LHCb and Belle II experiments and therefore limits the sensitivity of the measured quantities to new physics. We analyze the infrared QCD structure of this contribution and find that all soft and collinear divergences either cancel between different diagrams or factorize into matrix elements of local four-quark operators up to terms suppressed by $\Lambda_{QCD}/m_{\psi}$, where $m_{\psi}$ denotes the $J/\psi$ mass. Our results, which are based on an operator product expansion, allow us to calculate the penguin-to-tree ratio $P/T$ in terms of the matrix elements of these operators and to constrain the penguin contribution to the phase $2\beta$ as $|\Delta \phi_d|\leq {0.68}^\circ$. The penguin contribution to $2\beta_s$ is bounded as $|\Delta \phi_s^{0}|\leq {0.97}^\circ$, $|\Delta \phi_s^{\parallel}|\leq {1.22}^\circ$, and $|\Delta \phi_s^{\perp}|\leq {0.99}^\circ$ for the case of longitudinal, parallel, and perpendicular $\phi$ and $J/\psi$ polarizations, respectively. We further place bounds on $|\Delta \phi_d|$ for $B_d\to \psi(2S) K_S$ and the polarization amplitudes in $B_d\to J/\psi K^*$. In our approach it is further possible to constrain $P/T$ for decays in which $P/T$ is Cabibbo-unsuppressed and we derive upper limits on the penguin contribution to the mixing-induced CP asymmetries in $B_d\to J/\psi \pi^0$, $B_d\to J/\psi \rho^0$, $B_s\to J/\psi K_S$, and $B_s\to J/\psi K^*$. For all studied decay modes we also constrain the sizes of the direct CP asymmetries.
hep-ph/0211310
Eung Jin Chun
E.J Chun, D.-W. Jung and J.D Park
Bi-large neutrino mixing from bilinear R-parity violation with non-universality
13 pages, 4 eps figures, revtex4
Phys.Lett. B557 (2003) 233-239
10.1016/S0370-2693(03)00194-1
null
hep-ph
null
We investigate how the bi-large mixing required by the recent neutrino data can be accommodated in the supersymmetric standard model allowing bilinear R-parity violation and non-universal soft terms. In this scheme, the tree-level contribution and the so-called Grossman-Haber one-loop diagrams are two major sources of the neutrino mass matrix. The relative size of these two contributions falls into the right range to generate the atmospheric and solar neutrino mass hierarchy. On the other hand, the bi-large mixing is typically obtained by a mild tuning of input parameters to arrange a partial cancellation among various contributions.
[ { "created": "Wed, 20 Nov 2002 05:38:26 GMT", "version": "v1" } ]
2010-04-05
[ [ "Chun", "E. J", "" ], [ "Jung", "D. -W.", "" ], [ "Park", "J. D", "" ] ]
We investigate how the bi-large mixing required by the recent neutrino data can be accommodated in the supersymmetric standard model allowing bilinear R-parity violation and non-universal soft terms. In this scheme, the tree-level contribution and the so-called Grossman-Haber one-loop diagrams are two major sources of the neutrino mass matrix. The relative size of these two contributions falls into the right range to generate the atmospheric and solar neutrino mass hierarchy. On the other hand, the bi-large mixing is typically obtained by a mild tuning of input parameters to arrange a partial cancellation among various contributions.
2408.02486
J\"orn Knoll
J\"orn Knoll
The Fate of Weakly Bound Light Nuclei in Central Collider Experiments: a Challenge in Favor of a Late Continuous Decoupling Mechanism
6 pages, 3 figures, letter
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Arguments are presented that the reaction products of central high energy nuclear collisions up to collider energies can rigorously be interpreted in terms of a continuous decoupling mechanism based on continuous equations of motion. The various aspects of the collision dynamics are investigate in terms of the individual decoupling processes. Thereby each observed particle decouples during its own temporal decoupling window. This includes a ``very late'' decoupling of the faintly bound Hypertritons observed in recent ALICE experiments. The success of the strategy relays on 200 years old wisdom and leads to a revised interpretation of the entire decoupling process.
[ { "created": "Mon, 5 Aug 2024 14:06:08 GMT", "version": "v1" } ]
2024-08-06
[ [ "Knoll", "Jörn", "" ] ]
Arguments are presented that the reaction products of central high energy nuclear collisions up to collider energies can rigorously be interpreted in terms of a continuous decoupling mechanism based on continuous equations of motion. The various aspects of the collision dynamics are investigate in terms of the individual decoupling processes. Thereby each observed particle decouples during its own temporal decoupling window. This includes a ``very late'' decoupling of the faintly bound Hypertritons observed in recent ALICE experiments. The success of the strategy relays on 200 years old wisdom and leads to a revised interpretation of the entire decoupling process.
hep-ph/0306270
Robert Fleischer
Robert Fleischer (CERN)
Flavour Symmetry and Clean Strategies to Extract $\gamma$
Invited talk at the Workshop on the CKM Unitarity Triangle, IPPP Durham, April 2003 (eConf C0304052). 10 pages LaTeX
ECONF C0304052:WG303,2003
null
CERN-TH/2003-141
hep-ph
null
One of the key elements in the testing of the Standard-Model description of CP violation through $B$-meson decays is the direct determination of the angle $\gamma$ of the unitarity triangle in a variety of ways. We give a brief overview of the implications of the current $B$-factory data for flavour-symmetry strategies, and discuss new, theoretically clean methods employing pure tree decays of neutral $B_{d,s}$ mesons.
[ { "created": "Fri, 27 Jun 2003 08:51:35 GMT", "version": "v1" } ]
2010-11-23
[ [ "Fleischer", "Robert", "", "CERN" ] ]
One of the key elements in the testing of the Standard-Model description of CP violation through $B$-meson decays is the direct determination of the angle $\gamma$ of the unitarity triangle in a variety of ways. We give a brief overview of the implications of the current $B$-factory data for flavour-symmetry strategies, and discuss new, theoretically clean methods employing pure tree decays of neutral $B_{d,s}$ mesons.
1112.3174
Rumin Wang
Ru-Min Wang, Yuan-Guo Xu, Yi-Long Wang, Ya-Dong Yang
Revisiting B_s\to\mu^+\mu^- and B\to K^{(*)}\mu^+\mu^- decays in the MSSM with and without R-parity
20 pages, 9 figures, published version
Phys.Rev. D85, 094004 (2012)
10.1103/PhysRevD.85.094004
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The rare decays B_s -> \mu^+\mu^- and B -> K^{(*)}\mu^+\mu^- are sensitive to new particles and couplings via their interferences with the standard model contributions. Recently, the upper bound on B(B_s -> \mu^+\mu^-) has been improved significantly by the CMS, LHCb, CDF, and D{\O} experiments. Combining with the measurements of B(B-> K^{(*)}\mu^+\mu^-), we derive constraints on the relevant parameters of minimal supersymmetic standard model with and without R-parity, and examine their contributions to the dimuon forward-backward asymmetry in B-> K^{*}\mu^+\mu^- decay. We find that (i) the contribution of R-parity violating coupling products \lambda^{\prime}_{2i2}\lambda^{\prime*}_{2i3} due to squark exchange is comparable with the theoretical uncertainties in B-> K \mu^+\mu^- decay, but still could be significant in B-> K^{*}\mu^+\mu^- decay and could account for the forward-backward asymmetry in all dimuon invariant mass regions; (ii) the constrained mass insertion (\delta^{u}_{LL})_{23} could have significant contribution to dA_{FB}(B-> K^{*}\mu^+\mu^-)/ds, and such effects are favored by thr recent results of the Belle, CDF, and LHCb experiments.
[ { "created": "Wed, 14 Dec 2011 11:39:32 GMT", "version": "v1" }, { "created": "Thu, 15 Dec 2011 03:20:42 GMT", "version": "v2" }, { "created": "Fri, 13 Jul 2012 09:25:02 GMT", "version": "v3" } ]
2015-03-13
[ [ "Wang", "Ru-Min", "" ], [ "Xu", "Yuan-Guo", "" ], [ "Wang", "Yi-Long", "" ], [ "Yang", "Ya-Dong", "" ] ]
The rare decays B_s -> \mu^+\mu^- and B -> K^{(*)}\mu^+\mu^- are sensitive to new particles and couplings via their interferences with the standard model contributions. Recently, the upper bound on B(B_s -> \mu^+\mu^-) has been improved significantly by the CMS, LHCb, CDF, and D{\O} experiments. Combining with the measurements of B(B-> K^{(*)}\mu^+\mu^-), we derive constraints on the relevant parameters of minimal supersymmetic standard model with and without R-parity, and examine their contributions to the dimuon forward-backward asymmetry in B-> K^{*}\mu^+\mu^- decay. We find that (i) the contribution of R-parity violating coupling products \lambda^{\prime}_{2i2}\lambda^{\prime*}_{2i3} due to squark exchange is comparable with the theoretical uncertainties in B-> K \mu^+\mu^- decay, but still could be significant in B-> K^{*}\mu^+\mu^- decay and could account for the forward-backward asymmetry in all dimuon invariant mass regions; (ii) the constrained mass insertion (\delta^{u}_{LL})_{23} could have significant contribution to dA_{FB}(B-> K^{*}\mu^+\mu^-)/ds, and such effects are favored by thr recent results of the Belle, CDF, and LHCb experiments.
hep-ph/9411298
Kazuhiro Tobe
J. Hisano, T. Moroi, K. Tobe, and T. Yanagida
Limit on the Color-Triplet Higgs Mass in the Minimum Supersymmetric SU(5) Model
null
Mod.Phys.Lett. A10 (1995) 2267-2278
10.1142/S0217732395002428
TU-470
hep-ph
null
In the minimum supersymmetric SU(5) GUT, we derive the upper limit on the mass of the color-triplet Higgs multiplets as $\mhc\leq 2.4\times 10^{16}~\GEV$ (90 \% C.L.) taking all possible corrections into account in a renormalization group analysis. If the above upper limit is compared with a limit on $\mhc$ from the negative search for the proton decay; $\mhc \geq 2.0\times 10^{16}~\GEV$ (in which effects of the larger top-quark mass are included), the minimum supersymmetric SU(5) GUT is severely constrained.
[ { "created": "Tue, 15 Nov 1994 07:20:15 GMT", "version": "v1" }, { "created": "Thu, 17 Nov 1994 09:42:46 GMT", "version": "v2" } ]
2009-10-28
[ [ "Hisano", "J.", "" ], [ "Moroi", "T.", "" ], [ "Tobe", "K.", "" ], [ "Yanagida", "T.", "" ] ]
In the minimum supersymmetric SU(5) GUT, we derive the upper limit on the mass of the color-triplet Higgs multiplets as $\mhc\leq 2.4\times 10^{16}~\GEV$ (90 \% C.L.) taking all possible corrections into account in a renormalization group analysis. If the above upper limit is compared with a limit on $\mhc$ from the negative search for the proton decay; $\mhc \geq 2.0\times 10^{16}~\GEV$ (in which effects of the larger top-quark mass are included), the minimum supersymmetric SU(5) GUT is severely constrained.
2311.02998
Khiem Hong Phan
Dzung Tri Tran (DTU), Thanh Huy Nguyen (HCMUS), Khiem Hong Phan (DTU)
One-loop contributions for $h\rightarrow \ell \bar{\ell}\gamma$ and $e^-e^+\rightarrow h\gamma$ in $U(1)_{B-L}$ extension of the standard model
41 pages, to be published in Chinese Physics C
null
null
DTU2023-03
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present one-loop contributing for $h\rightarrow \ell \bar{\ell}\gamma$ with $\ell =\nu_{e,\mu, \tau}, e, \mu$ and $e^-e^+\rightarrow h\gamma$ in $U(1)_{B-L}$ extension of the standard models. In phenomenological results, the signal strengths for $h\rightarrow \ell \bar{\ell}\gamma$ at Large Hadron Collider and for $e^-e^+\rightarrow h\gamma$ at future Lepton Colliders are analyzed in physical parameter space for both vector and chiral $B-L$ models. We find that the contributions from neutral gauge boson $Z'$ to the signal strengths are rather small. Consequently, the effects are hard to probe at future colliders. While the impacts of charged Higgs, CP-odd Higgs in the chiral $B-L$ model on the signal strengths are significant and can be measured with the help of the initial polarization beams at future lepton colliders.
[ { "created": "Mon, 6 Nov 2023 10:06:10 GMT", "version": "v1" }, { "created": "Tue, 30 Jan 2024 11:09:05 GMT", "version": "v2" } ]
2024-01-31
[ [ "Tran", "Dzung Tri", "", "DTU" ], [ "Nguyen", "Thanh Huy", "", "HCMUS" ], [ "Phan", "Khiem Hong", "", "DTU" ] ]
We present one-loop contributing for $h\rightarrow \ell \bar{\ell}\gamma$ with $\ell =\nu_{e,\mu, \tau}, e, \mu$ and $e^-e^+\rightarrow h\gamma$ in $U(1)_{B-L}$ extension of the standard models. In phenomenological results, the signal strengths for $h\rightarrow \ell \bar{\ell}\gamma$ at Large Hadron Collider and for $e^-e^+\rightarrow h\gamma$ at future Lepton Colliders are analyzed in physical parameter space for both vector and chiral $B-L$ models. We find that the contributions from neutral gauge boson $Z'$ to the signal strengths are rather small. Consequently, the effects are hard to probe at future colliders. While the impacts of charged Higgs, CP-odd Higgs in the chiral $B-L$ model on the signal strengths are significant and can be measured with the help of the initial polarization beams at future lepton colliders.
1508.06645
Thomas Becher
Thomas Becher, Matthias Neubert, Lorena Rothen and Ding Yu Shao
An Effective Field Theory for Jet Processes
9 pages, 1 figure. v2: PRL version
Phys. Rev. Lett. 116, 192001 (2016)
10.1103/PhysRevLett.116.192001
MITP/15-065
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Processes involving narrow jets receive perturbative corrections enhanced by logarithms of the jet opening angle and the ratio of the energies inside and outside the jets. Analyzing cone-jet processes in effective field theory, we find that in addition to soft and collinear fields their description requires degrees of freedom which are simultaneously soft and collinear to the jets. These collinear-soft particles can resolve individual collinear partons, leading to a complicated multi-Wilson-line structure of the associated operators at higher orders. Our effective field theory provides, for the first time, a factorization formula for a cone-jet process, which fully separates the physics at different energy scales. Its renormalization-group equations control all logarithmically enhanced higher-order terms, in particular also the non-global logarithms.
[ { "created": "Wed, 26 Aug 2015 20:12:00 GMT", "version": "v1" }, { "created": "Mon, 9 May 2016 20:27:45 GMT", "version": "v2" } ]
2016-05-18
[ [ "Becher", "Thomas", "" ], [ "Neubert", "Matthias", "" ], [ "Rothen", "Lorena", "" ], [ "Shao", "Ding Yu", "" ] ]
Processes involving narrow jets receive perturbative corrections enhanced by logarithms of the jet opening angle and the ratio of the energies inside and outside the jets. Analyzing cone-jet processes in effective field theory, we find that in addition to soft and collinear fields their description requires degrees of freedom which are simultaneously soft and collinear to the jets. These collinear-soft particles can resolve individual collinear partons, leading to a complicated multi-Wilson-line structure of the associated operators at higher orders. Our effective field theory provides, for the first time, a factorization formula for a cone-jet process, which fully separates the physics at different energy scales. Its renormalization-group equations control all logarithmically enhanced higher-order terms, in particular also the non-global logarithms.
0704.1991
Ingo Schienbein
E. A. Paschos, I. Schienbein, J.-Y. Yu
Single pion electro-- and neutrinoproduction on heavy targets
21 pages, 8 figures
null
null
DO-TH-07-05,LPSC-07-29,SMU-HEP-07-07
hep-ph
null
We present a calculation of single pion electroproduction cross sections on heavy targets in the kinematic region of the Delta(1232) resonance. Final state interactions of the pions are taken into account using the pion multiple scattering model of Adler, Nussinov and Paschos (ANP model). For electroproduction and neutral current reactions we obtain results for carbon, oxygen, argon and iron targets and find a significant reduction of the W-spectra for pi^0 as compared to the free nucleon case. On the other hand, the charged pion spectra are only little affected by final state interactions. Measurements of such cross sections with the CLAS detector at JLAB could help to improve our understanding of pion rescattering effects and serve as important/valuable input for calculations of single pion neutrinoproduction on heavy targets relevant for current and future long baseline neutrino experiments. Two ratios, in Eq. (3.8) and (3.10), will test important properties of the model.
[ { "created": "Mon, 16 Apr 2007 12:35:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Paschos", "E. A.", "" ], [ "Schienbein", "I.", "" ], [ "Yu", "J. -Y.", "" ] ]
We present a calculation of single pion electroproduction cross sections on heavy targets in the kinematic region of the Delta(1232) resonance. Final state interactions of the pions are taken into account using the pion multiple scattering model of Adler, Nussinov and Paschos (ANP model). For electroproduction and neutral current reactions we obtain results for carbon, oxygen, argon and iron targets and find a significant reduction of the W-spectra for pi^0 as compared to the free nucleon case. On the other hand, the charged pion spectra are only little affected by final state interactions. Measurements of such cross sections with the CLAS detector at JLAB could help to improve our understanding of pion rescattering effects and serve as important/valuable input for calculations of single pion neutrinoproduction on heavy targets relevant for current and future long baseline neutrino experiments. Two ratios, in Eq. (3.8) and (3.10), will test important properties of the model.
1904.11035
Alessandro D.A.M. Spallicci di Filottrano
Jos\'e A. Helay\"el-Neto, Alessandro D.A.M. Spallicci
Frequency variation for in vacuo photon propagation in the Standard-Model Extension
To appear as a letter in Eur. Phys. J. C. The paper proposes a new shift to be superposed to the cosmological redshift
2019, Eur. Phys. J. C, 79, 590 in final form
10.1140/epjc/s10052-019-7105-9
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the presence of Lorentz Symmetry Violation (LSV) associated with the Standard-Model Extension (SME), we have recently shown the non-conservation of the energy-momentum tensor of a light-wave crossing an Electro-Magnetic (EM) background field even when the latter and the LSV are constant. Incidentally, for a space-time dependent LSV, the presence of an EM field is not necessary. Herein, we infer that in a particle description, the energy non-conservation for a photon implies violation of frequency invariance in vacuo giving rise to a red or blue shift. We discuss the potential consequences on cosmology.
[ { "created": "Wed, 24 Apr 2019 19:38:17 GMT", "version": "v1" }, { "created": "Wed, 3 Jul 2019 08:52:26 GMT", "version": "v2" } ]
2019-07-16
[ [ "Helayël-Neto", "José A.", "" ], [ "Spallicci", "Alessandro D. A. M.", "" ] ]
In the presence of Lorentz Symmetry Violation (LSV) associated with the Standard-Model Extension (SME), we have recently shown the non-conservation of the energy-momentum tensor of a light-wave crossing an Electro-Magnetic (EM) background field even when the latter and the LSV are constant. Incidentally, for a space-time dependent LSV, the presence of an EM field is not necessary. Herein, we infer that in a particle description, the energy non-conservation for a photon implies violation of frequency invariance in vacuo giving rise to a red or blue shift. We discuss the potential consequences on cosmology.
1903.07590
Matheus Hostert
Peter Ballett, Matheus Hostert and Silvia Pascoli
Neutrino Masses from a Dark Neutrino Sector below the Electroweak Scale
7 pages, 2 figures, matches published version
Phys. Rev. D 99, 091701 (2019)
10.1103/PhysRevD.99.091701
IPPP/19/21
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a minimal extension of the Standard Model which advocates a dark neutrino sector charged under a hidden $U(1)^\prime$. We show that neutrino masses can arise radiatively in this model. The observed values are compatible with a light dark sector below the electroweak scale and would imply new heavy fermions which may be testable in the next generation of beam dump searches at DUNE, NA62 and SHIP.
[ { "created": "Mon, 18 Mar 2019 17:31:32 GMT", "version": "v1" }, { "created": "Fri, 7 Jun 2019 14:58:01 GMT", "version": "v2" } ]
2019-06-10
[ [ "Ballett", "Peter", "" ], [ "Hostert", "Matheus", "" ], [ "Pascoli", "Silvia", "" ] ]
We consider a minimal extension of the Standard Model which advocates a dark neutrino sector charged under a hidden $U(1)^\prime$. We show that neutrino masses can arise radiatively in this model. The observed values are compatible with a light dark sector below the electroweak scale and would imply new heavy fermions which may be testable in the next generation of beam dump searches at DUNE, NA62 and SHIP.
hep-ph/0202097
Gautam Dutta
G. Dutta
Can radiative correction cause large neutrino mixing?
corrected references and minor changes in text
null
null
null
hep-ph
null
We investigate whether radiative corrections can be responsible for the generation of large mixing in a pair of degenerate neutrino with same CP parity. We find that this mechanism is fine tuned and doesn't work for arbitrary mixing at the high scale.
[ { "created": "Mon, 11 Feb 2002 12:40:53 GMT", "version": "v1" }, { "created": "Thu, 28 Feb 2002 11:07:07 GMT", "version": "v2" }, { "created": "Fri, 19 Apr 2002 12:53:41 GMT", "version": "v3" } ]
2007-05-23
[ [ "Dutta", "G.", "" ] ]
We investigate whether radiative corrections can be responsible for the generation of large mixing in a pair of degenerate neutrino with same CP parity. We find that this mechanism is fine tuned and doesn't work for arbitrary mixing at the high scale.
1309.0831
Rodolfo A. Diaz
Andres Castillo, Rodolfo A. Diaz, John Morales
Unitarity constraints for Yukawa couplings in the two Higgs doublet model type III
14 pages, 2 figures, LaTeX2e
Int. J. Mod Phys A. Vol. 29, No. 18 (2014) 1450085
10.1142/S0217751X14500857
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Unitarity constraints for Yukawa couplings are considered in the Two Higgs Doublet Model type III, by using a general expansion in partial waves for fermionic scattering processes. Constraints over general Flavor Changing Neutral Currents are found from that systematic, such bounds compete with those coming from Lagrangian perturbativity requirement but are weaker than those imposed from phenomenological processes and precision tests. Nevertheless, for bounds based on unitarity the number of assumptions is the lowest among phenomenological and theoretical limits. Indeed, these new theoretical constraints are independent of scalar masses or mixing angles for this extended Higgs sector, making them less model dependent.
[ { "created": "Tue, 3 Sep 2013 20:22:08 GMT", "version": "v1" } ]
2014-08-07
[ [ "Castillo", "Andres", "" ], [ "Diaz", "Rodolfo A.", "" ], [ "Morales", "John", "" ] ]
Unitarity constraints for Yukawa couplings are considered in the Two Higgs Doublet Model type III, by using a general expansion in partial waves for fermionic scattering processes. Constraints over general Flavor Changing Neutral Currents are found from that systematic, such bounds compete with those coming from Lagrangian perturbativity requirement but are weaker than those imposed from phenomenological processes and precision tests. Nevertheless, for bounds based on unitarity the number of assumptions is the lowest among phenomenological and theoretical limits. Indeed, these new theoretical constraints are independent of scalar masses or mixing angles for this extended Higgs sector, making them less model dependent.
hep-ph/0401189
Marco Peloso
Lev Kofman, Johannes Martin and Marco Peloso
Exact identification of the radion and its coupling to the observable sector
20 pages, 6 figures
Phys.Rev. D70 (2004) 085015
10.1103/PhysRevD.70.085015
null
hep-ph astro-ph gr-qc hep-th
null
Braneworld models in extra dimensions can be tested in laboratory by the coupling of the radion to the Standard Model fields. The identification of the radion as a canonically normalized field involves a careful General Relativity treatment: if a bulk scalar is responsible for the stabilization of the system, its fluctuations are entangled with the perturbations of the metric and they also have to be taken into account (similarly to the well-developed theory of scalar metric perturbations in 4D cosmology with a scalar field). Extracting a proper dynamical variable in a warped geometry/scalar setting is a nontrivial task, performed so far only in the limit of negligible backreaction of the scalar field on the background geometry. We perform the general calculation, diagonalizing the action up to second order in the perturbations and identifying the physical eigenmodes of the system for any amplitude of the bulk scalar. This computation allows us to derive a very simple expression for the exact coupling of the eigenmodes to the Standard Model fields on the brane, valid for an arbitrary background configuration. As an application, we discuss the Goldberger-Wise mechanism for the stabilization of the radion in the Randall-Sundrum type models. The existing studies, limited to small amplitude of the bulk scalar field, are characterized by a radion mass which is significantly below the physical scale at the observable brane. We extend them beyond the small backreaction regime. For intermediate amplitudes, the radion mass approaches the electroweak scale, while its coupling to the observable brane remains nearly constant. At very high amplitudes, the radion mass instead decreases, while the coupling sharply increases. Severe experimental constraints are expected in this regime.
[ { "created": "Mon, 26 Jan 2004 20:36:57 GMT", "version": "v1" } ]
2009-11-10
[ [ "Kofman", "Lev", "" ], [ "Martin", "Johannes", "" ], [ "Peloso", "Marco", "" ] ]
Braneworld models in extra dimensions can be tested in laboratory by the coupling of the radion to the Standard Model fields. The identification of the radion as a canonically normalized field involves a careful General Relativity treatment: if a bulk scalar is responsible for the stabilization of the system, its fluctuations are entangled with the perturbations of the metric and they also have to be taken into account (similarly to the well-developed theory of scalar metric perturbations in 4D cosmology with a scalar field). Extracting a proper dynamical variable in a warped geometry/scalar setting is a nontrivial task, performed so far only in the limit of negligible backreaction of the scalar field on the background geometry. We perform the general calculation, diagonalizing the action up to second order in the perturbations and identifying the physical eigenmodes of the system for any amplitude of the bulk scalar. This computation allows us to derive a very simple expression for the exact coupling of the eigenmodes to the Standard Model fields on the brane, valid for an arbitrary background configuration. As an application, we discuss the Goldberger-Wise mechanism for the stabilization of the radion in the Randall-Sundrum type models. The existing studies, limited to small amplitude of the bulk scalar field, are characterized by a radion mass which is significantly below the physical scale at the observable brane. We extend them beyond the small backreaction regime. For intermediate amplitudes, the radion mass approaches the electroweak scale, while its coupling to the observable brane remains nearly constant. At very high amplitudes, the radion mass instead decreases, while the coupling sharply increases. Severe experimental constraints are expected in this regime.
1106.0479
Biplab Dey
Biplab Dey, Curtis A. Meyer
Normalization discrepancies in photoproduction reactions
This expands upon a talk given at NSTAR'11. It is also a preliminary draft only
null
null
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent CLAS photoproduction results using a tagged bremsstrahlung photon beam for the ground-state pseudoscalar meson photoproduction channels ($K^+ \Lambda$, $K^+ \Sigma^0$, $\eta p$, $\pi^+ n$ and $\pi^0 p$) show a normalization discrepancy with older results from SLAC, DESY and CEA that used an untagged bremsstrahlung beam. The CLAS results are roughly a factor of two smaller than the older data. The CLAS $K^+\Lambda$ and $K^+\Sigma^0$ results are in excellent agreement with the latest LEPS results that also employed a tagged beam. For the vector meson ($\omega p$ and $\phi p$) channels, CLAS agrees with SLAC results that employed a linearly polarized beam using laser back-scattering, as well as Daresbury data that also came from tagged photon experiment. We perform a global survey of these normalization issues and stress on their significant effect on the coupling constants used in various partial wave analyses.
[ { "created": "Thu, 2 Jun 2011 18:18:38 GMT", "version": "v1" } ]
2011-06-03
[ [ "Dey", "Biplab", "" ], [ "Meyer", "Curtis A.", "" ] ]
Recent CLAS photoproduction results using a tagged bremsstrahlung photon beam for the ground-state pseudoscalar meson photoproduction channels ($K^+ \Lambda$, $K^+ \Sigma^0$, $\eta p$, $\pi^+ n$ and $\pi^0 p$) show a normalization discrepancy with older results from SLAC, DESY and CEA that used an untagged bremsstrahlung beam. The CLAS results are roughly a factor of two smaller than the older data. The CLAS $K^+\Lambda$ and $K^+\Sigma^0$ results are in excellent agreement with the latest LEPS results that also employed a tagged beam. For the vector meson ($\omega p$ and $\phi p$) channels, CLAS agrees with SLAC results that employed a linearly polarized beam using laser back-scattering, as well as Daresbury data that also came from tagged photon experiment. We perform a global survey of these normalization issues and stress on their significant effect on the coupling constants used in various partial wave analyses.
1810.10017
Yi-Ming Zhong
Martin Schmaltz, Yi-Ming Zhong
The Leptoquark Hunter's Guide: Large Coupling
33 pages + references, 15 figures, 9 tables, v2: references added
null
10.1007/JHEP01(2019)132
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Leptoquarks have recently received much attention especially because they may provide an explanation to the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ anomalies in rare $B$ meson decays. In a previous paper we proposed a systematic search strategy for all possible leptoquark flavors by focusing on leptoquark pair production. In this paper, we extend this strategy to large (order unity) leptoquark couplings which offer new search opportunities: single leptoquark production and $t$-channel leptoquark exchange with dilepton final states. We discuss the unique features of the different search channels and show that they cover complementary regions of parameter space. We collect and update all currently available bounds for the different flavor final states from LHC searches and from atomic parity violation measurements. As an application of our analysis, we find that current limits do not exclude the leptoquark explanation of the $B$ physics anomalies but that the high luminosity run of the LHC will reach the most interesting parameter space.
[ { "created": "Tue, 23 Oct 2018 18:00:01 GMT", "version": "v1" }, { "created": "Fri, 2 Nov 2018 19:11:19 GMT", "version": "v2" } ]
2019-02-20
[ [ "Schmaltz", "Martin", "" ], [ "Zhong", "Yi-Ming", "" ] ]
Leptoquarks have recently received much attention especially because they may provide an explanation to the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ anomalies in rare $B$ meson decays. In a previous paper we proposed a systematic search strategy for all possible leptoquark flavors by focusing on leptoquark pair production. In this paper, we extend this strategy to large (order unity) leptoquark couplings which offer new search opportunities: single leptoquark production and $t$-channel leptoquark exchange with dilepton final states. We discuss the unique features of the different search channels and show that they cover complementary regions of parameter space. We collect and update all currently available bounds for the different flavor final states from LHC searches and from atomic parity violation measurements. As an application of our analysis, we find that current limits do not exclude the leptoquark explanation of the $B$ physics anomalies but that the high luminosity run of the LHC will reach the most interesting parameter space.
1301.1695
Giulia Zanderighi
Barbara Jager and Giulia Zanderighi
Electroweak W+W-jj prodution at NLO in QCD matched with parton shower in the POWHEG-BOX
17 pages, 8 figures
null
10.1007/JHEP04(2013)024
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an implementation of electroweak W+W-jj production at hadron colliders in the POWHEG framework, a method that allows the interfacing of a next-to-leading order QCD calculation with parton shower Monte Carlo programs. We provide results for both, fully and semi-leptonic decay modes of the weak bosons, taking resonant and non-resonant contributions and spin correlations of the final-state particles into account. To illustrate the versatility of our implementation, we provide phenomenological results for two representative scenarios with a light and with a heavy Higgs boson, respectively, and in a kinematic regime of highly boosted gauge bosons. The impact of the parton shower is found to depend on the setup and the observable under investigation. In particular, distributions related to a central-jet veto are more sensitive to these effects. Therefore the impact of radiation by the parton shower on next-to-leading order predictions should be assessed carefully on a case-by-case basis.
[ { "created": "Tue, 8 Jan 2013 21:10:51 GMT", "version": "v1" } ]
2015-06-12
[ [ "Jager", "Barbara", "" ], [ "Zanderighi", "Giulia", "" ] ]
We present an implementation of electroweak W+W-jj production at hadron colliders in the POWHEG framework, a method that allows the interfacing of a next-to-leading order QCD calculation with parton shower Monte Carlo programs. We provide results for both, fully and semi-leptonic decay modes of the weak bosons, taking resonant and non-resonant contributions and spin correlations of the final-state particles into account. To illustrate the versatility of our implementation, we provide phenomenological results for two representative scenarios with a light and with a heavy Higgs boson, respectively, and in a kinematic regime of highly boosted gauge bosons. The impact of the parton shower is found to depend on the setup and the observable under investigation. In particular, distributions related to a central-jet veto are more sensitive to these effects. Therefore the impact of radiation by the parton shower on next-to-leading order predictions should be assessed carefully on a case-by-case basis.
2108.06550
Yao Fu
Siqi Yang, Yao Fu, Minghui Liu, Renyou Zhang, Tie-Jiun Hou, Chen Wang, Hang Yin, Liang Han, C.--P. Yuan
Reduction of the electroweak correlation in the PDF updating by using the forward-backward asymmetry of Drell-Yan process
null
null
10.1140/epjc/s10052-022-10280-6
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a new observable for the measurement of the forward-backward asymmetry $(A_{FB})$ in Drell-Yan lepton production. At hadron colliders, the $A_{FB}$ distribution is sensitive to both the electroweak (EW) fundamental parameter $\sin^2 \theta_{W}$, the weak mixing angle, and the parton distribution functions (PDFs). Hence, the determination of $\sin^2 \theta_{W}$ and the updating of PDFs by directly using the same $A_{FB}$ spectrum are strongly correlated. This correlation would introduce large bias or uncertainty into both precise measurements of EW and PDF sectors. In this article, we show that the sensitivity of $A_{FB}$ on $\sin^2 \theta_{W}$ is dominated by its average value around the $Z$ pole region, while the shape (or gradient) of the $A_{FB}$ spectrum is insensitive to $\sin^2 \theta_{W}$ and contains important information on the PDF modeling. Accordingly, a new observable related to the gradient of the spectrum is introduced, and demonstrated to be able to significantly reduce the potential bias on the determination of $\sin^2 \theta_{W}$ when updating the PDFs using the same $A_{FB}$ data.
[ { "created": "Sat, 14 Aug 2021 14:29:50 GMT", "version": "v1" }, { "created": "Fri, 12 Nov 2021 08:44:52 GMT", "version": "v2" } ]
2022-05-11
[ [ "Yang", "Siqi", "" ], [ "Fu", "Yao", "" ], [ "Liu", "Minghui", "" ], [ "Zhang", "Renyou", "" ], [ "Hou", "Tie-Jiun", "" ], [ "Wang", "Chen", "" ], [ "Yin", "Hang", "" ], [ "Han", "Liang", "" ], [ "Yuan", "C. --P.", "" ] ]
We propose a new observable for the measurement of the forward-backward asymmetry $(A_{FB})$ in Drell-Yan lepton production. At hadron colliders, the $A_{FB}$ distribution is sensitive to both the electroweak (EW) fundamental parameter $\sin^2 \theta_{W}$, the weak mixing angle, and the parton distribution functions (PDFs). Hence, the determination of $\sin^2 \theta_{W}$ and the updating of PDFs by directly using the same $A_{FB}$ spectrum are strongly correlated. This correlation would introduce large bias or uncertainty into both precise measurements of EW and PDF sectors. In this article, we show that the sensitivity of $A_{FB}$ on $\sin^2 \theta_{W}$ is dominated by its average value around the $Z$ pole region, while the shape (or gradient) of the $A_{FB}$ spectrum is insensitive to $\sin^2 \theta_{W}$ and contains important information on the PDF modeling. Accordingly, a new observable related to the gradient of the spectrum is introduced, and demonstrated to be able to significantly reduce the potential bias on the determination of $\sin^2 \theta_{W}$ when updating the PDFs using the same $A_{FB}$ data.
1109.6354
Argyris Nicolaidis
A. Nicolaidis
Neutrino Shortcuts in Spacetime
To appear in Mod. Phys. Lett. A 2012
null
10.1142/S0217732312501271
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Theories with large extra dimensions may be tested using sterile neutrinos living in the bulk. A bulk neutrino can mix with a flavor neutrino localized in the brane leading to unconventional patterns of neutrino oscillations. A resonance phenomenon, strong mixing between the flavor and the sterile neutrino, allows to determine the radius of the large extra dimension. If our brane is curved, then the sterile neutrino can take a shortcut through the bulk, leading to an apparent superluminal neutrino speed. The amount of "superluminality" is directly connected to parameters determining the shape of the brane. On the experimental side, we suggest that a long baseline neutrino beam from CERN to NESTOR neutrino telescope will help to clarify these important issues.
[ { "created": "Wed, 28 Sep 2011 20:51:29 GMT", "version": "v1" }, { "created": "Fri, 18 Nov 2011 18:32:09 GMT", "version": "v2" }, { "created": "Tue, 13 Dec 2011 16:07:31 GMT", "version": "v3" }, { "created": "Tue, 3 Jul 2012 11:24:58 GMT", "version": "v4" } ]
2016-11-27
[ [ "Nicolaidis", "A.", "" ] ]
Theories with large extra dimensions may be tested using sterile neutrinos living in the bulk. A bulk neutrino can mix with a flavor neutrino localized in the brane leading to unconventional patterns of neutrino oscillations. A resonance phenomenon, strong mixing between the flavor and the sterile neutrino, allows to determine the radius of the large extra dimension. If our brane is curved, then the sterile neutrino can take a shortcut through the bulk, leading to an apparent superluminal neutrino speed. The amount of "superluminality" is directly connected to parameters determining the shape of the brane. On the experimental side, we suggest that a long baseline neutrino beam from CERN to NESTOR neutrino telescope will help to clarify these important issues.
1403.3144
Qingguo Zeng
Qing-Guo Zeng, Shuo Yang, Chong-Xing Yue, You Yu
Associated production of the heavy charged gauge boson ${W_{H}}$ and a top quark at LHC
16 pages, 6 figures
null
10.1209/0295-5075/107/41002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the context of topflavor seesaw model, we study the production of the heavy charged gauge boson ${W_{H}}$ associated with a top quark at the LHC. Focusing on the searching channel $pp\rightarrow tW_H\rightarrow t\bar{t}b \rightarrow l\nu jjbbb$, we carry out a full simulation of the signal and the relevant standard model backgrounds. The kinematical distributions of final states are presented. It is found that the backgrounds can be significantly suppressed by sets of kinematic cuts, and the signal of the heavy charged boson might be detected at the LHC with $\sqrt{s}=14$ TeV. With a integrated luminosity of $\LL= $ 100 $fb^{-1}$, a $8.3 \sigma$ signal significance can be achieved for $m_{W_H}=1.6$ TeV.
[ { "created": "Thu, 13 Mar 2014 01:13:42 GMT", "version": "v1" } ]
2015-06-19
[ [ "Zeng", "Qing-Guo", "" ], [ "Yang", "Shuo", "" ], [ "Yue", "Chong-Xing", "" ], [ "Yu", "You", "" ] ]
In the context of topflavor seesaw model, we study the production of the heavy charged gauge boson ${W_{H}}$ associated with a top quark at the LHC. Focusing on the searching channel $pp\rightarrow tW_H\rightarrow t\bar{t}b \rightarrow l\nu jjbbb$, we carry out a full simulation of the signal and the relevant standard model backgrounds. The kinematical distributions of final states are presented. It is found that the backgrounds can be significantly suppressed by sets of kinematic cuts, and the signal of the heavy charged boson might be detected at the LHC with $\sqrt{s}=14$ TeV. With a integrated luminosity of $\LL= $ 100 $fb^{-1}$, a $8.3 \sigma$ signal significance can be achieved for $m_{W_H}=1.6$ TeV.
hep-ph/9704258
Csaba Balazs
C. Balazs and C.-P. Yuan
Soft gluon effects on lepton pairs at hadron colliders
50 pages, REVTeX, 16 figures (27 eps files)
Phys.Rev. D56 (1997) 5558-5583
10.1103/PhysRevD.56.5558
MSUHEP-70402, CTEQ-704
hep-ph
null
With a large integrated luminosity expected at the Tevatron, a next-to-leading order (NLO) calculation is no longer sufficient to describe the data which yield the precision measurement of $M_W$, etc. Thus, we extend the Collins-Soper-Sterman resummation formalism, for on-shell vector boson production, to correctly include the effects of the polarization and the width of the vector boson to the distributions of the decay leptons. We show how to test the rich dynamics of the QCD multiple soft gluon radiation, for example, by measuring the ratio $R_{CSS} \equiv \frac{\sigma (Q_T>Q_T^{\min})}{\sigma _{Total}}$. ($Q_T$ is the transverse momentum of the vector boson.) We conclude that both the total rates and the distributions of the lepton charge asymmetry predicted by the resummed and the NLO calculations are different when kinematic cuts are applied.
[ { "created": "Tue, 8 Apr 1997 22:58:56 GMT", "version": "v1" } ]
2009-10-30
[ [ "Balazs", "C.", "" ], [ "Yuan", "C. -P.", "" ] ]
With a large integrated luminosity expected at the Tevatron, a next-to-leading order (NLO) calculation is no longer sufficient to describe the data which yield the precision measurement of $M_W$, etc. Thus, we extend the Collins-Soper-Sterman resummation formalism, for on-shell vector boson production, to correctly include the effects of the polarization and the width of the vector boson to the distributions of the decay leptons. We show how to test the rich dynamics of the QCD multiple soft gluon radiation, for example, by measuring the ratio $R_{CSS} \equiv \frac{\sigma (Q_T>Q_T^{\min})}{\sigma _{Total}}$. ($Q_T$ is the transverse momentum of the vector boson.) We conclude that both the total rates and the distributions of the lepton charge asymmetry predicted by the resummed and the NLO calculations are different when kinematic cuts are applied.
hep-ph/0209185
Marcus Mauser
H.S. Do, S. Groote, J.G. K\"orner, M.C. Mauser
Electroweak and finite width corrections to top quark decays into transverse and longitudinal $ W $-bosons
4 pages, 7 postscript figures added
Phys.Rev.D67:091501,2003
10.1103/PhysRevD.67.091501
MZ-TH/01-03
hep-ph
null
We calculate the electroweak and finite width corrections to the decay of an unpolarized top quark into a bottom quark and a $ W $-gauge boson where the helicities of the $ W $ are specified as longitudinal, transverse-plus and transverse-minus. Together with the $ O(\alpha_s) $ corrections these corrections may become relevant for the determination of the mass of the top quark through angular decay measurements.
[ { "created": "Tue, 17 Sep 2002 10:36:05 GMT", "version": "v1" }, { "created": "Mon, 30 Sep 2002 08:19:12 GMT", "version": "v2" } ]
2011-03-23
[ [ "Do", "H. S.", "" ], [ "Groote", "S.", "" ], [ "Körner", "J. G.", "" ], [ "Mauser", "M. C.", "" ] ]
We calculate the electroweak and finite width corrections to the decay of an unpolarized top quark into a bottom quark and a $ W $-gauge boson where the helicities of the $ W $ are specified as longitudinal, transverse-plus and transverse-minus. Together with the $ O(\alpha_s) $ corrections these corrections may become relevant for the determination of the mass of the top quark through angular decay measurements.
1502.04199
Victor Ilisie
Victor Ilisie
New Barr-Zee contributions to $\mathbf{(g-2)_\mu}$ in two-Higgs-doublet models
28 pages, 17 figures. Typos corrected. Matches JHEP version. arXiv admin note: text overlap with arXiv:1210.8443 by other authors
JHEP 04 (2015) 077
10.1007/JHEP04(2015)077
FTUV/15-0213, IFIC/15-09
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the contribution of new sets of two-loop Barr-Zee type diagrams to the anomalous magnetic moment of the muon within the two-Higgs-doublet model framework. We show that some of these contributions can be quite sizeable for a large region of the parameter space and can significantly reduce, and in some cases even explain, the discrepancy between the theoretical prediction and the experimentally measured value of this observable. Analytical expressions are given for all the calculations performed in this work.
[ { "created": "Sat, 14 Feb 2015 12:07:38 GMT", "version": "v1" }, { "created": "Mon, 23 Feb 2015 09:45:47 GMT", "version": "v2" }, { "created": "Mon, 18 May 2015 13:54:08 GMT", "version": "v3" } ]
2015-05-19
[ [ "Ilisie", "Victor", "" ] ]
We study the contribution of new sets of two-loop Barr-Zee type diagrams to the anomalous magnetic moment of the muon within the two-Higgs-doublet model framework. We show that some of these contributions can be quite sizeable for a large region of the parameter space and can significantly reduce, and in some cases even explain, the discrepancy between the theoretical prediction and the experimentally measured value of this observable. Analytical expressions are given for all the calculations performed in this work.
1202.6012
Kuang-Ta Chao
Kai Wang, Yan-Qing Ma, Kuang-Ta Chao
$\Upsilon(1S)$ prompt production at the Tevatron and LHC in nonrelativistic QCD
Version published in PRD, references added, 15 pages, 3 figures
Phys. Rev. D85, 114003 (2012)
10.1103/PhysRevD.85.114003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With nonrelativistic QCD factorization, we calculate the $\Upsilon(1S)$ prompt production at hadron colliders at next-to-leading order in $\alpha_s$. In addition to the color-singlet contribution, color-octet channels (especially the P-wave channel) up to $O(v^4)$ are all considered. Aside from direct production, the feed-down contributions from higher excited S-wave and P-wave $b\bar b$ states to $\Upsilon(1S)$ production are also included. We use the potential model estimates as input for color-singlet long-distance matrix elements (LDMEs). While for color-octet contributions, we find they can be approximately described by three LDMEs: $\mo{}{3}{S}{1}{8}$, $\mo{}{1}{S}{0}{8}$ and $\mo{}{3}{P}{0}{8}$. By fitting the Tevatron data we can determine some linear combinations of these LDMEs, and then use them to predict $\Upsilon(1S)$ production at the LHC. Our predictions are consistent with the new experimental data of CMS and LHCb.
[ { "created": "Mon, 27 Feb 2012 18:03:10 GMT", "version": "v1" }, { "created": "Mon, 18 Jun 2012 18:29:08 GMT", "version": "v2" } ]
2015-06-04
[ [ "Wang", "Kai", "" ], [ "Ma", "Yan-Qing", "" ], [ "Chao", "Kuang-Ta", "" ] ]
With nonrelativistic QCD factorization, we calculate the $\Upsilon(1S)$ prompt production at hadron colliders at next-to-leading order in $\alpha_s$. In addition to the color-singlet contribution, color-octet channels (especially the P-wave channel) up to $O(v^4)$ are all considered. Aside from direct production, the feed-down contributions from higher excited S-wave and P-wave $b\bar b$ states to $\Upsilon(1S)$ production are also included. We use the potential model estimates as input for color-singlet long-distance matrix elements (LDMEs). While for color-octet contributions, we find they can be approximately described by three LDMEs: $\mo{}{3}{S}{1}{8}$, $\mo{}{1}{S}{0}{8}$ and $\mo{}{3}{P}{0}{8}$. By fitting the Tevatron data we can determine some linear combinations of these LDMEs, and then use them to predict $\Upsilon(1S)$ production at the LHC. Our predictions are consistent with the new experimental data of CMS and LHCb.
1012.0102
Pyungwon Ko
Dong-won Jung, P. Ko, Jae Sik Lee and Soo-hyeon Nam
Model-independent analysis of forward-backward asymmetry of top quark production at the Tevatron
Prepared for the proceedings of Blois Conference and ICHEP 2010
PoS ICHEP2010:397,2010
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a model independent analysis on $q \bar{q} \rightarrow t \bar{t}$ using an effective lagrangian with dim-6 four-quark operators, and derive necessary conditions on new physics that are consistent with the $t\bar{t}$ production cross section %($\sigma_{t\bar{t}}$) and and the forward-backward (FB) asymmetry ($A_{\rm FB}$) measured at the Tevatron. We also propose a new FB spin-spin correlation that is strongly correlated with the $A_{\rm FB}$, and discuss possible new physics scenarios that could generate such dim-6 operators.
[ { "created": "Wed, 1 Dec 2010 05:58:15 GMT", "version": "v1" } ]
2011-09-08
[ [ "Jung", "Dong-won", "" ], [ "Ko", "P.", "" ], [ "Lee", "Jae Sik", "" ], [ "Nam", "Soo-hyeon", "" ] ]
We perform a model independent analysis on $q \bar{q} \rightarrow t \bar{t}$ using an effective lagrangian with dim-6 four-quark operators, and derive necessary conditions on new physics that are consistent with the $t\bar{t}$ production cross section %($\sigma_{t\bar{t}}$) and and the forward-backward (FB) asymmetry ($A_{\rm FB}$) measured at the Tevatron. We also propose a new FB spin-spin correlation that is strongly correlated with the $A_{\rm FB}$, and discuss possible new physics scenarios that could generate such dim-6 operators.
1405.3987
Antonio Racioppi
Kristjan Kannike, Antonio Racioppi, Martti Raidal
Embedding inflation into the Standard Model - more evidence for classical scale invariance
20 pages, 6 figures, revised version published on JHEP
JHEP 1406 (2014) 154
10.1007/JHEP06(2014)154
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
If cosmological inflation is due to a slowly rolling single inflation field taking trans-Planckian values as suggested by the BICEP2 measurement of primordial tensor modes in CMB, embedding inflation into the Standard Model challenges standard paradigm of effective field theories. Together with an apparent absence of Planck scale contributions to the Higgs mass and to the cosmological constant, BICEP2 provides further experimental evidence for the absence of large $M_{\rm P}$ induced operators. We show that classical scale invariance, the paradigm that all fundamental scales in Nature are induced by quantum effects, solves the problem and allows for a remarkably simple scale-free Standard Model extension with inflaton without extending the gauge group. Due to trans-Planckian inflaton values and vevs, a dynamically induced Coleman-Weinberg-type inflaton potential of the model can predict tensor-to-scalar ratio $r$ in a large range, converging around the prediction of chaotic $m^2\phi^2$ inflation for a large trans-Planckian value of the inflaton vev. Precise determination of $r$ in future experiments will single out a unique scale-free inflation potential, allowing to test the proposed field-theoretic framework.
[ { "created": "Thu, 15 May 2014 20:00:19 GMT", "version": "v1" }, { "created": "Mon, 13 Oct 2014 12:21:09 GMT", "version": "v2" } ]
2014-10-14
[ [ "Kannike", "Kristjan", "" ], [ "Racioppi", "Antonio", "" ], [ "Raidal", "Martti", "" ] ]
If cosmological inflation is due to a slowly rolling single inflation field taking trans-Planckian values as suggested by the BICEP2 measurement of primordial tensor modes in CMB, embedding inflation into the Standard Model challenges standard paradigm of effective field theories. Together with an apparent absence of Planck scale contributions to the Higgs mass and to the cosmological constant, BICEP2 provides further experimental evidence for the absence of large $M_{\rm P}$ induced operators. We show that classical scale invariance, the paradigm that all fundamental scales in Nature are induced by quantum effects, solves the problem and allows for a remarkably simple scale-free Standard Model extension with inflaton without extending the gauge group. Due to trans-Planckian inflaton values and vevs, a dynamically induced Coleman-Weinberg-type inflaton potential of the model can predict tensor-to-scalar ratio $r$ in a large range, converging around the prediction of chaotic $m^2\phi^2$ inflation for a large trans-Planckian value of the inflaton vev. Precise determination of $r$ in future experiments will single out a unique scale-free inflation potential, allowing to test the proposed field-theoretic framework.
hep-ph/9607337
null
Marc Sher
The Coleman-Weinberg Phase Transition in Extended Higgs Models
13 pages, latex, one encoded figure
Phys.Rev. D54 (1996) 7071-7074
10.1103/PhysRevD.54.7071
WM-96-107
hep-ph
null
In Coleman-Weinberg symmetry breaking, all dimensionful parameters vanish and the symmetry is broken by loop corrections. Before Coleman-Weinberg symmetry breaking in the Standard Model was experimentally ruled out, it had already been excluded on cosmological grounds. In this Brief Report, the cosmological analysis is carried out for Coleman-Weinberg models with extended Higgs sectors, which are not experimentally ruled out, and general constraints on such models are given.
[ { "created": "Tue, 16 Jul 1996 14:27:54 GMT", "version": "v1" } ]
2009-10-28
[ [ "Sher", "Marc", "" ] ]
In Coleman-Weinberg symmetry breaking, all dimensionful parameters vanish and the symmetry is broken by loop corrections. Before Coleman-Weinberg symmetry breaking in the Standard Model was experimentally ruled out, it had already been excluded on cosmological grounds. In this Brief Report, the cosmological analysis is carried out for Coleman-Weinberg models with extended Higgs sectors, which are not experimentally ruled out, and general constraints on such models are given.
hep-ph/9611430
Peter Haberl
P. Haberl
CP violating couplings in Z -> 3 jet decays revisited
LaTeX, 11 pages, 4 figures
null
null
HD-THEP-96-16
hep-ph
null
Possible CP violating effects in $Z\rightarrow$ 3 jet decays are investigated. The analysis assumes the presence of CP violating $Zq\bar qG$ couplings. The contribution of these couplings to the $Z\rightarrow q\bar qG$ decay width is calculated for different cut algorithms, including nonzero quark masses. Various CP--odd observables are discussed and it is shown that their sensitivity can change significantly if one uses normalized or unnormalized momentum vectors for their construction. Optimal observables are proposed which allow to measure the new couplings simultaneously.
[ { "created": "Tue, 26 Nov 1996 15:09:25 GMT", "version": "v1" } ]
2007-05-23
[ [ "Haberl", "P.", "" ] ]
Possible CP violating effects in $Z\rightarrow$ 3 jet decays are investigated. The analysis assumes the presence of CP violating $Zq\bar qG$ couplings. The contribution of these couplings to the $Z\rightarrow q\bar qG$ decay width is calculated for different cut algorithms, including nonzero quark masses. Various CP--odd observables are discussed and it is shown that their sensitivity can change significantly if one uses normalized or unnormalized momentum vectors for their construction. Optimal observables are proposed which allow to measure the new couplings simultaneously.
hep-ph/9904215
Jan Kalinowski
Debajyoti Choudhury (Mehta Res. Inst.), Jan Kalinowski (Univ. of Warsaw) and Anna Kulesza (Durham Univ.)
CP-violating Anomalous $WW\gamma$ Couplings in e^+e^- Collisions
13 pages (LaTeX), 5 figures (embedded)
Phys.Lett.B457:193-201,1999
10.1016/S0370-2693(99)00527-4
DTP-99/06, IFT/99-01, MRI-PHY/P990173
hep-ph
null
We investigate the sensitivity of future linear collider experiments to CP violating $WW\gamma$ couplings in the process $e^{+}e^{-} \to \nu\bar{\nu}\gamma$. We consider several sets of machine parameters: centre of mass energies $\sqrt{s}$ = 350, 500 and 800 GeV and operating at different luminosities. From an analysis of the differential cross-section the following 95% C.L. limits $|\tilde{\kappa}_{\gamma}| < 0.18$, $|\tilde{\lambda}_{\gamma}| < 0.069$ are estimated to be obtained at a future 500 GeV LC with an integrated luminosity of $125 \fb^{-1}$, a great improvement as compared to the LEP2 reach, where a senstitivity of order 2 for both couplings is found.
[ { "created": "Fri, 2 Apr 1999 09:04:48 GMT", "version": "v1" } ]
2014-11-17
[ [ "Choudhury", "Debajyoti", "", "Mehta Res. Inst." ], [ "Kalinowski", "Jan", "", "Univ. of\n Warsaw" ], [ "Kulesza", "Anna", "", "Durham Univ." ] ]
We investigate the sensitivity of future linear collider experiments to CP violating $WW\gamma$ couplings in the process $e^{+}e^{-} \to \nu\bar{\nu}\gamma$. We consider several sets of machine parameters: centre of mass energies $\sqrt{s}$ = 350, 500 and 800 GeV and operating at different luminosities. From an analysis of the differential cross-section the following 95% C.L. limits $|\tilde{\kappa}_{\gamma}| < 0.18$, $|\tilde{\lambda}_{\gamma}| < 0.069$ are estimated to be obtained at a future 500 GeV LC with an integrated luminosity of $125 \fb^{-1}$, a great improvement as compared to the LEP2 reach, where a senstitivity of order 2 for both couplings is found.
hep-ph/0601156
Maxim Dvornikov
Maxim Dvornikov
Evolution of coupled fermions under the influence of an external axial-vector field
RevTeX4, 8 pages, 1 eps figure; revised variant, neutral currents interactions of flavor neutrinos are included, some typos corrected, 1 reference added; accepted for publication in Eur.Phys.J.C
Eur.Phys.J.C47:437-444,2006
10.1140/epjc/s2006-02597-3
HUPD 0603
hep-ph hep-th
null
The evolution of coupled fermions interacting with external axial-vector fields is described with help of the classical field theory. We formulate the initial conditions problem for the system of two coupled fermions in (3+1)-dimensional space-time. This problem is solved using the perturbation theory. We obtain in the explicit form the expressions for the leading and next to the leading order terms in the expansion over the strength of external fields. It is shown that in the relativistic limit the intensity of the fermion field coincides with the transition probability in the two neutrinos system interacting with moving and polarized matter.
[ { "created": "Thu, 19 Jan 2006 11:36:51 GMT", "version": "v1" }, { "created": "Thu, 25 May 2006 08:59:00 GMT", "version": "v2" } ]
2009-01-07
[ [ "Dvornikov", "Maxim", "" ] ]
The evolution of coupled fermions interacting with external axial-vector fields is described with help of the classical field theory. We formulate the initial conditions problem for the system of two coupled fermions in (3+1)-dimensional space-time. This problem is solved using the perturbation theory. We obtain in the explicit form the expressions for the leading and next to the leading order terms in the expansion over the strength of external fields. It is shown that in the relativistic limit the intensity of the fermion field coincides with the transition probability in the two neutrinos system interacting with moving and polarized matter.
2401.10000
Bao-Xi Sun
Bao-Xi Sun, Qin-Qin Cao and Ying-Tai Sun
The possible $K \bar{K}^*$ and $D \bar{D}^*$ bound and resonance states by solving Schrodinger equation
9 pages, 2 tables, 4 figures, to be published in Communications in Theoretical Physics
2024 Commun. Theor. Phys. 76, 105301
10.1088/1572-9494/ad51df
null
hep-ph nucl-th quant-ph
http://creativecommons.org/licenses/by/4.0/
The Schrodinger equation with a Yukawa type of potential is solved analytically. When different boundary conditions are taken into account, a series of solutions are indicated as Bessel function, the first kind of Hankel function and the second kind of Hankel function, respectively. Subsequently, the scattering processes of $K \bar{K}^*$ and $D \bar{ D}^*$ are investigated. In the $K \bar{K}^*$ sector, the $f_1(1285)$ particle is treated as a $K \bar{K}^*$ bound state, therefore, the coupling constant in the $K \bar{K}^*$ Yukawa potential can be fixed according to the binding energy of the $f_1(1285)$ particle. Consequently, a $K \bar{K}^*$ resonance state is generated by solving the Schrodinger equation with the outgoing wave condition, which lie at $1417-i18$MeV on the complex energy plane. It is reasonable to assume that the $K \bar{K}^*$ resonance state at $1417-i18$MeV might correspond to the $f_1(1420)$ particle in the review of Particle Data Group(PDG).In the $D \bar{D}^*$ sector, since the $X(3872)$ particle is almost located at the $D \bar{ D}^*$ threshold, the binding energy of it equals to zero approximately. Therefore, the coupling constant in the $D \bar{ D}^*$ Yukawa potential is determined, which is related to the first zero point of the zero order Bessel function. Similarly to the $K \bar{K}^*$ case, four resonance states are produced as solutions of the Schrodinger equation with the outgoing wave condition. It is assumed that the resonance states at $3885-i1$MeV, $4029-i108$ MeV, $4328-i191$MeV and $4772-i267$MeV might be associated with the $Zc(3900)$, the $X(3940)$, the $\chi_{c1}(4274)$ and $\chi_{c1}(4685)$ particles, respectively. It is noted that all solutions are isospin degenerate.
[ { "created": "Thu, 18 Jan 2024 14:15:46 GMT", "version": "v1" }, { "created": "Sun, 16 Jun 2024 10:54:43 GMT", "version": "v2" } ]
2024-08-08
[ [ "Sun", "Bao-Xi", "" ], [ "Cao", "Qin-Qin", "" ], [ "Sun", "Ying-Tai", "" ] ]
The Schrodinger equation with a Yukawa type of potential is solved analytically. When different boundary conditions are taken into account, a series of solutions are indicated as Bessel function, the first kind of Hankel function and the second kind of Hankel function, respectively. Subsequently, the scattering processes of $K \bar{K}^*$ and $D \bar{ D}^*$ are investigated. In the $K \bar{K}^*$ sector, the $f_1(1285)$ particle is treated as a $K \bar{K}^*$ bound state, therefore, the coupling constant in the $K \bar{K}^*$ Yukawa potential can be fixed according to the binding energy of the $f_1(1285)$ particle. Consequently, a $K \bar{K}^*$ resonance state is generated by solving the Schrodinger equation with the outgoing wave condition, which lie at $1417-i18$MeV on the complex energy plane. It is reasonable to assume that the $K \bar{K}^*$ resonance state at $1417-i18$MeV might correspond to the $f_1(1420)$ particle in the review of Particle Data Group(PDG).In the $D \bar{D}^*$ sector, since the $X(3872)$ particle is almost located at the $D \bar{ D}^*$ threshold, the binding energy of it equals to zero approximately. Therefore, the coupling constant in the $D \bar{ D}^*$ Yukawa potential is determined, which is related to the first zero point of the zero order Bessel function. Similarly to the $K \bar{K}^*$ case, four resonance states are produced as solutions of the Schrodinger equation with the outgoing wave condition. It is assumed that the resonance states at $3885-i1$MeV, $4029-i108$ MeV, $4328-i191$MeV and $4772-i267$MeV might be associated with the $Zc(3900)$, the $X(3940)$, the $\chi_{c1}(4274)$ and $\chi_{c1}(4685)$ particles, respectively. It is noted that all solutions are isospin degenerate.
0706.3399
Iain W. Stewart
Ambar Jain, Ira Z. Rothstein, Iain W. Stewart
Penguin Loops for Nonleptonic B-Decays in the Standard Model: Is there a Penguin Puzzle?
39 pages
null
null
MIT-CTP 3828
hep-ph
null
We compute standard model penguin amplitudes in nonleptonic B-decays to light charmless mesons using tree amplitude data to fix hadronic parameters. The leading calculation is carried out for the alphas(mb) penguin contributions from charm quark, up quark, and magnetic penguin loops in the NDR and HV renormalization schemes. Power suppressed penguins that are proportional to the chiral condensate are also computed using a new factorization formula for these terms, which is derived working to all orders in alphas(sqrt{mb\Lambda}). We demonstrate using SCET1 that this formula exhibits only small perturbative phases and does not have endpoint singularities. Due to our use of data to fix hadronic parameters we obtain significantly more accurate predictions for the short-distance standard model penguin amplitudes than have been found in the past. Analyzing data in B-> pi pi, B->K pi, and B->rho rho for the penguin amplitudes we find that standard model short-distance imaginary parts are an order of magnitude smaller than current measurements, while real parts are up to a factor of two smaller with the correct sign. This difference is most likely a consequence of long-distance charm contributions or new physics. Constraints on the type of new physics that could help explain the data are derived, and used to show that current data favors sizeable long-distance strong phases.
[ { "created": "Mon, 25 Jun 2007 19:53:44 GMT", "version": "v1" }, { "created": "Mon, 16 Jul 2007 21:18:51 GMT", "version": "v2" } ]
2007-07-17
[ [ "Jain", "Ambar", "" ], [ "Rothstein", "Ira Z.", "" ], [ "Stewart", "Iain W.", "" ] ]
We compute standard model penguin amplitudes in nonleptonic B-decays to light charmless mesons using tree amplitude data to fix hadronic parameters. The leading calculation is carried out for the alphas(mb) penguin contributions from charm quark, up quark, and magnetic penguin loops in the NDR and HV renormalization schemes. Power suppressed penguins that are proportional to the chiral condensate are also computed using a new factorization formula for these terms, which is derived working to all orders in alphas(sqrt{mb\Lambda}). We demonstrate using SCET1 that this formula exhibits only small perturbative phases and does not have endpoint singularities. Due to our use of data to fix hadronic parameters we obtain significantly more accurate predictions for the short-distance standard model penguin amplitudes than have been found in the past. Analyzing data in B-> pi pi, B->K pi, and B->rho rho for the penguin amplitudes we find that standard model short-distance imaginary parts are an order of magnitude smaller than current measurements, while real parts are up to a factor of two smaller with the correct sign. This difference is most likely a consequence of long-distance charm contributions or new physics. Constraints on the type of new physics that could help explain the data are derived, and used to show that current data favors sizeable long-distance strong phases.
hep-ph/9611366
Helmut Satz
Helmut Satz
Colour deconfinement in hot and dense matter
11 pages tex, uses macro-hs.tex, 10 figures; talk given at CRIS '96, First Catania Relativistic Ion Studies, Acicastello, Italy, May 27 - 31, 1996; to appear in the Proceedings
null
null
CERN-TH/96-172, BI-TP 96/25
hep-ph nucl-th
null
We first introduce the conceptual basis of critical behaviour in strongly interacting matter, with colour deconfinement as QCD analog of the insulator-conductor transition and chiral symmetry restoration as special case of the associated shift in the mass of the constituents. Next we summarize quark-gluon plasma formation in finite temperature lattice QCD. We consider the underlying symmetries and their spontaneous breaking/restoration in the transition, as well as the resulting changes in thermodynamic behaviour. Finally, we turn to the experimental study of strongly interacting matter by high energy nuclear collisions, using charmonium production to probe the confinement status of the produced primordial medium. Recent results from Pb-Pb collisions at CERN may provide first evidence for colour deconfinement.
[ { "created": "Tue, 19 Nov 1996 17:02:29 GMT", "version": "v1" } ]
2016-09-06
[ [ "Satz", "Helmut", "" ] ]
We first introduce the conceptual basis of critical behaviour in strongly interacting matter, with colour deconfinement as QCD analog of the insulator-conductor transition and chiral symmetry restoration as special case of the associated shift in the mass of the constituents. Next we summarize quark-gluon plasma formation in finite temperature lattice QCD. We consider the underlying symmetries and their spontaneous breaking/restoration in the transition, as well as the resulting changes in thermodynamic behaviour. Finally, we turn to the experimental study of strongly interacting matter by high energy nuclear collisions, using charmonium production to probe the confinement status of the produced primordial medium. Recent results from Pb-Pb collisions at CERN may provide first evidence for colour deconfinement.
0811.1787
Saba Zuberi
Francisco Campanario, Michael Luke, Saba Zuberi
High order perturbative corrections to the determination of |Vub| from the P+ spectrum in B -> Xu l nu
20 pages, 2 figures
Phys.Rev.D79:094007,2009
10.1103/PhysRevD.79.094007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the behaviour of the perturbative relation between the photon energy spectrum in B -> Xs gamma and the hadronic P+ spectrum in semileptonic B -> Xu l nu decay at high orders in perturbation theory in the "large-beta_0" limit, in which only terms of order alpha_s^n beta_0^(n-1) are retained. The leading renormalon in the weight function W(Delta,P_gamma) relating the two spectra is confirmed to be at u=1/2, corresponding to nonperturbative corrections at O(Lambda_QCD/m_b). We show that the P_gamma dependent pieces of the weight function have no infrared renormalons in this limit, and so the factorial growth in perturbation theory arises solely from the constant terms. We find no numerical enhancement of leading logarithms, suggesting that fixed-order perturbation theory is more appropriate than a leading-log resummation for the extraction of |Vub|. The importance of various terms in the expansion of the weight function is studied using a model for the B -> Xs gamma photon spectrum. Our analysis suggests that higher order perturbative corrections do not introduce a significant uncertainty in the extraction of |Vub|.
[ { "created": "Tue, 11 Nov 2008 22:29:22 GMT", "version": "v1" }, { "created": "Fri, 17 Apr 2009 20:02:17 GMT", "version": "v2" } ]
2009-09-02
[ [ "Campanario", "Francisco", "" ], [ "Luke", "Michael", "" ], [ "Zuberi", "Saba", "" ] ]
We investigate the behaviour of the perturbative relation between the photon energy spectrum in B -> Xs gamma and the hadronic P+ spectrum in semileptonic B -> Xu l nu decay at high orders in perturbation theory in the "large-beta_0" limit, in which only terms of order alpha_s^n beta_0^(n-1) are retained. The leading renormalon in the weight function W(Delta,P_gamma) relating the two spectra is confirmed to be at u=1/2, corresponding to nonperturbative corrections at O(Lambda_QCD/m_b). We show that the P_gamma dependent pieces of the weight function have no infrared renormalons in this limit, and so the factorial growth in perturbation theory arises solely from the constant terms. We find no numerical enhancement of leading logarithms, suggesting that fixed-order perturbation theory is more appropriate than a leading-log resummation for the extraction of |Vub|. The importance of various terms in the expansion of the weight function is studied using a model for the B -> Xs gamma photon spectrum. Our analysis suggests that higher order perturbative corrections do not introduce a significant uncertainty in the extraction of |Vub|.
2104.11804
Andreas Ekstedt
Andreas Ekstedt
Higher-Order Corrections to the Bubble-Nucleation Rate at Finite Temperature
Moved several subsections to the appendix. Additional details added in section 2
null
10.1140/epjc/s10052-022-10130-5
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this paper I discuss how to consistently incorporate higher-order corrections to the bubble-nucleation rate at finite temperature. Doing so I examine the merits of different approaches, with the goal of reducing uncertainties for gravitational-wave calculations. To be specific, the region of applicability and accuracy of the derivative expansion is discussed. The derivative expansion is then compared to a numerical implementation of the Gelfand-Yaglom theorem. Both methods are applied to popular first-order phase transition models, like a loop-induced barrier and a SM-EFT tree-level barrier. The results of these calculations are presented in easy-to-use parametrizations that can directly be used in gravitational-wave calculations. In addition, higher-order corrections for models with multiple scalar fields, such as singlet/triplet extensions, are studied. Lastly, the convergence and uncertainty of all calculations are discussed in detail. And I argue that leading-order results for the Standard Model with a tree-level barrier might be inaccurate.
[ { "created": "Fri, 23 Apr 2021 19:59:18 GMT", "version": "v1" }, { "created": "Mon, 28 Feb 2022 12:20:46 GMT", "version": "v2" } ]
2022-03-01
[ [ "Ekstedt", "Andreas", "" ] ]
In this paper I discuss how to consistently incorporate higher-order corrections to the bubble-nucleation rate at finite temperature. Doing so I examine the merits of different approaches, with the goal of reducing uncertainties for gravitational-wave calculations. To be specific, the region of applicability and accuracy of the derivative expansion is discussed. The derivative expansion is then compared to a numerical implementation of the Gelfand-Yaglom theorem. Both methods are applied to popular first-order phase transition models, like a loop-induced barrier and a SM-EFT tree-level barrier. The results of these calculations are presented in easy-to-use parametrizations that can directly be used in gravitational-wave calculations. In addition, higher-order corrections for models with multiple scalar fields, such as singlet/triplet extensions, are studied. Lastly, the convergence and uncertainty of all calculations are discussed in detail. And I argue that leading-order results for the Standard Model with a tree-level barrier might be inaccurate.
hep-ph/0511302
Gavin Salam
Yu. L. Dokshitzer, G. Marchesini and G. P. Salam
Revisiting parton evolution and the large-x limit
6 pages, v2 corrects misprints and contains an additional reference
Phys.Lett.B634:504-507,2006
10.1016/j.physletb.2006.02.023
Bicocca-FT-05-31, LPTHE-05-31
hep-ph
null
This remark is part of an ongoing project to simplify the structure of the multi-loop anomalous dimensions for parton distributions and fragmentation functions. It answers the call for a "structural explanation" of a "very suggestive" relation found by Moch, Vermaseren and Vogt in the context of the x->1 behaviour of three-loop DIS anomalous dimensions. It also highlights further structure that remains to be fully explained.
[ { "created": "Sun, 27 Nov 2005 15:06:41 GMT", "version": "v1" }, { "created": "Tue, 17 Jan 2006 17:23:50 GMT", "version": "v2" } ]
2008-11-26
[ [ "Dokshitzer", "Yu. L.", "" ], [ "Marchesini", "G.", "" ], [ "Salam", "G. P.", "" ] ]
This remark is part of an ongoing project to simplify the structure of the multi-loop anomalous dimensions for parton distributions and fragmentation functions. It answers the call for a "structural explanation" of a "very suggestive" relation found by Moch, Vermaseren and Vogt in the context of the x->1 behaviour of three-loop DIS anomalous dimensions. It also highlights further structure that remains to be fully explained.
hep-ph/0102188
Rohini M. Godbole
Rohini M. Godbole, G. Pancheri
$\sigma^{tot}_{ee \gamma \gamma}$ at $e^+e^-$ colliders}
10 pages, 3 figures, LaTeX, uses aipproc.cls and aipproc.sty. Talk to appear in the proceedings of International Linear Collider Workshop (LCWS) 2000, October 26-30, 2000, Fermilab
null
null
IISc-CTS/03/01, LNF-01/008(P)
hep-ph
null
In this talk I briefly summarize different models for $\sigma^{tot}_{2 \gamma}$ ($e^+e^- \to \gamma \gamma \to$ hadrons) and contrast model predictions with the data. I will then discuss the capability of the future $e^+e^-$ and $\gamma \gamma$ colliders to distinguish between various models and end with an outlook for future work.
[ { "created": "Thu, 15 Feb 2001 14:24:11 GMT", "version": "v1" } ]
2007-05-23
[ [ "Godbole", "Rohini M.", "" ], [ "Pancheri", "G.", "" ] ]
In this talk I briefly summarize different models for $\sigma^{tot}_{2 \gamma}$ ($e^+e^- \to \gamma \gamma \to$ hadrons) and contrast model predictions with the data. I will then discuss the capability of the future $e^+e^-$ and $\gamma \gamma$ colliders to distinguish between various models and end with an outlook for future work.
hep-ph/9212318
null
Z.G.Berezhiani, R.N.Mohapatra and G.Senjanovic
Planck-Scale Physics and Solutions to the Strong CP Problem without Axion
14 pages, LaTex, IC/92/432, UMDHEP 93-105, LMU-16/92 (minor clarifications in the introduction; missing references are added)
Phys.Rev.D47:5565-5570,1993
10.1103/PhysRevD.47.5565
null
hep-ph
null
We analyse the impact of quantum gravity on the possible solutions to the strong CP problem which utilize the spontaneously broken discrete symmetries, such as parity and time reversal invariance. We find that the stability of the solution under Planck scale effects provides an upper limit on the scale $\Lambda$ of relevant symmetry breaking. This result is model dependent and the bound is most restrictive for the seesaw type models of fermion masses, with $\Lambda < 10^6$ GeV.
[ { "created": "Thu, 31 Dec 1992 17:05:00 GMT", "version": "v1" }, { "created": "Fri, 15 Jan 1993 20:28:00 GMT", "version": "v2" } ]
2010-11-01
[ [ "Berezhiani", "Z. G.", "" ], [ "Mohapatra", "R. N.", "" ], [ "Senjanovic", "G.", "" ] ]
We analyse the impact of quantum gravity on the possible solutions to the strong CP problem which utilize the spontaneously broken discrete symmetries, such as parity and time reversal invariance. We find that the stability of the solution under Planck scale effects provides an upper limit on the scale $\Lambda$ of relevant symmetry breaking. This result is model dependent and the bound is most restrictive for the seesaw type models of fermion masses, with $\Lambda < 10^6$ GeV.
1603.05592
Davide Racco
Enrico Morgante, Davide Racco, Mohamed Rameez and Antonio Riotto
The 750 GeV Diphoton excess, Dark Matter and Constraints from the IceCube experiment
20 pages, 6 figures; v2: added references; v3: published version, with some minor edits and including the exclusion bounds from searches of gamma rays
JHEP 1607 (2016) 141
10.1007/JHEP07(2016)141
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recent LHC data show hints of a new resonance in the diphoton distribution at an invariant mass of 750 GeV. Interestingly, this new particle might be both CP odd and play the role of a portal into the dark matter sector. Under these assumptions and motivated by the fact that the requirement of $SU(2)_L$ invariance automatically implies the coupling of this alleged new resonance to $ZZ$ and $Z\gamma$, we investigate the current and future constraints coming from the indirect searches performed through the neutrino telescope IceCube. We show that these constraints can be stronger than the ones from direct detection experiments if the dark matter mass is larger than a few hundred GeV. Furthermore, in the scenario in which the dark matter is a scalar particle, the IceCube data limit the cross section between the DM and the proton to values close to the predicted ones for natural values of the parameters.
[ { "created": "Thu, 17 Mar 2016 17:53:35 GMT", "version": "v1" }, { "created": "Fri, 25 Mar 2016 17:07:38 GMT", "version": "v2" }, { "created": "Fri, 19 Aug 2016 14:03:28 GMT", "version": "v3" } ]
2016-08-23
[ [ "Morgante", "Enrico", "" ], [ "Racco", "Davide", "" ], [ "Rameez", "Mohamed", "" ], [ "Riotto", "Antonio", "" ] ]
Recent LHC data show hints of a new resonance in the diphoton distribution at an invariant mass of 750 GeV. Interestingly, this new particle might be both CP odd and play the role of a portal into the dark matter sector. Under these assumptions and motivated by the fact that the requirement of $SU(2)_L$ invariance automatically implies the coupling of this alleged new resonance to $ZZ$ and $Z\gamma$, we investigate the current and future constraints coming from the indirect searches performed through the neutrino telescope IceCube. We show that these constraints can be stronger than the ones from direct detection experiments if the dark matter mass is larger than a few hundred GeV. Furthermore, in the scenario in which the dark matter is a scalar particle, the IceCube data limit the cross section between the DM and the proton to values close to the predicted ones for natural values of the parameters.
2006.13942
Rebecca Leane
Djuna Croon, Gilly Elor, Rebecca K. Leane, Samuel D. McDermott
Supernova Muons: New Constraints on Z' Bosons, Axions, and ALPs
29 pages, several hot pink figures. v2: figs 7 and 8 updated, references added
null
10.1007/JHEP01(2021)107
MIT-CTP/5214, FERMILAB-PUB-20-246-A-T
hep-ph astro-ph.CO astro-ph.HE hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
New light particles produced in supernovae can lead to additional energy loss and a consequent deficit in neutrino production in conflict with the neutrinos observed from Supernova 1987A (SN1987A). Contrary to the majority of previous SN1987A studies, we examine the impact of $Z'$ bosons, axions, and axion-like particles (ALPs) interacting with the muons produced in SN1987A. For the first time, we find constraints on generic $Z'$ bosons coupled to muons, and apply our results to particle models including gauged $L_\mu-L_\tau$ number, $U(1)_{L_\mu-L_\tau}$, and gauged $B-L$ number, $U(1)_{B-L}$. We constrain $Z'$ bosons with masses up to about 250-500 MeV, and down to about $10^{-9}$ in $Z'$-muon coupling. We also extend previous work on axion-muon couplings by examining the importance of loop-level interactions, as well as performing calculations over a wider range of axion masses. We constrain muon-coupled axions from arbitrarily low masses up to about 200-500 MeV, with bounds extending down to axion-muon couplings of approximately $10^{-8}$ GeV$^{-1}$. We conclude that supernovae broadly provide a sensitive probe of new lightly-coupled particles interacting with muons.
[ { "created": "Wed, 24 Jun 2020 18:00:01 GMT", "version": "v1" }, { "created": "Tue, 30 Jun 2020 12:55:46 GMT", "version": "v2" } ]
2021-02-03
[ [ "Croon", "Djuna", "" ], [ "Elor", "Gilly", "" ], [ "Leane", "Rebecca K.", "" ], [ "McDermott", "Samuel D.", "" ] ]
New light particles produced in supernovae can lead to additional energy loss and a consequent deficit in neutrino production in conflict with the neutrinos observed from Supernova 1987A (SN1987A). Contrary to the majority of previous SN1987A studies, we examine the impact of $Z'$ bosons, axions, and axion-like particles (ALPs) interacting with the muons produced in SN1987A. For the first time, we find constraints on generic $Z'$ bosons coupled to muons, and apply our results to particle models including gauged $L_\mu-L_\tau$ number, $U(1)_{L_\mu-L_\tau}$, and gauged $B-L$ number, $U(1)_{B-L}$. We constrain $Z'$ bosons with masses up to about 250-500 MeV, and down to about $10^{-9}$ in $Z'$-muon coupling. We also extend previous work on axion-muon couplings by examining the importance of loop-level interactions, as well as performing calculations over a wider range of axion masses. We constrain muon-coupled axions from arbitrarily low masses up to about 200-500 MeV, with bounds extending down to axion-muon couplings of approximately $10^{-8}$ GeV$^{-1}$. We conclude that supernovae broadly provide a sensitive probe of new lightly-coupled particles interacting with muons.
1701.01761
P. Q. Hung
P. Q. Hung, Trinh Le, Van Que Tran and Tzu-Chiang Yuan
Muon-to-Electron Conversion in Mirror Fermion Model with Electroweak Scale Non-Sterile Right-handed Neutrinos
31 pages, 5 figures
null
10.1016/j.nuclphysb.2018.05.020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The muon-to-electron conversion in nuclei like aluminum, titanium and gold is studied in the context of a class of mirror fermion model with non-sterile right-handed neutrinos having mass at the electroweak scale. At the limit of zero momentum transfer and large mirror lepton masses, we derive a simple formula to relate the conversion rate with the on-shell radiative decay rate of muon into electron. Current experimental limits (SINDRUM II) and projected sensitivities (Mu2e, COMET and PRISM) for the muon-to-electron conversion rates in various nuclei and latest limit from MEG for the radiative decay rate of muon into electron are used to put constraints on the parameter space of the model. Depending on the nuclei targets used in different experiments, for the mirror lepton mass in the range of 100 to 800 GeV, the sensitivities of the new Yukawa couplings one can probe in the near future are in the range of one tenth to one hundred-thousandth, depending on the mixing scenarios in the model.
[ { "created": "Fri, 6 Jan 2017 21:25:12 GMT", "version": "v1" } ]
2018-08-01
[ [ "Hung", "P. Q.", "" ], [ "Le", "Trinh", "" ], [ "Tran", "Van Que", "" ], [ "Yuan", "Tzu-Chiang", "" ] ]
The muon-to-electron conversion in nuclei like aluminum, titanium and gold is studied in the context of a class of mirror fermion model with non-sterile right-handed neutrinos having mass at the electroweak scale. At the limit of zero momentum transfer and large mirror lepton masses, we derive a simple formula to relate the conversion rate with the on-shell radiative decay rate of muon into electron. Current experimental limits (SINDRUM II) and projected sensitivities (Mu2e, COMET and PRISM) for the muon-to-electron conversion rates in various nuclei and latest limit from MEG for the radiative decay rate of muon into electron are used to put constraints on the parameter space of the model. Depending on the nuclei targets used in different experiments, for the mirror lepton mass in the range of 100 to 800 GeV, the sensitivities of the new Yukawa couplings one can probe in the near future are in the range of one tenth to one hundred-thousandth, depending on the mixing scenarios in the model.
hep-ph/0611370
Ezequiel Alvarez
Ezequiel Alvarez (Buenos Aires U.) and Alejandro Szynkman (Montreal U.)
Direct test of time reversal invariance violation in B mesons
9 pages, no figures. Refined version matching published article in Modern Physics Letters A
Mod.Phys.Lett.A23:2085-2091,2008
10.1142/S021773230802728X
UdeM-GPP-TH-06-153
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this letter we reinterpret and reanalyze the available data of the B meson factories showing the existence of direct experimental evidence of time reversal invariance violation in B mesons. This reinterpretation consists of using the available observables to define a new observable which, in a model independent way and without assuming CPT invariance, compares a transition between a $B^0$ and a here-defined $B_\alpha$-state, with its time reversed transition. The observable then offers a direct way to probe time reversal invariance and it is therefore independent of any conclusion obtained from current experimental information on CP violation and CPT invariance. As far as the authors are concerned, this is the first direct evidence of time reversal invariance violation in B mesons and also the first one obtained from decaying particles whose mean life time difference is negligible.
[ { "created": "Wed, 29 Nov 2006 16:03:42 GMT", "version": "v1" }, { "created": "Tue, 12 Aug 2008 21:32:16 GMT", "version": "v2" } ]
2008-11-26
[ [ "Alvarez", "Ezequiel", "", "Buenos Aires U." ], [ "Szynkman", "Alejandro", "", "Montreal\n U." ] ]
In this letter we reinterpret and reanalyze the available data of the B meson factories showing the existence of direct experimental evidence of time reversal invariance violation in B mesons. This reinterpretation consists of using the available observables to define a new observable which, in a model independent way and without assuming CPT invariance, compares a transition between a $B^0$ and a here-defined $B_\alpha$-state, with its time reversed transition. The observable then offers a direct way to probe time reversal invariance and it is therefore independent of any conclusion obtained from current experimental information on CP violation and CPT invariance. As far as the authors are concerned, this is the first direct evidence of time reversal invariance violation in B mesons and also the first one obtained from decaying particles whose mean life time difference is negligible.
hep-ph/0003126
Hans-Christian Pauli
Hans-Christian Pauli (MPI Kernphysik, Heidelberg)
On the effective light-cone QCD-Hamiltonian
10 pages, 5 figures, 1 table, 16 references, Latex2e. Proceedings of the Workshop on Light-Cone QCD and Nonperturbative Hadron Physics December 13 - 22, 1999, National Institute for Theoretical Physics, University of Adelaide
Nucl.Phys.Proc.Suppl. 90 (2000) 154-160
null
null
hep-ph
null
Taking the effective interaction between a quark and an anti-quark from previous work, the dependendence on a regularization scale is removed in line with the renormalization group. In order to emphasize the essential point, the full spinor interaction is replaced by a model which includes only the Coulomb and the hyperfine interaction. By adjusting the effective quark masses, the only free parameters of the theory, the mass and the size of the pion are reproduced, as well as the mass of all other pseudo-scalar mesons. Estimates for the vector mesons are close to the empirical values. The model exposes screening rather than strict confinement. The ionization thresholds are in general much larger than the pion mass.
[ { "created": "Tue, 14 Mar 2000 14:45:47 GMT", "version": "v1" } ]
2015-07-29
[ [ "Pauli", "Hans-Christian", "", "MPI Kernphysik, Heidelberg" ] ]
Taking the effective interaction between a quark and an anti-quark from previous work, the dependendence on a regularization scale is removed in line with the renormalization group. In order to emphasize the essential point, the full spinor interaction is replaced by a model which includes only the Coulomb and the hyperfine interaction. By adjusting the effective quark masses, the only free parameters of the theory, the mass and the size of the pion are reproduced, as well as the mass of all other pseudo-scalar mesons. Estimates for the vector mesons are close to the empirical values. The model exposes screening rather than strict confinement. The ionization thresholds are in general much larger than the pion mass.
1202.4852
Swatantra Tiwari
S. K. Tiwari, P. K. Srivastava, and C. P. Singh
The effect of flow on Hadronic Spectra in an Excluded-Volume Model
24 pages, 12 figures, Accepted for publication in Journal of Physics G: Nuclear and Particle Physics
J. Phys. G : Nucl. Part. Phys. 40, 045102 (2013)
10.1088/0954-3899/40/4/045102
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, we proposed a thermodynamically consistent excluded-volume model for the HG fireball and we noticed that our model gives a suitable description for various properties of multiparticle production and their ratios in the entire range of temperatures and baryon densities. The aim in this paper is to obtain the variations of freeze-out volume in a slice of unit rapidity i.e. $dV/dy$ as well as total volume of the fireball with respect to center-of-mass energy $(\sqrt{s_{NN}})$ and confront our model calculations with the corresponding thermal freeze-out volume obtained from the Hanbury-Brown-Twiss (HBT) pion interferometry method. We also test the validity of our model in extracting the total multiplicities as well as the central rapidity densities of various hadrons and comparing them with the recent results. We further calculate the rapidity as well as transverse momentum spectra of various particles produced in different heavy-ion collider experiments in order to examine the role of flow by matching our predictions suitably with the available experimental results. Finally, we extend our analysis for the production of light nuclei, hypernuclei and their antinuclei over a broad energy range from Alternating Gradient Synchrotron (AGS) to Large Hadron Collider (LHC) energies.
[ { "created": "Wed, 22 Feb 2012 08:20:31 GMT", "version": "v1" }, { "created": "Fri, 8 Feb 2013 10:04:46 GMT", "version": "v2" } ]
2013-03-08
[ [ "Tiwari", "S. K.", "" ], [ "Srivastava", "P. K.", "" ], [ "Singh", "C. P.", "" ] ]
Recently, we proposed a thermodynamically consistent excluded-volume model for the HG fireball and we noticed that our model gives a suitable description for various properties of multiparticle production and their ratios in the entire range of temperatures and baryon densities. The aim in this paper is to obtain the variations of freeze-out volume in a slice of unit rapidity i.e. $dV/dy$ as well as total volume of the fireball with respect to center-of-mass energy $(\sqrt{s_{NN}})$ and confront our model calculations with the corresponding thermal freeze-out volume obtained from the Hanbury-Brown-Twiss (HBT) pion interferometry method. We also test the validity of our model in extracting the total multiplicities as well as the central rapidity densities of various hadrons and comparing them with the recent results. We further calculate the rapidity as well as transverse momentum spectra of various particles produced in different heavy-ion collider experiments in order to examine the role of flow by matching our predictions suitably with the available experimental results. Finally, we extend our analysis for the production of light nuclei, hypernuclei and their antinuclei over a broad energy range from Alternating Gradient Synchrotron (AGS) to Large Hadron Collider (LHC) energies.
2212.05073
Dawid Brzeminski
Dawid Brzeminski, Saurav Das, Anson Hook and Clayton Ristow
Constraining Vector Dark Matter with Neutrino experiments
23 pages, 5 figures, updated references
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Vector Dark Matter (VDM) that couples to lepton flavor ($L_e$, $L_{\mu}$, $L_{\tau}$) acts similarly to a chemical potential for the neutrino flavor eigenstates and modifies neutrino oscillations. VDM imparts unique signatures such as time and directional dependence with longer baselines giving better sensitivity. We use the non-observation of such a signal at Super-Kamiokande to rule out the existence of VDM in a region of parameter space several orders of magnitude beyond other constraints and show the projected reach of future experiments such as DUNE.
[ { "created": "Fri, 9 Dec 2022 19:00:01 GMT", "version": "v1" }, { "created": "Tue, 11 Apr 2023 20:00:28 GMT", "version": "v2" }, { "created": "Wed, 2 Aug 2023 16:18:58 GMT", "version": "v3" } ]
2023-08-03
[ [ "Brzeminski", "Dawid", "" ], [ "Das", "Saurav", "" ], [ "Hook", "Anson", "" ], [ "Ristow", "Clayton", "" ] ]
Vector Dark Matter (VDM) that couples to lepton flavor ($L_e$, $L_{\mu}$, $L_{\tau}$) acts similarly to a chemical potential for the neutrino flavor eigenstates and modifies neutrino oscillations. VDM imparts unique signatures such as time and directional dependence with longer baselines giving better sensitivity. We use the non-observation of such a signal at Super-Kamiokande to rule out the existence of VDM in a region of parameter space several orders of magnitude beyond other constraints and show the projected reach of future experiments such as DUNE.
2306.12961
Kazunori Nakayama
Kazunori Nakayama, Fuminobu Takahashi, Masaki Yamada
Quantum decay of scalar and vector boson stars and oscillons into gravitons
32 pages, 2 figures
null
null
TU-1197, KEK-QUP-2023-0013
hep-ph astro-ph.CO hep-th
http://creativecommons.org/licenses/by/4.0/
We point out that a soliton such as an oscillon or boson star inevitably decays into gravitons through gravitational interactions. These decay processes exist even if there are no apparent self-interactions of the constituent field, scalar or vector, since they are induced by gravitational interactions. Hence, our results provide a strict upper limit on the lifetime of oscillons and boson stars including the dilute axion star. We also calculate the spectrum of the graviton background from decay of solitons.
[ { "created": "Thu, 22 Jun 2023 15:20:05 GMT", "version": "v1" } ]
2023-06-23
[ [ "Nakayama", "Kazunori", "" ], [ "Takahashi", "Fuminobu", "" ], [ "Yamada", "Masaki", "" ] ]
We point out that a soliton such as an oscillon or boson star inevitably decays into gravitons through gravitational interactions. These decay processes exist even if there are no apparent self-interactions of the constituent field, scalar or vector, since they are induced by gravitational interactions. Hence, our results provide a strict upper limit on the lifetime of oscillons and boson stars including the dilute axion star. We also calculate the spectrum of the graviton background from decay of solitons.
1103.5156
Vitaly Beylin
V. Beylin, V. Kuksa, G. Vereshkov
The gauge model of quark--meson interactions and the Higgs status of scalar mesons
8 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electromagnetic and strong hadron processes at low energies are considered in the renormalizable model with the spontaneously broken $U_0(1)\times U(1)\times SU(2)$ gauge symmetry. Calculated radiative widths of vector mesons and effective couplings $g_{VVS}$ agree with the experimental data. Residual Higgs degrees of freedom are associated with scalar states $a_0(980)$ and $f_0(980)$ with the degeneration in masses. Two-gamma decays of $\pi^0-$ and $\sigma-$ mesons are analyzed in detail. To provide an "infrared confinement" a cutoff procedure has been also used in calculations.
[ { "created": "Sat, 26 Mar 2011 20:12:45 GMT", "version": "v1" } ]
2011-03-29
[ [ "Beylin", "V.", "" ], [ "Kuksa", "V.", "" ], [ "Vereshkov", "G.", "" ] ]
Electromagnetic and strong hadron processes at low energies are considered in the renormalizable model with the spontaneously broken $U_0(1)\times U(1)\times SU(2)$ gauge symmetry. Calculated radiative widths of vector mesons and effective couplings $g_{VVS}$ agree with the experimental data. Residual Higgs degrees of freedom are associated with scalar states $a_0(980)$ and $f_0(980)$ with the degeneration in masses. Two-gamma decays of $\pi^0-$ and $\sigma-$ mesons are analyzed in detail. To provide an "infrared confinement" a cutoff procedure has been also used in calculations.
1711.02607
Rafal Staszewski
Rafa{\l} Staszewski, Izabela Babiarz, Antoni Szczurek
Rescattering effects in jet-gap-jet processes
5 pages, 5 figures, presented at: EDS Blois 2017, Prague, Czech Republic, June 26-30, 2017
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the process of colour-singlet parton-parton scattering, which in hadron-hadron collision can lead to production of jet events, where a rapidity gap between the jets is present. The dynamics of the process is calculated within LL BFKL approximation. Using Pythia MC generator, hadronic shapes of jet-gap-jet events are studied, in particular the distributions of the rapidity gap size resulting from the jet formation processes. Using Pythia's modelling of multiple parton interactions, the rescattering effects are simulated. It is shown how these effects influence the gap size distributions. The kinematic dependence of the gap survival probability is discussed.
[ { "created": "Tue, 7 Nov 2017 16:56:38 GMT", "version": "v1" } ]
2017-11-08
[ [ "Staszewski", "Rafał", "" ], [ "Babiarz", "Izabela", "" ], [ "Szczurek", "Antoni", "" ] ]
We discuss the process of colour-singlet parton-parton scattering, which in hadron-hadron collision can lead to production of jet events, where a rapidity gap between the jets is present. The dynamics of the process is calculated within LL BFKL approximation. Using Pythia MC generator, hadronic shapes of jet-gap-jet events are studied, in particular the distributions of the rapidity gap size resulting from the jet formation processes. Using Pythia's modelling of multiple parton interactions, the rescattering effects are simulated. It is shown how these effects influence the gap size distributions. The kinematic dependence of the gap survival probability is discussed.
0810.4138
Pavel Fileviez Perez
Pavel Fileviez Perez, Tao Han, Tong Li, Michael J. Ramsey-Musolf
Leptoquarks and Neutrino Masses at the LHC
46 pages, 52 figures
Nucl.Phys.B819:139-176,2009
10.1016/j.nuclphysb.2009.04.009
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The properties of light leptoquarks predicted in the context of a simple grand unified theory and their observability at the LHC are investigated. The SU(5) symmetry of the theory implies that the leptoquark couplings to matter are related to the neutrino mass matrix. We study the resulting connection between neutrino masses and mixing parameters and the leptoquark decays, and show that different light neutrino hierarchies imply distinctive leptoquark decay signatures. We also discuss low-energy constraints implied by searches for charged lepton flavour violation, studies of meson decays, and electroweak precision data. We perform a detailed parton-level study of the leptoquark signals and the Standard Model backgrounds at the LHC. With the clean final states containing a di-lepton plus two jets, the QCD production of the leptoquark pair can be observed for a leptoquark mass of one TeV and beyond. By examining the lepton flavor structure of the observed events, one could further test the model predictions related to the neutrino mass spectrum. In particular, b-flavor tagging will be useful in distinguishing the neutrino mass pattern and possibly probing an unknown Majorana phase in the Inverted Hierarchy or the Quasi-Degenerate scenario. Electroweak associated production of the leptoquark doublet can also be useful in identifying the quantum numbers of the leptoquarks and distinguishing between the neutrino mass spectra, even though the corresponding event rates are smaller than for QCD production. We find that with only the clean channel of mu+ E_T jets, one could expect an observable signal for a leptoquark masses of about 600 GeV or higher.
[ { "created": "Wed, 22 Oct 2008 19:34:42 GMT", "version": "v1" } ]
2009-05-28
[ [ "Perez", "Pavel Fileviez", "" ], [ "Han", "Tao", "" ], [ "Li", "Tong", "" ], [ "Ramsey-Musolf", "Michael J.", "" ] ]
The properties of light leptoquarks predicted in the context of a simple grand unified theory and their observability at the LHC are investigated. The SU(5) symmetry of the theory implies that the leptoquark couplings to matter are related to the neutrino mass matrix. We study the resulting connection between neutrino masses and mixing parameters and the leptoquark decays, and show that different light neutrino hierarchies imply distinctive leptoquark decay signatures. We also discuss low-energy constraints implied by searches for charged lepton flavour violation, studies of meson decays, and electroweak precision data. We perform a detailed parton-level study of the leptoquark signals and the Standard Model backgrounds at the LHC. With the clean final states containing a di-lepton plus two jets, the QCD production of the leptoquark pair can be observed for a leptoquark mass of one TeV and beyond. By examining the lepton flavor structure of the observed events, one could further test the model predictions related to the neutrino mass spectrum. In particular, b-flavor tagging will be useful in distinguishing the neutrino mass pattern and possibly probing an unknown Majorana phase in the Inverted Hierarchy or the Quasi-Degenerate scenario. Electroweak associated production of the leptoquark doublet can also be useful in identifying the quantum numbers of the leptoquarks and distinguishing between the neutrino mass spectra, even though the corresponding event rates are smaller than for QCD production. We find that with only the clean channel of mu+ E_T jets, one could expect an observable signal for a leptoquark masses of about 600 GeV or higher.
hep-ph/9909515
Yi Bing Ding
Yi-Bing Ding, Xue-Qian Li, Pong-Nian Shen
Comment on " a unified scheme for flavored mesons and baryons"
Latex file, 11pages
Eur.Phys.J.A7:107-108,2000
10.1007/s100500050017
null
hep-ph
null
We would comment on the results of the paper "a unified scheme for flavored mesons and baryons" (P.C.Vinodkumar, J.N.Panandya, V.M.Bannur, and S.B.Khadkikar Eur. Phys. J. A4(1999)83), and point out some inconsistencies and mistakes in the work for solving the Dirac equation. In terms of an example for a single particle we investigate the reliability of the perturbative method for computing the Coulomb energy and discuss the contribution to the wavefunction at origin from the Coulomb potential. We conclude that the accuracy of their numerical results needs to be reconsidered.
[ { "created": "Mon, 27 Sep 1999 07:39:44 GMT", "version": "v1" } ]
2015-06-25
[ [ "Ding", "Yi-Bing", "" ], [ "Li", "Xue-Qian", "" ], [ "Shen", "Pong-Nian", "" ] ]
We would comment on the results of the paper "a unified scheme for flavored mesons and baryons" (P.C.Vinodkumar, J.N.Panandya, V.M.Bannur, and S.B.Khadkikar Eur. Phys. J. A4(1999)83), and point out some inconsistencies and mistakes in the work for solving the Dirac equation. In terms of an example for a single particle we investigate the reliability of the perturbative method for computing the Coulomb energy and discuss the contribution to the wavefunction at origin from the Coulomb potential. We conclude that the accuracy of their numerical results needs to be reconsidered.
hep-ph/0509076
Andreas Metz
J.C. Collins, A.V. Efremov, K. Goeke, S. Menzel, A. Metz, and P. Schweitzer
Sivers effect in semi-inclusive deeply inelastic scattering
Small additions, Fig.2 corrected, references and one figure added, correction in Eq.(13), version accepted for publication
Phys.Rev. D73 (2006) 014021
10.1103/PhysRevD.73.014021
null
hep-ph
null
The Sivers function is extracted from HERMES data on single spin asymmetries in semi-inclusive deeply inelastic scattering. Our analysis use a simple Gaussian model for the distribution of transverse parton momenta, together with the flavor dependence given by the leading 1/Nc approximation and a neglect of the Sivers antiquark distribution. We find that within the errors of the data these approximations are sufficient.
[ { "created": "Thu, 8 Sep 2005 13:46:38 GMT", "version": "v1" }, { "created": "Tue, 24 Jan 2006 10:30:21 GMT", "version": "v2" } ]
2009-11-11
[ [ "Collins", "J. C.", "" ], [ "Efremov", "A. V.", "" ], [ "Goeke", "K.", "" ], [ "Menzel", "S.", "" ], [ "Metz", "A.", "" ], [ "Schweitzer", "P.", "" ] ]
The Sivers function is extracted from HERMES data on single spin asymmetries in semi-inclusive deeply inelastic scattering. Our analysis use a simple Gaussian model for the distribution of transverse parton momenta, together with the flavor dependence given by the leading 1/Nc approximation and a neglect of the Sivers antiquark distribution. We find that within the errors of the data these approximations are sufficient.
1807.04066
Wolfgang Lucha
Wolfgang Lucha
Simplified Bethe-Salpeter Description of Basic Pseudoscalar-Meson Features
5 pages, 1 figure, contributed to "QCD@Work 2018 - International Workshop on Quantum Chromodynamics: Theory and Experiment" (25 - 28 June 2018, Matera, Italy)
EPJ Web of Conferences 192, 00040 (2018)
10.1051/epjconf/201819200040
HEPHY-PUB 1000/18 (2018)
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We assess a description of pseudoscalar mesons as pseudo-Goldstone bosons by its compatibility with some Gell-Mann-Oakes-Renner-type relation.
[ { "created": "Wed, 11 Jul 2018 10:56:46 GMT", "version": "v1" } ]
2019-06-03
[ [ "Lucha", "Wolfgang", "" ] ]
We assess a description of pseudoscalar mesons as pseudo-Goldstone bosons by its compatibility with some Gell-Mann-Oakes-Renner-type relation.
hep-ph/0304301
Mark Strikman
L. Frankfurt (Tel Aviv U.), M. Strikman (Penn State U.) and M.Zhalov (Petersburg Nuclear Physics Inst.)
Coherent Photoproduction from Nuclei
33 pages, 12 figs, To appear in the special issue of Acta Physica Polonica to celebrate the 65th Birthday of Professor Jan Kwiecinski
Acta Phys.Polon.B34:3215-3254,2003
null
null
hep-ph
null
We argue that study of the cross section of coherent photo(electro) production of vector mesons off nuclear targets provides an effective method to probe the leading twist hard QCD regimes of color transparency and perturbative color opacity as well as the onset of black body limit (BBL) in the soft and hard QCD interactions. In the case of intermediate energies we use the Generalized Vector Dominance Model to take into account coherence effects for two distinctive limits - the soft interactions for production of $\rho$ and $\rho'$-mesons and the color transparency regime for production of charmonium states. We demonstrate that GVDM describes very well $\rho$-meson coherent photoproduction at $6 \leq E_{\gamma} \leq 10$ GeV and predict an oscillating energy dependence for the coherent charmonium production. In the limit of small $x$ we find that hard QCD leads to onset of the perturbative color opacity even for production of very small onium states, like $\Upsilon$. The advantages of the process of coherent dijet photoproduction and hard diffractive processes in general for probing the onset of BBL and measuring the light-cone wave function of the photon in a hard scattering regime where decomposition over twists becomes inapplicable are explained. We apply this analysis to the study of the photon induced coherent processes in Ultra Peripheral Collisions of ions at LHC and demonstrate that the counting rates will be sufficient to study the physics of color opacity and color transparency at the energies beyond the reach of the electron-nucleon(nucleus) colliders.
[ { "created": "Wed, 30 Apr 2003 18:48:07 GMT", "version": "v1" } ]
2014-11-17
[ [ "Frankfurt", "L.", "", "Tel Aviv U." ], [ "Strikman", "M.", "", "Penn State U." ], [ "Zhalov", "M.", "", "Petersburg Nuclear Physics Inst." ] ]
We argue that study of the cross section of coherent photo(electro) production of vector mesons off nuclear targets provides an effective method to probe the leading twist hard QCD regimes of color transparency and perturbative color opacity as well as the onset of black body limit (BBL) in the soft and hard QCD interactions. In the case of intermediate energies we use the Generalized Vector Dominance Model to take into account coherence effects for two distinctive limits - the soft interactions for production of $\rho$ and $\rho'$-mesons and the color transparency regime for production of charmonium states. We demonstrate that GVDM describes very well $\rho$-meson coherent photoproduction at $6 \leq E_{\gamma} \leq 10$ GeV and predict an oscillating energy dependence for the coherent charmonium production. In the limit of small $x$ we find that hard QCD leads to onset of the perturbative color opacity even for production of very small onium states, like $\Upsilon$. The advantages of the process of coherent dijet photoproduction and hard diffractive processes in general for probing the onset of BBL and measuring the light-cone wave function of the photon in a hard scattering regime where decomposition over twists becomes inapplicable are explained. We apply this analysis to the study of the photon induced coherent processes in Ultra Peripheral Collisions of ions at LHC and demonstrate that the counting rates will be sufficient to study the physics of color opacity and color transparency at the energies beyond the reach of the electron-nucleon(nucleus) colliders.
2208.13036
G.R. Boroun
G.R.Boroun
One-to-One correspondence of soft and hard Pomeron with the CDP of the gluon density at low $x$
will be appear in JETP Letters
JETP Letters, Vol. 117, No. 4, 247 (2023)
10.1134/S0021364023600015
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The correspondence between the gluon density behavior of the color dipole picture and the two-Pomeron approach at low $x$ deep inelastic scattering is considered. For photon virtualities of $Q^{2}{\gtrsim}10~\mathrm{GeV}^{2}$, the results for the parametrization and CDP models are defined by the CDP asymptotic limit and are compatible with the soft and hard-Pomeron approach. These results show that the hard-Pomeron trajectory does not guarantee converging towards the asymptotic representation at low and large $Q^{2}$ ($Q^{2}{\lesssim}100~\mathrm{GeV}^{2}$) values in a wide range of the virtual-photon-proton energy squared. The gluon distributions can be obtained directly in terms of the proton structure functions and the running coupling and compared with the results from the GJR and MSTW parametrizations.
[ { "created": "Sat, 27 Aug 2022 15:03:18 GMT", "version": "v1" }, { "created": "Sat, 24 Sep 2022 13:28:59 GMT", "version": "v2" }, { "created": "Wed, 4 Jan 2023 13:48:05 GMT", "version": "v3" } ]
2023-03-16
[ [ "Boroun", "G. R.", "" ] ]
The correspondence between the gluon density behavior of the color dipole picture and the two-Pomeron approach at low $x$ deep inelastic scattering is considered. For photon virtualities of $Q^{2}{\gtrsim}10~\mathrm{GeV}^{2}$, the results for the parametrization and CDP models are defined by the CDP asymptotic limit and are compatible with the soft and hard-Pomeron approach. These results show that the hard-Pomeron trajectory does not guarantee converging towards the asymptotic representation at low and large $Q^{2}$ ($Q^{2}{\lesssim}100~\mathrm{GeV}^{2}$) values in a wide range of the virtual-photon-proton energy squared. The gluon distributions can be obtained directly in terms of the proton structure functions and the running coupling and compared with the results from the GJR and MSTW parametrizations.
1703.00244
Enrico Meggiolaro
M. Giordano, E. Meggiolaro, P.V.R.G. Silva
An investigation on the leading and subleading high-energy behavior of hadron-hadron total cross sections using a best-fit analysis of hadronic scattering data
33 pages, 7 tables, 7 figures
Phys. Rev. D 96, 034015 (2017)
10.1103/PhysRevD.96.034015
IFUP-TH/2017
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present investigation we study the leading and subleading high-energy behavior of hadron-hadron total cross sections using a best-fit analysis of hadronic scattering data. The parametrization used for the hadron-hadron total cross sections at high energy is inspired by recent results obtained by Giordano and Meggiolaro (2014) using a nonperturbative approach in the framework of QCD and it reads $\sigma_\text{tot} \sim B\ln^2 s + C\ln s\ln\ln s$. Both $B$ and $C$ are obtained by means of best-fits to data for proton-proton and antiproton-proton scattering, including recent data obtained at the LHC, and also to data for other meson-baryon and baryon-baryon scattering processes. The results are compared to the theoretical predictions existing in the literature. In particular, following the above-mentioned nonperturbative QCD approach, we also consider fits where the parameters $B$ and $C$ are set to $B = \kappa B_\text{th}$ and $C = \kappa C_\text{th}$, where $B_\text{th}$ and $C_\text{th}$ are universal quantities related to the QCD stable spectrum, while $\kappa$ (treated as an extra free parameter) is related to the asymptotic value of the ratio $\sigma_\text{el}/\sigma_\text{tot}$. Different possible scenarios are then considered and compared.
[ { "created": "Wed, 1 Mar 2017 11:38:15 GMT", "version": "v1" } ]
2017-08-30
[ [ "Giordano", "M.", "" ], [ "Meggiolaro", "E.", "" ], [ "Silva", "P. V. R. G.", "" ] ]
In the present investigation we study the leading and subleading high-energy behavior of hadron-hadron total cross sections using a best-fit analysis of hadronic scattering data. The parametrization used for the hadron-hadron total cross sections at high energy is inspired by recent results obtained by Giordano and Meggiolaro (2014) using a nonperturbative approach in the framework of QCD and it reads $\sigma_\text{tot} \sim B\ln^2 s + C\ln s\ln\ln s$. Both $B$ and $C$ are obtained by means of best-fits to data for proton-proton and antiproton-proton scattering, including recent data obtained at the LHC, and also to data for other meson-baryon and baryon-baryon scattering processes. The results are compared to the theoretical predictions existing in the literature. In particular, following the above-mentioned nonperturbative QCD approach, we also consider fits where the parameters $B$ and $C$ are set to $B = \kappa B_\text{th}$ and $C = \kappa C_\text{th}$, where $B_\text{th}$ and $C_\text{th}$ are universal quantities related to the QCD stable spectrum, while $\kappa$ (treated as an extra free parameter) is related to the asymptotic value of the ratio $\sigma_\text{el}/\sigma_\text{tot}$. Different possible scenarios are then considered and compared.
1602.08816
Zhaofeng Kang
Xiao-Jun Bi, Zhaofeng Kang, P. Ko, Jinmian Li and Tianjun Li
Asymmetric Dark Matter Bound State
PRD version; major revision in terms of the referee's reports; building a new model to avoid the strong DM direct detection constraint; new references added
Phys. Rev. D 95, 043540 (2017)
10.1103/PhysRevD.95.043540
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an interesting framework for asymmetric scalar dark matter (ADM), which has novel collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1)_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. Therefore, the ADM can form bound state due to its large self-interaction via $X$ mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with $b\bar b$. The resulting signature at the LHC depends on the decays of $X$. In this paper we consider a case of particular interest: $pp\ra b\bar b+ {\rm ADMonium}$ followed by ${\rm ADMonium}\ra 2X\ra 2e^+e^-$ where the electrons are identified as (un)converted photons. It may provide a competitive explanation to heavy di-photon resonance searches at the LHC.
[ { "created": "Mon, 29 Feb 2016 03:56:34 GMT", "version": "v1" }, { "created": "Wed, 9 Mar 2016 08:49:42 GMT", "version": "v2" }, { "created": "Thu, 29 Jun 2017 13:11:43 GMT", "version": "v3" } ]
2017-06-30
[ [ "Bi", "Xiao-Jun", "" ], [ "Kang", "Zhaofeng", "" ], [ "Ko", "P.", "" ], [ "Li", "Jinmian", "" ], [ "Li", "Tianjun", "" ] ]
We propose an interesting framework for asymmetric scalar dark matter (ADM), which has novel collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1)_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. Therefore, the ADM can form bound state due to its large self-interaction via $X$ mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with $b\bar b$. The resulting signature at the LHC depends on the decays of $X$. In this paper we consider a case of particular interest: $pp\ra b\bar b+ {\rm ADMonium}$ followed by ${\rm ADMonium}\ra 2X\ra 2e^+e^-$ where the electrons are identified as (un)converted photons. It may provide a competitive explanation to heavy di-photon resonance searches at the LHC.
1809.03128
Masamichi Ishihara
Masamichi Ishihara
Chiral phase transition within the linear sigma model in the Tsallis nonextensive statistics based on density operator
12 pages, 3 figures
International Journal of Modern Physics E Vol. 28, No. 4 (2019) 1950020 (14 pages)
10.1142/S0218301319500204
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We studied the chiral phase transition for small $|1-q|$ within the Tsallis nonextensive statistics of the entropic parameter $q$, where the quantity $|1-q|$ is the measure of the deviation from the Boltzmann-Gibbs statistics. We adopted the normalized $q$-expectation value in this study. We applied the free particle approximation and the massless approximation in the calculations of the expectation values. We estimated the critical physical temperature, and obtained the chiral condensate, the sigma mass, and the pion mass, as functions of the physical temperature $T_{\mathrm{ph}}$ for various $q$. We found the following facts. The $q$-dependence of the critical physical temperature is $1/\sqrt{q}$. The chiral condensate at $q$ is smaller than that at $q'$ for $q>q'$. The $q$-dependence of the pion mass and that of the sigma mass reflect the $q$-dependence of the condensate. The pion mass at $q$ is heavier than that at $q'$ for $q>q'$. The sigma mass at $q$ is heavier than that at $q'$ for $q>q'$ at high physical temperature, while the sigma mass at $q$ is lighter than that at $q'$ for $q>q'$ at low physical temperature. The quantities which are functions of the physical temperature $T_{\mathrm{ph}}$ and the entropic parameter $q$ are described by only the effective physical temperature defined as $\sqrt{q} T_{\mathrm{ph}}$ under the approximations.
[ { "created": "Mon, 10 Sep 2018 04:33:40 GMT", "version": "v1" }, { "created": "Fri, 25 Jan 2019 07:28:15 GMT", "version": "v2" } ]
2019-07-04
[ [ "Ishihara", "Masamichi", "" ] ]
We studied the chiral phase transition for small $|1-q|$ within the Tsallis nonextensive statistics of the entropic parameter $q$, where the quantity $|1-q|$ is the measure of the deviation from the Boltzmann-Gibbs statistics. We adopted the normalized $q$-expectation value in this study. We applied the free particle approximation and the massless approximation in the calculations of the expectation values. We estimated the critical physical temperature, and obtained the chiral condensate, the sigma mass, and the pion mass, as functions of the physical temperature $T_{\mathrm{ph}}$ for various $q$. We found the following facts. The $q$-dependence of the critical physical temperature is $1/\sqrt{q}$. The chiral condensate at $q$ is smaller than that at $q'$ for $q>q'$. The $q$-dependence of the pion mass and that of the sigma mass reflect the $q$-dependence of the condensate. The pion mass at $q$ is heavier than that at $q'$ for $q>q'$. The sigma mass at $q$ is heavier than that at $q'$ for $q>q'$ at high physical temperature, while the sigma mass at $q$ is lighter than that at $q'$ for $q>q'$ at low physical temperature. The quantities which are functions of the physical temperature $T_{\mathrm{ph}}$ and the entropic parameter $q$ are described by only the effective physical temperature defined as $\sqrt{q} T_{\mathrm{ph}}$ under the approximations.
0809.0370
Yin Lin
Yin Lin
Mass hierarchy and flavour mixing from discrete symmetries
Talk given at IFAE 2008, Bologna, Italy, 26-28 March 2008
Nuovo Cim.B123:883-885,2008
10.1393/ncb/i2008-10630-7
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a class of discrete flavour symmetries for leptons based on the group S(3) and A(4) with an hybrid breaking pattern. The aim is to construct models in which the same flavon fields producing the mixing pattern are also responsible for the mass hierarchy.
[ { "created": "Tue, 2 Sep 2008 08:24:44 GMT", "version": "v1" } ]
2010-11-11
[ [ "Lin", "Yin", "" ] ]
We consider a class of discrete flavour symmetries for leptons based on the group S(3) and A(4) with an hybrid breaking pattern. The aim is to construct models in which the same flavon fields producing the mixing pattern are also responsible for the mass hierarchy.
2105.07719
Tania Robens
Tania Robens
Extended scalar sectors at current and future colliders
6 pages, 3 figures; Contribution to the 2021 QCD session of the 55th Rencontres de Moriond
null
null
RBI-ThPhys-2021-021
hep-ph
http://creativecommons.org/licenses/by/4.0/
After the discovery of a particle that complies with the properties of the Higgs boson predicted by the Standard Model, particle physics has entered an exciting era. One important question is whether the scalar sector realized by Nature indeed corresponds to the one predicted by the SM, or whether the resonance at 125 GeV is a manifestation of a more extended scalar sector, and additional scalar states could be observed at current or future collider facilities.
[ { "created": "Mon, 17 May 2021 10:31:47 GMT", "version": "v1" } ]
2021-05-18
[ [ "Robens", "Tania", "" ] ]
After the discovery of a particle that complies with the properties of the Higgs boson predicted by the Standard Model, particle physics has entered an exciting era. One important question is whether the scalar sector realized by Nature indeed corresponds to the one predicted by the SM, or whether the resonance at 125 GeV is a manifestation of a more extended scalar sector, and additional scalar states could be observed at current or future collider facilities.
hep-ph/0607319
Pietro Santorelli
M. De Vito, P. Santorelli
Semileptonic B decays into even parity charmed mesons
11 pages, 2 figures
Eur.Phys.J.C48:441-449,2006
10.1140/epjc/s10052-006-0045-1
DSF-2006-21 (Napoli)
hep-ph
null
By using a constituent quark model we compute the form factors relevant to semileptonic transitions of B mesons into low-lying p-wave charmed mesons. We evaluate the q^2 dependence of these form factors and compare them with other model calculations. The Isgur-Wise functions tau(1/2) and tau(3/2) are also obtained in the heavy quark limit of our results.
[ { "created": "Fri, 28 Jul 2006 14:43:33 GMT", "version": "v1" } ]
2008-11-26
[ [ "De Vito", "M.", "" ], [ "Santorelli", "P.", "" ] ]
By using a constituent quark model we compute the form factors relevant to semileptonic transitions of B mesons into low-lying p-wave charmed mesons. We evaluate the q^2 dependence of these form factors and compare them with other model calculations. The Isgur-Wise functions tau(1/2) and tau(3/2) are also obtained in the heavy quark limit of our results.
2309.12079
Sah Deepak
Deepak Sah and Manoranjan P. Singh
Pair Production in time-dependent Electric field at Finite times
null
null
null
null
hep-ph cond-mat.other hep-th physics.plasm-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the finite-time behavior of pair production from the vacuum by a time-dependent Sauter pulsed electric field using the spinor quantum electrodynamics (QED). In the adiabatic basis, the one-particle distribution function in momentum space is determined by utilizing the exact analytical solution of the Dirac equation. By examining the temporal behavior of the one-particle distribution function and the momentum spectrum of created pairs in the sub-critical field limit $(E_0 = 0.2E_c)$, we observe oscillatory patterns in the longitudinal momentum spectrum(LMS) of particles at finite times. These oscillations arise due to quantum interference effects resulting from the dynamical tunneling. Furthermore, we derive an approximate and simplified analytical expression for the distribution function at finite times, which allows us to explain the origin and behavior of these oscillations. Additionally, we discuss the role of the vacuum polarization function and its counter term to the oscillations in LMS vacuum excitation. We also analyse the transverse momentum spectrum (TMS).
[ { "created": "Thu, 21 Sep 2023 13:49:43 GMT", "version": "v1" }, { "created": "Wed, 11 Oct 2023 15:15:16 GMT", "version": "v2" }, { "created": "Fri, 24 May 2024 19:59:06 GMT", "version": "v3" } ]
2024-05-28
[ [ "Sah", "Deepak", "" ], [ "Singh", "Manoranjan P.", "" ] ]
We investigate the finite-time behavior of pair production from the vacuum by a time-dependent Sauter pulsed electric field using the spinor quantum electrodynamics (QED). In the adiabatic basis, the one-particle distribution function in momentum space is determined by utilizing the exact analytical solution of the Dirac equation. By examining the temporal behavior of the one-particle distribution function and the momentum spectrum of created pairs in the sub-critical field limit $(E_0 = 0.2E_c)$, we observe oscillatory patterns in the longitudinal momentum spectrum(LMS) of particles at finite times. These oscillations arise due to quantum interference effects resulting from the dynamical tunneling. Furthermore, we derive an approximate and simplified analytical expression for the distribution function at finite times, which allows us to explain the origin and behavior of these oscillations. Additionally, we discuss the role of the vacuum polarization function and its counter term to the oscillations in LMS vacuum excitation. We also analyse the transverse momentum spectrum (TMS).
1204.3992
Jan-e Alam Dr.
Trambak Bhattacharyya and Jan-e Alam
Dead cone due to parton virtuality
null
Int. J. Mod. Phys. A, 28 (2013) 1350031
10.1142/S0217751X13500310
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A general expression for the dead cone of gluons radiated by virtual partons has been derived. The conventional dead cone for massive on-shell quarks and the dead cone for the massless virtual partons have been obtained by using different limits of the general expression. Radiative suppression due to the virtuality of initial parton jets in Heavy-Ion Collisions (HIC) has been discussed. It is observed that the suppression caused by the high virtuality is overwhelmingly large as compared to that on account of conventional dead-cone of heavy quarks. The dead cone due to virtuality may play a crucial role in explaining the observed similar suppression patterns of light and heavy quarks jets in heavy ion collisions at Relativistic Heavy Ion Collider (RHIC).
[ { "created": "Wed, 18 Apr 2012 06:51:15 GMT", "version": "v1" } ]
2015-06-04
[ [ "Bhattacharyya", "Trambak", "" ], [ "Alam", "Jan-e", "" ] ]
A general expression for the dead cone of gluons radiated by virtual partons has been derived. The conventional dead cone for massive on-shell quarks and the dead cone for the massless virtual partons have been obtained by using different limits of the general expression. Radiative suppression due to the virtuality of initial parton jets in Heavy-Ion Collisions (HIC) has been discussed. It is observed that the suppression caused by the high virtuality is overwhelmingly large as compared to that on account of conventional dead-cone of heavy quarks. The dead cone due to virtuality may play a crucial role in explaining the observed similar suppression patterns of light and heavy quarks jets in heavy ion collisions at Relativistic Heavy Ion Collider (RHIC).
1008.3116
Stefano Nicotri
Pietro Colangelo, Floriana Giannuzzi, Stefano Nicotri
Holography, Heavy-Quark Free Energy, and the QCD Phase Diagram
4 pages, 5 figures, version published on PRD
Phys.Rev.D83:035015,2011
10.1103/PhysRevD.83.035015
BARI-TH/629-2010, DCPT/10/138, IPPP/10/69
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use gauge/string duality to investigate the free energy of two static color sources (a heavy quark-antiquark pair) in a Yang-Mills theory in strongly interacting matter, varying temperature and chemical potential. The dual space geometry is Anti-de Sitter with a charged black-hole to describe finite temperature and density in the boundary theory, and we also include a background dilaton field to generate confinement. The resulting phase diagram in the chemical potential-temperature $\mu-T$ plane is in a quite good agreement with lattice results and effective models of QCD.
[ { "created": "Wed, 18 Aug 2010 15:39:52 GMT", "version": "v1" }, { "created": "Wed, 16 Mar 2011 12:14:26 GMT", "version": "v2" } ]
2011-03-23
[ [ "Colangelo", "Pietro", "" ], [ "Giannuzzi", "Floriana", "" ], [ "Nicotri", "Stefano", "" ] ]
We use gauge/string duality to investigate the free energy of two static color sources (a heavy quark-antiquark pair) in a Yang-Mills theory in strongly interacting matter, varying temperature and chemical potential. The dual space geometry is Anti-de Sitter with a charged black-hole to describe finite temperature and density in the boundary theory, and we also include a background dilaton field to generate confinement. The resulting phase diagram in the chemical potential-temperature $\mu-T$ plane is in a quite good agreement with lattice results and effective models of QCD.
1912.02720
Victor Goncalves
V. P. Goncalves, R. Palota da Silva
Exclusive and diffractive quarkonium -- pair production at the LHC and FCC
7 pages, 3 figures, 2 tables
Phys. Rev. D 101, 034025 (2020)
10.1103/PhysRevD.101.034025
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The production of a quarkonium -- pair in exclusive and diffractive processes in $pp$ collisions at the LHC and FCC energies is investigated. We consider the $J/\Psi J/\Psi$ and $\Upsilon \Upsilon$ production in these processes and present predictions for the transverse momentum and rapidity distributions considering the kinematical ranges expected to be covered by central and forward detectors. Results for the cross sections are also presented. Our results indicate that the double $J/\Psi$ production is dominated by the exclusive process, while the double $\Upsilon$ production receive a large contribution of the diffractive process. The impact of the modelling of the gap survival factor on our predictions is discussed.
[ { "created": "Thu, 5 Dec 2019 16:57:14 GMT", "version": "v1" } ]
2020-02-26
[ [ "Goncalves", "V. P.", "" ], [ "da Silva", "R. Palota", "" ] ]
The production of a quarkonium -- pair in exclusive and diffractive processes in $pp$ collisions at the LHC and FCC energies is investigated. We consider the $J/\Psi J/\Psi$ and $\Upsilon \Upsilon$ production in these processes and present predictions for the transverse momentum and rapidity distributions considering the kinematical ranges expected to be covered by central and forward detectors. Results for the cross sections are also presented. Our results indicate that the double $J/\Psi$ production is dominated by the exclusive process, while the double $\Upsilon$ production receive a large contribution of the diffractive process. The impact of the modelling of the gap survival factor on our predictions is discussed.
1701.00491
Marco Chianese Mr
F. Buccella, M. Chianese, G. Mangano, G. Miele, S. Morisi and P. Santorelli
A neutrino mass-mixing sum rule from SO(10) and neutrinoless double beta decay
5 pages, 2 figures. Version published in JEHP
JHEP 1704 (2017) 004
10.1007/JHEP04(2017)004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Minimal SO(10) grand unified models provide phenomenological predictions for neutrino mass patterns and mixing. These are the outcome of the interplay of several features, namely: i) the seesaw mechanism; ii) the presence of an intermediate scale where B-L gauge symmetry is broken and the right-handed neutrinos acquire a Majorana mass; iii) a symmetric Dirac neutrino mass matrix whose pattern is close to the up-type quark one. In this framework two natural characteristics emerge. Normal neutrino mass hierarchy is the only allowed, and there is an approximate relation involving both light-neutrino masses and mixing parameters. This differs from what occurring when horizontal flavour symmetries are invoked. In this case, in fact, neutrino mixing or mass relations have been separately obtained in literature. In this paper we discuss an example of such comprehensive mixing-mass relation in a specific realization of SO(10) and, in particular, analyse its impact on the expected neutrinoless double beta decay effective mass parameter $\langle m_{ee} \rangle$, and on the neutrino mass scale. Remarkably a lower limit for the lightest neutrino mass is obtained ($m_{\rm lightest} \gtrsim 7.5 \times 10^{-4}$ eV, at 3 $\sigma$ level).
[ { "created": "Mon, 2 Jan 2017 19:00:03 GMT", "version": "v1" }, { "created": "Wed, 11 Jan 2017 14:45:41 GMT", "version": "v2" }, { "created": "Fri, 7 Apr 2017 12:26:43 GMT", "version": "v3" } ]
2017-04-10
[ [ "Buccella", "F.", "" ], [ "Chianese", "M.", "" ], [ "Mangano", "G.", "" ], [ "Miele", "G.", "" ], [ "Morisi", "S.", "" ], [ "Santorelli", "P.", "" ] ]
Minimal SO(10) grand unified models provide phenomenological predictions for neutrino mass patterns and mixing. These are the outcome of the interplay of several features, namely: i) the seesaw mechanism; ii) the presence of an intermediate scale where B-L gauge symmetry is broken and the right-handed neutrinos acquire a Majorana mass; iii) a symmetric Dirac neutrino mass matrix whose pattern is close to the up-type quark one. In this framework two natural characteristics emerge. Normal neutrino mass hierarchy is the only allowed, and there is an approximate relation involving both light-neutrino masses and mixing parameters. This differs from what occurring when horizontal flavour symmetries are invoked. In this case, in fact, neutrino mixing or mass relations have been separately obtained in literature. In this paper we discuss an example of such comprehensive mixing-mass relation in a specific realization of SO(10) and, in particular, analyse its impact on the expected neutrinoless double beta decay effective mass parameter $\langle m_{ee} \rangle$, and on the neutrino mass scale. Remarkably a lower limit for the lightest neutrino mass is obtained ($m_{\rm lightest} \gtrsim 7.5 \times 10^{-4}$ eV, at 3 $\sigma$ level).