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1409.6322
Travis A.W. Martin
Travis A.W. Martin and David Morrissey
Electroweakino constraints from LHC data
30 pages, 15 figures
null
10.1007/JHEP12(2014)168
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the sensitivity of existing LHC searches to the charginos and neutralinos of the MSSM when all the other superpartners are decoupled. In this limit, the underlying parameter space reduces to a simple four-dimensional set $\{M_1,\,M_2,\,\mu,\,\tan\beta\}$. We examine the constraints placed on this parameter space by a broad range of LHC searches taking into account the full set of relevant production and decay channels. We find that the exclusions implied by these searches exceed existing limits from LEP only for smaller values of the Bino mass $M_1 \lesssim 150$ GeV. Our results have implications for MSSM dark matter and electroweak baryogenesis.
[ { "created": "Mon, 22 Sep 2014 20:00:45 GMT", "version": "v1" }, { "created": "Thu, 2 Oct 2014 18:55:27 GMT", "version": "v2" }, { "created": "Tue, 7 Oct 2014 15:30:51 GMT", "version": "v3" }, { "created": "Fri, 5 Dec 2014 19:53:47 GMT", "version": "v4" } ]
2015-06-22
[ [ "Martin", "Travis A. W.", "" ], [ "Morrissey", "David", "" ] ]
We investigate the sensitivity of existing LHC searches to the charginos and neutralinos of the MSSM when all the other superpartners are decoupled. In this limit, the underlying parameter space reduces to a simple four-dimensional set $\{M_1,\,M_2,\,\mu,\,\tan\beta\}$. We examine the constraints placed on this parameter space by a broad range of LHC searches taking into account the full set of relevant production and decay channels. We find that the exclusions implied by these searches exceed existing limits from LEP only for smaller values of the Bino mass $M_1 \lesssim 150$ GeV. Our results have implications for MSSM dark matter and electroweak baryogenesis.
hep-ph/0203056
Michael Spira
D. Cavalli, A. Djouadi, K. Jakobs, A. Nikitenko, M. Spira, C.E.M. Wagner, W.-M. Yao, K.A. Assamagan, G. Azuelos, S. Balatenychev, G. B\'elanger, M. Bisset, A. Bocci, F. Boudjema, C. Buttar, M. Carena, S. Catani, V. Cavasinni, Y. Coadou, D. Costanzo, A. Cottrant, A.K. Datta, A. Deandrea, D. de Florian, V. Del Duca, B. Di Girolamo, V. Drollinger, T. Figy, M. Frank, R.M. Godbole, M. Grazzini, M. Guchait, R. Harper, S. Heinemeyer, J. Hobbs, W. Hollik, C. Hugonie, V.I. Ilyin, W.B. Kilgore, R. Kinnunen, M. Klute, R. Lafaye, Y. Mambrini, R. Mazini, K. Mazumdar, F. Moortgat, S. Moretti, G. Negri, L. Neukermans, C. Oleari, A. Pukhov, D. Rainwater, E. Richter-Was, D.P. Roy, C.R. Schmidt, A. Semenov, J. Thomas, I. Vivarelli, G. Weiglein, D. Zeppenfeld
The Higgs Working Group: Summary Report (2001)
120 pages, latex, many figures, proceedings of the Workshop `Physics at TeV Colliders', Les Houches, France, 21 May - 1 June 2001, full Author list included in paper. Typos corrected, author list and acknowledgements completed. Convernors: D. Cavalli, A. Djouadi, K. Jakobs, A. Nikitenko, M. Spira, C.E.M. Wagner, W.-M. Yao
null
null
null
hep-ph
null
Report of the Higgs working group for the Workshop `Physics at TeV Colliders', Les Houches, France, 21 May - 1 June 2001. It contains 7 separate sections: A. Theoretical Developments B. Higgs Searches at the Tevatron C. Experimental Observation of an invisible Higgs Boson at LHC D. Search for the Standard Model Higgs Boson using Vector Boson Fusion at the LHC E. Study of the MSSM channel $A/H \to \tau \tau$ at the LHC F. Searching for Higgs Bosons in $t\bar t H$ Production G. Studies of Charged Higgs Boson Signals for the Tevatron and the LHC
[ { "created": "Tue, 5 Mar 2002 21:59:31 GMT", "version": "v1" }, { "created": "Fri, 15 Mar 2002 16:56:54 GMT", "version": "v2" } ]
2007-05-23
[ [ "Cavalli", "D.", "" ], [ "Djouadi", "A.", "" ], [ "Jakobs", "K.", "" ], [ "Nikitenko", "A.", "" ], [ "Spira", "M.", "" ], [ "Wagner", "C. E. M.", "" ], [ "Yao", "W. -M.", "" ], [ "Assamagan", "K. A.", "" ], [ "Azuelos", "G.", "" ], [ "Balatenychev", "S.", "" ], [ "Bélanger", "G.", "" ], [ "Bisset", "M.", "" ], [ "Bocci", "A.", "" ], [ "Boudjema", "F.", "" ], [ "Buttar", "C.", "" ], [ "Carena", "M.", "" ], [ "Catani", "S.", "" ], [ "Cavasinni", "V.", "" ], [ "Coadou", "Y.", "" ], [ "Costanzo", "D.", "" ], [ "Cottrant", "A.", "" ], [ "Datta", "A. K.", "" ], [ "Deandrea", "A.", "" ], [ "de Florian", "D.", "" ], [ "Del Duca", "V.", "" ], [ "Di Girolamo", "B.", "" ], [ "Drollinger", "V.", "" ], [ "Figy", "T.", "" ], [ "Frank", "M.", "" ], [ "Godbole", "R. M.", "" ], [ "Grazzini", "M.", "" ], [ "Guchait", "M.", "" ], [ "Harper", "R.", "" ], [ "Heinemeyer", "S.", "" ], [ "Hobbs", "J.", "" ], [ "Hollik", "W.", "" ], [ "Hugonie", "C.", "" ], [ "Ilyin", "V. I.", "" ], [ "Kilgore", "W. B.", "" ], [ "Kinnunen", "R.", "" ], [ "Klute", "M.", "" ], [ "Lafaye", "R.", "" ], [ "Mambrini", "Y.", "" ], [ "Mazini", "R.", "" ], [ "Mazumdar", "K.", "" ], [ "Moortgat", "F.", "" ], [ "Moretti", "S.", "" ], [ "Negri", "G.", "" ], [ "Neukermans", "L.", "" ], [ "Oleari", "C.", "" ], [ "Pukhov", "A.", "" ], [ "Rainwater", "D.", "" ], [ "Richter-Was", "E.", "" ], [ "Roy", "D. P.", "" ], [ "Schmidt", "C. R.", "" ], [ "Semenov", "A.", "" ], [ "Thomas", "J.", "" ], [ "Vivarelli", "I.", "" ], [ "Weiglein", "G.", "" ], [ "Zeppenfeld", "D.", "" ] ]
Report of the Higgs working group for the Workshop `Physics at TeV Colliders', Les Houches, France, 21 May - 1 June 2001. It contains 7 separate sections: A. Theoretical Developments B. Higgs Searches at the Tevatron C. Experimental Observation of an invisible Higgs Boson at LHC D. Search for the Standard Model Higgs Boson using Vector Boson Fusion at the LHC E. Study of the MSSM channel $A/H \to \tau \tau$ at the LHC F. Searching for Higgs Bosons in $t\bar t H$ Production G. Studies of Charged Higgs Boson Signals for the Tevatron and the LHC
1202.2426
Edoardo Mirabella Dr.
Ruth Britto and Edoardo Mirabella
Massive particles and unitarity cuts
To appear in the proceedings of the LCWS 2011, September 2011, Granada, Spain
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an extension of the spinor integration formalism of one loop amplitudes from the double-cut to the single-cut case. This technique can be applied for the computation of the tadpole coefficients. Moreover we describe an off-shell continuation of one loop amplitudes that allows a finite evaluation of the unitarity cuts in the channel of a single massive external fermion.
[ { "created": "Sat, 11 Feb 2012 10:03:57 GMT", "version": "v1" } ]
2012-02-14
[ [ "Britto", "Ruth", "" ], [ "Mirabella", "Edoardo", "" ] ]
We present an extension of the spinor integration formalism of one loop amplitudes from the double-cut to the single-cut case. This technique can be applied for the computation of the tadpole coefficients. Moreover we describe an off-shell continuation of one loop amplitudes that allows a finite evaluation of the unitarity cuts in the channel of a single massive external fermion.
2312.09290
Luigi Favaro
Florian Ernst, Luigi Favaro, Claudius Krause, Tilman Plehn, David Shih
Normalizing Flows for High-Dimensional Detector Simulations
24 pages, 9 figures, 5 tables
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Whenever invertible generative networks are needed for LHC physics, normalizing flows show excellent performance. A challenge is their scaling to high-dimensional phase spaces. We investigate their performance for fast calorimeter shower simulations with increasing phase space dimension. In addition to the standard architecture we also employ a VAE to compress the dimensionality. Our study provides benchmarks for invertible networks applied to the CaloChallenge.
[ { "created": "Thu, 14 Dec 2023 19:00:07 GMT", "version": "v1" } ]
2023-12-18
[ [ "Ernst", "Florian", "" ], [ "Favaro", "Luigi", "" ], [ "Krause", "Claudius", "" ], [ "Plehn", "Tilman", "" ], [ "Shih", "David", "" ] ]
Whenever invertible generative networks are needed for LHC physics, normalizing flows show excellent performance. A challenge is their scaling to high-dimensional phase spaces. We investigate their performance for fast calorimeter shower simulations with increasing phase space dimension. In addition to the standard architecture we also employ a VAE to compress the dimensionality. Our study provides benchmarks for invertible networks applied to the CaloChallenge.
1704.05917
Vladimir Skokov
Adrian Dumitru, Vladimir Skokov
Fluctuations of the gluon distribution from the small-x effective action
14 pages, 5 figures; v2: added section IV-A to discuss the parametric dependence of the selected fluctuations on the number of colors and on the thickness of the target; v3: version accepted to Phys. Rev. D
Phys. Rev. D 96, 056029 (2017)
10.1103/PhysRevD.96.056029
RBRC 1238
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The computation of observables in high energy QCD involves an average over stochastic semiclassical small-x gluon fields. The weight of various configurations is determined by the effective action. We introduce a method to study fluctuations of observables, functionals of the small-x fields, which does not explicitly involve dipoles. We integrate out those fluctuations of the gluon field under which a given observable is invariant. Thereby we obtain the effective potential for that observable describing its fluctuations about the saddle point. We determine explicitly the effective potential for the covariant gauge gluon distribution both for the McLerran-Venugopalan (MV) model and for a (non-local) Gaussian approximation for the small-x effective action. This provides insight into the correlation of fluctuations of the number of hard gluons versus their typical transverse momentum. We find that the spectral shape of the fluctuations of the gluon distribution is fundamentally different in the MV model, where there is a pile-up of gluons near the saturation scale, versus the solution of the small-x JIMWLK renormalization group, which generates essentially scale invariant fluctuations above the absorptive boundary set by the saturation scale.
[ { "created": "Wed, 19 Apr 2017 20:00:36 GMT", "version": "v1" }, { "created": "Wed, 3 May 2017 20:07:38 GMT", "version": "v2" }, { "created": "Wed, 11 Oct 2017 15:23:20 GMT", "version": "v3" } ]
2017-10-12
[ [ "Dumitru", "Adrian", "" ], [ "Skokov", "Vladimir", "" ] ]
The computation of observables in high energy QCD involves an average over stochastic semiclassical small-x gluon fields. The weight of various configurations is determined by the effective action. We introduce a method to study fluctuations of observables, functionals of the small-x fields, which does not explicitly involve dipoles. We integrate out those fluctuations of the gluon field under which a given observable is invariant. Thereby we obtain the effective potential for that observable describing its fluctuations about the saddle point. We determine explicitly the effective potential for the covariant gauge gluon distribution both for the McLerran-Venugopalan (MV) model and for a (non-local) Gaussian approximation for the small-x effective action. This provides insight into the correlation of fluctuations of the number of hard gluons versus their typical transverse momentum. We find that the spectral shape of the fluctuations of the gluon distribution is fundamentally different in the MV model, where there is a pile-up of gluons near the saturation scale, versus the solution of the small-x JIMWLK renormalization group, which generates essentially scale invariant fluctuations above the absorptive boundary set by the saturation scale.
hep-ph/0406067
Igor N. Mishustin
I. N. Mishustin (1,2,3), L. M. Satarov (1,2), D. Strottman (2,4), and W. Greiner (2) ((1) Kurchatov Institute, Moscow, (2) Goethe University, Frankfurt/M, (3) Niels Bohr Institute, Copenhagen, (4) Los Alamos National Laboratory)
Possible production of exotic baryonia in relativistic heavy-ion collisions
8 pages, 1 figure
J.Phys. G31 (2005) 803-808
10.1088/0954-3899/31/7/022
null
hep-ph
null
Properties of a hypothetical baryonium with the quark content ($uds\ov{u}\ov{d}\ov{s}$) are discussed. The MIT bag model predicts its mass to be unexpectedly low, approximately 1210 MeV. Possible hadronic decay modes of this state are analyzed. Ultrarelativistic heavy-ion collisions provide favorable conditions for the formation of such particles from the baryon-free quark-gluon plasma. We estimate multiplicities of such exotic baryonia on the basis of a simple thermal model.
[ { "created": "Mon, 7 Jun 2004 10:02:57 GMT", "version": "v1" } ]
2009-11-10
[ [ "Mishustin", "I. N.", "" ], [ "Satarov", "L. M.", "" ], [ "Strottman", "D.", "" ], [ "Greiner", "W.", "" ] ]
Properties of a hypothetical baryonium with the quark content ($uds\ov{u}\ov{d}\ov{s}$) are discussed. The MIT bag model predicts its mass to be unexpectedly low, approximately 1210 MeV. Possible hadronic decay modes of this state are analyzed. Ultrarelativistic heavy-ion collisions provide favorable conditions for the formation of such particles from the baryon-free quark-gluon plasma. We estimate multiplicities of such exotic baryonia on the basis of a simple thermal model.
hep-ph/0009105
Pyungwon Ko
S. Baek, J.-H. Jang, P. Ko and J. H. Park (KAIST)
Fully supersymmetric CP violations in the kaon system
Contribution to the Proceedings of ICHEP2000, Osaka, 2000
null
null
KAIST preprint KAIST-TH 2000/12
hep-ph
null
We show that, on the contrary to the usual claims, fully supersymmetric CP violations in the kaon system are possible through the gluino mediated flavor changing interactions. Both $\epsilon_K$ and ${\rm Re} (\epsilon' / \epsilon_K)$ can be accommodated for relatively large $\tan\beta$ without any fine tunings or contradictions to the FCNC and EDM constraints.
[ { "created": "Sun, 10 Sep 2000 05:01:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baek", "S.", "", "KAIST" ], [ "Jang", "J. -H.", "", "KAIST" ], [ "Ko", "P.", "", "KAIST" ], [ "Park", "J. H.", "", "KAIST" ] ]
We show that, on the contrary to the usual claims, fully supersymmetric CP violations in the kaon system are possible through the gluino mediated flavor changing interactions. Both $\epsilon_K$ and ${\rm Re} (\epsilon' / \epsilon_K)$ can be accommodated for relatively large $\tan\beta$ without any fine tunings or contradictions to the FCNC and EDM constraints.
hep-ph/0010129
Barry R. Holstein
Barry R. Holstein
Nucleon Polarizabilities
13 page Latex file; Talk given at Chiral Dynamics 2000 Workshop, Jefferson Lab, July 2000
null
10.1142/9789812810977_0018
null
hep-ph nucl-th
null
The subject of nucleon polarizabilities in real, virtual, and doubly virtual Compton scattering is discussed with respect to what is known and how such quantities can be extracted from data.
[ { "created": "Thu, 12 Oct 2000 17:11:18 GMT", "version": "v1" } ]
2017-08-23
[ [ "Holstein", "Barry R.", "" ] ]
The subject of nucleon polarizabilities in real, virtual, and doubly virtual Compton scattering is discussed with respect to what is known and how such quantities can be extracted from data.
2106.04190
Hsiang-nan Li
Hsiang-nan Li
Glauber gluons in annihilation amplitudes for heavy meson decays
10 pages, 3 figures
null
10.1016/j.cjph.2021.07.034
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the Glauber divergences in nonfactorizable annihilation amplitudes for two-body hadronic heavy meson decays in the $k_T$ factorization theorem at one-loop level. These divergences can be absorbed into the Glauber factors in the dominant kinematic regions of small parton momenta, which modify the interference between a nonfactorizable annihilation amplitude and other amplitudes by rotating it with a phase. We postulate that only the Glauber effect associated with a pion is significant, due to its special role as a $q\bar q$ bound state and as a pseudo Nambu-Goldstone boson simultaneously. It is elaborated that the data of the $D\to\pi\pi$ and $\pi K$ branching ratios have revealed prominent Glauber effects. This work provides a solid theoretical ground for the factorization-assisted topological-amplitude parametrization of two-body hadronic $D$ meson decays.
[ { "created": "Tue, 8 Jun 2021 09:02:02 GMT", "version": "v1" } ]
2021-09-22
[ [ "Li", "Hsiang-nan", "" ] ]
We investigate the Glauber divergences in nonfactorizable annihilation amplitudes for two-body hadronic heavy meson decays in the $k_T$ factorization theorem at one-loop level. These divergences can be absorbed into the Glauber factors in the dominant kinematic regions of small parton momenta, which modify the interference between a nonfactorizable annihilation amplitude and other amplitudes by rotating it with a phase. We postulate that only the Glauber effect associated with a pion is significant, due to its special role as a $q\bar q$ bound state and as a pseudo Nambu-Goldstone boson simultaneously. It is elaborated that the data of the $D\to\pi\pi$ and $\pi K$ branching ratios have revealed prominent Glauber effects. This work provides a solid theoretical ground for the factorization-assisted topological-amplitude parametrization of two-body hadronic $D$ meson decays.
1506.08364
Yevgeny Stadnik
Yevgeny V. Stadnik, Victor V. Flambaum
New generation low-energy probes for ultralight axion and scalar dark matter
10 pages, Invited brief review for Modern Physics Letters A, Guest Editor: Maxim Yu. Khlopov
Mod. Phys. Lett. A 32, 1740004 (2017)
10.1142/S0217732317400041
null
hep-ph astro-ph.CO nucl-th physics.atom-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a brief overview of a new generation of high-precision laboratory and astrophysical measurements to search for ultralight (sub-eV) axion, axion-like pseudoscalar and scalar dark matter, which form either a coherent condensate or topological defects (solitons). In these new detection methods, the sought effects are linear in the interaction constant between dark matter and ordinary matter, which is in stark contrast to traditional searches for dark matter, where the sought effects are quadratic or higher order in the underlying interaction constants (which are extremely small).
[ { "created": "Sun, 28 Jun 2015 06:38:21 GMT", "version": "v1" } ]
2017-05-30
[ [ "Stadnik", "Yevgeny V.", "" ], [ "Flambaum", "Victor V.", "" ] ]
We present a brief overview of a new generation of high-precision laboratory and astrophysical measurements to search for ultralight (sub-eV) axion, axion-like pseudoscalar and scalar dark matter, which form either a coherent condensate or topological defects (solitons). In these new detection methods, the sought effects are linear in the interaction constant between dark matter and ordinary matter, which is in stark contrast to traditional searches for dark matter, where the sought effects are quadratic or higher order in the underlying interaction constants (which are extremely small).
1608.02577
Cyrille Marquet
C. Marquet, E. Petreska and C. Roiesnel
Transverse-momentum-dependent gluon distributions from JIMWLK evolution
21 pages, 7 figures, version published in JHEP
JHEP 1610:065,2016
10.1007/JHEP10(2016)065
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Transverse-momentum-dependent (TMD) gluon distributions have different operator definitions, depending on the process under consideration. We study that aspect of TMD factorization in the small-x limit, for the various unpolarized TMD gluon distributions encountered in the literature. To do this, we consider di-jet production in hadronic collisions, since this process allows to be exhaustive with respect to the possible operator definitions, and is suitable to be investigated at small x. Indeed, for forward and nearly back-to-back jets, one can apply both the TMD factorization and Color Glass Condensate (CGC) approaches to compute the di-jet cross-section, and compare the results. Doing so, we show that both descriptions coincide, and we show how to express the various TMD gluon distributions in terms of CGC correlators of Wilson lines, while keeping Nc finite. We then proceed to evaluate them by solving the JIMWLK equation numerically. We obtain that at large transverse momentum, the process dependence essentially disappears, while at small transverse momentum, non-linear saturation effects impact the various TMD gluon distributions in very different ways. We notice the presence of a geometric scaling regime for all the TMD gluon distributions studied: the "dipole" one, the Weizs\"acker-Williams one, and the six others involved in forward di-jet production.
[ { "created": "Mon, 8 Aug 2016 19:59:54 GMT", "version": "v1" }, { "created": "Mon, 9 Jan 2017 09:46:36 GMT", "version": "v2" } ]
2017-01-10
[ [ "Marquet", "C.", "" ], [ "Petreska", "E.", "" ], [ "Roiesnel", "C.", "" ] ]
Transverse-momentum-dependent (TMD) gluon distributions have different operator definitions, depending on the process under consideration. We study that aspect of TMD factorization in the small-x limit, for the various unpolarized TMD gluon distributions encountered in the literature. To do this, we consider di-jet production in hadronic collisions, since this process allows to be exhaustive with respect to the possible operator definitions, and is suitable to be investigated at small x. Indeed, for forward and nearly back-to-back jets, one can apply both the TMD factorization and Color Glass Condensate (CGC) approaches to compute the di-jet cross-section, and compare the results. Doing so, we show that both descriptions coincide, and we show how to express the various TMD gluon distributions in terms of CGC correlators of Wilson lines, while keeping Nc finite. We then proceed to evaluate them by solving the JIMWLK equation numerically. We obtain that at large transverse momentum, the process dependence essentially disappears, while at small transverse momentum, non-linear saturation effects impact the various TMD gluon distributions in very different ways. We notice the presence of a geometric scaling regime for all the TMD gluon distributions studied: the "dipole" one, the Weizs\"acker-Williams one, and the six others involved in forward di-jet production.
1210.5074
Debasish Borah
Debasish Borah and Mrinal Kumar Das
Neutrino masses and mixings with non-zero $\theta_{13}$ in Type I+II Seesaw Models
Version 2: 20 pages, 12 figures, 3 tables, Major Revision, Accepted for publication in Nuclear Physics B. arXiv admin note: substantial text overlap with arXiv:1209.0280
Nuclear Physics B 870, 461 (2013)
10.1016/j.nuclphysb.2013.02.002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the survivability of neutrino mass models with normal as well as inverted hierarchical mass patterns in the presence of both type I and type II seesaw contributions to neutrino mass within the framework of generic left-right symmetric models. At leading order, the Dirac neutrino mass matrix is assumed to be diagonal with either charged lepton (CL) type or up quark (UQ) type structure which gets corrected by non-leading effects giving rise to deviations from tri-bi-maximal (TBM) mixing and hence non-zero value of $\theta_{13}$. Using the standard form of neutrino mass matrix which incorporates such non-leading effects, we parametrize the neutrino mass matrix incorporating both oscillation as well as cosmology data. Also considering extremal values of Majorana CP phases such that the neutrino mass eigenvalues have the structure $(m_1, -m_2, m_3)$ and $(m_1, m_2, m_3)$, we then calculate the predictions for neutrino parameters in the presence of both type I and type II seesaw contributions, taking one of them dominant and the other sub-dominant. We show that these mass models can survive in our framework with certain exceptions.
[ { "created": "Thu, 18 Oct 2012 09:58:02 GMT", "version": "v1" }, { "created": "Tue, 5 Feb 2013 13:19:52 GMT", "version": "v2" } ]
2013-02-27
[ [ "Borah", "Debasish", "" ], [ "Das", "Mrinal Kumar", "" ] ]
We study the survivability of neutrino mass models with normal as well as inverted hierarchical mass patterns in the presence of both type I and type II seesaw contributions to neutrino mass within the framework of generic left-right symmetric models. At leading order, the Dirac neutrino mass matrix is assumed to be diagonal with either charged lepton (CL) type or up quark (UQ) type structure which gets corrected by non-leading effects giving rise to deviations from tri-bi-maximal (TBM) mixing and hence non-zero value of $\theta_{13}$. Using the standard form of neutrino mass matrix which incorporates such non-leading effects, we parametrize the neutrino mass matrix incorporating both oscillation as well as cosmology data. Also considering extremal values of Majorana CP phases such that the neutrino mass eigenvalues have the structure $(m_1, -m_2, m_3)$ and $(m_1, m_2, m_3)$, we then calculate the predictions for neutrino parameters in the presence of both type I and type II seesaw contributions, taking one of them dominant and the other sub-dominant. We show that these mass models can survive in our framework with certain exceptions.
1512.06674
Sreerup Raychaudhuri
Debjyoti Bardhan, Disha Bhatia, Amit Chakraborty, Ushoshi Maitra, Sreerup Raychaudhuri, Tousik Samui
Radion Candidate for the LHC Diphoton Resonance
14 pages, pdfLatex, 2 pdf figures, small changes made in text and some references added
null
null
TIFR preprint TIFR-TH/15-45
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent observation of a modest excess in diphoton final states at the LHC, by both the ATLAS and CMS Collaborations, has sparked off the expected race among theorists to find the right explanation for this proto-resonance, assuming that the signal will survive and not prove to be yet another statistical fluctuation. We carry out a general analysis of this `signal' in the case of a scalar which couples only to pairs of gluons (for production) and photons (for diphoton decay modes), and establish that an explanation of the observed resonance, taken together with the null results of new physics searches in all the other channels, requires a scalar with rather exotic behaviour. We then demonstrate that a fairly simple-minded extension of the minimal Randall-Sundrum model can yield a radion candidate which might reproduce this exotic behaviour.
[ { "created": "Mon, 21 Dec 2015 15:53:08 GMT", "version": "v1" }, { "created": "Wed, 13 Jan 2016 14:55:32 GMT", "version": "v2" } ]
2016-01-14
[ [ "Bardhan", "Debjyoti", "" ], [ "Bhatia", "Disha", "" ], [ "Chakraborty", "Amit", "" ], [ "Maitra", "Ushoshi", "" ], [ "Raychaudhuri", "Sreerup", "" ], [ "Samui", "Tousik", "" ] ]
The recent observation of a modest excess in diphoton final states at the LHC, by both the ATLAS and CMS Collaborations, has sparked off the expected race among theorists to find the right explanation for this proto-resonance, assuming that the signal will survive and not prove to be yet another statistical fluctuation. We carry out a general analysis of this `signal' in the case of a scalar which couples only to pairs of gluons (for production) and photons (for diphoton decay modes), and establish that an explanation of the observed resonance, taken together with the null results of new physics searches in all the other channels, requires a scalar with rather exotic behaviour. We then demonstrate that a fairly simple-minded extension of the minimal Randall-Sundrum model can yield a radion candidate which might reproduce this exotic behaviour.
1202.0896
Pitayuth Wongjun
Antonio De Felice, Khamphee Karwan, Pitayuth Wongjun
Stability of the 3-form field during inflation
18 pages, 12 figures, add new informations in V2, correct some typos in V3
Phys. Rev. D 85, 123545 (2012)
10.1103/PhysRevD.85.123545
null
hep-ph astro-ph.CO gr-qc
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the minimally coupled 3-form field which has been considered as a candidate to realize inflation. We have studied the conditions to avoid ghosts and Laplacian instabilities and found that some classes of potentials, e.g. the Mexican-hat one, will in general be unstable. We then propose other classes of potentials which are instead free from any instability, drive a long-enough slow-roll regime followed by an oscillatory epoch, and as a consequence, can provide successful inflation. Finally, we also provide stable potentials which lead to a small enough propagation speed for the scalar perturbations, giving a possibility for these models to produce non-Gaussianities.
[ { "created": "Sat, 4 Feb 2012 13:58:03 GMT", "version": "v1" }, { "created": "Mon, 14 May 2012 08:05:50 GMT", "version": "v2" }, { "created": "Tue, 17 Jul 2012 15:03:14 GMT", "version": "v3" } ]
2012-07-18
[ [ "De Felice", "Antonio", "" ], [ "Karwan", "Khamphee", "" ], [ "Wongjun", "Pitayuth", "" ] ]
We consider the minimally coupled 3-form field which has been considered as a candidate to realize inflation. We have studied the conditions to avoid ghosts and Laplacian instabilities and found that some classes of potentials, e.g. the Mexican-hat one, will in general be unstable. We then propose other classes of potentials which are instead free from any instability, drive a long-enough slow-roll regime followed by an oscillatory epoch, and as a consequence, can provide successful inflation. Finally, we also provide stable potentials which lead to a small enough propagation speed for the scalar perturbations, giving a possibility for these models to produce non-Gaussianities.
hep-ph/0505240
Brian Cox
B. E. Cox, A. De Roeck, V. A. Khoze, T. Pierzchala, M. G. Ryskin, I. Nasteva, W. J. Stirling and M. Tasevsky
Detecting the Standard Model Higgs Boson in the WW decay channel using forward proton tagging at the LHC
12 pages, 6 figures
Eur.Phys.J.C45:401-407,2006
10.1140/epjc/s2005-02447-x
IPPP/05/20, DCPT/05/40, MAN/HEP/2005/2
hep-ph
null
We present a detailed study of the central exclusive production of the Standard Model Higgs Boson in the WW decay channel at the LHC. We include estimates of the experimental acceptance, including that of the proposed proton tagging detectors at 220m and 420m around either ATLAS and / or CMS, and the level 1 trigger acceptances. We give first estimates of the photon-photon and glue-glue background processes in the semi-leptonic and fully-leptonic decay channels. We find that there will be a detectable signal for Higgs masses between 140 GeV and 200 GeV, and that the backgrounds should be controllable.
[ { "created": "Fri, 27 May 2005 14:53:29 GMT", "version": "v1" }, { "created": "Tue, 19 Jul 2005 15:53:13 GMT", "version": "v2" }, { "created": "Mon, 12 Dec 2005 15:02:38 GMT", "version": "v3" } ]
2009-01-07
[ [ "Cox", "B. E.", "" ], [ "De Roeck", "A.", "" ], [ "Khoze", "V. A.", "" ], [ "Pierzchala", "T.", "" ], [ "Ryskin", "M. G.", "" ], [ "Nasteva", "I.", "" ], [ "Stirling", "W. J.", "" ], [ "Tasevsky", "M.", "" ] ]
We present a detailed study of the central exclusive production of the Standard Model Higgs Boson in the WW decay channel at the LHC. We include estimates of the experimental acceptance, including that of the proposed proton tagging detectors at 220m and 420m around either ATLAS and / or CMS, and the level 1 trigger acceptances. We give first estimates of the photon-photon and glue-glue background processes in the semi-leptonic and fully-leptonic decay channels. We find that there will be a detectable signal for Higgs masses between 140 GeV and 200 GeV, and that the backgrounds should be controllable.
2304.05415
Oliver Scholer
Oliver Scholer, Jordy de Vries, Luk\'a\v{s} Gr\'af
$\nu$DoBe -- A Python Tool for Neutrinoless Double Beta Decay
79 Pages, 6 Tables, 19 Figures, Download: https://github.com/OScholer/nudobe , Online-Tool: https://nudobe.streamlit.app
null
10.1007/JHEP08(2023)043
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by-nc-sa/4.0/
We present $\nu$DoBe, a Python tool for the computation of neutrinoless double beta decay ($0\nu\beta\beta$) rates in terms of lepton-number-violating operators in the Standard Model Effective Field Theory (SMEFT). The tool can be used for automated calculations of $0\nu\beta\beta$ rates, electron spectra and angular correlations for all isotopes of experimental interest, for lepton-number-violating operators up to and including dimension 9. The tool takes care of renormalization-group running to lower energies and provides the matching to the low-energy effective field theory and, at lower scales, to a chiral effective field theory description of $0\nu\beta\beta$ rates. The user can specify different sets of nuclear matrix elements from various many-body methods and hadronic low-energy constants. The tool can be used to quickly generate analytical and numerical expressions for $0\nu\beta\beta$ rates and to generate a large variety of plots. In this work, we provide examples of possible use along with a detailed code documentation. The code can be accessed through: GitHub: https://github.com/OScholer/nudobe Online User-Interface: https://nudobe.streamlit.app
[ { "created": "Tue, 11 Apr 2023 18:00:01 GMT", "version": "v1" }, { "created": "Wed, 13 Sep 2023 11:14:51 GMT", "version": "v2" } ]
2023-09-14
[ [ "Scholer", "Oliver", "" ], [ "de Vries", "Jordy", "" ], [ "Gráf", "Lukáš", "" ] ]
We present $\nu$DoBe, a Python tool for the computation of neutrinoless double beta decay ($0\nu\beta\beta$) rates in terms of lepton-number-violating operators in the Standard Model Effective Field Theory (SMEFT). The tool can be used for automated calculations of $0\nu\beta\beta$ rates, electron spectra and angular correlations for all isotopes of experimental interest, for lepton-number-violating operators up to and including dimension 9. The tool takes care of renormalization-group running to lower energies and provides the matching to the low-energy effective field theory and, at lower scales, to a chiral effective field theory description of $0\nu\beta\beta$ rates. The user can specify different sets of nuclear matrix elements from various many-body methods and hadronic low-energy constants. The tool can be used to quickly generate analytical and numerical expressions for $0\nu\beta\beta$ rates and to generate a large variety of plots. In this work, we provide examples of possible use along with a detailed code documentation. The code can be accessed through: GitHub: https://github.com/OScholer/nudobe Online User-Interface: https://nudobe.streamlit.app
1905.02203
Andreas Weiler
Javi Serra, Stefan Stelzl, Riccardo Torre, and Andreas Weiler
Hypercharged Naturalness
37 pages, 7 figures
null
10.1007/JHEP10(2019)060
TUM-HEP-1199/19, CERN-TH-2019-064
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an exceptional twin-Higgs model with the minimal symmetry structure for an exact implementation of twin parity along with custodial symmetry. Twin particles are mirrors of the Standard Model yet they carry hypercharge, while the photon is identified with its twin. We thoroughly explore the phenomenological signatures of hypercharged naturalness: long-lived charged particles, a colorless twin top with electric charge $2/3$ that once pair-produced, bounds via twin-color interactions and can annihilate to dileptons or a Higgs plus a photon or a $Z$, and glueballs produced from Higgs decays and twin-quarkonium annihilation that either decay displaced, or are stable on collider scales and eventually decay to diphotons. Prospects for detection of these signatures are also discussed.
[ { "created": "Mon, 6 May 2019 18:00:00 GMT", "version": "v1" } ]
2020-01-08
[ [ "Serra", "Javi", "" ], [ "Stelzl", "Stefan", "" ], [ "Torre", "Riccardo", "" ], [ "Weiler", "Andreas", "" ] ]
We present an exceptional twin-Higgs model with the minimal symmetry structure for an exact implementation of twin parity along with custodial symmetry. Twin particles are mirrors of the Standard Model yet they carry hypercharge, while the photon is identified with its twin. We thoroughly explore the phenomenological signatures of hypercharged naturalness: long-lived charged particles, a colorless twin top with electric charge $2/3$ that once pair-produced, bounds via twin-color interactions and can annihilate to dileptons or a Higgs plus a photon or a $Z$, and glueballs produced from Higgs decays and twin-quarkonium annihilation that either decay displaced, or are stable on collider scales and eventually decay to diphotons. Prospects for detection of these signatures are also discussed.
2012.14411
Cem Salih Un
K. S. Babu, Ilia Gogoladze, Cem Salih Un
Proton Lifetime in Minimal SUSY SU(5) in Light of LHC Results
null
Journal of High Energy Physics, 02 (2022), 164
10.1007/JHEP02(2022)164
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We examine proton decay mediated by color-triplet Higgsinos in minimal supersymmetric $SU(5)$ grand unified theory in light of the discovery of the Higgs boson and the absence of SUSY signals at the LHC. We pay special attention to various threshold effects arising from Planck-suppressed operators that affect the color-triplet Higgsino mass and also correct the wrong mass relations for the light fermions. Our analysis allows for a non-universal SUSY spectrum with the third family scalars having a separate mass compared to the first two families. We identify the allowed parameter space of the model and show that the SUSY scalar masses are constrained by current limits from proton lifetime to be above 5 TeV, while the glunio, Wino and the Higgsinos may be within reach of the LHC. When the SUSY scalar masses are required to be $\leq 20$ TeV, so that they are within reach of next generation collider experiments, we find that proton lifetime for the decay $p \rightarrow \overline{\nu} K^+$ is bounded by $\tau(p \rightarrow \overline{\nu} K^+) \leq 1.1 \times 10^{35}$ yrs.
[ { "created": "Mon, 28 Dec 2020 18:43:24 GMT", "version": "v1" }, { "created": "Sun, 31 Jan 2021 20:30:17 GMT", "version": "v2" }, { "created": "Mon, 8 Nov 2021 19:12:16 GMT", "version": "v3" }, { "created": "Thu, 24 Feb 2022 22:06:18 GMT", "version": "v4" } ]
2022-02-28
[ [ "Babu", "K. S.", "" ], [ "Gogoladze", "Ilia", "" ], [ "Un", "Cem Salih", "" ] ]
We examine proton decay mediated by color-triplet Higgsinos in minimal supersymmetric $SU(5)$ grand unified theory in light of the discovery of the Higgs boson and the absence of SUSY signals at the LHC. We pay special attention to various threshold effects arising from Planck-suppressed operators that affect the color-triplet Higgsino mass and also correct the wrong mass relations for the light fermions. Our analysis allows for a non-universal SUSY spectrum with the third family scalars having a separate mass compared to the first two families. We identify the allowed parameter space of the model and show that the SUSY scalar masses are constrained by current limits from proton lifetime to be above 5 TeV, while the glunio, Wino and the Higgsinos may be within reach of the LHC. When the SUSY scalar masses are required to be $\leq 20$ TeV, so that they are within reach of next generation collider experiments, we find that proton lifetime for the decay $p \rightarrow \overline{\nu} K^+$ is bounded by $\tau(p \rightarrow \overline{\nu} K^+) \leq 1.1 \times 10^{35}$ yrs.
0709.1553
Bernard Pire
B. Pire and L. Szymanowski
Probing Transversity GPDs in Photo and Electroproduction of Two Vector Mesons
3 pages, 5 figures, to be published in the proceedings of the International Conference on the Structure and Interactions of the Photon (Photon 2007) Paris, july 2007
Nucl.Phys.Proc.Suppl.184:243-246,2008
10.1016/j.nuclphysbps.2008.09.173
CPhT- PC 092.0807
hep-ph nucl-th
null
Electroproduction of two mesons well separated in rapidity allows the first feasible selective access to chiral-odd transversity GPDs provided one of these mesons is a transversely polarized vector meson rho_T.
[ { "created": "Tue, 11 Sep 2007 08:57:42 GMT", "version": "v1" } ]
2008-12-18
[ [ "Pire", "B.", "" ], [ "Szymanowski", "L.", "" ] ]
Electroproduction of two mesons well separated in rapidity allows the first feasible selective access to chiral-odd transversity GPDs provided one of these mesons is a transversely polarized vector meson rho_T.
2005.02288
Alessandro Bacchetta
Alessandro Bacchetta, Francesco Giovanni Celiberto, Marco Radici, Pieter Taels
Transverse-momentum-dependent gluon distribution functions in a spectator model
Small changes in the text. Correction after Eq. (5). Eq. (6) added. Fig. 1 slightly modified. Some references added. All results unchanged
null
10.1140/epjc/s10052-020-8327-6
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a model calculation of transverse-momentum-dependent distributions (TMDs) of gluons in the nucleon. The model is based on the assumption that a nucleon can emit a gluon, and what remains after the emission is treated as a single spectator particle. This spectator particle is considered to be on-shell, but its mass is allowed to take a continuous range of values, described by a spectral function. The nucleon-gluon-spectator coupling is described by an effective vertex containing two form factors. We fix the model parameters to obtain the best agreement with collinear gluon distributions extracted from global fits. We study the tomography in momentum space of gluons inside nucleons for various combinations of their polarizations. These can be used to make predictions of observables relevant for gluon TMD studies at current and future collider facilities.
[ { "created": "Tue, 5 May 2020 15:42:10 GMT", "version": "v1" }, { "created": "Mon, 7 Dec 2020 12:10:01 GMT", "version": "v2" } ]
2020-12-08
[ [ "Bacchetta", "Alessandro", "" ], [ "Celiberto", "Francesco Giovanni", "" ], [ "Radici", "Marco", "" ], [ "Taels", "Pieter", "" ] ]
We present a model calculation of transverse-momentum-dependent distributions (TMDs) of gluons in the nucleon. The model is based on the assumption that a nucleon can emit a gluon, and what remains after the emission is treated as a single spectator particle. This spectator particle is considered to be on-shell, but its mass is allowed to take a continuous range of values, described by a spectral function. The nucleon-gluon-spectator coupling is described by an effective vertex containing two form factors. We fix the model parameters to obtain the best agreement with collinear gluon distributions extracted from global fits. We study the tomography in momentum space of gluons inside nucleons for various combinations of their polarizations. These can be used to make predictions of observables relevant for gluon TMD studies at current and future collider facilities.
1610.03997
Jinmian Li
P. Ko, Jinmian Li
Interference effects of two scalar boson propagators on the LHC search for the singlet fermion DM
16 pages, 8 figures; published version
Phys. Lett. B 765 (2017) 53-61
10.1016/j.physletb.2016.11.056
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A gauge invariant UV-completion for singlet fermion DM interacting with the standard model (SM) particles involves a new singlet scalar. Therefore the model contains two scalar mediators, mixtures of the SM Higgs boson and a singlet scalar boson. Collider phenomenology of the interference effect between these two scalar propagators is studied in this work. This interference effect can be either constructive or destructive in the DM production cross section depending on both singlet scalar and DM masses, and it will soften the final state jets in the full mass region. Applying the CMS mono-jet search to our model, we find the interference effect plays a very important role in the DM search sensitivity, and the DM production cross section of our model is more than one order of magnitude below the LHC sensitivity at current stage.
[ { "created": "Thu, 13 Oct 2016 09:50:29 GMT", "version": "v1" }, { "created": "Tue, 13 Dec 2016 04:52:51 GMT", "version": "v2" } ]
2016-12-14
[ [ "Ko", "P.", "" ], [ "Li", "Jinmian", "" ] ]
A gauge invariant UV-completion for singlet fermion DM interacting with the standard model (SM) particles involves a new singlet scalar. Therefore the model contains two scalar mediators, mixtures of the SM Higgs boson and a singlet scalar boson. Collider phenomenology of the interference effect between these two scalar propagators is studied in this work. This interference effect can be either constructive or destructive in the DM production cross section depending on both singlet scalar and DM masses, and it will soften the final state jets in the full mass region. Applying the CMS mono-jet search to our model, we find the interference effect plays a very important role in the DM search sensitivity, and the DM production cross section of our model is more than one order of magnitude below the LHC sensitivity at current stage.
1610.06211
Marta Luszczak Mrs
Marta {\L}uszczak, Antoni Szczurek
Diffractive processes at the LHC within $k_t$ -factorization approach
7 pages, 7 figures, talk given by M. {\L}uszczak at the Low-X Meeting 2016, 6-11 June 2016, K\'aroly R\'obert College, Gy\"ongy\"os, Hungary. arXiv admin note: text overlap with arXiv:1606.09499
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the single diffractive production of $c \bar c$ pairs and charmed mesons at the LHC. In addition to standard collinear approach, for a first time we propose a $k_t$-factorization approach to the diffractive processes. The transverse momentum dependent (the unintegrated diffractive parton distributions) in proton are obtained with the help of the Kimber-Martin-Ryskin prescription where collinear diffractive PDFs are used as input. In this calculation the transverse momentum of the pomeron is neglected with respect to transverse momentum of partons entering the hard process. The results of the new approach are compared with those of the standard collinear one. Significantly larger cross sections are obtained in the $k_t$-factorization approach where some part of higher-order effects is effectively included. Some correlation observables, like azimuthal angle correlation between $c$ and $\bar c$, and $c \bar c$ pair transverse momentum distribution were obtained for the first time.
[ { "created": "Wed, 19 Oct 2016 20:54:46 GMT", "version": "v1" } ]
2016-10-21
[ [ "Łuszczak", "Marta", "" ], [ "Szczurek", "Antoni", "" ] ]
We discuss the single diffractive production of $c \bar c$ pairs and charmed mesons at the LHC. In addition to standard collinear approach, for a first time we propose a $k_t$-factorization approach to the diffractive processes. The transverse momentum dependent (the unintegrated diffractive parton distributions) in proton are obtained with the help of the Kimber-Martin-Ryskin prescription where collinear diffractive PDFs are used as input. In this calculation the transverse momentum of the pomeron is neglected with respect to transverse momentum of partons entering the hard process. The results of the new approach are compared with those of the standard collinear one. Significantly larger cross sections are obtained in the $k_t$-factorization approach where some part of higher-order effects is effectively included. Some correlation observables, like azimuthal angle correlation between $c$ and $\bar c$, and $c \bar c$ pair transverse momentum distribution were obtained for the first time.
0810.4918
Ahmed Ismail
Bruce A. Campbell and Ahmed Ismail
Leptonic Pion Decay And Physics Beyond The Electroweak Standard Model
31 pages, 3 figures
null
null
CERN-PH-TH/2008-212
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The ratio of branching ratios in leptonic pion decay $R_{\pi} \equiv (\Gamma(\pi^- \to e \nu_e))/(\Gamma(\pi^- \to \mu \nu_\mu))$ is a powerfully sensitive probe of new interactions beyond the electroweak standard model. This is due to the chirality suppression of the standard model amplitude for the decay, which results in a precise prediction for the ratio, and suppressed amplitudes for new contributions to interfere with. We calculate, including QCD corrections, the contributions to $R_{\pi}$ arising from a broad selection of standard model extensions to which it is sensitive, including: R-parity violating interactions in supersymmetric theories, theories with light (electroweak scale) leptoquark degrees of freedom, non-minimal models of extra doublet Higgs bosons, models in which the quarks and leptons are composite both with and without supersymmetry, and models with strong TeV scale gravitational interactions. Comparing with existing measurements of $R_{\pi}$ we provide limits on each of these classes of models; our calculations also represent state of the art theoretical benchmarks against which the results from the upcoming round of leptonic pion decay experiments may be compared.
[ { "created": "Mon, 27 Oct 2008 19:56:27 GMT", "version": "v1" } ]
2008-10-28
[ [ "Campbell", "Bruce A.", "" ], [ "Ismail", "Ahmed", "" ] ]
The ratio of branching ratios in leptonic pion decay $R_{\pi} \equiv (\Gamma(\pi^- \to e \nu_e))/(\Gamma(\pi^- \to \mu \nu_\mu))$ is a powerfully sensitive probe of new interactions beyond the electroweak standard model. This is due to the chirality suppression of the standard model amplitude for the decay, which results in a precise prediction for the ratio, and suppressed amplitudes for new contributions to interfere with. We calculate, including QCD corrections, the contributions to $R_{\pi}$ arising from a broad selection of standard model extensions to which it is sensitive, including: R-parity violating interactions in supersymmetric theories, theories with light (electroweak scale) leptoquark degrees of freedom, non-minimal models of extra doublet Higgs bosons, models in which the quarks and leptons are composite both with and without supersymmetry, and models with strong TeV scale gravitational interactions. Comparing with existing measurements of $R_{\pi}$ we provide limits on each of these classes of models; our calculations also represent state of the art theoretical benchmarks against which the results from the upcoming round of leptonic pion decay experiments may be compared.
hep-ph/9604398
Randy Kobes
P. Aurenche, F. Gelis, R. Kobes, E. Petitgirard
Enhanced photon production rate on the light--cone
17 pages, RevTeX, 4 uuencoded figures included by epsf, also available at http://theory.uwinnipeg.ca/users/randy/webfiles/soft.uu
Phys.Rev. D54 (1996) 5274-5279
10.1103/PhysRevD.54.5274
ENSLAPP-A-586/96; FISIST/4-96/CFIF; WIN-96-05
hep-ph
null
Recent studies of the high temperature soft photon production rate on the light--cone using Braaten--Pisarski resummation techniques have found collinear divergences present. We show that there exist a class of terms outside the Braaten--Pisarski framework which, although also divergent, dominate over these previously considered terms. The divergences in these new terms may be alleviated by application of a recently developed resummation scheme for processes sensitive to the light--cone.
[ { "created": "Wed, 24 Apr 1996 17:56:51 GMT", "version": "v1" } ]
2009-10-28
[ [ "Aurenche", "P.", "" ], [ "Gelis", "F.", "" ], [ "Kobes", "R.", "" ], [ "Petitgirard", "E.", "" ] ]
Recent studies of the high temperature soft photon production rate on the light--cone using Braaten--Pisarski resummation techniques have found collinear divergences present. We show that there exist a class of terms outside the Braaten--Pisarski framework which, although also divergent, dominate over these previously considered terms. The divergences in these new terms may be alleviated by application of a recently developed resummation scheme for processes sensitive to the light--cone.
hep-ph/9511288
Ralf Hempfling
Ralf Hempfling
Neutrino Masses and Mixing Angles in SUSY-GUT Theories with explicit R-Parity Breaking
Revised version as published in Nucl. Phys. B; several typos corrected
Nucl.Phys. B478 (1996) 3-30
10.1016/0550-3213(96)00412-9
null
hep-ph
null
In minimal SUSY GUT models the $R$-parity breaking terms are severely constrained by SU(5) gauge invariance. We consider the particular case where the explicit $R$-parity breaking occurs only via dimension 2 terms of the superpotential. This model possesses only three R-parity breaking parameters. We have studied the predictions of this model for the neutrino masses and mixing angles at the one-loop level within the framework of a radiatively broken unified supergravity model. We find that this model naturally yields masses and mixing angles that can explain the solar and atmospheric neutrino problems. In addition, there are regions in parameter space where the solution to the solar neutrino puzzle is compatible with either the LSND result or the existence of significant hot dark matter neutrinos.
[ { "created": "Fri, 10 Nov 1995 12:24:10 GMT", "version": "v1" }, { "created": "Sat, 11 Nov 1995 16:09:51 GMT", "version": "v2" }, { "created": "Tue, 10 Sep 1996 17:16:22 GMT", "version": "v3" } ]
2009-10-28
[ [ "Hempfling", "Ralf", "" ] ]
In minimal SUSY GUT models the $R$-parity breaking terms are severely constrained by SU(5) gauge invariance. We consider the particular case where the explicit $R$-parity breaking occurs only via dimension 2 terms of the superpotential. This model possesses only three R-parity breaking parameters. We have studied the predictions of this model for the neutrino masses and mixing angles at the one-loop level within the framework of a radiatively broken unified supergravity model. We find that this model naturally yields masses and mixing angles that can explain the solar and atmospheric neutrino problems. In addition, there are regions in parameter space where the solution to the solar neutrino puzzle is compatible with either the LSND result or the existence of significant hot dark matter neutrinos.
hep-ph/9708228
GLin
W.-S. Hou, G.-L. Lin and C.-Y. Ma
Flavor Changing Neutral Higgs Couplings and Top-Charm Production at Next Linear Collider
REVTEX, 18 pages, 7 figures; Report number changed
Phys.Rev. D56 (1997) 7434-7443
10.1103/PhysRevD.56.7434
NTUTH-97-10, NCTU-TH-97-04
hep-ph
null
We explore the possibility of detecting flavor changing neutral Higgs couplings at the Next Linear Collider (NLC) through $e^+e^-\to \nu_e\bar{\nu_e} t\bar{c}$. In the framework of a general two-Higgs doublet model, we perform a complete calculation and find that $\sigma (e^+e^-\to \nu_e\nu_e t\bar{c}, \nu_e\bar{\nu_e} {\bar t}c)$ could reach $\sim 9$ fb for $\sqrt{s}=2 TeV$. This amounts to an annual production of 500 $t\bar{c}$ plus $\bar{t}c$ pairs at the NLC with an integrated luminosity of 50 fb$^{-1}$. The dependence of $tc$-production rate on the neutral scalar mixing angle is mild except when $\sin^2\alpha \to 0 or 1$. The $\nu\nu W^+W^-$ background should be manageable after $b$-tagging, while $\nu\nu t\bar t$ background should not be a problem when the signal event rate is still interesting. The process, together with $e^+e^-\to \nu_e\bar{\nu_e} W^+W^-, \nu_e\bar{\nu_e} ZZ$ studies, offer the chance of measuring the $t$-$c$-Higgs coupling.
[ { "created": "Mon, 4 Aug 1997 07:22:36 GMT", "version": "v1" }, { "created": "Mon, 11 Aug 1997 02:56:49 GMT", "version": "v2" } ]
2009-10-30
[ [ "Hou", "W. -S.", "" ], [ "Lin", "G. -L.", "" ], [ "Ma", "C. -Y.", "" ] ]
We explore the possibility of detecting flavor changing neutral Higgs couplings at the Next Linear Collider (NLC) through $e^+e^-\to \nu_e\bar{\nu_e} t\bar{c}$. In the framework of a general two-Higgs doublet model, we perform a complete calculation and find that $\sigma (e^+e^-\to \nu_e\nu_e t\bar{c}, \nu_e\bar{\nu_e} {\bar t}c)$ could reach $\sim 9$ fb for $\sqrt{s}=2 TeV$. This amounts to an annual production of 500 $t\bar{c}$ plus $\bar{t}c$ pairs at the NLC with an integrated luminosity of 50 fb$^{-1}$. The dependence of $tc$-production rate on the neutral scalar mixing angle is mild except when $\sin^2\alpha \to 0 or 1$. The $\nu\nu W^+W^-$ background should be manageable after $b$-tagging, while $\nu\nu t\bar t$ background should not be a problem when the signal event rate is still interesting. The process, together with $e^+e^-\to \nu_e\bar{\nu_e} W^+W^-, \nu_e\bar{\nu_e} ZZ$ studies, offer the chance of measuring the $t$-$c$-Higgs coupling.
hep-ph/9910560
Anne-Christine Davis
Brandon Carter and Anne-Christine Davis
Chiral Vortons and Cosmological Constraints on Particle Physics
minor corrections made. This version will appear in PRD
Phys.Rev. D61 (2000) 123501
10.1103/PhysRevD.61.123501
DAMTP-1999-158
hep-ph astro-ph
null
We investigate the cosmological consequences of particle physics theories that admit stable loops of current-carrying string - vortons. In particular, we consider chiral theories where a single fermion zero mode is excited in the string core, such as those arising in supersymmetric theories with a D-term. The resulting vortons formed in such theories are expected to be more stable than their non-chiral cousins. General symmetry breaking schemes are considered in which strings formed at one symmetry breaking scale become current-carrying at a subsequent phase transition. The vorton abundance is estimated and constraints placed on the underlying particle physics theories from cosmological observations. Our constraints on the chiral theory are considerably more stringent than the previous estimates for more general theories.
[ { "created": "Mon, 1 Nov 1999 14:46:19 GMT", "version": "v1" }, { "created": "Tue, 4 Apr 2000 15:25:36 GMT", "version": "v2" } ]
2009-10-31
[ [ "Carter", "Brandon", "" ], [ "Davis", "Anne-Christine", "" ] ]
We investigate the cosmological consequences of particle physics theories that admit stable loops of current-carrying string - vortons. In particular, we consider chiral theories where a single fermion zero mode is excited in the string core, such as those arising in supersymmetric theories with a D-term. The resulting vortons formed in such theories are expected to be more stable than their non-chiral cousins. General symmetry breaking schemes are considered in which strings formed at one symmetry breaking scale become current-carrying at a subsequent phase transition. The vorton abundance is estimated and constraints placed on the underlying particle physics theories from cosmological observations. Our constraints on the chiral theory are considerably more stringent than the previous estimates for more general theories.
1704.04467
Adith Ramamurti
Adith Ramamurti, Edward Shuryak
An Effective Model of QCD Monopoles
4 pages, 3 figures. Proceeding based on talk given at the XXVIth International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2017)
null
10.1016/j.nuclphysa.2017.04.045
null
hep-ph hep-lat nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work, we carried out quantum many-body studies of magnetic monopole ensembles through numerical simulations of the path integral for one- and two-component Coulomb Bose systems. We found the relation between the critical temperature for the Bose-Einstein condensation phase transition and the Coulomb coupling strength using two methods, the finite-size scaling of the superfluid fraction and statistical analysis of permutation cycles. After finding parameters that match the correlation functions measured in our system with the correlation functions previously measured on the lattice, we arrived at an effective quantum model of color magnetic monopoles in QCD. From this matched model, we were able to extract the monopole contribution to QCD equation of state near $T_\text{c}$.
[ { "created": "Fri, 14 Apr 2017 16:16:14 GMT", "version": "v1" } ]
2018-03-14
[ [ "Ramamurti", "Adith", "" ], [ "Shuryak", "Edward", "" ] ]
In this work, we carried out quantum many-body studies of magnetic monopole ensembles through numerical simulations of the path integral for one- and two-component Coulomb Bose systems. We found the relation between the critical temperature for the Bose-Einstein condensation phase transition and the Coulomb coupling strength using two methods, the finite-size scaling of the superfluid fraction and statistical analysis of permutation cycles. After finding parameters that match the correlation functions measured in our system with the correlation functions previously measured on the lattice, we arrived at an effective quantum model of color magnetic monopoles in QCD. From this matched model, we were able to extract the monopole contribution to QCD equation of state near $T_\text{c}$.
hep-ph/9211269
null
S.M. Bilenky and C. Giunti
See-Saw Type Mixing and $ \nu_{\mu} \to \nu_{\tau} $ Oscillations
DFTT 66/92. LaTeX file, 7 pages, no figures
Phys.Lett. B300 (1993) 137-140
10.1016/0370-2693(93)90760-F
null
hep-ph
null
We consider $ \nu_{\mu} \to \nu_{\tau} $ oscillations under the assumption that there is a see-saw type mixing of the light neutrinos with heavy Majorana particles. It is shown that the existing data, including the recent LEP data, do not exclude the possibility that the additional terms in the transition probability due to this mixing could be of the same order of magnitude as the usual oscillating term. Detail investigations of $ \nu_{\mu} \to \nu_{\tau} $ transitions in future CERN and Fermilab experiments could allow to get informations not only about the neutrino masses and mixing but also about the mixing of neutrinos with heavy Majorana particles.
[ { "created": "Wed, 18 Nov 1992 18:03:00 GMT", "version": "v1" } ]
2009-10-22
[ [ "Bilenky", "S. M.", "" ], [ "Giunti", "C.", "" ] ]
We consider $ \nu_{\mu} \to \nu_{\tau} $ oscillations under the assumption that there is a see-saw type mixing of the light neutrinos with heavy Majorana particles. It is shown that the existing data, including the recent LEP data, do not exclude the possibility that the additional terms in the transition probability due to this mixing could be of the same order of magnitude as the usual oscillating term. Detail investigations of $ \nu_{\mu} \to \nu_{\tau} $ transitions in future CERN and Fermilab experiments could allow to get informations not only about the neutrino masses and mixing but also about the mixing of neutrinos with heavy Majorana particles.
hep-ph/9708495
M. D. Williams
B.C. Allanach, H. Dreiner, P. Morawitz and M.D.Williams
Single Sneutrino/Slepton Production at LEP2 and the NLC
10 pages, LaTeX and 5 encapsulated postscript figures. Requires axodraw macro
Phys.Lett.B420:307-313,1998
10.1016/S0370-2693(97)01559-1
null
hep-ph
null
We propose a new method of detecting supersymmetry at LEP2 when R-parity is violated by an LLE operator. We consider the processes $e\gamma\ra\snu_j e_k$ and $e\gamma \ra \slep_k \bar{\nu}_j$. These are sensitive to seven of the nine LLE-operators. A Monte-Carlo analysis is performed to investigate the sensitivity to the sneutrino signal, and the 5$\sigma$ discovery contours in the mass vs. coupling plane are presented. For an integrated luminosity of 100 pb^-1, sneutrinos with masses up to 170 GeV/c^2 could be discovered in the near future at LEP2. For the charged slepton production the cross-section is too low to be detectable.
[ { "created": "Fri, 29 Aug 1997 17:10:34 GMT", "version": "v1" } ]
2011-07-19
[ [ "Allanach", "B. C.", "" ], [ "Dreiner", "H.", "" ], [ "Morawitz", "P.", "" ], [ "Williams", "M. D.", "" ] ]
We propose a new method of detecting supersymmetry at LEP2 when R-parity is violated by an LLE operator. We consider the processes $e\gamma\ra\snu_j e_k$ and $e\gamma \ra \slep_k \bar{\nu}_j$. These are sensitive to seven of the nine LLE-operators. A Monte-Carlo analysis is performed to investigate the sensitivity to the sneutrino signal, and the 5$\sigma$ discovery contours in the mass vs. coupling plane are presented. For an integrated luminosity of 100 pb^-1, sneutrinos with masses up to 170 GeV/c^2 could be discovered in the near future at LEP2. For the charged slepton production the cross-section is too low to be detectable.
2304.01684
Duojie Jia
Ting-Qi Yan, Wen-Xuan Zhang and Duojie Jia
Mass spectra of hidden heavy-flavor tetraquarks with two and four heavy quarks
null
Euro. Phys. J. C 83 (2023) 810
10.1140/epjc/s10052-023-11956-3
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Inspired by the observation of the $X(6900)$ by LHCb and the $X(6600)$ (with mass $6552\pm 10$ $\pm 12$ MeV) recently by CMS and ATLAS experiments of the LHC in the di-$J/\Psi $ invariant mass spectrum, we systemically study masses of all ground-state configurations of the hidden heavy-flavor tetraquarks $q_{1}Q_{2}\bar{q}_{3}\bar{Q}_{4}$ and $Q_{1}Q_{2}\bar{Q}_{3}\bar{Q}_{4}$ ($Q=c,b$;$q=u,d,s$) contaning two and four heavy quarks in the MIT bag model with chromomagnetic interaction and enhanced binding energy. Considering color-spin mixing due to chromomagnetic interaction, our mass computation indicates that the observed $X(6600)$ is likely to be the $0^{++}$ ground states of hidden-charm tetraquark $cc\bar{c}\bar{c}$ with computed masses $6572$ MeV, which has a $0^{++}$ color partner around $6469$ MeV. The fully bottom system of tetraquark $bb\bar{b}\bar{b}$ has masses of 19685 MeV and 19717 MeV for the the $0^{++}$ ground states. Further computation is given to the tetraquark systems $sc\bar{s}\bar{c}$, $sb\bar{s}\bar{b}$, $cb\bar{c}\bar{b}$, $nc\bar{n}\bar{c}$ and $nb\bar{n}\bar{b}$, suggesting that the $Z_{c}(4200)$ is the tetraquark $nc\bar{n}\bar{c}$ with $J^{PC}=1^{+-}$. All of these tetraquarks are above their lowest thresholds of two mesons and unstable against the strong decays.
[ { "created": "Tue, 4 Apr 2023 10:21:25 GMT", "version": "v1" } ]
2023-09-14
[ [ "Yan", "Ting-Qi", "" ], [ "Zhang", "Wen-Xuan", "" ], [ "Jia", "Duojie", "" ] ]
Inspired by the observation of the $X(6900)$ by LHCb and the $X(6600)$ (with mass $6552\pm 10$ $\pm 12$ MeV) recently by CMS and ATLAS experiments of the LHC in the di-$J/\Psi $ invariant mass spectrum, we systemically study masses of all ground-state configurations of the hidden heavy-flavor tetraquarks $q_{1}Q_{2}\bar{q}_{3}\bar{Q}_{4}$ and $Q_{1}Q_{2}\bar{Q}_{3}\bar{Q}_{4}$ ($Q=c,b$;$q=u,d,s$) contaning two and four heavy quarks in the MIT bag model with chromomagnetic interaction and enhanced binding energy. Considering color-spin mixing due to chromomagnetic interaction, our mass computation indicates that the observed $X(6600)$ is likely to be the $0^{++}$ ground states of hidden-charm tetraquark $cc\bar{c}\bar{c}$ with computed masses $6572$ MeV, which has a $0^{++}$ color partner around $6469$ MeV. The fully bottom system of tetraquark $bb\bar{b}\bar{b}$ has masses of 19685 MeV and 19717 MeV for the the $0^{++}$ ground states. Further computation is given to the tetraquark systems $sc\bar{s}\bar{c}$, $sb\bar{s}\bar{b}$, $cb\bar{c}\bar{b}$, $nc\bar{n}\bar{c}$ and $nb\bar{n}\bar{b}$, suggesting that the $Z_{c}(4200)$ is the tetraquark $nc\bar{n}\bar{c}$ with $J^{PC}=1^{+-}$. All of these tetraquarks are above their lowest thresholds of two mesons and unstable against the strong decays.
2407.03586
Shile Chen
Shile Chen, Jiaxing Zhao and Pengfei Zhuang
Gluon decay into heavy quark pair under a strong magnetic field
null
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Due to the extreme large magnetic field produced in the initial stage of non-central heavy-ion collision, the dynamical process of gluon decay into heavy quark pair will take place under an external field rather than in vacuum. Unlike in the vacuum case, where the process is forbidden by energy momentum conservation, under the external field, a process emerges considering the background energy which recovers the conservation. We calculate the gluon decay rate at leading order under a uniform magnetic field.
[ { "created": "Thu, 4 Jul 2024 02:35:48 GMT", "version": "v1" } ]
2024-07-08
[ [ "Chen", "Shile", "" ], [ "Zhao", "Jiaxing", "" ], [ "Zhuang", "Pengfei", "" ] ]
Due to the extreme large magnetic field produced in the initial stage of non-central heavy-ion collision, the dynamical process of gluon decay into heavy quark pair will take place under an external field rather than in vacuum. Unlike in the vacuum case, where the process is forbidden by energy momentum conservation, under the external field, a process emerges considering the background energy which recovers the conservation. We calculate the gluon decay rate at leading order under a uniform magnetic field.
1810.04580
Tord Riemann
Johann Usovitsch and Ievgen Dubovyk and Tord Riemann
MBnumerics: Numerical integration of Mellin-Barnes integrals in physical regions
10 pages, contribution to the proceedings of the conference "Loops and Legs in Gauge Theories 2018 (LL2018)", accepted for publication on 16 August 2018
PoS(LL2018)046
null
DESY 18-121, KW 18-008
hep-ph
http://creativecommons.org/licenses/by-nc-sa/4.0/
We introduce techniques to treat numerically Mellin-Barnes integrals in physical regions, which arise in the need of the computation of Feynman integrals for the electroweak two-loop corrections to the pseudo observables at the Z-boson resonance.
[ { "created": "Wed, 10 Oct 2018 15:18:16 GMT", "version": "v1" } ]
2018-10-11
[ [ "Usovitsch", "Johann", "" ], [ "Dubovyk", "Ievgen", "" ], [ "Riemann", "Tord", "" ] ]
We introduce techniques to treat numerically Mellin-Barnes integrals in physical regions, which arise in the need of the computation of Feynman integrals for the electroweak two-loop corrections to the pseudo observables at the Z-boson resonance.
1005.3946
A. Tawfik
A. Tawfik (Egyptian Ctr. Theor. Phys., Cairo) and M. Wahba (Egyptian Ctr. Theor. Phys., Cairo)
Bulk and Shear Viscosity in Hagedorn Fluid
6 Pages, 5 figures with 5 eps graphs
Annalen Phys.522:849-856,2010
10.1002/andp.201000056
ECTP-2010-02
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Assuming that the Hagedorn fluid composed of known particles and resonances with masses $m<2\,$GeV obeys the {\it first-order} theory (Eckart) of relativistic fluid, we discuss the transport properties of QCD confined phase. Based on the relativistic kinetic theory formulated under the relaxation time approximation, expressions for bulk and shear viscosity in thermal medium are derived. The relaxation time in the Hagedorn dynamical fluid exclusively takes into account the decay and eventually van der Waals processes. We comment on the {\it in-medium} thermal effects on bulk and shear viscosities and averaged relaxation time with and without the excluded-volume approach. As an application of these results, we suggest the dynamics of heavy-ion collisions, non-equlibrium thermodynamics and the cosmological models, which require thermo and hydrodynamics equations of state.
[ { "created": "Fri, 21 May 2010 12:26:37 GMT", "version": "v1" }, { "created": "Mon, 27 Sep 2010 14:08:52 GMT", "version": "v2" } ]
2010-11-24
[ [ "Tawfik", "A.", "", "Egyptian Ctr. Theor. Phys., Cairo" ], [ "Wahba", "M.", "", "Egyptian\n Ctr. Theor. Phys., Cairo" ] ]
Assuming that the Hagedorn fluid composed of known particles and resonances with masses $m<2\,$GeV obeys the {\it first-order} theory (Eckart) of relativistic fluid, we discuss the transport properties of QCD confined phase. Based on the relativistic kinetic theory formulated under the relaxation time approximation, expressions for bulk and shear viscosity in thermal medium are derived. The relaxation time in the Hagedorn dynamical fluid exclusively takes into account the decay and eventually van der Waals processes. We comment on the {\it in-medium} thermal effects on bulk and shear viscosities and averaged relaxation time with and without the excluded-volume approach. As an application of these results, we suggest the dynamics of heavy-ion collisions, non-equlibrium thermodynamics and the cosmological models, which require thermo and hydrodynamics equations of state.
0802.2593
Masanori Hirai
M. Hirai, S. Kumano, M. Oka, and K. Sudoh
Determination of f_0(980) Structure by Fragmentation Functions
4page, 2eps figures, To appear in the proceedings of Chiral Symmetry in Hadron and Nuclear Physics (Chiral 07), Osaka, Japan, 13-16 Nov. 2007
Mod.Phys.Lett.A23:2226-2229,2008
10.1142/S0217732308029071
KEK-TH-1225
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss internal structure of an exotic hadron by using fragmentation functions. The fragmentation functions for the f_0(980) meson are obtained by a global analysis of e^++e^- \to f_0+X data. Quark configuration of the f_0(980) could be determined by peak positions and second moments of the obtained fragmentation functions.
[ { "created": "Tue, 19 Feb 2008 06:09:16 GMT", "version": "v1" } ]
2008-11-26
[ [ "Hirai", "M.", "" ], [ "Kumano", "S.", "" ], [ "Oka", "M.", "" ], [ "Sudoh", "K.", "" ] ]
We discuss internal structure of an exotic hadron by using fragmentation functions. The fragmentation functions for the f_0(980) meson are obtained by a global analysis of e^++e^- \to f_0+X data. Quark configuration of the f_0(980) could be determined by peak positions and second moments of the obtained fragmentation functions.
hep-ph/0209076
null
Thomas G. Rizzo
Effects of Radion Mixing on the Standard Model Higgs Boson
Latex. 7 pages, 5 figs; talk given at the International Workshop on Linear Colliders, Jeju Island, Korea, 26-30 August 2002
null
null
SLAC-PUB-9492
hep-ph
null
We discuss how mixing between the Standard Model Higgs boson and the radion of the Randall-Sundrum model can lead to significant shifts in the expected properties of the Higgs boson. In particular we show that the total and partial decay widths of the Higgs, as well as the $h\to gg$ branching fraction, can be substantially altered from their SM expectations, while the remaining branching fractions are modified less than about 5% for most of the parameter space volume. Precision measurements of Higgs boson properties at at a Linear Collider are shown to probe a large region of the Randall-Sundrum model parameter space.
[ { "created": "Fri, 6 Sep 2002 18:25:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rizzo", "Thomas G.", "" ] ]
We discuss how mixing between the Standard Model Higgs boson and the radion of the Randall-Sundrum model can lead to significant shifts in the expected properties of the Higgs boson. In particular we show that the total and partial decay widths of the Higgs, as well as the $h\to gg$ branching fraction, can be substantially altered from their SM expectations, while the remaining branching fractions are modified less than about 5% for most of the parameter space volume. Precision measurements of Higgs boson properties at at a Linear Collider are shown to probe a large region of the Randall-Sundrum model parameter space.
0907.1319
Ralf Lehnert
Ralf Lehnert
CPT and Lorentz violation as signatures for Planck-scale physics
6 pages
J.Phys.Conf.Ser.171:012036,2009
10.1088/1742-6596/171/1/012036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, the breakdown of spacetime symmetries has been identified as a promising research field in the context of Planck-scale phenomenology. For example, various theoretical approaches to the quantum-gravity problem are known to accommodate minute violations of CPT invariance. This talk covers various topics within this research area. In particular, some mechanisms for spacetime-symmetry breaking as well as the Standard-Model Extension (SME) test framework will be reviewed; the connection between CPT and Lorentz invariance in quantum field theory will be exposed; and various experimental CPT tests with emphasis on matter--antimatter comparisons will be discussed.
[ { "created": "Wed, 8 Jul 2009 00:33:10 GMT", "version": "v1" } ]
2009-10-08
[ [ "Lehnert", "Ralf", "" ] ]
In recent years, the breakdown of spacetime symmetries has been identified as a promising research field in the context of Planck-scale phenomenology. For example, various theoretical approaches to the quantum-gravity problem are known to accommodate minute violations of CPT invariance. This talk covers various topics within this research area. In particular, some mechanisms for spacetime-symmetry breaking as well as the Standard-Model Extension (SME) test framework will be reviewed; the connection between CPT and Lorentz invariance in quantum field theory will be exposed; and various experimental CPT tests with emphasis on matter--antimatter comparisons will be discussed.
1905.03771
Goutam Das
Ajjath A H, Amlan Chakraborty, Goutam Das, Pooja Mukherjee and V. Ravindran
Resummed prediction for Higgs boson production through $b\bar{b}$ annihilation at N$^3$LL
19 pages, 4 figures, 2 tables
JHEP 1911 (2019) 006
10.1007/JHEP11(2019)006
IMSC/2019/05/04, DESY 19-076
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present an accurate theoretical prediction for the production of Higgs boson through bottom quark annihilation at the LHC up to next-to-next-to-next-to leading order (N$^3$LO) plus next-to-next-to-next-to-leading logarithmic (N$^3$LL) accuracy. We determine the third order perturbative Quantum Chromodynamics (QCD) correction to the process dependent constant in the resummed expression using the three loop bottom quark form factor and third order quark soft distribution function. Thanks to the recent computation of N$^3$LO corrections to this production cross-section from all the partonic channels, an accurate matching can be obtained for a consistent predictions at N$^3$LO+N$^3$LL accuracy in QCD. We have studied in detail the impact of resummed threshold contributions to inclusive cross-sections at various centre-of-mass energies and also discussed their sensitivity to renormalization and factorization scales at next-to-next-to leading order (NNLO) matched with next-to-next-to leading logarithm (NNLL). At N$^3$LO+N$^3$LL, we predict the cross-section for different centre-of-mass energies using the recently available results in \cite{Duhr:2019kwi} as well as study the renormalization scale dependence at the same order.
[ { "created": "Thu, 9 May 2019 17:54:35 GMT", "version": "v1" }, { "created": "Wed, 25 Dec 2019 00:09:13 GMT", "version": "v2" } ]
2019-12-30
[ [ "H", "Ajjath A", "" ], [ "Chakraborty", "Amlan", "" ], [ "Das", "Goutam", "" ], [ "Mukherjee", "Pooja", "" ], [ "Ravindran", "V.", "" ] ]
We present an accurate theoretical prediction for the production of Higgs boson through bottom quark annihilation at the LHC up to next-to-next-to-next-to leading order (N$^3$LO) plus next-to-next-to-next-to-leading logarithmic (N$^3$LL) accuracy. We determine the third order perturbative Quantum Chromodynamics (QCD) correction to the process dependent constant in the resummed expression using the three loop bottom quark form factor and third order quark soft distribution function. Thanks to the recent computation of N$^3$LO corrections to this production cross-section from all the partonic channels, an accurate matching can be obtained for a consistent predictions at N$^3$LO+N$^3$LL accuracy in QCD. We have studied in detail the impact of resummed threshold contributions to inclusive cross-sections at various centre-of-mass energies and also discussed their sensitivity to renormalization and factorization scales at next-to-next-to leading order (NNLO) matched with next-to-next-to leading logarithm (NNLL). At N$^3$LO+N$^3$LL, we predict the cross-section for different centre-of-mass energies using the recently available results in \cite{Duhr:2019kwi} as well as study the renormalization scale dependence at the same order.
1712.02373
Farinaldo Queiroz
Giorgio Arcadi, C. P. Ferreira, Florian Goertz, M. M. Guzzo, Farinaldo S. Queiroz, A.C.O. Santos
Lepton Flavor Violation Induced by Dark Matter
11 pages, 5 figures
Phys. Rev. D 97, 075022 (2018)
10.1103/PhysRevD.97.075022
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Guided by gauge principles we discuss a predictive and falsifiable UV complete model where the Dirac fermion that accounts for the cold dark matter abundance in our universe induces the lepton flavor violation (LFV) decays $\mu \rightarrow e\gamma$ and $\mu \rightarrow e e e$ as well as $\mu-e$ conversion. We explore the interplay between direct dark matter detection, relic density, collider probes and lepton flavor violation to conclusively show that one may have a viable dark matter candidate yielding flavor violation signatures expected to be fully probed in the upcoming of experiments. Interestingly, keeping the dark matter mass not far from the TeV, our model has an approximate prediction for the maximum LFV signal one could have while reproducing the correct dark matter relic density.
[ { "created": "Wed, 6 Dec 2017 19:07:20 GMT", "version": "v1" } ]
2018-04-25
[ [ "Arcadi", "Giorgio", "" ], [ "Ferreira", "C. P.", "" ], [ "Goertz", "Florian", "" ], [ "Guzzo", "M. M.", "" ], [ "Queiroz", "Farinaldo S.", "" ], [ "Santos", "A. C. O.", "" ] ]
Guided by gauge principles we discuss a predictive and falsifiable UV complete model where the Dirac fermion that accounts for the cold dark matter abundance in our universe induces the lepton flavor violation (LFV) decays $\mu \rightarrow e\gamma$ and $\mu \rightarrow e e e$ as well as $\mu-e$ conversion. We explore the interplay between direct dark matter detection, relic density, collider probes and lepton flavor violation to conclusively show that one may have a viable dark matter candidate yielding flavor violation signatures expected to be fully probed in the upcoming of experiments. Interestingly, keeping the dark matter mass not far from the TeV, our model has an approximate prediction for the maximum LFV signal one could have while reproducing the correct dark matter relic density.
2111.06619
Tomona Kinugawa
Tomona Kinugawa and Tetsuo Hyodo
Range correction in the weak-binding relation for unstable states
5 pages, 2 figures, Proceedings of Particles and Nuclei International Conference (PANIC2021), 5-10 September 2021
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The compositeness is defined as the weight of the hadronic molecule in the hadron wave function. We can determine the internal structure of the weak-binding system without any specific models from the compositeness. In order to estimate the compositeness of the system with a large effective range, we introduce the range correction to Weinberg's weak-binding relation by modifying the correction terms. We study the applicability of the weak-binding relations by the numerical calculation and show that the improved relation can be applied to a larger parameter region compared with the previous one.
[ { "created": "Fri, 12 Nov 2021 09:15:07 GMT", "version": "v1" } ]
2021-11-15
[ [ "Kinugawa", "Tomona", "" ], [ "Hyodo", "Tetsuo", "" ] ]
The compositeness is defined as the weight of the hadronic molecule in the hadron wave function. We can determine the internal structure of the weak-binding system without any specific models from the compositeness. In order to estimate the compositeness of the system with a large effective range, we introduce the range correction to Weinberg's weak-binding relation by modifying the correction terms. We study the applicability of the weak-binding relations by the numerical calculation and show that the improved relation can be applied to a larger parameter region compared with the previous one.
1403.1179
Fabian Rennecke
Jan M. Pawlowski and Fabian Rennecke
Higher order quark-mesonic scattering processes and the phase structure of QCD
20 pages, 14 figures. v2: journal version
null
10.1103/PhysRevD.90.076002
null
hep-ph hep-th nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the impact of higher order quark-meson scattering processes on the chiral phase structure of two-flavour QCD at finite temperature and quark density. Thermal, density and quantum fluctuations are included within a functional renormalisation group approach to the quark-meson model. We present results on the chiral phase boundary, the critical endpoint, and the curvature of the phase transition line at vanishing density.
[ { "created": "Wed, 5 Mar 2014 16:23:49 GMT", "version": "v1" }, { "created": "Tue, 26 Sep 2017 15:40:18 GMT", "version": "v2" } ]
2017-09-27
[ [ "Pawlowski", "Jan M.", "" ], [ "Rennecke", "Fabian", "" ] ]
We study the impact of higher order quark-meson scattering processes on the chiral phase structure of two-flavour QCD at finite temperature and quark density. Thermal, density and quantum fluctuations are included within a functional renormalisation group approach to the quark-meson model. We present results on the chiral phase boundary, the critical endpoint, and the curvature of the phase transition line at vanishing density.
hep-ph/9807223
Melikhov
M. Beyer and D. Melikhov
Form factors of exclusive $b\to u$ transitions
revtex, 6 pages, 1 figure
Phys.Lett.B436:344-350,1998
10.1016/S0370-2693(98)00847-8
null
hep-ph
null
We present the form factors of the $B\to\pi,\rho$ transitions induced by the $b\to u$ quark currents at all kinematically accessible $q^2$. Our analysis is based on the spectral representations of the form factors within the constituent quark picture: we fix the soft meson wave functions and the constituent quark masses by fitting $A_1(q^2)$ and $T_2(q^2)$ to the lattice results at small recoils ($17\lesssim q^2\lesssim 20 GeV^2$). We then calculate the $B\to\pi,\rho$ transition form factors down to $q^2=0$. For the $B\to\pi$ case the region $q^2\lesssim 20 GeV^2$ however does not cover the whole kinematically accessible range. Due to the smallness of the pion mass the region of small recoils is close to the nearby $B^*(5234)$ resonance. We develop a parametrization which includes the $B^*$ dominance of the form factors $f_+$ and $f_-$ at small recoils and numerically reproduces the results of calculations at $q^2\lesssim 20 GeV^2$. We find $\Gamma(B\to\pi\ell\nu)=8.0^{+0.8}_{-0.2} |V_{ub}|^2 $ps$^{-1}$ and $\Gamma(B\to\rho\ell\nu)=15.8\pm 2.3 |V_{ub}|^2 $ps$^{-1}$.
[ { "created": "Thu, 2 Jul 1998 14:16:17 GMT", "version": "v1" } ]
2011-07-19
[ [ "Beyer", "M.", "" ], [ "Melikhov", "D.", "" ] ]
We present the form factors of the $B\to\pi,\rho$ transitions induced by the $b\to u$ quark currents at all kinematically accessible $q^2$. Our analysis is based on the spectral representations of the form factors within the constituent quark picture: we fix the soft meson wave functions and the constituent quark masses by fitting $A_1(q^2)$ and $T_2(q^2)$ to the lattice results at small recoils ($17\lesssim q^2\lesssim 20 GeV^2$). We then calculate the $B\to\pi,\rho$ transition form factors down to $q^2=0$. For the $B\to\pi$ case the region $q^2\lesssim 20 GeV^2$ however does not cover the whole kinematically accessible range. Due to the smallness of the pion mass the region of small recoils is close to the nearby $B^*(5234)$ resonance. We develop a parametrization which includes the $B^*$ dominance of the form factors $f_+$ and $f_-$ at small recoils and numerically reproduces the results of calculations at $q^2\lesssim 20 GeV^2$. We find $\Gamma(B\to\pi\ell\nu)=8.0^{+0.8}_{-0.2} |V_{ub}|^2 $ps$^{-1}$ and $\Gamma(B\to\rho\ell\nu)=15.8\pm 2.3 |V_{ub}|^2 $ps$^{-1}$.
hep-ph/0701067
Ruben Flores
Ruben Flores-Mendieta, Alfonso Martinez
Baryon semileptonic decays: the Mexican contribution
10 pages. Prepared for the Commemorative Volume of the Divison of Particles and Fields of the Mexican Physical Society
AIP Conf.Proc.857B:27-36,2006
10.1063/1.2359389
null
hep-ph
null
We give a detailed account of the techniques to compute radiative corrections in baryon semileptonic decays developed over the years by Mexican collaborations. We explain how the method works by obtaining an expression for the Dalitz plot of semileptonic decays of polarized baryons including radiative corrections to order ${\mathcal O}(\alpha q/\pi M_1)$, where $q$ is the four-momentum transfer and $M_1$ is the mass of the decaying baryon. From here we compute the totally integrated spin angular asymmetry coefficient of the emitted baryon and compare its value with other results.
[ { "created": "Tue, 9 Jan 2007 18:23:32 GMT", "version": "v1" } ]
2010-12-13
[ [ "Flores-Mendieta", "Ruben", "" ], [ "Martinez", "Alfonso", "" ] ]
We give a detailed account of the techniques to compute radiative corrections in baryon semileptonic decays developed over the years by Mexican collaborations. We explain how the method works by obtaining an expression for the Dalitz plot of semileptonic decays of polarized baryons including radiative corrections to order ${\mathcal O}(\alpha q/\pi M_1)$, where $q$ is the four-momentum transfer and $M_1$ is the mass of the decaying baryon. From here we compute the totally integrated spin angular asymmetry coefficient of the emitted baryon and compare its value with other results.
hep-ph/9710465
Martin Stock
R.L. Jaffe
Can Transversity Be Measured?
15 pages, 5 postscript figures, LaTeX & BoxedEPS; invited paper, presented at the 2nd Topical Workshop, DESY Zeuthen, September 1-5, 1997: "Deep Inelastic Scattering off Polarized Targets: Theory Meets Experiment"; email to jaffe@mitlns.mit.edu ; name of conference and proceedings added
null
null
MIT-CTP-2685
hep-ph nucl-th
null
I review the ways that have been proposed to measure the quark transversity distribution in the nucleon. I then explain a proposal, developed by Xuemin Jin, Jian Tang and myself, to measure transversity through the final state interaction between two mesons ($\pi\pi$, $K \bar K$, or $\pi K$) produced in the current fragmentation region in deep inelastic scattering on a transversely polarized nucleon.
[ { "created": "Fri, 24 Oct 1997 20:05:07 GMT", "version": "v1" }, { "created": "Mon, 27 Oct 1997 17:36:34 GMT", "version": "v2" } ]
2009-09-25
[ [ "Jaffe", "R. L.", "" ] ]
I review the ways that have been proposed to measure the quark transversity distribution in the nucleon. I then explain a proposal, developed by Xuemin Jin, Jian Tang and myself, to measure transversity through the final state interaction between two mesons ($\pi\pi$, $K \bar K$, or $\pi K$) produced in the current fragmentation region in deep inelastic scattering on a transversely polarized nucleon.
1005.1077
Christian Flacco
Christian J. Flacco, Daniel Whiteson, Tim M.P. Tait, Shaouly Bar-Shalom
Direct Mass Limits for Chiral Fourth-Generation Quarks in All Mixing Scenarios
null
Phys.Rev.Lett.105:111801,2010
10.1103/PhysRevLett.105.111801
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Present limits on chiral fourth-generation quark masses $m_{b'}$ and $m_{t'}$ are broadly generalized and strengthened by combining both $t'$ and $b'$ decays and considering the full range of $t'$ and $b'$ flavor-mixing scenarios (with the lighter generations). Various characteristic mass-splitting choices are considered. With $m_{t'} > m_{b'}$ we find that CDF limits on the $b'$ mass vary by no more than 10-20% with any choice of flavor-mixing, while for the $t'$ mass, we typically find stronger bounds, in some cases up to $m_{t'} > 430$ GeV. For $m_{b'} > m_{t'}$ we find $m_{b'} > 380 - 430$ GeV, depending on the flavor-mixing and the size of the $m_{t'} - m_{b'}$ mass splitting.
[ { "created": "Thu, 6 May 2010 20:12:32 GMT", "version": "v1" } ]
2014-11-21
[ [ "Flacco", "Christian J.", "" ], [ "Whiteson", "Daniel", "" ], [ "Tait", "Tim M. P.", "" ], [ "Bar-Shalom", "Shaouly", "" ] ]
Present limits on chiral fourth-generation quark masses $m_{b'}$ and $m_{t'}$ are broadly generalized and strengthened by combining both $t'$ and $b'$ decays and considering the full range of $t'$ and $b'$ flavor-mixing scenarios (with the lighter generations). Various characteristic mass-splitting choices are considered. With $m_{t'} > m_{b'}$ we find that CDF limits on the $b'$ mass vary by no more than 10-20% with any choice of flavor-mixing, while for the $t'$ mass, we typically find stronger bounds, in some cases up to $m_{t'} > 430$ GeV. For $m_{b'} > m_{t'}$ we find $m_{b'} > 380 - 430$ GeV, depending on the flavor-mixing and the size of the $m_{t'} - m_{b'}$ mass splitting.
1706.05071
David Latimer
David C. Latimer
Two-photon interactions with Majorana fermions
null
Phys. Rev. D 94, 093010 (2016)
10.1103/PhysRevD.94.093010
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Because Majorana fermions are their own antiparticles, their electric and magnetic dipole moments must vanish, leaving the anapole moment as their only static electromagnetic property. But the existence of induced dipole moments is not necessarily prohibited. Through a study real Compton scattering, we explore the constraints that the Majorana fermion's self-conjugate nature has on induced moments. In terms of the Compton amplitude, we find no constraints if the interactions are separately invariant under charge conjugation, parity, and time reversal. However, if the interactions are odd under parity and even under time reversal, then these contributions to the Compton amplitude must vanish. We employ a simple model to confirm these general findings via explicit calculation of the Majorana fermion's polarizabilities. We then use these polarizabilities to estimate the cross-section for $s$-wave annihilation of two Majorana fermions into photons. The cross-section is larger than a na\"ive estimate might suggest.
[ { "created": "Thu, 15 Jun 2017 20:31:35 GMT", "version": "v1" } ]
2017-06-19
[ [ "Latimer", "David C.", "" ] ]
Because Majorana fermions are their own antiparticles, their electric and magnetic dipole moments must vanish, leaving the anapole moment as their only static electromagnetic property. But the existence of induced dipole moments is not necessarily prohibited. Through a study real Compton scattering, we explore the constraints that the Majorana fermion's self-conjugate nature has on induced moments. In terms of the Compton amplitude, we find no constraints if the interactions are separately invariant under charge conjugation, parity, and time reversal. However, if the interactions are odd under parity and even under time reversal, then these contributions to the Compton amplitude must vanish. We employ a simple model to confirm these general findings via explicit calculation of the Majorana fermion's polarizabilities. We then use these polarizabilities to estimate the cross-section for $s$-wave annihilation of two Majorana fermions into photons. The cross-section is larger than a na\"ive estimate might suggest.
1907.10071
Debasish Borah
Basabendu Barman, Debasish Borah, Purusottam Ghosh, Abhijit Kumar Saha
Flavoured gauge extension of singlet-doublet fermionic dark matter: neutrino mass, high scale validity and collider signatures
56 pages, 20 figures, matches version accepted for publication in JHEP
null
10.1007/JHEP10(2019)275
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose an Abelian gauged version of the singlet-doublet fermionic dark matter (DM) model where DM, combination of a vector like fermion doublet and a fermion singlet, is naturally stabilised by the gauge symmetry without requiring any ad-hoc discrete symmetries. In order to have good detection prospects at collider experiments like the large hadron collider (LHC) and enlarged parameter space for low mass DM, we consider the additional gauge symmetry to be based on the quantum $B-3L_{\tau}$ where the restriction to third generation of leptons is chosen to have weaker bounds from the LHC on the corresponding gauge boson. The triangle anomalies arising in this model can be cancelled by including a right handed neutrino which takes part in generating light neutrino masses through type I seesaw mechanism. Apart from DM, collider prospects and light neutrino masses, the model also offers high scale validity giving rise to a stable electroweak vacuum and perturbative couplings all the way up to the Planck scale. We constrain our model parameters from these requirements as well as existing relevant constraints related to DM and colliders.
[ { "created": "Tue, 23 Jul 2019 18:00:03 GMT", "version": "v1" }, { "created": "Tue, 15 Oct 2019 13:43:12 GMT", "version": "v2" } ]
2020-01-08
[ [ "Barman", "Basabendu", "" ], [ "Borah", "Debasish", "" ], [ "Ghosh", "Purusottam", "" ], [ "Saha", "Abhijit Kumar", "" ] ]
We propose an Abelian gauged version of the singlet-doublet fermionic dark matter (DM) model where DM, combination of a vector like fermion doublet and a fermion singlet, is naturally stabilised by the gauge symmetry without requiring any ad-hoc discrete symmetries. In order to have good detection prospects at collider experiments like the large hadron collider (LHC) and enlarged parameter space for low mass DM, we consider the additional gauge symmetry to be based on the quantum $B-3L_{\tau}$ where the restriction to third generation of leptons is chosen to have weaker bounds from the LHC on the corresponding gauge boson. The triangle anomalies arising in this model can be cancelled by including a right handed neutrino which takes part in generating light neutrino masses through type I seesaw mechanism. Apart from DM, collider prospects and light neutrino masses, the model also offers high scale validity giving rise to a stable electroweak vacuum and perturbative couplings all the way up to the Planck scale. We constrain our model parameters from these requirements as well as existing relevant constraints related to DM and colliders.
hep-ph/9707279
Chi-Sing Lam
C.S. Lam (McGill University)
Exponentiation of the Sum of Nonabelian Amplitudes
null
null
null
null
hep-ph
null
This paper contains an implicit assumption that the summand in eq. (4.2) for different $n$'s commute. This paper should be replaced by hep-th/9804181 where this assumption is removedand the result generalized.
[ { "created": "Tue, 8 Jul 1997 17:02:18 GMT", "version": "v1" }, { "created": "Sun, 3 May 1998 18:04:21 GMT", "version": "v2" } ]
2008-02-03
[ [ "Lam", "C. S.", "", "McGill University" ] ]
This paper contains an implicit assumption that the summand in eq. (4.2) for different $n$'s commute. This paper should be replaced by hep-th/9804181 where this assumption is removedand the result generalized.
hep-ph/9512382
Hans Weber
H.J. Weber, Xiaoming Xu (University of Virginia)
Dependence of Electromagnetic Form Factors of Hadrons on Light Cone Frames
22 pages, Latex, run twice and type r enter after ? Nucl.Phys.A
Nucl.Phys. A600 (1996) 461-476
10.1016/0375-9474(95)00503-X
null
hep-ph
null
A constituent quark model is developed for an arbitrary light- cone direction \omega. Form factors are obtained from free one-body electromagnetic current matrix elements. They are found to be \omega- independent for spin-0 mesons, the nucleon and \Lambda hyperon, while there is \omega-dependence for spin-1 systems like the deuteron.
[ { "created": "Wed, 20 Dec 1995 22:08:00 GMT", "version": "v1" } ]
2009-10-28
[ [ "Weber", "H. J.", "", "University of Virginia" ], [ "Xu", "Xiaoming", "", "University of Virginia" ] ]
A constituent quark model is developed for an arbitrary light- cone direction \omega. Form factors are obtained from free one-body electromagnetic current matrix elements. They are found to be \omega- independent for spin-0 mesons, the nucleon and \Lambda hyperon, while there is \omega-dependence for spin-1 systems like the deuteron.
1712.09919
Keith R. Dienes
Keith R. Dienes, Jacob Fennick, Jason Kumar, Brooks Thomas
Dynamical Dark Matter from Thermal Freeze-Out
19 pages, LaTeX, 6 figures, 2 tables
Phys. Rev. D 97, 063522 (2018)
10.1103/PhysRevD.97.063522
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the Dynamical Dark Matter (DDM) framework, the dark sector comprises a large number of constituent dark particles whose individual masses, lifetimes, and cosmological abundances obey specific scaling relations with respect to each other. In particular, the most natural versions of this framework tend to require a spectrum of cosmological abundances which scale inversely with mass, so that dark-sector states with larger masses have smaller abundances. Thus far, DDM model-building has primarily relied on non-thermal mechanisms for abundance generation such as misalignment production, since these mechanisms give rise to abundances that have this property. By contrast, the simplest versions of thermal freeze-out tend to produce abundances that increase, rather than decrease, with the mass of the dark-matter component. In this paper, we demonstrate that there exist relatively simple modifications of the traditional thermal freeze-out mechanism which "flip" the resulting abundance spectrum, producing abundances that scale inversely with mass. Moreover, we demonstrate that a far broader variety of scaling relations between lifetimes, abundances, and masses can emerge through thermal freeze-out than through the non-thermal mechanisms previously considered for DDM ensembles. The results of this paper thus extend the DDM framework into the thermal domain and essentially allow us to "design" our resulting DDM ensembles at will in order to realize a rich array of resulting dark-matter phenomenologies.
[ { "created": "Thu, 28 Dec 2017 16:36:11 GMT", "version": "v1" }, { "created": "Thu, 22 Mar 2018 14:33:24 GMT", "version": "v2" } ]
2018-03-28
[ [ "Dienes", "Keith R.", "" ], [ "Fennick", "Jacob", "" ], [ "Kumar", "Jason", "" ], [ "Thomas", "Brooks", "" ] ]
In the Dynamical Dark Matter (DDM) framework, the dark sector comprises a large number of constituent dark particles whose individual masses, lifetimes, and cosmological abundances obey specific scaling relations with respect to each other. In particular, the most natural versions of this framework tend to require a spectrum of cosmological abundances which scale inversely with mass, so that dark-sector states with larger masses have smaller abundances. Thus far, DDM model-building has primarily relied on non-thermal mechanisms for abundance generation such as misalignment production, since these mechanisms give rise to abundances that have this property. By contrast, the simplest versions of thermal freeze-out tend to produce abundances that increase, rather than decrease, with the mass of the dark-matter component. In this paper, we demonstrate that there exist relatively simple modifications of the traditional thermal freeze-out mechanism which "flip" the resulting abundance spectrum, producing abundances that scale inversely with mass. Moreover, we demonstrate that a far broader variety of scaling relations between lifetimes, abundances, and masses can emerge through thermal freeze-out than through the non-thermal mechanisms previously considered for DDM ensembles. The results of this paper thus extend the DDM framework into the thermal domain and essentially allow us to "design" our resulting DDM ensembles at will in order to realize a rich array of resulting dark-matter phenomenologies.
1606.01492
Qiaoli Yang
Qiaoli Yang, Haoran Di
Vector Dark Matter Detection using the Quantum Jump of Atoms
5 pages, 3 figures; references added; matches version published in PLB
Phys. Lett. B 780 (2018) 622
10.1016/j.physletb.2018.03.045
null
hep-ph astro-ph.CO hep-ex physics.atom-ph physics.ins-det
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The hidden sector U(1) vector bosons created from inflationary fluctuations can be a substantial fraction of dark matter if their mass is around $10^{-5}$eV. The creation mechanism makes the vector bosons' energy spectral density $\rho_{cdm}/\Delta E$ very high. Therefore, the dark electric dipole transition rate in atoms is boosted if the energy gap between atomic states equals the mass of the vector bosons. By using the Zeeman effect, the energy gap between the 2S state and the 2P state in hydrogen atoms or hydrogen like ions can be tuned. The $2S$ state can be populated with electrons due to its relatively long life, which is about $1/7$s. When the energy gap between the semi-ground $2S$ state and the 2P state matches the mass of the cosmic vector bosons, induced transitions occur and the 2P state subsequently decays into the 1S state. The $2P\to1S$ decay emitted Lyman-$\alpha$ photons can then be registered. The choices of target atoms depend on the experimental facilities and the mass ranges of the vector bosons. Because the mass of the vector boson is connected to the inflation scale, the proposed experiment may provide a probe to inflation.
[ { "created": "Sun, 5 Jun 2016 11:16:58 GMT", "version": "v1" }, { "created": "Thu, 9 Jun 2016 08:45:39 GMT", "version": "v2" }, { "created": "Sun, 26 Jun 2016 04:15:30 GMT", "version": "v3" }, { "created": "Thu, 12 Oct 2017 18:40:03 GMT", "version": "v4" }, { "created": "Thu, 5 Apr 2018 09:56:12 GMT", "version": "v5" } ]
2018-08-27
[ [ "Yang", "Qiaoli", "" ], [ "Di", "Haoran", "" ] ]
The hidden sector U(1) vector bosons created from inflationary fluctuations can be a substantial fraction of dark matter if their mass is around $10^{-5}$eV. The creation mechanism makes the vector bosons' energy spectral density $\rho_{cdm}/\Delta E$ very high. Therefore, the dark electric dipole transition rate in atoms is boosted if the energy gap between atomic states equals the mass of the vector bosons. By using the Zeeman effect, the energy gap between the 2S state and the 2P state in hydrogen atoms or hydrogen like ions can be tuned. The $2S$ state can be populated with electrons due to its relatively long life, which is about $1/7$s. When the energy gap between the semi-ground $2S$ state and the 2P state matches the mass of the cosmic vector bosons, induced transitions occur and the 2P state subsequently decays into the 1S state. The $2P\to1S$ decay emitted Lyman-$\alpha$ photons can then be registered. The choices of target atoms depend on the experimental facilities and the mass ranges of the vector bosons. Because the mass of the vector boson is connected to the inflation scale, the proposed experiment may provide a probe to inflation.
hep-ph/9708490
Jan Kalinowski
Jan Kalinowski
Sleptons at LEP2 and Tevatron in R-Parity Violating SUSY
LaTeX file, 14 pages, 3 figures, uses epsfig, iopconf1. Presented at "Beyond the Desert 97 -- Accelerator and Non-Accelerator Approaches", Ringberg Castle, Germany, June 1997, to appear in the proceedings
null
null
DESY 97-145
hep-ph
null
In supersymmetric theories with R-parity breaking, sleptons could be produced singly in $e^+e^-$ collisions at LEP2 and in $q\bar{q}$ annihilation at the Tevatron through interactions in which two quark or two lepton fields are coupled to a slepton field. At LEP they could manifest themselves in Bhabha scattering, and in the annihilation to $\mu^+\mu^-$, \taus, and $q\bar{q}$ pairs. The formation of sneutrinos, $e^+e^-\ra \ti{\nu}$, and their signals for a mass within the reach of this machine, is an exciting speculation which can be investigated in the coming LEP2 runs with energies close to $\sqrt{s}=200$ GeV. At the Tevatron the sleptons can be searched for as resonances in $p\bar{p}\to \tilde{\nu} \to \ell^+\ell^-$ and $\tilde{\ell}\to \ell\nu $ final states. Existing LEP2 and Tevatron data can be exploited to derive bounds on the Yukawa couplings of sleptons to quark and lepton pairs.
[ { "created": "Fri, 29 Aug 1997 10:43:30 GMT", "version": "v1" } ]
2007-05-23
[ [ "Kalinowski", "Jan", "" ] ]
In supersymmetric theories with R-parity breaking, sleptons could be produced singly in $e^+e^-$ collisions at LEP2 and in $q\bar{q}$ annihilation at the Tevatron through interactions in which two quark or two lepton fields are coupled to a slepton field. At LEP they could manifest themselves in Bhabha scattering, and in the annihilation to $\mu^+\mu^-$, \taus, and $q\bar{q}$ pairs. The formation of sneutrinos, $e^+e^-\ra \ti{\nu}$, and their signals for a mass within the reach of this machine, is an exciting speculation which can be investigated in the coming LEP2 runs with energies close to $\sqrt{s}=200$ GeV. At the Tevatron the sleptons can be searched for as resonances in $p\bar{p}\to \tilde{\nu} \to \ell^+\ell^-$ and $\tilde{\ell}\to \ell\nu $ final states. Existing LEP2 and Tevatron data can be exploited to derive bounds on the Yukawa couplings of sleptons to quark and lepton pairs.
2209.10233
Trisha Sarkar
Trisha Sarkar
Probing non-unitarity of neutrino mixing in the scenario of Lorentz violation and dark nonstandard interaction
11 pages, 16 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Neutrino flavour oscillation is one of the primary indication of the existence of new physics beyond standard model. The presence of small neutrino mass is indispensable to explicate the oscillation among different flavours of neutrino. By the addition of a right handed neutral lepton with the standard model fermions, it is possible to generate tiny neutrino mass. Such additional fermion may induce non-unitarity to the $3\times 3$ PMNS mixing matrix which influences the propagation of neutrino in space-time. In this work the effect of non-unitary mixing matrix is analyzed in neutrino oscillation in presence of two new physics scenarios, Lorentz violation and dark non-standard interaction. Lorentz symmetry violation mainly appears at the Planck scale, which may also be manifested at a lower energy level. On the other hand, dark non standard interaction arises due to the interaction of neutrino with the environmental dark matter which contributes as a perturbative correction to the neutrino mass. In this analysis, the comparative study of unitary and non-unitary mixing matrix is carried out considering the scenario of Lorentz violation and dark NSI in the context of long baseline DUNE and short baseline Daya Bay experimental set up. The signature of dark nonstandard interaction is observable in both DUNE and Daya Bay set up in terms of large value of neutrino survival and oscillation probability respectively and is a possible explanation for the excess flux observed at $\sim5$ MeV in Daya Bay experiment. The signature of Lorentz violation is also possible to be observed in the short baseline Daya Bay experiment only.
[ { "created": "Wed, 21 Sep 2022 09:58:08 GMT", "version": "v1" }, { "created": "Thu, 22 Sep 2022 16:26:42 GMT", "version": "v2" }, { "created": "Mon, 30 Jan 2023 11:56:54 GMT", "version": "v3" } ]
2023-01-31
[ [ "Sarkar", "Trisha", "" ] ]
Neutrino flavour oscillation is one of the primary indication of the existence of new physics beyond standard model. The presence of small neutrino mass is indispensable to explicate the oscillation among different flavours of neutrino. By the addition of a right handed neutral lepton with the standard model fermions, it is possible to generate tiny neutrino mass. Such additional fermion may induce non-unitarity to the $3\times 3$ PMNS mixing matrix which influences the propagation of neutrino in space-time. In this work the effect of non-unitary mixing matrix is analyzed in neutrino oscillation in presence of two new physics scenarios, Lorentz violation and dark non-standard interaction. Lorentz symmetry violation mainly appears at the Planck scale, which may also be manifested at a lower energy level. On the other hand, dark non standard interaction arises due to the interaction of neutrino with the environmental dark matter which contributes as a perturbative correction to the neutrino mass. In this analysis, the comparative study of unitary and non-unitary mixing matrix is carried out considering the scenario of Lorentz violation and dark NSI in the context of long baseline DUNE and short baseline Daya Bay experimental set up. The signature of dark nonstandard interaction is observable in both DUNE and Daya Bay set up in terms of large value of neutrino survival and oscillation probability respectively and is a possible explanation for the excess flux observed at $\sim5$ MeV in Daya Bay experiment. The signature of Lorentz violation is also possible to be observed in the short baseline Daya Bay experiment only.
hep-ph/0511231
Stefano Forte
Riccardo Abbate and Stefano Forte
Re-evaluation of the Gottfried sum using neural networks
4 pages, 3 figures, latex with revtex
Phys.Rev. D72 (2005) 117503
10.1103/PhysRevD.72.117503
IFUM-855-FT
hep-ph
null
We provide a determination of the Gottfried sum from all available data, based on a neural network parametrization of the nonsinglet structure function F_2. We find S_G=0.244 +- 0.045, closer to the quark model expectation S_G=1/3 than previous results. We show that the uncertainty from the small x region is somewhat underestimated in previous determinations.
[ { "created": "Fri, 18 Nov 2005 16:24:52 GMT", "version": "v1" } ]
2009-11-11
[ [ "Abbate", "Riccardo", "" ], [ "Forte", "Stefano", "" ] ]
We provide a determination of the Gottfried sum from all available data, based on a neural network parametrization of the nonsinglet structure function F_2. We find S_G=0.244 +- 0.045, closer to the quark model expectation S_G=1/3 than previous results. We show that the uncertainty from the small x region is somewhat underestimated in previous determinations.
2308.01380
Marco Arroyo
M. A. Arroyo-Ure\~na, J. Lorenzo D\'iaz-Cruz, O. F\'elix-Beltr\'an and M. Zeleny-Mora
Lessons from LHC on the LFV Higgs decays $h \to \ell_a \ell_b$ in the Two-Higgs Doublet Models
Version accepted to be published in IJMPA
null
10.1142/S0217751X24500799
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
The non-conservation of the lepton number has been explored at the LHC through the Lepton-Flavor Violating (LFV) Higgs decays $h\to\ell_a\ell_b$, with $\ell_{a,\,b}=e,\,\mu,\,\tau$ $(a \neq b)$. Current limits on these decays are a source of valuable information on the structure of the Yukawa and Higgs sectors. The LFV Higgs couplings can arise within the general Two-Higgs Doublet Model (2HDM); the predicted rates for these decay modes depend on the specific Yukawa structure being considered, ranging from a vanishing branching ratio at tree-level for some versions (2HDM-I, II, X, Y), up to large and detectable ratios within the general 2HDM-III. An attractive scenario is given by the texturized version of the model (2HDM-Tx), with the Yukawa matrices having some texture zeros, such as the minimal version with the so-called Cheng-Sher ansazt. We study the constraints on the parameter space of the 2HDM provided by experimental and theoretical restrictions, and use them to study the detection of LFV Higgs modes at LHC. We find several encouraging scenarios to the search for the decay $h \to\tau\mu$ that could be achieved in the High-Luminosity LHC. On the other hand, LFV Higgs couplings can also be induced at one-loop level in the 2HDM with neutrino masses, with the loops being mediated by neutrino interactions; we find that the resulting branching ratios are of order $10^{-7}$ at best, which is out of the reach of current and future phases of the LHC.
[ { "created": "Wed, 2 Aug 2023 18:37:21 GMT", "version": "v1" }, { "created": "Tue, 16 Jul 2024 23:28:19 GMT", "version": "v2" } ]
2024-07-18
[ [ "Arroyo-Ureña", "M. A.", "" ], [ "Díaz-Cruz", "J. Lorenzo", "" ], [ "Félix-Beltrán", "O.", "" ], [ "Zeleny-Mora", "M.", "" ] ]
The non-conservation of the lepton number has been explored at the LHC through the Lepton-Flavor Violating (LFV) Higgs decays $h\to\ell_a\ell_b$, with $\ell_{a,\,b}=e,\,\mu,\,\tau$ $(a \neq b)$. Current limits on these decays are a source of valuable information on the structure of the Yukawa and Higgs sectors. The LFV Higgs couplings can arise within the general Two-Higgs Doublet Model (2HDM); the predicted rates for these decay modes depend on the specific Yukawa structure being considered, ranging from a vanishing branching ratio at tree-level for some versions (2HDM-I, II, X, Y), up to large and detectable ratios within the general 2HDM-III. An attractive scenario is given by the texturized version of the model (2HDM-Tx), with the Yukawa matrices having some texture zeros, such as the minimal version with the so-called Cheng-Sher ansazt. We study the constraints on the parameter space of the 2HDM provided by experimental and theoretical restrictions, and use them to study the detection of LFV Higgs modes at LHC. We find several encouraging scenarios to the search for the decay $h \to\tau\mu$ that could be achieved in the High-Luminosity LHC. On the other hand, LFV Higgs couplings can also be induced at one-loop level in the 2HDM with neutrino masses, with the loops being mediated by neutrino interactions; we find that the resulting branching ratios are of order $10^{-7}$ at best, which is out of the reach of current and future phases of the LHC.
hep-ph/0605317
Eef van Beveren
Eef van Beveren and George Rupp
Is the Y(4260) just a coupled-channel signal?
6 pages, 8 figures
null
null
null
hep-ph
null
The Ds-Ds*, D*-D*, and Ds*-Ds*, P-wave channels in the energy region of the Y(4260) charmonium structure are studied in a coupled-channel model applied to JPC=1-- c-cbar resonances. The three channels exhibit enhancements that peak at 4.27 GeV, 4.26 GeV, and 4.33 GeV, respectively, having widths ranging from 80 to 200 MeV. However, no S-matrix poles are found, other than those associated with the psi(2D,4160) and psi(4S,4415). The conclusion is that the observed Y(4260) signal(s) in pi-pi J/psi is (are) probably associated with the opening of the aforementioned channels, resulting in a resonance-like structure caused by the tail of the psi(3S,4040) resonance, roughly midway between the mentioned P-wave thresholds and a sharp kinematical minimum at about 4.4 GeV present in both the experimental and the model scattering amplitude.
[ { "created": "Mon, 29 May 2006 15:46:52 GMT", "version": "v1" } ]
2007-05-23
[ [ "van Beveren", "Eef", "" ], [ "Rupp", "George", "" ] ]
The Ds-Ds*, D*-D*, and Ds*-Ds*, P-wave channels in the energy region of the Y(4260) charmonium structure are studied in a coupled-channel model applied to JPC=1-- c-cbar resonances. The three channels exhibit enhancements that peak at 4.27 GeV, 4.26 GeV, and 4.33 GeV, respectively, having widths ranging from 80 to 200 MeV. However, no S-matrix poles are found, other than those associated with the psi(2D,4160) and psi(4S,4415). The conclusion is that the observed Y(4260) signal(s) in pi-pi J/psi is (are) probably associated with the opening of the aforementioned channels, resulting in a resonance-like structure caused by the tail of the psi(3S,4040) resonance, roughly midway between the mentioned P-wave thresholds and a sharp kinematical minimum at about 4.4 GeV present in both the experimental and the model scattering amplitude.
hep-ph/9402293
null
Hong-Jian He, Zhaoming Qiu, Chia-Hsiung Tze
Inconsistency of QED in the Presence of Dirac Monopoles
Extended and combined version, refinements added; 20 LaTex pages, Published in Z. Phys. C65, pp.175-182
Z.Phys.C65:175-182,1995
10.1007/BF01571318
VPI-IHEP-93-12
hep-ph astro-ph hep-th nucl-th
null
A precise formulation of $U(1)$ local gauge invariance in QED is presented, which clearly shows that the gauge coupling associated with the unphysical longitudinal photon field is non-observable and actually has an arbitrary value. We then re-examine the Dirac quantization condition and find that its derivation involves solely the unphysical longitudinal coupling. Hence an inconsistency inevitably arises in the presence of Dirac monopoles and this can be considered as a theoretical evidence against their existence. An alternative, independent proof of this conclusion is also presented.
[ { "created": "Wed, 16 Feb 1994 04:52:16 GMT", "version": "v1" }, { "created": "Fri, 2 Dec 1994 03:22:10 GMT", "version": "v2" } ]
2008-11-26
[ [ "He", "Hong-Jian", "" ], [ "Qiu", "Zhaoming", "" ], [ "Tze", "Chia-Hsiung", "" ] ]
A precise formulation of $U(1)$ local gauge invariance in QED is presented, which clearly shows that the gauge coupling associated with the unphysical longitudinal photon field is non-observable and actually has an arbitrary value. We then re-examine the Dirac quantization condition and find that its derivation involves solely the unphysical longitudinal coupling. Hence an inconsistency inevitably arises in the presence of Dirac monopoles and this can be considered as a theoretical evidence against their existence. An alternative, independent proof of this conclusion is also presented.
0909.3003
Yong-Yeon Keum
Sarira Sahu, Nissim Fraija and Yong-Yeon Keum
Propagation of Neutrinos through Magnetized Gamma-Ray Burst Fireball
Revtex, 19 pages, 7 figures, minor revised version
JCAP 0911:024,2009
10.1088/1475-7516/2009/11/024
preprint: ICN/000-03-HEP, KIAS-P09049
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The neutrino self-energy is calculated in a weakly magnetized plasma consists of electrons, protons, neutrons and their anti-particles and using this we have calculated the neutrino effective potential up to order $M^{-4}_W$. In the absence of magnetic field it reduces to the known result. We have also calculated explicitly the effective potentials for different backgrounds which may be helpful in different environments. By considering the mixing of three active neutrinos in the medium with the magnetic field we have derived the survival and conversion probabilities of neutrinos from one flavor to another and also the resonance condition is derived. As an application of the above, we considered the dense and relativistic plasma of the Gamma-Ray Bursts fireball through which neutrinos of 5-30 MeV can propagate and depending on the fireball parameters they may oscillate resonantly or non-resonantly from one flavor to another. These MeV neutrinos are produced due to stellar collapse or merger events which trigger the Gamma-Ray Burst. The fireball itself also produces MeV neutrinos due to electron positron annihilation, inverse beta decay and nucleonic bremsstrahlung. Using the three neutrino mixing and considering the best fit values of the neutrino parameters, we found that electron neutrinos are hard to oscillate to another flavors. On the other hand, the muon neutrinos and the tau neutrinos oscillate with equal probability to one another, which depends on the neutrino energy, temperature and size of the fireball. Comparison of oscillation probabilities with and without magnetic field shows that, they depend on the neutrino energy and also on the size of the fireball. By using the resonance condition, we have also estimated the resonance length of the propagating neutrinos as well as the baryon content of the fireball.
[ { "created": "Wed, 16 Sep 2009 18:49:07 GMT", "version": "v1" }, { "created": "Tue, 10 Nov 2009 04:54:24 GMT", "version": "v2" } ]
2009-12-10
[ [ "Sahu", "Sarira", "" ], [ "Fraija", "Nissim", "" ], [ "Keum", "Yong-Yeon", "" ] ]
The neutrino self-energy is calculated in a weakly magnetized plasma consists of electrons, protons, neutrons and their anti-particles and using this we have calculated the neutrino effective potential up to order $M^{-4}_W$. In the absence of magnetic field it reduces to the known result. We have also calculated explicitly the effective potentials for different backgrounds which may be helpful in different environments. By considering the mixing of three active neutrinos in the medium with the magnetic field we have derived the survival and conversion probabilities of neutrinos from one flavor to another and also the resonance condition is derived. As an application of the above, we considered the dense and relativistic plasma of the Gamma-Ray Bursts fireball through which neutrinos of 5-30 MeV can propagate and depending on the fireball parameters they may oscillate resonantly or non-resonantly from one flavor to another. These MeV neutrinos are produced due to stellar collapse or merger events which trigger the Gamma-Ray Burst. The fireball itself also produces MeV neutrinos due to electron positron annihilation, inverse beta decay and nucleonic bremsstrahlung. Using the three neutrino mixing and considering the best fit values of the neutrino parameters, we found that electron neutrinos are hard to oscillate to another flavors. On the other hand, the muon neutrinos and the tau neutrinos oscillate with equal probability to one another, which depends on the neutrino energy, temperature and size of the fireball. Comparison of oscillation probabilities with and without magnetic field shows that, they depend on the neutrino energy and also on the size of the fireball. By using the resonance condition, we have also estimated the resonance length of the propagating neutrinos as well as the baryon content of the fireball.
1606.01047
Smruti Patel
Smruti Patel and P C Vinodkumar
Tetraquark states in the bottom sector and the status of the $Y_b$(10890) state
arXiv admin note: text overlap with arXiv:1306.0695 by other authors
null
10.1140/epjc/s10052-016-4186-6
null
hep-ph
http://creativecommons.org/publicdomain/zero/1.0/
We have done the exploratory study of bottom tetraquarks ($[bq\bar b \bar q];{q\in u,d}$) in the diquark-antidiquark framework with the inclusion of spin hyperfine, spin-orbit and tensor components of the one gluon exchange interaction. Our focus here is on the $Y_b$(10890) and other exotic states in the bottom sector. We have predicted some of the bottom counterparts to the charm tetraquark candidates. Our present study shows that if $Z_b(10610)$ and $Z_b(10650)$ are diquark-diantiquark states then they have to be first radial excitations only and we have predicted $Z_b(10650)$ state as first radial excitation of tetraquark state $X_b$ (10.143-10.230). We have identified $X_b$ state with $J^{PC}= 1^{+-}/0^{++}$ as being the analogue of $Z_c(3900)$. An observation of the $X_b$ will provide a deeper insight into the exotic hadron spectroscopy and is helpful to unravel the nature of the states connected by the heavy quark symmetry. We particularly focus on the lowest P wave $[bq][\bar b\bar q]$ states with $J^{PC}=1^{--}$ by computing their leptonic, hadronic and radiative decay widths to predict the status of still controversial $Y_b$(10890) state. Apart from this, we have also shown here the possibility of mixing of P wave states. In the case of mixing of $1^{--}$ state with different spin multiplicities, we found that predicted masses of the mixed P states differ from $Y_b$(10890) state only by $\pm20$ MeV energy difference which can be helpful to resolve further the structure of $Y_b$(10890).
[ { "created": "Fri, 3 Jun 2016 11:27:19 GMT", "version": "v1" } ]
2016-07-20
[ [ "Patel", "Smruti", "" ], [ "Vinodkumar", "P C", "" ] ]
We have done the exploratory study of bottom tetraquarks ($[bq\bar b \bar q];{q\in u,d}$) in the diquark-antidiquark framework with the inclusion of spin hyperfine, spin-orbit and tensor components of the one gluon exchange interaction. Our focus here is on the $Y_b$(10890) and other exotic states in the bottom sector. We have predicted some of the bottom counterparts to the charm tetraquark candidates. Our present study shows that if $Z_b(10610)$ and $Z_b(10650)$ are diquark-diantiquark states then they have to be first radial excitations only and we have predicted $Z_b(10650)$ state as first radial excitation of tetraquark state $X_b$ (10.143-10.230). We have identified $X_b$ state with $J^{PC}= 1^{+-}/0^{++}$ as being the analogue of $Z_c(3900)$. An observation of the $X_b$ will provide a deeper insight into the exotic hadron spectroscopy and is helpful to unravel the nature of the states connected by the heavy quark symmetry. We particularly focus on the lowest P wave $[bq][\bar b\bar q]$ states with $J^{PC}=1^{--}$ by computing their leptonic, hadronic and radiative decay widths to predict the status of still controversial $Y_b$(10890) state. Apart from this, we have also shown here the possibility of mixing of P wave states. In the case of mixing of $1^{--}$ state with different spin multiplicities, we found that predicted masses of the mixed P states differ from $Y_b$(10890) state only by $\pm20$ MeV energy difference which can be helpful to resolve further the structure of $Y_b$(10890).
2103.06050
Murat Abdughani
Bin Zhu, Murat Abdughani
Thermal Relic of Self-Interacting Dark Matter with Retarded Decay of Mediator
20 pages, 6 figures, Version accepted for JHEP
null
10.1007/JHEP12(2021)059
null
hep-ph astro-ph.HE
http://creativecommons.org/publicdomain/zero/1.0/
The existence of a light mediator is beneficial to some phenomena in astroparticle physics, such as the core-cusp problem and diversity problem. It can decouple from Standard Model to avoid direct detection constraints, generally realized by retard decay of the mediator. Their out-of-equilibrium decay process changes the dark matter (DM) freeze-out via temperature discrepancy. This type of hidden sector (HS) typically requires a precision calculation of the freeze-out process considering HS temperature evolution and the thermal average of the cross-section. If the mediator is light sufficiently, we can not ignore the s-wave radiative bound state formation process from the perspective of CMB ionization and Sommerfeld enhancement. We put large mass splitting between DM and mediator, different temperature evolution on the same theoretical footing, discussing the implication for DM relic density in this HS. We study this model and illustrate its property by considering the general Higgs-portal dark matter scenario, which includes all the relevant constraints and signals. It shows that the combination of BBN and CMB constraint favors the not-too-hot HS, $r_{\mathrm{inf}}<10^2$, for the positive cubic interaction of mediator scenario. On the other hand, the negative cubic interaction is ruled out except for our proposed blind spot scenario.
[ { "created": "Wed, 10 Mar 2021 13:49:42 GMT", "version": "v1" }, { "created": "Tue, 30 Nov 2021 09:32:19 GMT", "version": "v2" } ]
2022-01-05
[ [ "Zhu", "Bin", "" ], [ "Abdughani", "Murat", "" ] ]
The existence of a light mediator is beneficial to some phenomena in astroparticle physics, such as the core-cusp problem and diversity problem. It can decouple from Standard Model to avoid direct detection constraints, generally realized by retard decay of the mediator. Their out-of-equilibrium decay process changes the dark matter (DM) freeze-out via temperature discrepancy. This type of hidden sector (HS) typically requires a precision calculation of the freeze-out process considering HS temperature evolution and the thermal average of the cross-section. If the mediator is light sufficiently, we can not ignore the s-wave radiative bound state formation process from the perspective of CMB ionization and Sommerfeld enhancement. We put large mass splitting between DM and mediator, different temperature evolution on the same theoretical footing, discussing the implication for DM relic density in this HS. We study this model and illustrate its property by considering the general Higgs-portal dark matter scenario, which includes all the relevant constraints and signals. It shows that the combination of BBN and CMB constraint favors the not-too-hot HS, $r_{\mathrm{inf}}<10^2$, for the positive cubic interaction of mediator scenario. On the other hand, the negative cubic interaction is ruled out except for our proposed blind spot scenario.
2302.13071
Karin Sch\"onning
Karin Sch\"onning, Varvara Batozskaya, Patrik Adlarson and Xiaorong Zhou
Production and decay of polarized hyperon-antihyperon pairs
27 pages, 9 figures
Chinese Physics C 47, 052002 (2023)
10.1088/1674-1137/acc790
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Polarized hyperon-antihyperon pairs shed light on various unresolved puzzles in contemporary physics: How the strong interaction confines quarks into hadrons, how accurately the Standard Model describes microcosmos and even why our universe consists of so much more matter than antimatter. Thanks to their weak, parity violating decays, hyperons reveal their spin properties. This can be exploited e.g. the decomposition of the electromagnetic structure of hyperons, precision tests of flavour symmetry and searches for CP violation. At the BESIII experiment at BEPC-II, Beijing, China, hyperon-antihyperon pairs can be produced in abundance. Recently collected large data samples have triggered the development of new methods that provide unprecedented precision and a plethora of new results have emerged. When applied at future high-intensity facilities like PANDA and STCF, precision physics will be taken to a new level which can contribute to the solution to the aforementioned puzzles.
[ { "created": "Sat, 25 Feb 2023 12:15:54 GMT", "version": "v1" } ]
2024-01-09
[ [ "Schönning", "Karin", "" ], [ "Batozskaya", "Varvara", "" ], [ "Adlarson", "Patrik", "" ], [ "Zhou", "Xiaorong", "" ] ]
Polarized hyperon-antihyperon pairs shed light on various unresolved puzzles in contemporary physics: How the strong interaction confines quarks into hadrons, how accurately the Standard Model describes microcosmos and even why our universe consists of so much more matter than antimatter. Thanks to their weak, parity violating decays, hyperons reveal their spin properties. This can be exploited e.g. the decomposition of the electromagnetic structure of hyperons, precision tests of flavour symmetry and searches for CP violation. At the BESIII experiment at BEPC-II, Beijing, China, hyperon-antihyperon pairs can be produced in abundance. Recently collected large data samples have triggered the development of new methods that provide unprecedented precision and a plethora of new results have emerged. When applied at future high-intensity facilities like PANDA and STCF, precision physics will be taken to a new level which can contribute to the solution to the aforementioned puzzles.
1410.0613
Sophia Chabysheva
S.S. Chabysheva
The light-front coupled-cluster method applied to $\phi_{1+1}^4$ theory
8 pages, 1 figure; RevTeX 4.1; based on talk at Lightcone 2014 workshop, Raleigh, NC, May 26-30, 2014
null
10.1007/s00601-014-0930-3
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the light-front coupled-cluster (LFCC) method to compute the odd-parity massive eigenstate of $\phi_{1+1}^4$ theory. A standard Fock-space truncation of the eigenstate yields a finite set of linear equations for a finite number of wave functions. The LFCC method replaces Fock-space truncation with a more sophisticated truncation; the eigenvalue problem is reduced to a finite set of nonlinear equations without any restriction on Fock space, but with restrictions on the Fock wave functions. We compare our results with those obtained with a Fock-space truncation.
[ { "created": "Thu, 2 Oct 2014 17:25:07 GMT", "version": "v1" } ]
2015-06-23
[ [ "Chabysheva", "S. S.", "" ] ]
We use the light-front coupled-cluster (LFCC) method to compute the odd-parity massive eigenstate of $\phi_{1+1}^4$ theory. A standard Fock-space truncation of the eigenstate yields a finite set of linear equations for a finite number of wave functions. The LFCC method replaces Fock-space truncation with a more sophisticated truncation; the eigenvalue problem is reduced to a finite set of nonlinear equations without any restriction on Fock space, but with restrictions on the Fock wave functions. We compare our results with those obtained with a Fock-space truncation.
0705.1504
Jeff Forshaw
Jeff Forshaw and Malin Sjodahl
Soft gluons in Higgs plus two jet production
15 pages and 5 figures
JHEP 0709:119,2007
10.1088/1126-6708/2007/09/119
null
hep-ph
null
We investigate the effects of an all order QCD resummation of soft gluon emissions for Higgs boson production in association with two hard jets. We consider both the gluon-gluon fusion and weak boson fusion processes and show how to resum a large part of the leading logarithms in the jet veto scale. Our resummation improves on previous analyses which also aim to include the effects of multiple soft gluon radiation. In addition we calculate the interference between weak boson fusion and gluon-gluon fusion and find that it is small.
[ { "created": "Thu, 10 May 2007 16:09:21 GMT", "version": "v1" }, { "created": "Fri, 28 Sep 2007 13:23:05 GMT", "version": "v2" } ]
2009-04-22
[ [ "Forshaw", "Jeff", "" ], [ "Sjodahl", "Malin", "" ] ]
We investigate the effects of an all order QCD resummation of soft gluon emissions for Higgs boson production in association with two hard jets. We consider both the gluon-gluon fusion and weak boson fusion processes and show how to resum a large part of the leading logarithms in the jet veto scale. Our resummation improves on previous analyses which also aim to include the effects of multiple soft gluon radiation. In addition we calculate the interference between weak boson fusion and gluon-gluon fusion and find that it is small.
hep-ph/0402172
Sally Dawson
S. Dawson, D. Dicus, C. Kao, and R. Malhotra
Discovering the Higgs Bosons of Minimal Supersymmetry with Muons and a Bottom Quark
Version to appear in Phys. Rev. Lett
Phys.Rev.Lett. 92 (2004) 241801
10.1103/PhysRevLett.92.241801
null
hep-ph
null
We investigate the prospects for the discovery at the CERN Large Hadron Collider of a neutral Higgs boson produced with one bottom quark followed by Higgs decay into a muon pair. We work within the framework of the minimal supersymmetric model. The dominant physics background from the production of $b \mu^+\mu^-$, $j\mu^+\mu^-$, j=g,u,d,s,c, and $b {\bar b} W^+W^-$ is calculated with realistic acceptance cuts. Promising results are found for the CP-odd pseudoscalar ($A^0$) and the heavier CP-even scalar ($H^0$) Higgs bosons with masses up to 600 GeV. This discovery channel with one energetic bottom quark greatly improves the discovery potential of the LHC beyond the inclusive channel $pp\to \phi^0\to \mu^+\mu^- +X$.
[ { "created": "Tue, 17 Feb 2004 17:26:36 GMT", "version": "v1" }, { "created": "Wed, 18 Feb 2004 02:23:32 GMT", "version": "v2" }, { "created": "Wed, 14 Apr 2004 19:38:43 GMT", "version": "v3" } ]
2009-11-10
[ [ "Dawson", "S.", "" ], [ "Dicus", "D.", "" ], [ "Kao", "C.", "" ], [ "Malhotra", "R.", "" ] ]
We investigate the prospects for the discovery at the CERN Large Hadron Collider of a neutral Higgs boson produced with one bottom quark followed by Higgs decay into a muon pair. We work within the framework of the minimal supersymmetric model. The dominant physics background from the production of $b \mu^+\mu^-$, $j\mu^+\mu^-$, j=g,u,d,s,c, and $b {\bar b} W^+W^-$ is calculated with realistic acceptance cuts. Promising results are found for the CP-odd pseudoscalar ($A^0$) and the heavier CP-even scalar ($H^0$) Higgs bosons with masses up to 600 GeV. This discovery channel with one energetic bottom quark greatly improves the discovery potential of the LHC beyond the inclusive channel $pp\to \phi^0\to \mu^+\mu^- +X$.
0709.2058
A. V. Luchinsky
S. S. Gershtein, A. K. Likhoded, G. P. Pronko
Possible nature of $Z^+(4430)$
5 pages, 6 figures
null
null
null
hep-ph
null
We discuss exotic states X(3872) and $Z^+(4430)$, observed recently in experiment Belle. The QCD-string based explanation is suggested.
[ { "created": "Thu, 13 Sep 2007 12:28:58 GMT", "version": "v1" } ]
2007-09-14
[ [ "Gershtein", "S. S.", "" ], [ "Likhoded", "A. K.", "" ], [ "Pronko", "G. P.", "" ] ]
We discuss exotic states X(3872) and $Z^+(4430)$, observed recently in experiment Belle. The QCD-string based explanation is suggested.
hep-ph/9906455
Oleg Teryaev
J. Soffer, O.V. Teryaev
Improved positivity bound for Deep Inelastic Scattering on transversely polarized nucleon
LaTeX, 4 pages; CPT--99/P.3845; Talk at Workshop Polarized Protons at High Eergies (DESY-Hamburg, May 17-20, 1999)
null
null
null
hep-ph
null
The positivity bound for the transverse asymmetry $A_2$ may be improved by making use of the fact, that the state of a photon and a nucleon with total spin 3/2, does not participate to the interference. The bound is therefore useful in the case of a longitudinal asymmetry small (say, at low $x$) or negative (like in the neuteron case).
[ { "created": "Tue, 22 Jun 1999 16:33:44 GMT", "version": "v1" } ]
2007-05-23
[ [ "Soffer", "J.", "" ], [ "Teryaev", "O. V.", "" ] ]
The positivity bound for the transverse asymmetry $A_2$ may be improved by making use of the fact, that the state of a photon and a nucleon with total spin 3/2, does not participate to the interference. The bound is therefore useful in the case of a longitudinal asymmetry small (say, at low $x$) or negative (like in the neuteron case).
hep-ph/0110048
Lokhtin
I.P. Lokhtin
High-mass dimuon, B anti-B and B --> J/Psi production in ultrarelativistic nucleus-nucleus interactions
Talk given at International Workshop on Physics of the Quark-Gluon Plasma, Palaiseau, France, September 4-7, 2001 ; 6 pages including 4 eps-figures
null
null
null
hep-ph
null
The potential of B-physics in ultrarelativistic heavy ion collisions is discussed. The different mechanisms of heavy quark production at high energies are considered. We analyze the sensitivity of high-mass mu+mu- pairs from BBbar semileptonic decays and secondary J/Psi's from single B decays to the medium-induced bottom quark energy loss at LHC energies.
[ { "created": "Wed, 3 Oct 2001 19:23:16 GMT", "version": "v1" }, { "created": "Thu, 11 Oct 2001 15:09:43 GMT", "version": "v2" } ]
2016-09-06
[ [ "Lokhtin", "I. P.", "" ] ]
The potential of B-physics in ultrarelativistic heavy ion collisions is discussed. The different mechanisms of heavy quark production at high energies are considered. We analyze the sensitivity of high-mass mu+mu- pairs from BBbar semileptonic decays and secondary J/Psi's from single B decays to the medium-induced bottom quark energy loss at LHC energies.
hep-ph/0606140
Michel Tytgat
Michel H.G. Tytgat
Relating leptogenesis and dark matter
4 pages, 1 figure, to appear in the proceedings of 40th Rencontres de Moriond, Electroweak Interactions and Unified Theories, March 11 - 18, 2006
null
null
null
hep-ph
null
A scenario that relates the abundance of dark matter to the baryon asymmetry of the Universe is presented. In this scenario, based on a left-right extension of the Standard Model, dark matter is made of light, ~ 1 GeV, right-handed Majorana neutrinos.
[ { "created": "Mon, 12 Jun 2006 13:14:09 GMT", "version": "v1" } ]
2007-05-23
[ [ "Tytgat", "Michel H. G.", "" ] ]
A scenario that relates the abundance of dark matter to the baryon asymmetry of the Universe is presented. In this scenario, based on a left-right extension of the Standard Model, dark matter is made of light, ~ 1 GeV, right-handed Majorana neutrinos.
hep-ph/9606270
A. Abada
Abdellatif Abada (Manchester U.)
Isoscalar NN spin-orbit potential from a Skyrme model with scalar mesons
10 pages (revtex) + 2 figures; use \psfig command. Minor changes in the text and some discussion added in the last section. To be published in Z. Phys. A
Z.Phys. A358 (1997) 85-89
10.1007/s002180050280
MC/TH 96/17
hep-ph
null
As a first step toward circumventing the difficulty to obtain an attractive isospin-independent NN spin-orbit force from Skyrme-type models involving only pions, we investigate an improved Skyrme Lagrangian that incorporates the scalar-isoscalar meson \epsilon which can be viewed as the cause behind the enhancement of the $\pi \pi S$-wave. We find that at large distances, the main contribution to the spin-orbit potential comes from the scalar Lagrangian and it is found to be attractive. We briefly discuss how to pursue this work to finally obtain a medium-range attractive interaction.
[ { "created": "Fri, 7 Jun 1996 17:19:16 GMT", "version": "v1" }, { "created": "Fri, 24 Jan 1997 11:04:48 GMT", "version": "v2" } ]
2016-09-06
[ [ "Abada", "Abdellatif", "", "Manchester U." ] ]
As a first step toward circumventing the difficulty to obtain an attractive isospin-independent NN spin-orbit force from Skyrme-type models involving only pions, we investigate an improved Skyrme Lagrangian that incorporates the scalar-isoscalar meson \epsilon which can be viewed as the cause behind the enhancement of the $\pi \pi S$-wave. We find that at large distances, the main contribution to the spin-orbit potential comes from the scalar Lagrangian and it is found to be attractive. We briefly discuss how to pursue this work to finally obtain a medium-range attractive interaction.
hep-ph/0204169
Stefano Rigolin
Stefano Rigolin (CERN)
An alternative approach to b->s\gamma in the unconstrained MSSM
6 pages, 4 eps figure, talk given at the XXXVIIth Rencontres de Moriond (ELECTROWEAK)
null
null
null
hep-ph
null
The gluino contributions to the $C'_{7,8}$ Wilson coefficients for b->s\gamma are calculated within the unconstrained MSSM. New stringent bounds on the \dRLbs and \dRRbs mass insertion parameters are obtained in the limit in which the SM and SUSY contributions to $C_{7,8}$ approximately cancel. Such a cancellation can plausibly appear within several classes of SUSY breaking models. Assuming this cancellation takes place, we perform an analysis of the b->s\gamma decay. We show that, in the unconstrained MSSM such an alternative is reasonable and it is possible to saturate the b->s\gamma branching ratio and produce a CP asymmetry of up to 20%, from only the gluino contribution to $C'_{7,8}$ coefficients. Using photon polarization a LR asymmetry can be defined that in principle allows the $C_{7,8}$ and $C'_{7,8}$ contributions to the b->s\gamma decay to be disentangled.
[ { "created": "Mon, 15 Apr 2002 13:27:27 GMT", "version": "v1" } ]
2007-05-23
[ [ "Rigolin", "Stefano", "", "CERN" ] ]
The gluino contributions to the $C'_{7,8}$ Wilson coefficients for b->s\gamma are calculated within the unconstrained MSSM. New stringent bounds on the \dRLbs and \dRRbs mass insertion parameters are obtained in the limit in which the SM and SUSY contributions to $C_{7,8}$ approximately cancel. Such a cancellation can plausibly appear within several classes of SUSY breaking models. Assuming this cancellation takes place, we perform an analysis of the b->s\gamma decay. We show that, in the unconstrained MSSM such an alternative is reasonable and it is possible to saturate the b->s\gamma branching ratio and produce a CP asymmetry of up to 20%, from only the gluino contribution to $C'_{7,8}$ coefficients. Using photon polarization a LR asymmetry can be defined that in principle allows the $C_{7,8}$ and $C'_{7,8}$ contributions to the b->s\gamma decay to be disentangled.
1305.3555
Anton Godizov
A.A. Godizov
The hard pomeron intercept and the data on the proton unpolarized structure function
5 pages, minor corrections
Nucl. Phys. A 927 (2014) 36-40
10.1016/j.nuclphysa.2014.03.011
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is demonstrated that the hard pomeron intercept value can be estimated directly from the data on the proton unpolarized structure function: $\alpha_{\rm P}^h(0)-1=0.317\pm 0.028$.
[ { "created": "Wed, 15 May 2013 17:23:08 GMT", "version": "v1" }, { "created": "Tue, 8 Oct 2013 13:33:20 GMT", "version": "v2" }, { "created": "Sat, 29 Mar 2014 09:02:40 GMT", "version": "v3" } ]
2014-06-10
[ [ "Godizov", "A. A.", "" ] ]
It is demonstrated that the hard pomeron intercept value can be estimated directly from the data on the proton unpolarized structure function: $\alpha_{\rm P}^h(0)-1=0.317\pm 0.028$.
2212.00282
Oleg Popov
Rena Ciftci, Abbas Kenan Ciftci, and Oleg Popov
Democratic parameterization and analysis for 331 model as a subgroup of $SU(6)$
21 pages, 5 figures, 2 tables. arXiv admin note: text overlap with arXiv:2211.16529
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A democratic parameterization is introduced for $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$ extension of the Standard Model, which is inspired by $SU(6)$ symmetry. In the novel scenario all Cabibbo-Kobayashi-Maskawa mixing angles and quark masses, nine observable quantities in total, are predicted within 1$-$3 standard deviations of the experimental values with a minimum number of input parameters. The present work provides the thorough numerical analysis and correlations between input parameters and predicted quantities. $\chi^2\approx 0.67$ with $\forall\sigma<0.61$ corresponds to the best global fit benchmark point. Benefits of the new parameterization and future prospects are discussed as well.
[ { "created": "Thu, 1 Dec 2022 05:00:45 GMT", "version": "v1" } ]
2022-12-02
[ [ "Ciftci", "Rena", "" ], [ "Ciftci", "Abbas Kenan", "" ], [ "Popov", "Oleg", "" ] ]
A democratic parameterization is introduced for $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$ extension of the Standard Model, which is inspired by $SU(6)$ symmetry. In the novel scenario all Cabibbo-Kobayashi-Maskawa mixing angles and quark masses, nine observable quantities in total, are predicted within 1$-$3 standard deviations of the experimental values with a minimum number of input parameters. The present work provides the thorough numerical analysis and correlations between input parameters and predicted quantities. $\chi^2\approx 0.67$ with $\forall\sigma<0.61$ corresponds to the best global fit benchmark point. Benefits of the new parameterization and future prospects are discussed as well.
hep-ph/0305142
Vladimir Smirnov
V.A. Smirnov
Analytical Result for Dimensionally Regularized Massless On-Shell Planar Triple Box
8 pages, LaTeX with axodraw.sty
Phys.Lett. B567 (2003) 193-199
10.1016/S0370-2693(03)00895-5
null
hep-ph
null
The dimensionally regularized massless on-shell planar triple box Feynman diagram with powers of propagators equal to one is analytically evaluated for general values of the Mandelstam variables s and t in a Laurent expansion in the parameter \ep=(4-d)/2 of dimensional regularization up to a finite part. An explicit result is expressed in terms of harmonic polylogarithms, with parameters 0 and 1, up to the sixth order. The evaluation is based on the method of Feynman parameters and multiple Mellin-Barnes representation. The same technique can be quite similarly applied to planar triple boxes with any numerators and integer powers of the propagators.
[ { "created": "Tue, 13 May 2003 15:51:43 GMT", "version": "v1" } ]
2009-11-10
[ [ "Smirnov", "V. A.", "" ] ]
The dimensionally regularized massless on-shell planar triple box Feynman diagram with powers of propagators equal to one is analytically evaluated for general values of the Mandelstam variables s and t in a Laurent expansion in the parameter \ep=(4-d)/2 of dimensional regularization up to a finite part. An explicit result is expressed in terms of harmonic polylogarithms, with parameters 0 and 1, up to the sixth order. The evaluation is based on the method of Feynman parameters and multiple Mellin-Barnes representation. The same technique can be quite similarly applied to planar triple boxes with any numerators and integer powers of the propagators.
0804.3050
Jason Evans
Eung Jin Chun, Jason L. Evans, David E. Morrissey, James D. Wells
Higgs Boson Exempt No-Scale Supersymmetry with a Neutrino Seesaw: Implications for Lepton Flavor Violation and Leptogenesis
25 pages, 11 figures; Added a reference
Phys.Rev.D79:015003,2009
10.1103/PhysRevD.79.015003
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Motivated by the observation of neutrino oscillations, we extend the Higgs boson exempt no-scale supersymmetry model (HENS) by adding three heavy right-handed neutrino chiral supermultiplets to generate the light neutrino masses and mixings. The neutrino Yukawa couplings can induce new lepton flavor violating couplings among the soft terms in the course of renormalization group running down from the boundary scale. We study the effects this has on the predictions for low-energy probes of lepton flavor violation(LFV). Heavy right-handed neutrinos also provide a way to generate the baryon asymmetry through leptogenesis. We find that consistency with LFV and leptogenesis puts strong requirements on either the form of the Yukawa mass matrix or the smallness of the Higgs up soft mass. In all cases, we generically expect that new physics LFV is non-zero and can be found in a future experiment.
[ { "created": "Fri, 18 Apr 2008 15:43:28 GMT", "version": "v1" }, { "created": "Mon, 21 Jul 2008 18:40:56 GMT", "version": "v2" } ]
2009-01-21
[ [ "Chun", "Eung Jin", "" ], [ "Evans", "Jason L.", "" ], [ "Morrissey", "David E.", "" ], [ "Wells", "James D.", "" ] ]
Motivated by the observation of neutrino oscillations, we extend the Higgs boson exempt no-scale supersymmetry model (HENS) by adding three heavy right-handed neutrino chiral supermultiplets to generate the light neutrino masses and mixings. The neutrino Yukawa couplings can induce new lepton flavor violating couplings among the soft terms in the course of renormalization group running down from the boundary scale. We study the effects this has on the predictions for low-energy probes of lepton flavor violation(LFV). Heavy right-handed neutrinos also provide a way to generate the baryon asymmetry through leptogenesis. We find that consistency with LFV and leptogenesis puts strong requirements on either the form of the Yukawa mass matrix or the smallness of the Higgs up soft mass. In all cases, we generically expect that new physics LFV is non-zero and can be found in a future experiment.
2308.16722
Andrea Dubla Dr
L. Vermunt, Y. Seemann, A. Dubla, S. Floerchinger, E. Grossi, A. Kirchner, S. Masciocchi, I. Selyuzhenkov
Mapping properties of the quark gluon plasma in Pb-Pb and Xe-Xe collisions at energies available at the CERN Large Hadron Collider
17 pages, 7 figures
null
10.1103/PhysRevC.108.064908
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A phenomenological analysis of the experimental measurements of transverse momentum spectra of identified charged hadrons and strange hyperons in Pb-Pb and Xe-Xe collisions at the LHC is presented. The analysis is based on the relativistic fluid dynamics description implemented in the numerically efficient \textsc{Fluid{\it u}M} approach. Building on our previous work, we separate in our treatment the chemical and kinetic freeze-out, and incorporate the partial chemical equilibrium to describe the late stages of the collision evolution. This analysis makes use of Bayesian inference to determine key parameters of the QGP evolution and its properties including the shear and bulk viscosity to entropy ratios, the initialisation time, the initial entropy density, and the freeze-out temperatures. The physics parameters and their posterior probabilities are extracted using a global search in multidimensional space with modern machine learning tools, such as ensembles of neural networks. We employ our newly developed fast framework to assess systematic uncertainties in the extracted model parameters by systematically varying key components of our analysis.
[ { "created": "Thu, 31 Aug 2023 13:40:00 GMT", "version": "v1" }, { "created": "Wed, 20 Dec 2023 15:29:11 GMT", "version": "v2" } ]
2023-12-21
[ [ "Vermunt", "L.", "" ], [ "Seemann", "Y.", "" ], [ "Dubla", "A.", "" ], [ "Floerchinger", "S.", "" ], [ "Grossi", "E.", "" ], [ "Kirchner", "A.", "" ], [ "Masciocchi", "S.", "" ], [ "Selyuzhenkov", "I.", "" ] ]
A phenomenological analysis of the experimental measurements of transverse momentum spectra of identified charged hadrons and strange hyperons in Pb-Pb and Xe-Xe collisions at the LHC is presented. The analysis is based on the relativistic fluid dynamics description implemented in the numerically efficient \textsc{Fluid{\it u}M} approach. Building on our previous work, we separate in our treatment the chemical and kinetic freeze-out, and incorporate the partial chemical equilibrium to describe the late stages of the collision evolution. This analysis makes use of Bayesian inference to determine key parameters of the QGP evolution and its properties including the shear and bulk viscosity to entropy ratios, the initialisation time, the initial entropy density, and the freeze-out temperatures. The physics parameters and their posterior probabilities are extracted using a global search in multidimensional space with modern machine learning tools, such as ensembles of neural networks. We employ our newly developed fast framework to assess systematic uncertainties in the extracted model parameters by systematically varying key components of our analysis.
hep-ph/9308225
null
Palash B. Pal, Utpal Sarkar
Proton Decay and Related Processes in Unified Models with Gauged Baryon Number:
(32 pages LATEX) [DOE-ER\,40757-022, CPP-93-22] {Small changes made and two references added. This version will appear in Phys. Rev. D}
Phys.Rev.D49:3721-3733,1994
10.1103/PhysRevD.49.3721
null
hep-ph
null
In unification models based on SU(15) or SU(16), baryon number is part of the gauge symmetry, broken spontaneously. In such models, we discuss various scenarios of important baryon number violating processes like proton decay and neutron-antineutron oscillation. Our analysis depends on the effective operator method, and covers many variations of symmetry breaking, including different intermediate groups and different Higgs boson content. We discuss processes mediated by gauge bosons and Higgs bosons parallely. We show how accidental global or discrete symmetries present in the full gauge invariant Lagrangian restrict baryon number violating processes in these models. In all cases, we find that baryon number violating interactions are sufficiently suppressed to allow grand unification at energies much lower than the usual $10^{16}$ GeV.
[ { "created": "Wed, 4 Aug 1993 18:33:33 GMT", "version": "v1" }, { "created": "Wed, 26 Jan 1994 00:02:25 GMT", "version": "v2" } ]
2010-11-01
[ [ "Pal", "Palash B.", "" ], [ "Sarkar", "Utpal", "" ] ]
In unification models based on SU(15) or SU(16), baryon number is part of the gauge symmetry, broken spontaneously. In such models, we discuss various scenarios of important baryon number violating processes like proton decay and neutron-antineutron oscillation. Our analysis depends on the effective operator method, and covers many variations of symmetry breaking, including different intermediate groups and different Higgs boson content. We discuss processes mediated by gauge bosons and Higgs bosons parallely. We show how accidental global or discrete symmetries present in the full gauge invariant Lagrangian restrict baryon number violating processes in these models. In all cases, we find that baryon number violating interactions are sufficiently suppressed to allow grand unification at energies much lower than the usual $10^{16}$ GeV.
hep-ph/9311352
Kiwoon Choi
Kiwoon Choi
Small SUSY phases in string-inspired supergravity
15pages, Latex, SNUTP 93-85
Phys.Rev.Lett.72:1592-1595,1994
10.1103/PhysRevLett.72.1592
null
hep-ph
null
In supersymmetric models, there are new CP violating phases which, if unsuppressed, would give a too large neutron electric dipole moment. We examine the possibility of small SUSY phases in string-inspired supergravity models in which supersymmetry is broken by the auxiliary components of the dilaton and moduli superfields. It is found that the SUSY phases can be suppressed by a small factor governing the breakdown of the approximate Peccei Quinn symmetries nonlinearly realized for the moduli superfields that participate in supersymmetry breaking. In many cases, the symmetry breaking factors are exponentially small for moderately large values of the moduli, leading to small phase values in a natural way.
[ { "created": "Wed, 24 Nov 1993 05:27:20 GMT", "version": "v1" } ]
2010-11-01
[ [ "Choi", "Kiwoon", "" ] ]
In supersymmetric models, there are new CP violating phases which, if unsuppressed, would give a too large neutron electric dipole moment. We examine the possibility of small SUSY phases in string-inspired supergravity models in which supersymmetry is broken by the auxiliary components of the dilaton and moduli superfields. It is found that the SUSY phases can be suppressed by a small factor governing the breakdown of the approximate Peccei Quinn symmetries nonlinearly realized for the moduli superfields that participate in supersymmetry breaking. In many cases, the symmetry breaking factors are exponentially small for moderately large values of the moduli, leading to small phase values in a natural way.
0906.2417
Konstantin Matchev
Konstantin T. Matchev, Filip Moortgat, Luc Pape, Myeonghun Park
Precise reconstruction of sparticle masses without ambiguities
37 pages, added a new figure in the Appendix, published version
JHEP 0908:104,2009
10.1088/1126-6708/2009/08/104
UFIFT-HEP-09-04
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We critically reexamine the standard applications of the method of kinematical endpoints for sparticle mass determination. We consider the typical decay chain in supersymmetry (SUSY) squark -> neutralino -> slepton -> LSP, which yields a jet j and two leptons ln and lf. The conventional approaches use the upper kinematical endpoints of the individual distributions m_{jll}, m_{jl(lo)} and m_{jl(hi)}, all three of which suffer from parameter space region ambiguities and may lead to multiple solutions for the SUSY mass spectrum. In contrast, we do not use m_{jll}, m_{jl(lo)} and m_{jl(hi)}, and instead propose a new set of (infinitely many) variables whose upper kinematic endpoints exhibit reduced sensitivity to the parameter space region. We then outline an alternative, much simplified procedure for obtaining the SUSY mass spectrum. In particular, we show that the four endpoints observed in the three distributions m^2_{ll}, m^2_{jln} U m^2_{jlf} and m^2_{jln}+m^2_{jlf} are sufficient to completely pin down the squark mass and the two neutralino masses, leaving only a discrete 2-fold ambiguity for the slepton mass. This remaining ambiguity can be easily resolved in a number of different ways: for example, by a single additional measurement of the kinematic endpoint of any one out of the many remaining 1-dimensional distributions at our disposal, or by exploring the correlations in the 2-dimensional distribution of m^2_{jln} U m^2_{jlf} versus m^2_{ll}. We illustrate our method with two examples: the LM1 and LM6 CMS study points. An additional advantage of our method is the expected improvement in the accuracy of the SUSY mass determination, due to the multitude and variety of available measurements.
[ { "created": "Fri, 12 Jun 2009 20:03:41 GMT", "version": "v1" }, { "created": "Mon, 31 Aug 2009 15:47:12 GMT", "version": "v2" } ]
2009-09-28
[ [ "Matchev", "Konstantin T.", "" ], [ "Moortgat", "Filip", "" ], [ "Pape", "Luc", "" ], [ "Park", "Myeonghun", "" ] ]
We critically reexamine the standard applications of the method of kinematical endpoints for sparticle mass determination. We consider the typical decay chain in supersymmetry (SUSY) squark -> neutralino -> slepton -> LSP, which yields a jet j and two leptons ln and lf. The conventional approaches use the upper kinematical endpoints of the individual distributions m_{jll}, m_{jl(lo)} and m_{jl(hi)}, all three of which suffer from parameter space region ambiguities and may lead to multiple solutions for the SUSY mass spectrum. In contrast, we do not use m_{jll}, m_{jl(lo)} and m_{jl(hi)}, and instead propose a new set of (infinitely many) variables whose upper kinematic endpoints exhibit reduced sensitivity to the parameter space region. We then outline an alternative, much simplified procedure for obtaining the SUSY mass spectrum. In particular, we show that the four endpoints observed in the three distributions m^2_{ll}, m^2_{jln} U m^2_{jlf} and m^2_{jln}+m^2_{jlf} are sufficient to completely pin down the squark mass and the two neutralino masses, leaving only a discrete 2-fold ambiguity for the slepton mass. This remaining ambiguity can be easily resolved in a number of different ways: for example, by a single additional measurement of the kinematic endpoint of any one out of the many remaining 1-dimensional distributions at our disposal, or by exploring the correlations in the 2-dimensional distribution of m^2_{jln} U m^2_{jlf} versus m^2_{ll}. We illustrate our method with two examples: the LM1 and LM6 CMS study points. An additional advantage of our method is the expected improvement in the accuracy of the SUSY mass determination, due to the multitude and variety of available measurements.
1110.3971
Joao G. Rosa
Mar Bastero-Gil, Arjun Berera, Rudnei O. Ramos and Joao G. Rosa
Warm baryogenesis
6 pages, 1 figure; version to be published in Phys. Lett. B
null
10.1016/j.physletb.2012.05.032
Edinburgh 2011/29; UG-FT-291/11; CFPE-161/11
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that a baryon asymmetry can be generated by dissipative effects during warm inflation via a supersymmetric two-stage mechanism, where the inflaton is coupled to heavy mediator fields that then decay into light species through B- and CP-violating interactions. In contrast with thermal GUT baryogenesis models, the temperature during inflation is always below the heavy mass threshold, simultaneously suppressing thermal and quantum corrections to the inflaton potential and the production of dangerous GUT relics. This naturally gives a small baryon asymmetry close to the observed value, although parametrically larger values may be diluted after inflation along with any gravitino overabundance. Furthermore, this process yields baryon isocurvature perturbations within the range of future experiments, making this an attractive and testable model of GUT baryogenesis.
[ { "created": "Tue, 18 Oct 2011 13:33:17 GMT", "version": "v1" }, { "created": "Tue, 15 May 2012 10:30:15 GMT", "version": "v2" } ]
2015-05-30
[ [ "Bastero-Gil", "Mar", "" ], [ "Berera", "Arjun", "" ], [ "Ramos", "Rudnei O.", "" ], [ "Rosa", "Joao G.", "" ] ]
We show that a baryon asymmetry can be generated by dissipative effects during warm inflation via a supersymmetric two-stage mechanism, where the inflaton is coupled to heavy mediator fields that then decay into light species through B- and CP-violating interactions. In contrast with thermal GUT baryogenesis models, the temperature during inflation is always below the heavy mass threshold, simultaneously suppressing thermal and quantum corrections to the inflaton potential and the production of dangerous GUT relics. This naturally gives a small baryon asymmetry close to the observed value, although parametrically larger values may be diluted after inflation along with any gravitino overabundance. Furthermore, this process yields baryon isocurvature perturbations within the range of future experiments, making this an attractive and testable model of GUT baryogenesis.
1903.03528
Najmul Haque
Aritra Das, Najmul Haque, Munshi G. Mustafa and Pradip K. Roy
Hard dilepton production from a weakly magnetized hot QCD medium
21 pages, 7 figures, published version
Phys. Rev. D 99, 094022 (2019)
10.1103/PhysRevD.99.094022
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have computed the hard dilepton production rate from a weakly magnetized deconfined QCD medium within one-loop photon self-energy by considering one hard and one thermomagnetic resummed quark propagator in the loop. In the presence of the magnetic field, the resummed propagator leads to four quasiparticle modes. The production of hard dileptons consists of rates when all four quasiquarks originating from the poles of the propagator individually annihilate with a hard quark coming from a bare propagator in the loop. Besides these, there are also contributions from a mixture of pole and Landau cut part. In weak field approximation, the magnetic field appears as a perturbative correction to the thermal contribution. Since the calculation is very involved, for a first effort as well as for simplicity, we obtained the rate up to first order in the magnetic field, i.e., ${\cal O}[(eB)]$, which causes a marginal improvement over that in the absence of magnetic field.
[ { "created": "Fri, 8 Mar 2019 16:13:15 GMT", "version": "v1" }, { "created": "Thu, 16 May 2019 16:21:42 GMT", "version": "v2" }, { "created": "Sun, 19 May 2019 12:02:55 GMT", "version": "v3" } ]
2019-05-21
[ [ "Das", "Aritra", "" ], [ "Haque", "Najmul", "" ], [ "Mustafa", "Munshi G.", "" ], [ "Roy", "Pradip K.", "" ] ]
We have computed the hard dilepton production rate from a weakly magnetized deconfined QCD medium within one-loop photon self-energy by considering one hard and one thermomagnetic resummed quark propagator in the loop. In the presence of the magnetic field, the resummed propagator leads to four quasiparticle modes. The production of hard dileptons consists of rates when all four quasiquarks originating from the poles of the propagator individually annihilate with a hard quark coming from a bare propagator in the loop. Besides these, there are also contributions from a mixture of pole and Landau cut part. In weak field approximation, the magnetic field appears as a perturbative correction to the thermal contribution. Since the calculation is very involved, for a first effort as well as for simplicity, we obtained the rate up to first order in the magnetic field, i.e., ${\cal O}[(eB)]$, which causes a marginal improvement over that in the absence of magnetic field.
1805.02925
Kenta Takagi
Yusuke Shimizu, Kenta Takagi, Morimitsu Tanimoto
Towards the minimal seesaw model for the prediction of neutrino CP violation
Proceedings of PPAP 2018
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the minimal seesaw model for the Dirac CP violating phase of the lepton mixing matrix. We introduce two right-handed Majorana neutrinos and obtain several textures of the tri-maximal lepton mixing matrices. Moreover, we discuss the observed baryon asymmetry of the universe through the leptogenesis mechanism. As the result, we obtain the specific model which predicts the negative sign of maximal Dirac CP violating phase and normal hierarchy of neutrino masses.
[ { "created": "Tue, 8 May 2018 09:58:34 GMT", "version": "v1" } ]
2018-05-09
[ [ "Shimizu", "Yusuke", "" ], [ "Takagi", "Kenta", "" ], [ "Tanimoto", "Morimitsu", "" ] ]
We discuss the minimal seesaw model for the Dirac CP violating phase of the lepton mixing matrix. We introduce two right-handed Majorana neutrinos and obtain several textures of the tri-maximal lepton mixing matrices. Moreover, we discuss the observed baryon asymmetry of the universe through the leptogenesis mechanism. As the result, we obtain the specific model which predicts the negative sign of maximal Dirac CP violating phase and normal hierarchy of neutrino masses.
2408.03720
J.K. Chen
He Song, Jia-Qi Xie, and Jiao-Kai Chen
Regge trajectories for the triply heavy triquarks
8 pages, 4 figures, 9 tables. arXiv admin note: text overlap with arXiv:2407.18280, arXiv:2407.04222
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We attempt to apply the Regge trajectory approach to the triply heavy triquarks. We present the triquark Regge trajectory relations, and then employ them to crudely estimate the spectra of the triquarks $((cc)\bar{c})$, $((cc)\bar{b})$, $((bc)\bar{c})$, $((bc)\bar{b})$, $((bb)\bar{c})$, and $((bb)\bar{b})$. The $\lambda$-trajectories and the $\rho$-trajectories are discussed. The triquark Regge trajectory becomes a new and very simple approach for estimating the spectra of triquarks.
[ { "created": "Wed, 7 Aug 2024 12:17:45 GMT", "version": "v1" } ]
2024-08-08
[ [ "Song", "He", "" ], [ "Xie", "Jia-Qi", "" ], [ "Chen", "Jiao-Kai", "" ] ]
We attempt to apply the Regge trajectory approach to the triply heavy triquarks. We present the triquark Regge trajectory relations, and then employ them to crudely estimate the spectra of the triquarks $((cc)\bar{c})$, $((cc)\bar{b})$, $((bc)\bar{c})$, $((bc)\bar{b})$, $((bb)\bar{c})$, and $((bb)\bar{b})$. The $\lambda$-trajectories and the $\rho$-trajectories are discussed. The triquark Regge trajectory becomes a new and very simple approach for estimating the spectra of triquarks.
2108.10544
Ho-Meoyng Choi
Ho-Meoyng Choi (Kyungpook National University)
Current-component independent transition form factors for semileptonic and rare $D\to \pi(K)$ decays in the light-front quark model
13 pages, 4 figures, Final version to appear in the Special Issues(Heavy Flavored Physics and CP Violation) of Advances in High Energy Physics (AHEP). arXiv admin note: text overlap with arXiv:2102.02015
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We investigate the exclusive semileptonic and rare $D\to \pi(K)$ decays within the standard model together with the light-front quark model (LFQM) constrained by the variational principle for the QCD-motivated effective Hamiltonian. The form factors are obtained in the $q^+=0$ frame and then analytically continue to the physical timelike region. Together with our recent analysis of the current-component independent form factors $f_\pm(q^2)$ for the semileptonic decays, we present the current-component independent tensor form factor $f_T(q^2)$ for the rare decays to make the complete set of hadronic matrix elements regulating the semileptonic and rare $D\to\pi(K)$ decays in our LFQM. The tensor form factor $f_T(q^2)$ are obtained from two independent sets $(J^{+\perp}_T, J^{+-}_T)$ of the tensor current $J^{\mu\nu}_T$. As in our recent analysis of $f_-(q^2)$, we show that $f_T(q^2)$ obtained from the two different sets of the current components gives the identical result in the valence region of the $q^+=0$ frame without involving the explicit zero modes and the instantaneous contributions. The implications of the zero modes and the instantaneous contributions are also discussed in comparison between the manifestly covariant model and the standard LFQM. In our numerical calculations, we obtain the $q^2$-dependent form factors $(f_\pm, f_T)$ for $D\to\pi(K)$ and branching ratios for the semileptonic $D\to \pi(K)\ell\nu_\ell$ ($\ell=e,\mu$) decays. Our results show in good agreement with the available experimental data as well as other theoretical model predictions.
[ { "created": "Tue, 24 Aug 2021 06:54:29 GMT", "version": "v1" }, { "created": "Tue, 5 Oct 2021 02:06:34 GMT", "version": "v2" }, { "created": "Sun, 14 Nov 2021 00:52:55 GMT", "version": "v3" } ]
2021-11-16
[ [ "Choi", "Ho-Meoyng", "", "Kyungpook National University" ] ]
We investigate the exclusive semileptonic and rare $D\to \pi(K)$ decays within the standard model together with the light-front quark model (LFQM) constrained by the variational principle for the QCD-motivated effective Hamiltonian. The form factors are obtained in the $q^+=0$ frame and then analytically continue to the physical timelike region. Together with our recent analysis of the current-component independent form factors $f_\pm(q^2)$ for the semileptonic decays, we present the current-component independent tensor form factor $f_T(q^2)$ for the rare decays to make the complete set of hadronic matrix elements regulating the semileptonic and rare $D\to\pi(K)$ decays in our LFQM. The tensor form factor $f_T(q^2)$ are obtained from two independent sets $(J^{+\perp}_T, J^{+-}_T)$ of the tensor current $J^{\mu\nu}_T$. As in our recent analysis of $f_-(q^2)$, we show that $f_T(q^2)$ obtained from the two different sets of the current components gives the identical result in the valence region of the $q^+=0$ frame without involving the explicit zero modes and the instantaneous contributions. The implications of the zero modes and the instantaneous contributions are also discussed in comparison between the manifestly covariant model and the standard LFQM. In our numerical calculations, we obtain the $q^2$-dependent form factors $(f_\pm, f_T)$ for $D\to\pi(K)$ and branching ratios for the semileptonic $D\to \pi(K)\ell\nu_\ell$ ($\ell=e,\mu$) decays. Our results show in good agreement with the available experimental data as well as other theoretical model predictions.
0710.0151
Eugene Golowich
E. Golowich
Charm Mixing - Theory
6 pages, to be published in the proceedings of CHARM07, Ithaca, NY, August 2007, eConf C070805
ECONF C070805:05,2007
null
null
hep-ph
null
We discuss Standard Model (SM) and New Physics (NP) descriptions of D0 mixing. The SM part of the discussion addresses both quark level and hadron level contributions. The NP part describes our recent works on the rate difference Delta Gamma_D and the mass difference Delta M_D. In particular, we describe how the recent experimental determination of Delta M_D is found to place tightened restrictions on parameter spaces for 17 of 21 NP models considered in a recent paper by Hewett, Pakvasa, Petrov and myself.
[ { "created": "Sun, 30 Sep 2007 15:47:46 GMT", "version": "v1" } ]
2011-06-15
[ [ "Golowich", "E.", "" ] ]
We discuss Standard Model (SM) and New Physics (NP) descriptions of D0 mixing. The SM part of the discussion addresses both quark level and hadron level contributions. The NP part describes our recent works on the rate difference Delta Gamma_D and the mass difference Delta M_D. In particular, we describe how the recent experimental determination of Delta M_D is found to place tightened restrictions on parameter spaces for 17 of 21 NP models considered in a recent paper by Hewett, Pakvasa, Petrov and myself.
hep-ph/9511279
Bohdan Grzadkowski
Bohdan Grzadkowski (Warsaw University)
Four-Fermi Effective Operators at e^+ e^- ---> \bar{t} t
LaTex, 10 pages, 4 PostScript figures (uuencoded)
Acta Phys.Polon. B27 (1996) 921-932
null
IFT 17/95
hep-ph
null
The process of top quark pair production at Next Linear Collider (NLC) has been considered adopting an effective Lagrangian approach and including all operators of dim~6 which can be tree-level-generated within unknown underlying theory. All contributing helicity amplitudes are presented. It has been found that four-fermion operators can provide the leading non-standard contribution to the total cross section. Expected statistical significance of the non-standard signal for the total cross section and forward-backward asymmetry have been calculated taking into account existing experimental constraints. It has been shown that adopting realistic luminosity of NLC and conservative efficiency for the top-quark pair detection, the total cross section may be sensitive to non-standard physics of an energy scale around $\Lambda=5\tev$.
[ { "created": "Thu, 9 Nov 1995 15:25:46 GMT", "version": "v1" } ]
2007-05-23
[ [ "Grzadkowski", "Bohdan", "", "Warsaw University" ] ]
The process of top quark pair production at Next Linear Collider (NLC) has been considered adopting an effective Lagrangian approach and including all operators of dim~6 which can be tree-level-generated within unknown underlying theory. All contributing helicity amplitudes are presented. It has been found that four-fermion operators can provide the leading non-standard contribution to the total cross section. Expected statistical significance of the non-standard signal for the total cross section and forward-backward asymmetry have been calculated taking into account existing experimental constraints. It has been shown that adopting realistic luminosity of NLC and conservative efficiency for the top-quark pair detection, the total cross section may be sensitive to non-standard physics of an energy scale around $\Lambda=5\tev$.
hep-ph/9905434
Daniel de Florian
Daniel de Florian (Zurich, ETH)
Jet Production with Polarized Beams at Next-to-Leading Order
3 pages, 4 figures, talk given at the DIS99 Workshop, Zeuthen, Germany, April 19-23, 1999
Nucl.Phys.Proc.Suppl. 79 (1999) 605-607
10.1016/S0920-5632(99)00796-3
ETH-TH/99-16
hep-ph
null
Jet production cross-sections in polarized proton-proton and electron-proton collisions are studied to next-to-leading order accuracy. Phenomenological results are presented for RHIC and HERA kinematics.
[ { "created": "Fri, 21 May 1999 10:05:39 GMT", "version": "v1" } ]
2009-10-31
[ [ "de Florian", "Daniel", "", "Zurich, ETH" ] ]
Jet production cross-sections in polarized proton-proton and electron-proton collisions are studied to next-to-leading order accuracy. Phenomenological results are presented for RHIC and HERA kinematics.
1811.12886
Ruben Sandapen
Mohammad Ahmady, Chandan Mondal and Ruben Sandapen
Dynamical spin effects within the pseudo scalar nonet within holographic QCD
7 pages, 6 figures, Proceedings Contribution to the XIII Quark Confinement and Hadron Spectrum Conference held at Maynooth University, Ireland, from July 31 to August 6, 2018
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the importance of dynamical spin effects in the holographic light-front wavefunctions of the pseudoscalar mesons. We find that these effects are crucial to describe the pion data while they are not necessary to describe the available kaon data. For $\eta-\eta^\prime$ system, we find that dynamical spin effects are required to describe their transition form factors data.
[ { "created": "Fri, 30 Nov 2018 16:53:48 GMT", "version": "v1" } ]
2018-12-03
[ [ "Ahmady", "Mohammad", "" ], [ "Mondal", "Chandan", "" ], [ "Sandapen", "Ruben", "" ] ]
We investigate the importance of dynamical spin effects in the holographic light-front wavefunctions of the pseudoscalar mesons. We find that these effects are crucial to describe the pion data while they are not necessary to describe the available kaon data. For $\eta-\eta^\prime$ system, we find that dynamical spin effects are required to describe their transition form factors data.
1004.0310
Cristina Volpe
R. Lazauskas and C. Volpe
Low energy neutrino scattering measurements at future Spallation Source facilities
12 pages, 4 figures, 5 tables
J.Phys.G37:125101,2010
10.1088/0954-3899/37/12/125101
null
hep-ph astro-ph.SR nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the future several Spallation Source facilities will be available worldwide. Spallation Sources produce large amount of neutrinos from decay-at-rest muons and thus can be well adapted to accommodate state-of-the-art neutrino experiments. In this paper low energy neutrino scattering experiments that can be performed at such facilities are reviewed. Estimation of expected event rates are given for several nuclei, electrons and protons at a detector located close to the source. A neutrino program at Spallation Sources comprises neutrino-nucleus cross section measurements relevant for neutrino and core-collapse supernova physics, electroweak tests and lepton-flavor violation searches.
[ { "created": "Fri, 2 Apr 2010 09:58:14 GMT", "version": "v1" } ]
2010-12-02
[ [ "Lazauskas", "R.", "" ], [ "Volpe", "C.", "" ] ]
In the future several Spallation Source facilities will be available worldwide. Spallation Sources produce large amount of neutrinos from decay-at-rest muons and thus can be well adapted to accommodate state-of-the-art neutrino experiments. In this paper low energy neutrino scattering experiments that can be performed at such facilities are reviewed. Estimation of expected event rates are given for several nuclei, electrons and protons at a detector located close to the source. A neutrino program at Spallation Sources comprises neutrino-nucleus cross section measurements relevant for neutrino and core-collapse supernova physics, electroweak tests and lepton-flavor violation searches.
1810.00099
Pia Zurita
Pia Zurita
Recent progress in Nuclear Parton Distributions
Talk presented CIPANP2018. 7 pages, LaTeX, 2 eps figures
null
null
CIPANP2018-Zurita
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The determination of the parton distribution functions (PDFs) is crucial for a complete understanding of the protons and neutrons that make most of the visible matter in the universe. Years of dedicated studies have yielded a quite precise knowledge of the behavior of partons moving collinearly within a proton. However Deep Inelastic Scattering (DIS) experiments off nuclei have shown a non-trivial difference with respect to DIS in protons, hinting that the partons in a nuclear medium do not behave the same way as in a free proton. In this work we will discuss the latest results in nuclear parton distribution functions (nPDFs) and how data from planned future experiments can help broaden our understanding of the nPDFs.
[ { "created": "Fri, 28 Sep 2018 21:57:24 GMT", "version": "v1" } ]
2018-10-02
[ [ "Zurita", "Pia", "" ] ]
The determination of the parton distribution functions (PDFs) is crucial for a complete understanding of the protons and neutrons that make most of the visible matter in the universe. Years of dedicated studies have yielded a quite precise knowledge of the behavior of partons moving collinearly within a proton. However Deep Inelastic Scattering (DIS) experiments off nuclei have shown a non-trivial difference with respect to DIS in protons, hinting that the partons in a nuclear medium do not behave the same way as in a free proton. In this work we will discuss the latest results in nuclear parton distribution functions (nPDFs) and how data from planned future experiments can help broaden our understanding of the nPDFs.
1205.0753
Georgios Orfanidis
Nikos Irges, Georgios Orfanidis, George Zoupanos
Dimensional Reduction of N=1, E_8 SYM over SU(3)/U(1) x U(1) x Z_3 and its four-dimensional effective action
Write-up for Proceedings of the 2011 Corfu Summer Institute on Elementary Particle Physics and Gravity
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an extension of the Standard Model inspired by the E_8 x E_8 Heterotic String. In order that a reasonable effective Lagrangian is presented we neglect everything else other than the ten-dimensional N=1 supersymmetric Yang-Mills sector associated with one of the gauge factors and certain couplings necessary for anomaly cancellation. We consider a compactified space-time M_4 x B_0 / Z_3, where B_0 is the nearly-Kaehler manifold SU(3)/U(1) x U(1) and Z_3 is a freely acting discrete group on B_0. Then we reduce dimensionally the E_8 on this manifold and we employ the Wilson flux mechanism leading in four dimensions to an SU(3)^3 gauge theory with the spectrum of a N=1 supersymmetric theory. We compute the effective four-dimensional Lagrangian and demonstrate that an extension of the Standard Model is obtained with interesting features including a conserved baryon number and fixed tree level Yukawa couplings and scalar potential. The spectrum contains new states such as right handed neutrinos and heavy vector-like quarks.
[ { "created": "Thu, 3 May 2012 16:16:56 GMT", "version": "v1" }, { "created": "Tue, 8 May 2012 12:11:36 GMT", "version": "v2" } ]
2012-05-14
[ [ "Irges", "Nikos", "" ], [ "Orfanidis", "Georgios", "" ], [ "Zoupanos", "George", "" ] ]
We present an extension of the Standard Model inspired by the E_8 x E_8 Heterotic String. In order that a reasonable effective Lagrangian is presented we neglect everything else other than the ten-dimensional N=1 supersymmetric Yang-Mills sector associated with one of the gauge factors and certain couplings necessary for anomaly cancellation. We consider a compactified space-time M_4 x B_0 / Z_3, where B_0 is the nearly-Kaehler manifold SU(3)/U(1) x U(1) and Z_3 is a freely acting discrete group on B_0. Then we reduce dimensionally the E_8 on this manifold and we employ the Wilson flux mechanism leading in four dimensions to an SU(3)^3 gauge theory with the spectrum of a N=1 supersymmetric theory. We compute the effective four-dimensional Lagrangian and demonstrate that an extension of the Standard Model is obtained with interesting features including a conserved baryon number and fixed tree level Yukawa couplings and scalar potential. The spectrum contains new states such as right handed neutrinos and heavy vector-like quarks.
0801.0529
Sandy Donnachie
A Donnachie and Yu S Kalashnikova
Scalar Meson Photoproduction
Talk given at HADRON07, Frascati
null
null
null
hep-ph
null
The scalar mesons f0(1370), f0(1500) and f0(1710) are of interest as there is as yet no consensus of their status, or indeed of the existence of the f0(1370). Radiative decays to rho and omega have been shown to provide effective probes of their structure and to discriminate among models. Scalar-meson photoproduction is proposed as an alternative and it is shown that it represents a feasible approach.
[ { "created": "Thu, 3 Jan 2008 14:30:09 GMT", "version": "v1" } ]
2008-01-04
[ [ "Donnachie", "A", "" ], [ "Kalashnikova", "Yu S", "" ] ]
The scalar mesons f0(1370), f0(1500) and f0(1710) are of interest as there is as yet no consensus of their status, or indeed of the existence of the f0(1370). Radiative decays to rho and omega have been shown to provide effective probes of their structure and to discriminate among models. Scalar-meson photoproduction is proposed as an alternative and it is shown that it represents a feasible approach.
0802.4171
A. D. Polosa
M. Moretti, F. Piccinini, A.D. Polosa
A Fully Numerical Approach to One-Loop Amplitudes
31 pages, revised and enlarged manuscript, axodraw.sty needed
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest a new approach for the automatic and fully numerical evaluation of one-loop scattering amplitudes in perturbative quantum field theory. We use suitably formulated dispersion relations to perform the calculation as a convolution of tree-level amplitudes. This allows to take advantage of the iterative numerical algorithms for the evaluation of leading order matrix elements.
[ { "created": "Thu, 28 Feb 2008 11:31:20 GMT", "version": "v1" }, { "created": "Mon, 29 Sep 2008 15:45:34 GMT", "version": "v2" } ]
2008-09-29
[ [ "Moretti", "M.", "" ], [ "Piccinini", "F.", "" ], [ "Polosa", "A. D.", "" ] ]
We suggest a new approach for the automatic and fully numerical evaluation of one-loop scattering amplitudes in perturbative quantum field theory. We use suitably formulated dispersion relations to perform the calculation as a convolution of tree-level amplitudes. This allows to take advantage of the iterative numerical algorithms for the evaluation of leading order matrix elements.
2203.14443
Tong Li
Tong Li, Jiajun Liao
Electron-target experiment constraints on light dark matter produced in primordial black hole evaporation
7 pages, 4 figures, 1 table. Version accepted for publication in PRD. arXiv admin note: text overlap with arXiv:2108.05608
null
10.1103/PhysRevD.106.055043
null
hep-ph astro-ph.CO hep-ex
http://creativecommons.org/licenses/by/4.0/
Light sub-GeV dark matter (DM) particles in the Milky Way or macroscopic objects such as primordial black holes (PBHs) become attractive DM candidates due to null results of WIMP from direct detection experiments. We explore the possibility in which the present PBHs play as a novel source to produce light boosted DM and confine light PBHs with current and future terrestrial facilities. We study the electron elastic scattering data and obtain the current constraints from Super-Kamiokande and XENON1T on the boosted DM from PBH evaporation. The prospective bounds on the sub-GeV DM-electron scattering cross section and the fraction of DM composed of PBHs $f_{\rm PBH}$ are also imposed for future Xenon experiments.
[ { "created": "Mon, 28 Mar 2022 01:48:45 GMT", "version": "v1" }, { "created": "Mon, 26 Sep 2022 13:09:03 GMT", "version": "v2" } ]
2022-10-12
[ [ "Li", "Tong", "" ], [ "Liao", "Jiajun", "" ] ]
Light sub-GeV dark matter (DM) particles in the Milky Way or macroscopic objects such as primordial black holes (PBHs) become attractive DM candidates due to null results of WIMP from direct detection experiments. We explore the possibility in which the present PBHs play as a novel source to produce light boosted DM and confine light PBHs with current and future terrestrial facilities. We study the electron elastic scattering data and obtain the current constraints from Super-Kamiokande and XENON1T on the boosted DM from PBH evaporation. The prospective bounds on the sub-GeV DM-electron scattering cross section and the fraction of DM composed of PBHs $f_{\rm PBH}$ are also imposed for future Xenon experiments.
1708.04641
Xiaohui Liu
Xiaohui Liu, Sven-Olaf Moch and Felix Ringer
Threshold and jet radius joint resummation for single-inclusive jet production
5 pages, 3 figures, minor text changes, PDF uncertainties included and more references added. Replaced to match the published version
Phys. Rev. Lett. 119, 212001 (2017)
10.1103/PhysRevLett.119.212001
DESY 17-119
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the first threshold and jet radius jointly resummed cross section for single-inclusive hadronic jet production. We work at next-to-leading logarithmic accuracy and our framework allows for a systematic extension beyond the currently achieved precision. Longstanding numerical issues are overcome by performing the resummation directly in momentum space within Soft Collinear Effective Theory. We present the first numerical results for the LHC and observe an improved description of the available data. Our results are of immediate relevance for LHC precision phenomenology including the extraction of parton distribution functions and the QCD strong coupling constant.
[ { "created": "Tue, 15 Aug 2017 18:49:24 GMT", "version": "v1" }, { "created": "Mon, 21 Aug 2017 19:59:12 GMT", "version": "v2" }, { "created": "Wed, 18 Oct 2017 23:57:03 GMT", "version": "v3" }, { "created": "Tue, 28 Nov 2017 17:20:33 GMT", "version": "v4" } ]
2017-11-29
[ [ "Liu", "Xiaohui", "" ], [ "Moch", "Sven-Olaf", "" ], [ "Ringer", "Felix", "" ] ]
We present the first threshold and jet radius jointly resummed cross section for single-inclusive hadronic jet production. We work at next-to-leading logarithmic accuracy and our framework allows for a systematic extension beyond the currently achieved precision. Longstanding numerical issues are overcome by performing the resummation directly in momentum space within Soft Collinear Effective Theory. We present the first numerical results for the LHC and observe an improved description of the available data. Our results are of immediate relevance for LHC precision phenomenology including the extraction of parton distribution functions and the QCD strong coupling constant.
1006.1688
Koichi Yoshioka
Shigeki Matsumoto and Koichi Yoshioka
Deep Correlation Between Cosmic-Ray Anomaly and Neutrino Masses
12 pages
Phys.Rev.D82:053009,2010
10.1103/PhysRevD.82.053009
UT-HET 040, KUNS-2271
hep-ph astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The positron anomaly recently reported by the cosmic-ray measurements suggests that, if explained by the decay of dark matter particle, the decay source is closely linked up with the leptonic sector of the standard model. It is observed that, with a simple dimensional analysis, the lifetime of dark matter for the anomaly is expressed by the energy scale of neutrino masses. We present two scenarios in which these two matter at issue (the dark matter width and the tiny neutrino masses) stem from a single operator involving a gauge-singlet scalar field.
[ { "created": "Wed, 9 Jun 2010 02:35:36 GMT", "version": "v1" }, { "created": "Fri, 3 Sep 2010 06:33:46 GMT", "version": "v2" } ]
2014-11-21
[ [ "Matsumoto", "Shigeki", "" ], [ "Yoshioka", "Koichi", "" ] ]
The positron anomaly recently reported by the cosmic-ray measurements suggests that, if explained by the decay of dark matter particle, the decay source is closely linked up with the leptonic sector of the standard model. It is observed that, with a simple dimensional analysis, the lifetime of dark matter for the anomaly is expressed by the energy scale of neutrino masses. We present two scenarios in which these two matter at issue (the dark matter width and the tiny neutrino masses) stem from a single operator involving a gauge-singlet scalar field.
2105.05257
Stefan Bi{\ss}mann
Stefan Bi{\ss}mann, Cornelius Grunwald, Gudrun Hiller, Kevin Kr\"oninger
Synergies of top and $B$ anomalies in SMEFT
4 pages, 2 figures, contribution to the "2021 Electroweak session of the 55th Rencontres de Moriond"
null
null
DO-TH 21/15
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present constraints on Wilson coefficients from a combined fit to data from top-quark and beauty-physics measurements within the Standard Model effective field theory. We consider present data on top-quark pair production and decay, $b\to s$ flavor changing neutral currents, and $Z\to b\bar b$ decay, as well as different future scenarios. These comprise projections for HL-LHC, Belle II, and a lepton collider using the example of CLIC. We investigate opportunities for detecting deviations from the Standard Model hinted at by present data on $b\to s$ transitions. In the fit, we find strong synergies between top-quark and beauty physics that allow to tighten constraints on various coefficients.
[ { "created": "Tue, 11 May 2021 18:00:01 GMT", "version": "v1" } ]
2021-05-13
[ [ "Bißmann", "Stefan", "" ], [ "Grunwald", "Cornelius", "" ], [ "Hiller", "Gudrun", "" ], [ "Kröninger", "Kevin", "" ] ]
We present constraints on Wilson coefficients from a combined fit to data from top-quark and beauty-physics measurements within the Standard Model effective field theory. We consider present data on top-quark pair production and decay, $b\to s$ flavor changing neutral currents, and $Z\to b\bar b$ decay, as well as different future scenarios. These comprise projections for HL-LHC, Belle II, and a lepton collider using the example of CLIC. We investigate opportunities for detecting deviations from the Standard Model hinted at by present data on $b\to s$ transitions. In the fit, we find strong synergies between top-quark and beauty physics that allow to tighten constraints on various coefficients.
hep-ph/0101349
Tomas Blazek
Gregory W. Anderson, Tomas Blazek
E_6 unification model building III. Clebsch-Gordan coefficients in E_6 tensor products of the 27 with higher dimensional representations
44 pages, 31 tables
null
null
NUHEP-TH-00-81, SHEP-01-05
hep-ph
null
$E_6$ is an attractive group for unification model building. However, the complexity of a rank 6 group makes it non-trivial to write down the structure of higher dimensional operators in an $E_6$ theory in terms of the states labeled by quantum numbers of the Standard Model gauge group. In this paper, we show the results of our computation of the Clebsch-Gordan coefficients for the products of the {\bf 27} with irreducible representations of higher dimensionality: ${\bf 78}$, ${\bf 351}$, ${\bf 351^\prime}$, ${\bf \ol{351}}$, and ${\bf \ol{351^\prime}}$. Application of these results to $E_6$ model building involving higher dimensional operators is straightforward.
[ { "created": "Wed, 31 Jan 2001 15:24:58 GMT", "version": "v1" } ]
2007-05-23
[ [ "Anderson", "Gregory W.", "" ], [ "Blazek", "Tomas", "" ] ]
$E_6$ is an attractive group for unification model building. However, the complexity of a rank 6 group makes it non-trivial to write down the structure of higher dimensional operators in an $E_6$ theory in terms of the states labeled by quantum numbers of the Standard Model gauge group. In this paper, we show the results of our computation of the Clebsch-Gordan coefficients for the products of the {\bf 27} with irreducible representations of higher dimensionality: ${\bf 78}$, ${\bf 351}$, ${\bf 351^\prime}$, ${\bf \ol{351}}$, and ${\bf \ol{351^\prime}}$. Application of these results to $E_6$ model building involving higher dimensional operators is straightforward.
2407.12071
Eva Los
E. E. Los, E. Gerstmayr, C. Arran, M. J. V. Streeter, C. Colgan, C. C. Cobo, B. Kettle, T. G. Blackburn, N. Bourgeois, L. Calvin, J. Carderelli, N. Cavanagh, S.J.D. Dann A. Di Piazza, R. Fitzgarrald, A. Ilderton, C. H. Keitel, M. Marklund, P. McKenna, C. D. Murphy, Z. Najmudin, P. Parsons, P. P. Rajeev, D. R. Symes, M. Tamburini, A. G. R. Thomas, J. C. Wood, M. Zepf, G. Sarri, C. P. Ridgers, S. P. D Mangles
Observation of quantum effects on radiation reaction in strong fields
31 pages, 14 figures
null
null
null
hep-ph physics.plasm-ph
http://creativecommons.org/licenses/by/4.0/
Radiation reaction describes the effective force experienced by an accelerated charge due to radiation emission. Quantum effects dominate charge dynamics and radiation production[1][2] for charges accelerated by fields with strengths approaching the Schwinger field, $\mathbf{E_{sch}=}$\textbf{\SI[detect-weight]{1.3e18}{\volt\per\metre}[3]. Such fields exist in extreme astrophysical environments such as pulsar magnetospheres[4], may be accessed by high-power laser systems[5-7], dense particle beams interacting with plasma[8], crystals[9], and at the interaction point of next generation particle colliders[10]. Classical radiation reaction theories do not limit the frequency of radiation emitted by accelerating charges and omit stochastic effects inherent in photon emission[11], thus demanding a quantum treatment. Two quantum radiation reaction models, the quantum-continuous[12] and quantum-stochastic[13] models, correct the former issue, while only the quantum-stochastic model incorporates stochasticity[12]. Such models are of fundamental importance, providing insight into the effect of the electron self-force on its dynamics in electromagnetic fields. The difficulty of accessing conditions where quantum effects dominate inhibited previous efforts to observe quantum radiation reaction in charged particle dynamics with high significance. We report the first direct, high significance $(>5{\sigma})$ observation of strong-field radiation reaction on charged particles. Furthermore, we obtain strong evidence favouring the quantum radiation reaction models, which perform equivalently, over the classical model. Robust model comparison was facilitated by a novel Bayesian framework which inferred collision parameters. This framework has widespread utility for experiments where parameters governing lepton-laser collisions cannot be directly measured, including those using conventional accelerators.
[ { "created": "Tue, 16 Jul 2024 12:53:04 GMT", "version": "v1" } ]
2024-07-18
[ [ "Los", "E. E.", "" ], [ "Gerstmayr", "E.", "" ], [ "Arran", "C.", "" ], [ "Streeter", "M. J. V.", "" ], [ "Colgan", "C.", "" ], [ "Cobo", "C. C.", "" ], [ "Kettle", "B.", "" ], [ "Blackburn", "T. G.", "" ], [ "Bourgeois", "N.", "" ], [ "Calvin", "L.", "" ], [ "Carderelli", "J.", "" ], [ "Cavanagh", "N.", "" ], [ "Di Piazza", "S. J. D. Dann A.", "" ], [ "Fitzgarrald", "R.", "" ], [ "Ilderton", "A.", "" ], [ "Keitel", "C. H.", "" ], [ "Marklund", "M.", "" ], [ "McKenna", "P.", "" ], [ "Murphy", "C. D.", "" ], [ "Najmudin", "Z.", "" ], [ "Parsons", "P.", "" ], [ "Rajeev", "P. P.", "" ], [ "Symes", "D. R.", "" ], [ "Tamburini", "M.", "" ], [ "Thomas", "A. G. R.", "" ], [ "Wood", "J. C.", "" ], [ "Zepf", "M.", "" ], [ "Sarri", "G.", "" ], [ "Ridgers", "C. P.", "" ], [ "Mangles", "S. P. D", "" ] ]
Radiation reaction describes the effective force experienced by an accelerated charge due to radiation emission. Quantum effects dominate charge dynamics and radiation production[1][2] for charges accelerated by fields with strengths approaching the Schwinger field, $\mathbf{E_{sch}=}$\textbf{\SI[detect-weight]{1.3e18}{\volt\per\metre}[3]. Such fields exist in extreme astrophysical environments such as pulsar magnetospheres[4], may be accessed by high-power laser systems[5-7], dense particle beams interacting with plasma[8], crystals[9], and at the interaction point of next generation particle colliders[10]. Classical radiation reaction theories do not limit the frequency of radiation emitted by accelerating charges and omit stochastic effects inherent in photon emission[11], thus demanding a quantum treatment. Two quantum radiation reaction models, the quantum-continuous[12] and quantum-stochastic[13] models, correct the former issue, while only the quantum-stochastic model incorporates stochasticity[12]. Such models are of fundamental importance, providing insight into the effect of the electron self-force on its dynamics in electromagnetic fields. The difficulty of accessing conditions where quantum effects dominate inhibited previous efforts to observe quantum radiation reaction in charged particle dynamics with high significance. We report the first direct, high significance $(>5{\sigma})$ observation of strong-field radiation reaction on charged particles. Furthermore, we obtain strong evidence favouring the quantum radiation reaction models, which perform equivalently, over the classical model. Robust model comparison was facilitated by a novel Bayesian framework which inferred collision parameters. This framework has widespread utility for experiments where parameters governing lepton-laser collisions cannot be directly measured, including those using conventional accelerators.
1904.08354
Mathew Thomas Mr.
Mathew Thomas Arun
Relaxing the $W'$ constraint on compactified extra-dimension
12 pages, 1 figure
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It has been known for some time that the inclusion of brane fluctuations, namely branons, helps in the suppression of KK-mode couplings to brane localised matter fields. In this paper we study the constraint on brane tension and compactification scale for such models using the results from the direct search of $W'$ at 13 TeV LHC, with an integrated luminosity of $36.1 fb^{-1}$, in the case for which branon forms the entire cold dark matter. Unlike the rigid brane scenario, where the compactification scale gets constrained to $\frac{1}{R} \gtrsim 5.2$ TeV, here we show that compactification scales as small as $\sim 1$ TeV are allowed for brane tensions of similar strength.
[ { "created": "Wed, 17 Apr 2019 16:39:58 GMT", "version": "v1" } ]
2019-04-18
[ [ "Arun", "Mathew Thomas", "" ] ]
It has been known for some time that the inclusion of brane fluctuations, namely branons, helps in the suppression of KK-mode couplings to brane localised matter fields. In this paper we study the constraint on brane tension and compactification scale for such models using the results from the direct search of $W'$ at 13 TeV LHC, with an integrated luminosity of $36.1 fb^{-1}$, in the case for which branon forms the entire cold dark matter. Unlike the rigid brane scenario, where the compactification scale gets constrained to $\frac{1}{R} \gtrsim 5.2$ TeV, here we show that compactification scales as small as $\sim 1$ TeV are allowed for brane tensions of similar strength.
2104.08750
Alexander S. Sakharov
Alexander S. Sakharov, Yury N. Eroshenko, Sergey G. Rubin
Looking at the NANOGrav Signal Through the Anthropic Window of Axion-Like Particles
39 pages, 3 figures, the version accepted for publication in Physical Review D
Phys. Rev. D 104, 043005 (2021)
10.1103/PhysRevD.104.043005
null
hep-ph astro-ph.CO gr-qc hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the inflationary dynamics leading to formation of closed domain walls in course of evolution of an axion like particle (ALP) field whose Peccei-Quinn-like phase transition occurred well before inflationary epoch. Evolving after inflation, the domain walls may leave their imprint in stochastic gravitational waves background, in the frequency range accessible for the pulsar timing array measurements. We derive the characteristic strain power spectrum produced by the distribution of the closed domain walls and relate it with the recently reported NANOGrav signal excess. We found that the slope of the frequency dependence of the characteristic strain spectrum generated by the domain walls is very well centered inside the range of the slopes in the signal reported by the NANOGrav. Analyzing the inflationary dynamics of the ALP field, in consistency with the isocurvature constraint, we revealed those combinations of the parameters where the signal from the inflationary induced ALPs domain walls could saturate the amplitude of the NANOGrav excess. The evolution of big enough closed domain walls may incur in formation of wormholes with the walls escaping into baby universes. We studied the conditions, when closed walls escaped into baby universes could leave a detectable imprint in the stochastic gravitational waves background.
[ { "created": "Sun, 18 Apr 2021 07:22:06 GMT", "version": "v1" }, { "created": "Sat, 26 Jun 2021 21:35:12 GMT", "version": "v2" } ]
2021-08-11
[ [ "Sakharov", "Alexander S.", "" ], [ "Eroshenko", "Yury N.", "" ], [ "Rubin", "Sergey G.", "" ] ]
We explore the inflationary dynamics leading to formation of closed domain walls in course of evolution of an axion like particle (ALP) field whose Peccei-Quinn-like phase transition occurred well before inflationary epoch. Evolving after inflation, the domain walls may leave their imprint in stochastic gravitational waves background, in the frequency range accessible for the pulsar timing array measurements. We derive the characteristic strain power spectrum produced by the distribution of the closed domain walls and relate it with the recently reported NANOGrav signal excess. We found that the slope of the frequency dependence of the characteristic strain spectrum generated by the domain walls is very well centered inside the range of the slopes in the signal reported by the NANOGrav. Analyzing the inflationary dynamics of the ALP field, in consistency with the isocurvature constraint, we revealed those combinations of the parameters where the signal from the inflationary induced ALPs domain walls could saturate the amplitude of the NANOGrav excess. The evolution of big enough closed domain walls may incur in formation of wormholes with the walls escaping into baby universes. We studied the conditions, when closed walls escaped into baby universes could leave a detectable imprint in the stochastic gravitational waves background.