Pub Date : 2020-03-19DOI: 10.1142/9789811238406_0025
Tam´as Cs¨org˝o, G. Kasza
We present a new class of exact fireball solutions of relativistic dissipative hydrodynamics. We describe new exact solutions both for the relativistic Navier-Stokes and for the Israel-Stewart theory, for arbitrary shear and bulk viscosities, as well as for other dissipative coefficients. The common property of these solutions is the presence of the relativistic Hubble flow. Our results generalize the recently found first solution in these classes, for an arbitrary temperature dependent speed of sound, shear and bulk viscosity, heat conduction and fluctuating initial temperature profiles. These solutions are causal and not only stable but also asymptotically perfect. A strong and narrow peak in the kinematic bulk viscosity is shown to imitate the effects of a first order phase transition. The new class of asymptotically perfect solutions is thus found to be very rich, but at the same time mostly academic as the solutions are limited by the spherical symmetry of the Hubble flow field.
{"title":"NEW, MULTIPOLE SOLUTIONS OF VISCOUS HYDRODYNAMICS","authors":"Tam´as Cs¨org˝o, G. Kasza","doi":"10.1142/9789811238406_0025","DOIUrl":"https://doi.org/10.1142/9789811238406_0025","url":null,"abstract":"We present a new class of exact fireball solutions of relativistic dissipative hydrodynamics. We describe new exact solutions both for the relativistic Navier-Stokes and for the Israel-Stewart theory, for arbitrary shear and bulk viscosities, as well as for other dissipative coefficients. The common property of these solutions is the presence of the relativistic Hubble flow. Our results generalize the recently found first solution in these classes, for an arbitrary temperature dependent speed of sound, shear and bulk viscosity, heat conduction and fluctuating initial temperature profiles. These solutions are causal and not only stable but also asymptotically perfect. A strong and narrow peak in the kinematic bulk viscosity is shown to imitate the effects of a first order phase transition. The new class of asymptotically perfect solutions is thus found to be very rich, but at the same time mostly academic as the solutions are limited by the spherical symmetry of the Hubble flow field.","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117129089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-11-14DOI: 10.1142/9789811238406_0030
K. Melnikov, A. Vainshtein
We discuss the use of dispersion relations for the evaluation of the pseudoscalar contributions to the muon anomalous magnetic moment. We point out that, in the absence of experimental data, reconstruction of light-by-light scattering amplitudes from their absorptive parts is ambiguous and requires additional theoretical input. The need for an additional input makes dispersive computations of the hadronic light-by-light scattering contribution to g-2 akin to phenomenological models, in spite of pretense to the contrary. In particular, we argue that the recent proposal [1], based on the dispersive approach, satisfies short distance constraints at the expense of unjustifiably large deviations from the chiral limit.
{"title":"ON DISPERSION RELATIONS AND HADRONIC LIGHT-BY-LIGHT SCATTERING CONTRIBUTION TO THE MUON ANOMALOUS MAGNETIC MOMENT","authors":"K. Melnikov, A. Vainshtein","doi":"10.1142/9789811238406_0030","DOIUrl":"https://doi.org/10.1142/9789811238406_0030","url":null,"abstract":"We discuss the use of dispersion relations for the evaluation of the pseudoscalar contributions to the muon anomalous magnetic moment. We point out that, in the absence of experimental data, reconstruction of light-by-light scattering amplitudes from their absorptive parts is ambiguous and requires additional theoretical input. \u0000The need for an additional input makes dispersive computations of the hadronic light-by-light scattering contribution to g-2 akin to phenomenological models, in spite of pretense to the contrary. In particular, we argue that the recent proposal [1], based on the dispersive approach, satisfies short distance constraints at the expense of unjustifiably large deviations from the chiral limit.","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132958273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-05DOI: 10.1142/9789811238406_0024
M. Csanád, M. Nagy, Z. F. Jiang, T. Csorgo
New, analytic solutions of relativistic viscous hydrodynamics are presented, describing expanding fireballs with Hubble-like velocity profile and ellipsoidal symmetry, similar to fireballs created in heavy ion collisions. We find that with these specifications, one obtains solutions where the shear viscosity essentially does not influence the time evolution of the system, thus these solutions are particularly adept tools to study the effect of bulk viscosity alone, which always results in a slower decrease of energy density as well as temperature compared to the case of perfect fluid. We investigate different scenarios for the bulk viscosity and find qualitatively different effects on the time evolution which suggests that there is a possibility to infer the value of bulk viscosity from energy density and temperature measurements in high-energy heavy-ion collisions.
{"title":"A SIMPLE FAMILY OF SOLUTIONS OF RELATIVISTIC VISCOUS HYDRODYNAMICS FOR FIREBALLS WITH HUBBLE FLOW AND ELLIPSOIDAL SYMMETRY","authors":"M. Csanád, M. Nagy, Z. F. Jiang, T. Csorgo","doi":"10.1142/9789811238406_0024","DOIUrl":"https://doi.org/10.1142/9789811238406_0024","url":null,"abstract":"New, analytic solutions of relativistic viscous hydrodynamics are presented, describing expanding fireballs with Hubble-like velocity profile and ellipsoidal symmetry, similar to fireballs created in heavy ion collisions. We find that with these specifications, one obtains solutions where the shear viscosity essentially does not influence the time evolution of the system, thus these solutions are particularly adept tools to study the effect of bulk viscosity alone, which always results in a slower decrease of energy density as well as temperature compared to the case of perfect fluid. We investigate different scenarios for the bulk viscosity and find qualitatively different effects on the time evolution which suggests that there is a possibility to infer the value of bulk viscosity from energy density and temperature measurements in high-energy heavy-ion collisions.","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114498533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-04DOI: 10.1142/9789811238406_0037
V. Kudryavtsev
A new approach to composite superconformal strings is considered . This composite string model has two scales: first one (~1 Gev) is for edging surfaces and second one (Planck scale) is for ridge surfaces . Nonlinear realization of two-dimensional superconformal symmetry on edging surfaces leads to superconvergence of one-loop planar diagrams. Some features of hadron amplitudes and of hadron spectrum are discussed. Spectrum of closed strings and a possibility of unified theory of fundamental interactions on the basis of this model are considered.
{"title":"NEW COMPOSITE SUPERCONFORMAL STRING MODEL WITH TWO SCALES AND UNIFICATION OF FUNDAMENTAL INTERACTIONS","authors":"V. Kudryavtsev","doi":"10.1142/9789811238406_0037","DOIUrl":"https://doi.org/10.1142/9789811238406_0037","url":null,"abstract":"A new approach to composite superconformal strings is considered . This composite string model has two scales: first one (~1 Gev) is for edging surfaces and second one (Planck scale) is for ridge surfaces . Nonlinear realization of two-dimensional superconformal symmetry on edging surfaces leads to superconvergence of one-loop planar diagrams. Some features of hadron amplitudes and of hadron spectrum are discussed. Spectrum of closed strings and a possibility of unified theory of fundamental interactions on the basis of this model are considered.","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132914444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-21DOI: 10.1142/9789811238406_0035
T. Fulop, T. Matolcsi
We show that the antisymmetric spinor tensor representation of spin-0 relativistic quantum mechanics provides a conserved current with positive definite timelike component, interpretable as probability density. The construction runs in complete analogy to the spin-1/2 case, and provides an analogously natural one-particle Hilbert space description for spin 0. Except for the free particle, the obtained formulation proves to be inequivalent to the one based on the Klein--Gordon equation. The second quantized version may lead to new field theoretical interaction terms for zero-spin particles.
{"title":"PROBABILITY CURRENT IN ZERO-SPIN RELATIVISTIC QUANTUM MECHANICS","authors":"T. Fulop, T. Matolcsi","doi":"10.1142/9789811238406_0035","DOIUrl":"https://doi.org/10.1142/9789811238406_0035","url":null,"abstract":"We show that the antisymmetric spinor tensor representation of spin-0 relativistic quantum mechanics provides a conserved current with positive definite timelike component, interpretable as probability density. The construction runs in complete analogy to the spin-1/2 case, and provides an analogously natural one-particle Hilbert space description for spin 0. Except for the free particle, the obtained formulation proves to be inequivalent to the one based on the Klein--Gordon equation. The second quantized version may lead to new field theoretical interaction terms for zero-spin particles.","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117044652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1142/9789811238406_0032
Gyorgy Wolf, G. Balassa, S. H. Lee
{"title":"OBSERVATION OF CHARMONIUM MASS MODIFICATION IN ANTIPROTON INDUCED REACTIONS","authors":"Gyorgy Wolf, G. Balassa, S. H. Lee","doi":"10.1142/9789811238406_0032","DOIUrl":"https://doi.org/10.1142/9789811238406_0032","url":null,"abstract":"","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122623708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1142/9789811238406_0019
M. Andreichikov, M. I. Eides, V. Novikov, M. Vysotsky
{"title":"THE PHYSICS OF THE η - η′ SYSTEM VERSUS B0 → J/Ψ η(η′) AND BS → J/Ψ η(η′) DECAYS","authors":"M. Andreichikov, M. I. Eides, V. Novikov, M. Vysotsky","doi":"10.1142/9789811238406_0019","DOIUrl":"https://doi.org/10.1142/9789811238406_0019","url":null,"abstract":"","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133993082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1142/9789811238406_fmatter
Yu.L. Dokshitzer, P. Lévai, Á. Lukács, J. Nyiri
{"title":"FRONT MATTER","authors":"Yu.L. Dokshitzer, P. Lévai, Á. Lukács, J. Nyiri","doi":"10.1142/9789811238406_fmatter","DOIUrl":"https://doi.org/10.1142/9789811238406_fmatter","url":null,"abstract":"","PeriodicalId":146790,"journal":{"name":"Gribov-90 Memorial Volume","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127897804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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