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Title Hybrid model with viscous relativistic hydrodynamics: a role of constraints on the shear-stress tensor Author info A. S. Khvorostukhin ... [et al.] Author Khvorostukhin A. S. (34%)
Co-authors Kolomeitsev Evgeni E. 1970- (33%) UMBFP06 - Katedra fyziky
Toneev V. D. (33%)
Source document The European Physical Journal A : Hadrons and Nuclei. Vol. 57, no. 10 (2021), pp. 294-1-294-25. - New York : Springer Nature, 2021 Keywords relativistic hydrodynamics heavy ion collisions viscosity Form. Descr. články - journal articles Language English Country Germany Annotation We present the hybrid model connecting the parton–hadron–string dynamic model (PHSD) and a hydrodynamic model taking into account shear viscosity within the Israel–Stewart approach. The numerical scheme, initialization, and particlization procedure are discussed in detail. The performance of the code is tested on the pion and proton rapidity and transverse mass distributions calculated for Au + Au and Pb+Pb collisions at AGS–SPS energies. The influence of the switch time from transport to hydro models, the viscous parameter, and freeze-out time are discussed. Since the applicability of the Israel–Stewart hydrodynamics assumes the perturbative character of the viscous stress tensor, πμν, which should not exceed the ideal energy–momentum tensor, T μν id , hydrodynamical codes usually rescale the shear stress tensor if the inequality πμν T μν id is not fulfilled in some sense. There are several conditions used in the literature and we analyze in detail the influence of different conditions and values of the cut-off parameter on observables.We show that the form of the corresponding condition plays an important role in the sensitivity of hydrodynamic calculations to the viscous parameter – a ratio of the shear viscosity to the entropy density, η/s. It is shown that the constraints used in the vHLLE and MUSIC models give the same results for the observables.With these constraints, the rapidity distributions and transverse momentum spectra are most sensitive to a change of the η/s ratio. We demonstrate that these constraints do not guarantee that each element of the πμν tensor is smaller than the corresponding element T μν id . As an alternative, a strict condition is used. When applied it reduces the sensitivity of the proton and pion momentum distributions to the viscosity parameter. We performed global fits of the rapidity and transverse mass distributions of pion and protons. It was also found that η/s as a function of the collision energy monotonically increases from Elab = 6 AGeV up to Elab = 40 AGeV and saturates for higher SPS energies. We observe that it is difficult to reproduce simultaneously pion and proton rapidity distribution within our model with the present choice of the equation of state without a phase transition. URL Link na plný text Public work category ADC No. of Archival Copy 50708 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika 
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Title Charge and isospin fluctuations in a non-ideal pion gas with dynamically fixed particle number Author info Evgeni E. Kolomeitsev ... [et al.] Author Kolomeitsev Evgeni E. 1970- (34%) UMBFP06 - Katedra fyziky
Co-authors Voskresensky Dmitri (33%)
Borisov Maxim E. (33%)
Source document The European Physical Journal A : Hadrons and Nuclei. Vol. 57, no. 4 (2021), pp. [1-29]. - Berlin : Springer, 2021 Keywords Bose-Einsteinova kondenzácia - Bose-Einstein condensation heavy ion collisions Form. Descr. články - journal articles Language English Country Germany Public work category ADC No. of Archival Copy 49947 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika article
Title Fluctuations in non-ideal pion gas with dynamically fixed particle number Author info E. E. Kolomeitsev, D. N. Voskresensky Author Kolomeitsev Evgeni E. 1970- (50%) UMBFP06 - Katedra fyziky
Co-authors Voskresensky Dmitri (50%)
Source document Nuclear Physics A. Vol. 973, (2018), pp. 89-103. - Amsterdam : Elsevier B.V., 2018 Keywords heavy ion collisions fluctuations Hartree approximation Bose-Einsteinova kondenzácia - Bose-Einstein condensation Language English Country Netherlands systematics 53 Annotation We consider a non-ideal hot pion gas with the dynamically fixed number of particles in the model with the λφ4interaction. The effective Lagrangian for the description of such a system is obtained after dropping the terms responsible for the change of the total particle number. Reactions π+π−↔π0π0, which deter-mine the isospin balance of the medium, are permitted. Within the self-consistent Hartree approximation we compute the effective pion mass, thermodynamic characteristics of the system and the variance of the particle number at temperatures above the critical point of the induced Bose–Einstein condensation when the pion chemical potential reaches the value of the effective pion mass. We analyze conditions for the con-densate formation in the process of thermalization of an initially non-equilibrium pion gas. The normalized variance of the particle number increases with a temperature decrease but remains finite in the critical point of the Bose–Einstein condensation. This is due to the non-perturbative account of the interaction and is in contrast to the ideal-gas case. In the kinetic regime of the condensate formation the variance is shown to stay finite also URL Link na plný text Public work category ADC No. of Archival Copy 43902 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika 
unrecognised
Title Vorticity and hyperon polarization at energies available at JINR Nuclotron-based Ion Collider fAcility Author info E. E. Kolomeitsev, V. D. Toneev ... [et al.] Author Kolomeitsev Evgeni E. 1970- (34%) UMBFP06 - Katedra fyziky
Co-authors Toneev V. D. (33%)
Voronyuk Vadym (33%)
Source document Physical Review C. Vol. 97, no. 6 (2018), pp. [1-9]. - Maryland : American Physical Society, 2018 Keywords heavy ion collisions vorticity hyperon polarization Language English Country United States of America systematics 53 Annotation We study the formation of fluid vorticity and the hyperon polarization in heavy-ion collisions at energies available at the JINR Nuclotron-based Ion Collider fAcility in the framework of the parton-hadron-string dynamic model, taking into account both hadronic and quark-gluonic (partonic) degrees of freedom. The vorticity properties in peripheral Au+Au collisions at √sNN= 7.7 GeV are demonstrated and confronted with other models. The obtained result for the Lambda polarization is in agreement with the experimental data by the STAR Collaboration, whereas the model is not able to explain the observed high values of the antihyperon anti-Lambda polarization URL Link na plný text Public work category ADC No. of Archival Copy 43912 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised
Title Delta isobars in relativistic mean-field models with sigma-scaled hadron masses and couplings Author info E. E. Kolomeitsev, K. A. Maslov, D. N. Voskresensky Author Kolomeitsev Evgeni E. 1970- (98%) UMBFP06 - Katedra fyziky
Co-authors Maslov Konstantin A. (1%)
Voskresensky Dmitri (1%)
Source document Nuclear Physics A. Vol. 961 (2017), pp. 106-141. - Amsterdam : Elsevier B.V., 2017 Keywords neutron stars equation of state heavy ion collisions Language English Country Netherlands systematics 53 Annotation We extend the relativistic mean-field models with hadron masses and meson-baryon coupling constants dependent on the scalar sigma field, studied previously to incorporate Delta(1232) baryons. Available empirical information is analyzed to put constraints on the couplings of Delta s with meson fields. Conditions for the appearance of Delta s are studied. We demonstrate that with inclusion of the Delta s our equations of state continue to fulfill majority of known empirical constraints including the pressure-density constraint from heavy-ion collisions, the constraint on the maximum mass of the neutron stars, the direct Urea and the gravitational baryon mass ratio constraints. (C) 2017 Elsevier B.V. All rights reserved. Public work category ADC No. of Archival Copy 39909 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised
Title Directed flow in asymmetric nucleus-nucleus collisions and the inverse Landau-Pomeranchuk-Migdal effect Author info V. D. Toneev ... [et al.] Author Toneev V. D. (1%)
Co-authors Voronyuk Vadym (1%)
Kolomeitsev Evgeni E. 1970- (97%) UMBFP06 - Katedra fyziky
Cassing W. (1%)
Source document Physical Review C. Vol. 95, no. 3 (2017), pp. [1-6]. - Maryland : American Physical Society, 2017 Keywords heavy ion collisions energia - energy dense matter Language English Country United States of America systematics 53 Annotation It is proposed to identify a strong electric field-created during relativistic collisions of asymmetric nuclei-via the observation of pseudorapidity and transverse momentum distributions of hadrons with the same mass but opposite charge. The results of detailed calculations within the parton-hadron string dynamics (PHSD) approach for the charge-dependent directed flow v(1) are presented for semicentral Cu+Au collision at root S-NN = 200 GeV incorporating the inverse Landau-Pomeranchuk-Migdal (iLPM) effect, which accounts for a delay in the electromagnetic interaction with the charged degrees of freedom. By including the iLPM effect, we achieve a reasonable agreement of the PHSD results for the charge splitting in v(1)(p(T)) in line with the recent measurements by the STAR Collaboration for Cu+Au collisions at root s(NN) = 200 GeV while an instant appearance and coupling of electric charges at the hard collision vertex overestimates the splitting by about a factor of 10. We predict that the iLPM effect should practically disappear at energies of root s(NN) approximate to 9 GeV, which should lead to a significantly larger charge splitting of v1 at the future FAIR/NICA facilities. Public work category ADC No. of Archival Copy 39312 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised
Title Observables of non-equilibrium phase transition Author info Boris Tomášik ... [et al.] Author Tomášik Boris 1972- (45%) UMBFP06 - Katedra fyziky
Co-authors Schulc Martin (5%)
Melo Ivan (45%)
Kopečná Renata (5%)
Source document The European Physical Journal A : Hadrons and Nuclei. Vol. 52, no. 8 (2016), pp. 236-241. - Berlin : Springer, 2016 Keywords phase diagram strongly interacting matter heavy ion collisions Language English Country United States of America systematics 53 Public work category ADC No. of Archival Copy 37236 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised
Title Complete strangeness measurements in heavy-ion collisions Author info Boris Tomášik, Evgeni E. Kolomeitsev Author Tomášik Boris 1972- (50%) UMBFP06 - Katedra fyziky
Co-authors Kolomeitsev Evgeni E. 1970- (50%) UMBFP06 - Katedra fyziky
Source document The European Physical Journal A : Hadrons and Nuclei. Vol. 52, no. 8 (2016), pp. 251-256. - Berlin : Springer, 2016 Keywords heavy ion collisions strangeness Language English Country United States of America systematics 53 Public work category ADC No. of Archival Copy 37239 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised
Title HBT radii from the multipole Buda-Lund model Author info Sándor Lökös ... [et al.] Author Lökös Sándor (10%)
Co-authors Csanád Máté (10%)
Tomášik Boris 1972- (70%) UMBFP06 - Katedra fyziky
Csörgő Tamás (10%)
Source document Acta Physica Polonica B : proceedings supplement. Vol. 9, no. 2 (2016), pp. 269-274. - Kraków : Faculty of Physics, Astronomy and Applied Computer Science, 2016 ; WPCF 2015 - workshop on particle correlations and femtoscopy workshop Keywords fyzika - physics ťažké kovy - heavy metals heavy ion collisions Language English Country Poland systematics 53 Public work category AFC No. of Archival Copy 37333 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised
Title Scalar quanta in Fermi liquids: zero sounds, instabilities, Bose condensation, and a metastable state in dilute nuclear matter Author info E. E. Kolomeitsev, D. N. Voskresensky Author Kolomeitsev Evgeni E. 1970- (99%) UMBFP06 - Katedra fyziky
Co-authors Voskresensky Dmitri (1%)
Source document The European Physical Journal A : Hadrons and Nuclei. Vol. 52, no. 12 (2016), pp. [1-18]. - Berlin : Springer, 2016 Keywords heavy ion collisions equation of state relativistic mean-field models hydrodynamics Language English Country United States of America systematics 53 Annotation The spectrum of bosonic scalar-mode excitations in a normal Fermi liquid with local scalar interaction is investigated for various values and momentum dependence of the scalar Landau parameter f(0) in the particle-hole channel. For f(0) > 0 the conditions are found when the phase velocity on the spectrum of zero sound acquires a minimum at non-zero momentum. For1 < f(0) < 0 there are only damped excitations, and for f(0) <1 the spectrum becomes unstable against the growth of scalar-mode excitations. An effective Lagrangian for the scalar excitation modes is derived after performing a bosonization procedure. We demonstrate that the instability may be tamed by the formation of a static Bose condensate of the scalar modes. The condensation may occur in a homogeneous or inhomogeneous state relying on the momentum dependence of the scalar Landau parameter. We show that in the isospin-symmetric nuclear matter there may appear a metastable state at subsaturation nuclear density owing to the condensate. Then we consider a possibility of the condensation of the zero-sound-like excitations in a state with a nonzero momentum in Fermi liquids moving with overcritical velocities, provided an appropriate momentum dependence of the Landau parameter f(0)( k) > 0. We also argue that in peripheral heavy-ion collisions the Pomeranchuk instability may occur already for f(0) >1. Public work category ADC No. of Archival Copy 38091 Catal.org. BB301 - Univerzitná knižnica Univerzity Mateja Bela v Banskej Bystrici Database xpca - PUBLIKAČNÁ ČINNOSŤ References PERIODIKÁ-Súborný záznam periodika unrecognised