arXiv subjects

D. Yu. Peressounko

Publications and source records attributed to D. Yu. Peressounko.

6 recordsLinked to original sources

arXiv2001

Thermalization temperature in Pb+Pb collisions at SpS energy from hadron yields and midrapidity pt distributions of hadrons and direct photons

In the frame of 2+1 Bjorken hydrodynamics we describe simultaneously hadron yields and midrapidity pt distributions of direct photons, unflavored, and strange hadrons measured in Pb+Pb collisions at SpS. We find, that a reasonably quantitative description of these data is possible only if we introduce some radial velocity at the beginning of the one-fluid hydrodynamic stage. We fix uniquely all parameters of this model, and estimate an initial temperature of the just thermalized state T_{in}=(200 +40 -20) MeV in the case of EoS with phase transition to Quark-Gluon Plasma, and T_{in}=(230 +60 -30) MeV in the pure hadronic scenario. We conclude that SpS data considered in our study can not distinguish between a production of QGP, and its absence.

hep-ph↗

arXiv2000

Emission of light mesons directly from the surface of quark-gluon plasma

On the basis of hydrodynamic model of evolution we consider emission of lightest (π,K,η,ρ,ω,K^*) mesons directly from the surface of quark-gluon plasma, created in the heavy ion collision, with accounting of their absorption by surrounding hadronic gas. We evaluate upper and lower limits on yields of these direct mesons in Pb+Pb collisions at SpS, RHIC and LHC energies, and find, that even in the case of the lowest yield, direct K, ηand heavier mesons dominate over freeze-out ones at soft p_t (p_t < 0.5 GeV/c). This leads to enhancement of the low p_t production of these mesons which hardly can be explained within pure hadronic gas scenario, and can be considered as quark-gluon plasma signature.

hep-ph↗

arXiv1999

Photon emission in Pb+Pb collisions at SpS and LHC

Yield of direct photons in Pb+Pb collisions at SpS and LHC energy is evaluated with emphasis on estimate of possible uncertainty. Possibility of experimental observation of direct photons at LHC is discussed. Predictions of several models at SpS energy are compared with experimental data.

hep-ph↗

arXiv1998

Direct emission of light mesons from quark-gluon plasma surface

On the basis of hydrodynamic model of evolution of heavy ion collision we consider emission of $π,K,η,ρ,ω,K^*$ mesons directly from the surface of quark-gluon plasma, with accounting of their absorption by surrounding plasma hadronic gas. We evaluate upper and lower limits on yields of these direct mesons in Pb+Pb collision at 158 AGeV (SpS) and 3150+3150 AGeV (LHC), and find, that even in the case of the lowest yield, direct $η$ and heavier mesons dominate at LHC energy at soft $p_t$ ($p_t\le 0.5 GeV/c$). This enhancement of the low $p_t$ meson production can be considered as a quark-gluon plasma signature.

hep-ph↗

arXiv1997

Direct hadron production and radial flow reduction as quark-gluon plasma signature

It is shown that due to contribution of the hadrons, emitted directly from the inner hot region of central heavy ion collision, radial flow of the final state hadrons is rather sensitive to the creation of quark-gluon plasma with mixed phase.

hep-ph↗

arXiv1997

Direct hadron production in ultrarelativistic heavy ion collisions

Hadrons emitted by the pre-surface layer of quark-gluon plasma (QGP) before phase transition into hadronic gas are considered as possible source of direct information about QGP. It is shown that these hadrons dominate at soft p_t if QGP is created in ultrarelativistic heavy ion collisions.

hep-ph↗