V. N. Russkikh

Kaon production in intermediate-energy nuclear collisions

Abstract Production of positive kaons in nuclear collisions at intermediate energies (∼1–2 GeV/nucleon) is studied within the 3-dimensional fluid dynamics combined with the hadrochemical kinetics for strangeness production. Sensitivity of the kaon probe to a form of the nuclear equation of state is analyzed. The model reproduces total and differential cross sections of Ne + NaF → K + + X and Ne + Pb → K + + X reactions at E lab = 2.1 GeV/nucleon, provided a soft equation of state is used. The pion-production data are also well described employing the same equation of state. Predictions are made for the current experiment on kaon production at the SIS accelerator. The obtained results are compared with the predictions of other models.

On freeze-out problem in relativistic hydrodynamics

A finite unbound system which is equilibrium in one reference frame is in general nonequilibrium in another frame. This is a consequence of the relative character of the time synchronization in the relativistic physics. This puzzle was a prime motivation of the Cooper-Frye approach to the freeze-out in relativistic hydrodynamics. Solution of the puzzle reveals that the Cooper-Frye recipe is far not a unique phenomenological method that meets requirements of energy-momentum conservation. Alternative freeze-out recipes are considered and discussed.

Elliptic Flow and Dissipation at AGS - SPS Energies

Elliptic flow in heavy-ion collisions at incident energies

Ultrarelativistic heavy-ion collisions within two-fluid model with pion emission

{E}_{\text{lab}}\ensuremath{\simeq}(1\char21{}160)A

Analysis of intermediate-energy heavy-ion collisions within relativistic mean-field two-fluid model☆

GeV is analyzed within the model of three-fluid dynamics (3FD). We show that a simple correction factor, taking into account dissipative effects, allows us to adjust the 3FD results to experimental data. This single-parameter fit results in a good reproduction of the elliptic flow as a function of the incident energy, centrality of the collision, and rapidity. The experimental scaling of pion eccentricity-scaled elliptic flow versus charged-hadron-multiplicity density per unit transverse area also turns out to be reasonably described. Proceeding from values of the Knudsen number, deduced from this fit, we estimate the upper limit of the shear viscosity-to-entropy ratio as

Stochastic multi-fluid models for intermediate-energy heavy-ion collisions☆

\ensuremath{\eta}/s~1\char21{}2

What we have learned so far from 3-fluid hydrodynamics

at the CERN Super Proton Synchrotron (SPS) incident energies. This value is of the order of minimal

Evolution of baryon-free matter produced in relativistic heavy-ion collisions

\ensuremath{\eta}/s

Extended transverse-momentum analysis for intermediate-energy heavy-ion collisions

observed in water and liquid nitrogen.

Collective flow of pions in relativistic heavy-ion collisions

Abstract Ultrarelativistic nuclear collisions are studied in the framework of the two-fluid dynamical model. In comparison with other versions of the two-fluid approach, this model explicitly takes into account pion-production processes. Their contribution to the friction force acting between projectile and target fluids increases with beam energy. The stopping power of nuclei, space-time picture of the collision process and characteristics of highly excited hadron matter formed in nuclear reactions are investigated. The possibility of reaching the conditions necessary for quarkgluon plasma formation is discussed. Apparently, the most serious limitation is due to short lifetimes of high energy density states. The secondary particle observables, such as the total energy distribution of pions, baryon rapidity spectra, etc., are calculated and compared with experimental data obtained in Dubna, Brookhaven and at CERN.