Phase Evolution and Freeze-out within Alternative Scenarios of Relativistic Heavy-Ion Collisions

Abstract: Global evolution of the matter in relativistic collisions of heavy nuclei and the resulting global freeze-out parameters are analyzed in a wide range of incident energies 2.7 GeV $\le \sqrt{s_{NN}}\le$ 39 GeV. The analysis is performed within the three-fluid model employing three different equations of state (EoS): a purely hadronic EoS, an EoS with the first-order phase transition and that with a smooth crossover transition. Global freeze-out parameters deduced from experimental data within the statistical model are well reproduced within the crossover scenario. The 1st-order-transition scenario is slightly less successful. The worst reproduction is found within the purely hadronic scenario. These findings make a link between the EoS and results of the statistical model, and indicate that deconfinement onset occurs at $\sqrt{s_{NN}}\gsim$ 5 GeV.