Chemical freeze-outs of strange and non-strange particles and residual chemical non-equilibrium

Abstract

We propose an elaborate version of the hadron resonance gas model with the combined treatment of separate chemical freeze-outs for strange and non-strange hadrons and with an additional γ_s factor which accounts for the remaining strange particle non-equilibration. Two sets of chemical freeze-outs parameters are connected by the conservation laws of entropy, baryonic charge, isospin projection and strangeness. The developed approach enables us to perform a high-quality fit of the hadron multiplicity ratios for AGS, SPS and RHIC energies with total χ²/dof ≃ 1.05. A special attention is paid to a complete description of the Strangeness Horn. A well-known p, Λand Ξselective suppression problem is also discussed.