The Freezeout Parameters in Heavy-Ion Collisions

It is shown that the freezeout parameters estimated in heavy-ion collisions all have the common property that the entropy density s normalized to T 3 is constant. The value of s/T 3 has been taken from lattice QCD simulations at zero baryo-chemical potential μB and assumed to remain constant at finite μB in a hadron resonance gas model. This implies that the hadronic matter in rest frame of produced system can be determined by constant degrees of freedom. The entropy content is reflected in the multiplicity of produced particles in final state. We made predictions for freezeout parameters at very low temperatures. Furthermore, we found that the strangeness degrees of freedom are very essential at low incident energies.