Chemical equilibrium study at SPS 158 A GeV

A detailed study of chemical freeze-out in nucleus–nucleus collisions at beam energy 158 A GeV is presented. By analysing hadronic multiplicities within the statistical hadronization approach, the chemical equilibration of p–p, C–C, Si–Si and Pb–Pb systems is studied as a function of the number of participating nucleons in the system. Additionally, the two-component statistical hadronization model is applied to the data and is found to be able to explain the observed strangeness hadronic phase space under-saturation.