Hadrosynthesis at SPS and RHIC and the statistical model

Abstract

An analysis of hadron abundances in heavy ion collisions from SPS to RHIC energy within the statistical-thermal model is presented. Pb--Pb collisions at 40 A GeV are analysed for the first time here. Unlike stated in similar recent studies, the data analysis rules out a complete strange chemical equilibrium in full phase space. In fact, the use of multiplicities integrated in full phase space or in a limited rapidity window at SPS energy gives rise to different results for the extra-strangeness suppression parameter gamma_S while the extracted values of temperature and baryon-chemical potential do not vary significantly. This behaviour rises the question whether the observed hadronic strangeness phase space saturation at RHIC within a small mid-rapidity window would hold in a possible full phase space analysis.

8 pages, 5 .eps figures, LaTeX macros iopart.cls and iopart12.clo needed, talk given at Strange Quarks in Matter 2001, to appear in J. Phys. G