Baryon number conservation and statistical production of antibaryons

The statistical production of antibaryons is considered within the canonical ensemble formulation. We demonstrate that the antibaryon suppression in small systems due to the exact baryon number conservation is rather different in the baryon-free (B=0) and baryon-rich (B≥2) systems. At constant values of temperature and baryon density in the baryon-rich systems the density of the produced antibaryons is only weakly dependent on the size of the system. For realistic hadronization conditions this dependence appears to be close to B/(B+1) which is in agreement with the preliminary data of the NA49 Collaboration for the p̄/π ratio in nucleus–nucleus collisions at the CERN SPS energies. The statistical hadronization model is also used to describe the data on the p̄/π ratio in e++e− interactions. We find that the assumption of a constant hadronization temperature leads in this case to a contradiction with data and should be substituted by another hadronization criterion.