Chemical Equilibration of Antihyperons

Abstract

Rapid chemical equilibration of antihyperons by means of the interplay between strong annihilation on baryons and the corresponding backreactions of multi-mesonic (fusion-type) processes in the later, hadronic stage of an ultrarelativistic heavy ion collision will be discussed. Explicit rate calculations for a dynamical setup are presented. At maximum SPS energies yields of each antihyperon specie are obtained which are consistent with chemical saturated populations of $T\approx 150-160$ MeV. The proposed picture supports dynamically the popular chemical freeze-out parameters extracted within thermal models.

revised version for some typos and two references; 6 pages, 4 figures; contribution to the Int. Workshop XXX on Gross Properties of Nuclei and Nuclear Excitations: Ultrarelativistic Heavy-Ion Collisions, Hirschegg, Jan. 13 - 19, 2002