Strange and multistrange baryon production in PbPb collisions at 158 A GeV/c

Abstract The series of experiments (WA85, WA94 and WA97) at the Omega spectrometer at CERN SPS have systematically studied the production of different strange particles. Strangeness enhancements at central rapidities have been reported by WA85 and WA94 in S-W and SS with respect to p-A collisions. For the investigation of PbPb interactions in the WA97 experiment a new detector suitable for high particle densities, the Pixel Tracking Chamber, has been developed based on silicon pixel detectors. The results on production ratios and cross sections of Λ, Λ , Ξ − , Ξ + , Ω − and Ω + detected by this experiment are presented. A significant enhancement of the Ω over Ξ ratio is observed when comparing p-Pb to PbPb data (a factor of about 3).