Strange Antibaryon Production Data and Reduction of Strangeness Suppression in Sulphur-Nucleus Collisions at 200A GeV

Abstract

We have used the event generator LUCIAE to analyse NA35 data of the $\bar p$ and $\barΛ$ yields, the ratio $\barΛ/\bar p$, and the transverse mass distributions of $\bar p$ and $\barΛ$ in pp and central sulphur-nucleus collisions at 200A GeV. The NA35 data could be reproduced reasonably if one assumes that the s quark pair suppression factor and concerns in nucleus-nucleus collisions are larger than the nucleon-nucleon collision. It seems to indicate that NA35 data might imply the reduction of strangeness suppression in ultrarelativistic nucleus-nucleus collisions comparing to the nucleon-nucleon collision at the same energy. However, the ratio $\barΛ/\bar p$ approaching to unity in AA collisions comparing to the pp collision does not necessarily mean a flavor symmetry since hadronic rescattering plays a role as well.