Strangeness enhancement in<i>p</i>+<i>A</i>and S+<i>A</i>interactions at energies near 200<i>A</i>GeV

Abstract

The systematics of strangeness enhancement is calculated using the hijing and venus models and compared to recent data on pp, pA, and AA collisions at CERN/SPS energies (200A GeV). The hijing model is used to perform a linear extrapolation from pp to AA. venus is used to estimate the effects of final state cascading and possible nonconventional production mechanisms. This comparison shows that the large enhancement of strangeness observed in S+Au collisions, interpreted previously as possible evidence for quark-gluon plasma formation, has its origins in nonequilibrium dynamics of few nucleon systems. A factor of 2 enhancement of ${\mathrm{\ensuremath{\Lambda}}}^{0}$ at midrapidity is indicated by recent pS data, where on the average one projectile nucleon interacts with only two target nucleons. There appears to be another factor of 2 enhancement in the light ion reaction SS relative to pS, when on the average only two projectile nucleons interact with two target ones.