MULTI-STRANGE PARTICLE ENHANCEMENTS IN PB-PB INTERACTIONS AT 158 GEV/C PER NUCLEON

摘要

Strange and multi-strange baryon and anti-baryon production is expected to be enhanced in heavy ion interactions if a phase transition from hadronic matter to a Quark-Gluon Plasma takes place. The production yields and transverse mass spectra of strange and multi-strange baryons and anti-baryons are presented for lead-lead interactions at 158 GeV/c per nucleon. Yields and transverse mass spectra from proton-lead and proton-beryllium interactions, where no phase transition is expected, are also presented and compared to those from lead-lead interactions. The results show a significant enhancement of strange and multi-strange baryons in Pb-Pb interactions. The enhancement increases with strangeness content as predicted in QGP models and exceeds one order of magnitude in the case of the Ω particle. These results represent some of the best evidence, to date, for a new phase of matter being formed in these collisions.