Collective Expansion in High Energy Heavy Ion Collisions

Abstract

Transverse mass spectra of pions, kaons, and protons from the symmetric heavy-ion collisions 200AGeV S+S and 158AGeV Pb+Pb, measured in the NA44 focusing spectrometer at CERN, are presented. The mass dependence of the slope parameters provides evidence of collective transverse flow from expansion of the system in heavy-ion induced central collisions. {copyright} {ital 1997} {ital The American Physical Society}