Exploratory Studies on Relativistic Heavy-Ion Central Collisions

Central nuclear collisions are studied with a 1.8-GeV/N /sup 40/Ar beam incident on a Pb target. Momentum and angular distributions of negative pions infer a pion temperature of 86.6 +- 3.9 MeV, and a pion-nucleon ratio of 0.21--0.24. The pion multiplicity suggests a suppression of high multiplicity events and a non-Poisson distribution. Pion interferometry analyses are performed; the relationship between pion multiplicity and the collision impact parameter is examined.