A Study of Collision Frequency and Particle Density in Ultrarelativistic Nuclear Collisions by an Event Generator URASiMA

Abstract

Local collision frequencies of produced hadrons in ultrarelativistic nucleus-nucleus collisions are studied by an event generator URASiMA. From these frequencies, local number densities of produced hadrons are derived. It turns out that thermalized high density local system is achievable in CERN-SPS energy region although its size is not always large. Time evolution and nuclear mass number dependence of these quantities, frequency and density, are also investigated.