What Can We Learn from Reaction Zone in Relativistic Nucleus-Nucleus Collisions?

Abstract

We apply the ``zone of reactions'' as a tool in studying the interacting system formed in a collision of relativistic nuclei. With the use of the intensity of collisions of particles (the number of collisions in unit volume per unit time), we study the space-time structure of a fireball. In this approach, three basic regions for the evolution of a system are separated by the scale of the intensity of collisions: the zone of a hot fireball, the zone of a cold fireball, and the zone of residual interaction. It is shown that the conception of a zone of reactions can be used for the determination of the hypersurfaces of a chemical freeze-out and a sharp kinetic freeze-out.

Comments: 10 pages, 5 figures, Extended version of the talk given at the 21st International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2009), March 30 - April 4, Knoxville, Tennessee