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.
We consider a possible mechanism of thermalization of nucleons in relativistic heavy-ion collisions. Our model belongs, to a certain degree, to the transport ones; we investigate the evolution of the system created in nucleus-nucleus collision, but w
e parametrize this development by the number of collisions of every particle during evolution rather than by the time variable. We based on the assumption that the nucleon momentum transfer after several nucleon-nucleon (-hadron) elastic and inelastic collisions becomes a random quantity driven by a proper distribution. This randomization results in a smearing of the nucleon momenta about their initial values and, as a consequence, in their partial isotropization and thermalization. The trial evaluation is made in the framework of a toy model. We show that the proposed scheme can be used for extraction of the physical information from experimental data on nucleon rapidity distribution.
We propose a mechanism of thermalization of nucleons in relativistic nucleus-nucleus collisions. Our model belongs, to a certain degree, to the transport ones; we consider the evolution of the system, but we parametrize this development by the number
of collisions of every particle in the system rather than by the time variable. We based on the assumption that the nucleon momentum transfer after several nucleon-nucleon (-hadron) collisions becomes a random quantity driven by a proper distribution.
