Pseudorapidity (rapidity) distribution of shower particles in relativistic nucleus-nucleus collisions

Abstract

The pseudorapidity distributions of shower particles from the interactions accompanied by the emission of backward relativistic hadrons in nucleus-emulsion collisions at Dubna energy have been studied by a thermalized cylinder model. The wide distribution fitted by two Gaussian distributions and the narrow distribution fitted by one Gaussian distribution can be described by the thermalized cylinder model. A Monte Carlo calculation shows that the thermalized cylinder model gives a good description of the statistical fluctuations in experimental pseudo-rapidity distribution. The calculated results are in agreement with the experimental data in the collisions of C, Ne and Si with emulsion nuclei at incident momentum in the range (4.1–4.5)AGeV/c. An isotropic emission fireball and a transverse or longitudinal flow are used to describe the rapidity distributions of charged particles produced in relativistic nucleus-nucleus collisions. A transverse flow is observed at a lower energy (1AGeV) and a longitudinal flow is observed at a higher energy (200AGeV). Our Monte Carlo calculated results are in agreement with the experimental data of Au-Au collisions at 1AGeV, O-Au collisions at 60A and 200AGeV, S-S collisions at 200AGeV, and S-Ag collisions at 200AGeV.