Central collisions of 4.5 GeV/c per nucleon 16O and 28Si nuclei in nuclear emulsion

Abstract

Central collisions of 16O and 28Si nuclei with heavy (AgBr) nuclei in nuclear emulsion at 4.5 GeV/c per nucleon are selected and investigated under several selecting criteria. Central cross sections and average number of interacting protons from both projectile and target nuclei, multiplicity distributions of shower particles and dispersions are discussed in the framework of the Glauber model. The multiplicities of produced charged secondaries are studied according to the nucleon-nucleus superposition model. The multiplicity distributions and mean values of grey particles are also investigated via a parameter free model whose input information is the distribution of grey particles produced in proton induced reactions. It is shown that the selection criterion of central collisions based only on the small total charge of stripping particles is too weak. The selection criteria based on the high multiplicity of total secondary charged particles, the high degree of target destruction and the large number of interacting protons augmented by the small total charge of stripping particles provide satisfactory agreement with the theoretical calculations.