Analysis of hadron production in nucleus-nucleus interactions up to and out of kinematical limit of free NN-collisions in the frame of FRITIOF model

In the framework of the modified FRITIOF model, the inclusive spectra of the cumulative $\pi ^0$-, $\pi ^-$-mesons and protons produced in the nucleus-nucleus interactions at 4.5 GeV/c/nucleon and 4.2 GeV/c/nucleon are calculated. It is shown that the model reproduces qualitatively, and in some cases quantitatively the main experimental regularities of $\pi$-mesons production, and "soft" part of the proton spectra. According to the model the production of the cumulative particles is connected with the mechanism of the "soft" nucleon-nucleon interaction.Comment: 12 pages, 11 figure

Central events in the interactions of 28Si\bf{^{28}Si} and 32S\bf{^{32}S} with heavy emulsion targets

Data on the multiplicity of secondaries in central events of $\mathsf{^{28}Si}$ (14.6 AGeV) and $\mathsf{^{32}S}$ (3.7 AGeV) interactions with AgBr emulsion nuclei have been compiled and studied. The dependence of the multiplicities of the outgoing charged stripping particles on the number of interacting nucleons and therefore on the impact parameter, as indicated by the target size, and consequently, on the degree of centrality is investigated. The resultant multiplicity distribution of the produced pions for each studied case is fitted by both Negative Binomial (NB) and Poisson distributions. The NB distribution is valid for most of the considered cases. The transparency of the target for a projectile was found to become more pronounced as the incident energy increased

Backward slow protons production in the inelastic interactions of 6^{\bf 6}Li and 7^{\bf 7}Li nuclei with emulsion nuclei at Dubna energy

We report the experimental measurements on the multiplicity of slow target associated particles, in the forward ($\theta_{lab} \le 90^{\circ}$) and backward ($\theta_{lab} > 90^{\circ}$) hemispheres, and the different correlations between the backward slow protons and the production of hadrons in both hemispheres in the interactions of $^{6}Li($3.7 A GeV) and $^{7}Li($2.2 A GeV) with emulsion nuclei. The study of the number of backward slow protons ($N^{b}_{b}$ and $N^{b}_{g}$) indicates that while the number of backward black particles, $N^{b}_{b}$, is a good factor representing the purely target fragments, the number of backward grey particles, $N^{b}_{g}$, can be considered as an accurate experimental factor for the impact parameter dependence of the collision. It is also shown that the most central collisions are events having $N^{b}_{g}>0$ and $N^{b}_{s}>0$. We confront the data with a multiple scattering model incorporating both binary cascading and evaporation of residual nucleus. The model applies well in the region of limited cascading (backward hemisphere). As for the forward hemisphere, where cascading becomes more branched, the model becomes less applicable