CENTRAL COLLISIONS INDUCED BY LIGHT TARGET NUCLEI

For the interactions of p, 3He, 4He, and 6Li with emulsion at 4.5A GeV/c, anexperimental study has been performed. The type of interactions chosen was centralwhich enable to analyze a specific interaction mechanism. The selection of the centralevents has been in the frame work of the particles emitted beyond the kinematic limits(Өlab . 90 ‹). This selection provides a strict criterion to distinguish the central collisions. For the sake of comparison an additional criterion is introduced. It dealswith interactions that exhibit an absence of projectile fragmentation. A detailed studyof the emitted pions multiplicity is presented. The focusing is on the light emulsion target H and CNO in comparison with the heavy AgBr. The analysis reveals that, the occultation of light projectile nuclei is possible in CNO targets along with the complete occultation in AgBr.