Abstract

N.M. Hassan, N.M. Sadek, Jamila Elsweedy and M.T. Hussein

The information carried by the medium energy nucleons (gray particles) emitted in heavy ion collisions is studied. A canonical thermo dynamical model is proposed to deal with the interacting nuclei as nucleon gas system. The predictions of the model are compared with a complete set of measured data for the reactions of proton, helium, carbon and neon nuclei with the nuclear emulsion at 4.2 A GeV. It is found that the angular distribution of the knocked on nucleons is almost independent of the projectile mass. A strong correlation between the energy of the gray particles and their emission angles is found. The gray particles emitted in the forward hemisphere show linear correlation with their average kinetic energy which reflects that these particles are emitted in non-equilibrium states. On the other hand, backward emission shows uniform behavior that represents particle emission in an almost equilibrium state.