The angular distributions of secondaries in proton-nucleus interactions at 200 and 300 GeV

The angular distributions of shower particles from proton-nucleus collisions at 200 and 300 GeV are investigated and correlated to the nuclear parameters (heavy prong emission), the inelasticity coefficient and the angle of the leading track. A partition is made into two components, the LP component associated with a single collision and the RC component corresponding to the excess from repeated collisions at the same proton and the nucleons inside the nucleus. Results from earlier investigations on the multiplicity distributions are confirmed. The LP component exhibits an excess of about 30% as compared to the shower particle emission in proton-proton collisions at the same energy. We find that the excess particles are slow moving in the equal velocity system, i.e., the frame in which the proton and the nucleus have equal but oppositely directed velocities. The opening angle of the cone inside which the proton-nucleus distributions are similar to the proton-proton distributions at the same energy is small (? 0.5°) and is energy dependent. We also find indications of A dependence and a noticeable correlation to the inelasticity coefficient and to the angle of the leading track.