Preferential emission of pions in asymmetric nucleus-nucleus collisions

Abstract

Pion production in Ne on Pb collisions at a beam energy of 800 MeV/nucleon is studied by solving a coupled set of transport equations for the phase-space distribution functions of nucleons, deltas, and pions. The experimentally observed preferential emission of pions away from the interaction zone towards the projectile side in the transverse direction is found to be due to the stronger pion absorption by the heavier target spectator. A model calculation of the pion transverse momentum distribution in the reaction plane agrees with that of the experimental data.