Evidence of a two-source emission for light charged particles in coincidence with pions produced in 16O + 27Al collisions at 94 MeV/nucleon

Abstract H and He ions have been detected in coincidence with charged pions in the reaction induced by 16 O on 27 Al target at 94 MeV/u incident energy. We analyse velocity spectra and cross sections of He ions emitted in the angular range 4°–150° in coincidence with charged pions detected at 90°. A two-source emission mechanism of the helium particles and a pion statistical production from an equilibrated participant zone is stressed. The absolute yields at different angles are compared with results of a theoretical model for medium energy heavy-ion reactions in the framework of a participant-spectator picture.