Multiplicity and charged particle emission in relativistic heavy ion collisions

Single-particle inclusive cross sections of precisely identified fragments are studied together with associated multiplicities of fast charged particles. Neon and argon projectiles are made to bombard uranium, calcium, and aluminium. It is found that all the observed fragment spectra are structureless and more or less exponentially decaying throughout the range of studied fragment masses. A catalogue of experimentally found qualitative features is given and the applicability of simple statistical thermodynamic models is examined by tracing down in the spectra kinematical effects in the framework of a source of a temperature and a velocity, leading to a nuclear fireball model. The production of complex particles is also discussed. A simple mass dependence in the cross section of the fragments is observed. The possibilities of a struck projectile and the explosion of a compound nucleus are considered. 7 references