Statistical fragmentation of Au projectiles at E/A = 600 MeV

The mean multiplicity of intermediate mass fragments (IMF) (MIME) ) produced by fragmentation of - Au projectiles interacting with targets of C, Al, Cu, and Pb at an incident energy of EIA=600 MeV is compared to predictions of statistical multifragmentation and sequential evaporation models. The initial conditions for the calculations were provided by Boltzmann-Uehling-Uhlenbeck simulations. In the high excitation energy regime where the IMF multiplicity reaches its maximum the observed universal correlation between ( MimF ) and the total charge Zbound of projectile fragments with charges Z ?. 2 can-not be reproduced by a sequential evaporation code. In this regime the data are better described by sta-tistical decay calculations which assume the formation of an expanded nuclear system and a rather fast breakup. PACS number(s): 24.60.Ky, 25.40.Sc, 25.70.P