FORMATION AND BREAKUP OF EXTRA-LARGE COMPOSITE SYSTEM IN CENTRAL AU+AU COLLISIONS

Recent data on multifragmentation in central Au+Au collisions at beam energy 100 MeV/nucleon are analyzed within the statistical and molecul ar dynamics models. The data are consistent with statistical breakup o f a thermalized source with radius of 14 fm, mass number around 250, a nd excitation energy about 7 MeV/nucleon, in good agreement with molec ular dynamics calculations. According to this model, fragment formatio n takes place within a time interval of 50 fm/c after the maximum comp ression. Intense preequilibrium emission of light particles and strong collective flow of fragments are predicted.