Spectator fragmentation in nucleus-nucleus collisions: Phase space approach

Dynamics of spectator matter break-up in non-central collisions of ¹⁹⁷Au+ ¹⁹⁷Au at 1000 MeV/A are explored within the framework of a quantum molecular dynamics (QMD) model. The phase space of nucleons bound in intermediate mass fragments are studied using two clustering subroutines. Backtracking the origin of fragments to the time of the initial contact between the colliding nuclei and applying the simulated annealing clusterization algorithm (SACA) indicates a significant yield of projectile-like and target-like fragments. The simplest clusterization approach based on the spatial correlation technique, however, predicted a much lesser production probability of fragments in the spectator zone.