Spectator fragmentation in nucleus-nucleus collisions: Phase space approach

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