Importance of momentum dependent interactions in multifragmentation

We analyze the role of different equations of state and momentum dependent interactions in fragmentation. Heavy ion collisions are simulated using a quantum molecular dynamics model and fragments are constructed with the minimum spanning tree method. A detailed study is carried out for Xe+Sn reactions at incident energies E=100 and 400 MeV/nucleon and over a wide range of impact parameters. Our analysis indicates that the light mass fragments in central collisions are sensitive towards different static equations of state whereas the heavy fragments are insensitive towards different static equations of state. The results with momentum dependent interactions are quite different. Now, the heavy fragments are also sensitive towards different equations of state. The momentum dependence of the equation of state is able to break the spectator matter into a large number of fragments at peripheral collisions whereas a simple static equation of state fails to produce any fragments. As a result, the properties of fragments (such as transverse flow, rapidity distribution, etc.) are also affected by the momentum dependence of the interaction.