EVIDENCE FOR ELASTOPLASTICITY IN DISSIPATIVE HEAVY-ION COLLISIONS

From the measured yield of delta-electrons with energies between 3 and 8 MeV, emitted in the heavy-ion reaction Pb+Pb at 12 MeV/nucleon incident energy, a very fast deceleration of the nuclei in the approach phase is inferred which is much faster than predicted by the microscopic one-body dissipation model. Since the deceleration time is smaller than or comparable to the thermal equilibration time, the dissipation process is non-Markovian and therefore memory effects have to be included. This is performed on the basis of dissipative diabatic dynamics, which describes elastoplastic properties. The new diabatic one-body dissipation model reproduces the fast deceleration and the long nuclear contact time.