Zero-temperature relaxation time. A test for the collision integral

Abstract

The collisional relaxation time of a momentum space deformation in nuclei, corresponding to an isoscalar giant mode, is evaluated solving numerically the collision integral with a procedure based on the concept of the mean free path. We apply this procedure to solve the collision integral for two case: (a) the momentum space distribution is divided in parallel ensembles; (b) no division of the momentum space distribution in parallel ensembles is made. The results are compared to an exact calculation, in a frozen Pauli blocking prescription. We show that method (b) is in good agreement to the exact calculation. The parallel ensembles simulation tends to the exact solution for very large atomic mass numbers.