Collisional damping of giant quadrupole resonance

We calculate the collisional width of giant quadrupole excitation for ''1''2''0Sn nucleus at finite temperature in Thomas-Fermi approximation using a description for the distortion functions by parameterizing the velocity field in terms of the second order Bessel functions. Recently, we have investigated the collisional damping of giant dipole resonance and giant monopole resonance in Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological SkM and Gogny forces. Here in this work we extend these calculations to the giant quadruple resonance. Theoretical investigations of nuclear collective vibrations built on the ground and excited states of nuclei are mostly based on the random phase approximation (RPA) theory. However, since RPA approach is the small amplitude limit of the time dependent Hartree-Fock (TDHF), it is not suitable for describing the damping of the collective excitations. In order to describe nuclear collective response including damping, it is necessary to incorporate coupling between the collective states and the doorway configurations