Collisional damping of giant monopole and quadrupole resonances

Collisional damping widths of giant monopole and quadrupole excitations for Sn-120 and Pb-208 at zero and finite temperatures are calculated within Th omas-Fermi approximation by employing the microscopic in-medium cross-secti ons of Li and Machleidt and the phenomenological Skyrme and Gogny forces, a nd are compared with each other. The results for the collisional widths of giant monopole and quadrupole vibrations at zero temperature as a function of the mass number show that the collisional damping of giant monopole vibr ations accounts for about 30 - 40% of the observed widths at zero temperatu re, while for giant quadrupole vibrations it accounts for only 20 - 30% of the observed widths at zero temperature.