On the Collisional Damping of Giant Dipole Resonance

Abstract

Collisional damping widths of giant dipole excitations are calculated in Thomas-Fermi approximation by employing the microscopic in-medium cross-sections of Li and Machleidt and the phenomenological Gogny force. The results obtained in both calculations compare well, but account for about 25-35% of the observed widths in ${}^{120}Sn$ and ${}^{208}Pb$ at finite temperatures.

Latex, 13 pages, 4 figures