Collisional effects in the finite temperature dipole response of 120Sn and 208Pb

We investigate for the first time the behavior of the GDR in 120Sn and 208Pb at zero and finite temperatures in the linearized version of the extended TDHF theory. It is shown that collisions between nucleons induce an increase of the GDR width together with a decrease of the collective energy with an increasing temperature. While in 120Sn, the GDR response has a relatively strong temperature dependence, a weaker temperature dependence is found in 208Pb. Influence of collisional coupling and of the range of the effective interaction on the presented results are discussed.