FINITE-TEMPERATURE NUCLEAR RESPONSE IN THE EXTENDED RANDOM-PHASE-APPROXIMATION

The nuclear collective response at finite temperature is investigated for the first time in the quantum framework of the small amplitude lim it of the extended time-dependent Hartree-Fock approach, including a n on-Markovian collision term. It is shown that the collision width sati sfies a secular equation. By employing a Skyrme force, the isoscalar m onopole, isovector dipole, and isoscalar quadrupole excitations in Ca- 40 are calculated and important quantum features are pointed out. The collisional damping due to decay into incoherent two-particle-two-hole states is small at low temperatures but increases rapidly at higher t emperatures. [S0556-2813(98)06310-9].