Semiclassical description of isovector giant multipole resonances

The method discussed here is related to the extension of the Vlasov approach to study isovector collective modes. We analyze dipole, quadrupole, and octupole resonances in ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$ and ${}_{}{}^{208}{}_{}{}^{}\mathrm{Pb}$. Full quantum random phase approximation results are well reproduced. A collision term is added through a relaxation time approach. It is shown that the widths of the giant resonances are dominated by an interplay between Landau damping and collision damping. A quite fair agreement with recent quadrupole data is found. Some temperature in the reference state is introduced, in order to study the behavior of collective motions built on excited states. We get a moderate increase of the widths and a clear quenching of the strengths. A shift of the resonance energy is also observed, actually very sensitive to the residual interaction used.