Dynamics of Exotic Nuclear Systems: Covariant QRPA and Extensions

Quasiparticle Random Phase Approximation (QRPA) based on covariant density functional theory provides a universal and self-consistent description of collective and noncollective excitations in nuclei. So far is was only possible to investigate spherical nuclei and all the investigations have been restricted to 1p-1h (or two-quasiparticle) configurations. We report on recent progress in this field: (i) we perform fully self-consistent axially deformed QRPA calculations in the framework of relativistic models with nonlinear meson couplings and (ii) we go beyond the mean field approximation and use the collective phonons obtained in relativistic QRPA to construct dressed particle and hole configurations. This leads to an enhancement of the level density in the neighborhood of the Fermi surface and to an increasing fragmentation of the giant resonances. This allows a microscopic description of the corresponding damping mechanism.