Self-consistent calculations within the Extended Theory of Finite Fermi Systems

The Extended Theory of Finite Fermi Systems(ETFFS) describes nuclear excitations considering phonons and pairing degrees of freedom, using experimental single particle energies and the effective Landau-Migdal interaction. Here we use the Skyrme interactions in order to extend the range of applicability of the ETFFS to experimentally not yet investigated short-lived isotopes. We find that Skyrme interactions which reproduce at the mean field level both ground state properties and nuclear excitations are able to describe the spreading widths of the giant resonances in the new approach, but produce shifts of the centroid energies. A renormalization of the Skyrme interactions is required for approaches going beyond the mean field level.