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

TL;DR

This paper extends the Extended Theory of Finite Fermi Systems by incorporating Skyrme interactions to better describe nuclear excitations and resonances, especially in short-lived isotopes, highlighting the need for renormalization beyond mean field.

Contribution

It introduces the use of Skyrme interactions within ETFFS to expand its applicability to exotic isotopes and discusses the necessary renormalization for accurate predictions.

Findings

Skyrme interactions can describe giant resonance widths

Centroid energies are shifted with Skyrme interactions

Renormalization is needed for beyond mean field approaches

Abstract

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.