New parametrization of Skyrme's interaction for regularized multireference energy density functional calculations

Background: Symmetry restoration and configuration mixing in the spirit of the generator coordinate method based on energy density functionals have become widely used techniques in low-energy nuclear structure physics. Recently, it has been pointed out that these techniques are ill defined for standard Skyrme functionals, and a regularization procedure has been proposed to remove the resulting spuriosities from such calculations. This procedure imposes an integer power of the density for the density-dependent terms of the functional. At present, only dated parametrizations of the Skyrme interaction fulfill this condition. Purpose: To construct a set of parametrizations of the Skyrme energy density functional for multireference energy density functional calculations with regularization using the state-of-the-art fitting protocols. Method: The parametrizations were adjusted to reproduce ground-state properties of a selected set of doubly magic nuclei and properties of nuclear matter. Subsequently, these parameter sets were validated against properties of spherical and deformed nuclei. Results: Our parameter sets successfully reproduce the experimental binding energies and charge radii for a wide range of singly magic nuclei. Compared to the widely used SLy5 and to the SIII parametrization that has integer powers of the density, a significant improvement of the reproduction of the data is observed. Similarly, a good description of the deformation properties at A similar to 80 was obtained. Conclusions: We have constructed new Skyrme parametrizations with integer powers of the density and validated them against a broad set of experimental data for spherical and deformed nuclei. These parametrizations are tailor-made for regularized multireference energy density functional calculations and can be used to study correlations beyond the mean field in atomic nuclei.