Extended Skyrme interaction (II): ground state of nuclei and of nuclear matter

TL;DR

This paper investigates the impact of time-odd components in extended Skyrme energy density functionals on nuclear ground states, showing minimal energy changes in odd nuclei and improving mass predictions with new spin-density terms.

Contribution

It introduces spin-density dependent terms into the Skyrme interaction and demonstrates their effects on nuclear binding energies and stability, refining the mass model and parameter constraints.

Findings

Spin-density terms minimally affect odd-nuclei binding energies

Inclusion of new terms slightly improves mass prediction accuracy

Parameters G_0 and G_0' can be tuned flexibly without altering ground-state properties

Abstract

We study the effect of time-odd components of the Skyrme energy density functionals on the ground state of finite nuclei and in nuclear matter. The spin-density dependent terms, which have been recently proposed as an extension of the standard Skyrme interaction, are shown to change the total binding energy of odd-nuclei by only few tenths of keV, while the time-odd components of standard Skyrme interactions give an effect that is larger by one order of magnitude. The HFB-17 mass formula based on a Skyrme parametrization is adjusted including the new spin-density dependent terms. A comprehensive study of binding energies in the whole mass table of 2149 nuclei gives a root mean square (rms) deviation of 0.575 MeV between experimental data and the calculated results, which is slightly better than the original HFB-17 mass formula. From the analysis of the spin instabilities of nuclear matter, restrictions on the parameters governing the spin-density dependent terms are evaluated. We conclude that with the extended Skyrme interaction, the Landau parameters $G_0$ and $G_0^\prime$ could be tuned with a large flexibility without changing the ground-state properties in nuclei and in nuclear matter.