The nuclear energy density functionals with modified radial dependence of the isoscalar effective mass

TL;DR

This paper explores modifications to nuclear energy density functionals to reconcile differences between nuclear matter calculations and empirical data on finite nuclei by enriching the radial dependence of the isoscalar effective mass.

Contribution

Introduction of four new terms into the Skyrme-force inspired functional to modify the radial dependence of the isoscalar effective mass in nuclear models.

Findings

Modified radial dependence of IEM achieved

Potential improvements in single-particle spectra modeling

Reconciliation of theoretical and empirical IEM values

Abstract

Calculations for infinite nuclear matter with realistic nucleon-nucleon interactions suggest that the isoscalar effective mass (IEM) of a nucleon at the saturation density equals $m^*/m\sim 0.8\pm 0.1$, at variance with empirical data on the nuclear level density in finite nuclei which are consistent with $m^*/m\approx 1$. This contradicting results might be reconciled by enriching the radial dependence of IEM. In this work four new terms are introduced into the Skyrme-force inspired local energy-density functional: $\tau(\nabla\rho)^2$, $\tau\frac{d\rho}{dr}$, $\tau^2$ and $\tau\Delta\rho$. The aim is to investigate how they influence the radial dependence of IEM and, in turn, the single-particle spectra.