The Nuclear Energy Density Functionals With Modified Radial Dependence of the Isoscalar Effective Mass

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 ∼ 0.8 ± 0.1, at variance with empirical data on the nuclear level density in finite nuclei which are consistent with m * /m ≈ 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: τ (∇ρ) 2 , τ dρ dr , τ 2 and τ ∆ρ. The aim is to investigate how they influence the radial dependence of IEM and, in turn, the single-particle spectra. * Maciej.Zalewski@fuw.edu.pl

Nuclear energy functional with a surface-peaked effective mass: global properties

“…An important dependence of the spin-orbit splitting and of the centroids as a function of the coefficient of the correction term have been observed in Ref. [28]. In our case, as shown in Figs.…”

“…We now compare our results to the recent ones of Zalewski et al [28,29] where correction terms such as (4) as well as others have been studied. The main differences between our approach and that of Refs.…”

“…where the first term have been first introduced in Ref. [28,29] and induces a surface-peaked effective mass while the second term is introduced to moderate the effect of the first one in the mean field. The effective mass is obtained from the functional derivative of the energy H and is expressed as (q runs over neutrons and protons: q = n, p):…”

“…The main differences between our approach and that of Refs. [28,29] are: (i) the moderating term is not present in Refs. [28,29], (ii) the effective mass in the bulk of nuclei is close to 0.8m in our case, while in the Refs.…”

“…[29] another procedure is adopted, the non-perturbative one, and the behavior of the the spin-orbit splitting and of the spin-orbit centroids is quite different from that shown in Ref. [28]. The non-perturbative prescription of Ref.…”