Effective pairing interactions with isospin density dependence

TL;DR

This paper demonstrates that incorporating an isovector component into density-dependent pairing interactions allows for accurate modeling of pairing phenomena across a wide range of semi-magic nuclei, aligning well with experimental data.

Contribution

It introduces a new microscopic-derived isovector density-dependent pairing interaction that effectively describes pairing in diverse nuclei.

Findings

Accurately reproduces experimental binding energies and pairing gaps.

Shows the pairing field from infinite matter approximates finite nuclei results.

Supports the use of isovector terms for global nuclear modeling.

Abstract

We perform Hartree-Fock-Bogoliubov (HFB) calculations for semi-magic Calcium, Nickel, Tin and Lead isotopes and $N$=20, 28, 50 and 82 isotones using density-dependent pairing interactions recently derived from a microscopic nucleon-nucleon interaction. These interactions have an isovector component so that the pairing gaps in symmetric and neutron matter are reproduced. Our calculations well account for the experimental data for the neutron number dependence of binding energy, two neutrons separation energy, and odd-even mass staggering of these isotopes. This result suggests that by introducing the isovector term in the pairing interaction, one can construct a global effective pairing interaction which is applicable to nuclei in a wide range of the nuclear chart. It is also shown with the local density approximation (LDA) that the pairing field deduced from the pairing gaps in infinite matter reproduces qualitatively well the pairing field for finite nuclei obtained with the HFB method.