Isovector proton-neutron pairing and Wigner energy in Hartree-Fock mean field calculations

TL;DR

This paper introduces a novel self-consistent mean field approach that conserves isospin and particle number, effectively describing isovector pairing and its contribution to symmetry and Wigner energies in nuclear systems.

Contribution

A new method for isovector pairing in mean field calculations that exactly conserves isospin and particle number, improving the description of Wigner energy.

Findings

Isovector pairing significantly contributes to Wigner energy.

The new approach outperforms BCS-like models in describing Wigner energy.

Exact isospin conservation enhances the accuracy of mean field calculations.

Abstract

We propose a new approach for the treatment of isovector pairing in self-consistent mean field calculations which conserves exactly the isospin and the particle number in the pairing channel. The mean field is generated by a Skyrme-HF functional while the isovector pairing correlations are described in terms of quartets formed by two neutrons and two protons coupled to the total isospin T=0. In this framework we analyse the contribution of isovector pairing to the symmetry and Wigner energies. It is shown that the isovector pairing provides a good description of the Wigner energy, which is not the case for the mean field calculations in which the isovector pairing is treated by BCS-like models.