Islands of shape coexistence for Z=38-84 in a non-relativistic mean-field approach using Hartree-Fock-Bogoliubov theory

TL;DR

This study uses non-relativistic Hartree-Fock-Bogoliubov theory to identify regions of shape coexistence in nuclei with Z=38-84, confirming previous findings and discovering new areas of coexistence related to particle-hole excitations.

Contribution

It demonstrates the effectiveness of the Skyrme-SKI3 functional in predicting islands of shape coexistence, corroborating covariant density functional theory results and expanding known regions.

Findings

Islands of shape coexistence found around Z=82 and Z=50 at N=104 and N=66.

Additional islands identified around N=90, Z=66, N=60, and Z=38.

New regions of shape coexistence adjacent to previously known areas.

Abstract

Based on the microscopic mechanism of the particle-hole (p-h) excitations in the proton and neutron single-particle energy levels relative to the Fermi energy, a search for islands of shape coexistence (SC) is performed over a wide range of even-even nuclei from Z=38 to 84 using non-relativistic self-consistent mean-field with the Hartree-Fock-Bogoliubov (HFB) theory using the Skyrme-SKI3 functional. The results of the present study show that neutron-induced islands of SC, corresponding to proton p-h excitations, are found around the magic numbers Z=82 and Z=50, centered at the relevant neutron midshells of N=104 and N=66 respectively, while proton-induced islands of SC, corresponding to neutron p-h excitations, are found around the neutron numbers N=90 and N=60, centered at the relevant proton midshells Z=66 and Z=38 respectively. In addition, islands of SC due to both neutron and proton particle-hole excitations are found around N=40, Z=40. The results of the present study are compared with the results of covariant density functional theory using the DDME2 functional, using the same p-h mechanism. The islands of SC that appeared in the CDFT work with the DDME2 functional are corroborated by the present study with the Skyrme-SKI3 functional, thus confirming the robustness of the particle-hole excitations mechanism in searching for islands of SC. In addition, the current study revealed new regions of SC, adjacent to the earlier islands and expanding their shores.