Magicity of neutron-rich isotopes within relativistic self-consistent approaches

TL;DR

This paper investigates the emergence of new shell gaps in neutron-rich nuclei using relativistic Hartree-Fock-Bogoliubov theory, highlighting the influence of Lorentz pseudo-vector and tensor interactions on nuclear magic numbers.

Contribution

It introduces a detailed analysis of how Lorentz pseudo-vector and tensor interactions affect shell gap formation in neutron-rich isotopes within a relativistic framework.

Findings

Identification of candidate nuclei with new magic numbers.

Role of Lorentz interactions in single-particle energy evolution.

Prediction of nuclei with large shell gaps and minimal pairing.

Abstract

The formation of new shell gaps in intermediate mass neutron-rich nuclei is investigated within the relativistic Hartree-Fock-Bogoliubov theory, and the role of the Lorentz pseudo-vector and tensor interactions is analyzed. Based on the Foldy-Wouthuysen transformation, we discuss in detail the role played by the different terms of the Lorentz pseudo-vector and tensor interactions in the appearing of the $N=16$, 32 and 34 shell gaps. The nuclei $^{24}$O, $^{48}$Si and $^{52,54}$Ca are predicted with a large shell gap and zero ($^{24}$O, $^{52}$Ca) or almost zero ($^{48}$Si, $^{54}$Ca) pairing gap, making them candidates for new magic numbers in exotic nuclei. We find from our analysis that the Lorentz pseudo-vector and tensor interactions induce very specific evolutions of single-particle energies, which could clearly sign their presence and reveal the need for relativistic approaches with exchange interactions.