Shell Evolution in Neutron-rich Ge, Se, Kr and Sr Nuclei within RHB Approach

TL;DR

This paper investigates shell evolution in neutron-rich Ge, Se, Kr, and Sr nuclei using the relativistic Hartree-Bogoliubov approach, predicting new shell closures and comparing results with experimental data and other models.

Contribution

It introduces a comprehensive RHB analysis of exotic isotopic chains, predicting a new shell closure at N=70 and validating it against experimental and theoretical data.

Findings

Reproduction of the N=50 magic number.

Prediction of a new shell closure at N=70.

Good agreement with experimental data and other models.

Abstract

The exotic even-even isotopic chains from Z=32 to Z=38 are investigated by means of the relativistic Hartree-Bogoliubov (RHB) approach with the explicit Density Dependent Meson-Exchange (DD-ME2) and Density Dependent Point-Coupling (DD-PC1) models. The classic magic number N=50 is reproduced and the new number N=70 is predicted to be a robust shell closure by analysing several calculated quantities such as: two-neutron separation energies, two-neutron shell gap, neutron pairing energy, potential energy surface and neutron single particle energies with and without the tensor force. The obtained results are corroborated by shell model calculations and compared with the predictions of finite range droplet model (FRDM) and with the available experimental data. A reasonable and satisfactory agreement between the theoretical models and experiment is established.