Shell Evolution in Neutron-rich Ge, Se, Kr and Sr Nuclei within RHB Approach (2007.02302v2)

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.