Shell model study of $N\ensuremath{\simeq}28$ neutron-rich nuclei

Shell model study of $N ≃ 28$ neutron-rich nuclei

L. Gaudefroy

Phys. Rev. C 81, 064329 – Published 30 June 2010

Abstract

A systematic study of the low-lying structure of $N = 27$ , $28,$ and $29$ isotones is performed within the shell model framework using the SDPF-U interaction [F. Nowacki and A. Poves, Phys. Rev. C 79, 014310 (2009)]. For each isotonic chain, correlation energy is found to increase while moving away from the stability line. Spherical shapes as well as small values of correlation energy are associated with the isotopes of $_{20}$ Ca and $_{19}$ K discussed in this study. Neutron intruder states appear at low excitation energy in the $_{18}$ Ar and $_{17}$ Cl studied isotopes. Coexistence between spherical and prolate deformed states is a systematic feature in $_{16}$ S isotopes. Below $Z = 16$ most of the studied nuclei are characterized by intruder ground states. The major role played by protons in determining the structure of $N ≃ 28$ nuclei is shown.