Neutron-rich calcium isotopes within realistic Gamow shell model calculations with continuum coupling

Abstract

Based on the realistic nuclear force of the high-precision CD-Bonn potential, we have performed comprehensive calculations for neutron-rich calcium isotopes using the Gamow shell model (GSM) which includes resonance and continuum. The realistic GSM calculations produce well binding energies, one- and two-neutron separation energies, predicting that ${}^{57}$Ca is the heaviest bound odd isotope and ${}^{70}$Ca is the dripline nucleus. Resonant states are predicted, which provides useful information for future experiments on particle emissions in neutron-rich calcium isotopes. Shell evolutions in the calcium chain around neutron numbers \textit{N} = 32, 34 and 40 are understood by calculating effective single-particle energies, the excitation energies of the first $2^{+}$ states and two-neutron separation energies. The calculations support shell closures at ${}^{52}$Ca (\textit{N} = 32) and ${}^{54}$Ca (\textit{N} = 34) but show a weakening of shell closure at ${}^{60}$Ca (\textit{N} = 40). The possible shell closure at ${}^{70}$Ca (\textit{N} = 50) is predicted.

24 pages, 6 figures