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 $^{57}\mathrm{Ca}$ is the heaviest bound odd isotope and $^{70}\mathrm{Ca}$ 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 $N=32$, 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 $^{52}\mathrm{Ca}$ ($N=32$) and $^{54}\mathrm{Ca}$ ($N=34$) but show a weakening of shell closure at $^{60}\mathrm{Ca}$ ($N=40$). The possible shell closure at $^{70}\mathrm{Ca}$ ($N=50$) is predicted.