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

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- A nd two-neutron separation energies, predicting that Ca57 is the heaviest bound odd isotope and Ca70 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 Ca52 (N=32) and Ca54 (N=34) but show a weakening of shell closure at Ca60 (N=40). The possible shell closure at Ca70 (N=50) is predicted.