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, oneand two-neutron separation energies, predicting that Ca-57 is the heaviest bound odd isotope and Ca-70 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 Ca-52 (N = 32) and Ca-54 (N = 34) but show a weakening of shell closure at Ca-60 (N = 40). The possible shell closure at Ca-70 (N = 50) is predicted.