Shell structure of the neutron-rich isotopes Co-69,Co-71,Co-73

The structures of the neutron-rich Co-69,Co-71,Co-73 isotopes were investigated via (p, 2p) knockout reactions at the Radioactive Isotope Beam Factory, RIKEN. Isotopes of interest were studied using the DALI2 gamma-ray detector array combined with the MINOS target and tracker system. Level schemes were reconstructed using the gamma-gamma coincidence technique, with tentative spin-parity assignments based on the measured inclusive and exclusive cross sections. Comparison with shell-model calculations using the Lenzi-Nowacki-Poves-Sieja LNPS and PFSDG-U interactions suggests coexistence of spherical and deformed shapes at low excitation energies in the Co-69,Co-71,Co-73 isotopes. The distorted-wave impulse approximation (DWIA) framework was used to calculate the single-particle cross sections. These values were compared with the experimental findings.