Shape Coexistence at Zero Spin in 64Ni Driven by the Monopole Tensor Interaction

Abstract

The low-spin structure of the semimagic 64Ni nucleus has been considerably expanded: combining four experiments, several 0+ and 2+ excited states were identified below 4.5 MeV, and their properties established. The Monte Carlo shell model accounts for the results and unveils an unexpectedly complex landscape of coexisting shapes: a prolate 0+ excitation is located at a surprisingly high energy (3463 keV), with a collective 2+ state 286 keV above it, the first such observation in Ni isotopes. The evolution in excitation energy of the prolate minimum across the neutron N = 40 subshell gap highlights the impact of the monopole interaction and its variation in strength with N.

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Cited by in corpus (6)

• Shape coexistence in even-even nuclei: A theoretical overview
• Shape and multiple shape coexistence of nuclei within covariant density functional theory
• First Evidence of Axial Shape Asymmetry and Configuration Coexistence in ${}^{74}$Zn: Suggestion for a Northern Extension of the $N=40$ Island of Inversion
• Low-spin particle/hole-core excitations in ${}^{41,47,49}$Ca isotopes studied by cold-neutron capture reactions
• Detailed low-spin spectroscopy of 65Ni via neutron capture reaction
• The pervasiveness of shape coexistence in nuclear pair condensates