Search for the terminating27−state inNd140

Abstract

In the search for the fully aligned ${27}^{\ensuremath{-}}$ state in $^{140}\mathrm{Nd}$ predicted by cranked Nilsson-Strutinsky calculations, new close-to-spherical high-spin states have been discovered. Both the close-to-spherical and the triaxial calculated states are in good agreement with the experimental results, supporting the existence of shape coexistence up to very high spins. Shell-model calculations using a newly developed effective interaction for the $50\ensuremath{\le}N,Z\ensuremath{\le}82$ mass region are in good agreement with the observed spherical states. The comparison between the experimental and calculated level energies allowed the relative energy to be established between several proton and neutron orbitals at high energy and spins.