Shell-model-like approach based on covariant density functional theory in 3D lattice space: Evolution of octupole shape in rotating 224Th

Abstract

The evolution of the octupole shape with rotation in pear-shaped nuclei is a topic of broad interest. Based on the cranking covariant density functional theory in 3D lattice space, a shell-model-like approach is implemented to take into account the pairing correlations, and applied for the interleaved positive- and negative-parity bands in [Formula: see text]Th. The experimental [Formula: see text] relations are well reproduced. It is found that the octupole deformation of yrast states in [Formula: see text]Th rises slightly and then declines with increasing spin. After the band crossing, the octupole deformation suddenly disappears, i.e., a sharp transition from an octupole shape to a nearly spherical shape takes place at high spins. This is explained by the evolution of the coupling strength between the proton [Formula: see text] and [Formula: see text] orbitals with spin.