$(h_{11/2})^2$ alignments in neutron-rich $^{132}$Ba with negative-parity pairs

Abstract

The shell-model collective-pair truncation with negative-parity pairs is adopted to study the $(h_{11/2})^2$ alignment in $^{132}$Ba. The proton $(h_{11/2})^2$-alignment state is predicted as an $E\sim4.6$ MeV and $\tau\sim 0.5~\mu$s isomer with relatively strong E3 decay channels. The oblately deformed neutron $(h_{11/2})^{-2}$ alignment in the yrast band and four negative-parity bands are confirmed, even although two of these negative-parity bands favor the prolate deformation, which directly manifests the $\gamma$ unstability of $^{132}$Ba.