$(h_{11/2}{)}^2$ 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 $E\sim 4.6$ 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.

Comments: 4 pages, 5 figures