The ${}^{147}$Ba nucleus has been studied in prompt $\gamma$-ray spectroscopy using the EUROGAM2 Ge array. Spin and parity of the ground state has been determined to be $5/2^{-}$. The unexpected, $5/2^{-}$ ground state results from interaction with other negative-parity configurations. A new ground-state band has been established in ${}^{147}$Ba and some previously reported levels have been arranged into a $3/2^{-}$ band, which may correspond to the $3/2^{-}$[532] configuration. The new spin assignments in ${}^{147}$Ba suggest that the theoretical predictions of static octupole deformation in the ground state of ${}^{147}$Ba may not be be valid. No candidates for parity doublets have been found in ${}^{147}$Ba. Instead, an octupole band built on the ground state has been proposed.

• Received 14 October 2012

DOI:https://doi.org/10.1103/PhysRevC.87.031305