Excited states in ${}^{164}\mathrm{Ta}$ were populated in the ${}^{142}\mathrm{Nd}{(}^{27}\mathrm{Al}{,5n)}^{164}\mathrm{Ta}$ reaction and investigated using the AFRODITE spectrometer array. The yrast rotational decay sequence up to spin ${21}^{-}$ is identified for the first time and assigned to the $\pi \left[514\right]{9/2}^{-}\otimes \nu \left[660\right]{1/2}^{+}$ configuration. A less intense, excited band is also identified. Low-spin signature inversion is observed in the yrast band, and is compared with the extended total Routhian surface calculations. It is likely that quadrupole pairing plays a role in generating the anomalous signature splitting, but an additional mechanism apart from the assumed mean field and quadrupole pairing interaction may be required to account for the experimental data.

• Received 16 July 2001

DOI:https://doi.org/10.1103/PhysRevC.65.014308