High-spin states in ${}^{170}\mathrm{Ta}$ have been studied via ${}^{159}{\mathrm{T}\mathrm{b}(}^{16}\mathrm{O},5n\gamma {)}^{170}\mathrm{Ta}$ reaction through excitation functions, K x-γ, and $\gamma -\gamma -t$ coincidence measurements. Three rotational bands have been identified which consist of two strongly coupled bands and a semidecoupled one. The quasiparticle configurations of these bands and the interpretation of experimental results are discussed based on the existing knowledge of neighboring odd-mass and odd-odd nuclei and in the framework of the cranked-shell model. Low-spin signature inversion in the $\pi {9/2}^{-}\left[514\right]\otimes \nu {5/2}^{+}\left[642\right]$ and $\pi {1/2}^{-}\left[541\right]\otimes \nu {5/2}^{+}\left[642\right]$ bands are discussed. A delay (reduction) of the band-crossing frequency is observed in the $\pi {1/2}^{-}\left[541\right]\otimes \nu {5/2}^{+}\left[642\right]$ $\left(\pi {5/2}^{+}\right[402]\otimes \nu {5/2}^{+}[642\left]\right)$ band. This configuration-dependent crossing frequency is discussed in comparison with the AB crossing frequencies in the related bands of neighboring odd-Z isotopes.

• Received 29 March 1999

DOI:https://doi.org/10.1103/PhysRevC.60.044311