High-spin states in the ${}^{129}\mathrm{Xe}$ nucleus are studied with the reaction ${}^{124}\mathrm{Sn}\left({}^9\mathrm{Be},4n\right)$ at a beam energy of 36 MeV. The level scheme is extended significantly. For the positive-parity band, the $\alpha =+1/2$ and the $\alpha =-1/2$ signature components are combined to form a complete band structure based on the $3/2^{+}$ state with spin and parity up to $21/2^{+}$. For the negative-parity band based on the $11/2^{-}$ state, the $\alpha =+1/2$ signature component is newly established and both the $\alpha =+1/2$ and the $\alpha =-1/2$ signature components also form a complete band structure up to the $35/2^{-}$ state. The positive- and negative-parity bands are proposed to originate from $\nu d_{3/2}3/2^{+}\left[402\right]$ and $\nu h_{11/2}11/2^{-}\left[505\right]$ Nilsson configurations, respectively. A backbending is observed in the negative-parity band, which originates from the alignments of two $h_{11/2}$ protons according to crank shell model calculations. Based on the total Routhian surface and quasiparticle triaxial rotor model calculations, the negative-parity band is interpreted as a triaxially deformed shape with $\gamma \approx -{30}^{\circ }$, while the positive-parity band is associated with $\gamma$ softness, in accordance with previous studies. In the high-spin states, three decoupled bands and one oblate band with $\gamma \approx -{60}^{\circ }$ are newly identified. The systematics and other characteristics of these bands are discussed.

• Received 11 December 2015

DOI:https://doi.org/10.1103/PhysRevC.93.064315