Properties of the rotational bands inEr161

High-spin states in $^{161}\mathrm{Er}$ have been studied experimentally using the $^{150}\mathrm{Nd}$($^{16}\mathrm{O}$,5$\mathit{n}$) reaction at a beam energy of 86 MeV. The $5/{2}^{+}[642]$, $3/{2}^{\ensuremath{-}}[521]$, and $11/{2}^{\ensuremath{-}}[505]$ bands are extended up to high-spin states, and particularly the $\ensuremath{\alpha}=\ensuremath{-}1/2$ branch of the ground state $3/{2}^{\ensuremath{-}}[521]$ band is revised significantly. The relatively enhanced $E1$ transitions from the $3/{2}^{\ensuremath{-}}[521]$ band to the $5/{2}^{+}[642]$ band are observed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and near-prolate shape and triaxial deformation are proposed to the $3/{2}^{\ensuremath{-}}[521]$ and $5/{2}^{+}[642]$ bands, respectively. Signature inversion occurs in the $3/{2}^{\ensuremath{-}}[521]$ band after the band crossing in $^{161}\mathrm{Er}$, and the systematics of the signature inversion associated with the $3/{2}^{\ensuremath{-}}[521]$ configuration are discussed. By analyzing the properties of the relatively enhanced $E1$ transitions, it is found that the $R(E1/E2)$ values show angular momentum dependence before the band crossing, and these enhanced $E1$ transitions could be attributed to octupole softness.