  In-beam $ \gamma $-ray spectroscopy of $^{131}$Xe has been carried out to
study the structure of the intruder $ \nu h_{11/2} $ band. Excited states were
populated via an $ \alpha $-induced fusion-evaporation reaction at E$ _{\alpha}
= 38 $ MeV. Inspection of $ \gamma \gamma $-coincidence data resulted in the
identification of a new rotational sequence. Based on the systematics of
excitation energy, assigned spin-parity, decay pattern, and the electromagnetic
character of the inter-band $ \Delta I = 1 $ $ \gamma $-transitions, this
sequence is proposed as the unfavoured signature partner of the $ \nu h_{11/2}
$ band. The structure of this band is further illuminated in the light of the
triaxial particle rotor model (TPRM). The possibility of wobbling excitation in
$ N = 77 $ Xe-Ba-Ce isotones has been explored in a systematic manner.
