An in-beam $\gamma$-ray spectroscopic study of the nuclear structure $\mathrm{of}{}^{125}\mathrm{I}$ has led to extensions and alterations of the level scheme of this nucleus. Several new intraband and interband transitions are observed in the positive parity bands based on $\pi d_{5/2}$ and $\pi g_{7/2}$ configurations, indicating mixing of the two configurations in these bands. The strongly coupled $\pi g_{9/2}$ band has also been extended and characteristic quadrupole crossover transitions, hitherto unreported, have been observed, providing estimates of the $B(M1;\overrightarrow{I}I-1)/B(E2;\overrightarrow{I}I-2)$ ratios for transitions in this band. New experimental results are presented concerning the three-quasiparticle structure and likely members of the unfavored signature of the prolate $\pi h_{11/2}$ band, showing excellent agreement with the theoretical results. Experimental results are discussed in relation to the systematics of the neighboring odd-$A$ nuclei.

• Received 13 October 1998

DOI:https://doi.org/10.1103/PhysRevC.59.2446