Excited states in the transitional doubly odd ${}^{98}\mathrm{Rh}$ nucleus were populated in the ${}^{75}\mathrm{As}$(${}^{28}\mathrm{Si}$,2$p$3$n$) fusion-evaporation reaction using the 120-MeV incident ${}^{28}\mathrm{Si}$ beam. The subsequent de-excitations were investigated through in-beam $\gamma$-ray spectroscopic techniques using an early implementation phase of the Indian National Gamma Array (INGA) spectrometer equipped with 18 clover Ge detectors. The level structures in ${}^{98}\mathrm{Rh}$ have been established up to excitation energy $\approx$10 MeV and angular momentum $\sim$23$\hslash$. The previously reported level schemes are considerably modified and extended substantially. Significant expansion of the level scheme at low excitation energies stipulates that the previously reported 842-726-994-980-265 keV $\gamma$-transition cascade in ${}^{98}\mathrm{Rh}$ is not directly based on the ground state (T${}_{1/2}$ = 8.7 min). Tilted-axis cranking (TAC) shell-model calculations have been used to put the present level scheme of ${}^{98}\mathrm{Rh}$ in perspective. Level structures have been interpreted in terms of the rotational bands based on the $\pi p_{1/2}\otimes \nu h_{11/2}$ [triaxiality parameter ($\gamma$) = 25${}^{\circ }$], and $\pi f_{5/2}\otimes \nu h_{11/2}$ proton-neutron configurations having moderate quadrupole deformation (${\epsilon }_2$ $\approx$ 0.13) and the admixtures. Excited band structures are based on the $\pi p_{1/2}/f_{5/2}\otimes \pi$($g_{9/2}$)${}^2\otimes \nu h_{11/2}$ configuration and the fully stretched [$\pi p_{1/2}\otimes \nu$($h_{11/2}$)${}^2\otimes \nu d_{5/2}$]${}_{{13}^{-}}$ configuration.

• Received 24 December 2013

DOI:https://doi.org/10.1103/PhysRevC.89.034303