The level structure of the odd-odd nuclide ${}_{}{}^{172}{}_{}{}^{}\mathrm{Lu}$ has been studied by means of the (${}_{}{}^3{}_{}{}^{}\mathrm{He}$, $d$) and ($\alpha ,t$) proton transfer reactions on ${}_{}{}^{171}{}_{}{}^{}\mathrm{Yb}$. The spectrum has been interpreted in terms of two-quasiparticle states formed by coupling the transferred proton with the ${1/2}^{-}$[521] neutron in the target ground state. Assignments have been proposed for the bands arising by parallel and antiparallel coupling of the target neutron with protons in the ${7/2}^{+}$[404], ${1/2}^{-}$[541], and ${5/2}^{+}$[402] Nilsson orbitals. Some evidence is also presented for the assignment of the {${\frac{1}{2}}^{-}{\mathrm{}\left[521\right]\mathrm{}}_n\pm {\frac{9}{2}}^{-}{\mathrm{}\left[514\right]\mathrm{}}_p$} levels. The $Q$ value of the ${}_{}{}^{171}{}_{}{}^{}\mathrm{Yb}({}_{}{}^3{}_{}{}^{}\mathrm{He},d){}_{}{}^{172}{}_{}{}^{}\mathrm{Lu}$ reaction is measured to be -792 ± 34 keV, yielding a mass excess of -56700 ± 37 keV for ${}_{}{}^{172}{}_{}{}^{}\mathrm{Lu}$.

NUCLEAR REACTIONS ${}_{}{}^{171}{}_{}{}^{}\mathrm{Yb}({}_{}{}^3{}_{}{}^{}\mathrm{He},d)$, $E=27\mathrm{}$ MeV; measured $\sigma \left(E_d\right)$. ${}_{}{}^{171}{}_{}{}^{}\mathrm{Yb}(\alpha ,t)$, $E=28.5\mathrm{}$ MeV; measured $\sigma \left(E_t\right)$. Model comparison. ${}_{}{}^{172}{}_{}{}^{}\mathrm{Lu}$ deduced levels $I$, $\pi$, $K$. Enriched target. Deduced ${}_{}{}^{172}{}_{}{}^{}\mathrm{Lu}$ mass.

• Received 22 April 1976

DOI:https://doi.org/10.1103/PhysRevC.14.583