New band structures in neutron-rich odd-$A$ Ge isotopes

Neutron-rich Ge isotopes were studied in a campaign of experiments with the Gammasphere Ge-detector array at ANL. Beams of $^{76}$Ge were incident upon thick $^{238}$U, $^{208}$Pb, and $^{198}$Pt targets in deep-inelastic reactions, populating excited states up to moderate spins. No previous high-spin work has been done on $^{75,77}$Ge, with most existing data coming from $\beta$ decay, neutron capture, or transfer reactions. The level schemes for both nuclides have been extended, including the observation of strongly-coupled band structures. In some cases, spin and parity assignments are strengthened by angular-correlation measurements. These isotopes straddle the neutrinoless double $\beta$-decay candidate $^{76}$Ge; additional data on the levels in these systems can provide tests of shell-model calculations for nuclei in this region involving the $p_{3/2}p_{1/2}f_{5/2}g_{9/2}$ proton and neutron subspace.