Band structures and alignment properties in [Formula Presented]

High-spin states in the even-even nucleus [Formula Presented] were investigated via the [Formula Presented] reaction at a beam energy of 50 MeV. On the basis of coincidence data three of the known bands were extended to higher spins and two new bands were found. Experimental crossing frequencies were deduced for various band structures and compared with cranked-shell-model results. Previous assignments of [Formula Presented] quasiproton and [Formula Presented] quasineutron alignments along the yrast line were confirmed when a near-prolate shape is assumed. Hartree-Fock-Bogoliubov calculations predict a deformed shape for excited states in [Formula Presented] which shows, however, a considerable softness in triaxiality. For the first time in the mass 70 region, band structures and quasiparticle alignments in [Formula Presented] were also investigated using the projected shell model. The calculations support the previous conclusions for the positive-parity states and predict that the lowest negative-parity bands are signature partners based on [Formula Presented] quasiproton excitations, with a [Formula Presented] quasineutron crossing at higher frequencies leading to a four-quasiparticle configuration at high spins.