High-spin proton alignments and coexisting coupling schemes in {sup 168}Hf

High-spin states in {sup 168}Hf were populated in the {sup 96}Zr({sup 76}Ge,4n) reaction and the decay {gamma} rays measured with the Gammasphere spectrometer array. Previously known bands were extended to significantly higher spins and seven new bands were established. The results were interpreted within the framework of the cranked shell model with the help of comparisons with neighboring nuclei. The observation of full alignment in band crossings at a rotational frequency ({Dirac_h}/2{pi}){omega}{approx}0.55 MeV revealed that these crossings are associated with proton alignments involving h{sub 11/2} and h{sub 9/2} orbitals. The characteristics of one strongly coupled high-K band indicate that the deformation-aligned configuration is built on the same six quasiparticles that constitute the high-spin structure of a rotationally aligned band. This leads to the coexistence of two coupling schemes, deformation and rotation alignment, in six-quasiparticle structures involving the same orbitals.