Two high-spin regularly spaced rotational bands with large dynamical moments of inertia have been identified in ${}^{175}\mathrm{Hf}$ with the Gammasphere spectrometer. These new bands are very similar to the previously identified triaxial superdeformed bands in the hafnium nuclei. However, the new bands in ${}^{175}\mathrm{Hf}$ have been linked into the known level scheme and thereby provide the first firm spin assignments for these structures in this region. In order to understand the new bands, theoretical calculations have been performed based on the ULTIMATE CRANKER code. The new bands in ${}^{175}\mathrm{Hf}$ are deduced to be built upon highly deformed structures. No experimental evidence for triaxiality was established and this work suggests that the structure of the so-called “triaxial” superdeformed bands in the $\mathrm{Hf}$ nuclei may be quite different from those identified in the lighter mass $\mathrm{Lu}$ nuclei. Since the two highly deformed bands in ${}^{175}\mathrm{Hf}$ are associated with different deformations, this work also identifies the role of the intruder orbits in polarizing the nuclear shape.

• Received 4 August 2004

DOI:https://doi.org/10.1103/PhysRevC.70.054314