Highly-Deformed Bands in 175 Hf

Abstract

Two high-spin regularly spaced rotational bands with large dynamical moments of inertia have been identified in 175Hf 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 175Hf 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 175Hf 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 Hf nuclei may be quite different from those identified in the lighter mass Lu nuclei. Since the two highly deformed bands in 175Hf are associated with different deformations, this work also identifies the role of the intruder orbits in polarizing the nuclear shape.