Search for Wobbling Excitations in Hf Nuclei: Are the SD Bands Triaxial?

Abstract

Two Gammasphere experiments have been performed in order to establish the possible triaxial nature of strongly deformed (SD) bands in174Hf. A lifetime measurement confirmed the large deformation of the four previously observed bands in this nucleus. In addition, a thin-target, high-statistics experiment was carried out to search for linking transitions between the SD bands. No such transitions, which represent an experimental signature for wobbling modes, were observed. Four new SD bands were found in174Hf together with a single SD band in173Hf. These results indicate that the strongly deformed sequences of N ≈ 102 Hf isotopes behave differently than the TSD bands found in Lu nuclei near N = 92. The interpretation of these bands in terms of possible stable triaxial deformation is confronted with the experimental findings and UC predictions.