Enhanced mixing of intrinsic states in deformed Hf nuclei

Abstract

Excited low-spin, nonyrast states in 170,172,174 Hf were populated in β + / decay and studied through off-beam γ -ray spectroscopy. New coincidence data allowed for a substantial revision of the level schemes of 170,172 Hf and a confirmation of the level scheme of 174 Hf. The Hf isotopes represent a unique situation in which a crossing of collective intrinsic excitations occurs, enhancing significantly the effects of mixing. Using branching ratios from excited 2 + states, this mixing is followed and studied. The resulting mixing matrix elements are found to be ∼30 keV-an order of magnitude larger than estimated previously for nearby nuclei. In the case of 170 Hf, the 2 + β and 2 + γ level are shown to be completely mixed.