Enhanced Mixing of Intrinsic States in Deformed Hf Nuclei

E. A. McCutchan
R. F. Casten
V. Werner
E. Williams
R. Winkler
A. Wolf
Z. Berant
G. Gurdal
J. Qian
H. Ai
L. Amon
C. W. Beausang, University of Richmond
D. S. Brenner
R. Cakirli
R. J. Casperson
C. R. Fitzpatrick
D Frank
A. B. Gransworthy
A. Heinz
R. Luttke
A. F. Mertz
Y. Oktem
N. Pietralla
P. H. Regan
B. Shoraka
J. R. Terry
N. J. Thompson


Excited low-spin, nonyrast states in 170,172,174Hf 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 170,172Hf and a confirmation of the level scheme of 174Hf. 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 170Hf, the 2+β and 2+γ level are shown to be completely mixed.