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

Abstract

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.