The combined data of two Coulomb excitation experiments has verified the purely electromagnetic population of the Kπ = 4+, 6+, 8−, and 16+rotational bands in 178Hf via 2≤ν ≤14 K-forbidden transitions, quantifying the breakdown of the K-selection rule with increasing spin in the low-K bands. The γ -, 4+, and 6+bands were extended, and four new states in a rotational band were tentatively assigned to a previously known Kπ = 0+band. The quasiparticle structure of the 6+(t1/2= 77 ns) and 8−(t1/2= 4 s) isomer bands were evaluated, showing that the gyromagnetic ratios of the 6+ isomer band are consistent with a pure π 7/2+, π 5/2+ structure. The 8−isomer band at 1147 keV and the second 8−band at 1479 keV, thought to be predominantly ν 7/2-, ν 9/2+ and π 9/2-, π 7/2+, respectively, are mixed to a degree approaching the strongmixing limit. Based on measured (Kπ = 16+‖E2‖Kπ = 0+) matrix elements, it was shown that heavy-ion bombardment could depopulate the 16+isomer at the ∼1% level, although no states were found that would mediate photodeexcitation of the isomer via low-energy x-ray absorption.
Copyright © 2007 The American Physical Society. This article first appeared in Physical Review C 75, no. 3 (March 16, 2007): 034308: 1-34308: 27. doi:10.1103/PhysRevC.75.034308.
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Hayes, A. B., D. Cline, C. Y. Wu, H. Ai, H. Amro, C. Beausang, R. Casten, J. Gerl, A. A. Hecht, A. Heinz, H. Hua, R. Hughes, R.V. F. Janssens, C. J. Lister, A. O. Macchiavelli, D. A. Meyer, E. F. Moore, P. Napiorkowski, R. C. Pardo, Ch. Schlegel, D. Seweryniak, M. W. Simon, J. Srebrny, R. Teng, K. Vetter, and H. J. Wollersheim. "Spin Dependence of K Mixing, Strong Configuration Mixing, and Electromagnetic Properties of 178Hf." Physical Review C 75, no. 3 (March 16, 2007): 034308: 1-34308: 27. doi:10.1103/PhysRevC.75.034308.