Kπ=8- rotational band and its fragmented decay through the Kπ=6+ intrinsic state in 170Hf

A Kπ=8- strongly coupled rotational band, which is built upon a 23 ns isomeric state, has been established in 170Hf. The single-particle configuration of the band has been determined from the in-band to out-of-band branching ratios and associated |(gK-gR)|/Q0 values. The γ-ray decay of the Kπ=8- isomeric state proceeds through a Kπ=6+ intrinsic state, in accordance with the K-selection rule. A complex array of delayed γ-ray transitions have been observed to link this Kπ=6+, intrinsic bandhead state into the yrast states. In particular, a new ΔK=8, 1141 keV, E1 transition links the Kπ=8- isomeric state directly to the ground-state band. The γ-ray reduced hindrance factor for this E1 decay in 170Hf is the smallest ΔK=8 transition observed in the Hf nuclei. However, its value is consistent with that expected on the basis of the increased Coriolis mixing which occurs in the lighter Hf isotopes.