AnomalousIsomericDecaysin 174 LuasaProbeof K MixingandInteractionsinDeformedNuclei

A K � � 13 � , 280 ns four-quasiparticle isomer in the odd-odd nucleus 174 Lu has been identified and characterized. The isomer decays to both K � � 7 � and K � � 0 � rotational bands obtained from the parallel and antiparallel coupling of the proton 7=2 � � 404� and neutron 7=2 � � 633� orbitals. K mixing caused by particle-rotation coupling explains the anomalously fast transition rates to the 7 � band but those to the 0 � band are caused by a chance degeneracy between the isomer and a collective state, allowing the mixing matrix element for a large K difference to be deduced.