Abstract:

The effect of Coriolis mixing on the gamma-decay of one-quasiparticle isomeric states is examined for transfermium nuclei with neutron number N = 153. It is shown that K-mixing of states sharply increases if the isomeric state closely approaches the rotational state with the same angular momentum, but built on another quasiparticle state. The model explains three order of magnitude enhancement of the decay rate of the K^π = 7=2⁺ isomeric state in ²⁵¹Cf, in comparison with decay of the similar state in ²⁴⁹Cm. Proposed mechanism is of general importance for the isomer decay properties in a wide range of heavy oddmass nuclei