Decay of the high-K isomeric state to a rotational band in (257)Rf

The (257)Rf isotope has been populated via the Pb-208(Ti-50, n) fusion-evaporation reaction and delayed gamma-ray and electron decay spectroscopy has been performed. The existence of a high-K isomeric state in (257)Rf has been confirmed. The isomeric state decays into a rotational band based on the 11/2(-)[725] excitation, which was observed up to spin of (23/2(-)). Three multipolarity-E1 gamma transitions depopulating the isomeric state have been observed, which fixes the spin for that state to (21/2(+)). This assignment agrees with theoretical predictions calculated with the microscopic-macroscopic approach, which suggest the isomeric state to be formed by coupling an unpaired 11/2(-)[725] quasineutron to the (1/2(-)[521] circle times 9/2(+)[624])(5)- two-quasiproton state. The same two-quasiproton excitation is possible for the lowest isomer in (256)Rf.Physics, NuclearSCI(E)4ARTICLE4null8