Long-Lived Isomeric States And Quasiparticle Band Structures In Neutron-Rich Gd-162,Gd-164 Nuclei From Beta Decay

Neutron-rich nuclei Eu-162,Eu-164 were produced by bombarding a proton beam on a U-238 target at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory and mass separating the (EU)-E-162,164 products. New level schemes and new gamma-ray transitions of the daughters Gd-162,Gd-164 were identified from beta-decay spectroscopy studies. Half-lives of the (EU)-E-162,164 were remeasured to clarify the previous ambiguous results. Two quasiparticle band structures were built and compared with neighboring nuclei. The beta and gamma bands were extended in Gd-162 and a gamma band was extended in Gd-164. Half-lives of the isomeric states at (6(-)) 1449 keV in Gd-162 and (4(-)) 1096 keV in Gd-164 were measured to be 99(3) mu s and 0.56(3) mu s, respectively. Projected shell model calculations were performed and found to be in good agreement with all of the experimental data.