Long-lived isomeric states and quasiparticle band structures in neutron-rich Gd162,164 nuclei from β decay

Neutron-rich nuclei162,164Eu were produced by bombarding a proton beam on a238Utarget at the Holifield Ra-dioactive Ion Beam Facility at Oak Ridge National Laboratory and mass separating the162,164Eu products. Newlevel schemes and newγ-ray transitions of the daughters162,164Gd were identified fromβ-decay spectroscopystudies. Half-lives of the162,164Eu were remeasured to clarify the previous ambiguous results. Two quasiparticleband structures were built and compared with neighboring nuclei. Theβandγbands were extended in162Gd andaγband was extended in164Gd. Half-lives of the isomeric states at (6−) 1449 keV in162Gd and (4−) 1096 keVin164Gd were measured to be 99(3)μs and 0.56(3)μs, respectively. Projected shell model calculations wereperformed and found to be in good agreement with all of the experimental data.