“Investigation of isomeric states in 255Rf”

Using the GABRIELA detector array, γ-ray and internal-conversion-electron decay spectroscopy has been performed on 255Rf nuclei that were produced via the 207Pb(50Ti,2n)255Rf fusion-evaporation reaction using the SHELS velocity filter. Three isomers were identified in 255Rf with the aid of Geant4 simulations. The existence of two high-K isomeric states in cascade has been confirmed. Possible three-quasiparticle configurations involving the coupling of the unpaired 9/2−[734] neutron to two-quasiparticle states have been suggested and a likely decay scenario has been proposed on the basis of comparisons to Geant4 simulations. The simulations have also confirmed the existence of the 5/2+[622] spin isomer at low excitation energy.