γ-ray spectroscopy of a four-quasiparticle isomer band in 174Re

Excited states in 174Re have been populated in fusion-evaporation reactions at the Australian National University, and γ-ray spectroscopy has been used to determine the level structure and to deduce the underlying nucleon configurations. The half-life of the bandhead of the Kπ=8−band has been measured to be 2.7(4) ns. A band built on an isomeric state of spin-parity (14−) and a half-life of 53(5) ns has been observed here for the first time, and has been determined to have a four-quasiparticle structure. Contrasting reduced-hindrance values for its decay are discussed in terms of deformation and configuration changes, as indicated by configuration-constrained potential energy surface calculations.The technical staff at the ANU 14UD accelerator facility are thanked for their excellent support. Funding is acknowledged from the UK Science and Technology Facilities Council under Grant No. ST/P005314/1Support for the ANU Heavy Ion Accelerator Facility operations through the Australian National Collaborative Research Infrastructure Strategy (NCRIS) program is acknowledged