Identification of excited states in 167Os and 168Os: shape coexistence at extreme neutron deficiency Original Research Article

Excited states in the very neutron-deficient isotopes 167Os and 168Os have been observed using the reaction 112Sn(58Ni, 2pxn). The jurosphereγ-ray spectrometer array was used in conjunction with the ritu gas-filled recoil separator to collect prompt γ radiation in coincidence with recoils implanted in a silicon strip detector located at the focal plane of ritu. Using a selective recoil decay tagging technique it has been possible to unambiguously assign γ-ray transitions to 167Os and 168Os through the characteristic α radioactivity of these nuclides. The high-spin structure of the bands is discussed in terms of quasiparticle configurations within the framework of the cranked shell model. The role of shape coexistence in 168Os is examined with phenomenological three-band mixing calculations.