Recoil-decay Tagging Spectroscopy Of74162w88

Excited states in the highly neutron-deficient nucleus $^{162}\mathrm{W}$ have been investigated via the $^{92}\mathrm{Mo}(^{78}\mathrm{Kr},{2\ensuremath{\alpha})}^{162}\mathrm{W}$ reaction. Prompt $\ensuremath{\gamma}$ rays were detected by the JUROGAM II high-purity germanium detector array and the recoiling fusion-evaporation products were separated by the recoil ion transport unit (RITU) gas-filled recoil separator and identified with the gamma recoil electron alpha tagging (GREAT) spectrometer at the focal plane of RITU. $\ensuremath{\gamma}$ rays from $^{162}\mathrm{W}$ were identified uniquely using mother-daughter and mother-daughter-granddaughter $\ensuremath{\alpha}$-decay correlations. The observation of a rotational-like ground-state band is interpreted within the framework of total Routhian surface (TRS) calculations, which suggest an axially symmetric ground-state shape with a $\ensuremath{\gamma}$-soft minimum at ${\ensuremath{\beta}}_{2}\ensuremath{\approx}0.15$. Quasiparticle alignment effects are discussed based on cranked shell model calculations. New measurements of the $^{162}\mathrm{W}$ ground-state $\ensuremath{\alpha}$-decay energy and half-life were also performed. The observed $\ensuremath{\alpha}$-decay energy agrees with previous measurements. The half-life of $^{162}\mathrm{W}$ was determined to be ${t}_{1/2}=990(30)$ ms. This value deviates significantly from the currently adopted value of ${t}_{1/2}=1360(70)$ ms. In addition, the $\ensuremath{\alpha}$-decay energy and half-life of $^{166}\mathrm{Os}$ were measured and found to agree with the adopted values.