6533b861fe1ef96bd12c42ee

RESEARCH PRODUCT

Precision measurements of proton emission from the ground states ofTa156andRe160

subject

description

The decays of the $\ensuremath{\pi}{d}_{3/2}$ ground states of $^{156}\mathrm{Ta}$ and $^{160}\mathrm{Re}$ have been studied in detail using the GREAT spectrometer. More than 7000 $^{160}\mathrm{Re}$ nuclei were produced in reactions of 290- and 300-MeV $^{58}\mathrm{Ni}$ ions with an isotopically enriched $^{106}\mathrm{Cd}$ target and separated in flight using the RITU separator. The proton and $\ensuremath{\alpha}$ decays of the $\ensuremath{\pi}{d}_{3/2}$ level were confirmed and the half-life and branching ratios of this state were determined with improved precision to be ${t}_{1/2}=611\ifmmode\pm\else\textpm\fi{}7$ $\ensuremath{\mu}$s and ${b}_{\mathrm{p}}=89\ifmmode\pm\else\textpm\fi{}1%$ and ${b}_{\ensuremath{\alpha}}=11\ifmmode\pm\else\textpm\fi{}1%$, respectively. The $\ensuremath{\alpha}$-decay branch populated the ground state of $^{156}\mathrm{Ta}$, allowing improved values for the proton-decay energy and half-life to be obtained (${E}_{p}=1011\ifmmode\pm\else\textpm\fi{}5$ keV; ${t}_{1/2}=106\ifmmode\pm\else\textpm\fi{}4$ ms). The $\ensuremath{\beta}$ decay of this level was identified for the first time and a branching ratio of ${b}_{\ensuremath{\beta}}=29\ifmmode\pm\else\textpm\fi{}3%$ was deduced. The spectroscopic factors deduced from these measurements are compared with predictions.