6533b838fe1ef96bd12a3d44

RESEARCH PRODUCT

Excited states in the proton-unbound nuclide Ta-158

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description

Excited states in the neutron-deficient odd-odd proton-unbound nuclide $^{158}\mathrm{Ta}$ have been investigated in two separate experiments. In the first experiment, $^{166}\mathrm{Ir}$ nuclei were produced in the reactions of 380 MeV $^{78}\mathrm{Kr}$ ions with an isotopically enriched $^{92}\mathrm{Mo}$ target. The $\ensuremath{\alpha}$-decay chain of the ${9}^{+}$ state in $^{166}\mathrm{Ir}$ was analyzed. Fine structure in the $\ensuremath{\alpha}$ decay of the ${9}^{+}$ state in $^{162}\mathrm{Re}$ established a 66 keV difference in excitation energy between the lowest-lying ${9}^{+}$ and ${10}^{+}$ states in $^{158}\mathrm{Ta}$. Higher-lying states in $^{158}\mathrm{Ta}$ were populated in the reactions of 255 MeV $^{58}\mathrm{Ni}$ ions with an isotopically enriched $^{102}\mathrm{Pd}$ target. Gamma-ray decay paths that populate, depopulate, and bypass a ${19}^{\ensuremath{-}}$ isomeric state have been identified. The general features of the deduced level scheme are discussed and the prospects for observing proton emission branches from excited states are considered.