Excited states in the proton-unbound nuclide ^{158}Ta

the neutron-deficient odd-odd proton-unbound nuclide 158 Ta have been investigated in two separate experiments. In the first experiment, 166 Ir nuclei were produced in the reactions of 380 MeV 78 Kr ions with an isotopically enriched 92 Mo target. The α -decay chain of the 9 + state in 166 Ir was analysed. Fine structure in the α decay of the 9 + state in 162 Re established a 66 keV difference in excitation energy between the lowest-lying 9 + and 10 + states in 158 Ta. Higher-lying states in 158 Ta were populated in the reactions of 255 MeV 58 Ni ions with an isotopically enriched 102 Pd target. Gamma-ray decay paths that populate, depopulate and bypass a 19 − 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.