In-beam γ-ray spectroscopy above<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">Sn</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow/><mml:mrow><mml:mn>100</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>using the new technique of recoil decay tagging

A novel method of selecting \ensuremath{\gamma}-ray transitions in heavy nuclei (A&gt;100) at the proton drip-line has been attempted. The characteristic charged-particle radioactivity of these nuclei (alpha decay, ground-state proton decay, and \ensuremath{\beta}-delayed proton emission) has been used to tag \ensuremath{\gamma}-ray transitions recorded by the highly efficient Eurogam spectrometer. The $^{58}\mathrm{Ni}$${+}^{54}$Fe and $^{58}\mathrm{Ni}$${+}^{58}$Ni fusion-evaporation reactions, at a beam energy of 240 MeV, have been used to populate specific states of these neutron-deficient nuclei and results are presented for $^{108,109}\mathrm{Te}$, $^{109}\mathrm{I}$, and $^{113}\mathrm{Xe}$, where \ensuremath{\gamma}-ray transitions have been identified. In the case of $^{109}\mathrm{I}$, this represents the first observation of \ensuremath{\gamma}-rays from a ground-state proton emitter.