Experimental study of the decays of 112 Cs and 111 Xe

An experiment to search for the $\ensuremath{\alpha}$ decay of ${}^{112}$Cs has been performed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. The $\ensuremath{\alpha}$ decay of ${}^{112}$Cs was not observed, thus setting the upper limit of the $\ensuremath{\alpha}$ branching ratio at 0.26$%$. The half-life of ${}^{112}$Cs was measured as $506\ifmmode\pm\else\textpm\fi{}55\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}$s. In the same measurement the decay properties of its proton decay daughter ${}^{111}$Xe were also reinvestigated. The newly measured $\ensuremath{\alpha}$ branching ratio for ${}^{111}$Xe is $10.4\ifmmode\pm\else\textpm\fi{}1.9\phantom{\rule{0.16em}{0ex}}%$. The experimental proton separation energies ${S}_{p}$ for odd-$Z$ nuclei above ${}^{100}$Sn were compared to shell model calculations. The calculated proton separation energies for ${}^{103}$Sb and ${}^{102}$Sb point to half-lives of the order of 10 ps and 1 ns, respectively