Proton radioactivity of medium heavy nuclei

For the proton radioactive nuclei /sup 109/I and /sup 113/Cs with decay energies of 0.83 MeV and 0.98 MeV the halflives have been measured as 109(17) μs and 33(7) μs respectively. These halflives are compared with calculations using the WKB approximation. The spectroscopic factors deduced are an order of magnitude smaller than expected for a pure d/sub 5/2/ single particle state of the emitter. For /sup 105/Sb a negative proton binding energy of B/sub P/ = -0.36(20) MeV could be established, but no proton radioactivity with T/sub 1/2/≥10 ns and E/sub P/≥0.5 MeV has been observed down to a cross section of 0.5 μb. In a search for proton radioactivity of /sup 108/I producd with the 54Fe(58Ni,p3n) reaction no new proton line was found. But the cross section limit of 5 μb reached cannot definitely rule out this possibility. With the reaction 40Ca(40Ca,p2n)/sup 77/Y direct proton emission was searched for in this region of well deformed nuclei. Assuming an L = 4 proton emission decay energies between 0.45 MeV and 0.90 MeV can be excluded