JYFL-ACCLAB-M15 Decays of Isomeric States near the Proton Drip Line

This proposal requests beam time to discover and measure the decay properties of high-spin multiparticle isomeric states in the spherical proton emitters 155Ta82 and 156Ta83. The measurements will firmly establish the properties of new isomers and their decay paths to lower-lying states and allow the decay properties of the known proton-emitting states in these nuclei to be measured with higher precision. The proposed experiment will also search for the anticipated 27/2- isomer in 155Hf83 and measure the isomer half-life. This will allow the dependence of B(E2) values on the occupation of the (pi)h11/2 sub shell to be extended towards the proton drip line and provide valuable constraints for shell model calculations. We will also use these measurements to assess the feasibility of measuring the rare two-proton radioactive decay mode from isomers in heavy nuclei by searching for the 10+ seniority isomer in 156W82.