Search for New Radioactivities at the Proton Drip-Line

A major achievement in the study of nuclei far from stability has been the observation of new radioactive modes 1. Besides broadening the scope of reported nuclear processes, new radioactive modes provide specific structure information. Among them, direct emission of more than one nucleon carries unaltered informations on nuclear correlations. The simplest case is the long-predicted and not yet observed: direct two-proton radioactivity. At the proton drip-line, it might happen that a nucleus is bound by a one-proton emission but is able to decay by the direct emission of two protons. This process, discussed long time ago by Goldanski 2 and Janecke 3 is governed by barrier penetration.