First observation of two-proton radioactivity from an atomic nucleus

Nature uses radioactivity to gain stability for an unstable atomic nucleus. The discovery of radioactivity is considered the starting point of nuclear physics. The classical types of radioactivity, α, β, γ decay and nuclear fission, have allowed for many detailed studies of nuclear structure and have found a wide range of applications in other fields of science. According to theoretical predictions, other types of nuclear transformation should occur for very short lived atomic nuclei. In recent experiments at the GANIL and GSI laboratories, two-proton radioactivity was observed for the first time in the decay of proton-rich 45Fe. (authors)