Two proton radioactivity of 19Mg as a genuine three-particle decay

Two-proton radioactivity is considered as a direct three-particle decay on example of the 19Mg nucleus which is still unobserved. The realistic three-body model calculations predict its half-life values up to 100 ps which is 1000 times longer than the life-time derived by the traditional diproton model. Specific observable, e.g. the p-p correlations from the 19Mg decay, differ drastically in predictions of these models as well. A possible radioactivity of 19Mg might be studied in a kinematically complete experiment detecting all fragments of 19Mg and the 17Ne+p+p coincidences. The experiment can be performed using a radioactive beam of 20Mg at intermediate energies. (orig.)