Proton-proton correlations observed in two-proton decay of 19Mg and 16Ne

Proton-proton correlations were observed for the two-proton decays of the ground states of Mg-19 and Ne-16. The trajectories of the respective decay products, Ne-17 + p + p and O-14 + p + p, were measured by using a tracking technique with microstrip detectors. These data were used to reconstruct the angular correlations of fragments projected on planes transverse to the precursor momenta. The measured three-particle correlations reflect a genuine three-body decay mechanism and allowed us to obtain spectroscopic information on the precursors with valence protons in the sd shell.