Proton-proton final state interaction in the p + 3He reaction

Abstract

The proton-proton final state interaction was studied using the 3He + p → d + p + p reaction both in single counter, kinematically “incomplete” ( E p = 30.2 and 46.0 MeV) and angular correlation, kinematically “complete” ( E p = 46.5 MeV) experiments. In the single counter experiment the angular dependence of the final state interaction was determined between ϑ lab = 10° and ϑ lab = 50°. A Watson-Migdal calculation was used to fit the experimental deuteron spectra near the high-energy cutoff; the calculated distributions obtained for a choice of reasonable parameters were found to be wider at the peak than the experimental data indicated. The angular correlation experiments were performed at counter settings at which the contributions from p-p final state interaction were expected to be relatively large; these particular experiments indicated: (i) that p-p final state interaction contributes significantly to the three-body process and, (ii) that the proton pair is preferentially emitted with an internal energy of E 2p ≈ 0.4 MeV. A Watson-Migdal calculation applied to the angular correlation experiments gave good agreement with the experimental results. An explanation for the difference in fitting single counter or angular correlation experiments is given.