The search for high-energy deuterons in the3He+3He reaction

High-energy deuterons have been detected from the3He+3He reaction with a system sensitive to cross-sections of 0.6 nb sr−1. Several tests have permitted to evaluate the small contribution of spurious events. The deuterons are kinematically consistent with the reaction3He+3He→2H+4He+e++ν, but the measured cross-section at 20° laboratory is too high for a weak-interaction process: (1.3±0.3) nb sr−1. It might be due to an interaction of intermediate strength causing the decay of pp pairs (2He) into deuterons. Other alternatives and the implications concerning fusion processes and the production of neutrinos in the Sun are discussed in the text.