T(T,2n)4He and 3He(3He,2p)4He: The Reaction Mechanism from Solar Energies to 10 MeV

We have studied the energy dependence of the reaction mechanism of the T(t,2n) 4 He reaction at stellar energies and of its charge symmetric analog reaction 3 He( 3 He,2p) 4 He at energies up 10 MeV. We find that the reaction mechanism changes dramatically over this energy range in part due to the interference of the two identical fermions in the three-body final state.