Triplet np final state interactions at large momentum transfers

Using the simple relation between the np scattering and bound state wave functions, the spin-triplet contributions to the pp → π+(pn) and backward dp → p(pn) reactions are estimated for low np excitation energies. The good agreement with the pion production data at 400 and 450 MeV over a range of angles shows that spin-singlet final states cannot be more than of the order of 10%. On the other hand it is seen that the spin-singlet states must provide about 30% of the strength in pion production at 1 GeV as well as deuteron-proton backward scattering at 1.6 GeV.