Measurement of A/sub N/ and A /sub NN/ for the reaction pp → dπ+ at six energies from 500 to 800 MeV

The values of A/sub n/ and A/sub nn/ for the reaction pp → dπ+ have been measured at six beam kinetic energies: 500, 600, 650, 700, 733, and 800 MeV. The angular distributions of the pion in the center of mass system range from 300 to 1100. The results indicate that A/sub nn/ is largely negative (approx.-1) for the entire energy region with a small minimum at THETAπ* = 900. It is seen that the large negative values for A/sub nn/ indicate the dominance of singlet-triplet transitions for this reaction at these energies and disagree strongly with a present phase shift analysis. The A/sub nn/ data also contain more angular dependence than predicted by present theoretical models but much less than that predicted by the phase shift analysis. A/sub n/ has a maximum vlaue of approximately +0.3 over this energy region with a rapidly changing minimum near THETAπ* = 900 which goes from -0.1 at 500 MeV to nearly the maximum at 650 MeV, back down to +0.2 at 800 MeV. These data indicate a smaller maximum value for A/sub n/ and more angular dependence than present theories predict