A study of single pion production in nucleon-nucleon collisions

A pion exchange model for NN pion production from threshold up to about 6 GeV/c is constructed. In contrast to other models of this type the full information from πN scattering is fed in whereby the πN partial waves on- and off-shell are identified with each other. Detailed comparison with the data for both the channels isospin one and zero, reveals that the shapes of angle and momentum distributions are, in general, well reproduced but the overall magnitude comes out too small for p_L ? 1.5 GeV/c. It is argued that this defect may be due to dibaryon resonances. For reaction cross sections their effects are quantitatively estimated.