Within the unitary πNN theory with Δ excitation, the effect of πd and πNN production channels on NN elastic scattering is examined. It is shown that the two-body coupled-channel method, which has been widely employed to study the Δ excitation in intermediate-energy NN scattering, is a valid approximation. Our results indicate that the difficulty encountered by the meson-exchange theory in understanding the NN data up to 1 GeV cannot be resolved within the model based on the one-pion-exchange Δ excitation mechanism.
- Received 22 July 1985
- Published in the issue dated December 1985
© 1985 The American Physical Society