NUCLEON-NUCLEON-SCATTERING ABOVE THE PION-PRODUCTION THRESHOLD

Starting from a simple nonrelativistic field theory of pions and nucleons, we derive linear integral equations coupling amplitudes of baryon number equal two systems. These equations guarantee two- and three-body unitarity above the threshold for single pion production, and include explicity the coupling of the NN to (e.g.) N Δ and πd channels. The relationship of this approach to earlier schemes is discussed. NUCLEAR REACTIONS Nucleon-nucleon scattering. Derived coupled equations for NN, N Δ, πd with heavy-boson exchange and NNπ vertex as input. © 1979 The American Physical Society.