Formalism for the systematic solution of the low-energy pion-trinucleon scattering problem

We present a systematic representation of the low-energy pion-trinucleon scattering problem derived from a reduction of the exact four-body formulation which is due to Haberzettl and Sandhas. This method removes many of the difficulties usually associated with the assignment of the parametric energy of pion-nucleon scattering in the pion-trinucleon center of mass which occur in the traditional optical potential approach based on multiple-scattering theories. In the present formulation both the pion-nucleon and nucleon-nucleon interactions provide the dynamical input and the quasideuteron mechanism appears naturally as a low-order approximation in our approach