Fermion--Pomeron interaction in a Reggeon field theory

A Reggeon field theory which describes the interaction of a Pomeron with a pair of fermions of opposite parity is studied using the renormalization group and the epsilon expansion. In the infrared limit a solution is found with a number of physically attractive features. The renormalized fermion trajectories are nearly proportional to u for small u even though the bare trajectories were proportional (for small u) to rootu. Furthermore, both renormalized parity poles are on the physical j-plane sheet for u < 0, but one of them moves under a cut for u > 0 and does not appear as a physical particle: all this despite the fact that the bare theory has physical fermions of both parities. Phenomenological implications for backward π-N scattering, and implications for the general structure of Reggeon field theories are also discussed