Regge Poles inπNScattering and inπ+π→N+N¯

We introduce the Regge-Froissart continuations of various partial-wave amplitudes for $\pi N$ scattering into the complex $J$ plane. The notion of $J$ parity is clarified by considering parity nonconservation. The analyticity and symmetry properties of the Regge-Froissart continuation in the energy plane are also studied and the results of analysis applied to backward pion-proton scattering. A similar discussion is given of the $\pi +\pi \to N+\overline{N}$ channel and the forward elastic pion-proton scattering.