Resonances of any spin in pion photoproduction and nucleon Compton scattering

Describing the vertices by form factors and the propagators by their spectral representations, we calculate the contribution of the exchange diagramsγπ→M ^j→ ¯N N andγN→N ^j+1/2→γN to the invariant and helicity amplitudes, for meson (M _j) and baryon (N ^j+1/2) resonances of any spin (j integer ≧ 1) and both parities ((?)^j and (?)^j+1).