Diffractive interactions of photons with hadrons

Diffractive interactions of photons with hadrons are described by a model based on (a) vector-meson dominance for vertex functions and (b) the $f$-coupled Pomeranchukon. Compton scattering, total photoabsorption, and vector-meson production on hydrogen as well as on complex nuclei are treated. The approach preserves the good results of the conventional vector-dominance model while accounting for its failures in a way that does no violence to the basic principles. Agreement with experiment is obtained for the process mentioned. The central point is that the Pomeranchukon coupling in Compton scattering is nonzero because of the existence of a fixed pole at $J=1$, and that this pole has two distinct contributions to its residue. The contribution due to the third double-spectral function is naturally included in the usual vector-meson-dominance scheme; however, that due to the Born singularity is not included, so must be put in separately.