Fixed Poles in Compton Amplitudes, and the Pomeranchukon Coupling

The nonperturbative formulation of the parton model is used to discuss the Regge properties of current amplitudes at fixed $q^2$. It is shown that, in addition to $j=1\mathrm{}$ wrong-signature fixed poles due to third-spectral-function effects, there are further poles of this type associated with current-algebra anticommutators. The two types of poles combine additively with each other and multiplicatively with even-signature Regge poles. Their consequences for the coupling of the Pomeranchukon, for gauge invariance, and for deep-inelastic scattering are investigated. In particular, it is found that the coupling of the Pomeranchukon in the total cross section for photoproduction arises solely from the third-spectral-function effects and not from the current-algebra fixed pole; hence it cannot be calculated with present knowledge. The existence of a right-signature $j=0\mathrm{}$ fixed pole with residue linear in $q^2$ is also confirmed.