Deep-inelastic electroproduction and the Q2 behavior of the J = 0 fixed pole

We construct a resonance model for deep-inelastic electroproduction on nucleons in which νW₂ shows explicit Regge behavior. The extrapolation of the full expression for νW₂ to the low-ω′ and fixed-Q² region provides a rather accurate average to the resonances in the sense of certain finite-energy sum rules. The residues of the proton and neutron J=0 fixed poles are computed as functions of Q² turning out to be nonpolynomial, and as Q²→0 they approach the well-known photoproduction values. The neutron residue never becomes greater than zero, while the proton residue changes sign at Q²=0.08 GeV². We finally obtain an interesting expression for the limiting value of the excitation vertex radius, i.e., $〈r^2〉=\left(\frac{3}{4{\pi }^2\alpha }\right)\left[\frac{{\sigma }_T^{\gamma N}(\infty )}{F_2(\infty )}\right]$.