Photoproduction of e⁺e^-, q-ω mixing and vector dominance

We discuss the ρ{variant}-ω mixing, in particular with respect to its possible effect on the invariant-mass spectrum of electron-positron pairs photoproduced off a nuclear target [1,2]. We find that with the order of magnitude of the mixing indicated by recent experiments, observing it in other processes [3,4] would yield a significant effect on the e⁺e^- photoproduction. We emphasize the necessity for a consistent analysis of all channels in evaluating the mixing effect.