Non-diffractive mechanisms in the φ-meson photoproduction on nucleons

We examine the non-diffractive mechanisms in the φ-meson photoproduction from threshold up to a few GeV using an effective Lagrangian in a constituent quark model. The new data from CLAS at large angles can be consistently accounted for in terms of s- and u-channel processes. Isotopic effects arising from the reactions γp→φp and γn→φn, are investigated by comparing the cross sections and polarized beam asymmetries. Our result highlights an experimental means of studying non-diffractive mechanisms in φ-meson photoproduction.