Exclusive photoproduction of $\Phi$ on Proton in the quark-diquark model

Abstract

We present predictions for the exclusive photoproduction of $\Phi$-meson on Proton at large tranfer, where we use a quark-diquark structure model for the proton. Extrapolation from our results to lower tranfers is comparable in magnitude with available data in that range. This may support the diquark model in its ability to provide, for that process, an appropriate link between diffractive physics at low transfer and the standard semi-perturbative approach of hard exclusive processes at very large tranfer, where the proton recovers its three-quark structure.

Comments: 24 pages, RevTex, 3 Figures.ps