An investigation of a possible hard contribution to φ photoproduction

We investigate the possibility that the process of φ photoproduction may have a significant hard perturbative QCD component. This suggestion is based on a study of the energy dependence of the forward φ photoproduction cross section followed by a calculation where we show that a coherent sum of the pQCD and conventional soft Pomeron contributions provides an excellent reproduction of the experimental data. Our results suggest that the transition from the predominantly soft photoproduction of light ρ and ω vector mesons to the predominantly hard photoproduction of heavy J/Ψ and ϒ is smooth and gradual, similar to the transition observed in deep inelastic scattering studies of the proton structure function in the small x limit. Our predictions for higher HERA energies are presented.