A Theoretical Study of ρ0 Photoproduction on Nucleons Near Threshold

We investigate the possibility that the process of ρ0-meson photoproduction on proton, γ + p → p + ρ0, in the near threshold region Eγ < 2 GeV can be considered in the framework of model with π-, σ- and N-exchanges. This suggestion is based on a study of the t-dependence of differential cross section, dσ(γp → pρ0)/dt, which has been measured by SAPHIR Collaboration. We find that the suggested model provides a good description of the experimental data with new values of ρNN-coupling constants in the region of the time-like po-meson momentum. Our results suggest that such model can be considered as a suitable nonresonant background mechanism for the future discussion of possible role of nucleon resonance contributions. Our predictions for ρ0-meson photoproduction on neutron target and for beam asymmetry on both proton and neutron targets are presented. (author)