Exclusive Vector Meson Electro-production In The Pomeron Exchange Model

Based on the Pomeron exchange model, elastic production of vector mesons in electron-proton interaction is investigated with both linear and non-linear Pomeron trajectory. The numerical calculations of differential cross section for vector meson J/ψ and (?) at different energies are performed. The effects of the energy scale S₀ and photon virtuality Q² on differential cross section are also studied. Our theoretical predictions for J/ψ electro-production are in good agreement with data. For J/ψ electro-production, our conclusions are that the Pomeron exchange model is a successful description of J/ψ electro-production, the dependence of the differential cross sections on Q² is negligible, the linear trajectory is a good approximation to non-linearity of the Pomeron trajectory, and the value of the energy scale parameter s₀ is dependent of the momentum transfer, namely its effect is moderate at low momentum transfer but it causes no difference at high momentum transfer, |t| ≥ 1.25GeV². At the same time, the theoretical predictions for (?) electro-production show that the dependence of the differential cross section on virtual photon virtuality, Q², is of moderation, the change of the energy scale parameter S₀ causes moderate effect on the differential cross section, and the linear trajectory is a good approximation to non-linearity of the Pomeron trajectory, in particular, at small momentum transfer region | t |< 0.2GeV².