Estimation of production in ep process near threshold

The near-threshold photo-productions of heavy quarkonia are important ways to test the QCD-inspired models and to constrain the gluon distribution of nucleon in the large x region. Investigating the various models, we choose a photon–gluon fusion model and a pomeron exchange model for photo-production near threshold, emphasising on the explanation of the recent experimental measurement by GlueX at JLab. We find that these two models are not only valid in a wide range of the center-of-mass energy of and proton, but also can be generalized to describe the photo-production. Using these two models, we predict the electro-production cross-sections of at EicC to be 48 fb to 85 fb at the center-of-mass energy of 16.75 GeV.