Phenomenology of diphoton photoproduction at next-to-leading order

We develop the analysis of diphoton exclusive photoproduction in the kinematics where a collinear QCD factorization framework applies, namely nearly forward large invariant mass diphoton production. We work at the leading twist level and at the next-to-leading order (NLO) in the strong coupling constant alpha(S). We compare our predictions for cross sections with Born order calculations for the experimental conditions accessible to JLab experiments and show the interesting sensitivity of our results to various models of generalized parton distributions (GPDs). The NLO corrections are rather large and negative but do not prevent the studied reaction from being a promising tool for the extraction of C-odd GPDs, which do not contribute to either spacelike or timelike deeply virtual Compton scattering amplitudes.

Automated summary

This study focuses on diphoton exclusive photoproduction in the kinematics where collinear QCD factorization framework applies. The results show that the predictions for cross sections are sensitive to various models of generalized parton distributions (GPDs). Despite the large and negative NLO corrections, the reaction studied remains a promising tool for extracting C-odd GPDs.