Perturbative QCD analysis of near threshold heavy quarkonium photoproduction at large momentum transfer

We apply perturbative QCD to investigate the near threshold heavy quarkonium photoproduction at large momentum transfer. From an explicit calculation, we show that the conventional power counting method will be modified and the three quark Fock state with nonzero orbital angular momentum dominates the near threshold production. It carries a power behavior of 1/(-t)(5) for the differential cross section. We further comment on the impact of our results on the interpretation of the experiment measurement in terms of the gluonic gravitational form factors of the proton. (C) 2021 The Author(s). Published by Elsevier B.V.

Automated summary

The study applies perturbative QCD to investigate near-threshold heavy quarkonium photoproduction at large momentum transfer. It reveals a modified power counting method and the dominance of the three quark Fock state with nonzero orbital angular momentum. The results have significant implications for the interpretation of experiment measurements in terms of the gluonic gravitational form factors of the proton.