We propose a method which allows the inclusion of exclusive heavy vector-meson production data at low x in future global parton analyses. As an example we perform a study within xFitter to determine the gluon parton distribution function (PDF) at next-to-leading order (NLO) at moderate-to-low x using the measurements of exclusive J/ψ production in ep and pp collisions from HERA and LHC. We further study the constraints from the corresponding Υ production process. We finish by discussing the possible effects at next-to-next-to-leading order (NNLO) through incorporation of a K factor for the exclusive heavy vector-meson coefficient function at NLO.
@article{arxiv.2408.01128,
title = {A method to include exclusive heavy vector-meson production data at small $x$ in global parton analyses},
author = {C. A. Flett and A. D. Martin and M. G. Ryskin and T. Teubner},
journal= {arXiv preprint arXiv:2408.01128},
year = {2025}
}