Exclusive heavy vector meson photoproduction in $pp$ and $pPb$ collisions within the GPD approach: A phenomenological analysis

TL;DR

This paper analyzes exclusive $J/$ and $$ photoproduction in $pp$ and $pPb$ collisions at LHC energies using the GPD approach, comparing linear and nonlinear gluon evolution models.

Contribution

It applies the GPD framework with the GK model to estimate cross sections and distributions, including nonlinear gluon effects, for the first time in this context.

Findings

Nonlinear corrections significantly affect the predicted cross sections.

Predictions depend strongly on the gluon distribution parametrization.

The factorization scale choice influences the results.

Abstract

The exclusive $J/\psi$ and $\Upsilon$ photoproduction in proton - proton ($pp$) and proton - lead ($pPb$) collisions at the LHC energies is investigated using the Generalized Parton Distribution (GDP) approach. Assuming the Goloskokov - Kroll (GK) model, we estimate the corresponding total cross - sections and rapidity distributions considering different parametrizations for the unpolarized gluon distribution of the proton. In particular, we compare the linear predictions, associated with DGLAP evolution, with those derived taking into account of the leading nonlinear corrections resulting from gluon recombination. The dependence of our predictions on the choice for the factorization scale is discussed.