Quarkonium plus prompt-photon associated hadroproduction and nuclear shadowing

TL;DR

This paper investigates how quarkonium plus prompt-photon production in high-energy collisions can reveal nuclear gluon distribution effects, especially shadowing, using NRQCD formalism to analyze transverse momentum dependencies.

Contribution

It introduces a detailed study of nuclear effects on quarkonium plus photon production, focusing on shadowing impacts within the NRQCD framework at high energies.

Findings

Nuclear shadowing significantly affects JPsi + photon production.

Transverse momentum dependence reveals shadowing/antishadowing effects.

Results help constrain nuclear gluon distributions in proton-nucleus collisions.

Abstract

The quarkonium hadroproduction in association with a photon at high energies provides a probe of the dynamics of the strong interactions as it is dependent on the nuclear gluon distribution. Therefore, it could be used to constrain the behavior of the nuclear gluon distribution in proton-nucleus and nucleus-nucleus collisions. Such processes are useful to single out the magnitude of the shadowing/antishadowing effects in the nuclear parton densities. In this work we investigate the influence of nuclear effects in the production of JPsi + photon and Upsilon + photon and estimate the transverse momentum dependence of the nuclear modification factors. The theoretical framework considered in the JPsi (Upsilon) production associated with a direct photon at the hadron collider is the non-relativistic QCD (NRQCD) factorization formalism.