Heavy quark & direct photon production and heavy quark parton densities

TL;DR

This paper explores how direct photon and heavy quark production can inform the understanding of heavy quark distributions and the gluon nuclear PDF, considering models with intrinsic charm.

Contribution

It analyzes the impact of intrinsic charm models on the b3 + c cross section and discusses the potential of pA collisions to constrain the gluon nuclear PDF.

Findings

Intrinsic charm models affect b3 + c cross sections.

pA collisions can help constrain the gluon nuclear PDF.

Heavy quark production is a useful probe for parton distributions.

Abstract

Direct photon production in association with a heavy quark can serve as an excellent tool for the study of the heavy quark distributions. Currently it is believed that heavy quarks are produced radiatively inside the nucleon, and so there is no need to take into account heavy quark parameters inside global PDF analyses. Certain models taking into account the possibility of an intrinsic charm component exist. Here we present how these affect the \gamma + c cross section. While at pA collisions the potential of this process to constrain the gluon nuclear PDF which is currently largely unconstrained is presented.