Gluon PDF constraints from the ratio of forward heavy quark production at the LHC at \sqrt{S}=7 and 13 TeV

TL;DR

This paper demonstrates that the ratio of forward heavy quark production rates at 13 TeV to those at 7 TeV at the LHC can precisely constrain the gluon parton distribution function despite large absolute rate uncertainties.

Contribution

It introduces a method to use the ratio of heavy quark production rates at different energies to reduce theoretical uncertainties and improve gluon PDF constraints.

Findings

The ratio of production rates can be predicted with a few percent accuracy.

Absolute rate predictions are limited by large scale uncertainties.

The method enhances sensitivity to the gluon distribution function.

Abstract

We discuss production of charm and bottom quarks at forward rapidity in pp collisions at the LHC, updating the QCD predictions for the run at \sqrt{S}=13 TeV. We show that, while the absolute rates suffer from large theoretical systematics, dominated by scale uncertainties, the increase relative to the rates precisely measured at 7 TeV can be predicted with an accuracy of a few percent, sufficient to highlight the sensitivity to the gluon distribution function.