Towards an automated tool to evaluate the impact of the nuclear modification of the gluon density on quarkonium, D and B meson production in proton-nucleus collisions

TL;DR

This paper introduces a simple, model-independent method to evaluate how nuclear modifications of gluon densities affect the production of quarkonium, D, and B mesons in proton-nucleus collisions, with applications to LHC data.

Contribution

The authors develop a novel, model-independent procedure to compute nuclear modification factors for heavy meson production using nuclear PDFs and proton-proton data constraints.

Findings

Computed nuclear modification factors for J/psi, Upsilon, and D^0 at LHC energies.

Extended the method to B meson production predictions.

Provided first predictions for eta_c nuclear modification in pPb collisions.

Abstract

We propose a simple and model-independent procedure to account for the impact of the nuclear modification of the gluon density as encoded in nuclear collinear PDF sets on two-to-two partonic hard processes in proton-nucleus collisions. This applies to a good approximation to quarkonium, D and B meson production, generically referred to H. Our procedure consists in parametrising the square of the parton scattering amplitude, A_{gg -> H X} and constraining it from the proton-proton data. Doing so, we have been able to compute the corresponding nuclear modification factors for J/psi, Upsilon and D^0 as a function of y and P_T at sqrt(s_NN)=5 and 8 TeV in the kinematics of the various LHC experiments in a model independent way. It is of course justified since the most important ingredient in such evaluations is the probability of each kinematical configuration. Our computations for D mesons can also be extended to B meson production. To further illustrate the potentiality of the tool, we provide --for the first time-- predictions for the nuclear modification factor for eta_c production in pPb collisions at the LHC.