Testing the nuclear TMD gluon densities with heavy flavor production in proton-lead collisions at LHC

TL;DR

This paper models nuclear modifications of gluon and quark distributions in nuclei using a global analysis and tests these models against LHC data on heavy flavor production, providing insights into nuclear parton densities.

Contribution

It introduces a simple model for nuclear TMDs based on the rescaling approach and validates it with CMS data, offering a new way to study nuclear modifications of parton densities.

Findings

Nuclear modification factors are predicted to be 0.8-1.2 in relevant kinematic regions.

Model predictions are consistent with existing estimations.

Applying different cuts on final states can help investigate nuclear modifications.

Abstract

We employ a simple model for nuclear modification of ordinary parton densities in a proton to evaluate the Transverse Momentum Dependent gluon and quark distributions in nuclei (nTMDs) within the popular Kimber-Martin-Ryskin/Watt-Martin-Ryskin approach. The model is based on a global analysis of available deep inelastic scattering data for different nuclear targets within the rescaling model, incorporating Fermi motion effects. The derived nTMDs are tested with latest CMS data on inclusive $b$-jet and $B^+$ meson production in proton-lead collisions collected at $\sqrt s = 5.02$ and $8.16$~TeV using the High Energy Factorization framework. We predict the corresponding nuclear medium modification factors to be about of $0.8 - 1.2$ in the probed kinematical region, which is consistent with other estimations. Specially we highlight a possibility to investigate the nuclear modification of parton densities by applying different cuts on the final states in such processes.