NNLO QCD predictions for Z-boson production in association with a charm jet within the LHCb fiducial region

TL;DR

This paper presents NNLO QCD calculations for Z-boson production with a charm jet at the LHC, improving theoretical precision and aiding in probing the proton's intrinsic charm content.

Contribution

The work provides the first NNLO QCD predictions for Z + charm jet production in the LHCb fiducial region, enhancing accuracy and reducing uncertainties compared to previous NLO results.

Findings

NNLO corrections reduce theoretical uncertainties by a factor of two.

Perturbative convergence is improved with a transverse momentum constraint.

Predictions are compatible with NLO within uncertainties.

Abstract

We compute next-to-next-to-leading order (NNLO) QCD corrections to neutral vector boson production in association with a charm jet at the LHC. This process is studied in the forward kinematics at $\sqrt{s}=13$ TeV, which may provide valuable constraints on the intrinsic charm component of the proton. A comparison is performed between fixed order and NLO predictions matched to a parton shower showing mutual compatibility within the respective uncertainties. NNLO corrections typically lead to a reduction of theoretical uncertainties by a factor of two and the perturbative convergence is further improved through the introduction of a theory-inspired constraint on the transverse momentum of the vector boson plus jet system. A comparison between these predictions with data will require an alignment of a flavour-tagging procedure in theory and experiment that is infrared and collinear safe.