Constraints on the intrinsic charm content of the proton from recent ATLAS data

TL;DR

This paper uses recent ATLAS data to set the first experimental upper limit on the intrinsic charm content in the proton, which is crucial for understanding proton structure and future collider physics.

Contribution

It provides the first constraints on the intrinsic charm probability in the proton using LHC data, highlighting the impact of theoretical and experimental uncertainties.

Findings

Upper limit on intrinsic charm probability: < 1.93% at 68% CL

Constraints mainly affected by theoretical scale and systematic uncertainties

Discussion on reducing uncertainties for future measurements

Abstract

Constraints on the intrinsic charm probability $\wccm = P_{{\mathrm{c}\bar \mathrm{c}} / \mathrm{p}}$ in the proton are obtained for the first time from LHC measurements. The ATLAS Collaboration data for the production of prompt photons, accompanied by a charm-quark jet in pp collisions at $\sqrt s = 8 $ TeV, are used. The upper limit \mbox{$\wccm < 1.93$~\%} is obtained at the 68~\% confidence level. This constraint is primarily determined from the theoretical scale and systematical experimental uncertainties. Suggestions for reducing these uncertainties are discussed. The implications of intrinsic heavy quarks in the proton for future studies at the LHC are also discussed.