The impact of the intrinsic charm quark content of a proton on the differential $\gamma +c$ cross section

Abstract

We present a comparative analysis of the impact of the non-perturbative intrinsic charm quark content of the proton on differential cross section of γ + c-jet in pp and pp collisions, for the kinematic regions that are sensitive to this contribution. We discuss the Q 2 evolution of intrinsic quark distributions at the next-to-leading order (NLO) and present a code which provide these distributions as a function of x and Q 2 for any arbitrary Fock state probability. For the pp collisions at the Tevatron, the results are compared with the recent experimental data of D0 at √ s = 1.96 TeV and also predictions for pp collisions at √ s = 8 TeV and √ s = 13 TeV for the LHC.

CT14 intrinsic charm parton distribution functions from CTEQ-TEA global analysis

“…Our conclusion at the moment is that the LHC inclusive W and Z production cross sections may provide helpful correlated constraints on m c and x IC in the future. We may also consider more exclusive scattering processes [120][121][122][123][124][125][126][127]129] to look for evidence of the IC in the LHC environment.…”

Parton distribution functions and constraints on the intrinsic charm content of the proton using the Brodsky-Hoyer-Peterson-Saka approach

“…In our previous results, we have shown the differential cross section of γ + c-jet is sensitive to intrinsic charm contribution [54]. In the near future, we will investigate the role of IC contributions in other processes, such as γ + c/b, and Z/W + c/b production cross section measurements in pp collisions at the LHC.…”

“…(5) we can fix the P cc/p value with 1%, which is only included in the intrinsic part of above equation, or can be considered as a free parameter. It should be noted that the extrinsic charm generated perturbatively using the DGLAP evaluation equation and the intrinsic charm evolve by a non-singlet evaluation equation [54].…”

“…The impact of IC contributions for the prediction of γ + cjet production in pp collisions at the LHC is reported in Ref. [54], where this impact for large p γ T can be distinguished from the case in which the IC contribution is not considered. Without considering IC contribution, the D0 data for γ + c-jet differential cross section [55] can not be described by solely using an extrinsic charm PDF based on the DGLAP evolution equation.…”

Summary of WG1: Structure functions and parton densities

“…There was a presentation of intrinsic charm based on [35], which looked at the impact on the differential γ + c cross section, showing this could be significant. Intrinsic charm was also discussed as part of a NNPDF study [36], where it is determined from a fit to heavy flavour distributions, on top of that generated dynamically from the gluon and light quarks via evolution.…”