Reanalysis of the EMC charm production data with extrinsic and intrinsic charm at NLO

TL;DR

This work reanalyzes EMC DIS charm data by incorporating recently available NLO exclusive EC distributions and NLO IC contributions, comparing both to the charm structure function $F_2(x,Q^2,m_c^2)$ and to EMC measurements. Using mass-sensitive kinematics and modern PDFs, the study finds that EC alone cannot account for the observed large-$x$ charm signal, requiring a small intrinsic charm component in the proton. A two-component fit places a tentative IC fraction around 0.86% in the highest-ν bin, with sizable uncertainties, highlighting the need for an experimental confirmation of IC. The results underscore the importance of NLO corrections and proper scale choices when disentangling EC and IC contributions in DIS charm production.

Abstract

A calculation of the next-to-leading order exclusive extrinsic charm quark differential distributions in deeply inelastic electroproduction has recently been completed. Using these results we compare the NLO extrinsic contributions to the charm structure function $F_2(x,Q^2,m_c^2)$ with the corresponding NLO intrinsic contributions. The results of this analysis are compared with the EMC DIS charm quark data and evidence for an intrinsic charm component in the proton is found.