Charm in the Nucleon

Abstract

A next-to-leading order analysis of inelastic electroproduction of charm is performed using an interpolating scheme which maps smoothly onto massless QCD evolution at large Q^2 and photon-gluon fusion at small Q^2. In contrast with earlier analyses, this scheme allows the inclusion of quark and target mass effects and heavy quark thresholds, as well as possible non-perturbative, or intrinsic, charm contributions. We find no conclusive evidence in favor of an intrinsic charm component in the nucleon, although several data points which disagree with perturbative QCD expectations will need to be checked by future experiments.