A Contribution of Photon Hadronic Component in the Leptoproduction Charmed Structure Function at Large x and Q^2

Abstract

We calculated the contribution of the photon hadronic component in the charmed structure function of the leptoproduction. The contribution comes from scattering of the c quarks of the virtual photon on the quarks and gluons of the proton. Comparison of our calculations with the measurements of the charm production in ${\mu }^{+}p$-scattering by EMC shows, that contribution of resolved photon can explain the excess of EMC data over the predictions of the photon-gluon fusion model at large momentum transfers. Thus, one does not need to use a non-perturbative admixture of the charmed quarks in the proton wave function (''intrinsic charm'') to describe such an excess in EMC data.

Comments: 18 pages, 2 PostScript figures, Latex2e. In new version two misprints in references corrected