Scaling violations in deep inelastic lepton scattering: how important is charm

The authors question the present belief, based on QCD calculations in the lowest order of the quark-gluon coupling constant, that the production of heavy quarks does not significantly contribute to the observed scaling violations in deep inelastic lepton scattering. It is estimated that the contribution to charm production of the fusion of charmed quarks, from fragmentation of the virtual photon, with valence quarks in the target exceeds the QCD estimates by roughly one order of magnitude. A 2=4 μb charm contribution to the γp total cross section at Fermilab energies is calculated and the level of photoproduction of strange particles when applying the calculation to strange quarks, is accomodated. (Auth.)