MEASUREMENT OF THE CHARM STRUCTURE FUNCTION AND ITS ROLE IN SCALE-NONINVARIANCE

From a sample of 20072 dimuon final states, a first determination of the structure function F/sub 2/(cc-bar) for diffractive charmed-quark pair production by 209-GeV muons is obtained. F/sub 2/(cc-bar) has a ..nu.. dependence similar to that of the photon-gluon fusion model, but its Q/sup 2/ dependence peaks at lower Q/sup 2/. Diffractive charm production accounts for approx.1/3 of the scale noninvariance observed in muon-nucleon scattering at low values of the Bjorken x variable, x/sub B/.