Measurement of the Charm Structure Function and Its Role in Scale Noninvariance

Abstract
From a sample of 20 072 dimuon final states, a first determination of the structure function F2(cc¯) for diffractive charmed-quark pair production by 209-GeV muons is obtained. F2(cc¯) has a ν dependence similar to that of the photon-gluon fusion model, but its Q2 dependence peaks at lower Q2. Diffractive charm production accounts for 13 of the scale noninvariance observed in muon-nucleon scattering at low values of the Bjorken x variable, xB.