Nuclear effects in deep-inelastic lepton scattering

We present a detailed study of a conventional nuclear model in which the observed differences between the deep-inelastic structure functions of nuclei and of free nucleons, $F_2$(x,$Q^2$) and q¯(x,$Q^2$), are due to scattering from exchange pions in nuclei associated with the mechanisms responsible for nuclear binding. We assume that the quark and antiquark momentum distributions of these nucleons and pions are unaffected by the nuclear medium. We write the nuclear structure functions as a sum of convolutions of (measured) isolated-hadron structure functions with hadron momentum distributions derived from nuclear potential models. We show that all but one feature of deep-inelastic neutrino and charged-lepton data are reproduced by our model. The exception is the magnitude of the excess above unity of the ratio $F_2^A$(x)/$F_2^{\mathrm{D}\left(\mathrm{x}\right)}$ for x<0.2, observed only by the European Muon Collaboration (EMC) experiment. If these EMC data are reduced in normalization by 5%, consistent with experimental uncertainties, then all features of the data are reproduced. We stress the importance of new neutrino and muon measurements at small x.