How Dirac-sea quarks affect the neutron charge distribution

The charge distribution of the neutron is investigated on the basis of a chiral quark-soliton model with full inclusion of the Dirac-sea quark degrees of freedom. This analysis demonstrates in the most transparent fashion that the effect of sea quarks incorporated in this model can be identified with that of a pion cloud surrounding the core of three valence quarks. We also analyze some other interesting observables which seem to indicate an isospin-asymmetric sea in the nucleon. These include the ratio of the anti uu to anti dd condensates in the proton, and the Gottfried sum recently measured by the New Muon Collaboration. (orig.)