NONLOCAL QUARK CONDENSATE FOR THE NUCLEON SEA-QUARK DISTRIBUTION

The intrinsic small-x quark distribution of the nucleon, which we iden tify as the sea-quark distribution, is calculated using the QCD sum ru le method with nonlocal quark condensates. With nonlocal condensates t he vacuum quarks carry a distribution of momenta, which is needed to b e consistent with the empirical sea-quark distribution. We find an iso spin symmetric seaquark distribution coming from the vacuum quarks wit h isospin symmetric condensates [: <(u)over bar u> :] = [: <(d)over ba r d> :]. We show that the euclidean correlation of the vacuum quarks i s crucial to the intrinsic sea-quark distribution, and that monopole-t ype space-time correlations in the nonlocal quark condensate can provi de such momentum distributions of the vacuum quarks.