Parton degrees of freedom from the path-integral formalism - art. no. 074501

We formulate the hadronic tensor W-mu nu of deep inelastic scattering in th e path-integral formalism. It is shown that there are 3 gauge invariant and topologically distinct contributions. In addition to the valence contribut ion, there are two sources for the sea-one in the connected insertion and t he other in the disconnected insertion. The operator product expansion is c arried out in this formalism. The operator rescaling and mixing reveal that the connected sea partons evolve the same way as the valence; i.e., their evolution is decoupled from the disconnected sea and the gluon distribution functions. We explore the phenomenological consequences of this classifica tion in terms of the small x behavior, Gottfried sum rule violation, and fl avor dependence. In particular, we point out that in the nucleon (u) over b ar and (d) over bar partons have both connected and disconnected sea contri butions, whereas the (s) over bar parton has only the disconnected sea cont ribution. This difference between (u) over bar + (d) over bar and (s) over bar, as far as we know, has not been taken into account in the fitting of p arton distribution functions to experiments.