Bound-valence-quark contributions to hadron structure functions

The conventional separation of "valence"- and "sea"-quark distributions of a hadron implicitly assumes that the quark and antiquark contributions to the sea are identical in shape, although this cannot be strictly correct due to the exclusion principle. A new separation of "bound-valence"- and -"non-valence"- quark distributions of a hadron is proposed which incorporates the Pauli principle and relates the valence component to the wave functions of the bound-state valence constituents. With this new definition, the non-valence-quark distributions correspond to structure functions which would be measured if the valence quarks of the target hadron were chargeless. The bound-valence-quark distributions are not singular at small $x$, thus allowing for the calculation of sum rules and expectation values which would otherwise be divergent.