PARTON INTERPRETATION OF THE NUCLEON SPIN-DEPENDENT STRUCTURE FUNCTIONS

We discuss the interpretation of the nucleon's polarized structure function g2(x). If the target state is represented by its Fock decomposition on the light cone, the operator-product expansion allows us to demonstrate that moments of g2(x) are related to overlap integrals between wave functions of opposite longitudinal polarizations. In the light-cone formalism such wave functions are related by the kinematical operator y, or light-cone parity. As a consequence, it can be shown that moments of g2 give information about the same parton wave function, or probability amplitude to find a certain parton configuration in the target which defines g1(x) or F2(x). Specific formulas are given, and possible applications to the phenomenology of the nucleon structure in QCD are discussed.