THE NONLOCAL OPERATOR EXPANSION FOR INCLUSIVE PARTICLE-PRODUCTION IN E+E- ANNIHILATION

We develop a unified operator formalism for studying both the deep inelastic scattering and the inclusive particle production in e+e- annihilation. The main ingredients are the stringlike nonlocal operators on the light-cone and the time-loop (Keldysh) diagram technique. Evolution of structure and fragmentation functions is obtained via the renormalization of a certain string operator. The structure of nonleading twist effects is outlined. In the case of deep inelastic scattering we come naturally to the concept of multiparton distribution functions and reproduce in this way earlier results by Jaffe. Further, we introduce the notion of a fragmentation function of higher twists and calculate in terms of them the 1/Q2 correction to the cross section of inclusive particle production in e+e- annihilation. Possible polarization effects are considered for the production of secondary baryons, including a specific twist-three contribution.