A comparison between the bilocal algebra on the light cone and the parton model

Abstract

The bilocal algebra on the light cone is used to obtain the structure functions for the reaction “γ”+ nucleon → “γ′” + anything, where one or both of the photons are highly virtual and in a special kinematical region of large momentum transfer between the two photons. It predicts a scaling behaviour for the structure functions and connects them to the structure functions of the deep inelastic lepton scattering. The impulse approximation of Bjorken and Paschos to the quark parton model gives exactly the same result even when both photons are real. This shows the identity of bilocal algebra and the quark parton model with general distribution functions in the domain where both models are applicable and further either puts some doubt on the validity of parton model when only one or none of the photons is highly virtual or justifies the dominance of the leading light cone singularity for these cases if one assumes the complementarity of the two pictures.