Range, light-cone dominance and scaling at low Q2 in electroproduction

Abstract

The analysis of light cone singularities is used to connect the y · P, or range, dependence of the current correlation function with the Q 2 dependence of the inelastic electroproduction structure functions. We study for what regions of the Q 2, ν plane and for what y · P dependence the leading light-cone singularity dominates contributions from less singular terms with the same y · P dependence. When the leading singularity can be shown to dominate for a particular region of Q 2 and ν, we study whether this implies scaling for νW 2 in that kinematic region. It is shown that a division of the current correlation function into short and long range contributions is fundamentally ambiguous and not related to scaling at low Q 2. Short range terms which are shown to be light-cone dominated for all Q 2 so long as ν → ∞, are found but are shown not to scale at low Q 2 and to be indistinguishable from corrections to long range terms which produce the leading Regge behavior. We show that leading Regge terms may receive contributions far away from the light cone for small virtual photon mass, but that light-cone dominance and scaling are recovered when the photon mass is taken very large.