Virtual Photon Structure at HERA

Abstract

Measurements of the structure of the virtual photon in the transition region between quasi-real photons and those far from mass-shell have been made with the ZEUS detector at HERA, using an integrated luminosity of 38pb-1. Dijet final states are identified, and differential cross sections are presented in terms of xgo, an estimator of the fraction of the photon energy which takes part in the QCD subprocess. Comparison is made to theoretical predictions.