Measurement of the Photon Structure Function at High Q^2 at LEP

TL;DR

This paper reports measurements of the photon structure function at high Q^2 values at LEP, providing insights into photon structure and testing QCD predictions using electron-positron collision data.

Contribution

It presents the first high Q^2 measurements of the photon structure function at LEP, comparing results with QCD models and the Quark Parton Model.

Findings

Photon structure functions measured between 40 and 500 GeV^2.

Results generally agree with QCD-based model predictions.

Provides new data for understanding photon structure at high energies.

Abstract

The structure functions of real and virtual photons are derived from cross section measurements of the reaction e^+e^ -> e^+e^- + hadrons at LEP. The reaction is studied at \sqrt{s} ~ 91 GeV with the L3 detector. One of the final state electrons is detected at a large angle relative to the beam direction, leading to Q^2 values between 40 GeV^2 and 500 GeV^2. The other final state electron is either undetected or it is detected at a four-momentum transfer squared P^2 between 1 GeV^2 and 8 GeV^2. These measurements are compared with predictions of the Quark Parton Model and other QCD based models.