Sense and Nonsense on Parton Distribution functions of the Photon

TL;DR

This paper discusses the organization of finite order QCD approximations to the photon structure function, focusing on separating pure QED effects from genuine QCD contributions.

Contribution

It introduces a method to distinguish pure QED contributions from genuine QCD effects in photon structure functions at finite order approximations.

Findings

Clarifies the separation of QED and QCD contributions

Provides a framework for organizing finite order QCD approximations

Enhances understanding of photon structure functions

Abstract

The organization of finite order QCD approximations to $F_2^{\gamma}(x,Q^2)$ based on the separation of pure QED contribution from those of genuine QCD nature is discussed.