A consistent and technically efficient treatment of the photon structure functions at higher orders of perturbation theory is presented. A factorization scheme avoiding the common perturbative instability problems encountered in the large-$x$ region is introduced. The resulting implications for a perturbative analysis of the photon structure in this recommended scheme are pointed out.

• Received 9 December 1991

DOI:https://doi.org/10.1103/PhysRevD.45.3986