Twist-2 Light-Ray Operators: Anomalous Dimensions and Evolution Equations1

The non–singlet and singlet anomalous dimensions of the twist–2 light–ray operators for unpolarized and polarized deep inelastic scattering are calculated in O(αs). We apply these results for the derivation of evolution equations for partition functions, structure functions, and wave functions which are defined as Fourier transforms of the matrix elements of the light-ray operators. Special cases are the Altarelli–Parisi and Brodsky–Lepage kernels. Finally we extend Radyushkin’s solution from the non–singlet to the singlet case. 1 Contribution to the Proceedings of the Int. Workshop Deep Inelastic Scattering off Polarized Targets : Theory Meets Experiment, September 1–5, 1997, DESY–Zeuthen, Germany