NNLO anomalous dimension matrix for twist-two flavor-singlet operators

Abstract

Conformal symmetry of QCD is restored at the Wilson-Fisher critical point in noninteger 4−2ϵ space-time dimensions. Correlation functions of multiplicatively renormalizable operators with different anomalous dimensions at the critical point vanish identically. We show that this property allows one to calculate off-diagonal parts of the anomalous dimension matrices for leading-twist operators from a set of two-point correlation functions of gauge-invariant operators which can be evaluated using standard computer algebra techniques. As an illustration, we present the results for the NNLO anomalous dimension matrix for flavor-singlet QCD operators for spin N≤8.

Keywords

• Conformal symmetry
• Anomalous dimensions
• DVCS