Two-loop QCD anomalous dimensions of flavour-changing four-quark operators within and beyond the Standard Model Original Research Article

We calculate the two-loop QCD anomalous dimension matrix (ADM) (γ̂(1))NDR in the NDR– MS scheme for all the flavour-changing four-quark dimension-six operators that are relevant in both the Standard Model and its extensions. Both current–current and penguin diagrams are included. Some of our NDR– MS results for ΔF=1 operators overlap with the previous calculations, but several others have never been published before. In the case of ΔF=2 operators, our results are compatible with the ones obtained by Ciuchini et al. in the regularization-independent renormalization scheme, but differ from their NDR– MS results. In order to explain the difference, we calculate the ADM of ΔF=2 operators again, extracting it from the ADM of ΔF=1 operators.