2-LOOP MIXING OF DIMENSION-5 FLAVOR-CHANGING OPERATORS

We calculate the two-loop QCD mixing of the dimension-five flavor-chan ging operators that arise in the Standard Model after integrating out the W, Z and Higgs bosons and the top-quark, i.e, the mixing among glu onic and photonic magnetic moment operators. Our calculation completes the two-loop anomalous dimension matrix of operators that govern low energy flavor-changing processes. It is an important ingredient of the next-to-leading calculation of the B --> X(s) gamma decay rate.