Evolution of Weinberg's gluonic CP-violation operator.

Abstract

The renormalization-group evolution of Weinberg's purely gluonic dimension-6 CP-violating operator is computed to first order in the QCD coupling constant, including its mixing with the quark color electric dipole moment. Our result for the anomalous dimension of the quark operator agrees with several previous calculations. For the gluonic operator, we find the anomalous dimension to have the same magnitude but opposite sign as a previous calculation. This significantly relaxes the constraints imposed on extensions of the standard model by experimental measurements of the neutron electric dipole moment.