  We use the Yang-Mills gradient flow to study the mixing of CP-violating pure
gauge operators in continuum QCD with special attention to Weinberg's d=6
purely gluonic operator. The gradient flow allows for a relatively clear
derivation of the Wilson coefficients of the CP-violating effective
Hamiltonian. This calculation is the first step towards a high-energy matching
of matrix elements involving the CP-violating operators between the
perturbative and lattice regimes.
