Non-forward and unequal mass virtual Compton scattering Original Research Article

We discuss the general operator product expansion of a non-forward unequal mass virtual Compton scattering amplitude. We find that the expansion now should be done in double moments with new moment variables. There are in the expansion new sets of leading twist operators which have overall derivatives, and they mix under renormalization. We compute the evolution kernels from which the anomalous dimensions for these operators can be extracted. We also obtain the lowest order Wilson coefficients. In the high-energy limit we find the explicit form of the dominant contributing anomalous dimensions and solve the resulting renormalization group equation. We find the same high-energy behavior as indicated by the conventional double leading logarithmic analysis.