Resummation of threshold logarithms in deeply-virtual Compton scattering

Abstract

I derive an all-order resummation formula for the logarithmically enhanced contributions proportional tothe N 3 LL accuracy, in the coefficient function of deeply-virtual-Compton scattering and the pion-photon transition form factor. The key observation is that the non-singlet coefficient function itself factorizes in the x → ±ξ limit, which allows for a resummation using renormalization group equations.