Resummation of threshold logarithms in deeply-virtual Compton scattering

I derive an all-order resummation formula for the logarithmically enhanced contributions proportional to alpha(n)( s)/ x +/-xi log( xi +/- x/ 2 xi )(k) in the quark coefficient function of deeply virtual-Compton scattering and the pion-photon transition form factor in momentum space. The resummation is performed at the next-to-next-to-leading logarithmic accuracy. The key observation is that the quark coefficient function itself factorizes in the x -> +/- xi limit, which allows for a resummation using renormalization group equations. A preliminary numerical analysis suggests that the corrections due to resummation for the quark contribution might be small.