On timelike and spacelike deeply virtual Compton scattering at next to leading order

TL;DR

This paper analyzes timelike and spacelike virtual Compton scattering at next-to-leading order, highlighting significant corrections and the importance of gluonic contributions in the medium energy range relevant for JLab12 and CERN experiments.

Contribution

It provides the first detailed next-to-leading order analysis of both timelike and spacelike virtual Compton scattering, emphasizing their differences and the role of gluonic effects.

Findings

O() corrections are sizeable in Born amplitudes

Gluonic contributions are significant at moderate energies

Timelike and spacelike cases show complementary features

Abstract

We study timelike and spacelike virtual Compton scattering in the generalized Bjorken scaling regime at next to leading order in the strong coupling constant, in the medium energy range which will be studied intensely at JLab12 and in the COMPASS-II experiment at CERN. We show that the Born amplitudes get sizeable O(\alpha_s) corrections and, even at moderate energies, the gluonic contributions are by no means negligible. We stress that the timelike and spacelike cases are complementary and that their difference deserves much special attention.