On the importance of gluon contributions to timelike and spacelike DVCS

TL;DR

This paper highlights the significant impact of gluonic contributions and large radiative corrections to virtual Compton scattering amplitudes in both timelike and spacelike regimes, especially relevant for upcoming experiments at JLab12 and CERN.

Contribution

It emphasizes the importance of gluonic contributions and large O(α_s) corrections in virtual Compton scattering, and discusses the differences between timelike and spacelike cases.

Findings

Large O(α_s) corrections are significant in the generalized Bjorken regime.

Gluonic contributions are important even at medium energies.

Timelike and spacelike cases have notable differences that require careful analysis.

Abstract

We emphasize how large O(\alpha_s) corrections to timelike and spacelike virtual Compton scattering amplitudes are in the generalized Bjorken scaling regime, and in particular the gluonic contributions, even in the medium energy range which will be studied intensely at JLab12 and in the COMPASS-II experiment at CERN. We stress that the timelike and spacelike cases are complementary and that their difference deserves much special attention.