Next-to-leading-power kinematic corrections to DVCS: a scalar target

Abstract

Using the recent results on the contributions of descendants of the leading twist operators to the operator product expansion of two electromagnetic currents we derive explicit expressions for the kinematic finite-t and target mass corrections to the DVCS helicity amplitudes to the 1/Q4 power accuracy. The cancellation of IR divergences for kinematic corrections is demonstrated to all powers in the leading order of perturbation theory. We also argue that target mass corrections in the coherent DVCS from nuclei are small and do not invalidate the factorization theorem.

NLO corrections to the deeply virtual meson production revisited: impact on the extraction of generalized parton distributions

“…This is evident in the ongoing efforts to enhance the precision of their theoretical descriptions by calculating higher-order perturbative QCD (pQCD) corrections to subprocess hard-scattering amplitudes: NLO DVCS [34][35][36][37], NLO DVMP [38][39][40], and NNLO DVCS [41][42][43]. Additionally, the power-corrections to DVCS have been determined [44][45][46][47][48], while the consistent inclusion of power-corrections in DVMP remains a challenging endeavor. The leading twist-2 contribution to DVMP accounts for the contribution of longitudinally polarized photons (γ * L N → MN ′ ).…”