Finite-t and target mass corrections to DVCS on a scalar target

TL;DR

This paper presents the first complete calculation of twist-four kinematic power corrections to DVCS helicity amplitudes on a scalar target, revealing their factorizability and numerical impact.

Contribution

It provides a novel, comprehensive analysis of finite-t and target mass corrections at twist-four accuracy in DVCS on scalar targets.

Findings

Finite-t and target mass corrections are factorizable at leading order.

Numerical impact of corrections is analyzed through a model study.

Corrections are relevant for precise DVCS amplitude calculations.

Abstract

Using the formalism developed in [1,2] we carry out the first complete calculation of kinematic power corrections to the helicity amplitudes of deeply-virtual Compton scattering to the twist-four accuracy for a study case of a (pseudo)scalar target. Our main result is that both finite-t, ~t/Q^2, and target mass, ~m^2/Q^2, twist-four kinematic power corrections turn out to be factorizable, at least to the leading order in the strong coupling. The structure of these corrections is discussed and a short model study of their numerical impact is presented.