Kinematic power corrections in off-forward hard reactions

TL;DR

This paper presents a comprehensive method to calculate kinematic power corrections in off-forward hard reactions, crucial for precise predictions in processes like deeply-virtual Compton scattering.

Contribution

It derives the complete expression for the time-ordered product of two electromagnetic currents including all kinematic corrections up to twist-four accuracy.

Findings

Derived a general approach for kinematic corrections in hard processes.

Provided explicit formulas applicable to deeply-virtual Compton scattering.

Enhanced accuracy of theoretical predictions in off-forward reactions.

Abstract

We develop a general approach to the calculation of kinematic corrections ~t/Q^2, ~m^2/Q^2 in hard processes which involve momentum transfer from the initial to the final hadron state. As the principal result, the complete expression is derived for the time-ordered product of two electromagnetic currents that includes all kinematic corrections to twist-four accuracy. The results are immediately applicable e.g. to the studies of deeply-virtual Compton scattering.