Sub-eikonal corrections to scattering amplitudes at high energy

TL;DR

This paper derives sub-eikonal corrections to quark and gluon propagators, enabling more precise studies of spin dynamics and hadron interactions at high energies beyond the traditional eikonal approximation.

Contribution

It introduces the first derivation of sub-eikonal quark and gluon propagators, extending high-energy QCD analysis beyond the eikonal approximation.

Findings

Derived sub-eikonal quark propagator

Derived sub-eikonal gluon propagator

Facilitates studies of spin effects at high energy

Abstract

Most of the progress in high-energy Quantum Chromodynamics has been obtained within the eikonal approximation and infinite Wilson-line operators. Evolution equations of Wilson lines with respect to the rapidity parameter encode the dynamics of the hadronic processes at high energy. However, even at high energy many interesting aspects of hadron dynamics are not accessible within the eikonal approximation, the spin physics being an obvious example. The higher precision reached by the experiments and the possibility to probe spin dynamics at future Electron Ion Colliders make the study of deviations from eikonal approximation especially timely. In this paper I derive the sub-eikonal quark and gluon propagators which can serve as a starting point of studies of these effects.