Coherent deeply virtual Compton scattering on helium-4 beyond leading power

TL;DR

This paper advances the understanding of helium-4's internal quark-gluon structure by including higher-twist and NLO corrections in deeply virtual Compton scattering, enabling the first tomographic imaging of helium-4 at this level.

Contribution

It provides a comprehensive analysis including twist-3, twist-4, and NLO corrections, offering the first detailed quark-gluon tomography of helium-4.

Findings

Higher-twist and NLO corrections are essential for accurate data description.

Achieved the first quark-gluon level tomographic image of helium-4.

Enhanced theoretical framework for light nuclei structure studies.

Abstract

Coherent hard exclusive reactions on light nuclei provide access to their quark and gluon structure and enable three-dimensional tomography of these complex systems. We study deeply virtual Compton scattering on a helium-4 target, including both kinematic twist-3 and twist-4 corrections, as well as next-to-leading-order corrections to the twist-2 amplitude in the strong coupling $\alpha_s$. We show that these contributions are crucial for achieving a precise description of the data and, as a result, obtain the first tomographic image of the helium-4 nucleus at the quark-gluon level.