# A Glimpse of Gluons through Deeply Virtual Compton Scattering on the Proton

## TL;DR

This paper investigates the internal structure of the proton by measuring the interference between DVCS and Bethe-Heitler processes, revealing insights into quark and gluon dynamics and providing 3D imaging of the proton.

## Contribution

First full determination of the BH-DVCS interference exploiting energy dependence, offering new insights into gluon contributions at high energies.

## Key findings

- Sensitive to gluons in high-energy regime
- First complete measurement of interference pattern
- Provides 3D imaging of proton structure

## Abstract

The proton is composed of quarks and gluons, bound by the most elusive mechanism of strong interaction called confinement. In this work, the dynamics of quarks and gluons are investigated using deeply virtual Compton scattering (DVCS): produced by a multi-GeV electron, a highly virtual photon scatters off the proton which subsequently radiates a high energy photon. Similarly to holography, measuring not only the magnitude but also the phase of the DVCS amplitude allows to perform 3D images of the internal structure of the proton. The phase is made accessible through the quantum-mechanical interference of DVCS with the Bethe-Heitler (BH) process, in which the final photon is emitted by the electron rather than the proton. We report herein the first full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the high energy regime where the scattering process is expected to occur off a single quark in the proton, these accurate measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.