Evidence of strong proton shape fluctuations from incoherent diffraction

TL;DR

This paper demonstrates that high-energy exclusive vector meson production measurements reveal significant geometric fluctuations in the proton's shape, with implications for understanding its internal structure and future experimental constraints.

Contribution

It provides evidence that geometric fluctuations dominate over saturation scale and color charge fluctuations in the proton's shape at high energies.

Findings

Strong geometric fluctuations observed in proton shape

Saturation scale and color charge fluctuations are comparatively weak

Future measurements can tightly constrain proton geometry

Abstract

We show within the saturation framework that measurements of exclusive vector meson production at high energy provide evidence for strong geometric fluctuations of the proton. In comparison, the effect of saturation scale and color charge fluctuations is weak. This knowledge will allow detailed future measurements of the incoherent cross section to tightly constrain the fluctuating geometry of the proton as a function of the parton momentum fraction $x$.