The 3D entangled structure of the proton; transverse degrees of freedom in QCD, momenta, spins and more

TL;DR

This paper explores the three-dimensional structure of protons in QCD, emphasizing transverse degrees of freedom, confinement, and the role of Wilson loops in understanding hadronic internal dynamics.

Contribution

It introduces ideas on emergent symmetries in the Standard Model and their connection to the 3D structure of hadrons, highlighting the significance of Wilson loops and transverse momentum distributions.

Findings

Wilson loops with light-like lines relate transverse spatial and gluonic degrees of freedom

Emergent symmetries connect the 3D structure of hadrons to confinement mechanisms

Transverse momentum dependent distributions (TMDs) are linked to Wilson line structures

Abstract

Light-front quantized quark and gluon states (partons) play a dominant role in high energy scattering processes. Initial state hadrons are mixed ensembles of partons, while produced pure partonic states appear as mixed ensembles of hadrons. The transition from collinear hard physics to the 3D structure including partonic transverse momenta is related to confinement which links color and spatial degrees of freedom. We outline ideas on emergent symmetries in the Standard Model and their connection to the 3D structure of hadrons. Wilson loops, including those with light-like Wilson lines such as used in the studies of transverse momentum dependent distribution functions (TMDs) may play a crucial role here, establishing a direct link between transverse spatial degrees of freedom and gluonic degrees of freedom.