Proton and Photon Structure

TL;DR

Advances in proton and photon structure measurements, combined with theoretical QCD improvements, have significantly enhanced our understanding of proton flavor decomposition, momentum distributions, and the universal properties of hadronic structures.

Contribution

This paper reviews recent experimental and theoretical progress that has improved the precision of proton and photon structure analyses and their implications for QCD and hadronic physics.

Findings

Enhanced precision in proton structure measurements.

Implications for the strong coupling constant alpha-s.

Insights into the universal properties of hadronic structures.

Abstract

The increasing precision of the measurements on the proton structure and an improved treatment of the correlated systematic experimental errors constitute a major step forward in our understanding of the flavour decomposition of the proton and the momentum distributions of the various flavours. Together with theoretical progress on the next-to-next-to-leading order QCD corrections to deep inelastic scattering processes, the proton measurements already imply a new level of precision for the strong coupling constant alpha-s. The progress in the measurements on the quantum fluctuations of the photon allows questions on the universal properties of hadronic structures to be addressed.