Deep Inelastic Lepton-Nucleon Scattering at HERA

TL;DR

This paper reviews HERA collider data on lepton-nucleon scattering, highlighting advances in understanding proton structure, QCD effects at low Bjorken-x, and future experimental prospects.

Contribution

It provides a comprehensive analysis of inclusive cross section measurements at HERA, emphasizing the low-x region and implications for QCD and parton densities.

Findings

Precise determination of proton parton densities.

Observation of QCD effects at low Bjorken-x.

Discussion of future HERA measurements and their potential.

Abstract

Data from the HERA collider experiments, H1 and ZEUS, have been fundamental to the rapid recent development of our understanding of the partonic composition of the proton and of QCD. This report focuses on inclusive measurements of neutral and charged current cross sections at HERA, using the full available data taken to date. The present precision on the proton parton densities and the further requirements for future measurements at the Tevatron and LHC are explored. Emphasis is also placed on the region of very low Bjorken-x and Q^2. In this region, the `confinement' transition takes place from partons to hadrons as the relevant degrees of freedom and novel or exotic QCD effects associated with large parton densities are most likely to be observed. Finally, prospects for the second phase of HERA running are discussed.