QCD at high energy (experiments)

TL;DR

This paper reviews recent experimental measurements of Quantum Chromodynamics (QCD) involving high momentum transfers, focusing on the strong coupling constant, deep inelastic scattering, and jet production, highlighting the need for advanced calculations for precise data interpretation.

Contribution

It summarizes recent experimental progress in high-energy QCD measurements and emphasizes the importance of next-to-next-to-leading order calculations for accurate analysis.

Findings

QCD at NLO qualitatively describes many processes

Next-to-NLO calculations are essential for quantitative analysis

Recent HERA data on dijet photoproduction illustrate these points

Abstract

Recent measurements of QCD interactions involving large momentum transfers are reviewed. The status of measurements of the strong coupling constant is summarised. Recent developments in the measurement and interpretation of deep inelastic scattering, proton-anti-proton collisions and two-photon processes are discussed. While QCD at next-to-leading order gives a qualitative description of many processes, next-to-NLO calculations are now required to allow quantitative information to be extracted from hadron-initiated multijet data. This is illustrated by a discussion of recent data on the photoproduction of dijet events at HERA.