Multi-Jet Event Rates in Deep Inelastic Scattering and Determination of the Strong Coupling Constant

TL;DR

This paper measures jet event rates in deep inelastic scattering at HERA to determine the strong coupling constant alpha_S(M_Z^2) using NLO QCD calculations, providing a precise value consistent with the Standard Model.

Contribution

It presents a novel determination of alpha_S(M_Z^2) from jet rates in deep inelastic scattering using the modified JADE algorithm and NLO QCD, covering a wide Q^2 range.

Findings

alpha_S(M_Z^2) = 0.117 ± 0.003 (stat) ± 0.009-0.013 (syst) ± 0.006 (jet algorithm)

Consistent with the Standard Model predictions for the strong coupling constant

Provides a Q^2-dependent analysis of alpha_S in deep inelastic scattering.

Abstract

Jet event rates in deep inelastic ep scattering at HERA are investigated applying the modified JADE jet algorithm. The analysis uses data taken with the H1 detector in 1994 and 1995. The data are corrected for detector and hadronization effects and then compared with perturbative QCD predictions using next-to-leading order calculations. The strong coupling constant alpha_S(M_Z^2) is determined evaluating the jet event rates. Values of alpha_S(Q^2) are extracted in four different bins of the negative squared momentum transfer~$\qq$ in the range from 40 GeV2 to 4000 GeV2. A combined fit of the renormalization group equation to these several alpha_S(Q^2) values results in alpha_S(M_Z^2) = 0.117+-0.003(stat)+0.009-0.013(syst)+0.006(jet algorithm).