Measurement of alpha_s with JADE using Moments of event shape observables and the Four-Jet Rate

TL;DR

This paper measures the strong coupling constant alpha_s at the Z boson mass scale using moments of event shape observables and the four-jet rate from e+e- annihilation data collected by JADE, comparing results to QCD predictions.

Contribution

It provides a novel measurement of alpha_s using moments of event shape distributions and the four-jet rate, incorporating NLO and NLLA calculations, and compares these to experimental data.

Findings

Alpha_s from moments: 0.1286 ± uncertainties

Alpha_s from four-jet rate: 0.1169 ± uncertainties

Results agree with the world average

Abstract

Data from e+e-annihilation into hadrons collected by the JADE experiment at centre-of-mass energies between 14 GeV and 44 GeV were used to study moments of event shape distributions and the four-jet rate as a function of the Durham algorithm's resolution parameter y_cut. The data were compared to a QCD NLO order calculations and including NLLA resummation in the case of the four-jet rate. The strong coupling measured from the moments was alpha_s(M_Z)=0.1286+-0.0007(stat)+-0.0011(exp)+-0.0022(had)+-0.0068(theo) and from the four-jet rate was alpha_s(M_Z)=0.1169+-0.0004(stat)+-0.0012(exp)+-0.0021(had)+-0.0007(theo) both in agreement with the world average.