Study of moments of event shapes in e+e- annihilation using JADE data

TL;DR

This paper analyzes moments of event shape distributions in e+e- annihilation data from the JADE experiment, comparing results with QCD predictions and Monte Carlo models, and measures the strong coupling constant with high precision.

Contribution

It provides a detailed comparison of event shape moments with QCD NLO predictions and measures alpha_S(M_Z) using JADE data, highlighting systematic deficiencies in the theoretical models.

Findings

Measured alpha_S(M_Z) = 0.1286 with total error 0.0072

QCD NLO predictions show systematic deficiencies for higher moments

Results are consistent with the world average of alpha_S(M_Z)

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. The data were compared with Monte Carlo models and with predictions from QCD NLO order calculations. The strong coupling constant measured from the moments is alpha_S(M_Z) = 0.1286 +/- 0.0007 (stat) +/- 0.0011 (expt) +/- 0.0022 (had) +/- 0.0068 (theo), alpha_S(M_Z) = 0.1286 +/- 0.0072 (total error), consistent with the world average. However, systematic deficiencies in the QCD NLO order predictions are visible for some of the higher moments.