Measurements of alpha_s from hadronic event shapes in e+e- annihilation

TL;DR

This paper measures the strong coupling constant alpha_s using hadronic event shapes in e+e- collisions across a wide energy range, confirming its energy dependence and refining its value at the Z boson mass.

Contribution

It provides new experimental data confirming the running of alpha_s and introduces improved methods for extracting its value with reduced theoretical uncertainties.

Findings

Confirmed the running of alpha_s across energies from 13 to 183 GeV

Achieved a more precise measurement of alpha_s(M_Z)

Validated non-perturbative power-law corrections in event shape analyses

Abstract

New studies of hadronic event shape observables in e+ e- collisions between 13 and 183 GeV CM energy have enabled the running of alpha_s to be confirmed and the validity of non-perturbative power-law corrections to be investigated. A more precise value of alpha_s(M_Z) with reduced theoretical errors has been reported from fitting 18 oriented event shape distributions measured in one experiment at the Z.