Determinations of alpha_s using JADE data of e^+e^- Annihilations at sqrt{s} = 22 to 44 GeV

TL;DR

This paper measures the strong coupling constant alpha_s at various energies using JADE e^+e^- collision data, comparing new event shape observables with advanced QCD calculations, and confirms the energy dependence predicted by QCD.

Contribution

It introduces new event shape observables measured at PETRA energies and provides a more precise determination of alpha_s, testing its energy dependence against QCD predictions.

Findings

Alpha_s values are consistent with previous results but with smaller uncertainties.

The energy dependence of alpha_s agrees with QCD predictions.

Results support the validity of resummed QCD calculations for event shape observables.

Abstract

Data recorded by the JADE experiment at the PETRA e^+e^- collider were used to measure distributions of new event shape observables. The distributions were compared with resummed QCD calulations (O(alpha_s^2)+NLLA), and the strong coupling constant alpha_s was determined at \sqrt{s}= 22, 35 and 44 GeV. The results are in agreement with previous combined results of PETRA but have smaller uncertainties. Together with corresponding data from LEP, the energy dependence of alpha_s is significantly tested and is found to be in good agreement with the QCD expectation.