Model-Independent Second-Order Determination of the Strong-Coupling Constantαs

Abstract

With use of the MARK-J detector at $\sqrt{s}=34.7\mathrm{}$ GeV 21 000 $e^{+}{e}^{-}\to \mathrm{hadron}$ events have been collected. By measurement of the asymmetry in angular energy correlations the strong coupling constant ${\alpha }_s=0.13\mathrm{}\pm 0.01 \left(\mathrm{statistical}\right)\pm 0.02 \left(\mathrm{systematic}\right)$ is determined, in complete second order, and independent of the fragmentation models and QCD cutoff values used.