Measurement of ${\mathrm{\alpha }}_{\mathit{s}}$(${\mathit{M}}_{\mathit{Z}}^2$) from hadronic event observables at the ${\mathit{Z}}^0$ resonance

The strong coupling ${\mathrm{\alpha }}_{\mathit{s}}$(${\mathit{M}}_{\mathit{Z}}^2$) has been measured using hadronic decays of ${\mathit{Z}}^0$ bosons collected by the SLD experiment at SLAC. The data were compared with QCD predictions both at fixed order O(${\mathrm{\alpha }}_{\mathit{s}}^2$) and including resummed analytic formulas based on the next-to-leading logarithm approximation. In this comprehensive analysis we studied event shapes, jet rates, particle correlations, and angular energy flow, and checked the consistency between ${\mathrm{\alpha }}_{\mathit{s}}$(${\mathit{M}}_{\mathit{Z}}^2$) values extracted from these different measures. Combining all results we obtain ${\mathrm{\alpha }}_{\mathit{s}}$(${\mathit{M}}_{\mathit{Z}}^2$)= 0.1200±0.0025 (expt) ±0.0078 (theor), where the dominant uncertainty is from uncalculated higher order contributions.