A measurement of energy correlations and a determination of αs(M2Z0) e+e- annihilations at √s=91 GeV

From an analysis of multi-hadron events from Z0 decays, values of the strong coupling constant αs(M2Z0)=0.131±0.006 (exp)±0.002(theor.) and αs(Mz02) = −0.009+0.007(exp.)−0.002+0.006(theor.) are derived from the energy-energy correlation distribution and its asymmetry, respectively, assuming the QCD renormalization scale μ=MZ0. The theoretical error accounts for differences between O(α2s) calculations. A two parameter fit ΛMS and the renormalization scale μ leads to Λ MS=216±85 MeV and μ2s=0.027±0.013 or to αs(M2Z0)=0.117+0.006−0.008(exp.) for the energy-energy correlation distribution. The energy-energy correlation asymmetry distribution is insensitive to a scale change: thus the αs value quoted above for this variable includes the theoretical uncertainty associated with the renormalization scale.