Direct extraction of QCD ΛMS from e+e− jet observables Original Research Ar

We directly fit the QCD dimensional transmutation parameter, ΛMS, to experimental data on e+e− jet observables, making use of next-to-leading order (NLO) perturbative calculations. In this procedure there is no need to mention, let alone to arbitrarily vary, the unphysical renormalisation scale μ, and one avoids the ad hoc and potentially meaningless “theoretical error” associated with standard αs determinations. PETRA, SLD, and LEP data are considered in the analysis. An attempt is made to estimate the importance of uncalculated next-NLO and higher order perturbative corrections, and power corrections, by studying the scatter in the values of ΛMS obtained for different observables.