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Measurement of the Strong Coupling alpha s from Four-Jet Observables in e+e- Annihilation

The OPAL Collaboration·G. Abbiendi
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Abstract

Data from e+e- annihilation into hadrons at centre-of-mass energies between 91 GeV and 209 GeV collected with the OPAL detector at LEP, are used to study the four-jet rate as a function of the Durham algorithm resolution parameter ycut. The four-jet rate is compared to next-to-leading order calculations that include the resummation of large logarithms. The strong coupling measured from the four-jet rate is alphas(Mz0)= 0.1182+-0.0003(stat.)+-0.0015(exp.)+-0.0011(had.)+-0.0012(scale)+-0.0013(mass) in agreement with the world average. Next-to-leading order fits to the D-parameter and thrust minor event-shape observables are also performed for the first time. We find consistent results, but with significantly larger theoretical uncertainties.

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The OPAL Collaboration, G. Abbiendi. 2006-01-31. Measurement of the Strong Coupling alpha s from Four-Jet Observables in e+e- Annihilation. https://doi.org/10.1140/epjc%2Fs2006-02581-y

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