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Measurement of alpha_s in radiative hadronic events at OPAL

Jochen Schieck
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Abstract

Hadronic final states with a hard isolated photon are studied using data taken at centre-of-mass energies around $\Mz$ with the OPAL detector at LEP. The strong coupling $\as$ is extracted by fitting event shape variables for the reduced centre-of-mass energies ranging from 20 GeV to 80 GeV, and the energy dependence of $\as$ is studied. Combining all the values using different event shape variables and energies gives: \asmz=0.1176\pm 0.0012(stat.)^{+0.0093}_{-0.0085}(syst.).

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Jochen Schieck. 2003-12-10. Measurement of alpha_s in radiative hadronic events at OPAL. https://arxiv.org/abs/hep-ex/0312036

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