Schael, S. and Bouhova-Thacker, E. V. and Bowdery, C. K. and Finch, A. J. and Hughes, Gareth and Jones, Roger W. L. and Smizanska, Maria and ALEPH Collaboration, The (2003) Measurements of the strong coupling constant and the QCD color factors using four jet observables from hadronic Z decays. European Physical Journal C: Particles and Fields, 27 (1). pp. 1-17. ISSN 1434-6044
Full text not available from this repository.Abstract
Data from annihilation into hadrons, taken with the ALEPH detector at the Z resonance, are analyzed. The four-jet rate is studied as a function of the resolution parameter and compared to next-to-leading order calculations combined with resummation of large logarithms. Angular correlations in four-jet events are measured and compared to next-to-leading order QCD predictions. With these observables two different measurements are performed. In a first analysis the strong coupling constant is measured from the four-jet rate yielding . In a second measurement the strong coupling constant and the QCD colour factors are determined simultaneously from a fit to the four-jet rate and the four-jet angular correlations, giving in good agreement with the expectation from QCD.