A simultaneous measurement of the QCD colour factors and the strong coupling

Abstract

Abstract.

Using data from \(e^+e^-\) annihilation into hadrons, taken with the OPAL detector at LEP at the Z pole between 1991 and 1995, we performed a simultaneous measurement of the colour factors of the underlying gauge group of the strong interaction, \(C_F\) and \(C_A\), and the strong coupling, \(\alpha_s\). The measurement was carried out by fitting next-to-leading order perturbative predictions to measured angular correlations of 4-jet events together with multi-jet related variables. Our results,

provide a test of perturbative QCD in which the only assumptions are non-abelian gauge symmetry and standard hadronization models. The measurements are in agreement with SU(3) expectations for \(C_F\) and \(C_A\) and the world average of \(\alpha_s(M_{Z})\).