Four-jet angular distributions and color charge measurements: Leading order versus next-to-leading order

We present the next-to-leading order perturbative QCD prediction to the four-jet angular distributions used by experimental collaborations at CERN LEP for measuring the QCD color charge factors. We compare our results to ALEPH data corrected to the parton level. We perform a leading order “measurement” of the QCD color factor ratios by fitting the leading order perturbative predictions to the next-to-leading order result. Our result shows that in an experimental analysis for measuring the color charge factors the use of the O(α_s³) QCD predictions instead of the O(α_s²) results may shift the center of the fit by a relative factor of 1+2α_s in the T_R/C_F direction.