A Measurement of the QCD Colour Factors using Event Shape Distributions at √ s = 14 to 189 GeV
نویسندگان
چکیده
Measurements of the QCD colour factors C A and C F and of the number of active quark flavours n f in the process e + e − → hadrons at high energy are presented. They are based on fits of O(α 2 s)+NLLA QCD calculations to distributions of the event shape observables 1 − T , C, B T and B W measured at centre-of-mass energies from 14 GeV to 189 GeV. Hadronisation effects are approximated with power correction calculations which also depend on the QCD gauge structure. In this approach potential biases from hadronisation models are reduced. Our results for individually measured quantities obtained from 1 − T and C are
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