A study of the recombination scheme dependence of jet production rates and of α s (\(M_{Z^0 } \)) in hadronicZ0 decays

Jet production rates in hadronicZ0 decays are studied using four different recombination schemes to define resolvable jets. The strong coupling constant α s (\(M_{Z^0 } \)) is determined in fits of the correspondingO(α s 2 ) QCD calculations to the differential 2-jet distributionsD2(y). Hadronisation corrections and renormalisation scale uncertainties are found to be different for each recombination scheme. Within their overall systematic uncertainties, the four schemes yield consistent values of α s (\(M_{Z^0 } \)), leading to a final result of $$\alpha _s (M_{Z^0 } ) = 0.118 \pm 0.008.$$ .