QCD results from studies of hadronic events produced in e+e− annihilations at =183 GeV

We present results obtained from a study of the structure of hadronic events recorded by the L3 detector at a centre-of-mass energy of 183 GeV. The data sample corresponds to an integrated luminosity of 55.3 pb−1. The distributions of event shape variables and the energy dependence of their mean values are measured. From a comparison with resummed O(αs2) QCD calculations, we determine the strong coupling constant αs(183GeV)=0.1086±0.0026(exp)±0.0054(th). The charged particle multiplicity distribution and momentum spectrum are studied and the energy dependence of the peak position of the ξ(=−lnxp) distribution is compared with lower energy measurements and QCD expectations.