Michael Donkers
Carleton University

Determination of alpha_s using Jet Rates at LEP2

Data collected at LEP in the energy range of 189 to 207 GeV
using the OPAL detector is analysed using jet-multiplicity based
observables. The goal of the analysis is to determine the energy
dependence of the strong coupling constant, alpha_s. The values are
determined at 7 energy points by fitting the differential 2-jet rate and
the average jet rate to several QCD predictions. The fits are performed on
the distributions that arise using both the Durham and Cambridge jet
clustering algorithms. The running of alpha_s is demonstrated by comparing
the values of the strong coupling constant with those determined at lower
energies.