title: A Simultaneous Measurement of the Strong Coupling Constant and the QCD Colour Factors, based on an Improved Theoretical Prediction for the Two-Jet Rate in $e^+e^-$ Annihilations
abstract: In the first part of this thesis we show that an Ansatz to resum all leading and next-to-leading logarithms in the theoretical prediction for the two-jet rate in $e^+e^-\rightarrow hadrons$, where jets are defined with the Durham algorithm, is consistent with a full ${\cal O}(\alpha_s^2)$ calculation done by Monte Carlo integration. From the asymptotic behaviour of the full ${\cal O}(\alpha_s^2)$ calculation we extract the subleading coefficient $G_{21}$ and the constant $C_2$. Then, using data 
journal: CERN Document Server (European Organization for Nuclear Research)