Determination Of Alpha Subscript S And Sin2thetaw From Measurements Of The Total Hadronic Cross Section In E E Annihilation PDF Download

One of the most important tasks in high energy physics is the precise determination of the strong coupling[alpha][sub s](M[sub Z][sup 2]). Not only does measurement of[alpha][sub s](M[sub Z][sup 2]) in different hard processes and at different hard scales Q provide a fundamental test of the theory of strong interactions, Quantum Chromodynamics (QCD), but it also allows constraints on extensions to the Standard Model of elementary particles. Here, the determination of[alpha][sub s](M[sub Z][sup 2]) using O([alpha][sub s][sup 2]) calculations of hadronic event shape observables in e[sup+]e[sup[minus]] annihilation is reviewed. The large scatter among[alpha][sub s](M[sub Z][sup 2]) values determined from different observables may be interpreted as arising from the effect of uncalculated higher-order contributions. The application of optimized perturbation theory and Pade approximants in an attempt to reduce this effect is discussed.