Experimental study of QCD and jets in e(sup +)e(sup (minus)) annihilation

摘要

This thesis is concerned with an experimental study of QCD and JETS using hadronic decays of Z(sup 0) bosons by the SLD experiment at the SLAC Linear Collider. The strong coupling (alpha)(sub s)(M(sub Z)(sup 2)) has been measured, which is an important test of perturbative QCD theory. This comprehensive study comprised fifteen observables that describe hadronic final states; six event shapes, differential 2-jet rates defined by six different jet resolution/recombination schemes, energy-energy correlations and their asymmetry, and the jet cone energy fraction. The data were compared with QCD predictions both at fixed order, O((alpha)(sub s)(sup 2)), and including resummed analytic formula based on the leading and next-to-leading logarithmic approximation. The consistency was checked between (alpha)(sub s)(M(sub Z)(sup 2)) values extracted from these different measures. A final average of (alpha)(sub s)(M(sub Z)(sup 2)) = 0.1200 (plus minus) 0.0025(exp.) (plus minus) 0.0078(theor.), corresponding to (Lambda)(sub (ovr MS)) = 253(sub (minus)96)(sup +130) MeV, was obtained by combining all results. The dominant uncertainty is from uncalculated higher order contributions.