Measurement and QCD analysis of jet cross sections in deep-inelastic positron-proton collisions at √(s) = 300 GeV

The aim of this thesis is to extend the measurements of multi-jet cross sections in deep inelastic scattering by the E665 collaboration (M. R. Adams et al. (1992)) regarding both the experimental measurement and the scope of the QCD analysis. A large variety of jet observables is measured as a function of kinematic and jet specific quantities using different jet algorithms. The predictions of perturbative QCD are tested in inclusive jet, in dijet, in three-jet and in four-jet production. The internal structure of jets is studied in a dijet event sample. In a QCD analysis of the inclusive jet and the dijet cross sections we determine αs and study its ''running'' as a function of the transverse jet energy. The inclusion of H1 structure function data with their direct sensitivity to the quark densities provides the opportunity to perform a consistent direct determination of the gluon density simultaneously with the quark densities in the proton. Since both data sets are measured by one experiment the correlated experimental uncertainties can fully be taken into account. We perform the first simultaneous direct determination of αs, the gluon and the quark densities in the proton. (orig.)