Journal article
Properties of hadronic events in e e- annihilation at s=91 GeV
D Decamp, B Deschizeaux, JP Lees, MN Minard, JM Crespo, M Delfino, E Fernandez, M Martinez, R Miquel, ML Mir, S Orteu, A Pacheco, JA Perlas, E Tubau, MG Catanesi, M De Palma, A Farilla, G Iaselli, G Maggi, A Mastrogiacomo Show all
Physics Letters B | Published : 1990
Abstract
We report on properties of hadronic events from e+e- annihilation observed by the ALEPH detector at the large Electron Positron Collider at CERN. The center-of-mass energy was s=91.0-91.3 GeV. Measured distributions of the global event-shape variables sphericity, aplanarity, thrust and minor value, and of the inclusive variables xp, p⊥ in, p⊥ out and y are presented. We measure a mean charged multiplicity in hadronic events of 〈Nch〉=21.3±0.1 (statistical)±0.6 (systematic). The data are in good agreement with QCD-based models which use the leading-logarithm approximation, and are less well described by a model using O(αs 2) QCD. © 1990.