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 sqrt(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 x-p , pT in, pT 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(alfa_s^2) QCD.
Properties of Hadronic Events In e+e- Annihilation At Square-root-s=91 Gev
CIOCCI, MARIA AGNESE;G. BATIGNANI;FERRANTE, ISIDORO;FIDECARO, FRANCESCO;F. FORTI;MESSINEO, ALBERTO MARIA;TONELLI, GUIDO EMILIO;G. TRIGGIANI;
1990-01-01
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 sqrt(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 x-p , pT in, pT out and y are presented. We measure a mean charged multiplicity in hadronic events ofI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
