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 of =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.
1990
Decamp, D.; Deschizeaux, B.; Lees, J. P.; Minard, M. N.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Martinez, M.; Miquel, R.; Mir, M. L.; Orteu, S.; P...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/828698
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