Infrared and collinear safe event shape distributions and their mean values are determined using the data taken at five different centre of mass energies above M-Z with the DELPHI detector at LEP. From the event shapes, the strong coupling alpha(s) is extracted in O(alpha(s)(2)), NLLA and a combined scheme using hadronisation corrections evaluated with fragmentation model generators as well as using an analytical power ansatz. Comparing these measurements to those obtained at M-Z, the energy dependence (running) of alpha(s) is accessible. The logarithmic energy slope of the inverse strong coupling is measured to be d alpha(s)(-1)/d log(E-cm) = 1.39 +/- 0.34 (stat) +/- 0.17(syst), in good agreement with the QCD expectation of 1.27. (C) 1999 Published by Elsevier Science B.V. All rights reserved.

Energy dependence of event shapes and of alpha(s) at LEP 2

AMAPANE, Nicola Carlo;MIGLIORE, Ernesto;ROMERO, Alessandra;
1999-01-01

Abstract

Infrared and collinear safe event shape distributions and their mean values are determined using the data taken at five different centre of mass energies above M-Z with the DELPHI detector at LEP. From the event shapes, the strong coupling alpha(s) is extracted in O(alpha(s)(2)), NLLA and a combined scheme using hadronisation corrections evaluated with fragmentation model generators as well as using an analytical power ansatz. Comparing these measurements to those obtained at M-Z, the energy dependence (running) of alpha(s) is accessible. The logarithmic energy slope of the inverse strong coupling is measured to be d alpha(s)(-1)/d log(E-cm) = 1.39 +/- 0.34 (stat) +/- 0.17(syst), in good agreement with the QCD expectation of 1.27. (C) 1999 Published by Elsevier Science B.V. All rights reserved.
1999
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P. Abreu;W. Adam;T. Adye;P. Adzic;Z. Albrecht;T. Alderweireld;G. D. Alekseev;R. Alemany;T. Allmendinger;P. P. Allport;S. Almehed;U. Amaldi...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/103345
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