Eur. Phys. J. C (2013) 73: 2332
https://doi.org/10.1140/epjc/s10052-013-2332-y

Regular Article - Experimental Physics

Measurement of the strong coupling α_S from the three-jet rate in e⁺e⁻-annihilation using JADE data

¹ Ludwig-Maximilians-Universität München, Am Coulombwall 1, 85748, Garching, Germany
² Excellence Cluster Universe, Boltzmannstr. 2, 85748, Garching, Germany
³ Max-Planck-Institut für Physik, Föhringer Ring 6, 80805, München, Germany
⁴ Institute of Physics, University of Debrecen, P.O.Box 105, 4010, Debrecen, Hungary

^* e-mail: Jochen.Schieck@lmu.de

Received: 16 May 2012
Revised: 12 February 2013
Published online: 2 March 2013

Abstract

We present a measurement of the strong coupling α_S using the three-jet rate measured with the Durham algorithm in e⁺e^--annihilation using data of the JADE experiment at centre-of-mass energies between 14 and 44 GeV. Recent theoretical improvements provide predictions of the three-jet rate in e⁺e^--annihilation at next-to-next-to-leading order. In this paper a measurement of the three-jet rate is used to determine the strong coupling α_S from a comparison to next-to-next-to-leading order predictions matched with next-to-leading logarithmic approximations and yields a value for the strong coupling

      αS(M_Z⁰) = 0.1199±0.0010(stat)±0.0021(exp)

                        ±0.0054(had)±0.0007(theo),

consistent with the world average.