A sample of 4148 four-jet events observed in the ALEPH-detector at LEP in 1989 and 1990 is used to test the underlying gauge group of strong interactions. A fit to the ratios of the "colour factors" C(F), N(C) and T(F), which determine the differential cross sections, yields N(C)/C(F) = 2.24 +/- 0.32stat +/- 0.24syst and T(F)/C(F) = 0.58 +/- 0.17stat +/- 0.23syst. This is in agreement with the values expected from QCD: N(C)/C(F) = 2.25 and T(F)/C(F) = 0.375. The non-zero value of N(C)/C(F) constitutes direct evidence for the existence of the triple-gluon coupling and excludes any abelian gauge theory by more than five standard deviations.

Decamp, D., Deschizeaux, B., Goy, C., Lees, J., Minard, M., Alemany, R., et al. (1992). Evidence for the triple-gluon vertex from measurements of the QCD colour factors in Z decay into four jets. PHYSICS LETTERS. SECTION B, 284(1-2), 151-162 [10.1016/0370-2693(92)91941-2].

Evidence for the triple-gluon vertex from measurements of the QCD colour factors in Z decay into four jets

CARPINELLI, Massimo;
1992

Abstract

A sample of 4148 four-jet events observed in the ALEPH-detector at LEP in 1989 and 1990 is used to test the underlying gauge group of strong interactions. A fit to the ratios of the "colour factors" C(F), N(C) and T(F), which determine the differential cross sections, yields N(C)/C(F) = 2.24 +/- 0.32stat +/- 0.24syst and T(F)/C(F) = 0.58 +/- 0.17stat +/- 0.23syst. This is in agreement with the values expected from QCD: N(C)/C(F) = 2.25 and T(F)/C(F) = 0.375. The non-zero value of N(C)/C(F) constitutes direct evidence for the existence of the triple-gluon coupling and excludes any abelian gauge theory by more than five standard deviations.
Articolo in rivista - Articolo scientifico
Physics
English
1992
284
1-2
151
162
none
Decamp, D., Deschizeaux, B., Goy, C., Lees, J., Minard, M., Alemany, R., et al. (1992). Evidence for the triple-gluon vertex from measurements of the QCD colour factors in Z decay into four jets. PHYSICS LETTERS. SECTION B, 284(1-2), 151-162 [10.1016/0370-2693(92)91941-2].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/390435
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