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.

D., D., B., D., C., G., J. P., L., M. N., M., R., A., et al. (1992). Evidence For the Triple-gluon Vertex From Measurements of the QCD Color Factors In Z-decay Into 4 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 Color Factors In Z-decay Into 4 Jets

BOTTIGLI, UBALDO;CIOCCI, MARIA AGNESE;MARROCCHESI, PIER SIMONE;
1992-01-01

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.
1992
D., D., B., D., C., G., J. P., L., M. N., M., R., A., et al. (1992). Evidence For the Triple-gluon Vertex From Measurements of the QCD Color Factors In Z-decay Into 4 Jets. PHYSICS LETTERS. SECTION B, 284(1-2), 151-162 [10.1016/0370-2693(92)91941-2].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/37319
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo