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.
Titolo: | EVIDENCE FOR THE TRIPLE-GLUON VERTEX FROM MEASUREMENTS OF THE QCD COLOR FACTORS IN Z-DECAY INTO 4 JETS | |
Autori: | ||
Data di pubblicazione: | 1992 | |
Rivista: | ||
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/0370-2693(92)91941-2 | |
Handle: | http://hdl.handle.net/11384/3613 | |
Appare nelle tipologie: | 1.1 Articolo in rivista |