par Abreu, Paulo;Bertrand, Daniel ;Bricman, Claude ;Vander Velde, Catherine ;Wickens, John H. ; [et al.]
Référence Zeitschrift für Physik. C, Particles and fields, 59, 3, page (357-368)
Publication Publié, 1993
Article révisé par les pairs
Résumé : From the combined data of 1990 and 1991 of the DELPHI experiment at LEP, 13057 4-jet events are obtained and used for determining the contribution of the triple-gluon vertex. The relevant variables are the generalized Nachtmann Reiter angle θNR * and the opening angle of the two least energetic jets. A fit to their two-dimensional distribution yields {Mathematical expression} where CA/CF is the ratio of the coupling strength of the triple-gluon vertex to that of gluon bremsstrahlung from quarks, and NC/NA, the ratio of the number of quark colours to the number of gluons. This constitutes a convincing model-independent proof of the existence of the triple-gluon vertex, since its contribution is directly proportional to CA/CF. The results are in agreement with the values expected from QCD:CA/CF=2.25, and NC/NA=3/8. © 1993 Springer-Verlag.