MEASUREMENT OF THE TRIPLE-GLUON VERTEX FROM 4-JET EVENTS AT LEP

Journal article

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.

Authors: Abreu, P; Adam, W; Adye, T; Agasi, E; Aleksan, R

• Publication status: Published
• Journal: ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS
• Volume: 59
• Issue: 3
• Pages: 357-368
• Publication date: 1993-08-01
• DOI: 10.1007/BF01498617
• EISSN: 1434-6052
• ISSN: 0170-9739
• Language: English