Using data collected from 1992 to 1995 with the ALEPH detector at LEP, a measurement of the colour factor ratios C-A/C-F and T-F/C-F and the strong coupling constant <(alpha)over bar (s)> = C-F alpha(s), (M-Z)/(2 pi) has been performed by fitting theoretical predictions simultaneously to the measured differential two-jet rate and angular distributions in four-jet events. The result is found to be in excellent agreement with QCD. C-A/C-F = 2.20 +/- 0.09 (stat) +/- 0.13 (syst), T-F/C-F = 0.29 +/- 0.05 (stat) +/- 0.06 (syst). Fixing C-A/C-F and T-F/C-F to the QCD values permits a determination of alpha(s) (M-Z) and n(f), the number of active flavours. With this measurement the existence of a gluino with mass below 6.3 GeV/c(2) is excluded at 95% confidence level.

A measurement of the QCD colour factors and a limit on the light gluino / Barate, R., Buskulic, D., Decamp, D., Ghez, P., Goy, C., Lees, J.p., Lucotte, A., Minard, M.n., Nief, J.y., Odier, P., Pietrzyk, B., Casado, M.p., Chmeissani, M., Comas, P., Crespo, J.m., Delfino, M., Fernandez, E., Fernandezbosman, M., Garrido, L., Juste, A., et al.. - In: ZEITSCHRIFT FÜR PHYSIK. C, PARTICLES AND FIELDS. - ISSN 0170-9739. - STAMPA. - 76:1(1997), pp. 1-14. [10.1007/s002880050522]

A measurement of the QCD colour factors and a limit on the light gluino

Creanza D;Gelao G;Iaselli G;Maggi G;
1997

Abstract

Using data collected from 1992 to 1995 with the ALEPH detector at LEP, a measurement of the colour factor ratios C-A/C-F and T-F/C-F and the strong coupling constant <(alpha)over bar (s)> = C-F alpha(s), (M-Z)/(2 pi) has been performed by fitting theoretical predictions simultaneously to the measured differential two-jet rate and angular distributions in four-jet events. The result is found to be in excellent agreement with QCD. C-A/C-F = 2.20 +/- 0.09 (stat) +/- 0.13 (syst), T-F/C-F = 0.29 +/- 0.05 (stat) +/- 0.06 (syst). Fixing C-A/C-F and T-F/C-F to the QCD values permits a determination of alpha(s) (M-Z) and n(f), the number of active flavours. With this measurement the existence of a gluino with mass below 6.3 GeV/c(2) is excluded at 95% confidence level.
1997
A measurement of the QCD colour factors and a limit on the light gluino / Barate, R., Buskulic, D., Decamp, D., Ghez, P., Goy, C., Lees, J.p., Lucotte, A., Minard, M.n., Nief, J.y., Odier, P., Pietrzyk, B., Casado, M.p., Chmeissani, M., Comas, P., Crespo, J.m., Delfino, M., Fernandez, E., Fernandezbosman, M., Garrido, L., Juste, A., et al.. - In: ZEITSCHRIFT FÜR PHYSIK. C, PARTICLES AND FIELDS. - ISSN 0170-9739. - STAMPA. - 76:1(1997), pp. 1-14. [10.1007/s002880050522]
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/11589/142
Citazioni
  • Scopus 56
  • ???jsp.display-item.citation.isi??? 58
social impact