Eur. Phys. J. C 18, 447-460
Production rates of quark pairs from gluons and events in hadronic Z0 decaysThe OPAL Collaboration G. Abbiendi and et al.
Dipartimento di Fisica dell' Università di Bologna and INFN, 40126 Bologna, Italy
(Received: 9 June 2000 / Published online: 23 January 2001 -© Società Italiana di Fisica, Springer-Verlag 2001)
The rates are measured per hadronic Z0 decay for gluon splitting to quark pairs, , and of events containing two quark pairs, g4b, using a sample of four-jet events selected from data collected with the OPAL detector. Events with an enhanced signal of gluon splitting to quarks are selected if two of the jets are close in phase-space and contain detached secondary vertices. For the event sample containing two quark pairs, three of the four jets are required to have a significantly detached secondary vertex. Information from the event topology is combined in a likelihood fit to extract the values of and g4b, namely
© Società Italiana di Fisica, Springer-Verlag 2001