Production rates of \(\mathrm{b\overline{b}}\) quark pairs from gluons and \(\mathrm{b\overline{b}b\overline{b}}\) events in hadronic \(\mathrm{Z}^0\) decays

  • The OPAL Collaboration
  • G. Abbiendi et al.
Experimental physics


The rates are measured per hadronic \(\mathrm{Z}^0\) decay for gluon splitting to \(\mathrm{b\overline{b}}\) quark pairs, \(g_{\mathrm{b\overline{b}}}\), and of events containing two \(\mathrm{b\overline{b}}\) quark pairs, \(g_{\mathrm{4b}}\), using a sample of four-jet events selected from data collected with the OPAL detector. Events with an enhanced signal of gluon splitting to \(\mathrm{b\overline{b}}\) quarks are selected if two of the jets are close in phase-space and contain detached secondary vertices. For the event sample containing two \(\mathrm{b\overline{b}}\) 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 \(g_{\mathrm{b\overline{b}}}\) and \(g_{\mathrm{4b}}\), namely



Production Rate Opal Detector Event Sample Hadronic Decay Event Topology 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • The OPAL Collaboration
  • G. Abbiendi et al.
    • 1
  1. 1.Dipartimento di Fisica dell' Università di Bologna and INFN, 40126 Bologna, Italy IT

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