We have measured the mean charged particle multiplicities separately for bb, cc and light quark (uu, dd, ss) initiated events produced in e+e- annihilations at LEP. The data were recorded with the OPAL detector at eleven different energies above the Z0 peak, corresponding to the full statistics collected at LEP1.5 and LEP2. The difference in mean charged particle multiplicities for bb and light quark events, δbl, measured over this energy range is consistent with an energy independent behaviour, as predicted by QCD, but is inconsistent with the prediction of a more phenomenological approach which assumes that the multiplicity accompanying the decay of a heavy quark is independent of the quark mass itself. Our results, which can be combined into the single measurement δbl = 3.44 ± 0.40(stat) ± 0.89(syst) at a luminosity weighted average centre-of-mass energy of 195 GeV, are also consistent with an energy independent behaviour as extrapolated from lower energy data.
|Number of pages||14|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - Dec 12 2002|
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics