Study of charge multiplicity in hadronic three-jet Z decays at LEP
  The mean charge multiplicity in hadronic three-jet Z decays has been measured with the DELPHI detector as a function of the event topology and compared with recent theoretical calculations. The QCD colour factor ratio C_A/C_F was determined, and the gluon contribution to this multiplicity was extracted giving a measurement of the mean charge multiplicity of a two-gluon colour-singlet system as a function of the effective c.m. energy covering the range from 16 to 52 GeV. 
V.A. Uvarov (IHEP, Protvino, Russia) (for the DELPHI Collaboration)