Updated Results on the Energy Dependence of the Differences Between the Quark and Gluon Jet Fragmentation

The analysis of the data collected by DELPHI during 1994 at the Z 0 peak, has allowed updating the results of the charged multiplicity of quark and gluon jets. The new values confirm the energy dependence of the multiplicity ratio, r, of gluon to quark jets, giving: \Deltar \DeltaE = (0:0112 \Sigma 0:0024) GeV \Gamma1 As a consequence of the energy dependence exhibited by the jet multiplicities, b quark and gluon initiated jets of 25 GeV manifest similar properties. The study of the string effect, by means of the particle flow in the q¯q inter-jet region of the q¯qg and q¯qfl events, confirms with increased accuracy the perturbative QCD calculation. Paper submitted to the HEP'97 Conference Jerusalem, August 19-26 1 Introduction The colour dynamics confers different colour charges to quarks and gluons. As gluons carry colour charge, they can interact among themselves (e.g. triple-gluon vertex). Therefore, gluons experience a hadronization process similar to the one for quarks. At..