A measurement of the gluon splitting rate into c(c)over-bar pairs in hadronic Z decays

The rate of gluon splitting into cc pairs in hadronic Z decays is measured using the data sample collected by ALEPHfrom 1991 to 1995. The selection is based on the identification of leptons (electrons and muons) originating from semileptonic charm decays, and on the topological propertiesof signal events. The result derived from the selected sample is g(cc) = (3.26 +/- 0.23(stat) +/- 0.42(syst))%. (C) 2003 Published by Elsevier Science B.V.