Measurement of the Probability of Gluon Splitting into Charmed Quarks in Hadronic Z Decays

We have measured the probability, $\overline{n}_{\rm{g} \rightarrow c\overline{c}}$, of a gluon splitting into a charm-quark pair using 1.7 million hadronic Z decays collected by the L3 detector. Two independent methods have been applied to events with a three-jet topology. One method relies on tagging charmed hadrons by identifying a lepton in the lowest energy jet. The other method uses a neural network based on global event shape parameters. Combining both methods, we measure $\overline{n}_{\rm{g} \rightarrow c\overline{c} } = [2.45 \pm 0.29 \pm 0.53]\$.