A measurement of the Gluon Splitting Rate into $c\bar{c}$ Pairs in Hadronic $Z^0$ Decays

A measurement of the gluon splitting rate to a $c \bar{c}$ pair ($g_{c \bar{c}}$) ispresented using data collected by {\textsc ALEPH} from 1991 to 1995 at the $Z^0$ resonance. The selection is based on a lepton tag and on the topological properties of the events. The result from electron and muon samples is: $g_{c \bar{c}}^e=(2.99 \pm 0.28 \rm{(stat)} \pm 0.41 \rm{(syst)}) \%$ and $g_{c \bar{c}}^{\mu}=(2.90 \pm 0.38 \rm{(stat)} \pm 0.74 \rm{(syst)}) \%$. The combined result is $g_{c\bar c}=\left(2.98\pm 0.48\right)\%$.