Measurement of the semileptonic branching ratio of charm hadrons produced in Z0 → cc̄ decays

Abstract

The inclusive charm hadron semileptonic branching fractions B(c → e) and B(c → μ) in Z0 → cc events have been determined using 4.4 million hadronic Z0 decays collected with the OPAL detector at LEP. A charm-enriched sample is obtained by selecting events with reconstructed D*± mesons. Using leptons found in the hemisphere opposite that of the D*± mesons, the semileptonic branching fractions of charm hadrons are measured to be B(c → e) = 0.103 ±0.009+0.009-0.008 and B(c→ μ) = 0.090 ±0.007+0.007-0.006, where the first errors are in each case statistical and the second systematic. Combining these measurements, an inclusive semileptonic branching fraction of charm hadrons of B(c → ℓ) = 0.095 ±0...