Heavy flavor studies with inclusive leptons in hadronic Z decays

From a sample of hadronic Z decays collected with the A scLEPH detector at L scEP events containing lepton candidates are used to study heavy flavor production and decay properties. From a fit to the observed momentum and transverse momentum distributions of the lepton candidates the semileptonic branching ratios and fragmentation properties of the heavy flavors are measured. This fit gives Br($b\to\ell)$ = 0.1063 $\pm$ 0.0025 $\pm$ 0.0050, Br($c\to\ell)$ = 0.074 $\pm$ 0.003 $\pm$ 0.014, $\langle x\sb{b}\rangle$ = $\langle E\sb{b\ {\rm hadron}}/E\sb{\rm beam}\rangle$ = 0.697 $\pm$ 0.010 $\pm$ 0.012, and $\langle x\sb{c}\rangle$ = 0.464 $\pm$ 0.022 $\pm$ 0.070. Pairs of lepton candidates with high momentum and transverse momentum are used to measure the probability that a b hadron is observed to decay as a b hadron, $\chi.$ $\chi$ is found to be 0.116 $\pm$ 0.030 $\pm$ 0.013. The angular distribution of the leptons is used to measure the forward-backward asymmetry in ${\rm Z}\to b\bar{b}$ and ${\rm Z}\to c\bar{c},$ giving the result $A\sbsp{\rm FB}{b}$ = 0.109 $\pm$ 0.024 $\pm$ 0.013 and $A\sbsp{\rm FB}{c}$ = 0.061 $\pm$ 0.051 $\pm$ 0.031. These asymmetries correspond to a value of the effective electroweak mixing angle at the Z mass of $\sin\sp2\theta\sb{W}(m\sbsp{Z}{2})$ = 0.2288 $\pm$ 0.0049.