Measurement of the e+e- → b overlineb and e +e- → c overlinec forward-backward asymmetries at the Z 0 resonance

We have measured the forward-backward asymmetry in e⁺e^-→ b overlineb and e ⁺e^-→ c overlinec processes using hadronic events containing muons or electrons. The data sample corresponds to 4100000 hadronic decays of the Z ⁰. From a fit to the single lepton and dilepton p and p_T spectra, we determine A _{b overlineb}=0.086±0.015±0.007 and A _{c overlinec}=0.083±0.038±0.027 at the effective center-of-mass energy √ s=91.24 GeV. These measurements yield a value of the electroweak mixing angle sin²overlineθ_w=0.2336±0.0029 .