Precision Measurements of the b Forward-Backward Asymmetry at the Z Pole from LEP

The four LEP experiments have measured the forward-backward asymmetry for the process e + e − → Z → b b at centre-of-mass energies close to mz with very high precision. Sophisticated techniques have been developed to reconstruct either the production flavour in exclusive final states like B → l ± , or the hemisphere charge on a large-size b-enriched sample. The two methods provide largely independent determinations of A FB b and are briefly presented.