Measurements of the bb~ production cross section and forward backward asymmetry at centre-of-mass energies above the Z pole at LEP

The measurements of R b = σ (e + e − → b¯b) /σ (e + e − → q¯q) and of the b quark forward–backward charge asymmetry, A bfb , at centre–of–mass energies above the Z pole are described. The measurement of R b is performed at √ s between 130 and 189 GeV using a b–tagging method that exploits the relatively large decay length of b–hadrons. The measurement of A bfb is performed using the large statistics event sample collected at √ s = 189 GeV with a lepton–tag analysis based on the selection of prompt muons and electrons. The results at √ s = 189 GeV are: the of Prof. Bianca Monteleoni Submitted Phys. Lett. B