Measurements of the b(b)over-bar production cross section and forward-backward asymmetry at centre-of-mass energies above the Z pole at LEP

The measurements of R(b) = sigma(e(+)e(-) --> b (b) over bar)/sigma(e(+)e(-) --> q (q) over bar) and of the b quark forward-backward charge asymmetry, A(fb)(b), at centre-of-mass energies above the Z pole an described. The measurement of R(b) is performed at root 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(fb)(b) is performed using the large statistics event sample collected at root s = 189 GeV with a lepton-tag analysis based on the selection of prompt muons and electrons. The results at root s = 189 GeV are R(b) = 0.163 +/- 0.013 (stat.) +/- 0.005 (syst.), A(fb)(b) = 0.61 +/- 0.18 (stat.) +/- 0.09 (syst.). (C) 2000 Elsevier Science B.V, All rights reserved.