Measurement of the e(sup +)e(sup (minus)) (yields) b(bar b) cross section and forward-backward charge asymmetry at a center-of-mass energy of 57.2 GeV.

摘要

Measurements of the e(sup +)e(sup (minus)) (yields) b(bar b) forward-backward charge asymmetry, A(sub b), and the ratio of the cross-section for e(sup +)e(sup (minus)) (yields) b(bar b) to the theoretical QED cross-section for e(sup +)e(sup (minus)) (yields) (mu)(sup +)(mu)(sup (minus)), R(sub b), at an average center-of-mass energy of 57.2 GeV are reported. We use 196 multihadronic inclusive muon events corresponding to an integrated luminosity of 33.3 pb(sup (minus)1) accumulated by the AMY detector at TRISTAN. The results, A(sub b) = (minus)0.82 (plus minus) 0.25(stat) (plus minus) 0.14(syst) and R(sub b) = 0.47 (plus minus) 0.12 (plus minus) 0.10 are consistent with the standard model predictions of (minus)0.58 and 0.56, respectively. The results for the charge asymmetry are used to set a 90% confidence level limit on (chi), the B(sup 0) (minus) (bar B)(sup 0) mixing parameter, of (chi) < 0.20. 15 refs., 5 figs.