Z-decays to b quarks and the Higgs boson mass

A model independent analysis of the most recent averages of precision electroweak data from LEP and SLD finds a 3 sigma deviation of the parameter A(b) from the standard model prediction. The fitted value of m(H) shows a strong dependence on the inclusion or exclusion of b quark data, and the standard model fits have poor confidence levels of a few percent when the latter are included. The good fits obtained to lepton data, c quark data and the directly measured top quark mass, give m(t) = 171.2+/-(+3.7)(3.8) GeV and indicate that the Higgs boson mass is most likely less than 200 GeV.