Measurement of the branching ratio for the process b -> t-.hivin.ntX.

The inclusive branching ratio for the process b -> t-.hivin.ntX was measured using hadronic Z decays collected by the OPAL expt. at LEP in the years 1992-2000. The result is BR(b -> t-.hivin.ntX) = (2.78 +- 0.18 +- 0.51)%. This measurement is consistent with the Std. Model expectation and puts a constraint of tanb/MH+- <0.53 GeV-1 at the 95% confidence level on Type II two Higgs doublet models. [on SciFinder (R)]