Measurement of the B+ and B-0 lifetimes and search for CP(T) violation using reconstructed secondary vertices

The lifetimes of the B+ and B-0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z(0) decays recorded at LEP. Z(0) --> b (b) over bar decays were tagged using displaced secondary v ertices and high momentum electrons and muons. The lifetimes were then meas ured using well-reconstructed charged and neutral secondary vertices select ed in this tagged data sample. The results are tau(B+) = 1.643 +/- 0.037 +/- 0.025 ps tau(Bo) = 1.523 +/- 0.057 +/- 0.053 ps tau(B+)/tau(Bo) = 1.079 +/- 0.064 +/- 0.041, where in each case the first error is statistical and the second systematic . A larger data sample of 3.1 million hadronic Z(o) decays has been used to s earch for CP and CPT violating effects by comparison of inclusive b and (b) over bar hadron decays, No evidence fur such effects is seen. The CP viola tion parameter Re(epsilon(B)) is measured to be Re(epsilon(B)) = 0.001 +/- 0.014 +/- 0.003 and the fractional difference between b and (b) over bar hadron lifetimes i s measured to (Delta tau/tau)(b) = tau(b hadron) - tau((b) over bar hadron)/tau(average) = -0.001 +/- 0.012 +/- 0.008.