The lifetimes of the B+ and B0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z0 decays recorded at LEP. Z0 → bb̄ decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructed charged and neutral secondary vertices selected in this tagged data sample. The results are τΒ+ = 1.643 ± 0.037 ± 0.025 ps τΒ0 = 1.523 ± 0.057 ± 0.053 ps τΒ+/τΒ0 = 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 Z0 decays has been used to search for CP and CPT violating effects by comparison of inclusive b and b hadron decays. No evidence for such effects is seen. The CP violation parameter Re(∈Β) is measured to be Re(∈Β) = 0.001 ± 0.014 ± 0.003 and the fractional difference between b and b̄ hadron lifetimes is measured to be (Δτ/τ)b ≡ τ(b hadron) - τ(b̄ hadron)/τ(average) = -0.001 ± 0.012 ± 0.008.
ASJC Scopus subject areas
- Engineering (miscellaneous)
- Physics and Astronomy (miscellaneous)