Using approximately 4 million hadronic Ζ decays recorded with the ALEPH detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact parameter distribution of candidate leptons in 1063 events with Λℓ- combinations, the average b baryon lifetime is measured to be 1.20 ± 0.08 ± 0.06 ps. From a sample of 193 fully reconstructed Λ+c candidates correlated with a lepton and a sample of 46 Λℓ+ℓ- combinations, the Λb lifetime is measured to be 1.21 ± 0.11 ps. The product branching fractions to these final states are Br(b → Λbb) · Br(Λb → Λℓ-v̄X) = 0.326 ± 0.016 ± 0.039% for the first sample and Br(b → Λb) · Br(Λb → Λ+cℓ-v̄X) = 0.86 ± 0.07 ± 0.14% for the second and third samples combined.
|Original language||English (US)|
|Number of pages||15|
|Journal||European Physical Journal C|
|State||Published - 1998|
ASJC Scopus subject areas
- Engineering (miscellaneous)
- Physics and Astronomy (miscellaneous)