Measurement of lambda(b) production and lifetime in Z0 hadronic decays

Evidence for the production of b- flavoured baryonsin Z0 decays is reported from the analysis of 365 000 hadronic events collected by the DELPHI detector. Assuming that most of the weakly decaying b flavoured baryonsproduced by the Z0 are Λb, the observed signal of View the MathMLsource pairs, where l is a high transverse momentum lepton in the same jet as the Λ, leads to a production rate: f(b→Λb)×Br(Λb→ΛlνX) = (0.41±0.13±0.09)%. Using a sample of 18 reconstructed Λb decay vertices, the lifetime is determined to be τ(Λb) = (1.04+0.48−0.38±0.10) ps.