par Alderweireld, Thomas;Alemany-Fernandez, Reyes;Augustinus, André;Baillon, P.;Battaglia, Marco;Begalli, Márcia;Benvenuti, A.;Bertrand, Daniel 
; [et al.]
Référence European Physical Journal C. Particles and Fields, 44, 3, page (299-309)
Publication Publié, 2005-10
; [et al.]Référence European Physical Journal C. Particles and Fields, 44, 3, page (299-309)
Publication Publié, 2005-10
Article révisé par les pairs
| Résumé : | The charmed strange baryon Ξc0 was searched for in the decay channel Ξc0 → Ξ-π+, and the beauty strange baryon Ξb in the inclusive channel Ξb → Ξ-ℓ-νX, using the 3.5 million hadronic Z events collected by the DELPHI experiment in the years 1992-1995. The Ξ- was reconstructed through the decay Ξ- → Λπ-, using a constrained fit method for cascade decays. An iterative discriminant analysis was used for the Ξc0 and Ξb selection. The production rates were measured to be fΞ0 c ×BR(Ξc0 → Ξ-π+) = (4.7 ± 1.4(stat.) ± 1.1(syst.)) × 10-4 per hadronic Z decay, and BR(b → Ξb)×BR(Ξb → Ξ-ℓ-X) = (3.0 ± 1.0(stat.) ± 0.3(syst.)) × 10-4 for each lepton species (electron or muon). The lifetime of the Ξb baryon was measured to be τΞ b = 1.45+0.55 -0.43(stat.) ± 0.13(syst.) ps. A combination with the previous DELPHI lifetime measurement gives τΞ b = 1.48+0.40 -0.31(stat.) ± 0.12(syst.) ps. © Springer-Verlag / Società Italiana di Fisica 2005. |
