# Observation of the decays Λ0b→χc1pK− and Λ0b→χc2pK−

Abstract : The first observation of the decays Λ0b→χc1pK− and Λ0b→χc2pK− is reported using a data sample corresponding to an integrated luminosity of 3.0 fb−1, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV. The following ratios of branching fractions are measured B(Λ0b→χc1pK−)B(Λ0b→J/ψpK−)=0.242±0.014±0.013±0.009,B(Λ0b→χc2pK−)B(Λ0b→J/ψpK−)=0.248±0.020±0.014±0.009,B(Λ0b→χc2pK−)B(Λ0b→χc1pK−)=1.02±0.10±0.02±0.05, where the first uncertainty is statistical, the second systematic and the third due to the uncertainty on the branching fractions of the χc1→J/ψγ and χc2→J/ψγ decays. Using both decay modes, the mass of the \Lb baryon is also measured to be mΛ0b=5619.44±0.28±0.26 MeV/c2, where the first and second uncertainties are statistical and systematic, respectively.
Type de document :
Article dans une revue
Physical Review Letters, American Physical Society, 2017, 119, pp. 062001. 〈https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.062001〉. 〈10.1103/PhysRevLett.119.062001〉

http://hal.in2p3.fr/in2p3-01515128
Contributeur : Claudine Bombar <>
Soumis le : jeudi 27 avril 2017 - 09:39:13
Dernière modification le : lundi 12 février 2018 - 11:28:17

### Citation

R. Aaij, L. Beaucourt, M. Chefdeville, D. Decamp, N. Déléage, et al.. Observation of the decays Λ0b→χc1pK− and Λ0b→χc2pK−. Physical Review Letters, American Physical Society, 2017, 119, pp. 062001. 〈https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.119.062001〉. 〈10.1103/PhysRevLett.119.062001〉. 〈in2p3-01515128〉

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