Observation of the decay Λb0 → χc1

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  • LHCb Collaboration

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  • Nikhef National Institute for Subatomic Physics
  • University of Zurich
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The Cabibbo-suppressed decay Λb0→ χc1 is observed for the first time using data from proton-proton collisions corresponding to an integrated luminosity of 6 fb−1, collected with the LHCb detector at a centre-of-mass energy of 13 TeV. Evidence for the Λb0→ χc2 decay is also found. Using the Λb0→ χc1pK decay as normalisation channel, the ratios of branching fractions are measured to be

B(Λb0→χc1)/B(Λb0→χc1pK) = (6.59±1.01±0.22)×10−2,
B(Λb0→χc2)/B(Λb0→χc1) = 0.95±0.30±0.04±0.04,
B(Λb0→χc2pK)/B(Λb0→χc1pK) = 1.06±0.05±0.04±0.04,

where the first uncertainty is statistical, the second is systematic and the third is due to the uncertainties in the branching fractions of χc1,2→ J/ψγ decays. [Figure not available: see fulltext.]

Bibliographic note

Publisher Copyright: © 2021, The Author(s).


Original languageEnglish
Article number95
Number of pages21
JournalJournal of High Energy Physics
Issue number5
Publication statusPublished - 12 May 2021


  • B physics, Branching fraction, Hadron-Hadron scattering (experiments), QCD, Quarkonium

ASJC Scopus subject areas