Test of lepton universality with Λb0→pK− ℓ+ ℓ− decays

The Lhcb Collaboration

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64 Scopus citations


The ratio of branching fractions of the decays Λb0 → pKe+e and Λb0 → pKμ+μ,RpK−1, is measured for the first time using proton-proton collision data corresponding to an integrated luminosity of 4.7 fb−1 recorded with the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV. In the dilepton mass-squared range 0.1 < q2< 6.0 GeV2/c4 and the pK mass range m(pK) < 2600 MeV/c2, the ratio of branching fractions is measured to be RpK−1=1.17−0.16+0.18±0.07, where the first uncertainty is statistical and the second systematic. This is the first test of lepton universality with b baryons and the first observation of the decay Λb0 → pKe+e. [Figure not available: see fulltext.].

Original languageEnglish (US)
Article number40
JournalJournal of High Energy Physics
Issue number5
StatePublished - May 1 2020


  • B physics
  • Branching fraction
  • Flavour Changing Neutral Currents
  • Hadron- Hadron scattering (experiments)
  • Rare decay

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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