@article{684ef3411a7a496d9b6de919a0a34cb4,

title = "Test of lepton universality with Λb0→pK− ℓ+ ℓ− decays",

abstract = "The ratio of branching fractions of the decays Λb0 → pK−e+e− and Λb0 → pK−μ+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 → pK−e+e−. [Figure not available: see fulltext.].",

keywords = "B physics, Branching fraction, Flavour Changing Neutral Currents, Hadron- Hadron scattering (experiments), Rare decay",

author = "{The Lhcb Collaboration} and R. Aaij and {Abell{\'a}n Beteta}, C. and T. Ackernley and B. Adeva and M. Adinolfi and H. Afsharnia and Aidala, {C. A.} and S. Aiola and Z. Ajaltouni and S. Akar and P. Albicocco and J. Albrecht and F. Alessio and M. Alexander and {Alfonso Albero}, A. and G. Alkhazov and {Alvarez Cartelle}, P. and Alves, {A. A.} and S. Amato and Y. Amhis and L. An and L. Anderlini and G. Andreassi and M. Andreotti and F. Archilli and {Arnau Romeu}, J. and A. Artamonov and M. Artuso and K. Arzymatov and E. Aslanides and M. Atzeni and B. Audurier and S. Bachmann and Back, {J. J.} and S. Baker and V. Balagura and W. Baldini and A. Baranov and Barlow, {R. J.} and S. Barsuk and W. Barter and M. Bartolini and F. Baryshnikov and G. Bassi and V. Batozskaya and B. Batsukh and A. Battig and Rudolph, {M. S.} and T. Skwarnicki and S. Stone",

note = "Funding Information: This article is distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited",

year = "2020",

month = may,

day = "1",

doi = "10.1007/JHEP05(2020)040",

language = "English (US)",

volume = "2020",

journal = "Journal of High Energy Physics",

issn = "1126-6708",

publisher = "Springer Verlag",

number = "5",

}