Search for the lepton-flavour violating decays B(s)0→e±μ

Research output: Contribution to journalArticlepeer-review


  • LHCb Collaboration

Colleges, School and Institutes

External organisations

  • European Organization for Nuclear Research (CERN)
  • Universidad de Santiago de Compostela
  • LPC
  • University of Cincinnati
  • Technische Universität Dortmund
  • University of Glasgow
  • Universitat Autònoma de Barcelona
  • Nikhef National Institute for Subatomic Physics
  • Petersburg Nuclear Physics Institute (PNPI)
  • Imperial College London
  • Universidade Federal Do Rio de Janeiro (UFRJ)
  • Department of Physics and Astronomy and INFN
  • IN2P3
  • Tsinghua University
  • Department of Biology and Evolution; University of Ferrara; Ferrara; Italy
  • University of Maryland, College Park, Maryland 20742 USA
  • University of Manchester
  • Ruprecht-Karls-Universität Heidelberg
  • CNRS/IN2P3
  • Institute for High Energy Physics (IHEP)
  • Syracuse University, Syracuse, New York 13244, USA
  • Universität Zürich
  • Universitat Ramon Llull
  • Pontifícia Universidade Católica Do Rio de Janeiro (PUC-Rio)
  • Laboratoire Leprince-Ringuet


A search for the lepton-flavour violating decays Bs0→e±μ and B0→e±μ is performed based on a sample of proton-proton collision data corresponding to an integrated luminosity of 3 fb−1, collected with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The observed yields are consistent with the background-only hypothesis. Upper limits on the branching fraction of the Bs0→e±μ decays are evaluated both in the hypotheses of an amplitude completely dominated by the heavy eigenstate and by the light eigenstate. The results are @/@ℬ(Bs0→e)<6.3(5.4)×10−9 and @/@ℬ(Bs0→e)<7.2(6.0)×10−9 at 95% (90%) confidence level, respectively. The upper limit on the branching fraction of the B0 → e±μ decay is also evaluated, obtaining @/@ℬ(B0→e)<1.3(1.0)×10−9 at 95% (90%) confidence level. These are the strongest limits on these decays to date.


Original languageEnglish
Article number78
Number of pages20
JournalJournal of High Energy Physics
Issue number3
Publication statusPublished - 13 Mar 2018


  • B physics, Branching fraction, Flavor physics, Hadron-Hadron scattering (experiments), Rare decay

ASJC Scopus subject areas