Search for heavy neutral leptons in W+μ+μ±jet decays

Research output: Contribution to journalArticlepeer-review


  • LHCb Collaboration

Colleges, School and Institutes

External organisations

  • CERN
  • Nikhef National Institute for Subatomic Physics
  • University of Zurich
  • University of Liverpool
  • Universidad de Santiago de Compostela
  • University of Bristol
  • Université Clermont Auvergne
  • University of Michigan
  • Istituto Nazionale di Fisica Nucleare, Sezione di Milano
  • University of Cincinnati
  • Technische Universität Dortmund
  • University of Glasgow
  • Universitat Autonoma de Barcelona
  • University of Manchester
  • Petersburg Nuclear Physics Institute (PNPI)
  • Universidade Federal Do Rio de Janeiro
  • Université Paris-Saclay
  • Sezione INFN di Firenze
  • Sezione INFN di Ferrara
  • Ruprecht-Karls-Universität Heidelberg
  • Institute for High Energy Physics (IHEP)
  • Syracuse University
  • Yandex School of Data Analysis
  • IN2P3
  • Ecole Polytechnique Federale de Lausanne
  • University of Warwick
  • Imperial College London
  • Sezione di Perugia
  • Instituto Galego de Física de Altas Enerxías (IGFAE)
  • Chinese Academy of Sciences


A search is performed for heavy neutrinos in the decay of a W boson into two muons and a jet. The data set corresponds to an integrated luminosity of approximately 3.0fb-1 of proton–proton collision data at centre-of-mass energies of 7 and 8TeV collected with the LHCb experiment. Both same-sign and opposite-sign muons in the final state are considered. Data are found to be consistent with the expected background. Upper limits on the coupling of a heavy neutrino with the Standard Model neutrino are set at 95 % confidence level in the heavy-neutrino mass range from 5 to 50GeV/c2. These are of the order of 10 - 3 for lepton-number-conserving decays and of the order of 10 - 4 for lepton-number-violating heavy-neutrino decays.

Bibliographic note

Publisher Copyright: © 2021, CERN for the benefit of the LHCb collaboration.


Original languageEnglish
Article number248
Number of pages15
JournalEuropean Physical Journal C
Issue number3
Publication statusPublished - 22 Mar 2021