Journal of High Energy Physics

, 2019:32 | Cite as

On lepton number violation in heavy neutrino decays at colliders

  • Marco Drewes
  • Juraj KlarícEmail author
  • Philipp Klose
Open Access
Regular Article - Theoretical Physics


We study the perspective to observe lepton number violating signatures from heavy Majorana neutrino decays at colliders in view of the requirement to explain the light neutrino masses via the seesaw mechanism. In the minimal model with only two heavy neutrinos and in the νMSM one can identify three distinct regions in the mass- mixing plane. For Majorana masses above the electroweak scale the branching ratio for lepton number violating processes at the LHC is generically suppressed. For masses well below the electroweak scale that are probed in displaced vertex searches or at fixed target experiments lepton number violation is the rule and can only be avoided at the cost of fine tuning. In between there is a mass regime where both possibilities coexist. In models with more than two heavy neutrinos the larger parameter space allows for more freedom, but our results remain qualitatively correct unless there is a mass degeneracy amongst more than two of the heavy neutrinos.


Beyond Standard Model Neutrino Physics 


Open Access

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© The Author(s) 2019

Authors and Affiliations

  1. 1.Centre for Cosmology, Particle Physics and PhenomenologyUniversité catholique de LouvainLouvain-la-NeuveBelgium
  2. 2.Institute of Physics, Laboratory for Particle Physics and Cosmology (LPPC)Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland

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