Constraining four-fermion operators using rare top decays

  • Mikael ChalaEmail author
  • Jose Santiago
  • Michael Spannowsky
Open Access
Regular Article - Theoretical Physics


New physics can manifest itself by an appreciable increase of the decay rate of top quarks in rare flavour-changing final states. Exploiting the large top quark production rate at the LHC, we bound four-fermion operators contributing to non-resonant t+j using different signal regions of the latest LHC searches for tZj. We also provide prospects for the high-luminosity LHC to test these as well as four-fermion operators contributing to \( t\to b\overline{b}j \), based on improved analysis strategies of existing searches. We single out all weakly-coupled ultraviolet completions inducing such contact interactions at tree level and translate the previous bounds to the parameter space of specific complete models. Being above the TeV, LHC bounds from rare top decays improve over those from flavour physics, electroweak precision data and other LHC searches in several cases.


Beyond Standard Model Effective Field Theories 


Open Access

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.


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Copyright information

© The Author(s) 2019

Authors and Affiliations

  1. 1.Institute of Particle Physics Phenomenology, Physics DepartmentDurham UniversityDurhamU.K.
  2. 2.CAFPE and Departamento de Física Teórica y del CosmosUniversidad de GranadaGranadaSpain

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