Closing in on a perturbative fourth generation

  • Mathieu Buchkremer
  • Jean-Marc Gérard
  • Fabio Maltoni
Article

Abstract

A perturbative new family of fermions is now severely constrained, though not excluded yet. We reconsider the current bounds (i.e., direct and from Higgs searches, Rb, oblique parameters) on the fourth generation parameter space assuming the case of a small CKM mixing with the third generation. We identify viable scenarios featuring either a light or a heavy Higgs boson. A set of representative benchmark points targeted for LHC searches is proposed with a normal (inverted) quark mass hierarchy where \( {t^{\prime }} \to {b^{\prime }}W\left( {{b^{\prime }} \to {t^{\prime }}W} \right) \) are sizable. In the case where the fourth generation couplings to the lighter quark families are small, we suggest that search strategies at the LHC should include both pair (strong) and single (weak) production with bb + nW (n = 2, … , 6) final state signatures.

Keywords

Higgs Physics Beyond Standard Model 

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Copyright information

© SISSA, Trieste, Italy 2012

Authors and Affiliations

  • Mathieu Buchkremer
    • 1
  • Jean-Marc Gérard
    • 1
  • Fabio Maltoni
    • 1
  1. 1.Centre for Cosmology, Particle Physics and Phenomenology (CP3)Université catholique de LouvainLouvain-la-NeuveBelgium

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