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Four generations and Higgs physics

Graham D. Kribs1, Tilman Plehn2, Michael Spannowsky3, and Tim M. P. Tait4

  • 1Department of Physics and Institute of Theoretical Science, University of Oregon, Eugene, Oregon 97403, USA
  • 2SUPA, School of Physics, University of Edinburgh, Edinburgh EH9 3JZ, Scotland
  • 3ASC, Department für Physik, Ludwig-Maximilians-Universität München, 80333 München, Germany
  • 4HEP Division, Argonne National Laboratory, 9700 Cass Avenue, Argonne, Illinois 60439, USA

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Phys. Rev. D 76, 075016 – Published 26 October, 2007

DOI: https://doi.org/10.1103/PhysRevD.76.075016

Abstract

In the light of the LHC, we revisit the implications of a fourth generation of chiral matter. We identify a specific ensemble of particle masses and mixings that are in agreement with all current experimental bounds as well as minimize the contributions to electroweak precision observables. Higgs masses between 115–315 (115–750) GeV are allowed by electroweak precision data at the 68% and 95% C.L. Within this parameter space, there are dramatic effects on Higgs phenomenology: production rates are enhanced, weak-boson-fusion channels are suppressed, angular distributions are modified, and Higgs pairs can be observed. We also identify exotic signals, such as Higgs decay to same-sign dileptons. Finally, we estimate the upper bound on the cutoff scale from vacuum stability and triviality.

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Phys. Rev. D 76, 075016– Published 26 October, 2007
  • Received 24 July 2007

© 2007 American Physical Society

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