English

Masses of a Fourth Generation with Two Higgs Doublets

High Energy Physics - Phenomenology 2015-06-05 v2 High Energy Physics - Experiment

Abstract

We use sampling techniques to find robust constraints on the masses of a possible fourth sequential fermion generation from electroweak oblique variables. We find that in the case of a light (115 GeV) Higgs from a single electroweak symmetry breaking doublet, inverted mass hierarchies are possible for both quarks and leptons, but a mass splitting more than M(W) in the quark sector is unlikely. We also find constraints in the case of a heavy (600 GeV) Higgs in a single doublet model. As recent data from the Large Hadron Collider hints at the existence of a resonance at 124.5 GeV and a single Higgs doublet at that mass is inconsistent with a fourth fermion generation, we examine a type II two Higgs doublet model. In this model, there are ranges of parameter space where the Higgs sector can potentially counteract the effects of the fourth generation. Even so, we find that such scenarios produce qualitatively similar fermion mass distributions.

Keywords

Cite

@article{arxiv.1205.5580,
  title  = {Masses of a Fourth Generation with Two Higgs Doublets},
  author = {Leo Bellantoni and Jens Erler and Jonathan J. Heckman and Enrique Ramirez-Homs},
  journal= {arXiv preprint arXiv:1205.5580},
  year   = {2015}
}

Comments

v2: 9 pages, 7 figures, improved analysis of Higgs decay constraints, typos corrected and reference added