Three Extra Mirror or Sequential Families: a Case for Heavy Higgs and Inert Doublet

TL;DR

This paper explores a theoretical model with three additional fermion families and an inert Higgs doublet, predicting a heavy Standard Model-like Higgs, heavy quarks, light neutral leptons, and an inert scalar, with implications for dark matter.

Contribution

It introduces a scenario with three extra mirror fermion families and an inert Higgs doublet, consistent with current constraints and predicting specific heavy particle masses.

Findings

Standard Model Higgs mass above 400 GeV

Heavy new quarks between 340 and 500 GeV

Inert scalar mass below M_Z

Abstract

We study the possibility of the existence of extra fermion families and an extra Higgs doublet. We find that requiring the extra Higgs doublet to be inert leaves space for three extra families, allowing for mirror fermion families and a dark matter candidate at the same time. The emerging scenario is very predictive: it consists of a Standard Model Higgs boson, with mass above 400\,\GeV, heavy new quarks between 340 and 500\,\GeV, light extra neutral leptons, and an inert scalar with a mass below $M_Z$.