126 GeV Higgs boson in the top-seesaw model

TL;DR

This paper explores a top-seesaw model with a fourth generation of vector-like quarks, fitting LHC Higgs data and predicting new states, providing an alternative explanation for electroweak symmetry breaking.

Contribution

It develops a low-energy effective theory of a top-seesaw model including third-generation matter, constrained by electroweak data and LHC Higgs measurements.

Findings

Model fits LHC Higgs data as well as the Standard Model.

Predicts new states accessible at the LHC.

Provides a viable alternative for electroweak symmetry breaking.

Abstract

We consider a model of dynamical electroweak symmetry breaking built on the idea of top-seesaw mechanism. The model features a fourth generation of vector-like QCD quarks responsible for the origin of the top-seesaw mechanism and leading to the natural explanation of the large splitting between the top and bottom quark masses. Motivated by the LHC data on the couplings of the Higgs boson, we include the entire third generation of Standard Model matter fields into the model. We determine the low energy effective theory and the resulting low energy spectrum of states, and constrain the model parameters with constraints from the precision electroweak data and from the requirement of a light scalar state with quantum numbers of the Standard Model Higgs boson. Finally, we perform a global fit of the model parameters to the LHC Higgs data and show that the model is equally viable as the Standard Model itself, and predicts new states accessible at the LHC.