Light Higgs and Vector-like Quarks without Prejudice

TL;DR

This paper explores how dimension five operators involving light vector-like quarks can significantly alter Higgs boson properties, providing new insights into solutions for the electroweak hierarchy problem beyond renormalizable models.

Contribution

It systematically analyzes the impact of leading dimension five operators on Higgs phenomenology with vector-like quarks, considering experimental constraints and implications for LHC searches.

Findings

Significant modifications of Higgs properties are possible with dimension five operators.

Constraints from precision electroweak and flavor observables are considered.

Higher dimensional operators influence direct searches for vector-like quarks at the LHC.

Abstract

Light vector-like quarks with non-renormalizable couplings to the Higgs are a common feature of models trying to address the electroweak (EW) hierarchy problem by treating the Higgs as a pseudo-goldstone boson of a global (approximate) symmetry. We systematically investigate the implications of the leading dimension five operators on Higgs phenomenology in presence of dynamical up- and down-type weak singlet as well as weak doublet vector-like quarks. After taking into account constraints from precision EW and flavour observables we show that contrary to the renormalizable models, significant modifications of Higgs properties are still possible and could shed light on the role of vector-like quarks in solutions to the EW hierarchy problem. We also briefly discuss implications of higher dimensional operators for direct vector-like quark searches at the LHC.