Strongly coupled gauge theories: What can lattice calculations teach us?

TL;DR

This paper explores the properties of many-flavor gauge-fermion systems through lattice calculations, revealing potential light scalar particles and predicting a 2 TeV vector resonance relevant for electroweak symmetry breaking models.

Contribution

It provides new numerical insights into the spectrum of strongly coupled gauge theories with both light and massive fermions, highlighting features relevant for beyond Standard Model physics.

Findings

Existence of a light $0^{++}$ isosinglet scalar separated from other states.

Prediction of a 2 TeV vector resonance in SU(3) gauge theories.

Insights into how massive fermions influence infrared dynamics.

Abstract

The dynamical origin of electroweak symmetry breaking is an open question with many possible theoretical explanations. Strongly coupled systems predicting the Higgs boson as a bound state of a new gauge-fermion interaction form one class of candidate models. Due to increased statistics, LHC run II will further constrain the phenomenologically viable models in the near future. In the meanwhile it is important to understand the general properties and specific features of the different competing models. In this work we discuss many-flavor gauge-fermion systems that contain both massless (light) and massive fermions. The former provide Goldstone bosons and trigger electroweak symmetry breaking, while the latter indirectly influence the infrared dynamics. Numerical results reveal that such systems can exhibit a light $0^{++}$ isosinglet scalar, well separated from the rest of the spectrum. Further, when we set the scale via the $vev$ of electroweak symmetry breaking, we predict a 2 TeV vector resonance which could be a generic feature of SU(3) gauge theories.