Light scalar spectrum in extra-dimensional gauge theories

TL;DR

This paper investigates the non-perturbative light scalar spectrum in five-dimensional SU(2) gauge theories with a compactified dimension, revealing how effective four-dimensional scalar fields emerge and interact with glueball states.

Contribution

It demonstrates how to control the scale hierarchy non-perturbatively and studies the emergence and mixing of light scalar states from the five-dimensional lattice theory.

Findings

Existence of a set of strong bare couplings where the theory behaves effectively four-dimensional.

Identification of a light scalar in the spectrum arising from extra-dimensional dynamics.

Analysis of scalar-glueball mixing to confirm the extra-dimensional origin of light scalars.

Abstract

The phase diagram of five-dimensional SU(2) gauge theories with one compactified dimension on anisotropic lattices has a rich structure. In this contribution we show how to control non-perturbatively the scale hierarchy between the cut-off and the compactification scale in the bare parameter space. There exists a set of strong bare couplings where the the five-dimensional lattice theory can be described by an effective four-dimensional theory with a scalar field in the adjoint representation. We present a detailed study of the light scalar spectrum as it arises from the non-perturbative dynamics of the full five-dimensional lattice theory. We also investigate the mixing with scalar glueball states in the attempt to further establish the extra-dimensional nature of light scalar states.