A light dilaton in a metastable vacuum

TL;DR

This paper identifies a parametrically light dilaton in metastable vacua of supergravity backgrounds dual to confining field theories, revealing a connection between phase transitions and light scalar states.

Contribution

It demonstrates the emergence of a light dilaton in metastable vacua within a holographic framework, linking phase transitions to scalar mass properties.

Findings

A light dilaton appears near phase transitions in metastable vacua.

Stable and unstable solutions are characterized within the supergravity backgrounds.

The light scalar inherits properties of the dilaton despite not being extremely light.

Abstract

We identify a parametrically light dilaton by studying the perturbations of metastable vacua along a branch of regular supergravity backgrounds that are dual to four-dimensional confining field theories. The branch includes also stable and unstable solutions. The former encompass, as a special case, the geometry proposed by Witten as a holographic model of confinement. The latter approach a supersymmetric solution, by enhancing a condensate in the dual field theory. A phase transition separates the space of stable backgrounds from the metastable ones. In proximity of the phase transition, one of the lightest scalar states inherits some of the properties of the dilaton, despite not being particularly light.