Mesons versus quasi-normal modes: undercooling and overheating

TL;DR

This paper investigates the relationship between meson spectra and quasi-normal modes in holographic gauge theories, revealing that overheated mesons become infinitely degenerate and no smooth spectrum connection exists in the Sakai-Sugimoto model.

Contribution

It provides a detailed analysis of meson and quasi-normal mode spectra near phase transition points in holographic models, highlighting the complexity of their connection.

Findings

Overheated meson masses become infinitely degenerate.

No smooth connection exists between meson and quasi-normal mode spectra in the Sakai-Sugimoto model.

The relationship between spectra is more subtle than previously thought.

Abstract

In holographic models of gauge theories with matter, there generically exists a first order phase transition in which mesons dissociate. We perform a careful analysis of the meson and quasi-particle spectra in the overheated resp. undercooled regimes close to the junction of the two phases. We show that all overheated finite meson masses eventually become infinitely degenerate, which implies that any connection to the quasi-particle spectrum is more subtle than previously suggested. For the Sakai-Sugimoto model no smooth connection between these spectra is possible.