Holographic Meson Melting

TL;DR

This paper models meson melting in a high-temperature plasma using holographic duality, analyzing D7-brane fluctuations and quasinormal modes to understand meson stability and relaxation times.

Contribution

It introduces a holographic approach to study meson melting via D7-brane quasinormal modes, linking meson stability to black hole embeddings in AdS space.

Findings

Quasinormal modes determine meson relaxation times.

Mesons melt at high temperatures modeled by D7-brane embeddings.

Potential application to quarkonium suppression in quark-gluon plasma.

Abstract

The plasma phase at high temperatures of a strongly coupled gauge theory can be holographically modelled by an AdS black hole. Matter in the fundamental representation and in the quenched approximation is introduced through embedding D7-branes in the AdS-Schwarzschild background. Low spin mesons correspond to the fluctuations of the D7-brane world volume. As is well known by now, there are two different kinds of embeddings, either reaching down to the black hole horizon or staying outside of it. In the latter case the fluctuations of the D7-brane world volume represent stable low spin mesons. In the plasma phase we do not expect mesons to be stable but to melt at sufficiently high temperature. We model the late stages of this meson melting by the quasinormal modes of D7-brane fluctuations for the embeddings that do reach down to the horizon. The inverse of the imaginary part of the quasinormal frequency gives the typical relaxation time back to equilibrium of the meson perturbation in the hot plasma. We briefly comment on the possible application of our model to quarkonium suppression.