# A Photon Peak due to Strong Coupling

## TL;DR

This paper predicts a universal photon peak in the spectrum of strongly coupled quark-gluon plasmas due to bound vector mesons with subluminal velocities, potentially observable at the LHC.

## Contribution

It demonstrates that a photon peak from bound mesons is a universal feature of strongly coupled plasmas with gravity duals, with specific predictions for the J/Ψ meson.

## Key findings

- A photon peak between 3 and 5 GeV for J/Ψ at the LHC
- Universal property of photon peaks in strongly coupled plasmas with gravity duals
- Bound vector mesons produce observable photon signals in quark-gluon plasma

## Abstract

We show that if a flavour-less vector meson remains bound after deconfinement, and if its limiting velocity in the quark-gluon plasma is subluminal, then this meson produces a distinct peak in the spectrum of thermal photons emitted by the plasma. We also demonstrate that this effect is a universal property of all strongly coupled, large-$\nc$ plasmas with a gravity dual. For the $J/\Psi$ the corresponding peak lies between 3 and 5 GeV and could be observed at the LHC.