# How brightly does the Glasma shine? Photon production off-equilibrium

## TL;DR

This paper estimates photon production during the early off-equilibrium Glasma phase in heavy-ion collisions, highlighting its significance relative to thermalized plasma, especially at high saturation scales.

## Contribution

It provides a parametric estimate of photon emission from the Glasma, incorporating constraints from experimental data and comparing it to thermalized plasma contributions.

## Key findings

- Glasma photon production is significant at large saturation scales.
- Off-equilibrium phase contributes notably before thermalization.
- Results depend on the saturation scale value.

## Abstract

We present a parametric estimate of photon production at early times in heavy-ion collisions based on a consistent weak coupling thermalization scenario. We quantify the contribution of the off-equilibrium Glasma phase relative to that of a thermalized Quark-Gluon Plasma. Taking into account the constraints from charged hadron multiplicity data, the Glasma contribution is found to be significant especially for large values of the saturation scale.