# Photon production spectrum above $T_c$ with a lattice quark propagator

## TL;DR

This study computes the photon production rate in a deconfined medium above the critical temperature using a lattice-derived quark propagator, finding results consistent with perturbative predictions at higher photon energies.

## Contribution

It introduces a nonperturbative approach to calculate photon production rates using lattice QCD quark propagators and the Schwinger-Dyson equation, ensuring gauge invariance.

## Key findings

- Photon production rate aligns with perturbative results above 0.5 GeV.
- Lattice-based quark propagator effectively models photon emission in deconfined matter.
- Method bridges lattice QCD and phenomenological photon production calculations.

## Abstract

The photon production rate from the deconfined medium is analyzed with the photon self-energy constructed from the quark propagator obtained by the numerical simulation on the quenched lattice for two values of temperature, $T=1.5T_{\rm c}$ and $3T_{\rm c}$, above the critical temperature $T_{\rm c}$. The photon self-energy is calculated by the Schwinger-Dyson equation with the lattice quark propagator and a vertex function determined so as to satisfy the Ward-Takahashi identity. The obtained photon production rate exhibits a similar behavior as the perturbative results at the energy of photons larger than $0.5$~GeV.