# XQCD 2016

1-3 August 2016
Plymouth University
Europe/London timezone
The 14th International workshop on QCD in extreme conditions, Aug. 1-3 2016

## Lattice constraints on the thermal photon rate

1 Aug 2016, 14:00
25m
Portland Square (Plymouth University)

### Portland Square

#### Plymouth University

Drake Circus Plymouth, Devon PL4 8AA, UK
Talk Transport properties and probes

### Speaker

Dr Olaf Kaczmarek (University of Bielefeld)

### Description

We estimate the photon production rate from an SU(3) plasma at temperatures of about $1.1~T_c$ and $1.3~T_c$. Lattice results for the vector current correlator at spatial momenta $k\sim (2-6)T$ are extrapolated to the continuum limit and analyzed with the help of a polynomial interpolation for the corresponding spectral function, which vanishes at zero frequency and matches to high-precision perturbative results at large invariant masses. For small invariant masses the interpolation is compared with the NLO weak-coupling result, hydrodynamics, and a holographic model. At vanishing invariant mass we extract the photon rate which for $k \sim 3T$ is found to be close to the NLO weak-coupling prediction. For $k \sim 2T$ uncertainties remain large but the photon rate is likely to fall below the NLO prediction, in accordance with the onset of a strongly interacting behaviour characteristic of the hydrodynamic regime.

### Primary author

Dr Olaf Kaczmarek (University of Bielefeld)

### Presentation Materials

 Slides Video