https://doi.org/10.1140/epjc/s10052-018-5593-7
Regular Article - Theoretical Physics
Finite-temperature gluon spectral functions from 
lattice QCD
1
Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, Joliot-Curie Str. 6, 141980, Dubna, Russia
2
Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120, Heidelberg, Germany
3
ExtreMe Matter Institute EMMI, GSI Helmholtzzentrum für Schwerionenforschung mbH, 64291, Darmstadt, Germany
4
Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 12, 69120, Heidelberg, Germany
* e-mail: rothkopf@thphys.uni-heidelberg.de
Received:
26
July
2017
Accepted:
26
January
2018
Published online:
14
February
2018
We investigate gluon correlation functions and spectral functions at finite temperature in Landau gauge on lattice QCD ensembles with dynamical twisted-mass quarks flavors, generated by the tmfT collaboration. They cover a temperature range from 
using the fixed-scale approach. Our study of spectral properties is based on a novel Bayesian approach for the extraction of non-positive-definite spectral functions. For each binned spatial momentum we take into account the gluon correlation functions at all available discrete imaginary frequencies. Clear indications for the existence of a well defined quasi-particle peak are obtained. Due to a relatively small number of imaginary frequencies available, we focus on the momentum and temperature dependence of the position of this spectral feature. The corresponding dispersion relation reveals different in-medium masses for longitudinal and transversal gluons at high temperatures, qualitatively consistent with weak coupling expectations.
© The Author(s), 2018
