Charm mass effects in bulk channel correlations
Abstract
The bulk viscosity of thermalized QCD matter at temperatures above a few hundred MeV could be significantly influenced by charm quarks because their contribution arises four perturbative orders before purely gluonic effects. In an attempt to clarify the challenges of a lattice study, we determine the relevant imaginary-time correlator (of massive scalar densities) up to NLO in perturbation theory, and compare with existing data. We find discrepancies much larger than in the vector channel; this may hint, apart from the importance of taking a continuum limit, to larger non-perturbative effects in the scalar channel. We also recall how a transport peak related to the scalar density spectral function encodes non-perturbative information concerning the charm quark chemical equilibration rate close to equilibrium.
Cite
@article{arxiv.1309.1573,
title = {Charm mass effects in bulk channel correlations},
author = {Y. Burnier and M. Laine},
journal= {arXiv preprint arXiv:1309.1573},
year = {2015}
}
Comments
24 pages. v2: clarifications added, published version