The non-perturbative QCD Debye mass from a Wilson line operator

According to a proposal by Arnold and Yaffe, the non-perturbative g2T-contribution to the Debye mass in the deconfined QCD plasma phase can be determined from a single Wilson line operator in the three-dimensional pure SU(3) gauge theory. We extend a previous SU(2) measurement of this quantity to the physical SU(3) case. We find a numerical coefficient which is more accurate and smaller than that obtained previously with another method, but still very large compared with the naive expectation: the correction is larger than the leading term up to T∼107Tc, corresponding to g2∼0.4. At moderate temperatures T∼2Tc, a consistent picture emerges where the Debye mass is mD∼6T, the lightest gauge invariant screening mass in the system is ∼3T, and the purely magnetic operators couple dominantly to a scale ∼6T. Electric (∼gT) and magnetic (∼g2T) scales are therefore strongly overlapping close to the phase transition, and the colour-electric fields play an essential role in the dynamics.