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

According to a proposal by Arnold and Yaffe, the non-perturbative g(2)T-con tribution to the Debye mass in the deconfined QCD plasma phase can be deter mined 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 accu rate and smaller than that obtained previously with another method, but sti ll very large compared with the naive expectation: the correction is larger than the leading term up to T similar to 10(7)T(c), corresponding to g(2) similar to 0.4. At moderate temperatures T similar to 2T(c), a consistent p icture emerges where the Debye mass is m(D) similar to 6T, the lightest gau ge invariant screening mass in the system is similar to 3T, and the purely magnetic operators couple dominantly to a scale similar to 6T. Electric (si milar to gT) and magnetic (similar to g(2)T) scales are therefore strongly overlapping close to the phase transition, and the colour-electric fields p lay an essential role in the dynamics. (C) 1999 Published by Elsevier Scien ce B.V. All rights reserved.