Pf. Kelly et al., CLASSICAL TRANSPORT-THEORY AND HARD THERMAL LOOPS IN THE QUARK-GLUON PLASMA, Physical review. D. Particles and fields, 50(6), 1994, pp. 4209-4218
Classical transport theory for colored particles is investigated and e
mployed to derive the hard thermal loops of QCD. A formal construction
of phase space for color degrees of freedom is presented. The gauge i
nvariance of the non-Abelian Vlasov equations is verified and used as
a guiding principle in our approximation scheme. We then derive the ge
nerating functional of hard thermal loops from a constraint satisfied
at leading order by the color current. This derivation is more direct
than alternative ones based on perturbative quantum field theory, and
shows that hard thermal effects in hot QCD are essentially classical.
As an illustration, we analyze color polarization in the QCD plasma.