On the Gluon Plasmon Self-Energy at O(g)

Abstract

The next-to-leading order contribution $\d¶\omn (ø,\vc q )$ to the polarization function of the hot gluon system is analysed at non-zero wave vectors $\vc q \,$. Using Braaten-Pisarski resummation and general covariant gauges, $\d¶\omn$ is found to be gauge-fixing independent and transverse on the longitudinal mass-shell. The real part of the longitudinal component $\d¶_\ell$ is UV and IR stable (for real $q$). At imaginary $q$ it is IR singular, and at the point $ø=0$, $q^2=-3m^2$ it coincides with the result of Rebhan for next-to-leading order Debye screening. When $q$ approaches the lightcone, $\d¶_\ell $ diverges like $1 / \wu {ø^2 - q^2} $, reflecting the breakdown of the Braaten-Pisarski decomposition scheme in this limit.