The damping rate γt(p) of on-shell transverse gluons with ultrasoft momentum p is obtained in the context of next-to-leading-order hard-thermal-loop-summed perturbation of high-temperature massless quantum chromodynamics (QCD). It is obtained in an expansion to the second order in p. The first coefficient known in the literature is recovered, but that of order p2 is found to be divergent in the infrared. Divergences from light-like momenta do also occur but are circumvented. By carrying out similar calculations in the context of scalar quantum electrodynamics, it is shown that early and late external-momentum expansions yield identical results.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Mathematical Physics
- Condensed Matter Physics