The Free Energy of High Temperature QED to Order $e^{5}$ From Effective Field Theory

Massless quantum electrodynamics is studied at high temperature and zero chemical potential. We compute the Debye screening mass to order $e^{4}$ and the free energy to order $e^{5}$} by an effective field theory approach, recently developed by Braaten and Nieto. Our results are in agreement with calculations done in resummed perturbation theory. This method makes it possible to separate contributions to the free energy from different momentum scales (order $T$ and $eT$) and provides an economical alternative to computations in the full theory which involves the dressing of internal propagators.