Three-loop Phi-derivable Approximation in QED
High Energy Physics - Phenomenology
2009-11-10 v2
Abstract
In this paper we examine Phi-derivable approximations in QED. General theorems tell us that the gauge dependence of the n-loop Phi-derivable approximation shows up at order g^(2n) where g is the coupling constant. We consider the gauge dependence of the two-loop Phi-derivable approximation to the Debye mass and show that it is of order e^4 as expected. We solve the three-loop Phi-derivable approximation in QED by expanding sum-integrals in powers of e^2 and m/T, where m is the Debye mass which satisfies a variational gap equation. The results for the pressure and the Debye mass are accurate to order e^5.
Cite
@article{arxiv.hep-ph/0406163,
title = {Three-loop Phi-derivable Approximation in QED},
author = {Jens O. Andersen and Michael Strickland},
journal= {arXiv preprint arXiv:hep-ph/0406163},
year = {2009}
}
Comments
10 pages, 5 figures. v2: typos corrected and references added