Soft photons and hard thermal loops
High Energy Physics - Phenomenology
2007-05-23 v1
Abstract
We calculate within the Hard Thermal Loop expansion the production rate of soft photons and lepton pairs by a hot quark-gluon plasma at thermal equilibrium, up to the 2-loop order. Strong collinear divergences appear to mix the orders of the perturbative expansion so that the 2-loop order is in fact dominant compared to the 1-loop order. More precisely, angular integrals that would otherwise be of order 1 are found to behave as powers of when the produced photon is massless, therefore breaking the standard HTL power counting rules.
Cite
@article{arxiv.hep-ph/9710203,
title = {Soft photons and hard thermal loops},
author = {Francois Gelis},
journal= {arXiv preprint arXiv:hep-ph/9710203},
year = {2007}
}
Comments
13 pages, Latex2e, 11 postscript figures included with the package graphics. Talk given at the RHIC Summer Study '97, 6-16 July 1997, Brookhaven National Laboratory, USA