1997/10/01 by Francois Gelis, Gelis, Francois
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9710203
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
arxiv created 1997/10/01 · arxiv updated 2009/11/30
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 1/g when the produced photon is massless, therefore breaking the standard HTL power counting rules.