Soft photons and hard thermal loops
Abstract
Description
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.
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
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