Landau-Pomeranchuk-Migdal resummation for dilepton production

Abstract

We consider the thermal emission rate of dileptons from a QCD plasma in the small invariant mass ($Q^2\sim {\text{gs}}^2{T}^2$) but large energy ($q^0\text{gsim}T$) range. We derive an integral equation which resums multiple scatterings to include the LPM effect; it is valid at leading order in the coupling. Then we recast it as a differential equation and show a simple algorithm for its solution. We present results for dilepton rates at phenomenologically interesting energies and invariant masses.

Comments: 19 pages, 7 postscript figures, test program available at http://www-spht.cea.fr/articles/T02/150/libLPM/