Selfconsistent Description of a Thermal Piongas
arXiv:nucl-th/9306016 · doi:10.1016/0370-2693(93)91604-L
Abstract
We examine a hot pion gas by including medium modifications of the two-body scattering amplitude as well as mean-field effects selfconsistently. In contrast to earlier calculations, the in-medium T-matrix is rather close to the free one while the mean-field potential agrees well with lowest-order estimates. We also discuss the validity of the quasiparticle approximation. It is found that it is reliable for temperatures up to $\sim 150$ MeV. Above this temperature off-shell effects in the pion selfenergy become important, especially if the pions are strongly out of chemical equilibrium.
11 pages, LATEX, 4 figures (not included, available from the authors), KFA-IKP(TH)-1993-18