rho properties in a hot meson gas - art. no. 024903

Using effective mason Lagrangians we study the interaction of rho mesons in a hot baryon-free system. Various mesonic resonances in direct s-channel r eactions are investigated employing standard self-energy techniques, includ ing new reactions that have up to now not been considered in a self-consist ent approach at finite temperature. The importance of subthreshold resonanc es, which are readily accounted for through off-shell effects within our fr amework, is emphasized. Special care is taken in reproducing radiative deca y widths, as they provide valuable constraints on the evaluation of dilepto n spectra. In particular, we compare our results for dilepton production ra tes to earlier calculations based on an incoherent summation of individual processes. [S0556-2813(99)04808-6].