Finite pion width effects on the rho-meson Original Research Article

We study the influence of the finite damping width of pions on the in-medium properties of the ρ-meson in an interacting meson-gas model at finite temperature. Using vector dominance also implications on the resulting dilepton spectra from the decay of the ρ-meson are presented. A set of coupled Dyson equations with self-energies up to the sunset diagram level is solved self-consistently. Following a Φ-derivable scheme the self-energies are dynamically determined by the self-consistent propagators. Some problems concerning the self-consistent treatment of vector or gauge bosons on the propagator level, in particular, if coupled to currents arising from particles with a sizable damping width, are discussed.