The dynamical evolution of nucleus-nucleus collisions is described by an extended Boltzmann-Uehling-Uhlenbeck transport equation including nucleons, deltas and pions. Whereas nucleons are propagated in the conventional selfconsistent mean field, pions and deltas are treated as quasiparticles which propagate with their own selfenergies. The latter are extracted from an effective pion-dispersion relation adopted from the Δ-hole model. Though quite substantial medium modifications are incorporated, the pion spectra and yields show only weak sensitivity to the in-medium effects. Also the dilepton signal from π+π- annihilation in the ρ-mass region is found to be only moderately affected.
ASJC Scopus subject areas
- Nuclear and High Energy Physics