Electric conductivity of hot and dense nuclear matter

Transport coefficients play an important role in characterising hot and dense nuclear matter, such as that created in ultra-relativistic heavy-ion collisions (URHIC). In the present work we calculate the electric conductivity of hot and dense hadronic matter by extracting it from the electromagnetic spectral function, through its zero energy limit at vanishing 3-momentum. We utilise the vector dominance model (VDM), in which the photon couples to hadronic currents predominantly through the ρ meson. Therefore, we use hadronic many-body theory to calculate the ρ -meson's self-energy in hot and dense hadronic matter, by dressing its pion cloud with π - ρ , π - σ , π - K , N-hole, and Δ-hole loops. We then introduce vertex corrections to maintain gauge invariance. Finally, we analyze the low-energy transport peak as a function of temperature and baryon chemical potential, and extract the conductivity along a proposed phase transition line. • We calculate the EM-spectral function at finite temperature and density, along the QCD phase transition line. • EM-currents couple to the medium through the vector mesons, with the dominate contribution coming from the ρ meson. • The transport peak is generated by the absorption of a virtual ρ by thermal pions, which act as charge carriers. • The pion's medium interactions are generated by scatterings with other thermal pions, kaons, and nucleons. • At μB = 0 the conductivity increases as T falls. At finite μB the conductivity decreases as μB rises.