Speaker
Description
Using hadronic many-body theory, the author calculates the rho meson self-energy in a pion gas. Previously the effects of in medium nucleons and delta particles (which have a large coupling to the rho) on the rho propagator, have been calculated. However the effects of in-medium pions were not included. Calculation of the electric conductivity requires one to consider the zero momentum and low energy limit of the rho spectral function. In this limit and at small temperatures, the effects of high mass particles like nucleons and deltas will be suppressed and the effects of the lower mass pion will become significant. Thus, the author has calculated the effects of in-medium pions on the rho self-energy, assuring that these calculations preserve gauge invariance. This requires the determination of the significant interactions between in-medium pions and the rho meson, and the calculation of these interactions. This calculation requires the dressing of the pion propagators in the rho self-energy with pion-rho loops. However, this violates gauge invariance. To correct for this one must calculate vertex corrections to the rho self-energy loops. Using guidance from previous works, the author calculates these vertex corrections. The author then combines the results with the results for nucleon and delta particles to obtain an improved calculation of the rho self-energy and spectral function in hadronic matter. The resulting spectral function was used to calculate the electric conductivity of hot hadronic matter.
Summary
An understanding of hot nuclear matter is crucial to the understanding of the basic building blocks of matter and the forces through which they interact. One way to characterize hot nuclear matter is through transport coefficients. Thus, the aim of this research has been to calculate the electric conductivity of hot nuclear matter. This quantity can be extracted from the rho meson’s spectral function, which is proportional to the electric conductivity in the zero energy limit, and is calculated using hadronic many-body theory. This approach requires one to determine how the rho meson’s self-energy is affected by hot nuclear matter. Recent calculations of the electric conductivity in hot nuclear matter have been performed, however they produce results which are not compatible with current lattice QCD calculations. This research has improved upon these results by including the effects of the pion cloud on the rho meson spectral function.
