The electric conductivity of hot pion matter
Abstract
The determination of transport coefficients plays a central role in characterizing hot and dense nuclear matter. Currently, there are significant discrepancies between various calculations of the electric conductivity of hot hadronic matter. It has been shown that dilepton emission spectra can be described by calculating the electromagnetic correlator within the vector dominance model (VDM). Transport coefficients probe the low-energy limit of the medium, thus the interactions of the low mass pion are expected to play an important role in determining the conductivity of hot hadronic matter. In the present work we calculate the electric conductivity of hot pion matter by extracting it from the electromagnetic spectral function, as its zero energy limit at vanishing 3-momentum. Within the VDM the photon couples primarily to the rho meson. Therefore, we use hadronic many-body theory to calculate the rho meson's self-energy in hot pion matter. This requires the dressing of the pion propagators within the rho self-energy with thermal $\pi$-$\rho$ and $\pi$-$\sigma$ loops, and the inclusion of vertex corrections to maintain gauge invariance. Furthermore, in order to obtain a finite conductivity, all intermediate particles must be dressed with self-energies. In particular, we analyze the transport peak of the spectral function and extract its behavior with temperature. Finally, we compare our results to previous calculations, including various calculations of the electric conductivity of hot pion matter, to a proposed quantum lower bound, and a proposed sum rule for the EM-spectral function.
Citation
Atchison, Joseph I (2021). The electric conductivity of hot pion matter. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /196100.