Electric conductivity of hot and dense nuclear matter

TL;DR

This paper calculates the electric conductivity of hot, dense nuclear matter using electromagnetic spectral functions and vector dominance model, revealing how conductivity varies with temperature and chemical potential.

Contribution

It introduces a method to compute electrical conductivity from spectral functions in hot, dense matter, incorporating vector dominance and hadronic many-body theory with vertex corrections.

Findings

Conductivity varies with temperature and baryon chemical potential.

The spectral function's low-energy peak informs conductivity near phase transitions.

The approach links electromagnetic properties to the phase structure of nuclear matter.

Abstract

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 $\rho$ meson. Therefore, we use hadronic many-body theory to calculate the $\rho$-meson's self-energy in hot and dense hadronic matter, by dressing its pion cloud with $\pi$-$\rho$, $\pi$-$\sigma$, $\pi$-$K$, N-hole, and $\Delta$-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.