Wiedemann-Franz law for hot QCD matter in a color string percolation scenario

Abstract

Transport coefficients serve as important probes in characterizing the QCD matter created in high-energy heavy-ion collisions. Thermal and electrical conductivities as transport coefficients have special significance in studying the time evolution of the created matter. We have adopted a color string percolation approach for the estimation of thermal conductivity (κ), electrical conductivity (σel), and their ratio, which is popularly known as the Wiedemann-Franz law in condensed matter physics. The ratio κ/σelT, which is also known as the Lorenz number (L), is studied as a function of temperature and is compared with various theoretical calculations. We observe that the thermal conductivity for a hot QCD medium is almost temperature independent in the present formalism and matches with the results obtained in an ideal equation of state for quark-gluon plasma with a fixed coupling constant (αs). The obtained Lorenz number is compared with the Stefan-Boltzmann limit for an ideal gas. We observe that a hot QCD medium with color degrees of freedom behaves like a free electron gas. © 2019 authors. Published by the American Physical Society.