# Wiedemann-Franz Law For Hot QCD Matter in a Color String Percolation Scenario

## TL;DR

This paper investigates the Wiedemann-Franz law in hot QCD matter using a color string percolation model, finding that thermal conductivity remains nearly constant with temperature and the medium behaves like a free electron gas.

## Contribution

It introduces a novel application of the color string percolation approach to estimate transport coefficients and analyze the Wiedemann-Franz law in hot QCD matter.

## Key findings

- Thermal conductivity is nearly temperature independent.
- The Lorenz number approaches the Stefan-Boltzmann limit.
- QCD medium behaves like a free electron gas.

## 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 got special significance in studying the time evolution of the created matter. We have adopted color string percolation approach for the estimation of thermal conductivity ($\kappa$), electrical conductivity ($\sigma_{el}$) and their ratio, which is popularly known as Wiedemann-Franz law in condensed matter physics. The ratio $\kappa/\sigma_{el}T$, which is also known as Lorenz number ($\mathbb{L}$) is studied as a function of temperature and is compared with various theoretical calculations. We observe that the thermal conductivity for hot QCD medium is almost temperature independent in the present formalism and matches with the results obtained in ideal equation of state (EOS) for quark-gluon plasma with fixed coupling constant ($\alpha_s$). 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.