Estimating transport coefficients of interacting pion gas with K-matrix cross sections

TL;DR

This paper estimates the transport coefficients of hot pionic matter using the relativistic Boltzmann equation with K-matrix pion-pion cross sections, incorporating resonances and unitarity, and compares results with existing literature.

Contribution

It introduces the use of K-matrix parametrization for calculating pionic transport coefficients, ensuring unitarity and resonance effects are properly included.

Findings

K-matrix estimations agree with previous results

Resonance effects are effectively incorporated

Transport coefficients are reliably estimated using this method

Abstract

We estimate the transport coefficients, $viz.$, shear and bulk viscosities as well as thermal and electrical conductivities, of hot pionic matter using relativistic Boltzmann equation in relaxation time approximation. We use K-matrix parametrization of pion-pion cross sections to estimate the transport coefficients which incorporate multiple heavy resonances while simultaneously preserving the unitarity of S-matrix. We compare transport coefficients estimated using K-matrix parametrization with existing literature on pionic transport coefficients. We find that the K-matrix scheme estimations are in reasonable agreement with previous results.