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

We estimate the transport coefficients, viz., shear and bulk viscosities as well as thermal and electrical conductivities, of hot pionic matter using a relativistic Boltzmann equation in a 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 the S-matrix. We compare transport coefficients estimated using K-matrix parametrization with the existing literature on pionic transport coefficients. We find that the K-matrix scheme estimations are in reasonable agreement with previous results. (paper)