Symmetry Breaking and Collisions with $\sigma$-Mesons

In this brief report we adress spontaneous symmetry breaking in a finite-temperature scalar meson plasma. We calculate the in-medium averaged thermal $\sigma-\sigma$ scattering crossection and the related shear viscosity $\eta(T)$ and mean-free-path $L(T)$. Our results suggest that slightly below the critical temperature there is a 30 percent peak in the crossection leading to equivalent dips in $\eta(T)$ and $L(T)$. We discuss the relevance of this observation.