Pion polarizabilities in hot medium

The pion polarisability is investigated in the Nambu-Jona-Lasinio model at finite temperature. The quark and pion loops, scalar and vector intermediate resonanses were considered. We have shown that the polarizabilities of charge and neutral pions have a very different behavior near the critical temperature if we consider the Compton effect off the pion. The charged pion polarizability is positive, decreases very quickly in the region where T > 200MeV and has no contributiolls from meson clouds. The neutral pion polarizability is negative and monotonically increases in absolute value with T together with contributions of pion clouds.