%0 Journal Article
%A Gómez Nicola, Ángel
%A Galán González, V.
%T Nonequilibrium chiral perturbation theory and pion decay functions
%D 1999
%@ 0370-2693
%U https://hdl.handle.net/20.500.14352/59584
%X We extend chiral perturbation theory to study a meson gas out of thermal equilibrium. Assuming that the system is initially in equilibrium at T-i < T-c and working within the Schwinger-Keldysh contour technique, we define consistently the time-dependent temporal and spatial pion decay functions, the counterparts of the pion decay constants, and calculate them to next to leading order. The link with curved space-time QFT allows to establish nonequilibrium renormalisation. The short-time behaviour and the applicability of our model to a heavy-ion collision plasma are also discussed in this work.
%~