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arXiv · hep-ph/9811433

Nonequilibrium chiral perturbation theory and pion decay functions

A. Gomez Nicola·V. Galan-Gonzalez
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Abstract

We extend chiral perturbation theory to study a meson gas out of thermal equilibrium. Assuming that the system is initially in equilibrium below the critical temperature and working within the Schwinger-Keldysh contour technique, we define consistently the time-dependent pion decay functions, the counterparts of the pion decay constants, and calculate them up to next to leading order. The link with curved space-time QFT allows to establish nonequilibrium renormalisation. The short-time behaviour and the applicability to a heavy-ion collision plasma are also discussed in this work.

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A. Gomez Nicola, V. Galan-Gonzalez. 1998-11-23. Nonequilibrium chiral perturbation theory and pion decay functions. https://doi.org/10.1016/s0370-2693(99)00067-2

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