The environment generated in the mid-rapidity region of a high-energy nuclear
collision endows the pionic degrees of freedom with a time-dependent effective
mass. Its specific evolution provides a mechanism for the production of
back-to-back charge-conjugate pairs of soft pions which may present an
observable signal of the non-equilibrium dynamics of the chiral order
parameter.Comment: revtex body and 3 eps figures (4 pages total
