  We develop a kinetic equation approach to nonequilibrium pion and sigma meson
production in a time-dependent, chiral symmetry breaking field (inertial
mechanism). We investigate the question to what extent the low-momentum pion
enhancement observed in heavy-ion collisions at CERN - LHC can be addressed
within this formalism. In a first step, we consider the inertial mechanism for
nonequilibrium production of $\sigma-$mesons and their simultaneous decay into
pion pairs for two cases of $\sigma$ mass evolution. The resulting pion
distribution shows a strong low-momentum enhancement which can be approximated
by a thermal Bose distribution with a chemical potential that appears as a
trace of the nonequilibrium process of its production.

High Energy Physics - Phenomenology