Kinematics and dynamics of independent pion emission

Multiparticle boson states, proposed recently for “independently” emitted pions in heavy-ion collisions, are reconsidered in standard second quantized formalism and shown to emerge from a simplistic chaotic current dynamics. Compact equations relate the density operator, the generating functional of multiparticle counts, and the correlator of the external current to each other. “Bose-Einstein condensation” is related to the external pulse. A quantum master equation is advocated for future Monte Carlo simulations.