Speed-up through entanglement -- many-body effects in neutrino processes

We study a system containing many particles of identical kinematics with a zero range interaction that scatters one from the other, and with the possible exchange of an attribute. Taking an initial condition in which the attribute is asymmetrically distributed in the regions of momentum space occupied by the particles, we study the rate at which it becomes uniformly distributed, through collisions. We find, in some circumstances, a rate that is much faster than that which would be estimated from cross-sections. This behavior is attributable in some general sense to N-particle entanglement. We suggest applications to neutrino physics, where the attribute is neutrino flavor.