Submitted by John Michael Williams, Markanix.

Consider a specific creation interaction, detector at distance L, and neutrino energy <E>. <E> and <p> are conserved, so <m> must be, too. If wavepackets are allowed to separate, then as L →∞ the mass of the final neutrino must approach M_ν1 (lightest eigenstate), because longest distance travels implies highest interaction rate. This is the opposite of entanglement and violates conservation laws.

Therefore, wave packet and neutrino oscillation wave function superposition are incompatible. Wavepackets refer to the detector, not the neutrino.