In the wave-packet approach, different neutrino mass eigenstates have different mass and thus propagate with different speeds. This will eventually lead to wave-packet separation and decoherence. My question is, can neutrinos be produced/detected incoherently? (In other words, can different neutrino mass eigenstates be produced/detected incoherently?) If they cannot, it should in principle be possible to have wave-packets sufficiently separated so that neutrinos become undetectable during the interaction time interval available in a detector.