# Neutrino mass eigenstate

1. Aug 13, 2011

### McLaren Rulez

Hi,

We know that when we have one flavour of neutrino, it can change into another flavour by neutrino oscillations. However, if we consider a mass eigenstate, then is it true that it can never change into a different mass eigenstate? In other words is a $|v_{1}>$ neutrino forever a $|v_{1}>$? I think the answer is yes but I would like to clarify.

If so, are the mass eigenstates the "real" fundamental particles then but it just happens to be that we can only observe neutrino flavours?

Thank you!

2. Aug 14, 2011

### Parlyne

3. Aug 14, 2011

### kith

It's not only a matter of observation, but also of production. Since the neutrino flavors are the eigenstates of the weak interaction Hamiltonian, these are the particles which are produced in weak interactions.

4. Aug 15, 2011

### McLaren Rulez

Thank you very much, Parlyne and kith.