I Possibilty of flavor oscillation of an electron

[Vanadium 50]

And on page one of that paper it says: "Do e±, μ± and ± oscillate into each other? The answer to this question is the immediate ‘no’, the reason being that these charged leptons are mass eigenstates, i.e. states of definite mass. "

 

[Vanadium 50]

ut how do you justify this claim?

Because it's not a claim, it's a definition. There are 3 leptonic mass eigenstates. We call the lightest one "electron", the middle one "muon", and the heavy one "tau".

 

[mfb]

We could go the opposite way: Give the neutrino mass eigenstates flavor names and see the charged leptons as mixtures of these flavors. It would be really impractical, that's why we don't do it.