Why do neutral kaons oscillate but neutrinos don't form mass eigenstates?

[Dmitry67]

I understand that
$$K_l = \frac{d\bar{s} + s\bar{d}}{\sqrt{2}}$$
$$K_s = \frac{d\bar{s} - s\bar{d}}{\sqrt{2}}$$
This happens because $$K_0$$ is oscillating into its own antiparticle.
My question is, why the same is not applicable to the neutrinos? They do oscillate. So instead of ‘pure’ e, mu, tau neutrinos we do not observe superposition?

 

[ansgar]

We detect mass eigenstates of neutrinos, but a mass eigenstate is a mixture of weak eigenstates. Similar for quarks, their mass and weak eigenstates are not the same.

 

[chrispb]

We DO observe superpositions; we observe one of three mass eigenstates, each of which is a linear superposition of flavors.

 

[Meir Achuz]

In each case, the mass eigenstate propagates, but the particle eigenstate (d sbar or
say e-neutrino) interacts in the weak interaction. The time scales are different.
When you say "observe" that is the weak interaction.

 

[ansgar]

In each case, the mass eigenstate propagates, but the particle eigenstate (d sbar or
say e-neutrino) interacts in the weak interaction. The time scales are different.
When you say "observe" that is the weak interaction.

that is correct, i mixed them up. Sorry OP

 

[Dmitry67]

that is correct, i mixed them up. Sorry OP

So your thoughts are in superposition? :)

Thank you