[drdeca]

Neutrino ≠ neutron. The “ino” in neutrino is like a diminutive. Neutrons are much heavier than a neutrino.

I don’t think they have a positive lower bound on the size of the smallest mass eigenstate of neutrinos (though they do on the other two).

[gus_massa]

I agree. (I missed the "ino".) It's also important that (as far as we know) the neutrino is an elementary particle, but the neutron is composed by three real quarks and a lot of virtual quarks and gluons, it's a huge mess of smaller particles together.