> This requires introducing a right-handed partner for each known (left-handed) neutrino, which some people don't like because right-handed particles don't partake in weak interactions, and weak interactions are the only (known) neutrino interactions (apart from gravity), so you end up with undetectable particles.
I'd be curious to hear more about this. What mechanism forces you to add right-handed partners? Is it some conservation property? Are calculations too difficult without them?
Maybe it's also not clear if there really is a difference between saying "right-handed neutrinos exist but are undetectable" and "right-handed neutrinos are fake particles added for ease of modeling".
Edit: Wikipedia also says
> The neutral-current Z^0 interaction can cause any two fermions in the standard model to deflect: Either particles or anti-particles, with any electric charge, and both left- and right-chirality, although the strength of the interaction differs.
So could right-handed neutrinos be detected this way?