Has anyone ever measured a particle in a way that allows it to continue moving on its path and then tested its spin at the end? Is it spin 0? I think wave collapse is what triggers other types of spin. Particles might not have a wave collapse event.
For energy eigenstates we define <n|m>=kroneker-delta(n,m).
For some n, <n|n>=0 for n=0.
I think we are going to discover n also implies it equals spin 0
or if an energy eigenstate = 0 then so does its spin
The ground state electron will NOT have a spin half, decohered waves all have spin 0 from start to end.
There is something very fitting about the higgs being a spin 0
Have we tested an unobserved matter wave without a vacuum? No light but let there be air in it. I don't think decoherence is very fragile to other free particles that are not light. It explains how tunneling can happen in our bodies.
