That stable neutron can be a stable tetraquark with zero electric charge, or something of that sort.
It has been eluding lhc experiments for the same reason dark matter has been eluding them: detecting neutron like particles is extremely difficult when there are only 5 of them per cm3. I suppose that in some experiments those neutral particles get hit by accident and physicists see some discrepancies in the results, but since those discrepancies aren't reproducible, they get swiped under the rug.
As for the early universe model, well, it's a nice theory and it's backed by a few indirect evidences, but it's still just a theory we can't verify directly. This theory invented before the dark matter came to light, right?
The experiment we're talking about would cost maybe 10 billions - a rounding error in a world where some people make multiples of that in just a few months.
It has been eluding lhc experiments for the same reason dark matter has been eluding them: detecting neutron like particles is extremely difficult when there are only 5 of them per cm3. I suppose that in some experiments those neutral particles get hit by accident and physicists see some discrepancies in the results, but since those discrepancies aren't reproducible, they get swiped under the rug.
As for the early universe model, well, it's a nice theory and it's backed by a few indirect evidences, but it's still just a theory we can't verify directly. This theory invented before the dark matter came to light, right?
The experiment we're talking about would cost maybe 10 billions - a rounding error in a world where some people make multiples of that in just a few months.