Why did it take so long to detect?
The article says the X boson is 30 x the mass of the electron, and that it decays into an electron-positron pair.
This implies that it loses 28 x electron masses when it decays. That's a lot of energy emitted - surely it should have been easily detectable previously?
I suppose I have succumbed to some fundamental misunderstanding here. Can someone help me out?