Linked from
The 9 pages that link to J/ψ meson, each with the reason it gives.
MesonBroader topic: Its 1974 discovery provided compelling evidence for the charm quark.
Charm quarkBroader topic: Its discovery in 1974 provided compelling evidence for the charm quark.
AntiquarkBroader topic: It is a clear heavy quark–antiquark bound state.
CharmoniumBroader topic: Its 1974 discovery revealed a remarkably long-lived charmonium state.
Samuel C. C. TingBroader topic: This is the particle whose discovery brought Ting the Nobel Prize.