ABSTRACT
Charm was actually first discovered in 1971 in cosmic ray experiments carried out by Niu and collaborators in Japan. Events were seen corresponding to the production of two associated particles that each decayed weakly. In 1974 simultaneous experiments led by Burton Richter at SLAC and by Sam Ting at Brookhaven observed a series of meson resonances. The correlation between states of charmonium and states of positronium is remarkably good considering the aforementioned problems with quarkonium. B -meson physics is playing an important role in mapping out much of the remaining uncharted territory in the Standard Model. Since the top quark is so unstable, there are no top hadrons. When a lighter quark is produced in some process it will move rapidly in a gluon field, whose energy density rapidly becomes so intense that the field materializes into quark-antiquark pairs, forming hadrons.
