Particle Physics - FSU Physics Department

Brief History of the Standard Model - 3
1974: J/Ψ discovered at BNL/SLAC;
1975: J/Ψ interpreted as cc
-
bound state (“charmonium”)
1976: τ lepton discovered at SLAC
-
1977: Υ discovered at Fermilab in 1977, interpreted as bb bound
state (“bottomonium”) ⇒ 3rd generation
-
1979: gluon – jets observed at DESY
-
1982: direct evidence for jets in hadron hadron interactions at
CERN (pp-
collider)
1983: W ± , Z observed at CERN (pp-
collider built for that purpose)
1995: top quark found at Fermilab (DØ, CDF)
1999: indications for “neutrino oscillations” (Super-Kamiokande
experiment)
2000: direct evidence for tau neutrino (ν τ
) at Fermilab (DONUT
experiment)
2005: clear evidence for neutrino oscillations (Kamiokande, SNO)
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