1.2: A Timeline of Particle Physics
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Year | Experiment | Theory |
---|---|---|
1927 | β decay discovered | |
1928 | Paul Dirac: Wave equation for electron | |
1930 | Wolfgang Pauli suggests existence of neutrino | |
1931 | Positron discovered | |
1931 | Paul Dirac realises that positrons are part of his equation | |
1931 | Chadwick discovers neutron | |
1933/4 | Fermi introduces theory for β decay | |
1933/4 | Hideki Yukawa discusses nuclear binding in terms of pions | |
1937 | μ discovered in cosmic rays | |
1938 | Baryon number conservation | |
1946 | μ is not Yukawa’s particle | |
1947 | π+ discovered in cosmic rays | |
1946-50 | Tomonaga, Schwinger and Feynman develop QED | |
1948 | First artificial π’s | |
1949 | K+ discovered | |
1950 | π0→γγ | |
1951 | ”V-particles” Λ0 and K0 | |
1952 | Δ: excited state of nucleon | |
1954 | Yang and Mills: Gauge theories | |
1956 | Lee and Yang: Weak force might break parity! | |
1956 | CS Wu and Ambler: Yes it does. | |
1961 | Eightfold way as organising principle | |
1962 | νμ and νe | |
1964 | Quarks (Gell-man and Zweig) u,d,s | |
1964 | Fourth quark suggested (c) | |
1965 | Colour charge all particles are colour neutral! | |
1967 | Glashow-Salam-Weinberg unification of electromagnetic and weak interactions. Predict Higgs boson. | |
1968-69 | DIS at SLAC constituents of proton seen! | |
1973 | QCD as the theory of coloured interactions. Gluons. | |
1973 | Asymptotic freedom | |
1974 | J/ψ (cˉc) meson | |
1976 | D0 meson (ˉuc) confirms theory. | |
1976 | τ lepton! | |
1977 | b (bottom quark). Where is top? | |
1978 | Parity violating neutral weak interaction seen | |
1979 | Gluon signature at PETRA | |
1983 | W± and Z0 seen at CERN | |
1989 | SLAC suggests only three generations of (light!) neutrinos | |
1995 | t (top) at 175 GeV mass | |
1997 | New physics at HERA (200 GeV) |