Note: Force between hadrons different from force between quarks (v) Three new quarks: charm, truth and beauty a) Glashow and Bjorken: leptons and quarks fundamental many similarities 4 lepton 4 quarks? → Also: electroweak theory: symmetry between quarks and leptons? 1970s: neutral weak currents additional channel of disintegration new quark with new flavour? – 1974: new hadronic resonance at SLAC, Brookhaven New particle : Nobel prize) – J/ψ ‘long’lifetime (1976 = meson made of (cc) charm J/ψ 1976: SLAC and Berkeley: neutral charmed meson D0 (cu) D+ and D- later observed b) 1977 Fermilab: new heavy meson У too heavy to be made of known quarks consists of pair of new quarks (beauty?) new search for b- mesons (bu or bd pairs) Discovered in Cornell storage ring in 1982; confirmation of b-quark c) Does beauty quark have a partner? truth quark? Discovered in 1992 (Tevatron, Fermilab): t + b →W+ P.S. 5th lepton discovered in 1975 (taon taon neutrino also) →
Note: Force between hadrons different from force between quarks (v) Three new quarks: charm, truth and beauty a) Glashow and Bjorken: leptons and quarks fundamental many similarities 4 lepton → 4 quarks? Also: electroweak theory: symmetry between quarks and leptons? 1970s: neutral weak currents additional channel of disintegration – new quark with new flavour? 1974: new hadronic resonance at SLAC, Brookhaven New particle – J/ψ : ‘long’lifetime (1976 Nobel prize) J/ψ = meson made of charm (cc) 1976: SLAC and Berkeley: neutral charmed meson D0 (cu) D+ and D- later observed b) 1977 Fermilab: new heavy meson У too heavy to be made of known quarks consists of pair of new quarks (beauty?) new search for b- mesons (bu or bd pairs) Discovered in Cornell storage ring in 1982; confirmation of b-quark c) Does beauty quark have a partner? truth quark? Discovered in 1992 (Tevatron, Fermilab): t →W+ + b P.S. 5th lepton discovered in 1975 (taon → taon neutrino also)
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