Tau lepton and bottom quark: the third generation
Leptón tau y quark bottom: tercera generación de la materia
- Date
- 1975-1977 · confidence high
- Place
- Fermilab, Batavia, Illinois / SLAC, Menlo Park, United States
- Credited to
- Martin Perl (tau); Leon Lederman (bottom)
- People
- 👤 Leon M. Lederman1922–2018👤 Martin Lewis Perl1927–2014
- Field
- Cosmos & Earth
What was discovered
Perl finds at SLAC a third charged lepton, the tau (1975), and Lederman discovers at Fermilab the upsilon particle, a bound state of a fifth quark, the bottom (1977). A third family of matter is confirmed, required to explain CP violation.
Nobel Prize for Perl in 1995 and for Lederman in 1988 (for the muon neutrino).
What it led to
- Complete CKM matrix and B factories
- Search for the top quark (1995)
- Open question of why there are three generations
- Flavour physics
Built on
- J/psi particle and the charm quark (November Revolution)1974
- Kobayashi-Maskawa theory (1973)
- 400 GeV accelerators
Made possible
- The top quark1995
- B-meson factories (BaBar, Belle, LHCb)