Quarks:
up (u) down (d)	1968	Physicists at the Stanford Linear Accelerator Center (SLAC) observe the first evidence for quarks inside the proton. Friedman, Kendall and Taylor receive the 1990 Nobel Prize.
strange (s)	1951	First observation of kaons (particles containing strange quarks) in cosmic-ray experiments.
	1956	Gell-Mann of Caltech explains the relative longevity of kaons with the concept of strangeness and receives Nobel Prize in 1969.
	1964	At Brookhaven National Laboratory (BNL), Cronin and Fitch find that kaons violate the matter-antimatter (CP) symmetry. They receive the 1980 Nobel Prize.
charm (c)	1974	Physicists at SLAC and BNL discover independently a new particle that contains a new kind of quark, called the charm quark. Richter (SLAC) and Ting (BNL) receive the 1976 Nobel Prize.
bottom (b)	1977	Led by Lederman, a group of scientists at Fermilab discover the upsilon, a particle containing a bottom quark and an anti-bottom quark.
top (t)	1995	The CDF and DZero collaborations at Fermilab announce the discovery of the top quark, an elementary particle as heavy as a gold atom.
Leptons:
electron (e)	1897	Using a cathode tube, Thomson discovers the electron at the Cavendish laboratory in England. He receives the Nobel Prize in 1906.
electron neutrino (νe)	1956	Experimenters led by Cowan and Reines at the Savannah River plant detect the first neutrino. Reines shares the 1995 Nobel Prize.
muon (μ)	1937	Neddermeyer and Anderson discover the muon in a cosmic-ray experiment.
muon neutrino (νμ)	1962	Scientists at BNL discover the muon neutrino. Lederman, Schwartz and Steinberger receive the 1988 Nobel Prize.
tau (τ)	1976	Experimenters at SLAC discover the tau lepton, the first observation of a third-generation particle. Perl shares the 1995 Nobel Prize.
tau neutrino (ντ)	2000	Fermilab announces first direct evidence for the interaction of a tau neutrino in a detector. Indirect indications for the existence of this particle existed since more than two decades.
Force carriers:
photon (γ)	1905	Based on Planck's introduction of quanta of energy, Einstein describes the photoelectric effect using light particles called photons. They are carriers of the electromagnetic force. Planck receives the 1918 Nobel Prize, and Einstein is honored in 1921.
gluon (g)	1979	At the Deutsches Elektronen-Synchrotron (DESY) in Germany, scientists report evidence for the gluon, the carrier of the strong force.
electroweak bosons (W, Z)	1983	Physicists at the European research laboratory CERN observe the W and Z bosons, the only force carriers with mass. Rubbia and van der Meer receive the 1984 Nobel Prize.
Antimatter: Every particle has its own antiparticle. Two major discoveries helped physicists to establish this fundamental principle:
positron (e+)	1931-	Examining-cosmic-ray data, Anderson discovers the positively charged electron – later named the positron. He receives the 1936 Nobel Prize.
antiprotron (p-)	1955-	Using an accelerator-at Berkeley University, Segre and Chamberlain discover the antiproton. They receive the 1959 Nobel Prize. (Later, physicists learn that a proton contains quarks and an antiproton consists of antiquarks.)
Theory: The theory of the Standard Model is intimately connected to the numerous discoveries in quantum physics in the first half of the 20th century. Here the major theoretical breakthroughs of the second half that were honored with Nobel Prizes.
	1965	Tomonaga, Schwinger and Feynman receive the Nobel Prize for formulating the theory of quantum electrodynamics, the most precisely tested theory in physics.
	1969	Gell-Mann receives the Nobel Prize for his contributions to the classification of elementary particles and their interactions
	1979	Glashow, Salam and Weinberg receive the Nobel Prize for the unification of the electromagnetic and weak interactions in an electroweak theory
	1999	‘t Hooft and Veltman receive the Nobel Prize for their quantum formulation of the electroweak theory.
Another major component of the Standard Model, the theory of strong interactions (quantum chromodynamics), also emerged in the second half of the 20th century. Technology: Several Nobel Prizes went to physicists who developed particle detectors
The Physics at Fermilab section provides a list of Discoveries at Fermilab, not all of which are listed on this page.