subatomic particles

  • 1800

    William Herschel discovers "heat rays" (now known as infrared)
  • 1801

    Johann Wilhelm Ritter made the hallmark observation that invisible rays just beyond the violet end of the visible spectrum were especially effective at lightening silver chloride-soaked paper.
  • 1895

    X-ray produced by Wilhelm Röntgen (later identified as photons)
  • 1895

    Discovery of the ultraviolet radiation below 200 nm, named vacuum ultraviolet later identified as photons)because it is strongly absorbed by air, by the German physicist Victor Schumann
  • 1897

    Electron discovered by J. J. Thomson
  • 1899

    Alpha particle discovered by Ernest Rutherford in uranium radiation
  • 1900

    Gamma ray (a high-energy photon) discovered by Paul Villard in uranium decay
  • 1911

    Atomic nucleus identified by Ernest Rutherford, based on scattering observed by Hans Geiger and Ernest Marsden
  • 1919

    Proton discovered by Ernest Rutherford
  • 1931

    Deuteron discovered by Harold Urey[9][10] (predicted by Rutherford in 1920)
  • 1932

    Neutron discovered by James Chadwick
  • 1932

    Antielectron (or positron), the first antiparticle, discovered by Carl D. Anderson
  • 1937

    Muon (or mu lepton) discovered by Seth Neddermeyer, Carl D. Anderson, J.C. Street, and E.C. Stevenson, using cloud chamber measurements of cosmic rays (it was mistaken for the pion until 1947)
  • 1947

    Kaon (or K meson), the first strange particle, discovered by George Dixon Rochester and Clifford Charles Butler
  • 1947

    Pion discovered by C. F. Powell's group, including César Lattes (first author) and Giuseppe Occhialini (predicted by Hideki Yukawa in 1935)
  • 1950

    or lambda baryon discovered during a study of cosmic-ray interactions[18]
  • 1955

    Antiproton discovered by Owen Chamberlain, Emilio Segrè, Clyde Wiegand, and Thomas Ypsilantis[
  • 1956

    Electron neutrino detected by Frederick Reines and Clyde Cowan (proposed by Wolfgang Pauli in 1930 to explain the apparent violation of conservation of energy in beta decay)[20] At the time it was simply referred to as neutrino since there was only one known neutrino.
  • 1962

    Muon neutrino shown to be distinct from the electron neutrino by a group headed by Leon Lederman
  • 1964

    Xi baryon discovery at Brookhaven National Laboratory
  • 1969

    Partons (internal constituents of hadrons) observed in deep inelastic scattering experiments between protons and electrons at SLAC; this was eventually associated with the quark model (predicted by Murray Gell-Mann and George Zweig in 1964) and thus constitutes the discovery of the up quark, down quark, and strange quark.
  • 1974

    J/ψ meson discovered by groups headed by Burton Richter and Samuel Ting, demonstrating the existence of the charm quark (proposed by James Bjorken and Sheldon Glashow in 1964)
  • 1975

    Tau discovered by a group headed by Martin Perl
  • 1977

    Upsilon meson discovered at Fermilab, demonstrating the existence of the bottom quark (proposed by Kobayashi and Maskawa in 1973)
  • 1979

    Gluon observed indirectly in three-jet events at DESY[30]
  • 1983

    W and Z bosons discovered by Carlo Rubbia, Simon van der Meer
  • 1995

    Antihydrogen produced and measured by the LEAR experiment at CERN
  • 1995

    op quark discovered at Fermilab
  • 2000

    Quark-gluon fireball discovered at CERN
  • 2000

    Tau neutrino first observed directly at Fermilab
  • 2011

    Antihelium-4 produced and measured by the STAR detector; the first particle to be discovered by the experiment
  • 2012

    A particle exhibiting most of the predicted characteristics of the Higgs boson discovered by researchers conducting the Compact Muon Solenoid and ATLAS experiments at CERN's Large Hadron Collider