From Cathode Rays to the Terascale: The Timeline of Discovery
| Year | Particle | Lead Figures / Collaboration | Facility / Method |
|---|---|---|---|
| 1897 | Electron ($e^-$) | J.J. Thomson | Cavendish Lab (Cathode Rays) |
| 1936 | Muon ($\mu^-$) | Anderson & Neddermeyer | Caltech (Cosmic Rays) |
| 1956 | $e$ Neutrino ($\nu_e$) | Reines & Cowan | Savannah River (Reactor) |
| 1957 | Parity Violation ($P$) | Chien-Shiung Wu | NBS Cryogenics |
| 1962 | $\mu$ Neutrino ($\nu_\mu$) | Lederman, Schwartz, Steinberger | Brookhaven (AGS) |
| 1964 | CP Violation | Cronin & Fitch | Brookhaven |
| 1969 | $u, d$ Quarks | Friedman, Kendall, Taylor | SLAC (DIS) |
| 1974 | Charm Quark ($c$) | Richter & Ting | SLAC / Brookhaven ($J/\psi$) |
| 1975 | Tau Lepton ($\tau^-$) | Martin Perl | SLAC (SPEAR) |
| 1977 | Bottom Quark ($b$) | Leon Lederman | Fermilab ($\Upsilon$ resonance) |
| 1979 | Gluon ($g$) | TASSO / PETRA Collabs. | DESY |
| 1983 | $W, Z$ Bosons | UA1 & UA2 Collabs | CERN (SppS Collider) |
| 1995 | Top Quark ($t$) | CDF & D0 Collabs | Fermilab (Tevatron) |
| 1998 | Neutrino Mass / Oscillation | Super-Kamiokande | Japan |
| 2000 | $\tau$ Neutrino ($\nu_\tau$) | DONUT Collaboration | Fermilab (Emulsion) |
| 2012 | Higgs Boson ($H^0$) | ATLAS & CMS | CERN (LHC) |
The Experiment: J.J. Thomson used cathode ray tubes to demonstrate that rays were composed of previously unknown negatively charged particles, much smaller than atoms.
Phil. Mag. 44, 293 (1897)The Experiment: Observed in cosmic rays using a cloud chamber. Its mass was intermediate between the electron and the proton, leading to the famous quote by I.I. Rabi: "Who ordered that?"
Phys. Rev. 51, 884 (1937)The Experiment: Reines and Cowan detected the flux from a nuclear reactor via Inverse Beta Decay. This provided the first physical proof of the neutrino's existence.
The Experiment: Using the AGS at Brookhaven, researchers showed that neutrinos from pion decay produced muons but never electrons, proving $\nu_\mu$ and $\nu_e$ are distinct.
PRL 9, 36 (1962)The Experiment: Martin Perl detected "e-mu" events at the SPEAR storage ring, which could only be explained by the decay of a new, heavy lepton.
PRL 35, 1489 (1975)The Experiment: The DONUT collaboration at Fermilab used a neutrino beam and 3D nuclear emulsion targets to directly image the production and decay of tau leptons.
PLB 504, 218 (2001)Quarks were confirmed as physical constituents (Partons) inside the proton at SLAC. The Strange quark was solidified by the discovery of the predicted $\Omega^-$ baryon.
PRL 23, 930 (1969)Simultaneous discovery of the $J/\psi$ resonance (a $c\bar{c}$ state) at SLAC and BNL. This proved the 4th quark existed and confirmed the GIM Mechanism.
PRL 33, 1404 (1974)The Bottom quark appeared as the $\Upsilon$ (Upsilon) resonance. The Top quark, roughly as heavy as a gold atom, required the Tevatron's full energy to produce $t\bar{t}$ pairs.
PRL 74, 2626 (1995)The Experiment: Discovery of Three-Jet Events at the PETRA storage ring (DESY). The third jet was identified as a gluon radiated from a quark.
PRL 43, 830 (1979)Carlo Rubbia and the UA1/UA2 teams at CERN found the $W$ and $Z$ bosons, confirming that the weak force is mediated by massive gauge particles.
PLB 122, 103 (1983)Observation of a new boson decaying into $\gamma\gamma$ and $ZZ^*$. This confirmed the mechanism of Spontaneous Symmetry Breaking and the origin of fundamental mass.
PLB 716, 1 (2012)The Experiment: Observing the Beta decay of polarized $^{60}\text{Co}$ nuclei. Electrons were emitted asymmetrically, proving the Weak interaction is left-handed.
Phys. Rev. 105, 1413 (1957)The Experiment: Observing the decay of Neutral Kaons ($K_L^0$). A tiny fraction decayed into two pions, revealing that the universe distinguishes between matter and antimatter.
PRL 13, 138 (1964)The Experiment: Super-Kamiokande observed that the flux of atmospheric muon neutrinos varied with the distance traveled, proving neutrinos have mass.
PRL 81, 1562 (1998)