Editing Subatomic particle (section)

== History ==
{{main|History of subatomic physics|Timeline of particle discoveries}}
The term "''subatomic'' particle" is largely a [[retronym]] of the 1960s, used to distinguish a large number of [[baryon]]s and [[meson]]s (which comprise [[hadron]]s) from particles that are now thought to be [[elementary particle|truly elementary]]. Before that hadrons were usually classified as "elementary" because their composition was unknown.{{Primary sources|section|date=March 2025}}

A list of important discoveries follows:
{| class="wikitable"
 !Particle
 !Composition
 !Theorized
 !Discovered
 !Comments
 |-
 |[[electron]] {{subatomic particle|electron}}
 |elementary ([[lepton]])
 |[[G. Johnstone Stoney]] (1874)<ref>
  {{cite journal
   |last=Stoney |first=G. Johnstone
   |date=1881 |title=LII. On the physical units of nature
   |url=https://www.tandfonline.com/doi/full/10.1080/14786448108627031
   |journal=The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science
   |language=en |volume=11 |issue=69 |pages=381–390 |doi=10.1080/14786448108627031 |issn=1941-5982
  |url-access=subscription }}</ref>
 |[[J. J. Thomson]] (1897)<ref name="referenceB">
  {{cite journal |last=Thomson |first=J. J. |year=1897 |title=Cathode Rays |url=https://books.google.com/books?id=vBZbAAAAYAAJ&pg=PA104 |journal=The Electrician |volume=39 |page=104}}</ref>
 |Minimum unit of electrical charge, for which Stoney suggested the name in 1891.<ref>
  {{cite journal
   |last=Klemperer |first=Otto |author1-link=Otto Ernst Heinrich Klemperer
   |date=1959
   |title=Electron physics: The physics of the free electron
   |journal=Physics Today |volume=13 |issue=6 |pages=64–66
   |bibcode=1960PhT....13R..64K |doi=10.1063/1.3057011
  }}</ref> First subatomic particle to be identified.<ref>
  {{cite magazine
   |last=Alfred |first=Randy
   |title=April 30, 1897: J.J. Thomson Announces the Electron ... Sort Of
   |date=April 30, 2012
   |magazine=Wired
   |url=https://www.wired.com/2012/04/april-30-1897-j-j-thomson-announces-the-electron-sort-of/
   |access-date=2022-08-22 |issn=1059-1028
  }}</ref>
 |-
 |[[alpha particle]] {{subatomic particle|alpha}}
 |composite (atomic nucleus)
 |{{no|''never''}}
 |[[Ernest Rutherford]] (1899)<ref name="Rutherford-1899">
  {{cite journal
   |last=Rutherford |first=E.
   |date=1899
   |title=VIII. Uranium radiation and the electrical conduction produced by it
   |url=https://www.tandfonline.com/doi/full/10.1080/14786449908621245
   |journal=The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science
   |language=en |volume=47 |issue=284 |pages=109–163
   |doi=10.1080/14786449908621245 |issn=1941-5982
  |url-access=subscription}}</ref>
 |Proven by Rutherford and [[Thomas Royds]] in 1907 to be helium nuclei. Rutherford won the Nobel Prize for Chemistry in 1908 for this discovery.<ref>
  {{cite web |title=The Nobel Prize in Chemistry 1908
   |url=https://www.nobelprize.org/prizes/chemistry/1908/rutherford/facts/
   |access-date=2022-08-22
   |website=NobelPrize.org
   |language=en-US
  }}</ref>
 |-
 |[[photon]] {{subatomic particle|photon}}
 |elementary ([[quantum]])
 |[[Max Planck]] (1900)<ref>
  {{cite journal
   |last=Klein |first=Martin J.
   |date=1961
   |title=Max Planck and the beginnings of the quantum theory
   |url=http://link.springer.com/10.1007/BF00327765
   |journal=Archive for History of Exact Sciences
   |language=en |volume=1 |issue=5 |pages=459–479
   |doi=10.1007/BF00327765 |s2cid=121189755 |issn=0003-9519
  |url-access=subscription}}</ref>
 |[[Albert Einstein]] (1905)<ref>
  {{cite journal |last=Einstein |first=Albert |date=1905 |title=Über einen die Erzeugung und Verwandlung des Lichtes betreffenden heuristischen Gesichtspunkt |journal=Annalen der Physik |language=de |volume=322 |issue=6 |pages=132–148 |bibcode=1905AnP...322..132E |doi=10.1002/andp.19053220607 |doi-access=free}}</ref>
 |Necessary to solve the [[thermodynamics|thermodynamic]] problem of [[black-body radiation]].
 |-
 |[[proton]] {{subatomic particle|proton}}
 |composite ([[baryon]])
 |William Prout (1815)<ref name=lederman>{{cite book|last=Lederman|first=Leon|title=The God Particle|url=https://archive.org/details/godparticle00leon|url-access=registration|year=1993|publisher=Delta |isbn=9780385312110 |author-link=Leon Lederman}}</ref>
 |Ernest Rutherford (1919, named 1920)<ref>{{cite journal |last=Rutherford |first=Ernest |date=1920 |title=The Stability of Atoms |url=https://iopscience.iop.org/article/10.1088/1478-7814/33/1/337 |journal=Proceedings of the Physical Society of London |volume=33 |issue=1 |pages=389–394 |bibcode=1920PPSL...33..389R |doi=10.1088/1478-7814/33/1/337 |issn=1478-7814}}</ref><ref name="protonDebate" />
 |The nucleus of {{SimpleNuclide|hydrogen|1|link=yes}}.
 |-
 |[[neutron]] {{subatomic particle|neutron}}
 |composite (baryon)
 |Ernest Rutherford ({{circa}}1920<ref>{{cite journal |last1=Rutherford |first1=Ernest |date=1920 |title=Bakerian Lecture: Nuclear constitution of atoms |journal=Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character |language=en |volume=97 |issue=686 |pages=374–400 |bibcode=1920RSPSA..97..374R |doi=10.1098/rspa.1920.0040 |issn=0950-1207 |doi-access=free}}</ref>)
 |[[James Chadwick]] (1932) <ref>{{cite journal |date=1932 |title=The existence of a neutron |journal=Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character |language=en |volume=136 |issue=830 |pages=692–708 |doi=10.1098/rspa.1932.0112 |bibcode=1932RSPSA.136..692C |issn=0950-1207|last1=Chadwick |first1=J. |doi-access=free }}</ref>
 |The second [[nucleon]].
 |-
 |[[antiparticle]]s
 |&nbsp;
 |[[Paul Dirac]] (1928)<ref>{{cite journal |date=1928 |title=The quantum theory of the electron |journal=Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character |language=en |volume=117 |issue=778 |pages=610–624 |doi=10.1098/rspa.1928.0023 |bibcode=1928RSPSA.117..610D |issn=0950-1207|last1=Dirac |first1=P. A. M. |doi-access=free }}</ref>
 |[[Carl D. Anderson]] ({{subatomic particle|positron|link=yes}}, 1932)
 |Revised explanation uses [[CPT symmetry]].
 |-
 |[[pion]]s {{subatomic particle|pion}}
 |composite ([[meson]]s)
 |[[Hideki Yukawa]] (1935)
 |[[César Lattes]], [[Giuseppe Occhialini]], [[Cecil Powell]] (1947)
 |Explains the [[nuclear force]] between nucleons. The first meson (by modern definition) to be discovered.
 |-
 |[[muon]] {{subatomic particle|muon}}
 |elementary (lepton)
 |{{no|''never''}}
 |Carl D. Anderson (1936)<ref>{{cite journal |last1=Anderson |first1=Carl D. |last2=Neddermeyer |first2=Seth H. |date=1936-08-15 |title=Cloud Chamber Observations of Cosmic Rays at 4300 Meters Elevation and Near Sea-Level |url=https://link.aps.org/doi/10.1103/PhysRev.50.263 |journal=Physical Review |language=en |volume=50 |issue=4 |pages=263–271 |doi=10.1103/PhysRev.50.263 |bibcode=1936PhRv...50..263A |issn=0031-899X|url-access=subscription }}</ref>
 |Called a "meson" at first; but today classed as a [[lepton]].
 |-
|[[tau (particle)|tau]] {{subatomic particle|tau}}
 |elementary ([[lepton]])
 |[[Antonio Zichichi]] (1960) <ref>
{{cite book
 |last=Zichichi |first=A.
 |title=History of Original Ideas and Basic Discoveries in Particle Physics
 |publisher=Springer
 |year=1996
 |editor-last=Newman |editor-first=H.B.
 |editor-last2=Ypsilantis |editor-first2=T.
 |series=NATO ASI Series (Series B: Physics)
 |volume=352
 |location=Boston, MA
 |pages=227–275
 |chapter=Foundations of sequential heavy lepton searches
 |chapter-url=https://cds.cern.ch/record/268975/files/laa-94-027.pdf </ref>
 |[[Martin Lewis Perl]] (1975)
 |-
|[[kaon]]s {{subatomic particle|kaon}}
 |composite (mesons)
 |{{no|''never''}}
 |[[George Rochester|G. D. Rochester]], [[Clifford Charles Butler|C. C. Butler]] (1947)<ref>{{cite journal |last1=Rochester |first1=G. D. |last2=Butler |first2=C. C. |date=December 1947 |title=Evidence for the Existence of New Unstable Elementary Particles |journal=[[Nature (journal)|Nature]] |volume=160 |issue=4077 |pages=855–857 |bibcode=1947Natur.160..855R |doi=10.1038/160855a0 |issn=0028-0836 |pmid=18917296 |s2cid=33881752}}</ref>
 |Discovered in [[cosmic ray]]s. The first [[strange particle]].
 |-
 |[[lambda baryon]]s {{subatomic particle|Lambda}}
 |composite (baryons)
 |{{no|''never''}}
 |[[University of Melbourne]] ({{subatomic particle|Lambda0}}, 1950)<ref>Some sources such as {{cite web |url=http://hyperphysics.phy-astr.gsu.edu/Hbase/Particles/quark.html#c4 |title=The Strange Quark}} indicate 1947.</ref>
 |The first [[hyperon]] discovered.
 |-
 |[[neutrino]] {{math|{{subatomic particle|neutrino}}}}
 |elementary (lepton)
 |[[Wolfgang Pauli]] (1930), named by [[Enrico Fermi]]
 |[[Clyde Cowan]], [[Frederick Reines]] ({{subatomic particle|electron neutrino|link=yes}}, 1956)
 |Solved the problem of energy [[spectrum]] of [[beta decay]].
 |-
 |[[quark]]s<br />({{subatomic particle|up quark}}, {{subatomic particle|down quark}}, {{subatomic particle|strange quark}})
 |elementary
 |[[Murray Gell-Mann]], [[George Zweig]] (1964)
 | colspan=2 {{No}} particular confirmation event for the [[quark model]].
 |-
 |[[charm quark]] {{subatomic particle|charm quark}}
 |elementary (quark)
 |[[Sheldon Glashow]], [[John Iliopoulos]], [[Luciano Maiani]] (1970)
 |[[Burton Richter|B. Richter]], [[Samuel C. C. Ting|S. C. C. Ting]] ({{SubatomicParticle|J/psi|link=yes}}, 1974)
 |
 |-
 |[[bottom quark]] {{subatomic particle|bottom quark}}
 |elementary (quark)
 |[[Makoto Kobayashi (physicist)|Makoto Kobayashi]], [[Toshihide Maskawa]] (1973)
 |[[Leon M. Lederman]] ({{SubatomicParticle|Upsilon|link=yes}}, 1977)
 |
 |-
 |[[gluon]]s
 |elementary (quantum)
 |[[Harald Fritzsch]], [[Murray Gell-Mann]] (1972)<ref>
  {{cite journal
   |last1=Fritzsch |first1=Harald
   |last2=Gell-Mann |first2=Murray
   |title=Current algebra: Quarks and what else?
   |journal=EConf
   |date=1972 |volume=C720906V2 |pages=135–165
   |arxiv=hep-ph/0208010
  }}</ref>
 |[[DESY]] (1979)
 |
 |-
 |[[W and Z bosons|weak gauge bosons]] {{SubatomicParticle|W boson+-}}, {{SubatomicParticle|Z boson0}}
 |elementary (quantum)
 |[[Sheldon Glashow]], [[Steven Weinberg]], [[Abdus Salam]] (1968)<ref>
 {{cite journal
  |last=Glashow |first=Sheldon L.
  |date=1961
  |title=Partial-symmetries of weak interactions
  |url=https://www.sciencedirect.com/science/article/abs/pii/0029558261904692
  |journal=Nuclear Physics
  |language=en
  |volume=22 |issue=4 |pages=579–588
  |doi=10.1016/0029-5582(61)90469-2|bibcode=1961NucPh..22..579G
 |url-access=subscription
  }}</ref><ref>
 {{cite journal
  |last=Weinberg |first=Steven
  |date=1967
  |title=A Model of Leptons
  |journal=Physical Review Letters
  |language=en
  |volume=19 |issue=21 |pages=1264–1266
  |bibcode=1967PhRvL..19.1264W
  |doi=10.1103/PhysRevLett.19.1264 |doi-access=free }}</ref><ref>
 {{cite journal
  |last=Salam |first=Abdus
  |date=1968
  |title=Weak and electromagnetic interactions
  |url=https://inspirehep.net/literature/53083
  |journal=Conf. Proc. C
  |series=World Scientific Series in 20th Century Physics
 |language=en
  |volume=680519 |pages=367–377
  |doi=10.1142/9789812795915_0034|isbn=978-981-02-1662-7
 |url-access=subscription
  }}</ref>
 |[[CERN]] (1983)
 |Properties verified through the 1990s.
 |-
 |[[top quark]] {{subatomic particle|top quark}}
 |elementary (quark)
 |[[Makoto Kobayashi (physicist)|Makoto Kobayashi]], [[Toshihide Maskawa]] (1973)<ref>{{cite journal |last1=Kobayashi |first1=Makoto |last2=Maskawa |first2=Toshihide |date=1973 |title=C P Violation in the Renormalizable Theory of Weak Interaction |url=https://academic.oup.com/ptp/article-lookup/doi/10.1143/PTP.49.652 |journal=Progress of Theoretical Physics |language=en |volume=49 |issue=2 |pages=652–657 |bibcode=1973PThPh..49..652K |doi=10.1143/PTP.49.652 |issn=0033-068X |s2cid=14006603 |hdl-access=free |hdl=2433/66179}}</ref>
 |[[Fermilab]] (1995)<ref>{{cite journal |last1=Abachi |first1=S. |last2=Abbott |first2=B. |last3=Abolins |first3=M. |last4=Acharya |first4=B. S. |last5=Adam |first5=I. |last6=Adams |first6=D. L. |last7=Adams |first7=M. |last8=Ahn |first8=S. |last9=Aihara |first9=H. |last10=Alitti |first10=J. |last11=Álvarez |first11=G. |last12=Alves |first12=G. A. |last13=Amidi |first13=E. |last14=Amos |first14=N. |last15=Anderson |first15=E. W. |date=1995-04-03 |title=Observation of the Top Quark |url=https://link.aps.org/doi/10.1103/PhysRevLett.74.2632 |journal=Physical Review Letters |language=en |volume=74 |issue=14 |pages=2632–2637 |doi=10.1103/PhysRevLett.74.2632 |pmid=10057979 |arxiv=hep-ex/9503003 |bibcode=1995PhRvL..74.2632A |hdl=1969.1/181526 |s2cid=42826202 |issn=0031-9007}}</ref>
 |Does not [[hadronization|hadronize]], but is necessary to complete the Standard Model.
 |-
 |[[Higgs boson]]
 |elementary (quantum)
 |[[Peter Higgs]] (1964)<ref>{{cite web |date=2014-02-12 |title=Letters from the Past – A PRL Retrospective |url=https://journals.aps.org/prl/50years/milestones |access-date=2022-08-22 |website=Physical Review Letters |language=en}}</ref><ref>{{cite journal |last=Higgs |first=Peter W. |date=1964-10-19 |title=Broken Symmetries and the Masses of Gauge Bosons |journal=Physical Review Letters |language=en |volume=13 |issue=16 |pages=508–509 |doi=10.1103/PhysRevLett.13.508 |bibcode=1964PhRvL..13..508H |issn=0031-9007|doi-access=free }}</ref>
 |CERN (2012)<ref>{{cite journal |last1=Aad |first1=G. |last2=Abajyan |first2=T. |last3=Abbott |first3=B. |last4=Abdallah |first4=J. |last5=Abdel Khalek |first5=S. |last6=Abdelalim |first6=A.A. |last7=Abdinov |first7=O. |last8=Aben |first8=R. |last9=Abi |first9=B. |last10=Abolins |first10=M. |last11=AbouZeid |first11=O.S. |last12=Abramowicz |first12=H. |last13=Abreu |first13=H. |last14=Acharya |first14=B.S. |last15=Adamczyk |first15=L. |date=2012 |title=Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC |url=https://linkinghub.elsevier.com/retrieve/pii/S037026931200857X |journal=Physics Letters B |language=en |volume=716 |issue=1 |pages=1–29 |doi=10.1016/j.physletb.2012.08.020|arxiv=1207.7214 |bibcode=2012PhLB..716....1A |s2cid=119169617 }}</ref>
 |Only known spin zero elementary particle.<ref>{{cite journal |last1=Jakobs |first1=Karl |last2=Zanderighi |first2=Giulia |date=2024-02-05 |title=The profile of the Higgs boson: status and prospects |url=https://royalsocietypublishing.org/doi/10.1098/rsta.2023.0087 |journal=Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences |language=en |volume=382 |issue=2266 |doi=10.1098/rsta.2023.0087 |pmid=38104616 |issn=1364-503X|arxiv=2311.10346 |bibcode=2024RSPTA.38230087J }}</ref>
 |-
 |[[tetraquark]]
 |composite
 | {{dunno}}
 |[[Zc(3900)|Z<sub>c</sub>(3900)]], 2013, <small>yet to be confirmed as a tetraquark</small>
 |A new class of hadrons.
 |-
 |[[pentaquark]]
 |composite
 | {{dunno}}
 | colspan=2 |Yet another class of hadrons. {{As of|2019}} several are thought to exist.
 |-
 |[[graviton]]
 |elementary (quantum)
 |Albert Einstein (1916)
 |
 |Interpretation of a [[gravitational wave]] as particles is controversial.<ref>{{cite web |last=Moskowitz |first=Clara |date=March 31, 2014 |title=Multiverse Controversy Heats Up over Gravitational Waves |url=https://www.scientificamerican.com/article/multiverse-controversy-inflation-gravitational-waves/ |access-date=2022-08-22 |website=[[Scientific American]] |language=en}}</ref>
 |-
 |[[magnetic monopole]]
 |elementary (unclassified)
 |Paul Dirac (1931)<ref>{{cite journal |last1=Dirac |first1=Paul A. M. |date=1931 |title=Quantised singularities in the electromagnetic field |url=https://royalsocietypublishing.org/doi/10.1098/rspa.1931.0130 |journal=Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character |language=en |volume=133 |issue=821 |pages=60–72 |bibcode=1931RSPSA.133...60D |doi=10.1098/rspa.1931.0130 |issn=0950-1207|url-access=subscription }}</ref>
 |{{not yet|''hypothetical''}}<ref name=PDG-2024>{{cite journal |last1=Navas |first1=S. |last2=Amsler |first2=C. |last3=Gutsche |first3=T. |last4=Hanhart |first4=C. |last5=Hernández-Rey |first5=J. J. |last6=Lourenço |first6=C. |last7=Masoni |first7=A. |last8=Mikhasenko |first8=M. |last9=Mitchell |first9=R. E. |last10=Patrignani |first10=C. |last11=Schwanda |first11=C. |last12=Spanier |first12=S. |last13=Venanzoni |first13=G. |last14=Yuan |first14=C. Z. |last15=Agashe |first15=K. |date=2024-08-01 |title=Review of Particle Physics |url=https://link.aps.org/doi/10.1103/PhysRevD.110.030001 |journal=Physical Review D |language=en |volume=110 |issue=3 |page=030001 |doi=10.1103/PhysRevD.110.030001 |issn=2470-0010|hdl=20.500.11850/695340 |hdl-access=free }}</ref>{{rp|loc=25}}
 |
|}

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