Editing Particle physics (section)

=== Quarks and leptons ===
{{Main|Quark|Lepton}}
[[File:Beta_Negative_Decay.svg|thumb|A [[Feynman diagram]] of the [[Beta decay|{{SubatomicParticle|Beta-}}&nbsp;decay]], showing a neutron (n, udd) converted into a proton (p, udu). "u" and "d" are the [[Up quark|up]] and [[down quark]]s, "{{Subatomic particle|electron}}" is the [[electron]], and "{{Subatomic particle|Electron antineutrino}}" is the [[Electron Antineutrino|electron antineutrino]].]]
Ordinary [[matter]] is made from first-[[Generation (particle physics)|generation]] quarks ([[Up quark|up]], [[Down quark|down]]) and leptons ([[electron]], [[electron neutrino]]).<ref name="Povh02">{{cite book |author=Povh |first1=B. |title=Particles and Nuclei: An Introduction to the Physical Concepts |last2=Rith |first2=K. |last3=Scholz |first3=C. |last4=Zetsche |first4=F. |last5=Lavelle |first5=M. |date=2004 |publisher=Springer |isbn=978-3-540-20168-7 |edition=4th |chapter=Part I: Analysis: The building blocks of matter |quote=Ordinary matter is composed entirely of first-generation particles, namely the u and d quarks, plus the electron and its neutrino. |access-date=28 July 2022 |chapter-url=https://books.google.com/books?id=rJe4k8tkq7sC&q=povh+%22building+blocks+of+matter%22&pg=PA9 |archive-url=https://web.archive.org/web/20220422024501/https://books.google.com/books?id=rJe4k8tkq7sC&q=povh+%22building+blocks+of+matter%22&pg=PA9 |archive-date=22 April 2022 |url-status=live}}</ref> Collectively, quarks and leptons are called [[fermion]]s, because they have a [[quantum spin]] of [[half-integer]]s (−1/2, 1/2, 3/2, etc.). This causes the fermions to obey the [[Pauli exclusion principle]], where no two particles may occupy the same [[quantum state]].<ref>{{cite book |author=Peacock |first=K. A. |url=https://archive.org/details/quantumrevolutio00peac |title=The Quantum Revolution |publisher=[[Greenwood Publishing Group]] |year=2008 |isbn=978-0-313-33448-1 |page=[https://archive.org/details/quantumrevolutio00peac/page/n143 125] |url-access=limited}}</ref> Quarks have fractional [[Elementary charge|elementary electric charge]] (−1/3 or 2/3)<ref>{{cite book |author=Quigg |first=C. |title=The New Physics for the Twenty-First Century |publisher=[[Cambridge University Press]] |year=2006 |isbn=978-0-521-81600-7 |editor=G. Fraser |page=91 |chapter=Particles and the Standard Model}}</ref> and leptons have whole-numbered electric charge (0 or -1).<ref>{{Cite book |last1=Serway |first1=Raymond A. |url=https://books.google.com/books?id=ecYWAAAAQBAJ |title=Physics for Scientists and Engineers, Volume 2 |last2=Jewett |first2=John W. |date=2013-01-01 |publisher=Cengage Learning |isbn=978-1-285-62958-2 |language=en}}</ref> Quarks also have [[color charge]], which is labeled arbitrarily with no correlation to actual light [[color]] as red, green and blue.<ref name="R. Nave">{{cite web |author=Nave |first=R. |title=The Color Force |url=http://hyperphysics.phy-astr.gsu.edu/hbase/forces/color.html#c2 |url-status=live |archive-url=https://web.archive.org/web/20181007142048/http://hyperphysics.phy-astr.gsu.edu/hbase/Forces/color.html#c2 |archive-date=7 October 2018 |access-date=2009-04-26 |work=[[HyperPhysics]] |publisher=[[Georgia State University]], Department of Physics and Astronomy}}</ref> Because the interactions between the quarks store energy which can convert to other particles when the quarks are far apart enough, quarks cannot be observed independently. This is called [[color confinement]].<ref name="R. Nave"/>

There are three known generations of quarks (up and down, [[Strange quark|strange]] and [[Charm quark|charm]], [[Top quark|top]] and [[Bottom quark|bottom]]) and leptons (electron and its neutrino, [[muon]] and [[Muon neutrino|its neutrino]], [[Tau (particle)|tau]] and [[Tau neutrino|its neutrino]]), with strong indirect evidence that a fourth generation of fermions does not exist.<ref>{{cite journal |author=Decamp |first=D. |year=1989 |title=Determination of the number of light neutrino species |url=https://cds.cern.ch/record/201511 |journal=[[Physics Letters B]] |volume=231 |issue=4 |pages=519–529 |bibcode=1989PhLB..231..519D |doi=10.1016/0370-2693(89)90704-1 |hdl-access=free |hdl=11384/1735}}</ref>