The Lepton reference article from the English Wikipedia on 24-Jul-2004 (provided by Fixed Reference: snapshots of Wikipedia from wikipedia.org)

Lepton

A lepton (λεπτο) is also €0.01 in Greek. See: Greek euro coins.

A lepton (Greek for "light", as opposed to hadrons which are "heavy") is a subatomic particle that is not made of quarks.

There are 12 known types of lepton, 3 of which are matter particles (the electron, the muon and the tauon), 3 corresponding neutrinos, and their 6 respective antiparticles. All known charged leptons have a single negative or positive electric charge (depending on whether they are particles or antiparticles) and all of the neutrinos and antineutrinos have neutral electric charge.

Table of contents

1 A table of the leptons 2 See also 3 External links

A table of the leptons

Charged particle / antiparticle					Neutrino / antineutrino
Name	Symbol	Electric charge	Mass(GeV)		Name	Symbol	Electric charge	Mass(GeV)
Electron / Antielectron (positron)		−1 / +1	0.000511		Electron neutrino / Electron antineutrino		0	~0
Muon / Anti-muon		−1 / +1	0.1056		Muon neutrino / Muon antineutrino		0	~0
Tauon / Anti-tauon		−1 / +1	1.777		Tau neutrino / Tau antineutrino		0	~0

See also

• List of particles

External links

• The Particle Data Group who compile authoritative information on particle properties.

Particles in Physics - Elementary particles	Edit
Fermions : Quarks | Leptons
Gauge Bosons : Photon | W+, W- and Z0 bosons | Gluons
Not yet observed
Higgs boson | Graviton
Supersymmetric Partners : Neutralinos | Charginos | Gravitino | Gluinos | Squarks | Sleptons

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