- A lepton is also a unit of currency.
In physics, a particle is a lepton if it has a spin of 1/2 and does not experience the strong nuclear force. The leptons form a family of elementary particles that are distinct from the gauge bosons and the quarks.
The name "lepton" comes from the Greek λεπτόν, meaning "small" or "thin". However, this name originates from before the discovery of a particularly heavy lepton called the tauon. The tauon is nearly twice the mass of a proton.
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.
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)
| <math>e^- \, / \, e^+<math>
| −1 / +1
| 0.000511
|
| Electron neutrino / Electron antineutrino
| <math>\nu_e \, / \, \overline{\nu_e}<math>
| 0
| ~0
|
| Muon / Antimuon
| <math>\mu^- \, / \, \mu^+ <math>
| −1 / +1
| 0.1056
|
| Muon neutrino / Muon antineutrino
| <math>\nu_\mu \, / \, \overline{\nu_\mu}<math>
| 0
| ~0
|
| Tauon / Antitauon
| <math>\tau^- \, / \, \tau^+<math>
| −1 / +1
| 1.777
|
| Tau neutrino / Tau antineutrino
| <math>\nu_\tau \, / \, \overline{\nu_\tau}<math>
| 0
| ~0
|
See also
External links
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