Leptons

Definition

Leptons are a class of elementary particles that do not participate in strong nuclear interactions but are subject to weak nuclear interactions and electromagnetic forces. They include electrons, muons, taus, and their associated neutrinos.

5 Must Know Facts For Your Next Test

1. Leptons come in six types: electron, muon, tau, and their corresponding neutrinos (electron neutrino, muon neutrino, tau neutrino).
2. Each lepton has a corresponding antiparticle with the same mass but opposite charge.
3. Leptons obey the Pauli exclusion principle and have half-integer spins (fermions).
4. The conservation of lepton number is a fundamental principle; the total number of leptons remains constant in any interaction.
5. Neutrinos have very small masses compared to other leptons and rarely interact with matter.

Review Questions

• What are the six types of leptons?
• How does the lepton number conservation law apply in particle interactions?
• What distinguishes leptons from quarks?

Related terms

Quark:

A type of elementary particle that combines to form composite particles such as protons and neutrons. Quarks experience all four fundamental forces.

Fermion: A particle with half-integer spin that follows the Pauli exclusion principle. Examples include quarks and leptons.

Neutrino:

A type of lepton with extremely small mass that interacts only via weak nuclear force and gravity, making it very difficult to detect.