Leptons

Intermediate

Electron, muon, tau and their neutrinos.

Six leptons: electron, muon, tau and their neutrinos. They don't feel the strong force. Electron stable; muon lives 2.2 μs; tau 0.29 ps.

Worked example

Muons from cosmic rays reach the ground.

Common mistake

Charged leptons come in three heavier copies.

In more detail

Leptons are elementary particles that do not feel the strong force. The charged leptons are electron, muon and tau, each with a neutrino partner.

Electrons carry current and form chemical bonds.
Muons are used in cosmic ray studies and muon tomography.
Particle detectors identify electrons and muons by how they interact, which helps physicists track collisions.

How many leptons are there?

Six, three charged leptons and three neutrinos, plus their antiparticles.

Are leptons heavier than quarks?

No, the lightest quarks are heavier than the electron, though the tau is heavier than many quarks.

Are leptons affected by the strong force?

No. Leptons do not carry colour charge, so they do not feel the strong force.