1. Up
  1. Charm
  1. Top
  1. Down
  1. Strange
  1. Bottom
  1. Electron neutrino
  1. Muon neutrino
  1. Tau neutrino
  1. Electron
  1. Muon
  1. Tau
  1. Photon (electromagnetism)
  1. Gluon
  1. Z (weak force)
  1. W (weak force)
  1. Higgs

Up

Electric charge: +2/3

Mass: 2.3 MeV

Constituent of ordinary matter; two up quarks, plus a down, make up a proton.

X

Charm

Electric charge: +2/3

Mass: 1.28 GeV*

Unstable heavier cousin of the up; constituent of the J/ψ particle, which helped physicists develop the Standard Model.

*GeV: giga-electron-volts

X

Top

Electric charge: +2/3

Mass: 173.5 GeV*

Heaviest known particle, comparable in mass to an atom of osmium. Very short-lived.

*GeV: giga-electron-volts

X

Down

Electric charge: –1/3

Mass: 4.8 MeV

Constituent of ordinary matter; two down quarks, plus an up, compose a neutron.

X

Strange

Electric charge: –1/3

Mass: 95 MeV

Unstable heavier cousin of the down; constituent of the much studied kaon particle.

X

Bottom

Electric charge: –1/3

Mass: 4.18 GeV*

Unstable and still heavier copy of the down; constituent of the much studied B-meson particle.

*GeV: giga-electron-volts

X

Electron Neutrino

Electric charge: 0

Immune to both electromagnetism and the strong force, it barely interacts at all but is essential to radioactivity.

X

Muon Neutrino

Electric charge: 0

Appears in weak reactions involving the muon.

X

Tau Neutrino

Electric charge: 0

Appears in weak reactions involving the tau lepton.

X

Electron

Electric charge: –1

Mass: 0.511 MeV

The lightest charged particle, familiar as the carrier of electric currents and the particles orbiting atomic nuclei.

X

Muon

Electric charge: –1

Mass: 105.7 MeV

A heavier version of the electron, with a lifetime of 2.2 microseconds; discovered as a component of cosmic-ray showers.

X

Tau

Electric charge: –1

Mass: 1.78 GeV*

Another unstable and still heavier version of the electron, with a lifetime of 0.3 picosecond.

*GeV: giga-electron-volts

X

Photon (electromagnetism)

Electric charge: 0

Mass: 0

Carrier of electromagnetism, the quantum of light acts on electrically charged particles. It acts over unlimited distances.

Particle Type: Boson
At the quantum level, each force of nature is transmitted by a dedicated particle or set of particles.

X

Gluon (strong force)

Electric charge: 0

Mass: 0

Eight species of gluons carry the strong interaction, acting on quarks and on other gluons. They do not feel electromagnetic or weak interactions.

X

z (weak force)

Electric charge: 0

Mass: 91.2 GeV*

Mediator of weak reactions that do not change the identity of particles. Its range is only about 10–18 meter.

*GeV: giga-electron-volts

X

W (weak force)

Electric charge: +1 or –1

Mass: 80.4 GeV*

Mediators of weak reactions that change particle flavor and charge. Their range is only about 10–18 meter.

*GeV: giga-electron-volts

X

Higgs

Electric charge: 0

Mass: ~125 GeV*

Believed to endow W and Z bosons, quarks and leptons with mass.

*GeV: giga-electron-volts

X