STANDARD MODEL

Lepton number

A conserved quantum number defined by L = number of leptons - number of antileptons

Elementary particle

A particle whose substructure is unknown

Antiparticle

A particle with the same mass and opposite charge and/or spin to a corresponding particle, for example positron and electron

Baryon number

A strictly conserve additive quantum number of a system defined by B = 1/3 (number of quarks - number of antiquarks)

Gauge bosons

Carrier or exchange particles that govern particle interaction and the mediation of the four fundemental forces

Baryon

Compositive subatomic particles made up of three quarks

Six types of leptons

Electron, electron neutrino, muon, muon neutrino, tau, tau neutrino

Four types of gauge bosons

Gluon, photon, Z boson and W boson

Electromagnetic forces

One of the four fundamental forces. The electromagnetic force is mediated by photons.

Strong nuclear force

One of the four fundamental forces. The strong nuclear force acts over small distances in the nucleus to hold the nucleons together against the repulsive electrostatic forces exerted between the protons. Mediated by gluons.

Weak nuclear force

One of the four fundamental forces. The weak nuclear force is responsible for radioactive decay and is mediated by W and Z bosons.

Leptons

Particles that are governed by the weak nuclear force and electromagnetism since they have charge

Meson

Subatomic particles composed on one quart and one antiquark

Quarks

Subatomic particles governed by the strong nuclear force that constitute hadrons

Six types of quarks

Up, down, charm, strange, top, bottom