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Colour charge and QCD
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Quarks carry colour; gluons bind them.
Quarks carry one of three colours; gluons carry colour too, so they interact among themselves. Quantum chromodynamics describes this and only colourless combinations are observed.
Proton: red + green + blue = white.
Colour has nothing to do with real colour.
In more detail
Quantum chromodynamics describes the strong interaction between quarks, which carry colour charge. Gluons carry colour and bind quarks together.
Real-world uses
- QCD predicts the properties of protons and neutrons from their quarks.
- Collider experiments test QCD through jets and particle production.
- Physicists use quantum chromodynamics to predict the masses and interactions of protons and neutrons from their quarks and gluons.
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Frequently asked questions
What is colour?
An internal property of quarks, unrelated to visible colour, that comes in three types.
Why are gluons special?
Unlike photons, gluons carry colour, so they interact with each other.
What is colour charge?
A property of quarks and gluons that comes in three types, analogous to but distinct from electric charge.
Related topics in Particle Physics & Cosmology
Gauge bosons · Higgs boson · Standard Model · Asymptotic freedom · Confinement · Weak interaction