Down quark
From Wikipedia, the free encyclopedia
Down quarks (sometimes written as a "d") are very small particles that help make up many larger particles, like protons and neutrons. Down quarks have a charge of -1/3. Since Down quarks are fermions (which means that no two of them can exist in the same space at the same time), they have a spin of 1/2. Down quarks are the second lightest quark, the first being up quarks.
The antiparticle of a Down quark is a Down antiquark, or simply an antidown.
| Particles in Physics | |||
|---|---|---|---|
| Elementary: | Fermions: | Quarks: up – down – strange – charm – bottom – top Leptons: electron – muon – tau – neutrinos |
|
| Bosons: | Gauge bosons: photon – W and Z bosons – gluons | ||
| Composite: | Hadrons: | Baryons: proton – neutron – hyperon | |
| Mesons: pion – kaon – J/ψ | |||
| Atomic nuclei – Atoms – Molecules | |||
| Hypothetical: | Higgs boson – Graviton – Tachyon | ||
