Key Stage 5
Meaning
Antimatter is a material made from antiparticles, which when in contact with matter will annihilate one another to produce gamma ray photons or other high energy particles.
About Antimatter
- Many particles of matter have antimatter counterparts which have the same mass but opposite electrical charge.
- During pair-production a particle and its antimatter counterpart appear.
- Most antiparticles are given the name of their counterpart particle with the addition of the prefix anti. However, the antiparticle counterpart of the electron is known as the positron.
- Antimatter appears to be rare in the universe compared to matter which confuses scientists as the Big Bang Theory should have produced equal quantities of matter and antimatter in the early universe.
| Antiparticle | Composition | Charge/e | Strangeness | Baryon Number | Lepton Number |
| \(\bar{u}\bar{u}\bar{d}\) | \(Q=-1\) | \(S=0\) | \(B=-1\) | \(L=0\) | |
| \(\bar{u}\bar{d}\bar{d}\) | \(Q=0\) | \(S=0\) | \(B=-1\) | \(L=0\) | |
| Fundamental | \(Q=+1\) | \(S=0\) | \(B=0\) | \(L=-1\) | |
| Fundamental | \(Q=0\) | \(S=0\) | \(B=0\) | \(L=-1\) |