Sigma baryon
Appearance
Sigma Baryon | ||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Classification | ||||||||||||||||||||
| ||||||||||||||||||||
Properties | ||||||||||||||||||||
|
Sigma particles are baryons composed of one strange quark and a combination of up and down quarks, arranged in an isospin 1 state. These are hyperons.
The symbol Σ is also used for similar heavier particles containing charm and bottom quarks. They are, by definition, not hyperons.
Particle | Symbol | Makeup | Rest mass MeV/c2 |
Spin | S | C | B | Mean lifetime s |
Decays to |
---|---|---|---|---|---|---|---|---|---|
Sigma | Σ+ | uus | 1189.4 | 1/2 | -1 | 0 | 0 | 0.8×10-10 | π0 + p or π+ + n |
Sigma | Σ0 | uds | 1192.5 | 1/2 | -1 | 0 | 0 | 6×10-20 | Λ0 + γ |
Sigma | Σ- | dds | 1197.4 | 1/2 | -1 | 0 | 0 | 1.5×10-10 | π- + n |
bottom Sigma | Σ+b | uub | 1/2 | 0 | 0 | -1 | Λ0b + π+ | ||
bottom Sigma | Σ-b | ddb | 1/2 | 0 | 0 | -1 | Λ0b + π- |
See also
References
- Particle Data Group: W.-M. Yao et al., J. Phys G 33, 1 (2006).
- The Sigma Baryon. HyperPhysics.
- "CDF finds exotic relatives of protons and neutrons". Fermilab Today. 2006-10-23