| Sigma Baryon | ||||||||||||||||||||
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| Classification | ||||||||||||||||||||
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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
| Particles in physics | |
|---|---|
| Elementary particles | Fermions:
Quarks: u · d ·
s · c · b ·
t • Leptons: e- · e+ · μ- ·
μ+ · τ- · τ+ · νe · νμ · ντ Bosons: Gauge bosons: γ · g · W± · Z0 Other: Ghosts |
| Composite particles | Hadrons: Baryons(list)/Hyperons/Nucleons:
p · n · Δ ·
Λ · Σ · Ξ ·
Ω · Ξb • Mesons(list)/Quarkonia:
π · K · ρ · J/ψ · Υ Other: Atomic nuclei • Atoms • Exotic atoms: Positronium • Molecules |
| Hypothetical elementary particles | Superpartners: Axino · Dilatino ·
Chargino · Gluino · Gravitino · Higgsino · Neutralino ·
Sfermion · Slepton · Squark Other: Axion · Dilaton · Goldstone boson · Graviton · Higgs boson · Tachyon · X · Y · W' · Z' |
| Hypothetical composite particles | Exotic
hadrons: Exotic baryons: Other: Mesonic molecule |
| Quasiparticles | Davydov soliton · Exciton · Magnon · Phonon · Plasmon · Polariton · Polaron |
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