Hiperon
’n Hiperon is ’n subatomiese deeltjie. Dit is enige barion wat bestaan uit een of meer vreemd-kwarke, maar geen sjarme- of onder-kwarke nie. Hulle is onstabiel en anders as nukleone word hulle nie normaalweg in materie waargeneem nie. Atoomkerns wat hiperone bevat, word hiperkerns genoem.
Die naam van die hiperon hang af van die getal vreemd-kwarke (s-kwarke), dus sy vreemdheid:
- 1 s-kwark: Lambda (Λ)-barion
- 2 s-kwarke: Xi (Ξ)-barion
- 3 s-kwarke: Omega (Ω)-barion
Die volgende hiperone bestaan:
| Hiperon | Kwarke | Spin | Isospin | Vreemdheid | Massa in MeV | Lewensduur in s | Vervalkanaal |
|---|---|---|---|---|---|---|---|
| Λ | uds[1] | 1/2+ | 0 | −1 | 1115,683(6) | 2,631(20) × 10−10 | pπ−,nπ0 |
| Σ+ | uus | 1/2+ | 1 | −1 | 1189,37(7) | 0,8018(26) × 10−10 | pπ0, nπ+ |
| Σ0 | uds | 1/2+ | 1 | −1 | 1192,642(24) | 7,4(7) × 10−20 | Λγ |
| Σ− | dds | 1/2+ | 1 | −1 | 1197,449(30) | 1,479(11) × 10−10 | nπ− |
| Ξ0 | uss | 1/2+ | 1/2 | −2 | 1314,86(20) | 2,90(9) × 10−10 | Λπ0 |
| Ξ− | dss | 1/2+ | 1/2 | −2 | 1321,71(7) | 1,639(15) × 10−10 | Λπ− |
| Ω− | sss | 3/2+ | 0 | −3 | 1672,45(29) | 0,821(11) × 10−10 | ΛK−, Ξ0π−, Ξ−π0 |
| Σ*+(1385) [2] | uus | 3/2+ | 1 | −1 | 1382,8(4) | Λπ, Σπ | |
| Σ*0(1385) [2] | uds | 3/2+ | 1 | −1 | 1383,7±1,0 | Λπ, Σπ | |
| Σ*−(1385) [2] | dds | 3/2+ | 1 | −1 | 1387,2(5) | Λπ, Σπ | |
| Ξ*0(1530) [3] | uss | 3/2+ | 1/2 | −2 | 1531,80(32) | Ξπ | |
| Ξ*−(1530) [3] | dss | 3/2+ | 1/2 | −2 | 1535,0(6) | Ξπ |
Verwysings
[wysig | wysig bron]- ↑ u = op-kwark, d = af-kwark, s = vreemd-kwark
- ↑ 2,0 2,1 2,2 "Particle Data Groups: 2006 Review of Particle Physics – Sigma(1385)" (PDF; 135 kB). Besoek op 20 April 2008.
- ↑ 3,0 3,1 "Particle Data Groups: 2006 Review of Particle Physics – Xi(1530)" (PDF; 89 kB). Besoek op 20 April 2008.
