Pion
| Pion | |
|---|---|
 | |
Kvarkstukturen af en π+ | |
| Klassificering | |
| Boson Hadron Meson | |
| Generelle egenskaber | |
| Sammensætning | π+: ud π0: uu og dd π-: du[1] |
| Interaktion(er) | Stærk kernekraft[2] |
| Symbol | π+, π0, π- |
| Antal typer | 3 |
| Antipartikel | π+ og π- hinandens π0 sig selv [2] |
| Fysikke egenskaber | |
| Masse | π+ og π-: 139,6 MeV/c2 π0: 135,0 MeV/c2[2] |
| Elektrisk ladning | π+: 1 e[3] π0: 0 e π-: -1 e [3] |
| Spin | 0 [2] |
| Levetid | π+ og π-: 2,60x10-8 s π0: 0,83x10-16 s[2] |
| Henfalder til | Med over 95 % sandsynlighed π+ → μ+ + νμ[4] π0: → 2 γ[5] π+ → μ- + νμ[4] |
| Historie | |
| Forudsagt | Hideki Yukawa (1935)[2] |
| Opdagelse | César Lattes, Giuseppe Occhialini og Cecil Powell (1947)[6] |
Pion eller pi-meson[3] (π-meson) er i partikelfysikken et fælles navn på tre subatomare partikler: π0, π+ og π−. Pioner er de letteste mesoner, der findes og spiller derfor en vigtig rolle i at bestemme egenskaberne for den stærke kernekraft.[2]
Referencer
- ^ Klinkby, Esben. "Partikelfysik" (PDF). Hentet 25. december 2011.
{{cite web}}: CS1-vedligeholdelse: url-status (link) - ^ a b c d e f g "HyperPhysics: Pion". Hentet 25. december 2011.
- ^ a b c Gaardhøje, Jens Jørgen (2001). "Det Lille Big Bang" (PDF). Aktuel Naturvidenskab (1): 19-23.
{{cite journal}}: CS1-vedligeholdelse: url-status (link) - ^ a b C. Amsler et al.. (2008): Particle listings – π+
- ^ C. Amsler et al.. (2008): Particle listings – π0
- ^ "Nature: Physics portal: Looking back: The discovery of the pion". Nature. 2006. Hentet 25. december 2011.
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Quark structure pion.svg
Forfatter/Opretter: No machine-readable author provided. Harp assumed (based on copyright claims)., Licens: CC BY-SA 2.5
The quark structure of the positive pion (π+). The positive pion is comprised of an up quark and an anti-down quark. The strong force is mediated by gluons (wavey). The strong force has three types of charges, the so called red, green and the blue. Here the up has blue, the anti-down anti-blue colour charge, so the pion is colour neutral.
Forfatter/Opretter: No machine-readable author provided. Harp assumed (based on copyright claims)., Licens: CC BY-SA 2.5
The quark structure of the positive pion (π+). The positive pion is comprised of an up quark and an anti-down quark. The strong force is mediated by gluons (wavey). The strong force has three types of charges, the so called red, green and the blue. Here the up has blue, the anti-down anti-blue colour charge, so the pion is colour neutral.