Topness
This articleneeds additional citations forverification.(September 2018) |
Flavourin particle physics |
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Flavourquantum numbers |
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Flavour mi xing |
Topness(symbolT) ortruthis aflavour quantum numberthat represents the difference between the number oftop quarks(t) and number oftop antiquarks(t) present in a particle:
By convention, top quarks have a topness of +1 and top antiquarks have a topness of −1. The term "topness" is rarely used; most physicists simply refer to "the number of top quarks" and "the number of top antiquarks".
Conservation
[edit]Like allflavour quantum numbers,topness is preserved understrongandelectromagnetic interactions,but not underweak interaction.However the top quark is extremely unstable, with ahalf-lifeunder 10−23s, which is the required time for the strong interaction to take place. For that reason the top quark does nothadronize,that is it never forms anymesonorbaryon,so the topness of a meson or a baryon is always zero. By the time it can interact strongly it has already decayed to another flavour of quark (usually to abottom quark).
References
[edit]- Anchordoqui, L.;Halzen, F.(2009). "Lessons in Particle Physics".arXiv:0906.1271[physics.ed-ph].
Further reading
[edit]- Anchordoqui, L.;Halzen, F.(2009). "Lessons in Particle Physics".arXiv:0906.1271[physics.ed-ph].