Topness (T, also called truth), a flavour quantum number, represents the difference between the number of top quarks (t) and number of top antiquarks (t) that are 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".
Conservationedit
Like all flavour quantum numbers, topness is preserved under strong and electromagnetic interactions, but not under weak interaction. However the top quark is extremely unstable, with a half-life under 10−23 s, which is the required time for the strong interaction to take place. For that reason the top quark does not hadronize, that is it never forms any meson or baryon, 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 a bottom quark).
Referencesedit
Further readingedit
Anchordoqui, L.; Halzen, F. (2009). "Lessons in Particle Physics". arXiv:0906.1271 [physics.ed-ph].
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topness, this, article, needs, additional, citations, verification, please, help, improve, this, article, adding, citations, reliable, sources, unsourced, material, challenged, removed, find, sources, news, newspapers, books, scholar, jstor, september, 2018, l. This article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Topness news newspapers books scholar JSTOR September 2018 Learn how and when to remove this template message Topness T also called truth a flavour quantum number represents the difference between the number of top quarks t and number of top antiquarks t that are present in a particle T n t n t displaystyle T n text t n bar text t 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 editLike all flavour quantum numbers topness is preserved under strong and electromagnetic interactions but not under weak interaction However the top quark is extremely unstable with a half life under 10 23 s which is the required time for the strong interaction to take place For that reason the top quark does not hadronize that is it never forms any meson or baryon 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 a bottom quark References editFurther reading editAnchordoqui L Halzen F 2009 Lessons in Particle Physics arXiv 0906 1271 physics ed ph nbsp This particle physics related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Topness amp oldid 1073414752, wikipedia, wiki, book, books, library,
