Strange quark

The bubble chamber picture of the first Ω- particle. An incoming K- meson interacts with a proton in the liquid hydrogen of the bubble chamber and produces an omega-minus, a K0 and a K+ meson which all decay into other particles. Neutral particles (invisible) are shown by dashed lines. Brookhaven Laboratry

The strange quark is a second-generation quark with a charge of -(1/3)e and a strangeness of −1. It is the third lightest quark after the up and down quarks, with a mass of somewhere between 80 and 130 MeV. The first strange particle (particle containing a strange valence quark) was discovered in 1947, with the identification of the kaon, but the strange quark itself was not identified until Gell-Mann and Zweig developed the quark model in 1964.

Hadrons containing strange valence quarks

Hadrons containing strange valence quarks include the following:

* Kaons are mesons containing a strange quark (or its antiparticle) and an up or down quark.

* The η and η' flavorless mesons are linear combinations of several quark-antiquark pairs, including the strange-antistrange.

* The φ flavorless meson is pure strange-antistrange.

* Strange baryons are known as hyperons: the Σ and Λ have one strange quark, the Ξ two, and the Ω three.

Strange Quark
Composition: Elementary particle
Family: Fermion
Group: Quark
Generation: Second
Mass: 80 - 130 MeV/c2
Electric charge: -1/3 e
Spin: ½

See also

* Strange matter

* Strange star

* Strangelet

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