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# 8.4: SU(4), SU(5), and SU(6) flavor symmetries

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Once we have three flavors of quarks, we can ask the question whether more flavors exists. At the moment we know of three generations of quarks, corresponding to three generations (pairs). These give rise to SU(4), SU(5), SU(6) flavor symmetries. Since the quarks get heavier and heavier, the symmetries get more-and-more broken as we add flavors.

The properties of the three quarks.
Quark label spin $$Q/e$$ mass (GEV/c$$^2$$)
Down $$d$$ $$\frac{1}{2}$$ $$-\frac{1}{3}$$ 0.35
Up $$u$$ $$\frac{1}{2}$$ $$+\frac{2}{3}$$ 0.35
Strange $$s$$ $$\frac{1}{2}$$ $$-\frac{1}{3}$$ 0.5
Charm $$c$$ $$\frac{1}{2}$$ $$+\frac{2}{3}$$ 1.5
Bottom $$b$$ $$\frac{1}{2}$$ $$-\frac{1}{3}$$ 4.5
Top $$t$$ $$\frac{1}{2}$$ $$+\frac{2}{3}$$ 93

This page titled 8.4: SU(4), SU(5), and SU(6) flavor symmetries is shared under a CC BY-NC-SA 2.0 license and was authored, remixed, and/or curated by Niels Walet via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.

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