Relation With Chirality
Fermions with negative chirality (also called left-handed fermions) have T = 1⁄2 and can be grouped into doublets with T3 = ±1⁄2 that behave the same way under the weak interaction. For example, up-type quarks (u, c, t) have T3 = +1⁄2 and always transform into down-type quarks (d, s, b), which have T3 = −1⁄2, and vice-versa. On the other hand, a quark never decays weakly into a quark of the same T3. Something similar happens with left-handed leptons, which exist as doublets containing a charged lepton (e−, μ−, τ−) with T3 = −1⁄2 and a neutrino (ν
e, ν
μ, ν
τ) with T3 = 1⁄2.
Fermions with positive chirality (also called right-handed fermions) have T = 0 and form singlets that do not undergo weak interactions.
Electric charge, Q, is related to weak isospin, T3, and weak hypercharge, YW, by
Read more about this topic: Weak Isospin
Famous quotes containing the word relation:
“There is a certain standard of grace and beauty which consists in a certain relation between our nature, such as it is, weak or strong, and the thing which pleases us. Whatever is formed according to this standard pleases us, be it house, song, discourse, verse, prose, woman, birds, rivers, trees, room, dress, and so on. Whatever is not made according to this standard displeases those who have good taste.”
—Blaise Pascal (16231662)