Weak hypercharge is twice the difference between the electrical charge and the weak isospin. It is the generator of the center of the electroweak gauge group. CPT-symmetry is a fundamental symmetry of physical laws under transformations that involve the inversions of charge, parity and time simultaneously. ... In the standard model of particle physics the Cabibbo Kobayashi Maskawa matrix (CKM matrix, sometimes earlier called KM matrix) is a unitary matrix which contains information on the strength of flavour changing weak decays. ... CP is the product of two symmetries: C for charge conjugation, which transforms a particle into its antiparticle, and P for parity, which creates the mirror image of a physical system. ... A phenomenon is said to be chiral if it is not identical to its mirror image (see Chirality (mathematics)). The spin of a particle may be used to define a handedness for that particle. ... Electric charge is a fundamental property of some subatomic particles, which determines their electromagnetic interactions. ... The weak isospin in theoretical physics parallels the idea of the isospin under the strong interaction, but applied under the weak interaction. ...

In a relation that parallels the Gell-Mann/Nishima Law (see hypercharge) we have In particle physics, the hypercharge (represented by Y) is the sum of the baryon number B and the flavor charges: strangeness S, charm C, bottomness and topness T, although the last one can be omitted given the extremely short life of the top quark (it decays to other quarks before...

where Q is the electrical charge (in elementary charge units), is the third component of the weak isospin, and Y^W is the weak hypercharge. From here we can define the weak hypercharge in terms of particle electrical charge and weak isospin. The elementary charge (symbol e or sometimes q) is the electric charge carried by a single proton, or equivalently, the negative of the electric charge carried by a single electron. ... The weak isospin in theoretical physics parallels the idea of the isospin under the strong interaction, but applied under the weak interaction. ...

Given that weak isospin is 1/2 for all left-handed fermions (and 0 for all right-handed fermions), all weak isospin doublets will have an average charge

with

• Y = −1 for left-handed leptons (+1 for antileptons)
• Y = +1/3 for left-handed quarks (−1/3 for antiquarks)

See also

• Field theoretical formulation of the standard model
• Weak isospin