The weak hypercharge in particle physics is a quantum number relating the electrical charge and the third component of weak isospin, and is similar to the Gell-Mann–Nishijima formula of strong interactions. It is the generator of the U(1) component of the electroweak gauge group, SU(2)xU(1) and its associated quantum field B mixes with the W³ electroweak quantum field to produce the observed Z⁰ gauge boson and the photon of quantum electrodynamics.

Weak hypercharge, usually written as Y_W, is defined as:

$qquad\; Q\; =\; T\_z\; +\; \{Y\_W\; over\; 2\}$

$qquad\; Y\_W\; =\; 2(Q\; -\; T\_z)$

See also

• Field theoretical formulation of the standard model
• Weak isospin