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The weak hypercharge in particle physics is a quantum number relating the electric charge and the third component of weak isospin. It is conserved (only terms that are overall weak-hypercharge neutral are allowed in the Lagrangian) and is similar to the Gell-Mann–Nishijima formula for the hypercharge of strong interactions (which is not conserved in weak interactions). It is frequently denoted ''Y''W and corresponds to the gauge symmetry U(1). ==Definition== Weak hypercharge is the generator of the U(1) component of the electroweak gauge group, and its associated quantum field ''B'' mixes with the ''W''3 electroweak quantum field to produce the observed gauge boson and the photon of quantum electrodynamics. Weak hypercharge, usually written as ''Y''W, satisfies the equality: : where ''Q'' is the electrical charge (in elementary charge units) and ''T''3 is the third component of weak isospin. Rearranging, the weak hypercharge can be explicitly defined as: : Note: sometimes weak hypercharge is scaled so that : although this is a minority usage. Hypercharge assignments in the Standard Model are determined up to a twofold ambiguity by demanding cancellation of all anomalies. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「weak hypercharge」の詳細全文を読む スポンサード リンク
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