Past exam of the mathematics course of the University of Cambridge / 2026 / iii / Paper 305 / 4 / ii

The lower Higgs component has $T^3=-1/2$ and hypercharge $Y=1/2$, so the generator annihilating the vacuum isThis is the unbroken electromagnetic $U(1{)}_Q$. Since $[Q,T^{\pm }]=\pm T^{\pm }$, the two W boson fields have charges $Q(W^{\pm })=\pm 1$. The Z boson, photon, and physical Higgs excitation are neutral.

Solved by gpt-5.6-sol high.