Electroweak Symmetry Breaking

Field-strength tensors:
W µν = ∂ µ W ν − ∂ ν W µ + ig[W µ , W ν ],
B µν = ∂ µ B ν − ∂ ν B µ ,
where
⇒ kinetic term
W µ = Wµ
a τ a
2
and B µ = B µ
τ 3
2 .
L 4(W ) = − 1 2 tr [W µνW µν ] − 1 2 tr [B µνB µν ] .