478 Q. Feynman Rules for Tree Graphs in QCD and the Electroweak Theory
Higgs couplings
(i) Trilinear couplings
HW
+ W
− vertex
igM W g νλ
HZ
0 Z
0 vertex
cos
ig
θW M Z g νλ
Fermion Yukawa couplings (fermion mass m f )
−i
g m f
2 MW
Trilinear self-coupling
2
3m H g
−i 2MW
(ii) Quadrilinear couplings:
HHW
+ W
− vertex
2
ig
2 g μν