Tag Info

If your theory is anything like scalar-QCD then the gauge field couples to the scalar current through a "derivative" interaction $$A^\mu J_\mu \supset A^\mu \; \left( \phi^\ast \partial_\mu \phi - \phi \partial_\mu \phi^\ast \right)$$ This would mean that each of the gauge-boson scalar vertices will have a factor of the scalar momentum, in the numerator. ...