A paper I am reading says My question is, "What does this mean?" The paper deals with WIMP annihilations into a photon and a Higgs which I suspect occurs via a fermion loop. I seem to recall that such triangle diagrams yield amplitudes proportional to the mass of the fermion in the loop (which is why, for some Standard Model processes, the top quark channel, if it is open, is the most significant). How does this proportionality arise? And what does it have to do with the "dynamics of electroweak symmetry-breaking"?