top channel and electroweak breaking

electroweak

A paper I am reading saysMy 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"?

Bill_K

"WIMP" means specifically, mass in the 100's of GeV and interactions of the same order as the electroweak interaction. This would be the case if it was "part of the dynamics of electroweak symmetry-breaking". Recent failure to detect such particles has increased the possibility that the dark matter particles may not be WIMPs after all. They may be lighter ("light dark matter"), or interact even more weakly.