# Difference between Higgs contribution to electroweak boson mass, and fermion mass?

Thanks in advance to anyone who takes the time to answer this, and apologies in advance for what is probably (yet another) question here due to unfamiliarity with The Math.

I had a chance recently to visit the CMS detector at CERN (sheer luck) and it's made me curious to better understand how the Higgs field interacts with the weak gauge particle field vs. the fermion field. I've read several descriptions that connect the former with electroweak symmetry breaking and the latter with "a different mechanism" which seems to be a Yukawa coupling (which I understand to be an interaction between a scalar field --the Higgs field --and the fermion field.) Damned if I really understand the difference though --do both involve virtual Higgs bosons?

The Higgs field gives mass to the weak gauge bosons and the fermions through interactions it has with them and the form of the interactions is dictated by basic principles (relativity and quantum mechanics). That much is the same. The main difference is that the relative strength of the Higgs coupling to the different gauge bosons is fixed by the gauge group and charge of the Higgs field, but the relative strength of the interactions with the different fermions is not fixed by any basic principle that we know of. So we understand why the $Z^0$ boson is slightly heavier than the $W^\pm$ (and precisely so), but we have no real idea why the top quark is so much heavier than the electron.