Vanadium 50 said:
I don't think Feynman would agree with the "must". As I alluded to before, if you work out how much of the mass is carried in the self-interaction with the electric field, it works out to 133% of the mass. That's (one reason) why this line of thinking is essentially dead. Another is that this is a purely classical theory attempting to describe a quantum mechanical object.
I agree with this, but let me also expand on it. It is true that there is "self-energy" of the electron coming from its interactions with the electromagnetic field. Classically this doesn't work, as Vanadium_50 says. In QED, this effect is real. There is an (infinite) contribution to the electron's mass. To a QFT expert: an infinite mass correction implies that the electron mas RUNS, that is, the value of the mass you measure for the electron depends on the energy at which you measure it. I do not want to hijack the thread with a talk about renormalization group methods, but if you're interested, read up on that as well.
HOWEVER, even in this case, the Higgs field has to play a role, since an electron mass is not allowed by the symmetries of the SM without a Higgs (see below). So you see, even with these EM contributions, the Higgs is involved. To see how this works explicitly would require some knowledge of QFT, but if you actually compute the QED corrections and be careful, you find the Higgs is part of the picture, at least in the current version of the SM. For the experts: the loop requires a mass insertion to renormalize the mass.
Another way to see this (although a little more technical): In the classical theory, the EM mass of the electron is "linearly divergent". In the quantum theory, it is "LOG divergent". Dimensional analysis then says that there must be a mass scale for the electron to get a correction, and the only mass scale around is the Higgs vev. This emphasizes that there is a VITAL difference between the classical calculation and the QFT calculation (the latter being the correct one!).
It does not say this. The only particles that the Higgs must give mass to are the W and Z bosons. Fermions can have a Dirac mass that has nothing to do with the Higgs. Alternatively, a completely different Higgs gives mass to the fermions.
Well, it is certainly true that this COULD be the case. However, the "Standard Model" has the Higgs doing double-duty. The point being that you cannot write a Dirac mass for any of the fermions without somehow breaking the gauge symmetry. Minimally, the Higgs is what does that. Extensions of the SM are interesting, but we might not want to go that way here.