Masses

What about masses?

Another disturbing feature of the Standard Model is that many fundamental interactions simply aren't explained by the theory. For example, why is the W particle is very massive and the photon massless, if both are force carriers? What causes the generation and distribution of particle mass?

To explain this gap in the Standard Model theory, physicists have theorized the existence of a particle called the Higgs boson. This particle supposedly interacts with other particles in such a way that masses are generated in a proper fashion. The Higgs boson has not yet been observed, but physicists hope that future studies at high-energy colliders will prove or disprove its existence.

This picture isn't real. As far as we know, neither W's nor photons have size -- they just have different masses.