© David Kaplan.

If the Higgs boson and top quark are not elementary particles, they could be made of smaller particles held together by a force stronger than any others in the Standard Model. This Feynman diagram represents an example of part of a calculation of the Higgs (and therefore W and Z) mass, which in the Standard Model is infinite. In a composite model in which the Higgs is made of other particles, the diagram is much more complicated when considering high energies and shorter length scales (with the purple loopy lines representing the new force carriers). The more complicated diagrams turn out to be finite, and therefore can complete the Standard Model. (Unit: 2)