The only applications of the standard model discussed up to this point have been calculations of the decay rates for the unstable weakly interacting elementary particles of the model. These are important applications since much of what is known about the fundamental interactions of nature comes from the basic properties of the particles involved, including their decay products and lifetimes. As we have seen, the standard model is able to do a good job of accounting for these properties to within the accuracy of current measurements, at least within the leptonic sector.

There are other applications which the model must also describe, however. Prominent among these are reactions that are observed within particle accelerators. This is, after all, how these unstable particles are produced. This chapter is meant to present some of the standard model predictions for the results of elementary-particle collisions among leptons and electroweak bosons. We focus here on these particles since their collisions are understandable with the fewest complications. Hadronic collisions are the topic of Chapter 9.

e+e−–annihilation processes are the lepton collisions that have been of particular interest since these have been studied in great detail near and beyond the Z0 resonance. The precision of these measurements has been used to test the model with exquisite precision.