Over the next few years, the Large Hadron Collider at CERN will advance the experimental frontier of particle physics to energies around 1012 eV, or 1 TeV, for collisions among the basic constituents of matter that make up the proton. The energy of the colliding protons themselves will be some 7 TeV. This sevenfold increase over the Fermilab Tevatron’s energy opens vast uncharted terrain and promises a profusion of exciting results.
Consider, for example, the electroweak theory—the quantum field theory that unifies electromagnetism with the weak force responsible for nuclear beta decay. The theory has survived dozens of experimental tests at the level of one part in a thousand. But one essential piece has eluded detection: the Higgs boson, the avatar of the so-called electroweak symmetry breaking that gives mass to quarks, leptons such as the electron and muon, and the W ± and Z gauge bosons—the weak partners...