QCD for electroweak precision measurements: Foundations

The couplings of the strong to electroweak sectors of the Standard Model enable the exploration of each using our growing knowledge of the other. In this review, we will follow the sweep of history. Starting with QED as a precision theory, deep inelastic scattering served as a gateway to the strong interactions, followed by leptonic annihilation and quark–antiquark annihilation in hadron–hadron scattering. In turn, the resulting understanding of QCD helped establish the Standard Model. The same techniques form the basis for many precision electroweak measurements at high energy and searches for signs of new physics.