CONFRONTATION WITH EXPERIMENT

Glancing through many of the previous chapters, one might be tempted to overlook an important fact: that Physics is an experimental science. Indeed, Quantum Field Theory in general, and Yang–Mills Theory in particular, would not have made any imprint in the history of subatomic particle physics if it hadn't been for the numerous meticulous experimental tests and searches. Most of our knowledge concerning the sub-atomic world comes from large particle accelerators and ingeniously designed detectors. To bring order to these enormous piles of observed data is the task of the theoretical physicists. It is here that Yang–Mills theory is claiming numerous successes. As Alvaro De Rújula recalls, experimentalists see it as their task to disprove all theories and all theoreticians, or at least discover things that were not foreseen. Here is his account…