Testing the Higgs Mechanism at High Energy Colliders

Abstract

In this talk I will review the implications of symmetry and unitarity for the physics of electroweak symmetry breaking and describe some of the signals of that physics that may emerge above 1 TeV at multi-TeV pp colliders. Though there is no direct experimental evidence, the Higgs mechanism1 is universally regarded as the only viable agent of SU(2) L × U(1) Y symmetry breaking.2 General considerations3,4 based only on unitarity and gauge symmetry insure that decisive experiments can be done within the next ten years to test the Higgs mechanism. (This ten-year unitarity bound does require the cooperation of the Good Lord and the U.S. Congress. Caution is therefore advisable: while the Former has always honored unitarity, the latter is a known source of unitarity violations.) The outcome of these experiments is certain to be exciting. If the Higgs mechanism is not confirmed, it would mean either that the electroweak interactions are not described by a gauge theory or that a breaking mechanism exists which is unimagined today. If the Higgs mechanism is confirmed than there may or may not be Higgs bosons, but there is necessarily a new force (the real #5) and associated new quanta.