The Journey Through Time Towards the Discovery of the Higgs Boson

Abstract

The Higgs mechanics is very powerful, it furnishes a description of the electroweak theory in the standard Model which has a convincing experimental verification. But although the Higgs mechanism had been applied successfully, the conceptual background is not clear. The Higgs mechanism is often presented as spontaneous breaking of local gauge symmetry. But local gauge symmetry is rooted in redundancy of description, gauge transformation connect states that cannot be physically distinguished. Gauge symmetry is therefore not symmetry of nature, but of our description of nature. The spontaneous breaking of such symmetry cannot be expected to have physical effects since asymmetries are not reflected in the physics. If spontaneous gauge symmetry breaking cannot have physical effects, this causes conceptual problems for the Higgs mechanism, if taken to be described as spontaneous gauge symmetry breaking. In a gauge invariant theory, gauge fixing is necessary to retrieve the physics from the theory. This means that also in a theory with spontaneous gauge symmetry breaking, a gauge should be fixed. But gauge fixing itself breaks the gauge symmetry, and thereby obscures the spontaneous breaking of the symmetry. It suggests that spontaneous gauge symmetry breaking is not part of the physics, but an unphysical artefact of the redundancy in description.