Gauge symmetry saved, mass endowed

In its original incarnation, the Higgs mechanism was designed to give mass to the gauge bosons that carry the weak force and to preserve a basic symmetry of the theory of weak interactions. Although many physicists may not be familiar with the gauge particles associated with the weak force, almost all are well acquainted with one gauge boson—the photon, which transmits the electromagnetic force. In quantum field theories, particles are expressed as fields; the photon field is a four-vector potential A^μ = (V/c, A_x, A_y, A_z) that incorporates the scalar (V) and vector (A) potentials, quantized versions of fields familiar from classical electrodynamics. Maxwell’s equations are invariant under the “gauge” transformation V → V − ∂Λ/∂t, A → A + ∇Λ for an arbitrary Λ(x,t). Similar gauge...