The quest for the Higgs boson is the central preoccupation of particle physics experimenters. The Higgs particle remains the only undiscovered building block required by the standard model of particle theory. The eponymous Peter Higgs (Edinburgh University) introduced it in 1964 to break the underlying symmetry between the weak and electromagnetic interactions and, in so doing, to give mass to the fundamental fermions (quarks and leptons) and the heavy gauge bosons that mediate their weak interactions.
The standard model makes no a priori prediction of the Higgs mass M H. But a global fit to the many well measured parameters of the electroweak interactions does provide an estimate of M H. In recent years, however, the best such estimate has been in slightly embarrassing conflict with the negative results of direct searches for the Higgs. Before the LEP electron–positron collider at CERN was finally shut down in December...
