Higgs

Higgs refers to the Higgs mechanism and the associated Higgs field in the Standard Model of particle physics. The Higgs field is a scalar field that permeates all of space. Through electroweak symmetry breaking, its nonzero vacuum expectation value gives mass to the W and Z bosons, while the photon remains massless. Fermions also acquire mass via Yukawa couplings to the field, with their masses proportional to the strength of these interactions. The vacuum expectation value is about 246 GeV.

The Higgs boson is the quantum excitation of the Higgs field. It is a scalar particle with spin zero and positive parity. The mechanism was proposed in 1964 by Peter Higgs and independently by others; the particle is named after Higgs. In 2012, experiments at the Large Hadron Collider, by the ATLAS and CMS collaborations, observed a new boson with a mass around 125 GeV, with decay modes matching predictions for the Higgs boson. The discovery was reported with a significance of five sigma, confirming the particle as the long-sought manifestation of the Higgs field.

Significance and status: the Higgs field is a cornerstone of the Standard Model, explaining how elementary particles acquire mass while preserving gauge invariance. Measurements of the Higgs boson’s properties, including its couplings to gauge bosons and fermions, have so far broadly agreed with Standard Model predictions, within experimental uncertainties. Ongoing studies continue to test its properties and to search for deviations that might indicate new physics beyond the Standard Model.