Scientists have confirmed that the Higgs boson is the only elementary particle that behaves as a scalar, meaning it has no spin. This finding comes from a comprehensive review of the Higgs field’s impact on the early universe and its role in particle physics.

The boson is responsible for giving mass to quarks, charged leptons, and the intermediate vector bosons W and Z. The process occurs through spontaneous symmetry breaking of the SU(2)×U(1) gauge symmetry, where the Higgs field acquires a non‑zero value and interacts with other particles via Yukawa couplings.

For the observed Higgs mass of 125 GeV, calculations show that the electroweak phase transition in the Standard Model was not a sharp change but a smooth crossover. The temperature at which the Higgs condensate changes most rapidly is around 160 GeV.

At the Large Hadron Collider, extensive searches for physics beyond the Standard Model have returned no convincing evidence of new particles up to the TeV scale. These null results challenge theories that rely on naturalness arguments to predict new physics near the electroweak scale.

The persistence of the Higgs boson as the sole fundamental scalar underscores the robustness of the Standard Model while leaving open questions about the origin of mass and the potential need for new theoretical frameworks.