Colloquia

How elementary particles get their masses

Masses for spin one gauge bosons (W,Z) and spin 1/2 fermions (quarks and leptons) require a mechanism for electroweak symmetry breaking (EWSB). For the standard model (SM) this is the Higgs mechanism predicting an observable spin zero Higgs boson. Other solutions introduce new dynamics (Technicolor, …) or new symmetries (SUSY) and predict a much richer spectrum of new particles. As the LHC is poised to reveal the correct approach, it is timely to explain these options and their theoretical motivation.