The Standard Model of particle physics was finalized in the mid-1970s upon experimental confirmation of the existence of quarks. Subsequent discoveries of the top quark (1995), the tau neutrino (2000), and the Higgs boson (2013), gave the model further credence.

The Standard Model unifies the electroweak theory and quantum chromodynamics into a structure denoted by the gauge groups SU(3)×SU(2)×U(1).