Forces of the World Unite!

The structure of matter and the forces that are important in particle physics are now understood in terms of the Standard Model, which is currently being tested at the Large Hadron Collider (LHC). Since the 1930s, physicists have used particle accelerators to investigate the structure of matter. Three forces are important in particle interactions, the strong force, the weak force and the electromagnetic force. The weak and electromagnetic forces are now recognized as two components of a unified electroweak force. The strong force and the electroweak force act on a small collection of fundamental particles that include quarks, the subcomponents of protons, neutrons and many other particles. The final missing piece of the Standard Model, the Higgs boson, was discovered by the LHC in 2012.