Broken Symmetries and the Higgs Boson

The 40 years old Standard Model, the theory of particle physics, seems to describe all experimental data very well. The theory is based on symmetries, some of them are broken, mostly by the weak interaction. All of its elementary particles were identified and studied apart from the Higgs boson until 2012, when the two main experiments of the Large Hadron Collider at CERN, CMS and ATLAS observed a new particle with properties close to those predicted for the Higgs boson. The discovery of the Higgs boson proves the validity of the Brout-Englert-Higgs mechanism of spontaneous symmetry breaking and François Englert and Peter Higgs received the 2013 Nobel Prize in Physics. There are several questions yet concerning the possible theoretical significance of the mass of the new particle