Physics is also called "high-energy physics" because many elementary particles do not occur naturally but are created only during high-energy collisions of other particles. Currently, the interactions of elementary particles and fields are described by the Standard Model. The model accounts for the 12 known particles of matter (quarks and leptons) that interact via the strong, weak, and electromagnetic fundamental forces. Dynamics are described in terms of matter particles exchanging gauge bosons (gluons, W and Z bosons, and photons, respectively). The Standard Model also predicts a particle known as the Higgs boson. In July 2012 CERN, the European laboratory for particle
Elementary charge known elementary particles, including quarks, have charges that are integer multiples of "e". Therefore, one can say that the "quantum of charge" is "e". In this case, one says that the "elementary charge" is three times as large as the "quantum of charge". On the other hand, all "isolatable" particles have charges that are integer multiples of "e". (Quarks cannot be isolated: they only exist in collective states like protons that have total charges that are integer multiples of "e".) Therefore, one can say that the "quantum of charge" is "e", with the proviso that quarks are not to be