摘要
The fundamental building blocks of matter are leptons and quarks. Leptons, consisting of charged leptons and neutrinos, come in three flavors: electron, muon, and tau. Quarks, on the other hand, come in six flavors: up, down, strange, charm, bottom, and top. They range in mass from a few thousandths of a gigaelectronvolt (GeV) to more than 100 GeV. Normal matter is made up of up and down quarks and electrons, while the other flavors occur very rarely in the nature. It took nearly 100 years after the discovery of electrons to progress to the most recent discovery of a fundamental particle, that of the top quark. Protons and neutrons, on the other hand, are composite particles made up of quarks. A proton is made up of two up quarks and one down quark, while a neutron is made up of one up quark and two down quarks. An antiproton, the antiparticle of proton, is made up of two antiup quarks and one antidown quark.