One of the most important discoveries in particle physics of the last 25 years has possibly just been made by experimentalists at CERN, the giant laboratory just outside of Geneva on the border of Switzerland and France. Scientists there think that they have discovered the Higgs field, also nicknamed the "God particle" by Nobel laureate Leon Lederman who wrote a book with that title. If the result is verified, the Higgs will have a mass about 125 times the mass of the proton, making it as heavy as a medium-sized nucleus, and it will "fill in" the last missing piece of a puzzle involving the solution of one of the great outstanding problems in physics of the 20th century: the origin of all mass. If the properties of the Higgs are confirmed, the picture of fundamental particle forces will have been completed. That picture is known as The Standard Model.
The Standard Model of particle physics provides a description of microscopic matter and their fundamental interactions. All matter is comprised of quarks and leptons. Three quarks bind to form the proton and neutron. The neutrons and protons stick together to form nuclei – the tiny, heavy central "hearts" of atoms. Leptons appear in nature in two types: electrically charged and neutral. Neutral leptons are called neutrinos and hardly interact with matter at all. There are three known charged leptons, the lightest of which is the electron. Electrons, which are negatively charged, are attracted to nuclei, which are positively charged, to form atoms. A good pictorial representation of an atom is a cloud of electrons swarming around a tiny nucleus, much the way bees might swarm around a queen who has left her hive. Since atoms make up everything in the world, quarks and leptons are the fundamental building blocks of nature.
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