"God Particle" Possibly Discovered
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.
There are three fundamental forces. The most familiar is gravity, which holds humans and other objects to the Earth, makes the Moon go around the Earth thereby leading to tides, lunar phases and eclipses, and causes the Earth to orbit the Sun thereby leading to seasons. Gravity is generated by objects with mass. But because gravity is such a weak force, only bodies of huge mass, such as the Earth and Sun, create a significant effect. In the subatomic world, where protons, neutrons and electrons are extremely light, gravity plays no role. The Higgs field produces masses for the quarks and the electrically charged leptons through its interactions with these fields. These masses are proportional to the strength with which the Higgs couples to the particles. Because the Higgs interacts most strongly with the top quark, the top quark weighs the most (about 200 times the mass of a proton). The electron interacts very weakly with the Higgs and that is why it is the lightest particle (about 2000 times lighter than a proton). Physicists do not understand why the Higgs couplings differ so greatly, so that even if the CERN experiment is confirmed and the Higgs mechanism is realized, certain features of the Standard Model will remain a mystery