An example is that changing voltages in an electromagnet by +100 volts, doesn't cause any change to the magnetic field it produces. Gauge invariant theories are theories which have a useful feature, that some kinds of changes to the value of certain items don't make any difference to the outcomes or the measurements we make. Gauge invariant theories and symmetries "It is only slightly overstating the case to say that physics is the study of symmetry" – Philip Anderson, Nobel Prize Physics Forces in the Standard Model are transmitted by particles known as gauge bosons. (A separate theory, general relativity, is used for gravity.) In the Standard Model, the particles and forces in nature (other than gravity) arise from properties of quantum fields, known as gauge invariance and symmetries. Physicists explain the fundamental particles and forces of our universe in terms of the Standard Model – a widely accepted framework based on quantum field theory that predicts almost all known particles and forces other than gravity with great accuracy. Introduction Standard Model of particle physics
In the mainstream media, the Higgs boson has often been called the " God particle" from the 1993 book The God Particle by Nobel Laureate Leon Lederman, although the nickname is Although Higgs's name has come to be associated with this theory, several researchers between about 19 independently developed different parts of it. Physicists from two of the three teams, Peter Higgs and François Englert, were awarded the Nobel Prize in Physics in 2013 for their theoretical predictions. The new particle was subsequently confirmed to match the expected properties of a Higgs boson. This particle was called the Higgs boson, and could be used to test whether the Higgs field was the correct explanation.Īfter a 40 year search, a subatomic particle with the expected properties was discovered in 2012 by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland. (All fundamental particles known at the time should be massless at very high energies, but fully explaining how some particles gain mass at lower energies, had been extremely difficult.) If these ideas were correct, a particle known as a scalar boson should also exist, with certain properties.
Its " Mexican hat-shaped" potential has a nonzero value everywhere (including otherwise empty space), which breaks the weak isospin symmetry of the electroweak interaction, and via the Higgs mechanism gives some particles mass.īoth the field and the boson are named after physicist Peter Higgs, who in 1964 along with five other scientists in three teams, proposed the Higgs mechanism, a way that some particles can acquire mass. The Higgs field is a scalar field, with two neutral and two electrically charged components that form a complex doublet of the weak isospin SU(2) symmetry. It is also very unstable, decaying into other particles almost immediately.
In the Standard Model, the Higgs particle is a massive scalar boson with zero spin, even (positive) parity, no electric charge, and no colour charge, that couples to (interacts with) mass. The Higgs boson, sometimes called the Higgs particle, is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field, one of the fields in particle physics theory.