Higgs boson. The Higgs boson is named after Peter Higgs, one of six physicists who, in 1964, proposed the mechanism that suggested the existence of such a particle. Although Higgs's name has come to be associated with this theory, several researchers between about 1960 and 1972 each independently developed different parts of it.
In mainstream media the Higgs boson has often been called the "God particle", from a 1993 book on the topic; the nickname is strongly disliked by many physicists, including Higgs, who regard it as inappropriate sensationalism.[17][18] In 2013 two of the original researchers, Peter Higgs and François Englert, were awarded the Nobel Prize in Physics for their work and prediction[19] (Englert's co-researcher Robert Brout had died in 2011).
A non-technical summary[edit] "Higgs" terminology[edit] Overview[edit] If this field did exist, this would be a monumental discovery for science and human knowledge, and is expected to open doorways to new knowledge in many fields. History[edit] Photon. Nomenclature[edit] In 1900, Max Planck was working on black-body radiation and suggested that the energy in electromagnetic waves could only be released in "packets" of energy. In his 1901 article [4] in Annalen der Physik he called these packets "energy elements". The word quanta (singular quantum) was used even before 1900 to mean particles or amounts of different quantities, including electricity. Later, in 1905, Albert Einstein went further by suggesting that electromagnetic waves could only exist in these discrete wave-packets.[5] He called such a wave-packet the light quantum (German: das Lichtquant).
The name photon derives from the Greek word for light, φῶς (transliterated phôs). Physical properties[edit] The cone shows possible values of wave 4-vector of a photon. A photon is massless,[Note 2] has no electric charge,[13] and is stable. Photons are emitted in many natural processes. Since p points in the direction of the photon's propagation, the magnitude of the momentum is. W and Z bosons. The W bosons are named after the weak force. The physicist Steven Weinberg named the additional particle the "Z particle",[3] and later gave the explanation that it was the last additional particle needed by the model.
The W bosons had already been named, and the Z bosons have zero electric charge.[4] The two W bosons are verified mediators of neutrino absorption and emission. During these processes, the W boson charge induces electron or positron emission or absorption, thus causing nuclear transmutation. The Z boson is not involved in the absorption or emission of electrons and positrons. The Z boson mediates the transfer of momentum, spin and energy when neutrinos scatter elastically from matter (a process which conserves charge). Basic properties[edit] These bosons are among the heavyweights of the elementary particles. Weak nuclear force[edit] W bosons[edit] The W bosons are best known for their role in nuclear decay. 60 27Co → 60 28Ni+ + e− + ν e n0 → p+ + e− + ν e d → u + W− Decay[edit] Gluon. Gluons /ˈɡluːɒnz/ are elementary particles that act as the exchange particles (or gauge bosons) for the strong force between quarks, analogous to the exchange of photons in the electromagnetic force between two charged particles.[6] In technical terms, gluons are vector gauge bosons that mediate strong interactions of quarks in quantum chromodynamics (QCD).
Gluons themselves carry the color charge of the strong interaction. This is unlike the photon, which mediates the electromagnetic interaction but lacks an electric charge. Gluons therefore participate in the strong interaction in addition to mediating it, making QCD significantly harder to analyze than QED (quantum electrodynamics). Properties[edit] Diagram 1: e+e− -> Y(9.46) -> 3g Numerology of gluons[edit] Unlike the single photon of QED or the three W and Z bosons of the weak interaction, there are eight independent types of gluon in QCD. This may be difficult to understand intuitively. Color charge and superposition[edit] A.
Lepton. A lepton is an elementary, spin-1⁄2 particle that does not undergo strong interactions, but is subject to the Pauli exclusion principle.[1] The best known of all leptons is the electron, which governs nearly all of chemistry as it is found in atoms and is directly tied to all chemical properties.
Two main classes of leptons exist: charged leptons (also known as the electron-like leptons), and neutral leptons (better known as neutrinos). Charged leptons can combine with other particles to form various composite particles such as atoms and positronium, while neutrinos rarely interact with anything, and are consequently rarely observed. The first charged lepton, the electron, was theorized in the mid-19th century by several scientists[3][4][5] and was discovered in 1897 by J.
J. Thomson.[6] The next lepton to be observed was the muon, discovered by Carl D. Leptons are an important part of the Standard Model. Etymology[edit] Following a suggestion of Prof. History[edit] Properties[edit] Quark. A quark (/ˈkwɔrk/ or /ˈkwɑrk/) is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei.[1] Due to a phenomenon known as color confinement, quarks are never directly observed or found in isolation; they can be found only within hadrons, such as baryons (of which protons and neutrons are examples), and mesons.[2][3] For this reason, much of what is known about quarks has been drawn from observations of the hadrons themselves.
The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964.[5] Quarks were introduced as parts of an ordering scheme for hadrons, and there was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968.[6][7] Accelerator experiments have provided evidence for all six flavors. Classification[edit]