|
ARGUS (experiment)
ARGUS (A Russian-German-United States-Swedish Collaboration; later joined by Canada and the former Yugoslavia) was a particle physics experiment that ran at the electron– positron collider ring DORIS II at the German national laboratory DESY. Its aim was to explore properties of charm and bottom quarks. Its construction started in 1979, the detector was commissioned in 1982 and operated until 1992. The ARGUS detector was a hermetic detector with 90% coverage of the full solid angle. It had drift chambers, a time-of-flight system, an electromagnetic calorimeter and a muon chamber system. It is the first experiment that observed the mixing of the B mesons into its antiparticle, the anti-B meson (in 1987). This observation led to the conclusion that the second-heaviest quark – the bottom quark – could under certain circumstances convert into a different, hitherto unknown quark, which had to have a huge mass. This quark, the top quark, was discovered in 1995 at Fermilab.Ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operation Argus
Operation Argus was a series of United States low-yield, high-altitude nuclear weapons tests and missile tests secretly conducted from 27 August to 9 September 1958 over the South Atlantic Ocean. The tests were performed by the Defense Nuclear Agency. The tests were to study the Christofilos effect, which suggested it was possible to defend against Soviet nuclear missiles by exploding a small number of nuclear bombs high over the South Pacific. This would create a disk of electrons over the United States that would fry the electronics on the Soviet warheads as they descended. It was also possible to use the effect to blind Soviet radars, meaning that any Soviet missile-based ABM system would be unable to attack the US counterstrike. The tests demonstrated that the effect did indeed occur, but also revealed that it dissipated too rapidly to be very effective. Papers on the topic were published the next year, focusing on the events as purely scientific endeavors. Objectives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drift Chamber
A wire chamber or multi-wire proportional chamber is a type of proportional counter that detects charged particles and photons and can give positional information on their trajectory, by tracking the trails of gaseous ionization. was located via Dr. C.N. BootPHY304 Particle Physics Sheffield University/ref> Description The multi-wire chamber uses an array of wires at high voltage (anode), which run through a chamber with conductive walls held at ground potential (cathode). Alternatively, the wires may be at ground potential and the cathode held at a high negative voltage; the important thing is that a uniform electric field draws extra electrons or negative ions to the anode wires with little lateral motion. The chamber is filled with carefully chosen gas, such as an argon/methane mix, such that any ionizing particle that passes through the tube will ionize surrounding gaseous atoms. The resulting ions and electrons are accelerated by the electric field across the chamber, causi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ARGUS Distribution
In physics, the ARGUS distribution, named after the particle physics experiment ARGUS, is the probability distribution of the reconstructed invariant mass of a decayed particle candidate in continuum background. Definition The probability density function (pdf) of the ARGUS distribution is: : f(x; \chi, c ) = \frac \cdot \frac \sqrt \exp\bigg\, for 0 \leq x 0,\,\chi>0,\,p>-1 : F(x) = \frac, \qquad 0 \leq x \leq c, \qquad c>0,\,\chi>0,\,p>-1 where Γ(·) is the gamma function, and Γ(·,·) is the upper incomplete gamma function. Here parameters ''c'', χ, ''p'' represent the cutoff, curvature, and power respectively. The mode is: :\frac\sqrt The mean is: :\mu=c \,p \, \sqrt\frac\frac\frac where M(·,·,·) is the Kummer's confluent hypergeometric function.Confluent hypergeometric function In mathematics, a confluent hypergeometric function is a solution of a confluent hypergeometric equation, which is a dege ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fermilab
Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy national laboratory specializing in high-energy particle physics. Since 2007, Fermilab has been operated by the Fermi Research Alliance, a joint venture of the University of Chicago, and the Universities Research Association (URA). Fermilab is a part of the Illinois Technology and Research Corridor. Fermilab's Main Injector, two miles (3.3 km) in circumference, is the laboratory's most powerful particle accelerator. The accelerator complex that feeds the Main Injector is under upgrade, and construction of the first building for the new PIP-II linear accelerator began in 2020. Until 2011, Fermilab was the home of the 6.28 km (3.90 mi) circumference Tevatron accelerator. The ring-shaped tunnels of the Tevatron and the Main Injector are visible from the air and by satellite. Fermilab aims to become a world center in neut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Top Quark
The top quark, sometimes also referred to as the truth quark, (symbol: t) is the most massive of all observed elementary particles. It derives its mass from its coupling to the Higgs Boson. This coupling y_ is very close to unity; in the Standard Model of particle physics, it is the largest (strongest) coupling at the scale of the weak interactions and above. The top quark was discovered in 1995 by the CDF and DØ experiments at Fermilab. Like all other quarks, the top quark is a fermion with spin and participates in all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong interactions. It has an electric charge of + ''e''. It has a mass of , which is close to the rhenium atom mass. The antiparticle of the top quark is the top antiquark (symbol: , sometimes called ''antitop quark'' or simply ''antitop''), which differs from it only in that some of its properties have equal magnitude but opposite sign. The top quark interacts with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bottom Quark
The bottom quark or b quark, also known as the beauty quark, is a third-generation heavy quark with a charge of − ''e''. All quarks are described in a similar way by electroweak and quantum chromodynamics, but the bottom quark has exceptionally low rates of transition to lower-mass quarks. The bottom quark is also notable because it is a product in almost all top quark decays, and is a frequent decay product of the Higgs boson. Name and history The bottom quark was first described theoretically in 1973 by physicists Makoto Kobayashi and Toshihide Maskawa to explain CP violation. The name "bottom" was introduced in 1975 by Haim Harari. The bottom quark was discovered in 1977 by the Fermilab E288 experiment team led by Leon M. Lederman, when collisions produced bottomonium. Kobayashi and Maskawa won the 2008 Nobel Prize in Physics for their explanation of CP-violation. While the name "beauty" is sometimes used, "bottom" became the predominant usage by analogy of "to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B Meson
In particle physics, B mesons are mesons composed of a bottom antiquark and either an up (), down (), strange () or charm quark (). The combination of a bottom antiquark and a top quark is not thought to be possible because of the top quark's short lifetime. The combination of a bottom antiquark and a bottom quark is not a B meson, but rather ''bottomonium'', which is something else entirely. Each B meson has an antiparticle that is composed of a bottom quark and an up (), down (), strange () or charm () antiquark respectively. List of B mesons – oscillations The neutral B mesons, and , spontaneously transform into their own antiparticles and back. This phenomenon is called flavor oscillation. The existence of neutral B meson oscillations is a fundamental prediction of the Standard Model of particle physics. It has been measured in the – system to be about , and in the – system to be measured by CDF experiment at Fermilab. A first estimation of the lower an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calorimeter (particle Physics)
In particle physics, a calorimeter is an experimental apparatus that measures the energy of particles. Most particles enter the calorimeter and initiate a particle shower and the particles' energy is deposited in the calorimeter, collected, and measured. The energy may be measured in its entirety, requiring total containment of the particle shower, or it may be sampled. Typically, calorimeters are segmented transversely to provide information about the direction of the particle or particles, as well as the energy deposited, and longitudinal segmentation can provide information about the identity of the particle based on the shape of the shower as it develops. Calorimetry design is an active area of research in particle physics. Types of calorimeters Electromagnetic versus hadronic An electromagnetic calorimeter is one specifically designed to measure the energy of particles that interact primarily via the electromagnetic interaction, while a hadronic calorimeter is one designed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermetic Detector
In particle physics, a hermetic detector (also called a 4π detector) is a particle detector designed to observe all possible decay products of an interaction between subatomic particles in a collider by covering as large an area around the interaction point as possible and incorporating multiple types of sub-detectors. They are typically roughly cylindrical, with different types of detectors wrapped around each other in concentric layers; each detector type specializes in particular particles so that almost any particle will be detected and identified. Such detectors are called "hermetic" because they are constructed so as the motion of particles are ceased at the boundaries of the chamber without any moving beyond due to the seals;R. Sube 2001 �Retrieved 2012-02-12 the name "4π detector" comes from the fact that such detectors are designed to cover nearly all of the 4π steradians of solid angle around the interaction point; in terms of the standard coordinate system used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argus Detector At DESY 2015
Argus is the Latinized form of the Ancient Greek word ''Argos''. It may refer to: Greek mythology * See Argus (Greek myth) for mythological characters named Argus ** Argus (king of Argos), son of Zeus (or Phoroneus) and Niobe ** Argus (son of Arestor), builder of the ship ''Argo'' in the tale of the Argonauts ** Argus Panoptes (Argus "All-Eyes"), a giant with a hundred eyes **Argus, the eldest son of Phrixus and Chalciope **Argus, the son of Phineus and Danaë, in a variant of the myth **Argus or Argos (dog), belonging to Odysseus **Argus or Argeus (king of Argos), son of Megapenthes **Argus, one of Actaeon's dogs **Argus, a watchful guardian Arts and entertainment Fictional entities * Argus (comics), in the DC Comics Universe * Argus (''Mortal Kombat''), a deity * ARGUS (''Splinter Cell''), a military contractor *A.R.G.U.S., a government agency in the DC Universe *Argus Filch, in the ''Harry Potter'' series *Argus, a planet in the ''Warcraft'' franchise *Argus, a hero in ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quarks
A quark () is a type of 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. All commonly observable matter is composed of up quarks, down quarks and electrons. Owing to a phenomenon known as ''color confinement'', quarks are never found in isolation; they can be found only within hadrons, which include baryons (such as protons and neutrons) and mesons, or in quark–gluon plasmas. There is also the theoretical possibility of more exotic phases of quark matter. For this reason, much of what is known about quarks has been drawn from observations of hadrons. Quarks have various intrinsic properties, including electric charge, mass, color charge, and spin. They are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as ''fundamental forces'' (elec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DESY
The Deutsches Elektronen-Synchrotron (English ''German Electron Synchrotron''), commonly referred to by the abbreviation DESY, is a national research center in Germany. It operates particle accelerators used to investigate the structure of matter, and conducts a broad spectrum of inter-disciplinary scientific research in three main areas: particle and high energy physics; photon science, and the development, construction and operation of particle accelerators. Its name refers to its first project, an electron synchrotron. DESY is publicly financed by the Federal Republic of Germany, the States of Germany, and the German Research Foundation (DFG). DESY is a member of the Helmholtz Association and operates at sites in Hamburg and Zeuthen. Functions DESY's function is to conduct fundamental research. It specializes in particle accelerator development, construction and operation, particle physics research to explore the fundamental characteristics of matter and forces, incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
