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Muon Neutrino
The muon neutrino is an elementary particle which has the symbol and zero electric charge. Together with the muon it forms the second generation of leptons, hence the name muon neutrino. It was discovered in 1962 by Leon Lederman, Melvin Schwartz and Jack Steinberger. The discovery was rewarded with the 1988 Nobel Prize in Physics. Discovery The muon neutrino or "neutretto" was hypothesized by several physicists in the 1940s. The first paper on it may be Shoichi Sakata and Takesi Inoue's two-meson theory of 1942, which also involved two neutrinos. In 1962 Leon M. Lederman, Melvin Schwartz and Jack Steinberger proved the existence of the muon neutrino in an experiment at the Brookhaven National Laboratory. This earned them the 1988 Nobel Prize. Apparent speed anomaly In September 2011 OPERA researchers reported that muon neutrinos were apparently traveling at faster than the speed of light. This result was confirmed in a second experiment in November 2011. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elementary Particle
In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. The Standard Model presently recognizes seventeen distinct particles—twelve fermions and five bosons. As a consequence of flavor and color combinations and antimatter, the fermions and bosons are known to have 48 and 13 variations, respectively. Among the 61 elementary particles embraced by the Standard Model number: electrons and other leptons, quarks, and the fundamental bosons. Subatomic particles such as protons or neutrons, which contain two or more elementary particles, are known as composite particles. Ordinary matter is composed of atoms, themselves once thought to be indivisible elementary particles. The name ''atom'' comes from the Ancient Greek word ''ἄτομος'' ( atomos) which means ''indivisible'' or ''uncuttable''. Despite the theories about atoms that had existed for thousands of years, the factual existence of ato ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shoichi Sakata
was a Japanese physicist and Marxist who was internationally known for theoretical work on the subatomic particles.Nussbaum, Louis-Frédéric. (2005). "''Sakata Shōichi''" in ; n.b., Louis-Frédéric is pseudonym of Louis-Frédéric Nussbaum, ''see'Deutsche Nationalbibliothek Authority File. He proposed the two meson theory, the Sakata model (an early precursor to the quark model), and the Pontecorvo–Maki–Nakagawa–Sakata neutrino mixing matrix. After the end of World War II, he joined other physicists in campaigning for the peaceful uses of nuclear power. Life and career Early life and education Sakata was born in Tokyo, Japan on January 18, 1911, to a family that held a tradition of public service. He was the eldest of six children of Tatsue Sakata and . At the time of Sakata's birth, Mikita was secretary to Prime Minister Katsura Tarō, who became Sakata's godfather. While attending Kōnan Middle School in Hyōgo Prefecture in 1924, Sakata was taught by the phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrino Oscillation
Neutrino oscillation is a quantum mechanics, quantum mechanical phenomenon in which a neutrino created with a specific lepton lepton number, family number ("lepton flavor": electron, muon, or tau lepton, tau) can later be Quantum measurement, measured to have a different lepton family number. The probability of measuring a particular Flavour (particle physics), flavor for a neutrino varies between three known states, as it propagates through space. First predicted by Bruno Pontecorvo in 1957, reproduced and translated in reproduced and translated in neutrino oscillation has since been observed by a multitude of experiments in several different contexts. Most notably, the existence of neutrino oscillation resolved the long-standing solar neutrino problem. Neutrino oscillation is of great theoretical physics, theoretical and experimental physics, experimental interest, as the precise properties of the process can shed light on several properties of the neutrino. In particular, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Neutrino
The electron neutrino () is an elementary particle which has zero electric charge and a spin of . Together with the electron, it forms the first generation of leptons, hence the name ''electron neutrino''. It was first hypothesized by Wolfgang Pauli in 1930, to account for missing momentum and missing energy in beta decay, and was discovered in 1956 by a team led by Clyde Cowan and Frederick Reines (see Cowan–Reines neutrino experiment). Proposal In the early 1900s, theories predicted that the electrons resulting from beta decay should have been emitted at a specific energy. However, in 1914, James Chadwick showed that electrons were instead emitted in a continuous spectrum. : → + : The early understanding of beta decay In 1930, Wolfgang Pauli theorized that an undetected particle was carrying away the observed difference between the energy, momentum, and angular momentum of the initial and final particles.Niels Bohr was notably opposed to this interpreta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laboratori Nazionali Del Gran Sasso
Laboratori Nazionali del Gran Sasso (LNGS) is the largest underground research center in the world. Situated below Gran Sasso mountain in Italy, it is well known for particle physics research by the INFN. In addition to a surface portion of the laboratory, there are extensive underground facilities beneath the mountain. The nearest towns are L'Aquila and Teramo. The facility is located about 120 km from Rome. The primary mission of the laboratory is to host experiments that require a low background environment in the fields of astroparticle physics and nuclear astrophysics and other disciplines that can profit of its characteristics and of its infrastructures. The LNGS is, like the three other European underground astroparticle laboratories ( Laboratoire Souterrain de Modane, Laboratorio subterráneo de Canfranc, and Boulby Underground Laboratory), a member of the coordinating group ILIAS. Facilities The laboratory consists of a surface facility, located within the G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibre Optic
An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss and are immune to electromagnetic interference. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, such as fiber optic sensors and fiber lasers. Glass optical fibers are typically made by drawing, while plastic fibers can be made either by drawing or by extrusion. Optical fibers typically include a core surrounded by a transparent cladding material with a lower index o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICARUS (experiment)
ICARUS (Imaging Cosmic And Rare Underground Signals) is a physics experiment aimed at studying neutrinos. It was located at the Laboratori Nazionali del Gran Sasso (LNGS) where it started operations in 2010. After completion of its operations there, it was refurbished at CERN for re-use at Fermilab, in the same neutrino beam as the MiniBooNE, MicroBooNE and Short Baseline Near Detector (SBND) experiments. The ICARUS detector was then taken apart for transport and reassembled at Fermilab, where data collection is expected to begin in fall 2021. The ICARUS program was initiated by Carlo Rubbia in 1977, who proposed a new type of neutrino detector. These are called Liquid Argon Time Projection Chambers (LAr-TPC), which should combine the advantages of bubble chambers and electronic detectors, evolving previous detectors. They detect neutrinos through the reaction: :^Ar + \nu \rightarrow ^K + e^ \, (a neutrino combining with an atom of argon-40 to yield an atom of potassium-40 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Of Light
The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time interval of second. The speed of light is invariant (physics), the same for all observers, no matter their relative velocity. It is the upper limit for the speed at which Information#Physics_and_determinacy, information, matter, or energy can travel through Space#Relativity, space. All forms of electromagnetic radiation, including visible light, travel at the speed of light. For many practical purposes, light and other electromagnetic waves will appear to propagate instantaneously, but for long distances and sensitive measurements, their finite speed has noticeable effects. Much starlight viewed on Earth is from the distant past, allowing humans to study the history of the universe by viewing distant objects. When Data communication, comm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Faster-than-light
Faster-than-light (superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light in vacuum (). The special theory of relativity implies that only particles with zero rest mass (i.e., photons) may travel ''at'' the speed of light, and that nothing may travel faster. Particles whose speed exceeds that of light ( tachyons) have been hypothesized, but their existence would violate causality and would imply time travel. The scientific consensus is that they do not exist. According to all observations and current scientific theories, matter travels at slower-than-light (subluminal) speed with respect to the locally distorted spacetime region. Speculative faster-than-light concepts include the Alcubierre drive, Krasnikov tubes, traversable wormholes, and quantum tunneling. Some of these proposals find loopholes around general relativity, such as by expanding or contracting space to make the object ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OPERA Experiment
The Oscillation Project with Emulsion-tRacking Apparatus (OPERA) was an instrument used in a scientific experiment for detecting tau neutrinos from muon neutrino neutrino oscillation, oscillations. The experiment is a collaboration between CERN in Geneva, Switzerland, and the Laboratori Nazionali del Gran Sasso (LNGS) in Gran Sasso d'Italia, Gran Sasso, Italy and uses the CERN Neutrinos to Gran Sasso (CNGS) Accelerator neutrino, neutrino beam. The process started with protons from the Super Proton Synchrotron (SPS) at CERN being fired in pulses at a carbon target to produce pions and kaons. These particles decay to produce muons and neutrinos. The beam from CERN was stopped on 3 December 2012, ending data taking, but the analysis of the collected data has continued. Detector OPERA, in Hall C of the Gran Sasso underground labs, was built in 2003–2008. The tau lepton, taus resulting from the interaction of tau neutrinos are observed in "bricks" of photographic films (nuclear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Nobel Foundation
The Nobel Foundation () is a private institution founded on 29 June 1900 to manage the finances and administration of the Nobel Prizes. The foundation is based on the last will of Alfred Nobel, the inventor of dynamite. It also holds Nobel Symposia on important breakthroughs in science and topics of cultural or social significance. History Alfred Nobel (; born 21 October 1833, in Stockholm, Sweden) was a chemist, engineer, innovator, armaments manufacturer and the inventor of dynamite. He owned Bofors, a major armaments manufacturer, which he had redirected from its original business as an iron and steel mill. Nobel held 355 different patents, dynamite being the most famous. Nobel amassed a sizeable personal fortune during his lifetime, thanks mostly to this invention. In 1896 Nobel died of a stroke in his villa in Sanremo, San Remo, Italy where he had lived his final years.AFP"Alfred Nobel's last will and testament", ''The Local''(5 October 2009): accessed 14 January 2009. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. The journal is considered one of the most prestigious in the field of physics. Over a quarter of Physics Nobel Prize-winning papers between 1995 and 2017 were published in it. ''PRL'' is published both online and as a print journal. Its focus is on short articles ("letters") intended for quick publication. The Lead Editor is Hugues Chaté. The Managing Editor is Robert Garisto. History The journal was created in 1958. Samuel Goudsmit, who was then the editor of '' Physical Review'', the American Physical Society's flagship journal, organized and published ''Letters to the Editor of Physical Review'' into a new standalone journal'','' which became ''Physical Review Letters''. It was the first journal intended for the rapid publication of short articles, a format that eventually became popular in many other fiel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
