Radioactive nuclei typically have way more neutrons, the neutral subatomic particle, than protons, the positive subatomic particle that determines an atom's identity.
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In the rods and cones, that trigger is light—a subatomic particle called a photon.
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It's a subatomic particle long thought to be a fundamental building block of the universe.
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While the nucleus of a normal hydrogen atom has a single subatomic particle called a proton, the nuclei of the hydrogen atoms in heavy water have both a proton and a neutron — another type of subatomic particle that weighs the same as a proton.
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A few years ago, a group of physicists created an unusual, never-before-seen subatomic particle.
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A subatomic particle is neither here nor there, the theory suggested; until you measure it, it is both.
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"Nobody knows what in the universe is able to give a subatomic particle such an energy," she says.
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She wants the boy from a world that is exactly like mine, down to the last subatomic particle.
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It was the smallest bullet you could possibly imagine, a subatomic particle weighing barely more than a thought.
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The most massive fundamental subatomic particle known is the top quark, discovered in 1995 at Fermilab, located outside Chicago.
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Some of the answers are there, along with a close-up look at subatomic particle events invisible from Earth.
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Scientists have captured a ghost-like subatomic particle on Earth, helping to solve a mystery baffling scientists for 100 years.
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The neutrino could be the weirdest subatomic particle; though abundant, it requires some of the most sensitive detectors to observe.
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The proton property, called its "weak charge," determines how strongly this subatomic particle interacts with one of physics' four fundamental forces.
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Neutrinos are a subatomic particle that are created in vast numbers in nuclear reactions and they interact very little with matter.
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Tevatron researchers discovered the top quark, another subatomic particle, and helped lay the groundwork for CERN's discovery of the Higgs boson.
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In standard quantum mechanics, a quantum system such as a subatomic particle is represented by a mathematical abstraction called the wave function.
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He went on to discover the Higgs boson subatomic particle, the so-called "God particle" that you can read more about here.
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A tetraquark (Artwork: Fermilab)A few months ago, physicists observed a new subatomic particle—essentially an awkwardly-named, crazy cousin of the proton.
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The camera in your phone works because photons — the subatomic particle that constitute light — activates a sensor at the back of the lens.
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Instead, they are a proposed solution to a different problem involving a subatomic particle that seems to be constantly changing its very identity.
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In the 1960s, physicist Luis Alvarez proposed using a subatomic particle called a muon to study the inside of a different Egyptian pyramid.
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Eventually they decay, and what filters down to the Earth's surface is a steady rain of an unstable subatomic particle called a muon.
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But four years ago, physicists at the Large Hadron Collider in Switzerland discovered the Higgs boson, a subatomic particle first predicted in the 1960s.
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Ghost particles In 2018, scientists were able to trace the origins of a ghostly subatomic particle that traveled 3.7 billion light-years to Earth.
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All of these hunt for the most likely dark matter candidate, a new subatomic particle that interacts very weakly with regular matter, called the WIMP.
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Hall uses them to perform seven thought experiments, as if Oppenheimer, like a subatomic particle, could be revealed only indirectly, through his collisions with others.
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Twentieth-century physics grew into a mathematical labyrinth as one weird subatomic particle after another was discovered and theory tried to keep up with experiment.
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They have observed the most massive known fundamental subatomic particle directly interacting with an energy field that gives mass to the building blocks of the universe.
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The photons that make up light (a subatomic particle in their own right) actually slow down a bit when they enter a dense substance like ice.
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Such a "gold standard" was applied in 2012, for instance, to confirm the discovery of the Higgs boson subatomic particle, a basic building block of the universe.
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In 2300, the Large Hadron Collider discovered the Higgs boson, a subatomic particle even smaller than a proton whose existence had long been theorized but never found.
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The findings from the three groups led, in 22005, to the discovery of the Higgs boson, the last subatomic particle predicted by the Standard Model to be found.
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The Large Hadron Collider is what was used to discover the subatomic particle called the Higgs boson back in 2012, and had been host to many other new discoveries.
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Using the same g-22 equipment, researchers measured very precisely a property of a subatomic particle called the muon and the measurement disagreed dramatically from what scientists had predicted.
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Photo: NASA/ISS 16 (Wikimedia Commons)Scientists in India observed the highest-voltage thunderstorm ever documented with the help of a subatomic particle you might not hear much about: the muon.
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Neutrinos (a type of extremely light, electrically neutral subatomic particle) would be produced in bulk only by more energetic collisions, as might cosmic rays, most of which are high-energy protons.
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When he was still at Columbia, Lederman and his colleagues discovered the muon neutrino, a subatomic particle, and only the second neutrino ever discovered, proving that electrons are not the only neutrino.
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For the last half-century, its main business has been the study of the tiniest insubstantial bit of matter in the universe, an ephemeral fly-by-night subatomic particle called the neutrino.
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Others have rallied around the axion, another subatomic particle that would simultaneously explain the missing dark matter and solve a separate problem in particle physics regarding the force that holds atomic nuclei together.
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Neutrinos are the second-most common subatomic particle type in the universe, and yet they're nearly impossible to detect—thanks to a sneaky tendency to fly through matter without disturbing it at all.
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My hope is that these students will form the team that cures cancer, splits the next subatomic particle at Fermilab National Laboratory in Batavia, builds the next Hoover Dam or a better robot.
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The uncertainty principle, which lies at the heart of quantum mechanics, states that, at any given moment, either the location or the velocity of a subatomic particle can be specified, but not both.
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It's a relatively small amount in the individual reactions—less than the amount of energy required to transmit a single bit of data—but a lot given that it's occurring in a subatomic particle.
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Or perhaps, this is evidence that a new type of subatomic particle that was zipping around the early Universe at light speeds (a fourth neutrino flavor perhaps) and is affecting the rate of expansion.
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The leading contender for a dark matter particle is a class of weakly interacting massive particle (WIMP), which is similar to another subatomic particle called a neutrino in that it rarely interacts with other matter.
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Scientists are well acquainted with the "observer effect", which, in physics, for example, stipulates that the characteristics of a subatomic particle can never be fully known because they are changed by the act of measuring them.
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CERN's Axion Solar Telescope (CAST) experiment has pushed past a critical boundary in its hunt for the elusive axion, a hypothesized subatomic particle with the potential to explain lingering problems in quantum physics, possibly even dark matter.
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The authors, led by University of Basel physicist Dominik Zumbühl, outline a new technique that can shed light on this bizarre subatomic particle and improve human manipulation of electron spin—a key goal for the quantum computing community.
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Scientists have been trying for decades to identify how that happened, to no avail There are many indirect approaches to trying to understand what could have tipped this balance, like a recent one involving an obscure subatomic particle called a neutrino.
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He suggests that the universe moves from tidiness to messiness, that the entire universe may have once been like a subatomic particle, that before-and-after, cause-and-effect thinking might be a human construct that prevents us from understanding cosmic events.
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Even the most massive objects — black holes or the ultradense spinning neutron stars — would roil space only enough to move the mirrors by a fraction of the diameter of a proton, a subatomic particle too small to be seen by even the most powerful microscopes.
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The technique, which Dr. Weiss called "a profound and significant advance in the technology," is now used in optical experiments that require light of a single precise wavelength — what is needed, for example, to sense a change of less than the size of a subatomic particle.
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Thus coddled, the lasers in the present incarnation, known as Advanced LIGO, can detect changes in the length of one of those arms as small as one ten-thousandth the diameter of a proton — a subatomic particle too small to be seen by even the most powerful microscopes — as a gravitational wave sweeps through.
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For months, evidence was mounting that the Large Hadron Collider, the biggest and most powerful particle accelerator in the world, had found something extraordinary: a new subatomic particle, which would be a discovery surpassing even the LHC's discovery of the Higgs boson in 2012, and perhaps the most significant advance since Einstein's theory of relativity.
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To try to ascertain the position of President TrumpDonald John TrumpFacebook releases audit on conservative bias claims Harry Reid: 'Decriminalizing border crossings is not something that should be at the top of the list' Recessions happen when presidents overlook key problems MORE on trade at any point in time is like trying to ascertain the position of a subatomic particle: It is better viewed as having a probabilistic distribution than as having a true position that could be discovered through sufficiently acute observation and analysis.
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Overlines are used in subatomic particle physics to denote antiparticles for some particles (with the alternate being distinguishing based on electric charge). For example, the proton is denoted as , and its corresponding antiparticle is denoted as .
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Donald Arthur Glaser (September 21, 1926 – February 28, 2013) was an American physicist, neurobiologist, and the winner of the 1960 Nobel Prize in Physics for his invention of the bubble chamber used in subatomic particle physics.
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Cesare Mansueto Giulio Lattes (11 July 1924 – 8 March 2005), also known as César Lattes, was a Brazilian experimental physicist, one of the discoverers of the pion, a composite subatomic particle made of a quark and an antiquark.
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"Should we be concerned when the world's largest subatomic particle experiment is switched on in Geneva?" guardian.co.uk. The Independent,Connor, Steve (5 September 2008). "The Big Question: Is our understanding of the Universe about to be transformed?". The Independent.
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Photodisintegration (also called phototransmutation) is a similar but different physical process, in which an extremely high energy gamma ray interacts with an atomic nucleus and causes it to enter an excited state, which immediately decays by emitting a subatomic particle.
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Cecil Frank Powell, FRS (5 December 1903 – 9 August 1969) was an English physicist, and Nobel Prize in Physics laureate for his development of the photographic method of studying nuclear processes and for the resulting discovery of the pion (pi-meson), a subatomic particle.
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Protium is a spin-½ subatomic particle and is therefore a fermion. Other fermions include neutrons, electrons, and the radioactive isotope tritium. Fermions are governed by Pauli's exclusion principle, where no two particles can have the same quantum number. However, bosons like deuterium and photons, are not bound by exclusion and multiple particles can occupy the same energy state.
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A photino is a hypothetical subatomic particle, the fermion WIMP superpartner of the photon predicted by supersymmetry. It is an example of a gaugino. Even though no photino has ever been observed so far, it is one of the candidates for the lightest supersymmetric particle in the universe. It is proposed that photinos are produced by sources of ultra-high-energy cosmic rays.
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The zero-point energy causes the ground-state of a harmonic oscillator to advance its phase (color). This has measurable effects when several eigenstates are superimposed. The idea of a quantum harmonic oscillator and its associated energy can apply to either an atom or subatomic particle. In ordinary atomic physics, the zero-point energy is the energy associated with the ground state of the system.
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For some ways in which entanglement may be achieved for experimental purposes, see the section below on methods. Entanglement is broken when the entangled particles decohere through interaction with the environment; for example, when a measurement is made.Asher Peres, Quantum Theory: Concepts and Methods, Kluwer, 1993; p. 115. As an example of entanglement: a subatomic particle decays into an entangled pair of other particles.
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Roach, p. 77 The booklet insert contains stylized separate portraits of the Strokes, Raphael, Gentles, and Bowersock, all photographed by Lane. For the American market and the October 2001 release, the cover art of Is This It was changed to a psychedelic photograph of subatomic particle tracks in a bubble chamber. Part of the same image had already been used for the cover of the Prince album Graffiti Bridge.
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In particle physics, a truly neutral particle is a subatomic particle that is its own antiparticle. In other words, it remains itself under the charge conjugation which replaces particles with their corresponding antiparticles. All charges of a truly neutral particle must be equal to zero. This requires particles to not only be electrically neutral, but also requires that all of their other charges (like the colour charge) are neutral.
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The neutron is a subatomic particle, symbol or , which has a neutral (not positive or negative) charge and a mass slightly greater than that of a proton. Protons and neutrons constitute the nuclei of atoms. Since protons and neutrons behave similarly within the nucleus, and each has a mass of approximately one atomic mass unit, they are both referred to as nucleons. Their properties and interactions are described by nuclear physics.
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The muon neutrino is a lepton, an elementary subatomic particle which has the symbol and no net electric charge. Together with the muon it forms the second generation of leptons, hence the name muon neutrino. It was first hypothesized in the early 1940s by several people, and was discovered in 1962 by Leon Lederman, Melvin Schwartz and Jack Steinberger. The discovery was rewarded with the 1988 Nobel Prize in Physics.
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Particle radiation is subatomic particle accelerated to relativistic speeds by nuclear reactions. Because of their momenta they are quite capable of knocking out electrons and ionizing materials, but since most have an electrical charge, they don't have the penetrating power of ionizing radiation. The exception is neutron particles; see below. There are several different kinds of these particles, but the majority are alpha particles, beta particles, neutrons, and protons.
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A pentaquark is a subatomic particle consisting of four quarks and one antiquark bound together. As quarks have a baryon number of +, and antiquarks of −, the pentaquark would have a total baryon number of 1, and thus would be a baryon. Further, because it has five quarks instead of the usual three found in regular baryons ( 'triquarks'), it is classified as an exotic baryon. The name pentaquark was coined by Claude Gignoux et al.
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In engineered nuclear devices, essentially all nuclear fission occurs as a "nuclear reaction" — a bombardment-driven process that results from the collision of two subatomic particles. In nuclear reactions, a subatomic particle collides with an atomic nucleus and causes changes to it. Nuclear reactions are thus driven by the mechanics of bombardment, not by the relatively constant exponential decay and half-life characteristic of spontaneous radioactive processes. Many types of nuclear reactions are currently known.
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In the physical sciences, subatomic particles are smaller than atoms. They can be composite particles, such as the neutron and proton; or elementary particles, which according to the standard model are not made of other particles. Particle physics and nuclear physics study these particles and how they interact. The concept of a subatomic particle was refined when experiments showed that light could behave like a stream of particles (called photons) as well as exhibiting wave-like properties.
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Particle decay is the spontaneous process of one unstable subatomic particle transforming into multiple other particles. The particles created in this process (the final state) must each be less massive than the original, although the total invariant mass of the system must be conserved. A particle is unstable if there is at least one allowed final state that it can decay into. Unstable particles will often have multiple ways of decaying, each with its own associated probability.
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The ' ('J/psi) meson or psion is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as "charmonium". The is the most common form of charmonium, due to its spin of 1 and its low rest mass. The has a rest mass of , just above that of the (), and a mean lifetime of .
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Individual particle physics events are modeled by scattering theory based on an underlying quantum field theory of the particles and their interactions. The S-matrix is used to characterize the probability of various event outgoing particle states given the incoming particle states. For suitable quantum field theories, the S-matrix may be calculated by a perturbative expansion in terms of Feynman diagrams. Events occur naturally in astrophysics and geophysics, such as subatomic particle showers produced from cosmic ray scattering events.
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The Geiger–Marsden experiment: Left: Expected results: alpha particles passing through the plum pudding model of the atom with negligible deflection. Right: Observed results: a small portion of the particles were deflected by the concentrated positive charge of the nucleus. In 1897, J. J. Thomson discovered that cathode rays are not electromagnetic waves but made of particles that are 1,800 times lighter than hydrogen (the lightest atom). Therefore, they were not atoms, but a new particle, the first subatomic particle to be discovered.
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The electron is a subatomic particle, symbol or , whose electric charge is negative one elementary charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron has a mass that is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum (spin) of a half-integer value, expressed in units of the reduced Planck constant, ħ.
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A stream of observations in the 1980s supported the presence of dark matter, including gravitational lensing of background objects by galaxy clusters, the temperature distribution of hot gas in galaxies and clusters, and the pattern of anisotropies in the cosmic microwave background. According to consensus among cosmologists, dark matter is composed primarily of a not yet characterized type of subatomic particle. The search for this particle, by a variety of means, is one of the major efforts in particle physics.
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With it he led a team that discovered a new subatomic particle he called a ψ (psi). This discovery was also made by the team led by Samuel Ting at Brookhaven National Laboratory, but he called the particle J. The particle thus became known as the J/ψ meson. Richter and Ting were jointly awarded the 1976 Nobel Prize in Physics for their work. During 1975 Richter spent a sabbatical year at CERN where he worked on the ISR experiment R702.
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In particle physics, a baryon is a type of composite subatomic particle which contains an odd number of valence quarks (at least 3). Baryons belong to the hadron family of particles; hadrons are composed of quarks. Baryons are also classified as fermions because they have half-integer spin. The name "baryon", introduced by Abraham Pais, comes from the Greek word for "heavy" (βαρύς, barýs), because, at the time of their naming, most known elementary particles had lower masses than the baryons.
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One possible signature of a Higgs boson from a simulated proton–proton collision. It decays almost immediately into two jets of hadrons and two electrons, visible as lines. On July 4, 2012, physicists working at CERN's Large Hadron Collider announced that they had discovered a new subatomic particle greatly resembling the Higgs boson, a potential key to an understanding of why elementary particles have mass and indeed to the existence of diversity and life in the universe. For now, some physicists are calling it a "Higgslike" particle.
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In particle physics, a diquark, or diquark correlation/clustering, is a hypothetical state of two quarks grouped inside a baryon (that consists of three quarks) (Lichtenberg 1982). Corresponding models of baryons are referred to as quark–diquark models. The diquark is often treated as a single subatomic particle with which the third quark interacts via the strong interaction. The existence of diquarks inside the nucleons is a disputed issue, but it helps to explain some nucleon properties and to reproduce experimental data sensitive to the nucleon structure.
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The ring-imaging Cherenkov, or RICH, detector is a device for identifying the type of an electrically charged subatomic particle of known momentum, that traverses a transparent refractive medium, by measurement of the presence and characteristics of the Cherenkov radiation emitted during that traversal. RICH detectors were first developed in the 1980s and are used in high energy elementary particle- , nuclear- and astro-physics experiments. This article outlines the origins and principles of the RICH detector, with brief examples of its different forms in modern physics experiments.
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Either of those interactions will cause the ejection of an electron from an atom at relativistic speeds, turning that electron into a beta particle (secondary beta particle) that will ionize many other atoms. Since most of the affected atoms are ionized directly by the secondary beta particles, photons are called indirectly ionizing radiation. Photon radiation is called gamma rays if produced by a nuclear reaction, subatomic particle decay, or radioactive decay within the nucleus. It is otherwise called x-rays if produced outside the nucleus.
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The X17 particle is a hypothetical subatomic particle proposed by Attila Krasznahorkay and his colleagues to explain certain anomalous measurement results. The particle has been proposed to explain wide angles observed in the trajectory paths of particles produced during a nuclear transition of beryllium-8 atoms and in stable helium atoms. The X17 particle could be the force carrier for a postulated fifth force, possibly connected with dark matter, and has been described as a protophobic (i.e., ignoring protons) X boson with a mass near .
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The dome acted as a shield, blocking any unwanted energy waves from entering the telescope and skewing the data. To actually create recordable, usable data, scientists used a process called electron-positron pair production, which is creating an electron and positron simultaneously near a nucleus or subatomic particle. In order to induce this process, scientists assembled a multilevel thin-plate spark chamber within the telescope. A spark chamber is basically a chamber with many plates of metal and gases such as helium or neon.
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A Feynman diagram showing the mutual annihilation of a bound state electron positron pair into two photons. This bound state is more commonly known as positronium. In particle physics, annihilation is the process that occurs when a subatomic particle collides with its respective antiparticle to produce other particles, such as an electron colliding with a positron to produce two photons. The total energy and momentum of the initial pair are conserved in the process and distributed among a set of other particles in the final state.
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Perhaps the most familiar example of subscripts is in chemical formulas. For example, the molecular formula for glucose is C6H12O6 (meaning that it is a molecule with 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms). Or the most famous molecule in the world, water, known almost universally by its chemical formula, H2O (meaning it has 2 hydrogen atoms and 1 oxygen atom.) A subscript is also used to distinguish between different versions of a subatomic particle. Thus electron, muon, and tau neutrinos are denoted and .
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It postulated the fundamental strong interaction, experienced by quarks and mediated by gluons. These particles were proposed as a building material for hadrons (see hadronization). This theory is unusual because individual (free) quarks cannot be observed (see color confinement), unlike the situation with composite atoms where electrons and nuclei can be isolated by transferring ionization energy to the atom. Then, the old, broad denotation of the term elementary particle was deprecated and a replacement term subatomic particle covered all the "zoo", with its hyponym "hadron" referring to composite particles directly explained by the quark model.
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Elementary particles included in the Standard Model In particle physics, an elementary particle or fundamental particle is a -->subatomic particle with no substructure, i.e. it is not composed of other particles. Particles currently thought to be elementary include the fundamental fermions (quarks, leptons, antiquarks, and antileptons), which generally are "matter particles" and "antimatter particles", as well as the fundamental bosons (gauge bosons and the Higgs boson), which generally are "force particles" that mediate interactions among fermions. A particle containing two or more elementary particles is called a composite particle.
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Pair production is the creation of a subatomic particle and its antiparticle from a neutral boson. Examples include creating an electron and a positron, a muon and an antimuon, or a proton and an antiproton. Pair production often refers specifically to a photon creating an electron–positron pair near a nucleus. For pair production to occur, the incoming energy of the photon must be above a threshold of at least the total rest mass energy of the two particles, and the situation must conserve both energy and momentum.
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Finnegans Wake is a difficult text, and Joyce did not aim it at the general reader.Who Reads Ulysses?, Julie Sloan Brannon, Routledge, 2003, p26 Nevertheless, certain aspects of the work have made an impact on popular culture beyond the awareness of it being difficult.For a list of some references to Finnegans Wake in film and television, see In the academic field, physicist Murray Gell-Mann named a type of subatomic particle as a quark, after the phrase "Three quarks for Muster Mark" on page 383 of Finnegans Wake, as he already had the sound "kwork".
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Anthony Burgess has lauded Finnegans Wake as "a great comic vision, one of the few books of the world that can make us laugh aloud on nearly every page". The prominent literary academic Harold Bloom has called it Joyce's masterpiece, and, in The Western Canon (1994), wrote that "if aesthetic merit were ever again to center the canon, [Finnegans Wake] would be as close as our chaos could come to the heights of Shakespeare and Dante". The now commonplace term quark – a subatomic particle – originates from Finnegans Wake.
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The Delta baryons (or Δ baryons, also called Delta resonances) are a family of subatomic particle made of three up or down quarks (u or d quarks). Four closely related Δ baryons exist: (constituent quarks: uuu), (uud), (udd), and (ddd), which respectively carry an electric charge of +2 e, +1 e, 0 e, and −1 e. The Δ baryons have a mass of about , a spin of , and an isospin of . Ordinary protons and neutrons (nucleons (symbol N)), by contrast, have a mass of about , a spin of , and an isospin of .
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This includes interactionist dualism, which claims that some non-physical mind, will, or soul overrides physical causality. Physical determinism implies there is only one possible future and is therefore not compatible with libertarian free will. As consequent of incompatibilism, metaphysical libertarian explanations that do not involve dispensing with physicalism require physical indeterminism, such as probabilistic subatomic particle behavior – theory unknown to many of the early writers on free will. Incompatibilist theories can be categorised based on the type of indeterminism they require; uncaused events, non-deterministically caused events, and agent/substance-caused events.
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The muon (; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 e and a spin of , but with a much greater mass. It is classified as a lepton. As with other leptons, the muon is not known to have any sub-structure – that is, it is not thought to be composed of any simpler particles. The muon is an unstable subatomic particle with a mean lifetime of , much longer than many other subatomic particles.
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In 1994, Gerdes and his team at Fermilab made the first observations of the top quark subatomic particle. Using data collected from the Dark Energy Survey between 2013 and 2016, Gerdes led a team of physicists and students at the University of Michigan which discovered a previously unknown dwarf planet in the Kuiper Belt. The dwarf planet was known informally as DeeDee until it was given its official designation of . Gerdes helped to develop the camera used to make the discovery, although it was designed to create a map of distant galaxies.
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In this symbolic representing of a nuclear reaction, lithium-6 () and deuterium () react to form the highly excited intermediate nucleus which then decays immediately into two alpha particles of helium-4 (). Protons are symbolically represented by red spheres, and neutrons by blue spheres. In nuclear physics and nuclear chemistry, a nuclear reaction is semantically considered to be the process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformation of at least one nuclide to another.
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Scientific glassblowing is a specialty field of lampworking used in industry, science, art and design used in research and production. Scientific glassblowing has been used in chemical, pharmaceutical, electronic and physics research including Galileo’s thermometer, Thomas Edison’s light bulb, and vacuum tubes used in early radio, TV and computers. More recently, the field has helped advance fiber optics, lasers, atomic and subatomic particle research, advanced communications development and semiconductors. The field combined hand skills using lathes and torches with modern computer assisted furnaces, diamond grinding and lapping machines, lasers and ultra-sonic mills.
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Dr Bibha Chowdhuri discovered a new subatomic particle, the pi-meson, from experiments in Darjeeling, with her mentor D.M. Bose, and published her results in three papers in (journal)Nature towards the discovery of mesons using photographic (nuclear emulsion) plates in the early Fourties. In 1947, the first true mesons, the charged pions, were found by the collaboration of Cecil Powell, César Lattes, Giuseppe Occhialini, et al., at the University of Bristol, in England. Since the advent of particle accelerators had not yet come, high-energy subatomic particles were only obtainable from atmospheric cosmic rays.
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Mesons are hadrons containing an even number of valence quarks (at least 2). Most well known mesons are composed of a quark- antiquark pair, but possible tetraquarks (4 quarks) and hexaquarks (6 quarks, comprising either a dibaryon or three quark-antiquark pairs) may have been discovered and are being investigated to confirm their nature.Mysterious Subatomic Particle May Represent Exotic New Form of Matter Several other hypothetical types of exotic meson may exist which do not fall within the quark model of classification. These include glueballs and hybrid mesons (mesons bound by excited gluons).
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Physicist Steven Chu in 2011 Chinese immigrants Tsung-Dao Lee and Chen Ning Yang received the 1957 Nobel Prize in Physics for theoretical work demonstrating that the conservation of parity did not always hold and later became American citizens. Samuel Chao Chung Ting received the 1976 Nobel Prize in physics for discovery of the subatomic particle J/ψ. Subrahmanyan Chandrasekhar shared the 1983 Nobel Prize in Physics and had the Chandra X-ray Observatory named after him. Steven Chu shared the 1997 Nobel Prize in Physics for his research in cooling and trapping atoms using laser light.
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E. Goldstein (May 4, 1876) "Vorläufige Mittheilungen über elektrische Entladungen in verdünnten Gasen" (Preliminary communications on electric discharges in rarefied gases), Monatsberichte der Königlich Preussischen Akademie der Wissenschaften zu Berlin (Monthly Reports of the Royal Prussian Academy of Science in Berlin), 279-295. He discovered several important properties of cathode rays, which contributed to their later identification as the first subatomic particle, the electron. He found that cathode rays were emitted perpendicularly from a metal surface, and carried energy. He attempted to measure their velocity by the Doppler shift of spectral lines in the glow emitted by Crookes tubes.
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Orson Scott Card, in his 1977 novelette and 1985 novel Ender's Game and its sequels, used the term "ansible" as an unofficial name for the philotic parallax instantaneous communicator, a machine capable of communicating across infinite distances with no time delay. In Ender's Game, a character states that "somebody dredged the name ansible out of an old book somewhere." In the universe of the Ender's Game series, the ansible's functions involved a fictional subatomic particle, the philote. The two quarks inside a pi meson can be separated by an arbitrary distance, while remaining connected by "philotic rays".
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It was eventually found that the "mu meson" did not participate in the strong nuclear interaction at all, but rather behaved like a heavy version of the electron, and was eventually classed as a lepton like the electron, rather than a meson. Physicists in making this choice decided that properties other than particle mass should control their classification. There were years of delays in the subatomic particle research during World War II (1939–1945), with most physicists working in applied projects for wartime necessities. When the war ended in August 1945, many physicists gradually returned to peacetime research.
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Animation of right-handed (clockwise) circularly polarized light, as defined from the point of view of a receiver in agreement with optics conventions. In physics, chirality may be found in the spin of a particle, where the handedness of the object is determined by the direction in which the particle spins. Not to be confused with helicity, which is the projection of the spin along the linear momentum of a subatomic particle, chirality is an intrinsic quantum mechanical property, like spin. Although both chirality and helicity can have left-handed or right-handed properties, only in the massless case are they identical.
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In 2017, she was selected to serve on a National Academy of Sciences committee to assess the justification for a domestic electron ion collider facility in the United States. In addition to researching subatomic particle structure, she is working on a foundational physics project deriving the standard mathematical frameworks for Hamiltonian and Lagrangian mechanics from physical assumptions. Aidala has participated in numerous outreach activities, including Saturday Morning Physics and coordinating physics demonstrations for elementary and middle school students. In 2013, she wrote an essay about her career path, which was published in the book "Blazing the Trail: Essays by Leading Women in Science".
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George Dixon Rochester, FRS (4 February 1908 – 26 December 2001) was a British physicist known for having co-discovered, with Sir Clifford Charles Butler, a subatomic particle called the kaon. Born in Wallsend, North Tyneside in northern England, he received a Bachelor of Science degree, a Master of Science degree, and a Ph.D. from Armstrong College, Newcastle (then part of Durham University now Newcastle University). He did his postdoctoral research at the University of California, Berkeley and then joined the faculty of Manchester University eventually becoming a Reader in 1953. In 1955, he was appointed Professor of Physics and Chair of the Department at Durham University.
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When quarks are in extreme proximity, the nuclear force between them is so weak that they behave almost like free particles. This result—independently discovered at around the same time by Gross and Wilczek at Princeton University—was extremely important in the development of quantum chromodynamics. With Thomas Appelquist, Politzer also played a central role in predicting the existence of "charmonium", a subatomic particle formed of a charm quark and a charm antiquark. Politzer was a junior fellow at the Harvard Society of Fellows from 1974 to 1977 before moving to the California Institute of Technology (Caltech), where he is currently professor of theoretical physics.
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He performed the first artificially induced nuclear reaction in 1917 in experiments where nitrogen nuclei were bombarded with alpha particles. As a result, he discovered the emission of a subatomic particle which, in 1919, he called the "hydrogen atom" but, in 1920, he more accurately named the proton. Rutherford became Director of the Cavendish Laboratory at the University of Cambridge in 1919. Under his leadership the neutron was discovered by James Chadwick in 1932 and in the same year the first experiment to split the nucleus in a fully controlled manner was performed by students working under his direction, John Cockcroft and Ernest Walton.
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Quantum mechanics is a set of principles describing physical reality at the atomic level of matter (molecules and atoms) and the subatomic particles (electrons, protons, neutrons, and even smaller elementary particles such as quarks). These descriptions include the simultaneous wave-like and particle-like behavior of both matter and radiation energy as described in the wave–particle duality. In classical mechanics, accurate measurements and predictions of the state of objects can be calculated, such as location and velocity. In quantum mechanics, due to the Heisenberg uncertainty principle, the complete state of a subatomic particle, such as its location and velocity, cannot be simultaneously determined.
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The Zc(3900) is a hadron, a type of subatomic particle made of quarks, believed to be the first tetraquark that has been observed experimentally. The discovery was made in 2013 by two independent research groups: one using the BES III detector at the Chinese Beijing Electron Positron Collider, the other being part of the Belle experiment group at the Japanese KEK particle physics laboratory.. The Zc(3900) is a decay product of the previously observed anomalous Y(4260) particle. The Zc(3900) in turn decays into a charged pion (π±) and a J/ψ meson. This is consistent with the Zc(3900) containing four or more quarks.
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In early 1974, under the advice of Abdus Salam, PAEC formed another group, "Fast Neutron Physics Group", under Samar Mubarakmand. The Fast Neutron Physics Group (FNPG) took research in and examined the problems in the science of neutron, a subatomic particle. The Fast Neutron Physics Group calculated the numerical ranges of neutrons—how much power would be produced by the neutrons—and the efficiency of neutrons—determined the number of neutrons would be produced—in a device. The Fast Neutron Physics Group discovered the treatment process for the Fast, thermal and slow neutrons, and examined the behaviour of Neutron fluxes, and Neutron sources in particle accelerator installed at PINSTECH.
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Several scientists, such as William Prout and Norman Lockyer, had suggested that atoms were built up from a more fundamental unit, but they envisioned this unit to be the size of the smallest atom, hydrogen. Thomson in 1897 was the first to suggest that one of the fundamental units was more than 1,000 times smaller than an atom, suggesting the subatomic particle now known as the electron. Thomson discovered this through his explorations on the properties of cathode rays. Thomson made his suggestion on 30 April 1897 following his discovery that cathode rays (at the time known as Lenard rays) could travel much further through air than expected for an atom-sized particle.
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Per its mathematical formulation, quantum mechanics is non-deterministic, meaning that it generally does not predict the outcome of any measurement with certainty. Instead, it indicates what the probabilities of the outcomes are, with the indeterminism of observable quantities constrained by the uncertainty principle. The question arises whether there might be some deeper reality hidden beneath quantum mechanics, to be described by a more fundamental theory that can always predict the outcome of each measurement with certainty: if the exact properties of every subatomic particle were known the entire system could be modeled exactly using deterministic physics similar to classical physics. In other words, it is conceivable that quantum mechanics is an incomplete description of nature.
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Crookes and Arthur Schuster believed they were particles of "radiant matter," that is, electrically charged atoms. German scientists Eilhard Wiedemann, Heinrich Hertz and Goldstein believed they were "aether waves", some new form of electromagnetic radiation, and were separate from what carried the electric current through the tube. The debate was resolved in 1897 when J. J. Thomson measured the mass of cathode rays, showing they were made of particles, but were around 1800 times lighter than the lightest atom, hydrogen. Therefore, they were not atoms, but a new particle, the first subatomic particle to be discovered, which he originally called "corpuscle" but was later named electron, after particles postulated by George Johnstone Stoney in 1874.
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Any subatomic particle, like any particle in the three- dimensional space that obeys the laws of quantum mechanics, can be either a boson (with integer spin) or a fermion (with odd half-integer spin). In the Standard Model, all the elementary fermions have spin 1/2, and are divided into the quarks which carry color charge and therefore feel the strong interaction, and the leptons which do not. The elementary bosons comprise the gauge bosons (photon, W and Z, gluons) with spin 1, while the Higgs boson is the only elementary particle with spin zero. The hypothetical graviton is required theoretically to have spin 2, but is not part of the Standard Model.
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A proton is a subatomic particle, symbol or , with a positive electric charge of +1e elementary charge and a mass slightly less than that of a neutron. Protons and neutrons, each with masses of approximately one atomic mass unit, are collectively referred to as "nucleons" (particles present in atomic nuclei). One or more protons are present in the nucleus of every atom; they are a necessary part of the nucleus. The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol Z). Since each element has a unique number of protons, each element has its own unique atomic number.
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Explanations of libertarianism that do not involve dispensing with physicalism require physical indeterminism, such as probabilistic subatomic particle behavior – a theory unknown to many of the early writers on free will. Physical determinism, under the assumption of physicalism, implies there is only one possible future and is therefore not compatible with libertarian free will. Some libertarian explanations involve invoking panpsychism, the theory that a quality of mind is associated with all particles, and pervades the entire universe, in both animate and inanimate entities. Other approaches do not require free will to be a fundamental constituent of the universe; ordinary randomness is appealed to as supplying the "elbow room" believed to be necessary by libertarians.
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A plot counting the rate of production of electron–positron pairs as a function of invariant mass (in GeV). The apparent peak around 6 GeV was initially identified as a new particle, but named Oops-Leon when it turned out not to exist. Oops-Leon is the name given by particle physicists to what was thought to be a new subatomic particle "discovered" at Fermilab in 1976. The E288 experiment team, a group of physicists led by Leon Lederman who worked on the E288 particle detector, announced that a particle with a mass of about 6.0 GeV, which decayed into an electron and a positron, was being produced by the Fermilab particle accelerator.
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In view of future warfare and contactless military conflict, DRDO initiated National Directed Energy Weapons Programme in colloboration with domestic private sector industries. It is working on several directed energy weapons (DEW) system such as KALI (electron accelerator) based on electromagnetic radiation or subatomic particle beam to achieve short, medium and long term national goals. Initially divided into two phases, Indian Army and Indian Air Force requested minimum of 20 tactical DEWs that can destroy smaller drones and electronic warfare radar systems within 6 km to 8 km distance. Under phase 2, another 20 tactical DEWs will be developed that can destroy target within 15 km to 20 km distance which will be used against troops and vehicles from ground or air platforms.
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Roe particle physics research career has included the analysis of subatomic particle properties in accelerator-based experiments at SLAC and Fermi National Accelerator laboratories, and her cosmology research has involved surveys using telescopes based in Arizona, New Mexico, and Chile to study the mystery of dark energy including the Baryon Oscillation Spectroscopic Survey (BOSS), the Dark Energy Survey (DES) and the Dark Energy Spectroscopic Instrument (DESI). She started her career in high energy physics with Professor Carlo Rubbia during her undergrad, which leads her to get a job at CERN for a year on the UA1 experiment. This experience at CERN plays a big impact on her ultimate career path in particle physics. During her PhD, she searched for Anomalous Single Photon at SLAC.
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The Nobel Prize in Physics 1936. nobelprize.org Fifty years later, Anderson acknowledged that his discovery was inspired by the work of his Caltech classmate Chung-Yao Chao, whose research formed the foundation from which much of Anderson's work developed but was not credited at the time. Also in 1936, Anderson and his first graduate student, Seth Neddermeyer, discovered a muon (or 'mu-meson', as it was known for many years), a subatomic particle 207 times more massive than the electron, but with the same negative electric charge and spin 1/2 as the electron, again in cosmic rays. Anderson and Neddermeyer at first believed that they had seen a pion, a particle which Hideki Yukawa had postulated in his theory of the strong interaction.
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From 1966 to 1978, Butt engaged in further scientific understanding of the neutron, an important subatomic particle, and studied the utilization of the Pakistan Atomic Research Reactor with Neutron Activation Analysis . In 1978, Butt passed over his work in understanding neutron applications when he was appointed director of Nuclear Physics Division where he became interested in the nuclear binding energy in the nucleus, the isotopic island of stability, phonon and the Mössbauer effect. While leading the Nuclear Physics Division, Butt oversaw the establishment of the "New Labs" where many of his contributions were vital in scientific understanding in synthetic elements such as plutonium 93Pu. In 1984, Butt was appointed as associate director of the Institute of Nuclear Science and Technology, and promoted to its director in 1991.
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Sir Joseph John Thomson (18 December 1856 – 30 August 1940) was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered. In 1897, Thomson showed that cathode rays were composed of previously unknown negatively charged particles (now called electrons), which he calculated must have bodies much smaller than atoms and a very large charge-to-mass ratio. Thomson is also credited with finding the first evidence for isotopes of a stable (non- radioactive) element in 1913, as part of his exploration into the composition of canal rays (positive ions). His experiments to determine the nature of positively charged particles, with Francis William Aston, were the first use of mass spectrometry and led to the development of the mass spectrograph.
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The neutrino is a subatomic particle first proposed by Wolfgang Pauli on December 4, 1930. The particle was required to resolve the problem of missing energy in observations of beta decay, when a neutron decays into a proton and an electron. The new hypothetical particle was required to preserve the fundamental law of conservation of energy. Enrico Fermi renamed it the neutrino, Italian for "little neutral one", and in 1934, proposed his theory of beta decay by which the electrons emitted from the nucleus were created by the decay of a neutron into a proton, an electron, and a neutrino: : → + + The neutrino accounted for the missing energy, but Fermi's theory described a particle with little mass and no electric charge that appeared to be impossible to observe directly.
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The scientific work of Pontecorvo is full of formidable intuitions, some of which have represented milestones in modern physics. Much of this involved the neutrino, a subatomic particle first proposed theoretically by Wolfgang Pauli in 1930 in order to explain undetected energy that escaped during beta decay so that the law of conservation of energy was not violated. Fermi named it the neutrino, Italian for "little neutral one", and in 1934, proposed his theory of beta decay which explained that the electrons emitted from the nucleus were created by the decay of a neutron into a proton, an electron, and a neutrino. Initially neutrinos were thought to be undetectable, but in 1945 Pontecorvo noted that a neutrino striking a chlorine nucleus could transform it into unstable argon-37 that emits, with a 34 days half-life, after a K-capture reaction, a 2.8 keV Auger electron allowing its direct detection: : + → + Supernova SN1987A (the bright object in the centre), as seen through the Hubble Space Telescope Pontecorvo's 1945 paper credits the idea using carbon tetrachloride (CCl4) to the French physicist Jules Guéron. Experiments were conducted at Chalk River using the NRX as a neutrino source, but were unsuccessful, and were abandoned in 1949, after Pontecorvo had left.
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