query: subatomic particle that has a negative charge is called

pos: Electron Electron 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". As it is a fermion, no two electrons can occupy the same quantum state, in accordance with

pos: Electron of electrons to manipulate electrical signals, and they played a critical role in the development of electronics technology. However, they have been largely supplanted by solid-state devices such as the transistor. Electron 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

pos: Atom smaller particles, in modern scientific usage the atom is composed of various subatomic particles. The constituent particles of an atom are the electron, the proton and the neutron; all three are fermions. However, the hydrogen-1 atom has no neutrons and the hydron ion has no electrons. The electron is by far the least massive of these particles at , with a negative electrical charge and a size that is too small to be measured using available techniques. It was the lightest particle with a positive rest mass measured, until the discovery of neutrino mass. Under ordinary conditions, electrons are bound

pos: Atom to the positively charged nucleus by the attraction created from opposite electric charges. If an atom has more or fewer electrons than its atomic number, then it becomes respectively negatively or positively charged as a whole; a charged atom is called an ion. Electrons have been known since the late 19th century, mostly thanks to J.J. Thomson; see history of subatomic physics for details. Protons have a positive charge and a mass 1,836 times that of the electron, at . The number of protons in an atom is called its atomic number. Ernest Rutherford (1919) observed that nitrogen under alpha-particle

pos: Electron predicted by the Standard Model, for at least half the age of the universe. Electrons have an electric charge of coulombs, which is used as a standard unit of charge for subatomic particles, and is also called the elementary charge. This elementary charge has a relative standard uncertainty of . Within the limits of experimental accuracy, the electron charge is identical to the charge of a proton, but with the opposite sign. As the symbol "e" is used for the elementary charge, the electron is commonly symbolized by , where the minus sign indicates the negative charge. The positron is

pos: Subatomic particle is the total number of nucleons (neutrons and protons collectively). Chemistry concerns itself with how electron sharing binds atoms into structures such as crystals and molecules. Nuclear physics deals with how protons and neutrons arrange themselves in nuclei. The study of subatomic particles, atoms and molecules, and their structure and interactions, requires quantum mechanics. Analyzing processes that change the numbers and types of particles requires quantum field theory. The study of subatomic particles "per se" is called particle physics. The term "high-energy physics" is nearly synonymous to "particle physics" since creation of particles requires high energies: it occurs only as

pos: Muon Muon 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 1/2, but with a much greater mass. It is classified as a lepton. As is the case with other leptons, the muon is not believed 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. As with the decay of the

pos: Antiparticle as an electron but rotate in the opposite direction with respect to the magnetic field direction due to their having the same magnitude of charge-to-mass ratio but with opposite charge and, therefore, opposite signed charge-to-mass ratios. The antiproton and antineutron were found by Emilio Segrè and Owen Chamberlain in 1955 at the University of California, Berkeley. Since then, the antiparticles of many other subatomic particles have been created in particle accelerator experiments. In recent years, complete atoms of antimatter have been assembled out of antiprotons and positrons, collected in electromagnetic traps. Solutions of the Dirac equation contained negative energy quantum

pos: Tau (particle) Tau (particle) The tau (τ), also called the tau lepton, tau particle, or tauon, is an elementary particle similar to the electron, with negative electric charge and a spin of. Together with the electron, the muon, and the three neutrinos, it is a lepton. Like all elementary particles with half-integer spin, the tau has a corresponding antiparticle of opposite charge but equal mass and spin, which in the tau's case is the antitau (also called the "positive tau"). Tau particles are denoted by and the antitau by . Tau leptons have a lifetime of and a mass of (compared to

pos: Tau (particle) Another one is an onium atom called "true tauonium" and is difficult to detect due to tau's extremely short lifetime at low (non-relativistic) energies needed to form this atom. Its detection is important for quantum electrodynamics. Tau (particle) The tau (τ), also called the tau lepton, tau particle, or tauon, is an elementary particle similar to the electron, with negative electric charge and a spin of. Together with the electron, the muon, and the three neutrinos, it is a lepton. Like all elementary particles with half-integer spin, the tau has a corresponding antiparticle of opposite charge but equal mass and

pos: Electron neutrino differs only in that some of its properties have equal magnitude but opposite sign. One open question of particle physics is whether or not neutrinos and anti-neutrinos are the same particle in which case it would be a Majorana fermion or whether they are different particles in which case they would be Dirac fermions. They are produced in beta decay and other types of weak interactions. Electron neutrino The electron neutrino () is a subatomic lepton elementary particle which has no net electric charge. Together with the electron it forms the first generation of leptons, hence the name electron neutrino.

pos: Carl David Anderson Hess. 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 the 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 the

pos: Antiparticle most widespread method of computing amplitudes in quantum field theory today. Since this picture was first developed by Stueckelberg, and acquired its modern form in Feynman's work, it is called the Feynman–Stueckelberg interpretation of antiparticles to honor both scientists. Antiparticle In particle physics, every type of particle has an associated antiparticle with the same mass but with opposite physical charges (such as electric charge). For example, the antiparticle of the electron is the antielectron (which is often referred to as "positron"). While the electron has a negative electric charge, the positron has a positive electric charge, and is produced naturally

pos: Electron valence band electrons, so it can be treated in the single particle formalism, by replacing its mass with the effective mass tensor. In the Standard Model of particle physics, electrons belong to the group of subatomic particles called leptons, which are believed to be fundamental or elementary particles. Electrons have the lowest mass of any charged lepton (or electrically charged particle of any type) and belong to the first-generation of fundamental particles. The second and third generation contain charged leptons, the muon and the tau, which are identical to the electron in charge, spin and interactions, but are more massive.

pos: Introduction to electromagnetism is a quantity used to determine how a particle will behave in an electric field. There are three possible "types" of charge: positive, negative, and neutral. However, the distinction between positive and negative is by convention only. Electric charge is quantized in units of the elementary charge, formula_1, where a proton has a charge of formula_2 and an electron has a charge of formula_3. The SI unit of charge is the coulomb. The elementary charge formula_1 was first measured by Robert Millikan in his oil drop experiment in which the electric force on the particle is set to exactly counter

pos: Charge radius the composite particle must be modeled as a sphere of negative rather than positive electric charge for the interpretation of electron scattering experiments. In these cases, the square of the charge radius of the particle is defined to be negative, with the same absolute value with units of length squared equal to the positive squared charge radius that it would have had if it was identical in all other respects but each quark in the particle had the opposite electric charge (with the charge radius itself having a value that is an imaginary number with units of length). It is

pos: Ionizing radiation through the photoelectric effect and the Compton effect. 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. The generic term photon is therefore used to

pos: Minicharged particle Minicharged particle Minicharged particles (or milli-charged particles) are a proposed type of subatomic particle. They are charged, but with a tiny fraction of the charge of the electron. They weakly interact with matter. Minicharged particles are not part of the Standard Model. One proposal to detect them involved photons tunneling through an opaque barrier in the presence of a perpendicular magnetic field, the rationale being that a pair of oppositely charged minicharged particles are produced that curve in opposite directions, and recombine on the other side of the barrier reproducing the photon again. Minicharged particles would result in vacuum magnetic

pos: J. J. Thomson J. J. Thomson Sir Joseph John Thomson (18 December 1856 – 30 August 1940) was an English physicist and Nobel Laureate in Physics, credited with the discovery and identification of the electron; and with the discovery of the first subatomic particle. 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

pos: Minicharged particle dichroism, and would cause energy loss in microwave cavities. Photons from the cosmic microwave background would be dissipated by galactic-scale magnetic fields if minicharged particles existed, so this effect could be observable. In fact the dimming observed of remote supernovae that was used to support dark energy could also be explained by the formation of minicharged particles. Tests of Coulomb's law can be applied to set bounds on minicharged particles. Minicharged particle Minicharged particles (or milli-charged particles) are a proposed type of subatomic particle. They are charged, but with a tiny fraction of the charge of the electron. They weakly

pos: History of subatomic physics of the Standard Model to be verified. 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 masses and indeed to the existence of diversity and life in the universe. Rolf-Dieter Heuer, the director general of CERN, said that it was too soon to know for sure whether it is an entirely new particle, which weighs in at 125 billion electron volts – one of the heaviest subatomic particles yet – or, indeed, the

pos: Electron neutrino Electron neutrino The electron neutrino () is a subatomic lepton elementary particle which has no net electric charge. 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). 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

pos: Antiparticle Antiparticle In particle physics, every type of particle has an associated antiparticle with the same mass but with opposite physical charges (such as electric charge). For example, the antiparticle of the electron is the antielectron (which is often referred to as "positron"). While the electron has a negative electric charge, the positron has a positive electric charge, and is produced naturally in certain types of radioactive decay. The opposite is also true: the antiparticle of the positron is the electron. Some particles, such as the photon, are their own antiparticle. Otherwise, for each pair of antiparticle partners, one is designated

pos: History of subatomic physics and other physicists; its charge was carefully measured by Robert Andrews Millikan and Harvey Fletcher in their oil drop experiment of 1909. Physicists theorized that negatively charged electrons are constituent part of "atoms", along with some (yet unknown) positively charged substance, and it was later confirmed. Electron became the first elementary, truly fundamental particle discovered. Studies of the "radioactivity", that soon revealed the phenomenon of radioactive decay, provided another argument against considering chemical elements as fundamental nature's elements. Despite these discoveries, the term "atom" stuck to Dalton's (chemical) atoms and now denotes the smallest particle of a chemical element, not

pos: Wave–particle duality operation of chemical reactions. Electricity, first thought to be a fluid, was now understood to consist of particles called electrons. This was first demonstrated by J. J. Thomson in 1897 when, using a cathode ray tube, he found that an electrical charge would travel across a vacuum. Since the vacuum offered no medium for an electric fluid to travel, this discovery could only be explained via a particle carrying a negative charge and moving through the vacuum. This electron flew in the face of classical electrodynamics, which had successfully treated electricity as a fluid for many years (leading to the

pos: Relativistic quantum mechanics to a similar particle with the same mass and spin states, but "negative" 4-momentum and "negative" charge , that is, negative energy states, time-reversed momentum, and negated charge. This was the first interpretation and prediction of a particle and "corresponding antiparticle". See Dirac spinor and bispinor for further description of these spinors. In the non-relativistic limit the Dirac equation reduces to the Pauli equation (see Dirac equation for how). When applied a one-electron atom or ion, setting and to the appropriate electrostatic potential, additional relativistic terms include the spin-orbit interaction, electron gyromagnetic ratio, and Darwin term. In ordinary QM these

pos: Air ioniser Air ioniser An air ioniser (or negative ion generator or Chizhevsky's chandelier) is a device that uses high voltage to ionise (electrically charge) air molecules. Negative ions, or anions, are particles with one or more extra electron, conferring a net negative charge to the particle. Cations are positive ions missing one or more electrons, resulting in a net positive charge. Some commercial air purifiers are designed to generate negative ions. Another type of air ioniser is the electrostatic discharge (ESD) ioniser (balanced ion generator) used to neutralise static charge. In 2002, in an obituary in "The Independent" newspaper, Cecil Alfred

pos: Extrinsic semiconductor an atom which, when incorporated in the crystal, releases a mobile conduction electron into the crystal lattice. An extrinsic semiconductor which has been doped with electron donor atoms is called an n-type semiconductor, because the majority of charge carriers in the crystal are negative electrons. An "electron acceptor" dopant is an atom which accepts an electron from the lattice, creating a vacancy where an electron should be called a "hole" which can move through the crystal like a positively charged particle. An extrinsic semiconductor which has been doped with electron acceptor atoms is called a p-type semiconductor, because the majority

pos: Degree of ionization incoming free electron (electron attachement). In both cases, the atom or molecule is no more a neutral particle and becomes a charge carrier. If the species has lost one or several electrons, it becomes positively charged and is called a positive ion, or cation. On the contrary, if the species has gained one or several additional electrons, it becomes negatively charged and is called a negative ion, or anion. Individual free electrons and ions in a plasma have very short lives typically inferior to the microsecond, as ionization and recombination, excitation and relaxation are collective continuous processes. The degree of

pos: Lepton to an external electric or magnetic field (see Lorentz force). Each generation contains one lepton with "Q" = −"e" (conventionally the charge of a particle is expressed in units of the elementary charge) and one lepton with zero electric charge. The lepton with electric charge is commonly simply referred to as a 'charged lepton' while the neutral lepton is called a neutrino. For example, the first generation consists of the electron with a negative electric charge and the electrically neutral electron neutrino . In the language of quantum field theory, the electromagnetic interaction of the charged leptons is expressed by

pos: Martin Lewis Perl also called the tau particle, tauon or simply tau) is an elementary particle similar to the electron, with negative electric charge and a spin of, but with 3477 times the mass. Together with the electron, the muon, and the three neutrinos, it is classified as a lepton. The tau was first detected in a series of experiments between 1974 and 1977 by Perl with his colleagues at the SLAC-LBL group. Their equipment consisted of SLAC's then-new – colliding ring, called SPEAR, and the LBL magnetic detector. They could detect and distinguish between leptons, hadrons and photons. SPEAR was able to

neg: Charge conservation charge in a region and the flow of charge into and out of that region, given by a continuity equation between charge density formula_1 and current density formula_2. This does not mean that individual positive and negative charges cannot be created or destroyed. Electric charge is carried by subatomic particles such as electrons and protons. Charged particles can be created and destroyed in elementary particle reactions. In particle physics, charge conservation means that in reactions that create charged particles, equal numbers of positive and negative particles are always created, keeping the net amount of charge unchanged. Similarly, when particles are

neg: Neutral current particles like other subatomic forces. Perhaps the most well known of the exchange particles for the weak force is the W particle which is involved in beta decay. W particles have electric charge – there are both positive and negative W particles – however the Z boson is also an exchange particle for the weak force but does "not" have any electrical charge. Exchange of a Z boson transfers momentum, spin, and energy, but leaves the interacting particles’ quantum numbers unaffected – charge, flavor, baryon number, lepton number, etc. Because there is no transfer of electrical charge involved, exchange of

neg: Truly neutral particle Truly neutral particle In particle physics, a truly neutral particle is a subatomic particle with all its charges equal to zero. This not only requires particles to be electrically neutral, but also requires that all of their other charges (like the colour charge) are neutral. Such a particle will be its own antiparticle. Mathematically, charge conjugation replaces all the constituent particles of a particle with their corresponding antiparticles. If a particle remains the same after charge conjugation, then it is its own antiparticle, and is truly neutral. Known examples of such elementary particles include photons, Z bosons, and Higgs bosons,

neg: Subatomic particle Subatomic particle In the physical sciences, subatomic particles are particles much smaller than atoms. The two types of subatomic particles are: elementary particles, which according to current theories are not made of other particles; and "composite" particles. Particle physics and nuclear physics study these particles and how they interact. The idea of a particle underwent serious rethinking when experiments showed that light could behave like a stream of particles (called photons) as well as exhibiting wave-like properties. This led to the new concept of wave–particle duality to reflect that quantum-scale "particles" behave like both particles and waves (they are sometimes

neg: Electric charge of positive charge minus the amount of negative charge, cannot change. Electric charge is carried by subatomic particles. In ordinary matter, negative charge is carried by electrons, and positive charge is carried by the protons in the nuclei of atoms. If there are more electrons than protons in a piece of matter, it will have a negative charge, if there are fewer it will have a positive charge, and if there are equal numbers it will be neutral. Charge is "quantized"; it comes in integer multiples of individual small units called the elementary charge, "e", about , which is the

neg: Subatomic particle a result of cosmic rays, or in particle accelerators. Particle phenomenology systematizes the knowledge about subatomic particles obtained from these experiments. The term ""subatomic" particle" is largely a retronym of the 1960s, used to distinguish a large number of baryons and mesons (which comprise hadrons) from particles that are now thought to be truly elementary. Before that hadrons were usually classified as "elementary" because their composition was unknown. A list of important discoveries follows: Subatomic particle In the physical sciences, subatomic particles are particles much smaller than atoms. The two types of subatomic particles are: elementary particles, which according to

neg: Electric charge matter. Electric charge is a characteristic property of many subatomic particles. The charges of free-standing particles are integer multiples of the elementary charge "e"; we say that electric charge is "quantized". Michael Faraday, in his electrolysis experiments, was the first to note the discrete nature of electric charge. Robert Millikan's oil drop experiment demonstrated this fact directly, and measured the elementary charge. It has been discovered that one type of particle, quarks, have fractional charges of either − or +, but it is believed they always occur in multiples of integral charge; free-standing quarks have never been observed. By convention,

neg: Mass-to-charge ratio the mass of a particle. Often, the charge-to-mass ratio can be determined from observing the deflection of a charged particle in an external magnetic field. The cyclotron equation, combined with other information such as the kinetic energy of the particle, will give the charge-to-mass ratio. One application of this principle is the mass spectrometer. The same principle can be used to extract information in experiments involving the cloud chamber. The ratio of electrostatic to gravitational forces between two particles will be proportional to the product of their charge-to-mass ratios. It turns out that gravitational forces are negligible on the subatomic

neg: Neutron Neutron The neutron is a subatomic particle, symbol or , with no net electric charge and a mass slightly larger 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. The chemical and nuclear properties of the nucleus are determined by the number of protons, called the atomic number, and the number of neutrons, called the neutron number. The atomic mass

neg: Subatomic particle turn tend to be heavier than leptons (meaning "lightweight"), but the heaviest lepton (the tau particle) is heavier than the two lightest flavours of baryons (nucleons). It is also certain that any particle with an electric charge is massive. All massless particles (particles whose invariant mass is zero) are elementary. These include the photon and gluon, although the latter cannot be isolated. Through the work of Albert Einstein, Satyendra Nath Bose, Louis de Broglie, and many others, current scientific theory holds that "all" particles also have a wave nature. This has been verified not only for elementary particles but also

neg: Baryon indirectly gives the quark content. For example, the rules above say that a contains a c quark and some combination of two u and/or d quarks. The c quark has a charge of ("Q" = +), therefore the other two must be a u quark ("Q" = +), and a d quark ("Q" = −) to have the correct total charge ("Q" = +1). Baryon 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, which are the quark-based

neg: Truly neutral particle along with the hypothetical neutralinos, sterile neutrinos, and gravitons. For a spin- particle such as the neutralino, being a truly neutral particle implies being a Majorana fermion. Composite particles can also be truly neutral. The best known example is onium, a system composed of a particle forming a bound state with its own antiparticle. Truly neutral particle In particle physics, a truly neutral particle is a subatomic particle with all its charges equal to zero. This not only requires particles to be electrically neutral, but also requires that all of their other charges (like the colour charge) are neutral. Such

neg: Overline conjugate and analogous operations. In physics, an overline sometimes indicates a vector, although boldface and arrows are also commonly used: In crystallography, an overline indicates an improper rotation or a negative number: In computational neuroscience, an overline is used to indicate the 'maximal' conductances in Hodgkin-Huxley models. This goes back to at least the landmark paper published by Nobel prize winners Alan Lloyd Hodgkin and Andrew Fielding Huxley around 1952. 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 ,

neg: Tau neutrino the second most recent particle of the Standard Model to be discovered. The DONUT experiment from Fermilab was built during the 1990s to specifically detect the tau neutrino. These efforts came to fruition in July 2000, when the DONUT collaboration reported its detection. Tau neutrino The tau neutrino or tauon neutrino is a subatomic elementary particle which has the symbol and no net electric charge. Together with the tau, it forms the third generation of leptons, hence the name tau neutrino. Its existence was immediately implied after the tau particle was detected in a series of experiments between 1974 and

neg: Neutron more energy than fission energy neutrons and are generated as secondary particles by particle accelerators or in the atmosphere from cosmic rays. These high-energy neutrons are extremely efficient at ionization and far more likely to cause cell death than X-rays or protons. Neutron The neutron is a subatomic particle, symbol or , with no net electric charge and a mass slightly larger 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

neg: Charge number that case, the charge of an ion could be written as formula_5. The charge number in chemistry normally relates to an electric charge. This is a property of specific subatomic atoms. These elements define the electromagnetic contact between the two elements. A chemical charge can be found by using the periodic table. An element's placement on the periodic table indicates whether its chemical charge is negative or positive. Looking at the table, one can see that the positive charges are on the left side of the table and the negative charges are on the right side of the table. Charges

neg: Proton been tested to one part in . The magnetic moment of antiprotons has been measured with error of nuclear Bohr magnetons, and is found to be equal and opposite to that of a proton. Proton A proton is a subatomic particle, symbol or , with a positive electric charge of +1"e" 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". One or more protons are present in the nucleus of every atom; they are a necessary part of the

neg: Proton Proton A proton is a subatomic particle, symbol or , with a positive electric charge of +1"e" 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". 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

neg: Charge radius customary when charge radius takes an imaginary numbered value to report the negative valued square of the charge radius, rather than the charge radius itself, for a particle. The best known particle with a negative squared charge radius is the neutron. The heuristic explanation for why the squared charge radius of a neutron is negative, despite its overall neutral electric charge, is that this is the case because its negatively charged down quarks are, on average, located in the outer part of the neutron, while its positively charged up quark is, on average, located towards the center of the neutron.

neg: Delta baryon neutron) and a pion of appropriate charge. The relative probabilities of allowed final charge states are given by their respective isospin couplings. More rarely and more slowly, the can decay into a proton and a photon and the can decay into a neutron and a photon. PDG reports the resonance width (Γ). Here the conversion formula_1 is given instead. Delta baryon 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

neg: Photon rocket Minkowski inner product (see four-vector), we get the following after rearranging: Standard theory says that the theoretical speed limit of a photon rocket is below the speed of light. Haug has recently, in Acta Astronautica, suggested a maximum speed limit for an ideal photon rockets that is just below the speed of light. This speed he has suggested is a function of the heaviest subatomic particle in the rocket. The maximum velocity can based on this be calculated to be where formula_17 is the Planck length and formula_18 is the reduced Compton wavelength of the subatomic fundamental particle. This velocity

neg: Tau neutrino Tau neutrino The tau neutrino or tauon neutrino is a subatomic elementary particle which has the symbol and no net electric charge. Together with the tau, it forms the third generation of leptons, hence the name tau neutrino. Its existence was immediately implied after the tau particle was detected in a series of experiments between 1974 and 1977 by Martin Lewis Perl with his colleagues at the SLAC–LBL group. The discovery of the tau neutrino was announced in July 2000 by the DONUT collaboration (Direct Observation of the Nu Tau). The tau neutrino is last of the leptons, and is

neg: Subatomic particle described as wavicles to reflect this). Another new concept, the uncertainty principle, states that some of their properties taken together, such as their simultaneous position and momentum, cannot be measured exactly. In more recent times, wave–particle duality has been shown to apply not only to photons but to increasingly massive particles as well. Interactions of particles in the framework of quantum field theory are understood as creation and annihilation of "quanta" of corresponding fundamental interactions. This blends particle physics with field theory. Any subatomic particle, like any particle in the three-dimensional space that obeys the laws of quantum mechanics, can

neg: Proton magnetic moment elementary charge and "ħ" is the reduced Planck constant. The magnetic moment of this particle is parallel to its spin. Since the proton has charge +1 "e", it should have magnetic moment equal to 1 "μ" by this expression. The larger magnetic moment of the proton indicates that it is not an elementary particle. The sign of the proton's magnetic moment is that of a positively charged particle. Similarly, the fact that the magnetic moment of the neutron, , is finite and negative indicates that it too is not an elementary particle. Protons and neutrons are composed of quarks, and

neg: History of subatomic physics indestructible. But when the nucleus change its charge and/or mass (by emitting or capturing a particle), the atom can become the one of another element. Special relativity explained how the "mass defect" is related to the energy produced or consumed in reactions. The branch of physics that studies transformations and the structure of nuclei is now called nuclear physics, contrasted to atomic physics that studies the structure and properties of atoms ignoring most nuclear aspects. The development in the nascent quantum physics, such as Bohr model, led to the understanding of chemistry in terms of the arrangement of electrons in

neg: Flavour (particle physics) baryon number . They also all carry weak isospin, . The positive- quarks (up, charm, and top quarks) are called "up-type quarks" and negative- quarks (down, strange, and bottom quarks) are called "down-type quarks". Each doublet of up and down type quarks constitutes one generation of quarks. For all the quark flavour quantum numbers listed below, the convention is that the flavour charge and the electric charge of a quark have the same sign. Thus any flavour carried by a charged meson has the same sign as its charge. Quarks have the following flavour quantum numbers: These five quantum numbers,

neg: Antimatter one another, but opposite electric charge and other differences in quantum numbers. For example, a proton has positive charge while an antiproton has negative charge. A collision between any particle and its anti-particle partner is known to lead to their "mutual annihilation", giving rise to various proportions of intense photons (gamma rays), neutrinos, and sometimes less-massive particle–antiparticle pairs. Annihilation usually results in a release of energy that becomes available for heat or work. The amount of the released energy is usually proportional to the total mass of the collided matter and antimatter, in accordance with the mass–energy equivalence equation, .

neg: Charge number having stripped off all electrons, the charge number is identical with the atomic number "Z", which corresponds to the number of protons in ordinary atomic nuclei. Unlike in chemistry, subatomic particles with electric charges of two elementary charges (e.g. some delta baryons) are indicated with a superscript "++" or "−−". In chemistry, the same charge numbers are usually indicated as superscript "+2" or "−2". In particle physics, the charge number is a (derived) flavor quantum number. For color-charged particles like quarks and hypothetical leptoquarks, the charge number is a multiple of 1/3. Charge number Charge number ("z") refers to a

neg: Isoelectric point is expected to be somewhat different than the point of zero charge at the particle surface, but this difference is often ignored in practice for so-called pristine surfaces, i.e., surfaces with no specifically adsorbed positive or negative charges. In this context, specific adsorption is understood as adsorption occurring in a Stern layer or chemisorption. Thus, point of zero charge at the surface is taken as equal to isoelectric point in the absence of specific adsorption on that surface. According to Jolivet, in the absence of positive or negative charges, the surface is best described by the point of zero charge.

neg: History of subatomic physics the mostly empty volume of atoms. In 1918, Rutherford confirmed that the hydrogen nucleus was a particle with a positive charge, which he named the proton. By then, Frederick Soddy's researches of radioactive elements, and experiments of J. J. Thomson and F.W. Aston conclusively demonstrated existence of isotopes, whose nuclei have different masses in spite of identical atomic numbers. It prompted Rutherford to conjecture that all nuclei other than hydrogen contain chargeless particles, which he named the neutron. Evidences that atomic nuclei consist of some smaller particles (now called "nucleons") grew; it became obvious that, while protons repulse each other

neg: Marcello Conversi of 1968, called the "start of modern particle physics" in his Nobel lecture. In 1946, they showed that the "mesotron", now known as the muon, which had been discovered in 1937 by Seth Neddermeyer and Carl David Anderson, was not the particle predicted by Hideki Yukawa as mediator of the strong force. If the "mesotron", a cosmic ray particle of negative charge, was indeed the meson postulated by Yukawa, it should be captured without decaying. Conversi, Piccioni and Pancini moved their experiment to a high school to avoid air raids. In their experimental setup negative and positive particles were separated

neg: Elementary particle these are normally called preons, which is derived from "pre-quarks". In essence, preon theory tries to do for the Standard Model what the Standard Model did for the particle zoo that came before it. Most models assume that almost everything in the Standard Model can be explained in terms of three to half a dozen more fundamental particles and the rules that govern their interactions. Interest in preons has waned since the simplest models were experimentally ruled out in the 1980s. Accelerons are the hypothetical subatomic particles that integrally link the newfound mass of the neutrino to the dark energy

neg: Ghirardi–Rimini–Weber theory suggesting that particles spontaneously collapse into stable states, GRW escapes the ideas that measurement is a special act or that some specific part of measuring a subatomic particle causes the particle's wave function to collapse. At the same time, GRW theory is compatible with single-particle experiments that do not observe spontaneous wave-function collapses; this is because spontaneous collapse is posited to be extremely rare. However, since measurement entails quantum entanglement, GRW still describes the observed phenomenon of quantum collapses whenever we measure subatomic particles. This is because the measured particle becomes entangled with the very large number of particles that

neg: Hermetic detector 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

neg: History of subatomic physics ones. Fermions are particles "like electrons and nucleons" and generally comprise the matter. Note that any subatomic or atomic particle composed of even "total" number of fermions (such as protons, neutrons, and electrons) is a boson, so a boson is not necessarily a force transmitter and perfectly can be an ordinary material particle. The spin is the quantity that distinguishes bosons and fermions. Practically it appears as an intrinsic angular momentum of a particle, that is unrelated to its motion but is linked with some other features like a magnetic dipole. Theoretically it is explained from different types representations of

neg: Electron hole hole moves this way as well. From the above, a hole (1) carries a positive charge, and (2) responds to electric and magnetic fields as if it had a positive charge and positive mass. (The latter is because a particle with positive charge and positive mass responds to electric and magnetic fields in the same way as a particle with negative charge and negative mass.) That explains why holes can be treated in all situations as ordinary positively charged quasiparticles. In some semiconductors, such as silicon, the hole's effective mass is dependent on direction (anisotropic), however a value averaged over

neg: Muon neutrino Muon neutrino 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. In 1962 Leon M. Lederman, Melvin Schwartz and Jack Steinberger established by performing an experiment at the Brookhaven National Laboratory that more than one type of neutrino exists

neg: Fifth force weak force, mediated by W' and Z' bosons. The search for a fifth force has increased in recent decades due to two discoveries in cosmology which are not explained by current theories. It has been discovered that most of the mass of the universe is accounted for by an unknown form of matter called dark matter. Most physicists believe that dark matter is some new undiscovered subatomic particle, but some believe that it could be related to an unknown fundamental force. Second, it has also recently been discovered that the expansion of the universe is accelerating, which has been attributed

neg: Burton Richter the U.S. Atomic Energy Commission. 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. Richter was a member of the JASON advisory group and served on the board of

neg: Particle physics Standard Model. Thus, modern particle physics generally investigates the Standard Model and its various possible extensions, e.g. to the newest "known" particle, the Higgs boson, or even to the oldest known force field, gravity. Modern particle physics research is focused on subatomic particles, including atomic constituents such as electrons, protons, and neutrons (protons and neutrons are composite particles called baryons, made of quarks), produced by radioactive and scattering processes, such as photons, neutrinos, and muons, as well as a wide range of exotic particles. Dynamics of particles is also governed by quantum mechanics; they exhibit wave–particle duality, displaying particle-like behaviour

neg: Delta baryon Delta baryon 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 .

neg: Neutron electric dipole moment Neutron electric dipole moment The neutron electric dipole moment (nEDM) is a measure for the distribution of positive and negative charge inside the neutron. A finite electric dipole moment can only exist if the centers of the negative and positive charge distribution inside the particle do not coincide. So far, no neutron EDM has been found. The current best upper limit amounts to . A permanent electric dipole moment of a fundamental particle violates both parity (P) and time reversal symmetry (T). These violations can be understood by examining the neutron's magnetic dipole moment and hypothetical electric dipole moment. Under

neg: Atomic theory of the 20th century, through various experiments with electromagnetism and radioactivity, physicists discovered that the so-called "uncuttable atom" was actually a conglomerate of various subatomic particles (chiefly, electrons, protons and neutrons) which can exist separately from each other. In fact, in certain extreme environments, such as neutron stars, extreme temperature and pressure prevents atoms from existing at all. Since atoms were found to be divisible, physicists later invented the term "elementary particles" to describe the "uncuttable", though not indestructible, parts of an atom. The field of science which studies subatomic particles is particle physics, and it is in this field

neg: Electron an excess (+) or deficit (-). He gave them the modern charge nomenclature of positive and negative respectively. Franklin thought of the charge carrier as being positive, but he did not correctly identify which situation was a surplus of the charge carrier, and which situation was a deficit. Between 1838 and 1851, British natural philosopher Richard Laming developed the idea that an atom is composed of a core of matter surrounded by subatomic particles that had unit electric charges. Beginning in 1846, German physicist William Weber theorized that electricity was composed of positively and negatively charged fluids, and their interaction

neg: Relativistic quantum mechanics inclusion of spin in the wavefunction incorporates the Pauli exclusion principle (1925) and the more general spin-statistics theorem (1939) due to Fierz, rederived by Pauli a year later. This is the explanation for a diverse range of subatomic particle behavior and phenomena: from the electronic configurations of atoms, nuclei (and therefore all elements on the periodic table and their chemistry), to the quark configurations and colour charge (hence the properties of baryons and mesons). A fundamental prediction of special relativity is the relativistic energy–momentum relation; for a particle of rest mass , and in a particular frame of reference with

neg: Particle accelerator accelerating field. This class, which was first developed in the 1920s, is the basis for most modern large-scale accelerators. Rolf Widerøe, Gustav Ising, Leó Szilárd, Max Steenbeck, and Ernest Lawrence are considered pioneers of this field, conceiving and building the first operational linear particle accelerator, the betatron, and the cyclotron. Because colliders can give evidence of the structure of the subatomic world, accelerators were commonly referred to as atom smashers in the 20th century. Despite the fact that most accelerators (but not ion facilities) actually propel subatomic particles, the term persists in popular usage when referring to particle accelerators in

neg: Cowan–Reines neutrino experiment the solar core. Observatories such as these detected neutrino bursts from supernova SN 1987A in 1987, the birth of neutrino astronomy. Through observations of solar neutrinos, the Sudbury Neutrino Observatory was able to demonstrate the process of neutrino oscillation. Neutrino oscillation shows that neutrinos are not massless, a profound development in particle physics. Cowan–Reines neutrino experiment The Cowan–Reines neutrino experiment was conducted by Clyde L. Cowan and Frederick Reines in 1956. The experiment confirmed the existence of neutrinos. Neutrinos, subatomic particles with no electric charge and very small mass, had been conjectured to be an essential particle in beta decay

neg: Charm quark Charm quark The charm quark, charmed quark or c quark (from its symbol, c) is the third most massive of all quarks, a type of elementary particle. Charm quarks are found in hadrons, which are subatomic particles made of quarks. Examples of hadrons containing charm quarks include the J/ψ meson (), D mesons (), charmed Sigma baryons (), and other charmed particles. It, along with the strange quark is part of the second generation of matter, and has an electric charge of + "e" and a bare mass of . Like all quarks, the charm quark is an elementary fermion

neg: Electric dipole moment theoretically perfect is usually negligible. The dipole's direction usually points from the negative charge towards the positive charge. Often in physics the dimensions of a massive object can be ignored and can be treated as a pointlike object, i.e. a point particle. Point particles with electric charge are referred to as point charges. Two point charges, one with charge +"q" and the other one with charge −"q" separated by a distance "d", constitute an "electric dipole" (a simple case of an electric multipole). For this case, the electric dipole moment has a magnitude and is directed from the negative charge

neg: Electron detectors and particle accelerators. Interactions involving electrons with other subatomic particles are of interest in fields such as chemistry and nuclear physics. The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without, allows the composition of the two known as atoms. Ionization or differences in the proportions of negative electrons versus positive nuclei changes the binding energy of an atomic system. The exchange or sharing of the electrons between two or more atoms is the main cause of chemical bonding. In 1838, British natural philosopher Richard Laming first hypothesized the concept of an indivisible

neg: V particle V particle In particle physics, V was a generic name for heavy, unstable subatomic particles that decay into a pair of particles, thereby producing a characteristic letter V in a bubble chamber or other particle detector. Such particles were first detected in cosmic ray interactions in the atmosphere in the late 1940s and were first produced using the Cosmotron particle accelerator at Brookhaven National Laboratory in the 1950s. Since all such particles have now been identified and given specific names, such as K meson or Sigma baryon, this term has fallen into disuse. V is still used on occasion to

neg: Induced-charge electrokinetics Induced-charge electrokinetics Induced-charge electrokinetics in physics is the electrically driven fluid flow and particle motion in a liquid electrolyte. Consider a metal particle (which is neutrally charged but electrically conducting) in contact with an aqueous solution in a chamber/channel. If different voltages apply to the end of this chamber/channel, electric field will generate in this chamber/channel. This applied electric field passes through this metal particle and causes the free charges inside the particle migrate under the skin of particle. As a result of this migration, the negative charges moves to the side which is close to the positive (or higher)

neg: Color charge be the anticolor of red, green, and blue, respectively, for the color charge to be conserved in particle-antiparticle creation and annihilation. Particle physicists call these antired, antigreen, and antiblue. All three colors mixed together, or any one of these colors and its complement (or negative), is "colorless" or "white" and has a net color charge of zero. Free particles have a color charge of zero: baryons are composed of three quarks, but the individual quarks can have red, green, or blue charges, or negatives; mesons are made from a quark and antiquark, the quark can be any color, and the

neg: History of subatomic physics all the elementary forms of matter would zoom around at the speed of light; there would be neither atoms nor life. The Higgs boson achieved a notoriety rare for abstract physics. To the eternal dismay of his colleagues, Leon Lederman, the former director of Fermilab, called it the "God particle" in his book of the same name, later quipping that he had wanted to call it "the goddamn particle". Professor Incandela also stated, In quantum theory, which is the language of particle physicists, elementary particles are divided into two rough categories: fermions, which are bits of matter like electrons, and

neg: History of subatomic physics elusive particle predicted by the Standard Model, the theory that has ruled physics for the last half-century. It is unknown if this particle is an impostor, a single particle or even the first of many particles yet to be discovered. The latter possibilities are particularly exciting to physicists since they could point the way to new deeper ideas, beyond the Standard Model, about the nature of reality. For now, some physicists are calling it a "Higgslike" particle. Joe Incandela, of the University of California, Santa Barbara, said, "It's something that may, in the end, be one of the biggest observations

neg: Muon neutrino of the fibre optic timing system in Gran-Sasso. After it was corrected the neutrinos appeared to travel with the speed of light within the errors of the experiment. Muon neutrino 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.

neg: Subatomic particle particles include all hadrons: these include baryons (such as protons and neutrons) and mesons (such as pions and kaons). In special relativity, the energy of a particle at rest equals its mass times the speed of light squared, "E" = "mc". That is, mass can be expressed in terms of energy and vice versa. If a particle has a frame of reference in which it lies at rest, then it has a positive rest mass and is referred to as "massive". All composite particles are massive. Baryons (meaning "heavy") tend to have greater mass than mesons (meaning "intermediate"), which in

neg: Xerography the drum or belt a brush of toner. By contact with the carrier each neutral toner particle has an electric charge of polarity opposite to the charge of the latent image on the drum. The charge attracts toner to form a visible image on the drum. To control the amount of toner transferred, a bias voltage is applied to the developer roller to counteract the attraction between toner and latent image. Where a negative image is required, as when printing from a microform negative, then the toner has the same polarity as the corona in step 1. Electrostatic lines of

neg: Surface charge Surface charge Surface charge is the electrical potential difference between the inner and outer surface of the dispersed phase in a colloid. There are many different processes which can lead to a surface being charged, including adsorption of ions, protonation/deprotonation, and the application of an external electric field. Surface charge causes a particle to emit an electric field, which causes particle repulsion and attraction, affecting many colloidal properties. Surface charge practically always appears on the particle surface when it is placed into a fluid. Most fluids contain ions, positive (cations) and negative (anions). These ions interact with the object surface.

neg: Rutherford model or 100) might be exactly the same. A month after Rutherford's paper appeared, the proposal regarding the exact identity of atomic number and nuclear charge "was" made by Antonius van den Broek, and later confirmed experimentally within two years, by Henry Moseley. These are the key indicators- After Rutherford's discovery, scientists started to realize that the atom is not ultimately a single particle, but is made up of far smaller subatomic particles. Subsequent research determined the exact atomic structure which led to Rutherford's gold foil experiment. Scientists eventually discovered that atoms have a positively charged nucleus (with an exact atomic

neg: Double layer (surface science) Double layer (surface science) A double layer (DL, also called an electrical double layer, EDL) is a structure that appears on the surface of an object when it is exposed to a fluid. The object might be a solid particle, a gas bubble, a liquid droplet, or a porous body. The DL refers to two parallel layers of charge surrounding the object. The first layer, the surface charge (either positive or negative), consists of ions adsorbed onto the object due to chemical interactions. The second layer is composed of ions attracted to the surface charge via the Coulomb force, electrically

neg: Charge radius This asymmetric distribution of charge within the particle gives rise to a small negative squared charge radius for the particle as a whole. But, this is only the simplest of a variety of theoretical models, some of which are more elaborate, that are used to explain this property of a neutron. For deuterons and higher nuclei, it is conventional to distinguish between the scattering charge radius, "r" (obtained from scattering data), and the bound-state charge radius, "R", which includes the Darwin–Foldy term to account for the behaviour of the anomalous magnetic moment in an electromagnetic field and which is appropriate

neg: History of subatomic physics development includes refining of the Standard Model, researching in its foundations such as the Yang–Mills theory, and researches in computational methods such as the lattice QCD. A long-standing problem is quantum gravitation. No solution that is useful for particle physics has been achieved. There are researches about quark–gluon plasma, a new (hypothetical) state of matter. There are also some recent experimental evidences that tetraquarks and glueballs exist. The proton decay is not observed (or, generally, non-conservation of the baryon number), but predicted by the Standard Model, so there are searches for it. History of subatomic physics The idea that matter

neg: Chirality is called chiral. For example, the unknot and the figure-eight knot are achiral, whereas the trefoil knot is chiral. 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 a purely quantum mechanical phenomenon like spin. Although both can have left-handed or right-handed properties, only in the massless case do they have a simple relation. In particular for a

neg: Induced-charge electrokinetics voltage while the positive charges moves to the opposite side of the particle. These charges under the skin of conducting particle attract the counter-ions of the aqueous solution; thus, the electric double layer (EDL) forms around the particle. The EDL sing on the surface of the conducting particle changes from positive to negative and the distribution of the charges varies along the particle geometry. Due to these variations, the EDL is non-uniform and has different sings. Thus, the induced zeta potential around the particle, and consequently slip velocity on the surface of the particle, vary as a function of local

neg: Saltation (geology) magnitude to the weight of the particle. These smaller particles are carried by the fluid in suspension, and advected downstream. The smaller the particle, the less important the downward pull of gravity, and the longer the particle is likely to stay in suspension. <br> A recent study finds that saltating sand particles induces a static electric field by friction. Saltating sand acquires a negative charge relative to the ground which in turn loosens more sand particles which then begin saltating. This process has been found to double the number of particles predicted by previous theory. This is significant in meteorology

neg: Negative mass of which correspond to the ratio of electric charge to inertial mass. Particle–antiparticle pairs are seen to travel in helices with opposite directions but identical radii, implying that the ratios differ only in sign; but this does not indicate whether it is the charge or the inertial mass that is inverted. However, particle–antiparticle pairs are observed to electrically attract one another. This behavior implies that both have positive inertial mass and opposite charges; if the reverse were true, then the particle with positive inertial mass would be repelled from its antiparticle partner. Physicist Peter Engels and a team of colleagues

neg: Jeff Forshaw shortlisted for the Royal Society science book prize. Forshaw lives in Manchester and has two daughters. Jeff Forshaw Jeffrey Robert Forshaw (born 1968) is a British particle physicist with a special interest in quantum chromodynamics (QCD): the study of the behaviour of subatomic particles, using data from the HERA particle accelerator, Tevatron particle accelerator and the Large Hadron Collider (LHC) at CERN. Since 2004 he has been professor of particle physics in the School of Physics and Astronomy at the University of Manchester. He is the co-author of 5 books, most notably the worldwide bestselling popular science books "Why Does

neg: Negative verb Imperative The negative verb is conjugated in moods and personal forms in Lule Sami. Indicative, conditional, and potential mood Hungarian has lost most evidence of a negative verb, but the negation particle "nem" becomes "ne" before verbs in the jussive/imperative (also sometimes called the conditional mood, or J-mood). Furthermore, the 3rd person present indicative of the copular verb ("lenni") has unique negative forms "nincs(en)" and "nincsenek" as opposed to "nem van" and "nem vannak", but only when the particle and verb would occur adjacently. In all other instances the copular verb acts regularly. These forms are also unique in that