"Tetraquark A tetraquark, in particle physics, is an exotic meson composed of four valence quarks. In principle, a tetraquark state may be allowed in quantum chromodynamics, the modern theory of strong interactions. Any established tetraquark state would be an example of an exotic hadron which lies outside the quark model classification. Several tetraquark candidates have been reported by particle physics experiments in the 21st century. The quark contents of these states are almost all qQ, where q represents a light (up, down or strange) quark, Q represents a heavy (charm or bottom) quark, and antiquarks are denoted with an overline."
"Bottomness In physics, bottomness (symbol ""B""′) or beauty is a flavour quantum number reflecting the difference between the number of bottom antiquarks (""n"") and the number of bottom quarks (""n"") that are present in a particle: Bottom quarks have (by convention) a bottomness of −1 while bottom antiquarks have a bottomness of +1. The convention is that the flavour quantum number sign for the quark is the same as the sign of the electric charge (symbol ""Q"") of that quark (in this case, Q = −). As with other flavour-related quantum numbers, bottomness is preserved under strong and electromagnetic interactions,"
"bottom and top quarks were sometimes referred to as ""beauty"" and ""truth"" respectively, but these names have somewhat fallen out of use. While ""truth"" never did catch on, accelerator complexes devoted to massive production of bottom quarks are sometimes called ""beauty factories"". Quarks have fractional electric charge values – either (−) or (+) times the elementary charge (e), depending on flavor. Up, charm, and top quarks (collectively referred to as ""up-type quarks"") have a charge of + e, while down, strange, and bottom quarks (""down-type quarks"") have − e. Antiquarks have the opposite charge to their corresponding quarks; up-type antiquarks"
"Flavour (particle physics) In particle physics, flavour or flavor refers to the ""species"" of an elementary particle. The Standard Model counts six flavours of quarks and six flavours of leptons. They are conventionally parameterized with ""flavour quantum numbers"" that are assigned to all subatomic particles. They can also be described by some of the family symmetries proposed for the quark-lepton generations. In classical mechanics, a force acting on a point-like particle can only alter the particle's dynamical state, i.e., its momentum, angular momentum, etc. Quantum field theory, however, allows interactions that can alter other facets of a particle's nature described"
"Topness Topness (T, also called truth), a flavour quantum number, represents the difference between the number of top quarks (t) and number of top antiquarks () that are present in a particle: By convention, top quarks have a topness of +1 and top antiquarks have a topness of −1.The term ""topness"" is rarely used; most physicists simply refer to ""the number of top quarks"" and ""the number of top antiquarks"". Like all flavour quantum numbers, topness is preserved under strong and electromagnetic interactions, but not under weak interaction. However the top quark is extremely unstable, with a half-life under 10"
"but not under weak interactions. For first-order weak reactions, it holds that formula_2. This term is rarely used. Most physicists simply refer to ""the number of bottom quarks"" and ""the number of bottom antiquarks"". Bottomness In physics, bottomness (symbol ""B""′) or beauty is a flavour quantum number reflecting the difference between the number of bottom antiquarks (""n"") and the number of bottom quarks (""n"") that are present in a particle: Bottom quarks have (by convention) a bottomness of −1 while bottom antiquarks have a bottomness of +1. The convention is that the flavour quantum number sign for the quark is"
"and spin. They are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as ""fundamental forces"" (electromagnetism, gravitation, strong interaction, and weak interaction), as well as the only known particles whose electric charges are not integer multiples of the elementary charge. There are six types, known as ""flavors"", of quarks: up, down, strange, charm, bottom, and top. Up and down quarks have the lowest masses of all quarks. The heavier quarks rapidly change into up and down quarks through a process of particle decay: the transformation from a higher mass"
"form and assume a new one. Again this form may be lost and the original acquired. Matter is classified as solid, liquid, gaseous, energy, fine Karmic materials and extra-fine matter i.e. ultimate particles. ""Paramāṇu"" or ultimate particle (atoms or sub-atomic particles) is the basic building block of all matter. It possesses at all times four qualities, namely, a color (""varna""), a taste (""rasa""), a smell (""gandha""), and a certain kind of palpability (""sparsha"", touch). One of the qualities of the ""paramāṇu"" and ""pudgala"" is that of permanence and indestructibility. It combines and changes its modes but its basic qualities remain"
"the original definition. For all the quark flavour quantum numbers (strangeness, charm, topness and bottomness) the convention is that the flavour charge and the electric charge of a quark have the same sign. With this, any flavour carried by a charged meson has the same sign as its charge. Strangeness was introduced by Murray Gell-Mann, Abraham Pais and Kazuhiko Nishijima to explain the fact that certain particles, such as the kaons or the hyperons and , were created easily in particle collisions, yet decayed much more slowly than expected for their large masses and large production cross sections. Noting that"
"go up and down along with particle mass. The higher the mass, the lower the strangeness (the more s quarks). Particles could be described with isospin projections (related to charge) and strangeness (mass) (see the uds octet and decuplet figures on the right). As other quarks were discovered, new quantum numbers were made to have similar description of udc and udb octets and decuplets. Since only the u and d mass are similar, this description of particle mass and charge in terms of isospin and flavour quantum numbers works well only for octet and decuplet made of one u, one"
"terms of quark content, these would become: By convention, the flavor quantum numbers (strangeness, charm, bottomness, and topness) carry the same sign as the electric charge of the particle. So, since the strange and bottom quarks have a negative charge, they have flavor quantum numbers equal to −1. And since the charm and top quarks have positive electric charge, their flavor quantum numbers are +1. Gell-Mann–Nishijima formula The Gell-Mann–Nishijima formula (sometimes known as the NNG formula) relates the baryon number ""B"", the strangeness ""S"", the isospin ""I"" of quarks and hadrons to the electric charge ""Q"". It was originally given"
"of isospin, which they carry. Strange quarks were given their name because they were discovered to be components of the strange particles discovered in cosmic rays years before the quark model was proposed; these particles were deemed ""strange"" because they had unusually long lifetimes. Glashow, who co-proposed charm quark with Bjorken, is quoted as saying, ""We called our construct the 'charmed quark', for we were fascinated and pleased by the symmetry it brought to the subnuclear world."" The names ""bottom"" and ""top"", coined by Harari, were chosen because they are ""logical partners for up and down quarks"". In the past,"
"interfere with each other, this can make many colors. An example of this is the colors in soap bubbles. Quarks and other elementary particles are the topic of this chapter. Quarks are very small things that make up everything we see (matter). There are six different ""flavors"" of quarks: the up quark, down quark, strange quark, charmed quark, bottom quark, and top quark. Quarks also have three ""colors"": red, green, and blue. There are also anti-quarks, which are the opposite of the regular quarks. In total, there are 18 different types of regular quarks, and 18 different types of anti"
"excess of charged particles that can be detected by AMS-02. Any peaks in the background positron, antiproton, or gamma ray flux could signal the presence of neutralinos or other dark matter candidates, but would need to be distinguished from poorly known confounding astrophysical signals. Six types of quarks (up, down, strange, charm, bottom and top) have been found experimentally; however, the majority of matter on Earth is made up of only up and down quarks. It is a fundamental question whether there exists stable matter made up of strange quarks in combination with up and down quarks. Particles of such"
"badly broken, due to the much higher mass of the strange quark compared to the up and down. The discovery of charm, bottomness and topness could lead to further expansions up to SU(6) flavour symmetry, which would hold if all six quarks were identical. However, the very much larger masses of the charm, bottom and top quarks means that SU(6) flavour symmetry is very badly broken in nature (at least at low energies) and assuming this symmetry leads to qualitatively and quantitatively incorrect predictions. In modern applications, such as lattice QCD, isospin symmetry is often treated as exact while the"
"spin- particles. The component of spin along a given axis – by convention the ""z"" axis – is often denoted by an up arrow ↑ for the value + and down arrow ↓ for the value −, placed after the symbol for flavor. For example, an up quark with a spin of + along the ""z"" axis is denoted by u↑. A quark of one flavor can transform into a quark of another flavor only through the weak interaction, one of the four fundamental interactions in particle physics. By absorbing or emitting a W boson, any up-type quark (up, charm,"
"topness) can characterize the quantum state of quarks, by the degree to which it exhibits six distinct flavours (u, d, s, c, b, t). Composite particles can be created from multiple quarks, forming hadrons, such as mesons and baryons, each possessing unique aggregate characteristics, such as different masses, electric charges, and decay modes. A hadron's overall flavour quantum numbers depend on the numbers of constituent quarks of each particular flavour. All of the various charges discussed above are conserved by the fact that the corresponding charge operators can be understood as ""generators of symmetries"" that commute with the Hamiltonian. Thus,"
"Model are classified according to how they interact (or equivalently, by what charges they carry). There are six quarks (up, down, charm, strange, top, bottom), and six leptons (electron, electron neutrino, muon, muon neutrino, tau, tau neutrino). Pairs from each classification are grouped together to form a generation, with corresponding particles exhibiting similar physical behavior (see table). The defining property of the quarks is that they carry color charge, and hence interact via the strong interaction. A phenomenon called color confinement results in quarks being very strongly bound to one another, forming color-neutral composite particles (hadrons) containing either a quark"
"s, which is the required time for the strong interaction to take place. For that reason the top quark does not hadronize, that is it never forms any meson or baryon, so the topness of a meson or a baryon is always zero. By the time it can interact strongly it has already decayed to another flavour of quark (usually to a bottom quark). Topness Topness (T, also called truth), a flavour quantum number, represents the difference between the number of top quarks (t) and number of top antiquarks () that are present in a particle: By convention, top quarks"
"Up quark The up quark or u quark (symbol: u) is the lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the down quark, forms the neutrons (one up quark, two down quarks) and protons (two up quarks, one down quark) of atomic nuclei. It is part of the first generation of matter, has an electric charge of + ""e"" and a bare mass of .. Like all quarks, the up quark is an elementary fermion with spin , and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong"
"Charm (quantum number) Charm (symbol C) is a flavour quantum number representing the difference between the number of charm quarks () and charm antiquarks () that are present in a particle: By convention, the sign of flavour quantum numbers agree with the sign of the electric charge carried by the quarks of corresponding flavour. The charm quark, which carries an electric charge (""Q"") of +, therefore carries a charm of +1. The charm antiquarks have the opposite charge (), and flavour quantum numbers (). As with any flavour-related quantum numbers, charm is preserved under strong and electromagnetic interaction, but not"
"the lower state (2593) by CLEO clarified the situation. The decay modes, the masses, the measured widths, and the decays via two charged pions rather than one charged and one neutral pion, all confirm the identification of the states. As noted above, charmed Sigma particles, like particles, comprise a charm quark and two light up, down, strange) quarks. However, particles have isospin 1. This is equivalent to saying that they can exist in three charged states, the doubly charged, the singly charged, and the neutral. The situation is directly analogous to the strange baryon nomenclature. The ground state (that is,"
"and strange () quarks to be ""light"" and the charm (), bottom (), and top () quarks to be ""heavy"". The rules cover all the particles that can be made from three of each of the six quarks, even though baryons made of top quarks are not expected to exist because of the top quark's short lifetime. The rules do not cover pentaquarks. It is also a widespread (but not universal) practice to follow some additional rules when distinguishing between some states that would otherwise have the same symbol. Quarks carry a charge, so knowing the charge of a particle"
"chiral symmetry breaking with the formation of a chiral condensate. Other phases of QCD may break the chiral flavour symmetries in other ways. Some of the historical events that led to the development of flavour symmetry are discussed in the article on isospin. Flavour (particle physics) In particle physics, flavour or flavor refers to the ""species"" of an elementary particle. The Standard Model counts six flavours of quarks and six flavours of leptons. They are conventionally parameterized with ""flavour quantum numbers"" that are assigned to all subatomic particles. They can also be described by some of the family symmetries proposed"
"up, down, and strange, then the color-flavor-locked pattern of Cooper pairing is This means that a Cooper pair of an up quark and a down quark must have colors red and green, and so on. This pairing pattern is special because it leaves a large unbroken symmetry group. The CFL phase has several remarkable properties. There are several variants of the CFL phase, representing distortions of the pairing structure in response to external stresses such as a difference between the mass of the strange quark and the mass of the up and down quarks. Color–flavor locking Color–flavor locking (CFL) is"
"should be strange matter in the universe: Strange matter Strange matter is a particular form of quark matter, usually thought of as a ""liquid"" of up, down and strange quarks. It is to be contrasted with nuclear matter, which is a liquid of neutrons and protons (which themselves are built out of up and down quarks), and with non-strange quark matter, which is a quark liquid containing only up and down quarks. At high enough density, strange matter is expected to be color superconducting. Strange matter is hypothesized to occur in the core of neutron stars, or, more speculatively, as"
"Bottom quark The bottom quark or b quark, also known as the beauty quark, is a third-generation quark with a charge of − ""e"". All quarks are described in a similar way by electroweak and quantum chromodynamics, but the bottom quark has exceptionally low rates of transition to lower-mass quarks. The bottom quark is also notable because it is a product in almost all top quark decays, and is a frequent decay product of the Higgs boson. The bottom quark was first described theoretically in 1973 by physicists Makoto Kobayashi and Toshihide Maskawa to explain CP violation. The name ""bottom"""
"on both quark content and isospin. The naming follows the rules established by the Particle Data Group. Charge is indicated with superscripts. Heavy quark (bottom, charm, or top quarks) content is indicated by subscripts. For example, a is made of one bottom, one charmed quark, and it can be deduced from the charge of the charm (+e) and bottom quark (−e) that the other quark must be an up quark (+e). Sometimes asterisks or primes are used to indicate a resonance. The important parameters of charmed baryons, to be studied, consist of four properties. They are firstly the mass, secondly"
"interactions are looked at, but they are not truly exact symmetries of the universe because the three quarks have different masses and different electroweak interactions. This approximate symmetry is called ""flavour symmetry"", or more specifically ""flavour SU(3) symmetry"". Assume we have a certain particle—for example, a proton—in a quantum state formula_4. If we apply one of the flavour rotations ""A"" to our particle, it enters a new quantum state which we can call formula_5. Depending on ""A"", this new state might be a proton, or a neutron, or a superposition of a proton and a neutron, or various other possibilities."
"Strange matter Strange matter is a particular form of quark matter, usually thought of as a ""liquid"" of up, down and strange quarks. It is to be contrasted with nuclear matter, which is a liquid of neutrons and protons (which themselves are built out of up and down quarks), and with non-strange quark matter, which is a quark liquid containing only up and down quarks. At high enough density, strange matter is expected to be color superconducting. Strange matter is hypothesized to occur in the core of neutron stars, or, more speculatively, as isolated droplets that may vary in size"
"Lambda baryon The Lambda baryons are a family of subatomic hadron particles containing one up quark, one down quark, and a third quark from a higher flavour generation, in a combination where the wavefunction changes sign upon the flavour of any two quarks being swapped (thus differing from a Sigma baryon). They are thus baryons, with Total Isospin of 0, and which are either neutral or have the elementary charge +1 Lambda baryons are usually given the symbols , , , and - the third quark can be either a strange (), a charm (), a bottom (), or a"
"Down quark The down quark or d quark (symbol: d) is the second-lightest of all quarks, a type of elementary particle, and a major constituent of matter. Together with the up quark, it forms the neutrons (one up quark, two down quarks) and protons (two up quarks, one down quark) of atomic nuclei. It is part of the first generation of matter, has an electric charge of − ""e"" and a bare mass of . Like all quarks, the down quark is an elementary fermion with spin , and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong"
"of elementary particle physics were proposed, which said that protons, neutrons and all other baryons, and also all mesons, are made from three kinds of fractionally-charged particles, the ""quarks"", that come in three different types or ""flavors"", called ""up"", ""down"", and ""strange"". Despite the capability of quark models to bring order to the ""elementary particle zoo"", their status was considered something like mathematical fiction at the time, a simple artifact of deeper physical reasons. Starting in 1969, deep inelastic scattering experiments at SLAC revealed surprising experimental evidence for particles inside of protons. Whether these were quarks or something else was"