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Encyclopedia > Top quark
Top Quark
Composition Elementary particle
Family Fermion
Group Quark
Generation Third
Discovered CDF and D0 collaborations, 1995
Symbol t
Mass 170.9±1.8 GeV/c2
Decay particle W boson and bottom quark
Electric charge +2/3 e
Spin ½
This box: view  talk  edit
Flavour in particle physics
v  d  e
Flavour quantum numbers:

Combinations: For the novel, see The Elementary Particles. ... In particle physics, fermions are particles with half-integer spin, such as protons and electrons. ... For other uses, see Quark (disambiguation). ... In particle physics, a generation is a division of the elementary particles. ... The Collider Detector at Fermilab (CDF) experimental collaboration studies high energy particle collisions at the Tevatron, the world’s highest energy particle accelerator. ... D0 under construction, the installation of the central tracking system D0s control room The D0 experiment consists of a worldwide collaboration of scientists conducting research on the fundamental nature of matter. ... Year 1995 (MCMXCV) was a common year starting on Sunday. ... The invariant mass or intrinsic mass or proper mass or just mass is a measurement or calculation of the mass of an object that is the same for all frames of reference. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... The bottom quark is a third-generation quark with a charge of -(1/3)e. ... The elementary charge (symbol e or sometimes q) is the electric charge carried by a single proton, or equivalently, the negative of the electric charge carried by a single electron. ... The elementary charge (symbol e or sometimes q) is the electric charge carried by a single proton, or equivalently, the negative of the electric charge carried by a single electron. ... In physics, spin refers to the angular momentum intrinsic to a body, as opposed to orbital angular momentum, which is the motion of its center of mass about an external point. ... Flavour (or flavor) is a quantum number of elementary particles related to their weak interactions. ... Thousands of particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... Quantum numbers describe values of conserved quantity in the dynamics of the quantum system. ... In high energy physics, the lepton number is the number of leptons minus the number of antileptons. ... In particle physics, the baryon number is an approximate conserved quantum number. ... In particle physics, strangeness, denoted as , is a property of particles, expressed as a quantum number for describing decay of particles in strong and electro-magnetic reactions, which occur in a short period of time. ... The charm quark is a second-generation quark with a charge of +(2/3)e. ... The bottom quark is a third-generation quark with a charge of -(1/3)e. ... Isospin (isotopic spin, isobaric spin) is a physical quantity which is mathematically analogous to spin. ... The weak isospin in theoretical physics parallels the idea of the isospin under the strong interaction, but applied under the weak interaction. ... This box:      Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. ...


Related topics: In particle physics, the hypercharge (represented by Y) is the sum of the baryon number B and the flavor charges: strangeness S, charm C, bottomness and topness T, although the last one can be omitted given the extremely short life of the top quark (it decays to other quarks before... Weak hypercharge is twice the difference between the electrical charge and the weak isospin. ... In high energy physics, B−L (pronounced bee minus ell) is the baryon number minus the lepton number. ...

The top quark is the third-generation up-type quark with a charge of +(2/3)e.[1] It was discovered in 1995 by the CDF and D0 experiments at Fermilab, and is by far the most massive of known elementary particles. As of 2007, its mass is measured at 170.9±1.8 GeV/c2.[2] nearly as heavy as a gold nucleus. CPT-symmetry is a fundamental symmetry of physical laws under transformations that involve the inversions of charge, parity and time simultaneously. ... In the standard model of particle physics the Cabibbo-Kobayashi-Maskawa matrix (CKM matrix, quark mixing matrix, sometimes earlier called KM matrix) is a unitary matrix which contains information on the strength of flavour-changing weak decays. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... A phenomenon is said to be chiral if it is not identical to its mirror image (see Chirality (mathematics)). The spin of a particle may be used to define a handedness for that particle. ... In particle physics, a generation is a division of the elementary particles. ... For other uses, see Quark (disambiguation). ... The elementary charge (symbol e or sometimes q) is the electric charge carried by a single proton, or equivalently, the negative of the electric charge carried by a single electron. ... The Collider Detector at Fermilab (CDF) experimental collaboration studies high energy particle collisions at the Tevatron, the world’s highest energy particle accelerator. ... D0 under construction, the installation of the central tracking system D0s control room The D0 experiment consists of a worldwide collaboration of scientists conducting research on the fundamental nature of matter. ... Aerial view of the Fermilab site. ... GOLD refers to one of the following: GOLD (IEEE) is an IEEE program designed to garner more student members at the university level (Graduates of the Last Decade). ... The nucleus of an atom is the very small dense region, of positive charge, in its centre consisting of nucleons (protons and neutrons). ...


The top quark interacts primarily by the strong interaction but can only decay through the weak force. It almost exclusively decays to a W boson and a bottom quark. The Standard Model predicts its lifetime to be roughly 1×10−25 s; this is about 20 times shorter than the timescale for strong interactions, and therefore it does not hadronize, giving physicists a unique opportunity to study a "bare" quark. The strong interaction or strong force is today understood to represent the interactions between quarks and gluons as detailed by the theory of quantum chromodynamics (QCD). ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... The bottom quark is a third-generation quark with a charge of -(1/3)e. ... The Standard Model of Fundamental Particles and Interactions For the Standard Model in Cryptography, see Standard Model (cryptography). ... In particle physics, hadronization is the process of the formation of hadrons out of quarks and gluons. ...

Contents

History

In the years leading up to the top quark discovery, it was realized that certain precision measurements of the electro-weak vector boson masses and couplings are very sensitive to the value of the top quark mass. These effects become much larger for higher values of the top mass and therefore could indirectly see the top quark even if it could not be directly produced in any experiment at the time. The largest effect from the top quark mass was on the T parameter and by 1994 the precision of these indirect measurements had led to a prediction of the top quark mass to be between 145 GeV and 185 GeV. It is the development of techniques that ultimately allowed such precision calculations that led to Gerardus 't Hooft and Martinus Veltman winning the Nobel Prize in physics in 1999. In particle physics, the Peskin-Takeuchi parameters are a set of three measurable quantities, called S, T, and U, that parameterize potential new physics contributions to electroweak radiative corrections. ... Gerard t Hooft at Harvard University Gerardus (Gerard) t Hooft [ut-hooft] (The prefix ’t is pronounced as ‘ut’ and stands for ‘het’) (born July 5, 1946) is a professor in theoretical physics at Utrecht University, The Netherlands. ... Martinus J.G. Veltman (Tini for short) (born June 27, 1931) is a 1999 Nobel Prize in Physics laureate for elucidating the quantum structure of electroweak interactions in physics, work done at Utrecht University, The Netherlands. ... The Nobel Prize (Swedish: ) was established in Alfred Nobels will in 1895, and it was first awarded in Physics, Chemistry, Physiology or Medicine, Literature, and Peace in 1901. ...


After the discovery of the first third-generation quark, an attempt was made to name it "beauty" and the predicted sixth quark "truth"; however, this later gave way to the names bottom and top.


The top quark was discovered in 1995 at Fermilab, whose Tevatron accelerator remains the only particle accelerator energetic enough to produce top quarks (until the LHC at CERN comes on-line in 2008). Year 1995 (MCMXCV) was a common year starting on Sunday. ... Aerial view of the Fermilab site. ... Tevatron is a circular particle accelerator (or synchrotron) at the Fermi National Accelerator Laboratory in Batavia, Illinois. ... Atom Smasher redirects here. ... , The Large Hadron Collider (LHC) is a particle accelerator and Hadron collider located at CERN, near Geneva, Switzerland. ... CERN logo The European Organization for Nuclear Research (French: ), commonly known as CERN (see Naming), pronounced (or in French), is the worlds largest particle physics laboratory, situated just northwest of Geneva on the border between France and Switzerland. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ...


Production and decay

As of 2007, Fermilab's Tevatron is the only place in the world where top quarks can be produced. Tevatron is an accelerator complex which collides protons and antiprotons at center-of-momentum energy of 1.96 TeV. There are two main top-production processes: 2007 is a common year starting on Monday of the Gregorian calendar. ... Aerial view of the Fermilab site. ... Tevatron is a circular particle accelerator (or synchrotron) at the Fermi National Accelerator Laboratory in Batavia, Illinois. ...

  • Pair production via strong interactions. This process was first observed simultaneously by two experimental collaboration at Fermilab, CDF and D0 in 1995.
  • Single production via weak interactions. As of December 2006, a three-sigma evidence has been observed for this production process by the D0 Collaboration at Fermilab.

The top quark is expected to decay to a W boson and a down-type quark (down, strange or bottom). In the standard model, the branching fraction for t→Wq is predicted to be |Vtq|2, where Vtq is an element in the CKM matrix. The predictions for the branching ratios of the top quark are then B(t→Wd)≈0.006%, B(t→Ws)≈0.17% and B(t→Wb)≈99.8%. Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon (or another neutral boson). ... The strong interaction or strong force is today understood to represent the interactions between quarks and gluons as detailed by the theory of quantum chromodynamics (QCD). ... The Collider Detector at Fermilab (CDF) experimental collaboration studies high energy particle collisions at the Tevatron, the world’s highest energy particle accelerator. ... D0 under construction, the installation of the central tracking system D0s control room The D0 experiment consists of a worldwide collaboration of scientists conducting research on the fundamental nature of matter. ... The weak interaction (often called the weak force or sometimes the weak nuclear force) is one of the four fundamental interactions of nature. ... In the standard model of particle physics the Cabibbo-Kobayashi-Maskawa matrix (CKM matrix, quark mixing matrix, sometimes earlier called KM matrix) is a unitary matrix which contains information on the strength of flavour-changing weak decays. ...


Top quark mass and relationship to the Higgs boson

The Standard Model describes fermion masses through the Higgs mechanism. The Higgs boson has a Yukawa coupling to the left- and right-handed top quarks. After electroweak symmetry breaking (when the Higgs acquires a vacuum expectation value), the left- and right-handed components mix, becoming a mass term. This box:      The Higgs mechanism, also called the Brout-Englert-Higgs mechanism, Higgs-Kibble mechanism or Anderson-Higgs mechanism, was proposed in 1964 by Robert Brout and Francois Englert [1], independently by Peter Higgs [2] and by Gerald Guralnik, C. R. Hagen, and Tom Kibble [3] following earlier work by... The Higgs boson, also known as the God particle, is a hypothetical massive scalar elementary particle predicted to exist by the Standard Model of particle physics. ... In particle physics, Yukawa interaction, named after Hideki Yukawa, is an interaction between a scalar field and a Dirac field of the type (scalar) or (pseudoscalar). ...


mathcal{L} = y_t h q u^c rightarrow frac{y_t v}{sqrt{2}}( 1 + h^0/v) u u^c


The top quark Yukawa coupling has a value of y_t = sqrt{2} m_t/v simeq 1, where v=246~{rm GeV} is the value of the Higgs vacuum expectation value.


Yukawa couplings

In the Standard Model, all of the quark and lepton Yukawa couplings are small compared to the top quark Yukawa coupling. Understanding this hierarchy in the fermion masses is an open problem in theoretical physics. Yukawa couplings are not constants and their values change depending on what energy scale (distance scale) at which they are measured. The dynamics of Yukawa couplings are determined by the renormalization group equation. Callan-Symanzik equation exact renormalization group equation Categories: ...


One of the prevailing views in particle physics is that the size of the top quark Yukawa coupling is determined by the renormalization group, leading to the "quasi-infrared fixed point." In theoretical physics, renormalization group (RG) refers to a set of techniques and concepts related to the change of physics with the observation scale. ... In physics, an infrared fixed point is a scale-invariant theory (fixed point) obtained by probing the very long-distance behavior of a quantum field theory or a model of statistical mechanics, as explained in the theory of the renormalization group. ...


The Yukawa couplings of the up, down, charm, strange and bottom quarks, are hypothesized to have small values at the extremely high energy scale of grand unification, 1015 GeV. They increase in value at lower energy scales, at which the quark masses are generated by the Higgs. The slight growth is due to corrections from the QCD coupling. The corrections from the Yukawa couplings are negligible for the lower mass quarks. Quantum chromodynamics (abbreviated as QCD) is the theory of the strong interaction (color force), a fundamental force describing the interactions of the quarks and gluons found in hadrons (such as the proton, neutron or pion). ...


If, however, a quark Yukawa coupling has a large value at very high energies, its Yukawa corrections will evolve and cancel against the QCD corrections. This is known as a (quasi-) infrared fixed point. No matter what the initial starting value of the coupling is, if it is sufficiently large it will reach this fixed point value. The corresponding quark mass is then predicted. In physics, an infrared fixed point is a scale-invariant theory (fixed point) obtained by probing the very long-distance behavior of a quantum field theory or a model of statistical mechanics, as explained in the theory of the renormalization group. ...


The top quark Yukawa coupling lies very near the infrared fixed point of the Standard Model. The renormalization group equation is: In physics, an infrared fixed point is a scale-invariant theory (fixed point) obtained by probing the very long-distance behavior of a quantum field theory or a model of statistical mechanics, as explained in the theory of the renormalization group. ... Callan-Symanzik equation exact renormalization group equation Categories: ...


mu frac{partial}{partialmu} y_t approx frac{y_t}{16pi^2}left(frac{9}{2}y_t^2 - 8 g_3^2- frac{9}{4}g_2^2 - frac{17}{20} g_1^2 right),


where g3 is the color gauge coupling and g2 is the weak isospin gauge coupling. This equation describes how the Yukawa coupling changes with energy scale μ. Solutions to this equation for large initial values yt cause the right-hand side of the equation to quickly approach zero, locking yt to the QCD coupling g3. The value of the fixed point is fairly precisely determined in the Standard Model, leading to a top quark mass of 230  GeV. However, if there is more than one Higgs doublet, the mass value will be reduced by Higgs mixing angle effects in an unpredicted way.


In the minimal supersymmetric extension of the Standard Model (the MSSM), there are two Higgs doublets and the renormalization group equation for the top quark Yukawa coupling is slightly modified: A Minimal Supersymmetric Standard Model is a class of proposed supersymmetric extensions to the Standard Model. ...


mu frac{partial}{partialmu} y_t approx frac{y_t}{16pi^2}left(6y_t^2 +y_b^2- frac{16}{3} g_3^2- 3g_2^2 -frac{13}{15} g_1^2 right),


where yb is the bottom quark Yukawa coupling. This leads to a fixed point where the top mass is smaller, 170–200 GeV. The uncertainty in this prediction arises because the bottom quark Yukawa coupling can be amplified in the MSSM. Some theorists believe this is supporting evidence for the MSSM.


The quasi-infrared fixed point has subsequently formed the basis of top quark condensation theories of electroweak symmetry breaking in which the Higgs boson is composite at extremely short distance scales, composed of a pair of top and anti-top quarks. In physics, an infrared fixed point is a scale-invariant theory (fixed point) obtained by probing the very long-distance behavior of a quantum field theory or a model of statistical mechanics, as explained in the theory of the renormalization group. ...


Properties

  • At the current Tevatron energy of 1.96 TeV, top/anti-top pairs are produced with a cross section of about 7 picobarns. The Standard Model prediction (at next-to-leading order with mt = 175 GeV) is 6.7–7.5 picobarns.
  • Combining measurements from both CDF and D0, the most recent estimation of the top quark mass is 170.9±1.8 GeV/c2.[2]
  • Production of single top quarks through weak vector bosons is predicted in the Standard Model and has a cross section of 0.9 picobarns in the s-channel and 2.0 picobarns in the t-channel. Neither experiment at the Tevatron has observed this process with statistical significance. However, on 8 December 2006, the D0 collaboration announced it had seen evidence for single top production at the 3 sigma level, measuring an s+t channel cross section of 4.9 picobarns.[3] A preprint article submitted to Physical Review Letters is available from the arXiv.org preprint server.[4]
  • The W bosons from top quark decays carry polarization from the parent particle, hence pose themselves as a unique probe to top polarization.
  • In the Standard Model, top quark is predicted to have a spin of ½ and charge ⅔. A first measurement of the top quark charge has been published, resulting in approximately 90% confidence limit that the top quark charge is indeed ⅔.[5]

In nuclear and particle physics, the concept of a cross section is used to express the likelihood of interaction between particles. ... A barn (symbol b) is a unit of area. ... A GEV (or Ground Effect Vehicle) is vehicle that takes advantage of the aerodynamic principle of ground effect (or Wing-in-ground). ... A line showing the speed of light on a scale model of Earth and the Moon, taking about 1â…“ seconds to traverse that distance. ... In theoretical physics, the Mandelstam variables are numerical quantities that encode the energy, momentum, and angles of particles in a scattering process in a Lorentz-invariant fashion. ... In probability and statistics, the standard deviation of a probability distribution, random variable, or population or multiset of values is a measure of the spread of its values. ... Physical Review Letters is one of the most prestigious journals in physics. ... The title given to this article is incorrect due to technical limitations. ...

References

  1. ^ H B Prosper and B Danilov (eds.) Scott Willenbrock (author) (2003). The standard model and the top quark; in Techniques and concepts of high-energy physics XII. Dordrecht: NATO Science Series Vol. 123; Kluwer Academic, Chapter 1. ISBN 1402015909. 
  2. ^ a b A Combination of CDF and D0 Results on the Mass of the Top Quark, arXiv:hep-ex/0703034
  3. ^ Fermilab press release, 13 Dec 2006, DZero finds evidence of rare single top quark
  4. ^ Evidence for production of single top quarks and first direct measurement of |Vtb|, arXiv:hep-ex/0612052
  5. ^ Experimental discrimination between charge 2e/3 top quark and charge 4e/3 exotic quark production scenarios, arXiv:hep-ex/0608044

arXiv (pronounced archive, as if the X were the Greek letter χ) is an archive for electronic preprints of scientific papers in the fields of physics, mathematics, computer science and quantitative biology which can be accessed via the Internet. ... arXiv (pronounced archive, as if the X were the Greek letter χ) is an archive for electronic preprints of scientific papers in the fields of physics, mathematics, computer science and quantitative biology which can be accessed via the Internet. ... arXiv (pronounced archive, as if the X were the Greek letter χ) is an archive for electronic preprints of scientific papers in the fields of physics, mathematics, computer science and quantitative biology which can be accessed via the Internet. ...

External links

Thousands of particles explode from the collision point of two relativistic (100 GeV per nucleon) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... For the novel, see The Elementary Particles. ... In particle physics, fermions are particles with half-integer spin, such as protons and electrons. ... For other uses, see Quark (disambiguation). ... The up quark is a first-generation quark with a charge of +(2/3)e. ... The down quark is a first-generation quark with a charge of -(1/3)e. ... The charm quark is a second-generation quark with a charge of +(2/3)e. ... The strange quark is a second-generation quark with a charge of -(1/3)e and a strangeness of −1. ... The bottom quark is a third-generation quark with a charge of -(1/3)e. ... For the former Greek currency unit, see Greek drachma. ... For other uses, see Electron (disambiguation). ... The first detection of the positron in 1932 by Carl D. Anderson The positron is the antiparticle or the antimatter counterpart of the electron. ... The muon (from the letter mu (μ)--used to represent it) is an elementary particle with negative electric charge and a spin of 1/2. ... The tau lepton (often called the tau, tau particle, or occasionally the tauon, symbol ) is a negatively charged elementary particle with a lifetime of 2. ... For other uses, see Neutrino (disambiguation). ... Antineutrinos, the antiparticles of neutrinos, are neutral particles produced in nuclear beta decay. ... In particle physics, bosons are particles with an integer spin, as opposed to fermions which have half-integer spin. ... Gauge bosons are bosonic particles which act as carriers of the fundamental forces of Nature. ... In modern physics the photon is the elementary particle responsible for electromagnetic phenomena. ... In particle physics, gluons are subatomic particles that cause quarks to interact, and are indirectly responsible for the binding of protons and neutrons together in atomic nuclei. ... In physics, the W and Z bosons are the elementary particles that mediate the weak nuclear force. ... In physics, Faddeev-Popov ghost ci is a field that violates the spin-statistics relation. ... In physics, a bound state is a composite of two or more building blocks (particles or bodies) that behaves as a single object. ... A hadron, in particle physics, is a subatomic particle which experiences the nuclear force. ... Combinations of three u, d or s-quarks with a total spin of 3/2 form the so-called baryon decuplet. ... In particle physics, a hyperon is any subatomic particle which is a baryon (and hence a hadron and a fermion) with non-zero strangeness, but with zero charm and zero bottomness. ... In physics a nucleon is a collective name for two baryons: the neutron and the proton. ... For other uses, see Proton (disambiguation). ... This article or section does not adequately cite its references or sources. ... The Delta baryon is a relatively light 1,232 MeV/c² baryon which contains only up (u) and down (d) quarks in a combination whose total spin is 3/2 and its ground state parity is +. All varieties of Δ quickly decay via the strong force into an ordinary nucleon plus... Properties In particle physics, the omega minus (Ω−) is a type of baryon (more specifically, a hyperon). ... Mesons of spin 1 form a nonet In particle physics, a meson is a strongly interacting boson, that is, it is a hadron with integral spin. ... In high energy physics, a quarkonium (pl. ... In particle physics, pion (short for pi meson) is the collective name for three subatomic particles: π0, π+ and π−. Pions are the lightest mesons and play an important role in explaining low-energy properties of the strong nuclear force. ... In particle physics, Kaons (also called K-mesons and denoted K) are a group of four mesons distinguished by the fact that they carry a quantum number called strangeness. ... In particle physics, a rho meson is a short-lived hadronic particle that is an isospin triplet whose three states are denoted as , and . ... The upsilon particle () is a flavorless meson formed from a bottom quark and its antiparticle. ... The nucleus of an atom is the very small dense region, of positive charge, in its centre consisting of nucleons (protons and neutrons). ... For other uses, see Atom (disambiguation). ... An exotic atom is the anologue of a normal atom in which one or more of the electrons are replaced by other negative particles, such as a muon or a pion, or the positively charged nucleus is replaced by other positively charged elementary particles, or both. ... Positronium (Ps) is a system consisting of an electron and its anti-particle, a positron, bound together into an exotic atom. The orbit of the two particles and the set of energy levels is similar to that of the hydrogen atom (electron and proton). ... A muonium particle is an exotic atom made up of a positive muon and an electron, and is given the symbol Mu or μ+e–. During the muons 2 microsecond lifetime, muonium can enter into compounds such as muonium chloride (MuCl) or sodium muonide (NaMu). ... 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ... This is a list of particles in particle physics, including currently known and hypothetical elementary particles, as well as the composite particles that can be built up from them. ... In supersymmetry, it is proposed that every fermion should have a partner boson, known as its Superpartner. ... The axino is a hypothetical elementary particle predicted by some theories of particle physics. ... In particle physics, chargino refers to a charged superpartner, i. ... 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In theoretical physics, dilaton originally referred to a theoretical scalar field; as a photon refers in one sense to the electromagnetic field. ... This article is about the hypothetical particle. ... The Higgs boson, also known as the God particle, is a hypothetical massive scalar elementary particle predicted to exist by the Standard Model of particle physics. ... A tachyon (from the Greek (takhús), meaning swift, fast) is any hypothetical particle that travels at superluminal velocity. ... In particle physics, the X and Y bosons are hypothetical elementary particles analogous to the W and Z bosons, but corresponding to a new type of force, such as the forces predicted by grand unified theory. ... It has been suggested that this article or section be merged with Z boson. ... In particle physics, a Z boson (or Z-prime boson) refers to a hypothetical new neutral gauge boson (named in analogy with the Standard Model Z boson). ... A sterile particle does not have any charge known to us. ... A regular meson made from a quark (q) and antiquark (q-bar) with spins s2 and s1 respectively and having an overall angular momentum L Exotic hadrons are subatomic particles made of quarks (and possibly gluons), but which do not fit into the usual schema of hadrons. ... Ordinary baryons are bound states of 3 quarks. ... A pentaquark is a subatomic particle consisting of a group of five quarks (compared to three quarks in normal baryons and two in mesons), or more specifically four quarks and one anti-quark. ... Identities and classification of possible tetraquark mesons. ... In particle physics, a glueball is a particle containing no valence quarks. ... A tetraquark is a subatomic particle composed of four quarks. ... A mesonic molecule is a set of two or more mesons bound together by the strong force. ... In physics, a quasiparticle refers to a particle-like entity arising in certain systems of interacting particles. ... Side view of an α-helix of alanine residues in atomic detail. ... This page is about the quasiparticle. ... There is a place named Magnon (pronunciation: ma-nyon) in Gabon, see Magnon, Gabon A magnon is a collective excitation of the electrons spin structure in a crystal lattice. ... Normal modes of vibration progression through a crystal. ... In physics, the plasmon is the quasiparticle resulting from the quantization of plasma oscillations just as photons and phonons are quantizations of light and sound waves, respectively. ... This article is in need of attention. ... In solid-state physics, a polaron is formed when a moving charge (typically an electron or a hole) in a crystal with some ionic character polarizes (by its electric field) the lattice around it. ... This is a list of particles in particle physics, including currently known and hypothetical elementary particles, as well as the composite particles that can be built up from them. ... 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