List of particles

List of particles
This article includes a list of the different types of atomic- and sub-atomicparticles found or hypothesized to exist in the whole of the
universe categorized by type. Properties of the various particles listed are also given, as well as the laws that the particles follow. For
individual lists of the different particles, see the list below.
Elementary particles
Fermions
Quarks
Leptons
Bosons
Hypothetical particles
Composite particles
Hadrons
Baryons
Mesons
Atomic nuclei
Atoms
Molecules
Condensed matter
Other
Classification by speed
See also
References
Elementaryparticles are particles with no measurableinternal structure; that is, they are not composed of other particles. They are the
fundamental objects of quantum field theory. Many families and sub-families of elementary particles exist. Elementary particles are
classified according to their spin. Fermions have half-integer spin while bosons have integer spin. All the particles of the Standard
Model have been experimentally observed, recently including theHiggs boson.[1][2]
Fermions are one of the two fundamentalclasses of particles, the other being bosons. Fermion particles are described by Fermi–Dirac
statistics and have quantum numbersdescribed by the Pauli exclusion principle. They include the quarks and leptons, as well as any
composite particles consisting of an odd number of these, such as allbaryons and many atoms and nuclei.
Fermions have half-integer spin; for all known elementary fermions this is 1⁄2. All known fermions, except neutrinos, are also Dirac
fermions; that is, each known fermion has its own distinct antiparticle. It is not known whether the neutrino is a Dirac fermion or a
Majorana fermion.[3] Fermions are the basic building blocks of all matter. They are classified according to whether they interact via
the color forceor not. In the Standard Model, there are 12 types of elementary fermions: sixquarks and six leptons.
Contents
Elementary particles
Fermions

Quarks are the fundamental constituents of hadrons and interact via the strong interaction. Quarks are the only known carriers of
fractional charge, but because they combine in groups of three (baryons) or in pairs of one quark and one antiquark (mesons), only
integer charge is observed in nature. Their respective antiparticles are the antiquarks, which are identical except that they carry the
opposite electric charge (for example the up quark carries charge +2⁄3, while the up antiquark carries charge −2⁄3), color charge, and
baryon number. There are six flavors of quarks; the three positively charged quarks are called "up-type quarks" and the three
negatively charged quarks are called "down-typequarks".
Quarks
Name Symbol Antiparticle
Charge
(e)
Mass (MeV/c2) [4] Spin
up u u +2⁄3 2.2
+0.6
−0.4
½
down d d −1⁄3 4.6
+0.5
−0.4
½
charm c c +2⁄3 1280±30 ½
strange s s −1⁄3 96
+8
−4
½
top t t +2⁄3 173,100±600 ½
bottom b b −1⁄3 4,180
+40
−30
½
Leptons do not interact via the strong interaction. Their respective antiparticlesare the antileptons which are identical, except for the
fact that they carry the opposite electric charge and lepton number. The antiparticle of an electron is an antielectron, which is nearly
always called a "positron" for historical reasons. There are six leptons in total; the three charged leptons are called "electron-like
leptons", while the neutral leptons are called "neutrinos". Neutrinos are known to oscillate, so that neutrinos of definite flavor do not
have definite mass, rather they exist in a superposition of mass eigenstates. The hypothetical heavy right-handed neutrino, called a
"sterile neutrino", has been left off the list.
Leptons
Charge
(e)
Mass (MeV/c2) [4]
Electron e
−
e
+
−1 0.511[note 1]
Electron neutrino νe νe
0 < 0.0000022
Muon μ
−
μ
+
−1 105.7[note 2]
Muon neutrino νμ νμ
0 < 0.170
Tau τ
−
τ
+
−1 1,776.86±0.12
Tau neutrino ντ ντ
0 < 15.5
1. The electron mass is known very precisely as 0.5109989461±0.0000000031 MeV
2. The muon mass is known very precisely as 105.6583745±0.0000024 MeV
Bosons are one of the two fundamental classes of particles, the other being fermions. Bosons are characterized by Bose–Einstein
statistics and all have integer spins. Bosons may be either elementary, like photons and gluons, or composite, likemesons.
Quarks
Leptons
Bosons

According to theStandard Modelthe elementary bosons are:
Charge
(e)
Spin
Mass (GeV/c2)
[4]
Interaction
mediated
Existence
Photon γ Self 0 1 0 Electromagnetism Confirmed
W boson W
−
W
+ −1 1 80.385±0.015 Weak interaction Confirmed
Z boson Z Self 0 1 91.1875±0.0021 Weak interaction Confirmed
Gluon g Self 0 1 0 Strong interaction Confirmed
Higgs
boson H
0 Self 0 0 125.09±0.24 Mass Confirmed
Graviton G Self 0 2 0 Gravitation Unconfirmed
Elementary bosons responsible for the four fundamental forcesof nature are called force particles(gauge bosons). Strong interaction
is mediated by the gluon, weak interaction is mediated by the W and Z bosons, and it is sometimes hypothetized that gravitation is
mediated by thegraviton, although it is not predicted by the Standard Modelbut by other theories in the framework of quantum field
theory.
The Higgs bosonis postulated by the electroweak theoryprimarily to explain the origin of particle masses. In a process known as the
"Higgs mechanism", the Higgs boson and the other gauge bosons in the Standard Model acquire mass via spontaneous symmetry
breaking of the SU(2) gauge symmetry. The Minimal Supersymmetric Standard Model (MSSM) predicts several Higgs bosons. A
new particle expected to be the Higgs boson was observed at the CERN/LHC on March 14, 2013, around the energy of 126.5 GeV
with an accuracy of close to five sigma (99.9999%, which is accepted as definitive). The Higgs mechanism giving mass to other
particles has not been observed yet.
Supersymmetrictheories predict the existence of more particles, none of which have been confirmed experimentally as of 2017:
Hypothetical particles

Superpartners (Sparticles)
Superpartner
Superpartner
of
Spin Notes
neutralino
neutral
bosons
1⁄2
The neutralinos aresuperpositionsof the superpartnersof neutral Standard
Model bosons: neutralHiggs boson, Z boson and photon.
The lightest neutralino is a leading candidate fordark matter.
The MSSM predicts four neutralinos.
chargino
charged
bosons
1⁄2
The charginos aresuperpositionsof the superpartnersof charged Standard
Model bosons: chargedHiggs bosonand W boson.
The MSSM predicts two pairs of charginos.
photino photon 1⁄2 Mixing with zino and neutral Higgsinos for neutralinos.
wino, zino W± and Z0
bosons
1⁄2
The charged wino mixing with the charged Higgsino for charginos, for the
zino see line above.
Higgsino Higgs boson 0
For supersymmetry there is a need for several Higgs bosons, neutral and
charged, according with their superpartners.
gluino gluon 1⁄2 Eight gluons and eight gluinos.
gravitino graviton 3⁄2
Predicted bysupergravity(SUGRA). The graviton is hypothetical, too – see
next table.
sleptons leptons 0 The superpartners of the leptons (electron, muon, tau) and the neutrinos.
sneutrino neutrino 0
Introduced by many extensions of the Standard Supermodel, and may be
needed to explain theLSND results.
A special role has the sterile sneutrino, the supersymmetric counterpart of
the hypothetical right-handed neutrino, called the "sterile neutrino".
squarks quarks 0
The stop squark (superpartnerof the top quark) is thought to have a low
mass and is often the subject of experimental searches.
Note: just as the photon, Z boson and W± bosons are superpositionsof the B0, W0, W1, and W2 fields – the photino, zino, and wino±
are superpositions of the bino0, wino0, wino1, and wino2 by definition.
No matter if one uses the original gauginos or this superpositionsas a basis, the only predicted physical particles are neutralinos and
charginos as a superposition of them together withthe Higgsinos.
Other theories predict the existence of additional bosons:

Other hypothetical bosons and fermions
Name Spin Notes
graviton 2 Has been proposed to mediate gravity in theories ofquantum gravity.
dual graviton 2
Has been hypothesized as dual ofgraviton under electric-magnetic dualityin
supergravity.
graviscalar 0 Also known as "radion".
graviphoton 1 Also known as "gravivector".[5]
axion 0
A pseudoscalar particle introduced inPeccei–Quinn theoryto solve thestrong-CP
problem.
axino 1⁄2
Superpartner of the axion. Forms, together with the saxion and axion, asupermultiplet
in supersymmetric extensions of Peccei–Quinn theory.
saxion 0
branon ? Predicted inbrane worldmodels.
dilaton 0 Predicted in some string theories.
dilatino 1⁄2 Superpartner of the dilaton.
X and Y
bosons
1
These leptoquarksare predicted byGUT theoriesto be heavier equivalents of the W
and Z.
W' and Z'
bosons
1
magnetic
photon
?
A. Salam (1966). "Magnetic monopole and two photon theories of C-violation." Physics
Letters 22 (5): 683–684.
majoron 0 Predicted to understandneutrino masses by theseesaw mechanism.
majorana
fermion
1⁄2 ;
3⁄2 ?...
gluino, neutralino, or other – is its ownantiparticle.
chameleon 0
a possible candidate fordark energyand dark matter, and may contribute tocosmic
inflation.
Mirror particlesare predicted by theories that restoreparity symmetry.
"Magnetic monopole" is a generic name for particles with non-zero magnetic charge. They are predicted by some GUTs.
"Tachyon" is a generic name for hypothetical particles that travel faster than the speed of light (and so paradoxically experience time
in reverse due to inversal ofTheory of relativity) and have animaginaryrest mass.
Preons were suggested as subparticles of quarks and leptons, but moderncollider experiments have all but ruled out their existence.
Kaluza–Klein towersof particles are predicted by some models of extra dimensions.The extra-dimensionalmomentumis manifested
as extra mass in four-dimensional spacetime.
Hadrons are defined asstrongly interactingcomposite particles. Hadrons are either:
Composite fermions (especially 3 quarks), in which case they are calledbaryons.
Composite bosons (especially 2 quarks), in which case they are calledmesons.
Composite particles
Hadrons

Quark models, first proposed in 1964 independently by Murray Gell-Mannand George Zweig (who called quarks "aces"), describe
the known hadrons as composed of valence quarks and/or antiquarks, tightly bound by the color force, which is mediated by gluons.
A "sea" of virtual quark-antiquark pairs is also present in each hadron.
Ordinary baryons (composite fermions) contain three valence quarks or three
valence antiquarks each.
Nucleons are the fermionic constituents of normal atomic nuclei:
Protons, composed of two up and one down quark (uud)
Neutrons, composed of two down and one up quark (ddu)
Hyperons, such as the Λ, Σ, Ξ, and Ω particles, which contain one or
more strange quarks, are short-lived and heavier than nucleons.
Although not normally present in atomic nuclei, they can appear in short-
lived hypernuclei.
A number ofcharmed and bottom baryons have also been observed.
Pentaquarksconsist of four valence quarks and one valence antiquark.
Other exotic baryonsmay also exist.
Ordinary mesons are made up of a valence quark and a valence antiquark. Because
mesons have spin of 0 or 1 and are not themselves elementary particles, they are
"composite" bosons. Examples of mesons include the pion, kaon, and the J/ψ. In
quantum hydrodynamic models, mesons mediate the residual strong force between
nucleons.
At one time or another, positive signatures have been reported for all of the following
exotic mesonsbut their existences have yet to be confirmed.
A tetraquark consists of two valence quarks and two valence antiquarks;
A glueball is a bound state of gluons with no valence quarks;
Hybrid mesons consist of one or more valence quark-antiquark pairs and
one or more real gluons.
Atomic nuclei consist of protons and neutrons. Each type of nucleus contains a
specific number of protons and a specific number of neutrons, and is called a
"nuclide" or "isotope". Nuclear reactions can change one nuclide into another. See
table of nuclidesfor a complete list of isotopes.
Atoms are the smallest neutral particles into which matter can be divided by
chemical reactions. An atom consists of a small, heavy nucleus surrounded by a
relatively large, light cloud of electrons. Each type of atom correspondsto a specific
chemical element. To date, 118 elements have been discovered or created.
The atomic nucleus consists of protons and neutrons. Protons and neutrons are, in turn, made ofquarks.
Baryons
A combination of three u, d or s-
quarks with a total spin of3⁄2 form the
so-called "baryon decuplet".
Proton quark structure: 2 up
quarks and 1 down quark. The
gluon tubes or flux tubes are now
known to be Y shaped.
Mesons
Mesons of spin 0 form a nonet
Atomic nuclei
Atoms
Molecules

Molecules are the smallest particles into which a non-elemental
substance can be divided while maintaining the physical properties of
the substance. Each type of molecule corresponds to a specific
chemical compound. Molecules are a composite of two or more
atoms. See list of compounds for a list of molecules. A molecule is
generally combined in a fixed proportion. It is the most basic unit of
matter and is homogenous.
The field equations of condensed matter physics are remarkably
similar to those of high energy particle physics. As a result, much of
the theory of particle physics applies to condensed matter physics as
well; in particular, there are a selection of field excitations, called
quasi-particles, that can be created and explored. These include:
Phonons are vibrational modes in acrystal lattice.
Excitons are bound states of anelectron and a hole.
Plasmons are coherent excitations of aplasma.
Polaritons are mixtures ofphotons with other quasi-
particles.
Polarons are moving, charged (quasi-) particles that are surrounded by ions in a material.
Magnons are coherent excitations of electron spins in a material.
An anyon is a generalization of fermion and boson in two-dimensional systems like sheets ofgraphene that obeys
braid statistics.
A plekton is a theoretical kind of particle discussed as a generalization of the braid statistics of the anyon to
dimension > 2.
A WIMP (weakly interacting massive particle) is any one of a number of particles that might explaindark matter
(such as theneutralino or the axion).
The pomeron, used to explain theelastic scatteringof hadrons and the location ofRegge polesin Regge theory.
The skyrmion, a topological solution of thepion field, used to model the low-energy properties of thenucleon, such
as the axial vector current coupling and the mass.
A genon is a particle existing in a closedtimelike world line where spacetime is curled as in aFrank Tipler or Ronald
Mallett time machine.
A goldstone bosonis a massless excitation of a field that has beenspontaneously broken. The pions are quasi-
goldstone bosons (quasi- because they are not exactly massless) of the brokenchiral isospin symmetry ofquantum
chromodynamics.
A goldstino is a goldstonefermion produced by the spontaneous breaking ofsupersymmetry.
An instanton is a field configuration which is a local minimum of the Euclidean action. Instantons are used in
nonperturbative calculations of tunneling rates.
A dyon is a hypothetical particle with both electric and magnetic charges.
A geon is an electromagnetic or gravitational wave which is held together in a confined region by the gravitational
attraction of its own field of energy.
An inflaton is the generic name for an unidentified scalar particle responsible for thecosmic inflation.
A spurion is the name given to a "particle" inserted mathematically into an isospin-violating decay in order to analyze
it as though it conserved isospin.
What is called"true muonium", a bound stateof a muon and an antimuon, is a theoretical exotic atom which has
never been observed.
A diphoton A resonance particle formed from two identical photons.
An ion (a charged atom or molecule) is either an anion or a cation.
A semi-accuratedepiction of thehelium atom. In
the nucleus, the protons are in red and neutrons
are in purple. In reality, the nucleus is also
spherically symmetrical.
Condensed matter
Other
Classification by speed

A tardyon or bradyontravels slower than light and has a non-zero rest mass.
A luxon travels at the speed of light and has no rest mass.
A tachyon (mentioned above) is a hypothetical particle that travels faster than the speed of light and has an
imaginary rest mass.
Acceleron
List of baryons
List of compoundsfor a list of molecules.
List of fictional elements, materials, isotopes and atomic particles
List of mesons
Periodic tablefor an overview of atoms.
Standard Modelfor the current theory of these particles.
Table of nuclides
Timeline of particle discoveries
1. Khachatryan, V.; et al. (CMS Collaboration) (2012). "Observation of a new boson at a mass of 125 GeV with the
CMS experiment at the LHC".Physics Letters B. 716 (2012): 30.arXiv:1207.7235 (https://arxiv.org/abs/1207.7235)
. Bibcode:2012PhLB..716...30C(http://adsabs.harvard.edu/abs/2012PhLB..716...30C).
doi:10.1016/j.physletb.2012.08.021(https://doi.org/10.1016%2Fj.physletb.2012.08.021).
2. Abajyan, T.; et al. (ATLAS Collaboration) (2012). "Observation of a new particle in the search for the Standard Model
Higgs boson with the ATLAS detector at the LHC". Physics Letters B. 716 (2012): 1–29.arXiv:1207.7214 (https://arxi
v.org/abs/1207.7214) . Bibcode:2012PhLB..716....1A(http://adsabs.harvard.edu/abs/2012PhLB..716....1A).
doi:10.1016/j.physletb.2012.08.020(https://doi.org/10.1016%2Fj.physletb.2012.08.020).
3. Kayser, Boris (2010). "Two Questions About Neutrinos".arXiv:1012.4469 (https://arxiv.org/abs/1012.4469) [hep-ph
(https://arxiv.org/archive/hep-ph)].
4. Particle Data Group (2016). "Review of Particle Physics".Chinese Physics C. 40: 100001.
5. Maartens, R. (2004)."Brane-World Gravity"(http://www.emis.de/journals/LRG/Articles/lrr-2004-7/download/lrr-2004-
7BW.pdf) (PDF). Living Reviews in Relativity. 7: 7. arXiv:gr-qc/0312059(https://arxiv.org/abs/gr-qc/0312059) .
Bibcode:2004LRR.....7....7M(http://adsabs.harvard.edu/abs/2004LRR.....7....7M). doi:10.12942/lrr-2004-7(https://do
i.org/10.12942%2Flrr-2004-7).
Retrieved from "https://en.wikipedia.org/w/index.php?title=List_of_particles&oldid=806501013"
This page was last edited on 22 October 2017, at 12:45.
Text is available under theCreative Commons Attribution-ShareAlike License; additional terms may apply. By using this
site, you agree to theTerms of Useand Privacy Policy. Wikipedia® is a registered trademark of theWikimedia
Foundation, Inc., a non-profit organization.
See also
References

List of particles

More Related Content

What's hot (20)

Similar to List of particles (20)

Recently uploaded (20)

List of particles