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Encyclopedia > List of mesons

A list of mesons. In particle physics, a meson is a strongly interacting boson, that is, it is a hadron with integral spin. ...

The various types of meson (not comprehensive)
Particle Symbol Anti-
particle
Quark
Makeup
Spin and parity Rest mass
MeV/c2
S C B Mean lifetime
s
Notes
Charged
Pion
π+ π- $mathrm{u bar{d}}$ Pseudoscalar 139.6 0 0 0 2.60×10-8
Neutral
Pion
π0 Self $mathrm{frac{ubar{u} + d bar{d}}{sqrt{2}}}$ Pseudoscalar 135.0 0 0 0 0.84×10-16 Makeup inexact due to
non-zero quark masses
Charged
Kaon
K+ K- $mathrm{ubar{s}}$ Pseudoscalar 493.7 +1 0 0 1.24×10-8
Neutral
Kaon
K0 $mathrm{bar{K}^0}$ $mathrm{dbar{s}}$ Pseudoscalar 497.7 +1 0 0 weak decay Strong eigenstate - no definite
lifetime (see kaon notes below)
K-Short $mathrm{K_S^0}$ $mathrm{K_S^0}$ $mathrm{frac{dbar{s} - sbar{d}}{sqrt{2}}}$ Pseudoscalar 497.7 (*) 0 0 0.89×10-10 Weak eigenstate - makeup is
missing small CP-violating term
(see kaon notes below)
K-Long $mathrm{K_L^0}$ $mathrm{K_L^0}$ $mathrm{frac{dbar{s} + sbar{d}}{sqrt{2}}}$ Pseudoscalar 497.7 (*) 0 0 5.2×10-8 Weak eigenstate - makeup is
missing small CP-violating term
(see kaon notes below)
Eta η Self $mathrm{frac{ubar{u} + dbar{d} - 2sbar{s}}{sqrt{6}}}$ Pseudoscalar 547.8 0 0 0 5×10-19 Makeup inexact due to
non-zero quark masses
Eta
Prime
η' Self $mathrm{frac{ubar{u} + dbar{d} + sbar{s}}{sqrt{3}}}$ Pseudoscalar 957.6 0 0 0 3×10-21 Makeup inexact due to
non-zero quark masses
Rho ρ+ ρ- $mathrm{ubar{d}}$ Vector 776 0 0 0 0.4×10-23
Phi φ Self $mathrm{sbar{s}}$ Vector 1019 0 0 0 16×10-23
D D+ D- $mathrm{cbar{d}}$ Pseudoscalar 1869 0 +1 0 10.6×10-13
D D0 $mathrm{bar{D^0}}$ $mathrm{cbar{u}}$ Pseudoscalar 1865 0 +1 0 4.1×10-13
Ds $mathrm{D_s^+}$ $mathrm{D_s^-}$ $mathrm{cbar{s}}$ Pseudoscalar 1968 +1 +1 0 4.9×10-13
J/Psi J/ψ Self $mathrm{cbar{c}}$ Vector 3096.9 0 0 0 7.2×10-21 See charmonium
B B+ B- $mathrm{ubar{b}}$ Pseudoscalar 5279 0 0 +1 1.7×10-12
B B0 $mathrm{bar{B^0}}$ $mathrm{dbar{b}}$ Pseudoscalar 5279 0 0 +1 1.5×10-12
Bs $mathrm{B_s^0}$ $mathrm{bar{B}_s^0}$ $mathrm{sbar{b}}$ Pseudoscalar 5369 -1 0 +1 1.46×10-12
Bc $mathrm{B_c^+}$ $mathrm{B_c^-}$ $mathrm{cbar{b}}$ Pseudoscalar 6400 0 +1 +1 5×10-13
Upsilon $Upsilon,$ Self $mathrm{bbar{b}}$ Vector 9460 0 0 0 1.3×10-20 See bottomonium

Quarks are one of the two basic constituents of matter in the Standard Model of particle physics. ... In physics, spin is an intrinsic angular momentum associated with microscopic particles. ... In physics, a parity transformation (also called parity inversion) is the simultaneous flip in the sign of all spatial coordinates: A 3Ã—3 matrix representation of P would have determinant equal to -1, and hence cannot reduce to a rotation. ... The term mass in special relativity is used in a couple of different ways, occasionally leading to a great deal of confusion. ... An electronvolt (symbol: eV) is the amount of energy gained by a single unbound electron when it falls through an electrostatic potential difference of one volt. ... Cherenkov effect in a swimming pool nuclear reactor. ... In particle physics, strangeness is the number of anti-strange quarks minus the number of strange quarks in a particle. ... Charm is the number of charm quarks (c) minus the number of charm anti-quarks () that are present in a particle: This makes charm quark to have a charm of +1 and anti-charm quark to have a charm of −1 (the charm sign agreeing with the quark charge sign). ... In Physics, Bottomness (also formerly called Beauty) quantum number is the number of bottom anti-quarks () minus the number of bottom quarks (b) that are present in a particle: Bottom quarks have a bottomness of −1 and bottom anti-quarks of +1, so the bottomness sign agrees with its charge... Given an assembly of elements, the number of which decreases ultimately to zero, the lifetime (also called the mean lifetime) is a certain number that characterizes the rate of reduction (decay) of the assembly. ... The second (symbol: s) is the SI base unit of time. ... In particle physics, pion (short for the Greek pi meson = P middle) is the collective name for three subatomic particles discovered in 1947: Ï€0, Ï€+ and Ï€âˆ’. Pions are the lightest mesons. ... In mathematics, a pseudoscalar in a geometric algebra is the highest-grade basis element of the algebra. ... 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. ... A list of mesons. ... The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ... In linear algebra, the eigenvectors (from the German eigen meaning inherent, characteristic) of a linear operator are non-zero vectors which, when operated on by the operator, result in a scalar multiple of themselves. ... A list of mesons. ... A list of mesons. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... In linear algebra, the eigenvectors (from the German eigen meaning inherent, characteristic) of a linear operator are non-zero vectors which, when operated on by the operator, result in a scalar multiple of themselves. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... A list of mesons. ... A list of mesons. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... In linear algebra, the eigenvectors (from the German eigen meaning inherent, characteristic) of a linear operator are non-zero vectors which, when operated on by the operator, result in a scalar multiple of themselves. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... A list of mesons. ... A vector boson is a boson with spin equal to one. ... The title given to this article is incorrect due to technical limitations. ... In high energy physics, a charmonium (plural charmonia) is a flavorless meson constituted by a charm quark and an anti-charm quark. ... The upsilon particle () is a flavorless meson formed from a bottom quark and its antiparticle. ... In high energy physics, a bottomonium is any of the flavorless, heavy mesons that are composed by a bottom quark and an anti-bottom quark. ...

## Notes on neutral kaons GA_googleFillSlot("encyclopedia_square");

There are two complications with neutral kaons: Some things which can be neutral are: Neutral country, in politics, a country takes no side in a conflict. ... 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. ...

1. Due to neutral kaon mixing, the $mathrm{K_S^0}$ and $mathrm{K_L^0}$ are not eigenstates of strangeness. However, they are eigenstates of the weak force, which determines how they decay, so these are the particles with definite lifetime.
2. Furthermore, the linear combinations given in the table for the $mathrm{K_S^0}$ and $mathrm{K_L^0}$ are not exactly correct, since there is a small correction due to CP violation. See CP violation in kaons.

Note that these issues also exist in principle for other neutral flavored mesons; however, the weak eigenstates are considered separate particles only for kaons because of their dramatically different lifetimes. 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 linear algebra, the eigenvectors (from the German eigen meaning inherent, characteristic) of a linear operator are non-zero vectors which, when operated on by the operator, result in a scalar multiple of themselves. ... In particle physics, strangeness is the number of anti-strange quarks minus the number of strange quarks in a particle. ... The weak nuclear force or weak interaction is one of the four fundamental forces of nature. ... Radioactive decay is the set of various processes by which unstable atomic nuclei (nuclides) emit subatomic particles (radiation). ... Given an assembly of elements, the number of which decreases ultimately to zero, the lifetime (also called the mean lifetime) is a certain number that characterizes the rate of reduction (decay) of the assembly. ... In mathematics, linear combinations are a concept central to linear algebra and related fields of mathematics. ... CP-symmetry is a symmetry obtained by a combination of the C-symmetry and the P-symmetry. ... 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. ... Flavour (or flavor) is a quantum number of elementary particles related to their weak interactions. ...

• Complete meson info from Particle Data Group

## Reference

• Griffiths, David J. (1998). Introduction to Electrodynamics (3rd ed.), Prentice Hall. ISBN 013805326X.

Results from FactBites:

 List of particles - Wikipedia, the free encyclopedia (1344 words) 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. Ordinary mesons (bosons) contain a valence quark and a valence antiquark, and include the pion, kaon, the J/ψ, and many other types of mesons. In quantum hadrodynamic models, the strong force between nucleons is mediated by mesons.
More results at FactBites »

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