Mesons
| K0 |
| K+ |
| π− |
| π0 |
| π+ |
| K− |
| K0 |
| D+ s |
| D0 |
| D+ |
| D− |
| D0 |
| D− s |
| B0 s |
| B− |
| B0 |
| B− c |
| B0 |
| B+ |
| B0 s |
| B+ c |
| η |
| η′ |
| η c |
| η b |
| K0 S |
| K0 L |
| pseudo- scalar (spin-0) mesons |
| vector (spin-1) mesons |
| (anti) quarks in mesons |
| mass |
| spin |
| charge |
| isospin |
| strangeness |
| charm |
| bottomness |
| topness |
| what's the pattern? |
| what about the bottom row? |
| what's missing? |
| what's the significance of spin? |
Notes
This representation of 52 mesons shows some of the weirder particles in the universe
Mesons are particles made up of one quark and one antiquark. None of the mesons forms part of our common picture of the atom, though the pion, Kaon and J/ψ are involved in the strong force between protons and neutrons in the nucleus.
The mesons shown represent every possible combination of down, up, strange, charm and bottom quarks and antiquarks (though some mesons represent superpositions of such combinations). Mesons that contain top quarks are not shown, because these have such high mass that it is difficult to create them in particle accelerators.
Every inch of this visualization is active. Move your mouse over a meson to show its name, properties and further information. Move your mouse over a page tab to show more mesons, or which quarks and antiquarks comprise each meson. Or move your mouse over a property to show the value of that property for each of the mesons. Click on a control to hold it down, then click elsewhere to release it.
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More
This is one of a series of visualizations of what things are made of, from elementary particles to organic molecules…
Mesons – this page
…check back soon for the next in the series
Latest things made thinkable
Sources
Introductory Nuclear Physics by Kenneth S. Krane
Text
A text summary of this presentation is shown below for easy reference
Particles
up quark
charm quark
top quark
up antiquark
charm antiquark
top antiquark
down quark
strange quark
bottom quark
down antiquark
strange antiquark
bottom antiquark
Kaon K0
this Kaon consists of a down quark and a strange antiquark (d and s)
Kaon K+
this Kaon consists of an up quark and a strange antiquark (u and s)
pion π−
this pion consists of a down quark and an up antiquark (d and u)
pion π0
this pion is a superposition of an up quark and antiquark (u and u) and a down quark and antiquark (d and d)
pion π+
this pion consists of an up quark and a down antiquark (u and d)
Kaon K−
this Kaon consists of a strange quark and an up antiquark (s and u)
Kaon K0
this Kaon consists of a strange quark and a down antiquark (s and d)
strange D meson D+
s
this strange D meson consists of a charm quark and a strange antiquark (c and s)
D meson D0
this D meson consists of a charm quark and an up antiquark (c and u)
D meson D+
this D meson consists of a charm quark and a down antiquark (c and d)
D meson D−
this D meson consists of a down quark and a charm antiquark (d and c)
D meson D0
this D meson consists of an up quark and a charm antiquark (u and c)
strange D meson D−
s
this strange D meson consists of a strange quark and a charm antiquark (s and c)
strange B meson B0
s
this strange B meson consists of a bottom quark and a strange antiquark (b and s)
B meson B−
this B meson consists of a bottom quark and an up antiquark (b and u)
B meson B0
this B meson consists of a bottom quark and a down antiquark (b and d)
charmed B meson B−
c
this charmed B meson consists of a bottom quark and a charm antiquark (b and c)
B meson B0
this B meson consists of a down quark and a bottom antiquark (d and b)
B meson B+
this B meson consists of an up quark and a bottom antiquark (u and b)
strange B meson B0
s
this strange B meson consists of a strange quark and a bottom antiquark (s and b)
charmed B meson B+
c
this charmed B meson consists of a charm quark and a bottom antiquark (c and b)
eta meson η
this eta meson is a superposition of an up quark and antiquark (u and u), a down quark and antiquark (d and d) and a strange quark and antiquark (s and s)
eta prime meson η′
this eta prime meson is a superposition of an up quark and antiquark (u and u), a down quark and antiquark (d and d) and a strange quark and antiquark (s and s)
charmed eta meson η
c
this charmed eta meson consists of a charm quark and a charm antiquark (c and c)
bottom eta meson η
b
this bottom eta meson consists of a bottom quark and a bottom antiquark (b and b)
K-Short K0
S
this K-Short is a superposition of a down quark and strange antiquark (d and s) and a strange quark and down antiquark (s and d)
K-Long K0
L
this K-Long is a superposition of a down quark and strange antiquark (d and s) and a strange quark and down antiquark (s and d)
Kaon K∗0
this Kaon consists of a down quark and a strange antiquark (d and s)
Kaon K∗+
this Kaon consists of an up quark and a strange antiquark (u and s)
charged rho meson ρ−
this charged rho meson consists of a down quark and an up antiquark (d and u)
neutral rho meson ρ0
this neutral rho meson is a superposition of an up quark and antiquark (u and u) and a down quark and antiquark (d and d)
charged rho meson ρ+
this charged rho meson consists of an up quark and a down antiquark (u and d)
Kaon K∗−
this Kaon consists of a strange quark and an up antiquark (s and u)
Kaon K∗0
this Kaon consists of a strange quark and a down antiquark (s and d)
strange D meson D∗+
s
this strange D meson consists of a charm quark and a strange antiquark (c and s)
D meson D∗0
this D meson consists of a charm quark and an up antiquark (c and u)
D meson D∗+
this D meson consists of a charm quark and a down antiquark (c and d)
D meson D∗−
this D meson consists of a down quark and a charm antiquark (d and c)
D meson D∗0
this D meson consists of an up quark and a charm antiquark (u and c)
strange D meson D∗−
s
this strange D meson consists of a strange quark and a charm antiquark (s and c)
strange B meson B∗0
s
this strange B meson consists of a bottom quark and a strange antiquark (b and s)
B meson B∗−
this B meson consists of a bottom quark and an up antiquark (b and u)
B meson B∗0
this B meson consists of a bottom quark and a down antiquark (b and d)
charmed B meson B∗−
c
this charmed B meson consists of a bottom quark and a charm antiquark (b and c)
B meson B∗0
this B meson consists of a down quark and a bottom antiquark (d and b)
B meson B∗+
this B meson consists of an up quark and a bottom antiquark (u and b)
strange B meson B∗0
s
this strange B meson consists of a strange quark and a bottom antiquark (s and b)
charmed B meson B∗+
c
this charmed B meson consists of a charm quark and a bottom antiquark (c and b)
omega meson ω
this omega meson is a superposition of an up quark and antiquark (u and u) and a down quark and antiquark (d and d)
phi meson φ
this phi meson consists of a strange quark and a strange antiquark (s and s)
J/psi J/ψ
this J/psi consists of a charm quark and a charm antiquark (c and c)
Upsilon meson Υ
this Upsilon meson consists of a bottom quark and a bottom antiquark (b and b)
Information
what's the pattern?
the mesons are arranged according to flavours of their constituent quarks and antiquarks; mesons containing only d, u and s quarks and antiquarks form the central hexagon; mesons containing a c quark or antiquark are shown to the right and left; mesons containing a b quark or antiquark are shown below and above; see what about the bottom row? below for more
what about the bottom row?
some mesons contain a quark and its own antiquark (e.g. the φ meson contains an s quark and an s antiquark), or a superposition of such states (e.g. the η meson is a combination of a u u, a d d and an s s); because all these mesons have a neutral flavour (as much s as s, etc.), they all belong at the centre of the central hexagon, but since there's no room for them all there, they are shown in a row at the bottom
what's missing?
mesons that contain top quarks are not shown, because these have such high mass that it is difficult to create them in particle accelerators
what's the significance of spin?
all mesons have integer spin (pseudoscalar mesons spin 0, vector mesons spin 1); in other words, all mesons are bosons, not subject to the exclusion principle, which means that there is no limit to the number of mesons you can squeeze into a small space; this is what allows the pion, Kaon and J/ψ to be involved in the strong nuclear force
Date
First published 31 March 2011
Comments
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Guy Pitman ⋅ 27 June 2014
VERY NICE-
The Isospin is not right though!
Mark Jeffery ⋅ 27 June 2014
Thanks for challenging the isospins, Guy! I took these values from the Wikipedia – List of mesons article. I've just double-checked, and my isospins match those in the article. So if these values are wrong, maybe you could edit the Wikipedia article to correct it? If the Wikipedia community agrees, I'll update this presentation accordingly. I appreciate your diligence!
Chris Bishop ⋅ 30 December 2014
It is not a matter of updating the Wikipedia List of mesons article. Instead, check out the Wikipedia isospin article. The more interesting parameter is I3, the isospin projection, which varies along the "x" axis of the central octet. Isospin (as opposed to the isospin projection) strips the sign and reports only the largest value for the row.
By the way, it's awesome that you put this together! I was trying to write down the organization myself, and you saved me at least some of the trouble.
Yuri ⋅ 16 November 2016
There is accidentally open the phenomenon
Masses of pseudoscalar mesons have symmetric position around mass of proton as undertones and overtones..
Tangensoide like musical instrument ...
Can this direction of research open new horizons in particle physics this puzzling phenomenon?
Don't forget that mass of proton really is unit all atoms of the Universe and equal to=1
Thank you for comment.
DIOMEDES ABCMNXYZ ⋅ 12 February 2018
~ How about the Chi mesons? I don't see them listed.
Mark Jeffery ⋅ 12 February 2018
Good question. The reason for the missing chi mesons is the lack of reliable information about their properties. Chi mesons do appear in the Summary table of the Wikipedia – List of mesons article, but with the disclaimer:
Because this table was initially derived from published results and many of those results were preliminary, as many as 64 of the mesons in the following table may not exist or have the wrong mass or quantum numbers.
Unfortunately, they don't appear in the Meson properties section, from which I pulled the data for this visualization. That's not to say there's not plenty of evidence for their existence: see Double-diffractive chi meson production at the hadron colliders and, more recently, Production of χb-mesons at LHC.