List of mesons

[[File:Kaon-Decay.svg|thumb|300px| The decay of a kaon (Template:Subatomic particle) into three pions (2 Template:Subatomic particle, 1 Template:Subatomic particle) is a process that involves both weak and strong interactions.

Weak interactions: The strange antiquark (Template:Subatomic particle) of the kaon transmutes into an up antiquark (Template:Subatomic particle) by the emission of a [[W and Z bosons|Template:Subatomic particle boson]]; the Template:Subatomic particle boson subsequently decays into a down antiquark (Template:Subatomic particle) and an up quark (Template:Subatomic particle).

Strong interactions: An up quark (Template:Subatomic particle) emits a gluon (Template:Subatomic particle) which decays into a down quark (Template:Subatomic particle) and a down antiquark (Template:Subatomic particle).]]

This list is of all known and predicted scalar, pseudoscalar and vector mesons. See list of particles for a more detailed list of particles found in particle physics.

This article contains a list of mesons, unstable subatomic particles composed of one quark and one antiquark. They are part of the hadron particle family—particles made of quarks. The other members of the hadron family are the baryons—subatomic particles composed of three quarks. The main difference between mesons and baryons is that mesons have integer spin (thus are bosons) while baryons are fermions (half-integer spin). Because mesons are bosons, the Pauli exclusion principle does not apply to them. Because of this, they can act as force mediating particles on short distances, and thus play a part in processes such as the nuclear interaction.

Since mesons are composed of quarks, they participate in both the weak and strong interactions. Mesons with net electric charge also participate in the electromagnetic interaction. They are classified according to their quark content, total angular momentum, parity, and various other properties such as C-parity and G-parity. While no meson is stable, those of lower mass are nonetheless more stable than the most massive mesons, and are easier to observe and study in particle accelerators or in cosmic ray experiments. They are also typically less massive than baryons, meaning that they are more easily produced in experiments, and will exhibit higher-energy phenomena sooner than baryons would. For example, the charm quark was first seen in the J/Psi meson (Template:Subatomic particle) in 1974, and the bottom quark in the upsilon meson (Template:Subatomic particle) in 1977. The top quark (the last and heaviest quark to be discovered to date) was first observed at Fermilab in 1995.

Each meson has a corresponding antiparticle (antimeson) where quarks are replaced by their corresponding antiquarks and vice versa. For example, a positive pion (Template:Subatomic particle) is made of one up quark and one down antiquark; and its corresponding antiparticle, the negative pion (Template:Subatomic particle), is made of one up antiquark and one down quark. Although tetraquarks with two quarks and two antiquarks can be considered mesons they are not listed here.

The symbols encountered in these lists are: P (parity), C (C-parity), G (G-parity), u (up quark), d (down quark), s (strange quark), c (charm quark), b (bottom quark), I (isospin), J (total angular momentum), Q (charge), B (baryon number), S (strangeness), C (charm), and B′ (bottomness), as well as a wide array of subatomic particles (hover mouse for name).

Summary table

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.

Meson summary table

Light unflavoured (S = C = B = 0)				Strange (S = ±1, C = B = 0)		Charmed, strange (C = S = ±1)		cc
	Template:ItcoG(Template:ItcoPC)		Template:ItcoG(Template:ItcoPC)		I(Template:ItcoP)		Template:Itco(Template:ItcoP)		Template:ItcoG(Template:ItcoPC)
π	1−(0−)	Φ(1680)	0−(1−−)	K	Template:Sfrac(0−)	D	0(0−)	η(1S)	0+(0−+)
π	1−(0−+)	ρ(1690)	1+(3−−)	K	Template:Sfrac(0−)	D	0(1−)	J/ψ(1S)	0−(1−−)
η	0+(0−+)	ρ(1700)	1+(1−−)	K	Template:Sfrac(0−)	D(2317)±	0(0+)	χ(1P)	0+(0++)
f(500)	0+(0++)	a(1700)	1−(2++)	K	Template:Sfrac(0−)	D(2460)±	0(1+)	χ(1P)	0+(1++)
ρ(770)	1+(1−−)	f0(1710)	0+(0++)	K(800)	Template:Sfrac(0+)	D(2536)±	0(1+)	h(1P)	0−(1+−)
ω(782)	0−(1−−)	η(1760)	0+(0−+)	K(892)	Template:Sfrac(1−)	D(2573)	0(2+)	χ(1P)	0+(2++)
η′ (958)	0+(0−+)	π(1800)	1−(0−+)	K(1270)	Template:Sfrac(1+)	D(2700)±	0(1−)	η(2S)	0+(0−+)
f(980)	0+(0++)	f(1810)	0+(2++)	K(1400)	Template:Sfrac(1+)	D(2860)±	0(3−)	ψ(2S)	0−(1−−)
a(980)	1−(0++)	X(1835)	0+(0−+)	K(1410)	Template:Sfrac(1−)	D(3040)±	0(??)	ψ(3770)	0−(1−−)
φ(1020)	0−(1−−)	φ(1850)	0−(3−−)	K(1430)	Template:Sfrac(0+)	Bottom (B = ±1)		ψ(3823)	0−(2−−)
h(1170)	0−(1+−)	η(1855)	0+(2−+)	K(1430)	Template:Sfrac(2+)			χ(3872)	0+(1++)
b(1235)	1+(1+−)	η(1870)	0+(2−+)	K(1460)	Template:Sfrac(0−)	B	Template:Sfrac(0−)	X(3900)±	?(1+)
a(1260)	1−(1++)	π(1880)	1−(2−+)	K(1580)	Template:Sfrac(2−)	B	Template:Sfrac(0−)	X(3900)0	?(??)
f(1270)	0+(2++)	ρ(1900)	1+(1−−)	K(1630)	Template:Sfrac(??)	B/B Admixture		χ(2P)	0+(0++)
f(1285)	0+(1++)	f(1910)	0+(2++)	K(1650)	Template:Sfrac(1+)	B/B/B/b-baryon Admixture		χ(2P)	0+(2++)
η(1295)	0+(0−+)	f(1950)	0+(2++)	K(1680)	Template:Sfrac(1−)			X(3940)	??(???)
π(1300)	1−(0−+)	ρ(1990)	1+(3−−)	K(1770)	Template:Sfrac(2−)	Vcb and Vub CKM Matrix Admixture		X(4020)±	?(??)
a(1320)	1−(2++)	f(2010)	0+(2++)	K(1780)	Template:Sfrac(3−)			ψ(4040)	0−(1−−)
f(1370)	0+(0++)	f(2020)	0+(0++)	K(1820)	Template:Sfrac(2−)	B	Template:Sfrac(1−)	X(4050)±	?(??)
h(1415)	0−(1+−)	a(1970)	1−(4++)	K(1830)	Template:Sfrac(0−)	B(5732)	?(??)	X(4140)	0+(??+)
π(1400)	1−(1−+)	f(2050)	0+(4++)	K(1950)	Template:Sfrac(0+)	B(5721)0	Template:Sfrac(1+)	ψ(4160)	0−(1−−)
η(1405)	0+(0−+)	π(2100)	1−(2−+)	K(1980)	Template:Sfrac(2+)	B(5721)0	Template:Sfrac(2+)	X(4160)	??(???)
f(1420)	0+(1++)	f(2100)	0+(0++)	K(2045)	Template:Sfrac(4+)	Bottom, strange (B = ±1, S = ∓1)		X(4250)±	?(??)
ω(1420)	0−(1−−)	f(2150)	0+(2++)	K(2250)	Template:Sfrac(2−)			X(4260)	??(1−−)
f(1430)	0+(2++)	ρ(2150)	1+(1−−)	K(2320)	Template:Sfrac(3+)	B	0(0−)	X(4350)	0+(??+)
a(1450)	1−(0++)	φ(2170)	0−(1−−)	K(2380)	Template:Sfrac(5−)	B	0(1−)	ψ(4360)	0−(1−−)
ρ(1450)	1+(1−−)	f(2200)	0+(0++)	K(2500)	Template:Sfrac(4−)	B(5830)0	0(1+)	ψ(4415)	0−(1−−)
η(1475)	0+(0−+)	fJ(2220)	0+(2++ or 4++)	K(3100)	??(???)	B(5840)0	0(2+)	X(4430)±	?(1+)
f(1500)	0+(0++)			Charmed (C = ±1)		B(5850)	?(??)	ψ(4660)	0−(1−−)
f(1510)	0+(1++)	η(2225)	0+(0−+)			Bottom, charmed (B = C = ±1)		bb
f′(1525)	0+(2++)	ρ(2250)	1+(3−−)	D	Template:Sfrac(0−)			η(1S)	0+(0−+)
f(1565)	0+(2++)	f2(2300)	0+(2++)	D	Template:Sfrac(0−)	B	0(0−)	Υ(1S)	0−(1−−)
ρ(1570)	1+(1−−)	f(2300)	0+(4++)	D(2007)0	Template:Sfrac(1−)	B(2S)±	0(0−)	χ(1P)	0+(0++)
h(1595)	0−(1+−)	f(2330)	0+(0++)	D(2010)±	Template:Sfrac(1−)			χ(1P)	0+(1++)
π(1600)	1−(1−+)	f(2340)	0+(2++)	D(2400)0	Template:Sfrac(0+)			χ(2P)	0+(0++)
a(1640)	1−(1++)	ρ(2350)	1+(5−−)	D(2400)±	Template:Sfrac(0+)			h(1P)	0−(1+−)
f(1640)	0+(2++)	a(2450)	1−(6++)	D(2420)0	Template:Sfrac(1+)			χ(1P)	0+(2++)
η(1645)	0+(2−+)	f(2510)	0+(6++)	D(2420)±	Template:Sfrac(??)			η(2S)	0+(0−+)
ω(1650)	0−(1−−)	Other light		D(2430)0	Template:Sfrac(1+)			Υ(2S)	0−(1−−)
ω(1670)	0−(3−−)	Further States		D(2460)0	Template:Sfrac(2+)			Υ(1D)	0−(2−−)
π(1670)	1−(2−+)	Further states		D(2460)±	Template:Sfrac(2+)			χ(2P)	0+(0++)
				D(2550)0	Template:Sfrac(0−)			χ(2P)	0+(1++)
				D(2600)	Template:Sfrac(??)			h(2P)	0−(1+−)
				D(2640)±	Template:Sfrac(??)			χ(2P)	0+(2++)
				D(2750)	Template:Sfrac(??)			Υ(3S)	0−(1−−)
								χ(3P)	??(??+)
								Υ(4S)	0−(1−−)
								X(10610)±	1+(1+)
								X(10610)0	1+(1+)
								X(10650)±	?+(1+)
								Υ(10860)	0−(1−−)
								Υ(11020)	0−(1−−)

Mesons named with the letter "f" are scalar mesons (as opposed to a pseudo-scalar meson), and mesons named with the letter "a" are axial-vector mesons (as opposed to an ordinary vector meson) a.k.a. an isoscalar vector meson, while the letters "b" and "h" refer to axial-vector mesons with positive parity, negative C-parity, and quantum numbers I^G of 1⁺ and 0⁻ respectively.

The, "f", "a", "b" and "h" mesons are not listed in the tables below and their internal structure and quark content is a matter of ongoing investigation. The particle described in the table above as f₀(500) has historically been known by two other names: f₀(600) and σ (sigma).

A complete set of meson naming conventions is set forth in a 2017 review article for the Particle Data Group which also contains a table mapping pre-2016 common names to the new Particle Data Group standard naming conventions for XYZ mesons.

Meson properties

The following lists details for all known and predicted pseudoscalar ([[total angular momentum|Template:Itco]]^P = 0⁻) and vector ([[total angular momentum|Template:Itco]]^P = 1⁻) mesons.

The properties and quark content of the particles are tabulated below; for the corresponding antiparticles, simply change quarks into antiquarks (and vice versa) and flip the sign of Q, B, S, C, and B′. Particles with ^† next to their names have been predicted by the standard model but not yet observed. Values in red have not been firmly established by experiments, but are predicted by the quark model and are consistent with the measurements.

Pseudoscalar mesons

Pseudoscalar mesons

Particle name	Particle symbol	Antiparticle symbol	Quark content	Rest mass [MeV/c2]	[[Isospin|Template:Itco]]G	[[Total angular momentum|Template:Itco]]PC	S	C	B′	Mean lifetime [s]	Commonly decays to (>5% of decays)
Pion	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		1−	0−	0	0	0		Template:Subatomic particle + Template:Subatomic particle
Pion	Template:Subatomic particle	Self	$\frac{u\overline{u}-d\overline{d}}{\sqrt{2}}$[a]		1−	0−+	0	0	0		Template:Subatomic particle + Template:Subatomic particle
Eta meson	Template:Subatomic particle	Self	$\frac{u\overline{u}+d\overline{d}-2s\overline{s}}{\sqrt{6}}$[a]		0+	0−+	0	0	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle
Eta prime meson	Template:Subatomic particle(958)	Self	$\frac{\mathrm{u}\overline{\mathrm{u}}\mathrm{+}\mathrm{d}\overline{\mathrm{d}}\mathrm{+}\mathrm{s}\overline{\mathrm{s}}}{\sqrt{3}}$[a]		0+	0−+	0	0	0		Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle or (Template:Subatomic particle + Template:Subatomic particle) / (Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle) or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle
Charmed eta meson	Template:Subatomic particle(1S)	Self	Template:Subatomic particleTemplate:Subatomic particle		0+	0−+	0	0	0		See Template:Subatomic particle decay modes
Bottom eta meson	Template:Subatomic particle(1S)	Self	Template:Subatomic particleTemplate:Subatomic particle		0+	0−+	0	0	0		See Template:Subatomic particle decay modes
Kaon	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	0−	1	0	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle
Kaon	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	0−	1	0	0	[c]	[c]
K-Short	Template:Subatomic particle	Self	$\frac{d\overline{s}-s\overline{d}}{\sqrt{2}}$[e]	[d]	Template:Sfrac	0−	(*)	0	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle
K-Long	Template:Subatomic particle	Self	$\frac{d\overline{s}+s\overline{d}}{\sqrt{2}}$[e]	[d]	Template:Sfrac	0−	(*)	0	0		Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle
D meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	0−	0	+1	0		See Template:Subatomic particle decay modes
D meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	0−	0	+1	0		See Template:Subatomic particle decay modes
strange D meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		0	0−	+1	+1	0		See Template:Subatomic particle decay modes
B meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	0−	0	0	+1		See Template:Subatomic particle decay modes
B meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	0−	0	0	+1		See Template:Subatomic particle decay modes
Strange B meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		0	0−	−1	0	+1		See Template:Subatomic particle decay modes
Charmed B meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		0	0−	0	+1	+1		See Template:Subatomic particle decay modes

^[a] ^ Makeup inexact due to non-zero quark masses.
^[b] ^ PDG reports the resonance width (Γ). Here the conversion τ = Template:Sfrac is given instead.
^[c] ^ Strong eigenstate. No definite lifetime (see kaon notes below)
^[d] ^ The mass of the Template:Subatomic particle and Template:Subatomic particle are given as that of the Template:Subatomic particle. However, it is known that a difference between the masses of the Template:Subatomic particle and Template:Subatomic particle on the order of exists.
^[e] ^ Weak eigenstate. Makeup is missing small CP–violating term (see notes on neutral kaons below).

Vector mesons

Vector mesons

Particle name	Particle symbol	Antiparticle symbol	Quark content	Rest mass [MeV/c2]	[[Isospin|Template:Itco]]G	[[Total angular momentum|Template:Itco]]PC	S	C	B′	Mean lifetime [s]	Commonly decays to (>5% of decays)
Charged rho meson	Template:Subatomic particle(770)	Template:Subatomic particle(770)	Template:Subatomic particleTemplate:Subatomic particle		1+	1−	0	0	0		Template:Subatomic particle + Template:Subatomic particle
Neutral rho meson	Template:Subatomic particle(770)	Self	$\frac{u\overline{u}-d\overline{d}}{\sqrt{2}}$		1+	1−−	0	0	0		Template:Subatomic particle + Template:Subatomic particle
Omega meson	Template:Subatomic particle(782)	Self	$\frac{u\overline{u}+d\overline{d}}{\sqrt{2}}$		0−	1−−	0	0	0		Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle
Phi meson	Template:Subatomic particle(1020)	Self	Template:Subatomic particleTemplate:Subatomic particle		0−	1−−	0	0	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle or (Template:Subatomic particle + Template:Subatomic particle) / (Template:Subatomic particle + Template:Subatomic particle + Template:Subatomic particle)
J/Psi	Template:Subatomic particle	Self	Template:Subatomic particleTemplate:Subatomic particle		0−	1−−	0	0	0		See Template:Subatomic particle(1S) decay modes
Upsilon meson	Template:Subatomic particle(1S)	Self	Template:Subatomic particleTemplate:Subatomic particle		0−	1−−	0	0	0		See Template:Subatomic particle(1S) decay modes
Kaon	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	1−	1	0	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle
Kaon	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	1−	1	0	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle
D meson	Template:Subatomic particle(2010)	Template:Subatomic particle(2010)	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	1−	0	+1	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle
D meson	Template:Subatomic particle(2007)	Template:Subatomic particle(2007)	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	1−	0	+1	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle
Strange D meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		0	1−	+1	+1	0		Template:Subatomic particle + Template:Subatomic particle or Template:Subatomic particle + Template:Subatomic particle
B meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	1−	0	0	+1	Unknown	Template:Subatomic particle + Template:Subatomic particle
B meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		Template:Sfrac	1−	0	0	+1	Unknown	Template:Subatomic particle + Template:Subatomic particle
Strange B meson	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle		0	1−	−1	0	+1	Unknown	Template:Subatomic particle + Template:Subatomic particle
Charmed B meson†	Template:Subatomic particle	Template:Subatomic particle	Template:Subatomic particleTemplate:Subatomic particle	Unknown	0	1−	0	+1	+1	Unknown	Unknown

^[f] ^ PDG reports the resonance width (Γ). Here the conversion τ = Template:Sfrac is given instead.
^[g] ^ The exact value depends on the method used. See the given reference for detail.

Notes on neutral kaons

There are two complications with neutral kaons:

• Due to neutral kaon mixing, the Template:Subatomic particle and Template:Subatomic particle 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.
• The linear combinations given in the table for the Template:Subatomic particle and Template:Subatomic particle 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.

See also

• List of baryons
• List of particles
• Timeline of particle discoveries

External links

• Particle Data Group: The Review of Particle Physics; pdgLive – Meson Summary Table
• Mesons made thinkable, an interactive visualisation allowing physical properties to be compared