List of mesons

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.

Mesons are 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 (J/ψ) in 1974,[1][2] and the bottom quark in the upsilon meson (?) in 1977.[3]

Each meson has a corresponding antiparticle (antimeson) where quarks are replaced by their corresponding antiquarks and vice-versa. For example, a positive pion (π+
) is made of one up quark and one down antiquark; and its corresponding antiparticle, the negative pion (π−
), is made of one up antiquark and one down quark. Some experiments show the evidence of tetraquarks – "exotic" mesons made of two quarks and two antiquark, but the particle physics community as a whole does not view their existence as likely, although still possible.[4]

Contents

Summary table

Meson summary table[5]
Light unflavoured
(S=C=B=0)		 Strange
(S=±1, C=B=0)		 Charmed
(C=±1, B=0)		 Bottom
(B=±1)
IG(JPC) IG(JPC) IG(JP) IG(JP) IG(JPC)
π± 1−(0−) π2(1670) 1−(2−+) K± ½(0−) D± ½(0−) B± ½(0−)
π0 1−(0−+) φ(1680) 0−(1−−) K0 ½(0−) D0 ½(0−) B0 ½(0−)
η 0+(0−+) ρ3(1690) 1+(3−−) K0S ½(0−) D*(2007)0 ½(1−) B±/B0 Admixture
f0(600) 0+(0++) ρ(1700) 1+(1−−) K0L ½(0−) D*(2010)± ½(1−) B±/B0/B0s/b-baryon
Admixture
ρ(770) 1+(1−−) a2(1700) 1−(2++) K*0(800) ½(0+) D*0(2400)0 ½(0+)
ω(782) 0−(1−−) f0(1710) 0+(0++) K*(892) ½(1−) D*0(2400)± ½(0+) B* ½(1−)
η'(958) 0+(0−+) η(1760) 0+(0−+) K1(1270) ½(1+) D1(2420)0 ½(1+) B*J(5732)  ?(??)
f0(980) 0+(0++) π(1800) 1−(0−+) K1(1400) ½(1+) D1(2420)± ½(??) B1(5721)0 ½(1+)
a0(980) 1−(0++) f2(1810) 0+(2++) K*(1410) ½(1−) D1(2430)0 ½(1+) B*2(5747)0 ½(2+)
φ(1020) 0−(1−−) X(1835)  ??(?−+) K*0(1430) ½(0+) D*2(2460)0 ½(2+) Bottom strange
h1(1170) 0−(1+−) φ3(1850) 0−(3−−) K*2(1430) ½(2+) D*2(2460)± ½(2+) B0s 0(0−)
b1(1235) 1+(1+−) η2(1870) 0+(2−+) K(1460) ½(0−) D*(2640)± ½(??) B*s 0(1−)
a1(1260) 1−(1++) π2(1880) 1−(2−+) K2(1580) ½(2−) Charmed strange Bs1(5830)0 ½(1+)
f2(1270) 0+(2++) ρ(1900) 1+(1−−) K(1630) ½(??) D±s 0(0−) B*s2(5840)0 ½(2+)
f1(1285) 0+(1++) f2(1910) 0+(2++) K1(1650) ½(1+) D*±s 0(??) B*sJ(5850)  ?(??)
η(1295) 0+(0−+) f2(1950) 0+(2++) K*(1680) ½(1−) D*s0(2317)± 0(0+) Bottom charmed
π(1300) 1−(0−+) ρ3(1990) 1+(3−−) K2(1770) ½(2−) Ds1(2460)± 0(1+) B±c 0(0−)
a2(1320) 1−(2++) f2(2010) 0+(2++) K*3(1780) ½(3−) Ds1(2536)± 0(1+) Bottom bottom
f0(1370) 0+(0++) f0(2020) 0+(0++) K2(1820) ½(2−) Ds2(2573) 0(??) ηb(1S) 0+(0−+)
h1(1380)  ?−(1+−) a4(2040) 1−(4++) K(1830) ½(0−) D*s1(2700)± 0(1−) Υ(1S) 0−(1−−)
π1(1400) 1−(1−+) f4(2050) 0+(4++) K*0(1950) ½(0+) D*sJ(2860)± 0(??) χb0(1P) 0+(0++)
η(1405) 0+(0−+) π2(2100) 1−(2−+) K*2(1980) ½(2+) DsJ(3040)± 0(??) χb1(1P) 0+(1++)
f1(1420) 0+(1++) f0(2100) 0+(0++) K*4(2045) ½(4+) Charmed charmed χb2(1P) 0+(2++)
ω(1420) 0−(1−−) f2(2150) 0+(2++) K2(2250) ½(2−) ηc(1S) 0+(0−+) Υ(2S) 0−(1−−)
f2(1430) 0+(2++) ρ(2150) 1+(1−−) K3(2320) ½(3+) J/ψ(1S) 0−(1−−) Υ(1D) 0−(2−−)
a0(1450) 1−(0++) φ(2150) 0−(1−−) K*5(2380) ½(5−) χc0(1P) 0+(0++) χb0(2P) 0+(0++)
ρ(1450) 1+(1−−) f0(2200) 0+(2++
or 4++)		 K4(2500) ½(4−) χc1(1P) 0+(1++) χb1(2P) 0+(1++)
η(1450) 0+(0−+) K(3100)  ??(???) hc(1P)  ??(1+−) χb2(2P) 0+(2++)
f0(1500) 0+(0++) η(2225) 0+(0−+) χc2(1P) 0+(2++) Υ(3S) 0−(1−−)
f1(1510) 0+(1++) ρ3(2250) 1+(3−−) ηc(2S) 0+(0−+) Υ(4S) 0−(1−−)
f'2(1525) 0+(2++) f2(2300) 0+(2++) ψ(2S) 0−(1−−) Υ(10860) 0−(1−−)
f2(1565) 0+(2++) f4(2300) 0+(4++) ψ(3770) 0−(1−−) Υ(11020) 0−(1−−)
ρ(1570) 1+(1−−) f0(2330) 0+(0++) X(3872) 0?(??+)
h1(1595) 0−(1+−) f2(2340) 0+(2++) χc2(2P) 0+(2++)
π1(1600) 1−(1−+) ρ5(2350) 1+(5−−) X(3940)  ??(???)
a1(1640) 1−(1++) a6(2450) 1−(6++) X(3945) 0+(??+)
f2(1640) 0+(2++) f6(2510) 0+(6++) ψ(4040) 0−(1−−)
η2(1645) 0+(2−+) X(4050)±  ?(??)
ω(1650) 0−(1−−) X(4140) 0+(??+)
ω3(1670) 0−(3−−) ψ(4160) 0−(1−−)
X(4160)  ??(???)
X(4250)±  ?(??)
X(4260)  ??(1−−)
X(4350) 0+(??+)
X(4360)  ??(1−−)
ψ(4415) 0−(1−−)
X(4430)±  ?(??)
X(4660)  ??(1−−)

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 above table may not exist or have the wrong mass or quantum numbers.

List of mesons

Main article: Meson

These lists detail all known and predicted pseudoscalar (JP = 0−) and vector (JP = 1−) mesons.

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

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) IG JPC S C B' Mean lifetime (s) Commonly decays to

(>5% of decays)
Pion[6] π+
 π−
 ud 139.57018±0.00035 1− 0− 0 0 0 2.6033±0.0005×10−8 μ+
 + ν
μ
Pion[7] π0
 Self \mathrm{\tfrac{u\bar{u} - d\bar{d}}{\sqrt{2}}}\,[a] 134.9766±0.0006 1− 0−+ 0 0 0 8.4±0.5×10−17 γ + γ
Eta meson[8] η Self \mathrm{\tfrac{u\bar{u} %2B d\bar{d} - 2s\bar{s}}{\sqrt{6}}}\,[a] 547.853±0.024 0+ 0−+ 0 0 0 5.0±0.3×10−19[b] γ + γ or
π0
 + π0
 + π0
 or

π+
 + π0
 + π−
Eta prime meson[9] η′(958) Self \mathrm{\tfrac{u\bar{u} %2B d\bar{d} %2B s\bar{s}}{\sqrt{3}}}\,[a] 957.78±0.06 0+ 0−+ 0 0 0 3.39±0.16×10−21[b] π+
 + π−
 + η or

(ρ0
 + γ) / (π+
 + π−
 + γ) or
π0
 + π0
 + η
Charmed eta meson[10] η
c(1S)		 Self cc 2,980.3±1.2 0+ 0−+ 0 0 0 2.30±0.17×10−23[b] See η
c decay modes
Bottom eta meson[11] η
b(1S)		 Self bb 9,390.9±2.8 0+ 0−+ 0 0 0 Unknown See η
b decay modes
Kaon[12] K+
 K−
 us 493.677±0.016 1⁄2 0− 1 0 0 1.2380±0.0021×10−8 μ+
 + ν
μ or

π+
 + π0
 or
π0
 + e+
 + ν
e
Kaon[13] K0
 K0
 ds 497.614±0.024 1⁄2 0− 1 0 0 [c] [c]
K-Short[14] K0
S		 Self \mathrm{\tfrac{d\bar{s} - s\bar{d}}{\sqrt{2}}}\,[e] 497.614±0.024[d] 1⁄2 0− (*) 0 0 8.953±0.005×10−11 π+
 + π−
 or

π0
 + π0
K-Long[15] K0
L		 Self \mathrm{\tfrac{d\bar{s} %2B s\bar{d}}{\sqrt{2}}}\,[e] 497.614±0.024[d] 1⁄2 0− (*) 0 0 5.116±0.020×10−8 π±
 + e∓
 + ν
e or
π±
 + μ∓
 + ν
μ or

π0
 + π0
 + π0
 or
π+
 + π0
 + π−
D meson[16] D+
 D−
 cd 1,869.60±0.16 1⁄2 0− 0 +1 0 1.040±0.007×10−12 See D+
 decay modes
D meson[17] D0
 D0
 cu 1,864.83±0.14 1⁄2 0− 0 +1 0 4.101±0.015×10−13 See D0
 decay modes
strange D meson[18] D+
s		 D−
s		 Error no link definedError no link defined 1,968.47±0.33 0 0− +1 +1 0 5.00±0.07×10−13 See Error no symbol defined decay modes
B meson[19] Error no link defined Error no link defined Error no link definedError no link defined 5,279.15±0.31 1⁄2 0− 0 0 +1 1.638±0.011×10−12 See Error no symbol defined decay modes
B meson[20] Error no link defined Error no link defined Error no link definedError no link defined 5,279.50±0.30 1⁄2 0− 0 0 +1 1.530±0.009×10−12 See Error no symbol defined decay modes
Strange B meson[21] Error no link defined Error no link defined Error no link definedError no link defined 5,366.3±0.6 0 0− −1 0 +1 1.472+0.024
−0.026×10−12		 See Error no symbol defined decay modes
Charmed B meson[22] Error no link defined Error no link defined Error no link definedError no link defined 6,277±6 0 0− 0 +1 +1 4.53±0.41×10−13 See Error no symbol defined decay modes

[a] ^ Makeup inexact due to non-zero quark masses.
[b] ^ PDG reports the resonance width (Γ). Here the conversion τ = ħ⁄Γ is given instead.
[c] ^ Strong eigenstate. No definite lifetime (see kaon notes below)
[d] ^ The mass of the Error no symbol defined and Error no symbol defined are given as that of the Error no symbol defined. However, it is known that a difference between the masses of the Error no symbol defined and Error no symbol defined on the order of 2.2×10−11 MeV/c2 exists.[15]
[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) IG JPC S C B' Mean lifetime (s) Commonly decays to

(>5% of decays)
Charged rho meson[23] Error no link defined(770) Error no link defined(770) Error no link definedError no link defined 775.11±0.34 1+ 1− 0 0 0 ~4.5×10−24[f][g] Error no link defined + Error no link defined
Neutral rho meson[23] Error no link defined(770) Self \mathrm{\tfrac{u\bar{u}-d\bar{d}}{\sqrt 2}}\, 775.49±0.34 1+ 1−− 0 0 0 ~4.5×10−24[f][g] Error no link defined + Error no link defined
Omega meson[24] Error no link defined(782) Self \mathrm{\tfrac{u\bar{u} %2B d\bar{d}}{\sqrt{2}}}\, 782.65±0.12 0− 1−− 0 0 0 7.75±0.07×10−23[f] Error no link defined + Error no link defined + Error no link defined or

Error no link defined + Error no link defined
Phi meson[25] Error no link defined(1020) Self Error no link definedError no link defined 1,019.445±0.020 0− 1−− 0 0 0 1.55±0.01×10−22[f] Error no link defined + Error no link defined or
Error no link defined + Error no link defined or
(Error no link defined + Error no link defined) / (Error no link defined + Error no link defined + Error no link defined)
J/Psi[26] Error no link defined Self Error no link definedError no link defined 3,096.916±0.011 0− 1−− 0 0 0 7.09±0.21×10−21[f] See Error no symbol defined(1S) decay modes
Upsilon meson[27] Error no link defined(1S) Self Error no link definedError no link defined 9,460.30±0.26 0− 1−− 0 0 0 1.22±0.03×10−20[f] See Error no symbol defined(1S) decay modes
Kaon[28] Error no link defined Error no link defined Error no link definedError no link defined 891.66±0.026 1⁄2 1− 1 0 0 ~7.35×10−20[f][g] See Error no symbol defined(892) decay modes
Kaon[28] Error no link defined Error no link defined Error no link definedError no link defined 895.94±0.22 1⁄2 1− 1 0 0 7.346±0.002×10−20[f] See Error no symbol defined(892) decay modes
D meson[29] Error no link defined(2010) Error no link defined(2010) Error no link definedError no link defined 2,010.25±0.14 1⁄2 1− 0 +1 0 6.9±1.9×10−21[f] Error no link defined + Error no link defined or
Error no link defined + Error no link defined
D meson[30] Error no link defined(2007) Error no link defined(2007) Error no link definedError no link defined 2,006.96±0.16 1⁄2 1− 0 +1 0 >3.1×10−22[f] Error no link defined + Error no link defined or
Error no link defined + Error no link defined
strange D meson[31] Error no link defined Error no link defined Error no link definedError no link defined 2,112.3±0.5 0 1− +1 +1 0 >3.4×10−22[f] Error no link defined + Error no link defined or
Error no link defined + Error no link defined
B meson[32] Error no link defined Error no link defined Error no link definedError no link defined 5,325.1±0.5 1⁄2 1− 0 0 +1 Unknown Error no link defined + Error no link defined
B meson[32] Error no link defined Error no link defined Error no link definedError no link defined 5,325.1±0.5 1⁄2 1− 0 0 +1 Unknown Error no link defined + Error no link defined
Strange B meson[33] Error no link defined Error no link defined Error no link definedError no link defined 5,415.4±1.4 0 1− −1 0 +1 Unknown Error no link defined+Error no link defined
Charmed B meson† Error no link defined Error no link defined Error no link definedError no link defined Unknown 0 1− 0 +1 +1 Unknown Unknown

[f] ^ PDG reports the resonance width (Γ). Here the conversion τ = ħ⁄Γ 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:[34]

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.[34]

See also

Book: Hadronic Matter

Book: Particles of the Standard Model
Wikipedia books are collections of articles that can be downloaded or ordered in print.


References

  1. ^ J.J. Aubert et al. (1974)
  2. ^ J.E. Augustin et al. (1974)
  3. ^ S.W. Herb et al. (1977)
  4. ^ C. Amsler et al. (2008): Charmonium States
  5. ^ http://pdg.lbl.gov/2010/tables/rpp2010-qtab-mesons.pdf
  6. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  7. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  8. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  9. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  10. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  11. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  12. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  13. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  14. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  15. ^ a b N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  16. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  17. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  18. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  19. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  20. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  21. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  22. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  23. ^ a b N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  24. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined(782)
  25. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  26. ^ N. Nakamura et al. (2010): Particle listings – J/Ψ
  27. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined(1S)
  28. ^ a b N. Nakamura et al. (2010): Particle listings – Error no symbol defined(892)
  29. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined(2010)
  30. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined(2007)
  31. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  32. ^ a b N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  33. ^ N. Nakamura et al. (2010): Particle listings – Error no symbol defined
  34. ^ a b J.W. Cronin (1980)

Bibliography

External links

Elementary
u · Error no link defined · d · Error no link defined · c · Error no link defined · s · Error no link defined · t · Error no link defined · b · Error no link defined
Error no link defined · Error no link defined · Error no symbol defined · Error no symbol defined
Others
Others
Others
A0 · Dilaton · G · Error no link defined · Error no link defined · m · Tachyon · Error no symbol defined · Error no symbol defined · W' · Z' · Sterile neutrino
Composite
Error no link defined (Error no link defined · Error no link defined) · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined
Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined · Error no link defined
Others
Hypothetical
Others
Quasiparticles
Lists
Wikipedia books
Book:Hadronic Matter · Book:Particles of the Standard Model · Book:Leptons · Book:Quarks