List of baryons

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Baryons are composite particles made of three quarks, as opposed to the mesons, which are composite particles made of one quark and one antiquark. Both baryons and mesons are part of the larger particle family comprising all particles made of quarks—the hadron. The term baryon is derived from the Greek "βαρύς" (barys), meaning "heavy", because at the time of their naming it was believed that baryons were characterized by having greater masses than other particles that were classed as matter.

Until a few years ago, it was believed that some experiments showed the existence of pentaquarks – "exotic" baryons made of four quarks and one antiquark.[1][2] The particle physics community as a whole did not view their existence as likely in 2006[3] and in 2008 considered evidence to be overwhelmingly against the existence of the reported pentaquarks.[4]

Since baryons are composed of quarks, they participate in the strong interaction. Leptons on the other hand, are not composed of quarks and as such do not participate in the strong interaction. The most famous baryons are the protons and neutrons that make up most of the mass of the visible matter in the universe, whereas electrons (the other major component of atoms) are leptons. Each baryon has a corresponding antiparticle (antibaryon) where quarks are replaced by their corresponding antiquarks. For example, a proton is made of two up quarks and one down quark; and its corresponding antiparticle, the antiproton, is made of two up antiquarks and one down antiquark.

Lists of baryons[edit]

These lists detail all known and predicted baryons in total angular momentum J = 12 and J = 32 configurations with positive parity.

  • Baryons composed of one type of quark (uuu, ddd, ...) can exist in J = 32 configuration, but J = 12 is forbidden by the Pauli exclusion principle.
  • Baryons composed of two types of quarks (uud, uus, ...) can exist in both J = 12 and J = 32 configurations
  • Baryons composed of three types of quarks (uds, udc, ...) can exist in both J = 12 and J = 32 configurations. Two J = 12 configurations are possible for these baryons.

The symbols encountered in these lists are: I (isospin), J (total angular momentum), P (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), B′ (bottomness), as well as a wide array of subatomic particles (hover for name). (See the baryon article for a detailed explanation of these symbols.)

Antiparticles are not listed in the tables; however, they simply would have all quarks changed to antiquarks (and antiquarks changed to quarks), and Q, B, S, C, B′, would be of opposite signs. 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.[5][6]

J P = 12+ baryons[edit]

JP = 12+ baryons 
Particle name Symbol Quark content Rest mass (MeV/c2) I J P Q (e) S C B' Mean lifetime (s) Commonly
decays to
nucleon/proton[7] p / p+ / N+ uud 938.272046(21)[a] 12 12+ +1 0 0 0 Stable[b] Unobserved
nucleon/neutron[8] n / n0 / N0 udd 939.565379(21)[a] 12 12+ 0 0 0 0 (8.800±0.009)×102[c] p+ + e + ν
e
Lambda[9] Λ0 uds 1115.683±0.006 0 12+ 0 −1 0 0 (2.632±0.020)×10−10 p+ + π or
n0 + π0
charmed Lambda[10] Λ+
c
udc 2286.46±0.14 0 12+ +1 0 +1 0 (2.00±0.06)×10−13 See Λ+
c
decay modes
bottom Lambda[11] Λ0
b
udb 5619.4±0.6 0 12+ 0 0 0 −1 (1.429±0.024)×10−12 See Λ0
b
decay modes
Sigma[12] Σ+ uus 1189.37±0.07 1 12+ +1 −1 0 0 (8.018±0.026)×10−11 p+ + π0 or

n0 + π+

Sigma[13] Σ0 uds 1192.642±0.024 1 12+ 0 −1 0 0 (7.4±0.7)×10−20 Λ0 + γ
Sigma[14] Σ dds 1197.449±0.030 1 12+ −1 −1 0 0 (1.479±0.011)×10−10 n0 + π
charmed Sigma[15] Σ++
c
uuc 2453.98±0.16 1 12+ +2 0 +1 0 (2.91±0.32)×10−22[d] Λ+
c
+ π+
charmed Sigma[15] Σ+
c
udc 2452.9±0.4 1 12+ +1 0 +1 0 >1.43×10−22[d] Λ+
c
+ π0
charmed Sigma[15] Σ0
c
ddc 2453.74±0.16 1 12+ 0 0 +1 0 (3.05±0.37)×10−22[d] Λ+
c
+ π
bottom Sigma[16] Σ+
b
uub 5811.3+0.9
−0.8
 ± 1.7
1 12+ +1 0 0 −1 6.8+2.7
−3.5
×10−23
[d]
Λ0
b
+ π+
bottom Sigma Σ0
b
udb Unknown 1 12+ 0 0 0 −1 Unknown Unknown
bottom Sigma[16] Σ
b
ddb 5815.5+0.6
−0.5
 ± 1.7
1 12+ −1 0 0 −1 1.34+0.87
−1.15
×10−22
[d]
Λ0
b
+ π
Xi[17] Ξ0 uss 1314.86±0.20 12 12+ 0 −2 0 0 (2.90±0.09)×10−10 Λ0 + π0
Xi[18] Ξ dss 1321.71±0.07 12 12+ −1 −2 0 0 (1.639±0.015)×10−10 Λ0 + π
charmed Xi[19] Ξ+
c
usc 2467.8+0.4
−0.6
12 12+ +1 −1 +1 0 (4.42±0.26)×10−13 See Ξ+
c
decay modes
charmed Xi[20] Ξ0
c
dsc 2470.88+0.34
−0.80
12 12+ 0 −1 +1 0 1.12+0.13
−0.10
×10−13
See Ξ0
c
decay modes
charmed Xi prime[21] Ξ′+
c
usc 2575.6±3.1 12 12+ +1 −1 +1 0 Unknown Ξ+
c
+ γ (seen)
charmed Xi prime[22] Ξ′0
c
dsc 2577.9±2.9 12 12+ 0 −1 +1 0 Unknown Ξ0
c
+ γ (seen)
double charmed Xi[e] Ξ++
cc
ucc Unknown 12 12+ +2 0 +2 0 Unknown Unknown
double charmed Xi[e][23] Ξ+
cc
dcc 3518.9±0.9[e] 12 12+ +1 0 +2 0 <3.3×10−14[e] Λ+
c
+ K + π+
[e] or
p+ + D+ + K[e]
bottom Xi[24]
(or Cascade B)
Ξ0
b
usb 5787.8±5.0 ± 1.3 12 12+ 0 −1 0 −1 Unknown See Ξ
b
decay modes
bottom Xi[24]
(or Cascade B)
Ξ
b
dsb 5791.1±2.2 12 12+ −1 −1 0 −1 (1.56+0.27
−0.25
 ± 0.02)×10−12
See Ξ
b
decay modes
bottom Xi prime Ξ′0
b
usb Unknown 12 12+ 0 −1 0 −1 Unknown Unknown
bottom Xi prime Ξ′
b
dsb Unknown 12 12+ −1 −1 0 −1 Unknown Unknown
double bottom Xi Ξ0
bb
ubb Unknown 12 12+ 0 0 0 −2 Unknown Unknown
double bottom Xi Ξ
bb
dbb Unknown 12 12+ −1 0 0 −2 Unknown Unknown
charmed bottom Xi Ξ+
cb
ucb Unknown 12 12+ +1 0 +1 −1 Unknown Unknown
charmed bottom Xi Ξ0
cb
dcb Unknown 12 12+ 0 0 +1 −1 Unknown Unknown
charmed bottom Xi prime Ξ′+
cb
ucb Unknown 12 12+ +1 0 +1 −1 Unknown Unknown
charmed bottom Xi prime Ξ′0
cb
dcb Unknown 12 12+ 0 0 +1 −1 Unknown Unknown
charmed Omega[25] Ω0
c
ssc 2695.2±1.7 0 12+ 0 −2 +1 0 (6.9±1.2)×10−14 See Ω0
c
decay modes
bottom Omega[26] Ω
b
ssb 6071±40 0 12+ −1 −2 0 −1 (1.13+0.55
−0.42
 ± 0.02)×10−12
(Ω + J/ψ seen)
double charmed Omega Ω+
cc
scc Unknown 0 12+ +1 −1 +2 0 Unknown Unknown
charmed bottom Omega Ω0
cb
scb Unknown 0 12+ 0 −1 +1 −1 Unknown Unknown
charmed bottom Omega prime Ω′0
cb
scb Unknown 0 12+ 0 −1 +1 −1 Unknown Unknown
double bottom Omega Ω
bb
sbb Unknown 0 12+ −1 −1 0 −2 Unknown Unknown
double charmed bottom Omega Ω+
ccb
ccb Unknown 0 12+ +1 0 +2 −1 Unknown Unknown
charmed double bottom Omega Ω0
cbb
cbb Unknown 0 12+ 0 0 +1 −2 Unknown Unknown

^ Particle has not yet been observed.
[a] ^ The masses of the proton and neutron are known with much better precision in atomic mass units (u) than in MeV/c2, due to the relatively poorly known value of the elementary charge. In atomic mass unit, the mass of the proton is 1.007276466812(90) u whereas that of the neutron is 1.00866491600(43) u.
[b] ^ At least 1035 years. See proton decay.
[c] ^ For free neutrons; in most common nuclei, neutrons are stable.
[d] ^ PDG reports the resonance width (Γ). Here the conversion τ = ħΓ is given instead.
[e] ^ Some controversy exists about this data.[23]

JP = 32+ baryons[edit]

JP = 32+ baryons 
Particle name Symbol Quark
content
Rest mass (MeV/c2) I J P Q (e) S C B' Mean lifetime (s) Commonly
decays to
Delta[27] Δ++(1232) uuu 1232±2 32 32+ +2 0 0 0 (5.63±0.14)×10−24[h] p+ + π+
Delta[27] Δ+(1232) uud 1232±2 32 32+ +1 0 0 0 (5.63±0.14)×10−24[h] π+ + n0 or

π0 + p+

Delta[27] Δ0(1232) udd 1232±2 32 32+ 0 0 0 0 (5.63±0.14)×10−24[h] π0 + n0 or

π + p+

Delta[27] Δ(1232) ddd 1232±2 32 32+ −1 0 0 0 (5.63±0.14)×10−24[h] π + n0
Sigma[28] Σ∗+(1385) uus 1382.8±0.4 1 32+ +1 −1 0 0 (1.839±0.0041)×10−23[h] Λ0 + π+ or

Σ+ + π0 or
Σ0 + π+

Sigma[28] Σ∗0(1385) uds 1383.7±1.0 1 32+ 0 −1 0 0 (1.83±0.25)×10−23[h] Λ0 + π0 or

Σ+ + π or
Σ0 + π0

Sigma[28] Σ∗−(1385) dds 1387.2±0.5 1 32+ −1 −1 0 0 (1.671±0.089)×10−23[h] Λ0 + π or

Σ0 + π or
Σ + π0 or

charmed Sigma[29] Σ∗++
c
(2520)
uuc 2517.9±0.6 1 32 + +2 0 +1 0 (4.42±0.44)×10−23[h] Λ+
c
+ π+
charmed Sigma[29] Σ∗+
c
(2520)
udc 2517.5±2.3 1 32 + +1 0 +1 0 >3.87×10−23[h] Λ+
c
+ π0
charmed Sigma[29] Σ∗0
c
(2520)
ddc 2518.8±0.6 1 32 + 0 0 +1 0 (4.54±0.47)×10−23[h] Λ+
c
+ π
bottom Sigma[30] Σ∗+
b
uub 5832.1±0.7 +1.7
−1.8
1 32 + +1 0 0 −1 (5.7±1.8)×10−23[h] Λ0
b
+ π+
bottom Sigma[e] Σ∗0
b
udb Unknown 1 32 + 0 0 0 −1 Unknown Unknown
bottom Sigma[30] Σ∗−
b
ddb 5835.1±0.6 +1.7
−1.8
1 32 + −1 0 0 −1 8.8+3.7
−3.6
×10−23
[h]
Λ0
b
+ π
Xi[31] Ξ∗0(1530) uss 1531.80±0.32 12 32+ 0 −2 0 0 (7.23±0.40)×10−23[h] Ξ0 + π0 or

Ξ + π+

Xi[31] Ξ∗−(1530) dss 1535.0±0.6 12 32+ −1 −2 0 0 6.6+1.3
−1.1
×10−23
[h]
Ξ0 + π or

Ξ + π0

charmed Xi[32] Ξ∗+
c
(2645)
usc 2645.9+0.5
−0.6
12 32 + +1 −1 +1 0 >2.1×10−22[h] Ξ+
c
+ π0 (seen)
charmed Xi[32] Ξ∗0
c
(2645)
dsc 2645.9±0.5 12 32 + 0 −1 +1 0 >1.2×10−22[h] Ξ+
c
+ π (seen)
double charmed Xi Ξ∗++
cc
ucc Unknown 12 32 + +2 0 +2 0 Unknown Unknown
double charmed Xi Ξ∗+
cc
dcc Unknown 12 32 + +1 0 +2 0 Unknown Unknown
bottom Xi[33] Ξ∗0
b
usb 5945.5±0.8 2.2 12 32 + 0 −1 0 −1 (3.1±2.5)×10−22[h] Ξ
b
+ π+ (seen)
bottom Xi Ξ∗−
b
dsb Unknown 12 32 + −1 −1 0 −1 Unknown Unknown
double bottom Xi Ξ∗0
bb
ubb Unknown 12 32 + 0 0 0 −2 Unknown Unknown
double bottom Xi Ξ∗−
bb
dbb Unknown 12 32 + −1 0 0 −2 Unknown Unknown
charmed bottom Xi Ξ∗+
cb
ucb Unknown 12 32 + +1 0 +1 −1 Unknown Unknown
charmed bottom Xi Ξ∗0
cb
dcb Unknown 12 32 + 0 0 +1 −1 Unknown Unknown
Omega[34] Ω sss 1672.45±0.29 0 32+ −1 −3 0 0 (8.21±0.11)×10−11[h] Λ0 + K or
Ξ0 + π or

Ξ + π0

charmed Omega[35] Ω∗0
c
(2770)
ssc 2765.9±2.0 0 32 + 0 −2 +1 0 Unknown Ω0
c
+ γ
bottom Omega Ω∗−
b
ssb Unknown 0 32 + −1> −2 0 −1 Unknown Unknown
double charmed Omega Ω∗+
cc
scc Unknown 0 32 + +1 −1 +2 0 Unknown Unknown
charmed bottom Omega Ω∗0
cb
scb Unknown 0 32 + 0 −1 +1 −1 Unknown Unknown
double bottom Omega Ω∗−
bb
sbb Unknown 0 32 + −1 −1 0 −2 Unknown Unknown
triple charmed Omega Ω++
ccc
ccc Unknown 0 32 + +2 0 +3 0 Unknown Unknown
double charmed bottom Omega Ω∗+
ccb
ccb Unknown 0 32 + +1 0 +2 −1 Unknown Unknown
charmed double bottom Omega Ω∗0
cbb
cbb Unknown 0 32 + 0 0 +1 −2 Unknown Unknown
triple bottom Omega Ω
bbb
bbb Unknown 0 32 + −1 0 0 −3 Unknown Unknown

^ Particle has not yet been observed.
[h] ^ PDG reports the resonance width (Γ). Here the conversion τ = ħΓ is given instead.

Baryon resonance particles[edit]

This short table gives the name, the quantum numbers (where known), and the status of baryons as given by PDG.[36] Baryon resonance particles are subatomic particles with short half life and high mass, given in brackets. The spin-parity JP (when known) is given with each particle. For the strongly decaying particles, the JP values are considered to be part of the names.

Baryon resonance particles
Nucleons Δ particles Λ particles Σ particles Ξ and Ω particles Charmed particles Bottomed particles
p 1/2+ **** Δ(1232) 3/2+ **** Λ 1/2+ **** Σ+ 1/2+ **** Ξ0 1/2+ **** Λ+
c
1/2+ **** Λ0
b
1/2+ ***
n 1/2+ **** Δ(1600) 3/2+ *** Λ(1405) 1/2- **** Σ0 1/2+ **** Ξ- 1/2+ **** Λc(2595)+ 1/2- *** Λb(5912)0 1/2- ***
N(1440) 1/2+ **** Δ(1620) 1/2- **** Λ(1520) 3/2- **** Σ 1/2+ **** Ξ(1530) 3/2+ **** Λc(2625)+ 3/2- *** Λb(5920)0 3/2- ***
N(1520) 3/2- **** Δ(1700) 3/2- **** Λ(1600) 1/2+ *** Σ(1385) 3/2+ **** Ξ(1620) * Λc(2765)+ * Σb 1/2+ ***
N(1535) 1/2- **** Δ(1750) 1/2+ * Λ(1670) 1/2- **** Σ(1480) * Ξ(1690) *** Λc(2880)+ 5/2+ *** Σ*
b
3/2+ ***
N(1650) 1/2- **** Δ(1900) 1/2- ** Λ(1690) 3/2- **** Σ(1560) ** Ξ(1820) 3/2- *** Λc(2940)+ *** Ξ0
b
, Ξ-
b
1/2+ ***
N(1675) 5/2- **** Δ(1905) 5/2+ **** Λ(1800) 1/2- *** Σ(1580) 3/2- * Ξ(1950) *** Ξb(5945)0 3/2+ ***
N(1680) 5/2+ **** Δ(1910) 1/2+ **** Λ(1810) 1/2+ *** Σ(1620) 1/2- * Ξ(2030) 5/2? *** Σc(2455) 1/2+ **** Ω-
b
1/2+ ***
N(1685) * Δ(1920) 3/2+ *** Λ(1820) 5/2+ **** Σ(1660) 1/2+ *** Ξ(2120) * Σc(2520) 3/2+ ***
N(1700) 3/2- *** Δ(1930) 5/2- *** Λ(1830) 5/2- **** Σ(1670) 3/2- **** Ξ(2250) ** Σc(2800) ***
N(1710) 1/2+ *** Δ(1940) 3/2- ** Λ(1890) 3/2+ **** Σ(1690) ** Ξ(2370) **
N(1720) 3/2+ **** Δ(1950) 7/2+ **** Λ(2000) * Σ(1750) 1/2- *** Ξ(2500) * Ξ+
c
1/2+ ***
N(1860) 5/2+ ** Δ(2000) 5/2+ ** Λ(2020) 7/2+ * Σ(1770) 1/2+ * Ξ0
c
1/2+ ***
N(1875) 3/2- *** Δ(2150) 1/2- * Λ(2100) 7/2- **** Σ(1775) 5/2- **** Ω 3/2+ **** Ξ′+
c
1/2+ ***
N(1880) 1/2+ ** Δ(2200) 7/2- * Λ(2110) 5/2+ *** Σ(1840) 3/2+ * Ω(2250) *** Ξ′0
c
1/2+ ***
N(1895) 1/2- ** Δ(2300) 9/2+ ** Λ(2325) 3/2- * Σ(1880) 1/2+ ** Ω(2380) ** Ξc(2645) 3/2+ ***
N(1900) 3/2+ *** Δ(2350) 5/2- * Λ(2350) 9/2+ *** Σ(1915) 5/2+ **** Ω(2470) ** Ξc(2790) 1/2- ***
N(1990) 7/2+ ** Δ(2390) 7/2+ * Λ(2585) ** Σ(1940) 3/2- *** Ξc(2815) 3/2- ***
N(2000) 5/2+ ** Δ(2400) 9/2- ** Σ(2000) 1/2- * Ξc(2930) *
N(2040) 3/2+ * Δ(2420) 11/2+ **** Σ(2030) 7/2+ **** Ξc(2980) ***
N(2060) 5/2- ** Δ(2750) 13/2- ** Σ(2070) 5/2+ * Ξc(3055) **
N(2100) 1/2+ * Δ(2950) 15/2+ ** Σ(2080) 3/2+ ** Ξc(3080) ***
N(2120) 3/2- ** Σ(2100) 7/2- * Ξc(3123) *
N(2190) 7/2- **** Σ(2250) ***
N(2220) 9/2+ **** Σ(2455) ** Ω0
c
1/2+ ***
N(2250) 9/2- **** Σ(2620) ** Ωc(2770)0 3/2+ ***
N(2300) 1/2+ ** Σ(3000) *
N(2570) 5/2- ** Σ(3170) * Ξ+
cc
*
N(2600) 11/2- ***
N(2700) 13/2+ **
**** Existence is certain, and properties are at least fairly well explored.
*** Existence ranges from fairly certain to certain, but further confirmation is desirable
and/or quantum numbers, branching fractions, etc. are not well determined.
** Evidence of existence is only fair.
* Evidence of existence is poor.

See also[edit]


References[edit]

  1. ^ H. Muir (2003)
  2. ^ K. Carter (2003)
  3. ^ W.-M. Yao et al. (2006): Particle listings – Positive Theta
  4. ^ K. Nakamura et al. (2010): Pentaquarks
  5. ^ J. Beringer et al. (2012) and 2013 partial update for the 2014 edition: Particle summary tables – Baryons
  6. ^ J.G. Körner et al. (1994)
  7. ^ J. Beringer et al. (2012): Particle listings – p+
  8. ^ J. Beringer et al. (2012): Particle listings – n0
  9. ^ J. Beringer et al. (2012): Particle listings – Λ
  10. ^ J. Beringer et al. (2012): Particle listings – Λ
    c
  11. ^ J. Beringer et al. (2012): Particle listings – Λ
    b
  12. ^ J. Beringer et al. (2012): Particle listings – Σ+
  13. ^ J. Beringer et al. (2012): Particle listings – Σ0
  14. ^ J. Beringer et al. (2012): Particle listings – Σ
  15. ^ a b c J. Beringer et al. (2012): Particle listings – Σ
    c
  16. ^ a b J. Beringer et al. (2012): Particle listings – Σ
    b
  17. ^ J. Beringer et al. (2012): Particle listings – Ξ0
  18. ^ J. Beringer et al. (2012): Particle listings – Ξ
  19. ^ J. Beringer et al. (2012): Particle listings – Ξ+
    c
  20. ^ J. Beringer et al. (2012): Particle listings – Ξ0
    c
  21. ^ J. Beringer et al. (2012): Particle listings – Ξ′+
    c
  22. ^ J. Beringer et al. (2012): Particle listings – Ξ′0
    c
  23. ^ a b J. Beringer et al. (2012): Particle listings – Ξ+
    cc
  24. ^ a b J. Beringer et al. (2012): Particle listings – Ξ
    b
  25. ^ J. Beringer et al. (2012): Particle listings – Ω0
    c
  26. ^ J. Beringer et al. (2012): Particle listings – Ω
    b
  27. ^ a b c d J. Beringer et al. (2012): Particle listings – Δ(1232)
  28. ^ a b c J. Beringer et al. (2012): Particle listings – Σ(1385)
  29. ^ a b c J. Beringer et al. (2012): Particle listings – Σ
    c
    (2520)
  30. ^ a b J. Beringer et al. (2012): Particle listings – Σ
    b
  31. ^ a b J. Beringer et al. (2012): Particle listings – Ξ(1530)
  32. ^ a b J. Beringer et al. (2012): Particle listings – Ξ
    c
    (2645)
  33. ^ J. Beringer et al. (2012): Particle listings – Ξ0
    b
    (5945)
  34. ^ J. Beringer et al. (2012): Particle listings – Ω
  35. ^ J. Beringer et al. (2012): Particle listings – Ω0
    c
    (2770)
  36. ^ http://pdg.lbl.gov/2013/tables/rpp2013-qtab-baryons.pdf

Bibliography[edit]

Further reading[edit]

External links[edit]