List of baryons

Baryons are composite particles made of three quarks, as opposed to mesons, which are composite particles made of an equal number of quarks and antiquarks. Baryons and mesons are both hadrons, which are particles composed solely of quarks or both quarks and antiquarks. 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.

Pentaquarks are exotic baryons composed of four quarks and one antiquark. In 2015, the LHCb collaboration at CERN definitively reported the observation of pentaquark states in the decay of bottom lambda baryons (Λ).R. Aaij et al. (2015) Since then, additional pentaquark states have been discovered, including new observations in 2019 and 2022. While primarily created in laboratory conditions, pentaquarks might also form naturally during neutron star formation.

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 best known baryons are protons and neutrons, which 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, known as an antibaryon, in which quarks are replaced by their corresponding antiquarks. For example, a proton is made of two up quarks and one down quark, while its corresponding antiparticle, the antiproton, is made of two up antiquarks and one down antiquark.

Baryon properties These lists detail all known and predicted baryons in total angular momentum J = and J = configurations with positive parity. Baryons composed of one type of quark (uuu, ddd, ...) can exist in J = configuration, but J = is forbidden by the Pauli exclusion principle. Baryons composed of two types of quarks (uud, uus, ...) can exist in both J = and J = configurations. Baryons composed of three types of quarks (uds, udc, ...) can exist in both J = and J = configurations. Two J = 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), (bottomness), as well as a wide array of subatomic particles (hover for name). (See Baryon for a detailed explanation of these symbols.)

Antibaryons are not listed in the tables; however, they simply would have all quarks changed to antiquarks, and Q, B, S, C, , would be of opposite signs. Particles with † next to their names have been predicted by the Standard Model but not yet observed. Values in parentheses have not been firmly established by experiments, but are predicted by the quark model and are consistent with the measurements.S. Navas et al. (2024): Particle summary tables – BaryonsJ.G. Körner et al. (1994)

JP = + baryons +JP = + baryons Particle name Symbol Quark content Rest mass I JP Q S C B′ Mean lifetime Commonlydecays to protonS. Navas et al. (2024): Particle listings – , ,

0 0 0

unobserved neutronS. Navas et al. (2024): Particle listings – , ,

+ 0 0 0 0

lambdaS. Navas et al. (2024): Particle listings –

0 + 0

0 0

charmed lambdaP.A. Zyla et al. (2020): Particle listings –

0 +

see decay modes bottom lambdaP.A. Zyla et al. (2020): Particle listings –

(0)

0 0 0

see decay modes sigmaP.A. Zyla et al. (2020): Particle listings –

1 +

0 0

sigmaP.A. Zyla et al. (2020): Particle listings –

1 + 0

0 0

sigmaP.A. Zyla et al. (2020): Particle listings –

1 +

0 0

charmed sigmaP.A. Zyla et al. (2020): Particle listings – (2455) (2455)

1 +

charmed sigma (2455)

1 +

charmed sigma (2455)

1 + 0 0

bottom sigmaP.A. Zyla et al. (2020): Particle listings –

(1)

0 0

bottom sigma

5 811.8 ± 1.0 (1) (+) 0 0 0

unknown unknown bottom sigma

(1)

0 0

xiP.A. Zyla et al. (2020): Particle listings –

(+) 0

0 0

xiP.A. Zyla et al. (2020): Particle listings –

(+)

0 0

charmed xiP.A. Zyla et al. (2020): Particle listings –

see decay modes charmed xiP.A. Zyla et al. (2020): Particle listings –

see decay modes charmed xi primeP.A. Zyla et al. (2020): Particle listings –

0 unknown charmed xi primeP.A. Zyla et al. (2020): Particle listings –

0 unknown double charmed xiP.A. Zyla et al. (2020): Particle listings –

0 unknown see decay modes double charmed xi

0 unknown bottom xiP.A. Zyla et al. (2020): Particle listings – or cascade B

see decay modes bottom xior cascade B

see decay modes bottom xi prime†

unknown

unknown unknown bottom xi prime†

unknown

unknown unknown double bottom xi†

unknown

0 0 0

unknown unknown double bottom xi†

unknown

0 0

unknown unknown charmed bottom xi†

unknown

unknown unknown charmed bottom xi†

unknown

0 0

unknown unknown charmed bottom xi prime†

unknown

unknown unknown charmed bottom xi prime†

unknown

0 0

unknown unknown charmed omegaP.A. Zyla et al. (2020): Particle listings –

(0)

see decay modes bottom omegaP.A. Zyla et al. (2020): Particle listings –

(0)

double charmed omega

(0)

0 unknown unknown charmed bottom omega†

unknown (0)

unknown unknown charmed bottom omega prime†

unknown (0)

unknown unknown double bottom omega†

unknown (0)

unknown unknown double charmed bottom omega†

unknown (0)

unknown unknown charmed double bottom omega†

unknown (0)

0 0

unknown unknown † Particle has not yet been observed. [a] The masses of the proton and neutron are known with much better precision in daltons (Da) than in MeV/c2. In atomic mass units, the mass of the proton is whereas that of the neutron is [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 = is given instead.

JP = + baryons +JP = + baryons Particle name Symbol Quarkcontent Rest mass I JP Q S C B′ Mean lifetime Commonlydecays to deltaP.A. Zyla et al. (2020): Particle listings – (1232) (1232)

0 0 0

delta (1232)

0 0 0

delta (1232)

0 0 0 0

delta (1232)

0 0 0

sigmaP.A. Zyla et al. (2020): Particle listings – (1385) (1385)

0 0

sigma (1385)

0 0

sigma (1385)

0 0

charmed sigmaP.A. Zyla et al. (2020): Particle listings – (2520) (2520)

charmed sigma (2520)

0 0

bottom sigmaP.A. Zyla et al. (2020): Particle listings –

(1)

0 0

bottom sigma

unknown (1)

0 0 0

unknown unknown bottom sigma

(1)

0 0

xiP.A. Zyla et al. (2020): Particle listings – (1530) (1530)

0 0

xi (1530)

0 0

charmed xiP.A. Zyla et al. (2020): Particle listings – (2645) (2645)

charmed xi (2645)

double charmed xi†

unknown

0 unknown unknown double charmed xi†

unknown

0 unknown unknown bottom xiP.A. Zyla et al. (2020): Particle listings – (5945)

bottom xiP.A. Zyla et al. (2020): Particle listings – (5955)

± 0.05

double bottom xi†

unknown

0 0 0

unknown unknown double bottom xi†

unknown

0 0

unknown unknown charmed bottom xi†

unknown

unknown unknown charmed bottom xi†

unknown

0 0

unknown unknown omegaJ. Beringer et al. (2012): Particle listings –

0 +

0 0

charmed omegaJ. Beringer et al. (2012): Particle listings – (2770) (2770)

0 unknown bottom omega†

unknown (0)

unknown unknown double charmed omega†

unknown (0)

0 unknown unknown charmed bottom omega†

unknown (0)

unknown unknown double bottom omega†

unknown (0)

unknown unknown triple charmed omega†

unknown (0)

0 unknown unknown double charmed bottom omega†

unknown (0)

unknown unknown charmed double bottom omega†

unknown (0)

0 0

unknown unknown triple bottom omega†

unknown (0)

0 0

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

Baryon resonance particles This table gives the name, quantum numbers (where known), and experimental status of baryon resonances confirmed by the PDG. Baryon resonance particles (including all not in the above two tables) are excited baryon states with short half lives and higher masses. Despite significant research, the fundamental degrees of freedom behind baryon excitation spectra are still poorly understood. 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, as is the mass for all resonances.

+ Baryon resonance particles Nucleons Δ particles Λ particles Σ particles Ξ and Ω particles Charmed particles Bottom particles p + **** Δ(1232) + **** Λ + **** Σ+ + **** Ξ0 + **** + **** + *** n + **** Δ(1600) + **** Λ(1405) − **** Σ0 + **** Ξ− + **** Λc(2595)+ − *** Λb(5912)0 − *** N(1440) + **** Δ(1620) − **** Λ(1520) − **** Σ− + **** Ξ(1530) + **** Λc(2625)+ − *** Λb(5920)0 − *** N(1520) − **** Δ(1700) − **** Λ(1600) + *** Σ(1385) + **** Ξ(1620) * Λc(2765)+ * Σb + *** N(1535) − **** Δ(1750) + * Λ(1670) − **** Σ(1480) * Ξ(1690) *** Λc(2860)+ + *** + *** N(1650) − **** Δ(1900) − *** Λ(1690) − **** Σ(1560) ** Ξ(1820) − *** Λc(2880)+ + *** , + *** N(1675) − **** Δ(1905) + **** Λ(1710) + * Σ(1580) − * Ξ(1950) *** Λc(2940)+ −*** Ξ'b(5935)− + *** N(1680) + **** Δ(1910) + **** Λ(1800) − *** Σ(1620) − * Ξ(2030) ≥ ? *** Σc(2455) + **** Ξb(5945)0 + *** N(1700) − *** Δ(1920) + *** Λ(1810) + *** Σ(1660) + *** Ξ(2120) * Σc(2520) + *** Ξb(5955)− + *** N(1710) + **** Δ(1930) − *** Λ(1820) + **** Σ(1670) − **** Ξ(2250) ** Σc(2800) *** + *** N(1720) + **** Δ(1940) − ** Λ(1830) − **** Σ(1690) ** Ξ(2370) ** Pc(4380)+ * N(1860) + ** Δ(1950) + **** Λ(1890) + **** Σ(1730) + * Ξ(2500) * + *** Pc(4450)+ * N(1875) − *** Δ(2000) + ** Λ(2000) * Σ(1750) − *** + *** N(1880) + *** Δ(2150) − * Λ(2020) + * Σ(1770) + * Ω− + **** + *** N(1895) − **** Δ(2200) − *** Λ(2050) − * Σ(1775) − **** Ω(2250)− *** + *** N(1900) + **** Δ(2300) + ** Λ(2100) − **** Σ(1840) + * Ω(2380)− ** Ξc(2645) + *** N(1990) + ** Δ(2350) − * Λ(2110) + *** Σ(1880) + ** Ω(2470)− ** Ξc(2790) − *** N(2000) + ** Δ(2390) + * Λ(2325) − * Σ(1900) − * Ξc(2815) − *** N(2040) + * Δ(2400) − ** Λ(2350) + *** Σ(1915) + **** Ξc(2930) * N(2060) − *** Δ(2420) + **** Λ(2585) ** Σ(1940) + * Ξc(2980) *** N(2100) + *** Δ(2750) − ** Σ(1940) − *** Ξc(3055) *** N(2120) − *** Δ(2950) + ** Σ(2000) − * Ξc(3080) *** N(2190) − **** Σ(2030) + **** Ξc(3123) * N(2220) + **** Σ(2070) + * N(2250) − **** Σ(2080) + ** + *** N(2300) + ** Σ(2100) − * Ωc(2770)0 + *** N(2570) − ** Σ(2250) *** Ωc(3000)0 *** N(2600) − *** Σ(2455) ** Ωc(3050)0 *** N(2700) + ** Σ(2620) ** Ωc(3065)0 *** Σ(3000) * Ωc(3090)0 *** Ωc(3120)0 *** * ***

**** 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 Baryons Eightfold way (physics) List of mesons List of particles Resonance (particle physics) Roper resonance Timeline of particle discoveries

References

Bibliography

List of baryons

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