Combinations of three u, d or s-quarks with a total spin of 3/2 form the so-called baryon decuplet.

The octet of light spin-1/2 baryons.

In particle physics, the baryons are the family of subatomic particles which are made of three quarks. The family notably includes the proton and neutron, which make up the atomic nucleus, but many other unstable baryons exist as well. 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 mass than other particles. Image File history File links Download high resolution version (999x817, 86 KB) Decupleto bariônico. ... Image File history File links Download high resolution version (999x817, 86 KB) Decupleto bariônico. ... Image File history File links Download high-resolution version (1059x769, 78 KB) Octeto bariônico. ... Image File history File links Download high-resolution version (1059x769, 78 KB) Octeto bariônico. ... Thousands of particles explode from the collision point of two relativistic (100 GeV per ion) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... A subatomic particle is a particle smaller than an atom: it may be elementary or composite. ... These are the six flavors of quarks and their most likely decay modes. ... // Properties [1][2] In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... This article or section does not adequately cite its references or sources. ... A semi-accurate depiction of the helium atom. ...

Background

Baryons are strongly interacting fermions — that is, they experience the strong nuclear force and are described by Fermi-Dirac statistics, which apply to all particles obeying the Pauli exclusion principle. This is in contrast to the bosons, which do not obey the exclusion principle. In particle physics, fermions are particles with half-integer spin. ... The strong nuclear force or strong interaction (also called color force or colour force) is a fundamental force of nature which affects only quarks and antiquarks, and is mediated by gluons in a similar fashion to how the electromagnetic force is mediated by photons. ... Fermi-Dirac distribution as a function of ε/μ plotted for 4 different temperatures. ... The Pauli exclusion principle is a quantum mechanical principle formulated by Wolfgang Pauli in 1925. ... In particle physics, bosons, named after Satyendra Nath Bose, are particles having integer spin. ...

Baryons, along with mesons, belong to the family of particles known as hadrons, meaning they are composed of quarks. Baryons are fermions composed of three quarks, while mesons are bosons composed of a quark and an antiquark. The quark model classification of baryons is based on this construction. Mesons of spin 1 form a nonet In particle physics, a meson is a strongly interacting boson, that is, it is a hadron with integral spin. ... In particle physics, a hadron is a subatomic particle which experiences the nuclear force. ... These are the six flavors of quarks and their most likely decay modes. ... In physics, the quark model is a classification scheme for hadrons in terms of their valence quarks, ie, the quarks (and antiquarks) which give rise to the quantum numbers of the hadrons. ...

In addition to the nucleons (protons and neutrons), other members of the baryon family include the Δ, Λ, Σ, Ξ and Ω particles. It has been suggested that this article or section be merged with delta radiation. ... In particle physics, the Lambda particle is any one of a number of baryons containing an up quark, a down quark, and a third quark such as that the resulting particle exhibits a state of bottomness, strangeness, or is charmed. ... Properties Sigma particles are baryons composed of one strange quark and a combination of up and down quarks, arranged in an isospin 1 state. ... In particle physics, Ξ (Xi) is a name given to a range of baryons with one up or down quark and two heavier quarks. ... Properties In particle physics, the omega minus (Ω−) is a type of baryon (more specifically, a hyperon). ...

Delta baryons (Δ⁺⁺, Δ⁺, Δ⁰, Δ⁻) are composed of a combination of up and down quarks such that the total spin is 3/2. They primarily decay into a pion and either a proton or neutron. In particle physics, pion (short for pi meson) is the collective name for three subatomic particles: Ï€0, Ï€+ and π−. Pions are the lightest mesons and play an important role in explaining low-energy properties of the strong nuclear force. ... // Properties [1][2] In physics, the proton (Greek proton = first) is a subatomic particle with an electric charge of one positive fundamental unit (1. ... This article or section does not adequately cite its references or sources. ...

Lambda baryons (Λ⁰) are composed of one up, one down, and one strange quark, with the up and down quarks in an isospin 0 (flavor-antisymmetric) state. The neutral lambda provided the first observational evidence of the strange quark. In almost all cases a lambda decays to a proton and a charged pion, or to a neutron and a neutral pion. Isospin (isotopic spin, isobaric spin) is a physical quantity which is mathematically analogous to spin. ...

Sigma baryons (Σ⁺, Σ⁰, Σ⁻), are also composed of one strange quark and a combination of up and down quarks, but arranged in an isospin 1 state. The neutral sigma has the same quark composition as the lambda (up, down, strange), and so decays much faster than either Σ⁺ (up, up, strange) or Σ⁻ (down, down, strange).

Xi baryons, (Ξ⁰, Ξ⁻), are composed of two strange quarks and either an up or down quark. They decay predominantly into a lambda and a pion; the lambda subsequently decays as described above. Because of this cascading sequence of decays, a Ξ state is sometimes referred to as a cascade.

The omega minus baryon (Ω⁻) is composed of three strange quarks. Its discovery was a great triumph in the study of quark processes, since it was found only after its existence, mass, and decay products had already been predicted.

There are additional baryon states which contain heavy quarks. These are denoted by the Greek letter corresponding to their light (up/down/strange) flavor content with a subscript indicating that a strange quark should be replaced by a heavier quark. For example, the Λ⁺_c has quark content (charm, up, down) instead of (strange, up, down). (See: charmed baryons, bottom baryons.) There are very few or no other articles that link to this one. ...

Baryonic matter

Baryonic matter is matter composed mostly of baryons (by mass), which includes atoms of any sort (and thus includes nearly all matter that we may encounter or experience in everyday life, including our bodies). Non-baryonic matter is the fundamental antithesis of such matter, being any sort of matter that is not primarily composed of baryons. This might include such ordinary matter as neutrinos or free electrons; however, it may also include exotic species of non-baryonic dark matter, such as supersymmetric particles, axions or black holes. The distinction between baryonic and non-baryonic matter is important in cosmology, because Big Bang nucleosynthesis models set tight constraints on the amount of baryonic matter present in the early universe. This article or section does not adequately cite its references or sources. ... Properties In chemistry and physics, an atom (Greek ἄτομος or átomos meaning indivisible) is the smallest particle still characterizing a chemical element. ... Look up Experience in Wiktionary, the free dictionary This article discusses the general concept of experience. ... Antithesis (Greek for setting opposite, from against + position) means a direct contrast or exact opposition to something. ... Neutrinos are elementary particles denoted by the symbol ν. Travelling close to the speed of light, lacking electric charge and able to pass through ordinary matter almost undisturbed, they are extremely difficult to detect. ... e- redirects here. ... In astrophysics and cosmology, dark matter is matter, not directly observed and of unknown composition, that does not emit or reflect enough electromagnetic radiation to be detected directly, but whose presence can be inferred from gravitational effects on visible matter. ... This article or section is in need of attention from an expert on the subject. ... The axion is an exotic subatomic particle postulated by Peccei-Quinn theory to resolve the strong-CP problem in quantum chromodynamics (QCD). ... For other senses of this word, see black hole (disambiguation). ... Physical cosmology, as a branch of astrophysics, is the study of the large-scale structure of the universe and is concerned with fundamental questions about its formation and evolution. ... In cosmology, Big Bang nucleosynthesis (or primordial nucleosynthesis) refers to the production of nuclei other than H-1, the normal, light hydrogen, during the early phases of the universe, shortly after the Big Bang. ... Universe is a word derived from the Old French univers, which in turn comes from the Latin roots unus (one) and versus (a form of vertere, to turn). Based on observations of the observable universe, physicists attempt to describe the whole of space-time, including all matter and energy and...

The very existence of baryons is also a significant issue in cosmology, since we have assumed that the Big Bang produced a state with equal amounts of baryons and anti-baryons. The process by which baryons come to outnumber their antiparticles is called baryogenesis (in contrast to a process by which leptons account for the predominance of matter over antimatter, leptogenesis). Baryogenesis is the generic designation for the physical processes that generate matter (more specifically, a class of fundamental particle called baryon) from an otherwise matter-empty state (such as it is generally believed to be the state of the Universe at its onset, the so-called Big Bang). ... In physics, a particle is a lepton if it has a spin of 1/2 and does not experience the strong nuclear force. ... In physics, leptogenesis is a process which creates leptons. ...

See also

• List of baryons
• Baryon number
• Particle physics
• Pentaquark
• List of particles
• Proton decay

Baryon decuplet: Spin=3/2 Baryon octet: Spin=1/2 This is a list of baryons. ... In particle physics, the baryon number is an approximate conserved quantum number. ... Thousands of particles explode from the collision point of two relativistic (100 GeV per ion) gold ions in the STAR detector of the Relativistic Heavy Ion Collider. ... A pentaquark is a subatomic particle consisting of a group of five quarks (compared to three quarks in normal baryons and two in mesons), or more specifically four quarks and one anti-quark. ... This is a list of particles in particle physics, including currently known and hypothetical elementary particles, as well as the composite particles that can be built up from them. ... In particle physics, proton decay is a hypothetical form of radioactive decay in which the proton decays into lighter subatomic particles, usually a neutral pion and a positron. ...

Notes

References and further reading