Exotic baryon
Encyclopedia
Exotic baryons are hypothetical composite particles which are bound states of 3 quark
s and additional elementary particle
s. This is to be contrasted with ordinary baryon
s, which are bound states of just 3 quarks. The additional particles may include quark
s, antiquarks or gluon
s.
One such exotic baryon is the pentaquark
, which consists of four quarks and an antiquark. Another exotic baryon which consists only of quarks is the H dibaryon
, which consists of two up quark
s, two down quark
s and two strange quark
s. Unlike the pentaquark, this particle might be long lived or even stable. There have been unconfirmed claims of detections of pentaquarks and dibaryons.
Several types of exotic baryons which require physics beyond the Standard Model have been conjectured in order to explain specific experimental anomalies. There is no independent experimental evidence for any of these particles. One example is supersymmetric
R-baryons, which are bound states of 3 quarks and a gluino
. The lightest R-baryon is denoted as
and consists of an up quark, a down quark, a strange quark and a gluino. This particle is expected to be long lived or stable and has been invoked to explain ultrahigh-energy cosmic rays. Stable exotic baryons are also candidates for strongly interacting dark matter
.
It has been speculated that by the end of the 21st century it may be possible by using femtotechnology
to create new chemical element
s composed of exotic baryons that would eventually constitute a new periodic table of elements in which the elements would have completely different properties than the regular chemical elements.
Quark
A quark is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as color confinement, quarks are never directly...
s and additional elementary particle
Elementary particle
In particle physics, an elementary particle or fundamental particle is a particle not known to have substructure; that is, it is not known to be made up of smaller particles. If an elementary particle truly has no substructure, then it is one of the basic building blocks of the universe from which...
s. This is to be contrasted with ordinary baryon
Baryon
A baryon is a composite particle made up of three quarks . Baryons and mesons belong to the hadron family, which are the quark-based particles...
s, which are bound states of just 3 quarks. The additional particles may include quark
Quark
A quark is an elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as color confinement, quarks are never directly...
s, antiquarks or gluon
Gluon
Gluons are elementary particles which act as the exchange particles for the color force between quarks, analogous to the exchange of photons in the electromagnetic force between two charged particles....
s.
One such exotic baryon is the pentaquark
Pentaquark
A pentaquark is a hypothetical subatomic particle consisting of four quarks and one antiquark bound together . As quarks have a baryon number of +, and antiquarks of −, it would have a total baryon number of 1, thus being classified as an exotic baryon...
, which consists of four quarks and an antiquark. Another exotic baryon which consists only of quarks is the H dibaryon
Dibaryon
Dibaryons are a large family of hypothetical particles that would consist of six quarks of any flavours. They are predicted to be fairly stable once formed...
, which consists of two up quark
Up quark
The up quark or u quark is the lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the down quark, forms the neutrons and protons of atomic nuclei...
s, two down quark
Down quark
The down quark or d quark is the second-lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the up quark, forms the neutrons and protons of atomic nuclei...
s and two strange quark
Strange quark
The strange quark or s quark is the third-lightest of all quarks, a type of elementary particle. Strange quarks are found in hadrons, which are subatomic particles. Example of hadrons containing strange quarks include kaons , strange D mesons , Sigma baryons , and other strange particles...
s. Unlike the pentaquark, this particle might be long lived or even stable. There have been unconfirmed claims of detections of pentaquarks and dibaryons.
Several types of exotic baryons which require physics beyond the Standard Model have been conjectured in order to explain specific experimental anomalies. There is no independent experimental evidence for any of these particles. One example is supersymmetric
Supersymmetry
In particle physics, supersymmetry is a symmetry that relates elementary particles of one spin to other particles that differ by half a unit of spin and are known as superpartners...
R-baryons, which are bound states of 3 quarks and a gluino
Gluino
A gluino is the hypothetical supersymmetric partner of a gluon. Gluinos are expected by supersymmetry theorists to be pair produced in particle accelerators such as the Large Hadron Collider if they exist....
. The lightest R-baryon is denoted as
and consists of an up quark, a down quark, a strange quark and a gluino. This particle is expected to be long lived or stable and has been invoked to explain ultrahigh-energy cosmic rays. Stable exotic baryons are also candidates for strongly interacting dark matterSIMP
In astrophysics SIMP is an abbreviation of Strongly Interacting Massive Particle. SIMPs could form the inferred dark matter despite their strong interactions with ordinary matter....
.
It has been speculated that by the end of the 21st century it may be possible by using femtotechnology
Femtotechnology
Femtotechnology is a hypothetical term used in reference to structuring of matter on a femtometer, which is 10-15 m. This is a smaller scale in comparison to nanotechnology and picotechnology which are 10-9 m and 10-12 m respectively...
to create new chemical element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
s composed of exotic baryons that would eventually constitute a new periodic table of elements in which the elements would have completely different properties than the regular chemical elements.