Exotic baryons are a type of

hadron In particle physics, a hadron (; grc, ἁδρός, hadrós; "stout, thick") is a composite subatomic particle made of two or more quarks held together by the strong interaction. They are analogous to molecules that are held together by the ele ...

(bound states of

quarks A quark () is a type of 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. All commonly ...

and

gluons A gluon ( ) is an elementary particle that acts as the exchange particle (or gauge boson) for the strong force between quarks. It is analogous to the exchange of photons in the electromagnetic force between two charged particles. Gluons bind qu ...

) with

half-integer spin In particle physics, a fermion is a particle that follows Fermi–Dirac statistics. Generally, it has a half-odd-integer spin: spin , spin , etc. In addition, these particles obey the Pauli exclusion principle. Fermions include all quarks and ...

, but with a quark content different from the three quarks (''qqq'') present in conventional

baryons In particle physics, a baryon is a type of composite subatomic particle which contains an odd number of valence quarks (at least 3). Baryons belong to the hadron family of particles; hadrons are composed of quarks. Baryons are also classified ...

. An example would be

pentaquark A pentaquark is a human-made subatomic particle, consisting of four quarks and one antiquark bound together; they are not known to occur naturally, or exist outside of experiments specifically carried out to create them. As quarks have a baryon ...

s, consisting of four quarks and one antiquark (''qqqqq̅''). So far, the only observed exotic baryons are the pentaquarks , discovered in 2015, in 2019 and in 2022 by the

LHCb The LHCb (Large Hadron Collider beauty) experiment is one of eight particle physics detector experiments collecting data at the Large Hadron Collider at CERN. LHCb is a specialized b-physics experiment, designed primarily to measure the paramet ...

collaboration. Several types of exotic baryons that require physics beyond the

Standard Model The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetism, electromagnetic, weak interaction, weak and strong interactions - excluding gravity) in the universe and classifying a ...

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 In a supersymmetric theory the equations for force and the equations for matter are identical. In theoretical and mathematical physics, any theory with this property has the principle of supersymmetry (SUSY). Dozens of supersymmetric theories ...

R-baryons, which are bound states of 3 quarks and a

gluino In supersymmetry, a gluino (symbol ) is the hypothetical supersymmetric partner of a gluon. In supersymmetric theories, gluinos are Majorana fermions and interact via the strong force as a color octet. Gluinos have a lepton number 0, baryon number ...

. The lightest R-baryon is denoted as S 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 ultra-high-energy cosmic rays. Stable exotic baryons are also candidates for

strongly interacting dark matter Strongly interacting massive particles (SIMPs) are hypothetical particles that interact strongly between themselves and weakly with ordinary matter, but could form the inferred dark matter despite this. Strongly interacting massive particles hav ...

. It has been speculated by

futurologist Futurists (also known as futurologists, prospectivists, foresight practitioners and horizon scanners) are people whose specialty or interest is futurology or the attempt to systematically explore predictions and possibilities abou ...

Ray Kurzweil Raymond Kurzweil ( ; born February 12, 1948) is an American computer scientist, author, inventor, and futurist. He is involved in fields such as optical character recognition (OCR), text-to-speech synthesis, speech recognition technology, and e ...

that by the end of the 21st century it might be possible by using

femtotechnology Femtotechnology is a hypothetical term used in reference to structuring of matter on the scale of a femtometer, which is 10−15 m. This is a smaller scale in comparison with nanotechnology and picotechnology which refer to 10−9 m and ...

to create new

chemical element A chemical element is a species of atoms that have a given number of protons in their nuclei, including the pure substance consisting only of that species. Unlike chemical compounds, chemical elements cannot be broken down into simpler sub ...

s composed of exotic baryons that would eventually constitute a new

periodic table of elements The periodic table, also known as the periodic table of the (chemical) elements, is a rows and columns arrangement of the chemical elements. It is widely used in chemistry, physics, and other sciences, and is generally seen as an icon of c ...

in which the elements would have completely different properties than the regular chemical elements. Kurzweil, Ray ''

The Age of Spiritual Machines ''The Age of Spiritual Machines: When Computers Exceed Human Intelligence'' is a non-fiction book by inventor and futurist Ray Kurzweil about artificial intelligence and the future course of humanity. First published in hardcover on January 1, 1 ...

'' 1999

References

{{Authority control Baryons Hypothetical composite particles