quark-gluon plasma


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Related to quark-gluon plasma: Bose-Einstein condensate, Fermionic condensate

Quark-gluon plasma

A predicted state of matter containing deconfined quarks and gluons. According to the theory of strong interactions, called quantum chromodynamics, hadrons such as mesons and nucleons (the generic name for protons and neutrons) are bound states of more fundamental objects called quarks. The quarks are confined within the individual hadrons by the exchange of particles called gluons. However, calculations indicate that at sufficiently high temperatures or densities, hadronic matter should evolve into a new phase of matter containing deconfined quarks and gluons, called a quark-gluon plasma or quark matter. Such a state of matter is thought to have existed briefly in the period about 1–10 microseconds after the big bang, and might also exist inside the cores of dense neutron stars. See Hadron, Quantum chromodynamics

The study of such a new state of matter requires a means for producing it under controlled laboratory conditions. Experimentally the transition from the hadronic to the quark-gluon phase requires collisions of beams of heavy ions such as nuclei of gold or uranium (although lighter nuclei can be used) with other heavy nuclei at high enough energies to produce the necessary extreme conditions of heat and compression. Quantum chromodynamics calculations using the lattice gauge model indicate that energy densities of at least 1–2 GeV/fm3 (1 femtometer = 10-15 m), about 10 times that found in ordinary nuclear matter, must be produced in the collision for plasma formation to occur. See Nuclear reaction, Relativistic heavy-ion collisions

Accelerator experiments using beams of nuclei with energies of 10–200 GeV/nucleon bombarding stationary nuclear targets have found interesting phenomena such as nuclear stopping. In such cases, the colliding nucleons of the target and projectile are observed to pile up on each other, achieving large nuclear matter densities (two to four times normal nuclear density, or higher) corresponding to energy densities near the threshold for quark matter production. Other results of these experiments suggest that conditions favorable to thermal and chemical equilibrium may be present in some of these collisions. Such experiments can provide critical tests of the theory of the strong interaction and illuminate the earliest moments of the universe. See Elementary particle, Gluons, Quarks

quark–gluon plasma

A state of matter thought to have existed in which isolated hadrons did not exist but in which quarks and gluons formed a ‘hot soup’. It is thought that this state ended about 10–5 seconds after the big bang when there was a phase transition in which hadrons formed as the Universe cooled.

quark-gluon plasma

[′kwärk ′glü‚än ‚plaz·mə]
(nuclear physics)
A state of nuclear matter postulated by quantum chromodynamics to exist at extremely high temperatures and densities in which the neutrons and protons lose their identities and the quarks and gluons form an unstructured collection of particles.
References in periodicals archive ?
To create and study the quark-gluon plasma, nuclear scientists used particle accelerators called the Relativistic Heavy-ion Collider (RHIC) at the Brookhaven National Laboratory in New York and the Large Hadron Collider (LHC) at CERN in Switzerland.
Roland notes that proton-lead collisions should not generate the extreme conditions necessary to produce quark-gluon plasma.
The quark-gluon plasma may look a lot like the hot and heavy goo that existed in the universe right after the Big Bang.
And if it were to be identified, it could give vital clues to how the universe came into being at a time when everything was so hot that it existed only in the form of the infamous quark-gluon plasma.
From the quark-gluon plasma created in a particle collider, light pulses can be emitted, which carry valuable information about the plasma.
With more data still being analyzed and further data-taking scheduled for next February, we are closer than ever to unraveling the properties of the primordial state of the universe: the quark-gluon plasma," he added.
of Orgeon) and Wang (Lawrence Berkeley National Laboratory), this collection of seven papers assesses findings of Brookhaven National Laboratory's Relativistic Heavy Ion Collider related to investigations concerning the potential, but not yet independently verified, creation of quark-gluon plasma, a phase of quantum chromodynamics which consists of quarks and gluons.
The resulting material, called quark-gluon plasma, was tentatively reported at RHIC several years ago.
Ninety-four papers presented at the September 2004 conference discuss recent investigations into the vacuum structure of quantum chromodynamics (QCD), the mechanism of confinement, both light and heavy quarks, the deconfinement mechanism, and quark-gluon plasma formation signals.
It is called quark-gluon plasma and they believe it is the key to understanding both the dawn of the universe and how atomic nuclei work.
It is predicted that the matter in these conditions forms a new phase which is called the quark-gluon plasma (QGP).