Chiral color
Encyclopedia
In particle physics phenomenology
, chiral color is a speculative model
which extends quantum chromodynamics
(QCD), the generally accepted theory for the strong interactions of quark
s. QCD is a gauge field theory based on a gauge group known as color SU(3)C with an octet of colored gluon
s known as gluons acting as the force carriers between a triplet of colored quarks.
In Chiral Color, QCD is extended to a gauge group which is SU(3)L × SU(3)R and leads to a second octet of force carriers. SU(3)C is identified with a diagonal subgroup of these two factors. The gluons correspond to the unbroken gauge bosons and the color octet axigluons -- which couple strongly to the quarks—are massive. Hence the name is Chiral Color. Although Chiral Color has presently no experimental support—which is not really any worse than most models currently investigated—it has the "aesthetic" advantage of rendering the Standard Model more similar in its treatment of the two short range forces, strong and weak interactions.
Unlike gluons, the axigluons are predicted to be massive. Extensive searches for axigluons at CERN
and Fermilab
have successfully placed a lower bound on the axigluon mass of about . Axigluons may be discovered when collisions are studied with higher energy at the Large Hadron Collider
.
Particle physics phenomenology
Particle physics phenomenology is the part of theoretical particle physics that deals with the application of theory to high-energy particle physics experiments. Within the Standard Model, phenomenology is the calculating of detailed predictions for experiments, usually at high precision...
, chiral color is a speculative model
Model building (particle physics)
In particle physics, the term model building refers to a construction of new quantum field theories beyond the Standard Model that have certain features making them attractive theoretically or for possible observations in the near future...
which extends quantum chromodynamics
Quantum chromodynamics
In theoretical physics, quantum chromodynamics is a theory of the strong interaction , a fundamental force describing the interactions of the quarks and gluons making up hadrons . It is the study of the SU Yang–Mills theory of color-charged fermions...
(QCD), the generally accepted theory for the strong interactions of 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. QCD is a gauge field theory based on a gauge group known as color SU(3)C with an octet of colored 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 known as gluons acting as the force carriers between a triplet of colored quarks.
In Chiral Color, QCD is extended to a gauge group which is SU(3)L × SU(3)R and leads to a second octet of force carriers. SU(3)C is identified with a diagonal subgroup of these two factors. The gluons correspond to the unbroken gauge bosons and the color octet axigluons -- which couple strongly to the quarks—are massive. Hence the name is Chiral Color. Although Chiral Color has presently no experimental support—which is not really any worse than most models currently investigated—it has the "aesthetic" advantage of rendering the Standard Model more similar in its treatment of the two short range forces, strong and weak interactions.
Unlike gluons, the axigluons are predicted to be massive. Extensive searches for axigluons at CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
and Fermilab
Fermilab
Fermi National Accelerator Laboratory , located just outside Batavia, Illinois, near Chicago, is a US Department of Energy national laboratory specializing in high-energy particle physics...
have successfully placed a lower bound on the axigluon mass of about . Axigluons may be discovered when collisions are studied with higher energy at the Large Hadron Collider
Large Hadron Collider
The Large Hadron Collider is the world's largest and highest-energy particle accelerator. It is expected to address some of the most fundamental questions of physics, advancing the understanding of the deepest laws of nature....
.