particle physics phenomenology In physics, phenomenology is the application of theoretical physics to experimental data by making quantitative predictions based upon known theories. It is related to the philosophical notion of the same name in that these predictions describe ...

, chiral color is a speculative model which extends

quantum chromodynamics In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons. Quarks are fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a ty ...

(QCD), the generally accepted theory for the strong interactions of

quark 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 common ...

s. QCD is a

gauge field theory In physics, a gauge theory is a type of field theory in which the Lagrangian (and hence the dynamics of the system itself) does not change (is invariant) under local transformations according to certain smooth families of operations (Lie groups ...

based on a

gauge group In physics, a gauge theory is a type of field theory in which the Lagrangian (and hence the dynamics of the system itself) does not change (is invariant) under local transformations according to certain smooth families of operations (Lie groups ...

known as color SU(3)_C with an octet of colored

gluon 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 bi ...

s 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 In the mathematical discipline of group theory, for a given group the diagonal subgroup of the ''n''-fold direct product is the subgroup :\. This subgroup is isomorphic to Properties and applications * If acts on a set the ''n''-fold diago ...

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, 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 Fermi National Accelerator Laboratory (Fermilab), located just outside Batavia, Illinois, near Chicago, is a United States Department of Energy United States Department of Energy National Labs, national laboratory specializing in high-energy parti ...

have 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 The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundr ...

References

Physics beyond the Standard Model {{particle-stub