Quantum Chromodynamics (QCD) is a physics theory that explains interactions mediated by the strong force, one of the four basic forces of nature.
It was developed as an analogue for Quantum Electrodynamics (QED), which describes interactions owing to the electromagnetic force carried by photons.
The theory of the strong interaction between quarks mediated by gluons, the basic particles that make up composite hadrons like the proton, neutron, and pion, is known as quantum chromodynamics (QCD).
QCD is a non-abelian gauge theory with the symmetry group SU, which is a form of quantum field theory (3).
The color attribute is the QCD equivalent of electric charge.
Gluons are the theory's force carriers, exactly as photons are in quantum electrodynamics for the electromagnetic force.
The hypothesis is an essential aspect of particle physics' Standard Model.
Over the years, a considerable amount of experimental data supporting QCD has accumulated.
How does the QCD scale work?
The quantity is known as the QCD scale in quantum chromodynamics (QCD).
When the energy-momentum involved in the process permits just the up, down, and strange quarks to be produced, but not the heavier quarks, the value is for three "active" quark flavors.
This is equivalent to energies less than 1.275 GeV.
Who was the first to discover quantum chromodynamics?
One of the founders of quantum chromodynamics, Harald Fritzsch, remembers some of the backdrop to the theory's development 40 years ago.
What is the Quantum Electrodynamics (QED) Theory?
Quantum electrodynamics (QED) is the quantum field theory of charged particles' interactions with electromagnetic fields.
It mathematically defines not just light's interactions with matter, but also the interactions of charged particles with one another.
Albert Einstein's theory of special relativity is integrated into each of QED's equations, making it a relativistic theory.
Because atoms and molecules are mainly electromagnetic in nature, all of atomic physics may be thought of as a test bed for the hypothesis.
Experiments using the behavior of subatomic particles known as muons have been some of the most exact tests of QED.
This sort of particle's magnetic moment has been found to accord with theory to nine significant digits.
QED is one of the most effective physics theories ever established, with such great precision.
Recent Developments In The Investigation Of QCD
A new collection of papers edited by Diogo Boito, Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Brazil, and Irinel Caprini, Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest, Romania, and published in The European Physical Journal Special Topics brings together recent developments in the investigation of QCD.
The editors explain in a special introduction to the collection that,
the divergence of perturbation expansions in the mathematical descriptions of a system can have important physical consequences because the strong force — carried by gluons between quarks, forming the fundamental building blocks of matter — described by QCD has a much stronger coupling than the electromagnetic force.
The editors note out that, with to developments in so-called higher-order loop computations, this has become more significant with recent high-precision calculations in QCD.
"The fact that perturbative expansions in QCD are divergent greatly influences the renormalization scheme and scale dependency of the truncated expansions," write Boito and Caprini, "which provides a major source of uncertainty in the theoretical predictions of the standard model."
"One of the primary problems for precision QCD to meet the needs of future accelerator facilities is to understand and tame this behavior."
A cadre of specialists in the subject discuss these and other themes pertaining to QCD, such as the mathematical theory of revival and the presence of infrared (IR) and ultraviolet (UV) renormalons, in the special edition.
These issues are approached from a range of perspectives, including a more basic viewpoint or phenomenological approach, and in the context of related quantum field theories.
~ Jai Krishna Ponnappan
You may also want to read more about Quantum Computing here.
