## What is QCD theory?

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.

What does QCD stand for in physics?

quantum chromodynamics (QCD), in physics, the theory that describes the action of the strong force. QCD was constructed in analogy to quantum electrodynamics (QED), the quantum field theory of the electromagnetic force.

### What are the 8 types of gluons?

The strong nuclear force which binds these together inside the nucleons is mediated by gluons which must carry a color-anticolor charge. This seems to give 9 types of gluon: red anti-red, red anti-blue, red anti-green, blue anti-red, blue anti-blue, blue anti-green, green anti-red, green anti-blue, green anti-green.

Who invented quantum chromodynamics?

Harald Fritzsch, one of the pioneers of quantum chromodynamics, recalls some of the background to the development of the theory 40 years ago.

#### What is QCD phase transition?

Concerning the chiral phase transition the possible existence of a first order phase transition implies that the transition line will end at a point known as the QCD critical point or critical end point (CEP): the CEP of a first order line is a critical point where the phase transition is of second order.

What is color in QCD?

QCD: Charge of QCD is called “ colour ” colour is a conserved quantum number with 3 values labelled red, green. and blue.

## What is the difference between photons and gluons?

But there is one major difference between the two: while photons aren’t affected by the force they exert, gluons are. This important fact means that while photons can’t exist in what’s known as a bound state, gluons can be bound together via their own strong nuclear force to form glueballs.

Is QED part of QFT?

The inception of QFT is usually dated 1927 with Dirac’s famous paper on “The quantum theory of the emission and absorption of radiation” (Dirac 1927). Here Dirac coined the name quantum electrodynamics (QED) which is the part of QFT that has been developed first.