Yang-Mills, QED, QCD and Yukawa theories

In summary, the difference between Yang-Mills and QED theories lies in their use of non-abelian and abelian gauge symmetries respectively. Yukawa theory focuses on fermions and scalars, and predicts the existence of a meson with specific properties. The meson-nucleon interaction is a key aspect of the theory, as it mediates the nucleon-nucleon interaction. This was a significant prediction at the time, as the existence of such a meson was not yet known. Yukawa's focus on pion-nucleon interactions was due to the fact that nucleons are fermions while pions are scalars. Additionally, the interaction Lagrangian in Yukawa theory is considered to be effective for
  • #1
Breo
177
0
What is the difference between Yang-Mills and QED theories? Yukawa and QCD? specially in terms of the lagrangians.

I really want to get into this subject with a previously first sight.
 
Physics news on Phys.org
  • #2
Breo said:
What is the difference between Yang-Mills and QED theories? Yukawa and QCD? specially in terms of the lagrangians.

I really want to get into this subject with a previously first sight.

Yang Mills and QCD ( which is just a particular Yang Mills theory) are based on non abelian gauge symmetries while QED is based on abelian gauge symmetry.

Yukawa theory doesn't have spin 1 particles, just fermions and scalars.

However, this is a very general question. I would recommend that you study the subject ( which would take some effort) and come back with more specific questions.
 
  • #3
Why Yukawa focused on the search of the meson-neutron interaction?
 
  • #4
Breo said:
Why Yukawa focused on the search of the meson-neutron interaction?

In what context? do you mean focused on meson-neutron and not meson-proton interactions?
 
  • #5
Nucleon* typo
 
  • #6
Breo said:
Nucleon* typo

In the Yukawa theory, the meson nucleon interaction is the pillar of theory. The nucleon-nucleon interaction is mediated by meson exchange, which is present due to the meson nucleon interaction.
The first and foremost prediction was that a meson with such properties exists, which was not known at the time the theory was published.
 
  • #7
Why did he focus on the pion-nucleons? Because nucleons are fermions spin 1/2 particles while pions are scalar spin 0 particles.
Of course the interaction Lagrangian would be an effective one, since it corresponds to energies lower than the QCD scale...
 

1. What is the Yang-Mills theory?

The Yang-Mills theory is a quantum field theory that describes the interactions between elementary particles. It is based on the idea of local gauge symmetry, which means that the equations of the theory are invariant under certain transformations. This theory is an essential component of the Standard Model of particle physics, which describes the fundamental building blocks of matter and their interactions.

2. What is QED?

QED stands for Quantum Electrodynamics, which is a quantum field theory that describes the interactions between charged particles through the exchange of photons. It is the theory that explains the behavior of electromagnetic forces, such as light and electricity, at the quantum level. QED is also a crucial component of the Standard Model.

3. What is QCD?

QCD stands for Quantum Chromodynamics, which is a quantum field theory that describes the interactions between particles that carry the strong nuclear force, known as gluons. QCD is the theory that explains the behavior of the strong force, which holds the nucleus of an atom together. It is also an important part of the Standard Model.

4. What is the Yukawa theory?

The Yukawa theory, also known as the Yukawa interaction, is a quantum field theory that describes the interactions between particles that carry the weak nuclear force, known as W and Z bosons. This theory was proposed by Hideki Yukawa in the 1930s and is an essential part of the Standard Model, as it explains processes such as radioactive decay.

5. How are these theories used in particle physics?

Yang-Mills, QED, QCD, and Yukawa theories are all used in particle physics to understand the fundamental forces and interactions between particles. These theories have been extensively tested and have accurately predicted the behavior of particles at the subatomic level. They are also used in experiments at particle accelerators, such as the Large Hadron Collider, to study the properties of particles and search for new ones.

Similar threads

A What are some example Feynman diagrams in Yang-Mills theory?
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
2K
A QCD as a classical field theory?
    • High Energy, Nuclear, Particle Physics
Replies
6
Views
2K
I Yang-Mills Lagrangian: Is ##F^{\mu \nu}F_{\mu \nu}## a Number?
    • High Energy, Nuclear, Particle Physics
Replies
6
Views
2K
Yang-Mills theory, confinement and chiral symmetry breaking
    • High Energy, Nuclear, Particle Physics
Replies
2
Views
2K
Classification of Gauge Theories
    • High Energy, Nuclear, Particle Physics
Replies
3
Views
4K
A Nonlocal transformations in Batalin-Vilkovisky theory
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
1K
A Derivation of the Yang-Mills 3 gauge boson vertex
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
2K
Lagrangian of Standard Model Deduction
    • High Energy, Nuclear, Particle Physics
Replies
6
Views
2K
A Generalized Forces and QED/QCD
    • Quantum Physics
Replies
14
Views
1K
I Phenomenological potentials and exchange of force carriers
    • High Energy, Nuclear, Particle Physics
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top