# Are Different Charged Gluons Repulsive in the Gluon-Gluon Four-Point Vertex?

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• simplemind
In summary, the conversation discusses six different Feynman graphs for the Four-Point vertex in QCD. The first of these graphs shows two gluons meeting at a point and going away. The question is asked whether two different charged gluons interacting in this way are repulsive. However, it is explained that calculating just one diagram is not sufficient and all diagrams must be considered together. The conversation ends with the conclusion that it is not possible to give an answer to this question.
simplemind
Hello,

First,i am an absolute beginner in QCD.

As i have seen there are six different Feynmangraphs for the Four-Point vertex.
Swordfish,Box,...

I am interested in the first of the six where the two gluons met in a point and goes away.
My question now is.
If for this case two different charged Gluons interact are they repulsive?

and take a look on the picture on (5.14)

I am interested in the action of the first of the three posibilities the cross and not the lines.

Last edited:
simplemind said:
i am an absolute beginner in CCD
I think you mean QCD.

simplemind said:
first of the six
There is no standard counting. "First" does not specify.

simplemind said:
If for this case

You can't get a physical quantity by calculating one diagram (it likely won't even be finite). You need to calculate the sum of all diagrams that contribute to a process.

Thanks but i only want to know if the first component acts repulsive or not.
From the sign it is different to the two negative others.
I think it is possible to anwer.

simplemind said:
i only want to know if the first component acts repulsive or not
And this is a meaningless question because, as @Vanadium 50 said, you have to look at all diagrams for a given process together; just looking at one tells you nothing. So it doesn't even make sense to ask if just one diagram "acts repulsive"; just one diagram by itself is physically meaningless.

Thanks but i am interested in it.Maybe it is meaningless in this case.
All diagrams are also interesting but as i said i am interested in the first component.
The background is that diagram 2 and 3 have a gluon between and diagram 1 not!
So i assume that the first diagram has repulsive results wenn the charge of the gluons is different.
For diagram 2 and 3 i think it is attracitve for different charged gluons (other sign as component 1 ) because there is a spin 1 gluon between.
Maybe i am completely wrong because i am a beginner.
I still think that it is possible to give an answer.

weirdoguy
simplemind said:
Maybe i am completely wrong because i am a beginner.
If you think you are asking a meaningful question that can be answered, yes, you are wrong.

simplemind said:
I still think that it is possible to give an answer.
Unfortunately it is not, for reasons that have already been explained.

## What is a Gluon-Gluon Four-point vertex?

A Gluon-Gluon Four-point vertex is a mathematical concept in quantum field theory that describes the interaction between two gluons. Gluons are particles that mediate the strong nuclear force, and the four-point vertex is a way to mathematically describe how these particles interact with each other.

## Why is the Gluon-Gluon Four-point vertex important?

The Gluon-Gluon Four-point vertex is important because it helps us understand and predict the behavior of particles in the strong nuclear force. It is also a key component in the study of quantum chromodynamics, which is the theory that describes the strong nuclear force.

## How is the Gluon-Gluon Four-point vertex calculated?

The Gluon-Gluon Four-point vertex is calculated using Feynman diagrams, which are graphical representations of mathematical equations. These diagrams help us visualize and calculate the interactions between particles in quantum field theory.

## What is the significance of the Gluon-Gluon Four-point vertex in particle physics?

The Gluon-Gluon Four-point vertex is significant in particle physics because it is a fundamental building block in our understanding of the strong nuclear force. It also plays a crucial role in the study of high-energy collisions, such as those at the Large Hadron Collider, where gluons are abundant.

## Are there any practical applications of the Gluon-Gluon Four-point vertex?

While the Gluon-Gluon Four-point vertex is primarily used in theoretical physics, it does have practical applications. For example, understanding the behavior of gluons can help us develop more efficient nuclear energy sources and improve our understanding of the early universe.

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