Does the strength of the strong interaction depend on the colour of the quarks?

In summary, color is a quantum number that is responsible for generating the strong interaction in the same way that electric charge is responsible for electromagnetism. This has been decided because it is simpler to only have one quantum number instead of two, and also because the strength of the strong interaction is color independent. This means that the colors of the quarks involved do not affect the strength of the interaction. Additionally, if there were two different quantum numbers, we would observe a different spectrum of particles. So, the concept of color is linked to the quantum number that was introduced to avoid violating the Pauli principle.
  • #1
jeebs
325
4
My understanding of colour so far is that if we had, say, a baryon with quark content uuu, we would need to invoke a new quantum number that would allow each quark not to be in the same quantum state to avoid violating the Pauli principle.

Now apparently this new quantum number is called colour charge, and is the source of the strong interaction in the way that electric charge is for electromagnetism. Two questions:
Why has it been decided that this thing we call colour is responsible for generating an attractive potential? Is it just that we do not assign colour to anything that doesn't involve quarks, and quarks are the only ones who participate in the strong interaction, so the two must be related?
Does the strength of the strong interaction vary between which quarks are doing the interacting, for example, does red and blue attract stronger than red and green etc?
 
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  • #2
We name the thing that causes the strong force "color". It's true by definition.

The strength is color independent.
 
  • #3
Vanadium 50 said:
We name the thing that causes the strong force "color". It's true by definition.

The strength is color independent.

but why have we linked what causes the strong force with the quantum number that had to be introduced to get around Pauli exclusion?
 
  • #4
Occam. Why invent two new properties if only one will do?
 
  • #5
Plus, if there were two different quantum numbers, we should observe a different spectrum, should we? Note the fundamental trick of obtaining "white" singlets for unconfined particles.
 
  • #6
You will definitely have trouble antisymmetrizing the wavefunction if you blindly add a duplicate of color.
 

1. What is the strong interaction?

The strong interaction is one of the four fundamental forces of nature, along with gravity, electromagnetism, and the weak interaction. It is responsible for the binding of quarks and gluons to form protons, neutrons, and other hadrons.

2. What are quarks?

Quarks are subatomic particles that make up the building blocks of matter. They are believed to be the smallest particles that make up protons and neutrons, and they come in six different types or "flavors": up, down, charm, strange, top, and bottom.

3. What is the color charge of quarks?

Quarks possess a property called color charge, which is similar to electric charge in that it comes in three different varieties: red, green, and blue. However, unlike electric charge, color charge is a property of the strong interaction and does not have a direct physical manifestation.

4. Does the strength of the strong interaction depend on the color of the quarks?

Yes, the strength of the strong interaction is directly related to the color charge of quarks. The interaction becomes stronger as the distance between quarks increases, which is known as asymptotic freedom. This is due to the exchange of gluons, which are particles that carry the strong force.

5. Are there any known exceptions to the dependence of strong interaction on quark color?

There are some rare cases where the strong interaction does not depend on the color of quarks. For example, in the phenomenon of color confinement, quarks are bound together in such a way that their individual colors cannot be observed. Additionally, in certain extreme environments, such as the early universe or the core of a neutron star, the strong interaction may behave differently than in everyday conditions.

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