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There is an unusual term called "QCD axion dark matter".

Do you have any idea what "QCD axion dark matter" is?

Here are among others the most recent documents on this subject:

https://arxiv.org/abs/1910.04163 QCD Axion Dark Matter from a Late Time Phase Transition

https://arxiv.org/abs/1905.04686 A Unique Multi-Messenger Signal of QCD Axion Dark Matter

https://arxiv.org/abs/1901.07401 A new experimental approach to probe QCD axion dark matter in the mass range above 40μμeV

https://arxiv.org/abs/1711.10486 QCD Axion Dark Matter with a Small Decay Constant

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The Axion was postulated about 40 years ago as a way of taking care of the strong CP problem in QCD; none have ever been found.
They are weakly interacting but to be a candidate for cold dark matter, must have a mass at least 3-4 orders of magnitude less than an electron, but not lighter.
They are easily included in Maxwell's Equations, but then again, so are magnetic monopoles.

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Here is what I had already written about it. Catch me if i'm wrong:

The difficulty of QCD lies in the interpretation of the SU(3) symmetry due to the convergence of the baryonic flow in relation to the coupling constant.

The role of dark matter in the case of QCD is found in the mass of the axion which is very often taken into account for example very early in the creation of the universe by particle exchange WIMPs.

If I have understood rightly, an outcome could be determined in the relic density in the supersymmetry particles like the neutralino. The SUSY is only an illusion insofar as the exchange of the flow can only be in a dynamic of oscillation alternating between its two potentials (DM-SM).

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On 7/12/2020 at 2:35 AM, Kartazion said:

The role of dark matter in the case of QCD is found in the mass of the axion

A physicist told me this was wrong. What is the relationship between a dark matter axion and the QCD axion?
Or quite simply what about the history of the dark matter in the functioning of the QCD?

Thank you.

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1 hour ago, Kartazion said:

What is the relationship between a dark matter axion and the QCD axion?

The axion is one possible candidate for dark matter.

There isn't a "dark matter axion" and a "QCD axion": https://en.wikipedia.org/wiki/Axion

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7 minutes ago, Strange said:

The axion is one possible candidate for dark matter.

There isn't a "dark matter axion" and a "QCD axion": https://en.wikipedia.org/wiki/Axion

Thank you strange. But what is the link (if there is one) between dark matter and QCD?

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26 minutes ago, Kartazion said:

Thank you strange. But what is the link (if there is one) between dark matter and QCD?

None, specifically, as far as I know. 

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44 minutes ago, Kartazion said:

Thank you strange. But what is the link (if there is one) between dark matter and QCD?

QCD is a model which would explain how the particles interact. Dark matter is a class of matter that is cold and dark. Some axions could be cold, and thus comprise dark matter. QCD (or some other model) would have to explain why they are dark.

But AFAIK, the potential role of the axion as dark matter is because they would have mass.

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19 hours ago, swansont said:

QCD is a model which would explain how the particles interact. Dark matter is a class of matter that is cold and dark. Some axions could be cold, and thus comprise dark matter. QCD (or some other model) would have to explain why they are dark.

Which means that thanks to the strong interaction, we could explain why dark matter is dark?
By what approach or reason do we make this deduction? Is it related to the very weak interaction that can occur?

19 hours ago, swansont said:

But AFAIK, the potential role of the axion as dark matter is because they would have mass.

The mass, and the interaction. The ideal would be to find an axion of a large mass which does not interact at all with baryonic matter. That's it ?
 

Quite the contrary. Are you wondering why dark matter does not interact with baryonic matter?

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4 hours ago, Kartazion said:

Which means that thanks to the strong interaction, we could explain why dark matter is dark?
By what approach or reason do we make this deduction? Is it related to the very weak interaction that can occur?

Do you understand that “weak interaction” has a specific meaning in physics?

 

Quote

The mass, and the interaction. The ideal would be to find an axion of a large mass which does not interact at all with baryonic matter. That's it ?

AFAIK the axion mass is thought to be small; if it was large we would have detected it already. Did you read the link Strange provided? The axion coupling is related to its mass, so what you say here is inconsistent with the axion model. You seem to be describing a WIMP.

 

Quote

Quite the contrary. Are you wondering why dark matter does not interact with baryonic matter?

Why are you asking me? You were the one inquiring about the subject.

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7 minutes ago, swansont said:

Do you understand that “weak interaction” has a specific meaning in physics?

No. Not really.

7 minutes ago, swansont said:

Why are you asking me? You were the one inquiring about the subject.

I have my little idea. But I think that will interest no one. Besides, why to put this thread in speculation?

Thank you for your answers.

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14 hours ago, swansont said:

Yes sorry. Finally I know.

I thought you were talking about a specific detail for the weak interaction with dark matter.

23 hours ago, swansont said:

Do you understand that “weak interaction” has a specific meaning in physics?

Yes.

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