New Theory: Dark Matter Acts Like Pion - Evidence Found

In summary, the conversation discusses the idea that dark matter could be a thermal relic of 3-to-2 scatterings in a strongly coupled hidden sector, with pions playing the role of dark matter particles. This theory is known as the SIMP mechanism and has been proposed in several papers. However, there are some constraints on this idea based on observational evidence that dark matter particles may not be strongly self-interacting. More research is needed to fully understand the viability of this theory.
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  • #2
I can't think of any reason to quickly dismiss the idea, and neither could the peer-reviewers or editors at PRL.

Now, how can it be tested ...
 
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  • #3
Note that it does not say that dark matter is a pion. It is saying it is like a pion under some new gauge symmetry. Pions decay way to fast to be dark matter.
 
  • #4
For reference, here is their article
http://arxiv.org/abs/1411.3727
The SIMPlest Miracle
Yonit Hochberg, Eric Kuflik, Hitoshi Murayama, Tomer Volansky, Jay G. Wacker
(Submitted on 13 Nov 2014)
It has recently been proposed that dark matter could be a thermal relic of 3-to-2 scatterings in a strongly coupled hidden sector. We present explicit classes of strongly coupled gauge theories that admit this behavior. These are QCD-like theories of dynamical chiral symmetry breaking, where the pions play the role of dark matter. The number-changing 3-to-2 process, which sets the dark matter relic abundance, arises from the Wess-Zumino-Witten term. The theories give an explicit relationship between the 3-to-2 annihilation rate and the 2-to-2 self-scattering rate, which alters predictions for structure formation. This is a simple calculable realization of the strongly-interacting-massive-particle (SIMP) mechanism.
7 pages, 2 figures published PRL(2015) with the title changed to "Model for Thermal Relic Dark Matter of Strongly Interacting Massive Particles"
http://inspirehep.net/record/1328090?ln=en
It already has 9 citations.

an earlier paper:
http://arxiv.org/abs/1402.5143
The SIMP Miracle
Yonit Hochberg, Eric Kuflik, Tomer Volansky, Jay G. Wacker
(Submitted on 20 Feb 2014 (v1), last revised 28 Oct 2014 (this version, v2))
We present a new paradigm for achieving thermal relic dark matter. The mechanism arises when a nearly secluded dark sector is thermalized with the Standard Model after reheating. The freezeout process is a number-changing 3->2 annihilation of strongly-interacting-massive-particles (SIMPs) in the dark sector, and points to sub-GeV dark matter. The couplings to the visible sector, necessary for maintaining thermal equilibrium with the Standard Model, imply measurable signals that will allow coverage of a significant part of the parameter space with future indirect- and direct-detection experiments and via direct production of dark matter at colliders. Moreover, 3->2 annihilations typically predict sizable 2->2 self-interactions which naturally address the `core vs. cusp' and `too-big-to-fail' small structure problems.
8 pages, 3 figures; v2: minor updates. Published in PRL(2014) with the title "Mechanism for Thermal Relic Dark Matter of Strongly Interacting Massive Particles."
http://inspirehep.net/search?p=find+eprint+1402.5143
32 citations
I'm not sure but think I've seen one or two papers that seen to constrain this idea using observational evidence that DM particles are not strongly self-interactive. Not sure, but it would be worth a look.

Yes here is something:
http://cerncourier.com/cws/article/cern/60874
but it could be wrong. DM could be more self-interactive than those people found.
another:
http://inspirehep.net/record/1381768
another:
http://arxiv.org/abs/1503.07675
(puts a limit on the self-interaction cross-section)
 
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  • #5
marcus said:
It already has 9 citations.
One of them being this:

Not the SIMPlest Miracle
Martin Hansen, Kasper Langaeble, Francesco Sannino
(Submitted on 6 Jul 2015)
We investigate the phenomenological viability of a recently proposed class of composite dark matter models where the relic density is determined by 3 to 2 number-changing processes in the dark sector. Here the pions of the strongly interacting field theory constitute the dark matter particles. By performing a consistent next-to-leading and next-to-next-to-leading order chiral perturbative investigation we demonstrate that the leading order analysis cannot be used to draw conclusions about the viability of the model. We further show that higher order corrections substantially increase the tension with phenomenological constraints challenging the viability of the simplest realisation of the strongly interacting massive particle (SIMP) paradigm.
 
  • #6
Yes : ^)
I included a link to the Hansen et al "Not the SIMPlest..." paper in my post. It is the second one here---the http://inspirehep.net/record/1381768
marcus said:
...
I'm not sure but think I've seen one or two papers that seen to constrain this idea using observational evidence that DM particles are not strongly self-interactive. Not sure, but it would be worth a look.

Yes here is something:
http://cerncourier.com/cws/article/cern/60874
but it could be wrong. DM could be more self-interactive than those people found.
another:
http://inspirehep.net/record/1381768
another:
http://arxiv.org/abs/1503.07675
(puts a limit on the self-interaction cross-section)
 
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1. What is the new theory about dark matter?

The new theory suggests that dark matter, which is a mysterious substance believed to make up about 85% of the universe's mass, behaves similarly to pions - subatomic particles that are responsible for holding the nucleus of an atom together.

2. What evidence has been found to support this theory?

A team of scientists observed a galaxy cluster and found that the distribution of dark matter within it closely resembles the distribution of pions in a nucleus. This suggests that dark matter may also have a strong self-attraction, similar to the strong force that binds pions together.

3. How does this new theory differ from previous theories about dark matter?

Previous theories proposed that dark matter interacts only through gravity, but this new theory suggests that dark matter may also have a strong nuclear force, similar to the strong force that acts between protons and neutrons in an atom.

4. What implications does this theory have for our understanding of the universe?

If this theory is proven to be true, it would significantly impact our understanding of the universe and the fundamental laws of physics. It could also potentially help us better understand the nature of dark matter and its role in the formation and evolution of galaxies.

5. What further research is needed to confirm this theory?

Further observations and experiments will be needed to confirm this new theory. Scientists will need to study other galaxy clusters and compare the distribution of dark matter to pions. They will also need to conduct simulations and theoretical calculations to test the validity of this theory.

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