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Are there any particles with all the properties of a WIMP

  1. Dec 1, 2014 #1
    Are there any particles on the Standard Model of Particle Physics with all the properties of a WIMP particle(Weakly Interacting Massive Particles)?
     
    Last edited: Dec 1, 2014
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  3. Dec 1, 2014 #2

    Orodruin

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    Not within the standard model of particle physics. In several extension, there are different WIMP candidates, but none have been discovered so far.
     
  4. Dec 2, 2014 #3

    Vanadium 50

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    Neutrinos have the properties of WIMPs. However, if DM were composed entirely of neutrinos we would see different large scale structure than we do.
     
  5. Dec 2, 2014 #4

    Matterwave

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    I've always thought of the "massive" in WIMPs to mean that they have large mass, and not just that they have some mass. I think most WIMP candidates are in the 100GeV range? Neutrinos are totally not...not even close by any stretch of the imagination, to this mass scale.
     
  6. Dec 2, 2014 #5

    Orodruin

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    You are correct. The WIMP concept typically refers to a weakly interacting particle with a mass large enough for the WIMP miracle to occur, i.e., produced by thermal freeze out when it is non-relativistic. Neutrinos certainly do not fit this description. However, the term WIMP is sometimes used more loosely to refer to any dark matter candidate which interacts weakly - but again, this is not the typical definition of a WIMP.
     
  7. Dec 2, 2014 #6

    Vanadium 50

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    The idea of a WIMP has evolved from when it was first proposed, based on observations and theoretical ideas. One idea is that "weak" means "Weak" - i.e. it is THE weak nuclear force, and not just a weak force. Another is "massive" - the reason people talk about masses in the 100's of GeVs today is because lighter alternatives have problems with observation. Non-discovery being a big one.

    I think my answer is still right - neutrinos could be dark matter candidates. They aren't, but they could be. That is, they have the right particle properties, but the wrong cosmology.
     
  8. Dec 2, 2014 #7

    Orodruin

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    keV sterile neutrinos are still dark matter candidates. However, putting an equal sign between WIMPs and dark matter is dangerous as there are still many other possibilities (axion-like particles, keV sterile neutrinos, WIMPzillas, asymmetric dark matter, SIMPs, FIMPs, just to mention a few). Of course, neutrinos were dark matter candidates, but I would not have considered them a WIMP candidate. I also believe this is still the most common usage of the WIMP terminology.
     
  9. Dec 2, 2014 #8

    Matterwave

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    I've read a few papers a while back published ~a decade ago that were discussing the potential for MeV sterile neutrino dark matter candidates (which I thought were "WIMPs" but apparently were not). That paper did not rule out much of the parameter space (150MeV-500MeV and sin^2(theta)<10^-4 I think) at that time. Has the rest of the parameter space been roughly ruled out in the decade since?
     
  10. Dec 3, 2014 #9

    Ken G

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    Some people hope that dark matter will be explained by "supersymmetry," whereby each particle in the standard model has a supersymmetric pair particle that we generally do not see. The lightest such particle would likely be some type of supersymmetric neutrino, so it would be like a neutrino, but it would need to be much more massive, so would still qualify as a WIMP.
     
  11. Dec 3, 2014 #10

    Chronos

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    Warm dark matter, as in neutrinos, is not yet entirely excluded and meets the WIMP definition. One of the problems with dark matter is we really don't have a clue about how massive the constituent particles need to be to match what little we know about dark matter. I still suspect we will eventually conclude there is a model for dark matter that is similarly diverse to that of the 'standard' model.
     
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