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Constraints on sterile neutrinos come from an amazingly wide range of different sources. From astrophysical observations (review1, review2) to particle physics experiments (MiniBooNE, Daya Bay, LSND, MINOS)

I have been reading about the astrophysical observations (e.g. XMM-Newton), but they rarely go much into detail about the constraints and searches for sterile neutrinos via experiments.

Having little experience in particle physics, I would truly appreciate it if someone could document here, in a sentence or two, what each experiment attempts to constrain, and how.

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    $\begingroup$ In general constraints on sterile neutrino numbers and masses are side effects of other measurements, not the main pursuit of any of these experiments. And they are model dependent, which means that you have to have a reasonably foundational knowledge of basic neutrino oscillation phenomenology to understand how the constraints arise. Can you give us some idea of where you stand on that ground? $\endgroup$ – dmckee Nov 7 '15 at 6:03
  • $\begingroup$ Thank you for your answer dmckee. I have read mostly about papers on cosmology, so my understanding of sterile neutrinos is that a) there are multiple models, b) some of the models allow decay and annihilation c) mass varies, d) cross-section varies, e) some of the models are constrained. If the question's scope is too wide or it is lacking in some aspect I can edit it. In all honesty, I have not studied particle physics much, or neutrino oscillations. $\endgroup$ – Otto Nov 8 '15 at 0:52
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    $\begingroup$ I think it is probably a good question, but I'm not an expert on sterile neutrinos, just some guy who can kinda follow along with the talks. Not sure if we have an expert. $\endgroup$ – dmckee Nov 8 '15 at 1:04
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    $\begingroup$ If I were to prepare an answer to your question, my starting point would be the PDG summary on neutrino oscillations and mixing. Note that experiments generally don't directly search for sterile neutrinos; experiments look at one or another or several properties of the neutrinos we already have, and then afterwards ask whether there is any room to comment on various sterile-neutrino scenarios. $\endgroup$ – rob Nov 8 '15 at 21:57
  • $\begingroup$ @rob Thanks a lot for the replies both, especially for Rob's summary link and comment. I see now that the question is not very simple to answer. I'll look through the summary and a few other sources and modify my question accordingly. $\endgroup$ – Otto Nov 9 '15 at 4:48
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First of all, one should distinguish the mass scale of the sterile neutrino. This review talks a lot about the keV sterile neutrino and even heavier cases, that however are not very interesting from the point of view of neutrino oscillations, because their mixing is typically very small. The keV sterile neutrino has possible implications as a dark matter candidate and to explain some astrophysical measurements, however.

A different case is the one of the "light sterile neutrino", with a mass around 1 eV, that could explain the so-called Short BaseLine (SBL) anomalies, which include the results of LSND, MiniBooNE and others. To finally verify the existence of this light sterile neutrino, there are currently ongoing dedicated experiments such as NEOS and DANSS, while many others are planned or under development. It would be very hard to resume here all the experiments and the details, but I think you should be able to find most of the significant information on the light sterile neutrino in the following papers:

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