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A IceCube search for the 'sterile neutrino' draws a blank

  1. Nov 24, 2016 #21
    Neutrino mass still needs to be explained, you can't just leave only LH neutrinos in SM.

    The most simple "vanilla" SM extension is to add RH neutrinos, giving the same mass generation mechanism as other fermions have. These RH neutrinos would be light, just like LH ones are (which are currently estimated to be below 200 meV, IIRC).

    Unless I'm missing something, IceCube result does not exclude this part of parameter space.
     
    Last edited: Nov 24, 2016
  2. Nov 24, 2016 #22
    would this work,
    LH neutrinos couple to protophobic x-boson 17 MeV, gaining mass and thus oscilation
     
  3. Nov 25, 2016 #23
    Then charged leptons would couple to this boson too, which is not observed.
     
  4. Nov 25, 2016 #24
    maybe muons and tau are electrons that coupled to this force
     
  5. Nov 25, 2016 #25
    I meant that (sufficiently energetic) lepton collisions would emit these bosons, and this would be discovered long ago.
     
  6. Nov 25, 2016 #26
    well if the couplings are weak enough to evade experimental bounds
     
  7. Nov 25, 2016 #27
    Electron interactions by now are measured to precisions on the order of ~10^-9, and they agree with theoretical predictions. This means that such hypothetical couplings are weaker than that, and can only induce neutrino masses below ~1 meV.
     
  8. Nov 25, 2016 #28
    maybe neutrino masses are below ~1 meV, or like the higgs, its couplings to neutrinos are higher than for charged leptons

    the feng boson or light neutral boson, is also postulated to solve anomalous magnetic dipole moment muon and muon radius puzzle
     
  9. Nov 25, 2016 #29
    Higgs-like coupling (IOW: fermion to scalar field coupling) would require existence of RH neutrinos.
     
  10. Nov 25, 2016 #30
    feng proposes his boson is a spin-1 vector boson with axial and vectorlike currents

    my point about the higgs is that it couples to top quarks is quite different from electrons
     
  11. Nov 25, 2016 #31
    Nonzero-spin fields with nonzero VEV break Lorentz invariance.
     
  12. Nov 25, 2016 #32
    perhaps this boson has zero VEV to preserve Lorentz invariance
     
  13. Nov 25, 2016 #33
    Then how it generates neutrino mass?
     
  14. Nov 25, 2016 #34
    if there is more than 1 higgs field, perhaps neutrinos couple to a second set of higgs
     
  15. Nov 28, 2016 #35

    ohwilleke

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    Depends on how "Higgs-like" it has to be. I don't see anything wrong in principle with a scalar field that couples only to left handed particles and thereby generates mass. It wouldn't be very Higgs-like, compared to the SM, but shouldn't be mathematically impossible.
     
  16. Nov 29, 2016 #36

    Urs Schreiber

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    Fuzzy dark matter.

    W. Hu, R. Barkana, and A. Gruzinov, “Cold and fuzzy dark matter,” Phys. Rev. Lett. 85, 1158–1161 (2000), https://arxiv.org/abs/astro-ph/0003365

    One of the big conundrums is that the assumption of dark matter works extremely well on large scales for explaining the structure of the cosmos, but seems to fail to work on the scale of galaxies. One interesting idea how to fix this (without giving up on the established theory of gravity as MOND does) is to assume that dark matter consists of massive but extremely light particles, whose de Broglie wavelength is of the order of thousands of parsecs. This has the consequence that at around the scale of that wavelength the behaviour of this dark matter changes.

    Now Edward Witten et al. have argued in more detail that this works really well, and consistent with existing null results on direct detection:

    Lam Hui, Jeremiah P. Ostriker, Scott Tremaine, Edward Witten, "On the hypothesis that cosmological dark matter is composed of ultra-light bosons" https://arxiv.org/abs/1610.08297
     
  17. Nov 29, 2016 #37
    does this fuzzy dark matter couple to higgs?
     
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