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Stable particles

  1. Dec 21, 2014 #1
    How can be sure than the unique stable particles are the neutrons, the electrons, the photons and the neutrinos? Couln´t it be possible than at low energies were there more particles??
  2. jcsd
  3. Dec 21, 2014 #2

    Vanadium 50

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    Protons are stable. Free neutrons are not.

    There could be more particles, but they cannot interact strongly with ordinary matter, or we would have seen them by now.
  4. Dec 21, 2014 #3


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  5. Dec 21, 2014 #4
    A 2014 result with 260kT·yr of data, searching for decay to K-mesons set a lower limit of 5.9 × 1033 yr,[5] close to a supersymmetry (SUSY) prediction of near 1034yr.[6]
    And the universe is 13.8 x 109 yrs old so that's pretty stable.
  6. Dec 21, 2014 #5


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    1033 and 1034 should be 1033 and 1034.
  7. Dec 22, 2014 #6
    Sorry, I copy and pasted from jtbell's link...
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