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How abundant is each elementary particle in nature?

  1. Feb 12, 2015 #1
    ...and what form may they found normally?

    Somebody asked me just how many of the particles we know are possible (say, delta baryons) can be found in nature and what is their usual state - are there many particles to be found outside of atoms?
    Although there are enough "abundance of elements" type articles they only address things on the atomic level when baryonic matter is already forming chemical elements. I found no sources that would say for example, how common different types of fermions are and where would you expect them to occur.
    I suspect it could be the wrong type of question as we know that elementary particles mostly arise due to complex field interactions, and yet at the same time, I feel that questions like, "how are these created" "in what kind of places (from a human POV) would they form" "would they exist in isolation from other particles" seem valid.

    I expect that the answer would be something like particles being birthed in stars, and then (presumably) going on to exist thorough space, limited by how easily some find and react with each other, but can anybody provide some more specific information and source on that?
  2. jcsd
  3. Feb 12, 2015 #2

    Simon Bridge

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    I think the answer is "nobody knows". Mainly because the question is too broad.
    A lot will depend on your model - and semantics: for instance, do you count virtual particles? Do vacuum fluctuations count?
    So your first step to providing an answer is to narrow the question down.

    I think you can get to a satisfactory answer though:
    i.e. the relative abundance in cosmic rays would be a good place to start - you'd get most of the parts of the question just there.

    For the short-life articles, you could probably get a guestimate based on how common the energy to create them is. i.e. virtual Higgs bosons would probably be extremely common but the real version would be just about non-existent.

    You should also be able to get a long way by searching "relative abundance" with a family of particle. i.e. "relative abundance of leptons".
  4. Feb 12, 2015 #3


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    As Simon said, the question is ill formed and any answer is model dependent.

    However, to first order, you'd be pretty safe in saying "The fermions that make up our visible universe are mostly the up and down quarks, along with the electron and electron neutrino. There are also a sprinkling of muons and strange quarks." This answer avoids the question of dark matter, naturally.

    You'd of course also be totally fine in saying "the fermions that make up the world of our everyday experience are the up and down quarks, and the electron, in the ratio of approx 6:1 quarks to electrons."
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