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LHC vs Cosmic Rays

  1. Sep 14, 2009 #1
    Short question.

    I know that COLLIDING beams are much more effective than when moving particle hits a target in observers reference frame. That is why they make a collider.

    However, when Oh My God particles are observed they actually hit something that something does not move.

    So, when we say that we cant reproduce Cosmic Rays energies on LHC, what exactly do we compare? What reference frame do we use?

    Do we compare energies per particle in our rest frame (ignoring that it is a collider) or not?
  2. jcsd
  3. Sep 14, 2009 #2

    Vanadium 50

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    First, please don't call them "Oh My God particles". That's like calling San Francisco "Frisco".

    To compare, we use energies in the center-of-mass frame. The highest energy cosmic rays have energies in the center of mass frame (assuming proton-proton collisions) of about 750 TeV. The LHC is designed to run proton beams at 14 TeV, and lead beams at about 1150 TeV.
  4. Sep 14, 2009 #3
    You compare apples to apples in the same reference. Just use a lorentz transformation on the energy to make the change.

    BTW what is an Oh My God particle?
  5. Sep 14, 2009 #4
  6. Sep 14, 2009 #5
    Last edited by a moderator: Apr 24, 2017
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