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Can someone explain conserved quantities in this activity

  1. Aug 21, 2012 #1
  2. jcsd
  3. Aug 21, 2012 #2


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    2017 Award

    Staff: Mentor

    Your link to the answer page is the same as the other link.

    The basic concept to find those quantities: For each observed event, list the sum of charges, number of baryons and so on at both sides (before and after the reaction). If one of those numbers differ in any allowed reaction, the quantity is not conserved. If they are always the same, it might be a conservation rule (you cannot prove conservation rules, just see that you cannot find a violation).

    The unobserved events can give you a hint which properties might be interesting to look at, especially if both sides are very similar.
  4. Aug 22, 2012 #3
  5. Aug 22, 2012 #4
    also as the answers are baryon number, electric charge and lepton number
    in the question it says that all three quantities should be in all the observed events while at least one is missing from all the unobserved events
    I can kinda find the missing ones in the unobserved events but the observed events some of them don't have any leptons to begin with, then how can they have lepton number????
  6. Aug 22, 2012 #5


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    In this case the lepton number is 0. (the lepton number of a baryon is 0)
  7. Aug 24, 2012 #6
    i think i get it now
    thanks for all the help guys :D
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