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Homework Help: Some reaction between a proton and antiproton

  1. Jun 20, 2007 #1
    1. The problem statement, all variables and given/known data
    Is the following reaction possible? If so, what is the type of interaction (EM, weak or strong)?
    [tex]p+\bar{p}\rightarrow\pi^+ + \pi^- + \pi^0[/tex]

    2. Relevant equations
    Conservation laws and rules of thumb regarding types of interactions.

    3. The attempt at a solution
    I don't think any conservation laws are broken so the process is possible. The question is how exactly. I don't have any idea how to put [itex]\pi^0[/itex] into Feynman diagrams... since its a superposition of two separate quark configurations. I drew the following:
    http://img220.imageshack.us/img220/6554/pixo3.png [Broken]
    If [itex]\pi^0[/itex] was just [itex]u\bar{u}[/itex] then my question would be whether only changing quark configuration means that it is a strong interaction. And if so, how to draw a Feynman diagram showing what really changed.
    But [itex]\pi^0[/itex] is neither it nor [itex]d\bar{d}[/itex] - so what should I do?

    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Jun 20, 2007 #2


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    The [itex]\pi^0[/itex] is a superposition of [itex]u\bar{u}[/itex] and [itex]d\bar{d}[/itex], so [itex]u\bar{u}[/itex] do form a [itex]\pi^0[/itex].
  4. Jun 21, 2007 #3

    Meir Achuz

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    Allowed Strong Interaction
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