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Homework Help: Pi mesons

  1. Apr 15, 2004 #1
    A quark and an anti - quark combine to form a meson. The pi-meson family is made up of u and d quarks only. A pi-meson can be positively, negatively or neutrally charged.
    Give the quark composition of each of the 3 types of pi-meson.

    The positively charged pion has a composition of an anti down quark and an up quark.

    The neutrally charged pion has a composition of an anti-up quark and an up quark + an anti down quark and a down quark / square root of 2. What does this mean??

    What is the composition of the negatively charged pi meson?

    Is it these 3 types of mesons it is asking me for the compositions of?
  2. jcsd
  3. Apr 15, 2004 #2


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    Staff Emeritus
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    The neutral pi meson is a resonance -- it's either anti-up and up or anti-down and down, and you can't tell the two apart. The total quantum-mechanical state is a combination of both of those possibilitities. That's where the [itex]\sqrt{2}[/itex] comes in.

    The negative pion is the "opposite" of the positive pion -- you can figure it out.

    - Warren
    Last edited: Apr 15, 2004
  4. Apr 15, 2004 #3
    thank you!
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