Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quark content of neutral pion

  1. Oct 27, 2013 #1
    The quark content of the neutral pion is listed as [itex]\frac{u\overline{u}-d\overline{d}}{\sqrt{2}}[/itex] What is the proper way to interpret this?
  2. jcsd
  3. Oct 27, 2013 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Can you elaborate? Is your question related to the quantum mechanical interpretation of a superposition of states, or is it more directly related to particle physics? If it is about particle physics, then perhaps the more appropriate way to look at this superposition is as a consequence of the approximate isospin symmetry.
  4. Oct 27, 2013 #3


    User Avatar
    Science Advisor
    Homework Helper

    what is [itex]\frac{u\overline{u}+d\overline{d}}{\sqrt{2}}[/itex] ? :confused:
  5. Oct 27, 2013 #4
    That should be a "-" instead of a "+" in the expession- it was correct in my original post.

    In, for example, the Wikipedia Pion article, the positive pion's quark composition is listed as [itex]u\overline{d}[/itex], and the neutral pion's composition is listed as [itex]u\overline{u}[/itex] or [itex]d\overline{d}[/itex]

    Additionally, the neutral pion's quark content is listed as[itex]\frac{u\overline{u}-d\overline{d}}{\sqrt{2}}[/itex]

    My question is, from a particle physics standpoint, how is [itex]\frac{u\overline{u}-d\overline{d}}{\sqrt{2}}[/itex] related to [itex]u\overline{u}[/itex] or [itex]d\overline{d}[/itex]?
  6. Oct 27, 2013 #5


    User Avatar
    Science Advisor
    Gold Member

    It represents a superposition of the two; the sqrt(2) is the normalization factor.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Quark content of neutral pion
  1. Pions and quarks? (Replies: 8)

  2. Neutral pions (Replies: 15)

  3. Neutral pions (Replies: 2)