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

Better Understanding Antimatter Annihilation?

  1. Sep 27, 2010 #1
    So I am taking an introductory particle physics class, and we have started learning about the leptons and how some particles, like neutrinos, have antiparticle pair based on a different in a different quantum number, like Lepton number. Another example is Neutrion and Anti-Neutron which differ in quark/anti-quark content.

    However, this got me wondering....

    Do antiparticle/particle pair that are electrically neutral still annihilate with each other? What about quarks and anti-quarks of the same flavor?

    If so, is the interaction any different from Positron/Electron annihilation?

    Why don't quark/antiquarks of different flavors but equal and opposite charge annihilate?
  2. jcsd
  3. Sep 27, 2010 #2
    For example if a neutron and an antineutron collide one of the quarks of the neutron can interact with an antiquark of the antinuetron producing a gluon, then this one leads to a pair of quarks that hadronize.

    Quarks and antiquarks of different flavors can anihilate, for example an s bar and a d.
  4. Sep 28, 2010 #3
    hmmm... it interesting they quark and antiquark produce a gluon....

    Is the reason its a gluon instead of photon due to the fact that quarks are normally in bound states and the interaction has to occur in the nucleous?

    Or is the gluon produced in a antineutron/neutron reaction just a special case?
  5. Sep 29, 2010 #4
    A quark and an antiquark of the same flavor can annihilate to produce gluons or photons or both. This is because quarks have electric charge, which photons couple to, and color charge, which gluons couple to.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook