Main Question or Discussion Point
Quick question. If particles that mediate interactions are called gauge bosons, why isn't Pion considered a gauge boson. I'm pretty sure I've come across a few interactions mediated by it.
You are mixing things up..Just realised that the pion is a meson. So I assume now that the two aren't mutually exclusive. I.e. a meson can also be a boson, or at least a goldstone boson.
No, that's wrong. The (strong) isospin symmetry group is a global symmetry, so there are no gauge bosons.I am sure I do not remember it correctly, but it seemed to me that pions were the gauge bosons of the isotopic symmetry group (Yang-Mills fields).