I was wondering in two Feynman diagrams (1 and 2)
1) in an electron positron annihilation two photons are created. Now, is the virtual electron the exchanged particle? I'm having problems understanding the diagrams.
2) A proton decays to a neutron as a mu-neutrino collide and a muon (u-) is emitted. As far as I know the exchange particle should be a Boson, but still I'm clueless as it comes to which. I'm ruling out the Z boson, and guessing it should be the W-.
1. e+ + e- -> y (photons) exchange particle?
2. v(u) + n -> p + u-
Here a down quark decays to an up quark and the exchange particle should be the W- boson. Am I on the right track here at all?
The Attempt at a Solution
Some help would be much appreciated.