What observation of the process: (anti muon neutrino) + (electron) -> (anti muon neutrino) + (electron) constitutes unambiguous evidence for weak neutral currents,
whereas the observation of (anti electron neutrino) + (electron) -> (anti electron neutrino) + (electron)
The Attempt at a Solution
The solution is the first one:
Since the second reaction can undergo via W+ as well as Z0:
My question is in the Feynman diagrams, why could you not have this for example:
An electron decaying to a muon neutrino ?
Apparently the weak interaction also violates charge conservation, but I have never seen a possible reaction with a Feynman diagram that is violated at the vertices's.
Many thanks for any help :)