Pion Plus Decay

Since the charged pions decay into two particles, a muon and a muon neutrino Fractional electric Charge disappeared, why?

The decay proceeds by the weak interaction $W^{+}$ and can be visualized in terms of Feynman diagrams.

my suggestion is that the Fractional electric Charge disappeared because it does not exist at all in the Quarks mechanism.


As you say, there exists a Feynman diagram Feynman diagram

for the process, and the real question is: "what happens with the quarks"

The up and antidown quarks manage to "annihilate" into a virtual W+ which decays into the mu+ and nu_mu.

Simple. All annihilations "disappear" some quantum numbers conserving the over all quantities.

  • 2
    $\begingroup$ +1: Just to make it absolutely clear to the OP, the +1/3 and +2/3 charges of the u and d(bar) add up to exactly the whole unit charge (+1) of the W+ so no charge disappears. $\endgroup$ – FrankH Sep 22 '12 at 14:09
  • $\begingroup$ @anna v "what happens with the quarks", strong interaction and fractional electric charge $\endgroup$ – Neo Sep 22 '12 at 14:13
  • $\begingroup$ @muster-mark In the instance you have chosen it is a weak interaction. $\endgroup$ – dmckee Sep 22 '12 at 14:35
  • $\begingroup$ quarks have non zero couplings with all four interactions: strong weak electromagnetic and gravitational.The weak is the one responsible for the decays. $\endgroup$ – anna v Sep 22 '12 at 14:59

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