Lets see the reaction:

$e^- \mu^- \to e^- \pi^- \nu_\mu$

I suppose, that this reaction occurs as follows

$e^- \mu^- \to e^- \mu^- \pi^+ \pi^- \to e^- \pi^- \nu_\mu$

Is it possible at energy less than 2*140 MeV?


The same is for the analogous reaction

$p^+ \mu^+ \to p^+ \pi^+ \bar{\nu}_\mu$

What are the experimental data?