Determine whether the following proposed decay for the charged pion ${\pi }^{-}$ is possible:

${\pi }^{-}\to {\mu }^{-}+{\underset{ˉ}{\nu }}_e$

State the quark configurations of the charged kaon $K^{+}$ and its antiparticle, the charged kaon $K^{-}$.

A student suggests that because the neutral pion ${\pi }^0$ is its own antiparticle, both the charged pion ${\pi }^{+}$ and the charged kaon $K^{+}$ must also be their own antiparticles.

Discuss whether this suggestion is correct, referencing their quark configurations, charges, or other physical properties.