Neutral antikaon
= Neutral antikaon
{title2=$\bar K^0=s\bar d$}
The neutral strange <meson> with <strangeness> $-1$ and valence content $s\bar d$. It is distinct from the neutral kaon flavour state $K^0=d\bar s$, which has strangeness $+1$. These are flavour eigenstates, not the weak-interaction propagation eigenstates of <neutral kaon mixing>.