Eta octet state
= Eta octet state
{c}
{title2=$\eta_8$}
The zero-<isospin>, zero-<flavor hypercharge> state $\eta_8=(u\bar u+d\bar d-2s\bar s)/\sqrt6$ in the pseudoscalar <meson octet>. It is a pure octet basis state; the physical eta may mix it with the flavor-singlet state.