  Decays of heavy mesons and of heavy hyperons are used to provide tests of the
standard model and information about new mixing schemes for the $\eta$ and
$\eta^{'}$ mesons. These include the two body decays $B_s \to J / \psi M$ and
$B_d \to J / \psi M$, $B \to \eta (\eta ^{'})K(K^\ast)$ and $\Lambda_b \to
\Lambda \eta (\eta ^{'})$, semileptonic $D$ decays, and properties of radially
excited mesons.
