TTP02-37 Parton--Hadron Duality in $B$ Meson Decays

We summarize the current view on Parton-Hadron duality as it applies to $B$ meson decays. It is emphasized that an OPE treatment is essential for properly formulating duality and its limitations. Duality violations are unlikely to become the limiting factor in describing semileptonic $B$ width vis-a-vie higher order corrections. The consistent extraction of the $b$ quark mass from $B$ production and decays provides a striking example of the theoretical control achieved.