Unified Description of Hadrons and Heavy Hadron Decays

We construct an effective Lagrangian which describes interactions of heavy and light hadrons utilizing the chiral flavor symmetry for light quarks and heavy quark symmetry. For both light and heavy sector we include pseudo scalars, vectors and baryons in the Lagrangian. Heavy hadron decays are discussed as application of our formalism. The $D_s$ decay constant and the coupling constant among heavy meson, heavy vector meson and light meson are fitted from the experimental data of $D^0 \rightarrow K^- e^+\nu_e$ decay. We also point out the possibility of model independent determination of $|V_{ub}|$ from $\Lambda_b \rightarrow p l \bar \nu$ decay.