EXCLUSIVE SEMILEPTONIC DECAY OF D-MESON AND B-MESON IN THE INDEPENDENT QUARK-MODEL

We investigate the exclusive semileptonic decay modes D-0 --> K,K and (B) over bar(0) --> D,D in a field-theoretic framework based on the independent quark model with a scalar-vector-harmonic potential. Our p redictions for the relevant form factors and their q(2) dependence are in reasonable agreement with the expectations of HQET and those of se veral other models. We predict that the decay width ratio and the pola rization ratio for D-0 decays are Gamma(D-0 --> K--)/Gamma(D-0 --> K- ) = 0.68 and Gamma(L)(D-0 --> K--)/Gamma(T)(D-0 --> K-*-) = 0.52 and those for (B) over bar(0) decays are Gamma((B) over bar(0) --> D-+)/G amma((B) over bar(0) --> D-+) = 1.87 and Gamma(L)((B) over bar(0) --> D-+)/Gamma(T)((B) over bar(0) --> D-*+) = 0.77, respectively.