Properties of semileptonic decays of charmed D mesons

The MARK III collaboration has collected a large sample of D mesons produced at the psi(3770) resonance. The reconstruction of several thousand hadronic D decays makes possible for the first time the reconstruction of exclusive semileptonic D decays. Absolute branching ratios are measured for the nine decays. The sums of exclusive branching ratios are in good agreement with the inclusive semileptonic branching ratios measured by the MARK III. The rate of the Cabibbo-suppressed decays is consistent with the predicted rate. The contribution of the K* (892) to the K-π invariant mass spectrum for decays of the type D → K π e+ nu/sub e/ is found to be about 55%. The vector form factor in the decays D0 → K- e+ nu/sub e/ and D0 → K+ μ+ nu/sub μ/ is measured and found to be consistent with a simple pole form