The Properties of Semileptonic Decays of Charmed D Mesons

[摘要]

The MARK III collaboration has collected a large sample of D mesons produced at the Ψ(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 D⁰ → K^- e⁺ ν_e, D⁰ → K^- π⁰ e⁺ ν_e, D⁰ → K̅⁰ π^- e⁺ ν_e, D⁺ → K̅⁰ e⁺ ν_e, D⁺ → K^- π⁺ e⁺ ν_e, D⁰ → π^- e⁺ ν_e, D⁰ → K^- μ⁺ ν_μ, D⁰ → K̅⁰ π^- μ⁺ ν_μ, and D⁺ → K̅⁰ μ⁺ ν_μ. The sums of the 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⁺ ν_e is found to be about 55%. The vector form factor in the decays D⁰ → K^- e⁺ ν_e and D⁰ → K^- μ⁺ ν_μ is measured and found to be consistent with a simple pole form.

[发布机构] University:California Institute of Technology;Department:Physics, Mathematics and Astronomy

[关键词] Physics