Georg Viehhauser

Abstract:

We have studied semileptonic B meson decays with a p-wave charm meson in the final state using 3.29×10⁶BB^¯ events collected with the CLEO II detector at the Cornell Electron-Positron Storage Ring.We find a value for the exclusive semileptonic product branching fraction B(B⁻→D1⁰ℓ⁻ν^¯ℓ)B(D1⁰→D*+π⁻) = (0.373±0.085±0.052±0.024)% and an upper limit for B(B⁻→D2^*0ℓ-ν^¯ℓ)B(D2^*0→D*+π⁻)<0.16% (90% C.L.).Furthermore, we present the first measurement of the q² spectrum for B⁻→D1⁰ℓ⁻ν^¯ℓ. © 1998 The American Physical Society.

Abstract:

Using a data sample with an integrated luminosity of 3.9 fb^-1 collected in e⁺e^- annihilation with the CLEO-II detector at the Cornell Electron Storage Ring, we have measured the branching ratios for the decay modes Ds⁺→(η,η′)π⁺ and Ds⁺→(η,η′)ρ⁺ relative to Ds⁺→φ⁺. These decay modes are among the most common hadronic decays of the Ds⁺ , and can be related by factorization to the semileptonic decays Ds⁺ →(η,η′)ℓ⁺νl. The results obtained are compared with previous CLEO results and with the branching ratios measured for the related semileptonic decays. We also report results on the Cabibbo-suppressed decays of the D⁺ to the same final states. © 1998 The American Physical Society.

Abstract:

Using the CLEO detector at the Cornell Electron Storage Ring, we have made a measurement of (Formula presented) at (Formula presented)=10.52 GeV. This implies a value for the strong coupling constant of (Formula presented), or (Formula presented). © 1998 The American Physical Society.

Abstract:

We present a measurement of the absolute branching fraction for D0 → K-π+ using the reconstruction of the decay chain ¯ B → D*+ Xℓ- ¯v where only the lepton and the low-momentum pion from the D*+ are detected. With data collected by the CLEO II detector at the Cornell Electron Storage Ring, we have determined B(D0 → K-π+)=[3.81±0.15(stat)±0.16(syst)]%. © 1998 The American Physical Society.

Abstract:

Using the CLEO II detector, we have measured the differential cross sections for exclusive two-photon production of light pseudoscalar mesons (Formula presented) η, and (Formula presented) From our measurements we have obtained the form factors associated with the electromagnetic transitions (Formula presented) We have measured these form factors in the momentum transfer ranges from 1.5 to 9, 20, and (Formula presented) for (Formula presented) η, and (Formula presented) respectively, and have made comparisons to various theoretical predictions. © 1998 The American Physical Society.