Georg Viehhauser

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.

Abstract:

Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using (Formula presented) of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis represents an update of a previous study and the addition of six decay channels. In all channels the numbers of events found are compatible with background estimates and branching fraction upper limits are set for 28 different decay modes. These limits are either more stringent than those set previously or represent the first attempt to find these decays. © 1998 The American Physical Society.

Abstract:

The decays Υ(4S)→BB, followed by B→D*π and D*→Dπ, permit reconstruction of all kinematic quantities that describe the sequence without reconstruction of the D, with reasonably low backgrounds. Using an integrated e⁺e⁻ luminosity of 3.1fb⁻¹ accumulated at the Υ(4S) by the CLEO-II detector, we report measurements of B(B⁰→D*⁺π⁻)=(2.81±0.11±0.21±0.05)×10⁻³ and B(B⁻→D*0π⁻)=(4.34±0.33±0.34±0.18) ×10⁻³. © 1998 The American Physical Society.

Abstract:

We have studied two-body charmless hadronic decays of B mesons into the final states ΠΠKΠand KK. Using 3.3 × 10⁶ BB¯ pairs collected with the CLEO-II detectorwe have made the first observation of the decay B⁰ → K⁺Π^-the sum of B⁺ → Π⁺Π⁰ and B⁺ → K⁺Π⁰ decaysand see strong evidence for the decay B⁺ → K⁰Π⁺ (an average over charge-conjugate states is always implied). We place upper limits on branching fractions for the remaining decay modes. © 1998 The American Physical Society.

Abstract:

We report the first observation of B → η′X transitions with high momentum η′ mesons. We observe 39.0 ± 11.6B decay events with 2.0 < pη′ < 2.7GeV/c, the high momentum region where background from b → c processes is suppressed. We discuss the physical interpretation of the signal, including the possibility that it is due to b → sg* transitions. Given that interpretation, we find B(B → η′Xs) = [6.2 ± 1.6(stat) ± 1.3(syst)+0.0-1.5(bkg)] × 10-4 for 2.0 < pη′ < 2.7GeV/c. © 1998 The American Physical Society.