Georg Viehhauser

Abstract:

We report a new measurement of the Cabibbo-Kobayashi-Maskawa parameter Vub made with a sample of 9.7 x 10(6) BB- events collected with the CLEO II detector. Using heavy quark theory, we combine the observed yield of leptons from semileptonic B decay in the end-point momentum interval 2.2-2.6 GeV/c with recent CLEO II data on B-->X(s)gamma to find Vub = (4.08+/-0.34+/-0.44+/-0.16+/-0.24)x10(-3), where the first two uncertainties are experimental and the last two are from theory.

Abstract:

We have searched a sample of 9.6 million BB̄ events for the lepton-flavor-violating decays B→he±μ±, B+→h-e-e+, B+→h-e+μ+, and B+→h-μ-μ+, where h is π, K, p, and K*(892), a total of sixteen modes. We find no evidence for these decays, and place 90% confidence level upper limits on their branching fractions that range from 1.0 to 8.3×10-6.

Abstract:

We describe several measurements using the decays D⁰→K⁺K^- and π⁺π^-. We find the ratio of partial widths, Γ(D⁰→K⁺K^-)/Γ (D⁰→π⁺π^-), to be 2.96±0.16±0.15, where the first error is statistical and the second is systematic. We observe no evidence for direct CP violation, obtaining ACP(KK)=(0.0±2.2±0.8)% and ACP(ππ)=(1.9±3.2±0.8)%. In the limit of no CP violation we measure the mixing parameter yCP=-0.012±0.025±0.014 by measuring the lifetime difference between D⁰→K⁺K^- or π⁺ π^- and the CP neutral state, D⁰→K^-π⁺. We see no evidence for mixing.

Abstract:

Using data recorded by the CLEO II and CLEO II.V detector configurations at CESR, we report new measurements of the masses of the ∑c⁺⁺ and ∑c⁰ charmed baryons, and the first measurements of their intrinsic widths. We find M(∑c⁺⁺)-M(Λc⁺) =167.4±0.1±0.2 MeV, Γ(∑c⁺⁺)=2.3±0.2±0.3 MeV, and M(∑c⁰) -M(Λc⁺)=167.2±0.1±0.2 MeV, Γ(∑c⁰)=2.5±0.2±0.3 MeV, where the uncertainties are statistical and systematic, respectively.

Abstract:

The origin and source of CP violation in fundamental fermion interactions was discussed. The CP violation in Lepton decay was analyzed in the context of a model where the CP symmetry was broken. No evidence of violation was found in lepton decays into the final state. Limits on the imaginary part of the coupling constant were provided describing a relative contribution of the CP violating processes with respect to the standard model. Systematic errors were estimated in order to estimate the limits on CP violating parameter.