Georg Viehhauser

Abstract:

From a data sample of 29058 τ+→π±π+π -π0ντdecays observed in the CLEO detector we derive a 95% confidence upper limit on the tau neutrino mass of 28 MeV. ©2000 The American Physical Society.

Abstract:

We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions and observe three new processes with the following branching fractions: B(B → π+π−) = (4.3+1.6−1.4±0.5)×10−6, B(B→K0π0)=(14.6+5.9+2.4−5.1−3.3) × 10−6, and B(B → K±π0) = (11.6+3.0+1.4−2.7−1.3) × 10−6. We also update our previous measurements for the decays B → K±π∓ and B± → K0π±. © 2000 American Physical Society.

Abstract:

We have searched for rare and forbidden decays of the η′ meson in hadronic events at the CLEO II detector. The search is conducted on 4.80 fb−1 of e+e− collisions at 10.6 GeV center-of-mass energy at the Cornell Electron Storage Ring. We find no signals and set 90% confidence level upper limits of their branching fractions: B(η′→e+e−η)<2.4×10−3, B(η′→e+e−π0)<1.4×10−3, B(η′→e+e−γ)<0.9×10−3, and B(η′→eμ)<4.7×10−4. We also fit the matrix element of the η′→π+π−η Dalitz plot with the parametrization |M|2=A|1+αy|2, where y is a linear function of the kinetic energy of the ηand find Re (α)=−0.021±0.025. © 2000 The American Physical Society.

Abstract:

In a sample of 19 × 106 produced B mesons, we have observed the decays B → ηK∗ and improved our previous measurements of B → η′K. The branching fractions we measure for these decay modes are B(B+ → ηK*+) = (26.4+9.6−8.2 ± 3.3) × 10−6, B(B0 → η K*0) = (13.8+5.5−4.6 ± 1.6) × 10−6, B (B+ → η′ K+) = (80+10−9 ± 7) × 10−6, and B (B0 → η′ K0) = (89+18−16 ± 9) × 10−6. We have searched with comparable sensitivity for related decays and report upper limits for these branching fractions. © 2000 American Physical Society.