Observation of the Ξc+\Xi_c^+ Charmed Baryon Decays to Σ+K−π+\Sigma^+ K^-\pi^+, Σ+Kˉ∗0\Sigma^+ \bar{K}^{*0}, and ΛK−π+π+\Lambda K^-\pi^+\pi^+

We have observed two new decay modes of the charmed baryon $\Xi_c^+$ into $\Sigma^+ K^-\pi^+$ and $\Sigma^+ \bar{K}^{*0}$ using data collected with the CLEO II detector. We also present the first measurement of the branching fraction for the previously observed decay mode $\Xi_c^+\to\Lambda K^-\pi^+\pi^+$. The branching fractions for these three modes relative to $\Xi_c^+\to\Xi^-\pi^+\pi^+$ are measured to be $1.18 \pm 0.26 \pm 0.17$, $0.92 \pm 0.27 \pm 0.14$, and $0.58 \pm 0.16 \pm 0.07$, respectively.Comment: 12 page uuencoded postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Study of B → ψϱ

We have studied the Cabibbo suppressed and color suppressed two-body decays B to ψϱ (ψω or ψa1). Using a data sample of 5.12 million B decays collected with the CLEO II detector we find the 90% confidence level upper limits for branching fractions of B<sup>0</sup> → ψϱ<sup>0</sup> and B<sup>0</sup> → ψω to be 2.5 · 10<sup>-4</sup> and 2.7 · 10<sup>-4</sup>, respectively. We also update the branching fraction B<sup>-</sup> → ψπ<sup>-</sup> to be (5.6 ± 2.7) · 10<sup>-5</sup>

A measurement of β(D⁰ → K^- π⁺ π⁰)/β(D⁰ → K^- π⁺)

Using a sample of 3.1 fb<sup>−1</sup> integrated luminosity accumulated with the CLEO II detector at the Cornell Electron Storage Ring, we measure the ratio of branching fractions β(D<sup>0</sup> → K<sup>-</sup> π<sup>+</sup> π<sup>0</sup>) /β(D<sup>0</sup> → K<sup>-</sup> gp<sup>+</sup>) = 3.81± 0.07 ± 0.26, the most precise determination of this quantity to date

Measurement of α_S from τ decays

We present measurements of spectral moments extracted from the invariant mass distributions of the final states of hadronic τ decay products recorded in the CLEO detector. From a fit of theoretical predictions to the measurements of spectral moments and the total hadronic decay width of the τ, we determine the strong coupling constant and a set of non-perturbative QCD parameters. The strong coupling constant is measured to be α<sub>s</sub>(m<sub>τ</sub>) = 0.306 ± 0.024, which when extrapolated to the Z mass, yields α<sub>s</sub>(M<sub>z</sub>) = 0.114 ± 0.003

Measurement of the tau lepton lifetime

We measure the τ lepton lifetime with τ<sup>+</sup>τ<sup>−</sup> pairs in which one or both of the τ's decays to three charged particles. The data were collected with the CLEO II detector operating at the electron-positron collider CESR at energies on and near the Y(4S). We use displacements of the three-track vertices to determine the τ lifetime. The results is ττ = 289.0±2.8±4.0 fs