Session M11: Cleo Bottomonia Physics

Update on $V_{ub}$ from Exclusive Charmless $B$-decays from CLEO

We present an updated result for the rates of semileptonic decays of $B$ mesons to exclusive charmless states $\pi$, $\rho/\omega$, and $\eta$ and an updated value for $|V_{ub}|$ using 15.7 million $B/\bar{B}$ events collected with the CLEO II, II.V, and III detectors. By performing the measurement in bins of $q^2$ and lepton decay angle (vector modes only) we are able to both test existing predictions for the decay form factor and measure the overall rate with minimal model dependence. We then combine this rate measurement with a variety of form factor calculations, in particular with recent unquenched lattice calculations, to extract a value for the CKM matrix element $|V_{ub}|$.   

Search for $\Upsilon$(1S) $\to \gamma\eta$ and $\gamma\eta'$

Using a data sample of around 20,000,000 $\Upsilon$(1S) decays collected by the CLEO III detector at CESR, we present the results of a search for the exclusive decays $\Upsilon$(1S) into $\gamma \eta$ and $\Upsilon$(1S) into $\gamma \eta'$.   

Search for Inclusive Decays of Hidden Beauty to Open Charm

\begin{document} A search for inclusive decays of hidden beauty mesons to open charm particles is underway using data taken with the CLEO~III detector at the CESR $e^+e^-$ collider. Decays of the the $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) to final states including pseudoscalar charmed mesons, vector charmed mesons, and $\Lambda_c$ baryons are being examined. Inclusive decays of the $\chi_b$(1P) and $\chi_b$(2P) to $D^*$ mesons will also be investigated. We report on the status and future plans for these studies. \end{document}   

Search for Lepton Flavor Violation in Upsilon Decays

\begin{document} With the data collected with the CLEO~III detector at CESR we report the first search for Lepton Flavor Violation in the decays of $\Upsilon(1S)$, $\Upsilon(2S)$, and $\Upsilon(3S)$ resonances. We present the analysis technique, Monte Carlo simulation studies, the background calibration method based on data, and preliminary results of our analysis. If discovered, LFV in $\Upsilon$ decays could be explained by low-mass quantum gravity, Abdus-Salam leptoquarks or neutrino oscillations arising in SUSY models. \end{document}   

Measurement of the Inclusive Bottomonium Spectrum

Using data collected from the CLEO III detector at the Cornell Electron Storage Ring, we measured the inclusive photon spectrum for the ${\Upsilon}$(1S), ${\Upsilon}$(2S) and ${\Upsilon}$(3S). By modeling the neutral radiative decay spectrum from observed charged particle momentum distributions, we obtained preliminary branching fractions for the ${\Upsilon}$(1S), ${\Upsilon}$(2S) and ${\Upsilon}$(3S) radiative decays. This is the first measurement of the ${\Upsilon}$(2S) and ${\Upsilon}$(3S) radiative branching ratios. Additionally, a refinement of the value of the nuclear strong force coupling constant ${\alpha}_s$ is discussed.   

Study of Two-Body Radiative $\Upsilon$(1S) Decays into the Exclusive Final States $\gamma\pi^0\pi^0$, $\gamma\pi^0\eta$ and $\gamma\eta\eta$

We report on a new study of exclusive radiative decays of the $\Upsilon$(1S) resonance into the final states $\gamma\pi^0\pi^0$, $\gamma\pi^0\eta$ an $\gamma\eta\eta$ with $\eta \rightarrow \gamma\gamma$ which were collected with the CLEO III detector operating at the Cornell Electron Storage Ring. In the channel $\gamma\pi^0\pi^0$ we present branching ratio and helicity amplitude measurements for the decay mode $\Upsilon$(1S) $\rightarrow \gamma f_2(1270)$. In addition, we place upper limits on branching ratios for the isoscalar resonances $f_0(1500)$ and $f_0(1710)$ in the $\pi^0\pi^0$, $\pi^0\eta$ and $\eta\eta$ decay channels.   

Radiative Decays of the $\Upsilon$(1S) to a Photon and Two Charged Tracks

Using the CLEO III detector, we report on a new study of exclusive radiative $\Upsilon$(1S) decays into the final states $\gamma\pi^+\pi^-$, $\gamma K^+ K^-$ and $\gamma p \bar{p}$. We present branching ratio and helicity amplitude measurements for the decay modes $\Upsilon(1S) \rightarrow \gamma f_2(1270)$ and $\Upsilon(1S) \rightarrow \gamma f_2'(1525)$, and upper limits for the decay $\Upsilon(1S) \rightarrow \gamma f_J(2200)$ with $f_J(2220) \rightarrow \pi^+\pi^-$, $K^+ K^-$ and $p \bar{p}$.   

Study of $\chi_b^{\prime} \to \chi_b$ Transitions

We have investigated the charged di-pion transition $\chi_{b}^{\prime}\to\pi^{+}\pi^{-}\chi_{b}$ in the CLEO III sample of 6 million $\Upsilon$(3S) decays using two techniques. In the first we observe both of the charged pions and use the recoil mass against them and the photon energy in the initial $\Upsilon$(3S) $\to\gamma_{1}\chi_{b}^{\prime}$ decay to distinguish the signal from background. In the second we require only one of the pions to be reconstructed and use the missing mass instead of the recoil mass as a discriminating variable. For comparisons we have used the well-established channels $\Upsilon$(3S)$\to\pi^{+}\pi^{-}\Upsilon$(2S), with either $\Upsilon$(2S)$\to\ell^{+}\ell^{-}$ or $\Upsilon$(2S)$\to\gamma\chi_{b}$. Preliminary results on yields, branching fractions, and di-pion distributions will be presented.