A Study of Exclusive Charmless Semileptonic B Decays and Extraction of |V_{ub}| at CLEO

We have studied semileptonic B decay to the exclusive charmless states pi, rho/omega, eta and eta' using the full 15.5 fb^-1 CLEO Upsilon(4S) sample, with measurements performed in subregions of phase space to minimize dependence on a priori knowledge of the form factors involved. We find total branching fractions B(B^0 -> pi^-l^+nu) = (1.37 +- 0.15_stat +- 0.11_sys) x 10^-4 and B(B^0 -> rho^- l^+ nu) = (2.93 +- 0.37_stat +- 0.37_sys) x 10^-4. We find evidence for B^+ -> eta' l^+ nu, with B(B^+ -> eta' l^+ nu) = (2.66 +- 0.80_stat +- 0.56_sys) x 10^-4 and 1.20 x 10^-4 eta' l^+ nu) < 4.46 x 10^-4 (90% CL). We also limit B(B^+ -> eta l^+ nu) < 1.01 x 10^-4 (90% CL). By combining our B -> pi l nu information with unquenched lattice calculations, we find |V_ub| = (3.6 +- 0.4 +- 0.2 +0.6 -0.4) x 10^-3, where the errors are statistical, experimental systematic, and theoretical systematic, respectively.Comment: 35 pages, 15 figures; revise

Measurement of the Decay Constant fDS+f_D{_S^+} using $D_S^+ --> ell^+ nu

We measure the decay constant fDs using the Ds -> l+ nu channel, where the l+ designates either a mu+ or a tau+, when the tau+ -> pi+ nu. Using both measurements we find fDs = 274 +-13 +- 7 MeV. Combining with our previous determination of fD+, we compute the ratio fDs/fD+ = 1.23 +- 0.11 +- 0.04. We compare with theoretical estimates.Comment: 6 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007

Measurement of Absolute Hadronic Branching Fractions of D Mesons and e^+ e^- --> D D-bar Cross Sections at the psi(3770)

Using 281 /pb of e^+ e^- collisions recorded at the psi(3770) resonance with the CLEO-c detector at CESR, we determine absolute hadronic branching fractions of charged and neutral D mesons using a double tag technique. Among measurements for three D^0 and six D^+ modes, we obtain reference branching fractions B(D^0 --> K^-pi^+) = (3.891 +- 0.035 +- 0.059 +- 0.035)% and B(D^+ --> K^-pi^+pi^+) = (9.14 +- 0.10 +- 0.16 +- 0.07)%, where the first uncertainty is statistical, the second is all systematic errors other than final state radiation (FSR), and the third is the systematic uncertainty due to FSR. We include FSR in these branching fractions by allowing for additional unobserved photons in the final state. Using an independent determination of the integrated luminosity, we also extract the cross sections sigma(e+e- --> D^0 D^0-bar) = (3.66+- 0.03 +- 0.06) nb and sigma(e+e- --> D^+ D^-) = (2.91+- 0.03 +- 0.05) nb at a center of mass energy, E_cm = 3774 +- 1 MeV.Comment: 47 pages, postscript also available through this http://www.lns.cornell.edu/public/CLNS/2007/, to be published in PRD, updated branching fractions using B(KS0 --> pi+ pi-) from PDG 2007, and updated text in response to the PRD reviewe

Measurement of \cal{B}(D^+ --> mu^+ nu) and the Pseudoscalar Decay Constant fD+f_{D^+}

In 60 pb-1 of data taken on the psi(3770) resonance with the CLEO-c detector, we find 8 D+ to mu+ nu event candidates that are mostly signal, containing only 1 estimated background. Using this statistically compelling sample, we measure preliminary values of B(D+ to mu+ nu) = (3.5 +- 1.4 +- 0.6)*10^{-4}, and determine f_{D+} =(201+- 41+- 17) MeV.Comment: 17 pages postscript, also available through http://www.lns.cornell.edu/public/CONF/2004/, Presented at ICHEP Aug 16-22,2004, Beijing, Chin

Search for Lepton Flavor Violation in Upsilon Decays

In this Letter we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays of Upsilon(nS)(n=1,2, and 3) into muon and tau using the data collected with the CLEO III detector. We identify the tau lepton using its leptonic decay into electron and utilize multidimensional likelihood fitting with PDF shapes measured from independent data samples. We report our estimates of 95% CL upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.Comment: 10 pages, 3 figures, available through http://www.lns.cornell.edu/public/CLNS/, submitted to PR

Measurement of the Total Hadronic Cross Section in e+e- Annihilations below 10.56 GeV

Using the CLEO III detector, we measure absolute cross sections for e+e- --> hadrons at seven center-of-mass energies between 6.964 and 10.538 GeV. The values of R, the ratio of hadronic and muon pair production cross sections, are determined within 2% total r.m.s. uncertainty.Comment: 17 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR

Search for Radiative Decays of Upsilon(1S) into eta and eta'

We report on a search for the radiative decay of Upsilon(1S) to the pseudoscalar mesons eta and etaprime in 21.2 +/- 0.2 times 10^6 Upsilon(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring (CESR). The eta meson was reconstructed in the three modes eta to gamma-gamma, eta to pi+pi-pi0 and eta to 3pi0. The etaprime meson was reconstructed in the mode etaprime to pi+ pi- eta with eta decaying through any of the above three modes, and also etaprime to gamma rho, where rho decays to pi^+ pi^-. Five out of the seven sub-modes are found to be virtually background-free. In four of them we find no signal candidates and in one Upsilon(1S) to gamma-etaprime, etaprime to pi+ pi- eta, eta to pi+pi-pi0 there are two good signal candidates, which is insufficient evidence to claim a signal. The other two sub-modes eta to gamma-gamma and etaprime to gamma rho are background limited, and show no excess of events in their signal regions. We combine the results from different channels and obtain upper limits at the 90% C.L. which are B(Upsilon(1S) to gamma eta) < 1.0 times 10^-6 and B(Upsilon(1S) to gamma etaprime) < 1.9 times 10^-6. Our limits are an order of magnitude tighter than the previous ones and below the predictions made by some theoretical models.Comment: 14 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR

Update of the measurement of the cross section for e^+e^- -> psi(3770) -> hadrons

We have updated our measurement of the cross section for e^+e^- -> psi(3770) -> hadrons, our publication "Measurement of sigma(e^+e^- -> psi(3770) -> hadrons) at E_{c.m.} = 3773 MeV", arXiv:hep-ex/0512038, Phys.Rev.Lett.96, 092002 (2006). Simultaneous with this arXiv update, we have published an erratum in Phys.Rev.Lett.104, 159901 (2010). There, and in this update, we have corrected a mistake in the computation of the error on the difference of the cross sections for e^+e^- -> psi(3770) -> hadrons and e^+e^- -> psi(3770) -> DDbar. We have also used a more recent CLEO measurement of cross section for e^+e^- -> psi(3770) -> DDbar. From this, we obtain an upper limit on the branching fraction for psi(3770) -> non-DDbar of 9% at 90% confidence level.Comment: 3 pages, 0 figures. This is an erratum to Phys.Rev.Lett.96:092002,2006. Added a reference

Branching Fraction Measurements of psi(2S) Decay to Baryon-Antibaryon Final States

Using 3.08 million psi(2S) decays observed in e^+e^- collisions by the CLEO detector, we present the results of a study of the psi(2S) decaying into baryon-antibaryon final states. We report the most precise measurements of the following eight modes: proton-antiproton, lambda-antilambda, Xi^- antiXi^-, Xi^0-antiXi^0 (first observation), Sigma+-antiSigma^+ (first observation), and Sigma^0-antiSigma^0, and place upper limits for the modes, Xi^0*-antiXi^0* and Omega^- antiOmega^-.Comment: 8 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005/, submitted to PR

The Search for eta(1440) --> K^0_S K^pm \pi^mp in Two-Photon Fusion at CLEO

We analyze 13.8 \rm fb^{-1} of the integrated e^+e^- luminosity collected at 10.6 GeV center-of-mass energy with the CLEO II and CLEO II.V detectors to study exclusive two-photon production of hadrons with masses below 1.7{\rm \ GeV/c^2} decaying into the K^0_S K^\pm \pi^\mp final state. We observe two statistically significant enhancements in the \eta(1440) mass region. These enhancements have large transverse momentum which rules them out as being due to pseudoscalar resonances but is consistent with the production of axial-vector mesons. We use tagged two-photon events to study the properties of the observed enhancements and associate them with the production of f_1(1285) and f_1(1420). Our non-observation of \eta(1440) is inconsistent by more than two standard deviations with the first observation of this resonance in two-photon collisions by the L3 experiment. We present our estimates for 90% confidence level upper limits on the products of two-photon partial widths of pseudoscalar hadrons and their branching fractions into K^0_S(\pi^+\pi^-)K^\pm\pi^\mp.Comment: 24 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR