Observation of the Dalitz Decay Ds*+ → Ds*+ e+e-

Using 586 \textrm{pb}^{-1} of e^{+}e^{-} collision data acquired at \sqrt{s}=4.170 GeV with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of D_{s}^{*+} \to D_{s}^{+} e^{+} e^{-} with a significance of 5.3 \sigma. The ratio of branching fractions \calB(D_{s}^{*+} \to D_{s}^{+} e^{+} e^{-}) / \calB(D_{s}^{*+} \to D_{s}^{+} \gamma) is measured to be [ 0.72^{+0.15}_{-0.13} (\textrm{stat}) \pm 0.10 (\textrm{syst})]%, which is consistent with theoretical expectations

Monte Carlo Studies of a Novel LiF Radiator for RICH Detectors

We show that a multifaceted LiF radiator produces more Cherenkov light and has better resolution per photon than a flat radiator slab when used in a ring imaging Cherenkov counter. Such a system is being considered for the CLEO III upgrade.Comment: 9 page

The Cleo III Ring Imaging Cherenkov Detector

The CLEO detector has been upgraded to include a state of the art particle identification system, based on the Ring Imaging Cherenkov Detector (RICH) technology, in order to take data at the upgraded CESR electron positron collider. The expected performance is reviewed, as well as the preliminary results from an engineering run during the first few months of operation of the CLEO III detector.Comment: 5 pages, 2 Figures Talk given by M. Artuso at 8th Pisa Meeting on Advanced Detectors, May 200

Determination of fs/fd for 7 TeV pp Collisions and a Measurement of the Branching Fraction of the Decay B0→D-K+

The relative abundance of the three decay modes B_d \to D^- K^+, B_d \to D^- \pi^+ and B_s \to D_s^- \pi^+ produced in 7 TeV pp collisions at the LHC is determined from data corresponding to an integrated luminosity of 35 pb^{-1}. The branching fraction of B_d \to D^- K^+ is found to be \cal B (B_d \to D^- K^+) = (2.01 \pm 0.18^{\textrm{stat}} \pm 0.14^{\textrm{syst}})\times 10^{-4}. The ratio of fragmentation fractions \fsfdt is determined through the relative abundance of B_s \to D_s^- \pi^+ to B_d \to D^- K^+ and B_d \to D^-\pi^+, leading to f_s/f_d = 0.253 \pm 0.017 \pm 0.017 \pm 0.020, where the uncertainties are statistical, systematic, and theoretical respectively

ϒ(1S)→γf\u272(1525); f\u272(1525)-\u3eK0sK0s Decays

We report on a study of exclusive radiative decays of the Upsilon(1S) resonance into a final state consisting of a photon and two K0s candidates. We find evidence for a signal for Upsilon(1S)-\u3egamma f_2\u27(1525); f_2\u27(1525)-\u3eK0sK0s, at a rate (4.0+/-1.3+/-0.6)x10^{-5}, consistent with previous observations of Upsilon(1S)-\u3egamma f_2\u27(1525); f_2\u27(1525)-\u3eK+K-, and isospin. Combining this branching fraction with existing branching fraction measurements of Upsilon(1S)-\u3egamma f_2\u27(1525) and J/psi-\u3egamma f_2\u27(1525), we obtain the ratio of branching fractions: B(Upsilon(1S)-\u3egamma f_2\u27(1525))/B(J/psi-\u3egamma f_2\u27(1525))=0.09+/-0.02, approximately consistent with expectations based on soft collinear effective theory

The Magnetic Distortion Calibration System of the LHCb RICH1 Detector

The LHCb RICH1 detector uses hybrid photon detectors (HPDs) as its optical sensors. A calibration system has been constructed to provide corrections for distortions that are primarily due to external magnetic fields. We describe here the system design, construction, operation and performance.Comment: 9 pages, 14 figure

Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector Using Multi-anode Photomultiplier Tubes

We report on test results of a novel ring imaging Cherenkov (RICH) detection system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror, and a photon detector array based on Hamamatsu multi-anode photomultiplier tubes. This system was developed to identify charged particles in the momentum range from 3-70 GeV/c for the BTeV experiment.Comment: 28 pages, 23 figures, submitted to Nuclear Instruments and Method

The CLEO-III Ring Imaging Cherenkov Detector

The CLEO-III Detector upgrade for charged particle identification is discussed. The RICH design uses solid LiF crystal radiators coupled with multi-wire chamber photon detectors, using TEA as the photosensor, and low-noise Viking readout electronics. Results from our beam test at Fermilab are presented.Comment: Invited talk by R.J. Mountain at ``The 3rd International Workshop on Ring Imaging Cherenkov Detectors," a research workshop of the Israel Science Foundation, Ein-Gedi, Dead-Sea, Israel, Nov. 15-20, 1998, 14 pages, 9 figure

The Cleo Rich Detector

We describe the design, construction and performance of a Ring Imaging Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones with a novel ``sawtooth''-shaped exit surface. Photons in the wavelength interval 135--165 nm are detected using multi-wire chambers filled with a mixture of methane gas and triethylamine vapor. Excellent pion/kaon separation is demonstrated.Comment: 75 pages, 57 figures, (updated July 26, 2005 to reflect reviewers comments), to be published in NIM