94 research outputs found

    Radar cross-section measurements and simulation of a tethered satellite. The small expendable deployer system end-mass payload

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    The first Small Expendable Deployer System (SEDS-1), a tethered satellite system, was developed by NASA and launched March 29, 1993 as a secondary payload on a United State Air Force (USAF) Delta-2 launch vehicle. The SEDS-1 successfully deployed an instrumented end-mass payload (EMP) on a 20-km nonconducting tether from the second stage of the Delta 2. This paper describes the effort of NASA Langley Research Center's Antenna and Microwave Research Branch to provide assistance to the SEDS Investigators Working Group (IWG) in determining EMP dynamics by analyzing the mission radar skin track data. The radar cross section measurements taken and simulations done for this study are described and comparisons of the measured data with the simulated data for the EMP at 6 GHz are presented

    Evidence for B^(*)_s bar{B}^(*)_s Production at the Upsilon(5S)

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    Using data collected by the CLEO III detector at CESR, we started a series of investigations on the Upsilon(5S) resonance decay properties. The data sample used for this analysis consists of 0.42 fb-1 of data taken on the Upsilon(5S) resonance, 6.34 fb-1 of data collected on the Upsilon(4S) and 2.32 fb-1 of data taken in the continuum below the Upsilon(4S). B_s mesons are expected to decay predominantly into D_s meson, while the lighter B mesons decay into D_s only about 10% of the time. We exploit this difference to make a preliminary model dependent estimate of the ratio of B_s(*) anti-B_s(*) to the total b anti-b quark pair production at the Upsilon(5S) energy to be (21 +- 3 +- 9)%.Comment: 17 pages postscript,also available through http://www.lns.cornell.edu/public/CONF/2004/, Presented at ICHEP Aug 16-22,2004, Beijing, Chin

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

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    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

    Search for X(3872) in gamma gamma Fusion and ISR at CLEO

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    We report on a search for the recently reported X(3872) state using 15.1 fb^{-1} e+ e- data taken in the \sqrt{s} = 9.46-11.30 GeV region. Separate searches for the production of X(3872) in untagged gamma-gamma fusion and e+ e- annihilation following initial state radiation (ISR) are made by taking advantage of the unique correlation of J/psi -> l+ l- in X(3872) decay to pi+ pi- J/psi. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)\Gamma_{\gamma\gamma}B(X -> pi+ pi- J/psi) < 12.9 eV and \Gamma_{ee}B(X -> pi+ pi- J/psi) < 8.3 eV.Comment: 8 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR

    Measurement of Absolute Hadronic Branching Fractions of D Mesons and e^+e^- --> D barD Cross Sections at E_cm = 3773 MeV

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    Using 55.8 pb^-1 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^+)=(3.91 +- 0.08 +- 0.09)% and B(D^+ -> K^- pi^+ pi^+)=(9.5 +- 0.2 +- 0.3)%, where the uncertainties are statistical and systematic, respectively. Final state radiation is included in these branching fractions by allowing for additional, unobserved, photons in the final state. Using a determination of the integrated luminosity, we also extract the cross sections sigma(e^+e^- -> D^0 \bar D^0)=(3.60 +- 0.07 +0.07-0.05) nb and sigma(e^+e^- -> D^+D^-)=(2.79 +- 0.07 +0.10-0.04) nb.Comment: 9 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005/, submitted to PR

    Observation of the ^1P_1 State of Charmonium

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    The spin-singlet P-wave state of charmonium, hc(1P1), has been observed in the decay psi(2S) -> pi0 hc followed by hc -> gamma etac. Inclusive and exclusive analyses of the M(hc) spectrum have been performed. Two complementary inclusive analyses select either a range of energies for the photon emitted in hc -> gamma etac or a range of values of M(etac). These analyses, consistent with one another within statistics, yield M(h_c) =[3524.9 +/- 0.7 (stat) +/- 0.4 (sys)]MeV/c^2 and a product of the branching ratios B_psi(psi(2S) -> pi0 hc) x B_h(hc -> gamma etac) = [3.5 +/- 1.0 (stat) +/- 0.7 (sys)] x 10^{-4}. When the etac is reconstructed in seven exclusive decay modes, 17.5 +/- 4.5 hc events are seen with an average mass M(hc) = [3523.6 +/- 0.9 (stat) +/- 0.5 (sys)] MeV/c^2, and B_psi x B_h = [5.3 +/- 1.5 (stat) +/- 1.0 (sys)] x 10^{-4}. Because the inclusive and exclusive data samples are largely independent they are combined to yield an overall mass M(hc) = [3524.4 +/- 0.6 (stat) +/- 0.4 (sys)]MeV/c^2 and product of branching ratios B_psi x B_h = [4.0 +/- 0.8 (stat) +/- 0.7 (sys)] x 10^{-4}. The hc mass implies a P-wave hyperfine splitting Delta M_{HF}(1P) \equiv M(1^3P)-M(1^1P_1) = [1.0 +/- 0.6 (stat) +/- 0.4 (sys)] MeV/c^2.Comment: 38 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005/, Submitted to PR

    Photon transitions in Upsilon(2S) and Upsilon(3S)

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    We have studied the inclusive photon spectra in Upsilon(2S) and \Upsilon(3S) decays using a large statistics data sample obtained with the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates and photon energies for Upsilon(2S)->gamma chi_bJ(1P) and Upsilon(3S)->gamma chi_bJ(2P) J=0,1,2. We measure the rate for a rare E1 transition Upsilon(3S)->gamma chi_b0(1P) for the first time. We also set upper limits on the rates for the hindered magnetic dipole (M1) transitions to the eta_b(1S) and eta_b(2S) states.Comment: 10 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR

    Radiative Decays of the Upsilon(1S) to a Pair of Charged Hadrons

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    Using data obtained with the CLEO~III detector, running at the Cornell Electron Storage Ring (CESR), 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 pbar.. We present branching ratio measurements for the decay modes Upsilon(1S) to gamma f_2(1270), Upsilon(1S) to gamma f_2'(1525), and Upsilon(1S) to gamma K^+K^-; helicity production ratios for f_2(1270) and f_2'(1525); upper limits for the decay Upsilon(1S) to gamma f_J(2200), with f_J(2220) to pi^+ pi^-, K^+ K^-, p pbar; and an upper limit for the decay Upsilon(1S) to gamma X(1860), with X(1860) to gamma p pbar.Comment: 17 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005/, Submitted to PR

    Study of tau Decays to Four-Hadron Final States with Kaons

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    The tau decays to four hadrons have been studied with the CLEO III detector at the Cornell Electron Storage Ring (CESR) using (7.56 +- 0.15) fb^{-1} of data collected near the Y(4S) resonance. We present the first statistically significant measurements of B(tau- -> K- pi+pi- pi0 nu, excluding K^0) = (7.4 +- 0.8 +- 1.1) x 10^{-4} and B(tau--> K- K+ pi- pi0 nu) = (5.5 +- 1.4 +- 1.2) x 10^{-5}, including the first observation of the decay, tau- -> K- omega nu, with branching fraction (4.1 +- 0.6 +- 0.7) x 10^{-4}. We also publish the first upper limit for B(tau- -> K- K+ K- pi0 nu) < 4.8 (6.1) x 10^{-6} at 90% (95%) confidence level (C.L.).Comment: 9 pages postscript, also available from http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR

    Observation of Thirteen New Exclusive Multi-Body Hadronic Decays of the ψ(2S)\psi(2S)

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    Using data accumulated with the CLEO detector corresponding to an integrated luminosity of 5.63 pb^-1 on the peak of the psi(2S) and 20.70 pb^-1 continuum at 3.67 GeV, we report first measurements of the branching fractions for the following 13 decay modes of the psi(2S): eta 3pi, eta^\prime 3pi, rho K^+K^-, K^+K^-pi^+pi^-pi^0, 2(K^+K^-), 2(K^+K^-)pi^0, rho p \bar p, p \bar p pi^+pi^-pi^0, eta p \bar p, p \bar p K^+K^-, Lambda \bar Lambda pi^+pi^-, Lambda \bar p K^+, Lambda \bar p K^+pi^+pi^-, and more precise measurements of 8 previously measured modes: 2(pi^+pi^-), rho pi^+pi^-, 2(pi^+pi^-)pi^0, omega pi^+pi^-, K^+K^-pi^+pi^-, omega K^+K^-, phi K^+K^-, p \bar p pi^+pi^-. We also report new branching fraction measurements of phi pi^+pi^- and omega p \bar p and upper limits for eta pi^+pi^-, eta K^+K^- and phi p \bar p. Results are compared, where possible, with the corresponding J/psi branching ratios to provide new tests of the 12% rule.Comment: 9pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005
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