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