4,618 research outputs found
Wess-Zumino Current and the Structure of the Decay τ → K^- π^- K^+ v_τ
We present the first study of the vector (Wess-Zumino) current in τ → K π^− K^+ ν_τ decay using data collected with the CLEO III detector at the Cornell Electron Storage Ring. We determine the quantitative contributions to the decay width from the vector and axial vector currents. Within the framework of a model by Kühn and Mirkes, we identify the quantitative contributions to the total decay rate from the intermediate states ωπ, ρ^(')π, and K^∗ K
Charm meson spectra in e^+e^- annihilation at 10.5 GeV center of mass energy
Using the CLEO detector at the Cornell Electron-positron Storage Ring, we have measured the scaled momentum spectra, dσ/dx_p, and the inclusive production cross sections of the charm mesons D^+, D^0, D^(⋆+), and D^(⋆0) in e^+e^− annihilation at about 10.5 GeV center of mass energy, excluding the decay products of B mesons. The statistical accuracy and momentum resolution are superior to previous measurements at this energy
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
Wess-Zumino Current and the Structure of the Decay τ → K^- π^- K^+ v_τ
We present the first study of the vector (Wess-Zumino) current in τ → K π^− K^+ ν_τ decay using data collected with the CLEO III detector at the Cornell Electron Storage Ring. We determine the quantitative contributions to the decay width from the vector and axial vector currents. Within the framework of a model by Kühn and Mirkes, we identify the quantitative contributions to the total decay rate from the intermediate states ωπ, ρ^(')π, and K^∗ K
Performance of the CLEO III LiF-TEA Ring Imaging Cherenkov Detector in a High Energy Muon Beam
The CLEO III Ring Imaging Cherenkov detector uses LiF radiators to generate Cherenkov photons which are then detected by proportional wire chambers using a mixture of CH and TEA gases. The first two photon detector modules which were constructed, were taken to Fermilab and tested in a beam dump that provided high momentum muons. We report on results using both plane and "sawtooth" shaped radiators. Specifically, we discuss the number of photoelectrons observed per ring and the angular resolution. The particle separation ability is shown to be sufficient for the physics of CLEO III
Observation of the Hadronic Transitions Chi_{b 1,2}(2P) -> omega Upsilon(1S)
The CLEO Collaboration has observed the first hadronic transition among
bottomonium (b bbar) states other than the dipion transitions among vector
states, Upsilon(nS) -> pi pi Upsilon(mS). In our study of Upsilon(3S) decays,
we find a significant signal for Upsilon(3S) -> gamma omega Upsilon(1S) that is
consistent with radiative decays Upsilon(3S) -> gamma chi_{b 1,2}(2P), followed
by chi_{b 1,2} -> omega Upsilon(1S). The branching ratios we obtain are
Br(chi_{b1} -> omega Upsilon(1S) = 1.63 (+0.35 -0.31) (+0.16 -0.15) % and
Br(chi_{b2} -> omega Upsilon(1S) = 1.10 (+0.32 -0.28) (+0.11 - 0.10)%, in which
the first error is statistical and the second is systematic.Comment: submitted to XXI Intern'l Symp on Lepton and Photon Interact'ns at
High Energies, August 2003, Fermila
New Measurements of Upsilon(1S) Decays to Charmonium Final States
Using substantially larger data samples collected by the CLEO III detector,
we report on new measurements of the decays of Upsilon(1S) to charmonium final
states, including J/Psi, psi(2S), and chi_cJ. The latter two are first
observations of these decays. We measure the branching fractions as follows:
B(Y(1S)--> J/Psi+X)=(6.4+-0.4+-0.6)x10^-4, B(Y(1S)--> psi(2S)+X)/B(Y(1S)-->
J/Psi+X)=0.41+-0.11+-0.08, B(Y(1S)--> chi_c1+X)/B(Y(1S)-->
J/Psi+X)=0.35+-0.08+-0.06, B(Y(1S)--> chi_c2+X)/B(Y(1S)-->
J/Psi+X)=0.52+-0.12+-0.09, and B(Y(1S)--> chi_c0+X)/B(Y(1S)--> J/Psi+X)<7.4% at
90% confidence level. We also report on the momentum and angular spectra of
J/Psi's in Upsilon(1S) decay. The results are compared to predictions of the
color octet and color singlet models.Comment: 27 pages postscript,also available through
http://w4.lns.cornell.edu/public/CLNS/, submitted to PR
Improved Measurement of the Form Factors in the Decay Lambda_c^+ --> Lambda e^+ nu_e
Using the CLEO detector at the Cornell Electron Storage Ring, we have studied
the distribution of kinematic variables in the decay Lambda_c^+ -> Lambda e^+
nu_e. By performing a four-dimensional maximum likelihood fit, we determine the
form factor ratio, R = f_2/f_1 = -0.31 +/- 0.05(stat) +/- 0.04(syst), the pole
mass, M_{pole} = (2.21 +/- 0.08(stat) +/- 0.14(syst)) GeV/c^2, and the decay
asymmetry parameter of the Lambda_c, alpha_{Lambda_c} = -0.86 +/- 0.03(stat)
+/- 0.02(syst), for = 0.67 (GeV/c^2)^2. We compare the angular
distributions of the Lambda_c^+ and Lambda_c^- and find no evidence for
CP-violation: A_{Lambda_c} = (alpha_{Lambda_c^+} + alpha_{Lambda_c^-})/
(alpha_{Lambda_c^+} - alpha_{Lambda_c^-}) = 0.00 +/- 0.03(stat) +/- 0.01(syst)
+/- 0.02, where the third error is from the uncertainty in the world average of
the CP-violating parameter, A_{Lambda}, for Lambda -> p pi^-.Comment: 8 pages postscript,also available through
http://www.lns.cornell.edu/public/CLNS/2004/, submitted to PR
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