The CLEO RICH detector Artuso, M.; Ayad, R.; Bukin, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2005, Letnik:
554, Številka:
1
Journal Article
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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
π
/
K
separation is demonstrated.
We have measured the branching fraction and photon energy spectrum for the radiative penguin process b-->s gamma. We find Beta(b-->s gamma) = (3.21+/-0.43+/-0.27(+0.18)(-0.10))x10(-4), where the ...errors are statistical, systematic, and from theory corrections. We obtain first and second moments of the photon energy spectrum above 2.0 GeV, <E( gamma)> = 2.346+/-0.032+/-0.011 GeV, and <E(2)(gamma)>-<E(gamma)>(2) = 0.0226+/-0.0066+/-0.0020 GeV(2), where the errors are statistical and systematic. From the first moment, we obtain (in the modified minimal subtraction renormalization scheme, to order 1/M(3)(B) and beta(0)alpha(2)(s)) the heavy quark effective theory parameter Lambda = 0.35+/-0.08+/-0.10 GeV.
We have studied exclusive, radiative B meson decays to charmless mesons in 9.7x10(6) B decays accumulated with the CLEO detector. We measure B(B0-->K(*0)(892)gamma) = (4.55(+0.72)(-0. ...68)+/-0.34)x10(-5) and B(B+-->K(*+)(892)gamma) = (3.76(+0.89)(-0. 83)+/-0.28)x10(-5). We have searched for CP asymmetry in B-->K(*)(892)gamma decays and measure A(CP) = +0.08+/-0.13+/-0.03. We report the first observation of B-->K(*)(2)(1430)gamma decays with a branching fraction of (1.66(+0.59)(-0.53)+/-0.13)x10(-5). No evidence for the decays B-->rhogamma and B0-->omegagamma is found and we limit B(B-->(rho/omega)gamma)/B(B-->K(*)(892)gamma)<0.32 at 90% C.L.
In a sample of 19 x 10(6) produced B mesons, we have observed the decays B-->eta K(*) and improved our previous measurements of B-->eta'K. The branching fractions we measure for these decay modes are ...B(B+-->eta K(*+)) = (26.4(+9.6)(-8.2)+/-3.3)x10(-6), B(B(0)-->eta K(*0)) = (13.8(+5.5)(-4.6)+/-1.6)x10(-6), B(B(+)-->eta'K(+) = (80(+10)(-9)+/-7)x10(-6), and B(B(0)-->eta'K0) = (89(+18)(-16)+/-9)x10(-6). We have searched with comparable sensitivity for related decays and report upper limits for these branching fractions.
Beamstrahlung radiation for beam-beam instability Ahmad, A.; Boulahouache, C.; Bonvicini, G. ...
2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC),
2012-Oct.
Conference Proceeding
The Large Angle Beamstrahlung Monitor measures the intensity, spectrum and polarization of light emitted in the beam-beam interaction, which are related to beam-beam interaction parameters. The hopes ...for this device are that the study of the beam-beam interaction can change from being mostly model-driven to being mostly data-driven. High precision is certainly desirable, and a 0.3% relative precision is sought. Design issues are discussed, and a design close to final is presented. A list of possible measurements available at SuperKEKB is then discussed.
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