91 research outputs found
On the influence of the cosmological constant on gravitational lensing in small systems
The cosmological constant Lambda affects gravitational lensing phenomena. The
contribution of Lambda to the observable angular positions of multiple images
and to their amplification and time delay is here computed through a study in
the weak deflection limit of the equations of motion in the Schwarzschild-de
Sitter metric. Due to Lambda the unresolved images are slightly demagnified,
the radius of the Einstein ring decreases and the time delay increases. The
effect is however negligible for near lenses. In the case of null cosmological
constant, we provide some updated results on lensing by a Schwarzschild black
hole.Comment: 8 pages, 1 figure; v2: extended discussion on the lens equation,
references added, results unchanged, in press on PR
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SuperB Progress Report: Detector
This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008
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Measurement of an Excess in Bbar to D(*) tau- nubar Decays and Implications for Charged Higgs Bosons
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Study of the Decay B0bar->LambdaC+ pbar pi+ pi- and its Intermediate States
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Exclusive Measurements of the b to s gamma Transition Rate and Photon Energy Spectrum
We use 429 fb{sup -1} of e{sup +}e{sup -} collision data collected at the {Upsilon}(4S) resonance with the BABAR detector to measure the radiative transition rate of b {yields} s{gamma} with a sum of 38 exclusive final states. The inclusive branching fraction with a minimum photon energy of 1.9 GeV is found to be {Beta}({bar B} {yields} Xs{gamma}) = (3.29 {+-} 0.19 {+-} 0.48) x 10{sup -4} where the first uncertainty is statistical and the second is systematic. We also measure the first and second moments of the photon energy spectrum and extract the best fit values for the heavy-quark parameters, m{sub b} and {mu}{sub {pi}}{sup 2}, in the kinetic and shape function models
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Time-Integrated Luminosity Recorded by the BABAR Detector at the PEP-II e+e- Collider
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