134 research outputs found
Hadronic B and D studies at BABAR
We present new results on hadronic B and D decays from the BABAR experiment.
The first part of this document presents searches for new channels which may be
used for CP measurements. The second part is dedicated to hadronic decays with
tests of QCD factorization predictions and other models for B structure and
decay mechanisms. A new result on the reference branching ratio Ds+ -->phi pi+
is also reported.Comment: 4 pages, 1 eps figure, contributed to the proceedings of 40th
Rencontres de Moriond QCD 200
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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Status of the Super-B factory Design
The SuperB international team continues to optimize the design of an electron-positron collider, which will allow the enhanced study of the origins of flavor physics. The project combines the best features of a linear collider (high single-collision luminosity) and a storage-ring collider (high repetition rate), bringing together all accelerator physics aspects to make a very high luminosity of 10{sup 36} cm{sup -2} sec{sup -1}. This asymmetric-energy collider with a polarized electron beam will produce hundreds of millions of B-mesons at the Y(4S) resonance. The present design is based on extremely low emittance beams colliding at a large Piwinski angle to allow very low {beta}{sub y} without the need for ultra short bunches. Use of crab-waist sextupoles will enhance the luminosity, suppressing dangerous resonances and allowing for a higher beam-beam parameter. The project has flexible beam parameters, improved dynamic aperture, and spin-rotators in the Low Energy Ring for longitudinal polarization of the electron beam at the Interaction Point. Optimized for best colliding-beam performance, the facility may also provide high-brightness photon beams for synchrotron radiation applications
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