The SuperB silicon vertex tracker.

In the current design of the high luminosity SuperB asymmetric e+-e- collider, the center of mass boost is reduced with respect to BaBar and to ef\ufb01ciently perform the time-dependent measurements an improved vertex resolution is required. A vertex tracker based on the layout of the BaBar Silicon Vertex Tracker (SVT) with an additional innermost layer (Layer0) is a design that achieves such a tracking resolution, provided that the extra layer is placed at radius of 1.5 cm from the interaction point, its thickness is less than 1% X_0 and it is able to withstand a background rate of several MHz/cm^2. The different options for the Layer0 are reviewed, starting from the most technologically mature solution, a high resistivity short strip detector, describing then a small-pitch hybrid pixel detector and \ufb01nally presenting the most challenging proposal, based on CMOS MAPS

SuperB: A High-Luminosity Asymmetric e+ e- Super Flavor Factory. Conceptual Design Report.

The physics objectives of SuperB, an asymmetric electron-positron collider with a luminosity above 10^36/cm^2/s are described, together with the conceptual design of a novel low emittance design that achieves this performance with wallplug power comparable to that of the current B Factories, and an upgraded detector capable of doing the physics in the SuperB environment

Measurement of the CP violating asymmetry amplitude sin 2beta

We present results on time-dependent CP-violating asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 88 million Y(4S) --> B Bbar decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B0 or B0bar from its decay products. The amplitude of the CP-violating asymmetry, which in the Standard Model is proportional to sin2beta, is derived from the decay-time distributions in such events. We measure sin2beta = 0.741 +/- 0.067 (stat) +/- 0.034 (syst) and |lambda| = 0.948 +/- 0.051 (stat) +/- 0.030 (syst). The magnitude of lambda is consistent with unity, in agreement with the Standard Model expectation of no direct CP violation in these modes.Comment: 7 pages, 2 postscript figures, submitted to PR