New measurements of (Formula presented) and (Formula presented) meson production rates from B decays and from (Formula presented) continuum events near the (Formula presented) resonance are presented. Using 20.8 (Formula presented) of data on the (Formula presented) resonance and 2.6 (Formula presented) off-resonance, we find the inclusive branching fractions (Formula presented) and (Formula presented) where the first error is statistical, the second is systematic, and t he third is due to the (Formula presented) branching fraction uncertainty. The production cross sections (Formula presented) and (Formula presented) are measured at center-of-mass energies about 40 MeV below the (Formula presented) mass. The branching fractions (Formula presented) and (Formula presented) are determined from the (Formula presented) momentum spectra. The mass difference (Formula presented) is also measured. © 2002 The American Physical Society.

We present a measurement of the time-dependent CP-violating asymmetries in neutral B decays to the eigenstate, and an updated measurement of the charge asymmetry in B0→K+π-~ decays. In a sample of 33 million Y(4S)→BB̄ decays collected with the BABAR detector at the SLAC PEP-II asymmetric B factory, we find 65-11+12 and 217±18 K+π- candidates and measure the asymmetry parameters Sππ=0.03-0.56+0.53±0.111, Cππ=-0.25-0.17+0.45±0.14, and AKπ = -0.07±0. 08±0.02, where the first error is statistical and the second is systematic. © 2002 The American Physical Society.

BABAR, the detector for the SLAC PEP-II asymmetric e+e- B Factory operating at the γ(4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagnetic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and by a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems, VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented. © 2002 Elsevier Science B.V. All rights reserved.