Tom Himel

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We report on exclusive decays of B mesons into final states containing charmonium using data collected with the BABAR detector at the PEP-II storage rings. The charmonium states considered here are J/ψ , ψ(2S), and χ c1. Branching fractions for several exclusive final states, a measurement of the decay amplitudes for the B 0 → J/ψ K * decay, and(More)
The BABAR detector, situated at the SLAC PEP-II asymmetric e + e − collider, has been recording data at energies on and around the Υ (4S) resonance since May 1999. In this paper, we briefly describe the PEP-II B Factory and the BABAR detector. The performance presently achieved by the experiment in the areas of tracking, vertexing, calorimetry and particle(More)
We describe a simple hybrid numerical method for beam orbit correction in particle accelerators. The method overcomes both degeneracy in the linear system being solved and respects boundaries on the solution. It uses the Singular Value Decomposition (SVD) to find and remove the null-space in the system, followed by a bounded Linear Least Squares analysis of(More)
We present a measurement of time-dependent CP asymmetries and an updated determination of the CP-odd fraction in the decay B 0 → D * + D * −. The measurements are derived from a data sample of 88 × 10 6 B ¯ B pairs collected by the BABAR detector at the PEP-II energy asymmetric B Factory at SLAC. All results are preliminary.
We present measurements of branching fractions and CP-violating asymmetries for two-body neutral B meson decays to charged pions and kaons based on a sample of about 88x10(6) Upsilon(4S)-->BB decays. From a time-independent fit we measure the charge-averaged branching fractions B(B0-->pi+pi-)=(4.7+/-0.6+/-0.2)x10(-6),(More)
A search for the exclusive radiative decays B → ρ(770)γ and B 0 → ω(782)γ is performed on a sample of 84 million BB events collected by the BABAR detector at the P EP − II asymmetric e + e − collider. No significant signal is seen in any of the channels. We set preliminary upper limits of B[B 0 → ρ 0 γ] < 1.4 × 10 −6 , B[B + → ρ + γ] < 2.3 × 10 −6 and B[B 0(More)
The D 0 mixing parameter y = ∆Γ/2Γ was determined by measuring the D 0 lifetime separately for the K − π + decay mode and the K − K + decay mode with 12.4 fb −1 of data collected by the BABAR experiment in 2001. Backgrounds were suppressed with the D * → D 0 π + decay and particle identification. The following preliminary result was obtained: y = (−1.0 ±(More)
Data collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC are used to study the lifetimes of the B 0 and B + mesons. The data sample consists of 7.4 fb −1 collected near the Υ (4S) resonance. B 0 and B + mesons are fully reconstructed in several exclusive hadronic decay modes to charm and charmonium final states. The B lifetimes are(More)
We reconstruct the charmonium mesons J/ψ , ψ(2S) and χ c using a sample of 8.46 × 10 6 BB events collected by the BABAR detector operating at e + e − center of mass energies near the Υ (4S) resonance. By measuring rates relative to the branching fraction of the J/ψ , we obtain preliminary inclusive B branching fractions of (0.25 ± 0.02 ± 0.02)% to the ψ(2S)(More)
Electron-positron annihilation data collected by the BABAR detector near the Υ(4S) resonance are used to study the inclusive decay of B mesons to D ± s and D * ± s mesons, where the D ± s is reconstructed using the decay D ± s → φπ ±. The production fraction of inclusive D (*)± s and the corresponding momentum spectra have been determined. The exclusive(More)