Malcolm John

Abstract:

We present the first measurement of Υ(4S) decays to π+π-Υ(1S) and π+π-Υ(2S) based on a sample of 230×106Υ(4S) mesons collected with the BABAR detector. We measure the product branching fractions B(Υ(4S)→π+π-Υ(1S)) ×B(Υ(1S)→μ+μ-)=(2.23±0.25stat±0.27syst) ×10-6 and B(Υ(4S)→π+π-Υ(2S))×B(Υ(2S) →μ+μ-)=(1.69±0.26stat±0.20syst)×10-6, from which we derive the partial widths Γ(Υ(4S)→π+π-Υ(1S))=(1. 8±0.4)keV and Γ(Υ(4S)→π+π-Υ(2S))=(2. 7±0.8)keV. © 2006 The American Physical Society.

Abstract:

Using 232fb-1 of e+e- collision data recorded by the BABAR experiment, we measure the rates of three-body Cabibbo-suppressed decays of the D0 meson relative to the Cabibbo-favored decay, D0→K-π+π0. We find: B(D0→π-π+π0)B(D0→K-π+π0)=(10.59±0.06±0. 13)×10-2 and B(D0→K-K+π0)B(D0→K-π+π0)=(2.37±0. 03±0.04)×10-2, where the errors are statistical and systematic, respectively. These measurements are significantly more precise than the current world average measurements. © 2006 The American Physical Society.

Abstract:

We describe searches for decays of B mesons to the charmless final states η′η′K. The data consist of 228×106 BB̄ pairs produced in e+e- annihilation, collected with the BABAR detector at the Stanford Linear Accelerator Center. The 90% confidence level upper limits for the branching fractions are B(B0→η′η′K0)<31×10-6 and B(B+→η′η′K+)<25×10-6. © 2006 The American Physical Society.

Abstract:

A search has been made for the decays B+→ π+ and B0→ π0 in a data sample of approximately 232×106 BB̄ pairs recorded at the Υ(4S) resonance with the BABAR detector at the PEP-II B-meson Factory at SLAC. No significant signals have been observed, and therefore upper limits have been set on the branching fractions: B(B+→ π+)<2.4×10-7 and B(B0→ π0)<2.8×10-7 at 90% probability. © 2006 The American Physical Society.

Abstract:

In a study of B+→J/ψγK+ decays, we find evidence for the radiative decay X(3872)→J/ψγ with a statistical significance of 3.4σ. We measure the product of branching fractions B(B+→X(3872)K+) •B(X(3872)→J/ψγ)=(3.3±1.0±0.3)×10-6, where the uncertainties are statistical and systematic, respectively. We also measure the branching fraction B(B+→χc1K+)=(4.9±0.2±0.4) ×10-4. These results are obtained from (287±3) million BB̄ decays collected at the Υ(4S) resonance with the BABAR detector at the PEP-II B Factory at SLAC. © 2006 The American Physical Society.