Malcolm John

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.

Abstract:

We analyze 230.4fb-1 of data collected with the BABAR detector at the PEP-II e+e- collider at SLAC to search for evidence of D0-D̄0 mixing using regions of phase space in the decay D0→K+π-π0. We measure the time-integrated mixing rate RM=(0.023-0.014+0.018(stat.)±0.004(syst.))%, and RM<0.054% at the 95% confidence level, assuming CP invariance. The data are consistent with no mixing at the 4.5% confidence level. We also measure the branching ratio for D0→K+π-π0 relative to D0→K-π+π0 to be (0.214±0.008(stat.)±0.008(syst.))%. © 2006 The American Physical Society.