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:

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 present a search for the decay of a B0 or B̄0 meson to a K̄*0K0 or K*0K̄0 final state, using a sample of approximately 232×106 BB̄ events collected with the BABAR detector at the PEP-II asymmetric energy e+e- collider at SLAC. The measured branching fraction is B(B0→K̄*0K0)+B(B0→K*0K̄0)=(0.2-0.8- 0.3+0.9+0.1)×10-6. We obtain the following upper limit for the branching fraction at 90% confidence level: B(B0→K̄*0K0) +B(B0→K*0K̄0)<1.9×10-6. We use our result to constrain the standard model prediction for the deviation of the CP asymmetry in B0→K0 from sin2β. © 2006 The American Physical Society.

Abstract:

We present the first search for the decay B0→KS0KS0KL0 using a data sample of 232×106 BB̄ pairs. We find no statistically significant evidence for the nonresonant component of this decay. Our central value for the branching fraction, assuming the true Dalitz distribution is uniform and excluding the resonance, is B(B0→KS0KS0KL0)=(2.4-2.5+2.7±0.6) ×10-6 where the errors are statistical and systematic, respectively. We set a single-sided Bayesian upper limit of B(B0→KS0KS0KL0)<7.4×10- 6 at 90% confidence level using a uniform prior probability for physical values. Assuming the worst-case true Dalitz distribution, where the signal is entirely in the region of lowest efficiency, the 90% confidence level upper limit is B(B0→KS0KS0KL0)<16×10-6. © 2006 The American Physical Society.