Malcolm John

Abstract:

The branching fractions of the decays B0 → K*0 γ and B+ → K*+ γ are measured using a sample of 88 × 106BB̄ events collected with the BABAR detector at the PEP-II asymmetric-energy e +e- collider. We find B(B0 → K* γ) = [3.92 ± 0.20(stat) ± 0.24(syst)] × 10 -5, B(B+ → K*+ γ) = [3.87 ± 0.28(stat) ± 0.26(syst)] × 10-5. Our measurements also constrain the direct CP asymmetry to be -0.074 < A(B → K* γ) < 0.049 and the isospin asymmetry to be -0.046 < Δ0-̈ < 0.146, both at the 90% confidence level.

Abstract:

We have investigated the exclusive, radiative B meson decays to K 2*(1430) in 89 × 106 BB̄ events with the BABAR detector at the PEP-II storage ring. We measure the branching fractions B(B0 → K2*(1430)0γ) = (1.22 ± 0.25 ± 0.10) × 10-5 and B(B+ → K2*(1430)+γ) = (1.45 ± 0.40 ± 0.15) × 10-5, where the first error is statistical and the second systematic. In addition, we measure the CP-violating asymmetry A CP[B0 → K2*(1430) 0γ] = -0.08 ± 0.15 ± 0.01.

Abstract:

We report on the inclusive branching fractions of B- and of B̄0 mesons decaying to D0X, D̄0X, D+X, D-X, Ds+X, Ds-X, Λc+X, Λc-X, based on a sample of 88.9 × 106 BB̄ events recorded with the BABAR detector at the Υ (4S) resonance. Events are selected by completely reconstructing one B and searching for a reconstructed charmed particle in the rest of the event. We measure the number of charmed and of anticharmed particles per B decay and derive the total charm yield per B - decay nc- = 1.313 ± 0.037 ± 0.062-0.042+0.063 and per B̄0 decay n c0 = 1.276 ± 0.062 ± 0.058 -0.046+0.066, where the first uncertainty is statistical, the second is systematic, and the third reflects the charm branching-fraction uncertainties.

Abstract:

We present a measurement of the branching fraction of the decay B ±→χc0K± sample of 89×106 BB̄ pairs collected by the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. The χc0 meson is reconstructed through its two-body decays toπ+ π- and K+K-. We measure B(B± → χc0K±) ×Β(χ c0→π+π-) = [1.32-027+0.28(stat)±0.26(syst)] × 10-6 and B(B ±→ χc0K±) × B(χc0 →K+K-) = [1.49 -0.34+0.36(stat) ±0.22(syst)] × 10 -6. Using the known values for the χc0 decays branching fractions, we combine these results to obtain Β(B ± →χc0K±) = (2.7±0.7)× 10-4. © 2004 The American Physical Society.

Abstract:

Branching fraction measurements using B-meson decays to Ks0π+π- are presented. These measurements were obtained by analyzing a data sample of 88.9 × 106 Υ(45) → BB̄ decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. Using a maximum likelihood fit, the following branching fraction results were obtained: B(B0π +π-) = (43.7 ± 3.8 ± 3.4) × 10 -6, B(B0 → K*+π-) (12.9 ± 2.4 ± 1.4) × 10-6, and B(B0 → D-(→Ks0π+π -)π+) = (42.7 ± 2.1 ± 2.2) × 10-6. The CP violating charge asymmetry AK*π for the decay B0 → K*+π- was measured to be AK*π = 0.23 ± 0.18-0.06+0.09. For all these measurements the first error is statistical and the second is systematic.