We present a measurement of the branching fractions for B → D/D */D(*)πℓ-̄νℓ decays based on 341.1 fb-1 of data collected at the γ(4S) resonance with the BABAR detector at the PEP-II e+e- storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We obtain B(B- → D0ℓ-̄νℓ) = (2.33 ± 0.09 (stat.) ± 0.09 (syst.))%, B(B- → D*0ℓ-̄νℓ) = (5.83±0.15 (stat.)±0.30 (syst.))%, B(B0 → D+ℓ-̄νℓ) = (2.21±0.11 (stat.)±0.12 (syst.))%, B(B0 → D*+ℓ-̄νℓ) = (5.49 ± 0.16 (stat.) ± 0.25 (syst.))%, B(B- → D+π-ℓ-̄νℓ) = (0.42 ± 0.06 (stat.) ± 0.03 (syst.))%, B(B- → D *+π-ℓ-̄νℓ) = (0.59±0.05 (stat.)±0.04 (syst.))%, B(B0 → D*π+ℓ- ̄νℓ) = (0.43±0.08 (stat.)±0.03 (syst.))% and B(B0 → D*0π+ℓ-̄νℓ) = (0.48±0.08 (stat.)±0.04 (syst.))%.

We study the decay B 0 → ρ 0 ρ 0 in a sample of about 427 million γ(4S) → BB decays collected with the BABAR detector at the PEP-II asymmetric-energy e + e - collider at SLAC. We find the branching fraction B = (0.84 ± 0.29 ± 0.17) × 10-6 and longitudinal polarization fraction of fL = 0.70 ± 0.14 ± 0.05, where the first uncertainty is statistical, and the second is systematic. The evidence for the B 0 → ρ 0 ρ 0 signal has 3.6σ significance. We investigate the proper-time dependence of the longitudinal component in the decay and measure the CP-violating coefficients S00 L = (0.5± 0.9 ± 0.2) and C00 L = (0.4 ± 0.9 ± 0.2), corresponding to the sine and cosine terms in the time evolution of asymmetry. We study the implication of these results for penguin contributions in B → ρρ decays and for the CKM unitarity angle α.

We present updated measurements of time-dependent CP asymmetries in fully reconstructed neutral B decays containing a charmonium meson. The measurements reported here use a data sample of (465±5)×106 Υ(4S) →BB̄ decays collected with the BABAR detector at the PEP-II asymmetric energy e+e- storage rings operating at the SLAC National Accelerator Laboratory. The time-dependent CP asymmetry parameters measured from JψKS0, JψKL0, ψ(2S)KS0, ηcKS0, χc1KS0, and J/ψK*(892)0 decays are: Cf=0.024±0.020(stat)±0.016(syst) and -ηfSf=0. 687±0.028(stat)±0.012(syst). © 2009 The American Physical Society.

We present a search for B decays to a charged scalar meson a0+ and a π0 where the a0+ decays to an η meson and a π+. The analysis was performed on a data sample consisting of 383×106 BB̄ pairs collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find no significant signal and set an upper limit on the product branching fraction B(B+→a0+π0)×B(a0+→ηπ+) of 1.4×10-6 at the 90% confidence level. © 2008 The American Physical Society.

Using an impact-parameter tag to select an enriched sample of Z0bb» events, we have measured the difference between the average charged multiplicity of bb» and all hadronic Z0 decays to be 2.11.8(stat) 0.6(syst) tracks per event. The resulting total (nonleading) charged multiplicity for Z0 bb» events is 23.1(12.0)1.8 0.6 tracks. A comparison of this nonleading multiplicity to hadronic multiplicity data in the range of 10 to 60 GeV supports the hypothesis of flavor-independent hadronic fragmentation, and yields a measurement of the average energy fraction of bottom hadrons in Z0 decays of xEb=0.620.100.04. © 1992 The American Physical Society.

We analyze the three-body charmless decay B±→K±K± K using a sample of 226.0±2.5 million BB̄ pairs collected by the BABAR detector. We measure the total branching fraction and CP asymmetry to be B=(35.2±0.9±1.6)×10-6 and ACP=(-1.7±2.6±1.5)%. We fit the Dalitz plot distribution using an isobar model and measure the magnitudes and phases of the decay coefficients. We find no evidence of CP violation for the individual components of the isobar model. The decay dynamics is dominated by the K+K- S-wave, for which we perform a partial-wave analysis in the region m(K+K-)<2GeV/c2. Significant production of the f0(980) resonance, and of a spin zero state near 1.55GeV/c2 are required in the isobar model description of the data. The partial-wave analysis supports this observation. © 2006 The American Physical Society.

A search for pair production of stable charged particles from Z decay has been performed with the Mark II detector at the SLAC Linear Collider. Particle masses are determined from momentum, ionization energy loss, and time-of-flight measurements. A limit excluding pair production of stable fourth-generation charged leptons and stable mirror fermions with masses between the muon mass and 36.3 GeV/c2 is set at the 95% confidence level. Pair production of stable supersymmetric scalar leptons with masses between the muon mass and 32.6 GeV/c2 is also excluded. © 1990 The American Physical Society.

We report a measurement of the branching fractions of B̄→D* *ℓ-ν̄ℓ decays based on 417fb-1 of data collected at the Υ(4S) resonance with the BABAR detector at the PEP-II e+e- storage rings. Events are selected by fully reconstructing one of the B mesons in a hadronic decay mode. A fit to the invariant mass differences m(D(*)π)- m(D(*)) is performed to extract the signal yields of the different D** states. We observe the B̄→D**ℓ- ν̄ℓ decay modes corresponding to the four D** states predicted by heavy quark symmetry with a significance greater than 5 standard deviations including systematic uncertainties. © 2008 The American Physical Society.

Measurement of time-dependent conjugation (C) and parity (P) asymmetries and the CP-odd fraction in the decay B0→D*+D *- was discussed. It was found that this measurement of R⊥ supersedesthe BABAR results with a factor of 3 reduction in statistical uncertainty. Results also showed that B0→D*+D*- is mostly CP even.