We report on a Dalitz plot analysis of B-→D+π-π- decays, based on a sample of about 383×106 Υ(4S)→BB̄ decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the total branching fraction of the three-body decay: B(B-→D+π- π-)=(1.08±0.03±0.05)×10-3. We observe the established D2*0 and confirm the existence of D0*0 in their decays to D+π-, where the D2*0 and D0*0 are the 2+ and 0+cū P-wave states, respectively. We measure the masses and widths of D2*0 and D0*0 to be: mD2*0=(2460.4±1.2±1.2±1.9)MeV/c2, ΓD2*0=(41.8±2.5±2.1±2.0)MeV, mD0*0=(2297±8±5±19)MeV/c2, and ΓD0*0= (273±12±17±45)MeV. The stated errors reflect the statistical and systematic uncertainties, and the uncertainty related to the assumed composition of signal events and the theoretical model. © 2009 The American Physical Society.

We present measurements of the semileptonic decays B-→D0τ- ν̄τ, B-→D*0τ-ν̄τ, B̄0→D+τ- ν̄τ, and B̄0→D*+τ-ν̄τ, which are sensitive to non-standard model amplitudes in certain scenarios. The data sample consists of 232×106Υ(4S)→BB̄ decays collected with the BABAR detector at the PEP-II e+e- collider. We select events with a D or D* meson and a light lepton (=e or μ) recoiling against a fully reconstructed B meson. We perform a fit to the joint distribution of lepton momentum and missing mass squared to distinguish signal B̄→D(*) τ-ν̄τ(τ-→-ν̄ντ) events from the backgrounds, predominantly B̄→D(*)-ν̄. We measure the branching-fraction ratios R(D)B(B̄→Dτ-ν̄τ)/ B(B̄→D-ν̄) and R(D*)B(B̄→D*τ- ν̄τ)/B(B̄→D*-ν̄) and, from a combined fit to B- and B̄0 channels, obtain the results R(D)=(41.6±11.7±5.2) % and R(D*)=(29.7±5.6±1.8)%, where the uncertainties are statistical and systematic. Normalizing to measured B-→D(*)0- ν̄ branching fractions, we obtain B(B̄→Dτ-ν̄τ) =(0.86±0.24±0.11±0.06)% and B(B̄→D*τ- ν̄τ)=(1.62±0.31±0.10±0.05)%, where the additional third uncertainty is from the normalization mode. We also present, for the first time, distributions of the lepton momentum, |p*|, and the squared momentum transfer, q2. © 2009 The American Physical Society.

A Dalitz plot analysis of approximately 13000 Ds+ decays to π+π-π+ has been performed. The analysis uses a 384 fb-1 data sample recorded by the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring running at center of mass energies near 10.6 GeV. Amplitudes and phases of the intermediate resonances which contribute to this final state are measured. A high precision measurement of the ratio of branching fractions is performed: B(Ds+→π+π-π+)/B(Ds+→K+K-π+)=0.199±0.004±0. 009. Using a model-independent partial wave analysis, the amplitude and phase of the S wave have been measured. © 2009 The American Physical Society.

We report the results of a search for the bottomonium ground state etab(1S) in the photon energy spectrum with a sample of (109+/-1) million of Upsilon(3S) recorded at the Upsilon(3S) energy with the BABAR detector at the PEP-II B factory at SLAC. We observe a peak in the photon energy spectrum at Egamma=921.2(-2.8)+2.1(stat)+/-2.4(syst) MeV with a significance of 10 standard deviations. We interpret the observed peak as being due to monochromatic photons from the radiative transition Upsilon(3S)-->gammaetab(1S). This photon energy corresponds to an etab(1S) mass of 9388.9(-2.3)+3.1(stat)+/-2.7(syst) MeV/c2. The hyperfine Upsilon(1S)-etab(1S) mass splitting is 71.4(-3.1)+2.3(stat)+/-2.7(syst) MeV/c2. The branching fraction for this radiative Upsilon(3S) decay is estimated to be [4.8+/-0.5(stat)+/-1.2(syst)]x10(-4).

We present branching fraction measurements for the radiative decays B+→ρ+γ, B0→ρ0γ, and B0→ωγ. The analysis is based on a data sample of 465×106 BB̄ events collected with the BABAR detector at the PEP-II asymmetric-energy B Factory located at the Stanford Linear Accelerator Center. We find B(B+→ρ+γ)=(1.20-0. 37+0.42±0.20)×10-6, B(B0→ρ0γ)=(0.97-0.22+0. 24±0.06)×10-6, and a 90% C.L. upper limit B(B0→ωγ) <0.9×10-6, where the first error is statistical and the second is systematic. We also measure the isospin-violating quantity Γ(B+→ρ +γ)/2Γ(B0→ρ0γ)-1=-0.43-0.22+0.25±0.10. © 2008 The American Physical Society.

We present the results of searches for B decays to charmless final states involving varphi, f_{0}(980), and charged or neutral rho mesons. The data sample corresponds to 384x10;{6} BB[over ] pairs collected with the BABAR detector operating at the PEP-II asymmetric-energy e;{+}e;{-} collider at SLAC. We find no significant signals and determine the following 90% confidence level upper limits on the branching fractions, including systematic uncertainties: B(B;{0}-->varphivarphi)<2.0x10;{-7}, B(B;{+}-->varphirho;{+})<30x10;{-7}, B(B;{0}-->varphirho;{0})<3.3x10;{-7}, B[B;{0}-->varphif_{0}(980)]xB[f_{0}(980)-->pi;{+}pi;{-}]<3.8x10;{-7}, and B[B;{0}-->f_{0}(980)f_{0}(980)]xB[f_{0}(980)-->pi;{+}pi;{-}]xB[f_{0}(980)-->K;{+}K;{-}]<2.3x10;{-7}.

We report a search for the decays B -→K+π-π- and B -→K-K-π+, which are highly suppressed in the standard model. Using a sample of (467±5)×106 BB̄ pairs collected with the BABAR detector, we do not see any evidence of these decays and determine 90% confidence level upper limits of B(B -→K+π-π-)<9. 5×10-7 and B(B-→K-K -π+)<1.6×10-7 on the corresponding branching fractions, including systematic uncertainties. © 2008 The American Physical Society.