Search for the rare leptonic decay B+ → μ+vμ
Physical Review Letters 92:22 (2004)
Abstract:
A search for the rare leptonic decay with data collected at the resonance by the BABAR experiment was carried out. The decay rate was sensitive to the product of the Cabibbo Kobayashi Maskawa matrix element (Vub and the B decay constant fb, which was propotional to the wave function for zero separation between the quarks. The data used in the analysis was collectd with BABAR detector at the PEP-II storage ring and the sample consisted of an integrity luminosity of 81.4 fb-1. The systematic uncertainty in the signal efficiency was evaluated which included the muon candidate selection and the reconstruction efficiency of the companion B.Determination of the branching fraction for B → Xc ℓ decays and of
Physical Review Letters 93:1 (2004)
Abstract:
The inclusive B→Xcℓν branching fraction, B cℓν, the Cabibo-Kobayashi-Maskawa matrix element, and other heavy quark parameters were determined from a simultaneous fit moments of the hadronic mass and lepton-energy distributions in semileptonic B-meson decays. Using data recorded with BABAR detector, the values were mesured as function of the lower limit on the lepton energy. The vaues for Bceν were extracted using heavy quark expansions (HQE) to the order of 1÷m b3. The stated errors were referred to the experimental, HQE and additional theoretical uncertainties.Measurement of time-dependent CP asymmetries and constraints on sin(2β + γ) with partial reconstruction of B0 → D*±π± decays
Physical Review Letters 92:25 I (2004)
Abstract:
The time-dependent CP-violating asymmetries in partial reconstruction of B0 → D*=∓π∓ decays and constraints on sin(2β + γ) were investigated. The events containing decays were selected with partial reconstruction technique in which only high-momentum π∓ from the B decay and low-momentum π+ from D*∓ were used. The analysis was carried out with series of unbinned maximum-likelihood fits, which were performed simultaneously on the on- and off-resonance data samples. The amplitude of asymmetry was observed to be -0.063∓0.024(stat)∓0.014(stat).Measurement of time-dependent CP asymmetries in B0 → D(*)±π± decays and constraints on sin(2β + γ)
Physical Review Letters 92:25 I (2004)
Abstract:
The CP-violating asymmetries in fully reconstructed B0 → D(*)∓π∓ decays and constraints on sin(2β + γ) were investigated. The time evolution of decays was sensitive to γ because of interference between the Cabibbo-Kobayashi-Maskawa (CKM) favored decay and doubly CKM-suppressed decay. The consistency of data was computed with given value of sin(2β + γ) by counting fraction of simulated experiments for which χ 2(sin(2β + γ))-χmin2 was smaller. The lower limit on |sin(2β + γ)| was observed at 68% confidence level which drops from 0.69 to 0.60.Study of B± → J/Ψπ± and B± → J/ΨK± decays: Measurement of the ratio of branching fractions and search for direct CP violation
Physical Review Letters 92:24 (2004)