Observation of the decay B → J/ψK and search for X(3872)→ J/ψ
Physical Review Letters 93:4 (2004)
Abstract:
The observation of charmonium production in B meson decays by color-supressed b → cc̄s quark transition was discussed. The data used in the observation correspond to a integrated luminosity of 81.9 fb -1 taken on the γ(4S) resonance. The data were collected at the asymmetric energy e+e- storage ring with BABAR detectors. The results show that with an upper limit of X(3872) in the product branching fraction the magnitude of possibole enhancements with charmonium hybrid states can restrict.Measurement of the direct CP asymmetry in b → sγ decays
Physical Review Letters 93:2 (2004)
Abstract:
A measurement of the direct CP asymmetry between inclusive b→sγ decays was performed. It was observed that this asymmetry was expected to be less than 0.01 in the standard model but could be enhanced up to 0.10. The different components of the signal and background events was also identified that was described by a crystal ball function. Monte Carlo simulations were also applied to the four contributions to the beam energy substituted mass distribution of events.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)