38 research outputs found

    Measurement of branching fraction ratios and CP asymmetries in B±DCPK±B^{\pm} \to D_{CP}K^{\pm}

    Full text link
    We report results on the decay BDCPKB^{-} \to D_{CP}K^{-} and its charge conjugate using a data sample of 85.4 million BBˉB\bar{B} pairs recorded at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric e+ee^{+}e^{-} storage ring. Ratios of branching fractions of Cabibbo-suppressed to Cabibbo-favored processes are determined to be B(BD0K)/B(BD0π)=0.077±0.005(stat)±0.006(sys){\cal B}(B^- \to D^0 K^-)/{\cal B}(B^- \to D^0 \pi^-)= 0.077 \pm 0.005(stat) \pm 0.006(sys), B(BD1K)/B(BD1π)=0.093±0.018(stat)±0.008(sys){\cal B}(B^- \to D_1 K^-)/{\cal B}(B^- \to D_1 \pi^-) = 0.093 \pm 0.018(stat) \pm 0.008(sys) and B(BD2K)/B(BD2π)=0.108±0.019(stat)±0.007(sys){\cal B}(B^- \to D_2 K^-)/{\cal B}(B^- \to D_2 \pi^-) = 0.108 \pm 0.019(stat) \pm 0.007(sys) where the indices 1 and 2 represent the CP=+1 and CP=-1 eigenstates of the D0D0ˉD^{0}-\bar{D^{0}} system, respectively. We find the partial-rate charge asymmetries for BDCPKB^{-} \to D_{CP}K^{-} to be A1=0.06±0.19(stat)±0.04(sys){\cal{A}}_1 = 0.06 \pm 0.19(stat) \pm 0.04(sys) and A2=0.19±0.17(stat)±0.05(sys){\cal{A}}_2 = -0.19 \pm 0.17(stat) \pm 0.05(sys).Comment: 10 pages, 3 figures, submitted to Physical Review

    Evidence for CP-Violating Asymmetries in B0->pi+pi- Decays and Constraints on the CKM Angle phi2

    Full text link
    We present an improved measurement of CP-violating asymmetries in B0 -> pi+ pi- decays based on a 78 fb^-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct one neutral B meson as a B0 -> pi+ pi- CP eigenstate and identify the flavor of the accompanying B meson from inclusive properties of its decay products. We apply an unbinned maximum likelihood fit to the distribution of the time intervals between the two B meson decay points. The fit yields the CP-violating asymmetry amplitudes Apipi = +0.77+/-0.27(stat)+/-0.08(syst) and Spipi = -1.23+/-0.41(stat)+0.08/-0.07(syst), where the statistical uncertainties are determined from Monte Carlo pseudo-experiments. We obtain confidence intervals for CP-violating asymmetry parameters Apipi and Spipi based on a frequentist approach. We rule out the CP-conserving case, Apipi=Spipi=0, at the 99.93% confidence level. We discuss how these results constrain the value of the CKM angle phi2.Comment: 26 pages, 13 figures, submitted to Phys. Rev.

    Long-Baseline Neutrino Facility (LBNF) and Deep Underground Neutrino Experiment (DUNE) Conceptual Design Report Volume 2: The Physics Program for DUNE at LBNF

    Get PDF
    The Physics Program for the Deep Underground Neutrino Experiment (DUNE) at the Fermilab Long-Baseline Neutrino Facility (LBNF) is described

    The Physics of the B Factories

    Get PDF
    corecore