148 research outputs found

    Measurement of the CP asymmetry and branching fraction of B-0 ->rho K-0(0)

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    We present a measurement of the branching fraction and time-dependent CP asymmetry of B-0 -> POKO. The results are obtained from a data sample of 227 x 10(6) Y(4S) -> BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at Stanford Linear Accelerator Center. From a time-dependent maximum likelihood fit yielding 111 +/- 19 signal events, we find B(B-0 -> rho K-0(0)) = (4.9 +/- 0.8 +/- 0.9) x 10(-6), where the first error is statistical and the second systematic. We report the measurement of the CP parameters S-rho 0KS0 = 0.20 +/- 0.52 +/- 0.24 and C-rho 0KS0 = 0.64 +/- 0.41 +/- 0.20

    Measurement of branching fractions and charge asymmetries in B decays to an eta meson and a K-* meson

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    We present measurements of branching fractions and charge asymmetries for the decays B ->eta K-*, where K-* indicates a spin 0, 1, or 2 K pi system. The data sample corresponds to 344x10(6) B (B) over bar pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at SLAC. We measure the branching fractions (in units of 10(-6)): B(B-0 ->eta K-*0(892))=16.5 +/- 1.1 +/- 0.8, B(B+->eta K*+(892))=18.9 +/- 1.8 +/- 1.3, B(B-0 ->eta(K pi)(0)(*0))=11.0 +/- 1.6 +/- 1.5, B(B+->eta(K pi)(0)(*+))=18.2 +/- 2.6 +/- 2.6, B(B-0 ->eta K-2(*0)(1430))=9.6 +/- 1.8 +/- 1.1, and B(B+->eta K-2(*+)(1430))=9.1 +/- 2.7 +/- 1.4. We also determine the charge asymmetries for all decay modes

    Observation of CP violation in B ->eta/K-0 decays

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    We present measurements of the time-dependent CP-violation parameters S and C in B-0 -> eta K-'(0) decays. The data sample corresponds to 384 x 10(6) B (B) over bar pairs produced by e(+)e(-) annihilation at the Upsilon(4S). The results are S = 0.58 +/- 0.10 +/- 0.03 and C = -0.16 +/- 0.07 +/- 0.03. We observe mixing-induced CP violation with a significance of 5.5 standard deviations in this b -> s penguin dominated mode

    Measurements of CP-violating asymmetries in B-0 -> a(1)(+/-)(1260)pi(-/+) decays

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    We present measurements of CP-violating asymmetries in the decay B-0 -> a(1)(+/-)(1260)pi(-/+) with a(1)(+/-)(1260)->pi(-/+)pi(+/-)pi(+/-). The data sample corresponds to 384x10(6) B(b) over bar pairs collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. We measure the CP-violating asymmetry A(CP)(a1 pi)=-0.07 +/- 0.07 +/- 0.02, the mixing-induced CP violation parameter S-a1 pi=0.37 +/- 0.21 +/- 0.07, the direct CP violation parameter C-a1 pi=-0.10 +/- 0.15 +/- 0.09, and the parameters Delta C-a1 pi=0.26 +/- 0.15 +/- 0.07 and Delta S-a1 pi=-0.14 +/- 0.21 +/- 0.06. From these measured quantities we determine the angle alpha(eff)=78.6 degrees +/- 7.3 degrees

    Branching fraction measurements of B+->rho(+)gamma, B-0 ->rho(0)gamma, and B-0 ->omega gamma

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    We present a study of the decays B+->rho(+)gamma, B-0 ->rho(0)gamma, and B-0 ->omega gamma. The analysis is based on data containing 347x10(6) B (B) over bar events recorded with the BABAR detector at the PEP-II asymmetric B factory. We measure the branching fractions B(B+->rho(+)gamma)=(1.10(-0.33)(+0.37)+/- 0.09)x10(-6) and B(B-0 ->rho(0)gamma)=(0.79(-0.20)(+0.22)+/- 0.06)x10(-6), and set a 90% C.L. upper limit B(B-0 ->omega gamma)(rho/omega)gamma)=(1.25(-0.24)(+0.25)+/- 0.09)x10(-6), from which we determine vertical bar V-td/V-ts vertical bar=0.200(-0.020)(+0.021)+/- 0.015, where the first uncertainty is experimental and the second is theoretical
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