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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Search for b -> u transitions in B- -> DK- and D*K- decays. Phys. Rev. D, 82(7), 072006–18pp.
Abstract: We report results from an updated study of the suppressed decays We report results from an updated study of the suppressed decays B- -> DK- and B- -> D*K- followed by D -> K+ pi(-), where D-(*()0) indicates a D-(*()0)or a (D) over bar (()*()0) meson, and D* -> D pi(0) or D* -> D gamma. These decays are sensitive to the Cabibbo-Kobayashi-Maskawa unitarity triangle angle gamma due to interference between the b -> c transition B- -> D-(*K-)0(-) followed by the doubly Cabibbo-suppressed decay D-0 -> K+ pi(-), and the b -> u transition B- -> (D) over bar (()*()0) K- followed by the Cabibbo-favored decay (D) over bar (0) -> K+ pi(-). We also report an analysis of the decay B- -> D-(*())pi(-) with the D decaying into the doubly Cabibbo-suppressed mode D -> K+ pi(-). Our results are based on 467 x 10(6) Gamma(4S) -> BB- decays collected with the BABAR detector at SLAC. We measure the ratios R-(*()) of the suppressed ([K+ pi(-)](D)K- / pi(-)) to favored ([K+ pi(-)](D)K- / pi(-)) branching fractions as well as the CP asymmetries A(()*()) of those modes. We see indications of signals for the B- -> DK- and B- -> D-D pi 0(()*()) K- suppressed modes, with statistical significances of 2.1 and 2.2 sigma, respectively, and we measure: R-DK = (1.1 +/- 0: 6 +/- 0.2) x 10(-2); A(DK) = -0.86 +/- 0: 47(-0.16)(+0.12), R-(D pi 0)K* = (1.8 +/- 0: 9 +/- 0: 4) x 10(-2); A ((D pi 0)K)* = +0.77 +/- 0: 35 +/- 0.12; R-(D gamma)K* = (1.3 +/- 1.4 +/- 0.8) x 10(-2); A((D gamma)K)* = +0.36 +/- 0: 94(-0.41)(+0.25), where the first uncertainty is statistical and the second is systematic. We use a frequentist approach to obtain the magnitude of the ratio r(B) equivalent to vertical bar A(B- -> (D) over bar 0K(-))/A(B- -> (DK-)-K-0)vertical bar = (9.5(-4.1)(+5.1))%, with r(B) < 16: 7% at 90% confidence level. In the case of B- -> D*K- we find r(B) equivalent to vertical bar A(B- -> <(D)over bar>0K(-))/A(B- -> (DK-)-K-0)vertical bar = (9.6(-5.1)(+3.5))%, with r(B)* < 15.0% at 90% confidence level.
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Search for f(J)(2220) in Radiative J/psi Decays. Phys. Rev. Lett., 105(17), 172001–7pp.
Abstract: We present a search for f(J)(2220) production in radiative J/psi --> gamma f(J)(2220) decays using 460 fb(-1) of data collected with the BABAR detector at the SLAC PEP-II e(+)e(-) collider. The f(J)(2220) is searched for in the decays to K+K- and (KSKS0)-K-0. No evidence of this resonance is observed, and 90% confidence level upper limits on the product of the branching fractions for J/psi --> gamma f(J)(2220) and f(J)(2220) --> K+K-((KSKS0)-K-0) as a function of spin and helicity are set at the level of 10(-5), below the central values reported by the Mark III experiment.
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Observation of the Y(1(3)D(J)) bottomonium state through decays to pi(+)pi Y-(1S). Phys. Rev. D, 82(11), 111102–7pp.
Abstract: Based on 122 X 10(6)Y(3S) events collected with the BABAR detector, we have observed the Y(1(3)D(J)) bottomonium state through the Y(3S) -> gamma gamma Y(1(3)D(J)) -> gamma gamma pi(+)pi Y-(1S) decay chain. The significance for the J = 2 member of the Y(1(3)D(J)) triplet is 5.8 standard deviations including systematic uncertainties. The mass of the J = 2 state is determined to be 10 164.5 +/- 0.8(stat) +/- 0.5(syst) MeV/c(2). We use the pi(+)pi(-) invariant mass distribution to confirm the consistency of the observed state with the orbital angular momentum assignment of the Y(1(3)D(J)).
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Study of B -> X gamma decays and determination of vertical bar V-td/V-ts vertical bar. Phys. Rev. D, 82(5), 051101–8pp.
Abstract: Using a sample of 471 x 10(6) B (B) over bar events collected with the BABAR detector, we study the sum of seven exclusive final states B -> X-s(d)gamma, where X-s(d) is a strange (nonstrange) hadronic system with a mass of up to 2.0 GeV/c(2). After correcting for unobserved decay modes, we obtain a branching fraction for b -> d gamma of (9.2 +/- 2.0(stat) +/- 2.3(syst) x 10(-6) in this mass range, and a branching fraction for b -> s gamma of (23.0 +/- 0.8(stat) +/- 3.0(syst) x 3.0(syst) x 10(-5) in the same mass range. We find B(b -> d gamma)/B(b -> s gamma) = 0.040 +/- 0.009(stat) +/- 0.010(syst), from which we determine vertical bar Vtd/Vts vertical bar = 0.199 +/- 0.022(stat) +/- 0.024(syst) +/- 0.002(th).
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Evidence for Direct CP Violation in the Measurement of the Cabbibo-Kobayashi-Maskawa Angle gamma with B-/+ -> D-(*K-)(()*()-/+) Decays. Phys. Rev. Lett., 105(12), 121801–7pp.
Abstract: We report the measurement of the Cabibbo-Kobayashi-Maskawa CP-violating angle gamma through a Dalitz plot analysis of neutral D-meson decays to K-S(0)pi(+) pi(-) and K-S(0) K+ K- produced in the processes B--/+ -> DK -/+, B--/+ -> D* K--/+ with D* -> D pi(0), D gamma and B -/+ DK*-/+ with K*(-/+) -> K-S(0)pi(-/+), using 468 million B (B) over bar pairs collected by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at SLAC. We measure gamma = (68 +/- 14 +/- 4 +/- 3)degrees (modulo 180 degrees), where the first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the uncertainty in the description of the neutral D decay amplitudes. This result is inconsistent with gamma = 0 ( no direct CP violation) with a significance of 3.5 standard deviations.
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