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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Amplitude analysis and measurement of the time-dependent CP asymmetry of B-0 -> (KSKSKS0)-K-0-K-0 decays. Phys. Rev. D, 85(5), 054023–21pp.
Abstract: We present the first results on the Dalitz-plot structure and improved measurements of the time-dependent CP-violation parameters of the process B-0 -> (KSKSKS0)-K-0-K-0 obtained using 468 x 10(6) B (B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The Dalitz-plot structure is probed by a time-integrated amplitude analysis that does not distinguish between B-0 and (B) over bar (0) decays. We measure the total inclusive branching fraction B(B-0 -> (KSKSKS0)-K-0-K-0) = (6.19 +/- 0.48 +/- 0.15 +/- 0.12) x 10(-6), where the first uncertainty is statistical, the second is systematic, and the third represents the Dalitz-plot signal model dependence. We also observe evidence for the intermediate resonant states f(0)(980), f(0)(1710), and f(2)(2010). Their respective product branching fractions are measured to be (2.70(-1.19)(+1.25) +/- 0.36 +/- 1.17) x 10(-6), (0.50(-0.24)(+0.46) +/- 0.04 +/- 0.10) x 10(-6), and (0.54(-0.20)(+0.21) +/- 0.03 +/- 0.52) x 10(-6). Additionally, we determine the mixing-induced CP-violation parameters to be S = -0.94(-0.21)(+0.24) +/- 0.06 and C = -0.17 +/- 0.18 +/- 0.04, where the first uncertainty is statistical and the second is systematic. These values are in agreement with the standard model expectation. For the first time, we report evidence of CP violation in B-0 -> (KSKSKS0)-K-0-K-0 decays; CP conservation is excluded at 3.8 standard deviations including systematic uncertainties.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Search for lepton-number violating processes in B+ -> h(-)l(+)l(+) decays. Phys. Rev. D, 85(7), 071103–8pp.
Abstract: We have searched for the lepton-number violating processes B+ -> h(-)l(+)l(+) with h(-) = K-/pi(-) and l(+) = e(+)/mu(+), using a sample of 471 +/- 3 million B (B) over bar events collected with the BABAR detector at the PEP-II e(+)e(-) collider at the SLAC National Accelerator Laboratory. We find no evidence for these decays and place 90%-confidence-level upper limits on their branching fractions B(B+ -> pi(-)e(+)e(+)) < 2.3 x 10(-8), B(B+ -> K(-)e(+)e(+)) < 3.0 x 10(-8), B(B+ -> pi(-)mu(+)mu(+)) < 10.7 x 10(-8), and B(B+ -> K-mu(+)mu(+)) < 6.7 x 10(-8).
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). B-0 meson decays to rho K-0*(0), f(0)K*(0), and rho K-*(+), including higher K* resonances. Phys. Rev. D, 85(7), 072005–16pp.
Abstract: We present branching fraction measurements for the decays B-0 -> rho K-0*(0), B-0 -> f(0)K*(0), and B-0 -> rho K-*(+), where K* is an S-wave (K pi)*(0) or a K*(892) meson; we also measure B-0 -> f(0)K*(2)(1430)(0). For the K*(892) channels, we report measurements of longitudinal polarization fractions (for rho final states) and direct CP violation asymmetries. These results are obtained from a sample of (471.0 +/- 2.8) X 10(6) B (B) over bar pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at the SLAC National Accelerator Laboratory. We observe rho K-0*(892)(0), rho(0)(K pi)*(0)(0), f(0)K*(892)(0), and rho K-*(892)(+) with greater than 5 sigma significance, including systematics. We report first evidence for f(0)(K pi)*(0)(0) and f(0)K*(2)(1430)(0), and place an upper limit on rho(-)(K pi)*(+)(0). Our results in the K*(892) channels are consistent with no direct CP violation.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2012). Search for Low-Mass Dark-Sector Higgs Bosons. Phys. Rev. Lett., 108(21), 211801–7pp.
Abstract: Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb(-1) of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the standard model-dark-sector mixing angle and the dark-sector coupling constant.
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BABAR Collaboration(Lees, J. P. et al), Lopez-March, N., Martinez-Vidal, F., & Oyanguren, A. (2012). Search for the decay D-0 -> gamma gamma and measurement of the branching fraction for D-0 -> pi(0)pi(0). Phys. Rev. D, 85(9), 091107–8pp.
Abstract: We search for the rare decay of the D-0 meson to two photons, D-0 -> gamma gamma, and present a measurement of the branching fraction for a D-0 meson decaying to two neutral pions, B(D-0 -> pi(0)pi(0)). The data sample analyzed corresponds to an integrated luminosity of 470.5 fb(-1) collected by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at SLAC. We place an upper limit on the branching fraction, B(D-0 -> gamma gamma) < 2.2 x 10(-6), at 90% confidence level. This limit improves on the existing limit by an order of magnitude. We also find B(D-0 -> pi(0)pi(0)) = (8.4 +/- 0.1 +/- 0.4 +/- 0.3 +/-) x 10(-4).
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