LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). First observation of the rare B+ -> D+K+pi(-) decay. Phys. Rev. D, 93(5), 051101–11pp.
Abstract: The B+ -> D+K+pi(-) decay is observed in a data sample corresponding to 3.0 fb(-1) of pp collision data recorded by the LHCb experiment during 2011 and 2012. The signal significance is 8 sigma and the branching fraction is measured to be B(B+ -> D+K+pi(-)) = (5.31 +/- 0.90 +/- 0.48 +/- 0.35) x 10(-6), where the uncertainties are statistical, systematic and due to the normalization mode B+ -> D-K+pi(+), respectively. The Dalitz plot appears to be dominated by broad structures. Angular distributions are exploited to search for quasi-two-body contributions from B+ -> D*(2)(2460)K-0(+) and B+ -> (D+K*)(892)(0) decays. No significant signals are observed and upper limits are set on their branching fractions.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Studies of the resonance structure in D-0 -> (KSK +/-)-K-0 pi(-/+) decays. Phys. Rev. D, 93(5), 052018–35pp.
Abstract: Amplitude models are applied to studies of resonance structure in D-0 -> (KSK-)-K-0 pi(+) and D-0 -> (KSK+)-K-0 pi(-) decays using pp collision data corresponding to an integrated luminosity of 3.0 fb(-1) collected by the LHCb experiment. Relative magnitude and phase information is determined, and coherence factors and related observables are computed for both the whole phase space and a restricted region of 100 MeV/c(2) around the K*(892)(+/-) resonance. Two formulations for the K pi S-wave are used, both of which give a good description of the data. The ratio of branching fractions B(D-0 -> (KSK+)-K-0 pi(-))/B(D-0 -> (KSK-)-K-0 pi(+)) is measured to be 0.655 +/- 0.004(stat) +/- 0.006(syst) over the full phase space and 0.370 +/- 0.003(stat) +/- 0.012(syst) in the restricted region. A search for CP violation is performed using the amplitude models and no significant effect is found. Predictions from SU(3) flavor symmetry for K*(892)K amplitudes of different charges are compared with the amplitude model results.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Measurement of the mass and lifetime of the Omega(-)(b) baryon. Phys. Rev. D, 93(9), 092007–12pp.
Abstract: A proton-proton collision data sample, corresponding to an integrated luminosity of 3 fb(-1) collected by LHCb at root s = 7 and 8 TeV, is used to reconstruct 63 +/- 9 Omega(-)(b) -> Omega(0)(c)pi(-), Omega(0)(c) -> pK(-)K(-)pi(+) decays. Using the Xi(-)(b) ->Xi(0)(c)pi(-), Xi(0)(c) -> pK(-)K(-)pi(+) decay mode for calibration, the lifetime ratio and the absolute lifetime of the Omega(-)(b) baryon are measured to be tau(Omega b-)/tau(Xi b-) = 1.11 +/- 0.16 +/- 0.03, tau(Omega b-) = 1.78 +/- 0.26 +/- 0.05 +/- 0.06 ps, where the uncertainties are statistical, systematic and from the calibration mode (for tau(Omega b-) only). A measurement is also made of the mass difference, m(Omega b-) – m(Xi b-), and the corresponding Omega(-)(b) mass, which yields m(Omega b-) – m(Xi b-) = 247.4 +/- 3.2 +/- 0.5 MeV/c(2), m(Omega b-) = 6045.1 +/- 3.2 +/- 0.5 +/- 0.6 MeV/c(2). These results are consistent with previous measurements.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Measurement of the B-s(0) -> D-s(()*D-)+(s)(*()-) branching fractions. Phys. Rev. D, 93(9), 092008–11pp.
Abstract: The branching fraction of the decay B-s(0) -> D-s(()*D-)+(s)(*()-) is measured using pp collision data corresponding to an integrated luminosity of 1.0 fb(-1), collected using the LHCb detector at a center-of-mass energy of 7 TeV. It is found to be B(B-s(0) -> D-s(()*D-)(s)(*()-)) = (3.05 +/- 0.10 +/- 0.20 +/- 0.34)%, where the uncertainties are statistical, systematic, and due to the normalization channel, respectively. The branching fractions of the individual decays corresponding to the presence of one or two D-s(*+/-) are also measured. The individual branching fractions are found to be B(B-s(0) -> D-s*D-+/-(s)-/+) = (1.35 +/- 0.06 +/- 0.09 +/- 0.15)%, B(B-s(0) -> D-s*D-+(s)*(-)) = (1.27 +/- 0.08 +/- 0.10 +/- 0.14)%. All three results are the most precise determinations to date.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Constraints on the unitarity triangle angle gamma from Dalitz plot analysis of B-0 -> DK+pi(-) decays. Phys. Rev. D, 93(11), 112018–19pp.
Abstract: The first study is presented of CP violation with an amplitude analysis of the Dalitz plot of B-0 -> DK+pi(-) decays, with D -> K+pi(-), K+K-, and pi(+)pi(-). The analysis is based on a data sample corresponding to 3.0 fb(-1) of pp collisions collected with the LHCb detector. No significant CP violation effect is seen, and constraints are placed on the angle gamma of the unitarity triangle formed from elements of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Hadronic parameters associated with the B-0 -> DK*(892)(0) decay are determined for the first time. These measurements can be used to improve the sensitivity to gamma of existing and future studies of the B-0 -> DK*(892)(0) decay.
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