141 research outputs found

    Application of Many-Body Rayleigh-Schrodinger Perturbation Theory to Excitations Accompanying Photoionization in Molecules

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    Excitations accompanying photoionizations in molecules (shake- up processes) are studied on the basis of degenerate many-body Rayleigh-Schr6dinger perturbation theory (MB - RSPT). These excitations give rise to satellite lines accompanyin ionization lines. Decomposition of correlation effects in these processes into those corresponding to single-particle excitation and single- particle ionization is discussed

    Search for B0B^{0} decays to invisible final states at Belle

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    We report a search for B0B^{0} decays into invisible final states using a data sample of 657×106657 \times 10^{6} BBˉB\bar{B} pairs collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB e+ee^{+}e^{-} collider. The signal is identified by fully reconstructing a hadronic decay of the accompanying BB meson and requiring no other particles in the event. No significant signal is observed, and we obtain an upper limit of 1.3×1041.3 \times 10^{-4} at the 90% confidence level for the branching fraction of invisible B0B^{0} decay.Comment: 6 pages, 5 figures (9 figure files

    Angular analysis of B0K(892)0+B^0 \to K^\ast(892)^0 \ell^+ \ell^-

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    We present a measurement of angular observables, P4P_4', P5P_5', P6P_6', P8P_8', in the decay B0K(892)0+B^0 \to K^\ast(892)^0 \ell^+ \ell^-, where +\ell^+\ell^- is either e+ee^+e^- or μ+μ\mu^+\mu^-. The analysis is performed on a data sample corresponding to an integrated luminosity of 711 fb1711~\mathrm{fb}^{-1} containing 772×106772\times 10^{6} BBˉB\bar B pairs, collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the asymmetric-energy e+ee^+e^- collider KEKB. Four angular observables, P4,5,6,8P_{4,5,6,8}' are extracted in five bins of the invariant mass squared of the lepton system, q2q^2. We compare our results for P4,5,6,8P_{4,5,6,8}' with Standard Model predictions including the q2q^2 region in which the LHCb collaboration reported the so-called P5P_5' anomaly.Comment: Conference paper for LHC Ski 2016. SM prediction for P6P_{6}' corrected and reference for arXiv:1207.2753 adde

    Search for B -> phi pi decays

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    We report on a search for the charmless decays B+ϕπ+B^{+} \to\phi\pi^{+} and B0ϕπ0B^{0} \to\phi \pi^{0} that are strongly suppressed in the Standard Model. The analysis is based on a data sample of 657×106657 \times 10^6 BBˉB \bar{B} pairs collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+ e^- collider. We find no significant signal and set upper limits of 3.3×1073.3 \times 10^{-7} for B+ϕπ+B^{+} \to \phi \pi^{+} and 1.5×1071.5 \times 10^{-7} for B0ϕπ0B^0 \to \phi \pi^0 at the 90% confidence level.Comment: submitted to Phys. Rev. D (RC

    Observation of BD()KKS0{B\to D^{(*)} K^- K^{0}_S} decays using the 2019-2022 Belle II data sample

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    We present a measurement of the branching fractions of four B0,D()+,0KKS0B^{0,-}\to D^{(*)+,0} K^- K^{0}_S decay modes. The measurement is based on data from SuperKEKB electron-positron collisions at the Υ(4S)\Upsilon(4S) resonance collected with the Belle II detector and corresponding to an integrated luminosity of 362 fb1{362~\text{fb}^{-1}}. The event yields are extracted from fits to the distributions of the difference between expected and observed BB meson energy to separate signal and background, and are efficiency-corrected as a function of the invariant mass of the KKS0K^-K_S^0 system. We find the branching fractions to be: B(BD0KKS0)=(1.89±0.16±0.10)×104, \text{B}(B^-\to D^0K^-K_S^0)=(1.89\pm 0.16\pm 0.10)\times 10^{-4}, B(B0D+KKS0)=(0.85±0.11±0.05)×104, \text{B}(\overline B{}^0\to D^+K^-K_S^0)=(0.85\pm 0.11\pm 0.05)\times 10^{-4}, B(BD0KKS0)=(1.57±0.27±0.12)×104, \text{B}(B^-\to D^{*0}K^-K_S^0)=(1.57\pm 0.27\pm 0.12)\times 10^{-4}, B(B0D+KKS0)=(0.96±0.18±0.06)×104, \text{B}(\overline B{}^0\to D^{*+}K^-K_S^0)=(0.96\pm 0.18\pm 0.06)\times 10^{-4}, where the first uncertainty is statistical and the second systematic. These results include the first observation of B0D+KKS0\overline B{}^0\to D^+K^-K_S^0, BD0KKS0B^-\to D^{*0}K^-K_S^0, and B0D+KKS0\overline B{}^0\to D^{*+}K^-K_S^0 decays and a significant improvement in the precision of B(BD0KKS0)\text{B}(B^-\to D^0K^-K_S^0) compared to previous measurements
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