850 research outputs found

    B decays to open and hidden charm at Belle

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    The recent Belle collaboration measurements of B decays to open and hidden charm are discussed. Color-suppressed decay branching fractions are measured with an improved accuracy. The branching fractions of the Bˉ0→Ds+K−\bar{B}^0 \to D_s^+ K^- and Bˉ0→Ds−π+\bar{B}^0 \to D_s^- \pi^+ decays, measured with improved accuracy, and Bˉ0→DsJ+K−\bar{B}^0 \to D_{sJ}^+ K^- and Bˉ0→DsJ−π+\bar{B}^0 \to D_{sJ}^- \pi^+ decays, measured for the first time, are compared. The two-body invariant masses of the three-body B0→D(∗)0π+π−B^0 \to D^{(*)0} \pi^+ \pi^- and B0→J/Ψπ+π−B^0 \to J/\Psi \pi^+ \pi^- decays are studied.Comment: 4 pages, 7 figures, proceedings submitted to the ICHEP 2004 conference, August 16-22, 2004, Beijing, Chin

    B_s decays at Belle

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    We report recent results obtained with the Belle detector using a 23.6 fb^{-1} data sample collected on the Y(5S) resonance at the KEKB asymmetric energy e^+ e^- collider. Inclusive semileptonic B_s^0 -> X^+ l^- \nu decays are studied for the first time and the branching fraction is measured. Combining the electron and muon channels, we obtain Bf(B_s^0 -> X^+ l^- \nu) = (10.2 \pm 0.8 \pm 0.9)%. Also, the radiative penguin decay B_s^0 -> \phi \gamma is observed for the first time, and an improved upper limit for the decay B_s^0 \to \gamma \gamma is obtained.Comment: Proceedings of the EPS/HEP 2007 Conference, Manchester, England, July 2007 (on behalf of the Belle collaboration), 3 pages, 2 figure

    Properties of the DsJ states

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    Recent measurements involving the newly discovered D_sJ particles are reported. The results of D_sJ production and decay branching fraction measurements are shown. Possible spin-parity and quark content assignments of D_sJ mesons are discussed. The results are based on a large data sample recorded by the Belle detector at the KEKB e^+ e^- collider.Comment: 4 pages, 3 figures, proceedings to the talk given on behalf of the Belle Collaboration at the First Meeting of the APS Topical Group on Hadron Physic

    Measurement of Br(H→Zγ){\cal B}r(H \to Z\gamma) at the 250 GeV ILC

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    The e+e−→HZe^+e^- \to HZ process with the subsequent decay of the Higgs boson H→ZγH \to Z\gamma is studied, where both ZZ bosons are reconstructed in the final states with two jets. The analysis is performed using Monte Carlo data samples obtained with detailed ILD (The International Large Detector) detector simulation assuming an integrated luminosity of 2 ab−1^{-1}, beam polarizations of Pe−e+=(−0.8,+0.3){\cal{P}}_{e^-e^+} = (-0.8, +0.3), and center-of-mass energy of s\sqrt{s} = 250 GeV. The analysis is repeated for the case of two 0.9 ab−1^{-1} data samples with polarizations Pe−e+=(∓0.8,±0.3){\cal{P}}_{e^-e^+} = (\mp0.8, \pm0.3). Contributions of the potential background processes are studied using all available ILD MC event samples. The largest background comes from the e+e−→W+W−e^+e^- \to W^+W^- process supplemented by an energetic photon produced by initial state radiation. To suppress this background we require that at least one of the ZZ bosons decays to bb-jets. To reduce the jet reconstruction uncertainties the MΔ=M(jjγ)−M(jj)+M(Znom)M_{\Delta} = M(jj\gamma) - M(jj) + M(Z_{\rm nom}) variable is used, where M(Znom)M(Z_{\rm nom}) = 91.2 GeV. The MΔM_{\Delta} distributions are obtained for the studied signal and backgrounds to estimate the expected accuracy of the Br(H→Zγ){\cal B}r(H \to Z\gamma) measurement. The accuracy is 22%\% for the option of the single polarization sample described above and deteriorate to 24%\% in case of the sample with two polarizations. The proposed method can be applied at any future e+e−e^+e^- collider.Comment: 7 pages, 5 figures. arXiv admin note: text overlap with arXiv:2108.0886
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