834 research outputs found

    Accession Site Does Not Influence the Risk of Stroke after Diagnostic Coronary Angiography or Intervention: Results from a Large Prospective Registry

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    INTRODUCTION: Periprocedural stroke represents a rare but serious complication of cardiac catheterization. Pooled data from randomized trials evaluating the risk of stroke following cardiac catheterization via transradial versus transfemoral access showed no difference. On the other hand, a significant difference in stroke rates favoring transradial access was found in a recent meta-analysis of observational studies. Our aim was to determine if there is a difference in stroke risk after transradial versus transfemoral catheterization within a contemporary real-world registry. METHODS: Data from 14,139 patients included in a single-center prospective registry between 2009 and 2016 were used to determine the odds of periprocedural transient ischemic attack (TIA) and stroke for radial versus femoral catheterization via multivariate logistic regression with Firth's correction. RESULTS: A total of 10,931 patients underwent transradial and 3,208 underwent transfemoral catheterization. Periprocedural TIA/stroke occurred in 41 (0.29%) patients. Age was the only significant predictor of TIA/stroke in multivariate analysis, with each additional year representing an odds ratio (OR) = 1.09 (CI 1.05-1.13, p < 0.000). The choice of accession site had no impact on the risk of periprocedural TIA/stroke (OR = 0.81; CI 0.38-1.72, p = 0.577). CONCLUSION: Observational data from a large prospective registry indicate that accession site has no influence on the risk of periprocedural TIA/stroke after cardiac catheterization

    Pressure-induced huge increase of Curie temperature of the van der Waals ferromagnet VI3

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    Evolution of magnetism in single crystals of the van der Waals compound VI3 in external pressure up to 7.3 GPa studied by measuring magnetization and ac magnetic susceptibility is reported. Four magnetic phase transitions, at T1 = 54.5 K, T2 = 53 K, TC = 49.5 K, and TFM = 26 K, respectively have been observed at ambient pressure. The first two have been attributed to the onset of ferromagnetism in specific crystal-surface layers. The bulk ferromagnetism is characterized by the magnetic ordering transition at Curie temperature TC and the transition between two different ferromagnetic phases TFM, accompanied by a structure transition from monoclinic to triclinic symmetry upon cooling. The pressure effects on magnetic parameters were studied with three independent techniques. TC was found to be almost unaffected by pressures up to 0.6 GPa whereas TFM increases rapidly with increasing pressure and reaches TC at a triple point at ~ 0.85 GPa. At higher pressures, only one magnetic phase transition is observed moving to higher temperatures with increasing pressure to reach 99 K at 7.3 GPa. In contrast, the low-temperature bulk magnetization is dramatically reduced by applying pressure (by more than 50% at 2.5 GPa) suggesting a possible pressure-induced reduction of vanadium magnetic moment. We discussed these results in light of recent theoretical studies to analyze exchange interactions and provide how to increase the Curie temperature of VI3.Comment: 20 pages, 16 figure

    Search for a dark vector gauge boson decaying to π+π\pi^+ \pi^- using ηπ+πγ\eta \rightarrow \pi^+\pi^- \gamma decays

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    We report a search for a dark vector gauge boson UU^\prime that couples to quarks in the decay chain D+D0π+,D0KS0η,ηUγD^{*+} \to D^0 \pi^+, D^0 \to K^0_S \eta, \eta \to U^\prime \gamma, Uπ+πU^\prime \to \pi^+ \pi^-. No signal is found and we set a mass-dependent limit on the baryonic fine structure constant of 10310210^{-3} - 10^{-2} in the UU^\prime mass range of 290 to 520 MeV/c2c^2. This analysis is based on a data sample of 976 fb1^{-1} collected by the Belle experiment at the KEKB asymmetric-energy e+ee^+e^- collider.Comment: 6 pages, 4 figure

    Invariant-mass and fractional-energy dependence of inclusive production of di-hadrons in e+ee^+e^- annihilation at s=\sqrt{s}= 10.58 GeV

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    The inclusive cross sections for di-hadrons of charged pions and kaons (e+ehhXe^+e^- \rightarrow hhX) in electron-positron annihilation are reported. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere di-hadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-dependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a 655fb1655\,{\rm fb}^{-1} data sample collected at or near the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^+ e^- collider.Comment: 21 pages, 18 figures plus 25 figures in supplemental material, submitted to PR

    Observation of X(3872)X(3872) in BX(3872)KπB \to X(3872) K\pi decays

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    We report the first observation of B0X(3872)(K+π)B^0 \to X(3872) (K^{+}\pi^{-}) and evidence for B+X(3872)(K0π+)B^+ \to X(3872) (K^{0}\pi^{+}). We measure the product of branching fractions for the former to be {\cal B}(B^0 \to X(3872) (K^+ \pi^-)) \times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) = (7.9 \pm 1.3(\mbox{stat.})\pm 0.4(\mbox{syst.})) \times 10^{-6} and find that B0X(3872)K(892)0B^{0}\to X(3872) K^{*}(892)^{0} does not dominate the B0X(3872)K+πB^{0}\to X(3872)K^{+}\pi^{-} decay mode. We also measure {\cal B}(B^+ \to X(3872) (K^0 \pi^+)) \times {\cal B}(X(3872) \to J/\psi \pi^+ \pi^-) = (10.6 \pm 3.0(\mbox{stat.}) \pm 0.9(\mbox{syst.})) \times 10^{-6}. This study is based on the full data sample of 711~fb1^{-1} (772×106BBˉ772\times 10^6 B\bar B pairs) collected at the Υ(4S)\Upsilon(4S) resonance with the Belle detector at the KEKB collider.Comment: 7 pages, 3 figure

    Inclusive study of bottomonium production in association with an η\eta meson in e+ee^+e^- annihilations near Υ(5S)\Upsilon(5S)

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    We study bottomonium production in association with an η\eta meson in e+ee^+e^- annihilations near the Υ(5S)\Upsilon(5S), at a center of mass energy of s=10.866\sqrt{s}=10.866\,GeV. The results are based on the 121.4121.4\,fb1^{-1} data sample collected by the Belle experiment at the asymmetric energy KEKB collider. Only the η\eta meson is reconstructed and the missing-mass spectrum of η\eta candidates is investigated. We observe the e+eηΥJ(1D)e^+e^-\to\eta\Upsilon_J(1D) process and find evidence for the e+eηΥ(2S)e^+e^-\to\eta\Upsilon(2S) process, while no significant signals of Υ(1S)\Upsilon(1S), hb(1P)h_b(1P), nor hb(2P)h_b(2P) are found. Cross sections for the studied processes are reported.Comment: Submitted to EPJ-

    Search for Bs0γγB_{s}^{0}\rightarrow\gamma\gamma and a measurement of the branching fraction for Bs0ϕγB_{s}^{0}\rightarrow\phi\gamma

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    We search for the decay Bs0γγB_{s}^{0}\rightarrow\gamma\gamma and measure the branching fraction for Bs0ϕγB_{s}^{0}\rightarrow\phi\gamma using 121.4~fb1\textrm{fb}^{-1} of data collected at the Υ(5S)\Upsilon(\mathrm{5}S) resonance with the Belle detector at the KEKB asymmetric-energy e+ee^{+}e^{-} collider. The Bs0ϕγB_{s}^{0}\rightarrow\phi\gamma branching fraction is measured to be (3.6±0.5(stat.)±0.3(syst.)±0.6(fs))×105(3.6 \pm 0.5 (\mathrm{stat.}) \pm 0.3 (\mathrm{syst.}) \pm 0.6 (f_{s})) \times 10^{-5}, where fsf_{s} is the fraction of Bs()Bˉs()B_{s}^{(*)}\bar{B}_{s}^{(*)} in bbˉb\bar{b} events. Our result is in good agreement with the theoretical predictions as well as with a recent measurement from LHCb. We observe no statistically significant signal for the decay Bs0γγB_{s}^{0}\rightarrow\gamma\gamma and set a 90%90\% confidence-level upper limit on its branching fraction at 3.1×106 3.1 \times 10^{-6}. This constitutes a significant improvement over the previous result.Comment: 6 pages, 3 figure

    Measurement of e+eγχcJe^+e^- \to \gamma\chi_{cJ} via initial state radiation at Belle

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    The process e+eγχcJe^+e^- \to \gamma\chi_{cJ} (JJ=1, 2) is studied via initial state radiation using 980 fb1^{-1} of data at and around the Υ(nS)\Upsilon(nS) (nn=1, 2, 3, 4, 5) resonances collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. No significant signal is observed except from ψ(2S)\psi(2S) decays. Upper limits on the cross sections between s=3.80\sqrt{s}=3.80 and 5.56 GeV5.56~{\rm GeV} are determined at the 90% credibility level, which range from few pb to a few tens of pb. We also set upper limits on the decay rate of the vector charmonium [ψ(4040\psi(4040), ψ(4160)\psi(4160), and ψ(4415)\psi(4415)] and charmoniumlike [Y(4260)Y(4260), Y(4360)Y(4360), and Y(4660)Y(4660)] states to γχcJ\gamma\chi_{cJ}.Comment: Accepted by PR
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