65 research outputs found

    Decoupling of Layers in the Three-dimensional Abelian Higgs Model

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    The Abelian Higgs model with anisotropic couplings in 2+1 dimensions is studied in both the compact and non-compact formulations. Decoupling of the space-like planes takes place in the extreme anisotropic limit, so charged particles and gauge fields are presumably localized within these planes. The behaviour of the model under the influence of an external magnetic field is examined in the compact case and yields further characterization of the phases.Comment: 23 pages, 12 figures, plain late

    Predictors of long-term outcome of percutaneous coronary intervention in octogenarians with acute coronary syndrome

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    AbstractThe majority of patients with acute coronary syndrome (ACS) are elderly. Limited evidence makes decision-making on the use of percutaneous coronary intervention (PCI) mainly empirical. Old age is one risk factor, but other factors than age may have an impact on mortality as well. Therefore, we investigated predictors of long-term all-cause mortality among octogenarians who have undergone PCI due to ACS. A total of 182 patients ≥ 80 years who underwent PCI during 2006–2007 at Sahlgrenska University Hospital were studied consecutively from recorded clinical data. All-cause five-year mortality of follow-up was 46.2%. Mean age was 83.7 ± 2.8, 62% were male, 76% were in sinus rhythm, and 42% had left ventricular ejection fraction < 45%. Indications for PCI were STEMI (52%), NSTEMI (36%) and unstable angina (11%). Multivariate analysis in two steps identified atrial fibrillation, moderate tricuspid valve regurgitation, moderate mitral valve regurgitation, dependency in ADL and eGFR ≤ 30 ml/min at the first step and moderate mitral valve regurgitation, atrial fibrillation and eGFR ≤ 30 ml/min at the last step, as independent predictors of all-cause mortality. Kaplan Meier analysis of positive parameters from both steps of multivariate analysis showed high significant difference in survival between patients having these parameters and those who were free from these parameters, with worst prognosis in patients with accumulation of these parameters. Accordingly, we have, in an octogenarian patient cohort who suffered from ACS, undergone PCI in daily clinical practice, identified five prognostic predictors for all-cause death after five years' follow-up

    Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta

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    Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and (7.24+-0.96+-1.11)X10^{-4}, respectively.Comment: 11 pages, 6 figure

    BESII Detector Simulation

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    A Monte Carlo program based on Geant3 has been developed for BESII detector simulation. The organization of the program is outlined, and the digitization procedure for simulating the response of various sub-detectors is described. Comparisons with data show that the performance of the program is generally satisfactory.Comment: 17 pages, 14 figures, uses elsart.cls, to be submitted to NIM

    Measurement of branching fractions for the inclusive Cabibbo-favored ~K*0(892) and Cabibbo-suppressed K*0(892) decays of neutral and charged D mesons

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    The branching fractions for the inclusive Cabibbo-favored ~K*0 and Cabibbo-suppressed K*0 decays of D mesons are measured based on a data sample of 33 pb-1 collected at and around the center-of-mass energy of 3.773 GeV with the BES-II detector at the BEPC collider. The branching fractions for the decays D+(0) -> ~K*0(892)X and D0 -> K*0(892)X are determined to be BF(D0 -> \~K*0X) = (8.7 +/- 4.0 +/- 1.2)%, BF(D+ -> ~K*0X) = (23.2 +/- 4.5 +/- 3.0)% and BF(D0 -> K*0X) = (2.8 +/- 1.2 +/- 0.4)%. An upper limit on the branching fraction at 90% C.L. for the decay D+ -> K*0(892)X is set to be BF(D+ -> K*0X) < 6.6%

    Study of J/ψωK+KJ/\psi \to \omega K^+K^-

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    New data are presented on J/ψωK+KJ/\psi \to \omega K^+K^- from a sample of 58M J/ψJ/\psi events in the upgraded BES II detector at the BEPC. There is a conspicuous signal for f0(1710)K+Kf_0(1710) \to K^+K^- and a peak at higher mass which may be fitted with f2(2150)KKˉf_2(2150) \to K\bar K. From a combined analysis with ωπ+π\omega \pi ^+ \pi ^- data, the branching ratio BR(f0(1710)ππ)/BR(f0(1710)KKˉ)BR(f_0(1710)\to\pi\pi)/BR(f_0(1710) \to K\bar K) is <0.11< 0.11 at the 95% confidence level.Comment: 11 pages, 5 figures. Submitted to Phys. Lett.

    Measurements of Cabibbo Suppressed Hadronic Decay Fractions of Charmed D0 and D+ Mesons

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    Using data collected with the BESII detector at e+ee^{+}e^{-} storage ring Beijing Electron Positron Collider, the measurements of relative branching fractions for seven Cabibbo suppressed hadronic weak decays D0KK+D^0 \to K^- K^+, π+π\pi^+ \pi^-, KK+π+πK^- K^+ \pi^+ \pi^- and π+π+ππ\pi^+ \pi^+ \pi^- \pi^-, D+K0ˉK+D^+ \to \bar{K^0} K^+, KK+π+K^- K^+ \pi^+ and ππ+π+\pi^- \pi^+ \pi^+ are presented.Comment: 11 pages, 5 figure

    Direct Measurement of the Pseudoscalar Decay Constant fD+

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    The absolute branching fraction of D+μ+νD^+ \to \mu^+ \nu has been directly measured by an analysis of a data sample of about 33 pb1{\rm pb^{-1}} collected around s=3.773\sqrt{s}=3.773 GeV with the BES-II at the BEPC. At these energies, DD^- meson is produced in pair as e+eD+De^+e^-\to D^{+} D^{-}. A total of 5321±149±1605321 \pm 149 \pm 160 DD^- mesons are reconstructed from this data set. In the recoil side of the tagged DD^- mesons, 2.67±1.742.67\pm1.74 purely leptonic decay events of D+μ+νD^+ \to \mu^+ \nu are observed. This yields a branching fraction of BF(D+μ+νμ)=(0.1220.053+0.111±0.010)BF(D^+ \to \mu^+ \nu_{\mu}) = (0.122^{+0.111}_{-0.053}\pm 0.010)%, and a corresponding pseudoscalar decay constant fD+=(371119+129±25)f_{D^+}=(371^{+129}_{-119}\pm 25) MeV.Comment: 7 pages, 8 figures, Submitted to Physics Letters B in October, 200

    Strategies for Controlled Placement of Nanoscale Building Blocks

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    The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others
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