1,022 research outputs found

    Rates for the reactions antiproton-proton --> pi phi and gamma phi

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    We study antiproton-proton annihilation at rest into πϕ\pi\phi and γϕ\gamma\phi. Rescattering by KK+KK\overline{K^*}K+K^*\overline{K} and ρ+ρ\rho^{+}\rho^{-} for ppπϕ\overline{p}p\rightarrow\pi\phi states is sizable, of order (0.90to2.6)×104(0.90\, {\rm to}\,2.6)\times 10^{-4} in the branching ratio, but smaller than experiment. For ppγϕ\overline{p}p\rightarrow\gamma\phi the rescattering contributions are negligible, but the γϕ\gamma\phi channel is well explained by a ρϕ\rho\phi intermediate state combined with vector meson dominance.Comment: 12 pages, plain latex, 2 postscript figures available upon request, PSI-PR-93-2

    The Use of Dispersion Relations in the ππ\pi\pi and KKˉK\bar K Coupled-Channel System

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    Systematic and careful studies are made on the properties of the IJ=00 ππ\pi\pi and KKˉK\bar K coupled-channel system, using newly derived dispersion relations between the phase shifts and poles and cuts. The effects of nearby branch point singularities to the determination of the f0(980)f_0(980) resonance are estimated and and discussed.Comment: 22 pages with 5 eps figures. A numerical bug in previous version is fixed, discussions slightly expanded. No major conclusion is change

    Branching Ratio and CP Asymmetry of B_s \to K^*_0(1430)\pi Decays in the PQCD Approach

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    In the two-quark model supposition for K0(1430)K_0^{*}(1430), the branching ratios and the direct CP-violating asymmetries for decays Bˉs0K00(1430)π0,K0+(1430)π\bar B_s^0\to K^{*0}_0(1430)\pi^0, K^{*+}_0(1430)\pi^- are studied by employing the perturbative QCD factorization approach. We find that although these two decays are both tree-dominated, the ratio of their penguin to tree contributions are very different: there is only a few percent for the decay Bˉs0K0+(1430)π\bar B_s^0\to K^{*+}_0(1430)\pi^-, while about 37% in scenario I, even 51% in scenario II for the decay Bˉs0K00(1430)π0\bar B_s^0\to K^{*0}_0(1430)\pi^0. It results that these two decays have very different values in the branching ratios and the direct CP asymmetries. The branching ratio of the decay Bˉs0K0+(1430)π\bar B_s^0\to K^{*+}_0(1430)\pi^- is at the order of 10510^{-5}, and its direct CP asymmetry is about (20-30)%. While for the decay Bˉs0K00(1430)π0\bar B_s^0\to K^{*0}_0(1430)\pi^0, its direct CP-violating asymmetry is very large and about 90%, but it is difficult to measure it, because the branching ratio for this channel is small and only 10710^{-7} order.Comment: 8pages, 2figure

    Systematic Theoretical Search for Dibaryons in a Relativistic Model

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    A relativistic quark potential model is used to do a systematic search for quasi-stable dibaryon states in the uu, dd, and ss three flavor world. Flavor symmetry breaking and channel coupling effects are included and an adiabatic method and fractional parentage expansion technique are used in the calculations. The relativistic model predicts dibaryon candidates completely consistent with the nonrelativistic model.Comment: 12 pages, latex, no figure

    HKF: Hierarchical Kalman Filtering with Online Learned Evolution Priors for Adaptive ECG Denoising

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    Electrocardiography (ECG) signals play a pivotal role in many healthcare applications, especially in at-home monitoring of vital signs. Wearable technologies, which these applications often depend upon, frequently produce low-quality ECG signals. While several methods exist for ECG denoising to enhance signal quality and aid clinical interpretation, they often underperform with ECG data from wearable technology due to limited noise tolerance or inadequate flexibility in capturing ECG dynamics. This paper introduces HKF, a hierarchical and adaptive Kalman filter, which uses a proprietary state space model to effectively capture both intra- and inter-heartbeat dynamics for ECG signal denoising. HKF learns a patient-specific structured prior for the ECG signal's intra-heartbeat dynamics in an online manner, resulting in a filter that adapts to the specific ECG signal characteristics of each patient. In an empirical study, HKF demonstrated superior denoising performance (reduced mean-squared error) while preserving the unique properties of the waveform. In a comparative analysis, HKF outperformed previously proposed methods for ECG denoising, such as the model-based Kalman filter and data-driven autoencoders. This makes it a suitable candidate for applications in extramural healthcare settings.Comment: Submitted to Transactions on Signal Processin

    Universal Scaling of Wave Propagation Failure in Arrays of Coupled Nonlinear Cells

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    We study the onset of the propagation failure of wave fronts in systems of coupled cells. We introduce a new method to analyze the scaling of the critical external field at which fronts cease to propagate, as a function of intercellular coupling. We find the universal scaling of the field throughout the range of couplings, and show that the field becomes exponentially small for large couplings. Our method is generic and applicable to a wide class of cellular dynamics in chemical, biological, and engineering systems. We confirm our results by direct numerical simulations.Comment: 4 pages, 3 figures, RevTe

    Design and characterization of purely textile patch antennas

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    Mutations in the C-terminal region of the HIV-1 reverse transcriptase and their correlation with drug resistance associated mutations and antiviral treatment

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    <p>Abstract</p> <p>Objective</p> <p>Replication of HIV-1 after cell entry is essentially dependent on the reverse transcriptase (RT). Antiretroviral drugs impairing the function of the RT currently aim at the polymerase subunit. One reason for failure of antiretroviral treatment is the evolvement of resistance-associated mutations in the viral genome. For RT inhibitors, almost all identified mutations are located within the polymerase; therefore, general genotyping confines to investigate this subunit. Recently several studies have shown that substitutions within the RNase H and the connection domain increase antiviral drug-resistance in vitro, and some of them are present in patient isolates.</p> <p>Aim</p> <p>The aim of the present study was to investigate the prevalence of these substitutions and their association with mutations in the polymerase domain arising during antiretroviral treatment.</p> <p>Materials and methods</p> <p>We performed genotypic analyzes on seventy-four virus isolates derived from treated and untreated patients, followed at the HIV Centre of the Johann Wolfgang Goethe University Hospital (Frankfurt/Main, Germany). We subsequently analysed the different substitutions in the c-terminal region to evaluate whether there were associations with each other, n-terminal substitutions or with antiretroviral treatment.</p> <p>Results</p> <p>We identified several primer grip substitutions, but almost all of them were located in the connection domain. This is consistent with other in-vivo studies, in which especially the primer grip residues located in the RNase H were unvaried. Furthermore, we identified other substitutions in the connection domain and in the RNase H. Especially E399D seemed to be associated with an antiretroviral treatment and N-terminal resistance-delivering mutations.</p> <p>Conclusion</p> <p>Some of the identified substitutions were associated with antiviral treatment and drug resistance-associated mutations. Due to the low prevalence of C-terminal mutations and as only a few of them could be associated with antiviral treatment and N-terminal resistance-delivering mutations, we would not recommend routinely testing of the C-terminal RT region.</p

    The detailed mechanism of the eta production in pp scattering up to the Tlab = 4.5 GeV

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    Contrary to very early beliefs, the experimental cross section data for the eta production in proton-proton scattering are well described if pi and only eta meson exchange diagrams are used to calculate the Born term. The inclusion of initial and final state interactions is done in the factorization approximation by using the inverse square of the Jost function. The two body Jost functions are obtained from the S matrices in the low energy effective range approximation. The danger of double counting in the p-eta final state interaction is discussed. It is shown that higher partial waves in meson-nucleon amplitudes do not contribute significantly bellow excess energy of Q=100 MeV. Known difficulties of reducing the multi resonance model to a single resonance one are illustrated.Comment: 10 pages, 5 figures, corrected typos in relation (3), changed content (added section with differential cross sections
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