1,730 research outputs found

    Charmonium Physics with PANDA at FAIR

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    One component of the future international Facility for Antiproton and Ion Research - FAIR is directed towards studies of hadronic matter at the sub-nuclear level with beams of antiprotons. These studies focus on two key aspects: confinement of quarks and the generation of the hadron masses. These goals will be pursued by performing precision measurements of charged and neutral decay products from antiproton-proton annihilation in the charmonium mass region. In this report an overview of the charmonium issues relevant to PANDA will be presented.Comment: Contribution to the proceedings of HQL06, Munich, October 16th-20th 200

    Application of NASTRAN for stress analysis of left ventricle of the heart

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    Knowing the stress and strain distributions in the left ventricular wall of the heart is a prerequisite for the determination of the muscle elasticity and contractility in the process of assessing the functional status of the heart. NASTRAN was applied for the calculation of these stresses and strains and to help in verifying the results obtained by the computer program FEAMPS which was specifically designed for the plane-strain finite-element analysis of the left ventricular cross sections. Adopted for the analysis are the true shape and dimensions of the cross sections reconstructed from multiplanar X-ray views of a left ventricle which was surgically isolated from a dog's heart but metabolically supported to sustain its beating. A preprocessor was prepared to accommodate both FEAMPS and NASTRAN, and it has also facilitated the application of both the triangular element and isoparameteric quadrilateral element versions of NASTRAN. The stresses in several crucial regions of the left ventricular wall calculated by these two independently developed computer programs are found to be in good agreement. Such confirmation of the results is essential in the development of a method which assesses the heart performance

    Empirical Parameterization of Nucleon-Nucleon Elastic Scattering Amplitude at High Beam Momenta for Glauber Calculations and Monte Carlo Simulations

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    A parameterization of the nucleon-nucleon elastic scattering amplitude is needed for future experiments with nucleon and nuclear beams in the beam momentum range of 2 -- 50 GeV/c/nucleon. There are many parameterizations of the amplitude at Plab>P_{lab} > 25--50 GeV/c, and at PlabP_{lab} \leq 5 GeV/c. Our paper is aimed to cover the range between 5 -- 50 GeV/c. The amplitude is used in Glauber calculations of various cross sections and Monte Carlo simulations of nucleon-nucleon scatterings. Usually, the differential nucleon-nucleon elastic scattering cross sections are described by an exponential expression. Corresponding experimental data on pppp interactions at t>|t|> 0.005 (GeV/c)2^2 and t|t|\leq 0.125 (GeV/c)2^2 have been fit. We propose formulae to approximate the beam momentum dependence of these parameters in the momentum range considered. The same was done for npnp interactions at t|t|\leq 0.5 (GeV/c)2^2. Expressions for the momentum dependence of the total and elastic cross sections, and the ratio of real to imaginary parts of the amplitude at zero momentum transfer are also given for pppp and npnp collisions. These results are sufficient for a first approximation of the Glauber calculations. For more exact calculations we fit the data at t>|t|> 0.005 (GeV/c)2^2 without restrictions on the maximum value of t|t| using an expression based on two coherent exponential. The parameters of the fits are found for the beam momentum range 2 -- 50 GeV/c.Comment: 14 pages, 10 figure

    Studies of the effects of gravitational and inertial forces on cardiovascular and respiratory dynamics

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    The current status and application are described of the biplane video roentgen densitometry, videometry and video digitization systems. These techniques were developed, and continue to be developed for studies of the effects of gravitational and inertial forces on cardiovascular and respiratory dynamics in intact animals and man. Progress is reported in the field of lung dynamics and three-dimensional reconstruction of the dynamic thoracic contents from roentgen video images. It is anticipated that these data will provide added insight into the role of shape and internal spatial relationships (which is altered particularly by acceleration and position of the body) of these organs as an indication of their functional status

    Properties of D-mesons in nuclear matter within a self-consistent coupled-channel approach

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    The spectral density of the DD-meson in the nuclear environment is studied within a self-consistent coupled-channel approach assuming a separable potential for the bare meson-baryon interaction. The DNDN interaction, described through a G-matrix, generates dynamically the Λc\Lambda_c (2593) resonance. This resonance is the charm counterpart of the Λ\Lambda (1405) resonance generated from the s-wave KˉN\bar{K}N interaction in the I=0 channel. The medium modification of the D-meson spectral density due to the Pauli blocking of intermediate states as well as due to the dressing of the D-mesons, nucleons and pions is investigated. We observe that the inclusion of coupled-channel effects and the self-consistent dressing of the DD-meson results in an overall reduction of the in-medium DD-meson changes compared to previous work which neglect those effects.Comment: 23 pages, 10 figures, submitted for publicatio

    Application of the time-dependent charge asymmetry method for longitudinal position determination in prototype proportional chambers for the PANDA experiment

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    The PANDA collaboration intends to build a state-of-the-art detector to study the physics of antiproton annihilation in the charm mass region at the future FAIR facility at GSI, Darmstadt. One major part of the PANDA detector is the straw tube tracker. It will consist of about 6000 individual straws grouped in 11 double layers and filled with an Ar+10%CO_2 gas mixture. The required radial spatial resolution is about 150 micron. Two different methods are considered for longitudinal coordinate measurements - skewed double layers and a novel method based on the time-dependent charge asymmetry. The latter method is presented in this article.Comment: 18 pages, 13 figures, Preprint submitted to NIM

    Strange Hadron Spectroscopy with a Secondary KL Beam at GlueX

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    We propose to create a secondary beam of neutral kaons in Hall D at Jefferson Lab to be used with the GlueX experimental setup for strange hadron spectroscopy. A flux on the order of 3 x 10^4 KL/s will allow a broad range of measurements to be made by improving the statistics of previous data obtained on hydrogen targets by three orders of magnitude. Use of a deuteron target will provide first measurements on the neutron which is {\it terra incognita}. The experiment will measure both differential cross sections and self-analyzed polarizations of the produced {\Lambda}, {\Sigma}, {\Xi}, and {\Omega} hyperons using the GlueX detector at the Jefferson Lab Hall D. The measurements will span c.m. cos{\theta} from -0.95 to 0.95 in the c.m. range above W = 1490 MeV and up to 3500 MeV. These new GlueX data will greatly constrain partial-wave analyses and reduce model-dependent uncertainties in the extraction of strange resonance properties (including pole positions), and provide a new benchmark for comparisons with QCD-inspired models and lattice QCD calculations. The proposed facility will also have an impact in the strange meson sector by providing measurements of the final-state K{\pi} system from threshold up to 2 GeV invariant mass to establish and improve on the pole positions and widths of all K*(K{\pi}) P-wave states as well as for the S-wave scalar meson {\kappa}(800).Comment: 97 pages, 63 figures, Proposal for JLab PAC45, PR12-17-001; v3 missed citation in Sec 9 (pg 22
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