28 research outputs found

    Progress in the determination of the J/ψ−πJ/\psi-\pi cross section

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    Improving previous calculations, we compute the J/ψπ→charmedmesonsJ/\psi \pi\to {charmed mesons} cross section using QCD sum rules. Our sum rules for the J/ψπ→DˉD∗J/\psi \pi\to \bar{D} D^*, DDˉ∗D \bar{D}^*, Dˉ∗D∗{\bar D}^* D^* and DˉD{\bar D} D hadronic matrix elements are constructed by using vaccum-pion correlation functions, and we work up to twist-4 in the soft-pion limit. Our results suggest that, using meson exchange models is perfectly acceptable, provided that they include form factors and that they respect chiral symmetry. After doing a thermal average we get ∼0.3\sim 0.3 mb at T=150\MeV.Comment: 22 pages, RevTeX4 including 7 figures in ps file

    Traumatic brain and spinal cord fatalities among high school and college football players — United States, 2005–2014

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    Summary What is already known about this topic? Fatalities resulting from catastrophic brain and spinal cord injuries occur infrequently among high school and college football players. What is added by this report? During 2005–2014, a total of 28 traumatic brain and spinal cord injury deaths in high school and college football were identified (2.8 deaths per year). The most common playing positions of those fatally injured were running back and linebacker. Approximately 18% of identified high school brain injury deaths were preceded by an earlier concussion, which might have led to second impact syndrome. What are the implications for public health practice? Implementing enhanced safety measures to prevent fatalities from catastrophic brain and spinal cord injuries among high school and college football players has the potential to reduce the number of these fatalities. Continued surveillance is important to monitor the circumstances of these deaths and develop risk scenarios to improve prevention measures

    Intermittent preventive therapy in pregnancy and incidence of low birth weight in malaria-endemic countries

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    Objectives. To estimate the impact of hypothetical antimalarial and nutritional interventions (which reduce the prevalence of low midupper arm circumference [MUAC]) on the incidence of low birth weight (LBW). Methods. We analyzed data from 14 633 pregnancies from 13 studies conducted across Africa and the Western Pacific from 1996 to 2015. We calculated population intervention effects for increasing intermittent preventive therapy in pregnancy (IPTp), full coverage with bed nets, reduction in malaria infection at delivery, and reductions in the prevalence of low MUAC. Results. We estimated that, compared with observed IPTp use, administering 3 or more doses of IPTp to all women would decrease the incidence of LBW from 9.9% to 6.9% (risk difference = 3.0%; 95% confidence interval = 1.7%, 4.0%). The intervention effects for eliminating malaria at delivery, increasing bed net ownership, and decreasing low MUAC prevalence were all modest. Conclusions. Increasing IPTp uptake to at least 3 doses could decrease the incidence of LBW in malaria-endemic countries. The impact of IPTp on LBW was greater than the effect of prevention of malaria, consistent with a nonmalarial effect of IPTp, measurement error, or selection bias

    Micro-optical structures for daylighting and led systems

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    Different micro-optical structures have been developed for the application in transparent building elements like windows or glazed partitions. In cooperation with the Department of Microstructure Technology, TU Dortmund, as well as partners from research institutions and industry solutions for the following two tasks were elaborated: (1) two-sided structures on glass panes for redirection of direct sunlight into the depth of rooms improving daylighting; and (2) one-sided structures on clear panes, edge-lit by LED, for one-way and selective light emission. High demands were made on the small structures (50–200 μm) as to efficiency of light redirection respectively light emission, and quality of image. Technologies for large scale manufacturing are developed in cooperation with partners from industry. Having tested laboratory samples (100 mm × 100 mm) successfully, larger prototypes are produced in hot embossing and UV embossing technique. Optimization of structure geometry and manufacturing process is continuing while design solutions for component and luminaire integration are developed. Architectural applications in transparent building elements for combined natural and artificial lighting are demonstrated, achieving high quality and low energy room illumination

    Beam dynamics simulations at the S-DALINAC for the optimal position of beam energy monitors Contributed paper to the European Particle Accelerator Conference (EPAC)

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    The superconducting Darmstadt linear accelerator (S-DALINAC) is a 130 MeV superconducting recirculating electron accelerator serving several nuclear and radiation physics experiments as well as driving an infrared free-electron laser. For the experiments an energy stability of 10"-"4 should be reached. Therefore noninvasive beam position monitors will be used to measure the beam energy. For the measurement the differences in flight time of the electrons to the ideal particle are compared, that means in the simulations the longitudinal dispersion of the beam transport system is used for the energy detection. The results of the simulations show that it is possible to detect an energy difference of 10"-"4 with this method. The results are also verified by measurements. (orig.)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
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