400 research outputs found

    Radiative Decay of Vector Quarkonium: Constraints on Glueballs and Light Gluinos

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    Given a resonance of known mass, width, and J^{PC}, we can determine its gluonic branching fraction, b(R->gg), from data on its production in radiative vector quarkonium decay, V -> gamma+R. For most resonances b(R->gg) is found to be O(10%), consistent with being q-qbar states, but we find that both pseudoscalars observed in the 1440 MeV region have b(R->gg) ~ 1/2 - 1, and b(f_0^{++}->gg) ~ 1/2. As data improves, b(R->gg) should be a useful discriminator between q-qbar and gluonic states and may permit quantitative determination of the extent to which a particular resonance is a mixture of glueball and q-qbar. We also examine the regime of validity of pQCD for predicting the rate of V -> gamma+eta_gluino, the ``extra'' pseudoscalar bound state which would exist if there were light gluinos. From the CUSB limit on peaks in Upsilon -> gamma X, the mass range 3 GeV < m(eta_gluino) < 7 GeV can be excluded. An experiment must be significantly more sensitive to exclude an eta_gluino lighter than this.Comment: 36pp (inc figs),RU-94-04. (Replaces original which didn't latex correctly and didn't have figures.

    Indications for stenting of coarctation of the aorta in children under 3 months of age

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    Introduction: Coarctation of the aorta in children under 3 months of age is usually treated surgically. However, there are clinical scenarios in which stenting of native or recurrent coarctation may become necessary in this age group. Case reports: Four cases illustrate possible indications: left ventricular dysfunction increasing the operative risk, thrombus formation after coarctation surgery, patient size (i.e. in premature babies), and retrograde arch obstruction after hybrid palliation of hypoplastic left heart syndrome. In all babies, coarctation stenting was carried out successfully without complications. Conclusion: Coarctation stenting can be carried out safely in small children. Usually, the stent has to be removed or redilated later. Results are encouraging

    Inoculation route-dependent Lassa virus dissemination and shedding dynamics in the natural reservoir – Mastomys natalensis

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    Lassa virus (LASV), a Risk Group-4 zoonotic haemorrhagic fever virus, affects sub-Saharan African countries. Lassa fever, caused by LASV, results in thousands of annual deaths. Although decades have elapsed since the identification of the Natal multimammate mouse (Mastomys natalensis) as a natural reservoir of LASV, little effort has been made to characterize LASV infection in its reservoir. The natural route of infection and transmission of LASV within M. natalensis remains unknown, and the clinical impact of LASV in M. natalensis is mostly undescribed. Herein, using an outbred colony of M. natalensis, we investigate the replication and dissemination dynamics of LASV in this reservoir following various inoculation routes. Inoculation with LASV, regardless of route, resulted in a systemic infection and accumulation of abundant LASV-RNA in many tissues. LASV infection in the Natal multimammate mice was subclinical, however, clinical chemistry values were transiently altered and immune infiltrates were observed histologically in lungs, spleens and livers, indicating a minor disease with coordinated immune responses are elicited, controlling infection. Intranasal infection resulted in unique virus tissue dissemination dynamics and heightened LASV shedding, compared to subcutaneous inoculation. Our study provides important insights into LASV infection in its natural reservoir using a contemporary infection system, demonstrating that specific inoculation routes result in disparate dissemination outcomes, suggesting intranasal inoculation is important in the maintenance of LASV in the natural reservoir, and emphasizes that selection of the appropriate inoculation route is necessary to examine aspects of viral replication, transmission and responses to zoonotic viruses in their natural reservoirs.Peer Reviewe

    Meson Decay Constants from Isospin Mass Splittings in the Quark Model

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    Decay constants of DD and BB mesons are estimated within the framework of a heavy-quark approach using measured isospin mass splittings in the DD, DD^*, and BB states to isolate the electromagnetic hyperfine interaction between quarks. The values fD=(262±29)f_D = (262 \pm 29) MeV and fB=(160±17)f_B = (160 \pm 17) MeV are obtained. Only experimental errors are given; possible theoretical ambiguities, and suggestions for reducing them, are noted.Comment: 7 pages, LaTeX, EFI-92-3

    Anti-PrP antibodies block PrPSc replication in prion-infected cell cultures by accelerating PrPC degradation.

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    manuscript received October 15, 2003; revised manuscript received December 15, 2003; accepted December 16, 2003. We thanks P. Rondard, O Bischof, J.-L. Laplanche and J.-P. Pin for their fruitful discussions. we are grateful to S. barrère for her assistance in the statistical analysis of the data and H. McMahon for her assistance in reading the manuscript

    Deep inelastic J/ψJ/\psi production at HERA in the kTk_T-factorization approach and its consequences for the nonrelativistic QCD

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    In the framework of the kTk_T-factorization approach, we analyse the inclusive and inelastic production of J/ψJ/\psi particles in deep inelastic epep scattering. We take into account both colour-singlet and colour-octet production channels. We inspect the sensitivity of theoretical predictions to the choice of model parameters. Our theoretical results agree reasonably well with recent experimental data collected by the collaboration H1 at HERA.Comment: 14 pages, 6 figure

    Measurement of the leptonic decay widths of the phi-meson with the KLOE detector

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    The phi-meson leptonic widths, Gee and Gmm, are obtained, respectively, from the e+e- forward-backward asymmetry and the muon cross section around the phi-mass energy. We find Gee=1.32&#8853;0.05&#8853;0.03 kev and sqrt(GeeGmm)= 1.320&#8853;0.018&#8853;0.017 kev. These results, compatible with Gee=Gmm, provide a precise test of lepton universality. Combining the two results gives G_lept=1.320&#8853;0.023 kev.Comment: 10 pages and 8 figures to be submitted to Phys.Lett.

    Dilating and fracturing side struts of open cell stents frequently used in pediatric cardiac interventions—An in vitro study

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    Background: Open cell stents are frequently used in interventional therapy of congenital heart disease. Overstenting of vessel branches may necessitate strut dilation. Methods and Results: The strut size achievable in Bard Valeo and Cook Formula stents, and the pressure necessary to fracture struts was assessed. In addition, a self expanding stent (Optimed SinusflexDS) was also tested. With the original balloon at nominal pressure, in Valeo stents side struts could be dilated to approximately 90% of the nominal stent diameter, in Formula stents to approximately 80%. With larger high pressure woven balloons, strut size increased to approximately 125% in Valeo stents, and to approximately 105% in the Formula. Strut fracture can connect two adjoining struts. Pressures were dependent on the balloon utilized. Sidestruts of the Sinusflex could lastingly overdilated with large balloons only. Conclusion: Dilation and overdilation of side struts in open cell stents can be achieved. Dependent on the clinical context, the original balloon used to place the premounted stent can be used to achieve strut dilation, but woven high pressure balloons maybe safer for patients. Should a larger diameter be required, these high pressure woven balloons can achieve bigger diameters and even strut fracture

    Upsilonium polarization as a touchstone in understanding the proton dynamics in QCD

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    In the framework of the k_t-factorization approach, the production of ΥmesonsattheFermilabTevatronandCERNLHCisconsidered,andthepredictionsonthespinalignmentparameter\Upsilon mesons at the Fermilab Tevatron and CERN LHC is considered, and the predictions on the spin alignment parameter \alpha$ are presented. We argue that measuring the polarization of quarkonium states can serve as a crucial test discriminating two competing theoretical approaches to parton dynamics in QCD.Comment: 8 pages, 2 figure
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