76 research outputs found

    Do final state interactions obscure short range correlation effects in quasielastic A(e,ep)A(e,e'p) scattering?

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    Are short range correlations in the ground state of the target nucleus (initial state correlations ISC)observable inexperiments on quasielastic A(e,ep)A(e,e'p) scattering at large missing momentum pmp_{m}? Will the missing momentum spectrum observed at CEBAF be overwhelmed by final state interactions of the struck proton? Taking the 4He^{4}He nucleus with a realistic model wave function for a testing ground, we present a full calculation of the missing momentum distribution in inclusive 4He(e,ep)^{4}He(e,e'p) scattering. We find a complex interplay and strong quantum-mechanical interference of FSI and ISC contributions to scattering at large pmp_{m}, with drastic change of the interference pattern from the (anti)parallel to transverse kinematics. We show that in all the kinematical conditions, for missing momenta p_{m}\gsim 1\,fm1^{-1}, quasielastic scattering is dominated by FSI effects and the sensitivity to details of the nuclear ground state is lost. The origin of the FSI dominance is well understood and can be traced back to the anisotropic behaviour of FSI which is long ranged in the longitudinal direction and short ranged in the transverse direction in the opposite to the short ranged ground state correlations

    Evidence for a narrow dip structure at 1.9 GeV/c2^2 in 3π+3π3\pi^+ 3\pi^- diffractive photoproduction

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    A narrow dip structure has been observed at 1.9 GeV/c2^2 in a study of diffractive photoproduction of the  3π+3π~3\pi^+3\pi^- final state performed by the Fermilab experiment E687.Comment: The data of Figure 6 can be obtained by downloading the raw data file e687_6pi.txt. v5 (2nov2018): added Fig. 7, the 6 pion energy distribution as requested by a reade

    MOG-Enzephalomyelitis: Internationale Empfehlungen zu Diagnose und Antikörpertestung [MOG encephalomyelitis: international recommendations on diagnosis and antibody testing]

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    Over the past few years, new-generation cell-based assays have demonstrated a robust association of autoantibodies to full-length human myelin oligodendrocyte glycoprotein (MOG-IgG) with (mostly recurrent) optic neuritis, myelitis and brainstem encephalitis, as well as with acute disseminated encephalomyelitis (ADEM)-like presentations. Most experts now consider MOG-IgG-associated encephalomyelitis (MOG-EM) a disease entity in its own right, immunopathogenetically distinct from both classic multiple sclerosis (MS) and aquaporin-4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorders (NMOSD). Owing to a substantial overlap in clinicoradiological presentation, MOG-EM was often unwittingly misdiagnosed as MS in the past. Accordingly, increasing numbers of patients with suspected or established MS are currently being tested for MOG-IgG. However, screening of large unselected cohorts for rare biomarkers can significantly reduce the positive predictive value of a test. To lessen the hazard of overdiagnosing MOG-EM, which may lead to inappropriate treatment, more selective criteria for MOG-IgG testing are urgently needed. In this paper, we propose indications for MOG-IgG testing based on expert consensus. In addition, we give a list of conditions atypical for MOG-EM ('red flags') that should prompt physicians to challenge a positive MOG-IgG test result. Finally, we provide recommendations regarding assay methodology, specimen sampling and data interpretation, and propose for the first time diagnostic criteria for MOG-EM

    Measurement of cross sections of exclusive e+eVPe^+ e^- \to VP processes at s=10.58\sqrt{s}=10.58 GeV

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    The cross sections for the reactions e+eϕη,ϕη,ρη,ρηe^+e^- \to \phi\eta, \quad \phi\eta', \quad \rho\eta, \quad \rho\eta' have been measured using a data sample of 516 fb1^{-1} collected with the Belle detector at the KEKB asymmetric-energy e+ee^+e^- collider. The corresponding values of the cross sections are: 1.4±0.4±0.11.4 \pm 0.4 \pm 0.1 fb (ϕη)(\phi\eta), 5.3±1.1±0.45.3 \pm 1.1 \pm 0.4 fb (ϕη)(\phi\eta'), 3.1±0.5±0.13.1 \pm 0.5 \pm 0.1 fb (ρη)(\rho\eta) and 3.3±0.6±0.23.3 \pm 0.6 \pm 0.2 fb (ρη)(\rho\eta'). The energy dependence of the cross sections is presented using Belle measurements together with those of CLEO and BaBar.Comment: 8 pages, 8 figure

    National identity predicts public health support during a global pandemic

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    Changing collective behaviour and supporting non-pharmaceutical interventions is an important component in mitigating virus transmission during a pandemic. In a large international collaboration (Study 1, N = 49,968 across 67 countries), we investigated self-reported factors associated with public health behaviours (e.g., spatial distancing and stricter hygiene) and endorsed public policy interventions (e.g., closing bars and restaurants) during the early stage of the COVID-19 pandemic (April-May 2020). Respondents who reported identifying more strongly with their nation consistently reported greater engagement in public health behaviours and support for public health policies. Results were similar for representative and non-representative national samples. Study 2 (N = 42 countries) conceptually replicated the central finding using aggregate indices of national identity (obtained using the World Values Survey) and a measure of actual behaviour change during the pandemic (obtained from Google mobility reports). Higher levels of national identification prior to the pandemic predicted lower mobility during the early stage of the pandemic (r = −0.40). We discuss the potential implications of links between national identity, leadership, and public health for managing COVID-19 and future pandemics.publishedVersio

    Physics with the KLOE-2 experiment at the upgraded DAϕ\phiNE

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    Investigation at a ϕ\phi--factory can shed light on several debated issues in particle physics. We discuss: i) recent theoretical development and experimental progress in kaon physics relevant for the Standard Model tests in the flavor sector, ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled kaon states, iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and eta/eta^\prime mesons, iv) the contribution to understand the nature of light scalar mesons, and v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the e+ee^+ e^- physics in the continuum with the measurements of (multi)hadronic cross sections and the study of gamma gamma processes.Comment: 60 pages, 41 figures; added affiliation for one of the authors; added reference to section
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