366 research outputs found

    Smart CMOS image sensor for lightning detection and imaging

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    We present a CMOS image sensor dedicated to lightning detection and imaging. The detector has been designed to evaluate the potentiality of an on-chip lightning detection solution based on a smart sensor. This evaluation is performed in the frame of the predevelopment phase of the lightning detector that will be implemented in the Meteosat Third Generation Imager satellite for the European Space Agency. The lightning detection process is performed by a smart detector combining an in-pixel frame-to-frame difference comparison with an adjustable threshold and on-chip digital processing allowing an efficient localization of a faint lightning pulse on the entire large format array at a frequency of 1 kHz. A CMOS prototype sensor with a 256×256 pixel array and a 60 μm pixel pitch has been fabricated using a 0.35 μm 2P 5M technology and tested to validate the selected detection approach

    In-flight calibration and verification of the Planck-LFI instrument

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    In this paper we discuss the Planck-LFI in-flight calibration campaign. After a brief overview of the ground test campaigns, we describe in detail the calibration and performance verification (CPV) phase, carried out in space during and just after the cool-down of LFI. We discuss in detail the functionality verification, the tuning of the front-end and warm electronics, the preliminary performance assessment and the thermal susceptibility tests. The logic, sequence, goals and results of the in-flight tests are discussed. All the calibration activities were successfully carried out and the instrument response was comparable to the one observed on ground. For some channels the in-flight tuning activity allowed us to improve significantly the noise performance.Comment: Long technical paper on Planck LFI in flight calibration campaign: 109 pages in this (not final) version, 100 page in the final JINST versio

    CMOS Image Sensor with on-chip Intelligence for Lightning Detection and Imaging

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    We present A CMOS image sensor dedicated to lightning detection and imaging. The detector has been designed for the pre-development phase of the lightning detector that will be implemented in Meteosat Third Generation Imager (MTG-I) satellite for European Space Agency (ESA). The lightning detection process (Patent applied) is performed by a smart detector combining on in-pixel frame to frame difference comparison with an adjustable threshold and onchip digital processing allowing an efficient localization of faint lightning pulse on the entire large format array at 1 kHz. A CMOS prototype sensor with a 256x256 pixel array and 60μm pixel pitch has been fabricated using a 0.35μm 2P 5M technology and tested to validate the selected detection approach. OCIS codes: (040.6070 ) Solid state detectors; (250.3140) Integrated optoelectronic circuits; (280.4788) Optical sensing and sensors; (110.2970) Image detection systems

    Subcutaneous anti-COVID-19 hyperimmune immunoglobulin for prevention of disease in asymptomatic individuals with SARS-CoV-2 infection: a double-blind, placebo-controlled, randomised clinical trialResearch in context

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    Summary: Background: Anti-COVID-19 hyperimmune immunoglobulin (hIG) can provide standardized and controlled antibody content. Data from controlled clinical trials using hIG for the prevention or treatment of COVID-19 outpatients have not been reported. We assessed the safety and efficacy of subcutaneous anti-COVID-19 hyperimmune immunoglobulin 20% (C19-IG20%) compared to placebo in preventing development of symptomatic COVID-19 in asymptomatic individuals with SARS-CoV-2 infection. Methods: We did a multicentre, randomized, double-blind, placebo-controlled trial, in asymptomatic unvaccinated adults (≥18 years of age) with confirmed SARS-CoV-2 infection within 5 days between April 28 and December 27, 2021. Participants were randomly assigned (1:1:1) to receive a blinded subcutaneous infusion of 10 mL with 1 g or 2 g of C19-IG20%, or an equivalent volume of saline as placebo. The primary endpoint was the proportion of participants who remained asymptomatic through day 14 after infusion. Secondary endpoints included the proportion of individuals who required oxygen supplementation, any medically attended visit, hospitalisation, or ICU, and viral load reduction and viral clearance in nasopharyngeal swabs. Safety was assessed as the proportion of patients with adverse events. The trial was terminated early due to a lack of potential benefit in the target population in a planned interim analysis conducted in December 2021. ClinicalTrials.gov registry: NCT04847141. Findings: 461 individuals (mean age 39.6 years [SD 12.8]) were randomized and received the intervention within a mean of 3.1 (SD 1.27) days from a positive SARS-CoV-2 test. In the prespecified modified intention-to-treat analysis that included only participants who received a subcutaneous infusion, the primary outcome occurred in 59.9% (91/152) of participants receiving 1 g C19-IG20%, 64.7% (99/153) receiving 2 g, and 63.5% (99/156) receiving placebo (difference in proportions 1 g C19-IG20% vs. placebo, −3.6%; 95% CI -14.6% to 7.3%, p = 0.53; 2 g C19-IG20% vs placebo, 1.1%; −9.6% to 11.9%, p = 0.85). None of the secondary clinical efficacy endpoints or virological endpoints were significantly different between study groups. Adverse event rate was similar between groups, and no severe or life-threatening adverse events related to investigational product infusion were reported. Interpretation: Our findings suggested that administration of subcutaneous human hyperimmune immunoglobulin C19-IG20% to asymptomatic individuals with SARS-CoV-2 infection was safe but did not prevent development of symptomatic COVID-19. Funding: Grifols

    Probing small Bjorken-xx nuclear gluonic structure via coherent J/ψ\psi photoproduction in ultraperipheral PbPb collisions at sNN\sqrt{s_\mathrm{NN}} = 5.02 TeV

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    International audienceQuasi-real photons exchanged in relativistic heavy ion interactions are powerful probes of the gluonic structure of nuclei. The first measurement of the coherent J/ψ\psi photoproduction cross section in ultraperipheral lead-lead collisions is presented over a wide range of photon-nucleus center-of-mass energies per nucleon (WγNPb^\text{Pb}_{\gamma\text{N}}). Results are obtained using data at the nucleon-nucleon center-of-mass energy of 5.02 TeV collected by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 1.52 nb1^{-1}. The cross section is observed to rise rapidly at low WγNPb^\text{Pb}_{\gamma\text{N}}, and plateau above WγNPb^\text{Pb}_{\gamma\text{N}}\approx 40 GeV, up to 400 GeV, a new regime of small Bjorken-xx (\approx 6 ×\times 105^{-5}) gluons being probed in a heavy nucleus. The observed energy dependence is not predicted by current quantum chromodynamic models

    Luminosity determination using Z boson production at the CMS experiment

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    International audienceThe measurement of Z boson production is presented as a method to determine the integrated luminosity of CMS data sets. The analysis uses proton-proton collision data, recorded by the CMS experiment at the CERN LHC in 2017 at a center-of-mass energy of 13 TeV. Events with Z bosons decaying into a pair of muons are selected. The total number of Z bosons produced in a fiducial volume is determined, together with the identification efficiencies and correlations from the same dataset, in small intervals of 2 pb1^{-1} of integrated luminosity, thus facilitating the efficiency and rate measurement as a function of time and instantaneous luminosity. Using the ratio of the efficiency-corrected numbers of Z bosons, the precisely measured integrated luminosity of one data set is used to determine the luminosity of another. For the first time, a full quantitative uncertainty analysis of the use of Z bosons for the integrated luminosity measurement is performed. The uncertainty in the extrapolation between two data sets, recorded in 2017 at low and high instantaneous luminosity, is less than 0.5%. We show that the Z boson rate measurement constitutes a precise method, complementary to traditional methods, with the potential to improve the measurement of the integrated luminosity

    Search for direct production of GeV-scale resonances decaying to a pair of muons in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceA search for direct production of low-mass dimuon resonances is performed using s\sqrt{s} = 13 TeV proton-proton collision data collected by the CMS experiment during the 2017-2018 operation of the CERN LHC with an integrated luminosity of 96.6 fb1^{-1}. The search exploits a dedicated high-rate trigger stream that records events with two muons with transverse momenta as low as 3 GeV but does not include the full event information. The search is performed by looking for narrow peaks in the dimuon mass spectrum in the ranges of 1.1-2.6 GeV and 4.2-7.9 GeV. No significant excess of events above the expectation from the standard model background is observed. Model-independent limits on production rates of dimuon resonances within the experimental fiducial acceptance are set. Competitive or world's best limits are set at 90% confidence level for a minimal dark photon model and for a scenario with two Higgs doublets and an extra complex scalar singlet (2HDM+S). Values of the squared kinetic mixing coefficient ε2\varepsilon^2 in the dark photon model above 106^{-6} are excluded over most of the mass range of the search. In the 2HDM+S, values of the mixing angle sin(θH)\sin(\theta_\text{H}) above 0.08 are excluded over most of the mass range of the search with a fixed ratio of the Higgs doublets vacuum expectation tanβ\tan\beta = 0.5

    First measurement of the top quark pair production cross section in proton-proton collisions at s \sqrt{s} = 13.6 TeV

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    The first measurement of the top quark pair (tt \textrm{t}\overline{\textrm{t}} ) production cross section in proton-proton collisions at s \sqrt{s} = 13.6 TeV is presented. Data recorded with the CMS detector at the CERN LHC in Summer 2022, corresponding to an integrated luminosity of 1.21 fb1^{−1}, are analyzed. Events are selected with one or two charged leptons (electrons or muons) and additional jets. A maximum likelihood fit is performed in event categories defined by the number and flavors of the leptons, the number of jets, and the number of jets identified as originating from b quarks. An inclusive tt \textrm{t}\overline{\textrm{t}} production cross section of 881 ± 23 (stat + syst) ± 20 (lumi) pb is measured, in agreement with the standard model prediction of 92440+32 {924}_{-40}^{+32} pb.[graphic not available: see fulltext

    Search for inelastic dark matter in events with two displaced muons and missing transverse momentum in proton-proton collisions at s\sqrt{s} = 13 TeV

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    International audienceA search for dark matter in events with a displaced muon pair and missing transverse momentum is presented. The analysis is performed using an integrated luminosity of 138 fb1^{-1} of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV produced by the LHC in 2016-2018. No significant excess over the predicted backgrounds is observed. Upper limits are set on the product of the inelastic dark matter production cross section σ\sigma(pp \to A' \toχ1\chi_1χ2\chi_2) and the decay branching fraction B\mathcal{B}(χ2\chi_2\toχ1μ+μ\chi_1\mu^+\mu^-), where A' is a dark photon and χ1\chi_1 and χ2\chi_2 are dark matter states with near mass degeneracy. This is the first dedicated collider search for inelastic dark matter
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