390 research outputs found

    Evaluating and improving social awareness of energy communities through semantic network analysis of online news

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    The implementation of energy communities represents a cross-disciplinary phenomenon that has the potential to support the energy transition while fostering citizens' participation throughout the energy system and their exploitation of renewables. An important role is played by online information sources in engaging people in this process and increasing their awareness of associated benefits. In this view, this work analyses online news data on energy communities to understand people's awareness and the media importance of this topic. We use the Semantic Brand Score (SBS) indicator as an innovative measure of semantic importance, combining social network analysis and text mining methods. Results show different importance trends for energy communities and other energy and society-related topics, also allowing the identification of their connections. Our approach gives evidence to information gaps and possible actions that could be taken to promote a low-carbon energy transition

    Search for heavy neutrinos mixing with tau neutrinos

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    We report on a search for heavy neutrinos (\nus) produced in the decay D_s\to \tau \nus at the SPS proton target followed by the decay \nudecay in the NOMAD detector. Both decays are expected to occur if \nus is a component of ντ\nu_{\tau}.\ From the analysis of the data collected during the 1996-1998 runs with 4.1×10194.1\times10^{19} protons on target, a single candidate event consistent with background expectations was found. This allows to derive an upper limit on the mixing strength between the heavy neutrino and the tau neutrino in the \nus mass range from 10 to 190 MeV\rm MeV. Windows between the SN1987a and Big Bang Nucleosynthesis lower limits and our result are still open for future experimental searches. The results obtained are used to constrain an interpretation of the time anomaly observed in the KARMEN1 detector.\Comment: 20 pages, 7 figures, a few comments adde

    Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

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    A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

    X-ray emission from the Sombrero galaxy: discrete sources

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    We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV

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    Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80 GeV with the CMS detector at the LHC. The measured ET spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon ET-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities.Comment: Submitted to Physics Letters

    Performance and Operation of the CMS Electromagnetic Calorimeter

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    The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

    Performance studies of the CMS strip tracker before installation

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    The CMS High Level Trigger

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    At the Large Hadron Collider at CERN the proton bunches cross at a rate of 40MHz. At the Compact Muon Solenoid experiment the original collision rate is reduced by a factor of O (1000) using a Level-1 hardware trigger. A subsequent factor of O(1000) data reduction is obtained by a software-implemented High Level Trigger (HLT) selection that is executed on a multi-processor farm. In this review we present in detail prototype CMS HLT physics selection algorithms, expected trigger rates and trigger performance in terms of both physics efficiency and timing.Comment: accepted by EPJ Nov 200

    Search for three-jet resonances in pp Collisions at √s=7  TeV

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    This article is published Open Access at sciencedirect.com. It is distributed under the terms of the Creative Commons Attribution License 3.0.-- et al.Results are reported from a search for the production of three-jet resonances in pp collisions at a center-of-mass energy √s=7  TeV. The study uses the data sample collected by the CMS experiment at the LHC in 2011, corresponding to an integrated luminosity of 5.0fb -1. Events with high jet multiplicity and a large scalar sum of jet transverse momenta are analyzed for the presence of resonances in the three-jet invariant mass spectrum. No evidence for a narrow resonance is found in the data, and limits are set on the cross section for gluino pair production in an R-parity-violating supersymmetry model, for gluino masses greater than 280 GeV. Assuming a branching fraction for gluino decay into three jets of 100%, gluino masses below 460 GeV are excluded at 95% confidence level. These results significantly extend the range of previous limits. © 2012 CERN.European Commission; Federal Ministry of Science, Research and Economy (Austria); ); Agency for Innovation by Science and Technology (Belgium); Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brasil); Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro; Fundação de Amparo à Pesquisa do Estado de São Paulo; Ministry of Science and Technology of the People's Republic of China; National Natural Science Foundation of China; Colciencias (Colombia); Ministry of Science, Education and Sports of the Republic of Croatia; Research Promotion Foundation (Cyprus); Centre National de la Recherche Scientifique (France); Bundesministerium für Bildung und Forschung (Deutschland); Deutsche Forschungsgemeinschaft; General Secretariat of Research and Technology (Greece); Helsinki Institute of Physics; National Office for Research and Technology (Hungary); Institute for Research in Fundamental Sciences (Iran); Science Foundation Ireland; Istituto Nazionale di Fisica Nucleare (Italia); Compagnia di San Paolo (Italia); National Research Foundation of Korea; Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (México); Consejo Nacional de Ciencia y Tecnología (México); Secretaría de Educación Pública (México); Universidad Autónoma de San Luis Potosí; Ministry of Science and Innovation (New Zealand); Pakistan Atomic Energy Commission; National Science Center (Poland); Fundação para a Ciência e a Tecnologia (Portugal); Joint Institute for Nuclear Research (Russia); Russian Foundation for Basic Research; Ministry of Education, Science and Technological Development (Serbia); Ministerio de Ciencia e Innovación (España); Swiss National Science Foundation.Peer Reviewe
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