4,032 research outputs found

    Characterization of the Hamamatsu R11265-103-M64 multi-anode photomultiplier tube

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    The aim of this paper is to fully characterize the new multi-anode photomultiplier tube R11265-103-M64, produced by Hamamatsu. Its high effective active area (77%), its pixel size, the low dark signal rate and the capability to detect single photon signals make this tube suitable for an application in high energy physics, such as for RICH detectors. Four tubes and two different bias voltage dividers have been tested. The results of a standard characterization of the gain and the anode uniformity, the dark signal rate, the cross-talk and the device behaviour as a function of temperature have been studied. The behaviour of the tube is studied in a longitudinal magnetic field up to 100 Gauss. Shields made of a high permeability material are also investigated. The deterioration of the device performance due to long time operation at intense light exposure is studied. A quantitative analysis of the variation of the gain and the dark signals rate due to the aging is described.Comment: 22 page

    Higgs boson properties and decays, searches for high mass Higgs bosons, and Higgs boson pair production

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    The study of the scalar sector of the standard model of particle physics is one of the main goals of the LHC physics programme. A precise characterisation of the Higgs boson, searches for extensions of the scalar sector, and the study of Higgs boson pair production are complementary in this exploration. This paper describes the status of Higgs boson physics analyses performed by the ATLAS and CMS Collaborations, focusing on the latest results from pp collisions at √s = 13 TeV recorded in 2016, for an integrated luminosity of about 36fb−1

    Reflecting a… “Bit”. What relationship between metacognition and ICT?

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    Abstract Using Information and Communication Technologies (ICT) in educational environments has become widespread in latest years. Since research underlined the important role played by metacognition and self-regulation abilities in fostering learning outcomes, the relationship between these aspects appears to be particularly worthy of investigation. In this review, we present 14 studies that have deepened the relationship between ICT, metacognitive skills and learning outcomes by identifying two main categories. Some articles investigated the effects of ICT environments combined with metacognitive aspects of learning outcomes, while others investigated the reciprocal relationship between ICT and metacognition. In general, from our review, the interaction between ICT and metacognition in producing better learning outcomes appears well established and the results highlight a bi-directional relationship between metacognition and ICT, but also allow to draw attention to gaps requiring further research

    Sport identification, moral perceptions and collective action: A study with young football players

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    We conducted a cross-sectional study investigating whether sport identification predicts different forms of collective action intentions aimed to redress the unfavourable condition faced by disadvantaged individuals. In doing so, moral perceptions (moral convictions, moral violation and moral obligation) were tested as mediators. Participants were young football players from the grassroots of a professional Italian club (N = 111). Results revealed that sport identification was indirectly associated with greater willingness to engage in both normative and non-normative solidarity-based collective action via stronger moral obligation perceptions; moral convictions mediated the relationship between sport identification and normative collective action, while no mediation effects emerged for moral violation. We discuss findings in relation to collective action and sport research

    Preliminary non-invasive study of Roman glasses from Jesolo (Venice), Italy

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    Archaeological excavations at ‘Le Mure’ site (Jesolo, VE, Italy) have followed each other since the sixties, when the first evidence of an Early Medieval church (6th–7th century AD) was found under the ruins of a Medieval Cathedral (11th–12th AD). The last few years of investigations by Ca’Foscari University have led to the collection of large amounts of glass fragments, including many tesserae, dating between the 4th and the 12th centuries AD. A selection of glass fragments and mosaic tesserae taken from the excavations performed in 2013–14 at this site were studied by means of reflectance spectroscopy in order to identify their chromophore ions, in particular Cu0, Cu2+, Co2+, Fe2+ and Fe3+, which were detected in both transparent and opaque samples. In addition, the use of high resolution close-up images allowed for the attribution of surface characteristics to specific manufacturing techniques, while glass chemistry was studied in order to group them into known compositional classes. This study, carried out by non-invasive analytical techniques that allowed for the acquisition of preliminary data, will prove useful in driving further methodologies involving other non-invasive and micro-invasive analysis in order to obtain archaeometric information that can be related to concurrent archaeological results

    Run 2 Upgrades to the CMS Level-1 Calorimeter Trigger

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    The CMS Level-1 calorimeter trigger is being upgraded in two stages to maintain performance as the LHC increases pile-up and instantaneous luminosity in its second run. In the first stage, improved algorithms including event-by-event pile-up corrections are used. New algorithms for heavy ion running have also been developed. In the second stage, higher granularity inputs and a time-multiplexed approach allow for improved position and energy resolution. Data processing in both stages of the upgrade is performed with new, Xilinx Virtex-7 based AMC cards.Comment: 10 pages, 7 figure

    Triggering on electrons, jets and tau leptons with the CMS upgraded calorimeter trigger for the LHC RUN II

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    The Compact Muon Solenoid (CMS) experiment has implemented a sophisticated two-level online selection system that achieves a rejection factor of nearly 10e5. During Run II, the LHC will increase its centre-of-mass energy up to 13 TeV and progressively reach an instantaneous luminosity of 2e34cm-2s-1. In order to guarantee a successful and ambitious physics programme under this intense environment, the CMS Trigger and Data acquisition (DAQ) system has been upgraded. A novel concept for the L1 calorimeter trigger is introduced the Time Multiplexed Trigger (TMT). In this design, nine main receive each all of the calorimeter data from an entire event provided by 18 preprocessors. This design is not different from that of the CMS DAQ and HLT systems. The advantage of the TMT architecture is that a global view and full granularity of the calorimeters can be exploited by sophisticated algortihms. The goal is to maintain the current thresholds for calorimeter objects and improve the performance for their selection. The performance of these algorithms will be demonstrated, both in terms of efficiency and rate reduction. The callenging aspects of the pile-up mitigation and firmware design will be presented

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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