The OPERA experiment: on the way to the direct observation of νμ→ντ\nu_\mu \to \nu_\tau oscillation

OPERA (\emph{O}scillation \emph{P}roject with \emph{E}mulsion t\emph{R}acking \emph{A}pparatus) is a long-baseline neutrino experiment, designed to provide the first direct proof of $\nu_\mu \to \nu_\tau$ oscillation in the atmospheric sector using the \emph{C}ERN \emph{N}eutrinos to \emph{G}ran \emph{S}asso (CNGS) $\nu_\mu$ beam. The detector, consisting of a modular target made of lead - nuclear emulsion units complemented by electronic trackers and muon spectrometers, has been conceived to select $\rm{\nu_\tau}$ charged current interactions, among all neutrino flavour events, through the observation of the outcoming tau leptons and subsequent decays. In this paper, the detector, the event analysis chain and the preliminary results from the first OPERA physics run are reported.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

Il metodo Montessori e le case dei bambini. Un modelo educativo per liberare l'infanzia e avviarla alla conquista dell'indipendenza

Il contributo approfondisce i principi alla base del metodo Montessori e analizza le sue ricadute pedagogiche nella storia dell’educazione nazionale e internazionale. In modo particolare si ripercorre la storia dell’istituzione delle Case dei Bambini, che rappresentano ancora una proposta didattica ampiamente diffusa e condivisa in Italia e all’estero e che tuttora vengono annoverate tra i modelli di scuola più efficaci in ambito nazionale e internazionale

Observation ofνμ→ ντoscillations in the CNGS beam with the OPERA experiment

The OPERA long-baseline neutrino experiment was exposed to the CNGS νμ beam from 2008 to 2012, collecting 19505 interactions in the target. The evidence for oscillated ντ appearance, based on the observation of three ντ candidate events, has been previously reported. A fourth candidate event has been recently found in an extended data sample, corresponding to about 89% of the final statistics. The absence of a signal from νμ → ντ oscillations is currently excluded at 4.2σ. The status of the analysis is described in detail with special emphasis on the procedures applied for the selection of signal candidate events and the assessment of efficiencies and background. The fourth ντ candidate event is presented and the significance of the observation is discussed

Social media and politics: the case of Ukraine

Abstract Nowadays, politics is undergoing several changes, especially because of the growing use of social media from politicians, who are using these virtual platforms as tools to gain more and more consent. Social media are also leading to extreme democratization of politics, making it possible for non-politicians not only to enter the sphere of politics but even to win major competitions, such as presidential elections. To bring an actual and highly illustrative example, in this article the authors go through a deep analysis of the former actor and recently elected prime minister of Ukraine Volodimir Zelenskij and his strategical use of social media compared to the one carried out by his opponents, leading him to win the presidential elections with an enormous consent

Efectos de cambios en la riqueza del agente sobre la ganancia esperada del principal

Fil: Chade, Héctor. University of ArizonaFil: Vera de Serio, Virginia. Universidad Nacional de Cuyo. Facultad de Ciencias Económica

Laboratory Experiments on Long Waves Interacting with Rigid Vertical Cylinders

The impact of waves caused by storm surges or floods could lead to significant damage to marine and fluvial structures. Hydraulic forces add significant hydrodynamic loads on bridges built in coastal and fluvial environments; therefore, the effect of the wave impact on bridge substructures must be properly considered for the safe and cost-effective design of the piers. The use of laboratory-scale models is a direct approach to investigate the effects of long waves on simple structures, mimicking bridge piers. The present study describes a laboratory-scale model, where the propagation of two different long waves in a flume, in the presence of two rigid cylinders, was investigated. The velocity measurements were acquired by the Particle Image Velocimetry (PIV) technique, providing instantaneous flow velocity vectors on 2D planes. For each experimental condition, the instantaneous velocity field close to the cylinders was analysed, in order i) to depict how it changes during the wave transit, and thus how the drag force acting on the cylinders could change, ii) to detect the spatial distributions of vorticity downstream. Some first interesting results have been obtained, showing a quite uniform distribution of the longitudinal velocity along the depth of the vertical plane upstream of the cylinders, with increasing values during the wave transit. No interactions in the central part of the flow downstream of the two cylinders was observed in the horizontal plane which are spaced approximately ten times their diameter. Finally, the vorticity has also been studied, displaying a phase-varying behaviour, which appears to lose symmetry during wave transit