The OPERA experiment

The aim of the OPERA experiment is to provide an unambiguous evidence for the νμ ↔ ντ oscillation by looking at the appearance of ντ in a pure νμ beam. This oscillation will be sought in the region of the oscillation parameters indicated by the atmospheric neutrino results. The experiment is part of the CNGS (Cern Neutrino beam to Gran Sasso) project. The νμ beam produced at CERN will be sent towards the Gran Sasso underground laboratory, where the OPERA detector is under construction. The detector, the physics potential and performance for neutrino oscillation studies including the subleading νμ ↔ νe search are presented

Double Chooz and recent results

Double Chooz is a reactor ¯νe disappearance experiment located in France near the power plant of Chooz. The main goal of the experiment is the measurement of the θ13 mixing angle and in 2011 for the first time the experiment observed an indication for a non-zero value of such an oscillation parameter. The mixing angle was successively measured using only the far detector finding the best fit value of sin2(2θ13) = 0.109 ± 0.035. The near detector is under construction and will start data taking by the middle of 2014 allowing to reduce the systematic errors. In this paper I make a review of the experimental results, focusing in particular on independent analyses such as the measurement of the mixing angle θ13 relying on the neutron absorption on gadolinium and hydrogen, and on the reactor rate modulation. I also present for the first time the capability of Double Chooz to identify the ortho-positronium state on event-by-event basis, which could be an additional handle for the electron/positron discrimination in future liquid-scintillator–based detectors

A new anti-neutrino detection technique based on positronium tagging with plastic scintillators

The main signature for anti-neutrino detection in reactor and geo-neutrino experiments based on scintillators is provided by the space-time coincidence of positron and neutron produced in the Inverse Beta Decay reaction. Such a signature strongly suppresses backgrounds and allows for measurements performed underground with a relatively high signal-to-background ratio. In an aboveground environment, however, the twofold coincidence technique is not sufficient to efficiently reject the high background rate induced by cosmogenic events. Enhancing the positron-neutron twofold coincidence efficiency has the potential to pave the way future aboveground detectors for reactor monitoring. We propose a new detection scheme based on a threefold coincidence, between the positron ionization, the ortho-positronium (o-Ps) decay, and the neutron capture, in a sandwich detector with alternated layers of plastic scintillator and aerogel powder. We present the results of a set of dedicated measurements on the achievable light yield and on the o-Ps formation and lifetime. The efficiencies for signal detection and background rejection of a preliminary detector design are also discussed.Comment: 18 pages, 10 figure

Measurement of ortho-Positronium Properties in Liquid Scintillators

Pulse shape discrimination in liquid scintillator detectors is a well-established technique for the discrimination of heavy particles from light particles. Nonetheless, it is not efficient in the separation of electrons and positrons, as they give rise to indistinguishable scintillator responses. This inefficiency can be overtaken through the exploitation of the formation of ortho-Positronium (o-Ps), which alters the time profile of light pulses induced by positrons. We characterized the o-Ps properties in the most commonly used liquid scintillators, i.e. PC, PXE, LAB, OIL and PC + PPO. In addition, we studied the effects of scintillator doping on the o-Ps properties for dopants currently used in neutrino experiments, Gd and Nd. Further measurements for Li-loaded and Tl-loaded liquid scintillators are foreseen. We found that the o-Ps properties are suitable for enhancing the electron-positron discrimination.Comment: 4 pages, 1 figure. Contribution to proceedings of the Low Radioactivity Techniques 2013 Workshop at LNGS, Assergi (AQ), Italy, April 10-12 201

Femme de conventionnel : un enjeu politique dans la république ?

L’article veut interroger les fonctions des « femmes de » dans le contexte de la Révolution française et, ici, plus spécifiquement de la Convention nationale. En étudiant la place que les épouses de député occupent dans la vie politique particulièrement passionnée et conflictuelle de l’époque de la Convention, il ne s’agit pas seulement d’aborder la question des entourages des élus, mais aussi de problématiser la question de l’espace que ces épouses peuvent occuper par elles-mêmes. Il s’agit de ne pas les installer d’emblée dans la dépendance, mais d’étudier comment certaines d’entre elles peuvent se saisir de l’égalité revendiquée et en cours d’acquisition de la femme mariée pour développer leur initiative politique propre. Ces actions politiques dans l’espace public de la « femme de », que nous aborderons ici à partir de l’exemple d’Adélaïde Guéritault, épouse du conventionnel de la Vienne, François Piorry, permettent de comprendre la façon dont la lecture sociale individualiste des révolutionnaires se combine avec le poids de longue durée d’un familialisme, porteur d’interdépendance et de co-responsabilité sociale qui, pour longtemps, bridera la possible expression politique des « épouses de ».The article examines the role of the wives in the context of the French Revolution, specifically during the National Convention. By studying the place that deputy's wives held during the particularly passionate and conflictual politics of the period of the Convention, it not only broaches the question of the entourage of those elected to public office, but it also conceptualizes the question of the « space » that the wives might occupy by themselves. It is important not to place them automatically in the role of dependency, but rather to study how certain among them might obtain a much-demanded equality, and in the course of this acquisition by a married women, develop their own political initiative. These political actions in the public space afforded by « the wife of » that I am examining here by the example of Adélaïde Guéritault, the wife of the deputy from the department of the Vienne, Francois Piorry, permits an understanding of the way that a social reading of the revolutionaries combines with prolonged familiarity as the agent of interdependency and co-responsibility, which for a longtime, restricted possible political expression of the « wives of »

Formes de présence et fonctions politiques des représentants en mission dans un microcosme urbain, l'exemple d'Amboise (Indre-et-Loire)

L'article cherche à montrer à travers l'étude de la vie politique d'une petite ville de Touraine combien les rapports de force politiques déterminant les prises de décision politique ont pu être complexes et mouvants, y compris au cœur de la période de la Terreur. Il observe notamment le rôle des représentants en mission dans le jeu de ces rapports de force locaux, représentants qui restent des individus de passage, en partie seulement au fait des enjeux des conflits locaux, représentants dont les pouvoirs sont mis en concurrence, entre ceux de divers représentants, mais aussi avec les pouvoirs d'autres institutions telles que l'Assemblée nationale ou le Comité de salut public. Cette approche permet de relire les rapports du local et du national, de la province et du pouvoir parisien dans le sens de l'existence d'une réelle marge d'autonomie -du moins dans certains contextes - des forces locales, elles-mêmes diverses, qui savent aussi utiliser la diversité réelle des pouvoirs nationaux pour les amener à coups de courriers, de publications, de déplacements, à décider dans leur sens.Presence and Political Action of the Representatives on Mission in an Urban Microcosm: the Example of Amboise (Indre-et-Loire)The article attempts to show, through the study of the political life of a small city in Touraine, how complex and fluid the balance of power and decision-making was, likewise during the period of the Terror. It surveys the role of the deputies on mission in this local balance of power, individuals on the move, barely au fait with local issues and conflicts, and often in competition with other sources of power, fellow-deputies and institutional bodies such as the National Assembly and the Committee of Public Safety. This approach authorizes a rereading of the relationship between the local provincial and the national Parisian authorities, and helps highlight a real, albeit contextual, margin of autonomy of local forces, themselves diverse, who were able to exploit the real diversity of national power, through letters, publications and visits, and thus bring the decision-making round to their view

The JUNO experiment

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector aiming at the measurement of anti-neutrinos issued from nuclear reactors at a 53km distance, having as primary goal the determination of the neutrino mass hierarhcy. The detector will be located 1800m.w.e. underground and consists of a 20 kiloton liquid scintillator contained in a 35.4m diameter acrylic sphere, instrumented by more than 17000 20 inch PMTs ensuring a 77% photocatode coverage. The required energy resolution to discriminate between the hierarchies at the 3–4 σ C.L. in about 6 years of data taking is 3% at 1MeV. To achieve such a precision, severe constraints on the detector components quality are set: the PMTs need a quantum efficiency of more than 27% and the attenuation length of the liquid has to be better than 20m (at 430nm). The precise measurement of the antineutrino spectrum will allow to reduce the uncertainty below 1% on solar oscillation parameters. The international collaboration of JUNO was established in 2014, the civil construction started in 2015 and the R&D of the detectors is ongoing. The expected start of data taking is set for 2020

Vivre libre et écrire. Anthologie des romancières de la période révolutionnaire (1789-1800)

Écrire pour les autres, écrire pour publier, devenir auteure. Les dernières années ont été propices à la réflexion des historien/nes et des spécialistes de littérature sur la place des femmes dans la production des textes à l’époque moderne, sur la possibilité pour une femme d’exister socialement en tant qu’auteure, de pouvoir, en termes culturels comme en termes matériels, vivre de sa plume. Le livre édité ici par Huguette Krief, un petit volume d’environ 300 pages présentant des extraits de..

Stefano Andretta, Stephane Pequignot, Marie-Karine Schaub, Jean-Claude Waquet Et Christian Windler (Dir.), Paroles de négociateurs. L’entretien dans la pratique diplomatique de la fin du Moyen Âge à la fin du XIXe siècle

Cet important volume de l’École française de Rome réunit dix-huit contributions en sus d’une introduction rédigée par Jean-Claude Waquet et d’une conclusion d’une vingtaine de pages rédigée collectivement par les responsables de l’édition du volume. L’usage du volume, très bien présenté, est facilité par la présence d’un index et de résumés des contributions. Cette production est le résultat d’un travail collectif au cours de séminaires qui se sont déroulés de 2005 à 2007 dans le cadre de l’É..