Top-quark mass measurements: review and perspectives

The top quark is the heaviest elementary particle known and its mass ($m_{\rm top}$) is a fundamental parameter of the Standard Model (SM). The $m_{\rm top}$ value affects theory predictions of particle production cross-sections required for exploring Higgs-boson properties and searching for New Physics (NP). Its precise determination is essential for testing the overall consistency of the SM, to constrain NP models, through precision electroweak fits, and has an extraordinary impact on the Higgs sector, and on the SM extrapolation to high-energies. The methodologies, the results, and the main theoretical and experimental challenges related to the $m_{\rm top}$ measurements and combinations at the Large Hadron Collider (LHC) and at the Tevatron are reviewed and discussed. Finally, the prospects for the improvement of the $m_{\rm top}$ precision during the upcoming LHC runs are briefly outlined.Comment: 18 pages, 2 figures, Preprint submitted to Reviews in Physics (REVIP

First results on top-quarks from ATLAS

The search for first top-quark pair candidate events and the related background studies using data-driven techniques are reported for about 300 inverse nb of 7 TeV proton-proton collision data delivered by the Large Hadron Collider (LHC) and collected with the ATLAS detector. Selected events are characterized by the presence of high-pT isolated charged lepton(s), high jet multiplicity, jet(s) identified as originating from b-quark by a secondary vertex tagger algorithm, and missing transverse energy. They reveal kinematics properties consistent with top pair production.Comment: 6 pages, 5 figures, Proceedings of HCP-2010, Toront

Alignment of the ATLAS Inner Detector Tracking System

ATLAS is a multi purpose detector built to study proton-proton collisions, at the center of mass energy of 14 TeV, as provided by the Large Hadron Collider at CERN. ATLAS is equipped with an inner charged particle tracking system composed of silicon and drift tube based detectors. The required precision for the alignment of the most sensitive coordinates of the silicon sensors is at the level of few microns, the limit being derived by the requirement that module misalignments should not worsen the resolution of the track parameter measurements by more than 20%. In these proceedings, the outline of the alignment approaches, and results obtained using real data from cosmic rays, and large scale computing simulation of physics samples, are presented. Cosmic ray data serves to derive an early set of alignment constants for the ATLAS ID before the LHC start up. The impact of the alignment on physics measurements will be discussed

Comparing Multimodality And Traditional Writing: An Experience In Secondary School

Numerous studies focus on how new technologies influence learning to write processes. Nowadays, when considering the writing process, we need to consider changes that have occurred in the concept of textuality: multiple forms can be considered as texts, and texts can be multimodal. Modes such as words, audio, images, hyperlinks and video are all signs that carry meaning. This study analyses the relationship between traditional writing and new ways of expression, analysing the effects of a multimodal approach to the writing of the essay that Italian students are traditionally required to produce at the end of secondary school

Level-3 Calorimetric Resolution available for the Level-1 and Level-2 CDF Triggers

As the Tevatron luminosity increases sophisticated selections are required to be efficient in selecting rare events among a very huge background. To cope with this problem, CDF has pushed the offline calorimeter algorithm reconstruction resolution up to Level 2 and, when possible, even up to Level 1, increasing efficiency and, at the same time, keeping under control the rates. The CDF Run II Level 2 calorimeter trigger is implemented in hardware and is based on a simple algorithm that was used in Run I. This system has worked well for Run II at low luminosity. As the Tevatron instantaneous luminosity increases, the limitation due to this simple algorithm starts to become clear: some of the most important jet and MET (Missing ET) related triggers have large growth terms in cross section at higher luminosity. In this paper, we present an upgrade of the Level 2 Calorimeter system which makes the calorimeter trigger tower information available directly to a CPU allowing more sophisticated algorithms to be implemented in software. Both Level 2 jets and MET can be made nearly equivalent to offline quality, thus significantly improving the performance and flexibility of the jet and MET related triggers. However in order to fully take advantage of the new L2 triggering capabilities having at Level 1 the same L2 MET resolution is necessary. The new Level-1 MET resolution is calculated by dedicated hardware. This paper describes the design, the hardware and software implementation and the performance of the upgraded calorimeter trigger system both at Level 2 and Level 1.Comment: 5 pages, 5 figures,34th International Conference on High Energy Physics, Philadelphia, 200

Promuovere la scrittura attraverso le nuove tecnologie

Communication technologies are heavily utilized in the lives of students: Prensky (2001) says that the constant exposure to technological resources lead’s today’s students to develop hypertext mind that are physiologically different from the minds of students from previous generations. He argues that today’s students are habituated to a graphic-first, multitasking way of getting information digitally that leads them to be frustrated with many of their teachers’ approach of instruction: teachers indeed are often unprepared to use new technologies in their teachings New technologies have changed also writing: digital writings are fluid, manipulated and easily allows the reorganization of working memory; it encourages interaction and the use of content, through the use of different modalities.In that context it urges to reflect on pedagogical implications and elaborated didactics proposals: a production that involves different media could foster theability to communicate and their motivation. That means for teachers to acceptthe challenge of new ways of expression. This article focuses on this researchproblem, proposing the trends emerging from the experimentation of two didactic methodologies.Le nuove tecnologie sono centrali nella vita degli studenti: Prensky (2001)sostiene che la costante esposizione a risorse tecnologiche porta i giovani asviluppare menti “ipertestuali” che sono differenti rispetto alle menti degli studenti di qualche anno fa. Gli studenti sono infatti abituati a considerare dapprima l’aspetto grafico e a ottenere informazioni da più fonti: questo rende molti approcci didattici obsoleti e frustanti, poiché gli insegnanti sono spesso inpreparati a utilizzare efficacemente le nuove tecnologie.Anche la scrittura ha risentito dei cambiamneti introdotti dalle nuove tecnologie:la scrittura digitale è fluida, manipolabile e permette facilmente la riorganizzazione della memoria di lavoro; favorisce l’interazione e la fruizione dei contenuti, attraverso l’utilizzo di molteplici modalità.Nell’ottica di una riflessione pedagogica è opportuno soffermarsi sui cambiamenti che le scritture digitali possono produrre sull’insegnamento della scrittura a scuola: una produzione che coinvolge media diversi può favorire la capacità di comunicare degli studenti e la loro motivazione. Si apre per i docenti la sfida di accogliere nuove modalità espressive, di comprendere se e come queste possano essere intrecciate all’apprendimento della scrittura tradizionale. Il presente articolo si focalizza su tale problema di ricerca, proponendo le tendenze emerse dalla sperimentazione di due metodologie didattiche

Tra le pieghe dell'orizzonte

Il percorso analizza alcune tappe della poesia francese moderna e cotemporanea che, partendo da Philippe Soupault e passando per René Char, arriva alle manifestazioni più recenti come Jean Tardieu e André du Bouchet, Infine J.F. Temple, Yves Bonnefoy, Jaques Réda, Philippe Jaccottet e Bernard Noël continuano a proporci le loro ricerche. Essenziale rsulta la componente spaziale con spesso sullo sfondo la figura do orizzonte

La traduzione filmica: un confronto preliminare tra due paesi «gemelli», l’Italia e la Spagna

The article claims to analyse all those reason, especially the historical ones, why both Italy and Spain have developed a tendency mainly oriented towards dubbing, leaving apart the circulation of subtitling audiovisual material. Starting from the universal definition of audiovisual translation, resting on the historical events that characterized both national history in the early xx century, this article gives prominence to likeness and differences between the two examined countries.‘Artículo quiere analizar cuál esperas, históricos sobre todo, hayan llevado sea Italia sea España a desarrollar una tendencia principalmente orientada hacia el doblaje, omitiendo el aspecto de la difusión de material audiovisual en lengua original. Partiendo de la definición de traducción fílmica, en términos universales, pasando por los acontecimientos históricos que caracterizan la historia de ambas los países en la primera mitad del Novecientos, el artículo se pone como objetivo aquel de evidenciar las similitudes y las diferencias entre los dos Países tomados en examen./n’articolo intende analizzare quali aspetti, storici soprattutto, abbiano portato sia l’Italia sia la Spagna a sviluppare una tendenza maggiormente orientata verso il doppiaggio, tralasciando l’aspetto della diffusione di materiale audiovisivo in lingua originale. Partendo dalla definizione di traduzione filmica, in termini universali, passando per gli eventi storici che caratterizzano la storia di entrambi i paesi nella prima metà del Novecento, l’articolo si pone come obiettivo quello di evidenziare le similitudini e le differenze tra i due Paesi presi in esame