ATLAS Pixel Detector: Operational Experience and Run-1 to Run-2 Transition

The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of LHC. Taking advantage of the long shutdown, the detector was extracted from the experiment and brought to surface, to equip it with new service quarter panels, to repair modules and to ease installation of a new innermost layer, the Insertable B-Layer (IBL). An overview of the operational experience, the refurbishing of the Pixel Detector and of the IBL project as well as the experience in its construction, integration and commissioning are described.Comment: presented at VERTEX 2014 - 23rd International Workshop on Vertex Detectors, Doksy, Czech Republic, 15 Sep 2014. PoS(Vertex2014)00

ATLAS IBL: a challenging first step for ATLAS Upgrade at the sLHC

With the LHC collecting data at 7 TeV, plans are already advancing for a series of upgrades leading eventually to about five times the LHC design luminosity some 10 years from now in the High Luminosity LHC (HL-LHC) project. The upgrades for ATLAS detector will be staged in preparation for HL-LHC. The first upgrade for the Pixel Detector will be the construction of a new pixel layer, which will be installed during the first shutdown of the LHC machine foreseen in 2013-14. The new detector, called the Insertable B-Layer (IBL) will be installed between the existing Pixel Detector and a new, smaller radius beam-pipe at the radius of 3.2 cm. The IBL will require the development of several new technologies to cope with increased radiation and pixel occupancy and also to improve the physics performance through reduction of the pixel size and more stringent material budget. Two different and promising Silicon sensor technologies (planar n-in-n and 3D) are currently under investigation for the IBL. An overview of the IBL module design and the qualification for these sensor technologies are presented in this proceeding. This proceeding also summarizes the improvements expected to the ATLAS detector at the HL-LHC.Comment: 4 pages, 2 figures, Proceeding of XXIst International Europhysics Conference on High Energy Physics (EPS-HEP 2011), Grenoble, 21-27 July 201

Studies on ToF-PET using Cherenkov radiation

La tomografia ad emissione di positroni (PET) è una tecnica di imaging di medicina nucleare, utilizzata oggi diffusamente in ambito clinico. Essa fornisce immagini e informazioni fisiologiche dei processi funzionali all’interno del corpo. La PET si basa sulla rilevazione di fotoni di annichilazione prodotti in seguito al decadimento di un radio farmaco iniettato nel paziente. I rilevatori convenzionali sono costituiti da un materiale scintillatore accoppiato ad un fotomoltiplicatore, solitamente un PMT o SiPM. Uno sviluppo della PET è la Time of Flight PET (ToF PET), attualmente già in commercio ed utilizzata con prestazioni eccellenti. Un’ulteriore modifica, che potenzialmente permetterebbe di ottenere una migliore risoluzione temporale, è la ToF PET basata sulla rilevazione di fotoni tramite radiazione Cherenkov, invece che luce di scintillazione. Questo lavoro di tesi è incentrato dunque su questa tecnica specifica. Si illustra una rassegna di pubblicazioni scientifiche degli ultimi anni riguardo ad essa con i relativi risultati ottenuti e i possibili sviluppi futuri. Infine si propone un approfondimento personale, nel quale, tramite un programma scritto in ROOT, si è realizzata una geometria di un sistema di rilevazione ToF PET. Esso prevede la rilevazione dei fotoni di annichilazione tramite un radiatore Cherenkov accoppiato ad un SiPM. In futuro questo potrà essere implementato e utilizzato per simulare il processo fisico della PET, verificando la validità e le prestazioni del sistema così sviluppato

“Red Rosa”: Rosa Luxemburg’s Utopia of Revolution

Rosa Luxemburg è stata un outsider sotto molti punti di vista: convinta fautrice dell’internazionalismo nel panorama politico polacco, in cui prevaleva la “questione nazionale” dell’indipendenza e dell’unificazione dei territori polacchi separati, ha polemizzato direttamente col Lenin sul problema della democrazia all’interno del partito e dello Stato comunista; la sua visione politica era i9n netto contrasto con quella del Partito Socialdemocratico Tedesco (SPD) sulla questione dei crediti di guerra; è stata, nella teoria e nella prassi, una sostenitrice dei diritti delle donne. Ma è rimasta un’ebrea senza radici, senza tradizione e senza patria. La morte di Rosa Luxemburg ha segnato la fine di ogni possibilità di una rivoluzione bolscevica in Germania, ma anche la fine di ogni alternativa alla dittatura del partito all’interno del movimento comunista internazionale. Al fallimento politico è seguita la condanna all’oblio. Esiste quasi una conventio ad excludendum nei confronti di Rosa Luxemburg: i polacchi la rifiutano a causa del suo internbazionalismo, gli ebrei a causa della sua freddezza nei confronti della “questione ebraica”, i comunisti perché la considerano “estremista e deviazionista”, i socialdemocratici perché “rivoluzionaria”, i liberali perché la considerano “una terrorista sovversiva e sanguinaria”. Rosa “la rossa”, ebrea senza patria, condizionata dalla sua furia per il suo internazionalismo, è stata vittima della sua stessa euforia, ha tentato di realizzare una rivoluzione politica e sociale, di fondare una repubblica dei consigli dei soldati, degli operai e dei contadini, sbagliando la valutazione delle forze in campo. Ma la sua scelta è stata consapevole e razionale. Una scelta politica e ideale che si pone sulla scia dell’ illuminismo tedesco e della Haskalah. Rosa Luxembur rappresenta una variante radicale degli ebrei assimilate tedeschi, polacchi e russi che hanno tentato di razionalizzare, di far crescere e di “rivoluzionare” la società civile per liberare l’umanità oppressa.Rosa Luxemburg was an outsider in many ways: she vehemently supported internationalism within the Polish political landscape, in which the “national question” of the independence and unification of Polish separated territories prevailed; she argued directly with Lenin about the democracy in the party and in the communist state; her views were in stark contrast to the German Social Democratic party (SPD) on the question of war credits; she was, in theory as well as in practice, a representative of women’s liberation. She remained a Jewess without roots, without tradition and without country. The death of Rosa Luxemburg marked the end of every possibility of Bolshevik revolution in Germany, but also the end of every alternative to the dictatorship of the party within the international communist movement. The political defeat was followed by the condemnation to oblivion. There is almost a conventio ad excludendum against Red Rosa: Poles reject her for her anti-nationalism, Jews because of her indifference to the “Jewish question”, the Communists because they considered her “extremist and deviationist”, the Social Democrats because she was “revolutionary”, the liberals because she was considered a “subversive and bloody terrorist”. Red Rosa, Jewess without homeland, conditioned by the fury of her internationalism, fell victim to her own utopia, she tried to realize a social and political revolution, to build a republic of councils of soldiers, workers, and peasants, missing the valuation of the fighting forces. But her choice was rational and conscious. An ideal and political choice that inherits the tradition of the deutsche Aufklärung and the Haskalah. Rosa Luxemburg represents a radical variant of German, Polish, Russian assimilated Jews who tried to rationalize, to improve, to “revolutionize” civil society to free oppressed humanity

The particle-hole transformation, supersymmetry and achiral boundaries of the open Hubbard model

We show that the particle-hole transformation in the Hubbard model has a crucial role in relating Shastry's R-matrix to the AdS/CFT S-matrix. In addition, we construct an achiral boundary for the open Hubbard chain which possesses twisted Yangian symmetry

Dreamt Spaces

Beyond a mere interdisciplinary relationship, the symbiosis of cinema, body and architecture conveys an illusion: showing a dreamt architecture. The vision of architecture through a cinematographic filter facilitates infinite possibilities, from creating habitability conditions in impossible spaces to endowing architecture with unimaginable attributes. Aspects such as movement or dematerialization, in principle far from classic architectural values, have a familiar ring due to experiences gained in cinema. Likewise, in recent decades architecture has dared to carry out spatial experiments whose only objective is experimentation on the interrelation between body and space. Despite the importance of this question to the perception of certain architecture, during many years architects absented themselves from this field of experimentation. In the majority of the cases, as mere spectators, they limited themselves exclusively to observe the proposals of some artists and film-makers who transformed space just in another plastic material. Many of these proposals of "space alteration" were left in the dust, however, some of them established a basis for certain events to come which would change forever the traditional ways of understanding space. This new perception emerging from cinematic images poses new processes of connectivity between body and space, as we may observe in some of the works of the US Americans Diller & Scofidio, intimately related to new technologies. Others, like Philippe Rahm, focus on the fusion of biological and sensorial aspects of life forms in determinate spaces. Some like the Fabric team propose a deliberate alteration of perceiving the interior-exterior interaction of habitable spaces by means of addition and fusion. None of the above is science fiction, but we can elaborate a new architectural map with clear cinematographic references

The Rose in 15h Century Love Poetry

En el presente trabajo analizo las diferentes funciones que la rosa tiene en la poesía del siglo XV: a) La rosa como metáfora de la belleza de la amada. En esta formulación, el color de la flor es irrelevante; b) La rosa roja o rosa como metáfora de las mejillas de la amada; c) La rosa roja para los labios femeninos; d) La rosa como regalo de la amada y el jardín de rosas como escenario en el que se mueve; y e) El amor y sus sufrimientos como rosa entre espinasIn this essay I study the different roles the rose plays in XVth century Spanish love poetry: a) The rose as a metaphor for the beloved’s beauty; b) The red or the pink rose as a metaphor of the beloved cheeks; c) The red rose for the lips; d) The rose as a present to the beloved, or the garden as the scene where she walks; and e) Love and its pains as a rose and its thorn

Overconfidence in a Career-Concerns Setting

We study the effects of overconfidence in a two-period investment-decision agency setting. Under common priors, agent risk aversion implies inefficiently low first-period investment. In our model, principal and agent disagree about the profitability of the investment decision conditional on a given public signal. An overconfident agent believes that the principal will update her beliefs upwards more often than not. As a consequence, the agent overestimates the benefits of learning from first-period investment. This implies that agent overconfidence mitigates the agency problems arising from the agent’s career concerns, even though an overconfident agent bears more project and reputational risk in equilibrium.overconfidence, heterogenous beliefs, career concerns