631 research outputs found
Jet Production at RHIC and LHC
No full textRecent results on jet production in heavy ion collisions at RHIC and the LHC are discussed, with emphasis on inclusive jet yields and semi-inclusive hadron-triggered and vector boson-triggered recoil jet yields as well as their azimuthal angular correlations. I will also discuss the constraints that these observables impose on the opacity of the medium, the flavour dependence of energy loss, the interplay of perturbative and non perturbative effects and the change of the degrees of freedom of the medium with the resolution of the probe
An analysis of the influence of background subtraction and quenching on jet observables in heavy-ion collisions
No full textSubtraction of the large background in reconstruction is a key ingredient in jet studies in high-energy heavy-ion collisions at RHIC and the LHC. Here we address the question to which extent the most commonly used subtraction techniques are able to eliminate the effects of the background on the most commonly discussed observables at present: single inclusive jet distributions, dijet asymmetry and azimuthal distributions. We consider two different background subtraction methods, an area-based one implemented through the FastJet pack- age and a pedestal subtraction method, that resemble the ones used by the experimental collaborations at the LHC. We also analyze different ways of defining the optimal parame- ters in the second method. We use a toy model that easily allows variations of the background characteristics: average background level and fluctuations and azimuthal structure, but cross- checks are also done with a Monte Carlo simulator. Furthermore, we consider the influence of quenching using Q-PYTHIA on the dijet observables with the different background subtrac- tion methods and, additionally, we examine the missing momentum of particles. The average background level and fluctuations affect both single inclusive spectra and dijet asymmetries, although differently for different subtraction setups. A large azimuthal modulation of the background has a visible effect on the azimuthal dijet distributions. Quenching, as imple- mented in Q-PYTHIA, substantially affects the dijet asymmetry but little the azimuthal dijet distributions. Besides, the missing momentum characteristics observed in the experiment are qualitatively reproduced by Q-PYTHIA.Subtraction of the large background in reconstruction is a key ingredient in jet studies in high-energy heavy-ion collisions at RHIC and the LHC. Here we address the question to which extent the most commonly used subtraction techniques are able to eliminate the effects of the background on the most commonly discussed observables at present: single inclusive jet distributions, dijet asymmetry and azimuthal distributions. We consider two different background subtraction methods, an area-based one implemented through the FastJet package and a pedestal subtraction method, that resemble the ones used by the experimental collaborations at the LHC. We also analyze different ways of defining the optimal parameters in the second method. We use a toy model that easily allows variations of the background characteristics: average background level and fluctuations and azimuthal structure, but cross-checks are also done with a Monte Carlo simulator. Furthermore, we consider the influence of quenching using Q-PYTHIA on the dijet observables with the different background subtraction methods and, additionally, we examine the missing momentum of particles. The average background level and fluctuations affect both single inclusive spectra and dijet asymmetries, although differently for different subtraction setups. A large azimuthal modulation of the background has a visible effect on the azimuthal dijet distributions. Quenching, as implemented in Q-PYTHIA, substantially affects the di-jet asymmetry but little the azimuthal dijet distributions. Besides, the missing momentum characteristics observed in the experiment are qualitatively reproduced by Q-PYTHIA.Subtraction of the large background in reconstruction is a key ingredient in jet studies in high-energy heavy-ion collisions at RHIC and the LHC. Here we address the question to which extent the most commonly used subtraction techniques are able to eliminate the effects of the background on the most commonly discussed observables at present: single inclusive jet distributions, dijet asymmetry and azimuthal distributions. We consider two different background subtraction methods, an area-based one implemented through the FastJet pack- age and a pedestal subtraction method, that resemble the ones used by the experimental collaborations at the LHC. We also analyze different ways of defining the optimal parame- ters in the second method. We use a toy model that easily allows variations of the background characteristics: average background level and fluctuations and azimuthal structure, but cross- checks are also done with a Monte Carlo simulator. Furthermore, we consider the influence of quenching using Q-PYTHIA on the dijet observables with the different background subtrac- tion methods and, additionally, we examine the missing momentum of particles. The average background level and fluctuations affect both single inclusive spectra and dijet asymmetries, although differently for different subtraction setups. A large azimuthal modulation of the background has a visible effect on the azimuthal dijet distributions. Quenching, as imple- mented in Q-PYTHIA, substantially affects the dijet asymmetry but little the azimuthal dijet distributions. Besides, the missing momentum characteristics observed in the experiment are qualitatively reproduced by Q-PYTHIA
Dead-cone searches in heavy-ion collisions using the jet tree
Get PDFWe explore the possibility of using the dead cone of heavy quarks as a region of the Lund plane where medium-induced gluon radiation can be isolated and characterized. The filling of the dead cone by medium-induced gluons is expected to be the result of the interplay between the minimum angle of such radiation due to transverse momentum broadening and the dead-cone angle. Since the measurement of a fully corrected Lund plane in heavy-ion collisions is currently challenging, we propose to use jet grooming techniques to identify a particular splitting in the jet tree that is both perturbative and sensitive to the dead-cone effect. To that end, we propose a new jet substructure groomer, dubbed Late-kt, that selects the most collinear splitting in a QCD jet above a certain transverse momentum cutoff kt,cut. The role of kt,cut is to guarantee perturbative splittings, while selecting the most collinear splitting enhances the sensitivity to mass effects. As a proof of concept, we study the angular distribution of the splitting tagged by Late-kt both analytically and with Monte Carlo simulations. First, we derive the logarithmic resummation structure in vacuum and demonstrate its capability to distinguish between inclusive and heavy-flavored jets. Next, we extend the calculation for in-medium jets and show that medium-induced emissions lead to an enhancement of collinear emissions below the dead-cone angle. Numerically, we demonstrate an excellent resilience of Late-kt against uncorrelated thermal background, thus confirming this observable as a potential candidate to unveil medium dynamics around the dead-cone regime.We explore the possibility of using the dead cone of heavy quarks as a region of the Lund plane where medium-induced gluon radiation can be isolated and characterised. The filling of the dead cone by medium-induced gluons is expected to be the result of the interplay between the minimum angle of such radiation due to transverse momentum broadening and the dead-cone angle. Since the measurement of a fully corrected Lund plane in heavy-ion collisions is currently challenging, we propose to use jet grooming techniques to identify a particular splitting in the jet tree that is both perturbative and sensitive to the dead-cone effect. To that end, we propose a new jet substructure groomer, dubbed Late-, that selects the most collinear splitting in a QCD jet above a certain transverse momentum cutoff . The role of is to guarantee perturbative splittings, while selecting the most collinear splitting enhances the sensitivity to mass effects. As a proof of concept, we study the angular distribution of the splitting tagged by Late- both analytically and with Monte Carlo simulations. First, we derive the logarithmic resummation structure in vacuum and demonstrate its capability to distinguish between inclusive and heavy-flavoured jets. Next, we extend the calculation for in-medium jets and show that medium-induced emissions lead to an enhancement of collinear emissions below the dead cone angle. Numerically, we demonstrate an excellent resilience of Late- against uncorrelated thermal background, thus confirming this observable as a potential candidate to unveil medium dynamics around the dead cone regime
Antagonistics Affinities: Cunqueiro, Translator of the "Beat Generation"
Get PDFEntre 1970 y 1978 Álvaro Cunqueiro fue dando a conocer traduciones de poemas de la Beat Generation en las páginas literarias de Faro de Vigo. Tradujo ocho poemas de Corso, Ferlinghetti, Ginsberg y Kerouac entre los más de 300 autores traducidos al gallego por el mindoniense en el diario vigués entre 1965 y 1981. Son relevantes y sorprendentes las traduciones de poetas beat por estar este movimiento a priori moi alejado de la sensibilidad vital y poética de Cunqueiro. Sin embargo, se demuestra así que nada de lo poético le fue ajeno a un Cunqueiro muy atento a todas las novedades literarias y deseoso de ampliar con sus traduciones al gallego el capital simbólico del campo literario gallego. Expondremos las traduciones al lado de los versos originales y, además, analizaremos si ese antagonismo poético es total o si existen afinidades entre la poética beat y la poética del mindoniense.Entre 1970 e 1978 Álvaro Cunqueiro foi dando a coñecer traducións de poemas da Beat Generation nas páxinas literarias do Faro de Vigo. Traduciu oito poemas de Corso, Ferlinghetti, Ginsberg e Kerouac entre os máis de 300 autores anosados ao galego polo mindoniense no xornal vigués entre 1965 e 1981. Son relevantes e sorprendentes as traducións de poetas beat por este movemento estar a priori moi afastado da sensibilidade vital e poética de Cunqueiro. Porén, demóstrase así que nada do poético lle foi alleo a un Cunqueiro moi atento a todas as novidades literarias e desexoso de ampliar coas súas traducións ao noso idioma o capital simbólico do campo literario galego. Exporemos as traducións a carón dos versos orixinais e, ademais, analizaremos se ese antagonismo poético é total ou se existen afinidades entre a poética beat e a poética do mindoniense.Between 1970 and 1978 Álvaro Cunqueiro was publishing poetic translations of Beat Generation in the literary pages of the Faro de Vigo. He translated eight poems from Corso, Ferlinghetti, Ginsberg and Kerouac among the more than 300 authors translated into Galician language by the author in this newspaper between 1965 and 1981. The translations of beat poets are astonishing because it is a priori a movement far away from the poetic sensibility of Cunqueiro. However, it is shown that no poetry was strange to Cunqueiro, very attentive to all literary novels and eager to extend –with its translations into our language– the symbolic capital of the Galician literary field. We will show the translations together with the original verses and, in addition, we will analyze if this poetic antagonism is total or if there are affinities between the poetic beat and the poetics of Álvaro Cunqueiro
¿Una Odisea antes de Homero? El Ulises de Álvaro Cunqueiro
Get PDFIn 1960, Álvaro Cunqueiro published Las Mocedades de Ulises, a ‘no novel’ of the so-called mythological type in which, following the outline of a Bildungsroman, the author fables the birth and youth of Ulysses and the process of his configuration as a hero, in a sort of 'Odyssey before Homer'. This paper studies the Galician writer's approach to Homer's hero, both in The Mocedades and in other texts, and analyses how much of Homer's Odysseus there is in Cunqueiro's Ulysses.Álvaro Cunqueiro publicó en 1960 Las Mocedades de Ulises, una ‘no novela’ de las denominadas mitológicas en la que, con el esquema de un Bildungsroman, fabula el nacimiento y juventud de Ulises y el proceso de su configuración como héroe, en una suerte de 'Odisea ante de Homero'. Este artículo estudia el acercamiento del escritor gallego al héroe de Homero, tanto en Las Mocedades como en otros textos, y analiza cuánto hay del Odiseo homérico en el Ulises cunqueiriano
Álvaro Cunqueiro. Viajes literarios, puertas de imaginación
Get PDFPrograma de doctorat: Estudis Lingüístics, Literaris i CulturalsLa investigación que nos proponemos abordar con la presente tesis doctoral tiene como objetivo situar, dentro de las obras no estrictamente literarias de Álvaro Cunqueiro, el fenómeno conocido como intertextualidad. La hipótesis de trabajo que se formula está orientada a demostrar que la presencia de citas o referencias literarias en la obra ensayística del autor gallego no tiene como principal finalidad mostrar erudición o servirse de argumentos de autoridad, sino dotar a sus textos de un poder fabulador que los transforma en verdaderos artefactos literarios, cercanos o amalgamados a su obra narrativa y poética. Como objetivo añadido a esta formulación de técnicas textuales que potencian la ficción en géneros poco proclives a ella, emprendemos una clasificación del corpus turístico, gastronómico y periodístico de Cunqueiro, apenas estudiado –sobre todo en los dos primeros ámbitos- y recuperamos alguna obra olvidada para integrarla en su bibliografía.
La investigación se articula en tres bloques. En primer lugar se despliega un marco teórico que perfila qué entendemos por intertextualidad, de qué técnicas se sirve para asaltar textos ajenos y cuáles son las diferentes maneras de actuar que van marcando su presencia. Sin pretensión alguna de exhaustividad, pero ahondando sobre todo en los conceptos y los mecanismos de conexión, se proporcionan los paradigmas de referencia necesarios para calibrar cómo Álvaro Cunqueiro encaja material de otros autores en su obra y qué pretende conseguir con ello. La base documental recoge desde los primeros artículos que se ocuparon del fenómeno –tomamos como inicio de su estudio a Mijail Bajtín- hasta autores que publican ya en el siglo XXI como José Enrique Martínez Fernández.
Un segundo apartado aborda la presencia de la intertextualidad en sus obras de carácter turístico –desde guías de viaje hasta folletos que habían permanecido olvidados- y gastronómico. Observamos en dichos textos cómo la intertextualidad es utilizada por Cunqueiro con el propósito de dinamitar géneros que están marcadamente sujetos a normas muy estrictas y, que en manos del escritor gallego, traspasan su carácter instructivo para situarse en el reino de la fantasía.
Una tercera parte explora estas técnicas intertextuales en sus textos periodísticos. Obligado, en muchas ocasiones, por motivos económicos, su producción en el campo del articulismo es ingente. Con un margen más elástico que en las obras del segundo apartado, Cunqueiro también logra aquí traspasar la frontera genérica para convertir unas piezas que de oficio han de prestar atención a la actualidad en verdaderos campos de fantasía en los que la noticia aparece únicamente como excusa irrelevante. Para ello, nos proponemos emprender en un principio la catalogación de todas las cabeceras en las que Cunqueiro participó, incluso aquellas que cuentan con un único texto salido de su mano.
En definitiva, la tesis doctoral que aquí se presenta abarca dos objetivos. Por un lado, ordenar el extenso corpus cunqueiriano en lo relativo a su obra turística y gastronómica –la periodística cuenta con algunos estudios clarificadores- y marcar ejes temáticos de sus abordajes intertextuales y de las técnicas que consiguen convertir textos que en un principio debían ser neutros en explosiones de imaginación.The research that we intend to address with this doctoral thesis has as its objective to place the phenomenon known as intertextuality within the non-strictly literary works of Álvaro Cunqueiro. The working hypothesis that is formulated is oriented to demonstrate that the main purpose of the presence of quotations or literary references in the essay work of the Galician author is not to boast scholarship or use arguments of authority, but to endow his texts with a power to fantasize that transform them into true literary artifacts, proximal or amalgamated to his narrative and poetic work. As an added objective to this formulation of textual techniques that enhance fiction in genres scarcely prone to it, we undertake a classification of the tourist, gastronomic and journalistic corpus by Cunqueiro, barely studied, especially in the first two areas, and we also bring forward some overlooked work to be integrated into his bibliography.
The research is divided into three blocks. First, a theoretical framework is displayed to outline what we understand by intertextuality, what techniques Cunqueiro used to tackle texts by other authors and the different ways in which he does it that reveal heir presence. Not intending to be exhaustive but instead specifically wanting to delve into the concepts and their connection mechanisms, we provide the reference paradigms necessary to calibrate how Álvaro Cunqueiro embeds material from other authors in his work and what he intends to achieve with it. The documentary base comprises articles from the early stages dealing with this phenomenon, considering Mijail Bajtín as the initial reference of the study of this phenomenon, to authors who are already publishing in the 21st century, such as José Enrique Martínez Fernández.
A second section focuses on the presence of intertextuality in Cunqueiro’s gastronomic and tourist works, from travel guides to brochures that had previously been forgotten. We observe in those texts how intertextuality is used by Cunqueiro with the purpose of dynamiting genres which are markedly subject to very strict norms which in the hands of the Galician writer go beyond the instructive character and are placed in the realm of fantasy.
A third section explores these intertextual techniques in his journalistic texts. As a result of many different occasion when he faced economic problems he ended up writing an enormous production in the field of articulism. With a more elastic margin than in the works of the second block, Cunqueiro also manages here to cross the generic line to change pieces that in fact need to pay attention to current affairs into real fantasy fields in which news appears only as an irrelevant excuse. To do this, initially we intend to undertake the cataloging of all the newspapers in which Cunqueiro collaborated, even those in which he only published a single article.
In short, this present doctoral thesis encompasses two objectives. On the one hand, to order the extensive Cunquerian corpus in relation to his tourist and gastronomic work, since his journalism has some other clarifying studies, and on the other, to mark thematic axes of his intertextual approaches as well as his techniques that successfully transform texts which essentially should be neutral into explosions of imagination
Heterolingüismo y autotraducción. El caso de Álvaro Cunqueiro
No full textA partir del análisis de las autotraducciones de Álvaro Cunqueiro, un autor reconocido por el canon tanto en la literatura gallega como en la castellana, se estudian las posibles implicaciones del bilingüismo endógeno en la autotraducción. Así se observa cómo se acentúa la tensión entre la tendencia a la preservación literal y literaria del heterolingüismo y el deseo de aceptabilidad en la cultura meta. Estas dos fuerzas opuestas, llevadas al extremo por un autor-traductor liberado del fantasma de la invisibilidad, acaban por ofrecer un texto excesivamente heterogéneo, marcado por estrategias enunciativas de signo diverso que, al mismo tiempo, manifiestan con claridad la voz propia y “distinta” del autotraductor como locutor segundo.À partir de l’analyse des autotraductions d’Álvaro Cunqueiro, un auteur appartenant au canon de la littérature galicienne et espagnole, nous étudions les éventuelles implications du bilinguisme endogène dans l’autotraduction. On constate ainsi une nette augmentation de la tension entre la tendance à la préservation littérale et littéraire de l’hétérolinguisme et, d’autre part le désir d’acceptabilité dans la culture d’arrivée. Ces deux forces opposées, exacerbées à l’extrême par un autotraducteur qui se sent libéré du fantôme de l’invisibilité engendrent, finalement, un texte trop hétérogène, marqué par des stratégies énonciatives variées qui, en même temps, laissent transparaître clairement une voix personnelle et « différente » de l’autotraducteur comme locuteur second.Based on the analysis of self-translation done by Álvaro Cunqueiro, a recognized author in both Galician and Spanish literature, possible implications of endogenous bilingualism in self-translation are studied. One observes increased tension between the trend of literal and literacy preservation of heterolingualism and the desire to be accepted in the target language. These two competing forces, taken to the extreme by an author-translator freed from the spectre of invisibility, ultimately offer an excessively heterogeneous text, marked by expository strategies of a diverse nature which, at the same time, clearly show the “unique” voice of the self-translator as a second interlocutor
Cunqueiro in Catalonia: A Model of Intersystemic Relations
No full textPanoramic study on Álvaro Cunqueiro and cunqueirian studies’ contact and exchanges with Catalan culture as a presentation of the context of intercultural relationships in which this monograph falls. The three areas dealt with, in a diverse criticism, are considered to be: personal relationships with Catalan cultural agents, allowing different collaborations and exchanges; professional relationships with the editorial and journalistic world, launching his work on the Spanish market; and repertorial relationships, shown in translations or in literary criticisms, made by the author of his own readings
Jet shapes in pp and Pb-Pb collisions at ALICE
No full textThe aim of this work is to explore possible medium modifications to the substructure of inclusive charged jets in Pb-Pb relative to proton-proton collisions by measuring a set of jet shapes. The set of shapes includes the radial moment, , and the momentum dispersion D. They provide complementary information on the fragmentation and can help to discriminate between two different scenarios: intra-jet broadening or collimation as a result of jet quenching. \noindent The shapes are measured in Pb--Pb collisions at = 2.76 TeV with a constituent cutoff of 0.15 GeV/c and jet resolution 0.2. New techniques for background subtraction are applied and a two-dimensional unfolding is performed to correct the shapes to particle level. The corrected jet shapes for jet GeV/c are presented and discussed. The observed jet shape modifications suggest that the in-medium fragmentation is harder and more collimated than vacuum fragmentation as obtained by a PYTHIA calculation. The PYTHIA calculation is validated with proton-proton data at 7 TeV.The aim of this work is to explore possible medium modifications to the substructure of inclusive charged jets in Pb-Pb relative to proton-proton collisions by measuring a set of jet shapes. The set of shapes includes the radial moment, g , and the momentum dispersion p T D . They provide complementary information on the fragmentation and can help to discriminate between two different scenarios: intra-jet broadening or collimation as a result of jet quenching. The shapes are measured in Pb–Pb collisions at sNN=2.76 TeV with a constituent cutoff of 0.15 GeV/ c and jet resolution R=0.2 . New techniques for background subtraction are applied and a two-dimensional unfolding is performed to correct the shapes to particle level. The corrected jet shapes for jet pT 40≤pT,jet≤60 GeV/c are presented and discussed. The observed jet shape modifications suggest that the in-medium fragmentation is harder and more collimated than vacuum fragmentation as obtained by a PYTHIA calculation. The PYTHIA calculation is validated with proton-proton data at 7 TeV.The aim of this work is to explore possible medium modifications to the substructure of inclusive charged jets in Pb-Pb relative to proton-proton collisions by measuring a set of jet shapes. The set of shapes includes the radial moment, , and the momentum dispersion D. They provide complementary information on the fragmentation and can help to discriminate between two different scenarios: intra-jet broadening or collimation as a result of jet quenching. \noindent The shapes are measured in Pb--Pb collisions at = 2.76 TeV with a constituent cutoff of 0.15 GeV/c and jet resolution 0.2. New techniques for background subtraction are applied and a two-dimensional unfolding is performed to correct the shapes to particle level. The corrected jet shapes for jet GeV/c are presented and discussed. The observed jet shape modifications suggest that the in-medium fragmentation is harder and more collimated than vacuum fragmentation as obtained by a PYTHIA calculation. The PYTHIA calculation is validated with proton-proton data at 7 TeV
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