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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Embracing Multiplicity: Autobiographical Personae in Ruth Hall

Schneck, Gina Marie 01 July 2016 (has links)
Sara Payson Willis Eldredge Farrington Parton, more famously known as the elusive Fanny Fern, employs three autobiographical personae mediated by fiction in her debut novel, Ruth Hall: (1) Ruth Hall, the novel's protagonist; (2) Floy, the fictional Ruth's pseudonym; and (3) Fanny Fern, Parton's real-life pseudonym and the name under which Ruth Hall was published. Together these personae assert a fragmented presence that incorporates various voices and lives, allowing for exploration, growth, and interactivity.Philippe Lejeune's autobiographical contract outlines three specific guidelines for autobiography—that it be a narrative, that it explore personal history, and that it link author and protagonist. Ruth Hall participates in two-thirds of Lejeune's contract, though Parton's conscious fictionalization demands a revisiting of the autobiographical contract, revealing the impossibility of recording truth as well as the impracticality of a unitary self.Through her use of autobiographical personae in Ruth Hall and in her personal life, Parton succeeds in rewriting the narrative of domesticity for the nineteenth-century American woman. Her self-conceptualization embraces multiplicity as she demands to be seen as "more than."
52

Petit périple aux confins du modèle standard avec HERA

Sauvan, E. 30 October 2009 (has links) (PDF)
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53

Study of Generalized Parton Distributions and Deeply Virtual Compton Scattering on the nucleon with the CLAS and CLAS12 detectors at the Jefferson Laboratory (Virginia, USA)

Guegan, Baptiste 27 November 2012 (has links) (PDF)
The Generalized Parton Distributions (GPDs) provide a new description of the nucleon structure in terms of its elementary constituents, the quarks and the gluons. The GPDs give access to a unified picture of the nucleon, correlating the information obtained from the measurements of the Form Factors and the Parton Distribution Functions. They describe the correlation between the transverse position and the longitudinal momentum fraction of the partons in the nucleon.Deeply Virtual Compton Scattering (DVCS), the electroproduction of a real photon on a single quark of the nucleon eN -> e'N'γ, is the most straightforward exclusive process allowing access to the GPDs. A dedicated experiment to study DVCS with the CLAS detector of Jefferson Lab has been carried out using a 5.883 GeV polarized electron beam and an unpolarized hydrogen target, allowing to collect DVCS events in the widest kinematic range ever explored in the valence region : 1 < Q^2 < 4.6 〖GeV〗^2, 0.1 < x_B < 0.58, 0.09 < -t < 3 〖GeV〗^2 .In this work, we present the extraction of three different DVCS observables: the unpolarized cross section, the difference of polarized cross sections and the beam spin asymmetry. We present comparisons with GPD model. We show a preliminary extraction of the GPDs using the latest fitting code procedure on our data, and a preliminary interpretation of the results in terms of parton density.
54

The Fashioning of Fanny Fern: A Study of Sara Willis Parton's Early Career, 1851-1854

Porche, Amy S 15 December 2010 (has links)
The purpose of this study is to trace how Sara Willis Parton achieved unprecedented literary celebrity status as Fanny Fern during the first three years of her professional career, 1851-1853. While most critics point to her famously lucrative contract with the most popular newspaper of the 1850s, the New York Ledger, in 1854 as the beginning of her fame, I argue that she had already fully achieved that fame and had done so by writing for small Boston newspapers and publishing a highly successful collection of her articles by 1853. Further, Fern was able to achieve such a high level of success because of a keen business sense, intuitive marketing savvy, an ability to promote herself, an original writing style, and a creative use of personas. My study provides an important addition to Fern scholarship by addressing the largely overlooked early years of her writing career. To date, scholars either make no mention of her first three years or do so only to demonstrate the point that Fern achieved notable success when she signed a contract for one hundred dollars a column with Robert Bonner, publisher and editor of the New York Ledger. Prior to that contract, Fern worked as a freelance writer for the Boston Olive Branch and the Boston True Flag, earning less than five dollars for each sketch she submitted. The critical assumption has been that her initial work prepared her for the fame she would achieve writing for Bonner, but in fact Bonner would not have hired her had she not already achieved significant fame, for Bonner hired only highly celebrated writers. My study explores how Fanny Fern became a famous writer. When she began writing, Fern wrote under a number of previously unknown pseudonyms for local newspapers, but within three years her distinctive style, rhetorical skill, and iconoclastic persona had made ―Fanny Fern a household name. Fern‘s unique ability to engage a popular audience, I would argue, is the principal difference between Fern and other famous contemporary women writers.
55

A measurement of jet cross sections at low Q'2 and an interpretation of the results in terms of a partonic structure of the virtual photon

Smith, Mark January 1999 (has links)
No description available.
56

Etude de la structure partonique de l'hélium

Perrin, Yohann 19 October 2012 (has links) (PDF)
La structure des nucléons et des noyaux a été intensivement étudiée au cours duvingtième siècle au travers de la diffusion élastique d'électrons (mesure des facteurs deforme électromagnétique) et de la diffusion profondément inélastique (mesure des distributionsde partons). Le formalisme des distributions généralisées de partons (GPD)a permis d'unifier les facteurs de forme et les distributions de partons. Ce lien procureune source d'information unique sur la dynamique des partons, telle la distribution desforces nucléaires et de moment orbital au sein des hadrons. L'accès expérimental le plussimple aux GPD est la diffusion Compton profondément virtuelle (DVCS), correspondantà l'électroproduction dure d'un photon réel. Tandis que plusieurs expériences sesont déjà focalisées sur la réaction DVCS sur le nucléon, les expériences sur une ciblenucléaire s'avèrent plus rares. Cette thèse se concentre sur l'étude du canal DVCS cohérentsur l'hélium 4, avec pour objectif l'extraction des parties réelle et imaginaire dufacteur de forme Compton via l'asymétrie de spin du faisceau.
57

Mesure des corrélations photon-hadron auprès de l'expérience ALICE au LHC pour l'étude du plasma de quarks et de gluons / Measurement of the gamma-hadron correlations with the ALICE experiment at the LHC for the study of the quark-gluon plasma

Vauthier, Astrid 26 September 2017 (has links)
La chromodynamique quantique (QCD), théorie actuellement utilisée pour décrire l’interaction forte, a prédit l’existence d’une transition de phase, à très haute température et/ou densité, vers un état de la matière nucléaire où les quarks et les gluons sont déconfinés : le Plasma de Quarks et de Gluons (QGP). Un tel milieu peut être produit en laboratoire, et la mesure de ses propriétés permet d’apporter un éclairage nouveau sur les mécanismes sur les mécanismes d’interactions entre les constituants ainsi que de tester la QCD dans des domaines inexplorés.Les collisions d’ions lourds ultra-relativistes délivrées par l’accélérateur LHC au CERN permettent d’obtenir les conditions thermodynamiques nécessaires à la formation du QGP. À l’aide d’une instrumentation diversifiée, l’expérience ALICE permet d’accéder à un grand nombre d’observables permettant de caractériser le QGP. Parmi celles-ci, la mesure de la fragmentation des partons (quarks et gluons) permet d’étudier en détail les mécanismes de perte d’énergie des partons dans le milieu et de sa redistribution dans l’état final, et peut également être comparée à des calculs théoriques modélisant, à partir de la QCD, l’interaction d’un parton énergétique avec le QGP qu’il traverse.Le travail de thèse présenté dans ce manuscrit s’articule autour de l’étude de la fonction de fragmentation par la mesure des corrélations photon-hadron en collisions proton-proton et proton-Plomb. Dans un premier temps, un travail de calibration en énergie du calorimètre électromagnétique de l’expérience ALICE a été réalisé, accompagné de la caractérisation des incertitudes de cette calibration. Dans un second temps, les corrélations photon-hadron, dont la difficulté majeure réside en l’identification des photons directs, ont été étudiées. Les résultats obtenus dans les deux systèmes de collisions démontrent la faisabilité de l’analyse qui pourra être étendue facilement aux collisions Plomb-Plomb périphériques. Enfin, ce travail montre que les incertitudes dominantes de la mesure seront réductibles avec les données prochainement délivrées par le LHC. / The quantum chromodynamics (QCD), the theory used at present to describe the strong interaction, predicts the existence of a phase transition, at very high temperature and/or density, towards a state of nuclear matter where quarks and gluons are deconfined : the Quark-Gluon Plasma (QGP). Such a medium can be produced in laboratory, and the measurement of its properties allows to give a new perspective on the mechanisms of interactions between the constituents as well as to test the QCD in unexplored domains.Ultra-relativistic heavy ion collisions delivered by the accelerator LHC at CERN allow to obtain the thermodynamical conditions necessary for the QGP to be formed. By means of a diversified instrumentation, the ALICE experiment allows to reach a large number of observables allowing to characterize the QGP. Among these, the measurement of the fragmentation of the partons (quarks and gluons) allows to study in detail the mechanisms of energy loss in the medium and its redistribution in the final state, and can also be compared with theoretical calculations, based on QCD, that model the interaction of an energetic parton with the QGP which is passing through.The work presented in this manuscript is articulated around the study of the fragmentation function via the measurement of the photon-hadron correlations in proton-proton and proton-Lead collisions. At first, a work on energy calibration of the ALICE experiment’s electromagnetic calorimeter was realized, along with the characterization of the uncertainties of this calibration. Secondly, the photon-hadron correlations, whose main difficulty is the identification of the direct photons, were studied. The results obtained in both systems of collisions demonstrate the feasibility of the analysis which can be easily widened to the peripheral Lead-Lead collisions. Finally, this work shows that the dominant uncertainties of the measurement will be reducible with the new data delivered by the LHC.
58

Zkoumání závislosti výpočtů v konečném řádu poruchové QCD na faktorizačním schématu / Investigation of the factorization scheme dependence of finite order perturbative QCD calculations

Kolář, Karel January 2012 (has links)
Title: Investigation of the factorization scheme dependence of finite order per- turbative QCD calculations Author: Karel Kolář Institute: Institute of Particle and Nuclear Physics Supervisor of the doctoral thesis: prof. Jiří Chýla, CSc., Institute of Physics of the Academy of Sciences of the Czech Republic Abstract: The main aim of this thesis is the investigation of phenomenological implications of the freedom in the choice of the factorization scheme for the de- scription of hard collisions with the potential application for an improvement of current NLO Monte Carlo event generators. We analyze the freedom associated with the definition of parton distribution functions and we derive general formu- lae governing the dependence of parton distribution functions and hard scattering cross-sections on unphysical quantities specifying the renormalization and factor- ization procedure. The issue of the specification of factorization schemes via the corresponding higher order splitting functions is discussed in detail. The main attention is paid to the so called ZERO factorization scheme, which allows the construction of consistent NLO Monte Carlo event generators in which initial state parton showers can be taken formally at the LO. Unfortunately, it has turned out that the practical applicability of the ZERO...
59

Deep Exclusive π<sup>0</sup> Electroproduction Measured in Hall A at Jefferson Lab with the Upgraded CEBAF

Karki, Bishnu 22 September 2020 (has links)
No description available.
60

Etude des Distributions de Parton Généralisées avec la Diffusion Compton Profondément Virtuelle "genre espace" et "genre temps" / Generalized Parton Distributions with spacelike and timelike Deeply Virtual Compton Scattering

Boër, Marie 28 November 2014 (has links)
Plus de quarante ans après la découverte de constituants ponctuels dans le nucléon, sa structure en quarks et gluons (partons) fait toujours l'objet d'études intenses. Certains processus exclusifs (où tous les produits de l'état final sont connus) de leptoproduction ou de photoproduction exclusive de photon ou de méson sur le nucléon permettent d'accéder aux Distributions de Parton Généralisées (GPDs). Ces fonctions paramétrisent la structure complexe du nucléon et contiennent des informations sur l'impulsion longitudinale et la position transverse des partons dans le nucléon. De tels processus exclusifs sont la Diffusion Compton Profondément Virtuelle "genre espace" et "genre temps" (DVCS et TCS respectivement) qui correspondent à la diffusion d'un photon de haute énergie sur un quark du nucléon et sont mesurés respectivement à partir des réactions lN⇾l'N'γ (N = proton ou neutron, l = lepton) et γN⇾N'l+l-. La première partie de cette thèse est une étude expérimentale du DVCS avec les données 2009 de l'expérience COMPASS au CERN. Dans un premier temps, la section efficace de diffusion profondément inélastique est mesurée, de façon à valider la mesure du flux de muons et à déterminer certains effets systématiques dans la recontruction des traces. Ensuite, la section efficace de production exclusive d'un photon est mesurée. Elle contient le processus DVCS (photon émis par un quark du nucléon) et le processus Bethe-Heitler (photon émis par le lepton diffusé) qui ont le même état final. L'étude des bruits de fond a aussi conduit à estimer une limite à la section efficace de production exclusive d'un pion neutre. La seconde partie de la thèse est dédiée à une étude phénoménologique du TCS aux énergies typiques de JLab 12 GeV. Les amplitudes du TCS et du Bethe-Heitler associé sont d'abord calculées. Puis, toutes les asymétries de simple et de double polarisation de la cible et/ou du faisceau linéairement ou circulairement polarisé sont calculées en fonction de diverses contributions de GPDs. Enfin, une méthode d'ajustement est présentée pour extraire les Facteurs de Forme Compton (qui sont des fonctions des GPDs) avec des données et/ou des simulations de DVCS et/ou de TCS. / More than forty years after the discovery of pointlike constituents inside the nucleon, its quarks and gluons structure is still intensively studied. Some exclusive processes (where all the final state products are known) of leptoproduction or of photoproduction of photon or meson off the nucleon provide access to the Generalized Parton Distributions (GPDs). These functions parameterize the complex structure of the nucleon and contain informations about the longitudinal momentum and the spatial transverse distribution of partons inside the nucleon. Such exclusive processes are the "Spacelike" and the "Timelike" Deeply Virtual Compton Scattering processes (DVCS and TCS respectively) which correspond to the scattering of a high-energy photon off a quark in the nucleon and are respectively measured in the reactions lN⇾l'N'γ (N = proton or neutron, l' = lepton) and γN⇾N'l+l- The first part of this thesis is devoted to the experimental study of DVCS, using the 2009 data from the COMPASS experiment at CERN. In a first step, the Deep Inelastic Scattering cross section is measured in order to check the muon flux measurement and to evaluate some systematic effects. Then, the cross section for the exclusive production of a photon is measured. It is made up of the DVCS process (the photon is emitted by a quark) and of the Bethe-Heitler process (the photon is emitted by the scattered lepton) which has the same final state. The study of the background has allowed to estimate in parallel an upper limit for the cross section of the exclusive production of a π° meson. The second part of the thesis is devoted to a phenomenological study of TCS at typical energies for the JLab 12 GeV upgrade. Firstly, the amplitudes for the TCS and for the associated Bethe-Heitler process are derived. Then, all single and double polarization (beam and/or target) observables are calculated as a function of different GPD contributions. Finally, a method is presented to extract the Compton Form Factors (functions of GPDs) from fits on DVCS and/or TCS data and/or simulations.

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