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In search of a Chinese school : ghostly encounters with the parochial/global discipline of international relationsCunningham-Cross, Linsay Dawn January 2014 (has links)
This thesis explores recent trends in Chinese international relations scholarship from the perspective of post-colonial and critical international relations theory. It begins by interrogating the now widespread view that ‘the discipline’ of international relations is profoundly Eurocentric. The claim to parochialism in international relations discourse is explained and substantiated through a critical re-reading of enduring myths in international relations discourse, which shape not only what we know to be international relations but how we mightknow it and who indeed the ‘we’ is that does the knowing. This research adopts a methodology of ghost hunting inspired by Avery Gordon’s work on ghosts and hauntings in the sociological imagination (Gordon 2008). It follows the meandering trail of a ghostly journey through international relations discourse, telling of multiple and conflicting encounters between Chinese international relations and the wider parochial/global discipline. In particular it examines recent debates surrounding the need for a distinctively Chinese approach to international relations research: a Chinese School of IR.Debates about the place of Chinese international relations research in the wider (parochial/global) discipline remain the focus of this research project. A close (re)reading of these debates reveals the many ways in which Chinese international relations discourse actively constructs ‘the discipline’ of international relations, singing it into life, whilst simultaneously unsettling the myths that make international relations possible. These trends are explored further through the use of two case studies of leading scholars – Yan Xuetong and Qin Yaqing – and the enduring debate between them (and between Chinese scholars in general) over whether or not China needs its own theory of international relations. The work of these two individuals has had a huge impact on wider trends within and about Chinese international relations. The thesis concludes with a return to the question of identity in international relations discourse and questions who is Chinese in the Chinese School and what are the implications of constructing ‘Chineseness’ through international relations discourse. I argue that the Chinese School project is perhaps best understood as an expression of contemporary Chinese nationalism.
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Azimuthal decorrelation between leptons in the Drell-Yan process as a probe of infrared QCD : phenomenology, predictions and measurement of a novel collider observable using perturbative resummation techniquesTomlinson, Lee January 2014 (has links)
This thesis presents phenomenological studies of a state-of-the-art NNLL+NLO theoretical calculation of a novel collider observable known as 'phi star'. In these studies the 'phi star' observable, a measure of azimuthal decorrelation, is applied directly to the leptons in the production of massive lepton pairs in hadron collisions (the Drell-Yan process). This provides an alternate measure of the recoil of the massive vector boson (Z/gamma) against initial state QCD radiation, but with distinct experimental advantages over the traditional boson transverse momentum. Attention is focused on the small-'phi star' regime (the quasi-back-to-back regime) where the infrared dynamics of soft/collinear gluon emissions become important. These phenomenological studies are followed up with the presentation of a measurement of 'phi star' in 'Z to mu mu' events using 20.3 fb^-1 of collision data collected by the ATLAS experiment in 2012. Finally, studies directly related to the ATLAS absolute luminosity calibration by the van der Meer (vdM) method are presented, with the objective of elucidating the role of transverse linear beam correlation. In particular, I present studies using an analytical method I have developed in order to precisely extract individual beam information by way of studying phenomena pertaining to the luminous region during vdM scans. In addition, a dedicated study of the long- and short-term stabilities of the principal detectors for luminosity monitoring is also presented, along with an appropriate recalibration of these detectors.
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Measurement of the transverse momentum of Drell-Yan lepton pairs over a wide mass range in proton-proton collisions at √s = 13 TeV in CMSMoureaux, Louis 24 September 2021 (has links) (PDF)
L’étude du processus Drell-Yan, ou la production dans des collisions entre hadrons à haute énergie d’une paire de leptons par l’intermédiaire d’un boson Z ou ɣ virtuel, est un moyen privilégié pour comprendre les mécanismes de production de particules massives comme le boson de Higgs. Dans cette thèse, les données collectées en 2016 par l’expérience CMS dans les collisions proton-proton à une énergie de 13 TeV dans le système du centre de masse, correspondant à une luminosité intégrée de 36,3 fb⁻¹, sont utilisées pour réaliser une mesure de précision de section efficaces du processus Drell-Yan différentielles en l’impulsion transverse de la paire de leptons, pour des masses invariantes de la paire allant de 50 à 1000 GeV.La mesure utilise les canaux comprenant deux électrons ou deux muons, qui ont l’avantage d’être aisément identifiables expérimentalement et, ainsi, de permettre des mesures précises de sections efficaces. Au total, environ dix millions d’événements comprenant deux électrons et vingt millions d’événements comprenant deux muons sont analysés. L’extension de l’analyse précédente de la collaboration CMS, limitée en masse invariante à l’intervalle entre 76 et 106 GeV, requiert un meilleur contrôle des bruits de fond, plus importants en-dessous de 76 et au-dessus de 106 GeV que dans l’intervalle précédemment considéré. La contribution dominante, la production d’une paire de quarks top se désintégrant en leptons, est étudiée en détail, ainsi que la contamination des données par des électrons mal identifiés. Après prise en compte de l’efficacité de détection, les résultats obtenus dans les deux canaux sont compatibles et sont combinés en une unique mesure.La précision obtenue, de l’ordre du pourcent, dans des régions jusqu’ici peu explorées permet d’obtenir de nouvelles contraintes sur des modèles largement utilisés en physique des particules. À cette fin, la mesure est comparée à six prédictions illustrant différentes approches pour la prédiction du spectre en impulsion transverse. Malgré d’assez bonnes performances générales, aucune d’entre elles ne permet une description complète des données après prise en compute des incertitudes théoriques et expérimentales. C’est en particulier le cas à grande masse invariante ou lorsqu’un jet est identifié dans l’état final. Certaines approches encore peu répandues obtiennent de meilleurs résultats dans les régions qu’elles visent spécifiquement. De nouveaux développements théoriques seront nécessaires pour combiner celles-ci afin d’obtenir des prédictions fiables dans l’ensemble de l’espace des phases. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
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Studium spinové struktury nukleonu s pomocí procesu Drell-Yan v experimentu Compass / Nucleon spin structure studies in Drell-Yan process at CompassMatoušek, Jan January 2018 (has links)
Jointly-supervised doctoral thesis Title: Nucleon spin structure studies in Drell-Yan process at COMPASS Author: Jan Matoušek Department I: Department of Low Temperature Physics, Faculty of Mathem- atics and Physics, Charles University Department II: Department of Physics, University of Trieste Supervisor I: prof. Miroslav Finger (Department I) Supervisor II: prof. Anna Martin (Department II) Abstract: The nucleon structure is presently described by Transverse Momentum Depend- ent (TMD) Parton Distribution Functions (PDFs), which generalise the collinear PDFs, adding partonic spin and transverse momentum degrees of freedom. The recent HERMES and COMPASS data on hadron production in deep inelastic scattering (SIDIS) of leptons off transversely polarised nucleons have provided a decisive validation of this framework. Nevertheless, the TMD PDFs should be studied in complementary reactions, like pp hard scattering and Drell-Yan pro- cesses. In particular the Sivers TMD PDF, which encodes the correlation between the nucleon transverse spin and quark transverse momentum and appears in the Sivers Transverse Spin Asymmetry (TSA), is expected to have opposite sign in Drell-Yan and SIDIS. In 2015 COMPASS measured for the first time the Drell- Yan process on a transversely polarised target π− p↑ → µ− µ+ X to test...
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Efeitos nucleares no processo Drell-Yan : formalismos de dipolos de cor e de momentum transversal intrínsecoOliveira, Emmanuel Gräve de January 2010 (has links)
O principal tema desenvolvido nesta tese é o estudo de efeitos nucleares na produção de diléptons por meio do processo Drell–Yan para energias compatíveis com as de RHIC e de LHC. Dois modelos são usados: o formalismo de dipolos de cor e o modelo de pártons com momentum transversal intrínseco. No primeiro capítulo, uma breve introdução histórica e a motivação para o estudo são apresentadas. No Cap. 2, o espalhamento profundamente inelástico (EPI) no modelo de pártons é revisado e são discutidas as distribuições partônicas de prótons (CTEQ) e de nucleons (EKS, EPS08 e EPS09). O EPI no formalismo de dipolos também é discutido. O Cap. 3 é dedicado ao embasamento teórico do formalismo de dipolos e ao estudo das seção de choque de dipolos. As principais equações que governam a evolução de dipolos são expostas, seguidas pelas parametrizações fenomenológicas GBW, DHJ, BUWe ABGS. Um novo modelo é proposto: a parametrização AGBS com flutuações. Quando ajustada aos dados de HERA, a nova parametrização não difere da antiga AGBS, indicando que flutuações não são necessárias para descrever os dados de EPI nas presentes energias. No Cap. 4, é apresentado o modelo de pártons no processo Drell–Yan. O formalismo é discutido em ordem dominante, em ordem seguinte à dominante (OSD) e em OSD com momentum transversal intrínseco, já que apenas na última possibilidade o momentum transversal do dilépton pode ser gerado de maneira consistente com os experimentos. Posteriormente, o formalismo de dipolos aplicado ao mesmo processo é debatido, que em ordem dominante possui distribuição em momentum transversal consistente com os experimentos. Os resultados são cálculos para o fator de modificação nuclear (RpA) para rapidezes negativas como função de rapidez e momentum transversal. A aplicação para rapidezes negativas do formalismo de dipolos é uma contribuição original, bem como a comparação deste formalismo com o modelo de pártons com momentum transversal intrínseco. Efeitos de grande (efeito EMC e anti-sombreamento) e de pequeno x (sombreamento) são observados. Mostra-se que o momentum transversal intrínseco é particularmente importante, alterando o fator de modificação nuclear em torno de 10%. Quando as diferentes parametrizações da seção de choque de dipolos são comparadas, a produção de diléptons não apresenta variações significativas, indicando que ela não é sensível aos detalhes das parametrizações, como a possível violação de escalamento geométrico presente na parametrização DHJ. Adicionalmente, os resultados do modelo de pártons são estendidos para rapidezes positivas e comparados com resultados do condensado de vidros de cor. Para energias de RHIC, os formalismos concordam, enquanto que para LHC, a menos que a parametrização nuclear tenha um sombreamento muito forte (caso da EPS08), os formalismos discordam, devido aos comportamentos distintos do sombreamento de glúons e do sombreamento de quarks. Como perspectiva, é discutido o modelo unidimensional, que é uma simplificação drástica da evolução de dipolos sem deixar de incluir os efeitos de flutuações. Em particular, as possibilidades de escalamento geométrico e escalamento difusivo nas seções de choque são discutidas. / The main topic of this thesis is the study of nuclear effects in Drell–Yan dilepton production at RHIC and LHC energies. Two approaches are employed: the color dipole approach and the parton model with intrinsic transverse momentum. In the first chapter, a brief introduction and the motivation to the study are presented. Chapt. 2 reviews the deep inelastic scattering (DIS) in the parton model and the parton distribution functions of protons (CTEQ) and of nucleons (EKS, EPS08 e EPS09) are examinated. The DIS in the dipole frame is also discussed. Chapt. 3 reviews the theoretical foundations of the color dipole approach and the dipole cross section. The main equations that drive the dipole evolution are shown, followed by the phenomenological parameterizations GBW, DHJ, BUW, and ABGS. A new model is proposed: the AGBS parameterization with fluctuations. When fitted to HERA data, the new parameterization does not differ from the old AGBS, indicating that fluctuations are not needed to reproduce DIS data at current energies. Chapt. 4 discusses the parton model in the Drell–Yan process. This approach is considered at leading order, at next-to-leading order (NLO), and at NLO with intrinsic transverse momentum, as only in the last case the dilepton transverse momentum distribution can be obtained in agreement with experiments. Afterwards, the color dipole approach applied to the process is examined, giving at leading order a transverse momentum distribution compatible with experiments. The results are calculations to the nuclear modification factor (RpA) at backward rapidities as function of rapidity and transverse momentum. The use of backward rapidities of the color dipole approach is an original contribution, as well as the comparison of this approach with the parton model with intrinsic transverse momentum. Effects of large (EMC effect and antishadowing) and of small x (shadowing) are seen. It is shown that the intrinsic transverse momentum is particularly important, changing the nuclear modification factor of about 10%. When different parameterizations of the dipole cross section are compared, the dilepton production does not show significant discrepancies, suggesting the it is not sensitive to the parametrization details, such as the possibility of geometric scaling breaking present in DHJ parameterization. Furthermore, the parton model results are extended to forward rapidities and compared with results of the color glass condensate. At RHIC energies, the approaches agree, while at LHC energies, unless the nuclear parameterization shows a very strong nuclear shadowing (EPS08 case), the approaches disagree, due to the different behaviors of gluon shadowing and quark shadowing. The unidimensional model, a toy model of the dipole evolution that includes the fluctuation effects is also investigated. Specificaly, the possibilities of geometric scaling and difusive scaling in cross sections are discussed.
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Diplomatická jednání jako platforma pro prezentaci etických názorů v textu Yanzi chunqiu / Diplomatic missions as an opportunity for presentation of ethical views in the Yanzi chunqiuRinglová, Linda January 2012 (has links)
This thesis deals with diplomatic relations in the Chunqiu period or the Spring and Autumn period. It introduces characterization of process of diplomatic meeting, how they are described in the text of the Zhouli. As a main source it uses early chinese text of the Yanzi chunqiu - Annals of Mister Yan. It gives information about a personage of Yan Ying - a minister in the state of Qi in the 6th century BC, as well as about the text itself, including history, authenticity and other questions. It presents own translations of episodes concerning diplomatic relations. For a comparison it presents episodes from the text of Zuo Zhuan, in which we can find Yan Ying. Based on a summary of political situation of this period it resumes, how could episodes of diplomatic meetings correspond to reality of this period. As a result it summarize, how opinions claimed during diplomatic meetings could differ from other episodes.
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中國近代平等觀念的形成(1895‐1915)—以康有為、嚴復、章太炎為中心 / The Formation of "Equality" Concept in Modern China(1895-1915)─Based on Kang You-wei, Yan Fu and Zhang Tai-yan邱偉雲, Chiu, Wei Yun Unknown Date (has links)
張灝先生曾指出中國近代思想具有一個轉型期。在這轉型期中,傳統概念資源在新時代命題下受到挑戰,使得中國知識分子必須在一個萬國之新世界秩序下,重新擘畫中國的位置,因此在中國要回應內在取向危機與外在列強的挑戰下,便啟動了思想轉型的旅程,上述這段從傳統到現代的發展過程,即稱之為中國近代思想史的轉型時代。「平等」觀念作為中國近代知識分子戮力追求的新價值,自然也經歷了這段思想轉型的過程;在轉型過程中隨著張灝先生所指出中國近代思想之普遍主義/特殊主義雙層建構現象,「平等」論述也呈現出普遍性平等與特殊性平等觀的雙重展演。本文即是欲從轉型時代的角度出發,觀察「平等」觀念從傳統發展至現代的過程中,如何在普遍性上成為中國近代知識分子於理想上的永恆追求;又如何在特殊性上滿足不同行動者於現實層面的生命–政治目的。追尋中國近代平等觀念在轉型時代中的發展,以及平等觀念如何回應中國近代三大兩歧命題:傳統/現代、理想/現實、政界/家界的矛盾與拉扯,即為本文之主要研究目的與論述核心所在。
本文在研究範圍上,主要以康有為、嚴復、章太炎等三人「平等」論述為主,而旁及中國近代其他知識分子的平等觀,以及與平等觀念發展相伴共生的其他相關近代論述。而在研究方法上,則採用綜合的觀念史研究法,一方面觀察宏觀面向的中國近代平等觀念史發展及其類型結構,一方面觀察微觀部分的論者個體「以言行事」(Illocutionary Act)與「以言取效」(Perlocutionary Act)的平等論述內在動機;而上述兼顧宏觀與微觀的綜合觀念史研究法,則必須透過數位人文技術(Digital Humanities)的協助才能達到研究方法循環,故本文研究即由綜合的觀念史研究法與數位人文研究法合作完成。而在研究結果上,本文分析了康有為、嚴復、章太炎等三人平等觀後,提出中國近代平等觀念的形成發展,依序有啟蒙平等、救亡平等、革命平等的歷時性發展特徵;以及三人皆各自代表了國學近代化下的儒家平等、道家平等、佛家平等觀之觀念類型。並在描繪出三人平等觀的特殊性後,更進一步地勾勒出三人平等觀的普遍性意義,即僅追求政界平等而不論家界秩序,呈現出一種有別於五四時期激進式三綱平等訴求的漸進式平等觀念形態,本文認為漸進式平等即是晚清平等觀念最為特殊之展演。
在本文研究貢獻上,則是對以往學者大都認為西方觀念一入中國,就立即挑戰了三綱,而呈現出三綱同時瓦解的主張進行商榷。本文認為以往學者忽略了晚清時期有一批知識分子,他們戮力於緩解家界倫常的平等革命而不贊成家界平等,這一行動群體的存在是前輩學者較為忽略的部份。因此本文透過康有為、嚴復、章太炎等三人,勾勒出中國近代知識分子中僅追求政界革命而反對家界革命一派的主張,並動態刻劃這個群體與主張三綱平等的無政府主義者之對詰過程,豐富清末民初歷史研究的厚度,即為本文之研究貢獻。
而在康有為以儒學本土資源完成啟蒙平等觀的建構、嚴復從道學出發建構救亡平等觀,以及章太炎從佛學會通革命平等觀的行動過程中,也標示了一個晚清階段國學再造的特殊意義,即:中國近代知識分子在意圖透過會通傳統本土資源與西方觀念,以追求啟蒙、救亡、革命目的下,也順勢促成了中國傳統國學的近代化發展。而中國近代平等觀念中所呈現出的國學近代化色彩僅為一個面向,中國近代知識分子乃是透過對於整個傳統國學觀念系統內涵的轉置,來強化國學與西方文明之間的對話能力,並完成國學從傳統邁入現代的再造歷程。故將來可從「國學近代化」的角度出發,觀察各種本土觀念如何透過與西學會通,完成中國近代思想觀念從傳統到現代的轉型過程,藉此更整全地掌握中國近代思想轉型之樣態,此即本文具有借鑑性之理論意義與推廣前景所在。
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Efeitos nucleares no processo Drell-Yan : formalismos de dipolos de cor e de momentum transversal intrínsecoOliveira, Emmanuel Gräve de January 2010 (has links)
O principal tema desenvolvido nesta tese é o estudo de efeitos nucleares na produção de diléptons por meio do processo Drell–Yan para energias compatíveis com as de RHIC e de LHC. Dois modelos são usados: o formalismo de dipolos de cor e o modelo de pártons com momentum transversal intrínseco. No primeiro capítulo, uma breve introdução histórica e a motivação para o estudo são apresentadas. No Cap. 2, o espalhamento profundamente inelástico (EPI) no modelo de pártons é revisado e são discutidas as distribuições partônicas de prótons (CTEQ) e de nucleons (EKS, EPS08 e EPS09). O EPI no formalismo de dipolos também é discutido. O Cap. 3 é dedicado ao embasamento teórico do formalismo de dipolos e ao estudo das seção de choque de dipolos. As principais equações que governam a evolução de dipolos são expostas, seguidas pelas parametrizações fenomenológicas GBW, DHJ, BUWe ABGS. Um novo modelo é proposto: a parametrização AGBS com flutuações. Quando ajustada aos dados de HERA, a nova parametrização não difere da antiga AGBS, indicando que flutuações não são necessárias para descrever os dados de EPI nas presentes energias. No Cap. 4, é apresentado o modelo de pártons no processo Drell–Yan. O formalismo é discutido em ordem dominante, em ordem seguinte à dominante (OSD) e em OSD com momentum transversal intrínseco, já que apenas na última possibilidade o momentum transversal do dilépton pode ser gerado de maneira consistente com os experimentos. Posteriormente, o formalismo de dipolos aplicado ao mesmo processo é debatido, que em ordem dominante possui distribuição em momentum transversal consistente com os experimentos. Os resultados são cálculos para o fator de modificação nuclear (RpA) para rapidezes negativas como função de rapidez e momentum transversal. A aplicação para rapidezes negativas do formalismo de dipolos é uma contribuição original, bem como a comparação deste formalismo com o modelo de pártons com momentum transversal intrínseco. Efeitos de grande (efeito EMC e anti-sombreamento) e de pequeno x (sombreamento) são observados. Mostra-se que o momentum transversal intrínseco é particularmente importante, alterando o fator de modificação nuclear em torno de 10%. Quando as diferentes parametrizações da seção de choque de dipolos são comparadas, a produção de diléptons não apresenta variações significativas, indicando que ela não é sensível aos detalhes das parametrizações, como a possível violação de escalamento geométrico presente na parametrização DHJ. Adicionalmente, os resultados do modelo de pártons são estendidos para rapidezes positivas e comparados com resultados do condensado de vidros de cor. Para energias de RHIC, os formalismos concordam, enquanto que para LHC, a menos que a parametrização nuclear tenha um sombreamento muito forte (caso da EPS08), os formalismos discordam, devido aos comportamentos distintos do sombreamento de glúons e do sombreamento de quarks. Como perspectiva, é discutido o modelo unidimensional, que é uma simplificação drástica da evolução de dipolos sem deixar de incluir os efeitos de flutuações. Em particular, as possibilidades de escalamento geométrico e escalamento difusivo nas seções de choque são discutidas. / The main topic of this thesis is the study of nuclear effects in Drell–Yan dilepton production at RHIC and LHC energies. Two approaches are employed: the color dipole approach and the parton model with intrinsic transverse momentum. In the first chapter, a brief introduction and the motivation to the study are presented. Chapt. 2 reviews the deep inelastic scattering (DIS) in the parton model and the parton distribution functions of protons (CTEQ) and of nucleons (EKS, EPS08 e EPS09) are examinated. The DIS in the dipole frame is also discussed. Chapt. 3 reviews the theoretical foundations of the color dipole approach and the dipole cross section. The main equations that drive the dipole evolution are shown, followed by the phenomenological parameterizations GBW, DHJ, BUW, and ABGS. A new model is proposed: the AGBS parameterization with fluctuations. When fitted to HERA data, the new parameterization does not differ from the old AGBS, indicating that fluctuations are not needed to reproduce DIS data at current energies. Chapt. 4 discusses the parton model in the Drell–Yan process. This approach is considered at leading order, at next-to-leading order (NLO), and at NLO with intrinsic transverse momentum, as only in the last case the dilepton transverse momentum distribution can be obtained in agreement with experiments. Afterwards, the color dipole approach applied to the process is examined, giving at leading order a transverse momentum distribution compatible with experiments. The results are calculations to the nuclear modification factor (RpA) at backward rapidities as function of rapidity and transverse momentum. The use of backward rapidities of the color dipole approach is an original contribution, as well as the comparison of this approach with the parton model with intrinsic transverse momentum. Effects of large (EMC effect and antishadowing) and of small x (shadowing) are seen. It is shown that the intrinsic transverse momentum is particularly important, changing the nuclear modification factor of about 10%. When different parameterizations of the dipole cross section are compared, the dilepton production does not show significant discrepancies, suggesting the it is not sensitive to the parametrization details, such as the possibility of geometric scaling breaking present in DHJ parameterization. Furthermore, the parton model results are extended to forward rapidities and compared with results of the color glass condensate. At RHIC energies, the approaches agree, while at LHC energies, unless the nuclear parameterization shows a very strong nuclear shadowing (EPS08 case), the approaches disagree, due to the different behaviors of gluon shadowing and quark shadowing. The unidimensional model, a toy model of the dipole evolution that includes the fluctuation effects is also investigated. Specificaly, the possibilities of geometric scaling and difusive scaling in cross sections are discussed.
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Efeitos nucleares no processo Drell-Yan : formalismos de dipolos de cor e de momentum transversal intrínsecoOliveira, Emmanuel Gräve de January 2010 (has links)
O principal tema desenvolvido nesta tese é o estudo de efeitos nucleares na produção de diléptons por meio do processo Drell–Yan para energias compatíveis com as de RHIC e de LHC. Dois modelos são usados: o formalismo de dipolos de cor e o modelo de pártons com momentum transversal intrínseco. No primeiro capítulo, uma breve introdução histórica e a motivação para o estudo são apresentadas. No Cap. 2, o espalhamento profundamente inelástico (EPI) no modelo de pártons é revisado e são discutidas as distribuições partônicas de prótons (CTEQ) e de nucleons (EKS, EPS08 e EPS09). O EPI no formalismo de dipolos também é discutido. O Cap. 3 é dedicado ao embasamento teórico do formalismo de dipolos e ao estudo das seção de choque de dipolos. As principais equações que governam a evolução de dipolos são expostas, seguidas pelas parametrizações fenomenológicas GBW, DHJ, BUWe ABGS. Um novo modelo é proposto: a parametrização AGBS com flutuações. Quando ajustada aos dados de HERA, a nova parametrização não difere da antiga AGBS, indicando que flutuações não são necessárias para descrever os dados de EPI nas presentes energias. No Cap. 4, é apresentado o modelo de pártons no processo Drell–Yan. O formalismo é discutido em ordem dominante, em ordem seguinte à dominante (OSD) e em OSD com momentum transversal intrínseco, já que apenas na última possibilidade o momentum transversal do dilépton pode ser gerado de maneira consistente com os experimentos. Posteriormente, o formalismo de dipolos aplicado ao mesmo processo é debatido, que em ordem dominante possui distribuição em momentum transversal consistente com os experimentos. Os resultados são cálculos para o fator de modificação nuclear (RpA) para rapidezes negativas como função de rapidez e momentum transversal. A aplicação para rapidezes negativas do formalismo de dipolos é uma contribuição original, bem como a comparação deste formalismo com o modelo de pártons com momentum transversal intrínseco. Efeitos de grande (efeito EMC e anti-sombreamento) e de pequeno x (sombreamento) são observados. Mostra-se que o momentum transversal intrínseco é particularmente importante, alterando o fator de modificação nuclear em torno de 10%. Quando as diferentes parametrizações da seção de choque de dipolos são comparadas, a produção de diléptons não apresenta variações significativas, indicando que ela não é sensível aos detalhes das parametrizações, como a possível violação de escalamento geométrico presente na parametrização DHJ. Adicionalmente, os resultados do modelo de pártons são estendidos para rapidezes positivas e comparados com resultados do condensado de vidros de cor. Para energias de RHIC, os formalismos concordam, enquanto que para LHC, a menos que a parametrização nuclear tenha um sombreamento muito forte (caso da EPS08), os formalismos discordam, devido aos comportamentos distintos do sombreamento de glúons e do sombreamento de quarks. Como perspectiva, é discutido o modelo unidimensional, que é uma simplificação drástica da evolução de dipolos sem deixar de incluir os efeitos de flutuações. Em particular, as possibilidades de escalamento geométrico e escalamento difusivo nas seções de choque são discutidas. / The main topic of this thesis is the study of nuclear effects in Drell–Yan dilepton production at RHIC and LHC energies. Two approaches are employed: the color dipole approach and the parton model with intrinsic transverse momentum. In the first chapter, a brief introduction and the motivation to the study are presented. Chapt. 2 reviews the deep inelastic scattering (DIS) in the parton model and the parton distribution functions of protons (CTEQ) and of nucleons (EKS, EPS08 e EPS09) are examinated. The DIS in the dipole frame is also discussed. Chapt. 3 reviews the theoretical foundations of the color dipole approach and the dipole cross section. The main equations that drive the dipole evolution are shown, followed by the phenomenological parameterizations GBW, DHJ, BUW, and ABGS. A new model is proposed: the AGBS parameterization with fluctuations. When fitted to HERA data, the new parameterization does not differ from the old AGBS, indicating that fluctuations are not needed to reproduce DIS data at current energies. Chapt. 4 discusses the parton model in the Drell–Yan process. This approach is considered at leading order, at next-to-leading order (NLO), and at NLO with intrinsic transverse momentum, as only in the last case the dilepton transverse momentum distribution can be obtained in agreement with experiments. Afterwards, the color dipole approach applied to the process is examined, giving at leading order a transverse momentum distribution compatible with experiments. The results are calculations to the nuclear modification factor (RpA) at backward rapidities as function of rapidity and transverse momentum. The use of backward rapidities of the color dipole approach is an original contribution, as well as the comparison of this approach with the parton model with intrinsic transverse momentum. Effects of large (EMC effect and antishadowing) and of small x (shadowing) are seen. It is shown that the intrinsic transverse momentum is particularly important, changing the nuclear modification factor of about 10%. When different parameterizations of the dipole cross section are compared, the dilepton production does not show significant discrepancies, suggesting the it is not sensitive to the parametrization details, such as the possibility of geometric scaling breaking present in DHJ parameterization. Furthermore, the parton model results are extended to forward rapidities and compared with results of the color glass condensate. At RHIC energies, the approaches agree, while at LHC energies, unless the nuclear parameterization shows a very strong nuclear shadowing (EPS08 case), the approaches disagree, due to the different behaviors of gluon shadowing and quark shadowing. The unidimensional model, a toy model of the dipole evolution that includes the fluctuation effects is also investigated. Specificaly, the possibilities of geometric scaling and difusive scaling in cross sections are discussed.
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顧炎武經學之研究孫劍秋, SUN, JIAN-GIU Unknown Date (has links)
一、研究動機:清代的「經學經世」思想,主要是表現在學說上,而代表人物便是顧
亭林。因此本論文選擇顧亭林為研究對象。
二、研究目的及方法:期能更進一步了解經學義理與經世致用彼此間之關係,以及亭
林以何種方式結合經義與經世。故本文先從整個時代之趨向述起,並試圖證明亭林之
經世學說與經學主張,實為開啟清代學術之第一人。
三、研究範圍及參考文獻:本文以研究亭林之經學為範圍。亭林之經學著作有〔五經
同異〕、〔左傳杜解補正〕、〔九經誤字〕、〔日知錄〕前十卷,另有〔音學五書〕
中之〔詩本音〕、〔易音〕,及〔亭林文集〕中有關經義之論述。
四、論文內容提要:本論文共壹冊,約十五萬字。全書共計十章。
第一章 明末清初之朵學術趨向:本章旨在探討當時學術環境與學者之主張。而其結
果都朝向「經世致用」。
第二章 亭林治學之態度與方法:本章從亭林思想傳承敘起並述其治學態度及方法,
以印證亭林之經學確是根基深厚,學有本源。
第三章至第八章 分別闡釋亭林經學之主張,計有易、書、詩、禮、春秋、論孟諸經
。各章首皆通論,次及考證,末則以鄙見對亭林之經學提出質疑。
第九章 亭林治經之意義與特色:亭林治經之意義在經世致用,特色則在於以經、史
、子、集諸文獻中之思想與其所欲闡釋者相發明。
第十章 結論:肯定亭林在清初經學經世史上之地位。雖其見解有些泥古,不合時用
,但仍不減損其開啟後學之功。
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