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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.
1

Exclusive B decays into final states with two charmed baryons

Chai, Xuedong 01 January 2007 (has links)
This Thesis presents measurements of the decays \Bm\to\Xi_c^0\bar{\Lambda}_c^-, \Bzb\to\Xi_c^+\bar{\Lambda}_c^- , \Bm\to\Lambda_c^+\bar{\Lambda}_c^-\Km, and \Bzb\to\Lambda_c^+\bar{\Lambda}_c^-\Kzb based on 228 million \upsbb decays collected with the \babar\ detector at the SLAC \pep2\ asymmetric-energy \B factory. The branching fraction of \Bm\to\Lambda_c^+\bar{\Lambda}_c^-\Km is measured to be $(1.22\pm0.16\pm 0.14\pm0.63)\times 10^{-3}$, and the branching fraction of $\Bz\to\Lambda_c^+\bar{\Lambda_c^-\Kzb$ is $(0.40\pm 0.33\pm 0.05 \pm 0.21)\times 10^{-3}$. The product $\BR(\Bm\to\Xi_c^0\bar{Lambda}_c^-)\times \BR(\Xi_c^0\to\Xi^-\pi^+)$ is measured to be $(2.04\pm0.59\pm0.26\pm0.53)\times 10^{-5}$, and $\BR(\Bzb\to\Xi_c^+\bar{\Lambda}_c^-)\times\BR(\Xi_c^+\to\Xi^-\pi^+\pi^+)$ is $(1.50\pm 1.07\pm 0.19 \pm 0.39)\times 10^{-5}$, where the uncertainties are statistical, systematic, and the uncertainty from the branching fraction $\BR(\Lambda_c^+\to\proton K^-\pi^+)$, respectively.
2

The CMS forward calorimeter prototype design studies and omega(c)0 search at E781 experiment at FermiLab

Ayan, Ahmet Sedat 01 January 2004 (has links)
In the first part, the Compact Muon Solenoid (CMS) forward calorimeter design studies are presented. The forward calorimeter consists of quartz fibers embedded in a steel absorber. Radiation damage studies of the quartz fiber and the absorber as well as the results of the first pre-production prototype PPP-I are presented. In the second part the Ωc0 search studies at the SELEX (E781) experiment at FermiLab are presented. 107±22Ωc0 events were observed in three decay modes. The relative branching ratio Ωc0 → Ω−π−π+π+)/Β(Ωc0→ Ω−π+)$ is measured as 2.00 ± 0.45 (stat) ± 0.32 (sys).
3

Charmed baryon resonances and mesons in hot and dense matter

Jiménez Tejero, Clara Estela 05 March 2012 (has links)
In this thesis we have studied baryon resonances generated from the dynamical interaction of two hadrons. We are interested on this study as an alternative approach to explain the increasing number of observed charmed states which apparently do not fit into the traditional three quark picture of a baryon. In particular, we study baryon molecules with JP = ½ - which can be formed from the attractive interaction of a pseudoscalar meson (0-) and a ground state baryon (1/2+) in s-wave (L = 0). Therefore our aim is to contribute to the understanding of the observed charm baryon spectra by checking if the dynamical origin can explain those states which are candidates to be a baryon resonance with JP =1/2-. The important feature of our model is the description of the meson-baryon interaction in terms of the t-channel vector meson exchange which is fully solved without any approximation. The first part of the thesis is devoted to study these sort of baryon molecules in free space. In order to learn about the nature of a baryon it is important to study its different types of decays. For this reason, we will calculate the strong decays of dynamically generated resonances into meson-baryon components, as well as the electromagnetic transition of such hadron molecules into the lowest-lying ground states. In the second part of the thesis we have included medium and temperature effects on the formalism to study the properties of the charmed baryon resonant states in hot and dense matter. This will allow us as well to study the properties of charmed mesons (D, D, Ds and Ds) in the nuclear medium which will be simultaneously dressed in the self-consistent calculation for the first time. The behaviour of these mesons will influence the charmonium production whose suppression is connected with the possible formation of quark-gluon plasma at a dense matter and high temperature scenario. / En esta tesis se han estudiado las resonancias bariónicas generadas a partir de la interacción dinámica de dos hadrones. Estamos interesados en este estudio como un enfoque alternativo para explicar el creciente número de estados observados con quark encanto y que aparentemente no encajan en la imagen tradicional de tres quarks de un barión. En particular, se estudian las moléculas de bariones con JP = ½ - que pueden formarse a partir de la interacción atractiva de un mesón pseudoescalar (0-) y un barión del estado fundamental ( 1/2+) en onda s (L = 0). Por tanto, nuestro objetivo es comprobar si el origen dinámico puede explicar aquellos estados que son candidatos a ser una resonancia bariónica con JP =1/2-. La característica importante del modelo es la descripción de la interacción mesón-barión en términos del canal t de intercambio de mesones vectoriales, que está resuelto sin ningún tipo de aproximación.La primera parte de la tesis está dedicada a estudiar este tipo de moléculas en el espacio libre. Con el fin de aprender sobre la naturaleza de un barión es importante estudiar sus diferentes tipos de desintegración. Por esta razón, calculamos las desintegraciones fuertes de las resonancias en canales mesón-barión, así como la transición electromagnética a bariones de estado fundamental.En la segunda parte de la tesis se ha incluido en el formalismo los efectos del medio y de la temperatura para estudiar las propiedades de los estados de bariones encantados en materia caliente y densa. Esto nos permitirá también estudiar las propiedades de los mesones encantados (D, D, Ds y Ds) en el medio nuclear, que serán vestidos autoconsistentemente en el cálculo por primera vez. El comportamiento de estos mesones influirá en la producción de “charmonium”, cuya supresión está relacionada con la posible formación de plasma de quark-gluón en materia densa y caliente.
4

Charmed baryon interaction from lattice QCD and its application to charmed hypernuclei / 格子QCDによるチャーム系バリオン間相互作用とチャーム原子核への応用

Miyamoto, Takaya 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21568号 / 理博第4475号 / 新制||理||1642(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 青木 慎也, 教授 田中 貴浩, 准教授 髙山 史宏 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
5

Measurement of charmed hadron production in e±p deep inelastic scattering with the ZEUS detector

Allfrey, Philip Daniel January 2007 (has links)
Charmed hadron production has been studied in 225 pb<sup>-1</sup> of data collected with the ZEUS detector in the HERA-II runnning period. Studies were made in the D* → D<sup>0</sup>π → Kππ decay channel to determine the potential for the microvertex detector to improve charm signals. Integrated cross sections were measured for the decays D<sup>0</sup> → K<sup>0</sup><sub>s</sub>π⁺ π⁻, D<sup>±</sup> → K<sup>0</sup><sub>s</sub> π<sup>±</sup>, D<sup>±</sup>_s → K<sup>0</sup>s K<sup>±</sup> and Lambda<sup>±</sup>_c → Lambda<sup>0</sup>π<sup>±</sup> in the kinematic region 5< Q² < 1000 GeV², 0.02 < y < 0.7, 1.5 < pT(D,Lambda_c) < 20.0 GeV, -1.6 < pseudorapidity(D, Lambda_c) < 1.6. The D<sup>0</sup> cross section was additionally measured down to pT(D<sup>0</sup>) > 1.0 GeV. Differential cross sections as a function of Q², x, pT(D) and pseudorapidity(D) were measured for the D<sup>0</sup>, D<sup>±</sup>, and D_s<sup>±</sup> channels. The measurements were compared to next-to-leading order (NLO) QCD calculations, and good agreement found for all variables in all channels over the measured kinematic region. The strangeness-suppression factor, gamma_s = D_s<sup>±</sup>/(D<sup>±</sup> + D<sup>0</sup>), was measured and found to be in good agreement with values previously measured at HERA and elsewhere, and with the DJANGOH and RAPGAP Monte Carlo. The ratio of charmed baryons to mesons, Lambda_c<sup>±</sup>/(D<sup>±</sup> + D<sup>0</sup>), was measured and also found to be in good agreement with Monte Carlo.
6

Qcd Sum Rules For The Anticharmed Pentaquark

Sarac, Yasemin 01 January 2007 (has links) (PDF)
For the anti-charmed pentaquark state with and without strangeness a QCD sum rule analysis, which is one of the nonperturbative approaches, is presented. For this purpose we employ pentaquark currents with and without strangeness, with two different current for each case. To refine the sum rules we also consider the DN continuum contribution in our analysis since this procedure is important to identify the signal of the pentaquark state. While the sum rules for most of the currents are either non-convergent or dominated by the DN continuum, the one for the non-strange pentaquark current composed of two diquarks and an antiquark, is convergent and has a structure consistent with a positive parity pentaquark state after subtracting out the DN continuum contribution. Arguments are presented on the similarity between the result of the present analysis and that based on the constituent quark models, which predict more stable pentaquark states when the antiquark is heavy.
7

Recherche des oscillations de neutrinos par apparition du τ avec désintégration muonique du vτ dans l’expérience OPERA

Tran, Ngoc Tiem 18 October 2010 (has links)
La physique des oscillations de neutrinos occupe une place majeure dans les études s’intéressant à cetteparticule. Le mécanisme des oscillations, basé sur un changement d’état de saveur d’un neutrino durant sapropagation, permet d’élucider les déficits observés de neutrinos solaires et atmosphériques et apporte des indicationsintéressantes de physique au delà du Modèle Standard par l'étude des angles de mélanges et du schéma de masse desneutrinos.OPERA est un détecteur hybride combinant à la fois latechnique d'une détection électronique en temps réel et la technique de la chambre à brouillard à émulsion ou ECC(EmulsionCloud Chamber). Le détecteur ECC est un détecteur massif (cible) composé de 150000 briques dontchacune est constituée de feuilles de plombs, utilisées comme cible, alternées avec des émulsions nucléaires dont laprécision de reconstruction des traces est de l'ordre du micron. Le détecteur comprend également deux spectromètresavec des plaques de fer magnétisé de 5 cm d'épaisseur alternées avec les détecteurs RPC (Resistive Plate Chamber)associés à six ensembles de drift tubes (PT) pour la mesure de la charge et de l'impulsion du muon, et un plan de vetoservant à la rejection des particules extérieures à la cible. / The physics of neutrino oscillations plays a major role in studies concerned with cetteparticule. The mechanism of oscillations, based on a change of state of a neutrino flavor during sapropagation, elucidates the deficits observed solar and atmospheric neutrinos and provides indicationsintéressantes of physics beyond the Standard Model by studying the angles mixtures and mass desneutrinos.OPERA scheme is a hybrid sensor combining both latechnique an electronic real-time detection technology and the cloud chamber emulsion or ECC (EmulsionCloud chamber). The ECC is a solid detector detector (target) consisting of bricks dontchacune 150000 consists of sheets of lead, used as a target, with alternate nuclear emulsion whose traces laprécision reconstruction is of the order of one micron. The detector also includes two spectromètresavec magnetized iron plates 5 cm alternating with RPC (Resistive Plate Chamber) detectors associated with six sets of drift tubes (PT) to measure the charge and momentum of the muon thickness and plan vetoservant the rejection of foreign particles to the target.
8

Study of the J/ψ production in pp collisions at √s = 5.02 TeV and of the J/ ψ production multiplicity dependence in p-Pb collisions at √sNN = 8.16 TeV with ALICE at the LHC / Étude de la production du J/ψ dans les collisions pp à √s = 5.02 TeV et de la dependence en multiplicité de la production du J/ψ dans les collisions p-Pb à √sNN = 8.16 TeV avec l’expérience ALICE au LHC

Crkovská, Jana 30 October 2018 (has links)
L’expérience ALICE au CERN examine l’état de la matière QCD chaude et dense créée lors de collisions d’ions lourds ultra-relativistes - le plasma de Quark Gluon (QGP). En raison de sa courte durée de vie, le QGP ne peut être étudié que via ses signatures.La suppression de J/ψ a été proposée comme preuve de la formation du milieu déconfiné.Néanmoins, il est devenu évident que la réalité est bien plus complexe, car il existe d’autres mécanismes concurrents qui affectent la production de J/ψ . Pour comprendre quels effets agissant sur la production de J/ψ dans les collisions noyau-noyau résultent véritablement de la présence du QGP, ALICE étudie également la production de J/ψ en collisions pp et p–Pb. Le QGP ne devrait pas se former dans ces systèmes. De plus, les mesures de la production de J/ψ dans les collisions p–Pb peuvent révéler des informations sur les effets provenant de la liaison des nucléons dans le noyau, appelés effets de la matière nucléaire froide (CNM). L’objectif de cette thèse est d’étudier la production de J/ψ à rapidité vers l’avant avec le spectromètre à muons ALICE. La section efficace de production J/ψ inclusive dans les collisions pp à √s = 5.02 TeV,et sa dépendance en pT et en rapidité, ont été examinées et comparées à des calculs théoriques ainsi qu’ à des mesures à d’autres énergies du LHC. Les données sont bien décrites par la somme des calculs de pQCD pour les J/ψ prompts et de FONLL pour les J/ψ non-prompts. La production différentielle en multiplicité des J/ψ a été étudiée dans les collisions p–Pb et Pb–p à √sNN = 8,16 TeV, ainsi que le moment transvers moyen. La mesure montre un comportement dépendant de la rapidité pour les taux de production relatifs des J/ψ . Le moment transvers moyen des J/ψ est par contre identique dans les deux intervalles de rapidité mesurés. La nouvelle analyse a augmenté la précision et étendu la mesure à des multiplicités plus élevées par rapport à la mesure précédente à √sNN = 5,02 TeV. Nous constatons que les taux de production relatifs et le <pti> relatif sont indépendants de l’énergie du centre de masse. / The ALICE experiment at CERN probesthe state of hot and dense QCD matter created in ultrarelativisticheavy ion collisions - the Quark GluonPlasma (QGP). Due to its short lifetime, the QGP canbe studied only via its signatures. The suppression ofJ/ ψ was proposed as a proof of formation of the deconfinedmedium. Nevertheless, it became clear thatthe real picture is far more complex as there are othercompeting mechanisms affecting the J/ ψ production.To understand which effects acting on the J/ productionin nucleus-nucleus collisions truly stem fromthe presence of the QGP, ALICE also studies the productionof J/ψ in pp and p–Pb collisions. The QGP isexpected not to form in these systems. Furthermore,measurements of the J/ ψ production in p–Pb collisionscan unveil information on the effects originatingfrom the binding of the nucleons in the nucleus, referredto as the cold nuclear matter effects (CNM).The objective of this thesis is to study the productionof J/ ψ at forward rapidity with the ALICE Muon Spectrometer.The inclusive J/ ψ production cross sectionin pp collisions at √s = 5.02 TeV, and its dependenceon pT and rapidity, were examined and compared withtheoretical calculations as well as measurement atother LHC energies. The data are well described bya sum of pQCD calculations for prompt and FONLLcalculations for non-prompt contribution. The multiplicitydifferential J/ ψ production was studied in p–Pband Pb–p collisions at √sNN = 8.16 TeV, as well asits mean transverse momentum. The measurementshows a rapidity dependent behaviour of relative J/ ψ yields. The J/ ψ mean transverse momentum on theother hand is identical in the two measured rapidityintervals. The new analysis increased the precisionand extended the measurement to higher multiplicitiescompared to previous measurement at √sNN =5.02 TeV. We find that both relative yields and relative<pti> are independent of centre-of-mass energy.
9

Personals förhållningssätt till sexualitet på gruppboenden. : En kvalitativ studie om utrymmet för sexualitet för vuxna personer med intellektuella funktionsnedsättningar. / Approaches to sexuality at group homes. : A qualitative study about the space for sexuality for adults with intellectual disabilities.

Håkansson, Hanna January 2019 (has links)
In Sweden there is a limited research about adults with intellectual disabilities and their sexuality through a social work perspective. This study aims to study how workers in group homes and their managers describes the residents sexuality and describes how they approaches their sexuality at work. And if there’s any facilities or hindrance that affects the sexual space. 5 semi-structured interviews with managers and coordinators, and 3 focus groups with carers where made. For analysis script theory and the charmed circle have been used. The result shows that people who works at group homes has no guidance or collective ways to approach sexuality in their work. They talk about an open approach but often describes the residents as asexual and connects sexuality with the level of disabilities. The respondents acknowledge that they need more knowledge. The conclusion is that there’s a need for more knowledge and guidance for people who work at group homes to extend the space for sexuality for adults with intellectual disabilities.
10

Mirror, Mirror : Embodying the sexed posthuman body of becoming in Sion Sono’s Antiporno (アンチポルノ, 2016) and Mika Ninagawa’s Helter Skelter (ヘルタースケルター, 2012)

Hjelm, Zara Luna January 2021 (has links)
This thesis examines the embodiment of the sexed body and the struggle of fitting into the narrow frames of what a woman is supposed to behave and look like in Japanese cinema. Using the medium of film, I, therefore, seek to produce knowledge regarding the internalized gaze of the oppressor, and self-objectification, caused by the capitalist heteropatriarchy. Thus, I am drawing from cyborg feminism, and the second wave of sexual difference theory’s concept of becoming, expanded upon by the Italian-Australian philosopher Rosi Braidotti. I further use the French sociologist Pierre Bourdieu’s notion of masculine domination and the American philosopher Gayle Rubin’s charmed circle, in creating a theoretical framework, and using the methods of cultural and feminist film analysis to contextualize the films and locate the subjectification of the women. The movies that I will be analyzing are the Japanese director and poet Sion Sono’s Antiporno (アンチポルノ, 2016) and the Japanese director and photographer Mika Ninagawa’s Helter Skelter (ヘルタースケルター, 2012), which both center around two women and their struggle in becoming-cyborg, in relation to power, trauma, sexuality, technology, and beauty ideals in ‘modernized’ Japan. In that sense, I will study the phenomenon of operating outside the lines of social norms of femininity and desire.

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