Measurement of Inclusive and DiJet D*-Meson Photoproduction at the H1 Experiment at HERA

In der vorliegenden Arbeit wird der Produktionsmechanismus von Charm-Quarks in Elektron-Proton-Streuungen am Speicherring HERA untersucht. Der analysierte Datansatz entspricht Luminositaeten von 30.68 pb^-1, 68.23 pb^-1 und 93.39 pb^-1. Der Nachweis von Ereignissen mit Charm-Quarks erfolgt durch die Rekonstruktion von D*-Mesonen im kinematischen Bereich der Photoproduktion. D*-Mesonen werden erstmals mit Hilfe der dritten Stufe des Fast-Track-Triggers des H1-Experiments selektiert. Hierdurch konnte der Phasenraum im Vergleich zur vorangegangenen Messung entscheidend erweitert und die Statistik um einen Faktor acht erhoeht werden. Der untersuchte kinematische Bereich erstreckt sich ueber eine Photonvirtualitaet von Q^2 4 GeV bzw. p_t > 3 GeV im Bereich der Pseudorapiditaet |eta| < 1.5 untersucht. Hierbei wird verlangt, dass einer der selektierten Jets mit dem D*-Meson assoziiert ist. Die Rekonstruktion von zwei harten Partonen ermoeglicht einen tieferen Einblick in den Produktionsmechanismus der Charm-Quarks. Diese Messung zeigt, dass Prozesse mit aufgeloesten Photonen im untersuchten Phasenraum eine entscheidene Rolle bei der Photoproduktion von Charm-Quarks spielen. Einfach- und doppeltdifferentielle Wirkungsquerschnitte beider Ereignismengen werden mit Vorhersagen der pertubativer QCD in fuehrender und naechsthoeherer Ordnung verglichen

A HIERARCHICAL FRAMEWORK FOR STATISTICAL MODEL VALIDATION OF ENGINEERED SYSTEMS

As the role of computational models has increased, the accuracy of computational results has been of great concern to engineering decision-makers. To address a growing concern about the predictive capability of the computational models, this dissertation proposed a generic model validation framework with four research objectives as: Objective 1 &mdash to develop a hierarchical framework for statistical model validation that is applicable to various computational models of engineered products (or systems); Objective 2 &mdash to advance a model calibration technique that can facilitate to improve predictive capability of computational models in a statistical manner; Objective 3 &mdash to build a validity check engine of a computational model with limited experimental data; and Objective 4 &mdash to demonstrate the feasibility and effectiveness of the proposed validation framework with five engineering problems requiring different experimental resources and predictive computational models: (a) cellular phone, (b) tire tread block, (c) thermal challenge problem, (d) constrained-layer damping structure and (e) energy harvesting device. The validation framework consists of three activities: validation planning (top-down), validation execution (bottom-up) and virtual qualification. The validation planning activity requires knowledge about physics-of-failure (PoF) mechanisms and/or system performances of interest. The knowledge facilitates to decompose an engineered system into subsystems and/or components such that PoF mechanisms or system performances of interest can be decomposed accordingly. The validation planning activity takes a top-down approach and identifies vital tests and predictive computational models of which contain both known and unknown model input variable(s). On the other hand, the validation execution activity takes a bottom-up approach, which improves the predictive capability of the computational models from the lowest level to the highest using the statistical calibration technique. This technique compares experimental results with predicted ones from the computational model to determine the best statistical distributions of unknown random variables while maximizing the likelihood function. As the predictive capability of a computational model at a lower hierarchical level is improved, this enhanced model can be fused into the model at a higher hierarchical level. The validation execution activity is then continued for the model at the higher hierarchical level. After the statistical model calibration, a validity of the calibrated model should be assessed; therefore, a hypothesis test for validity check method was developed to measure and evaluate the degree of mismatch between predicted and observed results while considering the uncertainty caused by limited experimental data. Should the model become valid, the virtual qualification can be executed in a statistical sense for new product developments. With five case studies, this dissertation demonstrates that the validation framework is applicable to diverse classes of engineering problems for improving the predictive capability of the computational models, assessing the fidelity of the computational models, and assisting rational decision making on new design alternatives in the product development process

東北大学電気通信研究所研究活動報告 第29号(2022年度)

紀要類（bulletin）departmental bulletin pape

Report of the Tevatron Higgs working group.

Despite the success of the Standard Model (SM), which provides a superb description of a wide range of experimental particle physics data, the dynamics responsible for electroweak symmetry breaking is still unknown. Its elucidation remains one of the primary goals of future high energy physics experimentation. Present day global fits to precision electroweak data based on the Standard Model favor the existence of a weakly-interacting scalar Higgs boson, which is a remnant of elementary scalar dynamics that drives electroweak symmetry breaking. The only known viable theoretical framework incorporating light elementary scalar fields employs low-energy supersymmetry, where the scale of supersymmetry breaking is {Omicron} (1 TeV). The Higgs sector of the Minimal Supersymmetric extension of the Standard Model (MSSM) is of particular interest because it predicts the existence of a light CP-even neutral Higgs boson with a mass below about 130 GeV. Moreover, over a significant portion of the MSSM parameter space, the properties of this scalar are indistinguishable from those of the SM Higgs boson

Herstellung, Charakterisierung und Simulation von Germanium-p-Kanal-Tunneltransistoren

Im Rahmen der Arbeit wird eine Einordnung gegeben, inwiefern der TFET in der heutigen Skalierung der Mikroprozessoren eine Alternative zum konventionellen MOSFET-Aufbau darstellen kann. Im Speziellen wurde der Germanium-p-Kanal-Tunneltransistor experimentell über die Prozessentwicklung eines GAA-Aufbaus (komplett umgebende Gate-Elektrode, engl. Gate-All-Around-Structure) realisiert und über die physikalische Modellierung des Schaltverhaltens betrachtet

Mesure de l'angle gamma de la matrice CKM dans les désintégrations B⁰->DK*⁰ en utilisant la méthode de Dalitz dans l'expérience LHCb au CERN et optimisation de la reconstruction des photons pour l'upgrade du détecteur LHCb

Quark mixing is described in the standard model of particle physics with the Cabibbo-Kobayashi-Maskawa mecanism. The angle gamma of the unitarity triangle is one of the parameters of this mecanism that is still determined with a large uncertainty. It can be measured without significant contribution of new physics, making it a standard model key measurement. The current precision of the best direct measurement of gamma is approximately 10°, whereas the global fits of the CKM parameters determine this angle up to a few degrees. Therefore precise measurement of this quantity is needed to further constrain the Unitarity Triangle of the CKM matrix, and check the consistency of the theory. This thesis reports a measurement of gamma with a Dalitz analysis of the B0->DK*0 channel where the D meson decays into K0Spipi, based on the 3 fb⁻¹ of proton-proton collision data collected by LHCb during the LHC Run I, at the centre-of-mass energy of 7 and 8 TeV. This channel is sensitive to gamma through the interference between the b->u and b->c transitions. The CP violation observables are measured to be x- = -0.09 ^{+0.13}_{-0.13} ± 0.09 ± 0.01 , x+ = -0.10 ^{+0.27}_{-0.26} ± 0.06 ± 0.01 , y- = 0.23 ^{+0.15}_{-0.16} ± 0.04 ± 0.01 , y+ = -0.74 ^{+0.23}_{-0.26} ± 0.07 ± 0.01 , where the first uncertainty is statistical, the second is the experimental systematic uncertainty and the third is the systematic uncertainty due to the Dalitz model. A frequentist interpretation of these observables leads to rB0 = 0.39±0.13 , deltaB0 = ( 186^{+24}_{-23} )°, gamma = ( 77^{+23}_{-24} )° , where rB0 is the magnitude of the ratio between the suppressed and favoured decays and deltaB0 the strong phase difference between these two decays. In addition, the work performed on the optimisation of the photon reconstruction for the upgraded LHCb detector is reported. During LHC Run III, the LHCb instantaneous luminosity will be increased by a factor five, implying a larger shower overlap in the electromagnetic calorimeter. The study shows that reducing the cluster size used in the photon reconstruction limits the effect of the overlap between the showers, without inducing a significant energy leakage. With some dedicated corrections, the new cluster reconstruction improves the Bs->Phi gamma mass resolution by 7 to 12%, depending on the calorimeter region.Le mélange des quarks est décrit dans le modèle standard de la physique des particules par le mécanisme de Cabibbo-Kobayashi-Maskawa (CKM). À ce jour, l'angle gamma du triangle d'unitarité est un des paramètres de ce mécanisme mesuré avec la moins bonne précision. La mesure de cet angle sert de référence pour le modèle standard, puisqu'elle peut être réalisée sans contribution significative de nouvelle physique. La précision actuelle de la meilleure mesure directe de gamma est d'environ 10°, alors que les ajustements globaux des paramètres CKM, potentiellement sujets à une contribution de nouvelle physique, déterminent cet angle à quelques degrés près. Par conséquent, une mesure directe précise de cette quantité est nécessaire pour contraindre d'avantage le triangle d'unitarité de la matrice CKM et ainsi tester la cohérence de ce modèle. Cette thèse présente une mesure de gamma par une analyse de Dalitz du canal B0->DK*0, avec une désintégration du méson D en K0Spipi. Elle est basée sur les 3 fb⁻¹ de données enregistrés par LHCb pendant le Run I du LHC, à une énergie de collision proton-proton dans le centre de masse de 7 et 8 TeV. Ce canal est sensible à gamma par l'interférence entre les transitions b->u et b->c. La mesure des observables de violation de CP réalisée est x- = -0.09 ^{+0.13}_{-0.13} ± 0.09 ± 0.01 , x+ = -0.10 ^{+0.27}_{-0.26} ± 0.06 ± 0.01 , y- = 0.23 ^{+0.15}_{-0.16} ± 0.04 ± 0.01 , y+ = -0.74 ^{+0.23}_{-0.26} ± 0.07 ± 0.01 , où le première incertitude est statistique, la deuxième est l'incertitude systématique expérimentale et la troisième est l'incertitude systématique venant du modèle de Dalitz. Une interprétation fréquentiste de ces observables donne rB0 = 0.39 ± 0.13 , deltaB0 = ( 186^{+24}_{-23} )° , gamma = ( 77^{+23}_{-24})° , où rB0 est le module du rapport des amplitudes des désintégrations supprimées et favorisées et deltaB0 la différence de phase forte entre ces deux désintégrations. Par ailleurs, un travail sur l'optimisation de la reconstruction des photons pour la mise à niveau du détecteur LHCb est aussi présenté. Lors du Run III du LHC, la luminosité instantanée reçue par LHCb sera augmentée d'un facteur cinq, générant un plus grand recouvrement entre les cascades se développant dans le calorimètre électromagnétique. L'étude montre que l'effet de ce recouvrement entre les gerbes est limité en réduisant la taille des clusters utilisés pour la détection des photons, tout en évitant une diminution significative de l'énergie reconstruite. Avec des corrections adaptées, la nouvelle reconstruction développée améliore la résolution en masse de 7 à 12%, suivant la région du calorimètre considérée

Course Catalogue of the Massachusetts Institute of Technology 1961 - 1962

Massachusetts Institute of Technology Bulletin. The General Catalogue Issue for the Year 1961-1962. Includes an index to members of the staff, an alphabetical list of subjects and alphabetical index; this issue also includes a campus directory and two appendices: student aid and prizes; student housing. Digitized from microfiche copies. Digital version may contain microfiche headers and targets