1,720,954 research outputs found
Search for a Z', a New Heavy Gauge Boson Beyond the Standard Model, as a Resonance Within a tt ̅tt ̅ Event in a Fully-Hadronic Decay Channel, With the ATLAS Detector
No full textThe Standard Model of particle physics is the ultimate cumulation of many theories and experimental results aiming to describe the elementary particles constructing the universe around us at its most fundamental level, and to define the interactions perceived by these tiny building blocks. Despite being one of the greatest achievements in modern physics, the SM, like any other model, has some limitations and shortcomings, for this reason, many approaches beyond the standard model (BSM) attempted to overcome these flaws. All these BSM approaches suggest new particles outside the contents of the SM, and the discovery of these particles is mandatory for their approval. In this Master thesis, we were interested in probing the observation of a new heavy gauge boson outside of the SM framework, as a resonance state within a very rare event predicted by the SM, the four top-quarks tt ̅tt ̅, using the ATLAS detector. Such a boson, called Z', is predicted by several BSM propositions, namely the Sequential Standard Model (SSM), the Left-Right Symmetric Model (LRM), and the Grand Unified Theories (GUTs). After introducing the SM, its limitations, and the requirement for BSM representations, we exposed different production and decay modes of the top quark within and beyond the SM. Next, we presented the experimental setup, specifically, the Large Hadron Collider (LHC), its acceleration chain, and the ATLAS detector. The process of translating the electrical signals from the detector to identified objects and reconstructed paths is mentioned for the physic objects used in this work, i.e. electrons, muons, and jets. Finally, we have proceeded with a fully hadronic event selection, using top-xaod, the main AnalysisTop program. Accomplishing a full and complete analysis was further on than this manuscript's scope, taking into consideration the limited abilities of a master’s student, and the research tight timeframe. However, in addition to the bibliography mentioned above, there were two main tasks addressed throughout this study journey. On the theoretical side, we re-calculated the BRs of the 12 deferent decay channels of a tt ̅tt ̅ event, and on the analysis side, we adapted the configuration file used as input for the main program in AnalysisTop, the top-xaod, to suit a fully-hadronic decay channel. The former task revealed results tunning to the ones we received, moreover, the sum of BRs we have calculated was 1.0001, while it was 0.996 in the given document, and this is due to us considering two digits after decimal instead of just one taken in the same document. As for the latter task, the configuration file was tested for different MC samples; MC16a, MC16d, MC16f, and MC16e, as well as data samples, and it did run with only some warnings but without any errors. However, we only presented in the last section of the last chapter some results from the output file we have obtained using the MC16e sample, and this is because it was the one with the greatest number of entries, so the plots are quite satisfying
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Low-Energy Calibration of the Hyper-Kamiokande Detector Utilizing a Deuterium Tritium Neutron Generator
No full textHyper-Kamiokande (HK) is a next-generation international neutrino experiment currently under construction in Japan. HK will explore proton decay and have the capability to detect Earth-crossing, atmospheric, solar, cosmic, and accelerator neutrinos. Expected to start data collection in 2027, HK will require periodic calibration for optimal performance. The calibration at lower energies will involve utilizing a Deuterium Tritium neutron Generator (DTG), entailing the generation of a radioactive N16 cloud strategically positioned in various locations within the water tank. A simulation of N16 cloud generation and decay was conducted in preparation for propagating the decay products through the detector volume using dedicated HK simulation software. The DTG will be deployed using a computer-controlled crane to achieve accurate positioning while prioritizing the cleanliness and safety of the detector
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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