1,720,961 research outputs found
Experimental Search for Magnetic Monopoles via the Schwinger Effect At the LHC and Beyond
No full textElectronic Thesis or DissertationMagnetic monopoles (MMs) naturally arise from Grand Unified Theories and are predicted by several beyond Standard Model (BSM) theories, some with masses detectable at the LHC. Previous collider searches, focused on elementary particle collisions, faced limitations that could have prevented MMs and complicated result interpretation. Most theoretical models predict MMs with internal structure, making their production in elementary particle collisions exponentially suppressed. Additionally, previous searches relied on tree-level diagrams to compute production rates, which are unreliable due to the MM's strong coupling. This thesis presents the first collider search for MMs that overcomes these limitations. The MoEDAL experiment at the LHC pioneered MM production searches in heavy-ion collisions via the Schwinger effect, which describes the generation of particle-antiparticle pairs in strong electromagnetic fields. Ultra-peripheral heavy-ion collisions at the LHC fleetingly generate the strongest magnetic fields known. The Schwinger cross section is calculable nonperturbatively, providing a reliable link between observed production rates and MM mass. The MM finite size enhances the production rate, allowing for the first reliable study of both elementary and composite monopoles at colliders. The author led the first MoEDAL analysis, published in Nature, which excluded MMs with 1 to 3 Dirac charges and masses up to 75 GeV/c^2 at 95% C.L., setting the first reliable limits on composite MMs. This thesis also extends the sensitivity to unprecedentedly high magnetic charges. The author led an analysis using data from the CMS beam pipe, donated to the MoEDAL collaboration. The beam pipe, exposed to heavy-ion collisions during LHC Run-1, was searched for MM signatures. This work, accepted to the Physical Review Letters, provides the strongest limits on MMs in the range of 2-45_gD and masses of up to 80 GeV/_c^2 at 95% C.L. Beyond collider searches, this thesis lays the groundwork for the next generation of MM searches in cosmic rays, which could either discover these elusive particles or refute the underlying theoretical models
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
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
Measuring the neutrino mixing angle theta-13 with the double chooz far detector
No full textElectronic Thesis or DissertationThe neutrino mixing angle theta-13 is the last one which value is still unknown. This dissertation presents an analysis suggesting a non-zero value of the theta-13. The analysis is based on four months of data taken with the far Double Chooz reactor anti-neutrino detector. Using only rate information yields a best fit value of sin2(2theta-13) equal to 0.0934±0.0785 (1 sigma). Incorporating information on the shape of the signal energy spectrum in the analysis results in a best fit value of 0.0849±0.0509 (1 sigma). Based on frequentist studies, sin2(2theta-13)=0 is excluded at the 92.6% confidence level. The frequentist construction using delta chi-square as an ordering rule gives [0.0098, 0.1825] interval for sin2(2theta-13) at 90% C.L
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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