1,721,271 research outputs found
Past present and future of the LHCb detector
No full textThe LHCb experiment has been designed as a high precision experiment devoted to the search of physics beyond the Standard Model through the study of CP violation and rare decays in hadrons containing b and c quarks. During the Run 1 of LHC, the LHCb detector has performed very well producing a large number of physics results on a vast number of subjects. The first Long Shutdown offered the opportunity to further optimise the detector, anticipating in some cases the interventions foreseen for Run 3. Nevertheless, the phase of upgrade of the detector, foreseen for 2019–2020, will be crucial to exploit the full potential of the LHCb experiment. In this context, an overview of the LHCb detector is presented, concerning its past, present, and foreseen future performance
Improvement of muon identification algorithms and perspectives on the D0 → μ+μ− search
Get PDFAfter the second long shutdown of the Large Hadron Collider, scheduled for 2020, LHCb will start a data taking period with increased instantaneous luminosity and collision energy to perform very high precision measurements. The present muon system has been designed to ensure high momentum resolution and high efficiency of the muon detectors to the current data taking luminosities and energies. This could be no more the optimum choice at upgrade luminosities, since the high particle fluxes will lead to a muon identification performance degradation and to a decrease of the muon detection efficiencies. In particular, the optimisation of muon identification and an improved rejection of misidentified particles are crucial for the analyses of rare B and D decays, key channels sensitive to New Physics, which require high-purity signal.
As a consequence it becomes mandatory to develop new algorithms that allow to maintain or even improve the current muon identification capabilities when operating at higher detector occupancies.
My thesis concentrates on my studies for the development of a novel algorithm for the muon identification at LHCb. The test on a Monte Carlo sample produced in upgrade conditions and the first applications on data are here presented. Finally, the use of the new method on the D0 → μ+μ− analysis to obtain an expected upper limit for the branching fraction of this decay channel is introduced.After the second long shutdown of the Large Hadron Collider, scheduled for 2020, LHCb will start a data taking period with increased instantaneous luminosity and collision energy to perform very high precision measurements. The present muon system has been designed to ensure high momentum resolution and high efficiency of the muon detectors to the current data taking luminosities and energies. This could be no more the optimum choice at upgrade luminosities, since the high particle fluxes will lead to a muon identification performance degradation and to a decrease of the muon detection efficiencies. In particular, the optimisation of muon identification and an improved rejection of misidentified particles are crucial for the analyses of rare B and D decays, key channels sensitive to New Physics, which require high-purity signal.
As a consequence it becomes mandatory to develop new algorithms that allow to maintain or even improve the current muon identification capabilities when operating at higher detector occupancies.
My thesis concentrates on my studies for the development of a novel algorithm for the muon identification at LHCb. The test on a Monte Carlo sample produced in upgrade conditions and the first applications on data are here presented. Finally, the use of the new method on the D0 → μ+μ− analysis to obtain an expected upper limit for the branching fraction of this decay channel is introduced
Improvements of muon identification algorithms and perspectives on the search
No full textAfter the second long shutdown of the Large Hadron Collider, scheduled for 2020, LHCb will start a data taking period with increased instantaneous luminosity and collision energy to perform very high precision measurements. The present muon system has been designed to ensure high momentum resolution and high efficiency of the muon detectors to the current data taking luminosities and energies. This could be no more the optimum choice at upgrade luminosities, since the high particle fluxes will lead to a muon identification performance degradation and to a decrease of the muon detection efficiencies. In particular, the optimisation of muon identification and an improved rejection of misidentified particles are crucial for the analyses of rare B and D decays, key channels sensitive to New Physics, which require high-purity signal.As a consequence it becomes mandatory to develop new algorithms that allow to maintain or even improve the current muon identification capabilities when operating at higher detector occupancies.My thesis concentrates on my studies for the development of a novel algorithm for the muon identification at LHCb. The test on a Monte Carlo sample produced in upgrade conditions and the first applications on data are here presented. Finally, the use of the new method on the D0 → μ+μ− analysis to obtain an expected upper limit for the branching fraction of this decay channel is introduced
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
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
- …
