1,721,037 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Search for light bosons in the final state with muons and tau leptons with CMS Run II data
No full textA search for a pair of light bosons produced in decays of the 125 GeV Higgs boson, with one of the light states decaying into a pair of muons and the other into a pair of tau leptons, is presented. The search is based on a data sample corresponding to an integrated luminosity of 137.2 fb−1, collected with the CMS detector at the CERN Large Hadron Collider in the years 2016, 2017, and 2018 at a center-of-mass energy of 13 TeV. An extended Higgs sector is well motivated in a vast set of Beyond the Standard Model theories such as the two Higgs doublets plus one additional singlet (2HDM+S) and the Dark Photon Model. In the context of these models, the 125 GeV Higgs boson can decay into a pair of light bosons, which subsequently decay to pairs of Standard Model particles. Considering the enhanced coupling of the light bosons to leptons for some of the scenarios within these models, the final state considered in this work results of particular interest. Masses of the light boson between 3.6 and 21 GeV are probed, which leads to an experimental signature in the detector with both the muon pair and visible decay products from the tau pair being highly collimated. The analysis benefits from the efficient identification and reconstruction of muons by the CMS detector. Using Multivariate Analysis Techniques, the information on several kinematic variables is exploited to enhance the sensitivity to the targeted topology. No significant excess of events is found above the Standard Model expectation. Therefore, model-independent upper limits at 95% confidence level on the 125 GeV Higgs boson production cross-section times the branching fraction into the studied final state are set. Model-specific upper bounds are obtained as constraints on the parameter space of the different benchmark scenarios within the 2HDM+S and the Dark Photon Model
CMS Tracker Alignment: Legacy results from LHC Run-II and Run-III prospects
No full textThe inner tracking system of the CMS experiment, which comprise of Silicon Pixel and Silicon Strip detectors, is designed to provide a precise measurement of the momentum of charged particles and to reconstruct the primary and secondary vertices. The movements of the different substructures of the tracker detectors driven by the operating conditions during data taking, require to regularly update the detector geometry in order to accurately describe position, orientation, and curvature of the tracker modules.The procedure in which new parameters of the tracker geometry are determined is known as alignment of the tracker. The alignment procedure is performed several times during data taking using reconstructed tracks from collisions and cosmic rays data, and later on, further refined after the data taking period is finished. The tracker alignment performance corresponding to the ultimate accuracy of the alignment calibration for the legacy reprocessing of the CMS Run-II data will be presented. The data-driven methods used to derive the alignment parameters and the set of validations that monitor the performance of physics observables after the alignment will be reviewed. Finally, the prospects for the alignment calibration during the upcoming run of the LHC, where more challenging operation conditions are expected, will be addressed
CMS tracker alignment with early Run 3 data
No full textThe strategies for and the performance of the CMS tracker alignment during the ongoing LHC Run 3 data-taking period are described. The data-driven methods used to derive the alignment parameters for data reprocessing and the set of validations that monitor the physics performance after the update of the tracker alignment constants are reviewed
CMS Tracker alignment during ongoing Run 3 data-taking
No full textThe performance of the CMS tracker alignment during the ongoing Run 3 data-taking period is described. The results of the tracker alignment calibration performed with cosmic rays and collision tracks recorded at a center-of-mass energy of 900 GeV and 13.6 TeV are presented. The performance of the Prompt Calibration Loop alignment for automated calibration after two data-taking years since the deployment online of the high-granularity implementation of the workflow is discussed. The usage of computing resources for both online and offline calibration is discussed. Finally, the prospects for the tracker alignment calibration towards the third year of data-taking in Run 3 are presented
Alignment of the CMS Tracker: Results from LHC Run 3
No full textThe strategies for and the performance of the CMS tracker alignment during the ongoing Run 3 data-taking period are described. The results of the very first tracker alignment for Run 3 data reprocessing performed with cosmic rays and collision tracks recorded at the unprecedented center of mass energy of 13.6 TeV are presented. Also, the performance after deployment of a more granular automated alignment associated with the improvement of the alignment calibration already during data taking is discussed. Finally, the prospects for the tracker alignment calibration during the Run 3 data-taking period, in light of the gained operational experience, are discussed
CMS Tracker Alignment activities during LHC Long Shutdown 2
No full textThe innermost tracking system of the CMS experiment, called the tracker, consists of two tracking devices, the Silicon Pixel and Silicon Strip detectors. The tracker was specifically designed to very accurately determine the trajectory of charged particles or tracks. This is achieved by ensuring an accuracy or so-called intrinsic resolution on the position measurement of the electrical signals registered in the detector modules as the particles pass through the tracker layers of 10 to 30 µm. The high-quality track reconstruction, in turn, paves the way for precise primary and secondary vertex reconstruction.The closest detector in proximity to the interaction point, the Silicon Pixel detector, deals with the highest intensity of particle collisions and, therefore, suffers more extensively the effects of the radiation damage. To tackle these effects, the pixel was extracted from the CMS experimental cavern, underwent extensive repairs, was provided of a new innermost layer, and reinstalled during the LHC Long Shutdown 2. After the reinstallation, the accuracy in the knowledge of the geometrical position of the pixel modules needed to be improved, to reach the precision of the intrinsic resolution of the sensors stated above. This, together with the movements of the structures of the Silicon Strip detector driven by the maintenance work during the shutdown, made it necessary to correct the position, orientation, and curvature of the tracker modules in a process known as tracker alignment.The strategies for and the performance of the CMS tracker alignment during the 2021-2022 LHC Commissioning preceding the Run 3 data-taking period are described. The results of the very first tracker alignment after the pixel reinstallation, performed with cosmic ray muons recorded at 0T magnetic field are presented. Also, the performance of the first alignment of the commissioning period with collision data events, collected during pilot test beam at a center of mass energy of 900 GeV, is presented. Finally, the tracker alignment effort during the final countdown to LHC Run 3 is discussed
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