1,722,617 research outputs found
The LHCb Vertex Locator - Performance and Radiation Damage
No full textLHCb is a dedicated flavour physics experiment at the Large Hadron Collider at CERN. The Vertex Locator (VELO) is an important part of a LHCb tracking system, enabling precision measurement of beauty and charm mesons’ flight distance. The VELO consist of a set of silicon micro-strip detectors, arranged in two retractable halves, operating only 7 mm from the interac- tion region. In these proceedings the VELO performance during the Run 1 is summarised and radiation damage studies are presented
Neutral B-meson Mixing and Violation at LHCb
No full textThe LHCb detector is a single-arm forward spectrometer that collects data at the LHC, designed for studies of flavour physics with high precision. We present a selection of recent measurements of mixing and CP-violating parameters, including sin 2β and weak phase ϕ (s), using several decays. A good understanding of the pollution from sub-leading penguin to pologies in these measurements can be achieved by measuring CP violation and polarization in the decay B(s) (0)→Jψ⁄K (0*) and B (0)→Jψ⁄ ρ (0). All results here presented are obtained using the full Run I dataset
Recent results from LHCb
No full textThe LHCb detector is a single-arm forward spectrometer that collects data at the LHC. In this review, a few of recent results in the field of -hadron decays performed by the LHCb Collaboration are presented. The analyses use proton-proton collision data corresponding to 3 fb collected by the LHCb detector during 2011 and 2012 physics runs with the center-of-mass energies of 7 and 8 TeV
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
Optimization of the track fit for the upgraded trigger
No full textThis note presents time profiling studies of the Kalman filter based track fitting software, used by the LHCb Collaboration to reconstruct charged particle trajec- tories, against the number of iterations of the fitter. Also, a detailed track quality analysis quantifying the impact of the number of fit iterations on reconstructed track parameters and selected physics quantities is shown. This work is a part of a large research project, still underway, that focuses on defining and implementing the next generation trigger system for the upgraded LHCb experiment that is foreseen to collect collision data beyond year 2020 (Run III). It should also be stressed that some of the ideas, regarding the upgraded trigger, have alrea
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