1,721,042 research outputs found
Heavy Vectors in Higgs-less models
No full textOne or more heavy spin-1 fields may replace the Higgs boson in keeping perturbative unitarity up to a few TeV. By means of two prototype chiral models for the heavy spin-1 bosons, a "composite" model or a "gauge" model, we discuss if and how the sole exchange of the same fields can also account for the ElectroWeak Precision Tests. While this proves impossible in the gauge model, the composite model hints to a positive solution, which we exploit to constrain the phenomenological properties of the heavy vectors
Rare kaon decays on the lattice
No full textAbstractWe show that long-distance contributions to the rare decays K→πνν¯ and K→πℓ+ℓ− can be computed using lattice QCD. The proposed approach requires well established methods, successfully applied in the calculations of electromagnetic and semileptonic form factors. The extra power divergences, related to the use of weak four-fermion operators, can be eliminated using only the symmetries of the lattice action without ambiguities or complicated non-perturbative subtractions. We demonstrate that this is true even when a lattice action with explicit chiral symmetry breaking is employed. Our study opens the possibility of reducing the present uncertainty in the theoretical predictions for these decays
The e+ e- --> P(1) P(2) gamma processes close to the phi peak: Toward a model-independent analysis
No full textDISCRETE 2010: Symposium on Prospects in the Physics of Discrete Symmetries
No full textThe Symposium on Prospects in the Physics of Discrete Symmetries is organized by the Physics Department of "Sapienza" University of Rome, and by INFN (Istituto Nazionale di Fisica Nucleare). This second edition of the Symposium, which was successfully held for the first time in Valencia in 2008, covers all theoretical and experimental progress in the field, and aims at a thorough discussion on the latest developments. The Symposium is organized in plenary sessions with invited talks, and parallel sessions with selected contributions from the submitted abstracts. The topics covered include T, C, P, CP symmetries; CPT symmetry, decoherence, Lorentz symmetry breaking; accidental symmetries (B, L conservation); neutrino mass and mixing; cosmology and astroparticles, dark matter searches; experimental prospects at LHC, Super flavor factories, and new facilities
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
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