1,721,199 research outputs found
ON THE INTERPRETATION OF THE ELECTROWEAK PRECISION DATA
No full textBILENKY M, KOLODZIEJ K, KURODA M, Schildknecht D. ON THE INTERPRETATION OF THE ELECTROWEAK PRECISION DATA. PHYSICS LETTERS B. 1993;319(1-3):319-326.The recent precision electroweak data on GAMMA(l), s(W)2BAR and M(W)/M(Z) are compared with the tree-level and the dominant-fermion-loop as well as the full one-loop standard-model predictions. While the tree-level predictions are ruled out, the dominant-fermion-loop predictions, defined by using alpha(M(Z)2) congruent-to 1/128.9 in the tree-level formulae, as well as the full one-loop predictions are consistent with the experimental data. Deviations from the dominant-fermion-loop predictions are quantified in terms of an effective Lagrangian containing three additional parameters which have a simple meaning in terms of SU(2) symmetry violation. The effective Lagrangian yields the standard one-loop predictions for specific values of these parameters, which are determined by m(t) and M(H
THE POTENTIAL OF A NEW LINEAR COLLIDER FOR THE MEASUREMENT OF THE TRILINEAR COUPLINGS AMONG THE ELECTROWEAK VECTOR BOSONS
No full textBILENKY M, KNEUR JL, RENARD FM, Schildknecht D. THE POTENTIAL OF A NEW LINEAR COLLIDER FOR THE MEASUREMENT OF THE TRILINEAR COUPLINGS AMONG THE ELECTROWEAK VECTOR BOSONS. NUCLEAR PHYSICS B. 1994;419(2):240-253.We study the accuracy to be obtained in measuring trilinear Z0W+W- and gammaW+W-couplings in the reaction e+e- --> W+W- at ''New Linear Collider'' (NLC) energies of 500 GeV to 1000 GeV. We derive simple scaling laws for the sensitivity in the measurement of these couplings. For most couplings the sensitivity increases as square-root L.s, where L denotes the integrated luminosity and square-root s denotes the e+e- center-of-mass energy. Detailed investigations based on various fits confirm these scaling laws and show that an accuracy of the order of the standard radiative corrections can be reached at the NLC for the design values of the luminosity
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
TRILINEAR COUPLINGS AMONG THE ELECTROWEAK VECTOR BOSONS AND THEIR DETERMINATION AT LEP2
No full textBILENKY M, KNEUR JL, RENARD FM, Schildknecht D. TRILINEAR COUPLINGS AMONG THE ELECTROWEAK VECTOR BOSONS AND THEIR DETERMINATION AT LEP2. NUCLEAR PHYSICS B. 1993;409(1):22-68.We present a detailed investigation of the potential of LEP2 to measure the (trilinear) couplings of the vector bosons, Z0W+ W- and gammaW+ W-, among one another. The restrictions imposed on non-standard trilinear couplings by symmetry requirements, thus excluding violent boson-loop divergences and a violent growth of tree amplitudes for vector-boson scattering, are discussed in detail. We elaborate on how to extract the W+/- spin-density matrix and the W+, W- spin correlations from future data. Various theoretically motivated fits to artificial ''data'' on e+ e- --> W+W- are carried out in order to evaluate the potential of LEP2 for, the measurement of trilinear vector boson couplings. We stress that a direct measurement of the couplings of the vector bosons with one another is indispensable for a verification of the basic SU(2)L X U(1)Y structure of the present electroweak theory. Such measurements at LEP2 improve indirect LEP1 bounds by factors which occasionally reach a full order of magnitude
STRONGLY COUPLED SU(2)NU BOSON AND LEP1 VERSUS LEP2
No full textBILENKY M, KNEUR JL, RENARD FM, Schildknecht D. STRONGLY COUPLED SU(2)NU BOSON AND LEP1 VERSUS LEP2. PHYSICS LETTERS B. 1993;316(2-3):345-354.If new strong interactions exist in the electroweak bosonic sector (e.g., strong Higgs sector, dynamical electroweak breaking, etc. ), it is natural to expect new resonances, with potentially strong couplings. We consider an additional vector-boson triplet, V+/-, V0, associated with an SU(2)V local symmetry under the specific (but rather natural) assumption that ordinary fermions are SU(2)v singlets. Mixing of the V triplet with the W+/- Z0 bosons effectively leads to an SU(2)L X U(1)Y violating vector-boson-fermion interaction which is strongly bounded by LEP1 data. In contrast, the potentially large deviation of the Z0W+W-coupling from its SU(2)L X U(1)Y value is hardly constrained by LEP1 data, Results from experiments with direct access to the trilinear Z0W+W- coupling (LEP200, NLC) are urgently needed
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