1,720,958 research outputs found
Erratum to: The minimal axion minimal linear σ model (The European Physical Journal C, (2018), 78, 5, (415), 10.1140/epjc/s10052-018-5892-z)
No full textIn this Erratum we clarify that in contrast to the statements made in the article the bounds on the axion coupling to two W’s and to two Z’s obtained from mono-W and mono-Z searches at the LHC are the following:(Formula presented.) The corresponding limits in terms of fa/ci are given by:(Formula presented.) This change has interesting phenomenological effects as the scale (Formula presented.) can be as low as 1 TeV: this MLσMALP can then be tested both at colliders and at flavour factories. Moreover, this model does not present any fine-tuning. Finally, a corrected version of the article is also available on the arXiv (arXiv:1710.10500)
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
Leptoquarks and real singlets: A richer scalar sector behind the origin of dark matter
Full text linkWe investigate scenarios with scalar leptoquarks that act as portals between the Standard Model and dark matter. We assume that dark matter is a scalar singlet which couples to a scalar leptoquark and the Higgs boson via the terms in the scalar potential. In addition, the leptoquark is endowed with Yukawa couplings to quarks and leptons that may address the anomalies in meson decays. We consider the annihilation cross sections to estimate the dark matter relic abundance and explore the interplay between astrophysical, collider, and flavor physics bounds on such models. In the heavy dark matter window, , the leptoquark portal becomes the dominant mechanism to explain the dark matter abundance. We find that the leptoquark Yukawa couplings, relevant for quark and lepton flavor physics, are decoupled from the dark matter phenomenology. By focussing on a scenario with a single leptoquark state, we find that relic density can only be explained when both and masses are lighter than
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
The minimal axion minimal linear σ model
Full text linkThe minimal SO(5) / SO(4) linear σ model is extended including an additional complex scalar field, singlet under the global SO(5) and the Standard Model gauge symmetries. The presence of this scalar field creates the conditions to generate an axion à la KSVZ, providing a solution to the strong CP problem, or an axion-like-particle. Different choices for the PQ charges are possible and lead to physically distinct Lagrangians. The internal consistency of each model necessarily requires the study of the scalar potential describing the SO(5) → SO(4) , electroweak and PQ symmetry breaking. A single minimal scenario is identified and the associated scalar potential is minimised including counterterms needed to ensure one-loop renormalizability. In the allowed parameter space, phenomenological features of the scalar degrees of freedom, of the exotic fermions and of the axion are illustrated. Two distinct possibilities for the axion arise: either it is a QCD axion with an associated scale larger than ∼ 105TeV and therefore falling in the category of the invisible axions; or it is a more massive axion-like-particle, such as a 1 GeV axion with an associated scale of ∼ 200 TeV, that may show up in collider searches.The authors acknowledge partial financial support by the
European Union’s Horizon 2020 research and innovation programme
under the Marie Sklodowska-Curie Grant agreements No 690575 and
No 674896. L.M. acknowledges partial financial support by the Spanish
MINECO through the “Ramón y Cajal” programme (RYC-2015-
17173), and by the Spanish “Agencia Estatal de Investigación” (AEI)
and the EU “Fondo Europeo deDesarrollo Regional” (FEDER) through
the project FPA2016-78645-P, and through the Centro de excelencia
Severo Ochoa Program under Grant SEV-2016-059
Revisiting the production of ALPs at B-factories
Full text linkIn this paper, the production of Axion-Like Particles (ALPs) at B-factories via the process e+e− → γa is revisited. To this purpose, the relevant cross-section is computed via an effective Lagrangian with simultaneous ALP couplings to b-quarks and photons. The interplay between resonant and non-resonant contributions is shown to be relevant for experiments operating at s=mΥ(nS), with n = 1, 2, 3, while the non-resonant one dominates at Υ(4S). These effects imply that the experimental searches performed at different quarkonia resonances are sensitive to complementary combinations of ALP couplings. To illustrate these results, constraints from existing BaBar and Belle data on ALPs decaying into invisible final states are derived, and the prospects for the Belle-II experiment are discussed
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
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