1,721,041 research outputs found
Measurement of the neutral current cross section and structure function for deep inelastic scattering at HERA
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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
Studies of final states in small x deep inelastic scattering
Get PDFWe investigate the possibility of identifying In(l/x) dynamics from studies of the final state in electron - proton deep inelastic scattering (DIS) in the small x region of the HERA collider at DESY. Motivated by recent observations at HERA we consider again the measurement of DIS events containing an identified forward jet as proposed by Mueller. We find that the shape of the x distribution of the data is described well by a prediction based on In(l/x) dynamics. Since forward jets are difficult to identify and measure accurately in the experiments we suggest the study of deep inelastic events containing an energetic isolated photon. We quantify the enhancement arising from the leading In(l/x) gluon emissions with a view to using such events to identify the underlying dynamics in the small x regime at HERA. To overcome the small event rate of jet + γ we propose that the forward jet may alternatively be identified through a single energetic decay product, the π . We investigate the feasibility of utilizing these deep inelastic + forward π events as an indicator of the small x dynamics. Motivated by this study the HI collaboration recently performed a DIS + π measurement. Therefore we update our BFKL prediction imposing the HI cuts in the calculation. We fix the normalisation by comparing with HERA data for DIS + jet. Finally we study the transverse momentum (pr) spectrum of charged particles produced in DIS at small Bjorken x in the central region between the current jet and the proton remnants. Again we normalize the BFKL prediction by comparing with the H1 DIS + jet data. We calculate the spectrum at large pr with the BFKL ln(l/x) resummation included and then repeat the calculation with it omitted. We find that data favour the former
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
Inclusive-jet cross sections in NC DIS at HERA and a comparison of the kT, anti-kT and SIScone jet algorithms
No full textFor the first time, differential inclusive-jet cross sections have been measured in neutral current deep inelastic ep scattering using the anti-kT and SIScone algorithms. The measurements were made for boson virtualities Q^2 > 125 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 82 pb^-1 and the jets were identified in the Breit frame. The performance and suitability of the jet algorithms for their use in hadron-like reactions were investigated by comparing the measurements to those performed with the kT algorithm. Next-to-leading-order QCD calculations give a good description of the measurements. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(alphas^3) terms. Values of alphas(Mz) were extracted from the data; the results are compatible with and have similar precision to the value extracted from the kT analysis
Erratum: Measurement of D± production in deep inelastic scattering at HERA
Get PDFErratum to: JHEP05(2013)09
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