1,722,621 research outputs found
Erratum: Measurement of e+e- →π+π-ψ (3686) from 4.008 to 4.600 GeV and observation of a charged structure in the π±ψ (3686) mass spectrum (Physical Review D (2017) 96 (032004) DOI: 10.1103/PhysRevD.96.032004)
No full textIn this Erratum, we report the changes on the product parameter B G e + e - in Table II. In the fit to the cross section, the resonance amplitude was normalized incorrectly. As a consequence, the product parameters B i G e + e - i for Y ( 4220 ) and Y ( 4390 ) were incorrect. After correcting this, the product parameters B i G e + e - i in Table II are updated as shown below. Other numerical results and all the figures are unchanged. (Formula Presented)
Sensitivity of the elastic electron–proton cross section to the proton radius
No full textThe precise determination of the proton radius from recent elastic scattering electron–proton data is discussed. The necessary precision on the elastic cross section to discriminate among the values coming from atomic spectroscopy is scrutinized in terms of the relevant quantity, i.e., the derivative of the form factor. It is shown that its uncertainty is two orders of magnitude larger that the error on the cross section, that is the measured observable. Different fits of the available data and of their discrete derivative, with analytical constraints are shown. The systematic error associated to the radius is evaluated taking into account the uncertainties from different sources, as the extrapolation to the static point, the choice of the class of fitting functions and the range of the data sample. This error is shown to be also orders of magnitude larger than commonly assumed
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
Modeling The Elastic Differential Cross-section At Lhc
No full textAn empirical model for the pp elastic differential cross section is proposed. Inspired by early work by Barger and Phillips, we parametrize the scattering amplitude in building blocks, comprising of two exponentials with a relative phase, supplementing the dominant term at small -t with the proton form factor. This model suitably applies to LHC7 and ISR data, enabling to make simple predictions for higher LHC energies and to check whether asymptotia might be achieved. © Copyright owned by the author(s).Antchev, G., (2013) Europhys. Lett., 101, p. 21002Phillips, R.J.N., Barger, V.D., (1973) Phys. Lett., B46, p. 412Grau, A., Pacetti, S., Pancheri, G., Srivastava, Y.N., (2012) Phys. Lett., B714, p. 70D.A. Fagundes, A. Grau, S. Pacetti, G. Pancheri and Y.N. Srivastava, arXiv:1306.0452 [hep-ph]Amaldi, U., Schubert, K.R., (1980) Nucl. Phys., B166, p. 301Ambrosio, M., (1982) Phys. Lett., B115, p. 495Breakstone, A., (1984) Nucl. Phys., B248, p. 253Amos, N.A., (1985) Nucl. Phys., B262, p. 689Breakstone, A., (1985) Phys. Rev. Lett., 54, p. 2180Grau, A., Godbole, R.M., Pancheri, G., Srivastava, Y.N., (2009) Phys. Lett., B682, p. 55Achilli, A., (2011) Phys. Rev., D84, p. 094009Khuri, N.N., Kinoshita, T., (1965) Phys. Rev., 137, pp. B720Froissart, M., (1961) Phys. Rev., 123, p. 1053Martin, A., (1963) Phys. Rev., 129, p. 1432Abreu, P., (2012) Phys. Rev. Lett., 109, p. 06200
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
Strong and electromagnetic amplitudes of the J/ψ decays into baryons and their relative phase
No full textThe Feynman amplitude for the decay of the J/ψ meson into baryon-antibaryon can be written as a sum of three sub-amplitudes: a purely strong, a purely electromagnetic and a mixed strong-electromagnetic. Assuming that the strong and mixed strong-electromagnetic sub-amplitudes have the same phase, the branching ratio of the decay contains an interference term that depends on the relative phase φ between strong and electromagnetic sub-amplitudes. In this work we calculate this phase, by using an effective strong Lagrangian density and considering, as final states, pairs of baryons, BB ̅, belonging to the spin-1/2 SU(3) octet. Moreover, we obtain the purely strong, purely electromagnetic and mixed strong-electromagnetic contributions to the total branching ratio and hence the moduli of the corresponding sub-amplitudes, for each pair of baryons. Of particular interest is the mixed strong-electromagnetic contribution that, not only is determined for the first time, but it is proven to be crucial, in the framework of our model, for the correct description of the decay mechanism. Finally we use the purely electromagnetic branching ratio to calculate the Born non-resonant cross section of the annihilation processes e+e−→BB ̅ at the J/ψ mass. By taking advantage from all available data, we obtain the relative phase between strong and electromagnetic sub-amplitudes: φ=(73±8)∘
Electrochemical noise resistance as a tool for corrosion rate prediction
No full textCurrent and potential fluctuations (electrochemical noise [EN]) between two nominally identical carbon steel electrodes were recorded in a solution of sodium phosphate (Na3PO4) at different concentrations. After passivation was reached, pitting was induced by addition of chlorides. Data were collected with different sampling rates. Linear polarization resistances (LPR) also were measured. Electrochemical signals were transposed in the frequency domains using the fast Fourier transform. Statistical parameters from the signals in the time and in the frequency domains were compared with corrosion rates (Vc) as measured by LPR. Noise resistance (Rn) also was calculated. From standard deviation (σ) values of the current and potential noises, pitting attack was revealed at its onset. Good correlation between data from the different techniques was found. Rn gave values proportional to the polarization resistance (Rp). The issue of how sampling rate can affect EN data collection also was addressed
Threshold phenomenology of nucleon form factors
No full textThe complete knowledge of nucleon form factors is a mandatory pass to deeply understand the dynamics of strong interaction at regimes where QCD is still non perturbative. Phenomenology, i. e., the description of the data by means models based of first principles and depending on physical quantities, represents one of the most powerful tools to attain such a degree of knowledge
- …
