1,721,016 research outputs found
K0 Regeneration In Nuclei And The Effect Of The Inelastic Intermediate States
No full textThe K0 regeneration in nuclei is considered in the frame-work of a Glauber-Regge model, including the contributions in the inelastic intermediate states of both C=+1 and C=−1. The valueα ω(0)=0.44 is shown to be consistent with recent high-energy experimental data
Effect Of The Large Intermediate Masses On The Hadronic Properties Of The Photon
No full textThe theory describing the hadron-mediated photon-nucleus interaction is generalized with the introduction of large-mass intermediate states. It is shown that if the VDM is valid for the photoproduction of large masses, the hadron-mediated photon-nucleus cross-section is proportional to the hadron-nucleus total cross-section also in the presence of large intermediate masses. The theory is applied to the available experiment of photon-nucleus total cross-section between 20 and 185 GeV, and explains the apparent increase of the transparency of the nucleus with the energy
Coupled Channel Model for the 3 pi Propagation in Nuclei
No full textThe large value of the effective total cross-section on nucleons of the three-pion system with 0− quantum numbers, experimentally found from the analysis of coherent nuclear product when the 3π mass is 1.1 GeV, is explained as due to the simulation by a one step model of a more complicated mechanism, containing as essential ingredient the interference with an intermediate 1+ channel. The model allows us to extract information on the transition 0−-1+
Glauber theory, unitarity and the AGK cancellation
No full textIt is shown that the Glauber theory for the scattering of a high- energy hadron on a nucleus becomes unitary when all the possible inelastic intermediate states are included between successive scatterings. This result is used to prove that the nth-order multiple inelastic contributions satisfy the Abramovskii, Gribov and Kancheli cancellation (1973), which is therefore a consequence of the multiple scattering structure of the theory. (12 refs)
Proton stripping and pion production in relativistic deuteron-nucleus collisions
No full textWe construct a Glauber theory for the proton stripping and the pion production in relativistic deuteron-nucleus collisions, taking into account the relativistic dilation of the internal deuteron wave function. The theory is applied to the experiments performed at the Bevalac with 1.05 and 2.1 GeV/nucl. incident deuterons. The observed broadening of the stripped proton spectrum is explained as coming from the relativistic dilation effect. The production of fast pions is described as initiated from nucleons of the incident deuteron, whose momenta are large, again due to the relativistic dilation. Both the momentum shapes and theΛ-dependence of the cross-sections for the different reactions are well reproduced
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
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