1,721,149 research outputs found
Interactions of 200 GeV/nucleon 16O and 32S ions in nuclear emulsions
No full textThis paper presents and contrasts features of the inelastic nuclear reactions of 200 GeV/nucleon 16O and 32S ions with emulsion nuclei. Both the multiplicities of shower particles and the extent of target fragmentation have been studied for varying degress of disruption of the projectile nuclei. The results may be interpreted within a simple geometrical model. In particular the rapidity distributions of those events which exhibit complete projectile break-up without any overt sign of low-energy target fragmentation have been determined. The interaction of secondary projectile fragments of charge two or more issuing from oxygen interactions were also studied and the mean free paths in emulsion of the primary 16O and 32S ions and all such fragments have been compared to those predicted by a simple Glauber model
The electromagnetic and hadronic diffractive dissociation of 16O ions
No full textEvents which satisfy the kinematics of p(16O,CHep), with low excitation energy in the (CHe) system and a low-energy recoil proton, have been identified in the interactions of 200 GeV/nucleon 16O ions with nuclear emulsion. An eikonal DWIA estimate of the target A-dependence of strong-interaction diffractive dissociation suggests that, on the basis of these hydrogen data, most of the (CHe) final states, previously ascribed to electromagnetic dissociation on heavy nuclei, might rather be hadronic in character. This contamination is very much less important in the dominant (NH) channel
Production of strange and multistrange hadrons in nucleus—nucleus collisions at the SPS
No full textWe report the main results from experiment WA97 on the production of strange and multistrange hadrons at midrapidity in Pb+Pb, p+Pb and p+Be collisions at 158 A GeV/c. A comparison with some of the available models is presented
Probing the specific entropy produced in ultra-relativistic heavy-ion collisions with a silicon pixel multiplicity detector: a simulation study
No full textA simulation study of a silicon pixel multiplicity detector proposed for the NA57 experiment at CERN SPS has been carried out to evaluate its capability to measure both the total multiplicity and the net baryon content created in Pb+Pb collisions at 40 and 160 GeV/c per nucleon in order to get information on the specific entropy produced in the reaction. A method of charge assignment is proposed and discussed in detail and the results of the simulation are presented. A benchmark of the method using computer-generated events is also performed
A hybrid set-up to study charmed particle production in 32S-nucleus central interactions
No full textAn emulsion-counter hybrid set-up to detect charmed particle decays in samples of triggered 32S-nucleus central interactions is described. A new tracking technique with two emulsion tapes was developed and used successfully
Hyperon and negative particle production at central rapidity in proton-Beryllium interactions at 158 GeV/c
No full textA study of the strangeness enhancement in Lead-Lead collisions with respect to proton-induced reactions is being carried out at the CERN SPS by the WA97 experiment: up to now, data from proton-Lead collisions have been used as a reference sample. In this paper we report on a study of particle production in proton-Beryllium collisions. These collisions are expected to constitute a better reference sample than p-Pb, because of the lighter target. The analysis of hyperon and negative particle production is presented and the results are compared with those previously obtained from Pb-Pb and p-Pb collisions
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
Recent results from NA57 on strangeness production in p-A and Pb-Pb collisions at 40 and 158 A GeV/c
No full textThe production of hyperons in Pb-Pb and p-Be interaction at 40 GeV/\ beam momentum has been measured by the NA57 experiment. Strange particle enhancements at 40 GeV/ are presented and compared to those measured at 158 GeV/. Their transverse mass spectra have been studied in the framework of the blast-wave model. The multiplicity of charged particles as a function of the energy is also discussed
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