1,721,030 research outputs found
Measurement of exclusive vector meson photoproduction in pPb and PbPb collisions with the CMS experiment
No full textThe exclusive photoproduction of vector mesons provides a unique opportunity to constrain the gluon distribution function within protons and nuclei. Measuring vector mesons of various masses over a wide range of rapidity and as a function of transverse momentum provides important information on the evolution of the gluon distribution within nuclei. A variety of measurements, including the exclusive J/, , and meson production in pPb (at nucleon-nucleon center of mass energies of 5.02 and 8.16 TeV) and PbPb (5.02 TeV) collisions, will be presented as a function of squared transverse momentum and the photon-proton center of mass energy. Finally, compilations of these data and previous measurements are compared to various theoretical predictions
Measurements of elliptic azimuthal anisotropies in p interactions in pPb collisions with the CMS experiment
No full textA wide variety of measurements suggest the existence of strong collectivity in collisions of small systems such as proton-proton (pp) and proton-nucleus (pPb) with hydrodynamic models or gluon saturation in the initial state as two theory alternatives showing consistency with the observations. These results raise the question as to whether such phenomena may be present in even smaller systems. Just recently ATLAS, ALEPH, and ZEUS collaborations have extended the studies to photon-Pb, electron-electron (ee), and electron-proton (ep) systems respectively. This talk will summarize the latest CMS results on the study of long-range particle correlations extended to photon-proton interactions using pPb collisions at 8.16 TeV. Such interactions provide unique initial conditions with event multiplicity lower than in pp and pPb systems but comparable with electron-positron and ep systems
Measurements of charge-dependent correlations with CMS
No full textCharge-dependent azimuthal anisotropy Fourier coefficients are measured with two- and three-particle correlations in pPb and PbPb collisions. The difference between positively and negatively charged particles for the second-order two-particle and three-particle coefficients for both pPb and PbPb, and third order two-particle coefficient for PbPb, are presented. The observed results are challenging the hypothesis that attributes charge-dependent azimuthal correlations in heavy ion collisions to the chiral magnetic effect. In addition, the two-particle electric charge balance function is used as a probe to study the charge creation mechanism in high energy heavy ion collisions, for the first time in CMS. The balance function is constructed using like and unlike charged-particle pairs. The width of the balance function, both in relative pseudo-rapidity and relative-azimuthal angle, increases from more central collisions to peripheral ones. Narrowing and widening of these widths indicate late and early hadronization, respectively
Recent heavy-ion results from the CMS experiment
No full textIn this talk, we will give an overview of recent exciting heavy-ion results from Compact Muon Solenoid experiment. We will cover many different areas of interest, for example, high-energy probes on QGP, initial states, and bulk QGP physics
Measurements of charge-dependent correlations with CMS
No full textIn this talk we discuss the measurement of charge balance function in PbPb collisions at = 5.02 TeV and pPb collisions at = 8.16 TeV. Two-particles electric charge balance function is used as a probe to study the charge creation mechanism in high energy heavy ion collisions. The balance function is constructed using like- and unlike charged-particle pairs. The width of the balance function, both in relative pseudorapidity () and relative-azimuthal angle (), increases from more central collisions to peripheral ones. Narrowing and widening of these widths indicate late and early hadronization, respectively
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
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
Recent heavy ion results from CMS
No full textThe conditions in collisions of ultra-relativistic nuclei correspond to a very early time of the universe. At CERN's Large Hadron Collider (LHC), studies of the properties of the produced hot and dense strongly-interacting matter are carried out by all four big experiments.
In this talk, we will give an overview of recent exciting heavy-ion results from the Compact Muon Solenoid experiment. We will cover different areas of interest, such as, heavy-flavour probes on Quark Gluon Plasma (QGP), initial states, and bulk QGP physics
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