87 research outputs found
Inelastic photoproduction of J/Psi mesons at HERA
An analysis of inelastic photoproduction of J/Psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80pb-1. Differential and double differential cross sections are measured in a wide kinematic region: 6
Pulse propagation in a linear and nonlinear diatomic periodic chain: effects of acoustic frequency band-gap
Elliptic flow of identified hadrons in Pb-Pb collisions at 1asNN = 2.76 TeV
The elliptic flow coefficient (v2) of identified particles in Pb-Pb collisions at 1asNN = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle corre- lation technique, using a pseudo-rapidity gap of | 06\u3b7| > 0.9 between the identified hadron under study and the reference particles. The v2 is reported for \u3c0\ub1, K\ub1, K0S, p+p, \u3c6, \u39b+\u39b, \u39e 12+\u39e+ and \u3a9 12+\u3a9+ in several collision centralities. In the low transverse momentum (pT) region, pT 3 GeV/c
J/psi production as a function of charged-particle pseudorapidity density in p-Pb collisions at root s(NN)=5.02 TeV
We report measurements of the inclusive J/ψ yield and average transverse momentum as a function of charged-particle pseudorapidity density dNch/dη in p–Pb collisions at sNN=5.02TeV with ALICE at the LHC. The observables are normalised to their corresponding averages in non-single diffractive events. An increase of the normalised J/ψ yield with normalised dNch/dη, measured at mid-rapidity, is observed at mid-rapidity and backward rapidity. At forward rapidity, a saturation of the relative yield is observed for high charged-particle multiplicities. The normalised average transverse momentum at forward and backward rapidities increases with multiplicity at low multiplicities and saturates beyond moderate multiplicities. In addition, the forward-to-backward nuclear modification factor ratio is also reported, showing an increasing suppression of J/ψ production at forward rapidity with respect to backward rapidity for increasing charged-particle multiplicity
APPLICATION DE LA MÉTHODE DES ÉLÉMENTS FINIS À LA MODÉLISATION DE STRUCTURES PÉRIODIQUES ACTIVES
Un modèle mathématique tridimensionnel a été développé pour analyser le rayonnement d'une onde acoustique plane par un réseau périodique actif à une ou deux dimensions. Il repose sur la méthode des éléments finis et exploite le code ATILA. Ce papier décrit les résultats obtenus pour différents types de piézocomposites 1-3. La comparaison à des résultats analytiques ou à des mesures permet une excellente validation du modèle.A three-dimensional mathematical model has been developed to analyze the radiation of a plane acoustic wave from simple or doubly periodic active structures. It relies upon the finite element method and uses the ATILA code. This paper describes results obtained for the radiation of a plane wave from piezocomposite 1-3. Comparison between finite element results and analytical or experimental results demonstrates the accuracy of the model
ANALYSE DE LA PROPAGATION D'ONDES ACOUSTIQUES DANS LES STRUCTURES PÉRIODIQUES À L'AIDE DE LA MÉTHODE DES ÉLÉMENTS FINIS
The finite element method has been extended to model, with the help of the
ATILA code, the propagation of plane harmonic waves in an infhite elastic medium, with a bi or
tri-dimensional periodicity. This article briefly describes the formalism and provides results
obtained for a periodic array of square inclusions.La méthode des éléments finis a été étendue pour modéliser, avec l'aide du code
ATILA, la propagation d'ondes planes harmoniques dans un milieu élastique, infini, périodique
dans deux ou trois directions de l'espace. Cette communication décrit brièvement le formalisme
puis présente les résultats obtenus pour un réseau d'inclusions carrées
Analysis of elastic waves transmitted through a 2D phononic crystal exhibiting negative refraction
Band structures tunability of bulk 2D phononic crystals made of magneto-elastic materials
The feasibility of contactless tunability of the band structure of two-dimensional phononic crystals is demonstrated by employing magnetostrictive materials and applying an external magnetic field. The influence of the amplitude and of the orientation with respect to the inclusion axis of the applied magnetic field are studied in details. Applications to tunable selective frequency filters with switching functionnality and to reconfigurable wave-guides and demultiplexing devices are then discussed
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