Soft Probes of the Quark-Gluon Plasma with ALICE at LHC

The Large Hadron Collider (LHC) should start its activity of data taking by the end of summer 2009, and will provide beams of p-p and Pb-Pb at colliding energies up to 14 TeV and 5.5 ATeV respectively. The Pb-Pb heavy-ion program aims at reaching the necessary conditions to create a deconfined state of partons, the Quark-Gluon Plasma (QGP), whose study is one of the most exciting physics topics to be explored thanks to the possibilites offered by this new-generation accelerator. In particular, the "soft" observables related to low and intermediate pT processes, will shed light on many fundamental properties of the system, such as thermodynamic parameters, chemical composition, expansion velocity etc. The p-p collisions will be of great interest as well, since they will serve as an essential reference for heavy ions. ALICE (A Large Ion Collider Experiment) is the LHC experiment dedicated to the study of the QGP. Its large acceptance and low magnetic field make it particularly suited for the study of soft phenomena. After having given an overview of this detector, I will present the main motivations and prospects for soft physics in both p-p and Pb-Pb collisions.Comment: 4 pages, 1 figure. Proceedings of the Lake Louise Winter Institute 200

Nanodust detection near 1 AU from spectral analysis of Cassini/RPWS radio data

Nanodust grains of a few nanometer in size are produced near the Sun by collisional break-up of larger grains and picked-up by the magnetized solar wind. They have so far been detected at 1 AU by only the two STEREO spacecraft. Here we analyze the spectra measured by the radio and plasma wave instrument onboard Cassini during the cruise phase close to Earth orbit; they exhibit bursty signatures similar to those observed by the same instrument in association to nanodust stream impacts on Cassini near Jupiter. The observed wave level and spectral shape reveal impacts of nanoparticles at about 300 km/s, with an average flux compatible with that observed by the radio and plasma wave instrument onboard STEREO and with the interplanetary flux models

On the charge of nanograins in cold environments and Enceladus dust

In very-low energy plasmas, the size of nanograins is comparable to the distance (the so-called Landau length) at which the interaction energy of two electrons equals their thermal energy. In that case, the grain's polarization induced by approaching charged particles increases their fluxes and reduces the charging time scales. Furthermore, for grains of radius smaller than the Landau length, the electric charge no longer decreases linearly with size, but has a most probable equilibrium value close to one electron charge. We give analytical results that can be used for nanograins in cold dense planetary environments of the outer solar system. Application to the nanodust observed in the plume of Saturn's moon Enceladus shows that most grains of radius about 1 nm should carry one electron, whereas an appreciable fraction of them are positively charged by ion impacts. The corresponding electrostatic stresses should destroy smaller grains, which anyway may not exist as crystals since their number of molecules is close to the minimum required for crystallization.Comment: Revised version of paper submitted to Icaru

El marc constitucional i estatutari de la llengua a debat: balanç i perspectives

El punt de partida d'aquest article és la valoració dels principis constitucionals del règim juridicolingüístic, que condueix l'autor a afirmar que el dictat constitucional no tracta en un sentit igualitari totes les llengües espanyoles. De manera més concreta, explica que el tractament donat a la llengua catalana per part de les institucions centrals i perifèriques de l'estat és insuficient, sobretot en àmbits la competència dels quals no és atribuïda a la Generalitat de Catalunya: justícia, publicitat, etiquetatge i oci. L'article acaba amb una proposta per emparar millor els drets lingüístics bàsics dels catalanoparlants i amb la reflexió d'adaptar les propostes a noves realitats com la integració europea o les noves migracions.The point of departure of this article is the assessment of the constitutional principles of the Spanish legal regulations, which leads the author to affirm that such principles do not treat all the Spanish languages in an equalitarian way. In a more concrete sense, the author explains that the treatment that the Catalan language receives from the central and peripheral sections of the state is insufficient, above all, in all of those domains whose jurisdiction do not belong to the Generalitat of Catalonia (the Catalan autonomous government): justice, advertising, product labelling and leisure activities. The articles finishes with a proposal for protecting the basic linguistic rights of the Catalan-speaking citizens in a better way, and with the reminder that all proposals should be adapted to new realities such as European integration and the new migrations.El punto de partida de este artículo es la valoración de los principios constitucionales del régimen juridicolingüístico, que conduce al autor a afirmar que el dictado constitucional no trata en un sentido igualitario a todas las lenguas españolas. De manera más concreta, explica que el tratamiento dado a la lengua catalana por parte de las instituciones centrales y periféricas del Estado es insuficiente, sobre todo en ámbitos cuya competencia no es atribuida a la Generalitat de Cataluña: justicia, publicidad, etiquetado y ocio. El artículo acaba con una propuesta para amparar mejor los derechos lingüísticos básicos de los catalanohablantes y con la reflexión de adaptar las propuestas a nuevas realidades como la integración europea o las nuevas migraciones

La fi del comerç internacional a la Mediterrània

The end of the importance of the Mediterranean trade routes was not only the result of new trade with America and of the Ottoman domination over the Mediterranean. There were other factors: first, the Ottoman Empire was cut off from the East by the consolidation of two powerful dynasties, the Safavids in Persia and the Great Mongols in India. Second, the Castilians and the Portuguese challenged the Ottoman rearguard; the Castilians opened up routes to the East across the Pacific around 1530, while the Portuguese defeated the Ottomans in the Indian Ocean at the battle of Diu. From that moment on, large-scale trading would cross the oceans

Touchez pas au grisbi, film épatant : argot, dernier cri et revendication nationale

International audienceAnalyse du film de Jacques Becker (1954), pour le replacer, par une étude iconographique de ses "objets figuratifs" (Francastel), dans son époque et en retracer les enjeux idéologiques, notamment au regard du roman initial