International School for Advanced Studies

About: International School for Advanced Studies is a education organization based out in Trieste, Friuli-Venezia Giulia, Italy. It is known for research contribution in the topics: Galaxy & Dark matter. The organization has 3751 authors who have published 13433 publications receiving 588454 citations. The organization is also known as: SISSA & Scuola Internazionale Superiore di Studi Avanzati.

Metal Work-Function Changes Induced by Organic Adsorbates: A Combined Experimental and Theoretical Study

Abstract: The role of molecular dipole moment, charge transfer, and Pauli repulsion in determining the work-function change (Deltaphi) at organic-metal interfaces has been elucidated by a combined experimental and theoretical study of (CH(3)S)(2)/Au(111) and CH(3)S/Au(111). Comparison between experiment and theory allows us to determine the origin of the interface dipole layer for both phases. For CH(3)S/Au(111), Deltaphi can be ascribed almost entirely to the dipole moment of the CH(3)S layer. For (CH(3)S)(2)/Au(111), a Pauli repulsion mechanism occurs. The implications of these results on the interpretation of Deltaphi in the presence of strongly and weakly adsorbed molecules is discussed.

Lattice dynamics of metals from density-functional perturbation theory.

Abstract: The density-functional perturbation theory approach to lattice-dynamical calculations is extended to metallic systems. The smearing technique is used to deal with the Fermi surface and its variational formulation is restated. First-principles phonon dispersions of Al, Pb and of the transition metal Nb are in good agreement with available experimental data. In particular an accurate description of the anomalies observed in lead and niobium is obtained.

Search for heavy Majorana neutrinos with the ATLAS detector in pp collisions at √s 8 TeV

Abstract: A search for heavy Majorana neutrinos in events containing a pair of high-p(T) leptons of the same charge and high-p(T) jets is presented. The search uses 20.3 fb(-1) of pp collision data collected with the ATLAS detector at the CERN Large Hadron Collider with a centre-of-mass energy of root s = 8TeV. The data are found to be consistent with the background-only hypothesis based on the Standard Model expectation. In the context of a Type-I seesaw mechanism, limits are set on the production cross-section times branching ratio for production of heavy Majorana neutrinos in the mass range between 100 and 500 GeV. The limits are subsequently interpreted as limits on the mixing between the heavy Majorana neutrinos and the Standard Model neutrinos. In the context of a left-right symmetric model, limits on the production cross-section times branching ratio are set with respect to the masses of heavy Majorana neutrinos and heavy gauge bosons W-R and Z'.

The European Large Area ISO Survey - I. Goals, definition and observations

Abstract: We describe the European Large Area ISO Survey (ELAIS). ELAIS was the largest single Open Time project conducted by ISO, mapping an area of 12deg^2 at 15μm with ISOCAM and at 90μm with ISOPHOT. Secondary surveys in other ISO bands were undertaken by the ELAIS team within the fields of the primary survey, with 6deg^2 being covered at 6.7μm and 1deg^2 at 175μm. This paper discusses the goals of the project and the techniques employed in its construction, as well as presenting details of the observations carried out, the data from which are now in the public domain. We outline the ELAIS `preliminary analysis' which led to the detection of over 1000 sources from the 15 and 90-μm surveys (the majority selected at 15μm with a flux limit of ~3mJy), to be fed into a ground-based follow-up campaign, as well as a programme of photometric observations of detected sources using both ISOCAM and ISOPHOT. We detail how the ELAIS survey complements other ISO surveys in terms of depth and areal coverage, and show that the extensive multi-wavelength coverage of the ELAIS fields resulting from our concerted and on-going follow-up programme has made these regions amongst the best studied areas of their size in the entire sky, and, therefore, natural targets for future surveys. This paper accompanies the release of extremely reliable subsets of the `preliminary analysis' products. Subsequent papers in this series will give further details of our data reduction techniques, reliability and completeness estimates and present the 15- and 90-μm number counts from the `preliminary analysis', while a further series of papers will discuss in detail the results from the ELAIS `final analysis', as well as from the follow-up programme.

Strongly correlated superconductivity.

Abstract: High-temperature superconductivity in doped Mott insulators such as the cuprates contradicts the conventional wisdom that electron repulsion is detrimental to superconductivity. Because doped fullerene conductors are also strongly correlated, the recent discovery of high-critical-temperature, presumably s-wave, superconductivity in C60 field effect devices is even more puzzling. We examine a dynamical mean-field solution of a model for electron-doped fullerenes that shows how strong correlations can indeed enhance superconductivity close to the Mott transition. We argue that the mechanism responsible for this enhancement could be common to a wider class of strongly correlated models, including those for cuprate superconductors.