Quasielastic K+ scattering in nuclei

The quasielastic scattering kaon-nucleus experiment performed at BNL is analyzed in a finite nucleus continuum random phase approximation framework, treating the reaction mechanism in Glauber theory up to two-step inelastic processes. A good description of the data is achieved, also providing a useful constraint on the strength of the effective particle-hole interaction in the scalar-isoscalar channel at intermediate momentum transfers.Comment: 4 pages, 3 figures, needs espcrc1 and epsfig; presented at the International Conference on Hypernuclear and Strange Particle Physics, BNL October 13-18, 199

ERAWATCH country reports 2011 : Malta

Acknowledgement: The University of Malta would like to acknowledge its gratitude to the European Commission, Joint Research Centre for their permission to upload this work on OAR@UoM. Further reuse of this document can be made, provided the source is acknowledged. This work was made available with the help of the Publications Office of the European Union, Copyright and Legal Issues Section.The main objective of the ERAWATCH Annual Country Reports is to characterise and assess the performance of national research systems and related policies in a structured manner that is comparable across countries. EW Country Reports 2011 identify the structural challenges faced by national innovation systems. They further analyse and assess the ability of the policy mix in place to consistently and efficiently tackle these challenges. The annex of the reports gives an overview of the latest national policy efforts towards the enhancement of European Research Area and further assess their efficiency to achieve the targets. These reports were originally produced in November - December 2011, focusing on policy developments over the previous twelve months. The reports were produced by the ERAWATCH Network under contract to JRC-IPTS. The analytical framework and the structure of the reports have been developed by the Institute for Prospective Technological Studies of the Joint Research Centre (JRC-IPTS) and Directorate General for Research and Innovation with contributions from ERAWATCH Network Asblpeer-reviewe

Randomness in nuclei and in the quark-gluon plasma

The issue of averaging randomness is addressed, mostly in nuclear physics, but shortly also in QCD. The Feshbach approach, so successful in dealing with the continuum spectrum of the atomic nuclei ("optical model"), is extended to encompass bound states as well ("shell model"). Its relationship with the random-matrix theory is discussed and the bearing of the latter on QCD, especially in connection with the spectrum of the Dirac operator, is briefly touched upon. Finally the question of whether Feshbach's theory can cope with the averaging required by QCD is considered.Comment: 24 pages, 6 figures; to appear in the Proceedings of the Workshop "Quark-Gluon Plasma and Relativistic Heavy Ions", Frascati, 14-18 January 200

Nuclear response functions with finite range Gogny force: tensor terms and instabilities

A fully-antisymmetrized random phase approximation calculation employing the continued fraction technique is performed to study nuclear matter response functions with the finite range Gogny force. The most commonly used parameter sets of this force, as well as some recent generalizations that include the tensor terms are considered and the corresponding response functions are shown. The calculations are performed at the first and second order in the continued fraction expansion and the explicit expressions for the second order tensor contributions are given. Comparison between first and second order continued fraction expansion results are provided. The differences between the responses obtained at the two orders turn to be more pronounced for the forces including tensor terms than for the standard Gogny ones. In the vector channels the responses calculated with Gogny forces including tensor terms are characterized by a large heterogeneity, reflecting the different choices for the tensor part of the interaction. For sake of comparison the response functions obtained considering a G-matrix based nuclear interaction are also shown. As first application of the present calculation, the possible existence of spurious finite-size instabilities of the Gogny forces with or without tensor terms has been investigated. The positive conclusion is that all the Gogny forces, but the GT2 one, are free of spurious finite-size instabilities. In perspective, the tool developed in the present paper can be inserted in the fitting procedure to construct new Gogny-type forces

Approximation of the potential in scalar field dark energy models

We study the nature of potentials in scalar field based models for dark energy - with both canonical and noncanonical kinetic terms. We calculate numerically, and using an analytic approximation around $a\approx 1$, potentials for models with constant equation-of-state parameter, $w_{\phi}$. We find that for a wide range of models with canonical and noncanonical kinetic terms there is a simple approximation for the potential that holds when the scale factor is in the range $0.6\lesssim a\lesssim 1.4$. We discuss how this form of the potential can also be used to represent models with non-constant $w_{\phi}$ and, hence, how it could be used in reconstruction from cosmological data.Comment: 17 pages, 6 figures. Accepted by Phys. Rev.