5,507 research outputs found
A simple functional form for proton-Pb total reaction cross sections
A simple functional form has been found that gives a good representation of
the total reaction cross sections for the scattering from Pb of
protons with energies in the range 30 to 300 MeV.Comment: 7 pages, 2 figure
A simple functional form for proton-nucleus total reaction cross sections
A simple functional form has been found that gives a good representation of
the total reaction cross sections for the scattering of protons from (15)
nuclei spanning the mass range Be to U and for proton
energies ranging from 20 to 300 MeV.Comment: 13 pages, 7 figures, bib fil
About Designing an Observer Pattern-Based Architecture for a Multi-objective Metaheuristic Optimization Framework
Multi-objective optimization with metaheuristics is an active and popular research field which is supported by the availability of
software frameworks providing algorithms, benchmark problems, quality indicators and other related components. Most of these tools follow a monolithic architecture that frequently leads to a lack of flexibility when a user intends to add new features to the included algorithms. In this paper, we explore a different approach by designing a component-based architecture for a multi-objective optimization framework based on the observer pattern. In this architecture, most of the algorithmic components
are observable entities that naturally allows to register a number of observers. This way, a metaheuristic is composed of a set of observable and observer elements, which can be easily extended without requiring to modify the algorithm. We have developed a prototype of this architecture and implemented the NSGA-II evolutionary algorithm on top of it as a case study. Our analysis confirms the improvement of flexibility using this architecture, pointing out the requirements it imposes and how performance is affected when adopting it.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Generalized model for anisotropic compact stars
In the present investigation an exact generalized model for anisotropic
compact stars of embedding class one is sought for under general relativistic
background. The generic solutions are verified by exploring different physical
aspects, viz. energy conditions, mass-radius relation, stability of the models,
in connection to their validity. It is observed that the model present here for
compact stars is compatible with all these physical tests and thus physically
acceptable as far as the compact star candidates ,
and are concerned.Comment: 19 pages, 12 figures, 3 table
Simple function form for n+208Pb total cross section between 5 and 600 MeV
The total cross section for neutron scattering from 208Pb with energies
between 5 and 600 MeV has been analyzed extending a previously defined simple
function of three parameters to reveal a Ramsauer-like effect throughout the
whole energy range. This effect can be parametrized in a simple way so that it
may be anticipated that the complete function prescription will apply for total
cross sections from other nuclei.Comment: 9 pages, 4 firgure
Low-Mass Dileptons at the CERN-SpS: Evidence for Chiral Restoration?
Using a rather complete description of the in-medium spectral function
- being constrained by various independent experimental information - we
calculate pertinent dilepton production rates from hot and dense hadronic
matter. The strong broadening of the resonance entails a reminiscence to
perturbative annihilation rates in the vicinity of the phase
boundary. The application to dilepton observables in Pb(158AGeV)+Au collisions
- incorporating recent information on the hadro-chemical composition at
CERN-SpS energies - essentially supports the broadening scenario. Possible
implications for the nature of chiral symmetry restoration are outlined.Comment: 6 pages ReVTeX including 5 eps-figure
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