285 research outputs found
New Results in the CBF theory for medium-heavy nuclei
Momentum distributions, spectroscopic factors and quasi-hole wave functions
of medium-heavy doubly closed shell nuclei have been calculated in the
framework of the Correlated Basis Function theory, by using the Fermi
hypernetted chain resummation techniques. The calculations have been done by
using microscopic two-body nucleon-nucleon potentials of Argonne type, together
with three-body interactions. Operator dependent correlations, up to the tensor
channels, have been used.Comment: 6 pages, 3 figures, proceeding of the "XI Convegno su problemi di
Fisica Nucleare Teorica" 11-14 Ottobre 2006, Cortona, Ital
Ground state of medium-heavy doubly-closed shell nuclei in correlated basis function theory
The correlated basis function theory is applied to the study of medium-heavy
doubly closed shell nuclei with different wave functions for protons and
neutrons and in the jj coupling scheme. State dependent correlations including
tensor correlations are used. Realistic two-body interactions of Argonne and
Urbana type, together with three-body interactions have been used to calculate
ground state energies and density distributions of the 12C, 16O, 40Ca, 48Ca and
208Pb nuclei.Comment: Latex 10 pages, 3 Tables, 10 Figure
Renormalized Fermi hypernetted chain approach in medium-heavy nuclei
The application of the Correlated basis function theory and of the Fermi
hypernetted chain technique, to the description of the ground state of
medium-heavy nuclei is reviewed. We discuss how the formalism, originally
developed for symmetric nuclear matter, should be changed in order to describe
finite nuclear systems, with different number of protons and neutrons. This
approach allows us to describe doubly closed shell nuclei by using microscopic
nucleon-nucleon interactions. We presents results of numerical calculations
done with two-nucleon interactions of Argonne type,implemented with three-body
forces of Urbana type. Our results regard ground-state energies, matter, charge
and momentum distributions, natural orbits, occupation numbers, quasi-hole wave
functions and spectroscopic factors of 12C, 16O, 40Ca, 48Ca and 208Pb nuclei.Comment: 127 Pages, 37 figures, Accepted for publication in Physics Report
On the existence of almost-periodic solutions for the 2D dissipative Euler equations
In this paper we study the two-dimensional dissipative Euler equations in a smooth and bounded domain. In presence of a large enough dissipative term (or equivalently a small enough external force) precise uniform estimates on the modulus of continuity of the vorticity are proved. These allow us to show existence of Stepanov almost-periodic solutions
Momentum distributions and spectroscopic factors of doubly-closed shell nuclei in correlated basis function theory
The momentum distributions, natural orbits, spectroscopic factors and
quasi-hole
wave functions of the C12, O16, Ca40, Ca48, and Pb208 doubly closed shell
nuclei, have been calculated in the framework of the Correlated Basis Function
theory, by using the Fermi hypernetted chain resummation techniques. The
calculations have been done by using the realistic Argonne v8' nucleon-nucleon
potential, together with the Urbana IX three-body interaction. Operator
dependent correlations, which consider channels up to the tensor ones, have
been
used. We found noticeable effects produced by the correlations. For high
momentum values, the momentum distributions show large enhancements with
respect to the independent particle model results. Natural orbits occupation
numbers are depleted by about the 10\% with respect to the independent particle
model values. The effects of the correlations on the spectroscopic factors are
larger on the more deeply bound states.Comment: Modified version of the previous paper (there are new figures). The
paper has been accepted for publication in Physical Review
An elementary proof of uniqueness of the particle trajectories for solutions of a class of shear-thinning non-Newtonian 2D fluids
We prove some regularity results for a class of two dimensional non-Newtonian
fluids. By applying results from [Dashti and Robinson, Nonlinearity, 22 (2009),
735-746] we can then show uniqueness of particle trajectories
A numerical code for the simulation of magma-rocks dynamics
We present a numerical code for the simulation of the dynamics of compressible to
incompressible, multicomponent ows, based on the _nite element algorithm by Hauke & Hughes (1998). Balance equations for mass, momentum, energy and composition are solved with space-time Galerkin least-squares and discontinuity-capturing stabilizing
techniques. The code is used to study the dynamics of convection and mixing in magmatic
systems such as replenishment of magma chambers and volcanic conduits, and it reveals the occurrence of previously not described processes. The uid-structure interaction of fully coupled magma-rock dynamics is being implemented by using the deforming-spatial domain method by Tezduyar (2006), that intrinsecally includes moving meshes
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