63 research outputs found
Isospin Dependence of Proton and Neutron Radii within Relativistic Mean Field Theory
The binding energies, shapes and sizes of even-even beta-stable nuclei with A
>= 40 and a few chains of isotopes with Z=50, 56, 82, 94 protons and isotones
with N=50, 82, 126 neutrons are analyzed. The average isospin dependence of the
radii of protons and neutrons evaluated within the relativistic mean field
theory is studied. A simple, phenomenological formula for neutron radii is
proposed.Comment: 10 pages in Latex and 14 figures in the eps forma
The effective force NL3 revisited
Covariant density functional theory based on the relativistic mean field
(RMF) Lagrangian with the parameter set NL3 has been used in the last ten years
with great success. Now we propose a modification of this parameter set, which
improves the description of the ground state properties of many nuclei and
simultaneously provides an excellent description of excited states with
collective character in spherical as well as in deformed nuclei.Comment: 8 pages, 5 figure
Relativistic nuclear energy density functional constrained by low-energy QCD
A relativistic nuclear energy density functional is developed, guided by two
important features that establish connections with chiral dynamics and the
symmetry breaking pattern of low-energy QCD: a) strong scalar and vector fields
related to in-medium changes of QCD vacuum condensates; b) the long- and
intermediate-range interactions generated by one-and two-pion exchange, derived
from in-medium chiral perturbation theory, with explicit inclusion of
excitations. Applications are presented for binding energies,
radii of proton and neutron distributions and other observables over a wide
range of spherical and deformed nuclei from to . Isotopic
chains of and nuclei are studied as test cases for the isospin
dependence of the underlying interactions. The results are at the same level of
quantitative comparison with data as the best phenomenological relativistic
mean-field models.Comment: 48 pages, 12 figures, elsart.cls class file. Revised version,
accepted for publication in Nucl. Phys.
Symmetry as a source of hidden coherent structures in quantum physics: general outlook and examples
A general algebraic approach, incorporating both invariance groups and
dynamic symmetry algebras, is developed to reveal hidden coherent structures
(closed complexes and configurations) in quantum many-body physics models due
to symmetries of their Hamiltonians . Its general ideas are manifested on
some recent new examples: 1) G-invariant bi-photons and a related
SU(2)-invariant treatment of unpolarized light; 2) quasi-spin clusters in
nonlinear models of quantum optics; 3) construction of composite particles and
(para)fields from G-invariant clusters due to internal symmetries.Comment: 10 pages, LATEX; Proceedings of VIII Int. Conf. on Symmetry Methods
in Physics (Dubna, July 28-August 2, 1997
Discovery of Tantalum, Rhenium, Osmium, and Iridium Isotopes
Currently, thirty-eight tantalum, thirty-eight rhenium, thirty-nine osmium,
and thirty-eight iridium, isotopes have been observed and the discovery of
these isotopes is discussed here. For each isotope a brief synopsis of the
first refereed publication, including the production and identification method,
is presented.Comment: To be published in At. Data Nucl. Data Table
Toward a global description of the nucleus-nucleus interaction
Extensive systematization of theoretical and experimental nuclear densities
and of optical potential strengths exctracted from heavy-ion elastic scattering
data analyses at low and intermediate energies are presented.The
energy-dependence of the nuclear potential is accounted for within a model
based on the nonlocal nature of the interaction.The systematics indicate that
the heavy-ion nuclear potential can be described in a simple global way through
a double-folding shape,which basically depends only on the density of nucleons
of the partners in the collision.The poissibility of extracting information
about the nucleon-nucleon interaction from the heavy-ion potential is
investigated.Comment: 12 pages,12 figure
Calculation of (n,α) reaction cross sections by using some Skyrme force parameters for Potassium ( 41
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