272 research outputs found
R-Matrix Calculations for Few-Quark Bound States
The R--matrix method is implemented to study the heavy charm and bottom
diquark, triquark, tetraquark and pentaquarks in configuration space, as the
bound states of quark--antiquark, diquark--quark, diquark--antidiquark and
diquark--antitriquark systems, respectively. The mass spectrum and the size of
these systems are calculated for different partial wave channels. The
calculated masses are compared with recent theoretical results obtained by
other methods in momentum and configuration spaces and also by available
experimental data
Photodisintegration of in a three dimensional Faddeev approach
An interaction of a photon with is invstigated based on a three
dimensional Faddeev approach. In this approach the three-nucleon Faddeev
equations with two-nucleon interactions are formulated with consideration of
the magnitude of the vector Jacobi momenta and the angle between them with the
inclusion of the spin-isospin quantum numbers, without employing a partial wave
decomposition. In this formulation the two body t-matrices and triton wave
function are calculated in the three dimensional approach using AV18 potential.
In the first step we use the standard single nucleon current in this article
Scaling functions of two-neutron separation energies of with finite range potentials
The behaviour of an Efimov excited state is studied within a three-body
Faddeev formalism for a general neutron-neutron-core system, where neutron-core
is bound and neutron-neutron is unbound, by considering zero-ranged as well as
finite-ranged two-body interactions. For the finite-ranged interactions we have
considered a one-term separable Yamaguchi potential. The main objective is to
study range corrections in a scaling approach, with focus in the exotic carbon
halo nucleus
Probing the Efimov discrete scaling in atom-molecule collision
The discrete Efimov scaling behavior, well-known in the low-energy spectrum
of three-body bound systems for large scattering lengths (unitary limit), is
identified in the energy dependence of atom-molecule elastic cross-section in
mass imbalanced systems. That happens in the collision of a heavy atom with
mass with a weakly-bound dimer formed by the heavy atom and a lighter one
with mass . Approaching the heavy-light unitary limit the wave
elastic cross-section will present a sequence of zeros/minima at
collision energies following closely the Efimov geometrical law. Our results
open a new perspective to detect the discrete scaling behavior from low-energy
scattering data, which is timely in view of the ongoing experiments with
ultra-cold binary mixtures having strong mass asymmetries, such as Lithium and
Caesium or Lithium and Ytterbium
Random walk of magnetic field lines for different values of the energy-range spectral index
An analytical nonlinear description of field-line wandering in partially
statistically magnetic systems was proposed recently [A. Shalchi, I. Kourakis,
Astronomy and Astrophysics, 470, 405 (2007)]. In this article we investigate
the influence of the wave-spectrum in the energy-range onto field line random
walk by applying this formulation. It is demonstrated that in all considered
cases we clearly obtain a superdiffusive behaviour of the field-lines. If the
energy-range spectral index exceeds unity a free-streaming behaviour of the
field-lines can be found for all relevant length-scales of turbulence. Since
the superdiffusive results obtained for the slab model are exact, it seems that
superdiffusion is the normal behavior of field line wandering.Comment: Submitted to Physics of Plasmas; 13 pages, no figure
Statistical Communication Theory
Contains reports on ten research projects.National Institutes of Health (Grant MH-04737-02
New DTR line selection method in a power system comprising DTR, ESS, and RES for increasing RES integration and minimising load shedding
Triton photodisintegration in three-dimensional approach
Two- and three- particles photodisintegration of the triton is investigated
in a three-dimensional (3D) Faddeev approach. For this purpose the Jacobi
momentum vectors for three particles system and spin-isospin quantum numbers of
the individual nucleons are considered. Based on this picture the three-nucleon
Faddeev integral equations with the two-nucleon interaction are formulated
without employing the partial wave decomposition. The single nucleon current as
well as and like exchange currents are used in an appropriate
form to be employed in 3D approach. The exchange currents are derived from AV18
NN force. The two-body t-matrix, Deuteron and Triton wave functions are
calculated in the 3D approach by using AV18 potential. Benchmarks are presented
to compare the total cross section for the two- and three- particles
photodisintegration in the range of . The 3D Faddeev
approach shows promising results
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