369 research outputs found
Solution of Two-Body Bound State Problems with Confining Potentials
The homogeneous Lippmann-Schwinger integral equation is solved in momentum
space by using confining potentials. Since the confining potentials are
unbounded at large distances, they lead to a singularity at small momentum. In
order to remove the singularity of the kernel of the integral equation, a
regularized form of the potentials is used. As an application of the method,
the mass spectra of heavy quarkonia, mesons consisting from heavy quark and
antiquark , are calculated for linear and
quadratic confining potentials. The results are in good agreement with
configuration space and experimental results.Comment: 6 pages, 5 table
Toward the Application of Three-Dimensional Approach to Few-body Atomic Bound States
The first step toward the application of an effective non partial wave (PW)
numerical approach to few-body atomic bound states has been taken. The two-body
transition amplitude which appears in the kernel of three-dimensional
Faddeev-Yakubovsky integral equations is calculated as function of two-body
Jacobi momentum vectors, i.e. as a function of the magnitude of initial and
final momentum vectors and the angle between them. For numerical calculation
the realistic interatomic interactions HFDHE2, HFD-B, LM2M2 and TTY are used.
The angular and momentum dependence of the fully off-shell transition amplitude
is studied at negative energies. It has been numerically shown that, similar to
the nuclear case, the transition amplitude exhibits a characteristic angular
behavior in the vicinity of 4He dimer pole.Comment: 8 pages, 6 figures, 4 tables. Oral contribution to the 19th
International IUPAP Conference on Few-Body Problems In Physics, 31 Aug-5 Sep
2009, Bonn, German
3D calculation of Tucson-Melbourne 3NF effect in triton binding energy
As an application of the new realistic three-dimensional (3D) formalism
reported recently for three-nucleon (3N) bound states, an attempt is made to
study the effect of three-nucleon forces (3NFs) in triton binding energy in a
non partial wave (PW) approach. The spin-isospin dependent 3N Faddeev integral
equations with the inclusion of 3NFs, which are formulated as function of
vector Jacobi momenta, specifically the magnitudes of the momenta and the angle
between them, are solved with Bonn-B and Tucson-Melbourne NN and 3N forces in
operator forms which can be incorporated in our 3D formalism. The comparison
with numerical results in both, novel 3D and standard PW schemes, shows that
non PW calculations avoid the very involved angular momentum algebra occurring
for the permutations and transformations and it is more efficient and less
cumbersome for considering the 3NF.Comment: 4 pages, 1 figure, 1 table
Effective range from tetramer dissociation data for cesium atoms
The shifts in the four-body recombination peaks, due to an effective range
correction to the zero-range model close to the unitary limit, are obtained and
used to extract the corresponding effective range of a given atomic system. The
approach is applied to an ultracold gas of cesium atoms close to broad Feshbach
resonances, where deviations of experimental values from universal model
predictions are associated to effective range corrections. The effective range
correction is extracted, with a weighted average given by 3.9,
where is the van der Waals length scale; which is consistent with the
van der Waals potential tail for the system. The method can be generally
applied to other cold atom experimental setups to determine the contribution of
the effective range to the tetramer dissociation position.Comment: A section for two-, three- and four-boson bound state formalism is
added, accepted for publication in Phys. Rev.
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
Solutions of the bound state Faddeev-Yakubovsky equations in three dimensions by using NN and 3N potential models
A recently developed three-dimensional approach (without partial-wave
decomposition) is considered to investigate solutions of Faddeev-Yakubovsky
integral equations in momentum space for three- and four-body bound states,
with the inclusion of three-body forces. In the calculations of the binding
energies, spin-dependent nucleon-nucleon (NN) potential models (named, S,
MT-I/III, YS-type and PGL) are considered along with the scalar
two-meson exchange three-body potential. Good agreement of the presently
reported results with the ones obtained by other techniques are obtained,
demonstrating the advantage of an approach in which the formalism is much more
simplified and easy to manage for direct computation.Comment: 16 pages, 1 figure and 6 tables; to appear in Physical review
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
Domain formation of modulation instability in spin-orbit-Rabi coupled Gross-Pitaevskii equation with cubic-quintic interactions
The effect of two- and three-body interactions on the modulation instability
(MI) domain formation of a spin-orbit (SO) and Rabi-coupled Bose-Einstein
condensate is studied within a quasi-one-dimensional model. To this aim, we
perform numerical and analytical investigations of the associated dispersion
relations derived from the corresponding coupled Gross-Pitaevskii equation. The
interplay between the linear (SO and Rabi) couplings with the nonlinear
cubic-quintic interactions are explored in the mixture, considering miscible
and immiscible configurations, with a focus on the impact in the analysis of
experimental realizations with general binary coupled systems, in which
nonlinear interactions can be widely varied together with linear couplings.Comment: 11 pages, 10 figure
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