433 research outputs found
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
Critical numbers of attractive Bose-condensed atoms in asymmetric traps
The recent Bose-Einstein condensation of ultracold atoms with attractive
interactions led us to consider the novel possibility to probe the stability of
its ground state in arbitrary three-dimensional harmonic traps. We performed a
quantitative analysis of the critical number of atoms through a full numerical
solution of the mean field Gross-Pitaevskii equation. Characteristic limits are
obtained for reductions from three to two and one dimensions, in perfect
cylindrical symmetries as well as in deformed ones.Comment: 5 pages, 3 figures. To appear in Phys. Rev.
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
Comment on "Efimov States and their Fano Resonances in a Neutron-Rich Nucleus"
By introducing a mass asymmetry in a non-Borromean three-body system, without
changing the energy relations, the virtual state pole cannot move from the
negative real axis of the complex energy plane (with nonzero width) and become
a resonance, because the analytical structure of the unitarity cuts remains the
same.Comment: To be published in PR
Nucleon-nucleon scattering within a multiple subtractive renormalization approach
A methodology to renormalize the nucleon-nucleon interaction, using a
recursive multiple subtraction approach to construct the kernel of the
scattering equation, is presented. We solve the subtracted scattering equation
with the next-leading-order (NLO) and next-to-next-leading-order (NNLO)
interactions. The results are presented for all partial waves up to ,
fitted to low-energy experimental data. In our renormalizaton group invariant
method, when introducing the NLO and NNLO interactions, the subtraction energy
emerges as a renormalization scale and the momentum associated with it comes to
be about the QCD scale (), irrespectively to the partial wave.Comment: Final versio
Path Dependence of the Quark Nonlocal Condensate within the Instanton Model
Within the instanton liquid model, we study the dependence of the gauge
invariant two--point quark correlator on the path used to perform the color
parallel transport between two points in the Euclidean space.Comment: 4 pages, 5 figure
Liquid-Gas phase transition in Bose-Einstein Condensates
We study the effects of a repulsive three-body interaction on a system of
trapped ultra-cold atoms in a Bose-Einstein condensed state. The corresponding
wave non-linear Schr\"{o}dinger equation is solved numerically and also by
a variational approach. A first-order liquid-gas phase transition is observed
for the condensed state up to a critical strength of the effective three-body
force.Comment: 4 pages, 3 figure
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