31 research outputs found
Full-Coupled Channel Approach to Doubly Strange -Shell Hypernuclei
We describe {\it ab initio} calculations of doubly strange, , -shell
hypernuclei (H, H,
He and He) as a first attempt to
explore the few-body problem of the {\it full}-coupled channel scheme for these
systems. The wave function includes , ,
and channels. Minnesota , D2 , and
simulated potentials based on the Nijmegen hard-core model, are used.
Bound state solutions of these systems are obtained. We find that a set of
phenomenological interactions among the octet baryons in and
-2 sectors, which is consistent with all of the available experimental binding
energies of and -2 -shell (hyper-)nuclei, can predict a particle
stable bound state of H.
For H and He,
and potentials enhance the net
coupling, and a large probability is obtained even for a weaker
potential.Comment: 4 pages, 1 figur
Ultra-low energy elastic scattering in a system of three He atoms
Differential Faddeev equations in total angular momentum representation are
used for the first time to investigate ultra-low energy elastic scattering of a
helium atom on a helium dimer. Six potential models of interatomic interaction
are investigated. The results improve and extend the Faddeev equations based
results known in literature. The employed method can be applied to
investigation of different elastic and inelastic processes in three- and
four-atomic weakly bounded systems below three-body threshold.Comment: 13 pages, 4 tables, 2 figures, elsar
Bound States and Scattering Processes in the ^4He_3 Atomic System
We present a mathematically rigorous method for solving three-atomic bound
state and scattering problems. The method is well suited for applications in
systems where the inter-atomic interaction is of a hard-core nature. It has
been employed to obtain the ground- and excited-state energies for the Helium
trimer and to calculate, for the first time, the scattering phase shifts and
wave-functions for the He atom-He dimer at ultra-low energies.Comment: 9 pages, main file 21 kB, 1 eps and 4 ps figure
Isolation of Novel Adenovirus from Fruit Bat (Pteropus dasymallus yayeyamae)
Isolation of Novel Adenovirus from Fruit Ba
Stochastic Variational Search for H
A four-body calculation of the bound state, $^{\
4}_{\Lambda\Lambda}NN\Lambda N\Lambda\Lambda\Lambda\Lambda_\Lambda^3{H}+\Lambda\Lambda\LambdaB_{\Lambda\Lambda}(^{6}_{\Lambda\Lambda}{He})d\Lambda\Lambda$ model in the Letter.Comment: Corrected typos, added addtional calculations regarding a truncated
to l=0 interaction model, 4 pages, 3 figure
Renormalization of the Three-Body System with Short-Range Interactions
We discuss renormalization of the non-relativistic three-body problem with
short-range forces. The problem becomes non-perturbative at momenta of the
order of the inverse of the two-body scattering length, and an infinite number
of graphs must be summed. This summation leads to a cutoff dependence that does
not appear in any order in perturbation theory. We argue that this cutoff
dependence can be absorbed in a single three-body counterterm and compute the
running of the three-body force with the cutoff. We comment on relevance of
this result for the effective field theory program in nuclear and molecular
physics.Comment: 5 pages, RevTex, 4 PS figures included with epsf.sty, some clarifying
comments added, version to appear in Phys. Rev. Let
The Three-Boson System with Short-Range Interactions
We discuss renormalization of the non-relativistic three-body problem with
short-range forces. The problem is non-perturbative at momenta of the order of
the inverse of the two-body scattering length. An infinite number of graphs
must be summed, which leads to a cutoff dependence that does not appear in any
order in perturbation theory. We argue that this cutoff dependence can be
absorbed in one local three-body force counterterm and compute the running of
the three-body force with the cutoff. This allows a calculation of the
scattering of a particle and the two-particle bound state if the corresponding
scattering length is used as input. We also obtain a model-independent relation
between binding energy of a shallow three-body bound state and this scattering
length. We comment on the power counting that organizes higher-order
corrections and on relevance of this result for the effective field theory
program in nuclear and molecular physics.Comment: 24 pages, RevTex, 15 PS figures included with epsf.st
Jost Function for Singular Potentials
An exact method for direct calculation of the Jost function and Jost
solutions for a repulsive singular potential is presented. Within this method
the Schrodinger equation is replaced by an equivalent system of linear
first-order differential equations, which after complex rotation, can easily be
solved numerically. The Jost function can be obtained to any desired accuracy
for all complex momenta of physical interest, including the spectral points
corresponding to bound and resonant states. The method can also be used in the
complex angular-momentum plane to calculate the Regge trajectories. The
effectiveness of the method is demonstrated using the Lennard-Jones (12,6)
potential. The spectral properties of the realistic inter-atomic He4-He4
potentials HFDHE2 and HFD-B of Aziz and collaborators are also investigated.Comment: 12 pages, latex, 2 eps-figures, submitted to Phys.Rev.
Ultra-low energy scattering of a He atom off a He dimer
We present a new, mathematically rigorous, method suitable for bound state
and scattering processes calculations for various three atomic or molecular
systems where the underlying forces are of a hard-core nature. We employed this
method to calculate the binding energies and the ultra-low energy scattering
phase shifts below as well as above the break-up threshold for the three
He-atom system. The method is proved to be highly successful and suitable for
solving the three-body bound state and scattering problem in configuration
space and thus it paves the way to study various three-atomic systems, and to
calculate important quantities such as the cross-sections, recombination rates
etc.Comment: LaTeX, RevTeX and amssymb styles, 7 pages (25 Kb), 3 table
Low-Energy Universality in Atomic and Nuclear Physics
An effective field theory developed for systems interacting through
short-range interactions can be applied to systems of cold atoms with a large
scattering length and to nucleons at low energies. It is therefore the ideal
tool to analyze the universal properties associated with the Efimov effect in
three- and four-body systems. In this "progress report", we will discuss recent
results obtained within this framework and report on progress regarding the
inclusion of higher order corrections associated with the finite range of the
underlying interaction.Comment: Commissioned article for Few-Body Systems, 47 pp, 16 fig